JP2005272535A - Composition for polyamide composite material and polyamide composite material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a composite material that has excellent dispersibility of clay, excellent mechanical strengths and gas barrier performance and comprises a polyamide resin and clay. <P>SOLUTION: The composition is obtained by mixing a polyamide oligomer prepared by subjecting a diamine component composed of meta-xylylenediamine as a main component and a dicarboxylic acid component composed of an α,ω-straight-chain aliphatic dicarboxylic acid as a main component to condensation polymerization or a nylon salt consisting of a diamine component composed of meta-xylylenediamine as a main component and an α,ω-straight-chain aliphatic dicarboxylic acid as a main component with clay in the presence of carbon dioxide in a supercritical state. The polyamide composite material is obtained by using the composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyamide composite material having excellent mechanical strength, heat resistance, gas barrier properties, and appearance. Specifically, the present invention relates to a composition comprising a polyamide oligomer or nylon salt and clay, and a method for producing the same, and to a method for producing a clay-containing polyamide composite material obtained by using the composition.

  Polyamide is excellent in mechanical performance and processability and has a relatively high gas barrier property. Therefore, it is not only used as an injection molding material for automobiles and electrical and electronic parts, but also as a packaging material for foods, beverages, chemicals, and electronic parts. Widely used. Among the polyamides, polymetaxylylene adipamide obtained by polycondensation from a diamine component mainly composed of metaxylylenediamine and a dicarboxylic acid component mainly composed of adipic acid is used for gaseous substances such as oxygen and carbon dioxide. Because it shows low permeability, superior strength, physical properties, etc. compared to other polyamides, it is a material that constitutes packaging materials such as films and bottles that require gas barrier properties, automobile parts, electrical and electronic parts, etc. Is being used as an injection molding material. However, in recent years, there has been an increasing demand for packaging materials that can maintain the freshness of foods and beverages for a longer period of time, and injection molding materials with better physical properties. Etc. are required to be improved.

  On the other hand, it has mechanical strength, heat resistance, gas barrier performance and workability such as strength and elastic modulus of resin used as packaging materials for automobiles, electrical and electronic parts, and food, beverages, chemicals, and electronic parts. In order to increase, a method of finely dispersing clay in a resin is known. There is a description that a uniform dispersion state can be achieved by contacting with a supercritical fluid. (See Patent Document 2)

However, in the method according to Patent Document 2, a large amount of supercritical fluid is required for processing with a supercritical fluid, which increases the running cost. In addition, the method according to Patent Document 2 is suitable for nylon 6 having a relatively low melting point or PBT having a carbon dioxide affinity different from that of nylon, but with a diamine component containing 70 mol% or more of metaxylylenediamine. When applying to a polyamide obtained by polycondensation with a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, the polyamide has a melting point higher than that of nylon 6. Since it is high, it is necessary to set the barrel temperature higher, and it has been difficult to sufficiently maintain the supercritical state. Moreover, even if it can be in a supercritical state, the physical properties such as the density of the supercritical fluid greatly change due to the temperature rise, so a good affinity with the polyamide cannot be obtained. Unlike nylon 6, The problem was that the clay was not sufficiently dispersed.
Japanese Patent Publication No. 8-22946 Japanese Patent Laid-Open No. 2000-53871

  An object of the present invention is to provide a composite material composed of a polyamide resin and clay, which solves the above-described problems and is excellent in mechanical strength and gas barrier performance in which clay is well dispersed.

As a result of diligent study every day, the present inventors solved the above problems by mixing a specific polyamide oligomer or nylon salt and clay in the presence of carbon dioxide in a supercritical state, and achieved mechanical strength and gas barrier performance. It was found that a polyamide composite material having excellent clay dispersion and excellent clay dispersion can be obtained, and the present invention has been completed.
That is, the present invention polycondenses a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. From the obtained polyamide oligomer (A1) or a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms It relates to a composition (hereinafter referred to as composition (C)) obtained by mixing nylon salt (A2) and clay (B) in the presence of carbon dioxide in a supercritical state. The present invention also relates to a polyamide composite material (hereinafter referred to as polyamide composite material (X)) using the composition (C). Furthermore, it is related with the packaging material and packaging container which utilize a polyamide composite material (X).

In the present invention, the dispersion of clay is particularly excellent by using a polyamide composite material composed of a specific composition. Therefore, the molded product composed of the composite material of the present invention is not only excellent in mechanical strength and gas barrier properties, but also in appearance. It becomes good. Moreover, since the carbon dioxide required at the time of manufacture decreases by taking a specific manufacturing method, production cost can also be made low compared with the conventional method.
That is, the composite material of the present invention is excellent in gas barrier performance, mechanical strength, appearance, and low in production cost.

The present invention is described in detail below.
The diamine component used as a raw material of the polyamide oligomer (A1) used in the present invention contains metaxylylenediamine at 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more. When the amount of metaxylylenediamine in the diamine component is less than 70 mol%, the gas barrier property of the polyamide is lowered, which is not preferable. Examples of diamine components that can be used in addition to metaxylylenediamine in the present invention include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, Aliphatic diamines such as dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (amino) Methyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) de Alicyclic diamines such as phosphorus and bis (aminomethyl) tricyclodecane; diamines having aromatic rings such as bis (4-aminophenyl) ether, paraphenylenediamine, paraxylylenediamine, and bis (aminomethyl) naphthalene However, the present invention is not limited to these examples.

  The dicarboxylic acid component which is a raw material of the polyamide oligomer (A1) used in the present invention is 50 mol% or more, preferably 60 mol% or more, more preferably 60 mol% or more of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Contains 70 mol% or more. When the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms in the dicarboxylic acid component is less than 50 mol%, the crystallinity of the polyamide is lowered and the gas barrier performance of the polyamide is lowered. Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Although aliphatic dicarboxylic acid can be illustrated, Adipic acid is preferable among these.

  In addition to the α, ω-linear aliphatic dicarboxylic acid, aromatic dicarboxylic acids can also be added to the dicarboxylic acid component. Examples of the aromatic dicarboxylic acid include, but are not limited to, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like. Of these, isophthalic acid is preferred. The dicarboxylic acid component preferably contains 50 to 99 mol% of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 1 to 50 mol% of aromatic dicarboxylic acid, and more preferably. Is a C 4-20 α, ω-linear aliphatic dicarboxylic acid 60-95 mol% and an aromatic dicarboxylic acid 5-40 mol%, more preferably a C 4-20 α, ω-linear fatty acid. It contains 65 to 90 mol% of an aromatic dicarboxylic acid and 10 to 35 mol% of an aromatic dicarboxylic acid. By containing aromatic dicarboxylic acid as the dicarboxylic acid component, gas barrier performance is improved and moldability is improved, which is preferable.

  The melting point of the polyamide oligomer (A1) is preferably 230 ° C. or lower, more preferably 225 ° C. or lower, and further preferably 210 ° C. or lower. When the melting point is higher than 230 ° C., the density of carbon dioxide is lowered when the carbon dioxide is brought into a supercritical state, and the pressure necessary for maintaining the density is increased. In addition, when the required pressure increases, it is necessary to increase the pressure resistance performance of the apparatus, leading to an increase in cost and worsening workability.

  The number average molecular weight of the polyamide oligomer (A1) is preferably 300 to 10,000, more preferably 500 to 9000, and still more preferably 1000 to 8,000. When the number average molecular weight is more than 10,000, mixing in the presence of carbon dioxide in a supercritical state is not preferable because the carbon dioxide permeability may be deteriorated and the clay may be insufficiently dispersed.

In the polyamide oligomer (A1), the apparent melt viscosity at a shear rate of 100 S ⁻¹ at a temperature equal to or higher than the melting point of the polyamide oligomer (A1) is preferably 0.001 to 1000 Pa · s, more preferably 0.001. It is -900 Pa.s, More preferably, it is 0.001-800 Pa.s. When the melt viscosity is greater than 1000 Pa · s, kneading in a melted state is not preferable because the necessary torque of the machine increases and mixing becomes difficult. Moreover, since dispersion | distribution of clay tends to become inadequate, it is not preferable.

  The polyamide oligomer (A1) can be produced by a publicly known method such as a melt polycondensation method. For example, it is manufactured by a method in which a nylon salt composed of metaxylylenediamine and adipic acid is heated in the presence of water in a pressurized state and polycondensed in a molten state while removing added water and condensed water. Further, it is also produced by a method in which metaxylylenediamine is directly added to molten adipic acid and polycondensed under normal pressure. In this case, in order to keep the reaction system in a uniform liquid state, metaxylylenediamine is continuously added to adipic acid, and during that time, the reaction system is set so that the reaction temperature does not fall below the melting point of the generated oligoamide and polyamide oligomer. The polycondensation proceeds while the temperature rises. In order to adjust the molecular weight, melt viscosity, etc. of the polyamide oligomer, the molar ratio of the charged dicarboxylic acid and diamine can be variously changed.

  The polyamide oligomer (A1) may be subjected to polycondensation by solid phase polymerization after being produced by a melt polycondensation method. The manufacturing method of a polyamide oligomer is not specifically limited, It manufactures by a conventionally well-known method and superposition | polymerization conditions.

  A known antioxidant can be added to the polyamide oligomer (A1) in order to prevent coloring during polymerization. For example, a phosphorus compound containing an alkali metal or an alkaline earth metal is preferably used.

  The diamine component used as a raw material for the nylon salt (A2) used in the present invention contains metaxylylenediamine at 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more. When the amount of metaxylylenediamine in the diamine component is less than 70 mol%, the gas barrier property of the polyamide is lowered, which is not preferable. Examples of diamine components that can be used in addition to metaxylylenediamine in the present invention include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, Aliphatic diamines such as dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (amino) Methyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) de Alicyclic diamines such as phosphorus and bis (aminomethyl) tricyclodecane; diamines having aromatic rings such as bis (4-aminophenyl) ether, paraphenylenediamine, paraxylylenediamine, and bis (aminomethyl) naphthalene However, the present invention is not limited to these examples.

  The dicarboxylic acid component used as a raw material for the nylon salt (A2) used in the present invention is 50 mol% or more, preferably 60 mol% or more, more preferably 60 mol% or more of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Contains 70 mol% or more. When the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms in the dicarboxylic acid component is less than 50 mol%, the crystallinity of the polyamide obtained by polycondensation of the nylon salt (A2) is lowered, and the polyamide This is not preferable because the gas barrier performance decreases. Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Although aliphatic dicarboxylic acid can be illustrated, Adipic acid is preferable among these.

  In addition to the α, ω-linear aliphatic dicarboxylic acid, aromatic dicarboxylic acids can also be added to the dicarboxylic acid component. Examples of the aromatic dicarboxylic acid include, but are not limited to, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like. Of these, isophthalic acid is preferred. The dicarboxylic acid component preferably contains 50 to 99 mol% of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 1 to 50 mol% of aromatic dicarboxylic acid, and more preferably. Is a C 4-20 α, ω-linear aliphatic dicarboxylic acid 60-95 mol% and an aromatic dicarboxylic acid 5-40 mol%, more preferably a C 4-20 α, ω-linear fatty acid. It contains 65 to 90 mol% of an aromatic dicarboxylic acid and 10 to 35 mol% of an aromatic dicarboxylic acid. The aromatic dicarboxylic acid contained as the dicarboxylic acid component is preferable because the gas barrier performance of the polyamide obtained by polycondensation of the nylon salt (A2) is improved and the moldability is improved.

  The nylon salt (A2) of the present invention is prepared by, for example, dissolving a dicarboxylic acid such as adipic acid or isophthalic acid in water at 80 ° C., then dropping diamine such as metaxylylene adipamide and washing the precipitate with water. Although it can manufacture, it is not restricted to these methods, A well-known public technique can be used.

  The clay (B) used in the present invention is mica, vermiculite, smectite, etc., preferably 2-octahedral or 3-octahedral layered silicate having a charge density of 0.25 to 0.6. Yes, examples of the 2-octahedron type include montmorillonite, beidellite, and nontronite, and examples of the 3-octahedron type include hectorite and saponite. Among these, montmorillonite is particularly preferable because it has high swellability, and osmotic swelling is likely to spread between layers, so that it can be easily dispersed in a polyamide composite material. The clay (B) used in the present invention may be a refined or synthesized clay mineral produced naturally. For the purpose of promoting the dispersion of clay (B), an organic agent such as a polymer compound or an organic compound is previously brought into contact with the clay to expand the clay layer (swelling treatment), and the clay surface is made oleophilic. It is preferably performed. As the organic agent, a quaternary ammonium salt can be preferably used. More preferably, a quaternary ammonium salt having at least one alkyl group or alkenyl group having 12 or more carbon atoms is used.

  Specific examples of the organic agent include, for example, trimethyl dodecyl ammonium salt, trimethyl tetradecyl ammonium salt, trimethyl hexadecyl ammonium salt, trimethyl octadecyl ammonium salt, trimethyl alkyl ammonium salt such as trimethyl eicosyl ammonium salt; trimethyl octadecenyl Trimethyl alkenyl ammonium salts such as ammonium salt and trimethyl octadecadienyl ammonium salt; triethyl alkyl ammonium salts such as triethyl dodecyl ammonium salt, triethyl tetradecyl ammonium salt, triethyl hexadecyl ammonium salt and triethyl octadecyl ammonium salt; tributyl dodecyl ammonium salt; Tributyltetradecylammonium salt, tributylhexadecylammonium , Tributyl alkyl ammonium salts such as tributyl octadecyl ammonium salt; dimethyl dialkyl ammonium salts such as dimethyl didodecyl ammonium salt, dimethyl ditetradecyl ammonium salt, dimethyl dihexadecyl ammonium salt, dimethyl dioctadecyl ammonium salt, dimethyl ditallow ammonium salt; Dimethyldialkenylammonium salts such as dimethyldioctadecenylammonium salt and dimethyldioctadecadienylammonium salt; diethyldidodecylammonium salt, diethylditetradecylammonium salt, diethyldihexadecylammonium salt, diethyldioctadecylammonium salt Diethyldialkylammonium salts such as dibutyldidodecylammonium salt, dibutylditetradecylammonium Salt, dibutyl dihexadecyl ammonium salt, dibutyl dialkyl ammonium salt such as dibutyl dioctadecyl ammonium salt; methyl benzyl dialkyl ammonium salt such as methyl benzyl dihexadecyl ammonium salt; dibenzyl dialkyl ammonium salt such as dibenzyl dihexadecyl ammonium salt Trialkylmethylammonium salts such as tridodecylmethylammonium salt, tritetradecylmethylammonium salt and trioctadecylmethylammonium salt; trialkylethylammonium salts such as tridodecylethylammonium salt; trialkylbutyl such as tridodecylbutylammonium salt; Ammonium salt; 4-amino-n-butyric acid, 6-amino-n-caproic acid, 8-aminocaprylic acid, 10-aminodecanoic acid, 12- Examples thereof include ω-amino acids such as aminododecanoic acid, 14-aminotetradecanoic acid, 16-aminohexadecanoic acid, and 18-aminooctadecanoic acid. In addition, hydroxyl group and / or ether group-containing ammonium salts, among them, methyl dialkyl (PAG) ammonium salt, ethyl dialkyl (PAG) ammonium salt, butyl dialkyl (PAG) ammonium salt, dimethyl bis (PAG) ammonium salt, diethyl bis (PAG) ) Ammonium salt, dibutyl bis (PAG) ammonium salt, methyl alkyl bis (PAG) ammonium salt, ethyl alkyl bis (PAG) ammonium salt, butyl alkyl bis (PAG) ammonium salt, methyl tri (PAG) ammonium salt, ethyl tri (PAG) ammonium Salt, butyl tri (PAG) ammonium salt, tetra (PAG) ammonium salt (wherein alkyl is carbon number such as dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl) 4 represents at least one alkyl group, such as a polyalkylene glycol residue, preferably a polyethylene glycol residue or a polypropylene glycol residue having 20 or less carbon atoms. A quaternary ammonium salt can also be used as an organic agent. Among them, trimethyldodecyl ammonium salt, trimethyl tetradecyl ammonium salt, trimethyl hexadecyl ammonium salt, trimethyl octadecyl ammonium salt, dimethyl didodecyl ammonium salt, dimethyl ditetradecyl ammonium salt, dimethyl dihexadecyl ammonium salt, dimethyl dioctadecyl ammonium salt, dimethyl A ditallow ammonium salt is preferred. These organic agents can be used alone or as a mixture of plural kinds. These organic agents can be used alone or as a mixture of plural kinds.

  The amount of the organic agent is preferably 60% by weight or less of the weight of the clay (B). When the amount of the organic agent is more than 60% by weight, many organic agents are deteriorated or decomposed by heat, and decomposed products of organic agents such as amine and ammonia may cause bad odor, which is not preferable.

  The blending ratio of the clay (B) in the composition (C) in the present invention is preferably 0.01 to 80% by weight, more preferably 0.1 to 65% by weight, and 3 to 50% by weight is more preferable. If the blending ratio of the clay (B) is within the above range, the effect of improving the gas barrier performance and mechanical strength of the polyamide composite material (X) using the composition (C) can be obtained. In addition, when the composition of the clay (B) in the composition (C) is within the above range, when the polyamide composite material (X) is produced using the composition (C), the amount of metaxylylenediamine is 70. A polyamide obtained by polycondensation of a diamine component containing at least mol% and a dicarboxylic acid component containing at least 50 mol% of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and a composition (C) Since the polyamide composite material (X) can be produced by dilution and the amount of carbon dioxide necessary for production can be reduced, the production cost can be reduced, which is preferable.

  The blending ratio of the clay (B) in the polyamide composite material (X) in the present invention is preferably added so as to be 0.01 to 50% by weight in the polyamide composite material, and 0.1 to 20% by weight. More preferably, 0.3 to 10% by weight is more preferable. If the blending ratio of the clay (B) is within the above range, an effect of improving gas barrier performance and mechanical strength can be obtained. In particular, when the transparency of the polyamide composite material (X) is required, the blending ratio of the clay (B) in the polyamide composite material (X) is preferably 0.01 to 10% by weight, more preferably Is 0.1 to 8% by weight.

  In the present invention, as a method for confirming uniform dispersion of clay (B), a method of observing the clay inside the sample with a transmission electron microscope, a method of observing the sample surface with a scanning electron microscope, and an X-ray diffraction method are used. There is a method of measuring the interlayer distance of clay. When using an electron microscope, the interlayer distance of clay can be measured directly, and when the X-ray diffraction method is used, when no clay-derived peak appears in the diffraction profile, it can be said that the dispersion of clay is good.

  In the present invention, the composition (C) is obtained by mixing the polyamide oligomer (A1) or the nylon salt (A2) and the clay (B) in the presence of carbon dioxide in a supercritical state. The pressure during mixing is preferably 7.4 to 50 MPa, more preferably 8 to 45 MPa, further preferably 10 to 40 MPa, and the temperature is preferably 31 to 300 ° C., more preferably 100 to 240 ° C., and still more preferably 180 to 220. ° C. In addition, supercritical fluids other than carbon dioxide may be used, but carbon dioxide is in a supercritical state at a relatively low temperature and low pressure, and the temperature range in which it becomes supercritical is polyamide oligomer (A1), nylon. Since it coincides with the melting point of the salt (A2), the permeability of the polyamide oligomer (A1) and the nylon salt (A2) into the clay (B) layer is increased, and the diffusibility of carbon dioxide is also high. ) Is preferable because it is easy to disperse, and carbon dioxide is particularly preferably used since the cost of carbon dioxide itself and the cost for heating and pressurization are relatively low.

  In the present invention, the production method of the composition (C) is not particularly limited. For example, the polyamide oligomer (A1) or the nylon salt (A2) and the clay (B) are charged into a heat-resistant and pressure-resistant reaction kettle. A composition in which carbon dioxide in a gas, liquid, or solid state is charged or distributed at the same time, replaced with air in the kettle, and then heated to bring the carbon dioxide into a supercritical state and mixed in a batch system. A product (C) is obtained. The pressure during mixing is preferably 7.4 to 50 MPa, more preferably 8 to 45 MPa, further preferably 10 to 40 MPa, and the temperature is preferably 31 to 300 ° C., more preferably 100 to 240 ° C., and still more preferably 180 to 220. The mixing time is 0.1 to 1500 minutes, more preferably 1 to 1000 minutes, and still more preferably 5 to 500 minutes. If the pressure is less than 7.4 MPa, the supercritical state cannot be obtained, which is not preferable. It is difficult to increase the pressure above 50 MPa because of the pressure resistance of the reaction kettle. If the reaction temperature is less than 31 ° C., carbon dioxide cannot be brought into a supercritical state, and if it is higher than 300 ° C., the polyamide oligomer (A1) or the nylon salt (A2) may be decomposed by heat, which is not preferable. If the reaction time is less than 0.1 minutes, carbon dioxide does not sufficiently permeate and clay is not sufficiently dispersed. This is not preferred, and if it is longer than 1500 minutes, the polyamide oligomer (A1) or nylon salt (A2) is decomposed or gelled. This is not preferable. When maintaining in a supercritical state, it is often preferable to stir the inside of the kettle with a stirring blade in order to promote dispersion of the clay.

  The composition (C), for example, supplies polyamide oligomer (A1) or nylon salt (A2) and clay (B) to the extruder, and supplies carbon dioxide in a supercritical state to the extruder while kneading. Alternatively, by supplying carbon dioxide in a gas, liquid, or solid state to the extruder and adjusting the temperature and pressure inside the extruder so that it becomes a supercritical state inside the extruder, You may mix and manufacture. At that time, it is preferable to use a screw part of which is reverse full flight so that the pressure inside the extruder can be increased. There is no limitation on the extruder to be used, and a known extruder such as a single screw extruder or a twin screw extruder can be used. However, from the viewpoint of kneading performance and versatility, a meshing twin screw extruder is particularly preferably used. It is done. The carbon dioxide inlet is preferably provided on the die side of the barrel position where the polyamide oligomer (A1) or the nylon salt (A2) is melted. Further, it is preferable to provide a vent port in the barrel on the die side of the carbon dioxide injection port to reduce the pressure.

A polyamide composite material (X) can be produced using the composition (C).
For example, the polyamide composite material (X) can be produced by polycondensation of the composition (C). Polycondensation is produced, for example, by a method in which the composition (C) is charged into a reaction kettle, heated in the presence of water, and heated in a pressurized state, and polycondensed in a molten state while removing added water and condensed water. Moreover, although polycondensation may be performed by performing solid phase polymerization, it is not restricted to this method, It can manufacture using a publicly known method.

  In polycondensation of the composition (C), a small amount of monoamine or monocarboxylic acid may be added as a molecular weight regulator.

  A phosphorus compound can be added to the polyamide composite material (X) in order to enhance the processing stability during melt molding or to prevent the polyamide from being colored. As the phosphorus compound, a phosphorus compound containing an alkali metal or an alkaline earth metal is preferably used. For example, an alkali metal or alkaline earth metal phosphate such as sodium, magnesium, calcium, hypophosphite, phosphorus Acid salts may be mentioned, but those using alkali metal or alkaline earth metal hypophosphites are particularly preferred because they are particularly excellent in the anti-coloring effect of polyamide. The density | concentration of the phosphorus compound in a polyamide composite material (X) is 1-500 ppm as a phosphorus atom, Preferably it is 1-350 ppm, More preferably, it is 1-200 ppm. Even if the phosphorus atom concentration exceeds 500 ppm, there is no change in the anti-coloring effect. Rather, the haze of the film obtained using this increases, which is not preferable. If the phosphorus atom concentration is less than 1 ppm, there is no anti-coloring effect, which is not preferable.

  The polyamide in the polyamide composite material (X) preferably has a number average molecular weight in the range of 10,000 to 50,000. The number average molecular weight is appropriately selected depending on the use of the polyamide composite material of the present invention and the molding method. For example, a film having a number average molecular weight of about 20000 to 30000 when a certain degree of fluidity is required during production, and a sheet having a melt strength of about 30000 to 45000 when melt strength is required during production. Is selected, but is not limited to this.

  When the polyamide composite material (X) is produced by this method, carbon dioxide necessary for production is necessary only when producing the composition (C), and therefore the amount of carbon dioxide used during production can be reduced. This is preferable because the manufacturing cost can be reduced.

  The polyamide composite material (X) includes a diamine component containing 70 mol% or more of metaxylylenediamine, a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, and Polyamide (D) obtained by polycondensation and composition (C) may be produced by melt-kneading with an extruder. There is no restriction | limiting in particular in an extruder, A well-known extruder, such as a single screw extruder and a twin screw extruder, can be used. The screw of the extruder is not particularly limited and a known one can be used. For example, a full flight type may be used, but a screw having a kneading zone is preferably used in order to improve kneading performance.

  The polyamide composite material (X) may be polycondensed by solid phase polymerization after being produced by an extruder. The method for producing the polyamide is not particularly limited, and it is produced by a conventionally known method and polymerization conditions.

  The diamine component used as a raw material for the polyamide (D) used in the present invention contains metaxylylenediamine in an amount of 70 mol% or more, preferably 75 mol% or more, and more preferably 80 mol% or more. When the amount of metaxylylenediamine in the diamine component is less than 70 mol%, the gas barrier property of the polyamide is lowered, which is not preferable. Examples of diamine components that can be used in addition to metaxylylenediamine in the present invention include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, Aliphatic diamines such as dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (amino) Methyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) de Alicyclic diamines such as phosphorus and bis (aminomethyl) tricyclodecane; diamines having aromatic rings such as bis (4-aminophenyl) ether, paraphenylenediamine, paraxylylenediamine, and bis (aminomethyl) naphthalene However, the present invention is not limited to these examples.

  The dicarboxylic acid component used as a raw material for the polyamide (D) used in the present invention is an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms in an amount of 50 mol% or more, preferably 60 mol% or more, more preferably. It contains 70 mol% or more. When the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms in the dicarboxylic acid component is less than 50 mol%, the crystallinity of the polyamide is lowered and the gas barrier performance of the polyamide is lowered. Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Although aliphatic dicarboxylic acid can be illustrated, Adipic acid is preferable among these.

  In addition to the α, ω-linear aliphatic dicarboxylic acid, aromatic dicarboxylic acids can also be added to the dicarboxylic acid component. Examples of the aromatic dicarboxylic acid include, but are not limited to, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like. Of these, isophthalic acid is preferred. The dicarboxylic acid component preferably contains 50 to 99 mol% of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 1 to 50 mol% of aromatic dicarboxylic acid, and more preferably. Is a C 4-20 α, ω-linear aliphatic dicarboxylic acid 60-95 mol% and an aromatic dicarboxylic acid 5-40 mol%, more preferably a C 4-20 α, ω-linear fatty acid. It contains 65 to 90 mol% of an aromatic dicarboxylic acid and 10 to 35 mol% of an aromatic dicarboxylic acid. By containing aromatic dicarboxylic acid as the dicarboxylic acid component, gas barrier performance is improved and moldability is improved, which is preferable.

  Furthermore, in the present invention, a small amount of monoamine or monocarboxylic acid may be added as a molecular weight regulator during the polycondensation of polyamide (D).

  The polyamide (D) can be produced by a publicly known method such as a melt polycondensation method. For example, it is manufactured by a method in which a nylon salt composed of metaxylylenediamine and adipic acid is heated in the presence of water in a pressurized state and polycondensed in a molten state while removing added water and condensed water. Further, it is also produced by a method in which metaxylylenediamine is directly added to molten adipic acid and polycondensed under normal pressure. In this case, in order to keep the reaction system in a uniform liquid state, metaxylylenediamine is continuously added to adipic acid, and during this time, the reaction system is raised so that the reaction temperature does not fall below the melting point of the generated oligoamide and polyamide. The polycondensation proceeds while warming.

  The polyamide (D) may be subjected to polycondensation by solid phase polymerization after being produced by a melt polycondensation method. The method for producing the polyamide is not particularly limited, and it is produced by a conventionally known method and polymerization conditions.

  A phosphorus compound can be added to the polyamide (D) in order to increase the processing stability during melt molding or to prevent the polyamide from being colored. As the phosphorus compound, a phosphorus compound containing an alkali metal or an alkaline earth metal is preferably used. For example, an alkali metal or alkaline earth metal phosphate such as sodium, magnesium, calcium, hypophosphite, phosphorus Acid salts may be mentioned, but those using alkali metal or alkaline earth metal hypophosphites are particularly preferred because they are particularly excellent in the anti-coloring effect of polyamide. The density | concentration of the phosphorus compound in polyamide is 1-500 ppm as a phosphorus atom, Preferably it is 1-350 ppm, More preferably, it is 1-200 ppm. Even if the phosphorus atom concentration exceeds 500 ppm, there is no change in the anti-coloring effect. Rather, the haze of the film obtained using this increases, which is not preferable. If the phosphorus atom concentration is less than 1 ppm, there is no anti-coloring effect, which is not preferable.

  The polyamide (D) preferably has a number average molecular weight in the range of 10,000 to 50,000. The number average molecular weight is appropriately selected depending on the use of the polyamide composite material of the present invention and the molding method. For example, a film having a number average molecular weight of about 20000 to 30000 when a certain degree of fluidity is required during production, and a sheet having a melt strength of about 30000 to 45000 when melt strength is required during production. Is selected, but is not limited to this.

  By producing the polyamide composite material (X) by this method, the polyamide composite material (X) can be produced by diluting the composition (C) with polyamide, so that the carbon dioxide required for the production is the composition (C). Since it is necessary only when producing the carbon dioxide, the amount of carbon dioxide used in the production can be reduced, and therefore the production cost can be reduced, which is preferable.

  The polyamide composite material (X) is, for example, a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Can be produced by adding the composition (C) to the polymerization kettle and proceeding with the synthesis. There is no particular limitation on the method and timing of charging the composition (C) into the polymerization kettle. For example, the composition (C) may be charged into the polymerization kettle before the start of polymerization, or after the polymerization has progressed to some extent, However, the clay of the composition (C) is preferably stirred for 5 to 240 minutes, more preferably 10 to 200 minutes, and further preferably 20 to 180 minutes so that the clay is uniformly dispersed in the polyamide. preferable. The polycondensation method is not particularly limited, and can be produced by a publicly known method such as a melt polycondensation method. For example, a nylon salt composed of metaxylylenediamine and adipic acid is raised under pressure in the presence of water. It is manufactured by a method of heating and polycondensing in a molten state while removing added water and condensed water. Further, it is also produced by a method in which metaxylylenediamine is directly added to molten adipic acid and polycondensed under normal pressure. In this case, in order to keep the reaction system in a uniform liquid state, metaxylylenediamine is continuously added to adipic acid, and during this time, the reaction system is raised so that the reaction temperature does not fall below the melting point of the generated oligoamide and polyamide. The polycondensation proceeds while warming.

  The diamine component used as a raw material in this method contains metaxylylenediamine at 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more. When the amount of metaxylylenediamine in the diamine component is less than 70 mol%, the gas barrier property of the polyamide is lowered, which is not preferable. Examples of diamine components that can be used in addition to metaxylylenediamine in the present invention include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, Aliphatic diamines such as dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (amino) Methyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) de Alicyclic diamines such as phosphorus and bis (aminomethyl) tricyclodecane; diamines having aromatic rings such as bis (4-aminophenyl) ether, paraphenylenediamine, paraxylylenediamine, and bis (aminomethyl) naphthalene However, the present invention is not limited to these examples.

  The dicarboxylic acid component as a raw material in this method is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Is included. When the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms in the dicarboxylic acid component is less than 50 mol%, the crystallinity of the polyamide is lowered and the gas barrier performance of the polyamide is lowered. Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Although aliphatic dicarboxylic acid can be illustrated, Adipic acid is preferable among these.

  In addition to the α, ω-linear aliphatic dicarboxylic acid, aromatic dicarboxylic acids can also be added to the dicarboxylic acid component. Examples of the aromatic dicarboxylic acid include, but are not limited to, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like. Of these, isophthalic acid is preferred. The dicarboxylic acid component preferably contains 50 to 99 mol% of α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and 1 to 50 mol% of aromatic dicarboxylic acid, and more preferably. Is a C 4-20 α, ω-linear aliphatic dicarboxylic acid 60-95 mol% and an aromatic dicarboxylic acid 5-40 mol%, more preferably a C 4-20 α, ω-linear fatty acid. It contains 65 to 90 mol% of an aromatic dicarboxylic acid and 10 to 35 mol% of an aromatic dicarboxylic acid. By containing aromatic dicarboxylic acid as the dicarboxylic acid component, gas barrier performance is improved and moldability is improved, which is preferable.

  Further, in the present invention, a small amount of monoamine or monocarboxylic acid may be added as a molecular weight regulator during polycondensation.

  Moreover, when manufacturing polyamide composite material (X), in order to improve the process stability at the time of melt molding, or in order to prevent coloring of polyamide, a phosphorus compound can be added. As the phosphorus compound, a phosphorus compound containing an alkali metal or an alkaline earth metal is preferably used. For example, an alkali metal or alkaline earth metal phosphate such as sodium, magnesium, calcium, hypophosphite, phosphorus Acid salts may be mentioned, but those using alkali metal or alkaline earth metal hypophosphites are particularly preferred because they are particularly excellent in the anti-coloring effect of polyamide. The density | concentration of the phosphorus compound in polyamide is 1-500 ppm as a phosphorus atom, Preferably it is 1-350 ppm, More preferably, it is 1-200 ppm. Even if the phosphorus atom concentration exceeds 500 ppm, there is no change in the anti-coloring effect. Rather, the haze of the film obtained using this increases, which is not preferable. If the phosphorus atom concentration is less than 1 ppm, there is no anti-coloring effect, which is not preferable.

  As the polyamide in the polyamide composite material (X), those having a number average molecular weight in the range of 10,000 to 50,000 are preferably used. The number average molecular weight is appropriately selected depending on the use of the polyamide composite material of the present invention and the molding method. For example, a film having a number average molecular weight of about 20000 to 30000 when a certain degree of fluidity is required during production, and a sheet having a melt strength of about 30000 to 45000 when melt strength is required during production. Is selected, but is not limited to this.

  The polyamide composite material (X) may be subjected to polycondensation by solid phase polymerization after being produced by a melt polycondensation method. The method for producing the polyamide is not particularly limited, and it is produced by a conventionally known method and polymerization conditions.

  By producing the polyamide composite material (X) by this method, the polyamide composite material (X) can be produced by diluting the composition (C) with polyamide, so that the carbon dioxide required for the production is the composition (C). Since it is necessary only when producing the carbon dioxide, the amount of carbon dioxide used in the production can be reduced, and therefore the production cost can be reduced, which is preferable.

  The ash content of the polyamide composite material (X) produced by the above methods is preferably 0.01 to 20% when treated at 1000 ° C. for 5 hours. 0.1-10 weight% is further more preferable, and 0.5-8 weight% is more preferable. When the ash content is within the above range, an effect of improving gas barrier properties and an effect of improving mechanical strength can be obtained. In particular, when transparency is required, 0.01 to 8% is preferable, and 0.5 to 5% by weight is more preferable.

  In the polyamide composite material (X), it is preferable that the clay (B) is uniformly dispersed without locally agglomerating. Here, the uniform dispersion means that the clay is separated into a flat plate shape in the polyamide composite material (X), and 50% or more of them have an interlayer distance of 5 nm or more. Here, the interlayer distance refers to the distance between the centers of gravity of the flat objects. The larger the distance, the better the dispersion state, the better the appearance such as transparency when made into a film, and the better the barrier property against gaseous substances such as oxygen, carbon dioxide, and aroma components.

  The polyamide composite material (X) of the present invention includes, for example, automobile underhood parts (radiator tank, fastener clip, rear combination lamp housing, cable liner, headlamp reflector, ornament cover, rocker cover, engine mount, oil pan, junction block, Connector, motor housing, various gears etc.), automotive interior parts (through anchor, tongue plate, instrument panel etc.), automotive exterior parts (wheel cover, fender etc.), automobile gasoline tank, motorcycle gasoline tank, hose, electricity, It is used as a structural material for electronic parts, bicycle wheel rims, chair / desk feet, rail presses, and also for a wide range of applications such as fibers, sheets, and films. Examples of the use of the molded article in the present invention include members for electronic / electrical equipment, OA equipment, precision equipment, and automobiles, such as housings, casings, covers, and the like. It is preferably used for housings such as displays, notebook computers, portable telephones, PHS, PDAs (portable information terminals such as electronic notebooks), video cameras, video cameras, digital still cameras, portable radio cassette players, inverters, etc. . Moreover, it is used for a heat insulating material, a soundproofing material, a silencer for an air conditioner, etc. used for buildings, airplanes, vehicles, ships, etc., but is not limited to these.

  The molding material made of the polyamide composite material (X) of the present invention can be produced using any of the conventionally used molding methods. For example, it is molded by a molding method such as injection molding (injection compression molding, gas assist injection molding, insert molding, etc.), blow molding, rotational molding, extrusion molding, press molding, transfer molding, filament winding molding or the like.

  The polyamide composite material (X) of the present invention can be processed into a single-layer film or sheet using, for example, an extrusion apparatus equipped with a T-die or an inflation film manufacturing apparatus, and other resins such as polyethylene and polypropylene. Nylon 6, PET, metal foil, paper, and the like can be processed into a packaging material such as a multi-layered film or sheet using a method such as extrusion lamination or coextrusion. Furthermore, it can be used for packaging containers such as wraps or various shapes of pouches, container lids, bottles, cups, trays, and tubes. The packaging container obtained using the composite material of the present invention is excellent in gas barrier performance etc., for example, carbonated drink, juice, water, milk, sake, whiskey, shochu, coffee, tea, jelly drink, Liquid drinks such as health drinks, seasoning liquids, sauces, soy sauce, dressings, liquid soups, seasonings such as mayonnaise, miso, grated spices, pasty foods such as jams, creams, chocolate pastes, liquid soups, boiled foods, pickles, Liquid foods typified by liquid processed foods such as stew, raw noodles such as buckwheat, udon, ramen and boiled noodles, polished rice, moisture-conditioned rice, non-washed rice, etc. Processed rice products such as red rice and rice bran, high-moisture foods such as powdered soup and powdered seasonings such as soup stock, dried vegetables, coffee beans, coffee powder, tea and grains Low-moisture foods such as confectionery, other solid and solution chemicals such as agricultural chemicals and insecticides, liquid and paste pharmaceuticals, lotions, cosmetic creams, cosmetic milks, hair conditioners, hair dyes, shampoos Various articles such as soap and detergent can be stored. In particular, the multilayer container of the present invention is suitable as a material for packaging containers that store articles with high water activity, packaging containers that are exposed to high humidity, and packaging containers that are subjected to heat sterilization treatment such as retort and boiling. It is a thing.

Hereinafter, the present invention will be specifically described with reference to examples and the like. In Examples and the like, the evaluation of metaxylylene group-containing polyamide and the evaluation of the obtained multilayer film were based on the following methods.
In Examples and the like, the composite material was evaluated by the following method.
(A) Clay dispersibility The film was measured by the X-ray diffraction method. The measuring device used was a Rigaku Corporation miniflex. CuKα is used as the X-ray source, the scattering slit is 4.2 degrees, the light receiving slit is 0.3 mm, the tube voltage is 30 kV, the tube current is 15 mA, the scanning range is 2 to 50 degrees, the sampling width is 0.02 degrees, and the scanning speed is 5 Measured under the condition of degree / minute.
(B) Tensile strength, tensile elastic modulus The tensile strength (yield), tensile strength (break), and tensile elastic modulus of the test piece (thickness 1/8 inch) were measured based on ASTM D-638.
(C) Bending strength and bending elastic modulus The bending strength and bending elastic modulus of the test piece (thickness 1/4 inch) were measured based on ASTM D-790.
(D) Deflection temperature under load Deflection temperature under load of the test piece was measured at a load of 1.86 MPa based on ASTM D-648.
(E) Appearance The film was observed visually and with a microscope, and a product in which no clay lump was seen was judged to be a product in which a clay with good appearance and poor dispersion was observed as poor appearance.
(F) Oxygen transmission coefficient (OTR)
The film was measured according to ASTM D3985. The measurement was carried out in an atmosphere of 23 ° C. and 60% relative humidity using a model manufactured by Modern Control Co., Ltd., model: OX-TRAN 10 / 50A.
(G) Melt viscosity Measured using a Capillograph manufactured by Toyo Seiki under conditions of a shear rate of 100 s ⁻¹ and 220 ° C.

<Example 1>
Metaxylylenediamine and adipic acid were polycondensed in a molten state for a predetermined time, then taken out as a strand from the nozzle at the bottom of the polymerization tank, air-cooled, and then cut into pellets to obtain a polymetaxylene adipamide oligomer (PA1). 90 wt% of synthesized PA1 (Mn = 500, melt viscosity = 0.01 Pa · s, molar ratio = 2) and 10 wt% of montmorillonite (trade name; Kunipia F manufactured by Kunimine Kogyo Co., Ltd.) were charged into a reaction kettle, and solid dioxide dioxide Filled with carbon (dry ice) and treated for 2 hr under conditions of 10 MPa and 200 ° C. to obtain a composition (C1).

<Example 2>
After metaxylenediamine, adipic acid (80 mol%) and isophthalic acid (20 mol%) are polymerized for a predetermined time in a molten state, they are taken out as a strand from the nozzle at the bottom of the polymerization tank, cooled in air, cut into pellets, and oligomer (PA2) is obtained. Obtained. 30 mm twin-screw extruder in which 80 wt% of synthesized PA2 (Mn = 5000, melt viscosity = 30 Pa · s, molar ratio 0.994) and organoclay (trade name; Nanomer manufactured by Nanocor) 20 wt% were set at 200 ° C. Is continuously supplied to the feed port at 10 kg / h, carbon dioxide is supplied from a carbon dioxide cylinder to the gas addition port attached to the barrel of the extruder, the mixture is brought into a critical state inside the extruder, kneaded, and the vent port is decompressed. The mixture was kneaded while being deaerated to obtain a composition (C2). The pressure inside the barrel, measured with a pressure gauge attached to the barrel between the gas addition port and the vent port, was 8 MPa. The indicated temperature of the barrel was 210 ° C.

<Example 3>
95 wt% of nylon salt consisting of metaxylylenediamine and adipic acid and 5 wt% of synthetic smectite (trade name; smecton manufactured by Kunimine Kogyo Co., Ltd.) are charged into the reaction kettle, and the inside of the kettle is filled with carbon dioxide with gaseous carbon dioxide. Substitution was carried out under the conditions of 20 MPa and 200 ° C. for 3 hours to obtain a composition (C3).

<Example 4>
Adipic acid was kept in a molten state in a 50 L reaction kettle under a nitrogen stream, and the synthesis proceeded while adding metaxylylenediamine. At the timing when the addition of metaxylylenediamine was completed, the composition (C1) obtained in Example 1 was supplied to the reaction kettle, and the synthesis reaction was further advanced. After polymerization for a predetermined time, it was taken out as a strand from the nozzle at the bottom of the polymerization tank, cooled with water, and then cut into pellets to obtain polyamide composite material (X1). Ηr (relative viscosity) of X1 was 2.1.

<Example 5>
The polyamide composite material (X1) obtained in Example 4 was charged into a tumbler equipped with a 250 L heating jacket, vacuum pump, and nitrogen introduction tube, purged with nitrogen, and then continuously heated while rotating to 150 ° C. The system was degassed with a vacuum pump when the pressure reached. The temperature was further increased while degassing with a vacuum pump was continued. When the pellet temperature reached 200 ° C., the temperature was kept constant and the reaction was continued for 50 minutes. Thereafter, nitrogen was introduced to return the inside of the system to normal pressure, and the system was cooled to 70 ° C. to obtain a polyamide composite material (X11). Ηr of X11 was 2.7.

<Example 6>
37 mmφ co-rotating twin screw extruder with a vibration feeder at 5 kg / h for the composition (C2) obtained in Example 2 and 15 kg / h for polymetaxylylenediamine (MX nylon, grade S6007) manufactured by Mitsubishi Gas Chemical Co., Ltd. After being melted and kneaded, it was taken out as a strand from the die and cut into a pellet shape to obtain a polyamide composite material (X2).

<Example 7>
After metacondensation of metaxylylenediamine, adipic acid (91 mol%) and isophthalic acid (9 mol%) in a molten state for a predetermined time, it is taken out as a strand from the nozzle at the bottom of the polymerization tank, cooled in air, cut into pellets, and polymetaxylene An oligomer (PA3) was obtained. Synthesized PA3 (Mn8000, melt viscosity = 110 Pa · s, molar ratio: 1.002) 97 wt% and organic montmorillonite (trade name; Nanomer) 3 wt% were charged in a reaction kettle, charged with carbon dioxide, 240 ° C., 1 hr, It processed at 35 Mpa and obtained the composition (C4). The obtained composition was placed in a tumbler equipped with a 250 L heating jacket, a vacuum pump, and a nitrogen introduction tube, purged with nitrogen, heated continuously while rotating, and when the temperature reached 150 ° C. Was degassed with a vacuum pump. The temperature was further raised while degassing with a vacuum pump was continued. When the pellet temperature reached 200 ° C., the temperature was kept constant and the reaction was continued for 50 minutes. Thereafter, nitrogen was introduced to return the inside of the system to normal pressure, and the system was cooled to 70 ° C. to obtain a polyamide composite material (X3).

<Example 8>
The composition C3 obtained in Example 3 and water were charged into a reaction kettle, heated in a pressurized state, and subjected to polycondensation in a molten state while removing added water and condensed water to obtain a polyamide composite material (X4). It was.

  The polyamide composite materials obtained in Examples 4 to 8 were supplied to a 20 mmφ single screw extruder at 2 kg / h, and formed into a film form from a die. The oxygen permeability of the obtained film was measured. In addition, the polyamide composite materials obtained in Examples 4 to 8 were injection molded, and using an injection molding machine (manufactured by FANUC, AUTOSHOT 100B), cylinder temperature 260 ° C., mold temperature 40 ° C., injection time 1 second, cooling time Injection molding was performed in 15 seconds, various test pieces were prepared, and physical property tests were performed. Table 1 shows the physical property evaluation results.

<Comparative Example 1>
97 wt% of PA3 synthesized in Example 7 and 3 wt% of organic montmorillonite (trade name: Nanomer) were charged into a reaction kettle, and charged at 240 ° C., 1 hr, 35 MPa without filling with carbon dioxide, and the composition (C5 ) The obtained composition was placed in a tumbler equipped with a 250 L heating jacket, a vacuum pump, and a nitrogen introduction tube, purged with nitrogen, heated continuously while rotating, and when the temperature reached 150 ° C. Was degassed with a vacuum pump. The temperature was further increased while degassing with a vacuum pump was continued. When the pellet temperature reached 200 ° C., the temperature was kept constant and the reaction was continued for 50 minutes. Thereafter, nitrogen was introduced to return the inside of the system to normal pressure and cooled to 70 ° C. to obtain a polyamide composite material (X5). About the obtained polyamide composite material (X5), various test pieces were created similarly to Examples 4-8, and the physical-property test was done. Table 1 shows the physical property evaluation results.

  As described in the above Examples and Comparative Examples, Examples 4 to 8 in which polyamide composite materials satisfying the requirements of the present invention were manufactured had good clay dispersion and the amount of carbon dioxide used was low. Can be lowered. When a molded product such as a film was produced using this, it was possible to obtain a product with excellent gas barrier performance, good appearance, and excellent quality. Moreover, the mechanical strength was also excellent. On the other hand, in Comparative Example 1 that does not satisfy the requirements of the present invention, the clay was agglomerated and a composite material with good dispersion could not be obtained, the appearance was poor, and the mechanical properties and gas barrier performance were not excellent.

Claims (14)

Polyamide oligomer obtained by polycondensation of a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms ( A1) or a nylon salt (A2) comprising a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms ) And clay (B) in the presence of carbon dioxide in a supercritical state. The composition according to claim 1, wherein the polyamide oligomer (A1) has a melting point of 230 ° C or lower. The composition according to claim 1, wherein the polyamide oligomer (A1) has a number average molecular weight of 300 to 10,000. The composition according to claim ^1, wherein the apparent melt viscosity at a shear rate of 100 S ⁻¹ is 0.001 to 1000 Pa · s at a temperature equal to or higher than the melting point of the polyamide oligomer (A1). The composition according to claim 1, wherein the clay (B) content is 0.01 to 80% by weight in the composition. The composition according to claim 1, wherein the clay (B) is contacted with an organic agent. The composition according to claim 1, which is obtained by mixing the polyamide oligomer (A1) or nylon salt (A2) and the clay (B) in a heat-resistant and pressure-resistant reaction kettle in a batch system. The composition according to claim 1, which is obtained by continuously mixing the polyamide oligomer (A1) or the nylon salt (A2) and the clay (B) using an extruder. A polyamide composite material using the composition according to claim 1. The polyamide composite material according to claim 9, which is obtained by polycondensation of the composition. Polyamide obtained by polycondensation of a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms (D And the composition obtained by melt-kneading the composition with an extruder. In the polycondensation of a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, the composition The polyamide composite material according to claim 9, which is obtained by adding to a polymerization kettle. The packaging material formed using the polyamide composite material in any one of Claims 9-12. The packaging container formed using the polyamide composite material in any one of Claims 9-12.