JP5640472B2 - Polyamide resin composition - Google Patents

Description

The present invention relates to a polyamide containing a metaxylylene group. Specifically, the present invention relates to a polyamide that generates less gel even during molding.

Polyamide containing a metaxylylene group in the polymer main chain has high rigidity, is widely used as a molding material, and has excellent performance for blocking oxygen, carbon dioxide, etc., and various packaging such as bottles, sheets and films It is also used as a gas barrier material. In particular, in polyamides used for bottles, sheets, films, fibers, and the like, attention is paid to contamination by foreign matters more than polyamides used for molding materials. This is due to the fact that the molded product is transparent or thin, requires advanced and delicate molding technology, and that foreign matter is very likely to impair the function of the molded product. As a result, the appearance rate of defects, the occurrence of defects such as breakage due to the occurrence of foreign matter, and the productivity are reduced. Examples of the foreign substances derived from polyamide include powder called fine, thin film called floss, yellowed matter / carbide subjected to thermal deterioration, and gel-like material called gel or fish eye. Preventing the generation of these foreign substances is the best measure, but if it is unavoidable, it must be separated and removed from the pellet product. Powders and thin films are generally removed by wind separation, and yellowing substances and carbides can be removed by a sorter using an optical sensor. Various separation devices are commercially available, and a reliable removal effect can be expected.

  Gels or fish eyes are damaged during polymerization and molding processes (degradation of polymer molecules due to generation of radicals, etc.), and abnormal reactions such as non-linear molecular growth (such as three-dimensional polymerization) occur. It is assumed that the molecular weight is extremely high compared to other polyamide molecules. For this reason, in order to obtain a polyamide with little gel or fish eye, it is necessary to reduce the heat history as much as possible in the production process, and a device such as addition of a heat stabilizer or an antioxidant is made. However, some of these additives have a catalytic effect on the amidation reaction, and conversely, the polymerization reaction may proceed excessively, resulting in an increase in gel or fish eye. Therefore, in general, by adding a specific amount of an alkali compound having a reaction-inhibiting effect, polymerization is carried out while maintaining a balance between promotion and inhibition of the reaction.

  Gels or fish eyes produced in the melt polymerization process can be removed with a filter, etc., but gels larger than the opening size of the filter are often dispersed and passed by the fluid pressure, and have a high viscosity. Even in the gel or fish eye produced during the solid phase polymerization carried out during the production of the product, it is impossible to completely remove it.

Furthermore, the gel or fish eye is formed during the production of polyamide, and also during melting during molding. In the quality evaluation after polyamide production, even if a polyamide that does not show a significant difference in the amount of gel or fisheye produced is used, there may be a difference when molded. A slight difference in damage to the polyamide molecules that is not observed, or a difference in the frequency of occurrence of abnormal reactions may cause excessive heat history to be applied to some polymers at the staying part of screw grooves, filters, dies, etc. Presumed to be amplified. Therefore, in order to finally obtain a molded product with less gel or fish eyes, it is important to produce a high-quality polyamide with less gel and to design a molding device with very few staying parts. However, in order to produce a polyamide with less gel, it is necessary to suppress the thermal history during production, to add an effective stabilizer, and to remove the gel or fisheye produced during melt polymerization and solid phase polymerization. There is a limit to the effect of any response. In addition, it is difficult to completely eliminate the staying part of the molding processing device due to the construction of the device, and it is necessary to adapt the design to each device for molding polyamide, which lacks practicality in terms of versatility and cost. . In particular, in the polyamide composed of a diamine component mainly composed of xylylenediamine according to the present invention, generation of gel is still a problem because the benzylmethylene moiety of xylylenediamine tends to generate radicals and has low thermal stability.

In Patent Document 1, when molding the polyamide, 0.0005 to 0.5 parts by weight of at least one selected from a lubricant, an organic phosphorus stabilizer, a hindered phenol compound, and a hindered amine compound. There has been proposed a method of suppressing the formation of gel or fish eye by adding. However, the advantages of the fish eye reduction of the additives required for the implementation results described are scarce from a practical point of view, and there is little mention of the specific basis for the suppression of gel formation by adding each additive. The effect itself is unclear.

In Patent Document 2, in order to improve the lubricity of polyamide and avoid the generation of shear heat during the molding process, the molding process is performed by adding 0.001 to 0.015 part by weight of a fatty acid metal salt and a polyhydric alcohol compound. A method for suppressing the generation of fish eyes at the time has been proposed. However, paying attention to the chemical properties of the polyamide, there is no description about suppressing the alteration of the polyamide itself.

JP 2001-164109 A Japanese Patent No. 3808847

An object of the present invention is to provide a polyamide that is industrially useful as an injection molding material, a packaging material such as a film or a sheet, and a fiber material by suppressing the generation of gel or fish eye when the polyamide is molded. is there.

The present invention provides a polyamide resin composition having excellent gas barrier properties and less gel formation during molding.

As described above, the alkali compound is used as a neutralizing agent for the phosphorus compound added during the polymerization. However, the amount of polyamide used during polymerization is limited from the viewpoint of balance with phosphorus compounds. With regard to this point, as a result of intensive studies, the present inventors have been able to suppress the formation of gel during molding processing by adding an alkali compound during molding processing to increase the concentration after polymerization of polyamide. It has been found that even when the polyamide melt staying state continues for a long period of time, the amount of gel produced is small, and the obtained molded product has a good appearance with little gel and coloring. The present invention has been made based on such findings.

That is, the present invention provides a polyamide resin comprising a polyamide obtained by polycondensation of a diamine containing 70% by mole or more of metaxylylenediamine and a dicarboxylic acid, an alkali compound (A), and satisfying the following formula (A): Relates to the composition.
a ≦ 1.12 b (a)
(Here, a represents the amino terminal group concentration (μmol / g) in the polymer, and b represents the sum of the alkaline earth metal concentration in the polyamide resin composition and the alkali metal concentration (μmol / g). .)

The polyamide resin composition of the present invention has a good color tone, generates little gel or fish eye even during molding, and is very useful for molding materials, various packaging materials and fiber materials. The value is very high.

It is the figure which showed the relationship between the amino terminal group density | concentration of a polymer, and a gelling fraction.

The polyamide constituting the polyamide resin composition of the present invention is a polyamide obtained by polycondensation of a diamine containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid (hereinafter referred to as “polyamide (X)”). It is.

The diamine constituting the polyamide (X) preferably contains 70% by mole or more of metaxylylenediamine, more preferably 80% by mole or more, and still more preferably 90% by mole or more. When the metaxylylenediamine in the diamine is 70 mol% or more, the polyamide obtained therefrom can exhibit excellent gas barrier properties. Examples of diamines that can be used in addition to metaxylylenediamine include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, Aliphatic diamines such as 2,2,4-trimethyl-hexamethylenediamine and 2,4,4-trimethylhexamethylenediamine; 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminomethyl) decalin, bis (amino Examples thereof include alicyclic diamines such as methyl) tricyclodecane; diamines having an aromatic ring such as bis (4-aminophenyl) ether, paraphenylenediamine, paraxylylenediamine, bis (aminomethyl) naphthalene, and the like. It is not limited to these.

Examples of the dicarboxylic acid constituting the polyamide (X) include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and dimer acid; -Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, xylylene dicarboxylic acid, naphthalenedicarboxylic acid, and the like, but are not limited thereto. The dicarboxylic acid preferably contains 70 mol% or more of adipic acid, more preferably 80 mol% or more, and still more preferably 90 mol% or more. When adipic acid is 70 mol% or more, it is possible to avoid a decrease in gas barrier properties and an excessive decrease in crystallinity. As the dicarboxylic acid that can be used in addition to adipic acid, one or more of α, ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms are preferably used.

In addition to the diamine and dicarboxylic acid, as components constituting the polyamide (X), lactams such as ε-caprolactam and laurolactam, fats such as aminocaproic acid, aminoundecanoic acid, etc., as long as the effects of the present invention are not impaired. Aromatic aminocarboxylic acids such as para-aminomethylbenzoic acid can also be used as copolymerization components.

The production method of polyamide (X) is not particularly limited, and is produced by a conventionally known method and polymerization conditions. A small amount of monoamine or monocarboxylic acid may be added as a molecular weight regulator during the polycondensation of polyamide (X). 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 polymerized 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, while the reaction temperature is not lower than the melting point of the generated oligoamide and polyamide (X). The polycondensation proceeds while the system is heated.

Polyamide (X) may be subjected to polycondensation by solid phase polymerization after being produced by a melt polymerization method. The production method of polyamide (X) is not particularly limited, and is produced by a conventionally known method and polymerization conditions.

Polyamide (X) having a number average molecular weight in the range of 10,000 to 50,000 is preferably used. In addition, about a number average molecular weight, it selects suitably by the use and the molding method of the polyamide resin composition of this invention. 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 number average molecular weight of the polyamide (X) is calculated from the following formula (1).
Number average molecular weight = 2 × 1000000 / ([COOH] + [NH ₂ ]) (1)
(In the formula, [COOH] represents the terminal carboxyl group concentration (μmol / g) in the polyamide, and [NH ₂ ] represents the terminal amino group concentration (μmol / g) in the polyamide (X).)
In the present invention, the terminal amino group concentration is a value obtained by neutralizing and titrating a polyamide dissolved in a phenol / ethanol mixed solution with a dilute hydrochloric acid aqueous solution, and the terminal carboxyl group concentration is a value obtained by dissolving polyamide in benzyl alcohol. The value calculated by neutralizing titration with an aqueous sodium hydroxide solution is used.

There are several indicators of the degree of polymerization of polyamide, but relative viscosity is generally used. In polyamide (X), the preferred relative viscosity is 1.5 to 4.2, more preferably 1.7 to 4.0, and still more preferably 2.0 to 3.8. When the relative viscosity of the polyamide (X) is less than 1.5, the fluidity of the melted polyamide (X) tends to be unstable, and the appearance of the molded product may be deteriorated. On the other hand, when the relative viscosity of the polyamide (X) exceeds 4.2, the melt viscosity of the polyamide (X) may be too high and the molding process may become unstable.
The relative viscosity referred to here is that of 1% polyamide (X) dissolved in 100 mL of 96% sulfuric acid, and the drop time (t) measured at 25 ° C. with a Canon Fenceke viscometer, and 96% sulfuric acid measured in the same manner. It is the ratio of its own drop time (t0), and is expressed by the following equation.
Relative viscosity = t / t0 (B)

In the production of polyamide (X), the phosphorus atom-containing compound (B) is used from the viewpoint of enhancing the processing stability during melt molding and preventing the coloring of the polyamide (X). Therefore, the polyamide resin composition of the present invention contains a phosphorus component.
Preferable specific examples of the phosphorus atom-containing compound (B) include hypophosphorous acid compounds (also referred to as phosphinic acid compounds or phosphonous acid compounds), phosphorous acid compounds (also referred to as phosphonic acid compounds), and the like. It is not limited to these. The phosphorus atom-containing compound (B) may be a metal salt or an alkali metal salt.
Examples of the phosphorus atom-containing compound (C) include dimethylphosphinic acid, phenylmethylphosphinic acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, ethyl hypophosphite, phenyl hypophosphite. Phosphonic acid, sodium phenylphosphonite, potassium phenylphosphonite, lithium phenylphosphonite, ethyl phenylphosphonite, phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate, potassium phenylphosphonate, lithium phenylphosphonate, Examples include diethyl phenylphosphonate, sodium ethylphosphonate, potassium ethylphosphonate, phosphorous acid, sodium hydrogen phosphite, sodium phosphite, triethyl phosphite, triphenyl phosphite, pyrophosphorous acid and the like.

The addition amount of the phosphorus atom-containing compound (C) is preferably 1 to 400 ppm in terms of phosphorus atom concentration in the polyamide (X), more preferably 2 to 350 ppm, and further preferably 3 to 300 ppm. When it is less than 1 ppm, the polyamide (X) tends to be colored or gel during polymerization, which is not preferable. Further, when it exceeds 400 ppm, the gelation reaction of polyamide (X) is promoted, filter clogging, which is considered to be caused by the thermally degraded product of the phosphorus atom-containing compound (C), and fish eyes are mixed in the molded product. In some cases, the appearance of the molded product tends to deteriorate, which is not preferable.

Further, it is preferable to add the alkali metal compound (D) in combination with the phosphorus atom-containing compound (C) in the polycondensation system of the polyamide (X). In order to prevent coloring of the polyamide (X) during the polycondensation, it is necessary to make a sufficient amount of the phosphorus atom-containing compound (C) present. However, in some cases, the polyamide (X) may be gelled. In order to adjust the amidation reaction rate, the alkali metal compound (D) is preferably allowed to coexist. As the alkali metal compound (D), alkali metal hydroxides and alkali metal acetates are preferable. Examples of the alkali metal compound (D) that can be used in the present invention include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate. However, it can be used without being limited to these compounds.

When the alkali metal compound (D) is added in the polycondensation system, the value obtained by dividing the number of moles of the compound by the number of moles of the phosphorus atom-containing compound (C) may be 0.5 to 1. More preferably, it is 0.55-0.95, More preferably, it is 0.6-0.9. When this value is less than 0.5, the effect of suppressing the amidation reaction promoting effect of the phosphorus atom-containing compound (C) may be insufficient, and in some cases, the gel in the polyamide (X) may increase. . On the other hand, if it exceeds 1, the effect of promoting the amidation reaction of the phosphorus atom-containing compound (C) is excessively suppressed, and the progress of polycondensation is delayed. In some cases, the heat history during the production of polyamide (X) increases, Since gel may increase, it is not preferable.

Molded products obtained by molding polyamide (X) as it is have excellent properties and appearance after the start of molding, but the gel or fish eye increases with the long molding process and the product quality is improved. If it becomes unstable or the film or the like is broken, the apparatus must be stopped and the production efficiency deteriorates. This is presumed to occur because the polyamide continues to stay locally between the melt-kneading part and the die to cause overheating and gelation, and the generated gel flows out.

The polyamide resin composition of the present invention is prepared by mixing an alkali compound (A) with polyamide (X) in order to prevent the gelation of polyamide that occurs during molding. In the present invention, as a result of investigating the relationship between the end group concentration of the polyamide (X) and gelation, the lower the amino group concentration of the polyamide (X), the more the gel formation is suppressed. It has been found that a gel suppressing effect can be obtained even at a high amino group concentration. The interaction between the amino group and the metal is unknown, but if the amino group concentration decreases, it is speculated that the three-dimensionalization of the polymer due to the bonding between amino groups, which is considered to be the cause of gel formation, is suppressed, and gel formation is suppressed. The Here, when a represents the amino terminal group concentration (μmol / g) in the polymer, and b represents the sum of the alkaline earth metal concentration twice the alkali metal concentration and the alkali metal concentration (μmol / g) in the polyamide resin composition, these It is necessary for the density balance of the following to satisfy the following equation.
a ≦ 1.5b (a)
When the sum b of the metal concentration with respect to the amino group concentration a does not satisfy the formula (A), it is difficult to obtain a sufficient concentration for suppressing the gel. The amino group concentration is desirably 85 μmol / g or less. When it is larger than 85 μmol / g, the molecular weight is low and good physical properties cannot be maintained as a product.

In particular, in the present invention, alkali metal hydroxide, alkali metal hydride, alkoxide, alkali metal carbonate, alkali metal bicarbonate, carboxylic anhydride, and carboxylic acid hydrate are preferably used as the alkali compound (A). Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, and calcium hydroxide. Examples of the alkali metal hydride include lithium hydride, sodium hydride, potassium hydride and the like. Examples of the alkoxide include sodium methoxide, potassium methoxide, lithium methoxide, magnesium methoxide, calcium methoxide, sodium ethoxide, potassium ethoxide, lithium ethoxide, magnesium ethoxide, calcium ethoxide, sodium-t-butoxide, Examples include potassium-t-butoxide, lithium-t-butoxide, magnesium-t-butoxide, calcium-t-butoxide and the like. Examples of the alkali metal carbonate and alkali metal hydrogen carbonate include sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium carbonate, calcium carbonate, magnesium carbonate, and the like, and these anhydrous salts and hydrated salts include Can be used. Examples of carboxylic acid anhydrides and carboxylic acid hydrates include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, capric acid, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and eico acid. Linear saturated fatty acids such as acid, behenic acid, montanic acid, triacontanoic acid; fatty acid derivatives such as 12-hydroxystearic acid; oxalic acid, fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberin Aliphatic dicarboxylic acids such as acids, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid; hydroxy acids such as glycolic acid, lactic acid, hydroxybutyric acid, tartaric acid, malic acid, citric acid, isocitric acid, mevalonic acid; benzoic acid , Terephthalic acid, isophthalic acid, orthophthalic acid, pyrometic acid, trimellit And aromatic carboxylic acids such as xylylene dicarboxylic acid and naphthalene dicarboxylic acid, and the metals that form salts with carboxylic acids include sodium, potassium, lithium, calcium, barium, magnesium, strontium, zinc, and the like. However, it is not particularly limited to these. The alkali compound (A) used in the present invention may be one of the above or may be used in combination of two or more. Among these, sodium hydroxide, sodium carbonate, sodium acetate, and calcium stearate are particularly preferable because they are inexpensive and have a high gel suppressing effect.

Examples of the alkali compound (A) include the same compounds as the alkali metal compound (D) that can be added when producing the polyamide (X). However, if the alkali metal compound (D) is added excessively during melt polymerization, The effect of promoting the amidation reaction of the atom-containing compound (C) is suppressed too much, and the progress of polycondensation is delayed. In some cases, the heat history during the production of the polyamide (X) increases, and the gel of the polyamide (X) increases May be. Therefore, by increasing the amount of the alkali metal compound (D) that is added when the polyamide (X) is melt polymerized from the monomer, it is not possible to effectively prevent gel formation during the molding process. Most preferably, the alkali compound (A) is added after the melt polymerization.

In the present invention, a polycarboxylic acid (B) may be added to the polyamide for the purpose of reducing the terminal amino group concentration after melt polymerization. The polyvalent carboxylic acid (B) is an aromatic or alicyclic compound having 2 to 3 carboxyl groups in one molecule, or two of the carboxyl groups form an acid anhydride group ( Having 0 to 1 carboxyl group and 1 acid anhydride group). That is, the polyvalent carboxylic acid (B) is at least one selected from an aromatic trivalent carboxylic acid, an alicyclic trivalent carboxylic acid, an aromatic divalent carboxylic acid, an alicyclic divalent carboxylic acid, and the acid anhydride. It consists of a kind of polyvalent carboxylic acid compound. The acid anhydride is an intramolecular acid anhydride.
Examples of the polyvalent carboxylic acid (B) include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid (including positional isomers) and anhydrides thereof, and anthracene dicarboxylic acid (including positional isomers). And its anhydride, biphenyldicarboxylic acid (including positional isomer) and its anhydride, benzophenone dicarboxylic acid (including positional isomer) and its anhydride, cyclohexanedicarboxylic acid (including positional isomer) and its anhydride, Trimellitic acid, trimellitic anhydride, hemimellitic acid and its anhydride, trimesic acid, 1,2,4-cyclohexanetricarboxylic acid and its anhydride, 1,2,3-cyclohexanetricarboxylic acid and its anhydride, 1, 3,5-cyclohexanetricarboxylic acid, naphthalenetricarboxylic acid ( Isomers) and their anhydrides, anthracentricarboxylic acids (including positional isomers) and their anhydrides, biphenyltricarboxylic acids (including positional isomers) and their anhydrides, benzophenone tricarboxylic acids (including positional isomers) ) And anhydrides thereof.
Of these, phthalic acid, phthalic anhydride, trimellitic acid and trimellitic anhydride are preferred, phthalic anhydride, trimellitic acid and trimellitic anhydride are more preferred, phthalic anhydride and trimellitic anhydride are more preferred, and phthalic anhydride is preferred. Acid is particularly preferred.

It is preferable that the manufacturing method of the polyamide resin composition of this invention is a manufacturing method including the process of melt-kneading polyamide (X) and an alkali compound (A) with an extruder. Alkaline compound (A) and / or polyvalent carboxylic acid other than at the time of melt polymerization in which the amidation rate varies greatly depending on the content ratio of phosphorus atom-containing compound (C) and alkali metal compound (D), that is, after melt polymerization. It is preferable to obtain the acid (B) by melt-kneading. For example, the alkali compound (A) may be added directly to the polyamide (X) during the molding process, or the polyvalent carboxylic acid (B) may be further added to the molding process. Alternatively, the polyamide (X) is melted and kneaded in advance using an extruder or the like together with 1 to 10 parts by weight of the alkali compound (A) to form pellets, and the alkali compound (A) -containing pellet and the polyvalent carboxylic acid (B) are converted into polyamide. You may blend with (X) and use for a shaping | molding process. Alternatively, the above-mentioned alkali compound (A) -containing pellets are blended with polyamide (X) and subjected to solid phase polymerization, and then subjected to molding as it is, or further blended with polyvalent carboxylic acid (C) to form. However, the present invention is not limited to these methods.

Examples of the apparatus for melt kneading include various known extruders such as a batch kneader, a kneader, a kneader, a planetary extruder, a single screw or a twin screw extruder, among these, kneading ability, From the viewpoint of excellent productivity, a single screw extruder or a twin screw extruder is preferably used.

In order to supply the polyamide (X) and the alkali compound (A), or the alkali compound (A) and the polyvalent carboxylic acid (B) to the extruder, a belt feeder, a screw feeder, a vibration feeder, or the like can be used. However, it is not limited to these methods. Further, the shape of the alkali compound (A) and the polyvalent carboxylic acid (B) is not limited as long as it can be uniformly dispersed in the resin composition, and may be added as it is, or added after heating and melting. Alternatively, it may be added after dissolving in a solvent. When adding powder as it is, the particle size is preferably 0.01 mm to 5.0 mm, more preferably 0.02 to 3.0 mm. When the alkali compound (A) is added after being dissolved in a solvent, it can be added to the extruder using a device such as a feeder for adding a liquid, or blended in advance with a tumbler or the like. As the solvent, water or any organic solvent can be used.

In the present invention, when dry blending is performed, a viscous liquid is adhered to the polyamide (X) as a spreading agent in order to prevent separation of the polyamide and the alkali compound (A) or the polyvalent carboxylic acid (B). Thereafter, a method of adding and mixing the alkali compound (A) or the alkali compound (A) and the polyvalent carboxylic acid (B) may be employed. Examples of the spreading agent include a surfactant and the like, but a known one can be used without being limited thereto.

In the present invention, the gel formation rate of the polyamide resin composition is compared with the gelation ratio of the polyamide heated for a certain time and at a certain temperature in a high pressure and molten state, assuming that the polyamide is exposed during molding. It was evaluated by doing. The gelation ratio is determined by immersing the pressurized and heated resin in hexafluoroisopropanol (HFIP) for 24 hours, while the ungelled resin is completely dissolved within the time, whereas the gelled resin is the time. Even after soaking, the gel remained in a swollen state and remained as an insoluble component. Therefore, the gelation fraction was calculated from the insoluble component and evaluated. In the present invention, the gelation fraction refers to a residue weight obtained as a result of filtering the insoluble component with a membrane filter under reduced pressure, dividing the resin weight weighed in advance before HFIP as a denominator, and a value obtained as a percentage. say. When the gelation fraction is lower than the value obtained using a polyamide to which no additive is added during the molding process, the amount of gel or fish eye produced during the molding process can be reduced. In the present invention, the gelation fraction is preferably 15% or less, more preferably 13% or less, and still more preferably 10% or less.

In addition, the polyamide resin composition of the present invention can be blended with one or more other resins such as nylon 6, nylon 66, nylon 66, 6, polyester, polyolefin, phenoxy resin, and the like within a range that does not impair the purpose. In addition, inorganic fillers such as glass fibers and carbon fibers; plate-like inorganic fillers such as glass flakes, talc, kaolin, mica, montmorillonite, and organized clay; impact modifiers such as various elastomers; crystal nucleating agents Lubricants such as fatty acid amides and fatty acid amides; antioxidants such as copper compounds, organic or inorganic halogen compounds, hindered phenols, hindered amines, hydrazines, sulfur compounds, phosphorus compounds; coloring inhibitors , Benzotriazole-based UV absorbers, mold release agents, plasticizers, colorants, flame retardants and other additives, compounds containing cobalt metal, benzoquinones, anthraquinones, naphthoquinones that provide oxygen scavenging ability Additives such as can be added.

The polyamide resin composition of the present invention has excellent gas barrier properties and transparency, and has stable melting characteristics. The polyamide resin composition of the present invention can be formed into various molded materials such as sheets, films, injection molded bottles, blow bottles, injection molded cups, etc. by using the resin composition as a molded product at least in part. Can be a container. There is no restriction | limiting in particular about the manufacturing method of these packaging materials or a packaging container, A well-known technique can be used. For example, it can be processed into a film or a sheet using an extrusion method equipped with a T die, an inflation film manufacturing method, or the like, and the obtained raw film can be obtained as a stretched film or a heat-shrinkable film by stretching. Moreover, it can be set as an injection molding cup by an injection molding method, and it can be set as a blow bottle by a blow molding method. Moreover, after manufacturing a preform by injection molding, it can be set as a bottle by blow molding. Moreover, it can be processed into a film or sheet having a multilayer structure with other resins such as polyethylene, polypropylene, nylon 6, PET, metal foil, paper, and the like using a method such as extrusion lamination or coextrusion. The processed film or sheet can be further used for wrapping or packaging containers such as pouches having various shapes, container lids, bottles, cups, trays, and tubes. The packaging container obtained using the polyamide resin composition of the present invention is excellent in gas barrier properties and excellent in transparency, for example, carbonated drink, juice, water, milk, sake, whiskey, shochu, Liquid drinks such as coffee, tea, jelly drinks, health drinks, seasonings, sauces, soy sauce, dressings, liquid soup, seasonings such as mayonnaise, miso, grated spices, pasty foods such as jam, cream, chocolate paste, Liquid foods such as liquid soups, boiled foods, pickles, stews, and raw foods such as buckwheat noodles, noodles, ramen, etc. High-moisture foods such as cooked rice, cooked rice, processed rice products such as red rice, rice bran; powdered soups, powdered seasonings such as dashi stock, dried vegetables, coffee beans, coffee Low-moisture foods typified by powder, tea, cereals and other sweets; other solid and solution chemicals such as pesticides and insecticides, liquid and paste pharmaceuticals, lotions, cosmetic creams, makeup Various articles such as emulsion, hair conditioner, hair dye, shampoo, soap and detergent can be stored. In addition, the polyamide resin composition of the present invention can be used as a gasoline barrier material for gasoline tanks and hoses of automobiles, motorcycles and the like. Moreover, the polyamide resin composition of the present invention can also be a fiber material such as a monofilament.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples. In addition, the measurement for evaluation in this invention was based on the following method.
(1) Terminal amino group concentration 0.3-0.5 g of polyamide was precisely weighed and dissolved in 30 ml of phenol / ethanol = 4/1 volume solution with stirring at 20-30 ° C. After complete dissolution, it was determined by neutralization titration with an aqueous N / 100 hydrochloric acid solution while stirring.
(2) Relative viscosity of polyamide 1 g of polyamide was precisely weighed and dissolved in 100 ml of 96% sulfuric acid at 20-30 ° C. with stirring. After completely dissolving, 5 ml of the solution was quickly taken into a Cannon-Fenceke viscometer and allowed to stand for 10 minutes in a constant temperature bath at 25 ° C., and then the drop time (t) was measured. Further, the dropping time (t0) of 96% sulfuric acid itself was measured in the same manner. The relative viscosity was calculated from t and t0 according to the following formula (B).
Relative viscosity = t / t0 (B)
(3) Metal concentration (Na, Ca) quantitative analysis The polyamide resin composition is ashed with a platinum crucible, perchloric acid is added to evaporate to dryness, and 1.0 molar hydrochloric acid is added, or polyamide After the resin composition was decomposed in nitric acid by microwave, an atomic absorption spectrometer (trade name: AA-6650, manufactured by Shimadzu Corporation) and an ICP emission spectrometer (trade name: ICPE-9000, (stock) ) (Manufactured by Shimadzu Corporation). In addition, since the measured value was obtained as a weight fraction (ppm), it calculated using atomic weight and valence.

<Example 1>
(Polymer melt polymerization)
15000 g (102.6 mol) of adipic acid weighed precisely in a reaction vessel having an internal volume of 50 liters equipped with a stirrer, a partial condenser, a full condenser, a thermometer, a dropping funnel and a nitrogen introduction tube, and a strand die, hypophosphorous acid After putting 432.6 mg of sodium (4.082 mol, 5 ppm as a phosphorus atom concentration in polyamide) and 206.4 mg of sodium acetate (2.516 mmol, 0.7 as a molar ratio with respect to phosphorus atom), and sufficiently purging with nitrogen, Further, the system was heated to 170 ° C. with stirring in a small amount of nitrogen. To this, 13854 g (101.7 mol) of metaxylylenediamine was added dropwise with stirring, and the inside of the system was continuously heated while removing the generated condensed water. After completion of the dropwise addition of metaxylylenediamine, the internal temperature was 260 ° C. and the reaction was continued for 40 minutes. Thereafter, the inside of the system was pressurized with nitrogen, and the polymer was taken out from the strand die and pelletized to obtain about 24 kg of polyamide.
(Polyamide solid phase polymerization)
Next, the polyamide is charged into a tumble dryer with a jacket provided with a nitrogen gas introduction tube, a vacuum line, a vacuum pump, and a thermocouple for measuring the internal temperature, and the purity inside the tumble dryer is 99% by volume while rotating at a constant speed. After sufficiently replacing with the above nitrogen gas, the tumble dryer was heated under the same nitrogen gas stream, and the pellet temperature was raised to 150 ° C. over about 150 minutes. When the pellet temperature reached 150 ° C., the pressure in the system was reduced to 1 torr or less. The temperature was further raised, and the pellet temperature was raised to 200 ° C. over about 70 minutes, and then held at 200 ° C. for 30 to 45 minutes. Next, nitrogen gas having a purity of 99% by volume or more was introduced into the system and cooled while rotating the tumble dryer, and the polyamide having a terminal amino group concentration of 10.6 μeq / g and a relative viscosity of 2.71 (X1 )
(Preparation of polyamide resin composition)
To 2 kg of polyamide 1, 2000 mg of sodium acetate dissolved in 2 ml of distilled water was added and stirred to obtain a polyamide resin composition 1.
(Film production)
Next, the polyamide resin composition 1 was removed from the extruder using a 25 mmφ single-screw extruder, a head provided with a 600 mesh filter, a film extruder composed of a T die, a cooling roll, a winder, and the like. The film was extruded in the form of a film while maintaining a discharge rate of 3 kg / h, and the take-up speed was adjusted to obtain a film having a width of 15 cm and a thickness of 250 microns, which was wound up by a winder. Further, the resin pressure of the extruder head was observed to confirm the presence or absence of the change.
(Creating a stagnant sample)
Next, the film was cut into concentric circles with a diameter of 30 mm, and four sheets were produced. The circular film is overlaid, and the film overlaid on the hole of a 1 mm-thick 100 × 100 mm polytetrafluoroethylene sheet having a hole hollowed out to a hole diameter of 30 mm is inserted. It was sandwiched between sheets.
Next, a Teflon (registered trademark) sheet with the above-mentioned film sandwiched in a 15 mm thick × 150 mm × 150 mm metal plate having a 120 mm × 120 mm groove with a depth of 3 mm at the center is arranged in the center of the groove, and further 15 mm thick × After covering from the top with a 150 mm × 150 mm metal plate, the metal plates were fixed with bolts. Subsequently, heating was continued at 290 ° C. for 24 hours with the metal plate sandwiched at 100 kg / cm ² or more by a pre-warmed hot press. After the elapse of 24 hours, the metal plate was taken out and rapidly cooled, and after sufficiently cooled to room temperature, the retained sample was taken out.
(Calculation of gelation fraction)
Next, after the above-mentioned staying sample was dried with a constant temperature dryer at 60 ° C. for 30 minutes, 100 mg of the dried sample was immediately weighed. The weighed residence sample was immersed in 10 ml of hexafluoroisopropanol (HFIP) having a purity of 99% or more for 24 hours, and then filtered under reduced pressure through a pre-weighed 300 μm pore polytetrafluoroethylene membrane filter.
The residue remaining on the membrane filter was washed with HFIP, and the filter with the residue adhered was dried at 60 ° C. for 30 minutes with a constant temperature dryer.
Next, the total weight of the dried residue and the filter was weighed, and the amount of HFIP insoluble component (gel amount) of the staying sample was calculated from the difference between the weight of the filter weighed in advance.
The gelation fraction was determined as the weight percent of the HFIP insoluble component relative to the residence sample. The results are shown in Table 1.

<Example 2>
Using the same polyamide (X1) as in Example 1, except that the amount of sodium acetate added was 4000 mg, film formation and melt residence with a hot press were carried out in the same manner as in Example 1 to obtain a residence sample. As in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Example 3>
A polyamide (X2) was obtained by synthesizing in the same manner as in Example 1 except that the amount of metaxylylenediamine was 13903 g (102.1 mol) (relative viscosity; 2.71, terminal amino group concentration; 19.6 μeq / g). Using polyamide (X2), except that the amount of sodium acetate added was 4000 mg, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample. The amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Example 4>
A polyamide (X3) was obtained by synthesizing in the same manner as in Example 1 except that the amount of metaxylylenediamine was changed to 13917 g (102.3 mol) (relative viscosity; 2.69, terminal amino group concentration; 26.4 μeq / g). Using polyamide (X3), except that sodium acetate was added in an amount of 4000 mg, film formation and melt residence with a hot press were carried out in the same manner as in Example 1 to obtain a residence sample, as in Example 1. The amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Example 5>
A polyamide (X4) was obtained in the same manner as in Example 1 except that the amount of metaxylylenediamine was 13910 g (102.2 mol) (relative viscosity: 2.72, terminal amino group concentration: 15.3 μeq / g). Using the polyamide (X4), adding 1000 mg of sodium acetate, and mixing 6000 mg of phthalic anhydride, film formation and melt residence by a hot press were performed in the same manner as in Example 1 to obtain a residence sample. In the same manner as in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Example 6>
Using the same polyamide (X4) as in Example 5, adding 1000 mg of sodium acetate, and mixing 10000 mg of phthalic anhydride, film formation and melt residence by a hot press were performed in the same manner as in Example 1. A retained sample was obtained, and the amount of insoluble components in HFIP was measured in the same manner as in Example 1.
The results are shown in Table 1.

<Example 7>
Filming and hot pressing were carried out in the same manner as in Example 1 except that the same polyamide (X4) as in Example 5 was used, calcium stearate was added in place of sodium acetate, the addition amount was 8000 mg, and phthalic anhydride 6000 mg was mixed. The melt was retained by a machine to obtain a retained sample, and the amount of insoluble components in HFIP was measured in the same manner as in Example 1.
The results are shown in Table 1.

<Comparative Example 1>
Using the same polyamide (X1) as in Example 1, except that sodium acetate was not added, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample. Similarly to 1, the amount of insoluble components in HFIP was measured.

<Comparative example 2>
Using the same polyamide (X2) as in Example 3, except that sodium acetate was not added, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample. Similarly to 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative Example 3>
Using the same polyamide (X3) as in Example 4, except that sodium acetate was not added, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample. Similarly to 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative example 4>
A polyamide (X5) was obtained in the same manner as in Example 1 except that the amount of metaxylylenediamine was 13970 g (102.6 mol) (relative viscosity: 2.74, terminal amino group concentration: 39.1 μeq / g). Using polyamide (X5), except that sodium acetate was not added, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample, and to HFIP as in Example 1. The amount of the insoluble component was measured.
The results are shown in Table 1.

<Comparative Example 5>
Using the same polyamide (X4) as in Example 5, except that sodium acetate was not added, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample. Similarly, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative Example 6>
Using the same polyamide (X4) as in Example 5, except that 6000 mg of phthalic anhydride was mixed in place of sodium acetate, film formation and melt residence by a hot press were carried out in the same manner as in Example 1, and a residence sample was obtained. As in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative Example 7>
The same polyamide (X4) as in Example 5 was used, and instead of sodium acetate, 8000 mg of phthalic anhydride was mixed, and film formation and melt residence by a hot press were carried out in the same manner as in Example 1, and a residence sample was obtained. As in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative Example 8>
Using the same polyamide (X4) as in Example 5, 1000 mg of sodium acetate was added, and 2000 mg of phthalic anhydride was mixed, and film formation and melt residence by a hot press were carried out in the same manner as in Example 1. A retained sample was obtained, and the amount of insoluble components in HFIP was measured in the same manner as in Example 1.
The results are shown in Table 1.

<Comparative Example 9>
Using the same polyamide (X2) as in Example 3, except that the amount of sodium acetate added was 1000 mg, film formation and melt residence by a hot press were carried out in the same manner as in Example 1 to obtain a residence sample, In the same manner as in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative Example 10>
The same polyamide (X3) as in Example 4 was used, except that the amount of sodium acetate added was 2000 mg, and the film was formed and melted and retained by a hot press in the same manner as in Example 1 to obtain a retained sample. In the same manner as in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

<Comparative Example 11>
The same polyamide (X5) as in Comparative Example 4 was used, except that the amount of sodium acetate added was 4000 mg, and the film was formed and melted and retained by a hot press in the same manner as in Example 1 to obtain a retained sample. In the same manner as in Example 1, the amount of insoluble components in HFIP was measured.
The results are shown in Table 1.

Abbreviations in Table 1 represent the following.
AcNa: sodium acetate PAn: phthalic anhydride

Claims (11)

A polyamide resin composition comprising a polyamide obtained by polycondensation of a diamine containing 70% by mole or more of metaxylylenediamine and a dicarboxylic acid, an alkali compound (A) and satisfying the following formula (A):
a ≦ 1.12 b (a)
(Here, a represents the terminal amino group concentration (μeq / g) in the polymer, and b represents the sum of the alkaline earth metal concentration in the polyamide resin composition and the alkali metal concentration (μmol / g). .)   Furthermore, the polyamide resin composition of Claim 1 containing polyhydric carboxylic acid (B).   The polyamide resin composition according to claim 2, wherein the polyvalent carboxylic acid (B) is at least one selected from phthalic acid, phthalic anhydride, trimellitic acid and trimellitic anhydride.   A product obtained by a production method including a step of melt-kneading the polyamide and the alkali compound (A) or the polyamide, the alkali compound (A) and the polyvalent carboxylic acid (B) with an extruder. The polyamide resin composition according to any one of the above.   The polyamide according to any one of claims 1 to 4, wherein the polyamide is a polyamide obtained by polycondensation of a diamine containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid containing 70 mol% or more of adipic acid. Resin composition.   The polyamide is a polyamide obtained by polycondensation of a diamine containing 70 mol% or more of metaxylylenediamine with a dicarboxylic acid containing 70 mol% or more of adipic acid and 1 to 30 mol% of isophthalic acid. The polyamide resin composition in any one of 1-4.   A molded article obtained by extruding the polyamide resin composition according to any one of claims 1 to 6.   A molded product obtained by uniaxially stretching or biaxially stretching the molded product according to claim 7.   A molded article obtained by injection molding the polyamide resin composition according to claim 1.   A molded product obtained by stretching and blowing the molded product according to claim 9.   It is a packaging material, a packaging container, or a fiber material, The molded article in any one of Claims 7-10.

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