JP2011089007A - Polyamide resin having excellent flexibility and barrier property, and molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin having more excellent barrier properties than a blend composition of an aliphatic polyamide resin such as nylon 6 etc., for imparting flexibility. <P>SOLUTION: The polyamide resin is obtained by polycondensation of meta-xylylenediamine, a 4-12C α,ω-straight-chain aliphatic dicarboxylic acid and ε-caprolactam or 6-aminocaproic acid as a copolymerization component. The content of a constituent unit derived from the copolymerization component is 25-45 mol%, difference between terminal carboxy group concentration [COOH] and terminal amino group concentration [NH<SB>2</SB>] is 8-82 μeq/g, (phosphorus atom concentration is obtained by adding concentration is obtained by adding) a phosphorus atom-containing compound is added to a polycondensation system so that a phosphorus atom concentration has 5-400 ppm, a temperature dropping semi-crystallization time of the polyamide resin at 160°C is ≥200 second and ≤1,800 seconds and the polyamide resin has one melt peak obtained by DSC measurement. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyamide resin excellent in transparency, flexibility and barrier properties, and a molded article thereof.

  Polyamide resins are widely used as materials for injection-molded articles such as automobiles and electric / electronic parts because they have excellent mechanical performance. It is also used as a packaging material for foods, beverages, medicines, electronic parts, etc., especially polyamides obtained from polycondensation reaction of xylylenediamine and aliphatic dicarboxylic acids, especially metaxylylenediamine and adipic acid. Since the obtained polyamide (N-MXD6) exhibits low permeability to gaseous substances such as oxygen and carbon dioxide, it is used as a gas barrier material in molded articles such as films and bottles.

  On the other hand, since the polyamide resin containing a metaxylylene group has very high rigidity, there have been various problems in using it as it is for an application requiring flexibility such as a film. In order to improve this property, polyamides containing metaxylylene groups have been melt blended with general polyamide resins with excellent flexibility such as nylon 6 and nylon 666, and multilayer structures are formed with them. Various methods have been proposed for use as those having both gas barrier properties and flexibility (see, for example, Patent Documents 1 to 3).

  However, when a polyamide resin containing a metaxylylene group and another polyamide resin are melt-mixed, an increase in melt viscosity far exceeding the arithmetic average may occur. As a method for preventing this phenomenon, the difference in concentration between the terminal carboxyl group and terminal amino group of the polyamide resin after melt mixing and the concentration of phosphorus atoms contained in the polyamide resin after melt mixing are used in a specific relationship. A method of selecting a polyamide resin has been proposed (see, for example, Patent Document 4). In this method, in order to prevent amidation from proceeding in the molten state, the molecular weight is increased by setting the balance of the end groups of the polyamide so that one is excessive or by reducing the number of phosphorus compounds that can serve as amidation catalysts. This method is based on the idea of preventing an increase in melt viscosity due to the fact that the polyamide usually used for packaging materials or the like cannot obtain a material having a sufficient degree of polymerization unless the reaction molar ratio is as close to 1 as possible. Therefore, it is essential to keep the phosphorus atom concentration in the polyamide resin low. When trying to obtain a polyamide resin in such a situation, the reaction time for obtaining a sufficient molecular weight in the polymerization process becomes long, or the oxidation of the polymer proceeds because there are few phosphorus compounds in the polymerization system, and the resulting polyamide resin Has a high yellowness or a lot of gel, and as a result, the commercial value of products such as packaging materials obtained by this method is low.

  Also, when melt-mixing a polyamide resin having excellent flexibility such as nylon 6 to give sufficient flexibility, a polyamide resin containing a metaxylylene group is melted at 30% by mass or less and nylon 6 is melted at 70% by mass or more. There is a problem in that the characteristics of the polyamide resin containing the metaxylylene group cannot be utilized because it is necessary to blend, and the gas barrier property is significantly lowered as compared with the polyamide resin containing the metaxylylene group. Furthermore, in a container in which a polyamide resin containing PET and a metaxylylene group is made into a multilayer without using an adhesive, in order to improve delamination, nylon 6 is melt-mixed by 5 to 30% by mass to perform a polycondensation reaction. Although a random copolymer has been obtained (see, for example, Patent Document 5), a random copolymer obtained by melt mixing has not yet improved sufficient delamination (delamination resistance).

JP 11-334006 A Japanese Patent Laid-Open No. 2000-21665 JP 2003-011307 A JP-A-7-247422 JP 2004-351716 A

  The present invention improves the flexibility of a polyamide resin composed of a highly rigid metaxylylenediamine, and has a higher barrier property than a blend composition with an aliphatic polyamide resin such as nylon 6 for the purpose of imparting flexibility. It is an object to provide a composition.

As a result of intensive studies to solve the above problems, the present inventors have found that a diamine component containing 70% by mole or more of metaxylylenediamine, an α, ω-linear aliphatic dicarboxylic acid having 4 to 12 carbon atoms, A polyamide resin obtained by polycondensation of ε-caprolactam or 6-aminocaproic acid as a polymerization component, and the content of structural units derived from the copolymerization component in the polyamide resin is in the range of 25 to 45 mol% The difference between the terminal carboxyl group concentration [COOH] and the terminal amino group concentration [NH ₂ ] of the polyamide resin ([COOH] − [NH ₂ ]) is in the range of 8 to 82 μeq / g, This is obtained by adding a phosphorus atom-containing compound into the polycondensation system so that the phosphorus atom concentration is 5 to 400 ppm, and the temperature drop of the polyamide resin at 160 ° C. The inventors have found that the object can be achieved by the fact that the crystallization time is 200 seconds or more and 1800 seconds or less and one melting peak is obtained from DSC measurement (differential scanning calorimetry), and the present invention has been achieved. .

  The polyamide resin of the present invention is a polyamide resin excellent in flexibility and barrier properties, and is suitable for industrial uses such as packaging containers, fuel tubes and fuel tanks that require flexibility.

In the present invention, a polyamide resin is formed using a diamine component and a dicarboxylic acid component. In the present invention, metaxylylenediamine is used as the diamine component, but other diamine components can also be used. For example, paraxylylenediamine, paraphenylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1, 4-bis (aminomethyl) cyclohexane, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, and the like can be used.
The content of metaxylylenediamine in the diamine component needs to be 70 mol% or more in the diamine component. It is because the polyamide resin obtained will express the outstanding gas barrier property if it is 70 mol% or more. The preferred content of metaxylylenediamine is 75 mol% or more, more preferably 85 mol% or more, and even more preferably 90 mol% or more (including 100 mol%).

  Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 12 carbon atoms used in the present invention include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecane. Aliphatic dicarboxylic acids such as diacid and dodecanedioic acid can be exemplified, but among these, adipic acid is preferred from the viewpoint of ease of polymerization and gas barrier properties.

  In the present invention, dicarboxylic acids other than the above aliphatic dicarboxylic acids, for example, aromatic dicarboxylic acids can be used. As the aromatic dicarboxylic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid and the like can be used. Moreover, since there exists a possibility that a softness | flexibility may be reduced, it is preferable that the copolymerization rate in the case of copolymerizing diamine and dicarboxylic acid which have an aromatic ring shall be 10 mol% or less in this dicarboxylic acid.

  In the present invention, ε-caprolactam or 6-aminocaproic acid can be used as a copolymerization component. From the viewpoint of industrial production, it is preferable to use ε-caprolactam. Copolymerization of ε-caprolactam can provide flexibility, but in order to obtain sufficient flexibility, it is preferable to copolymerize at least 25 mol% of the polyamide resin, particularly preferably 30 More than mol%.

  When a third component such as ε-caprolactam or 6-aminocaproic acid is copolymerized with a diamine component containing 70 mol% or more of metaxylylenediamine and an α, ω-linear aliphatic dicarboxylic acid having 4 to 12 carbon atoms , The direction becomes amorphous. Since gas barrier properties decrease when amorphous, ε-caprolactam in the polyamide resin is preferably 45 mol% or less.

When the polyamide resin is produced, the reaction monomer is used so that the value obtained by subtracting the amino group concentration ([NH ₂ ]) from the carboxyl group concentration ([COOH]) at the end of the polyamide resin is 8 to 82 μeq / g. Preferably, 15 to 75 μeq / g is more preferable. When the absolute value of the value obtained by subtracting the amino group concentration ([NH ₂ ]) from the carboxyl group concentration ([COOH]) at the end of the polyamide resin is within the above range, the desired balance is obtained from the balance between the diamine and dicarboxylic acid monomers. A high molecular weight polyamide resin can be obtained.

In addition, the temperature drop half crystallization time at 160 ° C. is 200 seconds or more and 1800 seconds or less because if the temperature drop half crystallization time exceeds 1800 seconds, the moldability of containers and the like deteriorates and the productivity also decreases. To do. On the other hand, if it is less than 200 seconds, flexibility is insufficient.
Here, the temperature drop half crystallization time is calculated by melting the pellet or film made of the polyamide resin of the present invention in a hot air environment of 260 ° C. for 3 minutes by the depolarization intensity method, and then crystallizing it in an oil bath of 160 ° C. It is time to be. The reason for crystallization at 160 ° C. is that the polyamide resin of the present invention has the fastest crystallization speed and is easy to measure.

  Since the polyamide resin becomes a stable random copolymer, flexibility and barrier properties can be obtained, so it is essential that there is only one melting peak obtained from DSC (differential scanning calorimetry). is there. If there is only one melting peak, a random copolymer is obtained, and physical properties such as flexibility and barrier properties are stably expressed.

  As described above, in order to obtain a stable random copolymer, the polyamide resin was previously melted with α, ω-linear aliphatic dicarboxylic acid and ε-caprolactam or 6-aminocaproic acid. It is preferable to proceed with the melt polycondensation reaction with MXDA later. When ε-caprolactam or 6-aminocaproic acid is added during the reaction, a partially block copolymerized polyamide resin may be obtained in which the reaction does not proceed or two melting peaks of DSC are observed. This is not preferable.

  Further, the tensile elongation at break obtained from the tensile test results of an unstretched film having a width of 10 mm, a length of 100 mm, and a thickness of 100 μm at 23 ° C. and 50% RH is used as one index for improving flexibility. If the tensile elongation at break is 100% or more, there is sufficient flexibility, and if it is 200% or more, a biaxially stretched film with a high draw ratio can be produced, or a multilayer PET bottle of PET and the polyamide resin This is more preferable because there is an effect of improving the flexibility such that no delamination occurs and the impact resistance of the polyamide resin container is sufficient.

In addition, PET multilayer bottles, which are multilayer stretch blow containers made of a polyamide resin obtained by polycondensation of PET and metaxylylenediamine and adipic acid as a barrier layer, are delaminated (delaminated) between PET and polyamide resin due to impact or the like. ) May occur. As an evaluation index of this delamination property, it was carried out according to ASTM D2463-95B. This evaluation of delamination resistance was also used as an index for improving the flexibility of the polyamide resin.

  Further, in an unstretched film comprising a mixed resin obtained by melt-mixing 70% by mass of an aliphatic polyamide resin with 30% by mass of a polyamide resin obtained by polycondensation of metaxylylenediamine and adipic acid, the tensile breaking strength is Although it is excellent in flexibility at 400% or more, the oxygen barrier property is remarkably deteriorated, so that it cannot be used as a polyamide resin having a barrier property. For this reason, the non-stretched film made of the polyamide resin of the present invention has an oxygen permeability coefficient value at 23 ° C. and 60% RH of 30% by mass of the polyamide resin obtained by polycondensation of metaxylylenediamine and adipic acid with 70% of the aliphatic polyamide resin. It is preferably 0.6 times or less of the oxygen permeability coefficient value at 23 ° C. and 60% RH of an unstretched film (corresponding to Comparative Example 3 of the present application) made of a mixed resin obtained by mass% melt mixing, 0.4 times or less. If it is 0.6 times or less, the component consisting of caprolactam is completely random copolymerized, and the decrease in barrier properties is suppressed as much as possible.

  In the present invention, a crystallization accelerator may be used as a means for adding crystallinity. Organic types include micromolecular to nano-level capsules consisting of bimolecular films, benzylidene sorbitol-based and phosphorus-based transparent crystal nucleating agents, rosinamide-based gelling agents, glass fillers (glass fibers, crushed glass) Fibers (milled fibers), glass flakes, glass beads, etc.), calcium silicate fillers (wollastonite, etc.), mica, talc (granular talc with powdered talc and rosin as binder), kaolin, titanic acid Clay such as potassium whisker, boron nitride, and layered silicate, nanofiller, carbon fiber, and the like may be used for thermoplastic resins, and two or more of these may be used in combination. Moreover, as an addition amount, 0.01-2 weight part is preferable, and 0.1-1 weight part is especially optimal.

  The polyamide resin of the present invention has a matting agent, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, a plasticizer, a flame retardant, an antistatic agent, an anti-coloring agent, and an anti-gelling agent as long as the effects of the present invention are not impaired. Additives such as agents, can be added as necessary,

  The polyamide resin of the present invention is preferably produced by a melt polycondensation (melt polymerization) method by adding a phosphorus atom-containing compound. As the melt polycondensation method, for example, there is a method in which a nylon salt composed of a diamine component and a dicarboxylic acid component is heated in the presence of water under pressure, and polymerized in a molten state while removing added water and condensed water. It can also be produced by a method in which a diamine component is directly added to a molten dicarboxylic acid component and polycondensed. In this case, in order to keep the reaction system in a uniform liquid state, the diamine component is continuously added to the dicarboxylic acid component, 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 resins. The polycondensation proceeds while warming.

  The phosphorus atom-containing compound added to the polycondensation system of the polyamide resin of the present invention includes dimethylphosphinic acid, phenylmethylphosphinic acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, hypophosphorous acid. Lithium acid, ethyl hypophosphite, phenylphosphonic acid, sodium phenylphosphonite, potassium phenylphosphonite, lithium phenylphosphonite, ethyl phenylphosphonite, phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate , Potassium phenylphosphonate, lithium phenylphosphonate, diethyl phenylphosphonate, sodium ethylphosphonate, potassium ethylphosphonate, phosphorous acid, sodium hydrogen phosphite, sodium phosphite, triethyl phosphite, triphosphite Phenyl, pyroa Among these, metal hypophosphite such as sodium hypophosphite, potassium hypophosphite, and lithium hypophosphite is particularly effective in promoting the amidation reaction and prevents coloration. It is preferably used because of its excellent effect, and sodium hypophosphite is particularly preferred. The phosphorus atom-containing compounds that can be used in the present invention are not limited to these compounds.

  The addition amount of the phosphorus atom-containing compound added to the polycondensation system of the polyamide resin of the present invention is preferably 5 to 400 ppm, more preferably 50 to 350 ppm in terms of the phosphorus atom concentration in the polyamide resin. Preferably it is 70-300 ppm.

  Moreover, it is preferable to add an alkali metal compound in combination with the phosphorus atom-containing compound in the polycondensation system of the polyamide resin of the present invention. To prevent coloring of the polyamide resin during polycondensation, a sufficient amount of phosphorus atom-containing compound needs to be present, but in some cases it may cause gelation of the polyamide resin, so the amidation reaction rate is adjusted In order to achieve this, it is preferable to coexist an alkali metal compound. As the alkali metal compound, an alkali metal hydroxide or an alkali metal acetate is preferable. Examples of the alkali metal compound 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, and the like. However, it can be used without being limited to these compounds.

  In the polyamide resin of the present invention, one or more metal atoms selected from Group VIII transition metals of the Periodic Table of Elements, manganese, copper, and zinc are compounds before the start of the polycondensation reaction, during the reaction, or during extrusion. It can be added as a complex. These metal atoms promote the oxidation reaction of the polyamide resin in the resin after polycondensation, and as a result, the oxygen absorption function of the polyamide resin of the present invention is expressed. Oxidation of the polyamide resin of the present invention caused by the metal atoms is caused by the generation of radicals due to the extraction of hydrogen atoms from the methylene chain adjacent to the arylene group of the polyamide resin by the metal atoms, and the addition of oxygen molecules to the radicals. It is considered to be caused by reactions such as generation of oxy radicals and extraction of hydrogen atoms by peroxy radicals.

In the present invention, a compound containing a metal atom (hereinafter referred to as a metal catalyst compound) is preferably used for adding and mixing the metal atom in the polyamide resin. The metal catalyst compound is used in the form of a low-valent inorganic acid salt, organic acid salt or complex salt of the metal atom.
Examples of inorganic acid salts include halides such as chlorides and bromides, sulfates, nitrates, phosphates, silicates, and the like. On the other hand, examples of the organic acid salt include a carboxylate, a sulfonate, and a phosphonate. Also, transition metal complexes with β-diketone or β-keto acid ester can be used. Of these, carboxylates, halides, and acetylacetonate complexes containing the above metal atoms are preferred because of their good oxygen absorption function.
One or more of the metal catalyst compounds can be added, but those containing cobalt as a metal atom are particularly excellent in oxygen absorption function and are preferably used.

  The concentration of the metal atom added to the polyamide resin is not particularly limited, but is preferably in the range of 0.01 to 0.10 parts by mass, more preferably 0.02 to 0.08, relative to 100 parts by mass of the polyamide resin. Part by mass. If the added amount of metal atoms is 0.01 parts by mass or more, the oxygen absorbing function is sufficiently developed, and the effect of improving the oxygen barrier property of the multilayer container is obtained. Moreover, if it is 0.10 mass part or less, the improvement effect of oxygen barrier property will be acquired according to the addition amount, and it is economical.

  The method of adding the metal catalyst compound to the polyamide resin is a method of melt-mixing the polyamide resin and the metal catalyst compound using an extruder or the like, mixing the metal catalyst compound with a solvent to form a solution or slurry, and then the polyamide resin And a method of removing the solvent and adhering to the polyamide resin, a method of adding a device capable of adding a metal catalyst compound to an apparatus for producing a multilayer container, and the like.

  The polyamide resin of the present invention obtained by melt polycondensation is once taken out, pelletized, and dried before use. In order to further increase the degree of polymerization, solid phase polymerization may be performed. As a heating device used in drying or solid phase polymerization, a continuous heating drying device, a rotary drum type heating device called a tumble dryer, a conical dryer, a rotary dryer or the like, and a rotary blade inside a nauta mixer are used. Although a conical heating apparatus provided with can be used suitably, a well-known method and apparatus can be used without being limited to these. Particularly when solid-phase polymerization of polyamide resin is performed, a batch-type heating device is preferable among the above-mentioned devices because the inside of the system can be sealed and the polycondensation can easily proceed in a state where oxygen that causes coloring is removed. Used.

The polyamide resin of the present invention obtained through the above-described steps is less colored and less gelled. In the present invention, among the polyamide resins obtained through the above-described steps, in the color difference test of JIS-K-7105. Those having a b ^* value of 3 or less are preferably used, particularly preferably 2 or less, and more preferably 1 or less. A polyamide resin having a b ^* value exceeding 3 is not preferable because a molded product obtained by post-processing is yellowish, and its commercial value is low.
In order to reduce the b ^* value to 3 or less, for example, by adding a phosphorus atom-containing compound in the polyamide resin polycondensation system in an amount of 50 to 400 ppm by mass in terms of the phosphorus atom concentration in the polyamide resin, the b ^* value decreases. Can be suppressed. Further, an appropriately shaped stirring blade may be used so that heat transfer to the polyamide resin during the melt polymerization step does not become local.

  The polyamide resin of the present invention is preferably subjected to polycondensation in the presence of at least a phosphorus atom-containing compound. In the present invention, it is preferable to add a phosphorus atom-containing compound at the stage of melt polycondensation. If there is no phosphorus atom-containing compound in the system at this stage, the resulting polyamide resin will be colored yellow, and the amidation reaction rate will be slow. If the polycondensation is to be advanced up to this point, the thermal history will increase, which may cause gelation and coloring of the polyamide resin.

Although there are several indexes of the degree of polymerization of the polyamide resin of the present invention, the relative viscosity is generally used. In the polyamide resin of the present invention, 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 resin of the present invention is less than 1.5, the fluidity of the melted polyamide resin tends to be unstable, and the appearance of the molded product may be deteriorated. On the other hand, if the relative viscosity of the polyamide resin exceeds 4.2, the melt viscosity of the polyamide resin is too high and the molding process may become unstable.
The relative viscosity referred to here is that of 1 g of polyamide resin dissolved in 100 mL of 96% sulfuric acid, the drop time (t) measured at 25 ° C. with a Canon Fenceke viscometer, and the 96% sulfuric acid itself measured in the same manner. It is the ratio of the drop time (t0) and is shown by the following equation.
Relative viscosity = t / t0

The polyamide resin of the present invention can be used after being molded into various packaging materials, packaging containers, industrial materials, fuel tubes, fuel tanks and the like. The packaging material can be processed into a film-like or sheet-like molded body, and the packaging container constitutes at least a part of bottles, trays, cups, tubes, various pouches such as flat bags and standing pouches, etc. Can be used as a material. Moreover, the direct blow tube and bottle combined with polyolefin are mentioned to a fuel tube and a fuel tank. Further, the structure of the packaging material, packaging container, industrial material, fuel tube, fuel container, etc. may be a single layer made of the polyamide resin of the present invention, or may be a multilayer structure combined with other thermoplastic resins. good. In order to improve the properties of the polyamide resin of the present invention, polyamide resin represented by nylon 6, nylon 66, nylon 6IT, polyester represented by polyethylene terephthalate and polybutylene terephthalate, polyethylene and polypropylene, etc. It can also be used as a polyamide resin composition mixed with various thermoplastic resins such as polyolefin, polystyrene, polycarbonate, ethylene vinyl alcohol copolymer and the like.
These mixtures can also be used for packaging materials and packaging containers.
In the packaging material or packaging container using the polyamide resin or resin composition of the present invention, the thickness of the layer using the polyamide resin or resin composition is not particularly limited, but is 1 μm or more. It is preferable to form the layer so as to have

A well-known method can be utilized about manufacturing methods, such as a packaging material using this invention polyamide resin or a resin composition, a packaging container, a fuel tube, and a fuel tank. For example, film, sheet, or tube-shaped packaging material can be formed by extruding the polyamide resin or resin composition melted through a T die, a circular die, or the like from an attached extruder. In addition, the film-form molded object obtained by the above-mentioned method can also be processed into a stretched film by extending | stretching this. A bottle-shaped packaging container can be obtained by injecting molten polyamide resin into a mold from an injection molding machine to manufacture a preform, and then heating to a stretching temperature and blow-stretching.
Also, containers such as trays and cups are manufactured by injecting the polyamide resin or resin composition melted into a mold from an injection molding machine, and sheet-like packaging materials are formed by vacuum forming or pressure forming. Can be obtained by molding. The packaging material and packaging container using the polyamide resin or resin composition of the present invention can be produced through various methods without depending on the production method described above.

  Various articles can be stored and stored in the packaging container using the polyamide resin or the resin composition of the present invention. For example, carbonated drinks, juice, water, milk, sake, whiskey, shochu, coffee, tea, jelly drinks, health drinks, etc. Seasonings such as jams, creams, chocolate pastes and other paste-like foods, liquid soups, boiled foods, pickles, stewed and other liquid processed foods such as soba, udon and ramen, and raw noodles and boiled noodles , Representatives of pre-cooked rice such as polished rice, moistened rice, and non-washed rice, cooked cooked rice, processed rice products such as gomoku rice, red rice, rice bran, powdered soup, and powdered seasonings such as dashi stock High-moisture foods, dried vegetables, coffee beans, coffee powder, tea, low-moisture foods such as confectionery made from grains, and other solid and solution chemicals and liquids such as agricultural chemicals and insecticides And pasty medicines, lotions, makeup creams, cosmetic milky lotion, hair dressing, it is possible to house a hair dye, shampoo, soap, detergent or the like, various articles.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, the measurement for evaluation in this invention was based on the following method.
(1) Relative viscosity 0.2 g of polyamide resin was precisely weighed and dissolved in 100 ml of 96% sulfuric acid at 20-30 ° C. with stirring. After completely dissolving, 5 cc of the solution was quickly taken into a Cannon Fenceke viscometer, and allowed to stand in a constant temperature bath at 25 ° C. for 10 minutes, and then the dropping speed (t) was measured. Further, the dropping speed (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 equation.
Relative viscosity = t / t0

(2) Terminal carboxyl group concentration and terminal amino group concentration The reaction molar ratio of the polyamide resin was determined by first dissolving the polyamide resin in a phenol / ethanol mixed solvent and a benzyl alcohol solvent, respectively, and then adding the terminal carboxyl group concentration [COOH] and the terminal amino group. The group concentration [NH ₂ ] was determined by neutralization titration with hydrochloric acid and aqueous sodium hydroxide.
(3) Semi-crystallization time of polyamide resin Using a semi-crystallization time measuring apparatus MK701 (Kotaki Seisakusho), 5 layers of polyamide resin films with a thickness of 100 μm were stacked in a hot air environment at 260 ° C. for 3 minutes by the depolarization intensity method. After melting, the half crystallization time when crystallization was performed in an oil bath at 160 ° C. was determined.

(4) Melting point of polyamide resin Using DSC-60 manufactured by Shimadzu Corporation, DSC measurement (differential scanning calorimetry) was performed under a nitrogen stream at a heating rate of 10 ° C./min, and from an endothermic peak caused by melting. The melting point was determined.

(5) Tensile test of unstretched film A polyamide resin film having a width of 10 mm, a length of 100 mm, and a thickness of 100 μm was conditioned for one week in an environment of 23 ° C. and 50% RH, and then a tensile tester (Toyo Seiki Co., Ltd.) A tensile test was carried out at a tensile speed of 50 mm / min using the manufactured strograph V1-C), and the tensile elongation at break obtained from this test was used as an index of flexibility.

(6) Oxygen permeability: OTR
According to ASTM D3985. A measuring device manufactured by Modern Controls (model: OX-TRAN 2 / 21SH) was used. In the case of film OTR (cc · mm / (m ² · day · atm)), the measurement conditions were a temperature: 23 ° C. and a relative humidity: 60%.

(7) Delamination resistance evaluation of multi-layer PET bottle It implemented based on the measuring method according to ASTM D2463-95B. After filling the PET bottle with 500 g of water and capping it, store it in an environment of 23 ° C. and 50% RH for 1 day (initial) and 1 year, and then carry out a stepwise drop test, The drop height at which delamination does not occur was used as an evaluation standard for delamination resistance.

Production Example 1
(Polymer resin melt polymerization)
14995 g (102.6 mol) of adipic acid and 4874 g of ε-caprolactam precisely weighed in a reaction vessel having an internal volume of 50 liters equipped with a stirrer, a partial condenser, a total condenser, a thermometer, a dropping funnel and a nitrogen introduction tube, and a strand die. (43.1 mol), sodium hypophosphite 12.9736 g (0.1224 mol), and sodium acetate 9.0368 g (0.1102 mol) were sufficiently substituted with nitrogen, and the system was further purged with a small amount of nitrogen. Heat to 170 ° C. with stirring. At this point, adipic acid and ε-caprolactam were in a completely molten state. To this, 13606 g (99.9 mol) of metaxylylenediamine was added dropwise with stirring, and the inside of the system was continuously heated while removing the condensed water produced. 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.
(Solid phase polymerization of polyamide resin)
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 minutes. Next, nitrogen gas having a purity of 99% by volume or more was introduced into the system, and cooling was performed while rotating the tumble dryer to obtain 30 mol% caprolactam copolymerized N-MXD6 (polyamide 1).

Production Example 2
Caprolactam 40 mol% copolymerized N-MXD6 (polyamide 2) was obtained in the same manner as in Production Example 1, except that 40 mol% of ε-caprolactam was copolymerized.

Production Example 3
N-MXD6 (polyamide 3) was obtained in the same manner as in Production Example 1 except that ε-caprolactam was not used and the amount of metaxylylenediamine charged was 13841 g (101.625 mol).

Production Example 4
Caprolactam 30 mol in the same manner as in Production Example 1 except that ε-caprolactam was not melted together with adipic acid, adipic acid was melted, metaxylylenediamine was added dropwise, and then ε-caprolactam was added. % Copolymerization N-MXD6 (polyamide 4) was obtained.

Production Example 5
Caprolactam 10 mol% copolymerized N-MXD6 (polyamide 5) was obtained in the same manner as in Production Example 1 except that 10 mol% of ε-caprolactam was copolymerized.

Example 1
The relative viscosity, terminal amino group concentration, and terminal carboxyl group concentration of polyamide 1 were measured.
Further, polyamide 1 pellets were formed into a non-stretched film having a width of 300 mm and a thickness of 95 to 105 μm using a 30 mmφ single screw extruder at an extrusion temperature of 260 ° C., a screw rotation speed of 60 rpm, and a take-off speed of 1.2 m / min. . The half crystallization time, tensile elongation at break and oxygen permeability coefficient of this film are shown in Table 1.
Furthermore, a multi-layer PET bottle subjected to a delamination resistance test was prototyped.
For the production of the three-layer parison, an injection molding machine (model: M200, 4 pieces) manufactured by Meiki Seisakusho Co., Ltd. was used. The intermediate layer is composed of polyethylene terephthalate resin (made by Invista, grade: 1101E, intrinsic viscosity 0.80), which is dried for 4 hours (using a dehumidifying dryer, dew point −40 ° C.) and adjusted to a moisture content of 94 ppm, in the injection cylinder a. The injection cylinder b was filled with polyamide 1 (resin B).
Using the above resin, first, the resin A was injected under the following conditions, a predetermined amount of the resin A was injected, then the resin B was injected simultaneously with the resin A, and then the resin A was injected to form a three-layer parison. .
Resin temperature in injection cylinder a: 280 ° C
Resin temperature in injection cylinder b: 270 ° C
Resin channel temperature in mold: 280 ° C
Mold cooling water temperature: 15 ° C
A three-layer parison obtained by injection molding has a total length of 110 mm, an outer shape of 26.5 mmφ, and a thickness of 4.5 mm.
The obtained three-layer parison contained 7% by mass of polyamide 1.
The above three-layer parison was biaxially stretched and blow-molded by a blow molding apparatus (EFB1000ET manufactured by Frontier Co., Ltd.), and a biaxially stretched hollow container having a height of 223 mm, a trunk diameter of 65 mm, a capacity of 500 mL, and an average thickness of about 300 μm Container). The bottom shape is a petaloid type.
The resulting three-layer container was filled with 500 cc of water and evaluated for delamination resistance by a drop test. The results are shown in Table 1.

(Example 2)
The same procedure as in Example 1 was performed except that polyamide 2 was used instead of polyamide 1. Table 1 shows the evaluation results of the relative viscosity of polyamide 2, terminal amino group concentration, terminal carboxyl group concentration, tensile elongation at break of unstretched film, oxygen permeability coefficient, and delamination resistance of multilayer PET bottles.

(Example 3)
When producing an unstretched film and a multilayer PET bottle, it was carried out in the same manner as in Example 1 except that the polyamide 1 was dry blended with cobalt stearate (cobalt content: 400 ppm). Table 1 shows the evaluation results of tensile elongation at break of unstretched film, oxygen permeation coefficient, and delamination resistance of multilayer PET bottles.

(Comparative Example 1)
The same operation as in Example 1 was performed except that polyamide 3 was used instead of polyamide 1. Table 2 shows the evaluation results of the relative viscosity of polyamide 3, terminal amino group concentration, terminal carboxyl group concentration, tensile elongation at break of unstretched film, oxygen permeability coefficient, and delamination resistance of multilayer PET bottles.

(Comparative Example 2)
When producing an unstretched film and a multilayer PET bottle, it was carried out in the same manner as Example 1 except that polyamide stearate (400 ppm in terms of cobalt content) was dry blended with polyamide 3. Table 2 shows the evaluation results of the tensile elongation at break of the unstretched film, the oxygen transmission coefficient, and the delamination resistance of the multilayer PET bottle.

(Comparative Example 3)
When producing an unstretched film, it was the same as in Example 1 except that 70% by mass of nylon 6 (UBE Nylon 6 1024B) and 30% by mass of polyamide 3 were dry blended. Carried out. Table 2 shows the evaluation results of the tensile elongation at break and oxygen permeability coefficient of the unstretched film.

(Comparative Example 4)
When making an unstretched film, polyamide stearate (400 ppm in terms of cobalt content) was blended with 70% by mass of nylon 3 (Ube Industries, Ltd. UBE nylon 6 1024B) with 30% by mass of polyamide 3. ) Was carried out in the same manner as in Example 1 except that it was used after dry blending. Table 2 shows the evaluation results of the tensile elongation at break and oxygen permeability coefficient of the unstretched film.

(Comparative Example 5)
The same procedure as in Example 1 was performed except that polyamide 4 was used instead of polyamide 1. Table 2 shows the evaluation results of the relative viscosity of polyamide 4, terminal amino group concentration, terminal carboxyl group concentration, tensile elongation at break of unstretched film, oxygen permeability coefficient, and delamination resistance of multilayer PET bottles.

(Comparative Example 6)
The same procedure as in Example 1 was performed except that polyamide 5 was used instead of polyamide 1. Table 2 shows the evaluation results of the relative viscosity of polyamide 5, terminal amino group concentration, terminal carboxyl group concentration, tensile elongation at break of unstretched film, oxygen permeability coefficient, and delamination resistance of multilayer PET bottles.

  From the above examples, as in Examples 1 and 2, by using the polyamide resin of the present invention, sufficient flexibility can be imparted, and high barrier properties within the practical range can be obtained. It was. Therefore, high delamination resistance could be imparted without affecting the moldability of PET multilayer bottles and the like. Moreover, the same effect was acquired also in Example 3 which added cobalt stearate, and the effect of the oxygen absorber was also able to be provided. Furthermore, since the degradation of the polyamide resin proceeds by absorbing oxygen, the delamination resistance deteriorates with time, but the delamination resistance after one year is also significantly improved compared to Comparative Example 2. Yes. On the other hand, in Comparative Example 1 in which ε-caprolactam is not copolymerized and Comparative Example 2 in which cobalt stearate is added to Comparative Example 1 and Comparative Example 6 in which the copolymerization ratio of ε-caprolactam is low, sufficient flexibility can be imparted. Therefore, the PET multilayer bottle has poor delamination resistance. Further, as in Comparative Examples 3 and 4, in the polyamide resin blended with nylon 6 and in Comparative Example 5 in which ε-caprolactam was introduced in the middle of the melt polymerization, two DSC melting peaks were observed, and some of the blocks were co-blocked. Polymerization occurred and stable flexibility was not obtained.

  Since the polyamide resin or resin composition of the present invention is excellent in flexibility and gas barrier properties, packaging of PET bottles, deep draw cups, direct blow bottles, unstretched films, stretched films, etc. that require flexibility and gas barrier properties It can be used for materials, fuel tubes of automobiles, and fuel tanks, and the effect is great.

Claims (7)

Obtained by polycondensation of a diamine component containing 70 mol% or more of metaxylylenediamine, an α, ω-linear aliphatic dicarboxylic acid having 4 to 12 carbon atoms, and ε-caprolactam or 6-aminocaproic acid as a copolymerization component. The polyamide resin has a content of structural units derived from the copolymerization component in the polyamide resin in a range of 25 to 45 mol%, and the terminal carboxyl group concentration [COOH] and terminal amino acid of the polyamide resin The phosphorus atom-containing compound is adjusted so that the difference in group concentration [NH ₂ ] ([COOH] − [NH ₂ ]) is in the range of 8 to 82 μeq / g and the phosphorus atom concentration in the polyamide resin is 5 to 400 ppm. It was obtained by adding into the polycondensation system, and the temperature-decreasing semi-crystallization time at 160 ° C. of the polyamide resin was 200 seconds to 1800 seconds, Polyamide resin, wherein the melting peak obtained from SC measurement (differential scanning calorimetry) is one.   2. The polyamide resin according to claim 1, wherein an unstretched film made of the polyamide resin has a tensile elongation at break of 100% or more.   The unstretched film made of the polyamide resin has an oxygen permeability coefficient value at 23 ° C. and 60% RH of 30% by mass of a polyamide resin obtained by polycondensation of metaxylylenediamine and adipic acid. The polyamide resin according to claim 1 or 2, which is 0.6 times or less of an oxygen permeation coefficient value at 23 ° C and 60% RH of an unstretched film made of a mixed resin.   The molded object which consists of a polyamide resin in any one of Claims 1-3.   The polyamide resin composition containing the polyamide resin in any one of Claims 1-3.   A polyamide resin composition obtained by melting and mixing one or more metal atoms selected from group VIII transition metals of the Periodic Table of the Elements, manganese, copper and zinc into the polyamide resin according to any one of claims 1 to 3.   The molded object which consists of a polyamide resin composition of Claim 5 or 6.