JP2017088661A - Polyamide resin composition and blow molded article made therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide resin composition that can produce a blow molded article excellent in barrier property and impact resistance with good productivity, and to provide a blow molded article formed using the polyamide resin composition.SOLUTION: Provided is a polyamide resin composition containing a polyamide resin (A) by 60 to 95 mass%, a modified polyolefin resin (B) by 1 to 20 mass%, and an unmodified polyolefin resin (C) by 0 to 35 mass%. The polyamide resin composition in which, in an elongational viscosity-shear rate curve obtained by elongation viscosity measurement at 290°C, the ratio (ηe/η) of elongation viscosity (ηe) to shear viscosity (η) at shear rate 500 sis 4 to 10 as well as the shear viscosity is 300 Pa-s<(η)<3000 Pa-s. The polyamide resin composition in which the polyamide preferably is nylon 46, nylon 66, nylon 610, nylon 612, nylon 6 or the like, and particularly the polyamide preferably is nylon 6, or nylon 66.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide resin composition excellent in impact resistance, barrier properties, and blow moldability.

  Polyamide resins have excellent mechanical properties, toughness, thermal properties, and other properties that are suitable as engineering plastics. Therefore, various types of electrical / electronic parts, mechanical parts, automobile parts, etc. are mainly used for injection molding. Widely used in applications. In recent years, there has been an increase in resin molded products that require gas barrier properties for the purpose of preventing leakage of contents and mixing of outside air in order to ensure safety, storage stability, and prevention of environmental pollution. Of these, polyamide resins have been used as various molded articles because of their excellent gas barrier properties.

  Examples of molded products that use barrier properties include bottle molded products. When manufacturing plastic bottles, the melt-plasticized resin is extruded through a die orifice in terms of ease of molding, high productivity, and relatively low equipment costs such as molding machines and molds. A so-called direct blow molding method is used in which a cylindrical parison is formed and air is blown into the mold by sandwiching the parison between the molds. And in the case of this direct blow molding, it is necessary to avoid that the parison extruded in the molten state is drawn down during blow molding in order to perform the molding smoothly. It is required to be. Accordingly, vinyl chloride resins, polyolefin resins, and the like are widely used in direct blow molding as such high-viscosity resins (see Patent Document 1).

  In recent years, the application of polyamide resins has also been studied in direct blow molded products, but polyamide resins generally do not have a high viscosity that is suitable for direct blow molding, so extruded parisons are blow molded. Occasionally, draw-down occurs, blow molding cannot be performed, crystallization is likely to occur during blow, and it is difficult to obtain a molded body having a uniform thickness. Moreover, the impact resistance was insufficient.

JP 2013-014031 A

  The present invention aims to provide a polyamide resin composition capable of solving the above-mentioned problems and obtaining a blow molded product excellent in barrier properties and impact resistance with high productivity. Furthermore, the present invention intends to provide a blow molded product formed using the polyamide resin composition of the present invention.

The inventors of the present invention have arrived at the present invention as a result of intensive studies in order to solve the above problems.
(1) A polyamide resin composition comprising 60 to 95% by mass of polyamide resin (A), 1 to 20% by mass of modified polyolefin resin (B), and 0 to 35% by mass of unmodified polyolefin resin (C). In the extensional viscosity-shear rate curve obtained by measuring the extensional viscosity at 290 ° C., the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) at a shear rate of 500 s ⁻¹ is 4-10. And a polyamide resin composition having a shear viscosity of 300 Pa · s <(η) <3000 Pa · s.
(2) The polyamide resin composition according to (1), wherein the modified polyolefin resin (B) is an ethylene / α-olefin copolymer modified with an unsaturated carboxylic acid or a derivative thereof.
(3) The polyamide resin composition according to (1) or (2), wherein the unmodified polyolefin resin (C) is ethylene and an α-olefin copolymer having 3 to 20 carbon atoms.
(4) 20-100 mass of polyamide resin (D) obtained from the polycondensation reaction of xylylenediamine and dicarboxylic acid with respect to 100 mass parts of the polyamide resin composition according to any one of (1) to (3). A mixed polyamide resin composition obtained by blending parts.
(5) A blow molded product formed using the polyamide resin composition according to any one of (1) to (3).
(6) A blow molded article formed by using the mixed polyamide resin composition described in (4).

The polyamide resin composition of the present invention is suitable for direct blow molding, and can provide a blow molded product having good moldability and excellent impact resistance and barrier properties without causing drawdown.
Furthermore, since the blow molded product of the present invention is formed using the polyamide resin composition of the present invention, it is excellent in impact resistance and barrier properties and can be used for various applications.

Hereinafter, the present invention will be described in detail.
The polyamide resin composition of the present invention is suitable for blow molding, and as blow molding, a melt-plasticized resin is extruded through a die orifice to form a cylindrical parison, which is sandwiched between molds and placed inside. Examples thereof include a direct blow molding method in which air is blown into the film, or a stretch blow molding method in which a parison is formed by injection molding and then stretch blow molded. Among these, the direct blow molding method is preferred.

  The polyamide resin (A) used in the present invention is a polymer having an amide bond in the main chain with aminocarboxylic acid, lactam, or diamine and dicarboxylic acid as main raw materials.

  Examples of the aminocarboxylic acid include 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of the lactam include ε-caprolactam, ω-undecanolactam, and ω-laurolactam. . Polyamide resins using such raw materials are polycaproamide (nylon 6), polyundecamide (nylon 11), polycaproamide / polyundecamide copolymer (nylon 6/11), polydecanamide (nylon 12), And polycaproamide / polydodecamide copolymer (nylon 6/12).

Examples of the diamine include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, and dodecamethylene diamine. Examples of the dicarboxylic acid include adipic acid, suberic acid, sebacic acid, dodecanedioic acid, terephthalic acid, and isophthalic acid. Is mentioned. These diamines and dicarboxylic acids can also be used as a pair of salts.
Polyamide resins using such raw materials are polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polycaproamide / polyhexamethylene adipamide copolymer (nylon 6/66). , Polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecamethylene adipamide (nylon 116), polyhexamethylene terephthalamide (nylon 6T), polydecamethylene terephthalamide ( Nylon 10T) and the like, and further, a mixture or a copolymer thereof. Among these, nylon 6 and nylon 66 are particularly preferable from the viewpoint of processability and economy.

  Although the relative viscosity of a polyamide resin (A) will not be specifically limited if the conditions of the extensional viscosity and shear viscosity mentioned later are satisfied, It is preferable to make relative viscosity 2-5.

  Content of the polyamide resin (A) in a polyamide resin composition needs to be 60-95 mass%, and 65-90 mass% is preferable. When the content of the polyamide resin (A) is less than 65% by mass, the barrier property and blow moldability may be deteriorated, and when it exceeds 95% by mass, the impact resistance becomes insufficient.

  The modified polyolefin resin (B) used in the present invention is a polyolefin containing a functional group having an affinity for a polyamide resin in its molecule, particularly an epoxy group, amino group, isocyanate group, hydroxyl group, mercapto. A polyolefin containing at least one selected from a group, a ureido group, a carboxylic acid group, a carboxylic acid anhydride group, a carboxylic acid ester group and a carboxylic acid metal base in the polymer molecular chain, particularly preferably unsaturated An ethylene / α-olefin copolymer modified with a carboxylic acid or a derivative thereof.

  The ethylene / α-olefin copolymer modified with an unsaturated carboxylic acid or derivative thereof preferably used as a component of the modified polyolefin resin (B) is at least one of ethylene and an α-olefin having 3 to 20 carbon atoms. Examples of the α-olefin having 3 to 20 carbon atoms, specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, -Octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-he Sen, 4,4-Dimethyl-1-pentene, 4-Ethyl-1-hexene, 3-Ethyl-1-hexene, 9-Methyl-1-decene, 11-Methyl-1-dodecene, 12-Ethyl-1- Examples include tetradecene and combinations thereof. Among these α-olefins, a copolymer using an α-olefin having 3 to 12 carbon atoms is preferable from the viewpoint of improving mechanical strength. The ethylene / α-olefin copolymer preferably has an α-olefin content of 1 to 30 mol%, more preferably 2 to 25 mol%, and still more preferably 3 to 20 mol%. Further, non-conjugated dienes such as 1,4-hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethylidene norbornene, 5-ethyl-2,5-norbornadiene, 5- (1′-propenyl) -2-norbornene, etc. At least one kind may be copolymerized.

  Examples of the modifier used for acid modification include unsaturated carboxylic acids or derivatives thereof, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methylfumaric acid, citraconic acid, Glutaconic acid and metal salts of these carboxylic acids, methyl hydrogen maleate, methyl hydrogen itaconate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, methacrylic acid 2 -Ethylhexyl, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo- (2,2,1) -5-heptene-2 3-dicarboxylic acid, endo Bicyclo- (2,2,1) -5-heptene-2,3-dicarboxylic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, glycidyl acrylate, glycidyl methacrylate, methacrylic acid Glycidyl, glycidyl itaconate, glycidyl citraconic acid, and 5-norbornene-2,3-dicarboxylic acid. Of these, unsaturated dicarboxylic acids and acid anhydrides thereof are preferred, and maleic acid and maleic anhydride are particularly preferred.

  The method for introducing these unsaturated carboxylic acid or its derivative component into the polyolefin resin is not particularly limited, and a method of copolymerizing an olefin compound, which is a main component, and an unsaturated carboxylic acid or its derivative compound in advance, or an unmodified polyolefin resin. A method of introducing an unsaturated carboxylic acid or a derivative compound thereof by a grafting treatment using a radical initiator can be used. The amount of unsaturated carboxylic acid or its derivative component introduced is preferably within the range of 0.001 to 40 mol%, more preferably 0.01 to 35 mol%, based on the entire olefin monomer in the modified polyolefin. It is.

  The melt flow rate of the modified polyolefin resin (B) of the present invention (MFR, in accordance with JIS K7210, temperature 190 ° C., load 21.2 N load) is preferably 0.01 to 50 g / 10 min, More preferably, it is ˜40 g / 10 minutes. When the MFR is less than 0.01 g / 10 minutes, the fluidity is poor, and when it exceeds 50 g / 10 minutes, the impact strength may be lowered depending on the shape of the molded product.

  Content of modified polyolefin resin (B) in the resin composition of this invention is 1-20 mass%, Preferably it is 3-18 mass%. If the content of the modified polyolefin resin exceeds 20% by mass, the blow moldability and the barrier property are lowered, which is not preferable. On the other hand, when the content of the modified polyolefin resin is less than 1% by mass, it is difficult to express impact resistance, which is not preferable.

  Examples of the unmodified polyolefin resin (C) used in the present invention include homopolymers such as polyethylene, polypropylene, polystyrene, poly-1-butene, poly-1-pentene, polymethylpentene, and unmodified ethylene / α-olefin. Polymer, vinyl alcohol ester homopolymer, polymer obtained by hydrolyzing at least a part of vinyl alcohol ester homopolymer, [at least one copolymer of [(ethylene and / or propylene) and vinyl alcohol ester] Polymer obtained by hydrolyzing part], a block copolymer of conjugated diene and vinyl aromatic hydrocarbon, a hydride of the block copolymer, and the like. Of these, an unmodified ethylene / α-olefin copolymer is preferable.

  A preferred ethylene / α-olefin copolymer used as a component of the unmodified polyolefin resin (C) used in the present invention is an ethylene / α-olefin copolymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms. The coalescence is a copolymer containing ethylene and at least one α-olefin having 3 to 20 carbon atoms as constituent components. Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and 1-undecene. 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1 -Pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl -1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, and combinations thereof. Among these α-olefins, a copolymer using an α-olefin having 6 to 12 carbon atoms is more preferable because mechanical strength is improved and the reforming effect is further improved.

  The melt flow rate of the unmodified polyolefin resin (C) of the present invention (MFR, in accordance with JIS K7210, temperature 190 ° C., load 21.2 N load) is preferably 0.01 to 50 g / 10 min. More preferably, it is 1-40 g / 10min. When the MFR is less than 0.01 g / 10 minutes, the fluidity is poor, and when it exceeds 50 g / 10 minutes, the impact strength may be lowered depending on the shape of the molded product.

  Content of unmodified polyolefin resin (C) in the resin composition of this invention is 0-35 mass%, Preferably it is 3-30 mass%. When the content of the modified polyolefin resin exceeds 35% by mass, it is not preferable because it becomes difficult to develop blow moldability, barrier properties, and impact resistance.

  In the polyamide resin composition of the present invention, the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) needs to be 4 to 10, and 5 to 9 is particularly preferable. The elongational viscosity is obtained by dividing the stress generated when an elongation deformation, for example, a deformation that pulls a rod-shaped sample in the direction of the central axis, by the elongation rate. The shear viscosity is obtained by dividing the shear stress generated when shear deformation is given by the shear rate at that time.

  In the present invention, it is not possible to obtain a resin composition having characteristics suitable for blow molding only by setting the above-described shear viscosity within a specific range, but elongation viscosity (ηe) and shear viscosity (b). By making the ratio (ηe / η) within an appropriate range, even in a molding method that tends to cause drawdown, such as direct blow, a molded product with high quality that does not cause drawdown and has no thickness unevenness. It has been found that it is possible to obtain high productivity.

  When the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) is 4 to 10, it is considered that the entanglement of the molecular chain of the polyamide resin and the polyolefin resin and the crosslink density are suitable. Therefore, the speed and viscosity when the polyamide resin composition falls due to its own weight can be particularly suitable for direct blow molding.

When the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) is less than 4, the drawdown of the parison increases during blow molding, making molding difficult, and the resulting molded product has uneven thickness. Will occur.
On the other hand, if the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) exceeds 10, the speed at which the polyamide resin composition falls due to its own weight during blow molding becomes slow, so it is necessary to raise the molding temperature. As a result, the color tone and impact resistance of the obtained molded product are deteriorated. Also, by increasing the molding temperature, the thermal decomposition of the resin is accelerated, the drawdown of the parison is increased, the molding becomes difficult, and the obtained molded product has uneven thickness.

In the present invention, the extensional viscosity (ηe) and the shear viscosity (η) are measured as follows.
Using a flow tester (CFT-500, manufactured by Shimadzu Corporation), the polyamide resin composition was sheared with two types of nozzles (nozzle diameter × length: 1 × 0.25 mm, 1 × 15 mm). η) is measured. At this time, the measurement is performed at a shear rate of 100 to 10,000 s ⁻¹ and a measurement temperature of 290 ° C. Then, using the value of the shear viscosity (η) measured at a shear rate of 500 s ⁻¹ , the elongational viscosity (ηe) is calculated by the following equation (1) proposed by Cogswell (Cogswell method).

These can be obtained by Baglay correction.
For the Cogswell method, see Cogswell, FN: Polym. Eng. Sci. 12, 64 (1972).
For Baglay correction, see Baglay, EB: J Appl. Phys, 28, 624 (1957).
The ratio (ηe / η) between the two is calculated using the values of the elongation viscosity (ηe) and the shear viscosity (η) thus measured and calculated.

  In order to make the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) within the above range, the modified polyolefin resin (B) and the unmodified polyolefin resin (C) in the polyamide resin composition are used. It is necessary to add a specific amount.

  Furthermore, the amino terminal group concentration of the polyamide resin (A) is preferably 30 to 70 mmol / kg, more preferably 35 to 55 mmol / kg. If the amino end group concentration is less than 30 mmol / kg, the ratio between the extensional viscosity and the shear rate may not be within the above range, and the impact resistance may be inferior. On the other hand, if it exceeds 70 mmol / kg, it may react excessively with the modified polyolefin resin to gelate and deteriorate the productivity and moldability of the resin, which is not preferable. That is, it is possible to cause the polyamide resin to have the above-mentioned viscosity characteristics and mechanical strength by causing a reaction with the polyolefin resin appropriately to obtain a resin composition having an appropriate cross-linked structure.

Furthermore, the shear viscosity (η) of the polyamide resin composition of the present invention needs to be 300 Pa · s <(η) <3000 Pa · s, and 500 Pa · s <(η) <2000 Pa · s. Is preferred.
When the shear viscosity is less than 300 Pa · s, the pressure of the die at the time of blow molding is small and non-uniform, resulting in non-uniform parison thickness and uneven thickness of the molded product. On the other hand, if the shear viscosity exceeds 3000 Pa · s, the extrusion torque of the molding machine is high and molding becomes difficult, so it is necessary to raise the molding temperature. As a result, the color tone and impact resistance of the molded product obtained are poor. Become.

  The mixed polyamide resin composition of the present invention is obtained by adding the weight of xylylenediamine and dicarboxylic acid to the above-described polyamide resin composition of the present invention (hereinafter sometimes referred to as the polyamide resin composition (M)). A polyamide resin (D) obtained from the condensation reaction is blended. By containing a specific amount of such a polyamide resin (D), the barrier property of the obtained molded product can be further improved.

  In the mixed polyamide resin composition of the present invention, it is necessary to blend 20 to 100 parts by mass of the polyamide resin (D) with respect to 100 parts by mass of the polyamide resin composition (M), and in particular, 50 to 90 parts by mass. It is preferable that When the blending amount of the polyamide resin (D) is less than 20 parts by mass, the effect of improving the barrier property is poor. On the other hand, when the amount exceeds 100 parts by mass, the impact resistance of the obtained molded product becomes insufficient.

  In the polyamide resin (D) obtained from the polycondensation reaction of xylylenediamine and dicarboxylic acid of the present invention, 70 mol% or more of the diamine structural unit (structural unit derived from diamine) is derived from metaxylylenediamine, It is preferable that 70 mol% or more of the acid structural unit (structural unit derived from dicarboxylic acid) is derived from dicarboxylic acid which is an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The polyamide is composed of a diamine component containing 70 mol% or more (including 100 mol%) of metaxylylenediamine and 70 mol% or more (100 mol%) of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. It is obtained by polycondensation of the dicarboxylic acid component contained.

  In the present invention, as a diamine other than metaxylylenediamine used as the diamine component, tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylene Aliphatic diamines such as diamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 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) Alicyclic diamines such as carine (including structural isomers) and bis (aminomethyl) tricyclodecane (including structural isomers); bis (4-aminophenyl) ether, paraphenylenediamine, paraxylylenediamine And diamines having an aromatic ring such as bis (aminomethyl) naphthalene (including structural isomers). These can be used in the range of 30 mol% or less in the total diamine component.

  Examples of the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Although aliphatic dicarboxylic acid can be illustrated, adipic acid is preferable among these.

  The dicarboxylic acid may contain isophthalic acid units. A preferable molar ratio of the α, ω-linear aliphatic dicarboxylic acid unit having 4 to 20 carbon atoms and the isophthalic acid unit is 30:70 to 100: 0, more preferably 40:60 to 95: 5, still more preferably 60. : 40-90: 10. When the isophthalic acid unit is contained within this range, the barrier property is improved.

  In the present invention, examples of the dicarboxylic acid other than the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms and isophthalic acid that can be used as the dicarboxylic acid component include phthalic acid compounds such as terephthalic acid and orthophthalic acid; , 2-Naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8 -Naphthalenedicarboxylic acids such as isomers such as naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid; monocarboxylic acids such as benzoic acid, propionic acid and butyric acid; Polycarboxylic acids such as trimellitic acid and pyromellitic acid; trimellitic anhydride, pyromellitic anhydride Carboxylic acid anhydrides such as acid. The amount of these dicarboxylic acids used is in the range of 30 mol% or less of the total dicarboxylic acid component.

  The polyamide resin (D) is obtained by melting a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 70 mol% or more of an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. It is produced by condensation, and its production method is not particularly limited, and it is produced by a conventionally known method such as an atmospheric pressure melt polymerization method or a pressure melt polymerization method.

  For example, metaxylylenediamine and adipic acid or a nylon salt consisting of metaxylylenediamine, adipic acid and isophthalic acid is heated in the presence of water under pressure, and melted while removing the added water and condensed water. It is manufactured by a method of polymerizing in a state. It can also be produced by a method in which metaxylylenediamine is directly added to molten adipic acid or a mixture of adipic acid and isophthalic acid and polycondensed under normal pressure. In this case, in order not to solidify the reaction system, metaxylylenediamine is continuously added, while raising the temperature of the reaction system so that the reaction temperature therebetween is equal to or higher than the melting point of the generated oligoamide and polyamide, Polycondensation proceeds.

  When the polyamide resin (D) is obtained by polycondensation, the polycondensation reaction system includes lactams such as ε-caprolactam, ω-laurolactam, ω-enantolactam, 6-aminocaproic acid, 7-aminoheptanoic acid, 11 Amino acids such as -aminoundecanoic acid, 12-aminododecanoic acid, 9-aminononanoic acid, and paraaminomethylbenzoic acid may be added within a range that does not impair the performance.

  The relative viscosity of the polyamide resin (D) is preferably 2.3 to 4.5, and more preferably 2.6 to 4.0. When the relative viscosity is less than 2.3, the pressure of the die at the time of blow molding is small and non-uniform when used in combination with the polyamide resin composition (M). Thickness unevenness will occur. On the other hand, if it exceeds 4.5, the extrusion torque of the molding machine is high and molding becomes difficult, so it is necessary to raise the molding temperature. As a result, the color tone and impact resistance of the molded product obtained deteriorate.

  If necessary, other additives may be added to the polyamide resin composition of the present invention as long as the effects of the present invention are not impaired. Examples of such additives include inorganic or organic fillers, pigments, heat stabilizers, antioxidants, antistatic agents, flame retardants, flame retardant aids, and the like. These addition methods include adding at the time of polymerization of polyamide, or adding at the time of melt-kneading the polyamide resin and the modified polyolefin resin or the unmodified polyolefin resin.

  Examples of the filler include glass fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone Fibrous fillers such as kou fiber, metal fiber, or silicates such as talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, alumina silicate, silicon oxide, magnesium oxide, Metal compounds such as alumina, zirconium oxide, titanium oxide and iron oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, calcium hydroxide, magnesium hydroxide and aluminum hydroxide Non-fibrous fillers such as hydroxides such as nium, glass beads, glass flakes, glass powders, ceramic beads, boron nitride, silicon carbide, carbon black and silica, and graphite are used, and two types of these fillers are used. The above can also be used together. These fillers may be used after pretreatment with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, and an epoxy compound.

  In order to improve long-term heat resistance as a heat stabilizer, a copper compound is preferably used. Specific examples of copper compounds include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide, cuprous iodide, cupric iodide, cupric sulfate, nitric acid. Cupric, copper phosphate, cuprous acetate, cupric acetate, cupric salicylate, cupric stearate, cupric benzoate and inorganic copper halides and xylylenediamine, 2-mercaptobenzimidazole And complex compounds such as benzimidazole. Of these, monovalent copper compounds, particularly monovalent copper halide compounds, are preferred, and cuprous acetate, cuprous iodide, and the like can be used particularly suitably. It is preferable that the addition amount of a copper compound is 0.01-2 mass parts normally with respect to 100 mass parts of polyamide resins, and it is further preferable that it is the range of 0.015-1 mass parts. If the amount added is too large, liberation of metallic copper occurs during melt molding, and the value of the product is reduced by coloring. In the present invention, an alkali halide can be added in combination with a copper compound. Examples of the alkali halide compound include lithium chloride, lithium bromide, lithium iodide, potassium chloride, potassium bromide, potassium iodide, sodium bromide and sodium iodide. Potassium halide is particularly preferred.

  Moreover, as an antioxidant, a phenol type, a phosphorus type compound, etc. can be used conveniently. As the phenolic antioxidant, a hindered phenolic compound is preferably used. Specific examples include triethylene glycol-bis [3-t-butyl- (5-methyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxy Phenyl) propionate] methane, pentaerythrityltetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-t -Butyl-4-hydroxybenzyl) -s-triazine-2,4,6- (1H, 3H, 5H) -trione, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butyl) Phenyl) butane, 4,4'-buty Redenbis (3-methyl-6-tert-butylphenol), n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxy-phenyl) propionate, 3,9-bis [2- (3- ( 3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 1,3,5 And -trimethyl-2,4,6-tris- (3,5-di-t-butyl-4-hydroxybenzyl) benzene. Among them, ester type polymer hindered phenol type is preferable. Specifically, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, pentaerythrityl. Tetrakis [3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate], 3,9-bis [2- (3- (3-t-butyl-4-hydroxy-5- Methylphenyl) propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane and the like are preferably used.

  Phosphorus antioxidants include bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-t-butylphenyl) penta Erythritol-di-phosphite, bis (2,4-di-cumylphenyl) pentaerythritol-di-phosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2 , 4-Di-t-butylphenyl) -4,4′-bisphenylene phosphite, di-stearyl pentaerythritol-di-phosphite, triphenyl phosphite, 3,5-dibutyl-4-hydroxybenzyl phosphonate Examples include diethyl ester. Among them, those having a high melting point of the antioxidant are preferably used in order to reduce volatilization and decomposition of the antioxidant in the compound.

Further, the polyamide resin composition of the present invention may contain a foaming agent as shown below, and the blow molded product of the present invention may be made into a blown blow molded product by foam blow molding.
Examples of the foaming agent include pyrolysis-type organic compounds containing decomposable groups such as azo, N-nitroso, heterocyclic nitrogen and sulfonyl hydrazide groups, and inorganic compounds such as ammonium carbonate and sodium hydrogen carbonate. Can be mentioned. Specific examples thereof include azodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile, diazoaminobenzene, dinitrosopentamethylenetetramine, N, N′-dimethyl-N, N′-dinitrosotephthalamide, benzenesulfonyl Hydrazide, 4,4′-oxy-bis (benzenesulfonyl) hydrazide, diphenylsulfone-3,3′-disulfonylhydrazide, 4-toluenesulfonyl hydrazide, 4,4′-oxy-bis (benzenesulfonyl) semicarbazide, 4- Examples include toluenesulfonyl semicarbazide, barium azodicarboxylate, 5-phenyltetrazole, trihydrazinotriazine, 4-toluenesulfonyl azide, 4,4′-diphenyldisulfonyl azide, and the like.

  As the foaming agent, gaseous agents such as gaseous fluorocarbon, nitrogen, carbon dioxide, air, helium, and argon, and those that are liquid at ordinary temperatures such as liquid fluorocarbon and pentane can be used.

  Next, the blow molded article of the present invention is formed using the polyamide resin composition of the present invention or the mixed polyamide resin composition of the present invention. The blow molded product of the present invention can be manufactured using a general-purpose direct blow molding machine or stretch blow molding machine, and the temperature of each part of the cylinder and the nozzle of the molding machine is in the range of 230 to 290 ° C. Is preferred.

  The blow molded article of the present invention may be a single-layer blow molded article formed using only the resin composition of the present invention, or at least a part of the resin composition of the present invention is used. It may be a blow molded article having a multilayer structure.

  As a method for producing the polyamide resin composition (M) of the present invention, the melting point of the polyamide resin is obtained by supplying the material to a generally known melt kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll. A typical example is a method of kneading at the above processing temperature. Specifically, when a twin-screw extruder is used, the cylinder temperature is set to a temperature between the melting point of the polyamide resin and the melting point + 20 to 80 ° C. At this time, the mixing order of the raw materials is not particularly limited, and a method in which all raw materials are blended and then melt kneaded by the above method, a part of the raw materials are blended, and then melt kneaded by the above method, and the remaining raw materials are Any method may be used, such as a method of blending and melt-kneading, or a method of mixing a part of raw materials and mixing the remaining raw materials using a side feeder during melt-kneading with a single-screw or twin-screw extruder. .

  Moreover, the manufacturing method similar to said polyamide resin composition (M) can be employ | adopted for the manufacturing method of the mixed polyamide resin composition of this invention.

Next, the present invention will be specifically described using examples. The measurement and evaluation methods for various characteristic values in the examples are as follows.
(1) Elongation viscosity (ηe) and shear viscosity (η)
It measured by the method similar to the above.
(2) Relative viscosity of polyamide resin (A) Using an Ubbelohde viscometer, 96 mass% sulfuric acid was used as a solvent, and measurement was performed under conditions of a temperature of 25 ° C and a concentration of 1 g / dl.
(3) Amino end group concentration 0.5 g of polyamide resin was dissolved in 20 ml of m-cresol, 0.1 ml of 0.1% thymol blue methanol solution was added to this solution, and 1/10 normal p-toluenesulfonic acid was added. Determined by titration with solution.
(4) Charpy impact strength About the test piece 1 obtained by injection molding, Charpy impact strength (kJ / m < ² >) was measured based on ISO179-1. The test temperature was 23 ° C.

(5) Gas permeability A disc having a diameter of 50 mm and a thickness of 1 mm was cut out from the test piece 2 obtained by injection molding. A cylindrical aluminum cup that can be sealed was used as a test container. 10 ml of ethyl methacrylate was placed in the aluminum cup, and the test piece of the disk was covered from above. At that time, the disk specimen was firmly fixed to the aluminum cup so that there was no gas leakage other than permeation from the disk specimen. An aluminum cup covered with a disk specimen was left in an atmosphere at 23 ° C., and the mass change per day was calculated as a gas permeability coefficient (mg · mm / m ² · day).

The raw materials used in Examples and Comparative Examples are shown below.
(1) Polyamide resin (A)
(A-1): Polyamide 6 resin (“A1030BRT” manufactured by Unitika Ltd.) relative viscosity 3.5, amino end group concentration 38 mmol / kg
(A-2): Polyamide 6 resin (“A1025” manufactured by Unitika Ltd.) relative viscosity 2.5, amino end group concentration 70 mmol / kg

(2) Modified polyolefin resin (B)
(B-1): Maleic anhydride-modified ethylene / α-olefin copolymer (“Tafmer MH5020” manufactured by Mitsui Chemicals)
(B-2): Ethylene / glycidyl methacrylate copolymer (“Bond First E” manufactured by Sumitomo Chemical Co., Ltd.)

(3) Unmodified polyolefin resin (C)
(C-1): Ethylene / 1-hexene copolymer (“Evolution SP0540” manufactured by Prime Polymer Co., Ltd.)
-(C-2): Ethylene / 1-octene copolymer ("Morac 0218CN" manufactured by Prime Polymer Co., Ltd.)

(4) Polyamide resin (D)
(D-1): Polyamide MXD6 composed of metaxylylenediamine and adipic acid (MX nylon “S6121” manufactured by Mitsubishi Gas Chemical Company) relative viscosity 3.8
(D-2): Polyamide MXD6 composed of metaxylylenediamine and adipic acid (MX nylon “S6001” manufactured by Mitsubishi Gas Chemical Company) relative viscosity 2.1

Example 1
A loss-in-weight type continuous quantitative supply device “CE-W” manufactured by Kubota Corporation comprises 80 parts by mass of polyamide resin (a-1), 5 parts by mass of acid-modified polyolefin (b-1), and 15 parts by mass of unmodified polyolefin (c-1). -1 "was supplied to the main supply port of a twin screw extruder (TEM26SS manufactured by Toshiba Machine Co., Ltd.) having a screw diameter of 26 mm and L / D50. The barrel temperature setting of the extruder was 250 ° C. to 280 ° C., the screw rotation speed was 400 rpm, and the discharge rate was 20 kg / h. Finally, the strand was taken out from the die into a strand shape, and then cooled and solidified by passing through a water tank, which was cut with a pelletizer to obtain polyamide resin composition pellets.

  Next, using an injection molding machine (EC100 manufactured by Toshiba Machine Co., Ltd.), the obtained polyamide resin composition pellets were injection-molded under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C., and a test piece 1 (length 100 mm, A width 10 mm, a thickness 4 mm) and a test piece 2 (length 60 mm × width 60 mm × thickness 1 mm) were obtained. Various evaluation tests were performed using the obtained test pieces 1 and 2. The results are shown in Table 1.

Examples 2-7 Comparative Examples 1-5
A polyamide resin composition was prepared in the same manner as in Example 1 except that the compounding amounts of the polyamide resin, modified polyolefin resin, and unmodified polyolefin resin were changed so that the content in the resin composition was as shown in Table 1. Pellets were obtained.
Then, in the same manner as in Example 1, injection molding was performed to obtain test pieces 1 and 2, and various evaluation tests were performed. The results are shown in Table 1.

  As is clear from Table 1, since the polyamide resin compositions obtained in Examples 1 to 7 satisfied the resin composition defined in the present invention, the elongation viscosity (ηe) and the shear viscosity (η) The ratio and the value of the shear viscosity were optimum values, and as a result, a molded product having good blow moldability and excellent impact resistance and barrier properties could be obtained.

  On the other hand, since the polyamide resin composition obtained in Comparative Example 1 contained too much polyamide resin, the obtained molded product was inferior in impact resistance and moldability. Since the polyamide resin composition obtained in Comparative Example 2 contained an excessive amount of the modified polyolefin resin, the ratio of the extension viscosity (ηe) to the shear viscosity (η) and the value of the shear viscosity are outside the range of the present invention. It became a thing. For this reason, it became inferior to blow moldability, and the obtained molded product was inferior in barrier property. Since the polyamide resin composition obtained in Comparative Example 3 contained too much unmodified polyolefin resin, the ratio of the extensional viscosity (ηe) to the shear viscosity (η) was outside the range of the present invention. For this reason, it became inferior to blow moldability, and the obtained molded product was inferior in impact resistance and barrier property. Since the polyamide resin composition obtained in Comparative Example 4 had an insufficient polyamide resin content, the resulting molded product was inferior in barrier properties. The polyamide resin composition obtained in Comparative Example 5 was obtained because the amount of the modified polyolefin resin was too small, and the ratio of the extensional viscosity (ηe) to the shear viscosity (η) was outside the range of the present invention. The molded product was inferior in impact resistance and barrier properties.

Example 8
Injection of the mixed polyamide resin composition using 100 parts by mass of the polyamide resin composition obtained in Example 1 and 90 parts by mass of the polyamide resin (d-1) using an injection molding machine (EC100 manufactured by Toshiba Machine Co., Ltd.) Molding was performed. At this time, the test was performed under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. to obtain a test piece 1 (length 100 mm, width 10 mm, thickness 4 mm) and test piece 2 (length 60 mm × width 60 mm × thickness 1 mm). . Various evaluation tests were performed using the obtained test pieces 1 and 2. The results are shown in Table 2.

Examples 9-13, Comparative Examples 6-11
Instead of the polyamide resin composition obtained in Example 1, as shown in Table 2, the polyamide resin compositions obtained in Examples 2 to 6 and Comparative Examples 1 to 4 were used to obtain a polyamide resin (d-1). The mixed polyamide resin composition was injection-molded in the same manner as in Example 8 except that the blending amount of) was changed to the values shown in Table 2. Various evaluation tests were performed using the obtained test pieces 1 and 2. The results are shown in Table 2.

Example 14
The mixed polyamide resin composition was injection molded in the same manner as in Example 8 except that the polyamide resin (d-2) was used in place of the polyamide resin (d-1). Various evaluation tests were performed using the obtained test pieces 1 and 2. The results are shown in Table 2.

  As is clear from Table 2, the mixed polyamide resin compositions obtained in Examples 8 to 14 satisfied the resin composition defined in the present invention, and thus molded articles excellent in impact resistance and barrier properties. Was something you could get.

On the other hand, the mixed polyamide resin compositions obtained in Comparative Examples 6 to 9 use the resin compositions shown in Comparative Examples 1 to 4 that do not satisfy the composition and characteristic values of the present invention as the polyamide resin composition (M). In either case, it was impossible to obtain a molded product excellent in both impact resistance and barrier properties. Since the mixed polyamide resin composition obtained in Comparative Example 10 had a low content of the polyamide resin (D), the effect of improving the barrier property was poor. Since the mixed polyamide resin composition obtained in Comparative Example 11 contained too much polyamide resin (D), the obtained molded product was inferior in impact resistance.

Claims (6)

A polyamide resin composition comprising 60 to 95% by mass of a polyamide resin (A), 1 to 20% by mass of a modified polyolefin resin (B), and 0 to 35% by mass of an unmodified polyolefin resin (C). In the extensional viscosity-shear rate curve obtained by measuring the extensional viscosity at ° C., the ratio (ηe / η) of the extensional viscosity (ηe) to the shear viscosity (η) at a shear rate of 500 s ⁻¹ is 4 to 10, and A polyamide resin composition having a shear viscosity of 300 Pa · s <(η) <3000 Pa · s. The polyamide resin composition according to claim 1, wherein the modified polyolefin resin (B) is an ethylene / α-olefin copolymer modified with an unsaturated carboxylic acid or a derivative thereof. The polyamide resin composition according to claim 1 or 2, wherein the unmodified polyolefin resin (C) is ethylene and an α-olefin copolymer having 3 to 20 carbon atoms. The polyamide resin composition (D) obtained from the polycondensation reaction of xylylenediamine and dicarboxylic acid is blended with 100 to 100 parts by mass of the polyamide resin composition according to any one of claims 1 to 3. A mixed polyamide resin composition. A blow molded product formed by using the polyamide resin composition according to any one of claims 1 to 3. A blow molded article formed by using the mixed polyamide resin composition according to claim 4.