JP2019172829A - Polyamide-based thermoplastic elastomer composition, molding, and hollow molding - Google Patents

Abstract

To provide a polyamide-based thermoplastic elastomer composition capable of giving a molding having high elongation at break while having flexibility and good tensile strength.SOLUTION: The polyamide-based thermoplastic elastomer composition is a crosslinked product of a rubber composition containing: two or more specific aliphatic polyamides [I] having a melting point (Tm) of 150-290°C; an ethylene/α-olefin/nonconjugated polyene copolymer rubber [II]; an olefinic polymer [III] containing 0.3-5.0 mass% of a functional group structural unit; and a phenolic resin-based crosslinking agent [IV].SELECTED DRAWING: None

Description

  The present invention relates to a polyamide-based thermoplastic elastomer composition, a molded body, and a hollow molded body.

  Thermoplastic elastomers, unlike vulcanized rubber, do not require a vulcanization process and can be processed with ordinary thermoplastic resin molding machines, so they are considered for use in various applications such as automotive parts and machine parts. Has been.

  As such a thermoplastic elastomer, it is obtained by dynamically crosslinking a composition containing polyamide [I], copolymer rubber [II], olefin polymer [III], crosslinking agent [IV] and a crosslinking aid. Thermoplastic elastomer compositions are known (see, for example, Patent Document 1).

International Publication No. 2015/083819

  Although the thermoplastic elastomer composition shown in Patent Document 1 has flexibility and good tensile strength, further improvement in breaking elongation is required.

  The present invention has been made in view of the above circumstances, and provides a polyamide-based thermoplastic elastomer composition capable of providing a molded article having high elongation at break while having flexibility and good tensile strength. With the goal.

[1] The melting point (Tm) measured by differential scanning calorimetry (DSC) is 150 to 290 ° C., and at least two aliphatic polyamides [I] having different compositions, ethylene structural unit [a], An α-olefin structural unit [b] having 3 to 20 carbon atoms and a non-conjugated polyene structural unit [c] having at least one carbon-carbon double bond polymerizable in a molecule by a metallocene catalyst. Ethylene / α-olefin / non-conjugated polyene copolymer rubber [II], olefin polymer [III] containing 0.3 to 5.0 mass% of functional group structural unit, and phenol resin crosslinker [IV] And a polyamide-based thermoplastic elastomer composition, which is a crosslinked product of a rubber composition, comprising: at least two aliphatic polyamides [I] at 290 ° C. and 2.16 kg load according to ISO 1133 Difference melt flow rate (MFR) in is not more than 30 g / 10 min, a polyamide-based thermoplastic elastomer composition.
[2] The at least two types of aliphatic polyamide [I] is an aliphatic polyamide containing a dicarboxylic acid unit having 6 to 12 carbon atoms and a diamine unit having 4 to 12 carbon atoms, and has 6 to 12 carbon atoms. The polyamide-based thermoplastic elastomer composition according to [1], which is selected from the group consisting of aliphatic polyamides containing lactam or aminocarboxylic acid units.
[3] The at least two kinds of aliphatic polyamides [I] are polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 66, polyamide 69, polyamide 910, polyamide 912, polyamide 116, polyamide 610, and The polyamide thermoplastic elastomer composition according to any one of [1] or [2], which is selected from the group consisting of polyamide 612 and polyamide 1010.
[4] The at least two aliphatic polyamides [I] have a relatively low melt flow rate (MFR) and a relatively low melt flow rate (MFR). The aliphatic polyamide [I] -B is included, and the aliphatic polyamide [I] -A is included in a larger amount than the aliphatic polyamide [I] -B. A polyamide-based thermoplastic elastomer composition.
[5] The polyamide-based thermoplastic elastomer composition according to any one of [1] to [4], wherein the at least two types of aliphatic polyamide [I] are polyamide 610 and polyamide 66.
[6] The functional group structural unit of the olefin polymer [III] includes a structural unit derived from one or more functional groups selected from the group consisting of a carboxylic acid group, an ester group, an ether group, an aldehyde group, and a ketone group. The polyamide-based thermoplastic elastomer composition according to any one of [1] to [5].
[7] The polyamide-based thermoplastic elastomer composition according to [6], wherein the functional group structural unit of the olefin polymer [III] is a maleic anhydride structural unit.
[8] The at least two aliphatic polyamides [I], the ethylene / α-olefin / nonconjugated polyene copolymer rubber [II], the olefin polymer [III], and the phenol resin crosslinking agent [IV] ], The total of 10 to 60 parts by mass of the at least two aliphatic polyamides [I] and 33 of the ethylene / α-olefin / non-conjugated polyene copolymer rubber [II]. [1] to [7], comprising -86 parts by mass, 0.1-30 parts by mass of the olefin polymer [III], and 1-10 parts by mass of the phenol resin-based crosslinking agent [IV]. The polyamide-based thermoplastic elastomer composition according to any one of the above.
[9] A molded product obtained from the polyamide-based thermoplastic elastomer composition according to any one of [1] to [8].
[10] A hollow molded article obtained from the polyamide-based thermoplastic elastomer composition according to any one of [1] to [8].
[11] The hollow molded body according to [10], wherein the hollow molded body is an automobile-related part.

  According to the present invention, it is possible to provide a polyamide-based thermoplastic elastomer composition that can give a molded article having high elongation at break while having flexibility and good tensile strength.

  By combining two or more types of aliphatic polyamides having different compositions, the present inventors can dramatically increase the elongation at break of the resulting thermoplastic elastomer composition over each of the single aliphatic polyamides, that is, We have found that it can be much higher than expected from the combination of two or more aliphatic polyamides. As a result, it has been found that a polyamide-based thermoplastic elastomer composition having good elongation at break can be obtained without impairing flexibility and tensile strength.

  The reason for this is not clear, but is presumed as follows. By melt-kneading two or more types of aliphatic polyamides having different compositions, it is considered that an amide exchange reaction occurs in which the main chains of the aliphatic polyamides are interchanged. When this reaction occurs, it is considered that the molecular structure of the aliphatic polyamide tends to be irregular, crystallinity is lowered, and elongation at break is increased.

  In particular, the difference in melt flow rate (MFR) between at least two aliphatic polyamides [I] of two or more aliphatic polyamides [I] is not more than a certain value (specifically, not more than 30 g / 10 minutes). It is preferable. This is presumably because at least two types of aliphatic polyamides having different compositions have moderate viscosities, so that they are easily mixed together and an amide exchange reaction is more likely to occur. The present invention has been made based on such findings.

1. Polyamide-based thermoplastic elastomer composition The polyamide-based thermoplastic elastomer composition of the present invention comprises two or more aliphatic polyamide [I], ethylene / α-olefin / non-conjugated polyene copolymer rubber [II], and olefin. A cross-linked product (dynamic cross-linked product) of a rubber composition containing a polymer [III], a phenol resin-based cross-linking agent [IV], and a cross-linking aid [V]. The crosslinked product is a partially crosslinked product or a completely crosslinked product.

1-1. About two or more types of aliphatic polyamide [I] Two or more types of aliphatic polyamide [I] are each “a structural unit containing an amide bond [—NH—C (═O) —] and no aromatic ring”. (An amide bond-containing structural unit not containing an aromatic ring) is included as a main component. Here, “including as a main component” means that the content ratio of the amide bond-containing structural unit not containing an aromatic ring is 80 moles relative to the total number of moles of the amide bond-containing structural unit constituting the aliphatic polyamide [I]. % Or more, preferably 90 to 100 mol%.

  The aliphatic polyamide [I] may be obtained by polycondensation reaction of dicarboxylic acid and diamine, may be obtained by ring-opening polymerization reaction of lactam, or aminocarboxylic acid A product obtained by polycondensation reaction may be used. That is, the aliphatic polyamide [I] is composed of at least one of an amide bond-containing structural unit composed of a dicarboxylic acid structural unit and a diamine structural unit; a lactam structural unit; and an aminocarboxylic acid structural unit.

(Dicarboxylic acid structural unit / diamine structural unit)
The dicarboxylic acid structural unit includes an aliphatic dicarboxylic acid structural unit. The aliphatic dicarboxylic acid structural unit is a structural unit derived from an aliphatic dicarboxylic acid or an ester thereof. The aliphatic dicarboxylic acid or an ester thereof is a linear or branched aliphatic dicarboxylic acid (preferably a saturated aliphatic dicarboxylic acid) having 3 to 20 carbon atoms, preferably 6 to 12 carbon atoms, or an ester thereof.

  Examples of aliphatic dicarboxylic acids or esters thereof include malonic acid, dimethyl malonic acid, succinic acid, 2,2-dimethyl succinic acid, 2,3-dimethyl glutaric acid, 2,2-diethyl succinic acid, 2,3- Diethyl glutaric acid, glutaric acid, 2,2-dimethyl glutaric acid, adipic acid, 2-methyl adipic acid, trimethyl adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanediate Acids, octadecanedioic acid, eicosanedioic acid, diglycolic acid and the like are included. One type of aliphatic dicarboxylic acid or ester thereof may be used, or two or more types may be combined.

  The dicarboxylic acid structural unit may further include an alicyclic dicarboxylic acid structural unit as necessary. Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid. The alicyclic dicarboxylic acid may further have a substituent. Examples of the substituent include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and tert-butyl group.

  The content ratio of the aliphatic dicarboxylic acid structural unit is preferably 80 mol% or more with respect to the total number of moles of the dicarboxylic acid structural unit. When the content ratio of the aliphatic dicarboxylic acid structural unit is 80 mol% or more, the degree of crystallinity of the aliphatic polyamide [I] tends to increase, and the molded article has sufficient heat resistance and mechanical strength (such as tensile strength and elongation at break). ). The content ratio of the aliphatic dicarboxylic acid structural unit is more preferably 85 to 100 mol%, and further preferably 90 to 100 mol%, based on the total number of moles of the dicarboxylic acid structural unit.

  The diamine structural unit includes an aliphatic diamine structural unit. The aliphatic diamine is a linear aliphatic diamine having 2 to 20 carbon atoms, preferably 4 to 12 carbon atoms (preferably a saturated aliphatic diamine) or a branched one having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms. Aliphatic diamines (preferably saturated aliphatic diamines). The branched aliphatic diamine has a group (side chain) branched from the main chain.

  Examples of linear aliphatic diamines having 2 to 20 carbon atoms, preferably 4 to 12 carbon atoms, include ethylene diamine, propylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, Nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, tridecamethylene diamine and the like are included. Examples of branched aliphatic diamines having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms include 2-methylpentamethylenediamine (also referred to as 2-methyl-1,5-diaminopentane), 2,2 , 4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyloctamethylenediamine, 2,4-dimethyloctamethylenediamine, and the like. One type of aliphatic diamine may be used, or two or more types may be combined.

  The content ratio of the aliphatic diamine structural unit is preferably 80 mol% or more with respect to the total number of moles of the diamine structural unit. If the content ratio of the aliphatic diamine structural unit is 80 mol% or more, the degree of crystallinity of the aliphatic polyamide [I] is likely to increase, and sufficient heat resistance and mechanical strength (tensile strength, elongation at break, etc.) for the molded product Can be given. The content ratio of the aliphatic diamine structural unit is more preferably from 85 to 100 mol%, and further preferably from 90 to 100 mol%, based on the total number of moles of the diamine structural unit.

  The diamine structural unit may further include an alicyclic diamine structural unit as necessary. Examples of the alicyclic diamine include 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, and the like.

(Lactam structural unit)
A lactam structural unit is a structural unit derived from a lactam. The lactam may be a lactam having 4 to 14 carbon atoms, preferably 6 to 12 carbon atoms. Examples of such lactams include butyrolactam, pivalolactam, epsilon-caprolactam, caprilactam, enantolactam, undecanolactam, laurolactam (dodecanolactam), and the like. Among these, ε-caprolactam and laurolactam are preferable, and ε-caprolactam is more preferable from the viewpoint of easily increasing the elongation at break (toughness) of the thermoplastic elastomer composition obtained. Only one type of lactam may be used, or two or more types may be combined.

(Aminocarboxylic acid structural unit)
An aminocarboxylic acid structural unit is a structural unit derived from an aminocarboxylic acid. The aminocarboxylic acid may be a compound in which the aforementioned lactam is ring-opened. The aminocarboxylic acid can be ω-aminocarboxylic acid, α, ω-aminocarboxylic acid, or the like. Among them, ω-aminocarboxylic acid is preferable from the viewpoint of increasing the crystallinity.

  The ω-aminocarboxylic acid is a linear or branched aliphatic carboxylic acid (preferably a saturated aliphatic carboxylic acid) having 4 to 14 carbon atoms, preferably 6 to 12 carbon atoms, substituted at the ω position with an amino group. It is. Examples of such aliphatic carboxylic acids include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and the like. Only one type of aminocarboxylic acid may be used, or two or more types may be combined.

  Examples of the aliphatic polyamide [I] include polyamide 4 (poly α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecanamide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene). Adipamide), polyamide 56 (polypentamethylene adipamide), polyamide 66 (polyhexamethylene adipamide), polyamide 116 (polyundecamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), Polyamide 612 (polyhexamethylene dodecamide), polyamide 1010 (polydecamethylene sebamide) and the like are included.

  In the aliphatic polyamide [I], it is preferable that at least some of the end groups of the molecular chain are sealed with an end-capping agent from the viewpoint of the thermal stability during compounding and molding. In particular, from the viewpoints of melt stability, heat resistance, and hydrolysis resistance, the amount of terminal amino groups of the aliphatic polyamide [I] is preferably 0.1 to 300 mmol / kg, and preferably 10 to 300 mmol / kg. More preferably, it is more preferably 20 to 300 mmol / kg, further preferably 35 to 300 mmol / kg, and particularly preferably 35 to 100 mmol / kg.

  The end-capping agent is not particularly limited as long as it is a monofunctional compound having reactivity with the amino group or carboxyl group at the molecular end of the aliphatic polyamide [I]. In view of the above, monocarboxylic acid or monoamine is preferred, and monocarboxylic acid is more preferred from the viewpoint of ease of handling. In addition, acid anhydride monoisocyanates, monoacid halides, monoesters, monoalcohols, and the like can be used.

  The monocarboxylic acid used as a terminal blocking agent is not particularly limited as long as it has reactivity with an amino group. Examples of monocarboxylic acids include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid. Acids: Alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. Two or more of these may be used in combination. Above all, from the viewpoint of reactivity, stability of the sealing end, price, etc., acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, stearic acid, benzoic acid Acid is more preferred.

  The monoamine used as a terminal blocking agent is not particularly limited as long as it has reactivity with a carboxyl group. Examples of monoamines include aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine; cyclohexylamine, dicyclohexylamine, etc. And aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine. Two or more of these may be used in combination. Of these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are more preferable from the viewpoints of reactivity, boiling point, stability of the sealing end and price.

  The amount of terminal amino groups can be measured by the following method. As for the terminal amino group amount of the aliphatic polyamide [I], 0.5 to 0.7 g of the aliphatic polyamide [I] is precisely weighed and dissolved in 30 mL of m-cresol. Then, 1 to 2 drops of 0.1% thymol blue / m-cresol solution as an indicator is added to obtain a sample solution. The sample solution is titrated with a 0.02 normal p-toluenesulfonic acid solution until it turns yellow to blue-violet, and the terminal amino group content ([NH 2], unit: μ equivalent / g) is specified.

  Although melting | fusing point of aliphatic polyamide [I] is not specifically limited, It is preferable that it is 150 degreeC or more, It is more preferable that it is 200 degreeC or more, It is further more preferable that it is 240 degreeC or more. By setting the melting point of the aliphatic polyamide [I] to the above lower limit value or more, the heat resistance of the resulting thermoplastic elastomer composition can be further improved. The melting point of the aliphatic polyamide [I] is preferably 290 ° C. or lower. By making the melting point of the aliphatic polyamide [I] not more than the above upper limit value, thermal decomposition and deterioration of the aliphatic polyamide [I] during melt processing can be more effectively suppressed.

  The melting point (Tm) of the aliphatic polyamide [I] can be measured under the following conditions. Using DSC (Differential Scanning Calorimetry), a sample of the aliphatic polyamide [I] is heated and held at 320 ° C. for 5 minutes, then lowered to 23 ° C. at a rate of 10 ° C./min, and then 10 ° C. The temperature is raised at a rate of ° C / min. The temperature of the endothermic peak based on melting at this time is defined as the melting point (Tm) of the polyamide.

  The melting point (Tm) of the aliphatic polyamide [I] can be adjusted by, for example, the monomer composition. In order to increase the melting point (Tm) of the aliphatic polyamide [I], for example, the number of carbon atoms of the dicarboxylic acid, diamine, lactam, or aminocarboxylic acid constituting the aliphatic polyamide [I] is preferably set to a certain value or less.

  The melt flow rate (MFR) of the aliphatic polyamide [I] at 290 ° C. under a load of 2.16 kg according to ISO 1133 is easy to finely disperse together with the viscosity of the copolymer rubber [II] at the time of compounding, It is preferably 0.1 to 500 g / 10 minutes, more preferably 0.1 to 300 g / 10 minutes, further preferably 0.1 to 100 g / 10 minutes, and 1 to 100 g / 10 minutes. It is particularly preferred that

  The melt flow rate (MFR) of the aliphatic polyamide [I] can be adjusted by, for example, the molecular weight of the aliphatic polyamide [I] or the amount of terminal amino groups. In order to lower the MFR of the aliphatic polyamide [I], it is preferable to increase the molecular weight and increase the amount of terminal amino groups.

  The amount of terminal amino groups of the aliphatic polyamide [I] is preferably 0.1 to 300 mmol / kg, more preferably 1 to 200 mmol / kg, still more preferably 1 to 100 mmol / kg, More preferably, it is 5-60 mmol / kg. When the amount of terminal amino group of the aliphatic polyamide [I] is within the above range, melt kneading is not excessively increased, and thus moldability is easily improved.

(Combination of two or more aliphatic polyamides [I])
As described above, the polyamide-based thermoplastic elastomer composition of the present invention contains two or more aliphatic polyamides [I] having different compositions. “Different composition” means that the monomer composition of the aliphatic polyamide is different.

  The difference ΔMFR in melt flow rate (MFR) at 290 ° C. under a load of 2.16 kg according to ISO 1133 of at least two of the two or more types of aliphatic polyamide [I] is 30 g / 10 min or less. If the difference in melt flow rate (MFR) between at least two types of aliphatic polyamides [I] is below a certain level, the aliphatic polyamides have similar molecular weights and are likely to mix with each other. Therefore, it is considered that the elongation at break of the resulting thermoplastic elastomer composition is likely to be increased.

  At least two types of aliphatic polyamides [I] are aliphatic dicarboxylic acid structural units having 6 to 12 carbon atoms and carbon atoms having 4 to 12 carbon atoms from the viewpoint of easily increasing the elongation at break of the resulting thermoplastic elastomer composition. It is preferably selected from the group consisting of an aliphatic polyamide containing an aliphatic diamine structural unit and an aliphatic polyamide containing an amidocarboxylic acid structural unit having 6 to 12 carbon atoms or a lactam structural unit having 6 to 12 carbon atoms. .

  Specifically, at least two kinds of aliphatic polyamide [I] are selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 66, polyamide 116, polyamide 610, and polyamide 612. It is preferable.

  The melt flow rate (MFR) of at least two aliphatic polyamides [I] may be the same or different as long as the difference ΔMFR in the melt flow rate (MFR) satisfies the above-mentioned range. Also good. From the viewpoint of easily increasing the elongation at break of the resulting thermoplastic elastomer composition, it is preferable that the melt flow rate (MFR) of at least two kinds of aliphatic polyamides [I] are different.

  For example, at least two types of aliphatic polyamide [I] are aliphatic polyamide [I] -A having a relatively high melt flow rate and aliphatic polyamide [I] -B having a relatively low melt flow rate. In this case, the content ratio of the aliphatic polyamide [I] -A and the aliphatic polyamide [I] -B is aliphatic polyamide [I] -A / from the viewpoint of easily increasing the elongation at break of the resulting thermoplastic elastomer composition. It is preferable that it is aliphatic polyamide [I] -B = 10 / 90-80 / 20 (mass ratio), and it is more preferable that it is 60 / 40-80 / 20 (mass ratio).

  The melting points (Tm) of at least two types of aliphatic polyamide [I] may be the same or different. For example, the melting point (Tm) of the aliphatic polyamide [I] -A may be lower than the melting point (Tm) of the aliphatic polyamide [I] -B. In that case, the difference in melting point (Tm) between the aliphatic polyamide [I] -B and the aliphatic polyamide [I] -A may be 100 ° C. or less.

  In particular, from the viewpoint of easily increasing the elongation at break of the resulting thermoplastic elastomer composition, the combination of at least two aliphatic polyamides [I] is polyamide 66 (aliphatic polyamide [I] -B) and polyamide 610 (aliphatic). A combination of polyamide [I] -A) and a combination of polyamide 610 (aliphatic polyamide [I] -A) and polyamide 6 (aliphatic polyamide [I] -B) are preferred.

  The total content of the two or more aliphatic polyamides [I] is 10 to 60% by mass with respect to the total mass of the [I] component, [II] component, [III] component and [IV] component. preferable. When the total content of two or more types of aliphatic polyamide [I] is 10% by mass or more, sufficient heat resistance and mechanical strength (such as tensile strength and elongation at break) are imparted to the resulting thermoplastic elastomer composition. It is easy and the flexibility of the resulting thermoplastic elastomer composition is less likely to be impaired when it is 60% by mass or less. The total content of the two or more aliphatic polyamides [I] is more preferably 20 to 60% by mass with respect to the total of the [I] component, [II] component, [III] component and [IV] component. Preferably, the content is 25 to 60% by mass.

1-2. Ethylene / α-olefin / non-conjugated polyene copolymer rubber [II]
The ethylene / α-olefin / nonconjugated polyene copolymer rubber [II] comprises an ethylene structural unit [a], an α-olefin structural unit [b] having 3 to 20 carbon atoms, and a nonconjugated polyene structural unit [c]. ] Is a copolymer rubber containing.

(Ethylene structural unit [a])
The content ratio of the ethylene structural unit [a] is preferably 50 to 89% by mass, and more preferably 55 to 83% by mass with respect to all the structural units constituting the copolymer rubber [II].

(C-C20 α-olefin structural unit [b])
Examples of the α-olefin having 3 to 20 carbon atoms constituting the copolymer rubber [II] include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-heptene. 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like. Among these, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene and 1-octene are preferable. One type of α-olefin may be used, or two or more types may be combined. These α-olefins [b] are preferable because the raw material costs are relatively low and the copolymerization is excellent, and the mechanical properties and good flexibility are imparted to the copolymer rubber [II].

  The content of the α-olefin structural unit [b] having 3 to 20 carbon atoms is preferably 10 to 49% by mass with respect to all the structural units constituting the copolymer rubber [II]. More preferably, it is mass%.

(Non-conjugated polyene structural unit [c])
The non-conjugated polyene constituting the copolymer rubber [II] is a non-conjugated polyene having at least one carbon / carbon double bond in one molecule that can be polymerized by a metallocene catalyst. Polyene and alicyclic polyene are included.

  Examples of aliphatic polyenes include 1,4-hexadiene, 1,5-heptadiene, 1,6-octadiene, 1,7-nonadiene, 1,8-decadiene, 1,12-tetradecadiene, 3-methyl- 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4-ethyl-1,4-hexadiene, 3,3-dimethyl-1,4-hexadiene, 5- Methyl-1,4-heptadiene, 5-ethyl-1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 5-ethyl-1,5-heptadiene, 4- Methyl-1,4-octadiene, 5-methyl-1,4-octadiene, 4-ethyl-1,4-octadiene, 5-ethyl-1,4-octadiene, 5-methyl-1,5-octadiene, 6- Methyl-1,5-o Tadiene, 5-ethyl-1,5-octadiene, 6-ethyl-1,5-octadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 6-ethyl-1,6- Octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 4-methyl-1,4-nonadiene, 5-methyl-1,4-nonadiene, 4-ethyl-1,4- Nonadiene, 5-ethyl-1,4-nonadiene, 5-methyl-1,5-nonadiene, 6-methyl-1,5-nonadiene, 5-ethyl-1,5-nonadiene, 6-ethyl-1,5- Nonadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 7-methyl-1,7- Nonadiene, 8-methyl-1,7-nonadiene 7-ethyl-1,7-nonadiene, 5-methyl-1,4-decadiene, 5-ethyl-1,4-decadiene, 5-methyl-1,5-decadiene, 6-methyl-1,5- Decadiene, 5-ethyl-1,5-decadiene, 6-ethyl-1,5-decadiene, 6-methyl-1,6-decadiene, 6-ethyl-1,6-decadiene, 7-methyl-1,6- Decadiene, 7-ethyl-1,6-decadiene, 7-methyl-1,7-decadiene, 8-methyl-1,7-decadiene, 7-ethyl-1,7-decadiene, 8-ethyl-1,7- Decadiene, 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 8-ethyl-1,8-decadiene, 6-methyl-1,6-undecadiene, 9-methyl-1,8- Undecadiene, and also 1,7-octadiene, 1,9-decadiene Α, ω-dienes such as ene are included. Of these, 7-methyl-1,6-octadiene is preferable.

  Examples of alicyclic polyenes include 5-ethylidene-2-norbornene (ENB), 5-propylidene-2-norbornene, 5-butylidene-2-norbornene, 5-vinyl-2-norbornene (VNB); 2-alkenyl-2-norbornene such as 2-norbornene; 2,5-norbornadiene, dicyclopentadiene (DCPD), norbornadiene, tetracyclo [4,4,0,12.5,17.10] dec-3,8 -Diene, 2-methyl-2,5-norbornadiene, 2-ethyl-2,5-norbornadiene and the like are included. Of these, 5-ethylidene-2-norbornene (ENB) is preferable. One type of nonconjugated polyene structural unit [c] may be used, or two or more types may be used in combination.

  The content ratio of the non-conjugated polyene structural unit [c] is preferably 1 to 20% by mass and more preferably 2 to 15% by mass with respect to all the structural units constituting the copolymer rubber [II]. preferable.

  The intrinsic viscosity [η] of the copolymer rubber [II] is preferably 0.5 to 5.0 dl / g, more preferably 1.0 to 4.5 dl / g, and 1.5 to Particularly preferred is 4.0 dl / g. This intrinsic viscosity [η] is a value measured in decalin at a temperature of 135 ° C. and can be determined by measuring according to ASTM D 1601.

  It is preferable that content of copolymer rubber [II] is 33-86 mass% with respect to the sum total of [I] component, [II] component, [III] component, and [IV] component. When the content of the copolymer rubber [II] is 33% by mass or more, sufficient flexibility can be easily imparted to the obtained thermoplastic elastomer composition, and when it is 86% by mass or less, the obtained thermoplastic elastomer composition The heat resistance and mechanical strength (tensile strength, elongation at break, etc.) of the object are not easily impaired. The content of the copolymer rubber [II] is more preferably 33 to 55% by mass with respect to the total of the [I] component, [II] component, [III] component and [IV] component. More preferably, it is 50 mass%, and it is especially preferable that it is 40-50 mass%.

  The mass ratio ([II] / [I]) of the copolymer rubber [II] and the aliphatic polyamide [I] is, for example, 20/80 to 20% from the viewpoint of facilitating fine dispersion by combining the viscosities at the time of compounding. 70/30 is preferable, and 30/70 to 60/40 is more preferable. When the mass ratio of the copolymer rubber [II] is not less than a certain value, it is easy to impart sufficient flexibility to the resulting thermoplastic elastomer composition, and the mass ratio of the copolymer rubber [II] is not more than a certain value. The mechanical strength (tensile strength, elongation at break, etc.) of the resulting thermoplastic elastomer composition is not easily impaired.

1-3. Olefin polymer [III]
The olefin polymer [III] is an olefin polymer containing 0.3 to 5.0% by mass of a functional group structural unit. The functional group structural unit is a structural unit derived from a compound having a functional group or a monomer having a functional group. Examples of functional groups in the functional group structural unit include carboxylic acid groups (including acid anhydride groups), ester groups, ether groups, aldehyde groups, and ketone groups. The olefin polymer [III] having such a functional group structural unit has an affinity for the aliphatic polyamide [I] by having a functional group, and has a copolymer structure rubber by having an olefin skeleton. Since it has an affinity with [II], the compatibility of both can be improved.

  The olefin polymer [III] is obtained by copolymerizing a modified polyolefin [III] -1, in which a functional group is introduced into a polyolefin molecular chain, and an olefin monomer and a monomer having a functional group by reacting a compound having a functional group. Functional group-containing olefin copolymer [III] -2.

  Examples of the polyolefin constituting the modified polyolefin [III] -1 are homopolymers or copolymers of olefins having 2 to 18 carbon atoms, such as low density polyethylene, medium density polyethylene, and high density polyethylene. , Polypropylene, and ethylene / α-olefin copolymers. Among these, an ethylene / α-olefin copolymer is preferable. The α-olefin in the ethylene / α-olefin copolymer is preferably an α-olefin having 3 to 10 carbon atoms, and examples thereof include propylene and 1-butene. Examples of the ethylene / α-olefin copolymer include an ethylene-propylene copolymer and an ethylene-butene copolymer.

  Examples of the compound having a functional group constituting the modified polyolefin [III] -1 include an unsaturated carboxylic acid having a functional group or a derivative thereof. Examples of unsaturated carboxylic acids having functional groups or derivatives thereof include acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endocis -Unsaturated carboxylic acids such as bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid (nadic acid), and derivatives of these acid halides, amides, imides, acid anhydrides, esters, etc. Is mentioned. Among these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, maleic acid, nadic acid or acid anhydrides thereof are more preferable, and maleic anhydride is particularly preferable. Maleic anhydride has a relatively high reactivity with the polyolefin before modification, polymerization of maleic anhydrides hardly occurs, and the basic structure tends to be stable. For this reason, it is easy to obtain modified polyolefin [III] -1 having stable quality.

Examples of the modified polyolefin [III] -1 include a modified ethylene / α-olefin copolymer. The density of the modified ethylene / α-olefin copolymer is preferably 0.80 to 0.95 g / cm ³ , more preferably 0.85 to 0.90 g / cm ³ .

  The olefin monomer constituting the functional group-containing olefin copolymer [III] -2 is preferably an olefin monomer having 2 to 18 carbon atoms, and examples thereof include ethylene and propylene, preferably ethylene. is there.

  Examples of the monomer having a functional group constituting the functional group-containing olefin copolymer [III] -2 include an acrylic monomer and a vinyl monomer.

  Examples of the functional group-containing olefin copolymer [III] -2 include ethylene / vinyl acetate / maleic anhydride copolymer (such as Orevac (registered trademark) manufactured by Arkema), ethylene / acrylic acid ester / functional acrylic. Acid ester (for example, glycidyl acrylate or glycidyl methacrylate) copolymers (such as Lotader (registered trademark) manufactured by Arkema) are included.

  The content of the functional group structural unit of the olefin polymer [III] is preferably 0.3 to 5.0% by mass, and more preferably 0.4 to 4.0% by mass. When the functional group structural unit is 0.3% by mass or more, not only the dispersibility of the ethylene / α-olefin / non-conjugated polyene copolymer rubber [II] in the aliphatic polyamide [I] is easily improved, but also the machine The mechanical strength is not easily lost. On the other hand, when the functional group structural unit is 5.0% by mass or less, excessive reaction with the aliphatic polyamide [I] is unlikely to occur, so that the melt fluidity is hardly reduced due to gelation, and the moldability is impaired. Hateful.

  The content of the functional group structural unit is the content of the compound having a functional group or the structural unit derived from a monomer having a functional group with respect to the total mass of the structural unit derived from the monomer having no functional group constituting the olefin polymer [III]. It is a ratio (mass%).

The content of the functional group structural unit of the olefin polymer [III] can be measured by ¹³ C-NMR measurement or ¹ H-NMR measurement. Specific measurement conditions are as follows.

^In the case of ¹ H-NMR measurement, an ECX400 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. is used, the solvent is deuterated orthodichlorobenzene, the sample concentration is 20 mg / 0.6 mL, the measurement temperature is 120 ° C., observation The nucleus is ¹ H (400 MHz), the sequence is a single pulse, the pulse width is 5.12 μs (45 ° pulse), the repetition time is 7.0 seconds, and the number of integrations is 500 times or more. The standard chemical shift is tetramethylsilane hydrogen of 0 ppm, but the same result can be obtained by setting the peak derived from residual hydrogen of deuterated orthodichlorobenzene to 7.10 ppm and setting the standard value for chemical shift. be able to. A peak such as 1H derived from the functional group-containing compound can be assigned by a conventional method.

^In the case of ¹³ C-NMR measurement, an ECP500 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. is used as a measurement apparatus, a mixed solvent of orthodichlorobenzene / heavy benzene (80/20 vol%), a measurement temperature is 120 ° C., The observation nucleus is ¹³ C (125 MHz), single pulse proton decoupling, 45 ° pulse, repetition time is 5.5 seconds, integration number is 10,000 times or more, and 27.50 ppm is a reference value for chemical shift. Assignment of various signals is performed based on a conventional method, and quantification can be performed based on an integrated value of signal intensity.

The intrinsic viscosity [η] measured in a 135 ° C. decalin (decahydronaphthalene) solution of the olefin polymer [III] is preferably 0.5 to 4.0 dl / g, preferably 0.7 to
It is more preferably 3.0 dl / g, and further preferably 0.8 to 2.5 dl / g. When the intrinsic viscosity [η] is within the above range, the melt fluidity of the obtained rubber composition and the toughness of the obtained thermoplastic elastomer composition can be compatible at a high level.

The intrinsic viscosity [η] of the olefin polymer [III] can be measured by the following method based on a conventional method.
20 mg of a sample is dissolved in 15 ml of decalin, and the specific viscosity (ηsp) is measured in an atmosphere of 135 ° C. using an Ubbelohde viscometer. After adding 5 ml of decalin to the decalin solution and diluting, the same specific viscosity is measured. Based on the measurement result obtained by repeating this dilution operation and viscosity measurement twice more, the “ηsp / C” value when the concentration (: C) is extrapolated to zero is defined as the intrinsic viscosity [η].

  Examples of commercially available olefin polymer [III] include Tafmer series (maleic anhydride modified ethylene-propylene rubber, maleic anhydride modified ethylene-butene rubber, etc.), Admer (maleic anhydride modified). Polypropylene, maleic anhydride modified polyethylene); Kuraray's kraprene (maleic anhydride modified isoprene rubber, maleic acid monomethyl ester modified isoprene rubber), Septon (maleic anhydride modified SEPS); Mitsui DuPont Polychemical Co., Ltd. (Ethylene-methacrylic acid copolymer), HPR (maleic anhydride modified EEA, maleic anhydride modified EVA); Chemtura Royaltuf (maleic anhydride modified EPDM); Kraton Kraton FG (maleic anhydride modified SEBS); JX Nippon Mining & Energy Co., Ltd. Nippon Polybutene (maleic anhydride modified polybutene); Arkema Bondine (maleic anhydride modified EEA); Asahi Kasei Co., Ltd. Tuftec M (maleic anhydride modified SEBS); Lexpearl ET (maleic anhydride modified EEA) from Mitsubishi Chemical Corporation Modic (maleic anhydride modified EVA, maleic anhydride modified polypropylene, maleic anhydride modified polyethylene); Sumitomo Chemical Co., Ltd. Bond First ( E-GMA); LANACESS Clinac (carboxy-modified nitrile rubber); Nippon Paper Industries Co., Ltd. aurorene (maleic anhydride-modified EEA) and the like (all are trade names). These may be used alone or in combination of two or more.

  It is preferable that content of olefin polymer [III] is 0.1-30 mass% with respect to the sum total of [I] component, [II] component, [III] component, and [IV] component. If the content of the olefin polymer [III] is 0.1% by mass or more, the compatibility between the [I] component and the [II] component can be sufficiently increased, and thus sufficient for the obtained thermoplastic elastomer composition. When it is 30% by mass or less, the properties of the [I] component and the [II] component are not easily impaired. The content of the olefin polymer [III] is more preferably 3 to 30% by mass based on the total of the [I] component, the [II] component, the [III] component and the [IV] component, More preferably, it is 20 mass%.

  Moreover, it is preferable that mass ratio ([III] / [II]) of olefin polymer [III] and copolymer rubber [II] is 1/500-1/1. If the mass ratio of the olefin polymer [III] is a certain value or more, the compatibility between the aliphatic polyamide [I] and the copolymer rubber [II] is difficult to be impaired, and thus sufficient for the resulting thermoplastic elastomer composition. When the mechanical strength is easily imparted and is below a certain level, the characteristics of the aliphatic polyamide [I] and the copolymer rubber [II] are not easily impaired. The mass ratio of the olefin polymer [III] and the copolymer rubber [II] is more preferably 1/20 to 1/1, and further preferably 1/20 to 1/2.

1-4. Phenolic resin crosslinking agent [IV]
The phenol resin-based crosslinking agent [IV] is typically a resole resin obtained by condensing an alkyl-substituted or unsubstituted phenol with an aldehyde (preferably formaldehyde) in the presence of an alkali catalyst. The alkyl group of the alkyl-substituted phenol is preferably an alkyl group having 1 to 10 carbon atoms. Particularly preferred are dimethylolphenols or phenol resins substituted with an alkyl group having 1 to 10 carbon atoms.

Examples of the phenol resin-based crosslinking agent [IV] include a compound represented by the following formula [IV-1].

In formula [IV-1], R is an organic group such as an alkyl group, preferably an organic group having less than 20 carbon atoms, more preferably an organic group having 4 to 12 carbon atoms. R ′ is a hydrogen atom or —CH ₂ —OH. n and m are integers of 0 to 20, preferably an integer of 0 to 15, more preferably an integer of 0 to 10.

Other examples of the phenol resin-based crosslinking agent [IV] include methylolated alkylphenol resins and halogenated alkylphenol resins. The halogenated alkylphenol resin is an alkylphenol resin in which a hydroxyl group at a molecular chain terminal is substituted with a halogen atom such as bromine, and examples thereof include a compound represented by the following formula [IV-2].

N, m and R in the formula [IV-2] have the same meanings as n, m and R in the formula [IV-1], respectively. R ′ in the formula [IV-2] is a hydrogen atom, —CH ₃ or —CH ₂ —Br.

  Examples of commercially available phenolic resin-based cross-linking agents [IV] include Takuro Chemical Industry Co., Ltd. Tacco Roll 201, Tacco Roll 250-I, Tacic Roll 250-III; SI Group SP1045, SP1055, SP1056; Showa Denko Co., Ltd. ) Shounol CRM; Amanagawa Chemical Industry Co., Ltd. Tamanoru 531; Sumitomo Bakelite Co., Ltd. Sumitrite Resin PR; Gunei Chemical Industry Co., Ltd. cash register top (all trade names). These may be used alone or in combination of two or more. Among them, Takiroll 250-III (brominated alkylphenol formaldehyde resin) manufactured by Taoka Chemical Industries, Ltd. and SP1055 (brominated alkylphenol formaldehyde resin) manufactured by SI Group are preferable.

  Among these, halogenated alkylphenol resins are particularly preferable. The halogen alkylphenol resin is preferable because it is excellent in compatibility with the copolymer rubber [II], has high reactivity, and can relatively quickly start the crosslinking reaction.

  When the phenol resin crosslinking agent [IV] is a powdery crosslinking agent, the average particle size is preferably 0.1 μm to 3 mm, more preferably 1 μm to 1 mm, particularly preferably 5 μm to 0.5 mm. . The flaky curing agent is preferably used after being powdered by a pulverizer such as a jet mill or a pulverizer with a pulverizing blade.

  The content of the phenol resin-based crosslinking agent [IV] is preferably 1 to 10% by mass with respect to the total of the [I] component, [II] component, [III] component and [IV] component. When the content of the phenol resin-based crosslinking agent [IV] is 1% by mass or more, the [II] component is sufficiently easily cross-linked, so that the resulting thermoplastic elastomer composition has sufficient heat resistance and mechanical strength (tensile Strength and elongation at break) are easily imparted, and when the content of the phenol resin-based crosslinking agent [IV] is 10% by mass or less, the properties of the [I] component and the [II] component are not easily impaired. The content of the phenol resin crosslinking agent [IV] is more preferably 1 to 8% by mass with respect to the total of the [I] component, [II] component, [III] component and [IV] component, More preferably, it is 2-6 mass%.

1-5. Other Components The rubber composition for obtaining the polyamide-based thermoplastic elastomer composition further includes other components other than the components [I] to [IV] as necessary, as long as the effects of the present invention are not impaired. May be. Examples of other components include cross-linking agents and cross-linking aids other than phenol resin cross-linking agents [IV], plasticizers, antioxidants, colorants, antistatic agents (conductive agents), fillers, etc. It is. The total content of other components is preferably 10% by mass or less, and more preferably 5% by mass or less, based on the polyamide-based thermoplastic elastomer composition (or rubber composition).

  The other crosslinking agent should just be a crosslinking agent which can perform dynamic crosslinking of the above-mentioned rubber composition, and the sulfur type crosslinking agent is contained in the example. However, it is preferable that the other crosslinking agent does not contain an organic peroxide. When an organic peroxide is used as the other cross-linking agent, the decomposition rate of the organic peroxide may become too fast because the melt kneading temperature suitable for the polyamide-based thermoplastic elastomer composition of the present invention is relatively high. is there. As a result, the crosslinking reaction of the rubber component ([II] component, [III] component) is likely to proceed rapidly, and may not be sufficiently kneaded with the aliphatic polyamide [I], resulting in insufficient dispersion. Therefore, the physical properties of the polyamide-based thermoplastic elastomer composition may be significantly reduced.

  Examples of the crosslinking aid include magnesium hydroxide, calcium hydroxide, magnesium oxide, zinc oxide and the like.

2. Process for Producing Polyamide-Based Thermoplastic Elastomer Composition The polyamide-based thermoplastic elastomer composition of the present invention comprises the above-mentioned aliphatic polyamide [I], ethylene / α-olefin / non-conjugated polyene copolymer rubber [II], Dynamically crosslinking at least a part of the rubber composition containing the olefin polymer [III] and the phenol resin crosslinking agent [IV], specifically, in a melt flow state (dynamic state). Can be obtained.

  Such a dynamic cross-linking reaction is usually performed by supplying the above-described composition to a melt-kneading apparatus, heating to a predetermined temperature, and melt-kneading.

  In the melt-kneading, the [I] component, [II] component, [III] component, and [IV] component may be kneaded simultaneously; the [I] component, [II] component, and [III] component are kneaded. Then, the component [IV] may be added and further kneaded.

  As the melt kneading apparatus, for example, a twin screw extruder, a single screw extruder, a kneader, a Banbury mixer, or the like can be used. Among these, a twin screw extruder is preferable from the viewpoint of good shearing force and continuous productivity. The melt kneading temperature is usually 200 to 320 ° C. The melt kneading time is usually 0.5 to 30 minutes.

  By this dynamic crosslinking, the ethylene / α-olefin / non-conjugated polyene copolymer rubber [II] is crosslinked in the polyamide-based thermoplastic elastomer composition. That is, the polyamide-based thermoplastic elastomer composition includes an aliphatic polyamide [I], a copolymer rubber [II] crosslinked with a phenol resin-based crosslinking agent [IV], and a functional group structural unit of 0.3 to 5 Olefin polymer [III] containing 0.0 mass% and crosslinking aid [V] may be included. Then, an island phase (dispersion) mainly composed of a sea phase (matrix phase) mainly composed of aliphatic polyamide [I], a crosslinked copolymer rubber [II], and an olefin polymer [III]. A sea-island structure is formed. The sea phase (matrix phase) containing aliphatic polyamide [I] as a main component can exhibit thermoplasticity. On the other hand, the island phase (dispersed phase) composed mainly of the crosslinked copolymer rubber [II] and the olefin polymer [III] can exhibit rubber elasticity. The average particle size of the island phase (dispersed phase) is relatively small and finely dispersed. Such a thermoplastic elastomer composition may have good tensile strength and elongation at break while having good flexibility.

3. Molded products and their uses Molded products obtained by molding the above-mentioned polyamide-based thermoplastic elastomer composition can be used for various applications, such as automobile parts, building material parts, sports equipment, medical instrument parts, industrial parts, etc. It is useful as a molded article for various uses.

  Among them, the molded body obtained from the above-mentioned polyamide-based thermoplastic elastomer composition has high tensile strength and elongation at break while having good flexibility, so that it is a hollow molded body (industrial tube) or a specific one. Suitable for molded products obtained by molding methods (blow molding, two-color molding, etc.).

<Hollow molding (industrial tube)>
The industrial tube includes at least a layer containing the above-described polyamide-based thermoplastic elastomer composition. An industrial tube means a tube used in particular for industrial equipment. Examples of industrial tubes include tubes through which fluids (fuel, solvent, chemicals, gas, etc.) necessary for industrial equipment such as vehicles (for example, automobiles), pneumatic / hydraulic equipment, painting equipment, medical equipment, and the like are passed. In particular, it is very useful in applications such as tubes for vehicle piping (for example, fuel system tubes, intake system tubes, cooling system tubes), pneumatic tubes, hydraulic tubes, paint spray tubes, medical tubes (for example, catheters).

<Molded body obtained by injection molding, blow molding or two-color molding>
Molded articles obtained by injection molding, blow molding or two-color molding can be widely used in various applications (for example, automobiles and electrical products) that require such physical properties. Examples of molded products obtained by injection molding, blow molding or two-color molding include constant velocity joint boots, boot parts such as dust covers, oil seals, gaskets, packing, dust covers, valves, stoppers, precision seal rubber, weather strips Etc. Among them, a constant velocity joint boot for automobiles is preferable. As a method for producing a constant velocity joint boot for automobiles, a known method such as an injection molding method or a blow molding method (an injection blow molding method or a press blow molding method) can be employed.

  Among these, molded articles obtained by molding the above-mentioned polyamide-based thermoplastic elastomer composition are resins such as intake / exhaust system parts, automobile constant velocity joint boots, dust covers, and various boot parts. It is particularly useful as a material for the flexible boot made, preferably as an intake / exhaust system part.

  Examples of the intake / exhaust system parts include an air hose, an air duct, a turbo duct, a turbo hose, an intake manifold, or an exhaust manifold.

  In the following, the invention will be described in more detail with reference to examples. These examples do not limit the scope of the present invention.

1. Material <Aliphatic polyamide [I]>
I-1: Aliphatic polyamide (nylon 66, manufactured by Asahi Kasei Corporation, Leona 1700S, melting point: 265 ° C., terminal amino group amount: 6 mmol / kg, MFR: 5 g / 10 minutes)
I-2: Aliphatic polyamide (nylon 610, manufactured by Dupont, Zytel RS LC3060, melting point: 225 ° C., terminal amino group amount: 52 mmol / kg, MFR: 31 g / 10 min)
I-3: Aliphatic polyamide (nylon 6, manufactured by Toray Industries, Inc., Alamin CM1061, melting point 225 ° C., terminal amino group amount: 30 mmol / kg, MFR: 2 g / 10 min)
I-4: Aliphatic polyamide (nylon 610, manufactured by Arkema, Rilsan SMVO F, melting point 225 ° C., terminal amino group amount: 17 mmol / kg, MFR: 92 g / 10 min)

  The melting point, terminal amino group amount, and MFR (melt flow rate at 290 ° C. and 2.16 kg load according to ISO 1133) of the aliphatic polyamide [I] are values measured by the methods described above.

<Ethylene / α-olefin / non-conjugated polyene copolymer rubber [II]>
As copolymer rubber [II], ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber ([η] = 2.4 dl / g, ethylene content 65 mass%, diene content 4.6 mass%) is used. Prepared.

<Olefin polymer [III]>
As the olefin polymer [III], a modified polyolefin synthesized as follows was prepared.

First, 0.63 mg of bis (1,3-dimethylcyclopentadienyl) zirconium dichloride is placed in a glass flask sufficiently substituted with nitrogen, and a toluene solution of methylaminoxan (Al: 0.13 mmol / liter). An additional 57 ml and 2.43 ml of toluene were added to obtain a catalyst solution.
912 ml of hexane and 320 ml of 1-butene were introduced into a 2 liter stainless steel autoclave sufficiently purged with nitrogen, and the temperature inside the system was raised to 80 ° C. Subsequently, polymerization was started by injecting 0.9 mmol of triisobutylaluminum and 2.0 ml of the above catalyst solution (0.0005 mmol as Zr) with ethylene.
By continuously supplying ethylene, the total pressure was kept at 8.0 kg / cm ² -G, and polymerization was carried out at 80 ° C. for 30 minutes. A small amount of ethanol was introduced into the system to stop the polymerization, and then unreacted ethylene was purged. The obtained solution was put into a large excess of methanol to precipitate a white solid.
The white solid was collected by filtration and dried overnight under reduced pressure to obtain a white solid ethylene / 1-butene copolymer. The density of this ethylene / 1-butene copolymer is 0.862 g / cm ³ , the MFR (ASTM D1238 standard, 190 ° C., 2160 g load) is 0.5 g / 10 minutes, and the 1-butene structural unit content is 4 Mol%.
100 parts by mass of this ethylene / 1-butene copolymer was mixed with 1.0 part by mass of maleic anhydride and 0.04 parts by mass of peroxide (trade name Perhexin 25B, manufactured by NOF Corporation). The obtained mixture was melt-grafted with a single screw extruder set at 230 ° C. to obtain the maleic anhydride-modified ethylene / 1-butene copolymer.

The maleic anhydride-modified ethylene / 1-butene copolymer obtained had a maleic anhydride graft modification amount (functional group structural unit content) of 0.97% by mass, and the intrinsic viscosity measured in a 135 ° C. decalin solution [ η] was 1.98 dl / g. The content of the functional group structural unit was measured by the ¹³ CNMR method described above, and the intrinsic viscosity [η] was measured by the method described above.

<Phenolic resin crosslinking agent [IV]>
As a phenol resin-based cross-linking agent [IV], a flake brominated alkylphenol formaldehyde resin (manufactured by Taoka Chemical Industry Co., Ltd., trade name Tackol 250-III) is stirred for 10 seconds with a Henschel mixer and powdered. Prepared.

<Crosslinking aid [V]>
2 types of zinc oxide manufactured by Hakusui Tech Co., Ltd.

2. Preparation of polyamide-based thermoplastic elastomer composition <Example 1>
As aliphatic polyamide [I] -A, 30% by mass of aliphatic polyamide [I-2] (polyamide 610) and as aliphatic polyamide [I] -B, aliphatic polyamide [I-1] (polyamide 66) 10% by mass of the copolymer rubber [II], 45% by mass of the ethylene / propylene / 5-ethylidene-2-norbornene copolymer rubber, and the synthesized maleic anhydride modified as the olefin polymer [III]. 12% by mass of an ethylene / 1-butene copolymer, 3% by mass of the brominated alkylphenol formaldehyde resin, which was stirred for 10 seconds with a Henschel mixer as a phenol resin-based crosslinking agent [IV], And as a small amount of crosslinking aid [V], two types of the above zinc oxide were premixed, and this was mixed with a twin-screw extruder (manufactured by Nippon Steel Works, TEX). Supplied to 30), a cylinder temperature of 280 ° C., at a screw rotation speed 300 rpm, and melt-kneaded. Strands extruded from this twin-screw extruder were cut to obtain polyamide thermoplastic elastomer composition pellets.

<Examples 2-4, Comparative Examples 1-6>
Except having changed into the composition shown in Table 1, it carried out similarly to Example 1, and obtained the pellet of the polyamide-type thermoplastic elastomer composition.

  The bending properties (bending strength, bending elastic modulus) and tensile properties (tensile strength and tensile elongation) of the polyamide-based thermoplastic elastomer compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 6 were respectively determined by the following methods. Measured with

(Bending strength / flexural modulus)
The polyamide-based thermoplastic elastomer resin composition was molded under the following molding conditions using the following injection molding machine to obtain a test piece having a length of 63.5 mm, a width of 12.5 mm, and a thickness of 3.2 mm.
Molding machine: Nissei Plastic Industry Co., Ltd. EP5 injection molding machine Molding machine cylinder temperature: 280 ° C
Mold temperature: 80 ℃
The obtained test piece was allowed to stand for 24 hours in a nitrogen atmosphere at a temperature of 23 ° C. Next, a bending test was performed in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, and bending strength (MPa) and bending elastic modulus (MPa) were measured.

(Tensile strength / tensile elongation)
The polyamide-based thermoplastic elastomer resin composition was molded under the following molding conditions using the following injection molding machine to obtain a dumbbell test piece having a length of 63.5 mm, a width of 3 mm, and a thickness of 3.2 mm.
Molding machine: Nissei Plastic Industry Co., Ltd. EP5 type injection molding machine Molding machine cylinder temperature: 280 ° C
Mold temperature: 80 ℃
The obtained test piece was allowed to stand for 24 hours in a nitrogen atmosphere at a temperature of 23 ° C. Next, a tensile test was performed in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, and the tensile strength (MPa) and the elongation (%) were measured.

  The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 6 are shown in Table 1.

As shown in Table 1, the thermoplastic elastomer compositions of Examples 1 to 3 in which two types of aliphatic polyamides having different compositions with an MFR difference of 30 g / 10 min or less were combined were one type of aliphatic Bending strength equivalent to the thermoplastic elastomer composition of Comparative Examples 1 and 2 using polyamide and the thermoplastic elastomer composition of Comparative Example 5 in which two types of aliphatic polyamides having a difference in ΔMFR exceeding 30 g / 10 min are combined It can be seen that it has a high elongation at break while having a tensile strength.
Similarly, the thermoplastic elastomer composition of Example 4 in which two types of aliphatic polyamides having different compositions with an MFR difference of 30 g / 10 min or less were combined was used in Comparative Example 2 in which one type of aliphatic polyamide was used. While having the same bending strength and tensile strength as the thermoplastic elastomer composition of Comparative Example 6 and the thermoplastic elastomer composition of Comparative Example 6 in which two types of aliphatic polyamides having a difference in ΔMFR of more than 30 g / 10 minutes are combined. It can be seen that they have higher elongation at break than those.

  In particular, when aliphatic polyamide [I] -A having a relatively high melt flow rate (MFR) is contained more than aliphatic polyamide [I] -B having a relatively low melt flow rate (MFR). It can be seen that the elongation at break of the resulting thermoplastic elastomer composition is further increased (contrast with Examples 1 to 3).

  According to the present invention, it is possible to provide a polyamide-based thermoplastic elastomer composition that can give a molded article having high elongation at break while having flexibility and good tensile strength.

Claims (11)

At least two aliphatic polyamides [I] having a melting point (Tm) measured by differential scanning calorimetry (DSC) of 150 to 290 ° C. and different compositions;
Non-conjugated polyene having an ethylene structural unit [a], an α-olefin structural unit [b] having 3 to 20 carbon atoms, and at least one carbon-carbon double bond polymerizable by a metallocene catalyst in one molecule. An ethylene / α-olefin / non-conjugated polyene copolymer rubber [II] containing a structural unit [c];
An olefin polymer [III] containing 0.3 to 5.0% by mass of a functional group structural unit;
A polyamide-based thermoplastic elastomer composition which is a crosslinked product of a rubber composition containing a phenol resin-based crosslinking agent [IV],
The difference in melt flow rate (MFR) at 290 ° C. under a load of 2.16 kg according to ISO 1133 between the at least two aliphatic polyamides [I] is 30 g / 10 minutes or less.
A polyamide-based thermoplastic elastomer composition. The at least two kinds of aliphatic polyamides [I] are aliphatic polyamides containing dicarboxylic acid units having 6 to 12 carbon atoms and diamine units having 4 to 12 carbon atoms, lactams having 6 to 12 carbon atoms, or amino acids. Selected from the group consisting of aliphatic polyamides containing carboxylic acid units,
The polyamide-based thermoplastic elastomer composition according to claim 1. The at least two aliphatic polyamides [I] are polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 66, polyamide 69, polyamide 910, polyamide 912, polyamide 116, polyamide 610, and polyamide 612. Selected from the group consisting of polyamide 1010,
The polyamide-based thermoplastic elastomer composition according to claim 1 or 2. The at least two types of aliphatic polyamides [I] include the aliphatic polyamide [I] -A having a relatively high melt flow rate (MFR) and the aliphatic polyamide having a relatively low melt flow rate (MFR). [I] -B,
The aliphatic polyamide [I] -A is contained more than the aliphatic polyamide [I] -B.
The polyamide-type thermoplastic elastomer composition as described in any one of Claims 1-3. The at least two aliphatic polyamides [I] are polyamide 610 and polyamide 66.
The polyamide-type thermoplastic elastomer composition as described in any one of Claims 1-4. The functional group structural unit of the olefin polymer [III] includes a structural unit derived from one or more functional groups selected from the group consisting of a carboxylic acid group, an ester group, an ether group, an aldehyde group, and a ketone group.
The polyamide-type thermoplastic elastomer composition as described in any one of Claims 1-5. The functional group structural unit of the olefin polymer [III] is a maleic anhydride structural unit.
The polyamide-based thermoplastic elastomer composition according to claim 6. The total of the at least two aliphatic polyamides [I], the ethylene / α-olefin / non-conjugated polyene copolymer rubber [II], the olefin polymer [III], and the phenol resin crosslinking agent [IV]. Is 100 parts by mass,
A total of 10 to 60 parts by mass of the at least two aliphatic polyamides [I],
33 to 86 parts by mass of the ethylene / α-olefin / non-conjugated polyene copolymer rubber [II],
0.1 to 30 parts by mass of the olefin polymer [III],
Including 1 to 10 parts by mass of the phenol resin-based crosslinking agent [IV],
The polyamide-type thermoplastic elastomer composition as described in any one of Claims 1-7. Obtained from the polyamide-based thermoplastic elastomer composition according to any one of claims 1 to 8,
Molded body. Obtained from the polyamide-based thermoplastic elastomer composition according to any one of claims 1 to 8,
Hollow molded body. The hollow molded body is an automobile-related part.
The hollow molded body according to claim 10.