WO2017115699A1 - Polyamide resin composition - Google Patents

Abstract

A polyamide resin composition which, even when kept in contact with a liquid chemical for a long time under high-temperature conditions, suffers no decrease in mechanical strength and has high durability and which is suitable for forming tubes, connectors, and the like for conveying various liquid chemicals. The polyamide resin composition is obtained by compounding a polyamide, a monocarbodiimide, and a polycarbodiimide.

Description

Polyamide resin composition

The present invention relates to a polyamide resin composition.

Polyamide resins are excellent in strength, heat resistance, chemical resistance, and the like, and have been conventionally used in automobile mechanism parts such as automobile fuel pipes and fuel pipe joints (connectors). For example, a polyamide resin composition is also used for the innermost layer of various chemical liquid transport tubes such as a long life coolant (hereinafter referred to as “LLC”) used for cooling an automobile engine and a tube for circulating a refrigerant for cooling an air conditioner.
In the case of a tube used as a refrigerant for an air conditioner, the innermost layer of the tube is hydrolyzed by a carboxylic acid generated by hydrolysis of a lubricant such as ester oil in the refrigerant, or a phosphate ester additive in the refrigerant. It is exposed to phosphoric acid etc. which arise by doing. Further, when the innermost layer of the tube is composed of a polyamide resin composition, it is also exposed to an acid derived from a terminal carboxyl group in the polyamide or a carboxyl group generated by hydrolysis of the polyamide. Accordingly, the material constituting the innermost layer of the chemical solution transport tube is required to have high acid hydrolysis resistance.

Polyamide resin compositions in which a polycarbodiimide compound is added to polyamide to improve the hydrolysis resistance of polyamide are known (see Patent Documents 1 to 4). However, it is necessary that the polyamide resin composition used for the innermost layer of the chemical solution transporting tube does not deteriorate even if it is brought into contact with the chemical solution for a long time. For this purpose, it is desired to further improve hydrolysis resistance. In particular, since the tube used in an automobile becomes a high temperature during use, high durability is required so that the mechanical strength does not decrease even when the tube is brought into contact with a LLC or air conditioner refrigerant for a long time under a high temperature condition.

Japanese Unexamined Patent Publication No. 6-16933 JP-A-9-328609 JP 11-343408 A JP 2011-38607 A

In view of the above circumstances, an object of the present invention is to provide a polyamide resin composition which is excellent in chemical resistance and suitable for forming various chemical transport tubes, connectors and the like.

The present inventors have found that the above problems can be solved by using a polyamide resin composition in which a predetermined carbodiimide is blended with polyamide.
That is, the present invention relates to the following [1] to [18].
[1] A polyamide resin composition comprising a polyamide (A), a monocarbodiimide (B1), and a polycarbodiimide (B2).
[2] The amount of the monocarbodiimide (B1) and the polycarbodiimide (B2) in the polyamide resin composition is 0.5 to 25 parts by mass with respect to 100 parts by mass of the polyamide (A). ] Polyamide resin composition.
[3] The polyamide resin according to [1] or [2], wherein the mass ratio (B1) / (B2) of the monocarbodiimide (B1) to the polycarbodiimide (B2) is 1: 0.1 to 1:10. Composition.
[4] The polyamide resin composition according to any one of the above [1] to [3], wherein the monocarbodiimide (B1) is an aromatic monocarbodiimide.
[5] The polyamide resin composition according to any one of [1] to [4], wherein the polycarbodiimide (B2) is an aromatic polycarbodiimide.
[6] The polyamide resin composition according to any one of [1] to [4], wherein the polycarbodiimide (B2) is an aliphatic polycarbodiimide.
[7] The polyamide resin composition according to any one of [1] to [6], wherein the polyamide (A) has a terminal amino group content of 5 to 60 μmol / g.
[8] The polyamide (A) includes a dicarboxylic acid unit containing 50 to 100 mol% of an aromatic dicarboxylic acid unit and a diamine unit containing 60 to 100 mol% of an aliphatic diamine unit having 6 to 13 carbon atoms. 8. The polyamide resin composition according to any one of [1] to [7], which is a semi-aromatic polyamide.
[9] The polyamide resin composition according to [8], wherein the semiaromatic polyamide further contains an aminocarboxylic acid unit and / or a lactam unit.
[10] The aromatic dicarboxylic acid unit is a terephthalic acid unit and / or a naphthalene dicarboxylic acid unit, and the aliphatic diamine unit is a 1,9-nonanediamine unit, a 2-methyl-1,8-octanediamine unit, and 1, The polyamide resin composition according to the above [8] or [9], which is at least one selected from the group consisting of 10-decanediamine units.
[11] The polyamide resin composition according to the above [10], wherein the aliphatic diamine unit is a 1,9-nonanediamine unit and / or a 2-methyl-1,8-octanediamine unit.
[12] The polyamide resin composition according to any one of [1] to [11], further comprising an elastomer (C).
[13] The elastomer (C) is an α-olefin copolymer, (ethylene and / or propylene) / (α, β-unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) copolymer, ionomer, It is at least one selected from the group consisting of an aromatic vinyl compound / conjugated diene compound block copolymer, and a polymer obtained by modifying these with an unsaturated compound having a carboxyl group and / or an acid anhydride group. 12] polyamide resin composition.
[14] The polyamide resin composition according to any one of [1] to [13], further comprising a step of melt-kneading a mixture containing the polyamide (A), the monocarbodiimide (B1), and the polycarbodiimide (B2). Manufacturing method.
[15] A chemical transport tube having at least one layer composed of the polyamide resin composition according to any one of [1] to [13].
[16] The chemical solution according to [15], wherein the chemical solution transport tube is a single-layer tube made of the polyamide resin composition or a multilayer tube having at least an innermost layer made of the polyamide resin composition. Transport tube.
[17] The chemical solution transport tube according to [15] or [16], wherein the chemical solution is at least one selected from the group consisting of an engine cooling refrigerant, an air conditioner refrigerant, and a reducing agent solution for a selective catalytic reduction system. .
[18] A connector comprising the polyamide resin composition according to any one of [1] to [13].

According to the present invention, a polyamide resin composition having excellent chemical resistance can be provided. The polyamide resin composition is a selective catalytic reduction (hereinafter also referred to as “SCR”) system for purifying nitrogen oxides in exhaust gas from engine cooling refrigerant, air conditioner refrigerant, diesel engine exhaust, etc. It is suitably used for tubes for transporting various chemicals such as reducing agent solutions, oils, fuels, connectors, intake pipes, blow-by tubes, and the like.

[Polyamide resin composition]
The polyamide resin composition of the present invention is a composition formed by blending polyamide (A), monocarbodiimide (B1), and polycarbodiimide (B2). The resin composition exhibits high chemical resistance by using two types of carbodiimides (B1) and (B2) in combination.
Carbodiimide enhances hydrolysis resistance of polyamide by sealing or capturing acid derived from components in chemicals or acid derived from polyamide, and bonding the ends of the molecular chain of polyamide to increase molecular weight. It is considered that chemical resistance is improved. Conventionally, carbodiimide is known as a hydrolysis resistance improver for thermoplastic resins such as polyamide. In the case of a thermoplastic resin having a low melting point (for example, less than 180 ° C.), it is also possible to use monocarbodiimide having low thermal stability as a hydrolysis resistance improver. However, among thermoplastic resins, polyamide has a high melting point, so generally, monocarbodiimide with low thermal stability is not applied as a hydrolysis resistance improver used at the time of compounding polyamide, and polycarbodiimide is used. I came.
However, the present inventors have found that a resin composition in which only polycarbodiimide is blended with polyamide is not always sufficient in improving chemical resistance, and that even better chemical resistance can be obtained by using monocarbodiimide in combination. .
If the chemical resistance is improved by simply increasing the amount of carbodiimide added to the polyamide, polycarbodiimide is considered to have high thermal stability and a high molecular chain extension effect without using monocarbodiimide. It would be advantageous to use only. However, the present inventors have confirmed that the chemical resistance is not sufficiently improved by simply increasing the amount of carbodiimide in the polyamide resin composition.
The reason why the above effect is obtained by the present invention is not clear, but during the compounding process of the polyamide, monocarbodiimide having high reactivity and low thermal stability is suitably added to the terminal carboxyl of the polyamide prior to polycarbodiimide. It is conceivable that the chemical resistance is improved while the mechanical properties derived from the polyamide are maintained by sealing the group.

As a method for reducing the hydrolysis of the polyamide resin composition, a method of reducing the terminal carboxyl group content of the polyamide and increasing the terminal amino group content is also conceivable. However, for example, when the acid-modified elastomer described later as the elastomer (C) is blended with the polyamide resin composition, if the amount of terminal amino groups of the polyamide is excessively increased, the terminal amino groups react with the acid-modified portion of the elastomer. There was also a concern that it would be too cross-linked and gelled. However, according to the present invention, it is possible to avoid the possibility of such a problem.

Hereinafter, each component used for the polyamide resin composition of this invention is demonstrated.
<Polyamide (A)>
The polyamide (A) used in the present invention is not particularly limited, and examples thereof include aromatic polyamides and aliphatic polyamides. Examples of the aromatic polyamide include wholly aromatic polyamides and semi-aromatic polyamides.
Among these, from the viewpoint of imparting high chemical resistance and heat resistance, the polyamide (A) is preferably an aromatic polyamide, and from the viewpoint of chemical resistance, heat resistance, and moldability, a semi-aromatic polyamide is more preferable. Hereinafter, the semi-aromatic polyamide will be described.

(Semi-aromatic polyamide)
In the present invention, the semi-aromatic polyamide means a polyamide containing a dicarboxylic acid unit containing an aromatic dicarboxylic acid unit as a main component and a diamine unit containing an aliphatic diamine unit as a main component, or an aliphatic dicarboxylic acid unit as a main component. Polyamide containing a dicarboxylic acid unit as a component and a diamine unit having an aromatic diamine unit as a main component. Here, “main component” refers to constituting 50 to 100 mol%, preferably 60 to 100 mol%, of all units.
As the polyamide (A) used in the present invention, among semi-aromatic polyamides, a polyamide containing a dicarboxylic acid unit having an aromatic dicarboxylic acid unit as a main component and a diamine unit having an aliphatic diamine unit as a main component is preferable. A semi-aromatic polyamide containing a dicarboxylic acid unit containing 50 to 100 mol% of an aromatic dicarboxylic acid unit and a diamine unit containing 60 to 100 mol% of an aliphatic diamine unit having 6 to 13 carbon atoms is more preferred. Hereinafter, the semi-aromatic polyamide will be described in more detail.

The dicarboxylic acid unit constituting the semiaromatic polyamide preferably contains 50 to 100 mol% of the aromatic dicarboxylic acid unit from the viewpoint of becoming a semiaromatic polyamide having good chemical resistance and heat resistance. The content of the aromatic dicarboxylic acid unit in the dicarboxylic acid unit is more preferably in the range of 75 to 100 mol%, and further preferably in the range of 90 to 100 mol%.
Aromatic dicarboxylic acid units include terephthalic acid units, naphthalenedicarboxylic acid units, isophthalic acid units, 1,4-phenylenedioxydiacetic acid units, 1,3-phenylenedioxydiacetic acid units, diphenic acid units, diphenylmethane-4 4,4′-dicarboxylic acid unit, diphenylsulfone-4,4′-dicarboxylic acid unit, 4,4′-biphenyldicarboxylic acid unit, and the like. Examples of the naphthalenedicarboxylic acid unit include units derived from 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 1,4-naphthalenedicarboxylic acid, and the 2,6-naphthalenedicarboxylic acid unit includes preferable.
Among these, the aromatic dicarboxylic acid unit is preferably a terephthalic acid unit and / or a naphthalene dicarboxylic acid unit, and more preferably a terephthalic acid unit.

The dicarboxylic acid unit constituting the semi-aromatic polyamide may contain a dicarboxylic acid unit other than the aromatic dicarboxylic acid unit, preferably in the range of 50 mol% or less. Examples of such other dicarboxylic acid units include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 2, Units derived from 2-diethylsuccinic acid, azelaic acid, sebacic acid, suberic acid and other aliphatic dicarboxylic acids; 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids; And one or more of these may be included. The content of these other dicarboxylic acid units in the dicarboxylic acid unit is preferably 25 mol% or less, and more preferably 10 mol% or less. The semi-aromatic polyamide used in the present invention may further contain a unit derived from a polyvalent carboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid within a range that allows melt molding.

The diamine unit constituting the semi-aromatic polyamide preferably contains 60 to 100 mol% of an aliphatic diamine unit having 6 to 13 carbon atoms. When the polyamide (A) containing an aliphatic diamine unit having 6 to 13 carbon atoms in this proportion is used, a polyamide resin composition excellent in toughness, slidability, heat resistance, moldability, low water absorption and lightness can be obtained. can get. The content of the aliphatic diamine unit having 6 to 13 carbon atoms in the diamine unit is more preferably in the range of 75 to 100 mol%, and further preferably in the range of 90 to 100 mol%.

Examples of the aliphatic diamine unit having 6 to 13 carbon atoms include 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine. Linear aliphatic diamines such as 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine; 2-methyl-1,5-pentanediamine, 3-methyl-1,5- Pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1, Examples thereof include units derived from branched aliphatic diamines such as 9-nonanediamine; and one or more of these units can be included.

The aliphatic diamine unit having 6 to 13 carbon atoms is at least one selected from the group consisting of a 1,9-nonanediamine unit, a 2-methyl-1,8-octanediamine unit, and a 1,10-decanediamine unit. More preferably, since a polyamide resin composition that is more excellent in heat resistance, low water absorption and chemical resistance can be obtained, it is possible to use 1,9-nonanediamine units and / or 2-methyl-1,8-octanediamine units. More preferred are 1,9-nonanediamine units and 2-methyl-1,8-octanediamine units. When the diamine unit includes both a 1,9-nonanediamine unit and a 2-methyl-1,8-octanediamine unit, the molar ratio of the 1,9-nonanediamine unit to the 2-methyl-1,8-octanediamine unit is 1,9-nonanediamine unit / 2-methyl-1,8-octanediamine unit = preferably in the range of 95/5 to 40/60, more preferably in the range of 90/10 to 40/60. 80/20 to 40/60 is more preferable.

The diamine unit constituting the semi-aromatic polyamide may contain a diamine unit other than the aliphatic diamine unit having 6 to 13 carbon atoms, preferably in the range of 40 mol% or less. Examples of such other diamine units include ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, and 2-methyl-1,3-propanediamine. Aliphatic diamines having 5 or less carbon atoms such as 2-methyl-1,4-butanediamine; cycloaliphatic diamines such as cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine; p-phenylenediamine, m-phenylenediamine, xylylenediamine Examples include units derived from aromatic diamines such as amines, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenyl ether, and one or two of these units. More than species can be included. The content of these other diamine units in the diamine unit is preferably 25 mol% or less, and more preferably 10 mol% or less.

The semi-aromatic polyamide may further contain an aminocarboxylic acid unit and / or a lactam unit as long as the effects of the present invention are not impaired.
Examples of the aminocarboxylic acid unit include units derived from 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like, and two or more aminocarboxylic acid units may be included. The content of aminocarboxylic acid units in the polyamide (A) is preferably 40 mol% or less, more preferably 20 mol% or less, based on 100 mol% of all monomer units constituting the polyamide (A). Preferably, it is 10 mol% or less.

Examples of the lactam unit include units derived from ε-caprolactam, enantolactam, undecane lactam, lauryl lactam, α-pyrrolidone, α-piperidone, etc., and two or more lactam units are included. It may be. The content of lactam units in the semiaromatic polyamide is preferably 40 mol% or less, more preferably 20 mol% or less, with respect to 100 mol% of all monomer units constituting the semiaromatic polyamide, More preferably, it is 10 mol% or less.

As a typical semi-aromatic polyamide containing a dicarboxylic acid unit mainly composed of an aromatic dicarboxylic acid unit and a diamine unit mainly composed of an aliphatic diamine unit having 6 to 13 carbon atoms, polyhexamethylene terephthalamide may be used. (Polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T), polyhexamethylene isophthalamide (polyamide 6I), a copolymer of polyamide 6I and polyamide 6T (polyamide 6I / 6T) ), And a copolymer of polyamide 6T and polyundecanamide (polyamide 11) (polyamide 6T / 11). Among these, at least one selected from the group consisting of polyamide 6T / 11, polynonamethylene terephthalamide (polyamide 9T) and polydecamethylene terephthalamide (polyamide 10T) is preferable, and polynonamethylene terephthalamide (polyamide 9T) and At least one selected from the group consisting of polydecamethylene terephthalamide (polyamide 10T) is more preferable, and polynonamethylene terephthalamide (polyamide 9T) is more preferable.

On the other hand, among the semi-aromatic polyamides, for the semi-aromatic polyamide containing a dicarboxylic acid unit having an aliphatic dicarboxylic acid unit as a main component and a diamine unit having an aromatic diamine unit as a main component, an aliphatic dicarboxylic acid unit is used. Can include units derived from the aforementioned aliphatic dicarboxylic acids, and can include one or more of these units. Moreover, as an aromatic diamine unit, the unit induced | guided | derived from the aromatic diamine mentioned above can be mentioned, The 1 type (s) or 2 or more types of these can be included. In addition, other units may be included within the range not impairing the effects of the present invention.
Typical semi-aromatic polyamides containing a dicarboxylic acid unit having an aliphatic dicarboxylic acid unit as a main component and a diamine unit having an aromatic diamine unit as a main component include polymetaxylylene adipamide (MXD6), poly And paraxylylene sebacamide (PXD10).
The said semi-aromatic polyamide can use 1 type (s) or 2 or more types.

The polyamide (A) blended in the polyamide resin composition of the present invention is preferably composed only of a semi-aromatic polyamide, but a polyamide other than a semi-aromatic polyamide such as wholly aromatic polyamide or aliphatic polyamide is used in combination. May be. The content of polyamide other than the semi-aromatic polyamide in the polyamide (A) is preferably 20% by mass or less, more preferably 10% by mass or less.

(Totally aromatic polyamide)
The wholly aromatic polyamide refers to a polyamide containing a dicarboxylic acid unit having an aromatic dicarboxylic acid unit as a main component and a diamine unit having an aromatic diamine unit as a main component. Examples of the aromatic dicarboxylic acid unit and the aromatic diamine unit are the same as those exemplified in the aforementioned semi-aromatic polyamide.
As fully aromatic polyamides, polyparaphenylene terephthalamide, polymetaphenylene isophthalamide, polymetaxylylene isophthalamide (MXDI), terephthalic acid component, 3,4'-diaminodiphenyl ether component and paraphenylenediamine component are copolymerized And poly (paraphenylene • 3,4′-oxydiphenylene terephthalamide).

(Aliphatic polyamide)
The aliphatic polyamide is a polyamide composed of an aliphatic polyamide-forming unit. Specifically, a lactam, an aminocarboxylic acid, or a nylon salt composed of an aliphatic diamine and an aliphatic dicarboxylic acid as a raw material is used for melt polymerization, solution polymerization, It can be obtained by polymerization or copolymerization by a known method such as solid phase polymerization.

Examples of the lactam include those similar to those exemplified in the aforementioned lactam unit, such as ε-caprolactam, enantolactam, undecane lactam, lauryl lactam, α-pyrrolidone and α-piperidone. Examples of the aminocarboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and the like. These can use 1 type (s) or 2 or more types.

Examples of the aliphatic diamine constituting the nylon salt include ethylenediamine, 1,3-propylenediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1, 8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,15 -Pentadecanediamine, 1,16-hexadecanediamine, 1,17-heptadecanediamine, 1,18-octadecanediamine, 1,19-nonadecanediamine, 1,20-eicosanediamine, 2 / 3-methyl-1, 5-pentanediamine, 2-methyl-1,8-octanediamine, 2,2, / 2,4,4-trimethyl-1,6-hexanediamine, 5-methyl-1,9-nonanediamine or the like. These can use 1 type (s) or 2 or more types.

Examples of the aliphatic dicarboxylic acid constituting the nylon salt include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, pentadecanedicarboxylic acid, hexadecanedicarboxylic acid. An acid, octadecanedicarboxylic acid, eicosane dicarboxylic acid, etc. are mentioned. These can use 1 type (s) or 2 or more types.

Examples of aliphatic polyamides include polycaproamide (polyamide 6), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), polyethylene adipamide (polyamide 26), polytetramethylene adipamide (polyamide 46), Polyhexamethylene adipamide (Polyamide 66), Polyhexamethylene azelamide (Polyamide 69), Polyhexamethylene sebamide (Polyamide 610), Polyhexamethylene undecamide (Polyamide 611), Polyhexamethylene dodecamide (Polyamide) 612), polynonamethylene adipamide (polyamide 96), polynonamethylene azelamide (polyamide 99), polynonamethylene sebamide (polyamide 910), polynonamethylene undecamide (polyamide 911). Polynonamethylene dodecamide (polyamide 912), polydecamethylene adipamide (polyamide 106), polydecamethylene azelamide (polyamide 109), polydecamethylene sebamide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012) ), Polydodecamethylene adipamide (polyamide 126), polydodecamethylene azelamide (polyamide 129), polydodecamethylene sebamide (polyamide 1210), polydodecamethylene dodecamide (polyamide 1212), and the like, Examples thereof include copolymers using several kinds of raw material monomers that form these.

Among these, it is selected from polycaproamide (polyamide 6), polyhexamethylene adipamide (polyamide 66), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), and polyhexamethylene dodecanamide (polyamide 612). And at least one homopolymer selected from the group consisting of polycaproamide (polyamide 6) and polydodecanamide (polyamide 12) is more preferable.

In the polyamide (A), it is preferable that 10% or more of the end groups of the molecular chain are sealed with an end-capping agent. When a polyamide (A) having a terminal blocking rate of 10% or more is used, a polyamide resin composition having more excellent physical properties such as melt stability and hot water resistance can be obtained. On the other hand, when an acid-modified elastomer is used as the elastomer (C) described later, from the viewpoint of reacting the acid-modified portion of the elastomer with the end group of the polyamide (A), the above-mentioned end capping rate is preferably 100%. Is less than.

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 end of the polyamide, but from the viewpoint of reactivity and stability of the capping end, Carboxylic acid or monoamine is preferable, and monocarboxylic acid is more preferable from the viewpoint of easy handling. In addition, monoisocyanates, monoacid halides, monoesters, monoalcohols, and the like can also be used as the end-capping agent.

The monocarboxylic acid used as the end-capping agent is not particularly limited as long as it has reactivity with an amino group. For example, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, laurin Aliphatic monocarboxylic acids such as acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid and isobutyric acid; cycloaliphatic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α-naphthalenecarboxylic acid , Β-naphthalene carboxylic acid, methyl naphthalene carboxylic acid, aromatic monocarboxylic acid such as phenyl acetic acid; any mixtures thereof. Among these, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearin, etc. Acid and benzoic acid are preferable, and benzoic acid is more preferable.

The monoamine used as the end-capping agent is not particularly limited as long as it has reactivity with a carboxyl group. For example, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearyl Aliphatic monoamines such as amine, dimethylamine, diethylamine, dipropylamine and dibutylamine; Cycloaliphatic monoamines such as cyclohexylamine and dicyclohexylamine; Aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine; any mixtures thereof Can be mentioned. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferable from the viewpoints of reactivity, boiling point, sealing end stability, price, and the like.

The terminal blocking rate of the polyamide (A) was determined by measuring the number of terminal carboxyl groups, terminal amino groups, and terminal groups blocked by the terminal blocking agent present in the polyamide (A), respectively, by the following formula ( It is obtained according to 1). The number of each end group is preferably determined from the integral value of the characteristic signal corresponding to each end group by ¹ H-NMR in terms of accuracy and simplicity.
Terminal sealing rate (%) = [(TS) / T] × 100 (1)
[Wherein T represents the total number of terminal groups of the molecular chain of the polyamide (A) (this is usually equal to twice the number of polyamide molecules), and S is the terminal carboxyl group and terminal remaining unblocked. Represents the total number of amino groups. ]

Polyamide (A) can be produced using any method known as a method for producing polyamide. For example, in the case of a polyamide containing a dicarboxylic acid unit and a diamine unit, a solution polymerization method or an interfacial polymerization method using an acid chloride and a diamine as raw materials, a melt polymerization method using a dicarboxylic acid and a diamine as raw materials, a solid phase polymerization method, a melting method It can be produced by a method such as extrusion polymerization.

When producing the polyamide (A), phosphoric acid, phosphorous acid, hypophosphorous acid, their salts or esters can be added as a catalyst. Examples of the salt or ester include phosphoric acid, phosphorous acid or hypophosphorous acid, potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, antimony, and the like. Salt with metal; ammonium salt of phosphoric acid, phosphorous acid or hypophosphorous acid; ethyl ester, isopropyl ester, butyl ester, hexyl ester, isodecyl ester, decyl of phosphoric acid, phosphorous acid or hypophosphorous acid Examples thereof include esters, stearyl esters, and phenyl esters. Of these, sodium hypophosphite and phosphorous acid are preferable because they are inexpensive and have a small amount of triamine.

The polyamide (A) preferably has an intrinsic viscosity [η] measured in concentrated sulfuric acid at 30 ° C. in the range of 0.6 to 2.0 dL / g, 0.7 to 1.9 dL / g More preferably, it is in the range of g, more preferably in the range of 0.8 to 1.8 dL / g. If the polyamide (A) having an intrinsic viscosity of 0.6 dL / g or more is used, the mechanical properties are improved. Moreover, if polyamide (A) whose intrinsic viscosity is 2.0 dL / g or less is used, the moldability of the obtained polyamide resin composition is favorable.

The polyamide (A) has a terminal amino group content ([NH ₂ ]) of preferably 5 to 60 μmol / g, more preferably 5 to 50 μmol / g, and more preferably 5 to 30 μmol. More preferably, it is in the range of / g. When the terminal amino group content ([NH ₂ ]) is 5 μmol / g or more, the compatibility between the polyamide (A) and the elastomer (C) described later is good. Further, when the terminal amino group content is 60 μmol / g or less, when an acid-modified elastomer described later is used as the elastomer (C), the terminal amino group and the modified part of the elastomer are excessively reacted and gelled. Can be avoided.
The terminal amino group content ([NH ₂ ]) as used herein refers to the amount of terminal amino groups (unit: μmol) contained in 1 g of the polyamide (A), and is based on the neutralization titration method using an indicator. Can be sought.

A polyamide (A) containing a dicarboxylic acid unit and a diamine unit and having a terminal amino group content ([NH ₂ ]) in the above-described range can be produced, for example, as follows.
First, a dicarboxylic acid, a diamine, and optionally an aminocarboxylic acid, a lactam, a catalyst, and a terminal blocking agent are mixed to produce a nylon salt. At this time, the number of moles (X) of all carboxyl groups and the number of moles (Y) of all amino groups contained in the reaction raw material are represented by the following formula (2)
−0.5 ≦ [(Y−X) / Y] × 100 ≦ 2.0 (2)
Is satisfied, it is easy to produce a polyamide (A) having a terminal amino group content ([NH ₂ ]) of 5 to 60 μmol / g, which is preferable. Next, the produced nylon salt is heated to a temperature of 200 to 250 ° C. to obtain a prepolymer having an intrinsic viscosity [η] at 30 ° C. in concentrated sulfuric acid of 0.10 to 0.60 dL / g, and the degree of polymerization is further increased. Thus, the polyamide (A) used in the present invention can be obtained. When the intrinsic viscosity [η] of the prepolymer is in the range of 0.10 to 0.60 dL / g, there is little shift in the molar balance of carboxyl groups and amino groups and a decrease in polymerization rate at the stage of increasing the degree of polymerization. Furthermore, polyamide (A) excellent in various performance and moldability with a small molecular weight distribution can be obtained. When the polymerization degree is increased by the solid phase polymerization method, it is preferably performed under reduced pressure or under an inert gas flow. When the polymerization temperature is in the range of 200 to 280 ° C., the polymerization rate is high and the productivity is increased. And can effectively suppress coloring and gelation. Further, when the polymerization degree is increased by a melt extruder, the polymerization temperature is preferably 370 ° C. or less. When polymerization is performed under such conditions, polyamide is hardly decomposed and polyamide (A) having little deterioration. Is obtained.

Also, the terminal amino group content ([NH _2]) is also by combining a plurality of different kinds of polyamides, it may be polyamide (A) having a terminal amino group content of the desired ([NH _2]).

The blending amount of the polyamide (A) in the polyamide resin composition of the present invention is preferably 50% by mass or more, more preferably 55% by mass or more from the viewpoint of imparting chemical resistance, heat resistance and mechanical strength. More preferably, it is 60% by mass or more, more preferably 70% by mass or more. Further, from the viewpoint of improving the chemical resistance by blending the monocarbodiimide (B1) and the polycarbodiimide (B2), the blending amount of the polyamide (A) in the polyamide resin composition is preferably 99.5% by mass or less. More preferably, it is 99 mass% or less.

<Monocarbodiimide (B1)>
The monocarbodiimide (B1) used in the present invention is a compound having one carbodiimide group represented by —N═C═N— in the molecule, and examples thereof include compounds represented by the following general formula (I). .
R ¹ —N═C═N—R ² (I)
In general formula (I), R ¹ and R ² each independently represent a monovalent hydrocarbon group. Examples of the hydrocarbon group include a chain aliphatic group, an alicyclic structure-containing aliphatic group, and an aromatic ring-containing group. The chain aliphatic group and the alicyclic structure-containing aliphatic group are preferably saturated aliphatic groups. The chain aliphatic group preferably has 3 or more carbon atoms, more preferably 3 to 20, more preferably 3 to 12, and the alicyclic structure-containing aliphatic group and aromatic ring-containing group preferably have 5 carbon atoms. More preferably, it is 6-20, and more preferably 6-12. Moreover, the said hydrocarbon group may have substituents, such as an amino group, a hydroxyl group, and an alkoxy group. R ¹ and R ² may be different from each other but are preferably the same.
Examples of the monocarbodiimide (B1) include aliphatic monocarbodiimides, aromatic monocarbodiimides, and mixtures thereof.

The aliphatic monocarbodiimide is preferably a carbodiimide in which R ¹ and R ² are both a chain aliphatic group or an alicyclic structure-containing aliphatic group in the general formula (I). The chain aliphatic group and the alicyclic structure-containing aliphatic group are preferably saturated aliphatic groups, and more preferably at least one selected from the group consisting of alkyl groups and cycloalkyl groups. The alkyl group preferably has 3 or more carbon atoms, more preferably 3 to 20, more preferably 3 to 12, and the cycloalkyl group preferably 5 or more carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 carbon atoms. ~ 12.
Specific examples of the aliphatic monocarbodiimide include diisopropylcarbodiimide, diisobutylcarbodiimide, t-butylisopropylcarbodiimide, di-t-butylcarbodiimide, dioctylcarbodiimide, N, N′-dioctyldecylcarbodiimide, N, N′-dicyclohexylcarbodiimide and the like. Can be mentioned.

As the aromatic monocarbodiimide, a carbodiimide in which at least one of R ¹ and R ² in the general formula (I) is an aryl group is preferable, and a carbodiimide in which both R ¹ and R ² are aryl groups is more preferable. The aryl group preferably has 5 or more carbon atoms, more preferably 6 to 20, and still more preferably 6 to 12.
Specific examples of the aromatic monocarbodiimide include N, N′-di-2,6-diisopropylphenylcarbodiimide, N, N′-diphenylcarbodiimide, N, N′-di-2,6-dimethylphenylcarbodiimide, N, N'-di-2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N, N'-di-p-nitrophenylcarbodiimide, N, N'-di-p-amino Phenylcarbodiimide, N, N′-di-p-hydroxyphenylcarbodiimide, N-octadecyl-N′-phenylcarbodiimide, N-benzyl-N′-phenylcarbodiimide, N, N′-di-o-ethylphenylcarbodiimide, N , N′-di-p-ethylphenylcarbodiimide, N, N′-di-o-isopropylphenylcarbodiimide N, N'-di-p-isopropylphenylcarbodiimide, N, N'-di-o-isobutylphenylcarbodiimide, N, N'-di-p-isobutylphenylcarbodiimide, N, N'-di-2, 6-diethylphenylcarbodiimide, N, N′-di-2-ethyl-6-isopropylphenylcarbodiimide, N, N′-di-2-isobutyl-6-isopropylphenylcarbodiimide, N, N′-di-2,4 , 6-trimethylphenylcarbodiimide, N, N′-di-2,4,6-triisopropylphenylcarbodiimide, N, N′-di-2,4,6-triisobutylphenylcarbodiimide, di-β-naphthylcarbodiimide, N, N'-di-o-tolylcarbodiimide, N-tolyl-N'-cyclohexylcarbodiimide, N, N'-di-p- Lil carbodiimide, N- octadecyl -N'- tolyl carbodiimide, N- cyclohexyl -N'- tolyl carbodiimide, N- benzyl -N'- tolyl carbodiimide, and the like.

Monocarbodiimide (B1) can also be used individually by 1 type or in combination of 2 or more types.
Among the above monocarbodiimides, aromatic monocarbodiimides are preferable from the viewpoint of reactivity and chemical resistance, and aromatic monocarbodiimides in which R ¹ and R ² in the general formula (I) are aryl groups having 6 to 12 carbon atoms. N, N′-di-2,6-diisopropylphenylcarbodiimide, N, N′-diphenylcarbodiimide, N, N′-di-2,6-dimethylphenylcarbodiimide, and N, N′-di- At least one selected from the group consisting of 2,6-di-tert-butylphenylcarbodiimide is more preferable, and N, N′-di-2,6-diisopropylphenylcarbodiimide is more preferable.

<Polycarbodiimide (B2)>
The polycarbodiimide (B2) used in the present invention is a compound having two or more carbodiimide groups represented by —N═C═N— in the molecule. The degree of polymerization of the polycarbodiimide is not particularly limited as long as it is 2 or more, but is preferably 2 to 50, more preferably 2 to 40, still more preferably 3 to 30, and still more preferably 5 to 20.
More specifically, the polycarbodiimide (B2) is preferably a compound having a repeating unit represented by the following general formula (II).

In the general formula (II), X ¹ represents a divalent hydrocarbon group. Examples of the hydrocarbon group include a chain aliphatic group, an alicyclic structure-containing aliphatic group, and an aromatic ring-containing group. The chain aliphatic group has 1 or more carbon atoms, preferably 1 to 20, more preferably 6 to 18, and the alicyclic structure-containing aliphatic group and aromatic ring-containing group preferably have 5 or more carbon atoms. More preferably, it is 6-20, and more preferably 6-18. The hydrocarbon group may have a substituent such as an amino group, a hydroxyl group, or an alkoxy group.

Examples of the polycarbodiimide (B2) include aliphatic polycarbodiimide, aromatic polycarbodiimide, or a mixture thereof.
As the aliphatic polycarbodiimide, a polycarbodiimide having a repeating unit represented by the general formula (II) and having X ¹ as a chain aliphatic group or an alicyclic structure-containing aliphatic group is preferable. X ¹ is a group selected from the group consisting of an alkylene group having 3 to 18 carbon atoms, a divalent group represented by the following general formula (1), and a divalent group represented by the following general formula (2) It is more preferable that it is a divalent group represented by the following general formula (2).

In the general formulas (1) and (2), R ^a1 to R ^a5 are each independently a single bond or an alkylene group having 1 to 8 carbon atoms. R ^a1 and R ^a2 in the general formula (1) are preferably single bonds. R ^a3 and R ^a5 in the general formula (2) are preferably single bonds, and R ^a4 is preferably an alkylene group having 1 to 6 carbon atoms, more preferably an alkylene group having 1 to 3 carbon atoms.

The aromatic polycarbodiimide has a repeating unit represented by the above general formula (II), and X ¹ is represented by a divalent group represented by the following general formula (3) and the following general formula (4). The divalent group is more preferably a group selected from the group consisting of divalent groups, and more preferably a divalent group represented by the following general formula (3).

In the general formula (3), R ^b1 to R ^b3 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. In the general formula (4), R ^b4 is a single bond, an alkylene group having 1 to 8 carbon atoms, or an arylene group having 6 to 8 carbon atoms. R ^b1 to R ^b3 in the general formula (3) are preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. It is more preferable that all of ^b1 to ^Rb3 are isopropyl groups. R ^b4 in the general formula (4) is preferably a single bond, an alkylene group having 1 to 6 carbon atoms, or a phenylene group.

Polycarbodiimide (B2) can also be used individually by 1 type or in combination of 2 or more types.
Among these, aliphatic polycarbodiimide is preferable from the viewpoint of the flexibility of the obtained molded body. In view of reactivity and chemical resistance, aromatic polycarbodiimide is preferable, and aromatic polycarbodiimide having a repeating unit represented by the following formula (II-3) is more preferable.

Polycarbodiimide can be produced by various methods. For example, a method for producing a polycarbodiimide having an isocyanate terminal by a condensation reaction involving decarbonization of an organic diisocyanate can be mentioned. Examples of organic diisocyanates that are raw materials for polycarbodiimides include 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and 2,4-triisocyanate. Diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4-diisocyanate, methylcyclohexane diisocyanate, Tetramethylxylylene diisocyanate, 2,6-diisopropylphenyl isocyanate, 1,3,5-triisopropyl Pirubenzen-2,4-diisocyanate, can be mentioned methylenebis (4,1-cyclohexylene) diisocyanate. 1 type (s) or 2 or more types can be used for organic diisocyanate.

Furthermore, the terminal isocyanate groups of the isocyanate-terminated polycarbodiimide can be sealed with all or part of the remaining terminal isocyanate groups using a terminal blocking agent. The end-capping agent is preferably a monoisocyanate compound, and examples thereof include phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, diisopropylphenyl isocyanate, cyclohexyl isocyanate, and butyl isocyanate.
When the terminal isocyanate group of the isocyanate-terminated polycarbodiimide is sealed with a monoisocyanate compound, a polycarbodiimide represented by the following general formula (II-a) can be obtained.

In the general formula (II-a), X ¹ is the same as described above. R ′ and R ″ are residues other than the isocyanate group of the monoisocyanate compound. R ′ and R ″ may be the same as or different from each other. n is the number of {degree of polymerization of polycarbodiimide-1}.

The blending amount of monocarbodiimide (B1) and polycarbodiimide (B2) in the polyamide resin composition of the present invention is preferably 0.5 to 25 parts by mass, more preferably 1 to 100 parts by mass of the polyamide (A). It is ˜10 parts by mass, more preferably 1 to 5 parts by mass, and further preferably 1 to 3 parts by mass. If the total amount of monocarbodiimide (B1) and polycarbodiimide (B2) to 100 parts by mass of polyamide (A) is 0.5 parts by mass or more, the chemical resistance is good. Moreover, if the said compounding quantity is 25 mass parts or less in total, the heat resistance and mechanical strength originating in a polyamide (A) can be maintained.
The mass ratio (B1) / (B2) of the monocarbodiimide (B1) to the polycarbodiimide (B2) is preferably 1: 0.1 to 1:10, more preferably 1: 0.2 to 1: 5. More preferably, it is in the range of 1: 0.5 to 1: 2. If mass ratio (B1) / (B2) is the said range, since the reaction balance with the terminal group of polyamide (A) and the acid-modified part of elastomer (C) mentioned later is good, chemical-resistant property improves. To do.

<Elastomer (C)>
In the polyamide resin composition of the present invention, an elastomer (C) is further blended from the viewpoint of imparting impact resistance and elongation characteristics to a molded article such as a chemical solution transporting tube and a connector composed of the resin composition. Is preferred. Examples of the elastomer (C) used in the present invention include rubbery polymers, and those having a flexural modulus of 500 MPa or less as measured in accordance with ASTM D-790 are preferred.
Specifically, α-olefin copolymer, (ethylene and / or propylene) / (α, β-unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) copolymer, ionomer, aromatic vinyl compound / Conjugated diene compound-based block copolymer. Moreover, the polymer which modified | denatured these with the unsaturated compound which has a carboxyl group and / or an acid anhydride group may be sufficient. These elastomers (C) can be used alone or in combination of two or more.

Examples of the α-olefin copolymer include a copolymer of ethylene and an α-olefin having 3 or more carbon atoms, and a copolymer of propylene and an α-olefin having 4 or more carbon atoms. The α-olefin copolymer is preferably a copolymer of ethylene and an α-olefin having 3 or more carbon atoms.
Examples of the α-olefin having 3 or more carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene and 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, and 12-ethyl-1-tetradecene. These can use 1 type (s) or 2 or more types. Among these, the α-olefin having 3 or more carbon atoms is preferably at least one selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene. Is more preferable.

In addition, 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1, 5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8- Decatriene (DMDT), dicyclopentadiene, cyclohexadiene, cyclooctadiene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl -5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2- Chiriden -3-isopropylidene-5-norbornene may be copolymerized non-conjugated diene polyene such as 2-propenyl-2,5-norbornadiene. These can use 1 type (s) or 2 or more types.

The above (ethylene and / or propylene) / (α, β-unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) -based copolymer includes ethylene and / or propylene and α, β-unsaturated carboxylic acid and / or Or a polymer obtained by copolymerizing an unsaturated carboxylic acid ester monomer. Examples of the α, β-unsaturated carboxylic acid monomer include acrylic acid and methacrylic acid, and α, β-unsaturated carboxylic acid. Examples of the ester monomer include methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, hexyl ester, heptyl ester, octyl ester, nonyl ester, and decyl ester of these unsaturated carboxylic acids. These can use 1 type (s) or 2 or more types.

The above ionomer is obtained by ionizing at least part of the carboxyl group of the olefin and the α, β-unsaturated carboxylic acid copolymer by neutralization of metal ions. As the olefin, ethylene is preferably used, and as the α, β-unsaturated carboxylic acid, acrylic acid and methacrylic acid are preferably used. However, the olefin is not limited to those exemplified here. The monomer may be copolymerized. Metal ions include alkali metals such as Li, Na, K, Mg, Ca, Sr, Ba, alkaline earth metals, Al, Sn, Sb, Ti, Mn, Fe, Ni, Cu, Zn, Cd, etc. Is mentioned. These can use 1 type (s) or 2 or more types.

The aromatic vinyl compound / conjugated diene compound block copolymer is a block copolymer comprising an aromatic vinyl compound polymer block and a conjugated diene polymer block. A block copolymer having at least one and at least one conjugated diene polymer block is used. In the block copolymer, the unsaturated bond in the conjugated diene polymer block may be hydrogenated.

The aromatic vinyl compound polymer block is a polymer block mainly composed of structural units derived from an aromatic vinyl compound. In this case, the aromatic vinyl compound includes styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, vinylnaphthalene, vinylanthracene, 4-propylstyrene, Examples include 4-cyclohexyl styrene, 4-dodecyl styrene, 2-ethyl-4-benzyl styrene, 4- (phenylbutyl) styrene, and the like, and one or more of them can be used. In addition, the aromatic vinyl compound-based polymer block may optionally have a structural unit composed of a small amount of other unsaturated monomer. Conjugated diene polymer blocks are conjugated such as butadiene, chloroprene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene, etc. A polymer block formed from one or more diene compounds. In a hydrogenated aromatic vinyl compound / conjugated diene compound-based block copolymer, one of unsaturated bonds in the conjugated diene polymer block. Part or all is hydrogenated.

The molecular structure of the aromatic vinyl compound / conjugated diene compound block copolymer and the hydrogenated product thereof may be any of linear, branched, radial, or any combination thereof. Among these, as an aromatic vinyl compound / conjugated diene compound block copolymer and / or a hydrogenated product thereof, one aromatic vinyl compound polymer block and one conjugated diene polymer block are linear. The three polymer blocks are linearly bonded in this order: diblock copolymer, aromatic vinyl compound polymer block-conjugated diene polymer block-aromatic vinyl compound polymer block. One or more of triblock copolymers and hydrogenated products thereof are preferably used. Unhydrogenated or hydrogenated styrene / butadiene block copolymer, unhydrogenated or hydrogenated styrene / isoprene block copolymer Copolymer, unhydrogenated or hydrogenated styrene / isoprene / styrene block copolymer, unhydrogenated or hydrogenated styrene / butadiene / styrene Block copolymers, unhydrogenated or hydrogenated styrene / isoprene / butadiene / styrene block copolymer.

Further, α-olefin copolymers used as elastomers, (ethylene and / or propylene) / (α, β-unsaturated carboxylic acids and / or unsaturated carboxylic esters) copolymers, ionomers, aromatic vinyls The compound / conjugated diene compound block copolymer is preferably a polymer modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group. When modified with such a component, the terminal amino group of the polyamide (A) reacts with the carboxyl group and / or the acid anhydride group of the polymer as the component (C), and the (A) phase ( C) The affinity of the interface with the phase is increased, and the impact resistance and elongation characteristics are improved. Among them, a polymer obtained by modifying an α-olefin copolymer with an unsaturated compound having a carboxyl group and / or an acid anhydride group is preferable, and a polymer obtained by modifying an ethylene-butene copolymer with the unsaturated compound. Is more preferable.

Examples of the unsaturated compound having a carboxyl group in a modified polymer modified with an unsaturated compound having a carboxyl group and / or an acid anhydride group (hereinafter, also simply referred to as “modified polymer”) include acrylic acid, methacrylic acid, and the like. Examples include α, β-unsaturated carboxylic acids such as acid, maleic acid, fumaric acid, and itaconic acid. Examples of the unsaturated compound having an acid anhydride group include dicarboxylic anhydrides having an α, β-unsaturated bond such as maleic anhydride and itaconic anhydride. The unsaturated compound having a carboxyl group and / or an acid anhydride group is preferably a dicarboxylic acid anhydride having an α, β-unsaturated bond, and more preferably maleic anhydride.

The content of carboxyl groups and acid anhydride groups in the modified polymer is preferably in the range of 25 to 200 μmol / g, and more preferably in the range of 50 to 100 μmol / g. If the content of the functional group is 25 μmol / g or more, the effect of improving the impact resistance is sufficient. On the other hand, if the content is 200 μmol / g or less, the fluidity of the resulting polyamide resin composition decreases. Thus, it is possible to avoid a decrease in moldability.

Examples of the modification method using an unsaturated compound having a carboxyl group and / or an acid anhydride group include the above-mentioned α-olefin copolymer, (ethylene and / or propylene) / (α, β-unsaturated carboxylic acid and / or Unsaturated carboxylic acid ester) type copolymer, ionomer, aromatic vinyl compound / conjugated diene compound type block copolymer (hereinafter also referred to as “base resin”), carboxyl group and / or acid anhydride group And a method in which an unsaturated compound having a carboxyl group and / or an acid anhydride group is grafted to the above base resin. Of these, a method in which an unsaturated compound having a carboxyl group and / or an acid anhydride group is grafted to the above base resin is preferable.

As the elastomer (C), a commercially available product manufactured industrially can be used, and examples thereof include “Tuffmer” manufactured by Mitsui Chemicals.

The blending ratio of the elastomer (C) in the polyamide resin composition of the present invention is preferably 1.0 part by mass or more with respect to 100 parts by mass of the polyamide (A) from the viewpoint of imparting impact resistance and elongation characteristics. Preferably it is 5.0 parts by mass or more, more preferably 15 parts by mass or more, and from the viewpoint of maintaining heat resistance and chemical resistance, it is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and still more preferably 40 parts by mass. It is below mass parts.
When the polyamide resin composition of the present invention is used for a chemical solution transport tube, from the viewpoint of improving the flexibility of the tube, the blending ratio of the elastomer (C) is 23 ° C. and 50% RH according to ISO 178. It is preferable to adjust to the quantity from which the bending elastic modulus of the molded object of the polyamide resin composition measured on condition will be 2.0 GPa or less, and it is more preferable to adjust to the quantity which will be 1.5 GPa or less.

<Other ingredients>
In addition to the polyamide (A), monocarbodiimide (B1), polycarbodiimide (B2), and elastomer (C), the polyamide resin composition of the present invention includes components other than the components (A) to (C) as necessary. Other components such as a resin, a filler, a crystal nucleating agent, an antioxidant, a colorant, an antistatic agent, a plasticizer, a lubricant, a flame retardant, and a flame retardant aid may be blended. Among these, it is preferable to mix | blend at least 1 sort (s) chosen from the group which consists of antioxidant, a coloring agent, and a lubrication agent in the polyamide resin composition used for the innermost layer of the chemical | medical solution transport tube. Further, when the chemical solution transport tube is used for fuel transportation, it is preferable to blend at least an antistatic agent in the polyamide resin composition used for the innermost layer.

Examples of the resin other than the components (A) to (C) include polyether resins such as polyacetal and polyphenylene oxide; polysulfone resins such as polysulfone and polyethersulfone; polythioether resins such as polyphenylene sulfide and polythioether sulfone; Polyketone resins such as ether ether ketone and polyallyl ether ketone; such as polyacrylonitrile, polymethacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, methacrylonitrile-butadiene-styrene copolymer Polynitrile resins; polymethacrylate resins such as polymethyl methacrylate and polyethyl methacrylate; polyvinyl ester resins such as polyvinyl acetate; polyvinylidene chloride, polychlorinated Polyvinyl chloride resins such as nyl, vinyl chloride-vinylidene chloride copolymer, vinylidene chloride-methyl acrylate copolymer; cellulose resins such as cellulose acetate and cellulose butyrate; polyvinylidene fluoride, polyvinyl fluoride, ethylene-tetrafluoro Fluorine series such as ethylene copolymer, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer Resin; polycarbonate resin; polyimide resin such as thermoplastic polyimide, polyamideimide, and polyetherimide; thermoplastic polyurethane resin; and the like.

Examples of the filler include fibrous fillers such as glass fibers, powder fillers such as calcium carbonate, wollastonite, silica, silica alumina, alumina, titanium dioxide, potassium titanate, magnesium hydroxide, and molybdenum disulfide. A flaky filler such as hydrotalcite, glass flakes, mica, clay, montmorillonite and kaolin;

The crystal nucleating agent is not particularly limited as long as it is generally used as a crystal nucleating agent for polyamide. For example, talc, calcium stearate, aluminum stearate, barium stearate, zinc stearate, antimony oxide, oxidation Magnesium, any mixture thereof and the like can be mentioned. Of these, talc is preferred because of its great effect of increasing the crystallization rate of polyamide. The crystal nucleating agent may be treated with a silane coupling agent, a titanium coupling agent or the like for the purpose of improving the compatibility with the polyamide.

The antioxidant is not particularly limited as long as it is generally used as an antioxidant for polyamide. For example, a phenol-based antioxidant, a benzotriazole-based antioxidant, a sulfur-based antioxidant, a phosphorus-based antioxidant Antioxidants, copper-based antioxidants, amine-based antioxidants and the like can be mentioned. Among these, a phenolic antioxidant is preferable, and a hindered phenolic compound is more preferable.
The blending amount of the antioxidant in the polyamide resin composition is usually 0.1 to 10% by mass, preferably 0.2 to 5.0% by mass.

The colorant is not particularly limited, and can be appropriately selected from inorganic or organic pigments and dyes according to the use of the polyamide resin composition. As the colorant to be blended in the polyamide resin composition used for the chemical solution transport tube, black inorganic pigments such as carbon black, lamp black, acetylene black, bone black, thermal black, channel black, furnace black, titanium black and the like are preferable. As mentioned.
The antistatic agent is not particularly limited, and may be organic or inorganic. For example, examples of the organic antistatic agent include ionic compounds such as lithium ion salts, quaternary ammonium salts, and ionic liquids; and electron conductive polymer compounds such as polythiophene, polyaniline, polypyrrole, and polyacetylene. Examples of the inorganic antistatic agent include metal oxide conductive agents such as ATO, ITO, PTO, GZO, antimony pentoxide, and zinc oxide; and carbon conductive agents such as carbon nanotubes and fullerenes. From the viewpoint of heat resistance, an inorganic antistatic agent is preferred. Note that carbon black, which is a colorant, may also function as an antistatic agent.

The plasticizer is not particularly limited as long as it is generally used as a plasticizer for polyamides. For example, benzenesulfonic acid alkylamide compounds, toluenesulfonic acid alkylamide compounds, hydroxybenzoic acid alkylester compounds Etc.

The lubricant is not particularly limited as long as it is generally used as a lubricant for polyamide. For example, higher fatty acid compounds, oxy fatty acid compounds, fatty acid amide compounds, alkylene bis fatty acid amide compounds, fatty acid lower alcohols. Examples thereof include ester compounds, metal soap compounds, and polyolefin waxes. Fatty acid amide compounds such as stearic acid amide, palmitic acid amide, methylene bisstearyl amide, ethylene bisstearyl amide and the like are preferable because of their excellent external lubricity effect.

The content of these other components in the polyamide resin composition is preferably 50% by mass or less, more preferably 20% by mass or less, and further preferably 5% by mass or less.

[Production Method of Polyamide Resin Composition]
The manufacturing method in particular of the polyamide resin composition of this invention is not restrict | limited, A well-known method can be used. For example, a polyamide resin composition was prepared by melt-kneading a mixture obtained by dry blending polyamide (A), monocarbodiimide (B1), polycarbodiimide (B2), and elastomer (C) blended as necessary and other components. Thereafter, a method of pelletizing is mentioned. By using the pellets for various moldings, a molded body containing the polyamide resin composition can be obtained.
The method for producing a polyamide resin composition of the present invention includes a step of melt-kneading the above-mentioned mixture containing polyamide (A), monocarbodiimide (B1), and polycarbodiimide (B2). The terminal group, the monocarbodiimide (B1), the polycarbodiimide (B2), and the modified portion of the elastomer (C) react with each other, and the resulting resin composition has excellent chemical resistance. The temperature and time during the melt-kneading can be appropriately adjusted according to the melting point of the polyamide (A) used.

Since the polyamide resin composition of the present invention is excellent in chemical resistance, it is used for transportation of various chemicals such as engine cooling refrigerant such as LLC, refrigerant for air conditioner, reducing agent solution for SCR system, oil, fuel, and connector. It is suitably used for intake pipes, blow-by tubes and the like.

[Chemical solution transport tube]
The tube for transporting a chemical solution of the present invention is characterized by having at least one layer composed of the polyamide resin composition of the present invention described above. The chemical solution transport tube of the present invention may be a single-layer tube or a multi-layer tube, and from the viewpoint of chemical resistance, at least a single-layer tube made of the polyamide resin composition or a layer made of the polyamide resin composition. A multilayer tube in the innermost layer is preferable.

Examples of the chemical solution to which the chemical solution transport tube of the present invention can be applied include aromatic hydrocarbon solvents such as benzene, toluene, xylene, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, diethylene glycol, and phenol. , Alcohols such as cresol, polyethylene glycol and polypropylene glycol, phenol solvents, dimethyl ether, dipropyl ether, methyl-t-butyl ether, dioxane, tetrahydrofuran and other ether solvents, chloroform, methylene chloride, trichloroethylene, ethylene dichloride, perchlor Halogen solvents such as ethylene, monochloroethane, dichloroethane, tetrachloroethane, perchloroethane, chlorobenzene, acetone, Ketone solvents such as tilethyl ketone, diethyl ketone, acetophenone, urea solution, gasoline, kerosene, diesel gasoline, alcohol-containing gasoline, oxygen-containing gasoline, amine-containing gasoline, sour gasoline, castor oil base brake fluid, glycol ether brake fluid, Boric ester brake fluid, brake fluid for extremely cold regions, silicone oil brake fluid, mineral oil brake fluid, power steering oil, hydrogen sulfide oil, engine coolant, window washer fluid, pharmaceutical agent, ink, paint, etc. It is done. In addition, an aqueous solution containing the above exemplified chemical solution as a component is also included in the chemical solution.

From the point of use of the chemical solution transport tube of the present invention, the chemical solution is at least one selected from the group consisting of an engine cooling refrigerant such as LLC, an air conditioner refrigerant, and a reducing agent solution for a selective catalytic reduction system. It is preferable that Examples of the reducing agent solution for the selective catalytic reduction system include a urea solution.

The outer diameter of the chemical solution transport tube is designed in consideration of the chemical flow rate. In addition, the tube thickness does not increase the permeability of the chemical solution, it is a thickness that can maintain the normal breaking pressure of the tube, and the tube is easy to assemble and has good vibration resistance during use. Designed to a thickness that can maintain flexibility. Preferably, the outer diameter of the tube is 2.5 to 200 mm and the wall thickness is 0.5 to 20 mm.

When the chemical solution transport tube of the present invention is a multilayer tube, the thickness of the innermost layer constituted by the polyamide resin composition is preferably in the range of 0.01 to 1 mm, more preferably in the range of 0.02 to 0.7 mm. A range of 0.03 to 0.5 mm is more preferable. If the thickness of the innermost layer is 0.01 mm or more, chemical resistance and impact resistance are good. Moreover, if the layer thickness of the innermost layer is 1 mm or less, the flexibility is good, which is advantageous from the viewpoint of economy. The thickness of the innermost layer of the tube can be measured from an actual image obtained by observing the tube cross section with a microscope.
The number of layers constituting the multilayer tube is 2 to 2 from the viewpoints of excellent chemical resistance and impact resistance, hardly cracking when inserted into other members, excellent elongation characteristics, and productivity. 7 layers are preferable, and 3 to 6 layers are more preferable. When the number of layers constituting the multilayer tube is 3 or more, the chemical solution transport tube of the present invention may have two or more layers composed of the polyamide resin composition of the present invention.
When the chemical solution transport tube is a multilayer tube, the layers other than the innermost layer (the outermost layer and the intermediate layer located between the innermost layer and the outermost layer) are not particularly limited, but from the viewpoint of the moldability of the tube Is preferably a thermoplastic resin.
The thermoplastic resin can be appropriately selected in consideration of the use of the tube and the adhesion with an adjacent layer. Specifically, for example, polyester resins such as polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate; ethylene-tetrafluoroethylene copolymer (ETFE), vinylidene fluoride polymer ( PVDF), polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, etc .; Polyolefin resins such as polyethylene, polypropylene, polystyrene, saponified ethylene-vinyl acetate copolymer (EVOH); polyacetal, polyphenylenesulfite Polyether resins and the like; semiaromatic polyamide, polyamide resins such as aliphatic polyamides.

The production of the chemical solution transport tube of the present invention can be performed using a molding method such as injection molding or extrusion molding. A molding method combining the above molding methods can also be employed.

[connector]
The connector of the present invention is characterized by including the above-described polyamide resin composition of the present invention. Since the polyamide resin composition of the present invention is excellent in chemical resistance, it is suitable for a connector for a tube that comes into contact with the chemical. In addition, examples of the connector of the present invention include a quick connector for an automobile fuel pipe.

EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example and a comparative example, this invention is not limited to the following Example.
In addition, each evaluation in an Example and a comparative example was performed in accordance with the method shown below.

(Intrinsic viscosity [η])
The intrinsic viscosity (η _inh ) of a sample solution having a concentration of 0.05, 0.1, 0.2, 0.4 g / dL was measured in concentrated sulfuric acid at 30 ° C., and this was extrapolated to a concentration of 0. The value was defined as the intrinsic viscosity [η].
η _inh = [ln (t1 / t0)] / c
[ _Wherein η _inh represents the intrinsic viscosity (dL / g), t0 represents the flow time (second) of the solvent, t1 represents the flow time (second) of the sample solution, and c represents the concentration of the sample in the solution (G / dL). ]

(Melting point)
The melting point of the polyamide was measured using a differential scanning calorimeter “DSC822” manufactured by METTLER TOLEDO. In a nitrogen atmosphere, the sample (polyamide) was heated from 30 ° C. to 340 ° C. at a rate of 10 ° C./min, held at 340 ° C. for 2 minutes to completely melt the sample, and then at a rate of 10 ° C./min. Cool to 30 ° C and hold at 30 ° C for 2 minutes. The peak temperature of the melting peak that appears when the temperature is again raised to 360 ° C. at a rate of 10 ° C./min is defined as the melting point (° C.). did.

(Terminal amino group content)
1 g of polyamide was dissolved in 35 mL of phenol, and 2 mL of methanol was mixed therewith to obtain a sample solution. Timol blue was used as an indicator, and titration was performed using a 0.01 N aqueous hydrochloric acid solution, and the terminal amino group content ([NH ₂ ], unit: μmol / g) of the polyamide was measured.

(Terminal carboxyl group content)
0.2 g of polyamide was added to 15 mL of o-cresol and heated to 110 ° C. to dissolve. After cooling to near room temperature, 10 mL of benzyl alcohol, 50 mL of o-cresol and 50 μL of formaldehyde were added. The terminal carboxyl group content ([COOH], unit: μmol / g) of the polyamide was measured with a potentiometric titrator using 0.05N ethanolic potassium hydroxide as a titrant.

(Tensile breaking strength and tensile breaking elongation)
Using an injection molding machine manufactured by Toshiba Machine Co., Ltd. (clamping force: 80 tons, screw diameter: φ32 mm), and using the polyamide resin compositions (pellets) of the following examples and comparative examples, from the melting point of polyamide In addition, an ISO multipurpose test piece A-type dumbbell was produced by injection molding (mold temperature 80 ° C.) using a T-runner mold at a cylinder temperature 20 to 30 ° C. higher. Using the obtained test piece, the tensile strength at break (MPa) and the tensile elongation at break (%) at 23 ° C. were measured using an autograph (manufactured by Shimadzu Corporation) according to ISO 527-1. did.

(Evaluation of chemical resistance)
An ISO multi-purpose specimen A-type dumbbell produced by the same method as above was immersed in LLC (an aqueous solution in which Toyota Super Long Life Coolant (pink) was diluted twice with water) and immersed at 120 ° C. for 2000 hours. Tensile rupture strength and tensile rupture elongation were measured according to ISO 527. The ratio (retention rate,%) of the tensile rupture strength and tensile rupture elongation of the test piece after immersion to the tensile rupture strength and tensile rupture elongation of the test piece before immersion was calculated, and the chemical resistance was evaluated. The higher the retention value, the better the chemical resistance.

Production Example 1 (Production of polyamide 1)
9870.6 g (59.42 mol) of terephthalic acid, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine [50/50 (molar ratio)] 9497.4 g (60.00 mol), benzoic acid 142.9 g (1.17 mol) of acid, 19.5 g of sodium hypophosphite monohydrate (0.1% by mass with respect to the total mass of the raw material) and 5 liters of distilled water in an autoclave having an internal volume of 40 liters And replaced with nitrogen. The mixture was stirred at 100 ° C. for 30 minutes, and the temperature inside the autoclave was increased to 220 ° C. over 2 hours. At this time, the pressure inside the autoclave was increased to 2 MPa. The reaction was continued as it was for 2 hours, then the temperature was raised to 230 ° C., and then the temperature was maintained at 230 ° C. for 2 hours, and the reaction was carried out while gradually removing water vapor and keeping the pressure at 2 MPa. Next, the pressure was reduced to 1 MPa over 30 minutes, and the reaction was further continued for 1 hour to obtain a prepolymer having an intrinsic viscosity [η] of 0.2 dL / g. This was pulverized to a particle size of 2 mm or less using a flake crusher manufactured by Hosokawa Micron Corporation, dried at 100 ° C. under reduced pressure for 12 hours, and then solid-phase polymerized at 230 ° C. and 13 Pa (0.1 mmHg) for 10 hours. A white polyamide resin (polyamide 1) was obtained. Polyamide 1 comprises terephthalic acid units, 1,9-nonanediamine units and 2-methyl-1,8-octanediamine units (1,9-nonanediamine units / 2-methyl-1,8-octanediamine units = 50/50 ( The melting point is 265 ° C., the intrinsic viscosity [η] is 1.30 dL / g, the terminal amino group content ([NH ₂ ]) is 15 μmol / g, and the terminal carboxyl group content ([COOH]). Was 60 μmol / g.

Example 1 (Production of polyamide resin composition)
Polyamide, carbodiimide and elastomer shown in Table 1, and a phenolic antioxidant were premixed at a predetermined mass ratio. The mixing ratio of polyamide, carbodiimide and elastomer is as shown in Table 1. The phenolic antioxidant was added in an amount of 1 part by mass based on 100 parts by mass of the total of polyamide, carbodiimide and elastomer.
The obtained mixture was supplied to a twin-screw extruder (manufactured by Pla Giken Co., Ltd.) and melt-kneaded under conditions of a cylinder temperature of 300 to 320 ° C. to obtain a polyamide resin composition as pellets. Test pieces for evaluating various physical properties were prepared using the pellets, and various evaluations were performed by the methods described above. The results are shown in Table 1.

Example 2 and Comparative Examples 1-7
A polyamide resin composition was prepared in the same manner as in Example 1 except that the composition of the polyamide resin composition was changed as shown in Table 1, and various evaluations were performed. The results are shown in Table 1.

In addition, each component shown in Table 1 is as follows.
<Polyamide (A)>
Polyamide 1 obtained in Production Example 1
<Monocarbodiimide (B1)>
Aromatic monocarbodiimide represented by the following structure (N, N'-di-2,6-diisopropylphenylcarbodiimide)

<Aliphatic polycarbodiimide (B2-1)>
Aliphatic polycarbodiimide represented by the following structure (molecular weight 4,000, k = 17)

<Aromatic polycarbodiimide (B2-2)>
Aromatic polycarbodiimide represented by the following structure (molecular weight 3,000, m = 11)

<Elastomer (C)>
Modified polymer of ethylene-butene copolymer modified with maleic anhydride (“Tuffmer” manufactured by Mitsui Chemicals, Inc.)

As shown in Table 1, it can be seen that the polyamide resin composition of the present invention has little change in mechanical properties even when kept in contact with high temperature LLC for a long time, and is excellent in chemical resistance. In particular, when Example 1 is compared with Comparative Examples 4 and 5, and Example 2 is compared with Comparative Examples 6 and 7, chemical resistance is not improved as the amount of carbodiimide groups in the polyamide resin composition increases. It turns out that the effect of this invention is show | played by using together carbodiimide and polycarbodiimide.

According to the present invention, a polyamide resin composition having excellent chemical resistance can be provided. This polyamide resin composition is particularly suitable for engine cooling refrigerants such as LLC, refrigerants for air conditioners, reducing agent solutions for SCR systems, tubes for transporting various chemicals such as oil, fuel, connectors, intake pipes, blow-by tubes, etc. Used for.

Claims (18)

1. Polyamide resin composition formed by blending polyamide (A), monocarbodiimide (B1), and polycarbodiimide (B2).
2. The amount of the monocarbodiimide (B1) and the polycarbodiimide (B2) in the polyamide resin composition is 0.5 to 25 parts by mass with respect to 100 parts by mass of the polyamide (A). Polyamide resin composition.
3. The polyamide resin composition according to claim 1 or 2, wherein a mass ratio (B1) / (B2) of the monocarbodiimide (B1) to the polycarbodiimide (B2) is 1: 0.1 to 1:10.
4. The polyamide resin composition according to any one of claims 1 to 3, wherein the monocarbodiimide (B1) is an aromatic monocarbodiimide.
5. The polyamide resin composition according to any one of claims 1 to 4, wherein the polycarbodiimide (B2) is an aromatic polycarbodiimide.
6. The polyamide resin composition according to any one of claims 1 to 4, wherein the polycarbodiimide (B2) is an aliphatic polycarbodiimide.
7. The polyamide resin composition according to any one of claims 1 to 6, wherein the polyamide (A) has a terminal amino group content of 5 to 60 µmol / g.
8. The polyamide (A) is a semi-aromatic containing a dicarboxylic acid unit containing 50 to 100 mol% of an aromatic dicarboxylic acid unit and a diamine unit containing 60 to 100 mol% of an aliphatic diamine unit having 6 to 13 carbon atoms. The polyamide resin composition according to any one of claims 1 to 7, which is a polyamide.
9. The polyamide resin composition according to claim 8, wherein the semi-aromatic polyamide further contains an aminocarboxylic acid unit and / or a lactam unit.
10. The aromatic dicarboxylic acid unit is a terephthalic acid unit and / or a naphthalene dicarboxylic acid unit, and the aliphatic diamine unit is a 1,9-nonanediamine unit, a 2-methyl-1,8-octanediamine unit and 1,10-decane. The polyamide resin composition according to claim 8 or 9, which is at least one selected from the group consisting of diamine units.
11. The polyamide resin composition according to claim 10, wherein the aliphatic diamine unit is a 1,9-nonanediamine unit and / or a 2-methyl-1,8-octanediamine unit.
12. The polyamide resin composition according to any one of claims 1 to 11, further comprising an elastomer (C).
13. The elastomer (C) is an α-olefin copolymer, (ethylene and / or propylene) / (α, β-unsaturated carboxylic acid and / or unsaturated carboxylic acid ester) copolymer, ionomer, aromatic vinyl The compound / conjugated diene compound-based block copolymer and at least one selected from the group consisting of polymers obtained by modifying these with an unsaturated compound having a carboxyl group and / or an acid anhydride group. Polyamide resin composition.
14. The method for producing a polyamide resin composition according to any one of claims 1 to 13, further comprising a step of melt-kneading a mixture containing the polyamide (A), the monocarbodiimide (B1), and the polycarbodiimide (B2).
15. A chemical transport tube having at least one layer composed of the polyamide resin composition according to any one of claims 1 to 13.
16. The chemical solution transport tube according to claim 15, wherein the chemical solution transport tube is a single-layer tube composed of the polyamide resin composition or a multilayer tube having at least an innermost layer composed of the polyamide resin composition. tube.
17. The chemical liquid transport tube according to claim 15 or 16, wherein the chemical liquid is at least one selected from the group consisting of an engine cooling refrigerant, an air conditioner refrigerant, and a reducing agent solution for a selective catalytic reduction system.
18. A connector comprising the polyamide resin composition according to any one of claims 1 to 13.