JP2014012773A - Polyamide composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide composition which is more excellent in reflow resistance, heat discoloration resistance, and extrusion processability.SOLUTION: The polyamide composition of the present invention contains: (A) a polyamide; (B) a titanium oxide; (C) a phenol-based antioxidant and/or an amine-based antioxidant; and (D) an organophosphorus antioxidant. The polyamide (A) has a unit comprising (a) a dicarboxylic acid and (b) a diamine. The dicarboxylic acid (a) contains at least 50 mol% of (a-1) an alicyclic dicarboxylic acid.

Description

  The present invention relates to a polyamide composition and a molded article comprising the polyamide composition.

  Polyamides represented by polyamide 6 and polyamide 66 (hereinafter sometimes abbreviated as “PA6” and “PA66”, respectively) and the like are excellent in molding processability, mechanical properties, and chemical resistance. Widely used as various parts materials for automobiles, electric and electronic, industrial materials, industrial materials, daily products and household products.

  In the automobile industry, weight reduction of the vehicle body is required to reduce exhaust gas as an environmental effort. In order to meet this demand, polyamides are increasingly used in place of metals as exterior materials and interior materials for automobiles. Polyamides used for automobile exterior materials and interior materials are required to have higher levels of heat resistance, strength, appearance, and other characteristics. Among these, polyamides used as materials in the engine room are increasingly required to have high heat resistance because the temperature in the engine room tends to increase.

  In addition, in the electrical and electronic industries such as home appliances, lead-free surface mount (SMT) solder is being promoted. Polyamides used for materials such as home appliances are required to have high heat resistance that can withstand the rise in melting point of solder accompanying such lead-free soldering.

  Polyamides such as PA6 and PA66 have a low melting point and cannot satisfy these requirements in terms of heat resistance.

  Therefore, in order to solve the above-mentioned problems of conventional polyamides such as PA6 and PA66, high melting point polyamides have been proposed. Specifically, a polyamide composed of terephthalic acid and hexamethylenediamine (hereinafter sometimes abbreviated as “PA6T”) has been proposed.

  However, since PA6T is a high melting point polyamide having a melting point of about 370 ° C., even if an attempt is made to obtain a molded product from PA6T by melt molding, the thermal decomposition of the polyamide occurs vigorously, and a molded product having sufficient characteristics can be obtained. difficult.

  In order to solve the above-mentioned problems of PA6T, PA6T may be abbreviated as aliphatic polyamide such as PA6 and PA66, or amorphous aromatic polyamide (hereinafter referred to as “PA6I”) composed of isophthalic acid and hexamethylenediamine. )) And the like, and a high melting point semi-aromatic polyamide (hereinafter referred to as “6T copolymer polyamide”) mainly composed of terephthalic acid and hexamethylenediamine whose melting point is lowered to about 220 to 340 ° C. Have been abbreviated in some cases).

  As a 6T copolymer polyamide, Patent Document 1 discloses an aromatic polyamide (hereinafter referred to as “a mixture of hexamethylene diamine and 2-methylpentamethylene diamine”), which is composed of an aromatic dicarboxylic acid and an aliphatic diamine. "May be abbreviated as" PA6T / 2MPDT ").

  Further, an alicyclic polyamide composed of an alicyclic dicarboxylic acid and an aliphatic diamine has been proposed as opposed to an aromatic polyamide composed of an aromatic dicarboxylic acid and an aliphatic diamine. As the alicyclic polyamide, a high melting point aliphatic polyamide (hereinafter sometimes abbreviated as “PA46”) composed of adipic acid and tetramethylenediamine has been proposed.

  Patent Document 2 discloses a semi-alicyclic polyamide containing 1 to 40% of 1,4-cyclohexanedicarboxylic acid as a dicarboxylic acid unit, and the electric and electronic members of the semi-alicyclic polyamide are solder heat resistant. Is disclosed to improve.

  Patent Document 3 discloses a polyamide resin (hereinafter referred to as “PA9T”) comprising a dicarboxylic acid containing a terephthalic acid unit and a diamine containing a 1,9-nonanediamine unit and / or a 2-methyl-1,8-octanediamine unit. A polyamide composition comprising titanium oxide, magnesium hydroxide and a specific reinforcing material, and it is disclosed that the polyamide composition is excellent in heat resistance.

  Patent Document 4 discloses a polyamide containing a semi-alicyclic polyamide containing 70% or more of 1,4-cyclohexanedicarboxylic acid as a dicarboxylic acid unit, titanium oxide, and an inorganic filler, and specifying the weight ratio thereof. A composition is disclosed, and it is disclosed that the polyamide composition is excellent in reflow resistance and heat resistance.

JP-T 6-503590 Japanese National Patent Publication No. 11-512476 JP 2006-257314 A JP 2011-219697 A

  Conventional polyamides or polyamide compositions disclosed in Patent Documents 1 to 4 and the like have insufficient reflow resistance, heat discoloration resistance, and extrusion processability, and further improvements in these properties are required.

  Accordingly, the problem to be solved by the present invention is to provide a polyamide composition that is more excellent in reflow resistance, heat discoloration resistance and extrusion processability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a polyamide having a unit composed of a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and a diamine, titanium oxide, and phenol. The present inventors have found that a polyamide composition containing a system antioxidant and / or an amine antioxidant and an organic phosphorus antioxidant can solve the above-mentioned problems, and has completed the present invention.

  That is, the present invention is as follows.

[1]
(A) polyamide, (B) titanium oxide, (C) a phenolic antioxidant and / or an amine antioxidant, and (D) an organic phosphorus antioxidant,
(A) Polyamide has a unit consisting of (a) dicarboxylic acid and (b) diamine,
(A) The polyamide composition in which dicarboxylic acid contains at least 50 mol% of (a-1) alicyclic dicarboxylic acid.

[2]
(B) The polyamide composition according to [1], wherein the diamine contains (b-1) at least 50 mol% of a diamine having a substituent branched from the main chain.

[3]
(B-1) The polyamide composition according to [2], wherein the diamine having a substituent branched from the main chain is 2-methylpentamethylenediamine.

[4]
(A) The polyamide composition according to any one of [1] to [3], wherein the polyamide has a melting point of 270 to 350 ° C.

[5]
(A-1) The polyamide composition according to any one of [1] to [4], wherein the alicyclic dicarboxylic acid is 1,4-cyclohexanedicarboxylic acid.

[6]
(D) The polyamide composition according to any one of [1] to [5], wherein the organophosphorus antioxidant is a pentaerythritol phosphite compound.

[7]
(E) The polyamide composition according to any one of [1] to [6], further containing an inorganic phosphorus compound.

[8]
(E) The inorganic phosphorus compound is selected from the group consisting of metal phosphates, metal phosphites, metal hypophosphites, intramolecular condensates of these metal salts and intermolecular condensates of these metal salts. The polyamide composition according to [7], which is one or more.

[9]
(F) The polyamide composition according to any one of [1] to [8], further containing an inorganic filler.

[10]
(F) The polyamide composition according to [9], wherein the inorganic filler is at least one selected from the group consisting of glass fiber, potassium titanate fiber, talc, wollastonite, kaolin, mica, calcium carbonate, and clay. object.

[11]
(G) The polyamide composition according to any one of [1] to [10], further comprising an amine light stabilizer.

[12]
(A) For 100 parts by mass of polyamide,
(B) 5 to 120 parts by weight of titanium oxide,
(C) 0.01-2 parts by mass of a phenolic antioxidant and / or an amine antioxidant,
(D) 0.01-2 parts by mass of an organophosphorus antioxidant,
(E) 0 to 2 parts by mass of an inorganic phosphorus compound,
(F) The polyamide composition according to any one of [1] to [11], containing 0 to 200 parts by mass of an inorganic filler, and (G) 0 to 2 parts by mass of an amine light stabilizer.

[13]
The phosphorus element concentration (x) in the polyamide composition is 500 ppm to 1200 ppm with respect to 100 mass% in total of (A) polyamide, (D) organic phosphorus antioxidant and (E) inorganic phosphorus compound. Yes,
The ratio (y) of phosphorus element derived from (D) organophosphorus antioxidant to phosphorus element in the polyamide composition is 50 to 80%, and
The polyamide composition according to [7] or [8], wherein (x) and (y) satisfy the following formula (1).
600 <30y-x <1500 (1)

[14]
[1] A molded article comprising the polyamide composition according to any one of [13].

  According to the present invention, it is possible to provide a polyamide composition that is more excellent in reflow resistance, heat discoloration resistance and extrusion processability.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  The polyamide composition of the present embodiment includes (A) polyamide, (B) titanium oxide, (C) a phenolic antioxidant and / or an amine antioxidant, and (D) an organophosphorus antioxidant. And containing.

[(A) Polyamide]
The polyamide (A) used in the present embodiment is a polyamide having units consisting of the following (a) and (b).
(A) A dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid.
(B) Diamine.

  (A) In the polyamide, the proportion of the units consisting of the above (a) and (b) is preferably 20 to 100 mol%, and 90 to 100 mol%, in 100 mol% of all structural units of the polyamide. Is more preferable, and it is still more preferable that it is 100 mol%.

  (A) In the polyamide, the structural unit other than the units consisting of the above (a) and (b) is not particularly limited, and examples thereof include a unit consisting of (c) described later.

  In the present embodiment, the polyamide means a polymer having an amide (—NHCO—) bond in the main chain.

<(A) Dicarboxylic acid>
The (a) dicarboxylic acid used in the present embodiment contains at least 50 mol% (a-1) alicyclic dicarboxylic acid (based on the total number of moles of dicarboxylic acid). (A) When the ratio (mol%) of (a-1) alicyclic dicarboxylic acid in dicarboxylic acid is in the above range, heat resistance, fluidity, toughness, low water absorption, rigidity and the like are satisfied at the same time. A polyamide can be obtained.

  (A-1) The alicyclic dicarboxylic acid (also referred to as alicyclic dicarboxylic acid) is not particularly limited. For example, the alicyclic structure has 3 to 10 alicyclic dicarboxylic acids, preferably 5-10 alicyclic dicarboxylic acid of an alicyclic structure is mentioned. Specific examples of such alicyclic dicarboxylic acids include, but are not limited to, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid.

  (A-1) The alicyclic dicarboxylic acid may be unsubstituted or may have a substituent. Although this substituent is not particularly limited, for example, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Etc.

  (A-1) The alicyclic dicarboxylic acid is preferably 1,4-cyclohexanedicarboxylic acid from the viewpoints of heat resistance, low water absorption, rigidity and the like of the polyamide.

  (A-1) As alicyclic dicarboxylic acid, you may use by 1 type and may be used in combination of 2 or more types.

  An alicyclic dicarboxylic acid has a trans isomer and a cis geometric isomer. As the raw material monomer (a-1), the alicyclic dicarboxylic acid may be used in either a trans form or a cis form, or may be used as a mixture of various ratios of the trans form and the cis form.

  The alicyclic dicarboxylic acid has the characteristics that it is isomerized at a high temperature to have a certain ratio, and that the cis isomer has higher water solubility of the equivalent salt with the diamine than the trans isomer. From this, the trans isomer / cis isomer ratio (molar ratio) of the (a-1) alicyclic dicarboxylic acid as a raw material monomer is preferably 50/50 to 0/100, more preferably 40/60 to 10/90, more preferably 35/65 to 15/85.

  (A-1) The trans isomer / cis isomer ratio (molar ratio) of the alicyclic dicarboxylic acid can be determined by liquid chromatography (HPLC) or nuclear magnetic resonance spectroscopy (NMR).

  The (a) dicarboxylic acid used in the present embodiment may contain (a-2) a dicarboxylic acid other than (a-1). (A-2) The dicarboxylic acid other than (a-1) is not particularly limited, and examples thereof include aliphatic dicarboxylic acids and aromatic dicarboxylic acids.

  Examples of the aliphatic dicarboxylic acid include, but are not limited to, for example, malonic acid, dimethyl malonic acid, succinic acid, 2,2-dimethyl succinic acid, 2,3-dimethyl glutaric acid, 2,2-diethyl succinic acid, 2, 3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, Examples thereof include straight-chain or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms such as hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid, and diglycolic acid.

  The aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium sulfoisophthalic acid. Or an aromatic dicarboxylic acid having 8 to 20 carbon atoms which is unsubstituted or substituted with various substituents.

  Examples of the various substituents include, but are not limited to, halogens such as alkyl groups having 1 to 4 carbon atoms, aryl groups having 6 to 10 carbon atoms, arylalkyl groups having 7 to 10 carbon atoms, chloro groups, and bromo groups. Groups, silyl groups having 1 to 6 carbon atoms, sulfonic acid groups and salts thereof (sodium salts and the like), and the like.

  (A-2) As the dicarboxylic acid other than (a-1), it is preferable to use an aliphatic dicarboxylic acid from the viewpoints of heat resistance, fluidity, toughness, low water absorption, rigidity, and the like of the polyamide. Preferably, an aliphatic dicarboxylic acid having 6 or more carbon atoms is used.

  Among them, (a-2) As the dicarboxylic acid other than (a-1), an aliphatic dicarboxylic acid having 10 or more carbon atoms is preferable from the viewpoint of heat resistance and low water absorption of polyamide. Examples of the aliphatic dicarboxylic acid having 10 or more carbon atoms include sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedioic acid. Among these, sebacic acid and dodecanedioic acid are preferable from the viewpoint of heat resistance of the polyamide.

  (A-2) As the dicarboxylic acid other than (a-1), one kind may be used, or two or more kinds may be used in combination.

  (A) As the dicarboxylic acid component, a trivalent or higher polyvalent carboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid may be further included within the range not impairing the object of the present embodiment. As the polyvalent carboxylic acid, one kind may be used, or two or more kinds may be used in combination.

  The proportion (mol%) of (a-1) alicyclic dicarboxylic acid in (a) dicarboxylic acid is at least 50 mol%. The ratio of (a-1) alicyclic dicarboxylic acid in (a) dicarboxylic acid is 50 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%. Particularly preferred is 100 mol%. When the ratio of (a-1) alicyclic dicarboxylic acid in (a) dicarboxylic acid is at least 50 mol%, a polyamide having excellent heat resistance, low water absorption, rigidity, and the like can be obtained.

  (A) The ratio (mol%) of the dicarboxylic acid other than (a-2) (a-1) in the dicarboxylic acid is 0 to 50 mol%, preferably 0 to 40 mol%.

  When (a) the dicarboxylic acid component contains (a-2) an aliphatic dicarboxylic acid having 10 or more carbon atoms, (a-1) the alicyclic dicarboxylic acid is 50 to 99.9 mol% and (a- 2) The aliphatic dicarboxylic acid having 10 or more carbon atoms is preferably 0.1 to 50 mol%, (a-1) the alicyclic dicarboxylic acid is 60 to 95 mol%, and (a-2) 10 carbon atoms. More preferably, the aliphatic dicarboxylic acid is 5 to 40 mol%, (a-1) the alicyclic dicarboxylic acid is 80 to 95 mol%, and (a-2) the aliphatic dicarboxylic acid has 10 or more carbon atoms. Is more preferably 5 to 20 mol%.

  In the present embodiment, the (a) dicarboxylic acid is not limited to the compounds described as the dicarboxylic acid, and may be a compound equivalent to the dicarboxylic acid. The compound equivalent to the dicarboxylic acid is not particularly limited as long as it can be a dicarboxylic acid structure similar to the dicarboxylic acid structure derived from the dicarboxylic acid, and examples thereof include anhydrides and halides of dicarboxylic acids. Can be mentioned.

<(B) Diamine>
(A) The (b) diamine constituting the polyamide is not particularly limited, and examples thereof include a diamine having a substituent branched from the main chain, an aliphatic diamine, an alicyclic diamine, and an aromatic diamine. It is done. (B) The diamine preferably includes (b-1) a diamine having a substituent branched from the main chain. (B-1) By using a diamine containing a diamine having a substituent branched from the main chain, the desired polyamide composition can satisfy the fluidity, toughness, rigidity and the like at the same time. (B) The diamine more preferably contains (b-1) at least 50 mol% of a diamine having a substituent branched from the main chain.

  Although it does not specifically limit as a substituent branched from the principal chain, For example, C1-C1 such as a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and tert-butyl group 4 alkyl groups and the like.

  (B-1) The diamine having a substituent branched from the main chain is not particularly limited. For example, 2-methylpentamethylenediamine (also referred to as 2-methyl-1,5-diaminopentane), 2 , 2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 2-methyloctamethylenediamine, 2,4-dimethyloctamethylenediamine, etc., branched saturated aliphatic groups having 3 to 20 carbon atoms Examples include diamines.

  (B-1) The diamine having a substituent branched from the main chain is preferably 2-methylpentamethylenediamine from the viewpoints of heat resistance and rigidity. (B-1) As the diamine having a substituent branched from the main chain, one kind may be used, or two or more kinds may be used in combination.

  The diamine other than (b-2) (b-1) of (b) diamine used in the present embodiment is not particularly limited. For example, aliphatic diamine (however, excluding (b-1) above) ), Alicyclic diamines, and aromatic diamines.

  The aliphatic diamine (excluding the above (b-1)) is not particularly limited, and examples thereof include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, Examples thereof include linear saturated aliphatic diamines having 2 to 20 carbon atoms such as nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, and tridecamethylene diamine.

  The alicyclic diamine (also referred to as alicyclic diamine) is not particularly limited, and examples thereof include 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, and 1,3-cyclopentanediamine. It is done.

  The aromatic diamine is not particularly limited as long as it is an aromatic diamine, and examples thereof include metaxylylenediamine.

  (B-2) The diamine other than (b-1) is preferably an aliphatic diamine (provided that the above (b-) is used in view of heat resistance, fluidity, toughness, low water absorption, rigidity, and the like of the polyamide. 1) and alicyclic diamines, more preferably linear saturated aliphatic diamines having 4 to 13 carbon atoms, and still more preferably linear saturated aliphatic diamines having 6 to 10 carbon atoms. And more preferably hexamethylenediamine. (B-2) As the diamine other than (b-1), one kind may be used, or two or more kinds may be used in combination.

  (B) As the diamine component, a trivalent or higher polyvalent aliphatic amine such as bishexamethylene triamine may be further included within a range not impairing the object of the present embodiment. As the polyvalent aliphatic amine, one kind may be used, or two or more kinds may be used in combination.

  The ratio (mol%) of the diamine having a substituent branched from the main chain (b-1) in (b) diamine is not particularly limited, but is preferably 50 to 100 mol%, more preferably 60 to 100. It is mol%, More preferably, it is 85-100 mol%, Especially preferably, it is 90-100 mol%, Most preferably, it is 100 mol%. (B) When the ratio of the diamine having a substituent branched from the main chain (b-1) in the diamine is at least 50 mol%, a polyamide having excellent fluidity, toughness, and rigidity can be obtained.

  (B) Ratio (mol%) of diamine other than (b-2) (b-1) in diamine is preferably 0 to 50 mol%, more preferably 0 to 40 mol%. .

  (A) When manufacturing polyamide, it is preferable that the addition amount of (a) dicarboxylic acid and the addition amount of (b) diamine are the same molar amount vicinity. The amount of (b) diamine escaped from the reaction system during the polymerization reaction is also considered in terms of the molar ratio, and (a) the molar amount of (b) diamine as a whole is 0 It is preferable that it is 0.9-1.2, More preferably, it is 0.95-1.1, More preferably, it is 0.98-1.05.

<(C) Lactam and / or aminocarboxylic acid>
(A) Polyamide can further contain the unit which consists of (c) lactam and / or aminocarboxylic acid from a viewpoint of the toughness of polyamide. In addition, the (c) lactam and / or aminocarboxylic acid used in the present embodiment means a lactam and / or aminocarboxylic acid that can be condensed (condensed).

  When (A) polyamide is a polyamide obtained by polymerizing (a) dicarboxylic acid, (b) diamine, and (c) lactam and / or aminocarboxylic acid, (c) as lactam and / or aminocarboxylic acid Is preferably a lactam and / or aminocarboxylic acid having 4 to 14 carbon atoms, and more preferably a lactam and / or aminocarboxylic acid having 6 to 12 carbon atoms.

  Although it does not specifically limit as a lactam, For example, a butyrolactam, a pivalolactam, (epsilon) -caprolactam, a caprilactam, an enantolactam, undecanolactam, a laurolactam (dodecanolactam), etc. are mentioned. Among these, from the viewpoint of polyamide toughness, as the lactam, ε-caprolactam, laurolactam and the like are preferable, and ε-caprolactam is more preferable.

  The aminocarboxylic acid is not particularly limited, and examples thereof include ω-aminocarboxylic acid and α, ω-amino acid which are compounds in which the lactam is ring-opened.

  The aminocarboxylic acid is preferably a linear or branched saturated aliphatic carboxylic acid having 4 to 14 carbon atoms substituted at the ω position with an amino group. Such aminocarboxylic acid is not particularly limited, and examples thereof include 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of the aminocarboxylic acid include paraaminomethylbenzoic acid.

  (C) As a lactam and / or aminocarboxylic acid, you may use by 1 type and may be used in combination of 2 or more types.

  (A) When producing polyamide, (c) the addition amount (mol%) of lactam and / or aminocarboxylic acid is based on the total molar amount of each monomer of (a), (b) and (c). It is preferable that it is 0-20 mol%.

<End sealant>
When (A) polyamide is produced from (a) dicarboxylic acid and (b) diamine, a known end-capping agent can be further added for molecular weight adjustment.

  The end-capping agent is not particularly limited, and examples thereof include monocarboxylic acids, monoamines, acid anhydrides such as phthalic anhydride, monoisocyanates, monoacid halides, monoesters, and monoalcohols. From the viewpoint of thermal stability, monocarboxylic acids and monoamines are preferred. As the terminal blocking agent, one kind may be used, or two or more kinds may be used in combination.

  The monocarboxylic acid that can be used as the end-capping agent is not particularly limited as long as it has reactivity with an amino group. For example, formic acid, 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; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; and benzoic acid, toluyl Examples thereof include aromatic monocarboxylic acids such as acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. As monocarboxylic acid, you may use by 1 type and may be used in combination of 2 or more types.

  The monoamine that can be 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, Aliphatic monoamines such as decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; and aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine Is mentioned. Monoamines may be used alone or in combination of two or more.

<A combination of (a) dicarboxylic acid and (b) diamine>
The combination of (a) dicarboxylic acid and (b) diamine is not limited to the following, but (a-1) a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and (b-1) a branched branch from the main chain Preferred is a combination of diamines containing at least 50 mol% of diamines having a group, and (a-1) at least dicarboxylic acid containing at least 50 mol% of 1,4-cyclohexanedicarboxylic acid and (b-1) 2-methylpentamethylenediamine. A combination of diamines containing 50 mol% is more preferred.

  By using the polyamide (A) obtained by polymerizing using these combinations as raw material components, a polyamide that simultaneously satisfies heat resistance, fluidity, toughness, low water absorption, and rigidity is obtained. it can.

<Trans isomer ratio>
In (A) polyamide, the part derived from (a-1) alicyclic dicarboxylic acid exists as a geometric isomer of trans isomer and cis isomer.

  (A) In polyamide, the trans isomer ratio of the part derived from (a-1) alicyclic dicarboxylic acid is in the whole part derived from (a-1) alicyclic dicarboxylic acid in (A) polyamide. Represents the ratio of trans isomers. The trans isomer ratio is preferably 50 to 85 mol%, more preferably 50 to 80 mol%, still more preferably 60 to 80 mol%.

  (A-1) As the alicyclic dicarboxylic acid, it is preferable to use an alicyclic dicarboxylic acid having a trans isomer / cis isomer ratio (molar ratio) of 50/50 to 0/100. The polyamide obtained by the polymerization of (a) dicarboxylic acid and (b) diamine preferably has a trans isomer ratio of 50 to 85 mol% of the portion derived from (a-1) alicyclic dicarboxylic acid.

  When the ratio of the trans isomer is within the above range, (A) polyamide has a high melting point, toughness and rigidity, and has a high glass transition temperature (Tg) thermal rigidity and usually heat resistance. It has the property of satisfying both fluidity and high crystallinity, which are properties contrary to the properties.

  These characteristics of (A) polyamide are from the combination of (a) a dicarboxylic acid containing at least 50 mol% 1,4-cyclohexanedicarboxylic acid and (b) a diamine containing at least 50 mol% 2-methylpentamethylenediamine. This is particularly noticeable for polyamides obtained and having a trans isomer ratio of 50 to 85 mol%.

  In the present embodiment, the trans isomer ratio can be measured by the method described in the following examples.

<(A) Polyamide production method>
(A) The method for producing polyamide is not particularly limited, and includes, for example, a step of polymerizing (a) a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and (b) a diamine. And a method for producing polyamide.

  (A) As a manufacturing method of polyamide, it is preferable to further include the process of raising the polymerization degree of polyamide.

(A) As a concrete manufacturing method of polyamide, various methods are mentioned, for example so that it may illustrate below.
1) A method in which an aqueous solution or a suspension of water of a dicarboxylic acid / diamine salt or a mixture thereof is heated and polymerized while maintaining a molten state (hereinafter sometimes referred to as “hot melt polymerization method”),
2) A method of increasing the degree of polymerization while maintaining the solid state of the polyamide obtained by the hot melt polymerization method at a temperature below the melting point (hereinafter, sometimes abbreviated as “hot melt polymerization / solid phase polymerization method”). ,
3) A method in which an aqueous solution or a suspension of water of a diamine / dicarboxylate salt or a mixture thereof is heated and the precipitated prepolymer is melted again with an extruder such as a kneader to increase the degree of polymerization (hereinafter referred to as “pre-polymerization”). Abbreviated as “polymer / extrusion polymerization method”).
4) A method of heating an aqueous solution or a suspension of water of a diamine dicarboxylate or a mixture thereof and increasing the degree of polymerization while maintaining the solid state of the precipitated prepolymer at a temperature below the melting point of the polyamide (hereinafter, And may be abbreviated as “prepolymer / solid phase polymerization method”).
5) A method of polymerizing a diamine dicarboxylate or a mixture thereof while maintaining a solid state (hereinafter sometimes abbreviated as “solid phase polymerization method”),
6) A “solution method” in which a dicarboxylic acid halide component equivalent to a dicarboxylic acid and a diamine component are used for polymerization.

  (A) In the polyamide production method, from the viewpoint of the fluidity of the polyamide, it is preferable to carry out the polymerization while maintaining the trans isomer ratio of the alicyclic dicarboxylic acid at 85% or less, and in particular, the trans of the alicyclic dicarboxylic acid. By maintaining the isomer ratio at 80% or less, it is possible to obtain a polyamide having excellent color tone and tensile elongation and having a high melting point.

  (A) In the method for producing polyamide, it is preferable to increase the heating temperature or lengthen the heating time in order to increase the degree of polymerization and increase the melting point of the polyamide. When the heating temperature is increased or the heating time is increased, the polyamide may be colored by heating or the tensile elongation may decrease due to thermal deterioration. In addition, the rate at which the molecular weight of the polyamide increases may decrease significantly.

  Since it is possible to prevent a decrease in tensile elongation due to polyamide coloring or thermal deterioration, it is preferable to perform polymerization while maintaining the trans isomer ratio at 80% or less.

  (A) As a method for producing polyamide, since it is easy to maintain the trans isomer ratio at 85% or less and because the resulting polyamide has excellent color tone, 1) hot melt polymerization method, and 2 ) Hot melt polymerization / solid phase polymerization is preferred.

  (A) In the production method of polyamide, the polymerization form may be a batch type or a continuous type.

  The polymerization apparatus is not particularly limited, and examples thereof include known apparatuses such as an autoclave type reactor, a tumbler type reactor, and an extruder type reactor such as a kneader.

  (A) A more specific method for producing polyamide is not particularly limited, and examples thereof include a method for producing polyamide by a batch-type hot melt polymerization method described below.

  First, for example, about 40 to 60 containing raw material components of polyamide ((a) dicarboxylic acid, (b) diamine, and (c) lactam and / or aminocarboxylic acid, if necessary) using water as a solvent. The concentrated solution is concentrated to about 65 to 90% by weight in a concentration tank operated at a temperature of 110 to 180 ° C. and a pressure of about 0.035 to 0.6 MPa (gauge pressure). The concentrated solution is then transferred to an autoclave and heating is continued until the pressure in the autoclave is about 1.5 to 5.0 MPa (gauge pressure). Thereafter, in the autoclave, the pressure is maintained at about 1.5 to 5.0 MPa (gauge pressure) while removing water and / or gas components, and when the temperature reaches about 250 to 350 ° C., the pressure is reduced to atmospheric pressure. (The gauge pressure is 0 MPa). In the autoclave, the by-product water can be effectively removed by reducing the pressure to atmospheric pressure and then reducing the pressure as necessary. Thereafter, the autoclave is pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded as a strand from the autoclave. The strand is cooled and cut to obtain polyamide pellets.

  (A) As a more concrete manufacturing method of polyamide, it is not specifically limited, For example, polyamide can be manufactured with the continuous hot melt polymerization method described below.

  First, for example, about 40 to 60 containing raw material components of polyamide ((a) dicarboxylic acid, (b) diamine, and (c) lactam and / or aminocarboxylic acid, if necessary) using water as a solvent. The mass% solution is preheated to about 40-100 ° C. in a pre-equipment vessel and then transferred to a concentrator / reactor at a pressure of about 0.1-0.5 MPa (gauge pressure) and about 200-270. Concentrate to about 70-90% at a temperature of 0 C to obtain a concentrated solution. The concentrated solution is discharged into a flasher maintained at a temperature of about 200-350 ° C. Thereafter, the pressure in the flasher is reduced to atmospheric pressure (gauge pressure is 0 MPa). After reducing the pressure in the flasher to atmospheric pressure, the pressure is reduced as necessary. Thereafter, the polyamide melt is extruded from the flasher into strands, cooled and cut into pellets.

<(A) Polyamide polymer terminal>
The polymer terminal of (A) polyamide used in this embodiment is classified and defined as follows. That is, 1) amino terminal, 2) carboxylic acid terminal, 3) cyclic amino terminal, 4) terminal by sealing agent, and 5) other terminal.

1) The amino terminal is an amino group (—NH ₂ group) bonded to the polymer terminal, and is derived from the raw material diamine.

  2) The carboxylic acid terminal is a carboxyl group (—COOH group) bonded to the polymer terminal and is derived from the raw material dicarboxylic acid.

  3) The cyclic amino terminus is a cyclic amino group (group represented by the following formula 1) bonded to the polymer terminus. In the following formula 1, R represents a substituent bonded to the carbon constituting the piperidine ring. Specific examples of R include a hydrogen atom, a methyl group, an ethyl group, and a t-butyl group. Further, for example, even when piperidine cyclized by a deammonia reaction of a diamine having a pentamethylenediamine skeleton as a raw material is bonded to the polymer terminal, it becomes the terminal of this cyclic amino group. These structures may be taken when a monomer having a pentamethylenediamine skeleton is included.

４）封止剤による末端は、重合時に封止剤を添加した場合に形成される。封止剤としては、カルボン酸又はアミンが挙げられる。該封止剤によりポリマー末端が封止される。

4) The terminal by a sealing agent is formed when a sealing agent is added at the time of superposition | polymerization. Examples of the sealant include carboxylic acid or amine. The polymer ends are sealed with the sealant.

  5) The other terminal is a polymer terminal not classified into 1) to 4), such as a terminal generated by deammonia reaction at the amino terminal or a terminal generated by decarboxylation from a carboxylic acid terminal.

  In the present embodiment, 3) the amount of the cyclic amino terminus is preferably 30 μeq / g or more and 65 μeq / g or less, more preferably 30 μeq / g or more and 60 μeq / g or less, More preferably, it is 35 μeq / g or more and 55 μeq / g or less. When the amount of the cyclic amino terminal is within the above range, the toughness, hydrolysis resistance, and processability of the polyamide can be improved.

The amount of the cyclic amino terminus can be measured using ¹ H-NMR. For example, it can be calculated based on the integral ratio of hydrogen bonded to the carbon adjacent to the nitrogen atom of the heterocyclic ring of nitrogen and hydrogen bonded to the carbon adjacent to the nitrogen atom of the amide bond of the polyamide main chain.

  The cyclic amino terminus is generated by a dehydration reaction between a cyclic amine and a carboxylic acid terminus, or by a deammonification reaction of the amino terminus within a polymer molecule.

  The cyclic amino terminus can also be generated by adding a cyclic amine as a terminal blocking agent, or a diamine having a pentamethylenediamine skeleton, which is a polyamide raw material, is deammoniated and cyclized to form in the reaction system. It is also possible. In the present embodiment, the cyclic amino terminal is preferably derived from a raw material diamine. Adding a cyclic amine as an end-capping agent at the initial stage of polymerization results in the end of the low molecular weight carboxylic acid being capped at the initial stage of polymerization. It becomes difficult to obtain. In contrast, when a cyclic amine is generated during the reaction, the end of the carboxylic acid is capped with the cyclic amine at a later stage of polymerization, so that a high molecular weight polymer of polyamide is easily obtained.

  Cyclic amines, which produce a cyclic amino terminus, are produced as a by-product during the polyamide polymerization reaction. In this cyclic amine formation reaction, the higher the reaction temperature, the higher the reaction rate. Therefore, in order to make the cyclic amino terminal of the polyamide (A) used in this embodiment constant, it is preferable to promote the generation of cyclic amine. Therefore, the reaction temperature for the polymerization of polyamide is preferably 300 ° C. or higher, and more preferably 320 ° C. or higher.

  As a method for adjusting these cyclic amino ends to a certain amount, there is a method of controlling by appropriately adjusting the polymerization temperature, the time of 300 ° C. or more during the polymerization step, the addition amount of amine forming a cyclic structure, and the like. Can be mentioned.

  In the polyamide (A) used in the present embodiment, 2) the amount of the amino terminal is preferably 20 to 100 μeq / g, more preferably 25 to 70 μeq / g. When the amount of the amino terminal is within the above range, the hydrolysis resistance and heat retention stability of the polyamide can be improved.

<(A) Properties of polyamide>
As the molecular weight of the polyamide (A) used in the present embodiment, sulfuric acid relative viscosity ηr at 25 ° C. can be used as an index.

  The polyamide (A) used in the present embodiment has a 98% sulfuric acid concentration of 1% and a sulfuric acid relative viscosity ηr of 25 ° C. measured according to JIS-K6920 from the viewpoint of mechanical properties such as toughness and rigidity, and moldability. Preferably it is 1.5-7.0, More preferably, it is 1.7-6.0, More preferably, it is 1.9-5.5.

  In this embodiment, measurement of sulfuric acid relative viscosity ηr at 25 ° C. can be performed according to JIS-K6920 as described in the following examples.

  The melting point Tm2 of the (A) polyamide used in the present embodiment is preferably 270 to 350 ° C. from the viewpoint of heat resistance. (A) Melting | fusing point Tm2 of polyamide becomes like this. Preferably it is 270 degreeC or more, More preferably, it is 275 degreeC or more, More preferably, it is 280 degreeC or more. The melting point Tm2 of the (A) polyamide is preferably 350 ° C. or lower, more preferably 340 ° C. or lower, still more preferably 335 ° C. or lower, and still more preferably 330 ° C. or lower.

  (A) By setting the melting point Tm2 of the polyamide to 270 ° C. or higher, a polyamide having excellent heat resistance can be obtained. Further, by setting the melting point Tm2 of the polyamide (A) to 350 ° C. or lower, it is possible to suppress the thermal decomposition of the polyamide in the melt processing such as extrusion and molding.

  The heat of fusion ΔH of the polyamide (A) used in the present embodiment is preferably 10 J / g or more, more preferably 14 J / g or more, and further preferably 18 J / g or more, from the viewpoint of heat resistance. More preferably, it is 20 J / g or more.

  Measurement of the melting point Tm2 and the heat of fusion ΔH of the polyamide (A) used in the present embodiment can be performed according to JIS-K7121 by the method described in the examples below.

  Examples of the measuring device for the melting point and the heat of fusion include Diamond-DSC manufactured by PERKIN-ELMER.

  The glass transition temperature Tg of the (A) polyamide used in this embodiment is preferably 90 to 170 ° C. (A) The glass transition temperature of polyamide is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 110 ° C. or higher. Moreover, the glass transition temperature of (A) polyamide is preferably 170 ° C. or lower, more preferably 165 ° C. or lower, and further preferably 160 ° C. or lower.

  (A) By setting the glass transition temperature of polyamide to 90 ° C. or higher, a polyamide having excellent heat resistance and chemical resistance can be obtained. Moreover, the molded article with a good external appearance can be obtained by setting the glass transition temperature of (A) polyamide to 170 ° C. or lower.

  The glass transition temperature can be measured according to JIS-K7121 as described in the following examples.

  Examples of the glass transition temperature measuring device include Diamond-DSC manufactured by PERKIN-ELMER.

[(B) Titanium oxide]
The (B) titanium oxide used in the present embodiment is not particularly limited, and examples thereof include titanium oxide (TiO), dititanium trioxide (Ti ₂ O ₃ ), and titanium dioxide (TiO ₂ ). Of these, titanium dioxide is preferable.

  The crystal structure of (B) titanium oxide is not particularly limited, but is preferably a rutile type from the viewpoint of light resistance of the polyamide composition.

  (B) The number average particle diameter of titanium oxide is preferably 0.1 to 0.8 μm, more preferably 0.15 to 0.4 μm, from the viewpoint of toughness and extrusion processability of the polyamide composition. More preferably, it is 0.15-0.3 micrometer.

  (B) The number average particle diameter of titanium oxide can be measured by an electron micrograph. For example, the polyamide composition is put in an electric furnace, the organic matter contained in the polyamide composition is incinerated, and, for example, 100 or more arbitrarily selected titanium oxides from the residue are observed with an electron microscope. By measuring the particle diameter, it is possible to determine the number average particle diameter of (B) titanium oxide.

  (B) Titanium oxide may be obtained, for example, by a so-called sulfuric acid method in which a titanium sulfate solution is hydrolyzed, or may be obtained by a so-called chlorine method in which titanium halide is vapor-phase oxidized, and there is no particular limitation.

  (B) The surface of the titanium oxide particles is preferably coated. More preferably, the surface of the (B) titanium oxide particles is first coated with an inorganic coating and then with an organic coating applied over the inorganic coating. (B) The titanium oxide particles may be coated using any method known in the art. The inorganic coating preferably contains a metal oxide. The organic coating preferably includes one or more of carboxylic acids, polyols, alkanolamines and / or organosilicon compounds. Among these, from the viewpoint of light resistance and extrusion processability of the polyamide composition, the surface of the (B) titanium oxide particles is more preferably coated using polyols and organosilicon compounds. From the viewpoint of reducing generated gas, it is more preferable that coating is performed using an organosilicon compound.

  In addition, as (B) titanium oxide, 1 type may be used and it may be used in combination of 2 or more types.

  In the polyamide composition of the present embodiment, the content of (B) titanium oxide is 5 to 120 parts by mass with respect to 100 parts by mass of (A) polyamide from the viewpoint of whiteness of the polyamide composition. Preferably, it is 20-100 mass parts.

[(C) Phenol-based antioxidant and / or amine-based antioxidant]
The polyamide composition of the present embodiment contains (C) a phenol-based antioxidant and / or an amine-based antioxidant from the viewpoint of thermal stability.

  Although it does not specifically limit as a phenolic antioxidant, For example, a hindered phenol compound is mentioned. Phenol-based antioxidants, particularly hindered phenol compounds, have the property of imparting heat resistance and light resistance to resins such as polyamide and fibers.

  The hindered phenol compound is not particularly limited. For example, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide), penta Erythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydro Cinnamamide), triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3-t-butyl- 4-hydroxy-5-methylphenyl) propynyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxapyro [5,5] undecane, 3,5-di- -Butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, and 1,3,3 5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid. In this Embodiment, a phenolic antioxidant may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, from the viewpoint of improving the heat aging resistance, the phenolic antioxidant is preferably N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropylene). Onamide)].

  In the polyamide composition of the present embodiment, the content of the phenolic antioxidant is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the (A) polyamide. 1 part by mass. When the content of the phenolic antioxidant is within the above range, the polyamide composition can further improve the heat aging resistance and further reduce the amount of generated gas.

  The amine-based antioxidant is not particularly limited, and examples thereof include poly (2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1,2-dihydro-2,2,4-trimethyl. Quinoline, phenyl-α-naphthylamine, 4,4-bis (α, α-dimethyldendyl) diphenylamine, (p-toluenesulfonylamido) diphenylamine, N, N′-diphenyl-p-phenylenediamine, N, N′- Di-β-naphthyl-p-phenylenediamine, N, N′-di (1,4-dimethylpentyl) -p-phenylenediamine, N-phenyl-N′-isopropyl-p-phenylenediamine, N-phenyl-N '-1,3-dimethylbutyl-p-phenylenediamine, N- (1-methylheptyl) -N'-phenyl-p-phenylenediamine Which aromatic amines. In this embodiment, the amine-based antioxidant, refers to an aromatic amine compound.

  In the polyamide composition of the present embodiment, the content of the amine-based antioxidant is preferably 0.01 to 2 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the (A) polyamide. 1 part by mass. When the content of the amine-based antioxidant is within the above range, the polyamide composition can further improve the heat aging resistance and further reduce the amount of generated gas.

[(D) Organophosphorus antioxidant]
The (D) organophosphorus antioxidant used in the present embodiment is not particularly limited. For example, pentaerythritol phosphite compound, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphine Phyto, trisisodecyl phosphite, phenyl diisodecyl phosphite, phenyl di (tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite Phyto, tris (2,4-di-t-butylphenyl) phosphite, tris (2,4-di-t-butyl-5-methylphenyl) phosphite, tris (butoxyethyl) phosphite, , 4′-butylidene-bis (3-methyl-6-tert-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4′-isopropylidene diphenyldiphosphite, 4,4 ′ -Isopropylidenebis (2-t-butylphenyl) .di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-t-butyl) -4-hydroxyphenyl) butanediphosphite, tetra (tridecyl) -4,4'-butylidenebis (3-methyl-6-tert-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4'- Isopropylidene diphenyl diphosphite, tris (mono- and di-mixed nonylphenyl) phosphite, 9, 0-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris (3,5-di-t-butyl-4-hydroxyphenyl) phosphite, hydrogenated-4 , 4′-isopropylidene diphenyl polyphosphite, bis (octylphenyl) · bis (4,4′-butylidenebis (3-methyl-6-tert-butylphenyl)) · 1,6-hexanol diphosphite, hexatri Decyl-1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) diphosphite, tris (4,4′-isopropylidenebis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphine 2,2-methylenebis (3-methyl-4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4 Examples include '-biphenylene diphosphite and tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene diphosphite.

  In this Embodiment, (D) organophosphorus antioxidant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among the organophosphorus antioxidants (D) listed above, from the viewpoint of further improving the heat aging resistance of the polyamide composition and reducing the generated gas, pentaerythritol phosphite compound, tris (2,4-di- -T-butylphenyl) phosphite is preferred, and pentaerythritol phosphite compound is more preferred. The pentaerythritol-type phosphite compound is not particularly limited. For example, 2,6-di-t-butyl-4-methylphenyl phenyl pentaerythritol diphosphite, 2,6-di-t-butyl- 4-methylphenyl methyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl 2-ethylhexyl pentaerythritol diphosphite, 2,6-di-t-butyl-4- Methylphenyl isodecyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl lauryl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl isotridecyl Pentaerythritol diphosphite, 2,6-di-t-butyl-4- Tilphenyl stearyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl cyclohexyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl benzyl Pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl ethyl cellosolve pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl butyl carbitol penta Erythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl octylphenyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl nonylphenyl pentaerythritol di Phosphite, bis (2,6-di-t-butyl 4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-ethylphenyl) pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl 2,6-di-t-butylphenyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl, 2,4-di-t-butylphenyl pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl · 2,4-di-t-octylphenyl · pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl · 2-cyclohexyl Phenyl pentaerythritol diphosphite, 2,6-di-t-amyl-4-methylphenyl phenyl pentaerythritol Rudiphosphite, bis (2,6-di-t-amyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-octyl-4-methylphenyl) pentaerythritol diphosphite, And bis (2,4-dicumylphenyl) pentaerythritol diphosphite. In the present embodiment, the pentaerythritol phosphite compound may be used alone or in combination of two or more.

  Among the pentaerythritol type phosphite compounds listed above, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-) Ethylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-amyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,6-di-t-octyl-4-methylphenyl) Pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,4-dicumylphenyl) pentaerythritol diphosphite are preferred.

  In the polyamide composition of the present embodiment, the content of the (D) organophosphorus antioxidant is preferably 0.01 to 2 parts by mass, more preferably 100 parts by mass of the (A) polyamide. 0.1 to 2 parts by mass. (D) When the content of the organophosphorus antioxidant is within the above range, the polyamide composition can further improve the heat discoloration resistance and extrusion processability, and further reduce the amount of generated gas.

[(E) inorganic phosphorus compound]
The polyamide composition of the present embodiment can further contain (E) an inorganic phosphorus compound from the viewpoint of heat discoloration.

  (E) The inorganic phosphorus compound is not particularly limited. For example, 1) phosphoric acid, phosphorous acid, hypophosphorous acid, and intramolecular and / or intermolecular condensates thereof, 2) phosphoric acid, Examples thereof include phosphoric acid, hypophosphorous acid, and metal salts of intramolecular and / or intermolecular condensates thereof. (E) An inorganic phosphorus type compound may be used individually by 1 type, and may be used in combination of 2 or more type.

  The phosphoric acid, phosphorous acid, hypophosphorous acid, and intramolecular and / or intermolecular condensates thereof in 1) are not particularly limited, and examples thereof include phosphoric acid, pyrophosphoric acid, metaphosphoric acid, and phosphorous acid. And hypophosphorous acid, pyrophosphorous acid, diphosphorous acid and the like.

  2) Metal salts of phosphoric acid, phosphorous acid, hypophosphorous acid, and intramolecular and / or intermolecular condensates thereof are not particularly limited. For example, the phosphorous compound and periodic table of 1) above Examples include salts with Group 1 and Group 2, manganese, zinc, and aluminum.

  More preferable (E) inorganic phosphorus compounds are selected from the group consisting of metal phosphates, metal phosphites, metal hypophosphites, intramolecular condensates of these metal salts, and intermolecular condensates of these metal salts. One or more selected. Further preferred (E) inorganic phosphorus compounds are phosphorus compounds selected from phosphoric acid, phosphorous acid and hypophosphorous acid, and metals selected from Groups 1 and 2 of the periodic table, manganese, zinc and aluminum. Or an intramolecular condensate of these metal salts or an intermolecular condensate of these metal salts. A particularly preferred (E) inorganic phosphorus compound is a metal salt comprising a phosphorus compound selected from phosphoric acid, phosphorous acid and hypophosphorous acid and a metal selected from Groups 1 and 2 of the periodic table. Examples of such metal salts include, but are not limited to, monosodium phosphate, disodium phosphate, trisodium phosphate, monocalcium phosphate, dicalcium phosphate, tricalcium phosphate, sodium pyrophosphate, metalin Examples thereof include sodium acid, calcium metaphosphate, sodium hypophosphite, calcium hypophosphite and the like, and anhydrous salts and hydrates thereof. Among these, sodium hypophosphite and calcium hypophosphite are extremely preferable.

  In the polyamide composition of the present embodiment, the content of the (E) inorganic phosphorus compound is preferably 0 to 2 parts by mass, more preferably 0.01 to 100 parts by mass of the (A) polyamide. 2 parts by mass. (E) When the content of the inorganic phosphorus compound is within the above range, the polyamide composition can further improve the heat discoloration.

  In the polyamide composition of the present embodiment, when (E) an inorganic phosphorus compound is contained, the phosphorus element concentration (x) in the polyamide composition is (A) polyamide and (D) an organic phosphorus antioxidant. From the viewpoint of heat discoloration of the polyamide composition, it is preferably from 500 to 1200 ppm, more preferably from 500 to 1000 ppm, based on 100% by mass in total of (E) and the inorganic phosphorus compound.

  Furthermore, the ratio (y) of the phosphorus element derived from the organic phosphorus antioxidant (D) to the phosphorus element in the polyamide composition is 50 to 80%, from the viewpoint of the heat discoloration property of the polyamide composition To 60, more preferably 60 to 80%.

  Further, the phosphorus element concentration (x) in the polyamide composition and the ratio (y) of the phosphorus element derived from (D) the organic phosphorus antioxidant to the phosphorus element in the polyamide composition are expressed by the following formula ( Satisfying 1) is preferable from the viewpoint of heat discoloration of the polyamide composition.

600 <30y-x <1500 (1)
In addition, Formula (1) shows the range which exhibits the synergistic effect of (D) organic phosphorus antioxidant and (E) inorganic phosphorus compound. When x is too small, improvement in heat discoloration and the like may not be exhibited, and when x is too large, discoloration of the resin may be promoted by an increase in metal salt. Furthermore, when y is too small, the effect of the organic phosphorus antioxidant may not be exhibited. When y is too large, the composition may be discolored due to discoloration of the antioxidant itself. From the above, when 30y-x is within the above range, the synergistic effect of (D) the organic phosphorus antioxidant and (E) the inorganic phosphorus compound is exhibited, and the reflow resistance and heat discoloration of the polyamide composition are exhibited. Can be further improved, and stability during extrusion can be further improved.

In the polyamide composition of the present embodiment, satisfying the following (i) to (iii) is particularly preferable from the viewpoint of further improving the heat discoloration resistance of the polyamide composition.
(I) The phosphorus element concentration (x) in the polyamide composition is 500 with respect to 100% by mass in total of (A) polyamide, (D) organic phosphorus antioxidant and (E) inorganic phosphorus compound. ˜1200 ppm.
(Ii) The ratio (y) of phosphorus element derived from (D) organophosphorus antioxidant to phosphorus element in the polyamide composition is 50 to 80%.
(Iii) The phosphorus element concentration (x) in the polyamide composition and the ratio (y) of the phosphorus element derived from (D) the organic phosphorus antioxidant to the phosphorus element in the polyamide composition are 600 <30y− x <1500 must be satisfied.

  The polyamide composition satisfying the above (i) to (iii) is obtained by appropriately adjusting the addition amounts of the raw materials (A) polyamide, (D) organic phosphorus antioxidant and (E) inorganic phosphorus compound. Can do.

  In the present embodiment, the above (x) and (y) can be calculated by the method described in the examples described later.

[(F) Inorganic filler]
The polyamide composition of the present embodiment may further contain (F) an inorganic filler from the viewpoint of mechanical properties such as strength and rigidity.

  (F) The inorganic filler is not particularly limited. For example, glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, glass flake, talc, kaolin, mica, hydrotalcite, Calcium carbonate, zinc carbonate, zinc oxide, calcium monohydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, silicic acid Examples include magnesium, ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swellable fluoromica, and apatite. It is. Among these, (F) the inorganic filler is at least one selected from the group consisting of glass fiber, potassium titanate fiber, talc, wollastonite, kaolin, mica, calcium carbonate, and clay. It is preferable from the viewpoint of the mechanical strength, appearance, whiteness, etc. of the object.

  The shape of the glass fiber or carbon fiber may be a perfect circle or a flat cross section. Examples of the flat cross section include a rectangle, an oval close to a rectangle, an ellipse, and a bowl shape with a narrowed central portion in the longitudinal direction. The flatness ratio is expressed by D2 / D1, where D2 is the major axis of the fiber cross section and D1 is the minor axis of the fiber cross section. In the case of a perfect circle, the flatness is about 1.

  Glass fibers and carbon fibers have a number average fiber diameter of 3 to 30 μm and a weight average fiber length of 100 to 750 μm from the viewpoint that excellent mechanical strength characteristics can be imparted to the polyamide composition. More preferably, the aspect ratio (L / D) between the weight average fiber length L and the number average fiber diameter D is 10 to 100.

  Further, the glass fiber or carbon fiber preferably has a flatness of 1.5 or more, more preferably from the viewpoint of reduction of warpage of the plate-shaped molded product, heat resistance, toughness, low water absorption, and heat aging resistance. It is 1.5-10.0, More preferably, it is 2.5-10.0, Most preferably, it is 3.1-6.0. Glass fibers and carbon fibers having an aspect ratio within the above range are less likely to be crushed during mixing, molding, and other treatments in addition to mixing with other components, and the desired effect is easily exhibited.

  The thickness of the glass fiber or carbon fiber having an aspect ratio of 1.5 or more is arbitrary, but the minor axis D1 of the fiber cross section is 0.5 to 25 μm, and the major axis D2 of the fiber cross section is 1.25 to 250 μm. Preferably there is. When the thickness of the glass fiber or carbon fiber is within the above range, the fiber is easily spun, and the strength of the molded product tends to be improved by increasing the contact area with the resin.

  The minor axis D1 of the cross section of the fiber is preferably 3 μm or more. Furthermore, it is preferable that the minor axis D1 of the cross section of the fiber is 3 μm or more and the flatness of the fiber is larger than 3.

  These glass fibers and carbon fibers having a flatness ratio of 1.5 or more are produced, for example, by the method described in Japanese Patent Publication No. 3-59019, Japanese Patent Publication No. 4-13300, Japanese Patent Publication No. 4-32775, and the like. be able to. Particularly, in an orifice plate having a large number of orifices on the bottom surface, an orifice plate which surrounds a plurality of orifice outlets and has a convex edge extending downward from the bottom surface of the orifice plate, or a nozzle chip having one or a plurality of orifice holes. A glass fiber having a flatness ratio of 1.5 or more produced using a nozzle chip for deformed cross-section glass fiber spinning provided with a plurality of convex edges extending downward from the front end of the outer peripheral portion is preferable. These fibrous inorganic fillers may be used as fiber strands as rovings as they are, or may be used as chopped glass strands after further cutting.

  Here, the number average fiber diameter and the weight average fiber length in the present specification are, for example, arbitrarily selected from the residue, for example, by placing the polyamide composition in an electric furnace and incinerating the organic matter contained in the polyamide composition. More than 100 glass fibers were observed with a scanning electron microscope (SEM), and the number average fiber diameter was obtained by measuring the fiber diameters of these glass fibers, and SEM photographs at a magnification of 1000 times were used. There is a method of obtaining the weight average fiber length by measuring the fiber length.

  Further, the minor axis D1 and the major axis D2 of the cross section of the fiber in this specification can also be measured in the same manner as the method for measuring the number average fiber diameter and the weight average fiber length.

  You may surface-treat said glass fiber and carbon fiber with a silane coupling agent etc. Although it does not specifically limit as said silane coupling agent, For example, aminosilanes, such as (gamma) -aminopropyl triethoxysilane, (gamma) -aminopropyl trimethoxysilane, and N- (beta)-(aminoethyl) -gamma-aminopropylmethyldimethoxysilane. And the like; mercaptosilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane; epoxysilanes; vinylsilanes. Especially, it is preferable that it is 1 or more types selected from said enumeration component, and aminosilanes are more preferable.

  In addition, for the above glass fiber and carbon fiber, as a sizing agent, an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer containing the carboxylic acid anhydride-containing unsaturated vinyl monomer; An epoxy compound, a polyurethane resin, a homopolymer of acrylic acid, a copolymer of acrylic acid and other copolymerizable monomers; and their primary, secondary, and tertiary amines And a copolymer containing an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer and the carboxylic acid anhydride-containing unsaturated vinyl monomer. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Among them, from the viewpoint of the mechanical strength of the polyamide composition, the carboxylic acid anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer as structural units. Including copolymers, epoxy compounds and polyurethane resins, and combinations thereof, unsaturated vinyl monomers excluding carboxylic acid anhydride-containing unsaturated vinyl monomers and said carboxylic acid anhydride-containing unsaturated vinyl monomers And a combination of these as a structural unit and a polyurethane resin, and combinations thereof are more preferable.

  Glass fiber or carbon fiber is a fiber strand produced by applying a known sizing agent to a glass fiber or carbon fiber using a known method such as a roller-type applicator in a known glass fiber or carbon fiber production process. Can be obtained by continuous reaction by drying. The fiber strand may be used as a roving as it is, or may be used as a chopped glass strand by further obtaining a cutting step.

  The sizing agent preferably imparts (adds) 0.2 to 3% by mass, more preferably 0.3 to 2% by mass (as a solid fraction), with respect to 100% by mass of glass fiber or carbon fiber. Added. From the viewpoint of maintaining the bundling of the glass fiber or carbon fiber, the addition amount of the bundling agent is preferably 0.2% by mass or more as a solid content with respect to 100% by mass of the glass fiber or carbon fiber. On the other hand, the addition amount of the sizing agent is preferably 3% by mass or less from the viewpoint of improving the thermal stability of the polyamide composition. The strand may be dried after the cutting step, or may be cut after the strand is dried.

  Inorganic fillers other than glass fiber and carbon fiber include wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate, aluminum borate from the viewpoint of the strength, rigidity and surface appearance of the polyamide composition. Clay can be preferably used. More preferred are wollastonite, kaolin, mica and talc, still more preferred are wollastonite and mica, and particularly preferred is wollastonite. These inorganic fillers may be used individually by 1 type, and may be used in combination of 2 or more type.

  The average particle diameter of the inorganic filler other than glass fiber and carbon fiber is preferably 0.01 to 38 μm, more preferably 0.03 to 30 μm, further preferably 0.05 to 25 μm, in terms of toughness and surface appearance. 0.1-20 micrometers is still more preferable, and 0.15-15 micrometers is especially preferable.

  By setting the average particle size to 38 μm or less, a polyamide composition having excellent toughness and surface appearance can be obtained. Further, by making the average particle size 0.1 μm or more, the balance between cost and powder handling surface and physical properties is excellent.

  In addition, the average particle diameter in this specification can be measured by SEM, for example.

  Among inorganic fillers, the number average fiber diameter is the average particle diameter for an inorganic filler having a needle-like shape such as wollastonite. Furthermore, in the case of an inorganic filler whose cross section is not a circle, the maximum value of the length is taken as the fiber diameter.

  Regarding the aspect ratio (L / D) between the weight average fiber length L and the number average fiber diameter D of the inorganic filler having a needle shape, from the viewpoint of the appearance of the molded product and the wear of metallic parts such as injection molding machines. 1.5 to 10 is preferable, 2.0 to 5 is more preferable, and 2.5 to 4 is still more preferable.

  Further, inorganic fillers other than glass fibers and carbon fibers used in the present embodiment are subjected to a surface treatment with a usual surface treatment agent, for example, a coupling agent such as a silane coupling agent or a titanate coupling agent. Can be used. Although it does not specifically limit as a silane coupling agent, For example, an epoxy silane coupling agent can be mentioned preferably. As the silane coupling agent, a mixture of polyalkoxysiloxane and epoxysilane coupling agent and / or a reaction product of polyalkoxysiloxane and epoxysilane coupling agent can also be preferably used. Such a surface treatment agent may be added in advance to the surface of the (F) inorganic filler, or may be added when the (A) polyamide and the (F) inorganic filler are mixed. Moreover, the addition amount of a preferable surface treating agent is the range of 0.05 mass%-1.5 mass% with respect to (F) inorganic filler.

  In the polyamide composition of the present embodiment, the content of (F) inorganic filler is preferably 0 to 200 parts by mass, more preferably 1 to 200 parts by mass with respect to 100 parts by mass of (A) polyamide. More preferably, it is 2 to 180 parts by mass. (F) When content of an inorganic filler exists in said range, the intensity | strength of a polyamide composition, rigidity, and toughness can be maintained with sufficient balance.

[(G) Amine-based light stabilizer]
The polyamide composition of the present embodiment may further contain (G) an amine light stabilizer from the viewpoint of light stability.

  (G) The amine light stabilizer is not particularly limited, and examples thereof include 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine. 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6- Tetramethylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6- Tetramethylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine 4- (ethylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy)- 2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) oxalate, Bis (2,2,6,6-tetramethyl-4-piperidyl) malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl) -4-piperidyl) adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) terephthalate, bis (1,2,2,6,6-pentamethy -4-piperidyl) carbonate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) oxalate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) malonate, bis (1 , 2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) adipate, bis (1,2,2,6,6-pentamethyl) -4-piperidyl) terephthalate, N, N′-bis-2,2,6,6-tetramethyl-4-piperidinyl-1,3-benzenedicarboxamide, 1,2-bis (2,2,6, 6-tetramethyl-4-piperidyloxy) ethane, α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2,6,6- Tetramethyl -4-piperidyltolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylene-1,6-dicarbamate, tris (2,2,6, 6-tetramethyl-4-piperidyl) -benzene-1,3,5-tricarboxylate, N, N ′, N ″, N ′ ″-tetrakis- (4,6-bis- (butyl- (N -Methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine, dibutylamine 1,3,5- Triazine N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) -1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl ) Butylamine polycondensate, poly {6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino } Hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4- Butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tris (2,2,6,6-tetramethyl- 4-piperidyl) -benzene-1,3,4-tricarboxylate, 1- [2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} butyl] -4- [ 3- (3,5-di-t Butyl-4-hydroxyphenyl) propionyloxy] 2,2,6,6-tetramethylpiperidine, and 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4- Examples include condensates of piperidinol and β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol. In this Embodiment, (G) amine light stabilizer may be used individually by 1 type, and may be used in combination of 2 or more type.

  The amine light stabilizer (G) is preferably a low molecular weight type having a molecular weight of less than 2,000 from the viewpoint of further improving the light stability of the polyamide composition. More preferably, the molecular weight of the (G) amine light stabilizer is less than 1,000.

  In addition, (G) amine light stabilizers are NH type (indicating that hydrogen is bonded to an amino group), NR type (indicating that an alkyl group is bonded to an amino group). There are types such as NOR type (indicating that an alkoxy group is bonded to an amino group) and the like. Among them, the NH type is preferable from the viewpoint of further improving the light stability of the polyamide composition. .

  (G) As amine-based light stabilizers, bis (2,2,6,6-tetramethyl-4-piperidyl) carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) oxalate, bis (2,2,6,6-tetramethyl-4-piperidyl) malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl- 4-piperidyl) adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) terephthalate, N, N′-bis-2,2,6,6-tetramethyl-4-piperidinyl-1,3 Benzenedicarboxamide, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate is preferred, bis (2,2,6,6-tetra Methyl-4-piperidyl) sebacate, N, N′-bis-2,2,6,6-tetramethyl-4-piperidinyl-1,3-benzenedicarboxamide, tetrakis (2,2,6,6-tetra More preferred is methyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, N, N′-bis-2,2,6,6-tetramethyl-4-piperidinyl-1,3-benzene More preferred is dicarboxamide.

  In the polyamide composition of the present embodiment, the content of the (G) amine light stabilizer is preferably 0 to 2 parts by mass, more preferably 0.01 to 100 parts by mass of the (A) polyamide. It is -1 mass part, More preferably, it is 0.1-1 mass part. (G) When the content of the amine light stabilizer is within the above range, the light stability and heat aging resistance of the polyamide composition can be further improved, and the amount of generated gas can be further reduced.

[Other components that may be included in the polyamide composition]
In the polyamide composition of the present embodiment, in addition to the above-described components, other components may be added as necessary within a range not impairing the effects of the present embodiment.

  Examples of other components include, but are not limited to, colorants such as pigments and dyes (including colored master batches), mold release agents, flame retardants, fibrillating agents, lubricants, optical brighteners, plasticizers, Copper compounds, alkali metal halide compounds, antioxidants, stabilizers, UV absorbers, antistatic agents, fluidity improvers, fillers, reinforcing agents, spreading agents, nucleating agents, rubbers, reinforcing agents and other polymers Etc. Here, since the above-mentioned other components are greatly different in properties, there are various suitable contents for each component that hardly impair the effects of the present embodiment. A person skilled in the art can easily set a suitable content for each of the other components described above.

[Method for producing polyamide composition]
The production method of the polyamide composition of the present embodiment includes (A) polyamide, (B) titanium oxide, (C) phenolic antioxidant and / or amine antioxidant, (D) organophosphorus oxidation. If it is the method of mixing each raw material component containing an inhibitor and also (E) inorganic phosphorus compound, (F) inorganic filler, and (G) amine photo-antioxidant as needed, it will not specifically limit.

  The method for mixing (A) polyamide and (B) titanium oxide is not particularly limited. For example, it can be obtained by mixing (A) polyamide and (B) titanium oxide using a tumbler, Henschel mixer or the like. And a method of blending (B) titanium oxide from the side feeder into (A) polyamide that has been melted with a single-screw or twin-screw extruder.

  (F) The same method can also be used when blending an inorganic filler, (A) a method of mixing with polyamide or the like, supplying the resulting mixture to a melt kneader, kneading, Examples thereof include a method of blending (F) an inorganic filler from a side feeder into (A) polyamide and (B) titanium oxide that have been melted by a twin-screw extruder.

  The method of supplying each component of the polyamide composition to the melt kneader may be a method of supplying all the components to the same supply port at a time, or a method of supplying each component from a different supply port. .

  The melt kneading temperature is preferably 250 to 375 ° C. as the resin temperature, and the melt kneading time is preferably 0.25 to 5 minutes.

  The apparatus for performing the melt-kneading is not particularly limited, and a known apparatus such as a single- or twin-screw extruder, a Banbury mixer, and a mixing roll can be used.

  The 25 ° C. sulfuric acid relative viscosity ηr, the melting point Tm2, the heat of fusion ΔH, and the glass transition temperature Tg of the polyamide composition of the present embodiment can be measured by the same method as that for the polyamide. Moreover, when the measured value in a polyamide composition exists in the range similar to a preferable range as a measured value of the said polyamide, the polyamide composition excellent in heat resistance, a moldability, and chemical resistance can be obtained.

[Molding]
The molded article of the present embodiment includes the above-described polyamide composition.

  The molded product of the present embodiment can be obtained, for example, by molding the above-described polyamide composition by a known molding method. The known molding method is not particularly limited, and generally includes, for example, press molding, injection molding, gas assist injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, and melt spinning. Known plastic molding methods can be mentioned.

  The molded article of the present embodiment is excellent in heat resistance, moldability, mechanical strength, and low water absorption by being obtained from the above polyamide composition. Therefore, the above-mentioned polyamide composition can be suitably used as various parts materials for automobiles, electric and electronic use, industrial materials, daily use and household goods, and also suitably used for extrusion applications. be able to.

  It is not particularly limited for automobiles, and is used for, for example, intake system parts, cooling system parts, fuel system parts, interior parts, exterior parts, and electrical parts.

  The automobile intake system parts are not particularly limited, and examples include an air intake manifold, an intercooler inlet, an exhaust pipe cover, an inner bush, a bearing retainer, an engine mount, an engine head cover, a resonator, and a throttle body.

  The automobile cooling system component is not particularly limited, and examples thereof include a chain cover, a thermostat housing, an outlet pipe, a radiator tank, an oil netter, and a delivery pipe.

  The automobile fuel system parts are not particularly limited, and examples thereof include a fuel delivery pipe and a gasoline tank case.

  The automobile interior part is not particularly limited, and examples thereof include an instrument panel, a console box, a glove box, a steering wheel, and a trim.

  The automobile exterior part is not particularly limited, and examples thereof include a mall, a lamp housing, a front grille, a mud guard, a side bumper, a door mirror stay, and a roof rail.

  The automobile electrical component is not particularly limited, and examples thereof include a connector, a wire harness connector, a motor component, a lamp socket, a sensor on-vehicle switch, and a combination switch.

  The electrical and electronic use is not particularly limited, and examples thereof include connectors, switches, relays, printed wiring boards, electronic component housings, outlets, noise filters, coil bobbins, reflectors, and motor end caps.

  The industrial equipment is not particularly limited, and examples thereof include gears, cams, insulating blocks, valves, power tool parts, agricultural equipment parts, engine covers, and the like.

  There are no particular limitations on daily and household items, and examples include buttons, food containers, and office furniture.

  The extrusion application is not particularly limited, and examples thereof include films, sheets, filaments, tubes, rods, and hollow molded products.

  Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples. However, the present embodiment is not limited to these examples.

The raw materials and measurement methods used in Examples and Comparative Examples are shown below. In this example, 1 kg / cm ² means 0.098 MPa.

[raw materials]
≪ (A) Polyamide≫
The polyamide (A) used in the present examples and comparative examples was prepared by appropriately using the following (a) and (b).

<(A) Dicarboxylic acid>
(A-1-1) 1,4-cyclohexanedicarboxylic acid (CHDA) (manufactured by Eastman Chemical Co., Ltd., trade name: 1,4-CHDA HP grade (trans isomer / cis isomer = 25/75))
(A-2-1) Terephthalic acid (TPA) (manufactured by Wako Pure Chemical Industries, Ltd.)
<(B) Diamine>
(B-1-1) 2-methylpentamethylenediamine (2MC5DA) (manufactured by Tokyo Chemical Industry)
(B-2-1) 1,9-nonamethylenediamine (C9DA) (manufactured by Aldrich)
(B-1-2) 2-methyloctamethylenediamine (2MC9DA) (produced with reference to the production method described in JP-A No. 05-17413)
(B-2-2) 1,10-diaminodecane (C10DA) (manufactured by Tokyo Chemical Industry Co., Ltd.)

≪ (B) Titanium oxide≫
(B-1) TiO ₂ (manufactured by Ishihara Sangyo Co., Ltd., trade name: Taipei (registered trademark) CR-63, number average particle size: 0.21 μm, coating: alumina, silica and siloxane compound)
In this example, the number average particle diameter of (B) titanium oxide was measured by electron micrograph as follows. The polyamide composition is put into an electric furnace, the organic matter contained in the polyamide composition is incinerated, and 100 or more titanium oxides arbitrarily selected from the residue are observed with an electron microscope, and the particle diameters thereof are determined. The number average particle diameter of (B) titanium oxide was calculated | required by measuring.

≪ (C) Phenolic antioxidants≫
(C-1) Phenolic antioxidant (manufactured by Sumitomo Chemical Co., Ltd., trade name: SUMILIZER (registered trademark) GA-80)

≪ (D) Organophosphorus antioxidant≫
(D-1) Organophosphorus antioxidant (Dover Chemical Co., bis (2,4-dicumylphenyl) pentaerythritol diphosphite, trade name: Doverphos (registered trademark) S-9228, molecular weight: 852)
(D-2) Organophosphorus antioxidant (manufactured by Adeka Corporation, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, trade name: ADK STAB (registered trademark) PEP-36 , Molecular weight: 633)
(D-3) Organophosphorus antioxidant (manufactured by Ciba, Tris (2,4-di-t-butylphenyl) phosphite, trade name: IRGAFOS (registered trademark) 168, molecular weight: 647)

≪ (E) Inorganic phosphorus compound≫
(E-1) Inorganic phosphorus compound (made by Wako Pure Chemical Industries, Ltd., trade name: sodium hypophosphite monohydrate)

≪ (F) Inorganic filler≫
(F-1) Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., trade name: ECS 03T-275H, number average fiber diameter 10 μmφ, cut length 3 mm)
(F-2) Wollastonite (manufactured by NYCO, trade name: NYGLOS8, number average fiber diameter 8 μm)
In this example, the number average fiber diameter of the inorganic filler (F) was arbitrarily selected from the residue by putting the polyamide composition into an electric furnace and incinerating the organic matter contained in the polyamide composition. The number average fiber diameter was determined by observing 100 or more glass fibers with an SEM and measuring the fiber diameter of these glass fibers.

≪ (G) Amine-based light stabilizer≫
(G-1) Hindered amine light stabilizer (HALS) (manufactured by Clariant, trade name: Nylostab (registered trademark) S-EED, molecular weight: 443)
[Calculation of polyamide content]
(A-1) The mol% of the alicyclic dicarboxylic acid is (the number of moles of (a-1) alicyclic dicarboxylic acid added as a raw material monomer / the number of moles of all (a) dicarboxylic acids added as raw material monomers. ) × 100.

  (B-1) The mol% of the diamine having a substituent branched from the main chain was added as the raw material monomer (b-1) The number of moles of the diamine having the substituent branched from the main chain / the raw material monomer. All (b) moles of diamine) × 100 were obtained by calculation.

  In addition, when calculating by the above formula, the denominator and the numerator do not include the number of moles of the diamine having a branched main chain (b-1) added as an additional component.

[Measuring method]
(1) Melting point Tm2 (° C.), heat of fusion ΔH (J / g)
According to JIS-K7121, the melting point Tm2 (° C.) and the heat of fusion ΔH (J / g) of polyamide were measured using Diamond-DSC manufactured by PERKIN-ELMER. Specifically, it measured as follows. First, about 10 mg of a sample was heated to 300 to 350 ° C. in a nitrogen atmosphere at a temperature rising rate of 20 ° C./min depending on the melting point of the sample. The temperature of the endothermic peak (melting peak) appearing at this time was defined as Tm1 (° C.). Next, the temperature was kept for 2 minutes in the molten state at the highest temperature rise. Thereafter, the temperature was decreased to 30 ° C. at a temperature decrease rate of 20 ° C./min, and held at 30 ° C. for 2 minutes. Then, it heated up to 300-350 degreeC according to melting | fusing point of the sample at the temperature increase rate of 20 degreeC / min. The maximum peak temperature of the endothermic peak (melting peak) appearing at this time was the melting point Tm2 (° C.), and the total peak area was the heat of fusion ΔH (J / g). When there were a plurality of peaks, those having ΔH of 1 J / g or more were regarded as peaks, and the endothermic peak temperature having the maximum ΔH was defined as the melting point Tm2 (° C.). For example, when there are two peaks, an endothermic peak temperature of 295 ° C. (ΔH = 20 J / g) and an endothermic peak temperature of 325 ° C. (ΔH = 25 J / g), the melting point Tm2 is 325 ° C. = 25 J / g.

(2) Trans isomer ratio (A) The trans isomer ratio of the part derived from (a-1) alicyclic dicarboxylic acid in polyamide was measured as follows. 30-40 mg of polyamide was dissolved in 1.2 g of hexafluoroisopropanol deuteride, and the trans isomer ratio was measured by ¹ H-NMR using the obtained solution. In the case of 1,4-cyclohexanedicarboxylic acid, the trans isomer ratio was determined from the ratio of the peak area of 1.98 ppm derived from the trans isomer and the peak areas of 1.77 ppm and 1.86 ppm derived from the cis isomer. .

(3) Glass transition temperature Tg (° C)
The glass transition temperature Tg (° C.) was measured using Diamond-DSC manufactured by PERKIN-ELMER according to JIS-K7121. Specifically, it measured as follows. The sample was melted on a hot stage (EP80 manufactured by Mettler), and the obtained sample in a molten state was rapidly cooled using liquid nitrogen and solidified to obtain a measurement sample. 10 mg of the measurement sample was heated by the DSC in the range of 30 to 350 ° C. under a temperature rising rate of 20 ° C./min, and the glass transition temperature Tg (° C.) observed at the time of the temperature rising. Was measured.

(4) Sulfuric acid relative viscosity ηr at 25 ° C
The sulfuric acid relative viscosity ηr at 25 ° C. was measured according to JIS-K6810. Specifically, a 1% concentration solution ((polyamide 1 g) / (98% sulfuric acid 100 mL)) was prepared using 98% sulfuric acid, and a temperature of 25 ° C. was obtained using the obtained solution. The sulfuric acid relative viscosity ηr was measured under the conditions.

(5) Reflectance after reflow process (%)
The polyamide composition pellets obtained in the examples and comparative examples were molded using an injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], whereby length 60 mm × width 60 mm × thickness 2.0 mm. A molded piece of was made. During the molding, the injection + holding time was 10 seconds, the cooling time was 15 seconds, the mold temperature was set to 120 ° C., and the molten resin temperature was set to (A) the melting point Tm2 + 20 ° C. of the polyamide.

  The obtained molded piece was heat-treated (reflow process) three times in a hot air reflow furnace (280 ° C. × 10 seconds). The reflectance of the molded piece before and after the treatment (reflow process) was measured with a spectrophotometer.

(6) Reflectance retention after heat treatment (%)
The molded piece obtained by the above (5) was heat-treated in a hot air dryer at 180 ° C. for 100 hours or in a hot air dryer at 120 ° C. for 500 hours. The reflectance of the molded piece after the heat treatment was measured with a spectrophotometer in the same manner as in (5) above. Based on the measurement results, the retention ratio of the reflectance of the molded piece after the heat treatment relative to the reflectance of the molded piece before the heat treatment was calculated from the following formula.
Reflectivity retention after heat treatment (%) = (reflectance of molded piece after heat treatment) / (reflectance of molded piece before heat treatment) × 100

(7) Extrudability The pellets of the polyamide composition obtained in Examples and Comparative Examples were extruded by a twin screw extruder having a screw diameter of 26 mm. During the extrusion process, the temperature of the cylinder was set to Tm2 + 20 ° C. of (A) polyamide, the screw rotation speed was set to 250 rpm, and the discharge amount was set to 25 kg / h. The number of strand breaks generated in 20 minutes from the start of extrusion was measured. The smaller the number of strand breaks, the better the extrudability.

≪ (A) Manufacture of polyamide≫
[Production Example 1]
CHDA 896 g (5.20 mol) and 2MC5DA 604 g (5.20 mol) were dissolved in 1500 g of distilled water to prepare an aqueous mixture of 50 mol% of equimolar amounts of the raw material monomers.
The obtained water mixture and 21 g (0.18 mol) of 2MC5DA, which is an additive at the time of melt polymerization, were charged into an autoclave (made by Nitto Koatsu) with an internal volume of 5.4 L. Next, it heated until the liquid temperature (internal temperature) in an autoclave became 50 degreeC. Thereafter, the inside of the autoclave was purged with nitrogen. Until the pressure in the autoclave tank (hereinafter also referred to simply as “inside the tank”) reaches about 2.5 kg / cm ² as gauge pressure (hereinafter, all pressure in the tank is expressed as gauge pressure). Heating was continued (at this time the liquid temperature was up to about 145 ° C.). While maintaining the pressure in the tank at about 2.5 kg / cm ² , heating was continued while removing water out of the system, and the solution was concentrated until the concentration of the aqueous solution in the tank was about 85% by mass. The removal of water was stopped, and heating was continued until the pressure in the tank reached about 30 kg / cm ² . While maintaining the pressure in the tank at about 30 kg / cm ² , the water was removed from the system, and heating was continued until the temperature reached 50 ° C. (about 295 ° C.) lower than the final temperature (about 345 ° C.). While further heating, the pressure in the tank was reduced to atmospheric pressure (gauge pressure was 0 kg / cm ² ) over 60 minutes. The heater temperature was adjusted so that the final temperature of the resin temperature (liquid temperature) in the tank was about 345 ° C. While maintaining the resin temperature in the tank, the inside of the tank was maintained for 10 minutes under a reduced pressure of 100 torr with a vacuum apparatus. Then, the inside of the tank was pressurized with nitrogen, and the product was discharged in a strand form from the lower nozzle (nozzle). Furthermore, the strand-like product was cooled with water and cut to obtain pellets of polyamide (polyamide pellets).

[Production Example 2]
10 kg of polyamide pellets obtained using the melt polymerization described in Production Example 1 are placed in a conical ribbon vacuum dryer (trade name ribocorn RM-10V, manufactured by Okawara Seisakusho Co., Ltd.), and the inside of the vacuum dryer is sufficiently nitrogen-substituted. did. The polyamide pellets were heated at 260 ° C. for 6 hours with stirring while nitrogen was passed through the vacuum dryer at 1 L / min. Thereafter, the temperature in the vacuum dryer is lowered to about 50 ° C. while circulating nitrogen, and the polyamide pellets are taken out from the vacuum dryer in the form of pellets, and polyamide (hereinafter also abbreviated as “PA-1”) is removed. Obtained. The obtained polyamide was dried in a nitrogen stream to adjust the moisture content to less than about 0.2% by mass, and then each property of the polyamide was measured based on the above measurement method. As a result of the measurement, the polyamide (PA-1) had a melting point Tm2 of 327 ° C., a glass transition temperature Tg of 150 ° C., a trans isomer ratio of 71%, and a sulfuric acid relative viscosity of 25 ° C. of 3.1.

[Production Example 3]
CHDA 782 g (4.54 mol), C9DA 575 g (3.63 mol), and 2MC8DA 144 g (0.91 mol) were dissolved in distilled water 1500 g to prepare an aqueous mixed solution of equimolar 50 mass% of the raw material monomer.
The obtained water mixture and 11 g (0.07 mol) of C9DA, which is an additive at the time of melt polymerization, were charged into an autoclave (made by Nitto Koatsu Co., Ltd.) having an internal volume of 5.4 L. Next, it heated until the liquid temperature (internal temperature) in an autoclave became 50 degreeC. Thereafter, the inside of the autoclave was purged with nitrogen.
Until the pressure in the autoclave tank (hereinafter also referred to simply as “inside the tank”) reaches about 2.5 kg / cm ² as gauge pressure (hereinafter, all pressure in the tank is expressed as gauge pressure). Heating was continued (at this time the liquid temperature was up to about 145 ° C.). Heating was continued while removing water out of the system in order to keep the pressure in the tank at about 2.5 kg / cm ^2, and the solution was concentrated until the concentration of the aqueous solution in the tank was about 75% by mass. The removal of water was stopped, and heating was continued until the pressure in the tank reached about 30 kg / cm ² . While maintaining the pressure in the tank at about 30 Kg / cm ² , heating was continued until the temperature reached 50 ° C. (about 290 ° C.) lower than the final temperature (about 340 ° C.) while removing water from the system. While further heating, the pressure in the tank was reduced to atmospheric pressure (gauge pressure was 0 kg / cm ² ) over 90 minutes. The heater temperature was adjusted so that the final temperature of the resin temperature (liquid temperature) in the tank was about 340 ° C. While maintaining the resin temperature in the tank, the inside of the tank was maintained for 30 minutes under a reduced pressure of 400 torr with a vacuum apparatus. Then, the inside of the tank was pressurized with nitrogen, and the product was discharged in a strand form from the lower nozzle (nozzle). Further, the strand-like product was cooled with water and cut to obtain a pellet-like polyamide (hereinafter also abbreviated as “PA-2”). The obtained polyamide was dried in a nitrogen stream to adjust the moisture content to less than about 0.2% by mass, and then each property of the polyamide was measured based on the above measurement method. As a result of the measurement, the polyamide (PA-2) had a melting point Tm2 of 316 ° C., a glass transition temperature Tg of 119 ° C., a trans isomer ratio of 70%, and a sulfuric acid relative viscosity at 25 ° C. of 2.4.

[Production Example 4]
CHDA 750 g (4.35 mol) was used as the raw material dicarboxylic acid, C10DA 750 g (4.35 mol) was used as the raw material diamine, C10DA 15 g (0.09 mol) was used as an additive during melt polymerization, and the resin temperature ( Polymerization was carried out in the same manner as described in Production Example 3 except that the final temperature of the liquid temperature was 355 ° C. to obtain polyamide (hereinafter also abbreviated as “PA-3”). The obtained polyamide was dried in a nitrogen stream to adjust the moisture content to less than about 0.2% by mass, and then each property of the polyamide was measured based on the above measurement method. As a result of the measurement, the polyamide (PA-3) had a melting point Tm2 of 334 ° C., a glass transition temperature Tg of 121 ° C., a trans isomer ratio of 70%, and a sulfuric acid relative viscosity at 25 ° C. of 2.3.

[Comparative Production Example 1]
Polyamide 9T (hereinafter also abbreviated as “PA-4”) was produced according to the method described in Example 1 of JP-A-7-228689. At that time, terephthalic acid was used as the starting dicarboxylic acid, and 1,9-nonamethylenediamine and 2-methyloctamethylenediamine [1,9-nonamethylenediamine: 2-methyloctamethylenediamine = 80: 20 (molar ratio)] was used.
Specifically, the above raw materials, distilled water and the like were put into a 20 liter autoclave to obtain a water mixture. Next, the inside of the autoclave was replaced with nitrogen. Thereafter, the water mixture in the autoclave was stirred at 100 ° C. for 30 minutes. Next, the internal temperature of the autoclave was raised to 210 ° C. over 2 hours. At that time, the autoclave was pressurized to 22 kg / cm ² . After the reaction was continued for 1 hour, the internal temperature of the autoclave was raised to 230 ° C. Thereafter, the internal temperature of the autoclave was kept constant at 230 ° C. for 2 hours, and the reaction was carried out while gradually removing water vapor and maintaining the pressure in the autoclave at 22 kg / cm ² . Next, the pressure in the autoclave was lowered to 10 kg / cm ² over 30 minutes, and the reaction was further continued for 1 hour to obtain a prepolymer. The obtained prepolymer was dried at 100 ° C. under reduced pressure for 12 hours and pulverized to a size of 2 mm or less. The pulverized prepolymer was subjected to solid phase polymerization at 230 ° C. and 0.1 mmHg for 10 hours to obtain polyamide (PA-4). Each characteristic of this polyamide (PA-4) was measured based on the said measuring method. As a result of the measurement, the polyamide (PA-4) had a melting point Tm2 of 298 ° C., a glass transition temperature Tg of 122 ° C., and a sulfuric acid relative viscosity of 2.6 ° C. of 2.6.

≪Manufacture of polyamide composition≫
[Examples 1 to 12 and Comparative Examples 1 to 4]
Using the polyamides obtained in Production Examples 1 to 3 or Comparative Production Example 1 and the respective raw materials in the types and proportions described in Table 1-1 or Table 1-2, a polyamide composition is produced as follows. did.

  The polyamide obtained in Production Examples 1 to 3 or Comparative Production Example 1 was dried in a nitrogen stream and adjusted to a moisture content of about 0.2% by mass, and then used as a raw material for the polyamide composition.

  As an apparatus for producing the polyamide composition, a twin screw extruder [ZSK-26MC: manufactured by Coperion (Germany)] was used. The twin screw extruder has an upstream supply port in the first barrel from the upstream side of the extruder, a downstream first supply port in the sixth barrel, and a downstream second supply in the ninth barrel. Had a mouth. In the twin-screw extruder, L / D (extruder cylinder length / extruder cylinder diameter) was 48, and the number of barrels was 12. In the twin-screw extruder, the temperature from the upstream supply port to the die was set to the melting point Tm2 + 20 ° C. of each (A) polyamide produced in the above production example, the screw rotation speed was set to 250 rpm, and the discharge amount was set to 25 kg / h. .

  (A) Polyamide, (C) Phenol-based antioxidant, (D) Organic phosphorus-based antioxidant, (E) Inorganic phosphorus-based so as to have the types and ratios described in Table 1-1 or Table 1-2 The compound and (G) amine light stabilizer were supplied from the upstream supply port of the twin-screw extruder after dry blending. Next, (B) titanium oxide was supplied from the downstream first supply port of the twin-screw extruder at the types and ratios shown in Table 1-1 or Table 1-2. Furthermore, (F) inorganic filler (glass fiber) was supplied from the downstream second supply port of the twin-screw extruder at the types and ratios shown in Table 1-1 or Table 1-2. The raw material supplied as described above was melt-kneaded with the twin-screw extruder to prepare polyamide composition pellets. The obtained polyamide composition pellets were dried in a nitrogen stream, and the water content in the polyamide composition was reduced to 500 ppm or less. Various evaluations were performed as described above using the polyamide composition after adjusting the water content. The evaluation results are shown in Table 1-1 or Table 1-2.

表１−１及び表１−２の結果から、脂環族ジカルボン酸を少なくとも５０モル％含むジカルボン酸とジアミンとからなる単位を含むポリアミドと、酸化チタンと、フェノール系酸化防止剤と、有機リン系酸化防止剤とを含むポリアミド組成物は、リフロー工程後の反射率ならびに熱処理後の反射率保持率に優れていることを確認した。なお、これらの反射率並びに反射率保持率が優れているのは、ポリアミド組成物の変色が少ないためであり、耐熱変色性に優れることを意味する。

From the results of Table 1-1 and Table 1-2, polyamide containing a unit consisting of a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and a diamine, titanium oxide, a phenolic antioxidant, and organic phosphorus It was confirmed that the polyamide composition containing the system antioxidant is excellent in the reflectance after the reflow process and the reflectance retention after the heat treatment. The reason why these reflectances and reflectance retention ratios are excellent is that the discoloration of the polyamide composition is small, which means that the heat discoloration resistance is excellent.

[Example 13 and Comparative Examples 5 to 7]
A polyamide composition was produced in the same manner as in Example 1 except that each raw material was used in the types and proportions shown in Table 2. The extrusion processability of the obtained polyamide composition was evaluated as described above. The evaluation results are shown in Table 2.

表２の結果から、少なくとも５０モル％の脂環族ジカルボン酸を少なくとも５０モル％含むジカルボン酸とジアミンとからなる単位を含むポリアミドと、酸化チタンと、フェノール系酸化防止剤と、有機リン系酸化防止剤とを含むポリアミド組成物は、押出中のストランド切れ回数が少なくなっており、押出加工性に優れることを確認した。また、実施例１３のポリアミド組成物について、実施例１と同様に物性を評価し、リフロー工程後の反射率並びに熱処理後の反射率保持率が実施例７のポリアミド組成物と同程度に優れていることも確認した。

From the results in Table 2, polyamides containing units consisting of dicarboxylic acids and diamines containing at least 50 mol% of alicyclic dicarboxylic acids and diamines, titanium oxides, phenolic antioxidants, and organophosphorus oxidations. It was confirmed that the polyamide composition containing the inhibitor has a low number of strand breaks during extrusion and is excellent in extrusion processability. Moreover, about the polyamide composition of Example 13, the physical properties were evaluated in the same manner as in Example 1, and the reflectance after the reflow process and the reflectance retention after the heat treatment were as excellent as the polyamide composition of Example 7. I also confirmed.

Claims (14)

(A) polyamide, (B) titanium oxide, (C) a phenolic antioxidant and / or an amine antioxidant, and (D) an organic phosphorus antioxidant,
(A) Polyamide has a unit consisting of (a) dicarboxylic acid and (b) diamine,
(A) The polyamide composition in which dicarboxylic acid contains at least 50 mol% of (a-1) alicyclic dicarboxylic acid.   The polyamide composition according to claim 1, wherein the (b) diamine contains at least 50 mol% of a diamine having a substituent branched from the main chain (b-1).   (B-1) The polyamide composition according to claim 2, wherein the diamine having a substituent branched from the main chain is 2-methylpentamethylenediamine.   (A) Polyamide composition as described in any one of Claims 1-3 whose melting | fusing point of polyamide is 270-350 degreeC.   (A-1) The polyamide composition according to any one of claims 1 to 4, wherein the alicyclic dicarboxylic acid is 1,4-cyclohexanedicarboxylic acid.   (D) The polyamide composition according to any one of claims 1 to 5, wherein the organophosphorus antioxidant is a pentaerythritol phosphite compound.   (E) The polyamide composition according to any one of claims 1 to 6, further comprising an inorganic phosphorus compound.   (E) The inorganic phosphorus compound is selected from the group consisting of metal phosphates, metal phosphites, metal hypophosphites, intramolecular condensates of these metal salts and intermolecular condensates of these metal salts. The polyamide composition according to claim 7, wherein the polyamide composition is one or more.   (F) The polyamide composition according to any one of claims 1 to 8, further comprising an inorganic filler.   (F) The polyamide composition according to claim 9, wherein the inorganic filler is at least one selected from the group consisting of glass fiber, potassium titanate fiber, talc, wollastonite, kaolin, mica, calcium carbonate and clay. object.   (G) The polyamide composition according to any one of claims 1 to 10, further comprising an amine light stabilizer. (A) For 100 parts by mass of polyamide,
(B) 5 to 120 parts by weight of titanium oxide,
(C) 0.01-2 parts by mass of a phenolic antioxidant and / or an amine antioxidant,
(D) 0.01-2 parts by mass of an organophosphorus antioxidant,
(E) 0 to 2 parts by mass of an inorganic phosphorus compound,
The polyamide composition according to any one of claims 1 to 11, comprising (F) 0 to 200 parts by mass of an inorganic filler, and (G) 0 to 2 parts by mass of an amine light stabilizer. The phosphorus element concentration (x) in the polyamide composition is 500 ppm to 1200 ppm with respect to 100 mass% in total of (A) polyamide, (D) organic phosphorus antioxidant and (E) inorganic phosphorus compound. Yes,
The ratio (y) of phosphorus element derived from (D) organophosphorus antioxidant to phosphorus element in the polyamide composition is 50 to 80%, and
The polyamide composition according to claim 7 or 8, wherein the (x) and the (y) satisfy the following formula (1).
600 <30y-x <1500 (1)   The molded article containing the polyamide composition as described in any one of Claims 1-13.