JP2012184293A - Polyamide composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide composition having excellent toughness and color, and further having excellent discoloration resistance.SOLUTION: The polyamide composition includes (A) the following polyamide and (B) titanium oxide: the polyamide (A) obtained by polymerizing (a) dicarboxylic acids containing at least 50 mol% of an alicyclic dicarboxylic acid, and (b) diamines containing at least 50 mol% of a diamine having a pentamethylenediamine skeleton, and having 30-60 μeq/g of the content of cyclic amino terminals.

Description

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

  Polyamides typified 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, daily use and household goods.

In the automobile industry, as an environmental measure, there is a demand for weight reduction of a vehicle body by metal replacement in order to reduce exhaust gas. In order to meet this requirement, polyamide materials are increasingly used for exterior materials, interior materials, and the like, and the level of required properties such as heat resistance, strength, and appearance with respect to polyamide materials is further improved. In particular, since the temperature in the engine room is on the rise, there is an increasing demand for higher heat resistance for polyamide materials.
Further, in the electrical and electronic industries such as home appliances, in order to cope with the lead-free surface mount (SMT) solder, it is required to increase the heat resistance of the polyamide material that can withstand the rise in the melting point of the solder.

Polyamides such as PA6 and PA66 have a low melting point and cannot satisfy these requirements in terms of heat resistance.
In order to solve the problems related to the heat resistance 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 by melt molding, the polyamide undergoes severe thermal decomposition, making it difficult to obtain a molded product having sufficient characteristics.

In order to solve the problems related to the thermal decomposition of PA6T, PA6T is composed of an aliphatic polyamide such as PA6 and PA66, or an amorphous aromatic polyamide composed of isophthalic acid and hexamethylenediamine (hereinafter abbreviated as “PA6I”). High melting point semi-aromatic polyamide (hereinafter referred to as “6T copolymer”) containing terephthalic acid and hexamethylenediamine as main components, which have been melted to about 220-340 ° C. And may be abbreviated as “polyamide”).
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, in contrast to an aromatic polyamide composed of an aromatic dicarboxylic acid and an aliphatic diamine, a high melting point aliphatic polyamide composed of adipic acid and tetramethylene diamine (hereinafter sometimes abbreviated as “PA46”) or an alicyclic ring. An alicyclic polyamide composed of an aliphatic dicarboxylic acid and an aliphatic diamine has been proposed.
For example, in Patent Documents 2 and 3, a semi-alicyclic ring of an alicyclic polyamide (hereinafter sometimes abbreviated as “PA6C”) composed of 1,4-cyclohexanedicarboxylic acid and hexamethylenediamine and another polyamide. Group polyamides (hereinafter may be abbreviated as “PA6C copolymerized polyamides”) are disclosed.
Patent Document 2 discloses that semi-alicyclic polyamide electrical and electronic members containing 1 to 40% 1,4-cyclohexanedicarboxylic acid as a dicarboxylic acid unit have improved solder heat resistance. Discloses that semi-alicyclic polyamide automobile parts are excellent in fluidity and toughness.

In Patent Document 4, an alicyclic polyamide composed of an alicyclic dicarboxylic acid and a diamine having a branched substituent has excellent heat resistance, fluidity, toughness, low water absorption, rigidity, and a high melting point. It is disclosed to be a polyamide.
Patent Document 5 discloses that a polyamide comprising a dicarboxylic acid unit containing 1,4-cyclohexanedicarboxylic acid and a diamine unit containing 2-methyl-1,8-octanediamine is light resistance, toughness, moldability, lightness, and It is disclosed that it is excellent in heat resistance and the like. Further, as a method for producing the polyamide, 1,4-cyclohexanedicarboxylic acid and 1,9-nonanediamine are reacted at 230 ° C. or lower to form a prepolymer, and the prepolymer is solid-phase polymerized at 230 ° C. to have a melting point of 311 ° C. The production of polyamides is disclosed.
In Patent Document 6, a polyamide using 1,4-cyclohexanedicarboxylic acid having a trans / cis ratio of 50/50 to 97/3 as a raw material is excellent in heat resistance, low water absorption, light resistance, and the like. It is disclosed.

In Patent Document 7, in the production of a polyamide comprising a diamine component containing an aromatic diacid containing terephthalic acid and 2-methylpentanediamine, cyclization of 2-methylpentamethylenediamine by addition of formic acid (with cyclic amino group and Is significantly reduced.
In Patent Documents 8 and 9, in polypentamethylene adipamide resin, the retention of the polyamide is stabilized by reducing the bonding of the cyclic amino group derived from pentamethylenediamine to the polymer terminal by controlling the polymerization temperature. It is disclosed that the heat resistance and the heat resistance can be improved.

JP-T 6-503590 Japanese National Patent Publication No. 11-512476 Special table 2001-514695 gazette International Publication No. 2009/113590 Japanese Patent Laid-Open No. 9-12868 International Publication No. 2002/048239 Pamphlet Japanese National Patent Publication No. 8-503018 JP 2003-292612 A JP 2004-75932 A

Although 6T copolymer polyamide certainly has the characteristics of low water absorption, high heat resistance, and high chemical resistance, it has low flowability and insufficient moldability and molded product surface appearance, and toughness. Inferior to light resistance. For this reason, when it is used for an application that requires an excellent appearance as a molded product such as an exterior part or is exposed to sunlight or the like, improvement of those characteristics is required.
In addition, 6T copolymer polyamide has a large specific gravity, and improvement in lightness is also desired.

The PA6T / 2MPDT disclosed in Patent Document 1 can partially improve the problems of the conventional PA6T copolymerized polyamide, but the flowability, moldability, toughness, surface appearance of the molded product, and light resistance However, the level of improvement is insufficient.
In addition, PA46 has good heat resistance and moldability, but has a high water absorption rate, and has a problem that a dimensional change and a decrease in mechanical properties due to water absorption are remarkably large. There are cases where the requirements cannot be met in terms of dimensional changes.

The PA6C copolymer polyamides disclosed in Patent Documents 2 and 3 also have problems such as high water absorption and insufficient fluidity.
Furthermore, the polyamides disclosed in Patent Documents 5 and 6 are also insufficiently improved in terms of toughness, rigidity, and fluidity.

In addition, regarding the polyamide disclosed in Patent Document 7, it is described that a high molecular weight product can be obtained by reducing the amount of cyclic amino group bonded to the polymer terminal, but cyclic amino bonded to the polymer terminal is described. There is no mention of the advantages of having a certain amount of groups.
In addition, with respect to the polyamides disclosed in Patent Documents 8 and 9, there is no description about the advantage of having a certain amount or more of the cyclic amino group bonded to the polymer terminal, and the polymer is obtained by lowering the polycondensation temperature. Since the amount of the cyclic amino group bonded to the terminal is reduced, it is not assumed that a polyamide having a high melting point of 300 ° C. or higher is produced.

  In addition, these conventionally proposed polyamides cannot satisfy the requirements in the electrical and electronic industries, particularly in terms of toughness and discoloration resistance.

  The problem to be solved by the present invention is to provide a polyamide composition and a molded article which are excellent in toughness and color tone and further excellent in discoloration resistance.

As a result of intensive studies to solve the above problems, the present inventors have found that a diamine containing a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and a diamine having a pentamethylenediamine skeleton of at least 50 mol%. It was found that a polyamide composition containing a specific amount of a cyclic amino terminal and a titanium oxide can solve the above-mentioned problems, and has completed the present invention.
That is, the present invention is as follows.

[1]
A polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol% alicyclic dicarboxylic acid and (b) a diamine containing a diamine having a pentamethylenediamine skeleton at least 50 mol%, (A) polyamide having a terminal amount of 30 to 60 μeq / g;
(B) titanium oxide;
A polyamide composition.
[2]
The polyamide composition according to [1], wherein the polyamide (A) has a sulfuric acid relative viscosity ηr at 25 ° C. of 2.3 or more.
[3]
The polyamide composition according to [1] or [2], wherein the (A) polyamide is a polyamide obtained by further copolymerizing (c) a lactam and / or an aminocarboxylic acid.
[4]
The polyamide composition according to any one of [1] to [3], wherein the cyclic amino terminal of the polyamide (A) is formed by a cyclization reaction of a diamine having a pentamethylenediamine skeleton.
[5]
The polyamide composition according to any one of [1] to [4], wherein (A) the polyamide is a polyamide obtained through a solid phase polymerization step in at least a part of the polymerization step.
[6]
The polyamide composition according to any one of [1] to [5], wherein the polyamide (A) has a melting point of 270 to 350 ° C.
[7]
The polyamide composition according to any one of [1] to [6], wherein (B) titanium oxide is titanium oxide having a number average particle diameter of 0.1 to 0.8 μm.
[8]
The polyamide composition according to any one of [1] to [7], wherein the (B) titanium oxide is coated with an inorganic coating and / or an organic coating.
[9]
The polyamide composition according to [8], wherein the inorganic coating is a metal oxide coating.
[10]
(C) The polyamide composition according to any one of [1] to [9], further including an inorganic filler.
[11]
(C) 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. Polyamide composition.
[12]
(D) The polyamide composition according to any one of [1] to [11], further including a phenol-based heat stabilizer.
[13]
(E) The polyamide composition according to any one of [1] to [12], further including an amine light stabilizer.
[14]
The polyamide composition according to [13] above, wherein the molecular weight of the (E) amine light stabilizer is less than 1,000.
[15]
(A) a polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and (b) a diamine containing a diamine having a pentamethylenediamine skeleton of at least 50 mol%. 30 to 95% by mass of polyamide having a cyclic amino terminal amount of 30 to 60 μeq / g,
(B) 5 to 45% by mass of titanium oxide,
(C) 0-50 mass% of inorganic filler,
(D) 0 to 1% by mass of a phenol-based heat stabilizer,
(E) 0 to 1% by mass of an amine light stabilizer,
Containing polyamide composition.
[16]
A molded article comprising the polyamide composition according to any one of [1] to [15].

  ADVANTAGE OF THE INVENTION According to this invention, the polyamide composition which is excellent in toughness and a color tone, and also excellent in discoloration resistance can be provided.

  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.

[Polyamide composition]
The polyamide composition of this embodiment is
(A): a polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and (b) a diamine containing a diamine having a pentamethylenediamine skeleton of at least 50 mol%. A polyamide having a cyclic amino terminal amount of 30 to 60 μeq / g;
(B): titanium oxide;
Is a polyamide composition containing

((A) Polyamide)
(A) Polyamide is a polyamide obtained by polymerizing the following (a) and (b).
(A) A dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid.
(B) A diamine containing a diamine having a pentamethylenediamine skeleton of at least 50 mol%.
In the present specification, polyamide means a polymer having an amide (—NHCO—) bond in the main chain.

<(A) Dicarboxylic acid>
(A) The (a) dicarboxylic acid constituting the polyamide contains at least 50 mol% of an alicyclic dicarboxylic acid (based on the total number of moles of dicarboxylic acid).
(A) By using a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid, it is possible to obtain a polyamide that simultaneously satisfies heat resistance, fluidity, toughness, low water absorption, rigidity, and the like. it can.

Examples of the alicyclic dicarboxylic acid (hereinafter sometimes referred to as (a-1) alicyclic dicarboxylic acid, or simply referred to as alicyclic dicarboxylic acid) include, for example, 1, Examples thereof include alicyclic dicarboxylic acids having 3 to 10 carbon atoms, preferably 5 to 10 carbon atoms, such as 4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. It is done.
The alicyclic dicarboxylic acid may be unsubstituted or may have a substituent.
Examples of this substituent include alkyl groups 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.
The alicyclic dicarboxylic acid is preferably 1,4-cyclohexanedicarboxylic acid from the viewpoints of heat resistance, low water absorption, rigidity, and the like.
As alicyclic dicarboxylic acid, you may use individually by 1 type and may be used in combination of 2 or more type.

An alicyclic dicarboxylic acid has a trans isomer and a cis geometric isomer.
As the alicyclic dicarboxylic acid as a raw material monomer, either a trans isomer or a cis isomer may be used, or a mixture of various ratios of a trans isomer and a cis isomer may be used.
The alicyclic dicarboxylic acid is isomerized at a high temperature to a certain ratio, and the cis isomer has a higher water solubility in the equivalent salt with the diamine than the trans isomer. The cis-isomer ratio is preferably 50/50 to 0/100, more preferably 40/60 to 10/90, and still more preferably 35/65 to 15/85 as a molar ratio.
The trans / cis ratio (molar ratio) of the alicyclic dicarboxylic acid can be determined by liquid chromatography (HPLC) or nuclear magnetic resonance spectroscopy (NMR).

  Examples of (a) dicarboxylic acids other than alicyclic carboxylic acids (hereinafter referred to as (a-2) dicarboxylic acids other than alicyclic dicarboxylic acids) in dicarboxylic acids include, for example, fatty acids. Group dicarboxylic acid and aromatic dicarboxylic acid.

  Examples of the aliphatic dicarboxylic acid include malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, 2,2-diethylsuccinic acid, and 2,3-diethylglutaric acid. 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, hexadecanedioic acid, Examples thereof include linear or branched saturated aliphatic dicarboxylic acids having 3 to 20 carbon atoms such as octadecanedioic acid, eicosanedioic acid, and diglycolic acid.

Examples of the aromatic dicarboxylic acid include unsubstituted terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, and 5-sodium sulfoisophthalic acid. Examples thereof include aromatic dicarboxylic acids having 8 to 20 carbon atoms substituted with various substituents.
Examples of the various substituents in the aromatic dicarboxylic acid include 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) When dicarboxylic acid other than alicyclic dicarboxylic acid is copolymerized, it is preferable to use aliphatic dicarboxylic acid from the viewpoint of heat resistance, fluidity, toughness, low water absorption, rigidity, and the like. Preferably, an aliphatic dicarboxylic acid having 6 or more carbon atoms is used.
Among these, aliphatic dicarboxylic acids having 10 or more carbon atoms are preferable from the viewpoints of heat resistance and low water absorption.
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. Of these, sebacic acid and dodecanedioic acid are preferable from the viewpoint of heat resistance and the like.
As the dicarboxylic acid other than the alicyclic dicarboxylic acid, one kind may be used alone, or two or more kinds may be used in combination.

(A) The dicarboxylic acid may further contain a trivalent or higher polyvalent carboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid as long as the object of the present embodiment is not impaired.
A polyvalent carboxylic acid may be used individually by 1 type, and may be used in combination of 2 or more type.

The proportion (mol%) of (a-1) alicyclic dicarboxylic acid in (a) dicarboxylic acid is at least 50 mol%. The proportion 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%, More preferably, it is 100 mol%.
When the proportion of the alicyclic 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 dicarboxylic acid other than (a-2) alicyclic dicarboxylic acid in dicarboxylic acid is 0 to 50 mol%, and preferably 0 to 40 mol%.

  (A) When dicarboxylic acid other than (a-2) alicyclic dicarboxylic acid in dicarboxylic acid contains aliphatic dicarboxylic acid having 10 or more carbon atoms, (a-1) alicyclic dicarboxylic acid is It is preferable that 50-99.9 mol% and (a-2) C10 or more aliphatic dicarboxylic acid is 0.1-50 mol%, and (a-1) alicyclic dicarboxylic acid is 60-95. It is more preferable that the mol% and (a-2) the aliphatic dicarboxylic acid having 10 or more carbon atoms is 5 to 40 mol%, and (a-1) the alicyclic dicarboxylic acid is 80 to 95 mol% and (a- 2) More preferably, the aliphatic dicarboxylic acid having 10 or more carbon atoms is 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 at least 50 mol% of a diamine having a pentamethylenediamine skeleton (hereinafter, referred to as (b-1) a diamine having a pentamethylenediamine skeleton). including.
(B) By using a diamine containing at least 50 mol% of a diamine having a pentamethylenediamine skeleton, a polyamide having excellent strength, strength at heat, durability, and the like can be obtained. It can also be obtained as a polyamide having excellent moldability.
(B-1) The diamine having a pentamethylenediamine skeleton can also be expressed as a diamine having a 1,5-diaminopentane skeleton.

(B-1) Examples of the diamine having a pentamethylenediamine skeleton include pentamethylenediamine, 2-methylpentamethylenediamine, 2-ethylpentamethylenediamine, 3-n-butylpentamethylenediamine, and 2,4-dimethylpenta. Examples thereof include saturated aliphatic diamines having 5 to 20 carbon atoms such as methylenediamine, 2-methyl-3-ethylpentamethylenediamine, and 2,2,4-trimethylpentamethylenediamine.
The diamines having the pentamethylenediamine skeleton are 1,5-diaminopentane, 2-methyl-1,5-diaminopentane, 2-ethyl-1,5-diaminopentane, and 3-n-butyl-1,5, respectively. -Diaminopentane, 2,4-dimethyl-1,5-diaminopentane, 2-methyl-3-ethyl-1,5-diaminopentane, 2,2,4-trimethyl-1,5-diaminopentane .
The diamine having a pentamethylenediamine skeleton is preferably pentamethylenediamine and 2-methylpentamethylenediamine, more preferably 2-methylpentamethylenediamine, from the viewpoints of heat resistance and strength.
One type of diamine having a pentamethylenediamine skeleton may be used alone, or two or more types may be used in combination.

  (B) Among diamines, diamines other than diamines having a pentamethylenediamine skeleton (hereinafter referred to as (b-2) diamines other than diamines having a pentamethylenediamine skeleton) may be, for example, Aliphatic diamines, alicyclic diamines, aromatic diamines and the like can be mentioned.

Examples of the aliphatic diamine include ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, 2-methylhexamethylenediamine, 2,4-dimethylhexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, Examples thereof include saturated aliphatic diamines having 2 to 20 carbon atoms such as 2-methyloctamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, and tridecamethylenediamine.
Aliphatic diamines do not include diamines having a pentamethylenediamine skeleton.

  Examples of the alicyclic diamine (also referred to as alicyclic diamine) include 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine, and the like.

  Examples of the aromatic diamine include diamines having an aromatic structure such as metaxylylenediamine.

(B-2) The diamine other than the diamine having a pentamethylenediamine skeleton is preferably an aliphatic diamine and an alicyclic diamine in terms of heat resistance, fluidity, toughness, low water absorption, strength, and the like. More preferably, it is a linear saturated aliphatic diamine having 4 to 13 carbon atoms, more preferably a linear saturated aliphatic diamine having 6 to 10 carbon atoms, and even more preferably hexamethylene diamine.
(B-2) A diamine other than a diamine having a pentamethylenediamine skeleton may be used singly or in combination of two or more.

(B) As the diamine, a trivalent or higher polyvalent aliphatic amine such as bishexamethylenetriamine may be further included within a range not impairing the object of the present embodiment.
A polyvalent aliphatic amine may be used individually by 1 type, and may be used in combination of 2 or more type.

The proportion (mol%) of the diamine having (b-1) pentamethylenediamine skeleton in (b) diamine is at least 50 mol%. (B) The proportion of the diamine having a (b-1) pentamethylenediamine skeleton in the diamine is 50 to 100 mol%, preferably 60 to 100 mol%, more preferably 80 to 100 mol%, More preferably, it is 85-100 mol%, More preferably, it is 90-100 mol%, Most preferably, it is 100 mol%.
(B-1) When the ratio of the diamine having a pentamethylenediamine skeleton is at least 50 mol%, that is, 50 mol% or more, a polyamide having excellent toughness and strength can be obtained.
The ratio (mol%) of diamine other than the diamine having (b-2) pentamethylenediamine skeleton in (b) diamine is 0 to 50 mol%, preferably 0 to 40 mol%, more preferably 0. It is -20 mol%, More preferably, it is 0-15 mol%, More preferably, it is 0-10 mol%, Most preferably, it is 0 mol%.

  The addition amount of (a) dicarboxylic acid and the addition amount of (b) diamine are preferably around the same molar amount. In view of the molar ratio of (b) the escape of diamine out of the reaction system during the polymerization reaction, the molar amount of (b) diamine is preferably Is 0.9 to 1.2, more preferably 0.95 to 1.1, and still more preferably 0.98 to 1.05.

<(C) Lactam and / or aminocarboxylic acid>
The polyamide (A) constituting the polyamide composition of the present embodiment may be a polyamide obtained by further copolymerizing (c) lactam and / or aminocarboxylic acid from the viewpoint of toughness.
In addition, (c) lactam and / or aminocarboxylic acid means lactam and / or aminocarboxylic acid capable of heavy (condensation).
When (A) the polyamide is a polyamide obtained by copolymerizing (a) dicarboxylic acid, (b) diamine, and (c) lactam and / or aminocarboxylic acid, (c) 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.

Examples of the lactam include butyrolactam, pivalolactam, ε-caprolactam, caprilactam, enantolactam, undecanolactam, laurolactam (dodecanolactam), and the like. Among these, from the viewpoint of toughness, ε-caprolactam and laurolactam are preferable, and ε-caprolactam is more preferable.
Examples of the aminocarboxylic acid include ω-aminocarboxylic acid and α, ω-amino acid that 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 with an amino group at the ω position, such as 6-aminocaproic acid, 11-aminoundecanoic acid, And 12-aminododecanoic acid and the like, and examples of the aminocarboxylic acid include paraaminomethylbenzoic acid and the like.
As the lactam and / or aminocarboxylic acid, one kind may be used alone, or two or more kinds may be used in combination.

  (C) The addition amount (mol%) of the lactam and / or aminocarboxylic acid is 0 to 20 mol% with respect to the molar amount of each monomer in (a), (b) and (c). preferable.

<End sealant>
When the polyamide is polymerized from (a) dicarboxylic acid and (b) diamine, a known end-capping agent can be further added to adjust the molecular weight.
Examples of the end-capping agent include monocarboxylic acids, monoamines, acid anhydrides such as phthalic anhydride, monoisocyanates, monoacid halides, monoesters, monoalcohols, and the like, from the viewpoint of thermal stability. And monocarboxylic acids and monoamines are preferred.
As the terminal blocking agent, one kind may be used alone, 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, 1 type may be used independently and 2 or more types may be used in combination.

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; aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine Can be mentioned.
As the monoamine, one kind may be used alone, or two or more kinds may be used in combination.

The combination of (a) dicarboxylic acid and (b) diamine is not particularly limited. For example, (a-1) at least 50 mol% of alicyclic dicarboxylic acid and (b-1) at least 50 mol% of A combination of 2-methylpentamethylenediamine is preferred, with (a-1) at least 50 mol% 1,4-cyclohexanedicarboxylic acid and (b-1) at least 50 mol% 2-methylpentamethylenediamine being more preferred.
By polymerizing these combinations of (a) dicarboxylic acid and (b) diamine as components of polyamide, a polyamide having excellent heat resistance, fluidity, toughness, low water absorption, rigidity, and high melting point can be obtained. it can.

<Ratio of monomer and polyamide trans isomer>
In the polyamide (A) constituting the polyamide composition of the present embodiment, the alicyclic dicarboxylic acid structure exists as a geometric isomer of a trans isomer and a cis isomer.
(A) The trans isomer ratio of the alicyclic dicarboxylic acid structure in the polyamide represents the ratio of the trans isomer in the entire alicyclic dicarboxylic acid in the (A) polyamide, and the trans isomer ratio is preferably 50 It is -85 mol%, More preferably, it is 50-80 mol%, More preferably, it is 60-80 mol%.
(A) As an alicyclic dicarboxylic acid which is a monomer for polymerizing polyamide, an alicyclic dicarboxylic acid having a trans isomer / cis isomer ratio (molar ratio) of 50/50 to 0/100 However, the polyamide obtained by polymerization of (a) dicarboxylic acid and (b) diamine preferably has a trans isomer ratio of 50 to 85 mol%.
When the trans isomer ratio is within the above range, the polyamide is contrary to the characteristics of high melting point, toughness, and rigidity, as well as the thermal rigidity due to the high glass transition temperature (Tg), and usually the heat resistance. It has the properties of satisfying both the fluidity and high crystallinity that are properties.
These characteristics of the polyamide consist of a combination of (a) at least 50 mol% or more of 1,4-cyclohexanedicarboxylic acid, (b) at least 50 mol% or more of 2-methylpentamethylenediamine, and the trans isomer ratio is This is particularly noticeable with polyamides of 50 to 85 mol%.
In this embodiment, the trans isomer ratio of polyamide can be measured by the method described in the following examples.

((A) Polyamide production method)
The method for producing the polyamide (A) constituting the polyamide composition of the present embodiment is not particularly limited, and (a) a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid, and (b) It can be produced by a polyamide production method comprising a step of polymerizing at least 50 mol% of a diamine containing a diamine having a pentamethylenediamine skeleton.
(A) As a manufacturing method of polyamide, it is preferable to further include the process of raising the polymerization degree of polyamide.
(A) It does not specifically limit as a manufacturing method of polyamide, For example, various methods are mentioned 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 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 “prepolymer”).・ It may be abbreviated as “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 method of polymerizing using a dicarboxylic acid halide component equivalent to a dicarboxylic acid and a diamine component (hereinafter sometimes abbreviated as “solution method”).

(A) The production method of polyamide is preferably 1) hot melt polymerization method, 2) hot melt polymerization / solid phase polymerization method, 4) prepolymer / solid phase polymerization method, and 5) one-stage solid phase polymerization method. More preferably, 2) hot melt polymerization / solid phase polymerization and 4) prepolymer / solid phase polymerization.
(A) In the method for producing a polyamide, it is preferable to perform solid phase polymerization in terms of improving the molecular weight of the polyamide, and the method for improving the molecular weight of the polyamide by performing solid phase polymerization is to increase the molecular weight by a hot melt polymerization method. Rather than improving, it is preferable in that the cyclic amino terminal amount of the polyamide can be controlled to a predetermined amount.

(A) In the polyamide production method, when performing hot melt polymerization, it is preferable to add an additive during the polymerization.
As an additive at the time of polymerization, (b) diamine which is a raw material of polyamide is mentioned.
The amount of (b) diamine added as an additive during polymerization means the amount of diamine added to (b) diamine used in the production of an equimolar amount of dicarboxylic acid / diamine salt, preferably 0. 0.1 to 10 mol%, more preferably 0.5 to 5 mol%, still more preferably 1.5 to 4.5 mol%, still more preferably 2.6 to 4 mol%. .
(B) When the addition amount of the diamine is within the above range, the cyclic amino terminal amount and the amino terminal amount can be controlled to target values.

  As additives during polymerization, organic acids such as formic acid and acetic acid can also be added. By adding formic acid or the like, it may be possible to more easily control the amount of cyclic amino terminal at the polymer terminal.

(A) In the method for producing polyamide, the polymerization form may be a batch type or a continuous type.
In the hot melt polymerization method, for example, the polymerization reaction can be performed using an autoclave type reactor, a tumbler type reactor, an extruder type reactor such as a kneader, or the like.

(A) The method for producing the polyamide is not particularly limited, and the polyamide can be produced by a batch-type hot melt polymerization method.
Examples of the batch-type hot melt polymerization method include, for example, a polyamide component ((a) dicarboxylic acid, (b) diamine, and, if necessary, (c) lactam and / or aminocarboxylic acid) using water as a solvent. About 40 to 60% by mass of the contained solution is concentrated to about 65 to 90% by mass 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). To obtain a concentrated solution. The concentrated solution is then transferred to an autoclave and heating is continued until the pressure in the container is about 1.5-5.0 MPa (gauge pressure). Thereafter, the pressure is maintained at about 1.5 to 5.0 MPa (gauge pressure) while draining water and / or gas components, and when the temperature reaches about 250 to 350 ° C., pressure reduction is started to atmospheric pressure (gauge The pressure is 0 MPa). By reducing the pressure to atmospheric pressure and then reducing the pressure as necessary, by-product water can be effectively removed. It is preferable to control the temperature so that the reaction temperature at the end of the reaction becomes the maximum temperature, and the maximum temperature is preferably 280 to 400 ° C. Pressurize with an inert gas such as nitrogen to extrude the polyamide melt as a strand. The strand is cooled and cut to obtain pellets.

(A) The method for producing the polyamide is not particularly limited, and the polyamide can be produced by a continuous hot melt polymerization method.
Examples of the continuous hot melt polymerization method include, for example, a polyamide component ((a) dicarboxylic acid, (b) diamine, and, if necessary, (c) lactam and / or aminocarboxylic acid) using water as a solvent. About 40-60 wt% solution containing is preheated to about 40-100 ° C. in a pre-container vessel and then transferred to a concentrator / reactor and about 0.1-0.5 MPa (gauge pressure) Concentrate to about 70-90% under pressure and temperature of about 200-270 ° C. to obtain a concentrated solution. Next, the concentrated solution is discharged to a flasher maintained at a temperature of about 200 to 400 ° C., and then the pressure is reduced to atmospheric pressure (gauge pressure is 0 MPa). After reducing the pressure to atmospheric pressure, reduce the pressure as necessary. It is preferable to control the temperature so that the reaction temperature at the end of the reaction becomes the maximum temperature, and the maximum temperature is preferably 280 to 400 ° C. The polyamide melt is extruded into strands, cooled and cut into pellets.

  The maximum reaction temperature in the hot melt polymerization is preferably 280 to 400 ° C, more preferably a temperature exceeding 300 ° C. The maximum temperature is more preferably 360 ° C. or lower. In the hot melt polymerization, the amount of the cyclic amino terminal can be easily controlled while suppressing the thermal decomposition of the polyamide by setting the reaction temperature to the highest temperature within the above range.

(A) It does not specifically limit as a manufacturing method of polyamide, Polyamide can be manufactured with the solid-phase polymerization method described below.
As the solid phase polymerization method, for example, a tumbler type reactor, a vibration dryer type reactor, a nauter mixer type reactor, a stirring type reactor, or the like can be used.
Put polyamide pellets, flakes, or powder into the above reactor, under an inert gas stream such as nitrogen, argon, and helium, or under reduced pressure, and while pulling the internal gas under reduced pressure at the top of the reactor An inert gas may be supplied from below, and the molecular weight of the polyamide is improved by heating at a temperature below the melting point of the polyamide. The reaction temperature of the solid phase polymerization is preferably 100 to 350 ° C, more preferably 120 to 300 ° C, and further preferably 150 to 270 ° C.
The inert gas may be supplied from the lower part of the reactor under the flow of inert gas or under reduced pressure, and while pulling the internal gas to the reduced pressure at the upper part of the reactor, and the heating is stopped, preferably 0 to 100 ° C. More preferably, after the reaction temperature is lowered from room temperature to 60 ° C., the polyamide can be taken out from the reactor.

  (A) As a production method of polyamide, preferably, hot melt polymerization is performed at a maximum reaction temperature exceeding 300 ° C., and dicarboxylic acid and diamine (including lactam and / or aminocarboxylic acid, if necessary). And a polyamide produced by polymerizing a polyamide obtained by a hot melt polymerization method or a prepolymer method by solid phase polymerization at a reaction temperature not higher than the melting point of the polyamide. preferable. By these production methods, a high molecular weight can be obtained while easily controlling the amount of the cyclic amino terminus, and a polyamide excellent in strength, hot strength, durability and the like can be obtained.

(A) The polymer terminal of the polyamide is any one of 1) amino terminal, 2) carboxyl terminal, 3) cyclic amino terminal, 4) terminal by end capping agent, and 5) other terminal.
The polymer terminal of the polyamide means a terminal part of a polymer chain of a polymer obtained by polymerizing dicarboxylic acid and diamine (including lactam and / or aminocarboxylic acid, if necessary) by an amide bond.

1) The amino terminal means that the polymer terminal is an amino group (—NH ₂ group), and the terminal of the polymer chain is derived from the raw material diamine.
2) The carboxyl end means that the polymer end is a carboxyl group (—COOH group), and the end of the polymer chain is derived from the raw dicarboxylic acid.
3) Cyclic amino terminal means that the polymer terminal is a cyclic amino group.
The cyclic amino group is a group represented by the following formula (1).

In said formula (1), R shows a C1-C4 alkyl group, such as a hydrogen atom or a methyl group, an ethyl group, or a t-butyl group.
The cyclic amino terminal may be a piperidine structure formed by cyclization by a deammonification reaction of a diamine having a pentamethylenediamine skeleton as a raw material. In this case, R is a pentamethylene skeleton of a diamine having a pentamethylenediamine skeleton. The alkyl group of the side chain part other than is shown. In the above formula, R is exemplified as mono-substitution, but may be di-substitution or poly-substitution of three or more substitutions so as to match the side chain portion of the diamine having a pentamethylenediamine skeleton. Also good.

4) The end by the end-capping agent means that the end of the polymer is capped by the end-capping agent added at the time of polymerization, and has a structure derived from end-capping agents such as monocarboxylic acid and monoamine. .
5) The other terminal is a polymer terminal not classified in the above 1) to 4), and examples thereof include a terminal generated by deammonia reaction at the amino terminal and a terminal generated by decarboxylation reaction at the carboxyl terminal. It is done.

The cyclic amino terminal amount of (A) polyamide is 30 to 60 μeq / g, preferably 35 to 55 μeq / g.
When the cyclic amino terminal amount is within the above range, the toughness, color tone and discoloration resistance of the polyamide composition of the present embodiment can be improved.

The cyclic amino terminal amount is represented by the number of moles of cyclic amino terminal present in 1 g of polyamide.
The amount of cyclic amino terminal can be measured using 1H-NMR as described in the following examples.
For example, it can be calculated based on the integral ratio of hydrogen bonded to carbon adjacent to the nitrogen atom of the piperidine ring and hydrogen bonded to carbon adjacent to the nitrogen atom of the amide bond of the polyamide main chain.

The cyclic amino terminus is generated by (1) a dehydration reaction between a cyclic amine compound having a piperidine ring and a carboxyl terminus, or (2) a deammonia reaction within the polymer molecule at the amino terminus of the polymer terminus. .
(1) The cyclic amino compound produced by the dehydration reaction between the cyclic amine compound having a piperidine ring and the carboxyl terminal is added to the polymerization reaction system using (1a) the cyclic amine compound having a piperidine ring as a terminal blocking agent. (1b) A diamine having a pentamethylenediamine skeleton can also be produced from a cyclic amine compound produced in a polymerization reaction system by deammonia reaction in the monomer molecule.

(A) The cyclic amino terminal of the polyamide is preferably a terminal derived from a cyclization reaction of a raw material diamine having a pentamethylenediamine skeleton. That is, the diamine having the (1b) pentamethylenediamine skeleton is obtained by a deammonia reaction in the monomer molecule to cause a dehydration reaction between the cyclic amine compound generated in the polymerization reaction system and the carboxyl group, or ( 2) The amino terminal of the polymer terminal is preferably obtained by deammonia reaction in the polymer molecule.
Adding a cyclic amine compound having a piperidine ring as an end capping agent at the initial stage of polymerization results in the low molecular weight carboxyl end being capped at the initial stage of polymerization, thus reducing the polymerization reaction rate of the polyamide. While it is difficult to obtain a high molecular weight product, a cyclic amine having a piperidine ring generated in the middle of the reaction will be sealed at a later stage of polymerization after a certain degree of high molecular weight. Getting a body becomes easier.
Although it is possible to add a cyclic amine compound having a piperidine ring as an end-capping agent in the latter stage of polymerization with a high molecular weight, it is necessary to provide equipment to be added to the polymerization system in a high pressure state. It is preferable because the production methods 1b) and (2) are simple.

In order to produce a cyclic amino terminus from a raw material diamine having a pentamethylenediamine skeleton in the polymerization system and adjust the amount of cyclic amino terminus within the scope of the present invention, a polymerization temperature, a reaction time, and a diamine that produces a cyclic amine. A method of controlling by appropriately adjusting the amount of addition and the like is effective.
(A) In order to bring the cyclic amino terminal amount of the polyamide within the scope of the present invention, it is necessary to promote the formation of a cyclic amine having a piperidine ring, and the reaction temperature of the polymerization of the polyamide is preferably 280 to 400 ° C. More preferably, it exceeds 300 ° C., more preferably 320 ° C. or higher. The reaction temperature for polyamide polymerization is preferably 360 ° C. or lower.
The reaction temperature is preferably 280 ° C. or higher from the viewpoint of promoting the formation of the cyclic amino terminus, while 400 ° C. or lower is preferable from the viewpoint of suppressing the formation of an excessive cyclic amino terminus.
Moreover, the adjustment of the reaction time is also an effective method, and it is particularly effective to adjust the time of the reaction temperature exceeding 300 ° C. as appropriate.

(A) The amino terminal amount of polyamide is preferably 20 μeq / g or more, more preferably 20 to 100 μeq / g, and even more preferably 25 to 70 μeq / g.
When the amino terminal amount is within the above range, the hydrolysis resistance and heat retention stability of the (A) polyamide can be improved.

The amino terminal amount is represented by the number of moles of amino terminal present in 1 g of polyamide.
Amino terminal amount can be measured using the method described in the following Example.

(A) The molecular weight of the polyamide is preferably 25 ° C. sulfuric acid relative viscosity ηr as an index, and the sulfuric acid relative viscosity ηr at 25 ° C. is preferably 2.3 or more. More preferably, it is 2.3-7.0, More preferably, it is 2.5-5.5, More preferably, it is 2.8-4.0.
When the sulfuric acid relative viscosity ηr at 25 ° C. is 2.3 or more, the polyamide composition of the present embodiment is excellent in strength, durability, and the like. (A) When the relative viscosity ηr of sulfuric acid at 25 ° C. of the polyamide is 7.0 or less, a polyamide composition having excellent fluidity can be obtained.

  Measurement of the relative viscosity of sulfuric acid at 25 ° C. can be measured at 25 ° C. in 98% sulfuric acid according to JIS-K6920 as described in the following examples.

(A) As for melting | fusing point of polyamide, it is preferable that Tm2 is 270-350 degreeC from a heat resistant viewpoint. Melting | fusing point Tm2 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 is preferably 350 ° C. or lower, more preferably 340 ° C. or lower, further preferably 335 ° C. or lower, and still more preferably 330 ° C. or lower.
When the melting point Tm2 of the polyamide is 270 ° C. or higher, a polyamide having excellent heat resistance can be obtained. Moreover, when the melting point Tm2 of the polyamide is 350 ° C. or less, the thermal decomposition of the polyamide in the melt processing such as extrusion and molding can be suppressed.

(A) Melting | fusing point (Tm1 or Tm2) of a polyamide can be measured according to JIS-K7121 as described in the following Example.
Examples of the melting point measuring device include Diamond-DSC manufactured by PERKIN-ELMER.

  The blending amount of (A) polyamide in the polyamide composition is preferably 30 to 95% by mass, more preferably 35 to 80% by mass, and still more preferably 35 to 95% by mass with respect to 100% by mass of the polyamide composition. 70% by mass. When it is within the above range, the strength, toughness, color tone, discoloration resistance and the like can be maintained in a well-balanced manner.

((B) Titanium oxide)
The (B) titanium oxide contained in the polyamide composition in the present embodiment will be described.
Examples of (B) titanium oxide 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 these titanium oxides is not particularly limited, but is preferably a rutile type from the viewpoint of light resistance.
(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, and still more preferably 0.15, from the viewpoint of toughness and extrusion processability. ~ 0.3 μm.
(B) The number average particle diameter of titanium oxide can be measured by an electron micrograph. For example, the polyamide composition is put into an electric furnace, the contained organic matter is incinerated, and, for example, 100 or more titanium oxides are arbitrarily selected from the residue, and these particle sizes are measured by observing with an electron microscope. It is obtained by calculating the number average particle size.

  (B) Titanium oxide can be obtained, for example, by a so-called sulfuric acid method in which a titanium sulfate solution is hydrolyzed or a so-called chlorine method in which titanium halide is vapor-phase oxidized, and is not particularly limited.

(B) It is preferable that the titanium oxide particles have an inorganic coating and / or an organic coating on the surface. Specifically, it is preferable to first perform an inorganic coating and then perform an organic coating on the inorganic coating.
In addition, the surface coating of (B) titanium oxide particles is not limited to the above example, and may be coated using any method known in the art.

The inorganic coating preferably includes a metal oxide.
The organic coating preferably includes one or more of carboxylic acids, polyols, alkanolamines and / or organosilicon compounds. In particular, polyols and organosilicon compounds are more preferable from the viewpoints of light resistance and film processability, and organosilicon compounds are more preferable from the viewpoint of reducing gas generated during processing.

  Examples of the carboxylic acids of the organic coating material include adipic acid, terephthalic acid, lauric acid, myristic acid, palmitic acid, stearic acid, polyhydroxystearic acid, oleic acid, salicylic acid, malic acid and maleic acid. These may be esters or metal salts of carboxylic acids. Examples of the metal salt include aluminum salt, zinc salt, magnesium salt, calcium salt, barium salt and the like.

  Examples of the alkanolamines of the organic coating material include monoethanolamine, monopropanolamine, diethanolamine, dipropanolamine, triethanolamine, and tripropanolamine, and may be derivatives thereof. Examples of the derivatives include organic acid salts such as acetate, oxalate, tartrate, formate and benzoate.

  Examples of the polyol of the organic coating material include trimethylolpropane, trimethylolethane, ditrimethylolpropane, trimethylolpropane ethoxylate, pentaerythritol and the like, and trimethylolpropane and trimethylolethane are preferable.

  Examples of the organic silicon compound of the organic coating material include organosilanes, organopolysiloxanes, and organosilazanes.

  Examples of organosilanes include (a) aminosilane (aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, etc.), (b ) Epoxy silane (γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, etc.), (c) methacrylsilane (γ- (methacryloyloxypropyl) trimethoxysilane, etc.), (D) vinylsilane (vinyltrimethoxysilane, vinyltriethoxysilane, etc.), (e) mercaptosilane (3-mercaptopropyltrimethoxysilane, etc.), (f) chloroalkylsilane (3-chloropropyltriethoxysilane, etc.), (G) Alkylsilane (n-butyl Riethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexylmethyldimethoxysilane, hexylmethyldiethoxysilane, cyclohexylmethyldiethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane Etc.), (h) phenylsilane (phenyltriethoxysilane etc.), (i) fluoroalkylsilane (trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane etc.) and the like, and their hydrolysis products. It is done.

  Examples of organopolysiloxanes include (a) straight polysiloxane (dimethylpolysiloxane, methylhydrogen polysiloxane, methylmethoxypolysiloxane, methylphenylpolysiloxane, etc.), (b) modified polysiloxane (dimethylpolysiloxane). Siloxane diol, dimethylpolysiloxane dihydrogen, side-chain or both-end amino-modified polysiloxane, side-chain or both-end or one-end epoxy-modified polysiloxane, both-end or one-end methacryl-modified polysiloxane, side-chain or both-end carboxyl-modified Polysiloxane, side chain or both ends or one end carbinol modified polysiloxane, both ends phenol modified polysiloxane, side chain or both ends mercapto modified polysiloxane, both ends or side chain polyether modified polysiloxane, side chain Lukyl modified polysiloxane, side chain methylstyryl modified polysiloxane, side chain higher carboxylic acid ester modified polysiloxane, side chain fluoroalkyl modified polysiloxane, side chain alkyl / carbinol modified polysiloxane, side chain amino / both end carbinol modified Polysiloxane and the like) or copolymers thereof.

  Furthermore, examples of organosilazanes include hexamethylsilazane and hexamethylcyclotrisilazane.

Among the organosilicon compounds, hydrophobic functional groups such as a methacryl group (—OCOC (CH ₃ ) ═CH ₂ ), a vinyl group (—CH═CH ₂ ), an alkyl group (—R), an aryl group (— Ph, -Ar, etc.), a carboxylic acid ester group (-OCOR), an acyl group (-COR), a polyether group _{^{(- (R 1 O) n}} (R 2 O) m R 3), the fluorine-containing group (- ( CH ₂ ) _n CF ₃ , — (CF ₂ ) _n CF _3, etc.) are more preferable, and organosilanes or organopolysiloxanes having a hydrophobic functional group are more preferable.
R ¹ , R ² and R ³ all represent an alkyl group.
Further, among the organosilicon compounds that can be used as the organic coating material described above, at least one selected from alkylsilanes having 4 to 10 carbon atoms, hydrolysis products thereof, dimethylpolysiloxane, and methylhydrogenpolysiloxane are more preferable. preferable. When an alkylsilane having 6 (hexyl group) having the largest number of carbon atoms in the alkyl group is used as the alkylsilane, the dispersibility and heat resistance are further improved.
The hydrolyzed products of the organosilanes are those in which the hydrolyzable groups of the organosilanes are hydrolyzed to form silanols, and those in which silanols are condensed to form dimers, oligomers, and polymers. Say.

  Examples of the inorganic coating material include metal oxides and hydrated oxides including oxides and hydrated oxides of silicon, aluminum, zirconium, phosphorus, zinc, rare earth elements, and the like. Among these, preferred metal oxides are silica, alumina, and zirconia from the viewpoint of light resistance, and more preferred are silica and alumina. These inorganic coatings may be one kind of metal oxide or a combination of two or more kinds of metal oxides.

The coating amount of the inorganic coating is preferably 0.25 to 50% by mass, more preferably 0.25 to 10% by mass, with respect to (B) 100% by mass of the total amount of titanium oxide. More preferably, it is mass%.
(B) Although there is no restriction | limiting in particular in a titanium oxide, an ignition loss does not have a restriction | limiting, It is preferable from a viewpoint of extrusion workability that it is the range of 0.7-2.5 mass% with respect to 100 mass% of titanium oxide whole quantity. More preferably, it is 0.7-2.0 mass%, More preferably, it is 0.8-1.5 mass%. Here, the loss on ignition can be calculated from the weight loss rate when titanium oxide is dried at 120 ° C. for 4 hours to remove moisture adhering to the surface and then heat-treated at 650 ° C. for 2 hours. .

  (B) As the material for the organic and / or inorganic coating of titanium oxide, one of the various materials described above may be used alone, or two or more of them may be used in combination.

  The blending amount of (B) titanium oxide in the polyamide composition of the present embodiment is preferably 5 to 45% by mass, more preferably 10 to 45% by mass with respect to 100% by mass of the polyamide composition. More preferably, it is 20-45 mass%. When it is within the above range, toughness, color tone, discoloration resistance and the like can be maintained in a well-balanced manner.

((C) inorganic filler)
The polyamide composition of the present embodiment may further contain (C) an inorganic filler from the viewpoint of mechanical properties such as strength and rigidity.
(C) 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, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, silica Magnesium oxide, ketjen black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, mica, montmorillonite, swellable fluoromica, apatite, etc. It is below.
Among these, it is at least one selected from the group consisting of glass fiber, potassium titanate fiber, talc, wollastonite, kaolin, mica, calcium carbonate and clay, such as mechanical strength, appearance, whiteness, etc. It is preferable from the viewpoint.
The glass fiber or carbon fiber may have a perfect cross section 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. (A perfect circle has a flatness ratio of about 1)

Among the glass fibers and carbon fibers, from the viewpoint that excellent mechanical strength characteristics can be imparted to the polyamide composition, the number average fiber diameter is 3 to 30 μm, and in the polyamide resin composition, the weight average fiber length is It is 100-750 micrometers, and the thing whose aspect ratio (L / D) of a weight average fiber length and a number average fiber diameter is 10-100 is used more preferably.
Here, as a method for measuring the number average fiber diameter and the weight average fiber length, for example, the polyamide composition is put in an electric furnace, the contained organic matter is incinerated, and from the residue, for example, 100 or more glass fibers or carbon The fiber is arbitrarily selected, observed with an SEM, and the number average fiber diameter is calculated by measuring the fiber diameter of these glass fibers and carbon fibers, and the fiber length is calculated using an SEM photograph at a magnification of 1000 times. There is a method of obtaining the weight average fiber length by measuring.

In addition, from the viewpoint of reducing warpage, heat resistance, toughness, low water absorption, and heat aging resistance of a molded product obtained by molding a polyamide composition into a plate shape, (C) a cross-sectional shape of an inorganic filler, particularly glass fiber or carbon fiber The flatness is preferably 1.5 or more. More preferably, it is 1.5-10.0, More preferably, it is 2.5-10.0, More preferably, it is 3.1-6.0. When the aspect ratio is extremely large, in addition to mixing with other components, it may be crushed during processing such as kneading and molding, and the desired effect may be reduced.
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. It is preferable that If it is too thin, it may be difficult to spin the fiber. If it is too thick, the strength of the molded product may decrease due to a decrease in the contact area with the resin. The short diameter D1 is preferably 3 μm or more. Furthermore, it is preferable that the minor axis D1 is 3 μm or more and the flatness is a value larger than 3.
The glass fiber or carbon fiber having a flatness ratio of 1.5 or more is produced by the method described in, for example, Japanese Patent Publication No. 3-59019, Japanese Patent Publication No. 4-13300, Japanese Patent Publication No. 4-32775, and the like. Can do. Particularly, in an orifice plate having a large number of orifices on the bottom surface, an orifice plate that surrounds a plurality of orifice outlets and has a convex edge extending downward from the bottom surface of the orifice plate, or a nozzle tip having one or more orifice holes. Glass fibers and carbon fibers having a flatness ratio of 1.5 or more manufactured using a nozzle chip for spinning a modified cross-section glass fiber provided with a plurality of convex edges extending downward from the front end of the outer periphery are preferred. These (C) inorganic fillers may use fiber strands as rovings as they are, or may be used as chopped glass strands by further obtaining a cutting step.

The (C) inorganic filler may be subjected to a surface treatment with a silane coupling agent or the like.
Although it does not restrict | limit especially 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. In particular, at least one selected from the above listed components is preferable, 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 anhydride-containing unsaturated vinyl monomer and the unsaturated vinyl monomer containing the carboxylic anhydride Copolymer, epoxy compound, polyurethane resin, homopolymer of acrylic acid, copolymer of acrylic acid and other copolymerizable monomers, and these primary, secondary and tertiary amines A salt, a copolymer containing an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer, and the unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer may be included. 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 the above bundling agent to glass fiber or carbon fiber using a known method such as a roller-type applicator in the 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, from the viewpoint of improving the thermal stability of the polyamide composition, it is preferably 3% by mass or less. The strand may be dried after the cutting step, or may be cut after the strand is dried.

  (C) inorganic fillers other than glass fibers and carbon fibers include wollastonite, kaolin, mica, talc, calcium carbonate, magnesium carbonate, potassium titanate, aluminum borate, from the viewpoint of strength and rigidity, and surface appearance. Clay can be preferably used. More preferred are wollastonite, kaolin, mica and talc, still more preferred are wollastonite and mica, and even more 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 particle size of the inorganic filler (C) other than glass fiber or carbon fiber is preferably 0.01 to 38 μm, more preferably 0.03 to 30 μm, and more preferably 0.05 to 25 μm from the viewpoint of toughness and surface appearance. Preferably, 0.1-20 micrometers is still more preferable, and 0.15-15 micrometers is still more preferable.
(C) By setting the average particle size of the inorganic filler to 38 μm or less, a polyamide composition having excellent toughness and surface appearance can be obtained. Further, when the thickness is 0.1 μm or more, the balance between cost, powder handling surface and physical properties is excellent.
Further, among the inorganic fillers (C), those having an acicular shape such as wollastonite have an average fiber diameter as an average particle diameter. Further, when the cross section is not a circle, the maximum value of the length is regarded as the fiber diameter, the average fiber diameter is calculated from the fiber diameter, and this is regarded as the average particle diameter.

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

  In addition, (C) inorganic fillers other than glass fiber and carbon fiber are those subjected to surface treatment with a normal surface treatment agent, for example, a coupling agent such as a silane coupling agent or a titanate coupling agent. There is no problem. As the silane coupling agent, an epoxy silane coupling agent can be preferably exemplified. Further, a mixture of a polyalkoxysiloxane and an epoxy silane coupling agent and / or a reaction product of a polyalkoxy siloxane and an epoxy silane coupling agent can also be preferably used. Such a surface treating agent may be previously treated on the surface of the inorganic filler, or may be added when (A) the polyamide and (C) the inorganic filler are mixed. Moreover, the quantity of a preferable surface treating agent is the range of 0.05 mass%-1.5 mass% with respect to (C) inorganic filler.

  The blending amount of the inorganic filler (C) in the polyamide composition of the present embodiment is preferably 0 to 50% by mass, more preferably 1 to 50% by mass with respect to 100% by mass of the polyamide composition. More preferably, it is 5 to 40% by mass. In the case of the above range, the strength, rigidity and toughness can be kept in a good balance.

((D) Phenolic stabilizer)
The polyamide composition of the present embodiment may further contain (D) a phenol-based heat stabilizer from the viewpoint of heat stability.
(D) Although it does not restrict | limit as a phenol type heat stabilizer below, For example, a hindered phenol compound is mentioned. The hindered phenol compound has a property of imparting heat resistance and light resistance to resins and fibers such as polyamide.
Examples of the hindered phenol compound include, but are not limited to, for example, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide), Pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-) Hydrocinnamamide), 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 t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, and 1,3 , 5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid.
These may be used alone or in combination of two or more. Among these, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide)] is preferable from the viewpoint of improving heat aging resistance.

  The blending amount of the (D) phenol-based heat stabilizer in the polyamide composition of the present embodiment is preferably 0 to 1% by mass, more preferably 0.01 to 1% with respect to 100% by mass of the polyamide composition. It is mass%, More preferably, it is 0.1-1 mass%. When it is within the above range, the heat aging resistance can be further improved and the amount of generated gas can be further reduced.

The polyamide composition of the present embodiment may further contain (E) an amine light stabilizer from the viewpoint of light stability.
((E) amine light stabilizer)
Examples of (E) amine light stabilizers include, but are not limited to, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethyl. Piperidine, 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 Gin, 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-pentameth) Ru-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) -Tetramethi -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-piperidinol Examples include condensates with β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] diethanol.
These may be used alone or in combination of two or more.

  Among these amine light stabilizers, low molecular weight materials having a molecular weight of less than 2,000 are preferable from the viewpoint of further improving light stability. More preferably, the molecular weight is less than 1,000.

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

  Among these amine 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-benzene Dicarboxyamide, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate is preferred, and 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.

  The blending amount of the (E) amine light stabilizer in the polyamide composition of the present embodiment is preferably 0 to 1% by mass, more preferably 0.01 to 1% by mass with respect to 100% by mass of the polyamide composition. %, And more preferably 0.1 to 1% by mass. In the above range, light stability and heat aging resistance can be further improved, and the amount of generated gas can be reduced.

(Phosphorus heat stabilizer)
In the polyamide composition of this embodiment, a phosphorus-based heat stabilizer can be blended within a range that does not impair the purpose of this embodiment.
Examples of the phosphorus-based heat stabilizer include, but are not limited to, for example, pentaerythritol type phosphite compound, trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl diphenyl phosphite, trisisodecyl phosphite, phenyl Diisodecyl phosphite, phenyl di (tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di -T-butylphenyl) phosphite, tris (2,4-di-t-butyl-5-methylphenyl) phosphite, tris (butoxyethyl) phosphite, 4,4'-butylidene-bis (3- Til-6-tert-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4′-isopropylidene diphenyldiphosphite, 4,4′-isopropylidenebis (2-tert-butyl) Phenyl) .di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butanediphosphite , Tetra (tridecyl) -4,4′-butylidenebis (3-methyl-6-tert-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4′-isopropylidene diphenyldiphosphite, tris (mono , Dimixed nonylphenyl) phosphite, 4,4′-isopropylidenebis (2- -Butylphenyl) .di (nonylphenyl) phosphite, 9,10-di-hydro-9-oxa-9-oxa-10-phosphaphenanthrene-10-oxide, tris (3,5-di-t -Butyl-4-hydroxyphenyl) phosphite, hydrogenated-4,4'-isopropylidenediphenyl polyphosphite, bis (octylphenyl) bis (4,4'-butylidenebis (3-methyl-6-tert-butyl) Phenyl)) · 1,6-hexanol diphosphite, hexatridecyl-1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) diphosphite, tris (4,4′-isopropyl Redenbis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phosphite, 2, 2 Methylene bis (4,6-di-t-butylphenyl) octyl phosphite, 2,2-methylene bis (3-methyl-4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, tetrakis (2,4- And di-t-butyl-5-methylphenyl) -4,4′-biphenylene diphosphite and tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylene diphosphite.
These may be used alone or in combination of two or more.

Among those listed above, pentaerythritol phosphite compounds and tris (2,4-di-t-butylphenyl) phosphite are preferable from the viewpoint of further improving the heat aging resistance and reducing the generated gas.
Examples of the pentaerythritol phosphite compound include, but are not limited to, 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 Methylphenyl-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-butylcarbitol- Pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-octylphenyl-pentaerythritol diphosphite, 2,6-di-t-butyl-4-methylphenyl-nonylphenyl pentaerythritol Diphosphite, bis (2,6-di-t- Til-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 Diphosphite, bis (2,6-di-t-amyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,6-di-t-octyl-4-methylphenyl) pentaerythritol diphos Fight is mentioned.
These 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 is preferred, and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite is more preferred.

  When using a phosphorus heat stabilizer, the compounding amount of the phosphorus heat stabilizer in the polyamide composition is preferably 0.01 to 1% by mass, more preferably 0, relative to 100% by mass of the polyamide composition. 0.1 to 1% by mass. When it is within the above range, the heat aging resistance can be further improved and the amount of generated gas can be further reduced.

(Phosphorus compound)
In the polyamide composition of this embodiment, a phosphorus compound can be mix | blended in the range which does not impair the objective of this embodiment.
Examples of phosphorus compounds include, but are not limited to, 1) phosphoric acid, phosphorous acid, hypophosphorous acid, and intramolecular and / or intermolecular condensates thereof, 2) phosphoric acid, phosphorous acid, One or more selected from the group consisting of phosphorous acid and metal salts of intramolecular and / or intermolecular condensates thereof may be mentioned.
Examples of 1) phosphoric acid, phosphorous acid, hypophosphorous acid, and intramolecular and / or intermolecular condensates thereof include, for example, phosphoric acid, pyrophosphoric acid, metaphosphoric acid, phosphorous acid, and hypophosphorous acid. , Pyrophosphorous acid, diphosphorous acid and the like.
2) Phosphoric acid, phosphorous acid, hypophosphorous acid, and metal salts of intramolecular and / or intermolecular condensates thereof are the phosphorous compounds of 1) and groups 1 and 2 of the periodic table. , Salts with manganese, zinc and aluminum.

The preferred phosphorus compound is one or more selected from metal phosphates, metal phosphites or metal hypophosphites, and intramolecular and / or intermolecular condensates thereof, more preferably phosphorus. Salts of phosphorus compounds selected from acids, phosphorous acid, hypophosphorous acid and metals selected from Groups 1 and 2 of the periodic table, manganese, zinc, and aluminum, and their molecules and / or molecules It is an intercondensate. More preferably, it is a metal salt consisting of 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, for example, monosodium phosphate, Disodium phosphate, trisodium phosphate, monocalcium phosphate, dicalcium phosphate, tricalcium phosphate, sodium pyrophosphate, sodium metaphosphate, calcium metaphosphate, sodium hypophosphite, calcium hypophosphite, etc. These anhydrous salts and hydrates can be mentioned. Among these, sodium hypophosphite and calcium hypophosphite are even more preferable.
When using a phosphorus compound, the compounding amount of the phosphorus compound in the polyamide composition of the present embodiment is preferably 0.01 to 1% by mass, more preferably 0.05 to 100% by mass with respect to 100% by mass of the polyamide composition. 1% by mass. In the above range, the heat discoloration can be further improved.

(Other ingredients)
In addition to the components described above, other other components may be added as necessary within the range not impairing the effects of the present embodiment.
For example, coloring agents 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 Agents, stabilizers, ultraviolet absorbers, antistatic agents, fluidity improvers, fillers, reinforcing agents, spreading agents, crystal nucleating agents, rubbers, reinforcing agents, and other polymers may be mixed.
Here, since the above-mentioned other components have greatly different 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.

[Production method of polyamide composition]
The manufacturing method of the polyamide composition of this embodiment will not be specifically limited if it is a method which has the process of mixing the said (A) polyamide and (B) titanium oxide.
As a mixing method of (A) polyamide and (B) titanium oxide, for example, (A) polyamide and (B) titanium oxide are mixed using a tumbler, a Henschel mixer, etc., supplied to a melt kneader, and kneaded. Examples thereof include a method and a method of blending titanium oxide from a side feeder into a polyamide melted with a single or twin screw extruder.
(C) The same method can also be used when blending inorganic fillers. (A) A method of mixing with polyamide or the like and supplying it to a melt-kneader or melting with a single-screw or twin-screw extruder Examples include a method of blending (C) inorganic filler from the side feeder into (A) polyamide and (B) titanium oxide in a state.
In the method of supplying the components constituting the polyamide composition to the melt kneader, all the components may be supplied to the same supply port at once, or the components may be supplied from different supply ports.
The melt kneading temperature is preferably about 250 to 375 ° C. as the resin temperature, and the melt kneading time is preferably about 0.25 to 5 minutes.
The apparatus for performing melt kneading is not particularly limited, and a known apparatus, for example, a melt kneader such as a single or twin screw extruder, a Banbury mixer, and a mixing roll can be used.

[Physical properties of polyamide composition]
The polyamide composition of the present embodiment can be measured for the sulfuric acid relative viscosity ηr and the melting point Tm2 at 25 ° C. by the same method as that for the polyamide (A).
That is, the measurement of sulfuric acid relative viscosity at 25 ° C. can be performed at 25 ° C. in 98% sulfuric acid according to JIS-K6920 as described in the following examples.
The measurement of melting | fusing point (Tm1 or Tm2) can be performed according to JIS-K7121 as described in the following Example. Examples of the melting point measuring device include Diamond-DSC manufactured by PERKIN-ELMER.
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 color tone, discoloration resistance, and moldability can be obtained.

[Molded body of polyamide composition]
Molded articles of the polyamide composition of this embodiment are known molding methods such as press molding, injection molding, gas assist injection molding, welding molding, extrusion molding, blow molding, film molding, hollow molding, multilayer molding, and melt spinning. Etc., and can be obtained by using a generally known plastic molding method.
The molded product obtained from the polyamide composition of this embodiment is excellent in toughness, color tone, and discoloration resistance. Therefore, the polyamide composition of the present embodiment can be suitably used as various parts materials for automobiles, electrical and electronic products, industrial materials, daily products and household products, and for extrusion applications.
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. Among these, it is suitable for interior and exterior parts.
The 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 exterior parts are not particularly limited, and examples include a mall, a lamp housing, a front grille, a mud guard, a side bumper, a door mirror stay, and a roof rail.
The electric and electronic devices are not particularly limited, and are used for connectors, switches, relays, printed wiring boards, electronic component housings, outlets, noise filters, coil bobbins, motor end caps, and the like.
For industrial equipment, it is not particularly limited. For example, it is used for gears, cams, insulating blocks, valves, electric tool parts, agricultural equipment parts, engine covers, and the like.
It is not specifically limited as for daily use and household goods, for example, it is used for buttons, food containers, office furniture and the like.
The extrusion application is not particularly limited. For example, it is used for a film, a sheet, a filament, a tube, a rod, a hollow molded article, and the like.

Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples, but the present embodiment is not limited to only 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]
The following compounds were used in this example.
[(A) Polyamide raw material]
<(A) Dicarboxylic acid>
(A-1) 1,4-cyclohexanedicarboxylic acid (CHDA) (trade name: 1,4-CHDA HP grade (trans isomer / cis isomer = 25/75) (manufactured by Eastman Chemical Co.))
(A-2) Terephthalic acid (TPA) (manufactured by Wako Pure Chemical Industries, Ltd.)
(A-3) Adipic acid (ADA) (Wako Pure Chemical Industries, Ltd.)
(A-4) Dodecanedioic acid (C12DA) (manufactured by Wako Pure Chemical Industries, Ltd.)
<(B) Diamine>
(B-1) 2-methylpentamethylenediamine (2MPD) (manufactured by Tokyo Chemical Industry)
(B-2) Pentamethylenediamine (PMD) (manufactured by Wako Pure Chemical Industries, Ltd.)
(B-3) Hexamethylenediamine (HMD) (manufactured by Wako Pure Chemical Industries, Ltd.)
<(C) Lactam and / or aminocarboxylic acid>
(C-1) ε-caprolactam (CPL) (manufactured by Wako Pure Chemical Industries, Ltd.)

[(B) titanium oxide: rutile titanium oxide]
Number average particle diameter: 0.21 μm
Coating: Alumina, silica, siloxane compound Loss on ignition: 1.21% by mass

[(C) inorganic filler: glass fiber]
Product name: ECS 03T-275H (Nippon Electric Glass Co., Ltd.)
Average fiber diameter 10μmφ, cut length 3mm

[(D) Phenolic heat stabilizer]
Product name: IRGANOX (registered trademark) 1098 (manufactured by BASF)

[(E) amine light stabilizer]
Product name: Nylostab (registered trademark) S-EED (manufactured by Clariant)
Molecular weight: 443

[(F) phosphorus compound]
Product name: Sodium hypophosphite monohydrate (Wako Pure Chemical Industries, Ltd.)

[(G) Crystal nucleating agent: Boron nitride]
Product name: DENKABORON NITRIDE SP-2 (manufactured by Denki Kagaku Kogyo Co., Ltd.)

[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 pentamethylenediamine skeleton is ((b-1) moles of diamine having a pentamethylenediamine skeleton added as a raw material monomer / all (b) diamines added as a raw material monomer. The number of moles) was determined by calculation as 100.
The mole% of (c) lactam and / or aminocarboxylic acid is: (c) moles of lactam and / or aminocarboxylic acid added as raw monomer / moles of all (a) dicarboxylic acid added as raw monomer Number + (b) mole number of all diamines + (c) mole number of lactam and / or aminocarboxylic acid) × 100.
In addition, when calculating by the above formula, the denominator and numerator do not include the number of moles of diamine having (b-1) pentamethylenediamine skeleton added as an additive during melt polymerization.

[Measurement method of physical properties]
<(1) Melting points Tm1, Tm2 (° C.)>
According to JIS-K7121, it measured using Diamond-DSC by PERKIN-ELMER. The measurement condition is that the temperature of an endothermic peak (melting peak) that appears when about 10 mg of a sample is heated to 300 to 350 ° C. according to the melting point of the sample at a heating rate of 20 ° C./min in a nitrogen atmosphere is Tm1 (° C.). After maintaining the temperature in the molten state at the highest temperature rise for 2 minutes, the temperature was lowered to 30 ° C. at a temperature drop rate of 20 ° C./min, held at 30 ° C. for 2 minutes, and the same at the temperature rise rate of 20 ° C./min. The maximum peak temperature of the endothermic peak (melting peak) that appears when the temperature is raised to is the melting point Tm2 (° C.).

<(2) Sulfuric acid relative viscosity ηr at 25 ° C.>
It carried out according to JIS-K6920. Specifically, a polymer solution (a ratio of (polyamide 1 g) / (98% sulfuric acid 100 mL)) was prepared using 98% sulfuric acid and measured under a temperature condition of 25 ° C.

<(3) Cyclic amino terminal amount (μ equivalent / g)>
The amount of cyclic amino terminal was measured using 1H-NMR.
Signal of hydrogen bonded to carbon adjacent to nitrogen atom of nitrogen heterocycle (chemical shift value 3.5 to 4.0 ppm) and signal of hydrogen bonded to carbon adjacent to nitrogen atom of amide bond of polyamide main chain ( The cyclic amino terminal amount was calculated using an integral ratio of chemical shift value of 3.0 to 3.5 ppm. The total number of polymer terminals used at that time is 2 / using Mn measured by GPC (converted by Tosoh Corporation, HLC-8020, hexafluoropropanol solvent, PMMA standard sample (manufactured by Polymer Laboratories)). Calculated as Mn × 1,000,000.

<(4) Loss on ignition of titanium oxide>
Titanium oxide was dried at 120 ° C. for 4 hours to remove moisture adhering to the surface, and then allowed to stand for 30 minutes in a desiccator and cooled. Subsequently, about 10 g was precisely weighed in a magnetic crucible and heated in an electric furnace at 650 ° C. for 2 hours. After heating, it was allowed to stand for 30 minutes in a desiccator and cooled, and then the weight was measured. The weight loss rate before and after heating was calculated and used as ignition loss.

<(5) Bending amount (mm)>
Using the injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], the polyamide composition pellets obtained in the examples or comparative examples were injected + pressure holding time 10 seconds, cooling time 15 seconds, and mold temperature. A strip-shaped molded piece (test piece) having a length of 128 mm, a width of 12.8 mm, and a thickness of 0.7 mm was formed by setting the molten resin temperature to 120 ° C. and Tm2 + 20 ° C. of (A) polyamide.
Using the obtained test piece, a bending test was performed at a span distance of 28 mm and a compression speed of 5 mm / min, and the amount of deflection at the maximum load was measured.

<(6) Whiteness, color tone (b value)>
Using the injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], the polyamide composition pellets obtained in the examples or comparative examples were injected + pressure holding time 10 seconds, cooling time 15 seconds, and mold temperature. A molded resin piece having a length of 60 mm, a width of 60 mm and a thickness of 1.0 mm was molded at 120 ° C. and the molten resin temperature was set to Tm2 + 20 ° C. of (A) polyamide.
Using the spectral color difference meter [SE6000: manufactured by Nippon Denshoku Industries Co., Ltd.], the obtained molded piece is compliant with JIS Z8730, brightness (L value), redness (a value), yellow according to Hunter's color difference formula. The degree (b value) was determined, and the whiteness (W value) was calculated.
W = 100 − [(100−L) ² + a ² + b ² ] ^1/2
In Examples 13 to 15 and Comparative Example 11 described later, the color tone was measured using the sheet obtained by extrusion as it was, and the whiteness was calculated.

<(7) Initial whiteness, color tone (b value)>
The molded piece obtained as described in (6) above was allowed to stand at 23 ° C. for 24 hours, and then the color tone was measured with a color difference meter to calculate the whiteness.
In Examples 13 to 15 and Comparative Example 11 described later, the color tone was measured using the sheet obtained by extrusion as it was, and the whiteness was calculated.

<(8) Whiteness after heat treatment>
The molded piece obtained as described in (6) above was heat-treated in a hot air dryer at 150 ° C. for 48 hours. The processed molded piece was measured for color tone with a color difference meter in the same manner as described above, and the whiteness was calculated.
In addition, it was judged that it was suitable for the use exposed to a high temperature atmosphere that there was little change in the whiteness after heat processing compared with the initial stage, and it was judged industrially useful.

<(9) Whiteness after remelting>
After the molded piece obtained as described in (6) above was pulverized using a pulverizer, a single screw extruder with a screw diameter of 40 mm was used in which the temperature of the cylinder and the die was set to Tm2 + 20 ° C. of (A) polyamide. Then, the mixture was melt-kneaded to produce pellets.
Using the obtained pellets, a molded piece was obtained as in (6) above, and allowed to stand at 23 ° C. for 24 hours, and then the color tone was measured with a color difference meter to calculate the whiteness.
Note that less change in whiteness after remelting compared to the initial value indicates that it is suitable for recycling and the like, and was judged to be industrially useful.
Similarly, in Examples 13 to 15 and Comparative Example 11 described later, after a sheet obtained by extrusion molding is pulverized, pellets are produced using a single screw extruder, and extrusion molding is performed using the pellets. The color tone of the obtained sheet was measured, and the whiteness was calculated.

<(10) Hue-conditioning color tone (b value)>
The molded piece obtained as described in the above (6) was subjected to humidity control for 100 hours in a constant temperature and humidity chamber at 85 ° C. and 85% humidity. The tone of the molded piece after treatment was measured with a color difference meter in the same manner as described above.
Note that the fact that the change in the color tone after the humidity conditioning treatment is small compared to the initial value indicates that the color tone is suitable for applications exposed to a high humidity atmosphere, and was judged to be industrially useful.

<(11) Reflow heat resistance>
Using the injection molding machine [PS-40E: manufactured by Nissei Resin Co., Ltd.], the polyamide composition pellets obtained in the examples or comparative examples were injected + pressure holding time 10 seconds, cooling time 15 seconds, and mold temperature. A molded resin piece having a length of 60 mm, a width of 60 mm and a thickness of 1.0 mm was molded at 120 ° C. and the molten resin temperature was set to Tm2 + 20 ° C. of (A) polyamide.
The obtained molded piece was heated in a hot air reflow furnace to confirm the shape change of the molded piece, and judged according to the following criteria.
○: No deformation of the molded piece.
Δ: Slight deformation is observed in the molded piece.
X: There is obvious deformation in the molded piece.
The hot-air reflow furnace used at this time was a lead-free solder compatible reflow furnace (UNI-6116H, manufactured by Nippon Antom Co., Ltd.). Set to ° C. The conveyor belt speed in the reflow furnace was set to 0.3 m / min. Under this condition, the temperature profile in the furnace was confirmed. The heat exposure time at 140 ° C. to 200 ° C. was 90 seconds, the heat exposure time at 220 ° C. or higher was 48 seconds, and the heat exposure time at 260 ° C. or higher was 11 seconds. There was a maximum temperature of 265 ° C.

<(12) Bending resistance>
Using a single screw extruder with a screw diameter of 40 mm, the polyamide composition pellets obtained in the examples or comparative examples were set to a cylinder temperature and a T die (width: 40 cm) temperature (A) polyamide Tm2 + 20 ° C. Extrusion molding was performed at a screw speed of 30 rpm and a discharge rate of 6 kg / h. At this time, the clearance of the T die and the take-up speed of the sheet were adjusted so that the sheet had a thickness of 150 μm.
The obtained sheet was punched into a length of 128 mm and a width of 12.8 mm. The obtained punched sheet was bent 180 degrees so as to be half in the longitudinal direction (length 64 mm × width 12.8 mm), and judged according to the following criteria.
○: The molded piece had a crease, but no crack occurred.
X: The molded piece was broken into two.

[polyamide]
[Production Example 1]
Polymerization reaction of polyamide was carried out by “hot melt polymerization method”.
(A) CHDA 896 g (5.20 mol) and (b) 2MPD 604 g (5.20 mol) were dissolved in distilled water 1500 g to prepare a 50% by mass aqueous solution containing equimolar raw material monomers.
The obtained aqueous solution and 2MPD 21 g (0.18 mol), which is an additive at the time of melt polymerization, are charged into an autoclave (made by Nitto Koatsu) with an internal volume of 5.4 L until the liquid temperature (internal temperature) reaches 50 ° C. The temperature inside the autoclave was replaced with nitrogen. From the liquid temperature of about 50 ° C., heating was continued until the pressure in the tank of the autoclave reached about 2.5 kg / cm ² as gauge pressure (hereinafter, all pressure in the tank was expressed as gauge pressure). . In order to keep the pressure in the tank at about 2.5 kg / cm ² , heating was continued while removing water out of the system, and the aqueous solution was concentrated to a concentration of about 85%. The removal of water was stopped, and heating was continued until the pressure in the tank reached about 30 kg / cm ² . In order to keep the pressure in the tank at 30 kg / cm ² , heating was continued until the final temperature of the liquid temperature reached −50 ° C. while removing water out of the system. Further, while the heating was continued, the pressure in the tank was reduced from 30 kg / cm ² 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 liquid temperature was 345 ° C. The liquid temperature was maintained in that state for 10 minutes under a reduced pressure of 100 torr with a vacuum apparatus. Thereafter, it was pressurized with nitrogen to form a strand from the lower nozzle (nozzle), water-cooled, cut, and discharged in a pellet form to obtain a polyamide.
The obtained polyamide was dried in a nitrogen stream and the moisture content was adjusted to be less than about 0.2% by mass, and then the above measurements (1) to (3) were performed. The measurement results are shown in Table 1.

[Production Example 2]
Polyamide was polymerized by the hot melt polymerization method described in Production Example 1 except that the amount of the additive during melt polymerization was the amount described in Table 1 below.
Further, “solid phase polymerization” was performed.
10 kg of polyamide pellets obtained by melt polymerization were placed in a conical ribbon vacuum dryer (trade name ribocorn RM-10V, manufactured by Okawara Seisakusho Co., Ltd.), and sufficiently substituted with nitrogen. While flowing nitrogen at 1 L / min, heating was performed at 260 ° C. for 6 hours while stirring. Thereafter, the temperature was lowered while flowing nitrogen, and when the temperature reached about 50 ° C., the pellets were taken out from the apparatus to obtain polyamide.
Table 1 below shows the measurement results of the obtained polyamide based on the above-described measurement method.

[Production Example 3]
Polyamide was polymerized by the hot melt polymerization method described in Production Example 1 except that the time taken to lower the pressure in the tank from 30 kg / cm ² to atmospheric pressure was 90 minutes. Table 1 below shows the measurement results of the obtained polyamide based on the above-described measurement method.

[Production Examples 4 to 9]
The compounds and amounts shown in Table 1 below were used as (a) dicarboxylic acid, (b) diamine, (c) lactam and / or aminocarboxylic acid, and additives during melt polymerization.
Further, polyamide was polymerized by the hot melt polymerization method described in Production Example 1 except that the final temperature of the melt polymerization was set to the temperature described in Table 1 below.
For Production Examples 4, 5, and 7-9, the solid phase polymerization described in Production Example 2 was performed except that the temperature and time described in Table 1 below were applied as the solid phase polymerization temperature and time. It was. Table 1 shows the measurement results of the obtained polyamide based on the above measurement method.

[Comparative Production Example 1]
The hot melt polymerization method described in Production Example 1 except that the time taken to lower the pressure in the tank from 30 kg / cm ² to atmospheric pressure was 120 minutes and the final temperature of the melt polymerization was 350 ° C. Polymerization of polyamide was performed.
Table 2 below shows the results of measurements performed on the obtained polyamide based on the above-described measurement method.

[Comparative Production Example 2]
As the (a) dicarboxylic acid, (b) diamine, and additives during melt polymerization, the compounds and amounts shown in Table 2 below were used.
Further, the polyamide was polymerized by the hot melt polymerization method described in Production Example 1 except that the final temperature of the melt polymerization was set to the temperature described in Table 2 below. Furthermore, the solid phase polymerization described in Production Example 2 was performed except that the temperature and time described in Table 2 below were applied as the solid phase polymerization temperature and time.
Table 2 below shows the results of measurements performed on the obtained polyamide based on the above-described measurement method.

[Comparative Production Examples 3 to 9]
As the (a) dicarboxylic acid, (b) diamine, and additives during melt polymerization, the compounds and amounts shown in Table 2 below were used.
Further, the polyamide was polymerized by the hot melt polymerization method described in Production Example 1 except that the final temperature of the melt polymerization was set to the temperature described in Table 2 below.
Table 2 below shows the results of measurements performed on the obtained polyamide based on the above-described measurement method.

[Polyamide composition]
[Examples 1 to 9]
The polyamides of Production Examples 1 to 9 described above were used by drying in a nitrogen stream and adjusting the water content to about 0.2% by mass.
L / D (of the extruder) having 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 port in the ninth barrel. Production example from upstream feed port to die using twin screw extruder [ZSK-26MC: Coperion (Germany)] with cylinder length / cylinder diameter of extruder = 48 (number of barrels: 12) The polyamide (A) produced in (1) was set to Tm2 + 20 ° C., the rotation speed of the screw was 250 rpm, the discharge amount was 25 kg / h, and the polyamide, phenol-based heat stabilizer, Amine-based light stabilizer, phosphorus compound, and crystal nucleating agent are supplied after dry blending, titanium oxide is supplied from the downstream first supply port, and inorganic filler is supplied from the downstream second supply port, and melt-kneaded and polyamide composition. Pellet It was manufactured.
The obtained polyamide composition was dried in a nitrogen stream to reduce the water content to 500 ppm or less, and then molded and subjected to various evaluations. The physical property values are shown in Table 3 below together with the composition.

[Comparative Examples 1-9]
Using the polyamides of Comparative Production Examples 1 to 9 described above, polyamide composition pellets were prepared by melt-kneading in the same manner as in Example 1 except that the ratios shown in Table 4 below were obtained.
The obtained polyamide composition was dried in a nitrogen stream to reduce the water content to 500 ppm or less, and then molded and subjected to various evaluations. The physical property values are shown in Table 4 below together with the composition.

From the comparison of the results of Table 3 and Table 4, it contains at least 50 mol% alicyclic dicarboxylic acid and at least 50 mol% diamine having a pentamethylenediamine skeleton, and the cyclic amino terminal amount is 30-60 μeq / g. It was confirmed that the polyamide composition containing polyamide and titanium oxide had a large amount of bending deflection and excellent toughness, a high initial whiteness, and a low b value.
Moreover, since the whiteness after heat processing and the whiteness after a remelt process are high and b value after a humidity control process is low, it confirmed that it was excellent also in discoloration resistance.
Furthermore, the reflow heat resistance test also confirmed that there was no deformation and the heat resistance was high.

[Examples 10 to 12, Comparative Example 10]
Using the polyamides of Production Examples 2, 4, 5 or Comparative Production Example 6 except that the proportions shown in Table 5 below were used, melt-kneading was conducted in the same manner as in Example 1 to produce polyamide composition pellets.
The obtained polyamide composition was dried in a nitrogen stream to reduce the water content to 500 ppm or less, and then molded and subjected to various evaluations. The physical property values are shown in Table 5 below together with the composition.

  From the results in Table 5, it was confirmed that the color tone, discoloration resistance, and heat resistance were also high when the blending ratio of each component in the polyamide composition was changed.

[Examples 13 to 15, Comparative Example 11]
Polyamide composition pellets were produced by melt-kneading in the same manner as in Example 1 except that the ratios shown in Table 6 below were used using the polyamides of Production Examples 2, 4, 5 or Comparative Production Example 6.
The obtained polyamide composition was dried in a nitrogen stream, and the water content was reduced to 500 ppm or less. Extrusion molding was performed using a single screw extruder at a screw speed of 30 rpm and a discharge rate of 6 kg / h. At this time, the clearance of the T die and the take-up speed of the sheet were adjusted so that the sheet had a thickness of 150 μm.
Various evaluation was implemented using the obtained sheet | seat. The physical property values are shown in Table 6 below together with the composition.

  From the results of Table 6, the obtained sheet molded article is also excellent in toughness because it is good in the bending resistance test, and has high initial whiteness and high whiteness after remelting treatment. It was confirmed that the color fastness was excellent.

  The polyamide composition of the present invention has industrial applicability as a molding material for various parts such as automobiles, electric and electronic, industrial materials, industrial materials, daily products and household products.

Claims (16)

A polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol% alicyclic dicarboxylic acid and (b) a diamine containing a diamine having a pentamethylenediamine skeleton at least 50 mol%, (A) polyamide having a terminal amount of 30 to 60 μeq / g;
(B) titanium oxide;
A polyamide composition.   The polyamide composition according to claim 1, wherein the (A) polyamide has a sulfuric acid relative viscosity ηr at 25 ° C of 2.3 or more.   The polyamide composition according to claim 1 or 2, wherein the (A) polyamide is a polyamide obtained by further copolymerizing (c) a lactam and / or an aminocarboxylic acid.   The polyamide composition according to any one of claims 1 to 3, wherein the cyclic amino terminal of the (A) polyamide is formed by a cyclization reaction of a diamine having a pentamethylenediamine skeleton.   The polyamide composition according to any one of claims 1 to 4, wherein the (A) polyamide is a polyamide obtained through a solid phase polymerization step in at least a part of the polymerization step.   The polyamide composition according to any one of claims 1 to 5, wherein the polyamide (A) has a melting point of 270 to 350 ° C.   The polyamide composition according to any one of claims 1 to 6, wherein the (B) titanium oxide is titanium oxide having a number average particle diameter of 0.1 to 0.8 µm.   The polyamide composition according to any one of claims 1 to 7, wherein the (B) titanium oxide is coated with an inorganic coating and / or an organic coating.   The polyamide composition according to claim 8, wherein the inorganic coating is a metal oxide coating.   (C) The polyamide composition according to any one of claims 1 to 9, further comprising an inorganic filler.   The polyamide according to claim 10, wherein the inorganic filler (C) is at least one selected from the group consisting of glass fiber, potassium titanate fiber, talc, wollastonite, kaolin, mica, calcium carbonate, and clay. Composition.   (D) The polyamide composition according to any one of claims 1 to 11, further comprising a phenol-based heat stabilizer.   (E) The polyamide composition according to any one of claims 1 to 12, further comprising an amine light stabilizer.   The polyamide composition according to claim 13, wherein the molecular weight of the (E) amine light stabilizer is less than 1,000. (A) a polyamide obtained by polymerizing (a) a dicarboxylic acid containing at least 50 mol% of an alicyclic dicarboxylic acid and (b) a diamine containing a diamine having a pentamethylenediamine skeleton of at least 50 mol%. 30 to 95% by mass of polyamide having a cyclic amino terminal amount of 30 to 60 μeq / g,
(B) 5 to 45% by mass of titanium oxide,
(C) 0-50 mass% of inorganic filler,
(D) 0 to 1% by mass of a phenol-based heat stabilizer,
(E) 0 to 1% by mass of an amine light stabilizer,
Containing polyamide composition.   A molded article comprising the polyamide composition according to any one of claims 1 to 15.