JP2013253197A - Polyamide composition, and molded product obtained by molding polyamide composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide composition excellent in mechanical strength, toughness, heat resistance and dimensional stability, and excellent also in vibration fatigue resistance, slidability and low water absorption.SOLUTION: A polyamide composition contains: (A) a polyamide having a unit composed of (a) an alicyclic dicarboxylic acid and (b) at least one 8C diamine (here, in the case of being composed of two or more diamines, a mixture of diamines having the same number of carbon atoms); and (B) a fibrous reinforcing material having a number-average fiber diameter of 3 to 9 μm.

Description

  The present invention relates to a polyamide composition and a molded body obtained by molding the polyamide composition.

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

Such polyamides are required to be further improved in the future.
For example, in the automobile industry, there is a demand for reducing the body weight by replacing metal to reduce exhaust gas as an environmental effort. In order to meet such requirements, polyamides 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 increased.

In particular, since the temperature in the engine room is also increasing, 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 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 the above-mentioned requirement for high heat resistance.

Conventionally, high melting point polyamides have been proposed in order to solve the problems related to high heat resistance such as PA6 and PA66.
Specifically, a polyamide composed of terephthalic acid and hexamethylenediamine (hereinafter sometimes abbreviated as “PA6T”) has been proposed.
Further, a semi-alicyclic polyamide (hereinafter referred to as “PA6C”) composed of an alicyclic polyamide (hereinafter sometimes referred to as “PA6C”) composed of 1,4-cyclohexanedicarboxylic acid and hexamethylenediamine and another polyamide. (In some cases, it is abbreviated as “polymerized polyamide”) (see, for example, Patent Documents 1 and 2).
Specifically, Patent Document 1 discloses that the semi-alicyclic polyamide electrical and electronic members containing 1 to 40% 1,4-cyclohexanedicarboxylic acid as a dicarboxylic acid unit have excellent solder heat resistance. Patent Document 2 discloses that semi-alicyclic polyamide automobile parts are excellent in fluidity and toughness.

Furthermore, in Patent Document 3, 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, and lightness. And excellent heat resistance and the like.
Furthermore, Patent Document 4 proposes that a composition containing a polyamide 66 resin and glass fiber having a fiber diameter of 5 to 25 μm is excellent in welding strength. Further, Patent Document 5 discloses polyamide 6 It is also disclosed that by adding glass fibers having an average diameter of 3 to 8 μm to the resin, the resin has excellent impact resistance.

Japanese National Patent Publication No. 11-512476 Special table 2001-514695 gazette Japanese Patent Laid-Open No. 9-12868 JP-A-9-176484 Japanese Unexamined Patent Publication No. 60-38559

  However, in using a polyamide composition obtained by using polyamide as a material for parts for an automobile engine room, in recent years, a polyamide composition having further excellent mechanical strength, toughness, heat resistance and vibration fatigue resistance properties. Things are sought. Also, in the field of electrical and electronic parts and the like, a polyamide composition having excellent mechanical strength, toughness, heat resistance, and dimensional stability is required for use in parts that are smaller and more precise. Thus, the conventionally proposed polyamide composition has not yet obtained sufficient characteristics and needs to be improved.

  Therefore, in the present invention, in view of the above-described problems of the prior art, the polyamide is excellent in mechanical strength, toughness, heat resistance, dimensional stability, and also excellent in vibration fatigue resistance, slidability, and low water absorption. It aims at providing a composition and a molded object using the same.

As a result of intensive studies aimed at solving the above-described problems of the prior art, the present inventors have found that an alicyclic dicarboxylic acid and at least one diamine having 8 or more carbon atoms (however, composed of two or more diamines). In the case of the above-mentioned prior art, a polyamide composition containing a polymer obtained by polymerizing a polyamide having a same carbon number and a fibrous reinforcing material having a number average fiber diameter of 3 to 9 μm. The present inventors have found that the problem can be solved and have completed the present invention.
That is, the present invention is as follows.

[1]
(A): (a) alicyclic dicarboxylic acid and (b) at least one diamine having 8 or more carbon atoms (however, when it is composed of 2 or more diamines, it is a mixture of diamines having the same carbon number) Polyamide having a unit consisting of
(B): Fibrous reinforcing material having a number average fiber diameter of 3 to 9 μm,
A polyamide composition.
[2]
The polyamide composition according to [1], wherein the (B) fibrous reinforcing material is glass fiber.
[3]
The polyamide composition according to [1] or [2], wherein the (B) fibrous reinforcing material has a weight average fiber length of 100 to 500 μm in the polyamide composition.
[4]
The bundle (B) wherein the fibrous reinforcing material includes a copolymer of a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer. The polyamide composition according to any one of [1] to [3], which is a fibrous reinforcing material treated with an agent.
[5]
The polyamide composition according to any one of [1] to [4], wherein (a) the alicyclic dicarboxylic acid is 1,4-cyclohexanedicarboxylic acid.
[6]
The (b) at least one diamine having 8 or more carbon atoms is octamethylenediamine, nonamethylenediamine, a mixture of nonamethylenediamine and 2-methyloctamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine. The polyamide composition according to any one of [1] to [5], which is at least one selected from the group consisting of:
[7]
The polyamide composition according to any one of [1] to [6], wherein the polyamide (A) has a melting point of 270 to 350 ° C.
[8]
The polyamide composition according to any one of [1] to [7], wherein the trans isomer ratio of the alicyclic dicarboxylic acid structure in the (A) polyamide is 50 to 85%.
[9]
The ratio of the amount of amino end groups to the total amount of amino end groups and carboxyl end groups in the (A) polyamide [amino end group amount / (amino end group amount + carboxyl end group amount)] is 0.3 or more and 1 The polyamide composition according to any one of [1] to [8], which is less than 0.0.
[10]
The polyamide composition according to any one of [1] to [9], which contains 1 to 200 parts by mass of the (B) fibrous reinforcing material with respect to 100 parts by mass of the (A) polyamide.
[11]
(C) Phenol-based heat stabilizer, phosphorus-based heat stabilizer, amine-based heat stabilizer, elements of Group Ib, Group IIb, Group IIIa, Group IIIb, Group IVa and Group IVb of the periodic table Any one of [1] to [10], further comprising one or more thermal stabilizers selected from the group consisting of: metal salts of the above, alkali metal halides, and alkaline earth metal halides. The polyamide composition described.
[12]
The polyamide composition according to [11], wherein the heat stabilizer (C) is a mixture of a copper salt and an alkali metal halide and / or an alkaline earth metal halide.
[13]
(D) The polyamide composition according to any one of [1] to [12], further including one or more nucleating agents selected from the group consisting of boron nitride, talc, and carbon black.
[14]
The molded object which shape | molded the polyamide composition as described in any one of said [1] thru | or [13].
[15]
The molded product according to [14], which is a sliding component.

  According to the present invention, a polyamide composition excellent in mechanical strength, toughness, heat resistance, dimensional stability, vibration fatigue resistance, slidability, and low water absorption and a molded body using the same are obtained. It is done.

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 restrict | limited to the following embodiment, A various deformation | transformation can be implemented within the range of the summary.

[Polyamide composition]
The polyamide composition of this embodiment is
(A): (a) alicyclic dicarboxylic acid and (b) at least one diamine having 8 or more carbon atoms (however, when it is composed of 2 or more diamines, it is a mixture of diamines having the same carbon number) Polyamide having a unit consisting of
(B): Fibrous reinforcing material having a number average fiber diameter of 3 to 9 μm,
A polyamide composition.
Hereinafter, the components of the polyamide composition of the present embodiment will be described.

((A) Polyamide)
The polyamide contained in the polyamide composition of the present embodiment (hereinafter referred to as (A) polyamide, (A) component) may include the following (a) alicyclic dicarboxylic acid and (b) diamine. It is a copolymer containing as a polymerization monomer component.
(A) Alicyclic dicarboxylic acid.
(B) At least one diamine having 8 or more carbon atoms (however, when it is composed of 2 or more diamines, it is a mixture of diamines having the same carbon number).
Polyamide means a polymer having an amide (—NHCO—) bond in the main chain.

<(A) Alicyclic dicarboxylic acid>
The dicarboxylic acid which is a polymerization monomer component of the polyamide (A) constituting the polyamide composition of the present embodiment is (a) an alicyclic dicarboxylic acid.
By using an alicyclic dicarboxylic acid as the dicarboxylic acid, a polyamide that simultaneously satisfies heat resistance, fluidity, toughness, low water absorption, strength, and the like can be obtained.
(A) The alicyclic dicarboxylic acid (also referred to as alicyclic dicarboxylic acid) is not limited to the following, and examples thereof include 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid. And alicyclic dicarboxylic acids having 3 to 10 carbon atoms, preferably 5 to 10 carbon atoms, such as 1,3-cyclopentanedicarboxylic acid.
(A) The alicyclic dicarboxylic acid may be unsubstituted or may have a substituent.
Examples of the substituent include, but are not limited to, for example, 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. 4 alkyl groups and the like.
(A) The alicyclic dicarboxylic acid is preferably 1,4-cyclohexanedicarboxylic acid from the viewpoints of heat resistance, fluidity, strength, and the like.
(A) An alicyclic dicarboxylic acid may be used individually by 1 type, and may be used in combination of 2 or more types.

(A) Transcyclic and cis geometric isomers exist in alicyclic dicarboxylic acids.
As the raw material monomer (a), either the trans isomer or the cis isomer may be used, or a mixture of various ratios of the trans isomer and the cis isomer may be used.
(A) The alicyclic dicarboxylic acid is isomerized at a high temperature to have a certain ratio, and the cis isomer has higher water solubility in the equivalent salt with the diamine than the trans isomer. The isomer / 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 in terms of 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).

The (a) alicyclic dicarboxylic acid which is a polymer monomer of the polyamide (A) constituting the polyamide composition of the present embodiment is limited to the compounds described as the above (a) alicyclic dicarboxylic acid. It may be a compound equivalent to the above (a) alicyclic dicarboxylic acid.
The compound equivalent to the alicyclic dicarboxylic acid is not particularly limited as long as it can be an alicyclic dicarboxylic acid structure similar to the alicyclic dicarboxylic acid structure derived from the alicyclic dicarboxylic acid, Examples include alicyclic dicarboxylic acid anhydrides and halides.

<(B) Diamine>
The (b) diamine, which is a polymerizable monomer component of the polyamide (A) constituting the polyamide composition of the present embodiment, is at least one diamine having 8 or more carbon atoms (hereinafter referred to as (b) diamine). There is.)
(B) By using at least one diamine having 8 or more carbon atoms as the diamine, a polyamide that simultaneously satisfies fluidity, toughness, low water absorption, strength, and the like can be obtained.
The (b) diamine is preferably a saturated aliphatic diamine having 8 to 16 carbon atoms, more preferably a saturated aliphatic diamine having 8 to 14 carbon atoms, and further preferably 8 to 13 carbon atoms. It is a saturated aliphatic diamine, and more preferably a saturated aliphatic diamine having 9 to 12 carbon atoms. Two or more kinds of diamines having 8 or more carbon atoms may be combined, and in that case, the mixture is a mixture of diamines having the same carbon number.

Examples of the diamine having 8 or more carbon atoms include, but are not limited to, for example, octamethylene diamine, nonamethylene diamine, 2-methyloctamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, And tridecamethylenediamine and the like.
These (b) diamines may be used alone or in combination of two or more. In particular, from the viewpoint of mechanical strength and heat resistance, it is selected from octamethylenediamine, nonamethylenediamine, a mixture of nonamethylenediamine and 2-methyloctamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine. More preferred.

  (A) The amount of (a) alicyclic dicarboxylic acid added when polymerizing polyamide is preferably in the vicinity of the same molar amount as that of (b) diamine. In consideration of the escape of (b) diamine out of the reaction system during the polymerization reaction, the molar amount of (b) diamine as a whole is (b) 1.00 mol of the total amount of alicyclic dicarboxylic acid, Preferably it is 0.90-1.20, More preferably, it is 0.95-1.10, More preferably, it is 0.98-1.05.

<End sealant>
When the (A) polyamide is polymerized from the above-mentioned (a) alicyclic dicarboxylic acid and (b) diamine, a known end-capping agent can be further added to adjust the molecular weight.
Examples of end-capping agents include, but are not limited to, acid anhydrides such as monocarboxylic acids, monoamines, and phthalic anhydride, monoisocyanates, monoacid halides, monoesters, and monoalcohols. From the viewpoint of the thermal stability of the polyamide, monocarboxylic acids and monoamines are preferable.
As a terminal blocker, one type may be used alone, or two or more types 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 And aromatic monocarboxylic acids such as acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid.
One kind of monocarboxylic acid as the terminal blocking agent may be used alone, or two or more kinds 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; and aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine; Etc.
One kind of monoamine as a terminal blocking agent may be used alone, or two or more kinds may be used in combination.

(A) The (a) alicyclic dicarboxylic acid structure in polyamide exists as a geometric isomer of a trans isomer and a cis isomer.
(A) The trans isomer ratio of the (a) alicyclic dicarboxylic acid structure in the polyamide represents the ratio of the trans isomer in the entire (a) alicyclic dicarboxylic acid in the polyamide, and the trans isomer ratio is , Preferably it is 50-85 mol%, More preferably, it is 50-80 mol%, More preferably, it is 60-80 mol%.
(A) As the alicyclic dicarboxylic acid, it is preferable to use an alicyclic dicarboxylic acid having a trans isomer / cis isomer ratio (molar ratio) of 50/50 to 0/100, but (a) an alicyclic dicarboxylic acid. The polyamide obtained by polymerization of the acid and (b) diamine preferably has an alicyclic dicarboxylic acid structure, that is, a trans isomer ratio of a portion derived from the alicyclic dicarboxylic acid of 50 to 85 mol%.
When the trans isomer ratio is within the above range, the polyamide (A) has a high melting point, toughness and strength, and in addition to the heat-induced rigidity due to the high glass transition temperature, and usually heat resistance. It has the property of simultaneously satisfying the fluidity, which is a property, and high crystallinity and low water absorption.
These characteristics of (A) polyamide are (a) 1,4-cyclohexanedicarboxylic acid, (b) octamethylenediamine, nonamethylenediamine, a mixture of nonamethylenediamine and 2-methyloctamethylenediamine, decamethylenediamine, This is particularly remarkable in a polyamide comprising a combination of diamines selected from decamethylenediamine and dodecamethylenediamine, and having a trans isomer ratio of 50 to 85 mol% in a portion derived from an alicyclic dicarboxylic acid.
(A) The trans isomer ratio of the alicyclic dicarboxylic acid structure in the polyamide can be measured by NMR.

The polyamide (A) constituting the polyamide composition of the present embodiment has a ratio of amino end group amount to total amount of amino end group amount and carboxyl end group amount [amino end group amount / (amino end group) at the polymer end. Amount + carboxyl terminal group amount)] is preferably 0.3 or more and less than 1.0. When the ratio of the amino terminal group amount falls within this range, a polyamide composition having better mechanical strength, toughness, and vibration fatigue resistance can be obtained. More preferably, it is 0.3 or more and less than 0.6, and further preferably 0.4 or more and less than 0.6.
Although there is no restriction | limiting in the measuring method of the terminal group amount of these polyamides, The method measured by 1H-NMR, the method measured by neutralization titration, etc. are mentioned. When measured by titration, the number of carboxyl group ends (eq / g) is determined by the method of titrating a polyamide benzyl alcohol solution with 0.1N sodium hydroxide, and the number of amino group ends (eq / g) is determined by polyamide phenol. A method of titrating the solution with 0.1N hydrochloric acid can be mentioned.

((A) Polyamide production method)
(A) As a manufacturing method of polyamide, if it is a manufacturing method of polyamide including the process of polymerizing (a) alicyclic dicarboxylic acid and (b) at least 1 sort of C8 or more diamine, There is no particular limitation.
(A) As a manufacturing method of polyamide, it is preferable to further include the process of raising the polymerization degree of polyamide.

(A) As a manufacturing method of polyamide, various methods are mentioned, for example as illustrated below:
1) Suspension of aqueous solution or water of dicarboxylic acid and diamine or suspension of water or water of a mixture of dicarboxylic acid and diamine salt and other components (hereinafter abbreviated as “the mixture” in this paragraph). A method in which a turbid liquid is heated and polymerized while maintaining a molten state (hereinafter, sometimes referred to as “hot melt polymerization method”).
2) A method of increasing the degree of polymerization while maintaining the solid state of the polyamide obtained by the hot melt polymerization method at a temperature below the melting point (hereinafter, sometimes abbreviated as “hot melt polymerization / solid phase polymerization method”). .
3) A method in which an aqueous solution or a suspension of water of dicarboxylic acid and diamine or a mixture thereof is heated, and the precipitated prepolymer is further melted again by 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 in which an aqueous solution or a suspension of water of dicarboxylic acid and diamine or a mixture thereof is heated, and the degree of polymerization is increased while maintaining the solid state of the precipitated prepolymer at a temperature below the melting point of the polyamide (hereinafter referred to as “ It may be abbreviated as “prepolymer / solid phase polymerization method”).
5) A method of polymerizing a dicarboxylic acid and a diamine or a mixture thereof while maintaining a solid state (hereinafter sometimes abbreviated as “solid phase polymerization method”).
6) A “solution method” in which a dicarboxylic acid halide and a diamine equivalent to dicarboxylic acid are used for polymerization.

(A) In the polyamide production method, it is preferable to carry out the polymerization while maintaining the trans isomer ratio of the alicyclic dicarboxylic acid structure in the polyamide at 50 to 85%. From the viewpoint of the fluidity of the polyamide, It is more preferable to perform polymerization while maintaining the trans isomer ratio of the alicyclic dicarboxylic acid structure at 50 to 80%.
By maintaining the trans isomer ratio within the above range, particularly 80% or less, it is possible to obtain a polyamide having an excellent color tone and tensile elongation and a high melting point.
In the polyamide production method, it is necessary to increase the heating temperature and / or lengthen the heating time in order to increase the melting point of the polyamide by increasing the degree of polymerization. There is a case where the tensile elongation is lowered due to coloring of the polyamide or thermal deterioration. In addition, the rate at which the molecular weight increases may decrease significantly.
Since it is possible to prevent a decrease in tensile elongation due to polyamide coloring or thermal deterioration, it is preferable to perform polymerization while maintaining the trans isomer ratio at 80% or less.
(A) As a method for producing a polyamide, since it is easy to maintain the trans isomer ratio of the alicyclic dicarboxylic acid structure in the polyamide at 80% or less, and because the resulting polyamide is excellent in color tone, It is preferable to produce polyamide by 1) hot melt polymerization method and 2) hot melt polymerization / solid phase polymerization method.

(A) As a polymerization form applied in the manufacturing method of polyamide, a batch type or a continuous type may be sufficient.
(A) The polymerization apparatus used in the polyamide polymerization step is not particularly limited, and known apparatuses, for example, autoclave type reactors, tumbler type reactors, extruder type reactors such as kneaders, etc. Can be mentioned.
(A) It does not specifically limit as a manufacturing method of polyamide, The batch type hot-melt-polymerization method described below is mentioned as a preferable method.
As a batch-type hot melt polymerization method, for example, a solution of about 40 to 60% by mass containing a polyamide component ((a) alicyclic dicarboxylic acid, (b) diamine) using water as a solvent is 110 to 180%. In a concentration tank operated at a temperature of ° C. and a pressure of about 0.035 to 0.6 MPa (gauge pressure), it is concentrated to about 65 to 90% by mass 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., the pressure is reduced to atmospheric pressure (gauge 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. Then, it pressurizes with inert gas, such as nitrogen, and extrudes a polyamide melt as a strand. The strand is cooled and cut to obtain pellets.
(A) As a manufacturing method of polyamide, the continuous hot melt polymerization method described below can be applied.
As such a continuous hot melt polymerization method, for example, a solution of about 40 to 60% by mass containing a polyamide component in water as a solvent is preheated to about 40 to 100 ° C. in a container of a preliminary apparatus, and then concentrated. Transfer to bed / reactor and concentrate to about 70-90% at a pressure of about 0.1-0.5 MPa (gauge pressure) and a temperature of about 200-270 ° C. to obtain a concentrated solution. The concentrated solution is discharged into a flasher maintained at a temperature of about 200 to 350 ° 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. The polyamide melt is then extruded into strands, cooled and cut into pellets.

((A) Physical properties of polyamide)
<Molecular weight>
(A) The molecular weight of the polyamide can be determined using a relative viscosity ηr at 25 ° C. as an index.
(A) The molecular weight of the polyamide is relative to mechanical properties such as toughness and strength, and impregnating properties of the resin during production of the polyamide composition, measured in accordance with JIS-K6920 at a concentration of 1% in 98% sulfuric acid and 25 ° C. The viscosity ηr is preferably 1.5 to 7.0, more preferably 1.7 to 6.0, and still more preferably 1.9 to 5.0.
The measurement of the relative viscosity at 25 ° C. can be performed according to JIS-K6920 as described in the following examples.

<Melting point>
(A) The melting point of polyamide is preferably 270 to 350 ° C. as Tm2 from the viewpoint of heat resistance.
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.
(A) By setting the melting point Tm2 of the polyamide to 270 ° C. or higher, a polyamide having excellent heat resistance can be obtained. (A) By setting the melting point Tm2 of the polyamide to 350 ° C. or lower, the thermal decomposition of the polyamide in the melt processing such as extrusion and molding can be suppressed.
The melting point Tm2 of the polyamide will be further described in detail in the following examples.

<Heat of fusion>
(A) From the viewpoint of heat resistance, the heat of fusion ΔH of polyamide is preferably 10 J / g or more, more preferably 14 J / g or more, still more preferably 18 J / g or more, and even more preferably 20 J. / G or more.
(A) The measurement of the melting point (Tm1 or Tm2) of polyamide and the heat of fusion ΔH can be performed according to JIS-K7121 as described in the following examples.
Examples of the measuring device for the melting point and the heat of fusion include Diamond-DSC manufactured by PERKIN-ELMER.

<Glass transition temperature>
(A) The glass transition temperature Tg of the polyamide is preferably 90 to 170 ° C. The glass transition temperature is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 110 ° C. or higher. Further, the glass transition temperature is preferably 170 ° C. or lower, more preferably 165 ° C. or lower, and further preferably 160 ° C. or lower.
By setting the glass transition temperature to 90 ° C. or higher, a polyamide having excellent heat resistance and chemical resistance can be obtained. Moreover, the molded object with a favorable external appearance can be obtained by making glass transition temperature 170 degrees C or less.
The glass transition temperature can be measured according to JIS-K7121 as described in the following examples.
Examples of the glass transition temperature measuring device include Diamond-DSC manufactured by PERKIN-ELMER.

((B) Fibrous reinforcement)
The polyamide composition of the present embodiment includes the above-described (A) polyamide, (B) a fibrous reinforcing material having a number average fiber diameter of 3 to 9 μm (hereinafter referred to as (B) fibrous reinforcing material, (B) component, and In some cases).
(B) By containing a fibrous reinforcing material, in addition to these properties, mechanical strength, dimensional stability, resistance to heat, resistance to toughness, fluidity, rigidity, etc. are not impaired. A polyamide composition having excellent vibration fatigue characteristics can be obtained.
(B) The fibrous reinforcing material is not particularly limited, and examples thereof include glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, and aluminum borate fiber.
In particular, glass fibers and carbon fibers are preferable from the viewpoint of strength and rigidity, and glass fibers are particularly preferable from the viewpoint of vibration fatigue resistance.
(B) One type of fibrous reinforcing material may be used, or two or more types may be used in combination.
The (B) fibrous reinforcing material contained in the polyamide composition of the present embodiment has a number average fiber diameter of 3 to 9 μm.
The number average fiber diameter can be used as it is if there is a nominal value by the manufacturer, but if there is no nominal value, it can be easily obtained from the measured value with a microscope.
(B) By making the number average fiber diameter of the fibrous reinforcing material 3 μm or more, the mechanical strength, heat resistance, rigidity and the like of the polyamide composition of the present embodiment are improved, and by making it 9 μm or less, the mechanical strength is improved. A polyamide composition having excellent strength, toughness, heat resistance, dimensional stability and vibration fatigue resistance can be obtained.

(B) The amount of the fibrous reinforcing material is preferably 0.1 to 200 parts by mass, more preferably 1 to 200 parts by mass, and still more preferably with respect to 100 parts by mass of the polyamide (A) described above. Is 5 to 150 parts by mass.
(B) By making the compounding quantity of a fibrous reinforcement into 0.1 mass part or more with respect to 100 mass parts of (A) polyamide, mechanical properties, such as toughness and rigidity of the polyamide composition of this embodiment, improve. Moreover, the polyamide composition excellent in a moldability is obtained by making a compounding quantity into 200 mass parts or less.

(B) As the fibrous reinforcing material, glass fiber is preferable from the viewpoint of mechanical strength and heat resistance.
(B) When a fibrous reinforcement is glass fiber, E glass composition, C glass composition, S glass composition, alkali-resistant glass composition etc. are mentioned as a specific composition.
The tensile strength of the glass fiber is arbitrary, but is usually 290 kg / mm ² or more.
Among these, E glass is preferable from the viewpoint of easy availability.
These glass fibers are not limited to the following, but include, for example, silane coupling agents such as γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane. It is preferable that the surface is treated, and the adhesion amount is usually 0.01% by mass or more with respect to the glass fiber weight (total amount of the glass fiber and the surface treatment agent).

In the polyamide composition of the present embodiment, the (B) fibrous reinforcing material preferably has a weight average fiber length of 100 to 500 μm from the viewpoint of mechanical strength and appearance of a molded product.
The weight average fiber length is more preferably 200 to 500 μm, and further preferably 200 to 450 μm.

Further, (B) the fibrous reinforcing material can be treated with a sizing agent, if necessary.
As the sizing agent, a copolymer containing a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer as a structural unit, an epoxy compound, Polyurethane resins, homopolymers of acrylic acid, copolymers of acrylic acid and other copolymerizable monomers, and salts thereof with primary, secondary and tertiary amines, and unsaturated vinyl monomers containing carboxylic acid anhydrides And a copolymer containing an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer.
These may be used individually by 1 type and may be used in combination of 2 or more type.
In particular, from the viewpoint of 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. A copolymer, an epoxy compound and a polyurethane resin, and a combination thereof are preferable. Among them, from the viewpoint of toughness and vibration fatigue resistance, the carboxylic anhydride-containing unsaturated vinyl monomer and the carboxylic anhydride-containing unsaturated It is more preferable to include a copolymer containing an unsaturated vinyl monomer excluding a vinyl monomer as a constituent unit, and a carboxylic acid anhydride-containing unsaturated vinyl monomer and the carboxylic acid anhydride-containing unsaturated material. A combination of a copolymer containing an unsaturated vinyl monomer excluding a vinyl monomer as a structural unit and a polyurethane resin is more preferable.

(Inorganic filler other than (B))
The polyamide composition of this embodiment may use a predetermined inorganic filler in addition to the above (B): fibrous reinforcing material having a number average fiber diameter of 3 to 9 μm.
In the molded article of the polyamide composition in the present embodiment, from the viewpoint of reducing the occurrence of warping and reducing the dimensional anisotropy, inorganic fillers other than (B) are inorganic other than glass fibers and carbon fibers. It is preferable to include a filler.
Examples of inorganic fillers other than (B) include, but are not limited to, for example, flaky glass, glass beads, hollow glass beads, talc, kaolin, mica, hydrotalcite, calcium carbonate, Zinc carbonate, zinc oxide, calcium monohydrogen phosphate, wollastonite, silica, zeolite, alumina, boehmite, aluminum hydroxide, titanium oxide, silicon oxide, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, kettle Examples thereof include chain black, acetylene black, furnace black, carbon nanotube, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, mica, montmorillonite, swellable fluorine mica, and apatite.
The inorganic filler other than (B) may be surface-treated.
As the inorganic filler other than (B), one kind may be used, or two or more kinds may be used in combination.
As the inorganic filler other than (B), wollastonite is more preferable. Among the wollastonites, the number average fiber diameter is 3 to 30 μm, the weight average fiber length is 10 to 500 μm, and the aspect ratio ( Those having L / D) of 3 to 100 are more preferably used.
Note that L = fiber length of the inorganic filler and D = fiber diameter of the inorganic filler.
Furthermore, as the inorganic filler other than (B), talc, mica, kaolin, silicon nitride, and the like are more preferable. Among talc, mica, kaolin, silicon nitride, and the like, the number average fiber diameter is 0.1 to 3 μm. Are more preferably used.

  The number average fiber diameter and the weight average fiber length of the above-mentioned (B) fibrous reinforcing material and inorganic filler other than (B) are obtained by dissolving the molded article of the polyamide composition with a solvent in which polyamide is soluble, such as formic acid. From the obtained insoluble components, for example, 100 or more fibrous reinforcing materials and inorganic fillers are arbitrarily selected, and observed with an optical microscope, a scanning electron microscope, etc. Incineration, for example, 100 or more fibrous reinforcing materials and inorganic fillers are arbitrarily selected from the residue, and are observed and measured with an optical microscope, a scanning electron microscope, or the like.

((C) heat stabilizer)
In the polyamide composition of this embodiment, (C) a phenol-based heat stabilizer, a phosphorus-based heat stabilizer, an amine-based heat stabilizer, Group Ib, Group IIb, Group IIIa, Group IIIb of the periodic table One or more heat stabilizers selected from the group consisting of metal salts of elements of Group IVa and Group IVb and alkali metal halides and alkaline earth metal halides (hereinafter referred to as (C) heat stability) And may be described as an agent (component) (C).).

<Phenolic heat stabilizer>
Although it does not restrict | limit especially as said phenol type heat stabilizer, For example, a hindered phenol compound is mentioned.
Phenol-based heat stabilizers, particularly hindered phenol compounds, have the property of imparting heat resistance and light resistance to resins such as polyamide and fibers.
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.
A phenol type heat stabilizer may be used individually by 1 type, and may be used in combination of 2 or more type.
In particular, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide)] is preferable from the viewpoint of improving heat aging resistance.
When using a phenol-based heat stabilizer, the blending amount of the phenol-based heat stabilizer in the polyamide composition is preferably 0.01 to 1 part by weight, more preferably 0.1 to 100 parts by weight of the polyamide. -1 part 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 heat stabilizer>
Examples of the phosphorus-based heat stabilizer include, but are not limited to, pentaerythritol type phosphite compounds, 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 ( -Methyl-6-t-butylphenyl-tetra-tridecyl) diphosphite, tetra (C12-C15 mixed alkyl) -4,4'-isopropylidene diphenyl diphosphite, 4,4'-isopropylidenebis (2-t- Butylphenyl) -di (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butanediphos Phyto, tetra (tridecyl) -4,4′-butylidenebis (3-methyl-6-tert-butylphenyl) diphosphite, tetra (C1-C15 mixed alkyl) -4,4′-isopropylidenediphenyl diphosphite, tris ( Mono, di-mixed nonylphenyl) phosphite, 4,4′-isopropylidenebis ( -T-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-t) -Butylphenyl))-1,6-hexanol diphosphite, hexatridecyl-1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) diphosphite, tris (4,4 ' -Isopropylidenebis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phosphite, 2, -Methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 2,2-methylenebis (3-methyl-4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, tetrakis (2,4 -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 the phosphorus-based heat stabilizers, among those listed above, pentaerythritol phosphite compounds, tris (2,4-di-t-butylphenyl), from the viewpoint of further improving heat aging resistance and reducing generated gas. ) Phosphite is preferred.
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-tert-butyl-4-methylphenyl-octylphenyl-pentaerythritol diphosphite, 2,6-di-tert-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.

(C) When using a phosphorus heat stabilizer as a heat stabilizer, the compounding amount of the phosphorus heat stabilizer in the polyamide composition of the present embodiment is 0.01 to 100 parts by weight of the polyamide (A). 1 part by mass, more preferably 0.1-1 part 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.

<Amine heat stabilizer>
Examples of the amine heat stabilizer include, but are not limited to, 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetra Methylpiperidine, 4-methoxy-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetra Methylpiperidine, 4-benzyloxy-2,2,6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine 4- (ethylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy)- 2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) -carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl)- Oxalate, bis (2,2,6,6-tetramethyl-4-piperidyl) -malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) -sebacate, bis (2,2,6, 6-tetramethyl-4-piperidyl) -adipate, bis (2,2,6,6-tetramethyl-4-piperidyl) -terephthalate, 1,2-bis (2,2,6 6-tetramethyl-4-piperidyloxy) -ethane, α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2,6,6) -Tetramethyl-4-piperidyltolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylene-1,6-dicarbamate, tris (2,2 , 6,6-tetramethyl-4-piperidyl) -benzene-1,3,5-tricarboxylate, 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) Lopionyloxy] 2,2,6,6-tetramethylpiperidine, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 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.

  (C) When an amine heat stabilizer is used as the heat stabilizer, the compounding amount of the amine heat stabilizer in the polyamide composition of the present embodiment is preferably 0. It is 01-1 mass part, More preferably, it is 0.1-1 mass part. 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.

<Metal salts of elements of Group Ib, Group IIb, Group IIIa, Group IIIb, Group IVa, and Group IVb of the periodic table>
The metal salt of the elements of Group Ib, Group IIb, Group IIIa, Group IIIb, Group IVa and Group IVb of the periodic table is not particularly limited, but is preferably a copper salt. .
Examples of the copper salt include, but are not limited to, copper halides (copper iodide, cuprous bromide, cupric bromide, cuprous chloride, etc.), copper acetate, copper propionate, benzoic acid. Examples thereof include copper, copper adipate, copper terephthalate, copper isophthalate, copper salicylate, copper nicotinate and copper stearate, and copper complex salts in which copper is coordinated to a chelating agent such as ethylenediamine and ethylenediaminetetraacetic acid.
These may be used alone or in combination of two or more.
Among the copper salts listed above, one or more selected from the group consisting of copper iodide, cuprous bromide, cupric bromide, cuprous chloride and copper acetate are preferred, and copper iodide is more preferred. And / or copper acetate.
When such a preferable copper salt is used, a polyamide composition having excellent heat aging resistance and capable of suppressing metal corrosion of the screw or cylinder during extrusion (hereinafter also simply referred to as “metal corrosion”) can be obtained.

(C) When using the said copper salt as a heat stabilizer, the compounding quantity of the copper salt in the polyamide composition of this embodiment becomes like this. Preferably it is 0.01-0.2 with respect to 100 mass parts of (A) polyamide. It is a mass part, More preferably, it is 0.02-0.15 mass part.
When it is within the above range, the heat aging resistance is further improved, and copper precipitation and metal corrosion can be suppressed.
Further, from the viewpoint of improving the heat aging resistance, the content concentration of the copper element is preferably 10 to 500 ppm, more preferably 30 to 500 ppm, and still more preferably 50 to the total amount of the polyamide composition of the present embodiment. ~ 300 ppm.

<Alkali metal halides, alkaline earth metal halides>
Examples of the alkali metal halide and alkaline earth metal halide include, but are not limited to, potassium iodide, potassium bromide, potassium chloride, sodium iodide and sodium chloride, and mixtures thereof. .
In particular, from the viewpoint of improvement in heat aging resistance and suppression of metal corrosion, potassium iodide and potassium bromide, and a mixture thereof are preferable, and potassium iodide is more preferable.
(C) When the alkali metal halide and / or alkaline earth metal halide is used as the heat stabilizer, the alkali metal halide and / or alkaline earth metal in the polyamide composition of this embodiment is used. The blending amount of the halide is preferably 0.05 to 5 parts by mass and more preferably 0.2 to 2 parts by mass with respect to 100 parts by mass of the (A) polyamide. When it is within the above range, the heat aging resistance is further improved, and copper precipitation and metal corrosion can be suppressed.

The component of the (C) heat stabilizer mentioned above may be used individually by 1 type, and may be used in combination of 2 or more type. In particular, a mixture of a copper salt and an alkali metal halide and / or an alkaline earth metal halide is preferred.
The ratio of the copper salt to the alkali metal halide and / or alkaline earth metal halide is such that the molar ratio of halogen to copper (halogen / copper) is 2/1 to 40/1. It is preferable to make it contain in a thing, More preferably, it is 5/1-30/1. In the above range, the heat aging resistance can be further improved.
When the halogen / copper is 2/1 or more, it is preferable because copper precipitation and metal corrosion can be suppressed.
On the other hand, when the halogen / copper is 40/1 or less, corrosion of the screw of the molding machine and the like can be prevented without substantially impairing mechanical properties such as toughness.

((D) Nucleating agent)
In the polyamide composition of this embodiment, (D) one or more nucleating agents selected from the group consisting of boron nitride, talc, and carbon black (hereinafter referred to as (D) nucleating agent, (D) component) Can be further blended.
(D) The nucleating agent is not limited to the following, but increases the crystallization peak temperature by addition, reduces the difference between the extrapolation start temperature and the extrapolation end temperature of the crystallization peak, It means a substance capable of obtaining the effect of refining spherulites or making the size uniform. Examples include talc, boron nitride, mica, kaolin, calcium carbonate, barium sulfate, silicon nitride, carbon black, potassium titanate, and molybdenum disulfide.
(D) A nucleating agent may be used by 1 type and may be used in combination of 2 or more types.
(D) It is preferable that a nucleating agent is 1 or more types chosen from the group which consists of boron nitride, a talc, and carbon black from a viewpoint of a nucleating agent effect.
In the polyamide composition of the present embodiment, by adding the (D) nucleating agent, the mechanical strength, toughness, heat resistance, and dimensional stability, which are the effects of the present invention, can be further improved.
When (D) the nucleating agent is used, the blending amount of the (D) nucleating agent in the polyamide composition is preferably 0.01 to 2 parts by mass, more preferably 100 parts by mass of the (A) polyamide. It is 0.02-0.5 mass part. In the above range, the mechanical strength, heat resistance, and dimensional stability can be further improved.

(Other ingredients)
In the polyamide composition of the present embodiment, in addition to the components (A) to (D) described above, other components may be added as necessary within a range not impairing the effects of the present embodiment.
Examples of other components include, but are not limited to, for example, antioxidants, ultraviolet absorbers, photodegradation inhibitors, plasticizers, lubricants, mold release agents, flame retardants, colorants, dyes, and pigments. Etc. may be added, or other thermoplastic resins may be mixed. Here, since the above-mentioned other components are greatly different in properties, there are various suitable contents for each component that hardly impair the effects of the present embodiment.
A person skilled in the art can easily set a suitable content for each of the other components described above.

[Production method of polyamide composition]
The method for producing the polyamide composition of the present embodiment is not particularly limited as long as it is a method of mixing the (A) polyamide and (B) the fibrous reinforcing material.
As a mixing method of (A) polyamide and (B) fibrous reinforcing material, for example, a method of mixing polyamide and fibrous reinforcing material using a Henschel mixer or the like, supplying to a melt kneader, kneading, Examples thereof include a method of blending a fibrous reinforcing material from a side feeder into polyamide melted by a twin screw extruder.
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.
The melt kneading time is preferably about 0.25 to 5 minutes.
The apparatus for performing the melt kneading is not particularly limited, and a known apparatus such as a single or twin screw extruder, a Banbury mixer, a mixing roll, or the like can be used.

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

[Molded body using polyamide composition]
The molded body of the polyamide composition of the present embodiment is a known molding method 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 body obtained from the polyamide composition of the present embodiment is excellent in heat resistance, toughness, rigidity, low water absorption, and also excellent in heat aging resistance.

[Use of polyamide composition and molded product]
The polyamide composition of the present embodiment is suitably used as various component materials for automobiles, electricity, electronics, industrial materials, daily necessities, household goods, and 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.
The automobile intake system parts are not particularly limited, and examples include an air intake manifold, an intercooler inlet, an exhaust pipe cover, an inner bush, a bearing retainer, an engine mount, an engine head cover, a resonator, and a throttle body.
The automobile cooling system component is not particularly limited, and examples thereof include a chain cover, a thermostat housing, an outlet pipe, a radiator tank, an oil netter, and a delivery pipe.
The automobile fuel system parts are not particularly limited, and examples thereof include a fuel delivery pipe and a gasoline tank case.
The 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 electrical component is not particularly limited, and examples thereof include a connector, a wire harness connector, a motor component, a lamp socket, a sensor on-vehicle switch, and a combination switch.
For electrical and electronic use, there is no particular limitation. For example, connectors, switches, relays, printed wiring boards, housings for electronic devices such as mobile phones, portable information terminals, music players, portable game machines, Used in housings, outlets, noise filters, coil bobbins, motor end caps, etc.
For industrial equipment, it is not particularly limited. For example, it is used for gears, bearings, cams, insulating blocks, valves, power tool parts, agricultural equipment parts, engine covers, and the like.
Daily and household items are not particularly limited, and are used for buttons, food containers, office furniture, and the like.
The extrusion application is not particularly limited, and for example, it is used for a film, a sheet, a filament, a tube, a rod, a hollow molded article, and the like.
Among them, it is excellent in mechanical strength, toughness, heat resistance, and vibration fatigue resistance, so it is suitable as a component material for automobiles. Furthermore, the molded article of the polyamide composition of this embodiment is excellent in slidability. Therefore, it is suitable as various sliding parts, and specifically, is particularly suitable as a material for sliding parts for gears and bearings. Moreover, since it is excellent in mechanical strength, toughness, heat resistance, and dimensional stability, it is also suitable as an electrical and electronic component material.

  Hereinafter, the present invention will be described in detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

First, the constituent material of the polyamide composition used in the following Examples and Comparative Examples, the applied physical property measurement method, and the property evaluation method are shown.
In this specification, 1 kg / cm ² is 0.098 MPa.

[Raw material of polyamide composition]
As raw materials for the polyamide composition, (A) polyamide, (B) fibrous reinforcing material, (C) copper compound and metal halide as heat stabilizer, and (D) nucleating agent are shown below.
((A) Polyamide)
(A-1): Polyamide (PA-1) obtained by polymerizing 1,4-cyclohexanedicarboxylic acid and dodecamethylenediamine described in Production Example 1
(A-2): Polyamide (PA-2) obtained by polymerizing 1,4-cyclohexanedicarboxylic acid and decamethylenediamine described in Production Example 2
(A-3): Polyamide obtained by polymerizing 1,4-cyclohexanedicarboxylic acid and decamethylenediamine as described in Production Example 3 (PA-3)
(A-4): Polyamide obtained by polymerizing 1,4-cyclohexanedicarboxylic acid described in Production Example 4, nonamethylenediamine and 2-methyloctamethylenediamine (PA-4)
(A-5): Polyamide obtained by polymerizing 1,4-cyclohexanedicarboxylic acid described in Comparative Production Example 1, hexamethylenediamine, and ε-caprolactam (PA-5)
(A-6): Polyamide 66 (PA-6)
Relative viscosity: 2.8
(A-7): Polyamide 9T (PA-7) described in Comparative Production Example 2 described later

(A) dicarboxylic acid, (b) diamine, (c) caprolactam, and (d) terminal blocker used as monomers for polymerizing (A) polyamide in Production Examples 1 to 4 and Comparative Production Examples 1 and 2 described later Is shown below.
(A) Dicarboxylic acid (a-1) 1,4-cyclohexanedicarboxylic acid (CHDA)
Product name: 1,4-CHDA HP grade (trans / cis = 25/75) (Eastman Chemical)
(A-2) Terephthalic acid (TPA) (manufactured by Wako Pure Chemical Industries, Ltd.)

(B) Diamine (b-1) 1,12-diaminododecane (dodecamethylenediamine) (C12DA) (manufactured by Tokyo Chemical Industry)
(B-2) 1,10-diaminodecane (decamethylenediamine) (C10DA) (manufactured by Tokyo Chemical Industry)
(B-3) 1,9-Diaminononane (nonamethylenediamine) (C9DA) (manufactured by Tokyo Chemical Industry)
(B-4) 1,6-diaminohexane (hexamethylenediamine) (C6DA) (manufactured by Tokyo Chemical Industry)
(B-5) 2-methyloctamethylenediamine (2MC8DA) This was produced with reference to the production method described in JP-A No. 05-17413.

(C) ε-caprolactam (CPL) (manufactured by Wako Pure Chemical Industries)
(D) Acetic acid (Wako Pure Chemical Industries)

((B) Fibrous reinforcement)
(B-1): Glass fiber (GF-1) treated with a sizing agent containing maleic anhydride copolymer
Number average fiber diameter: 7 μm
(B-2): Glass fiber (GF-2) treated with a sizing agent containing maleic anhydride copolymer
Number average fiber diameter: 5 μm
(B-3): Glass fiber (GF-3) treated with a sizing agent containing a urethane resin
Number average fiber diameter: 7 μm
(B-4): Glass fiber (GF-4) treated with a sizing agent containing maleic anhydride copolymer
Number average fiber diameter: 10 μm

It shows below about the component which comprises the sizing agent used for the process of the (B) fibrous reinforcement of the manufacture examples 5-8 mentioned later.
(X-1) Polyurethane resin emulsion Product name: Bondic (registered trademark) 1050 (Dainippon Ink Co., Ltd.)
(Aqueous solution with a solid content of 50% by mass)
(X-2) Maleic anhydride copolymer emulsion Product name: Acro Binder (registered trademark) BG-7 (manufactured by Sanyo Chemical Industries, Ltd.)
(Aqueous solution with a solid content of 25% by mass)
(X-3) Aminosilane coupling agent Product name: KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.)
γ-Aminopropyltriethoxysilane (x-4) Lubricant Brand name: Carnauba wax (manufactured by Hiroyuki Kato)

((C) Copper compound and metal halide)
(C-1): Copper iodide (CuI) (manufactured by Wako Pure Chemical Industries, Ltd.)
(C-2): Potassium iodide (KI) (manufactured by Wako Pure Chemical Industries, Ltd.)

((D) Nucleating agent)
(D-1): Boron nitride (BN)
Product name: DENKABORON NITRIDE SP-2 (manufactured by Denki Kagaku Kogyo Co., Ltd.)
(D-2): Talc Product name: Microace (registered trademark) L-1 (Nippon Talc Co., Ltd.)
(D-3): Carbon black (CB)
Product name: Mitsubishi (registered trademark) carbon black # 2300 (Mitsubishi Chemical Corporation)

[Method for measuring physical properties]
((1) melting point 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 a temperature rise rate of 20 ° C./min The maximum peak temperature of the endothermic peak (melting peak) that appears when the temperature was raised to the melting point was Tm2 (° C.), and the total peak area was the heat of fusion ΔH (J / g).
When there were a plurality of peaks, those having ΔH of 1 J / g or more were regarded as peaks.
For example, when two peaks of melting point 295 ° C., ΔH = 20 J / g and melting point 325 ° C., ΔH = 5 J / g are present, the melting point is 325 ° C.

((2) Trans isomer ratio)
30-40 mg of polyamide was dissolved in 1.2 g of hexafluoroisopropanol deuteride and measured by 1H-NMR.
When the alicyclic dicarboxylic acid is 1,4-cyclohexanedicarboxylic acid, the ratio of the peak area of 1.98 ppm derived from the trans isomer and the peak areas of 1.77 ppm and 1.86 ppm derived from the cis isomer is The trans isomer ratio of the alicyclic dicarboxylic acid structure was determined.

((3) Glass transition temperature Tg (° C))
According to JIS-K7121, it measured using Diamond-DSC by PERKIN-ELMER.
Measurement conditions were such that a sample in a molten state obtained by melting a sample on a hot stage (EP80 manufactured by Mettler) was rapidly cooled using liquid nitrogen and solidified to obtain a measurement sample.
Using 10 mg of the sample, the glass transition temperature was measured by raising the temperature in the range of 30 to 350 ° C. under a temperature raising speed of 20 ° C./min.

((4) Ratio of amino end group amount to total amount of amino end group amount and carboxyl end group amount)
The number of carboxyl group ends of the polyamide by titration (eq / g) [polyamide benzyl alcohol solution titrated with 0.1N sodium hydroxide] and the number of amino group ends (eq / g) [polyamide phenol solution 0.1N Titration with hydrochloric acid] was measured, and the ratio of amino end group amount was determined by the ratio of amino end group amount = amino end group amount / (amino end group amount + carboxyl end group amount).

((5) End sealing rate (%))
(A) The number average molecular weight (Mn) of the polyamide was measured by GPC, and the total number of molecular chain end groups was calculated using the relational expression: total number of molecular chain end groups (eq / g) = 2 / Mn.
The number of carboxyl group ends of the polyamide by titration (eq / g) [polyamide benzyl alcohol solution titrated with 0.1N sodium hydroxide] and the number of amino group ends (eq / g) [polyamide phenol solution 0.1N Titration with hydrochloric acid] was measured, and the end-capping rate was determined by the following formula (1).
Terminal sealing rate (%) = [(A−B) ÷ A] × 100 (1)
[Wherein A represents the total number of molecular chain end groups (this is usually equal to twice the number of polyamide molecules), and B represents the total number of carboxyl group ends and amino group ends. ]
The number average molecular weight (Mn) of the polyamide was determined by gel permeation chromatography (GPC) using polyamide.
The apparatus is HLC-8020 manufactured by Tosoh Corporation, the detector is a differential refractometer (RI), the solvent is hexafluoroisopropanol (HFIP) in which 0.1 mol% of sodium trifluoroacetate is dissolved, and the column is Tosoh ( Two TSKgel-GM HHR-H and one G1000 HHR manufactured by the same company were used. The solvent flow rate was 0.6 mL / min, and the sample concentration was 1 to 3 (mg sample) / 1 (mL solvent). Based on the obtained elution curve, the number average molecular weight (Mn) and the weight average molecular weight (Mw) were calculated in terms of polymethyl methacrylate (PMMA).

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

((7) Glass fiber weight average fiber length (μm))
The polyamide composition pellets obtained in Examples and Comparative Examples described later were incinerated by heating in an electric furnace at 650 ° C. for 2 hours.
From the residue, 100 glass fibers were arbitrarily selected, and the weight average fiber length was determined by measuring the fiber length using an SEM photograph at a magnification of 1000 times.

((8) Tensile fracture stress (MPa), tensile fracture strain (%))
Polyamide composition pellets produced in Examples and Comparative Examples described later are injected using an injection molding machine (PS-40E: manufactured by Nissei Resin Co., Ltd.), injection + pressure holding time 25 seconds, cooling time 15 seconds, mold temperature. Was set to 120 ° C. and the molten resin temperature was set to Tm2 + 20 ° C. of (A) polyamide, and a molded piece of ISO 3167, a multipurpose test piece A-type was molded.
The obtained multipurpose test piece (A type) was subjected to a tensile test at a tensile speed of 5 mm / min in accordance with ISO 527, and the tensile fracture stress and tensile fracture strain were measured.

((9) Bending strength (MPa), bending deflection (mm))
The above multi-purpose test piece (A type) is cut and used, and a bending test is performed at a test speed of 2 mm / min in accordance with ISO 178 using a test piece of length 80 mm × width 10 mm × thickness 4 mm. Strength was measured. Further, the amount of deflection (displacement) when the test piece breaks was defined as the amount of bending deflection.

((10) Charpy impact strength (kJ / m ² ))
The above multi-purpose test piece (A type) was cut and used, and a test piece having a length of 80 mm × width of 10 mm × thickness of 4 mm was used in accordance with ISO 179 / 1eA, with notched Charpy impact strength, ISO 179 / Based on 1 eU, the impact strength without notch was measured by the edgewise impact method. The notched Charpy strength was measured with a 2J hammer and the notched Charpy strength was measured with a 4J hammer. In addition, what did not fracture | rupture at the time of a test was described as NB. Those that did not break indicate the strongest impact strength.

((11) Deflection temperature under load (℃))
The above multi-purpose test piece (A type) is used by cutting, using a test piece of length 80 mm × width 10 mm × thickness 4 mm, in accordance with ISO 75, under the condition of a bending stress of 1.80 MPa, the flatwise method The deflection temperature under load was measured.

((12) Warpage (mm))
The polyamide composition pellets produced in Examples and Comparative Examples described later are injected using an injection molding machine (PS-40E: manufactured by Nissei Resin Co., Ltd.), injection + holding time 10 seconds, cooling time 15 seconds, mold temperature. Was set to 120 ° C., the molten resin temperature was set to Tm2 + 20 ° C. of (A) polyamide, and a molded piece of 60 mm × 60 mm × 1 mm was molded using a mold of type D1 according to ISO 294-3. This test piece is left in a constant temperature and humidity (23 ° C., 50 RH%) atmosphere for 24 hours, placed on a horizontal surface, and an arbitrary one of the four corners is fixed to the horizontal surface. Was measured as the amount of warpage.

((13) Warpage after annealing (mm))
Polyamide composition pellets produced in Examples and Comparative Examples described later are injected using an injection molding machine (PS-40E: manufactured by Nissei Resin Co., Ltd.), injection + pressure holding time 10 seconds, cooling time 10 seconds, mold temperature. Is set to (A) polyamide Tg + 10 ° C., and the molten resin temperature is set to (A) polyamide Tm 2 + 20 ° C., a cavity of length 125 mm × width 12.5 mm × thickness 0.5 mm, one side 125 mm, thickness 0 A test piece was molded by filling a resin from a 3 mm fan gate. This test piece was allowed to stand in a constant temperature and humidity (23 ° C., 50 RH%) atmosphere for 24 hours, and then heated in an oven at 170 ° C. for 2 hours for annealing treatment. The test piece after the annealing treatment was placed on a horizontal surface, the side on the gate side was fixed to a horizontal surface, and the rising height of the opposite end surface was measured as the amount of warpage after annealing. In all the test pieces, the amount of warpage of the test piece before annealing was less than 0.5 mm.

((14) Bending vibration fatigue characteristics)
The polyamide composition pellets produced in Examples and Comparative Examples described later are injected using an injection molding machine (PS-40E: manufactured by Nissei Resin Co., Ltd.), injection + holding time 10 seconds, cooling time 15 seconds, mold temperature. Is set to 120 ° C., the molten resin temperature is set to Tm2 + 20 ° C. of (A) polyamide, and a type I test piece described in JIS K7119-1972 (dimensions: length × width (b) × thickness = 80 mm × 20 mm × 3 mm, R = 40 mm) and a test piece for evaluating fatigue characteristics was formed.
Using the obtained test piece, in accordance with JIS K7119-1972, using a repeated vibration fatigue tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the number of breaks at 120 ° C., 20 Hz, maximum bending stress 70 MPa It was measured.

((15) Friction coefficient)
Using the multi-purpose test piece (A type), a reciprocating friction and wear tester (AFT-15MS: manufactured by Toyo Seimitsu Co., Ltd.) under a load of 500 g, a linear velocity of 30 mm / sec, and a reciprocating distance of 20 mm at an environmental temperature of 23 ° C. The reciprocating test was performed 10,000 times, and the friction coefficient at the 10,000th time was measured. As the counterpart material, a SUS ball (SUS304, R = 2.5 mm) was used.

((16) Wear depth (μm))
Rmax was measured using a surface roughness meter (Surfcom: manufactured by Tokyo Seimitsu Co., Ltd.), and the wear depth was evaluated for the shaved portion of the multipurpose test piece after evaluating the friction coefficient.

((17) Water absorption rate (%))
The mass before test (mass before water absorption) was measured in the absolutely dry state after shaping | molding the said multipurpose test piece (A type).
It was immersed in pure water at 80 ° C. for 48 hours. Then, the test piece was taken out from the water, the surface adhering moisture was wiped off, and after standing in a constant temperature and humidity (23 ° C., 50 RH%) atmosphere for 30 minutes, the mass after test (mass after water absorption) was measured.
The increment of the mass after water absorption with respect to the mass before water absorption was taken as the water absorption amount, the ratio of the water absorption amount with respect to the mass before water absorption was determined by the number of trials n = 3, and the average value was taken as the water absorption rate (%).

[Production example of polyamide]
<Production Example 1>
Polymerization reaction of polyamide was carried out by “hot melt polymerization method”.
(A) Dicarboxylic acid: CHDA 693 g (4.02 mol) and (b) diamine: C12DA 807 g (4.02 mol) were dissolved in 1500 g of distilled water to prepare an equimolar 50 mass% homogeneous aqueous solution of the raw material monomer.
To this homogeneous aqueous solution, 16 g (0.08 mol) of (b) diamine: C12DA was added.
The aqueous solution thus obtained was charged into an autoclave (made by Nitto High Pressure Co., Ltd.) having an internal volume of 5.4 L, kept at a liquid temperature (internal temperature) of 50 ° C., and the autoclave was purged with nitrogen.
The liquid temperature was continuously heated from about 50 ° C. until the pressure in the autoclave tank reached about 2.5 kg / cm ² as gauge pressure (hereinafter, all pressure in the tank was expressed as gauge pressure). (The liquid temperature in this system was about 145 ° C.).
In order to keep the pressure in the tank at about 2.5 kg / cm ² , water was removed from the system while heating was continued until the concentration of the aqueous solution reached about 75% by mass (the liquid temperature in this system was It was about 160 ° C.).
The removal of water was stopped, and heating was continued until the pressure in the tank reached about 30 kg / cm ² (the liquid temperature in this system was about 245 ° C.).
Heating was continued until the final temperature reached −50 ° C. while removing water out of the system in order to keep the pressure in the tank at about 30 kg / cm ² . After the liquid temperature rises to a final temperature of −40 ° C. (here, 310 ° C., the final temperature is listed in Table 1), the pressure in the tank becomes atmospheric pressure (gauge pressure is 0 kg / cm ² ) while continuing heating. The pressure was lowered while taking about 90 minutes.
Thereafter, the heater temperature was adjusted so that the final temperature of the resin temperature (liquid temperature) was about 350 ° C. With the resin temperature kept in this state, the inside of the tank was maintained for 30 minutes under a reduced pressure of 400 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 polyamide (PA-1).
The polyamide (PA-1) thus obtained was dried in a nitrogen stream, the moisture content was adjusted to about 0.2% by mass, and the polyamide was measured based on the above measurement method. The melting point Tm2, glass transition temperature Tg, trans isomer ratio, amino terminal group amount, terminal satire rate, and relative viscosity at 25 ° C. are shown in Table 1 below.

<Production Examples 2 to 4, Comparative Production Example 1>
As (a) dicarboxylic acid, (b) diamine, (c) caprolactam and (d) terminal blocker, the compounds and amounts shown in Table 1 below were used. The final temperature of the resin temperature was set to the temperature shown in Table 1 below.
Other conditions were such that the polyamide was polymerized by the same method as shown in Production Example 1 (“hot melt polymerization method”).
Table 1 below shows the results of measurements performed on the obtained polyamides (PA-2 to PA-5) based on the above measurement method.

<Comparative Production Example 2>
Polyamide 9T (hereinafter abbreviated as “PA9T”) was produced with reference to the method described in Example 1 of JP-A-7-228689. At that time, the terephthalic acid unit was a dicarboxylic acid unit. On the other hand, 1,9-nonamethylenediamine unit and 2-methyloctamethylenediamine unit [1,9-nonamethylenediamine unit: 2-methyloctamethylenediamine unit = 80: 20 (molar ratio)] were used as diamine units.
The raw materials shown in Table 1 and 1500 g of distilled water were placed in an autoclave (made by Nitto Koatsu Co., Ltd.) having an internal volume of 5.4 L (non-uniform slurry state) and replaced with nitrogen. The mixture was stirred at 100 ° C. for 30 minutes, and the internal temperature was raised to 210 ° C. over 2 hours. At that time, the autoclave was pressurized to 22 kg / cm 2. The reaction was continued as it was for 1 hour, then the temperature was raised to 230 ° C., and then the temperature was kept constant at 230 ° C. for 2 hours. Next, the pressure was reduced to 10 kg / cm 2 over 30 minutes, and the reaction was further continued for 1 hour to obtain a prepolymer. This was dried at 100 ° C. under reduced pressure for 12 hours and pulverized to a size of 2 mm or less. This was subjected to solid state polymerization at 230 ° C. and 0.1 mmHg for 10 hours to obtain PA9T (PA-7).
Table 1 shows the measurement results of the polyamide (PA-7) obtained based on the above-described measurement method.

[Production example of glass fiber]
<Production Example 5>
First, the solid content is 2% by mass of polyurethane resin, 4% by mass of maleic anhydride-butadiene copolymer, 0.6% by mass of γ-aminopropyltriethoxysilane, and 0.1% by mass of carnauba wax. Dilution with water gave a glass fiber sizing agent. The obtained glass fiber sizing agent was adhered to the glass fiber by an applicator provided in the middle of being wound around the rotating drum with respect to the melt-proofed glass fiber having a number average fiber diameter of 7 μm. And the roving of the glass fiber bundle surface-treated with the said glass fiber sizing agent was obtained by drying after that. At that time, the glass fiber was made to be a bundle of 1,000 pieces. The adhesion amount of the glass fiber sizing agent was 0.6% by mass. This was cut into a length of 3 mm to obtain a chopped strand (hereinafter abbreviated as “GF-1”).

<Production Example 6>
A chopped strand (GF-2) was obtained in the same manner as in Production Example 5, except that a glass fiber having a number average fiber diameter of 5 μm was used instead of the glass fiber having a number average fiber diameter of 7 μm. The adhesion amount of the glass fiber sizing agent was 0.7% by mass.

<Production Example 7>
First, it diluted with water so that it might become 6 mass% of polyurethane resins, 0.6 mass% of (gamma) -aminopropyl triethoxysilane, and 0.1 mass% of carnauba wax as solid content, and the glass fiber sizing agent was obtained. . A chopped strand (GF-3) was obtained in the same manner as in Production Example 5 except that the obtained glass fiber sizing agent was used. The adhesion amount of the glass fiber sizing agent was 0.6% by mass.

<Production Example 8>
GF-4 was obtained in the same manner as in Production Example 5 except that glass fibers having a number average fiber diameter of 10 μm were used. The adhesion amount of the glass fiber sizing agent was 0.5% by mass.

[Production Example of Polyamide Composition]
<Example 1>
The polyamide was dried in a nitrogen stream and the moisture content was adjusted to about 0.2% by mass.
L / D (extruder cylinder length / extruder cylinder diameter) having an upstream supply port in the first barrel from the upstream side of the extruder and a downstream supply port in the ninth barrel = A 48 (number of barrels: 12) twin screw extruder [ZSK-26MC: manufactured by Coperion (Germany)] was used to manufacture from the upstream supply port to the die according to the above manufacturing example and comparative manufacturing example. ) Polyamide Tm2 + 20 ° C.
From the upstream supply port, (A) polyamide, (C) copper compound, metal halide, and (D) nucleating agent so that the screw rotation speed is 300 rpm and the discharge rate is 25 kg / h, and the ratio shown in Table 2 below is obtained. It supplied after dry blending, (B) Glass fiber (GF) which is a fibrous reinforcing material was supplied from the downstream supply port, and it melt-kneaded and produced the polyamide composition pellet. The weight average fiber length of the glass fibers in the obtained polyamide composition pellets was 305 μm.
The obtained polyamide composition was dried in a nitrogen stream to reduce the water content to 500 ppm or less. The obtained polyamide composition pellets are processed into a predetermined molded body, and tensile fracture stress, tensile fracture strain, bending strength, bending deflection, Charpy impact strength, deflection temperature under load, warpage, warpage after annealing, bending vibration. Fatigue properties, coefficient of friction, wear depth, and water absorption were evaluated. The physical property values are shown in Table 2 below together with the composition.
Moreover, the weight average fiber length of the glass fiber in a multipurpose test piece (A type) was 292 micrometers.

<Examples 2-9, Comparative Examples 1-10>
A polyamide composition pellet was produced in the same manner as in Example 1 except that the ratio shown in Table 2 below was obtained. The obtained polyamide composition pellets are processed into a predetermined molded body, and tensile fracture stress, tensile fracture strain, bending strength, bending deflection, Charpy impact strength, deflection temperature under load, warpage, warpage after annealing, bending vibration. Fatigue properties, coefficient of friction, wear depth, and water absorption were evaluated. The physical property values are shown in Table 2 below together with the composition.

As shown in Table 2 above, the polyamide compositions of Examples 1 to 9 have high mechanical strength and high tensile fracture strain, bending deflection, and Charpy impact strength because of high tensile fracture stress and bending strength. From this, it was found that because of excellent toughness and high deflection temperature under load, excellent heat resistance, warpage, and small warpage after annealing, it was found to be excellent in dimensional stability.
Furthermore, it was excellent in low water absorption and vibration fatigue resistance.
Moreover, since the polyamide compositions of Examples 1 to 5 and 9 have a low coefficient of friction and a small wear depth, they were excellent in slidability.
In particular, when Example 2 and Comparative Examples 1 to 4 are compared, a polyamide comprising a polyamide mainly composed of an alicyclic dicarboxylic acid and a diamine having 8 or more carbon atoms and a fibrous reinforcing material having a number average fiber diameter of 7 μm. For a polyamide composition containing a fibrous reinforcing material having a number average fiber diameter of 10 μm, the composition specifically has bending strength, Charpy impact strength, deflection temperature under load, warpage after annealing, bending vibration fatigue characteristics, low water absorption It was also found that the slidability was improved.
On the other hand, from the viewpoint of warping after annealing and low water absorption, as can be seen from Comparative Examples 3, 8 and 10, it is a problem that was not found in resin compositions using conventional polyamides based on terephthalic acid. It was a problem peculiar to the resin composition using the polyamide using the dicarboxylic acid containing the alicyclic dicarboxylic acid. That is, when terephthalic acid-based polyamide is used, the warpage after annealing of the polyamide resin composition is good both when the fiber diameter is large and when the fiber diameter is small, and even if the fiber diameter is changed, the warpage after annealing does not change. In the case of a resin composition using an alicyclic polyamide, if the fiber diameter is 10 μm, the warp after annealing of the polyamide resin composition is not good, but by making the fiber diameter 3-9 μm The warpage after annealing was good.

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

Claims (15)

(A): (a) alicyclic dicarboxylic acid and (b) at least one diamine having 8 or more carbon atoms (however, when it is composed of 2 or more diamines, it is a mixture of diamines having the same carbon number) Polyamide having a unit consisting of
(B): Fibrous reinforcing material having a number average fiber diameter of 3 to 9 μm,
A polyamide composition.   The polyamide composition according to claim 1, wherein the (B) fibrous reinforcing material is a glass fiber.   The polyamide composition according to claim 1 or 2, wherein the (B) fibrous reinforcing material has a weight average fiber length of 100 to 500 µm in the polyamide composition.   The bundle (B) wherein the fibrous reinforcing material includes a copolymer of a carboxylic acid anhydride-containing unsaturated vinyl monomer and an unsaturated vinyl monomer excluding the carboxylic acid anhydride-containing unsaturated vinyl monomer. The polyamide composition according to any one of claims 1 to 3, which is a fibrous reinforcing material treated with an agent.   The polyamide composition according to any one of claims 1 to 4, wherein the (a) alicyclic dicarboxylic acid is 1,4-cyclohexanedicarboxylic acid.   The (b) at least one diamine having 8 or more carbon atoms is octamethylenediamine, nonamethylenediamine, a mixture of nonamethylenediamine and 2-methyloctamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine. The polyamide composition according to any one of claims 1 to 5, which is at least one selected from the group consisting of:   The polyamide composition according to any one of claims 1 to 6, wherein the melting point of the polyamide (A) is 270 to 350 ° C.   The polyamide composition according to any one of claims 1 to 7, wherein the trans isomer ratio of the alicyclic dicarboxylic acid structure in the (A) polyamide is 50 to 85%.   The ratio of the amount of amino end groups to the total amount of amino end groups and carboxyl end groups in the (A) polyamide [amino end group amount / (amino end group amount + carboxyl end group amount)] is 0.3 or more and 1 The polyamide composition according to any one of claims 1 to 8, which is less than 0.0. For 100 parts by mass of the (A) polyamide,
The polyamide composition as described in any one of Claims 1 thru | or 9 containing the said (B) fibrous reinforcement 1-200 mass parts.   (C) Phenol-based heat stabilizer, phosphorus-based heat stabilizer, amine-based heat stabilizer, elements of Group Ib, Group IIb, Group IIIa, Group IIIb, Group IVa and Group IVb of the periodic table 11. The heat stabilizer according to claim 1, further comprising at least one heat stabilizer selected from the group consisting of a metal salt of the above, an alkali metal halide, and an alkaline earth metal halide. Polyamide composition.   The polyamide composition according to claim 11, wherein the heat stabilizer (C) is a mixture of a copper salt and an alkali metal halide and / or an alkaline earth metal halide.   The polyamide composition according to any one of claims 1 to 12, further comprising (D) one or more nucleating agents selected from the group consisting of boron nitride, talc, and carbon black.   The molded object which shape | molded the polyamide composition as described in any one of Claims 1 thru | or 13.   The molded article according to claim 14, which is a sliding part.