JP2003082228A - Polyamide composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide composition having low warpage, excellent dimensional stability, fluidity, sliding properties, blister resistance and strength. SOLUTION: This polyamide composition comprises 100 parts. wt. of a polyamide (A) composed of a dicarboxylic acid unit (a) containing 60-100 mol% of a terephthalic acid unit and a diamine unit (b) containing 60-100 mol% of a 1,9-nonanediamine unit or the 1,9-nonanediamine unit and a 2-methyl-1,8- octanedimaine unit in the molar ratio of the 1,9-nonanediamine unit: the 2- methyl-1,8-octanedimaine unit of 100:0-20:80 and 0.1-250 parts. wt. of glass fibers (B) having >1 modification ratio of cross section.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyamide composition and a molded article made of the same. INDUSTRIAL APPLICABILITY The polyamide composition of the present invention provides a molded article excellent in low warpage, dimensional accuracy, slidability, strength, and heat resistance, and therefore, industrial materials, industrial materials, household products, electric / electronic parts, automobile parts, etc. It can be suitably used for applications requiring low warpage and high dimensional accuracy.

[0002]

2. Description of the Related Art Aliphatic polyamides represented by nylon 6 and nylon 66 have excellent properties such as heat resistance, chemical resistance, rigidity, abrasion resistance, and moldability, and therefore have many uses as engineering plastics. Has been used for. In the electric / electronic field, since high flame retardancy based on UL-94 standard is required, many flame retardant methods using various flame retardants have been proposed and put into practical use. However, these aliphatic polyamides have high water absorption,
There have been problems such as dimensional changes of molded products and deterioration of physical properties.
Furthermore, in recent years, for electrical and electronic parts that require flame retardancy, a method called surface mounting method (SMT) has rapidly spread for the purpose of high-density mounting of parts and efficiency of soldering process. As a result, conventional polyamides are no longer able to handle heat resistance. In addition, card connectors are rapidly becoming widespread as mobile phones and personal computers become more sophisticated. In addition to heat resistance, the card connector is required to have low warpage, high slidability, and high strength. Such a requirement is a problem common to applications such as connector connection, housings for relays, and cards.

On the other hand, recently, a semi-aromatic polyamide called 6T-based polyamide, which is mainly composed of a polyamide composed of 1,6-hexanediamine and terephthalic acid, has entered the field of electric / electronic parts requiring flame retardancy. Therefore, JP-A-3-239755, JP-A-4-96970, and the like propose flame-retardant techniques for semi-aromatic polyamides such as 6T-based polyamides. However, a polyamide composed of terephthalic acid and 1,6-hexanediamine has a temperature of 370 ° C, which is higher than the decomposition temperature of the polymer.
Since there is a melting point in the vicinity, melt polymerization and melt molding are difficult, and it is not practical. Therefore, in practice, a dicarboxylic acid component such as adipic acid or isophthalic acid or an aliphatic polyamide such as nylon 6 is contained in an amount of 30 to 40 mol%.
At present, the copolymer is used in a composition in which the melting point is lowered to a practical usable temperature range, that is, about 280 to 320 ° C. Copolymerization of such a large amount of the third component (in some cases, the fourth component) is effective for lowering the melting point of the polymer, but on the other hand, it is accompanied by a decrease in crystallization rate and ultimate crystallinity. As a result, not only the physical properties such as rigidity at high temperature, chemical resistance, and dimensional stability are deteriorated, but also the productivity is deteriorated as the molding cycle is extended. Also, with regard to changes in physical properties such as dimensional stability due to water absorption, the introduction of aromatic groups has made some improvements compared to conventional aliphatic polyamides, but has reached the level of practical problem solving. Absent.

Further, as high heat resistant resins other than polyamide, liquid crystal polymers (hereinafter, sometimes referred to as LCP) and polyphenylene sulfide (hereinafter, referred to as PCP).
(Sometimes called PS). Although LCP is excellent in low warpage, it has been pointed out that the sliding property is low, the surface is turned over by inserting and removing the card, and the weld strength is low, causing cracking. PPS has low fluidity and is often difficult to mold. Under these circumstances, it is the actual situation that a material satisfying the required performance of the card connector has not been proposed yet.

[0005]

SUMMARY OF THE INVENTION The object of the present invention, however, is to provide a polyamide composition excellent in low warpage and dimensional stability, as well as fluidity, slidability, blister resistance, and strength, and a molded article made from the same. To provide.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that terephthalic acid and 1,9-nonanediamine, or 1,9-nonanediamine and 2-methyl-1, A polyamide composition containing polyamide having 8-octanediamine as a main component and glass fibers having a specific cross-sectional shape has low warpage and dimensional stability, and further has fluidity, slidability, blister resistance, and strength. The present invention has been completed by finding that it is excellent.

That is, the present invention provides a dicarboxylic acid unit (a) containing 60 to 100 mol% of a terephthalic acid unit.
And 1,9-nonanediamine unit, or 1,9-nonanediamine unit and 2-methyl-1,8-octanediamine unit in an amount of 60 to 100 mol%, and 1,9-
A non-diamine unit: a 2-methyl-1,8-octanediamine unit having a molar ratio of 100: 0 to 20:80 and a diamine unit (b), which is 100 parts by weight of a polyamide (A). Is a polyamide composition containing 0.1 to 250 parts by weight of a glass fiber (B) of more than 1.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The dicarboxylic acid unit (a) constituting the polyamide (A) used in the present invention has a terephthalic acid unit of 60 to 1
The content of terephthalic acid units is preferably in the range of 75 to 100 mol%,
It is more preferably in the range of -100 mol%. When the content of the terephthalic acid unit is less than 60 mol%, the heat resistance of the obtained polyamide composition decreases.

The above-mentioned dicarboxylic acid unit (a) may contain other dicarboxylic acid units other than the terephthalic acid unit as long as it is 40 mol% or less. As the other dicarboxylic acid unit, malonic acid, Dimethyl malonic acid, succinic acid,
Aliphatic dicarboxylic acids such as glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid; 1,3
Alicyclic dicarboxylic acids such as cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid,
1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid,
Diphenyl sulfone-4,4'-dicarboxylic acid, 4,
A unit derived from an aromatic dicarboxylic acid such as 4′-biphenyldicarboxylic acid can be mentioned, and one or more of these can be used. Of these, units derived from aromatic dicarboxylic acids are preferred. As the content rate of these other dicarboxylic acid units,
It is preferably 25 mol% or less, and more preferably 10 mol% or less. Furthermore, a unit derived from a polyvalent carboxylic acid such as trimellitic acid, trimesic acid, or pyromellitic acid may be contained within the range where melt molding is possible.

The diamine unit (b) constituting the polyamide (A) used in the present invention is a 1,9-nonanediamine unit or 60 of a 1,9-nonanediamine unit and a 2-methyl-1,8-octanediamine unit. ~ 100 mol%
contains. That is, when the diamine unit (b) contains a 1,9-nonanediamine unit and a 2-methyl-1,8-octanediamine unit, the total content of both is 60.
The content of 1,9-nonanediamine units is 60 to 100 mol% when the content of 2-methyl-1,8-octanediamine units is not contained. The content is preferably in the range of 75 to 100 mol%,
The range of 90 to 100 mol% is more preferable. 1,9-
When the content of the nonanediamine unit or the content of the 1,9-nonanediamine unit and the 2-methyl-1,8-octanediamine unit is within the above range, the heat resistance of the obtained polyamide becomes high.

1,9 in the above diamine unit (b)
The molar ratio of nonanediamine unit: 2-methyl-1,8-octanediamine unit is in the range of 100: 0 to 20:80, preferably in the range of 100: 0 to 60:40, and 100 More preferably, it is in the range of: 0 to 80:20. When the molar ratio of the 1,9-nonanediamine unit: 2-methyl-1,8-octanediamine unit is within the above range, the heat resistance of the obtained polyamide becomes high.

The above diamine unit (b) is 40 mol%
Below, 1,9-nonanediamine units and 2-
It may contain a diamine unit other than the methyl-1,8-octanediamine unit, and as the other diamine unit, ethylenediamine, propylenediamine, 1,4
-Butanediamine, 1,6-hexanediamine, 1,8
-Octanediamine, 1,10-decanediamine, 1,
12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 5-methyl- Aliphatic diamines such as 1,9-nonanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine and isophoronediamine; p-phenylenediamine, m-phenylenediamine, xylenediamine, 4,4′-diaminodiphenylmethane, 4, Examples thereof include units derived from aromatic diamines such as 4'-diaminodiphenyl sulfone and 4,4'-diaminodiphenyl ether, and one or more of these can be used.
The content of these other diamine units is preferably 25 mol% or less, more preferably 10 mol% or less.

The polyamide (A) used in the present invention is
It is preferable that 10% or more of the terminal groups of the molecular chain are capped with a terminal capping agent. The ratio of the terminal group of the molecular chain blocked by the terminal blocking agent (terminal blocking rate) is
It is more preferably at least 40%, even more preferably at least 70%. The use of a polyamide having a terminal sealing rate of 10% or more makes it possible to obtain more excellent physical properties such as melt moldability and surface beauty.

The end-capping ratio of the polyamide (A) is determined by measuring the number of carboxyl-group ends, amino-group ends and end-groups blocked by a terminal-blocking agent, which are present in the polyamide. Can be obtained by The number of each terminal group is preferably determined by ¹ H-NMR from the integrated value of the characteristic signal corresponding to each terminal group in terms of accuracy and simplicity.

End capping rate (%) = [(X−Y) / X] × 100 (1) [wherein, X is the total number of molecular chain end groups (this is usually equal to twice the number of polyamide molecules). ), And Y represents the total number of carboxyl group terminals and amino group terminals. ]

The terminal blocking agent is not particularly limited as long as it is a monofunctional compound having reactivity with an amino group or a carboxyl group at the polyamide terminal, but is not limited in terms of reactivity and stability of the terminal. Therefore, a monocarboxylic acid or a monoamine is preferable, and a monocarboxylic acid is more preferable from the viewpoint of easy handling. In addition, acid anhydrides such as phthalic anhydride, monoisocyanates, monoacid halides, monoesters, monoalcohols and the like can also be used.

The monocarboxylic acid used as the terminal blocking agent is not particularly limited as long as it has reactivity with an amino group, and examples thereof include acetic acid, propionic acid, butyric acid,
Valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid,
Aliphatic monocarboxylic acids such as pivalic acid and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid And other aromatic monocarboxylic acids; any mixture thereof, and the like. Among these,
In terms of reactivity, stability of sealed ends, price, etc., acetic acid,
Propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid and benzoic acid are preferred.

The monoamine used as the terminal blocking agent is not particularly limited as long as it has reactivity with a carboxyl group, and examples thereof include methylamine, ethylamine, propylamine, butylamine, hexylamine,
Aliphatic monoamines such as octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine; cycloaliphatic amines such as cyclohexylamine, dicyclohexylamine;
Aromatic monoamines such as aniline, toluidine, diphenylamine, naphthylamine and the like; and arbitrary mixtures thereof can be mentioned. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferable from the viewpoints of reactivity, high boiling point, stability of capped terminal and cost.

The polyamide (A) used in the present invention is
It can be produced by any method known as a method for producing a crystalline polyamide. For example, it can be produced by a method such as a solution polymerization method using an acid chloride and a diamine as raw materials or an interfacial polymerization method, a melt polymerization method using a dicarboxylic acid and a diamine as raw materials, a solid phase polymerization method, and a melt extruder polymerization method.

For the polyamide (A), for example, a diamine, a dicarboxylic acid, a catalyst and, if necessary, an end-capping agent are added all at once to produce a nylon salt, and then 200
Heat polymerization at a temperature of ~ 250 ° C in concentrated sulfuric acid 30 ° C
It can be produced by using a prepolymer having an intrinsic viscosity [η] of 0.1 to 0.6 dl / g and solid phase polymerization or polymerization using a melt extruder. The intrinsic viscosity [η] of the prepolymer is 0.1 to 0.6d
Within the range of 1 / g, there is little deviation of the molar balance between the carboxyl group and the amino group and the decrease in the polymerization rate in the post-polymerization stage, and a polyamide having a small molecular weight distribution and excellent physical properties and moldability is obtained. To be When the final stage of the polymerization is carried out by solid phase polymerization, it is preferably carried out under reduced pressure or under an inert gas flow, and the polymerization temperature is 200 to 280 ° C.
Within the range, the polymerization rate is high, the productivity is excellent,
It is possible to effectively suppress coloring and gelation. When the final stage of the polymerization is carried out by a melt extruder, the polymerization temperature is preferably 370 ° C. or lower. When the polymerization is carried out under such conditions, the polyamide is hardly decomposed and a polyamide having no deterioration is obtained.

In producing the polyamide (A), in addition to the above-mentioned terminal blocking agent, for example, phosphoric acid as a catalyst,
Phosphorous acid, hypophosphorous acid, their salts or esters can be added. As the above-mentioned salt or ester, phosphoric acid, phosphorous acid or hypophosphorous acid and a metal such as potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, antimony Salts; ammonium salts of phosphoric acid, phosphorous acid or hypophosphorous acid; ethyl esters, isopropyl esters, butyl esters, hexyl esters, isodecyl esters, octadecyl esters, decyl esters of phosphoric acid, phosphorous acid or hypophosphorous acid , Stearyl ester, phenyl ester and the like.

The polyamide (A) used in the present invention is
The intrinsic viscosity [η] measured in concentrated sulfuric acid at 30 ° C is 0.4 to
It is preferably 3.0 dl / g, and 0.5 to 2.0 d
1 / g is more preferable, and 0.6 to 1.8 dl /
More preferably, it is g. If the intrinsic viscosity [η] is within the above range, a molded product excellent in mechanical properties, heat resistance and the like can be obtained.

The polyamide composition of the present invention contains glass fiber (B) having a cross-sectional irregularity ratio of more than 1 as a constituent component other than the above polyamide (A). The irregular shape ratio of the cross section as used herein defines the major axis and the minor axis as shown in FIG. 1 and is represented by the ratio of the major axis and the minor axis (major axis / minor axis). The cross-sectional shape of the glass fiber is not particularly limited as long as the cross-sectional irregularity ratio is greater than 1, and examples thereof include an ellipse, a cocoon shape, and a rectangle. From the viewpoint of fluidity, mechanical properties, and low warpage, a cocoon shape is used. , Rectangular is preferred. From the viewpoint of low warpage and mechanical properties, the above variant ratio is preferably within the range of 1.2 to 10,
The range of 6 is more preferable. In addition, it is preferable that the glass fiber is cut to a length of 1 to 10 mm from the viewpoint of compound productivity. Further, the above glass fibers are surface-treated with a silane coupling agent, a titanium coupling agent, or other high molecular weight or low molecular weight surface treating agent for the purpose of improving dispersibility and adhesion in polyamide. Is preferred. The content of glass fiber (B) is 0.1 to 100 parts by weight of polyamide (A).
It is in the range of 250 parts by weight, preferably in the range of 50 to 240 parts by weight, from the viewpoint of low warpage and fluidity, 100
It is more preferably in the range of ˜230 parts by weight.

The polyamide composition of the present invention may contain one or more fillers other than the glass fiber (B). Examples of the filler include glass fibers (milled fiber, cut glass, etc.) having a fiber length / fiber diameter ratio (fiber length / fiber diameter) of 50 or less, glass flake, glass beads, and the like. These fillers are preferably surface-treated with a silane coupling agent, a titanium coupling agent, or another high molecular weight or low molecular weight surface treatment agent. Among these fillers, milled fiber is preferable from the viewpoint of low warpage. The compounding ratio of the glass fiber (B) and the filler is 100: 0 to 10:90.
Is preferable, and the range of 99: 1 to 60:40 is more preferable. When the compounding ratio is within the above range, a polyamide composition excellent in low warp property and strength can be obtained.

By adding a brominated flame retardant (C) to the polyamide composition of the present invention, excellent flame retardancy can be imparted. Examples of the brominated flame retardant (C) include brominated polystyrene, polybrominated styrene, brominated polyphenylene ether, brominated bisphenol type epoxy polymer, brominated styrene maleic anhydride polymer, brominated epoxy resin,
Brominated phenoxy resin, decabromodiphenyl ether, decabromobiphenyl, brominated polycarbonate,
Examples thereof include perchlorocyclopentadecane and brominated crosslinked aromatic polymers, and one or more of these can be used. Among these, polybrominated styrene and brominated polyphenylene ether are preferable. Also,
The brominated flame retardant may be modified with an acid anhydride group, an epoxy group or the like in order to improve the compatibility with the polyamide. The content of bromine atom in the brominated flame retardant is 15 to 8
It is preferably 7% by weight. The content of the brominated flame retardant (C) is preferably 1 to 100 parts by weight, based on 100 parts by weight of the polyamide (A).
More preferably, it is ˜75 parts by weight.

By adding a flame retardant aid (D) to the polyamide composition of the present invention in addition to the above-mentioned brominated flame retardant (C), excellent flame retardancy can be imparted with a small amount of flame retardant. Examples of the flame retardant aid (D) include antimony trioxide, antimony pentoxide, sodium antimonate, sodium oxide, tin oxide, zinc stannate, zinc oxide, iron oxide, magnesium hydroxide, calcium hydroxide, zinc borate. , Kaolin clay, calcium carbonate and the like, and one or more of them can be used. These flame retardant aids may be treated with a silane coupler, a titanium coupler or the like. Of these, zinc borate and zinc stannate are preferably used. Flame retardant aid (D)
Content of 100 parts by weight of polyamide (A),
It is preferably 0.1 to 50 parts by weight, and more preferably 1 to 30 parts by weight. By blending these flame retardant aids, excellent flame retardancy can be imparted with a small amount of flame retardant.

In the polyamide composition of the present invention, if necessary, an acid catcher such as hydrotalcite; polyphenylene sulfide, polyolefin, polyester,
Other polymers such as aliphatic polyamides, polyphenylene oxides, liquid crystal polymers, colorants, UV absorbers, light stabilizers, antioxidants such as hindered phenols, thios, phosphorus and amines; antistatic agents; Crystal nucleating agent; Plasticizer;
A release agent; a lubricant and the like can also be added.

Glass fiber (B) and optional fillers, brominated flame retardant (C), flame retardant aid (D), and various additives mentioned above are blended with polyamide (A). By doing so, the polyamide composition of the present invention can be produced. As the compounding method, for example, a method of adding components such as glass fiber (B) during the polycondensation reaction of polyamide (A), polyamide (A) and glass fiber (B)
Examples thereof include a method of dry blending components, a method of melt kneading using an extruder, and the like. Among them, a method of melt kneading using an extruder is usually advantageous from the viewpoint of easy operation. . The extruder used at this time is preferably a twin screw extruder, and the melt kneading temperature is 28
It is preferably in the range of 0 to 340 ° C.

Injection molding of the polyamide composition of the present invention,
Extrusion molding, press molding, blow molding, calendar molding,
Molded articles having various shapes can be produced by molding by a molding method that is generally used for thermoplastic resin compositions such as cast molding. For example,
The polyamide composition of the present invention is melted in a cylinder of an injection molding machine in which the cylinder temperature is adjusted within the range of the melting point of polyamide to 350 ° C. and then introduced (injected) into a mold having a predetermined shape. A molded product having a predetermined shape can be manufactured. Further, the polyamide composition is melted in an extruder in which the cylinder temperature is adjusted within the above range,
A fibrous molded article can be produced by spinning from a nozzle for die. Further, a polyamide composition is melted in an extruder whose cylinder temperature is adjusted within the above range and extruded from a T die, whereby a film or sheet shaped molded article can be manufactured. Further, it is also possible to use it in a form in which a coating layer made of a paint, a metal, another kind of polymer or the like is formed on the surface of the molded product manufactured by such a method.

[0030]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The warpage, fluidity, slidability, blister resistance and strength in the examples were evaluated by the following methods.

Warpage: An injection-molded product is produced with a connector die for smart media, and a gap between card insertion portions is measured with a dimension measuring instrument (Xyzax GJ600D manufactured by Tokyo Seimitsu Co., Ltd.).
It was measured at. ○, if the gap is 0.085 mm or more
When the card was smaller than 0.085 mm, it was rated as Δ, and when it was not, it was rated as x.

Flowability: The flow length was measured when a flat plate having a thickness of 0.5 mm was injection-molded under the conditions of a cylinder temperature of 320 ° C., an injection pressure of 750 kgf and a mold temperature of 140 ° C. The higher the fluidity, the higher the value.

Sliding property: length 10 cm × width 4 cm × thickness 1 m
An injection-molded article was prepared with a m-shaped mold and left at 23 ° C. in an absolutely dry state for 48 hours. Place a metal needle (steel material: S45C) with a conical tip with a weight of 500 g on a flat plate, 5 cm
I moved it. The depth of the groove cut at that time was measured with a surface roughness meter. ○ If the depth is less than 10 μm, 10 μm
If the value is 20 μm or more, the value is Δ, and if the value is 20 μm or more, the value is ×.
It was determined.

Evaluation of blister resistance: A test piece having a thickness of 0.5 mm, a width of 10 mm and a length of 30 mm formed by injection molding was conditioned for 72 hours at a temperature of 40 ° C. and a relative humidity of 95%. Using an infrared heating furnace (Sanyo Seiko, SMT scope), the reflow process of the temperature profile shown in FIG. 2 was performed. A temperature sensor was installed on the molded product and the profile was measured. The measured peak temperature in FIG.
The test was conducted at intervals of 5 ° C. up to 70 ° C. After passing through the process, the appearance of the test piece was observed. The limit temperature at which the test piece did not melt and blisters did not occur was defined as the blister resistance temperature. Blister is a phenomenon in which a blister-like swelling occurs on the surface of a molded product. When there was a change below 250 ° C., it was judged as “X”, when there was a change within the range of 250 to 260 ° C., it was judged as “Δ”, and the others were judged as “◯”.

Strength: Tensile strength was measured according to ASTM D638.

In the following examples and comparative examples, the following polyamides were used. PA9MT: a terephthalic acid unit as a dicarboxylic acid unit, a 1,9-nonanediamine unit and 2-methyl-
The 1,8-octanediamine unit is replaced with the diamine unit (1,9
-Mole ratio of nonanediamine unit: 2-methyl-1,8 octanediamine unit is 85:15), intrinsic viscosity [η] 1.00 dl / g, melting point 308 ° C, terminal sealing rate 9
0% polyamide (endcapper: benzoic acid). PA6IT: terephthalic acid unit and isophthalic acid unit are dicarboxylic acid units (terephthalic acid unit: isophthalic acid unit molar ratio is 60:40), 1,6-hexanediamine unit is diamine unit, melting point 312 ° C., intrinsic viscosity [Η] 1.02 dl / g, a polyamide having a terminal blocking rate of 91% (terminal blocking agent: benzoic acid).

<Examples 1 to 4> In contrast to PA9MT, cocoon-shaped glass fiber (“CSH-3PA 87 manufactured by Nitto Boseki Co., Ltd.”) was used.
0 ”: cross-sectional irregularity ratio = 2.0 ± 0.3), milled fiber (“ PF401 ”manufactured by Nitto Boseki Co., Ltd .: fiber length / fiber diameter = 3), bromine with 2.0 mol% of glycidyl methacrylate added. Polystyrene (hereinafter referred to as "GMA-PB
abbreviated as "rS"), zinc borate ("Fire Break 415" manufactured by Borax), zinc stannate (Nippon Light Metals Co., Ltd.)
"FLAMTARD-S") was premixed in the proportions shown in Table 1 below. This was fed to a twin-screw extruder (“TEX44C” manufactured by Nippon Steel Co., Ltd.), and the cylinder temperature was 32.
Melt kneading under 0 ° C, extruding, cooling, cutting,
The polyamide composition pellets were obtained. Injection molding of these pellets (cylinder temperature 330 ° C, mold temperature 150 ° C)
Table 1 shows the results of evaluation of the molded product obtained by the above method.

<Comparative Example 1> Compared to PA9MT, glass fibers having a circular cross section (“CS-3J-256” manufactured by Nitto Boseki: variant ratio of cross section = 1) without using cocoon type glass fibers are shown in the table below. Pellets of the polyamide composition were obtained by the same method as in Example 2 except that the proportions shown in 1 were used. Table 1 shows the results of evaluation of the molded product obtained by injection molding (cylinder temperature 330 ° C., mold temperature 150 ° C.) of this pellet by the above method. <Comparative Example 2> PA instead of PA9MT as polyamide
Pellets of the polyamide composition were obtained in the same manner as in Example 2 except that 6T was blended in the proportion shown in Table 1 below. This pellet is injection molded (cylinder temperature 330
℃, mold temperature of 150 ℃)
Table 1 shows the results evaluated by the above method. <Comparative Examples 3 and 4> LCP (“Sumika Super E6006L” manufactured by Sumitomo Chemical Co., Ltd.), which is a high heat resistant resin, or P
Table 1 shows the results of evaluation by the above-mentioned method for the molded product obtained by injection molding PS (“Fortron A4” manufactured by Polyplastics).

[0039]

[Table 1]

From the results shown in Table 1 above, the polyamide compositions of Examples 1 to 4 containing PA9MT and cocoon-shaped glass fibers had low warpage, fluidity, slidability, blister resistance and tensile strength. It turns out that both are excellent. On the other hand, the polyamide composition of Comparative Example 1 containing no cocoon-shaped glass fiber and containing glass fiber having a cross-sectional irregularity ratio of 1,
Poor low warpage, PA9MT is not contained, and PA6T
The polyamide composition of Comparative Example 2 containing
Inferior in slidability and blister resistance. Furthermore, the molded product of Comparative Example 3 using LCP is inferior in slidability and tensile strength, and in the case of Comparative Example 4 using PPS, the fluidity of PPS is low and the mold should be completely filled. The card connector could not be molded. Furthermore, the molded product (test piece) obtained in Comparative Example 4 was inferior in blister resistance.

[0041]

EFFECTS OF THE INVENTION According to the present invention, there are provided a polyamide composition excellent in low warpage and dimensional stability as well as fluidity, slidability, blister resistance, and strength, and a molded article comprising the same.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a modification ratio of a glass fiber cross section.

[Fig. 2] Temperature profile of test piece when passing through infrared heating furnace

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Claims (5)

[Claims] 1. A terephthalic acid unit of 60 to 100 mol%.
The dicarboxylic acid unit (a) and the 1,9-nonanediamine unit or the 1,9-nonanediamine unit and the 2-methyl-1,8-octanediamine unit contained are contained in an amount of 60 to 1
00 mol% and 1,9-nonanediamine unit:
With respect to 100 parts by weight of the polyamide (A) composed of the diamine unit (b) in which the molar ratio of the 2-methyl-1,8-octanediamine unit is 100: 0 to 20:80, the cross-sectional irregularity ratio is 1 or more. Large glass fiber (B) 0.1-250
A polyamide composition containing parts by weight. 2. The profile ratio of the glass fiber (B) in cross section is 1.
It is 2-10, The polyamide composition of Claim 1 characterized by the above-mentioned. 3. The polyamide composition according to claim 1, which further comprises 1 to 100 parts by weight of a brominated flame retardant (C) with respect to 100 parts by weight of the polyamide (A). 4. The polyamide composition according to claim 3, which further comprises 0.1 to 50 parts by weight of the flame retardant auxiliary (D) with respect to 100 parts by weight of the polyamide (A). 5. A molded article made of the polyamide composition according to claim 1.