JP5321434B2 - Polyamide resin composition for SMT connectors - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition for SMT connectors, which has a sufficiently high molecular weight although it has low water-absorbing property, and a wide moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature, is excellent in melt-moldability and mechanical strength, and further which is superior in chemical resistance, hydrolysis resistance, or the like in comparison with a conventional aliphatic polyamide resin. <P>SOLUTION: The polyamide resin composition for SMT connectors includes an inorganic filler in a polyamide resin in which a carboxylic acid component is composed of oxalic acid, and a diamine component is composed of a mixture (hereinafter referred to as "C9-diamine mixture") comprising 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,6-hexanediamine (hereinafter referred to as "C6-diamine"), wherein the molar ratio of the C9-diamine mixture to the C6-diamine is 1:99 to 40:60. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a novel polyamide resin composition for SMT connectors. Specifically, it is a polyamide resin composition whose dicarboxylic acid component is oxalic acid and is characterized by a melting point, which has excellent chemical resistance and mechanical properties, has a wide moldable temperature range, excellent molding processability, and low water absorption. The present invention relates to a polyamide resin composition for an SMT connector using a polyamide resin having excellent properties, such as resistance to hydrolysis.

  Crystalline polyamides such as nylon 6 and nylon 66 are widely used as clothing, industrial material fibers, or general-purpose engineering plastics because of their excellent properties and ease of melt molding. Problems such as changes in physical properties due to water absorption, acid, high-temperature alcohol, and deterioration in hot water have also been pointed out, and there is an increasing demand for polyamides with superior dimensional stability and chemical resistance.

  On the other hand, a polyamide resin using oxalic acid as a dicarboxylic acid component is called a polyoxamide resin, and is known to have a higher melting point and lower water absorption than other polyamide resins having the same amino group concentration (Patent Document 1). It is expected to be used in fields where the use of conventional polyamide, where physical properties change due to water absorption, is difficult to use, specifically for SMT connectors.

  So far, polyoxamide resins using various aliphatic linear diamines as diamine components have been proposed. However, for example, a polyoxamide resin using 1,6-hexanediamine as a diamine component has a melting point (about 320 ° C.) higher than the thermal decomposition temperature (1% weight loss temperature in nitrogen; about 310 ° C.) (non-patent document). 1) Melt polymerization and melt molding were difficult and could not withstand practical use.

  For a polyoxamide resin whose diamine component is 1,9-nonanediamine (hereinafter abbreviated as PA92), L. Franco et al. Discloses a production method and its crystal structure when diethyl oxalate is used as the oxalic acid source ( Non-patent document 2). The PA 92 obtained here is a polymer having an intrinsic viscosity of 0.97 dL / g and a melting point of 246 ° C., but only a low molecular weight substance that cannot form a tough molded article is obtained. It is also shown that PA92 having an intrinsic viscosity of 0.99 dL / g and a melting point of 248 ° C. was produced when dibutyl oxalate was used as the dicarboxylic acid ester (Patent Document 2). In this case as well, there is a problem that only a low molecular weight body that cannot be formed into a tough molded body is obtained.

  Also, in applications where the usage conditions of parts using polyamide resin are severe, when used for SMT connectors, for example, there is a need to improve mechanical strength, chemical resistance, and especially heat resistance against solder at high temperature (Patent Document 3).

The present inventors use oxalic acid as a dicarboxylic acid component, and a polyamide resin using 1,9-nonanediamine and 2-methyl-1,8-octanediamine in a specific ratio as a diamine component has low water absorption, It has been disclosed that it is a polyamide resin (PA92C) having a wider moldable temperature range, a melting temperature higher than a necessary temperature, and excellent properties (Patent Document 4).
However, this polyamide resin uses oxalic acid as the dicarboxylic acid component, and has a specific ratio of three diamines of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine as the diamine component. It is not the polyoxamide resin used in 1.

  The problem to be solved by the present invention is that a sufficiently high molecular weight is achieved, the moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature is wider, the melting temperature is higher than the required temperature, and the melt moldability To provide a new polyamide resin composition for SMT connectors that is superior in chemical resistance, flexibility, hydrolysis resistance, etc. without impairing the low water absorption observed in aliphatic linear polyoxamide resins. It is in.

  As a result of intensive studies to solve the above problems, the present inventors have found that the dicarboxylic acid component is oxalic acid, and the diamine component is a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine. (Hereinafter also referred to as “C9 diamine mixture”) and 1,6-hexanediamine (hereinafter also referred to as “C6 diamine”), and the molar ratio of C9 diamine mixture to C6 diamine is 1:99 to 40: Surprisingly, by using a polyamide resin of 60 (hereinafter also referred to as “PA92 / 62T”), the same mechanical properties as those of the polyamide resin (PA92C) previously disclosed by the present inventors in Patent Document 3 were used. While having excellent physical properties and chemical resistance, it has a high molecular weight, sufficiently large difference between melting point and thermal decomposition temperature, and excellent melt moldability. In addition to obtaining a polyamide resin composition excellent in hydrolysis resistance and the like as compared with conventional polyamide without impairing the low water absorption, this novel polyamide resin (PA92 / 62T) is compared with PA92C. The melting point is higher, the mechanical properties such as flexural modulus and deflection temperature under load are better, and the cost is advantageous. The present invention has been completed by finding that it has the characteristic of not being lost.

  The polyamide resin composition of the present invention is excellent in mechanical properties and chemical resistance, has low water absorption, can have a high molecular weight by melt polymerization, has a wide moldable temperature range of 50 ° C. or more, and 60 It can be as wide as ℃ or more, the melting temperature is higher than the required temperature, is excellent in melt moldability, and is also excellent in hydrolysis resistance, and can be used for an SMT connector.

(1) Constituent Component of Polyamide Resin The polyamide used in the present invention has a dicarboxylic acid component composed of oxalic acid, and a diamine component comprising a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter referred to as “C9 diamine”). And a polyamide resin having a molar ratio of the C9 diamine mixture to the C6 diamine of 1:99 to 40:60, and a 1,6-hexanediamine (hereinafter referred to as “C6 diamine”). A characteristic polyamide resin composition (PA92 / 62T).

  As the oxalic acid source used in the production of the polyamide used in the present invention, oxalic acid diesters are used, and these are not particularly limited as long as they have reactivity with amino groups. Dimethyl oxalate, diethyl oxalate, di-n-oxalate (Or i-) propyl, oxalic acid diester of aliphatic monohydric alcohol such as di-n- (or i-, or t-) butyl oxalate, oxalic acid diester of alicyclic alcohol such as dicyclohexyl oxalate, aromatic such as diphenyl oxalate Examples include oxalic acid diester of alcohol.

  Among the above oxalic acid diesters, oxalic acid diesters of aliphatic monohydric alcohols having more than 3 carbon atoms, oxalic acid diesters of alicyclic alcohols, and oxalic acid diesters of aromatic alcohols are preferred, and among them, dibutyl oxalate and diphenyl oxalate are particularly preferred.

  The molar ratio of the 1,9-nonanediamine component to the 2-methyl-1,8-octanediamine component in the C9 diamine mixture used in the polyamide resin of the present invention is generally 1:99 to 40:60, preferably It is 5: 95-40: 60, More preferably, it is 10: 90-40: 60. By copolymerizing 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine in the above specific amounts, the moldable temperature range is wide, the melt moldability is excellent, and the water absorption is low. Polyamide having excellent properties, chemical resistance, hydrolysis resistance, transparency and the like can be obtained.

  In the polyamide resin of the present invention, as the diamine component, the C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine) mixed with 1,6-hexanediamine is used. The molar ratio of the C9 diamine mixture to 1,6-hexanediamine is 1:99 to 40:60. By mixing 1,6-hexanediamine in a molar ratio of 1/99 or more with respect to the C9 diamine mixture, the above excellent effect of the polyamide resin (PA92C) comprising oxalic acid as the dicarboxylic acid component and C9 diamine mixture as the diamine component Can be maintained (particularly without impairing melt moldability and low water absorption), the melting point of the polyamide resin can be increased, and particularly the mechanical properties can be improved. The molar ratio of the C9 diamine mixture to 1,6-hexanediamine is preferably 5:95 to 40:60, more preferably 10:90 to 40:60. In this polyamide resin, the change to the melting point appears clearly by copolymerizing 1,6-hexanediamine in a molar ratio of 1/99 or more with respect to the C9 diamine mixture, and the melting point of the resin rises. If 6-hexanediamine is within a molar ratio of 99/1, an acceptable melt moldability can be obtained. If 1,6-hexanediamine is within a molar ratio of 80/20 or less, the melting point of the polyamide resin is 300 ° C. or less, and polymerization and molding (melt moldability) are easier, and 60/40 or more. More preferably, the melting point becomes 275 ° C. or higher and the solder has heat resistance.

(2) Manufacture of polyamide resin Polyamide resin PA92 / 62T used for this invention can be manufactured using the arbitrary methods known as a method of manufacturing polyamide. According to the study by the present inventors, it can be obtained by subjecting diamine and oxalic acid diester to a polycondensation reaction in a batch or continuous manner. Specifically, it is preferable to carry out in the order of (i) pre-polycondensation step and (ii) post-polycondensation step as shown by the following operations.

  (I) Pre-polycondensation step: First, the inside of the reactor is purged with nitrogen, and then diamine (diamine component) and oxalic acid diester (oxalic acid source) are mixed. When mixing, a solvent in which both the diamine and the oxalic acid diester are soluble may be used. The solvent in which both the diamine component and the oxalic acid source are soluble is not particularly limited, but toluene, xylene, trichlorobenzene, phenol, trifluoroethanol, and the like can be used, and particularly, toluene can be preferably used. For example, after heating the toluene solution which melt | dissolved diamine to 50 degreeC, oxalic acid diester is added with respect to this. At this time, the charging ratio of the oxalic acid diester and the diamine is oxalic acid diester / the diamine, 0.8 to 1.5 (molar ratio), preferably 0.91 to 1.1 (molar ratio), more preferably 0. .99 to 1.01 (molar ratio).

  The temperature in the reactor charged in this way is increased under normal pressure while stirring and / or nitrogen bubbling. The reaction temperature is preferably controlled so that the final temperature reaches 80 to 150 ° C., preferably 100 to 140 ° C. The reaction time at the final temperature reached is 3-6 hours.

  (Ii) Post-polycondensation step: In order to further increase the molecular weight, the polymer produced in the pre-polycondensation step is gradually heated in the reactor under normal pressure. In the temperature raising process, the temperature is finally reached from the final reached temperature of the prepolycondensation step, that is, from 80 to 150 ° C., to a temperature range of 290 to 330 ° C., preferably 290 to 320 ° C. It is preferable to carry out the reaction for 1 to 8 hours including the temperature raising time, preferably 2 to 6 hours. Furthermore, in the post-polymerization step, polymerization can be performed under reduced pressure as necessary. The preferable final ultimate pressure in the case of performing the vacuum polymerization is less than 0.1 MPa to 13.3 Pa.

The specific example of the manufacturing method of the polyamide resin used for this invention is demonstrated.
First, the raw oxalic acid diester is charged into the container. A container will not be restrict | limited especially if it can endure the temperature and pressure of the polycondensation reaction performed later. Thereafter, the container is heated to a temperature at which it is mixed with the raw material diamine, and then the diamine is injected to start the polycondensation reaction. The temperature at which the raw materials are mixed is not particularly limited as long as it is a temperature not lower than the boiling point and lower than the boiling point of the oxalic acid diester and diamine, and the polyoxamide generated by the polycondensation reaction of the oxalic acid diester and diamine does not thermally decompose. For example, a mixture of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,6-hexanediamine, and C9 diamine (1,9-nonanediamine and 2-methyl-1,8-octanediamine) In the case of a polyoxamide resin made from diamine and dibutyl oxalate having a molar ratio of 1: 6-hexanediamine of 1:99 to 40:60 as raw materials, the mixing temperature is preferably 15 ° C to 330 ° C. When the molar ratio of C9 diamine (a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine) and 1,6-hexanediamine is about 5:95 to 40:60, it is liquid at room temperature. Or it is more preferable because it is easy to handle because it liquefies only by heating to about 50 ° C. When the mixing temperature is equal to or higher than the boiling point of the alcohol produced by the condensation reaction, it is desirable to use a container equipped with a device for distilling and condensing the alcohol. In addition, when pressure polymerization is performed in the presence of an alcohol generated by a condensation reaction, a pressure vessel is used. The charging ratio of oxalic acid diester to diamine is oxalic acid diester / the above diamine, 0.8 to 1.2 (molar ratio), preferably 0.91 to 1.09 (molar ratio), more preferably 0.98 to 1. 0.02 (molar ratio).

  Next, the inside of the container is heated to a temperature not lower than the melting point of the polyoxamide resin and not higher than the temperature at which it is not thermally decomposed. For example, C9 diamine (a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine) and 1,6-hexanediamine, and C9 diamine (1,9-nonanediamine and 2-methyl-1, The molar ratio of the mixture of 8-octanediamine) and 1,6-hexanediamine is 37:63, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 50:50. In the case of a polyoxamide resin using diamine and dibutyl oxalate as raw materials, the melting point is 280 ° C., so it is preferable to raise the temperature from 290 ° C. to 330 ° C. (pressure is 2 MPa to 4 MPa). While distilling off the produced alcohol, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. When the raw materials are mixed in a pressure vessel and subjected to pressure polymerization in the presence of an alcohol produced by a condensation reaction, the pressure is first released while the produced alcohol is distilled off. Thereafter, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. The preferable final pressure in the case of carrying out the vacuum polymerization is 760 to 0.1 Torr. The temperature is preferably 290 to 320 ° C. The alcohol is cooled and liquefied by a water-cooled condenser and recovered.

(3) Properties and Physical Properties of Polyamide Resin There is no particular restriction on the molecular weight of the polyamide resin used in the present invention, but 96% concentrated sulfuric acid is used as a solvent and a polyamide resin concentration of 1.0 g / dl is used at 25 ° C. The measured relative viscosity ηr is in the range of 1.8 to 6.0. Preferably it is 2.0-5.5, and 2.5-4.5 is especially preferable. If ηr is lower than 1.8, the molded product becomes brittle and the physical properties deteriorate. On the other hand, if ηr is higher than 6.0, the melt viscosity becomes high, and the molding processability deteriorates.

  The polyamide resin used in the present invention uses oxalic acid as the carboxylic acid component, and copolymerizes 1,9-nonanediamine and 2-methyl-1,8-octanediamine as the diamine component, whereby oxalic acid and 1,9-nonanediamine are copolymerized. It is possible to increase the relative viscosity, that is, increase the molecular weight as compared with the polyamide. The polyamide resin PA92 / 62T used in the present invention uses oxalic acid as the carboxylic acid component, and 1,9-nonanediamine and 2-methyl-1,8-octanediamine as the diamine component and further 1,6-hexamethylenediamine. By copolymerizing, it is possible to raise the melting point of the resin as compared with polyamides composed of succinic acid, 1,9-nonanediamine and 2-methyl-1,8-octanediamine.

(4) Reinforcing fiber The present invention is characterized in that a reinforcing fiber is blended with the above polyamide resin. However, the reinforcing fiber is not particularly limited as long as it does not produce conductivity, such as glass fiber and mineral fiber. Organic fibers such as inorganic fibers and aramid fibers that are tougher than polyamide resins. By blending the reinforcing fibers, the effect of improving the physical properties such as the strength and creep resistance of the composition is remarkable. Glass fiber is particularly preferable.

  The glass fiber is not particularly limited. The glass fiber diameter is not limited, but is preferably 5 to 15 μm.

  The fiber length may be a short fiber or a long fiber depending on the use, but is preferably 5 to 1000 μm.

  2-40 mass parts is suitable with respect to 100 mass parts of resin whole, as for the mixture ratio of glass fiber, 2-38 mass parts is more preferable, and 3-35 mass parts is preferable. If the blending amount of the glass fiber is small, the improvement in rigidity and creep resistance is lowered, and the bonding with a tube or the like may be deteriorated. On the other hand, when the compounding amount of the glass fiber is increased, the fluidity of the composition is deteriorated, which may cause a short shot or the surface state.

  The polyamide resin used in the present invention has excellent mechanical strength, chemical resistance, low water absorption, hydrolysis resistance, etc., has a wide moldable temperature range, and excellent melt moldability. In the case of blending, basically, it is held as it is, and certain properties such as mechanical strength and heat resistance are remarkably improved by blending the reinforcing fibers.

(5) Inorganic particles Examples of the inorganic particles that can be used in the present invention include particles such as metal oxides and inorganic compounds that do not have electrical conductivity. Specific examples include particles of metal oxides such as iron oxide and zinc oxide, and sulfides such as molybdenum sulfide.

  For example, inorganic particles having a density of 5 g / cm 3 or more can be preferably used in the application of a molded product having a high specific gravity using the polyamide resin composition of the present invention. For example, in the application of a resin magnet using the polyamide resin composition of the present invention, magnetic particles such as ferrite such as barium ferrite and strontium ferrite, and rare earth magnetic materials such as samarium-cobalt and neodymium-iron-boron are used. It can be preferably used.

  The inorganic particles may be used alone or in combination of two or more, and may be subjected to surface treatment. Examples of the surface treatment include surface treatment with a titanate coupling agent, surface treatment with a silane surface treatment agent, and the like. The surface treatment with a titanate coupling agent is described in, for example, the known technique described in the above-mentioned JP-A-2-255760, and the surface treatment with a silane-based surface treatment agent is described in, for example, the above-mentioned JP-A-10-158507. Any known method can be employed.

  In the present invention, the mass ratio of the above-mentioned polyamide resin and inorganic particles may be within the range of 50/50 to 5/95, more preferably 20/80 to 5/95 for polyamide resin / inorganic particles, In this case, it is possible to more easily provide characteristics such as higher specific gravity and magnetism.

(6) Other components that can be blended The polyamide resin PA92 / 62T used in the present invention can be mixed with other dicarboxylic acid components within a range not impairing the effects of the present invention. Examples of dicarboxylic acid components other than succinic acid include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3, Aliphatic dicarboxylic acids such as 3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid, alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and terephthalic acid , Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid Acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenyls Hong-4,4'-dicarboxylic acid, 4,4'-biphenyl and the like alone aromatic dicarboxylic acids such as dicarboxylic acids, or may be added to any mixture thereof during the polycondensation reaction. Furthermore, polyvalent carboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid can be used as long as melt molding is possible. In general, the amount of the dicarboxylic acid component other than oxalic acid is preferably 5 mol% or less based on the total dicarboxylic acid component.

  In addition, the polyamide resin PA92 / 62T used in the present invention can be mixed with other diamine components as long as the effects of the present invention are not impaired. As other diamine components other than 1,9-nonanediamine and 2-methyl-1,8-octanediamine, ethylenediamine, propylenediamine, 1,4-butanediamine, 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, -Aliphatic diamines such as methyl-1,9-nonanediamine, alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, p-phenylenediamine, m-phenylenediamine, p-xylenediamine, m-xylene Diamine, 4,4'-diaminodiphenylmethane, 4 4'-diaminodiphenyl sulfone, 4,4'-aromatic diamines, such as diaminodiphenyl ether, etc. alone or can be added any mixture thereof during the polycondensation reaction. The blending amount of diamine components other than 1,9-nonanediamine and 2-methyl-1,8-octanediamine is generally preferably 5 mol% or less based on the total diamine components.

  In addition, the polyamide resin PA92 / 62T used in the present invention can be mixed with other polyoxamides, polyamides such as aromatic polyamides, aliphatic polyamides, and alicyclic polyamides, as long as the effects of the present invention are not impaired. is there.

  Furthermore, thermoplastic polymers other than polyamide, elastomers, and the like can be similarly blended. However, the novel polyamide resin PA92 / 62T used in the present invention is preferably contained in an amount of 50% by mass or more of the resin component.

  Furthermore, the polyamide resin composition of the present invention may be optionally provided with a filler, a stabilizer such as a copper compound, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, and a crystallization. Accelerators, glass fibers, plasticizers, lubricants and the like can be added during or after the polycondensation reaction.

(7) Molding process of polyamide resin composition As a molding method of the polyamide resin composition of the present invention, polyamide resin and reinforcing fibers are blended in advance, or reinforcing fibers are put in the middle of a molding machine, injection, extrusion, hollow Any known molding process that can be applied to the polyamide resin composition, such as press, roll, foaming, vacuum / compressed air, and stretching, is possible, and the SMT connector can be processed by these molding processes.

[Physical property measurement, molding, evaluation method]
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
In addition, the measurement in an Example was performed with the following method.

(1) Relative viscosity (ηr):
ηr was measured at 25 ° C. using an Ostwald viscometer using a 96% polyamide sulfuric acid solution (concentration: 1.0 g / dl).

(2) Melting point (Tm) and crystallization temperature (Tc):
Tm and Tc were measured under a nitrogen atmosphere using a PYRIS Diamond DSC manufactured by PerkinELmer. The temperature was raised from 30 ° C. to 320 ° C. at a rate of 10 ° C./min (called temperature rise first run), held at 320 ° C. for 3 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first). Next, the temperature was raised to 320 ° C. at a rate of 10 ° C./min (called a temperature rising second run). For the plasticizer-containing sample, the endothermic peak temperature of the temperature rising first run from the obtained DSC chart, and for the sample not containing the plasticizer, the endothermic peak temperature of the temperature rising second run is the exothermic peak temperature of the temperature decreasing first run. Temperature.

(3) 1% weight loss temperature (Td):
Td was measured by thermogravimetric analysis (TGA) using THERMOGRAVIMETRIC ANALYZER TGA-50 manufactured by Shimadzu Corporation. The temperature was raised from room temperature to 500 ° C. at a rate of 10 ° C./min under a nitrogen stream of 20 ml / min, and Td was measured.

(4) Melt viscosity:
The melt viscosity was measured by attaching a 25 mm cone plate to a melt viscoelasticity measuring apparatus ARES manufactured by TA Instruments Japan, under conditions of 320 ° C. and a shear rate of 0.1 s −1 in nitrogen.

(5) Film molding:
Film forming was performed using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. 5 MPa after being melted by heating at 320 ° C. in a reduced pressure atmosphere of 500 to 700 Pa (260 ° C. when nylon 6 is used, 290 ° C. when nylon 66 is used and 230 ° C. when nylon 12 is used) for 5 minutes. Was pressed for 1 minute to form a film. Next, the reduced-pressure atmosphere was returned to normal pressure, and then cooled and crystallized at room temperature of 5 MPa for 1 minute to obtain a film.

(6) Water absorption rate (saturated water absorption rate, equilibrium water absorption rate):
A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; weight about 0.05 g) obtained by molding the polyamide resin under the conditions of (5) is immersed in ion exchange water at 23 ° C., and the film is taken out every predetermined time. The weight of the film was measured. When the rate of increase in the film weight lasts 3 times within a range of 0.2% or less, it is determined that the absorption of water into the polyamide resin film has reached saturation, and the weight of the film before being immersed in water (Xg) From the weight (Yg) of the film when reaching saturation, the saturated water absorption (%) was calculated by the formula (1).
Saturated water absorption (%) = 100 (Y−X) / X (1)
The water absorption rate (equilibrium water absorption rate) calculated by the formula (1) from the weight (Yg) immediately after forming the film and the weight (Yg) when the film reached equilibrium at a humidity of 65% and a temperature of 23 ° C. ) As the wet water absorption.

(7) Chemical resistance:
After the polyamide hot press film obtained according to the present invention was immersed in the chemicals listed below for 7 days, the weight residual ratio (%) and changes in the appearance of the film were observed. In each of concentrated hydrochloric acid, 64% sulfuric acid, and glacial acetic acid solutions, tests were performed on samples immersed at 23 ° C.

(8) Hydrolysis resistance:
The polyamide hot press film obtained by the present invention was put in an autoclave, and each was 121 in water (pH = 7), 0.5 mol / l sulfuric acid (pH = 1), and 1 mol / l sodium hydroxide aqueous solution (pH = 14). The residual weight ratio (%) after 60 minutes of treatment at 0 ° C. and the appearance change were examined.

(9) Mechanical properties:
In the following [1] to [4], the following test pieces were measured at a resin temperature of 320 ° C. (260 ° C. when nylon 6 was used, 290 ° C. when nylon 66 was used, and nylon 12 used. Was 230 ° C.) and was molded by injection molding at a mold temperature of 80 ° C. The ones evaluated at 23 ° C. without conditioning immediately after molding are shown in the table as dry, and the ones evaluated at 23 ° C. after conditioning at a humidity of 65% and a temperature of 23 ° C. after molding are shown in the table.
[1] Tensile test (tensile yield point strength): Measured in accordance with ASTM D638 using a Type I test piece described in ASTM D638.
[2] Bending test (flexural modulus): Measured at 23 ° C. in accordance with ASTM D790 using a test piece having dimensions of 127 mm × 12.7 mm × 3.2 mm.
[3] Izod impact strength: Measured at 23 ° C. in accordance with ASTM D256 using a test piece having dimensions of 127 mm × 12.7 mm × 3.2 mm.
[4] Deflection temperature under load: Measured at a load of 1.82 MPa in accordance with ASTM D648 using a test piece having a test piece size of 127 mm × 12.7 mm × 3.2 mm.

(10) Calcium chloride resistance:
The film molded under the condition (5) was immersed in a saturated calcium chloride aqueous solution at 23 ° C. After one day, the appearance of the film was visually observed to evaluate the presence or absence of cracks.

[Example 1: PA92 / 62T-1]
A stirrer, thermometer, torque meter, pressure gauge, raw material inlet directly connected to the diaphragm pump, nitrogen gas inlet, pressure relief port, pressure regulator, and polymer outlet are placed in a pressure vessel with an internal volume of about 150 liters. The operation of charging 30.265 kg (149.62 mol) of dibutyl acid, pressurizing the inside of the pressure vessel to 0.5 MPa with nitrogen gas having a purity of 99.9999%, and then releasing nitrogen gas to normal pressure After repeating nitrogen substitution 5 times, the system was heated while stirring under a sealing pressure. After bringing the temperature of dibutyl oxalate to 100 ° C. over about 30 minutes, 7.491 kg (47.31 mol) of 1,9-nonanediamine and 1.322 kg (8.35 mol) of 2-methyl-1,8-octanediamine were used. ) And 1,6-hexanediamine 10.922 kg (93.96 mol) (1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine molar ratio is 31.62). : 5.58: 62.80) was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 240 ° C. over 1 hour. Meanwhile, the temperature was raised while adjusting the internal pressure to 1 MPa while extracting the generated butanol from the pressure release port. Immediately after the temperature of the polycondensate reached 280 ° C., butanol was extracted from the pressure relief port over about 20 minutes, and the internal pressure was brought to normal pressure. Starting from normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, and the temperature of the polycondensate was changed to 290 ° C. over about 0.5 hours, and the reaction was performed at 290 ° C. for 1.5 hours. I let you. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer, and ηr = 2.73.
[Example 2: PA92 / 62T-2]
30.265 kg (149.62 mol) of dibutyl oxalate was charged, and 4.406 kg (27.83 mol) of 1,9-nonanediamine and 4.406 kg (27.83 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 10.922 kg (93.96 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 18.60: 18 .60: 62.80) was reacted in the same manner as in Production Example 1 to obtain a polyamide. The obtained polyamide was a white tough polymer with ηr = 2.71.
[Example 3: PA92 / 62T-3]
Charge 30.265 kg (149.62 mol) of dibutyl oxalate, 0.529 kg (3.34 mol) of 1,9-nonanediamine and 8.284 kg (52.32 mol) of 2-methyl-1,8-octanediamine, A mixture of 10.922 kg (93.96 mol) of 1,6-hexanediamine (molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine is 2.23: 34 .97: 62.80) was reacted in the same manner as in Production Example 1 to obtain a polyamide. The obtained polyamide was a white tough polymer with ηr = 2.80.
[Example 4: PA92 / 62T-4]
30.500 kg (150.78 mol) of dibutyl oxalate was charged, and 6.311 kg (39.86 mol) of 1,9-nonanediamine and 1.114 kg (7.03 mol) of 2-methyl-1,8-octanediamine were obtained. Mixture of 12.6-76 kg (103.89 mol) of 1,6-hexanediamine (molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 26.44: 4 .67: 68.90) was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump, and the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 180 ° C. Thereafter, the temperature was raised to 240 ° C. over 1 hour. Meanwhile, the temperature was raised while adjusting the internal pressure to 1 MPa while extracting the generated butanol from the pressure release port. Immediately after the temperature of the polycondensate reached 290 ° C., butanol was extracted from the pressure relief port over about 20 minutes, and the internal pressure was brought to normal pressure. Starting from normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was brought to 300 ° C. over about 0.5 hour, and the reaction was carried out at 300 ° C. for 1 hour. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer, and ηr = 2.59.
[Example 5: PA92 / 62T-5]
30.773 kg (152.13 mol) of dibutyl oxalate was charged, and 4.934 kg (31.16 mol) of 1,9-nonanediamine and 0.871 kg (5.50 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 13.422 kg (115.42 mol) of 1,6-hexanediamine (molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 20.49: 3 .62: 75.90) was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump, and the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 200 ° C. Thereafter, the temperature was raised to 260 ° C. over 1 hour. Meanwhile, the temperature was raised while adjusting the internal pressure to 1 MPa while extracting the generated butanol from the pressure release port. Immediately after the temperature of the polycondensate reached 300 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was brought to 305 ° C. over about 0.5 hour, and the reaction was carried out at 305 ° C. for 1 hour. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer with ηr = 2.46.
[Example 6: PA92 / 62T-6]
30.773 kg (152.13 mol) of dibutyl oxalate was charged, and 2.902 kg (18.33 mol) of 1,9-nonanediamine and 2.902 kg (18.33 mol) of 2-methyl-1,8-octanediamine were obtained. A mixture of 13.422 kg (115.47 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 12.05: 12 0.05: 75.90), and a reaction was carried out in the same manner as in Production Example 1 to obtain a polyamide. The obtained polyamide was a white tough polymer with ηr = 2.53.
[Example 7: PA92 / 62T-7]
Charge 30.773 kg (152.13 mol) of dibutyl oxalate, 0.348 kg (2.20 mol) of 1,9-nonanediamine and 5.457 kg (34.46 mol) of 2-methyl-1,8-octanediamine A mixture of 13.422 kg (115.47 mol) of 1,6-hexanediamine (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 1.45: 22. .65: 75.90) was reacted in the same manner as in Production Example 1 to obtain a polyamide. The obtained polyamide was a white tough polymer with ηr = 2.44.

[Reference Example 1: PA92C]
A mixture of 11.11 kg (70.2 mol) of 1,9-nonanediamine and 11.11 kg (70.2 mol) of 2-methyl-1,8-octanediamine was charged with 28.40 kg (140.4 mol) of dibutyl oxalate. Was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump, and at the same time the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 235 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 0.5 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 235 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was brought to 260 ° C. over about 1 hour, and the reaction was carried out at 260 ° C. for 4.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer, and ηr = 3.35.

[Comparative Example 1: Production of PA92]
Using only 22.25 kg (140.4 mol) of 1,9-nonanediamine as a diamine raw material, a reaction was carried out in the same manner as in Production Example 1 to obtain a polyamide. The obtained polymer was a yellowish white polymer, and ηr = 2.78.

[Comparative Example 2: PA92 / 62T-8]
29.864 kg (147.64 mol) of dibutyl oxalate was charged, and 5.598 kg (35.36 mol) of 1,9-nonanediamine, 5.598 kg (35.36 mol) of 2-methyl-1,8-octanediamine and 1 , 6-hexanediamine 8.941 kg (76.92 mol) of a mixture (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 23.95: 23. 95: 52.10) was supplied to the reaction vessel by a diaphragm pump at a flow rate of 1.49 liters / minute over about 17 minutes, and at the same time the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 250 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 1.00 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 250 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. The temperature was raised from normal pressure while flowing nitrogen gas at 1.5 liters / minute, and the temperature of the polycondensate was increased to 270 ° C. over about 1 hour and reacted at 270 ° C. for 2 hours. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer with ηr = 2.83.

  Polyamides PA92 / 62T-1 to PA92 / 62T-7, PA92C, PA92, PA92 / 62T-8 produced in Examples 1 to 7, Reference Example 1 and Comparative Examples 1 to 2, and nylon 6 (UBE, UBE) Nylon 1015B: PA6), nylon 66 (Ube Industries, UBE nylon 2020B: PA66) and nylon 12 (Ube Industries, UBESTA3020U: PA12), relative viscosity, melting point, crystallization temperature, 1% weight loss temperature, melt viscosity Saturated water absorption, chemical resistance, hydrolysis resistance, dry and wet mechanical properties were measured. The results are shown in Table 1.

[Examples 8 to 17, Comparative Examples 3 to 5]
Polyamide PA92 / 62T-1 to PA92 / 62T-7, PA92C, PA92, and PA92 / 62T-8 produced in Production Examples 1 to 7, Reference Example 1 and Comparative Examples 1 to 2, glass fiber (manufactured by Nippon Electric Glass) Using ECST-289 (fiber diameter 13 μm), a mixture having the ratio shown in Table 2 was prepared.

  Furthermore, these mixtures were melt-kneaded at 320 ° C. (260 ° C. when PA-92 and PA92 / 62T were used) using a twin-screw kneader with a cylinder diameter of 40 mm, extruded into a strand, and cooled in a water bath. A pellet was prepared using a post pelletizer. A predetermined test piece was prepared by injection molding using the obtained pellet.

  Tensile strength, Izod impact, solder resistance, chemical resistance, calcium chloride resistance, melting point, and 1% weight loss temperature were evaluated using the resin composition and test piece obtained above. For solder resistance, the tensile strength was measured after the test piece was immersed in a lead-free solder bath at 260 ° C. for 30 seconds.

  The evaluation results are shown in Table 2.

S. W. Shalaby., J. Polym. Sci., 11, 1 (1973) L. Franco et al., Macromolecules., 31, 3912 (1988)

JP 2006-57033 A Japanese National Patent Publication No. 5-506466 Patent 3036666 WO2008 / 072754

Claims (5)

  The carboxylic acid component is composed of oxalic acid, and the diamine component is a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter referred to as “C9 diamine mixture”) and 1,6-hexanediamine (hereinafter referred to as “C9 diamine mixture”). A polyamide resin composition for SMT connectors comprising a polyamide resin having a molar ratio of C9 diamine mixture to C6 diamine of 1:99 to 40:60.   2. The polyamide resin has a relative viscosity (ηr) of 1.8 to 6.0 measured at 25 ° C. using a polyamide resin solution having a concentration of 1.0 g / dl using 96% sulfuric acid as a solvent. The polyamide resin composition for SMT connectors as described.   The polyamide resin is obtained by differential scanning calorimetry measured at a 1% weight loss temperature in a thermogravimetric analysis measured at a heating rate of 10 ° C./min in a nitrogen atmosphere and at a heating rate of 10 ° C./min in a nitrogen atmosphere. The polyamide resin composition for SMT connectors according to claim 1 or 2, wherein the temperature difference from the measured melting point is 50 ° C or more.   The said polyamide resin consists of a diamine component whose molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 5: 95-95: 5. The polyamide resin composition for SMT connectors described in 1.   The polyamide resin composition for an SMT connector according to any one of claims 1 to 4, wherein the polyamide resin contains an inorganic filler.