JP2009298857A - Polyamide resin composition and molded article formed from the polyamide resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin composition with a low water-absorption property having a wide moldable temperature range, being excellent in melt moldability, being excellent in chemical-resistance and hydrolysis-resistance and capable of further attaining sufficient slide property of a die and a molded article at molding and/or a short molding time, and a molded article formed from the polyamide resin composition. <P>SOLUTION: The polyamide resin composition contains a polyamide resin in which a dicarboxylic acid component comprises oxalic acid, a diamine component comprises 1,9-nonanediamine and 2-methyl-1,8-octanediamine and a molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine is 1:99-99:1 and a mold release agent. The molded article is formed from the polyamide resin composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyamide resin composition using a novel polyamide resin. Specifically, it contains a polyamide resin in which the dicarboxylic acid component is oxalic acid and a release agent, has low water absorption, a wide moldable temperature range, excellent melt moldability, excellent chemical resistance and hydrolysis resistance, and further molding The present invention relates to a polyamide resin composition capable of achieving good sliding properties between a mold and a molded product and / or a short molding time.

  Polyamide resins typified by crystalline polyamides such as nylon 6 and nylon 66 are widely used as textiles for clothing, industrial materials, or general-purpose engineering plastics because of their excellent characteristics and ease of melt molding. However, on the other hand, problems such as changes in physical properties due to water absorption, acid, high-temperature alcohol, deterioration in hot water, etc. have been pointed out, and the dimensional stability and chemical resistance are superior without impairing moldability. There is an increasing demand for polyamides.

  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 polyamides, where changes in physical properties have become a problem, is difficult.

  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 (hereinafter abbreviated as PA92) whose diamine component is 1,9-nonanediamine, L. Franco et al. Discloses a production method and crystal structure when diethyl oxalate is used as the oxalic acid source ( Non-patent document 2). The PA92 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 product that cannot be molded into a tough molded product is obtained. Patent Document 2 shows 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. In this case as well, there is a problem that only a low molecular weight body that cannot form a tough molded body is obtained.

  On the other hand, in order to improve the moldability of a polyamide resin, it is conventionally known to use a resin composition containing a polyamide resin and a release agent. For example, Patent Document 3 discloses that a molding time is short by using a polyamide resin composition comprising polyamide or a resin containing the polyamide, a layered silicate uniformly dispersed in the resin, and a moldability improver, and It is disclosed to provide a polyamide composition that gives a shaped body with excellent mechanical properties. However, this technique does not satisfy low water absorption, chemical resistance and hydrolysis resistance at the same time as shortening the molding time and imparting excellent mechanical properties.

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 JP-A-1-301750

  The present inventors have disclosed that a polyamide resin comprising a dicarboxylic acid component comprising oxalic acid and a diamine component comprising 1,9-nonanediamine and 2-methyl-1,8-octanediamine has a low water absorption and a melting point and thermal decomposition. It has already been found that the moldable temperature range estimated from the difference in temperature is wide and excellent in melt moldability, and further excellent in chemical resistance and hydrolysis resistance. However, there is a demand for improving the moldability of such a polyamide resin, in particular, for improving the slip property between the mold and the molded product during molding and for shortening the molding time.

  The problem to be solved by the present invention is a wide range of moldable temperature estimated from the difference between the melting point and the thermal decomposition temperature while being low in water absorption, excellent in melt moldability, excellent in chemical resistance and hydrolysis resistance, It is an object of the present invention to provide a polyamide resin that can achieve good sliding properties between a mold and a molded product during molding and / or a short molding time.

  As a result of intensive studies to solve the above problems, the present inventors have found that the dicarboxylic acid component is composed of oxalic acid, and the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine. In addition, by using a combination of a polyamide resin having a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine of 1:99 to 99: 1 and a release agent, low water absorption However, the moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature is as wide as, for example, 50 ° C. or more, excellent in melt moldability, excellent in chemical resistance and hydrolysis resistance, and between the mold and the molded product during molding. The present inventors have found that a polyamide resin composition capable of achieving good sliding properties and / or a short molding time can be obtained, and the present invention has been completed. That is, the present invention is as follows.

[1] A resin composition comprising a polyamide resin and a release agent,
The dicarboxylic acid component of the polyamide resin comprises oxalic acid, the diamine component comprises 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,9-nonanediamine and 2-methyl-1,8-octane. The polyamide resin composition whose molar ratio with diamine is 1: 99-99: 1.

  [2] The polyamide resin has a relative viscosity (ηr) of 1.8 to 6.0 when 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 according to [1] above.

  [3] 1% weight loss temperature in thermogravimetric analysis of polyamide resin measured at 10 ° C./min in nitrogen atmosphere and differential scanning measured at 10 ° C./min in nitrogen atmosphere The polyamide resin composition according to the above [1] or [2], wherein the temperature difference from the melting point measured by a calorimetric method is 50 ° C. or more.

  [4] Any of [1] to [3] above, wherein the diamine component has a molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine of 5:95 to 95: 5. The polyamide resin composition described in 1.

  [5] The polyamide resin composition according to any one of [1] to [4], wherein the release agent is blended within a range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the polyamide resin. object.

  [6] The release agent is a polyalkylene glycol end-modified product, phosphate ester or phosphite ester, higher fatty acid monoester, higher fatty acid or metal salt thereof, ethylene bisamide compound, low molecular weight polyethylene, silicic acid The polyamide resin composition according to any one of [1] to [5], wherein the polyamide resin composition is one or more compounds selected from the group consisting of magnesium and substituted benzylidene sorbitols.

  [7] A molded product formed from the polyamide resin composition according to any one of [1] to [6].

  The polyamide resin composition of the present invention has a wide moldable temperature range, which is estimated from the difference between the melting point and the thermal decomposition temperature, while having low water absorption, excellent melt moldability, excellent chemical resistance and hydrolysis resistance, and molding. Since good sliding property and / or short molding time can be achieved, it can be widely used as molding materials for industrial materials, industrial materials, household products and the like.

(I) Polyamide resin (1) Constituent component of polyamide resin In the polyamide resin used in the present invention, the dicarboxylic acid component is composed of oxalic acid, and the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine. And a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 1:99 to 99: 1.

  As the oxalic acid source used in the production of the polyamide resin, oxalic acid diesters can be employed, and there is no particular limitation as long as they have reactivity with amino groups. Dimethyl oxalate, diethyl oxalate, di-n-oxalate (or i-) oxalic acid diesters of aliphatic monohydric alcohols such as propyl, di-n- (or i-, or t-) butyl oxalate, oxalic acid diesters of alicyclic alcohols such as dicyclohexyl oxalate, and aromatic alcohols such as diphenyl oxalate Examples include oxalic acid diesters.

  Among the 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.

  As the diamine component, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is used. Furthermore, the molar ratio of the 1,9-nonanediamine component and the 2-methyl-1,8-octanediamine component is 1:99 to 99: 1, preferably 5:95 to 95: 5, more preferably 5: It is 95-40: 60 or 60: 40-95: 5, Most preferably, it is 5: 95-30: 70 or 70: 30-90: 10. By copolymerizing 1,9-nonanediamine and 2-methyl-1,8-octanediamine in the above-mentioned specific amount, it is possible to increase the molecular weight by melt polymerization while having low water absorption, and the molding temperature range is wide. A polyamide having excellent melt moldability and excellent chemical resistance and hydrolysis resistance can be obtained.

  In particular, when the molar ratio is 5:95 to 40:60, and further 5:95 to 30:70, the crystallinity is excellent, so that the low water absorption and mechanical properties are particularly excellent, and liquid and / or gas (for example, For example, the permeability of alcohol and the like is low, and the water absorption is lower than when the content of 1,9-nonanediamine is higher than the content of 2-methyl-1,8-octanediamine, for example. It also has the advantage of. On the other hand, when the molar ratio is 60:40 to 95: 5, further 70:30 to 95: 5, and further 70:30 to 90:10, low water absorption and mechanical properties are particularly excellent, and good transparency. The advantage that the property is imparted is obtained.

(2) Components that can be blended in the production of polyamide resin When producing the polyamide resin used in the present invention, other dicarboxylic acid components can be mixed within a range not impairing the effects of the present invention. Other 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, diphenylsulfuric acid Down-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. It is preferable that the usage-amount of another dicarboxylic acid component is 5 mol% or less of the whole dicarboxylic acid component.

  Moreover, when manufacturing the polyamide resin used in this invention, another diamine component can be mixed in the range which does not impair the effect of this invention. Examples of diamine components other than 1,9-nonanediamine and 2-methyl-1,8-octanediamine include ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, and 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, aliphatic diamines such as 5-methyl-1,9-nonanediamine, cyclohexanediamine, methylcyclohexanediamine, and cycloaliphatic diamines such as isophoronediamine, p-phenylenediamine, m-phenylenediamine, p -Xylenediamine, m-xylenediamine, 4,4'-diamy Diphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-and aromatic diamines, such as diaminodiphenyl ether by itself, or may be added to any mixture thereof during the polycondensation reaction. It is preferable that the usage-amount of another diamine component is 5 mol% or less of the whole diamine component.

  The polyamide resin used in the present invention may be one in which a part thereof is replaced with another polymer component as long as the effects of the present invention are not impaired. As other polymer components, the dicarboxylic acid component consists of oxalic acid, the diamine component consists of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,9-nonanediamine and 2-methyl-1, Polyamides such as polyoxamides, aromatic polyamides, aliphatic polyamides, and alicyclic polyamides as thermoplastics other than polyamides having a molar ratio with 8-octanediamine of 1:99 to 99: 1, and thermoplastics other than polyamides Examples thereof include polymers. In the polyamide resin used in the present invention, the dicarboxylic acid component is composed of oxalic acid, the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,9-nonanediamine and 2-methyl- The proportion of polyamide having a molar ratio with 1,8-octanediamine of 1:99 to 99: 1 is preferably more than 50% by mass, and more preferably 70% by mass or more.

(3) Properties and properties of polyamide resin The molecular weight of the polyamide resin used in the present invention is not particularly limited, but the relative viscosity measured at 25 ° C. using a 96% concentrated sulfuric acid solution with a polyamide resin concentration of 1.0 g / dl. ηr is preferably in the range of 1.8 to 6.0, more preferably 2.0 to 5.5, and particularly preferably 2.5 to 4.5. If ηr is lower than 1.8, the molded product tends to be brittle and the physical properties tend to decrease. On the other hand, when ηr is higher than 6.0, the melt viscosity becomes high and the molding processability tends to deteriorate.

  The polyamide resin used in the present invention uses oxalic acid as the dicarboxylic acid component, and copolymerizes 1,9-nonanediamine and 2-methyl-1,8-octanediamine as the diamine component, so that 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 moldable temperature range represented by the difference (Td−Tm) between the 1% weight loss temperature (hereinafter abbreviated as Td) and the melting point (hereinafter abbreviated as Tm), which is a substantial thermal decomposition index, is oxalic acid. And a moldable temperature range can be preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even 90 ° C. or higher. The polyamide resin used in the present invention has a Td of preferably 280 ° C. or higher, more preferably 300 ° C. or higher, still more preferably 320 ° C. or higher, and has high heat resistance.

(4) Manufacture of polyamide resin The polyamide resin used in the present invention can be manufactured using any method known as a method of manufacturing polyamide. According to the study by the present inventors, a polyamide resin can be obtained by polycondensation reaction of diamine and oxalic acid diester 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 is, for example, 3 to 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 rising process, the final temperature of the prepolycondensation step, that is, from 80 to 150 ° C, is finally 220 ° C to 300 ° C, preferably 230 ° C to 280 ° C, more preferably 240 ° C to 270 ° C. Let reach the range. 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.

  A more specific example of the method for producing the polyamide resin used in the present invention will be described below. First, the raw oxalic acid diester is charged into the container. The container is not particularly limited as long as it can withstand the temperature and pressure of the polycondensation reaction to be 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 melting point and lower than the boiling point of the oxalic acid esters and diamines of the raw materials and the polyoxamide generated by the polycondensation reaction between the oxalic acid diester and the diamine is not thermally decomposed. For example, it consists of a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is from 1:99 to In the case of a polyoxamide resin starting from 99: 1 diamine and dimethyl oxalate, the mixing temperature is preferably 15 ° C to 240 ° C. Further, when the molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine is 5:95 to 90:10, it is liquid at room temperature or liquefied only by heating to about 40 ° C. It is more preferable because it is easy to handle. 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 preferably oxalic acid diester / the above diamine, preferably 0.8 to 1.2 (molar ratio), more preferably 0.91 to 1.09 (molar ratio), and still more preferably 0. .98 to 1.02 (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 does not decompose. For example, a diamine composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine and having a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine of 85:15 In the case of a polyoxamide resin using dibutyl oxalate as a raw material, the melting point is 235 ° C., so it is preferable to raise the temperature from 240 ° C. to 280 ° 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 240 to 280 ° C. The alcohol is cooled and liquefied by a water-cooled condenser and recovered.

(II) Mold Release Agent The mold release agent used in the present invention imparts excellent moldability to the polyamide resin, in particular, good slippage between the mold and the molded product during molding, and / or a short molding time. . Release agents include polyalkylene glycol end-modified products, phosphate esters or phosphites, higher fatty acid monoesters, higher fatty acids or metal salts thereof, ethylene bisamide compounds, low molecular weight polyethylene, magnesium silicate, and substitution. Examples thereof include benzylidene sorbitols. These can be used alone or in combination of two or more.

  It is preferable that the compounding quantity of a mold release agent exists in the range of 0.01-5 mass parts with respect to 100 mass parts of the above-mentioned polyamide resin used in this invention, and also 0.05-3 mass parts. When the blending amount is 0.01 parts by mass or more, and further 0.05 parts by mass or more, the moldability improvement effect is particularly good. Is sufficiently obtained, but the physical properties of the molded product are hardly lowered. Each more specific example will be described below.

Examples of preferable terminal modified products of polyalkylene glycol include terminal modified products of polyethylene glycol and terminal modified products of polypropylene glycol. The terminal modification is preferably performed with an amino group, a carboxyl group or a methyl group. As a more specific example, the following formula (1):
X—R ₁ — (O—CH ₂ —CH ₂ ) _n —O—R ₂ —X (1)
(In the formula, X represents NH ₂ , COOH, or H, R represents a linear or branched alkylene group having 1 to 10 carbon atoms, and n is a number of 4 to 1200).
Or the following formula (2):
X—R ₃ — (O—CH ₂ —C (CH ₃ ) H) _n —O—R ₄ —X (2)
(Wherein X represents NH ₂ , COOH, or H, R represents a linear or branched alkylene group having 1 to 10 carbon atoms, and n is a number from 1 to 200)
The thing represented by is mentioned.

  As a compounding quantity of the terminal modification product of polyalkylene glycol, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable.

  When the blended amount of the terminal modified product of polyalkylene glycol is 0.01 parts by mass or more, the effect of shortening the molding time due to the shortening of the cooling time during molding is particularly good. When the blending amount exceeds 5 parts by mass, the effect of shortening the molding time is not greatly improved, while the mechanical properties of the molded product tend to be lowered.

Examples of preferred phosphate esters include the following formula:
(RO) _n PO (OH) _3-n
(In the formula, n is 1 or 2, and R is an alkyl group having 1 to 10 carbon atoms)
The thing represented by is mentioned. In the above formula, the two RO groups in the case of n = 2 may be the same or different. Examples of R include an ethyl group, a butyl group, an octyl group, and an ethylhexyl group.

Examples of preferred phosphites include the following formula:
(RO) ₃ P
(In the formula, R represents hydrogen, an alkyl group having 10 to 25 carbon atoms, more preferably 12 to 20 carbon atoms, a phenyl group, or a group in which a part of these groups is substituted with a hydrocarbon group)
The thing represented by is mentioned. The three RO groups in the above formula may be the same or different. As R, aliphatic groups such as decyl group, lauryl group, tridecyl group, stearyl group and oleyl group; aromatic groups such as phenyl group and biphenyl group; ethyl group, propyl group, t-butyl group, nonyl group and the like Examples thereof include an aromatic group having a substituent.

  More specific examples of the above-mentioned phosphate ester and phosphite ester include aliphatic phosphate esters such as di (2-ethylhexyl) phosphate, tridecyl phosphite, tris (tridecyl) phosphite, and tristearyl phosphite. And aromatic phosphites such as aliphatic phosphites, triphenyl phosphites and diphenyl monodecyl phosphites.

  As a compounding quantity of phosphoric acid ester and phosphorous acid ester, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the blending amount of phosphoric acid ester and phosphorous acid ester is 0.01 parts by mass or more, the slip property between the mold and the molded product at the time of molding is particularly good and the effect of shortening the molding cycle time is particularly good. is there. When the blending amount is 5 parts by mass or less, the compatibility of the phosphoric acid ester and phosphite ester with the polyamide resin is good, the occurrence of silver (silver mark) on the surface of the molded product, and the mechanical properties of the molded product. Is less likely to occur.

Preferred higher fatty acid monoesters include the following formula:
R ₁ —CO—O—R ₂
(Wherein R ₁ and R ₂ each independently represents an alkyl group having 8 to 32 carbon atoms, preferably 10 to 30 carbon atoms)
, That is, an ester compound of a higher fatty acid and a higher aliphatic monohydric alcohol. Examples of R ₁ and R ₂ in the above formula include aliphatic groups such as a decyl group, a lauryl group, a tridecyl group, a stearyl group, and an oleyl group.

  Examples of the higher fatty acid include myristic acid, palmitic acid, behenic acid, oleic acid, and alginic acid. Examples of higher aliphatic alcohols include myristyl alcohol, behenyl alcohol, oleyl alcohol, stearyl alcohol, hexyldecyl alcohol, and the like.

  More specific examples of higher fatty acid monoesters include higher fatty acid monoalkyl esters such as myristyl myristate, stearyl stearate, behenyl behenate, oleyl oleate, hexyldecyl myristate, and the like.

  As a compounding quantity of higher fatty acid monoester, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the compounding amount of the higher fatty acid monoester is 0.01 parts by mass or more, the slip property between the mold and the molded product at the time of molding is particularly good, and when it is 5 parts by mass or less, the higher fatty acid monoesters And the polyamide resin have good compatibility, and the occurrence of silver on the surface of the molded product and the deterioration of the mechanical properties of the molded product are unlikely to occur.

Examples of preferred higher fatty acids or salts thereof include:
CH ₃ — (CH ₂ ) _n —COOX
(In the formula, n represents a number of 9 to 25, preferably 11 to 20, and X represents H or a metal of Groups I to III of the periodic table)
The thing represented by is mentioned.

  Examples of the higher fatty acid include stearic acid, palmitic acid, oleic acid, aragydic acid, and behenic acid. Examples of the metal salt of higher fatty acid include zinc stearate, lithium stearate, calcium stearate, aluminum palmitate and the like.

  As a compounding quantity of a higher fatty acid and its metal salt, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the blending amount of the higher fatty acid and the metal salt thereof is 0.01 parts by mass or more, the slip property between the mold and the molded product at the time of molding is particularly good, and when it is 5 parts by mass or less, the higher fatty acid monoester The compatibility between the resin and the polyamide resin is good, and the formation of silver on the surface of the molded product and the mechanical properties of the molded product, in particular, the elongation at break at break and the impact strength are hardly reduced.

Examples of preferred ethylene bisamide compounds include:
CH ₃ (CH ₂ ) _m CONH (CH ₂ ) ₂ NHCO (CH ₂ ) _n CH ₃
(In the formula, m and n are each independently 9-25, preferably 10-20)
The thing represented by is mentioned.

  More specific examples of the ethylene bisamide compound include ethylene bisstearylamide and ethylene bispalmitylamide.

  As a compounding quantity of an ethylene bisamide compound, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the blending amount of the ethylene bisamide compound is 0.01 parts by mass or more, the slip property between the mold and the molded product during molding is particularly good. When the blending amount exceeds 5 parts by mass, the effect of shortening the molding time is not greatly improved, but the surface appearance and mechanical properties of the molded product tend to be lowered.

  Preferred low molecular weight polyethylene includes those having a molecular weight in the range of 500 to 5000, and those having a molecular weight in the range of 1000 to 3000 are more preferred.

  As a compounding quantity of low molecular weight polyethylene, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the blending amount of the low molecular weight polyethylene is 0.01 parts by mass or more, the slip property between the mold and the molded product during molding is particularly good. When the blending amount is 5 parts by mass or less, the compatibility between the low molecular weight polyethylene and the polyamide resin is good, and the occurrence of silver on the surface of the molded product and the deterioration of the mechanical properties of the molded product are unlikely to occur.

  Examples of preferable magnesium silicate include those having an average particle diameter of 1 to 10 μm. When the average particle size is 1 μm or more, white unevenness is hardly generated on the surface of the molded product, and when the average particle size is 10 μm or less, the mechanical properties of the molded product, in particular, the tensile elongation at break and the impact strength are difficult to decrease. For the purpose of improving the adhesion with the polyamide resin, the magnesium silicate may be subjected to a surface treatment with aminosilane or the like.

  As a compounding quantity of magnesium silicate, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the said compounding quantity of magnesium silicate is 0.01 mass part or more, the improvement effect of a moldability is especially favorable. When the blending amount is 5 parts by mass or less, mechanical properties of the molded product, in particular, elongation at break at break and impact strength are hardly lowered.

  Examples of preferred substituted benzylidene sorbitols include substituted benzylidene sorbitols synthesized by dehydration condensation of sorbitol and substituted benzaldehyde under an acid catalyst. The condensation ratio of substituted benzaldehyde to sorbitol is preferably 1 mol or 2 mol with respect to 1 mol of sorbitol. Accordingly, these substituted benzylidene sorbitols have the following formula:

(Wherein R ₁ represents H, a hydroxyl group, a halogen, or an alkyl group having 1 to 200 carbon atoms)
Or the following formula:

(Wherein R ₂ and R ₃ each independently represents H, a hydroxyl group, a halogen, or an alkyl group having 1 to 200 carbon atoms)
It is represented by

  Examples of the substituted benzylidene sorbitols include 1,3-benzylidene sorbitol, 1,3,2,4-dibenzylidene sorbitol, 1,3-mono (p-hydroxybenzylidene) sorbitol, 1,3,2,4-di (P-hydroxybenzylidene) sorbitol, 1,3-mono (p-chlorobenzylidene) sorbitol, 1,3,2,4-di (p-chlorobenzylidene) sorbitol, 1,3-mono (m-nitrobenzylidene) sorbitol 1,3,2,4-di (m-nitrobenzylidene) sorbitol, 1,3- (p-chlorobenzylidene) 2,4- (p-ethylbenzylidene) -d-sorbitol, and the like.

  As a compounding quantity of substituted benzylidene sorbitols, 0.01-5 mass parts is preferable with respect to 100 mass parts of polyamide resins, and 0.05-3 mass parts is more preferable. When the said compounding quantity of substituted benzylidene sorbitol is 0.01 mass part or more, the shortening effect of the molding time by shortening the cooling time at the time of shaping | molding is especially favorable. When the blending amount exceeds 5 parts by mass, the effect of shortening the molding time is not greatly improved, while silver is generated on the surface of the molded product or the mechanical properties of the molded product tend to be lowered.

(III) Other components In the present invention, in addition to the above, various additives can be combined as necessary, and these can be combined during or after the polyamide polycondensation reaction.

  Various additives include reinforcing agents such as layered silicates, fillers, reinforcing fibers, stabilizers such as copper compounds, coloring agents, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, flame retardants, crystals Accelerators, glass fibers, plasticizers, lubricants, heat-resistant agents and the like.

  Here, the layered silicate is a component that imparts excellent mechanical properties and heat resistance to the polyamide resin. The layered silicate is preferably a flat plate having a side length of 0.002 to 1 μm and a thickness of 6 to 20 mm. Moreover, when the said layered silicate is disperse | distributed in a polyamide resin, it is preferable that each layer maintains the interlayer distance of about 18 mm or more, and is disperse | distributed uniformly.

  Here, “interlayer distance” refers to the distance between the centroids of the plate-like layered silicate, and “uniformly dispersed” means that each layer exists mainly in a random state, and the layered silicate 50% by mass or more, preferably 70% by mass or more is dispersed in a single layer without forming a multilayer.

  Examples of the raw material for the layered silicate include layered phyllosilicate minerals composed of magnesium silicate or aluminum silicate layers, that is, aluminum silicate phyllosilicate or magnesium silicate phyllosilicate. Specific examples include smectite clay minerals such as montmorillonite, saponite, beidellite, nontronite, hectorite, and stevensite, vermiculite, and halloysite. It may be what was done.

  Further, in order to disperse the layered silicate in the polyamide resin, a swelling agent is usually used. The swelling agent has a role of expanding the interlayer of the clay mineral and a role of giving the clay mineral a force for taking up the interlayer polymer. In the present invention, it is preferable to use 1,9-nonanediamine and 2-methyl-1,8-octanediamine as the swelling agent.

  The layered silicate is preferably pulverized using a mixer, a ball mill, a vibration mill, a pin mill, a jet mill, a beating machine, or the like to have a desired shape and size in advance.

  The amount of the layered silicate is not particularly limited as long as the effect of improving the mechanical strength and heat resistance is obtained, but is preferably 0.1% with respect to 100 parts by mass of the polyamide resin used in the present invention. 05 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, particularly preferably 0.05 to 5 parts by mass. When the proportion of the layered silicate decreases, the mechanical strength and heat resistance tend to be reduced, and when the proportion increases, the fluidity of the resin composition and the physical properties of the resulting molded product, particularly the impact strength, tend to decrease. There is.

  Examples of the method for uniformly dispersing the layered silicate in the polyamide resin include the following methods. When the raw material of the layered silicate is a multilayered clay mineral, the layered silicate is ionized with hydrochloric acid or the like, and a swelling agent such as 1,9-nonanediamine and 2-methyl-1,8-octanediamine is added thereto. And the space | interval of each layer of layered silicate is expanded previously. Next, a polyamide raw material can be introduced between the layers, and the raw materials can be polymerized between the layers.

  Alternatively, using a polymer compound as a swelling agent, the layers may be preliminarily spread to about 100 mm or more, melt-mixed with the polyamide resin, and each layer may be dispersed in the polyamide resin.

(IV) Molding process from polyamide resin composition to molded product The present invention also provides a molded product formed from the above-described polyamide resin composition of the present invention. As a molding method from a polyamide resin composition to a molded product, all known molding methods applicable to polyamide such as injection, extrusion, hollow, press, roll, foaming, vacuum / pressure air, and stretching can be used. It can be processed into a molded product such as a film, a sheet, a molded product, and a fiber by a molding method.

  More specifically, for example, a predetermined amount of polyamide resin, mold release agent and various additives used as needed is used using a low-speed rotary mixer such as a V-type blender or tumbler or a high-speed rotary mixer such as a Henschel mixer. Then, after mixing in advance, a method of directly molding a molded product using an injection molding machine or an extrusion molding machine can be applied.

(V) Use of molded product The molded product obtained according to the present invention includes various extruded products, various injection molded products, sheets, films, pipes, tubes, monofilaments, fibers, containers, etc. for which polyamide molded products have been conventionally used. The molded article can be suitably used for a wide range of applications such as automobile parts, computers and related equipment, optical equipment parts, electrical / electronic equipment, information / communication equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods.

[Physical property measurement, molding, evaluation method]
The characteristic value was measured by the following method.

(1) Relative viscosity (ηr)
ηr was measured at 25 ° C. with an Ostwald viscometer using a 96% sulfuric acid solution of polyamide (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 270 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run), held at 270 ° C. for 3 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first). Then, the temperature was raised to 270 ° C. at a rate of 10 ° C./min (called a temperature raised second run). From the obtained DSC chart, the exothermic peak temperature of the temperature decrease first run was Tc, and the endothermic peak temperature of the temperature increase second run was Tm.

(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 Melt viscosity was measured by attaching a 25 mm cone plate to a melt viscoelasticity measuring device ARES manufactured by TA Instruments Japan Co., Ltd., at 250 ° C. in nitrogen and at a shear rate of 0.1 s ⁻¹ . Measured under conditions.

(5) Film formation A film was formed from the pellets using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. In a reduced pressure atmosphere of 500 to 700 Pa, the film was heated and melted at 260 ° C. (290 ° C. when PA66 was used, and 230 ° C. when PA12 was used) for 5 minutes, and then pressed at 5 MPa 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) Saturated water absorption rate A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass of about 0.05 g) formed under the conditions of (5) above is immersed in ion-exchanged water at 23 ° C., and every predetermined time. The film was taken out and the mass of the film was measured. When the increase rate of the film mass is continued three times in the range of 0.2%, it is determined that the absorption of moisture into the polyamide resin film has reached saturation, and the mass (Xg) of the film before being immersed in water The saturated water absorption (%) was calculated from the mass (Yg) of the film when saturation was reached by the following equation (1).

  Saturated water absorption (%) = (Y−X) / X × 100 (1)

(7) Chemical Resistance After the polyamide hot press film obtained according to the present invention was immersed in the following chemicals for 7 days, changes in mass residual rate (%) and appearance of the film were observed. Tests were conducted on samples immersed in concentrated hydrochloric acid, 64% sulfuric acid, and glacial acetic acid at 23 ° C.

(8) Hydrolysis resistance The film molded under the condition (5) above is put in an autoclave, and in water, 0.5 mol / l sulfuric acid, 1 mol / l sodium hydroxide aqueous solution (that is, pH = 7, pH = 1, pH = 14), and the mass residual ratio (%) after treatment at 121 ° C. for 60 minutes was examined.

(9) Mechanical properties The measurement shown below is performed by injection molding of the following test piece at a resin temperature of 260 ° C. (290 ° C. when using PA66, 230 ° C. when using PA12) and a mold temperature of 80 ° C. It shape | molded and performed using this.

  [1] Tensile yield strength: Measured according to ASTM D638 using a Type I test piece described in ASTM D638.

  [2] Flexural modulus: Measured at 23 ° C. in accordance with ASTM D790 using a test piece with a test piece size of 3.2 mm × 12.7 mm × 127 mm. What was evaluated without humidity adjustment after molding was described in the table as dry, and what was evaluated after conditioning at 23 ° C. and 65% humidity after molding was shown in the table.

  [3] Izod impact strength: Measured at 23 ° C. in accordance with ASTM D256 using a test piece with a test piece size of 3.2 mm × 12.7 mm × 127 mm.

  [4] Deflection temperature under load (thermal deformation temperature): Measured at a load of 1.82 MPa in accordance with ASTM D648 using a test piece having a test piece size of 3.2 mm × 12.7 mm × 127 mm.

(10) Water absorption rate A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass of about 0.05 g) formed under the condition (5) above is placed under conditions of 23 ° C. and 65% RH, and the film is taken every predetermined time. Was taken out and the mass of the film was measured. When the rate of increase in the film mass continues three times within the range of 0.2%, it is determined that the absorption of moisture into the polyamide resin film has reached saturation, and before the 23 ° C. and 65% RH conditions are satisfied. The water absorption rate (%) was calculated from the mass (Xg) of the film and the mass (Yg) of the film when saturation was reached by the following formula (2).

  Water absorption (%) = (Y−X) / X × 100 (2)

(11) Mold Release Force and Molded Product Deformation FIG. 1 is a cross-sectional view showing an outline of an injection molding machine for measuring the mold release force. The cylinder 1 of the injection molding machine, the molded product (box molded product). Or, it has a cavity 2, a fixed mold 3, an ejector pin 4, a core 5, a moving mold 6, an ejector plate 7, a pressure sensor 8, a pressure sensor fixing plate 9, a knockout bar 10, and a recorder 11. The mold release force and deformation of a molded product obtained by injection molding were measured under the conditions described later using a mold and an injection molding machine equipped with a mold release force measuring device shown in FIG.

  In FIG. 1, the fixed mold 3 and the movable mold 6 are processed so as to form a box having a width of 80 mm, a length of 100 mm, a depth of 30 mm, a wall thickness of 2.3 mm, and a cross rib inside. After the injection molding, the movable mold 6 is moved backward, the knockout rod 10 is pressed against the pressure sensor 8, and the force applied to the pressure sensor 8 when the box is separated from the movable mold 6 via the ejector plate 7 and the ejector pin 4 (release The mold force) was measured with a recorder 11. Also, the deformation of the removed molded product was checked.

Molding conditions Injection molding machine: N140BII manufactured by Nippon Steel Works
Cylinder set temperature: C ₁ 250 ° C., C ₂ 255 ° C., C ₃ 260 ° C., C ₄ 260 ° C., NH 260 ° C.
Injection pressure: primary pressure 650 kg / cm ²
Mold temperature: Moving mold 90 ℃, Fixed mold 85 ℃
Injection time: 10 seconds Cooling time: 15 seconds, 30 seconds

[Production Example 1: Production of PA92-1]
Oxalic acid in a pressure vessel with a volume of 150 liters equipped with a stirrer, thermometer, torque meter, pressure gauge, raw material inlet directly connected with a diaphragm pump, nitrogen gas inlet, pressure relief port, pressure regulator and polymer outlet The operation of charging 28.40 kg (140.4 mol) of dibutyl, 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 is performed 5 After repeated nitrogen substitution, the system was heated while stirring under a sealing pressure. After adjusting the temperature of dibutyl oxalate to 100 ° C. over about 30 minutes, 18.89 kg (119.3 mol) of 1,9-nonanediamine and 3.34 kg (21.1 mol) of 2-methyl-1,8-octanediamine were obtained. ) (Molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 85:15) into a reaction vessel by a diaphragm pump at a flow rate of 1.49 liters / minute for about 17 minutes. The temperature was raised simultaneously with the supply. 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 = 3.20.

[Production Example 2: Production of PA92-2]
A mixture of 17.62 kg (111.3 mol) of 1,9-nonanediamine and 4.45 kg (28.1 mol) of 2-methyl-1,8-octanediamine (1,9-nonanediamine and 2-methyl-1,8 -Polyamide was obtained by carrying out the reaction in the same manner as in Production Example 1 except that the molar ratio of octanediamine was 80:20). The obtained polyamide was a white tough polymer and had ηr = 3.10.

[Production Example 3: Production of PA92-3]
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 (1,9-nonanediamine and 2-methyl-1,8 -Polyamide was obtained by carrying out the reaction in the same manner as in Production Example 1 except that the molar ratio of octanediamine was 50:50). The obtained polymer was a white tough polymer, and ηr = 3.35.

[Production Example 4: Production of PA92-4]
A mixture of 6.67 kg (42.1 mol) of 1,9-nonanediamine and 15.56 kg (98.3 mol) of 2-methyl-1,8-octanediamine (1,9-nonanediamine and 2-methyl-1,8 -Polyamide was obtained by reacting in the same manner as in Production Example 1 except that the octanediamine molar ratio was 30:70). The obtained polyamide was a white tough polymer, and ηr = 3.55.

[Production Example 5: Production of PA92-5]
A mixture of 1.33 kg (8.4 mol) of 1,9-nonanediamine and 20.88 kg (131.9 mol) of 2-methyl-1,8-octanediamine (1,9-nonanediamine and 2-methyl-1,8 -Polyamide was obtained by carrying out the reaction in the same manner as in Production Example 1 except that the molar ratio of octanediamine was 6:94). The obtained polymer was a white tough polymer, and ηr = 3.53.

[Production Example 6: Production of PA92-6]
A mixture of 1.33 kg (8.4 mol) of 1,9-nonanediamine and 20.88 kg (131.9 mol) of 2-methyl-1,8-octanediamine (1,9-nonanediamine and 2-methyl-1,8 -The octanediamine molar ratio was 6:94), and the reaction was carried out in the same manner as in Production Example 1 except that the internal pressure by extracting butanol was maintained at 0.25 MPa to obtain polyamide. The obtained polymer was a white tough polymer, and ηr = 4.00.

[Production Example 7: Production of PA-1]
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.

  Table 1 shows the characteristic data of the polyamides prepared in Production Examples 1 to 7, and commercially available products PA6 (UBE Nylon 2020B), PA66 (UBE Nylon 2020B), and PA12 (Ube Industries, UBESTA3020U).

[Examples 1 to 13, Comparative Examples 1 and 2]
The composition shown in Table 2 is melt-kneaded at a cylinder setting temperature of 260 ° C. and a rotation speed of 150 rpm in a twin-screw kneader PCM-45 manufactured by Ikekai Tekko Co., Ltd. Various evaluations shown in Table 2 were performed by the above-described methods using the test pieces obtained by molding according to the above.

  The polyamide resin composition of the present invention has a low water absorption, a wide moldable temperature range, excellent melt moldability, excellent chemical resistance and hydrolysis resistance, and good mold and molded product during molding. Since it can achieve slipperiness and / or a short molding time, it can be suitably used as a molding material for industrial materials, industrial materials, household goods and the like. Molded products formed from the polyamide resin composition of the present invention include, for example, various extrusion molded products, various injection molded products, sheets, films, pipes, tubes, monofilaments, fibers, etc., automobile members, optical equipment members, electric / electronics, etc. It can be used for a wide range of applications such as equipment, information / communication equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods.

It is sectional drawing which shows the outline of the injection molding machine for measuring mold release force.

Explanation of symbols

1 Cylinder of injection molding machine 2 Molded product (box molded product) or cavity 3 Fixed mold 4 Ejector pin
5 Core 6 Moving mold 7 Ejector plate 8 Pressure sensor 9 Pressure sensor fixing plate 10 Knockout stick 11 Recorder

Claims (7)

A resin composition comprising a polyamide resin and a release agent,
The dicarboxylic acid component of the polyamide resin comprises oxalic acid, the diamine component comprises 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,9-nonanediamine and 2-methyl-1,8-octane. The polyamide resin composition whose molar ratio with diamine is 1: 99-99: 1.   The relative viscosity (ηr) of the polyamide resin when measured at 25 ° C. using a polyamide resin solution having a concentration of 1.0 g / dl using 96% sulfuric acid as a solvent is 1.8 to 6.0. 2. The polyamide resin composition according to 1.   1% weight loss temperature in thermogravimetric analysis of the polyamide resin measured at a heating rate of 10 ° C./min in a nitrogen atmosphere and by differential scanning calorimetry measured at a heating rate of 10 ° C./min in a nitrogen atmosphere. The polyamide resin composition of Claim 1 or 2 whose temperature difference with melting | fusing point measured is 50 degreeC or more.   The polyamide resin composition according to any one of claims 1 to 3, wherein the diamine component has a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine of 5:95 to 95: 5. object.   The polyamide resin composition in any one of Claims 1-4 with which the said mold release agent is mix | blended within the range of 0.01-5 mass parts with respect to 100 mass parts of said polyamide resins.   The release agent is a polyalkylene glycol end-modified product, phosphate ester or phosphite ester, higher fatty acid monoester, higher fatty acid or metal salt thereof, ethylene bisamide compound, low molecular weight polyethylene, magnesium silicate, and substitution The polyamide resin composition according to any one of claims 1 to 5, which is one or more compounds selected from the group consisting of benzylidene sorbitols.   The molded product formed from the polyamide resin composition in any one of Claims 1-6.

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