JP2009298852A - Plasticizer-containing polyamide resin composition and molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasticizer-containing polyamide resin composition with no bleed-out of a plasticizer capable of attaining sufficient high molecular weight as compared with conventional polyamide 92, having a wider moldable temperature range estimated from a difference of a melting point and a thermal decomposition temperature, being excellent in melt moldability, and being further excellent in chemical-resistance, flexibility and hydrolysis-resistance as compared with a conventional aliphatic polyamide resin without impairing a low water-absorption property seen in an aliphatic straight chain polyoxamide resin. <P>SOLUTION: The plasticizer-containing resin composition contains the polyamide resin and the plasticizer. The polyamide resin is 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 and 2-methyl-1,8-octanediamine is 6:94-99:1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel plasticizer-containing polyamide resin composition and a molded product. More specifically, the present invention relates to a plasticizer-containing polyamide resin composition and a molded article having a wide moldable temperature range, excellent molding processability, low water absorption, chemical resistance, hydrolysis resistance and the like.

  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.

  In order to improve the flexibility and impact resistance of resins such as polyamide to a high degree, it is necessary to increase the amount of plasticizer. However, problems such as bleed out of the plasticizer have been pointed out. There is an increasing demand for plasticizer-containing resin compositions and molded articles that do not have bleeding out.

  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 the change in physical properties due to water absorption has been 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 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. In addition, JP-A-5-506466 discloses 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 form a tough molded body is obtained.

In the prior literature, there is no specific disclosure of a polyoxamide resin using two kinds of diamines of 1,9-nonanediamine and 2-methyl-1,8-octanediamine as a diamine component in a specific ratio.
SW 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

  The problem to be solved by the present invention is that there is no bleed out of the plasticizer, a sufficiently high molecular weight is achieved as compared with the conventional PA92, and the moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature is wide. Excellent in melt moldability, and without impairing the low water absorption found in aliphatic linear polyoxamide resin, compared to conventional aliphatic polyamide resin, it has chemical resistance, flexibility, hydrolysis resistance, etc. The object is to provide an excellent plasticizer-containing polyamide resin composition.

  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 composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine. By using a polyamide resin (hereinafter also referred to as “PA92C”) having a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine of 6:94 to 99: 1, a plasticizer is obtained. No bleed-out, high molecular weight, large difference between melting point and thermal decomposition temperature, excellent melt moldability, and more resistant to the low water absorption found in linear polyoxamide resin compared to conventional polyamide. The inventors have found that a plasticizer-containing polyamide resin composition excellent in chemical properties, flexibility and hydrolysis resistance can be obtained, and completed the present invention.

  The plasticizer-containing polyamide resin composition of the present invention is excellent in low water absorption, chemical resistance, flexibility, hydrolysis resistance, can be increased in molecular weight, and has a moldable temperature range of 50 ° C. or higher. It is a resin composition having a wide range of 60 ° C. or higher, excellent melt moldability, and no bleed-out of a plasticizer, and can be widely used as a molding material for industrial materials, industrial materials, household products and the like.

(1) Constituent Component of Polyamide Resin In the polyamide used in the present invention, the dicarboxylic acid component is oxalic acid, the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,9- It is a polyamide resin which is a diamine mixture in which the molar ratio of 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 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 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: 95-40: 60 or 60: 40-95: 5, especially 5: 95-30: 70 or 70: 30-90: 10. By copolymerizing 1,9-nonanediamine and 2-methyl-1,8-octanediamine as described above, the moldable temperature range is wide, the melt moldability is excellent, and the low water absorption, chemical resistance, resistance A polyamide having excellent hydrolyzability and transparency can be obtained.

(2) Manufacture of polyamide resin The polyamide resin 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 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.

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. 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 that is not lower than the melting 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 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 1:99 to 99: In the case of a polyoxamide resin using diamine 1 and dibutyl oxalate as raw materials, the mixing temperature is preferably 15 ° C to 240 ° C. Moreover, since the molar ratio of 1,9-nonanediamine and 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 and diamine is oxalic acid diester / diamine as described above, 0.8 to 1.2 (molar ratio), preferably 0.91 to 1.09 (molar ratio), more preferably 0.98. -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 and shu comprising 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 85:15. In the case of a polyoxamide resin using dibutyl acid 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.

(3) Properties and Physical Properties of Polyamide Resin There is no particular restriction on the molecular weight of the polyamide resin PA92C used in the present invention, but a 96% concentrated sulfuric acid solution having a polyamide resin concentration of 1.0 g / dl using 96% concentrated sulfuric acid as a solvent. The relative viscosity ηr measured at 25 ° C. 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 PA92C 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. The relative viscosity can be increased, that is, the molecular weight can be increased as compared with the polyamide made of 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 polyamide composed of 1,9-nonanediamine, preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and further 80 ° 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) Plasticizer This invention is the polyamide resin composition which mix | blended the plasticizer with the said polyamide resin PA92C.
The plasticizer used in the present invention may be any plasticizer known to be used in polyamide resins, but is preferably one or more compounds selected from esters and alkylamides.

  The esters referred to in the plasticizer of the present invention are phthalic acid esters, fatty acid esters, polyhydric alcohol esters, phosphoric acid esters, trimellitic acid esters, and hydroxybenzoic acid esters. Specific examples of phthalic acid esters include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisodecyl phthalate, ditridecyl phthalate, and phthalic acid Examples include dicyclohexyl, butyl benzyl phthalate, diisononyl phthalate, ethyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, diundecyl phthalate, and di-2-ethylhexyl tetrahydrophthalate.

  Specific examples of fatty acid esters include dimethyl adipate, dibutyl adipate, diisobutyl adipate, dibutyl diglycol adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, diisodecyl adipate, diisononyl adipate, adipine Dibasic acid di-n-mixed alkyl ester, dimethyl sebacate, dibutyl sebacate, di-2-ethylhexyl sebacate, di-2-ethylhexyl azelate, di-2-ethylhexyl mixed acid ester, bis-2-ethylhexyl dodecamate, etc. Saturated carboxylic acid ester, dibutyl fumarate, bis-2-methylpropyl fumarate, bis-2-ethylhexyl fumarate, dimethyl maleate, diethyl maleate, dibutyl maleate, bis-2-ethylhexyl maleate, etc. Basic unsaturated carboxylic acid ester include butyl oleate, Izobuchiru oleate, acetyl butyl ricinoleate, and the like acetyl tributyl citrate and 2-ethylhexyl acetate.

  Specific examples of polyhydric alcohol esters include 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, diethylene glycol di Examples include benzoate, triethylene glycol di-2-ethylbutyrate, pentaerythritol monooleate, pentaerythritol monostearate, pentaerythritol trialkyl ester, behenic acid monoglyceride, 2-ethylhexyl triglyceride, glycerin triacetate and glycerin tributyrate. .

  Specific examples of phosphoric acid esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, n-octyldiphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, and Examples include 2-ethylhexyl diphenyl phosphate.

  Specific examples of trimellitic acid esters include tributyl trimellitic acid, tri-2-ethylhexyl trimellitic acid, tri-n-octyl trimellitic acid, triisononyl trimellitic acid, triisodecyl trimellitic acid, and trimellitic acid tri-mixed alcohol ester Is mentioned.

  Specific examples of hydroxybenzoates include ethyl hexyl o- or p-hydroxybenzoate, hexyl decyl o- or p-hydroxybenzoate, ethyl decyl o- or p-hydroxybenzoate, o- or p-hydroxybenzoic acid. Octyloctyl, o- or p-hydroxybenzoic acid decyldodecyl, o- or p-hydroxymethyl benzoate, o- or p-hydroxybenzoic acid butyl, o- or p-hydroxybenzoic acid hexyl, o- or p-hydroxy Examples include n-octyl benzoate, decyl o- or p-hydroxybenzoate, and dodecyl o- or p-hydroxybenzoate.

  The alkylamides are toluenesulfonic acid alkylamides and benzenesulfonic acid alkylamides. Specific examples of toluenesulfonic acid alkylamides include N-ethyl-o-toluenesulfonic acid butyramide, N-ethyl-p-toluenesulfonic acid butyramide, N-ethyl-o-toluenesulfonic acid 2-ethylhexylamide, N- Examples include ethyl-p-toluenesulfonic acid 2-ethylhexylamide. Specific examples of the benzenesulfonic acid alkylamides include benzenesulfonic acid propylamide, benzenesulfonic acid butyramide, benzenesulfonic acid 2-ethylhexylamide, and the like. The plasticizers mentioned above may be used alone or in combination of two or more.

  Among these plasticizers, phthalates such as dibutyl phthalate, diisodecyl phthalate, di-2-ethylhexyl phthalate, hydroxy benzoates such as ethyl hexyl p-hydroxybenzoate and hexyl decyl p-hydroxybenzoate Alkylamides such as benzenesulfonic acid butyramide and benzenesulfonic acid 2-ethylhexylamide are preferably used.

  The compounding ratio of the plasticizer is 1 to 30 parts by mass, preferably 1 to 25 parts by mass, and more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the polyamide resin. This is because when the blending ratio of the plasticizer is less than 1 part by mass, the effect of imparting flexibility is not seen, whereas when the blending ratio of the plasticizer is more than 30 parts by mass, the plasticizer bleeds out.

  The polyamide resin PA92C used in the present invention has excellent characteristics (low water absorption, chemical resistance, flexibility, hydrolysis resistance, wide moldable temperature range, mechanical properties, even if a plasticizer is added. Strength, etc.) are basically kept as they are or relatively. Regarding the moldable temperature range, the polyamide resin generally becomes more flexible by adding a plasticizer, and the melting point is lowered, so that the moldable temperature is lowered. However, the polyamide resin PA92C has a wider molding than the conventional PA92. The characteristics of the possible temperature range are maintained even when the plasticizer is retained. As a result, in the polyamide resin composition containing the plasticizer in the polyamide resin of the present invention, a 1% weight reduction in the thermogravimetric analysis of the polyamide resin not containing the plasticizer measured at a heating rate of 10 ° C./min in a nitrogen atmosphere. The temperature difference between the temperature and the melting point measured by the differential scanning calorimetry of the polyamide resin composition containing the plasticizer measured at a heating rate of 10 ° C./min in a nitrogen atmosphere is preferably 50 ° C. or more, more preferably 60 It can be not lower than 90 ° C., and further not lower than 90 ° C. Moreover, the polyamide resin PA92C of the present invention has an advantage that it can be molded without bleeding out by adding a plasticizer.

(5) Other components that can be blended in the polyamide resin composition The polyamide resin PA92C used in the present invention can contain other dicarboxylic acid components as long as the effects of the present invention are not impaired. 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, 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. The amount of the dicarboxylic acid component other than oxalic acid is preferably 5 mol% or less based on the total dicarboxylic acid component.

  Further, the polyamide resin used in the present invention can contain other diamine components as long as the effects of the present invention are not impaired. 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, alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine and isophoronediamine, p-phenylenediamine, m-phenylenediamine, p -Xylenediamine, m-xylenediamine, 4,4'-di Mino 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. The blending amount of diamine components other than 1,9-nonanediamine and 2-methyl-1,8-octanediamine is preferably 5 mol% or less based on the total diamine components.

  A part of the polyamide resin PA92C used in the present invention can be substituted with other polyoxamides, polyamides such as aromatic polyamides, aliphatic polyamides, and alicyclic polyamides within a range not impairing the effects of the present invention. .

Moreover, it can substitute by thermoplastic resins, such as polyolefin, such as polyvinyl chloride, polyurethane, polyester, ABS resin, acid-modified polyethylene, acid-modified polypropylene other than a polyamide resin, or an elastomer.
When a part of the polyamide resin PA92C used in the present invention is replaced with another resin, the amount of the resin to be replaced is preferably 50% by mass or less of the entire resin.

  In addition, the polyamide resin composition used in the present invention is optionally provided with 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. Various additives such as accelerators, reinforcing fibers such as glass fibers, fillers, and lubricants can be added. These additives can also be added during or after the polycondensation reaction of the polyamide resin.

(7) Molding of polyamide resin composition The method for obtaining the polyamide resin composition of the present invention is not particularly limited, and various known methods can be used. For example, polyamide, plasticizer, and various additives are mixed in advance using a low-speed rotary mixer such as a V-type blender or tumbler, or a constrained rotary mixer such as a Henschel mixer, and then a single screw extruder, twin screw A method of pelletizing after melt-kneading with an extruder, etc., or pre-mixing a predetermined amount of polyamide, plasticizer and various additives using a constrained rotary mixer such as a low-speed rotary mixer or a Henschel mixer, and then injection molding A method of directly obtaining a molded product of the composition using a machine or an extrusion molding machine can be applied.

  As the molding method of the polyamide resin composition, all known molding processing methods applicable to polyamide such as injection, extrusion, blow, hollow, press, roll, foaming, vacuum / pressure air, and stretching can be used.

  The plasticizer-containing polyamide resin composition of the present invention can be used to obtain molded products such as tubes, filaments, sheets, films, fibers, etc. by the molding method as described above.

  The plasticizer-containing polyamide resin composition of the present invention can also be used as a coating material, but as a molded product, molding materials such as industrial materials, industrial materials, household goods, especially automobile members, optical device members, electric / electronic devices, It can be suitably used for a wide range of applications such as information / communication-related equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods. For example, sports shoes materials, ski surface materials, gears, connectors and seals for machinery and electrical precision equipment, automotive moldings, sealing materials, various tubes and hoses, sheets, films, monofilaments, automotive mirror boots, constant velocity joints Boots etc.

  The plasticizer-containing polyamide resin composition of the present invention has low water absorption, excellent melt moldability, excellent moldability, no plasticizer bleed-out, excellent impact resistance, and hydrolysis resistance. Property and property retention after hydrolysis, and chemical resistance.

  The plasticizer-containing polyamide resin composition of the present invention preferably has a tensile elongation at break of 90% or more, more preferably about 100%.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited to these Examples.
The characteristic value was measured as follows.

(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 of the plasticizer-containing sample and the sample not containing the plasticizer 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). 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 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 Film formation was performed using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. It was melted by heating at 260 ° C. (290 ° C. when nylon 66 was used, 230 ° C. when nylon 12 was used) in a reduced pressure atmosphere of 500 to 700 Pa for 5 minutes, and then pressed at 10 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) 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 three times in the range of 0.2%, it is determined that the absorption of water into the polyamide resin film has reached saturation, and the film weight (Xg) before dipping in water The saturated water absorption (%) was calculated from the weight (Yg) of the film when the saturation was reached 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 hot-pressed film of polyamide resin used in the present invention was immersed in the chemicals listed below for 7 days, changes in the weight residual ratio (%) and 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 hot-pressed film of the polyamide resin used in the present invention is placed in an autoclave, and water (pH = 7), 0.5 mol / l sulfuric acid (pH = 1), 1 mol / l sodium hydroxide aqueous solution (pH) = 14), the residual weight ratio (%) and appearance change after treatment at 121 ° C. for 60 minutes were examined.

(9) Mechanical properties [1] to [4] shown below are measured using the following test piece with a resin temperature of 260 ° C. (290 ° C. when nylon 66 is used, 230 ° C. when nylon 12 is used). Molding was carried out 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) Breaking elongation retention after hydrolysis The sample cut out from a 100 mm x 300 x 2 mm thick plate formed by injection molding using a JIS No. 3 dumbbell is placed in a 5 liter stainless steel container so as not to overlap. Then, about 2 liters of distilled water was added and the container was sealed with a lid, and then placed in an 80 ° C. hot water bath. After the treatment for 2000 hours, the test piece was taken out and the moisture on the surface was removed. Then, the chuck of the tensile tester was sandwiched at a distance between chucks of 50 mm, a tensile test was performed at a speed of 500 mm / min, and elongation at break was measured. The test piece not hydrolyzed was measured, and the elongation at break was calculated from the following formula (2).
Breaking elongation retention ratio (%) = [(breaking elongation of hydrolyzed sample) / (breaking elongation of untreated sample)] × 100 (2)

[Production Example 1: Production of PA92C-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 to 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 PA92C-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 PA92C-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 PA92C-4]
1,9-nonanediamine 6.67 kg (42.1 mol), 2-methyl-1,8-octanediamine 15.56 kg (98.3 mol) in a mixture (1,9-nonanediamine and 2-methyl-1, A polyamide was obtained by reacting in the same manner as in Production Example 1 except that the molar ratio of 8-octanediamine was 30:70). The obtained polyamide was a white tough polymer, and ηr = 3.55.

[Production Example 5: Production of PA92C-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 PA92C-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.

[Comparative Production 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.

About the polyamide resins obtained in Production Examples 1 to 6 and Comparative Production Example 1, nylon 6 (Ube Industries, UBE nylon 1015B), nylon 66 (Ube Industries, UBE nylon 2020B)) and nylon 12 (UBESTA 3020U), Relative viscosity, melting point, crystallization temperature, 1% weight loss temperature, melt viscosity, saturated water absorption, chemical resistance, hydrolysis resistance, mechanical properties in dry and wet were measured. The results are shown in Table 1.

[Examples 1 to 9, Reference Example 1, Comparative Examples 1 to 3]
Polyamide PA92C-1 to PA92C-6, PA92, nylon 6 (manufactured by Ube Industries, UBE nylon 1015B), nylon 66 (manufactured by Ube Industries, UBE nylon 2020B) and nylon 12 manufactured in Production Examples 1-6 and Comparative Production Example 1 (UBESTA3020U) and benzenesulfonic acid butyramide or ethylhexyl p-hydroxybenzoate as a plasticizer were used to prepare a mixture having the ratio shown in Table 5.
The polyamide / plasticizer mixture was evaluated for melting point, crystallization temperature, melt viscosity, saturated water absorption, chemical resistance, hydrolysis resistance, and mechanical strength.
The evaluation results are shown in Table 2.

  Further, these mixtures were melt-kneaded at 260 ° C. (290 ° C. for nylon 66, 230 ° C. for nylon 12) using a twin-screw kneader with a cylinder diameter of 40 mm, extruded into a strand, and cooled in a water bath Pellets were made using a pelletizer.

Test pieces for bending test and impact test were prepared from the obtained pellets by injection molding. No plasticizer bleed-out was observed in any of the test pieces of Examples. Moreover, the bending test piece of the said description was heat-processed for 100 hours in 80 degreeC hot-air oven. The presence or absence of bleed-out was evaluated by visually observing the surface of the heat-treated test piece. The results are shown in Table 2.
Using these test pieces, the bending elastic modulus, Izod impact value, saturated water absorption, and elongation at break after hydrolysis treatment were evaluated.
The evaluation results are shown in Table 3.

  The plasticizer-containing polyamide resin composition of the present invention has no plasticizer bleed-out, is excellent in low water absorption, chemical resistance, flexibility, hydrolysis resistance, and the like, and is excellent in melt molding processability. It can be suitably used as a molding material for industrial materials, industrial materials, household goods and the like. For example, various injection-molded products, sheets, films, pipes, tubes, monofilaments, fibers, etc., automotive parts, optical equipment members, electrical / electronic equipment, information / communication equipment, precision equipment, civil engineering / building supplies, medical supplies, households Can be used for a wide range of applications such as goods.

Claims (7)

  A plasticizer-containing polyamide resin composition comprising a polyamide resin and a plasticizer, wherein the polyamide resin is composed of carboxylic acid component and diamine component is 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.   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 plasticizer-containing polyamide resin composition according to claim 1.   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 plasticizer-containing polyamide resin composition according to claim 1 or 2, wherein the temperature difference from the measured melting point is 50 ° C or more.   The polyamide resin is composed of a diamine component having a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine of 5:95 to 95: 5. The plasticizer-containing polyamide resin composition according to any one of the above.   The plasticizer-containing polyamide resin composition according to any one of claims 1 to 4, wherein the plasticizer is contained in an amount of 1 to 30 parts by weight with respect to 100 parts by weight of the polyamide resin.   Measured at 1% weight loss temperature in thermogravimetric analysis of the polyamide resin measured at a rate of temperature increase of 10 ° C./min in a nitrogen atmosphere and at a rate of temperature increase of 10 ° C./min of the polyamide resin composition in a nitrogen atmosphere. The plasticizer-containing polyamide resin composition according to any one of claims 1 to 5, wherein a temperature difference with a melting point measured by a differential scanning calorimetry is 50 ° C or more.   A molded article comprising the plasticizer-containing polyamide resin composition according to claim 1.