JPH0453827A - Production of polyamide resin - Google Patents

Abstract

PURPOSE:To obtain the title resin suitable for a thin-walled molded article used at a high temp., such as a connector or a coil bobbin, by preparing a condensate having a low degree of condensation from monomers which constitute specific structural units and converting the condensate into a polymer having a high degree of polymn. with a melt extruder. CONSTITUTION:In producing a copolyamide comprising repeating units of formulas I, II, and III (wherein R is a 6-18C aliph. group; R' is a 4-18C aliph. group or a group of formula IV; and n is 5-18) and contg. the units of formula I and/or formula II as an essential unit, a diamine component in an amt. of 0.3-10mol% excess based on the number of total moles of monomers constituting units of formulas I, II, and III is used and the condensation is conducted at 150-300 deg.C under a pressure of 20kg/cm<2>G or lower to give an NH2-rich condensate having a low degree of condensation and a relative viscosity etar of 1% sulfuric acid soln at 25 deg.C of 1.01-1.6. A dicarboxylic acid component in an amt. offsetting the shortage is added to the condensate when it is converted into a polymer having a high degree of polymn. with a melt extruder, giving the title resin.

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for producing a polyamide resin, in which a low-order condensate is prepared from an aqueous solution of monomers or salts as constituent units, and the degree of polymerization is increased using a melt extruder. This polyamide resin is especially suitable for thin-walled molded products such as connectors and coil bobbins that are used in high-temperature environments! This is related to the 2-way method. <Prior art> Polyamide has been widely used in the automobile field, electric/electronic field, etc. due to its excellent properties as an engineering plastic, and is used as a material for thin-walled molded products such as connectors and coil bobbins. It is also often used as Conventionally, nylon 6 and nylon 66 reinforced with glass fibers have been used for these molded products (Japanese Patent Laid-Open No. 59-1
61461), and with the rise in temperature in automobile engine compartments due to recent technological innovations and advances in microelectronics, there has been a demand for materials for ultra-thin molded products that can withstand use in even higher temperature environments. However, the melting points (Tm) of nylon 6 and nylon 66 are 220°C and 220°C, respectively.
Even when the temperature is 260° C. and reinforced with glass fiber, the limit of the heat distortion temperature remains at the melting point. Recently, many copolyamide resin compositions containing terephthalic acid and inophthalic acid, or glass-reinforced products thereof, have been proposed as copolyamide resin compositions that can withstand use in these high-temperature environments (Japanese Patent Laid-Open No. 59-1614).
28, JP 59155426, JP 59-5353
6, Japanese Patent Publication No. 62-156130). <Problems to be Solved by the Invention> However, in these copolyamide resin compositions containing terephthalic acid and isophthalic acid, as the number of terephthalic acid component units increases, the melt viscosity becomes high, and it may be impossible to discharge using a normal melt polymerization method. Because the polymer melting point is close to the thermal decomposition temperature of the polymer, decomposition and deterioration occurred during melt polymerization. In addition, the method of conducting a polymerization reaction from a nylon salt to a polymer in a solid state has problems such as the composition of the polymer being unstable. In view of the above circumstances, the present inventors have conducted extensive studies on a method for producing a polyamide resin composition that is inexpensive and has good fluidity, has high rigidity and heat resistance that can withstand use in high-temperature atmospheres. . <Means for Solving the Problems> As a result of intensive studies by the present inventors to solve the above problems,
[NI+2] By creating a rich low-order condensate and adding a dicarboxylic acid component when increasing the degree of polymerization using a melt extruder, a stable polymer with a high degree of polymerization can be obtained and the above problems can be efficiently achieved. We have discovered this and arrived at the present invention. That is, the present invention consists of the following repeating components (I) to (III) (I)-118-(CR2)e-C (wherein R is an aliphatic group having 6 to 18 carbon atoms, R. 7, (1) in producing a polyamide containing (summer) and/or (II) as essential components.
A noamino component of 0.3 to 10 mol% is charged in excess to the average total mole number of the monomer components constituting ~(Ill), and the mixture is heated at 150°C to 300°C, 20 kg/cm'
The relative viscosity (ηr) of a 1% sulfuric acid solution at 25°C satisfies 1.01-1.6 under the following conditions: -G [N)
12] A method for producing a polyamide resin, which is characterized in that when a rich low-order condensate is produced and the low-order condensate is increased in degree of polymerization using a melt extruder, an insufficient dicarboxylic acid component is added. The polyamide resin of the present invention is (1) an aliphatic alkylene terephthalamide unit synthesized from an aliphatic alkylene diamine having 6 to 18 carbon atoms and terephthalic acid, (11) an aliphatic alkylene diamine having 6 to 18 carbon atoms and isophthalic acid. an aliphatic alkylene isophthalamide unit synthesized from or a condensate formed from an aliphatic alkylene 7-noamine having 6 to 18 carbon atoms and an aliphatic alkylene dicarboxylic acid having 4 to 18 carbon atoms; (I) lactams or 5 carbon atoms; ~
It is a composite formed from the il1 position of 18 aliphatic aminocarboxylic acid components and in which (1) or (11) is an essential component. Specific examples of aliphatic alkylene 7-noamines having 6 to 18 carbon atoms include ], 6-diaminohebyusan, 1,7-diaminohebbutane, 1. 8-Noaminooctane, l, 9
-diaminononane, l, 10diaminodecane, 111
-Noaminooctane, 1,12-diaminododecane,
1. Examples include 4-diaminododecane, 116-diaminohexadecane, and 18-diaminooctadecane. In addition, specific examples of aliphatic alkylene dicarboxylic acid components having a return prime number of 4 to 18 include succinic acid, glutaric acid, adipic acid, pimelic acid, superic acid, azelaic acid, sepa/noic acid, undecanionic acid,
Examples include dodecanoic acid, gly/phosphoric acid, tetradecanoic acid, pentadecanoic acid, and octadeca/diacid. Among these aliphatic alkaline dicarboxylic acid components, adipic acid, sebannic acid, unodecandioic acid, and dodecanoic acid are preferred. Furthermore, specific examples of lactams include ε-caprolactam, ζ-enanotractam, η-capryllactam, and ω-laurolactam. Specific examples of the aliphatic aminocarboxylic acid component having a return prime number of 5 to 18 include 6-amitsucabronoic acid, 11-aminododecanoic acid, and 12-aminododecanoic acid. The polyamide of the present invention is a polyamide containing (T) and/or (■) as essential components, (I), (n
) are ih, respectively, and (+)/(I+
), (1)/([[+> and (■)/(t[I) binary copolymer polyamide or (1)/(n)/(I)
It contains a tertiary copolymerized polyamide. There is no particular restriction on the degree of polymerization of the polyamide used here, and any polyamide having a relative viscosity (ηr) of 1% sulfuric acid solution at 25° C. of 15 to 5.0 can be used. 150°C to 300°C, 20 kg/c■2-G of the present invention
The lower-order condensate prepared under the following conditions is as follows: (1) The aqueous solution described in (1) is charged into a pressure polymerization kettle, and under tgI stirring conditions 150
Heat to 300°C. Reaction temperature is 150℃~300℃
℃, preferably 180°C to 280°C
It is. If the reaction temperature is lower than 150°C, the reaction time will be longer, which is undesirable. Conversely, if the reaction temperature is higher than 300°C, the viscosity of the lower-order condensate will become too high, or it will precipitate, making it impossible to discharge, so it is not preferable. do not have. The pressure when producing the low-order condensate of the present invention means the equilibrium pressure due to the mixture of the low-order condensate and water at that time, and the pressure increases as the internal temperature rises, so the pressure inside the system is 20
The pressure is maintained at a constant pressure of 2-f kg/c; The lower condensate can be discharged from the polymerization vessel in a molten state at a temperature of 150 DEG C. to 300 DEG C., since the presence of a small amount of water provides a significant freezing point depression. Therefore, the pressure inside the pot must be maintained at 20 kg/cm2-G or less, preferably 5-18 kg/cm2-G. The [NH2]-rich low-order condensate of the present invention refers to the raw materials that are generally prepared in normal polyamide polymerization so that the total amount of NH2 groups contained in the monomer and salt is equal to the total amount of NH2 groups. However, in the present invention, the diamine component is added in large excess when preparing raw materials [N112]
The main focus is on actively producing low-order rich condensates. This means that the diamine component is charged in an excess of 03 to IO mol % relative to the total number of moles of the carboxylic acid component units and diamine component units of the monomers or salts as constituent components. The diamine component here refers to the return prime number 6.
-18 aliphatic γ-alkylene 7 diamine/, but it is preferable to add the diamine component constituting the present polyamide. The amount of the diamine component added must be in the range of 0.3 to 10 mol%, preferably 0.6 to 8 mol%. If the amount of addition (2) is less than 0.3 mol%, the conditions for increasing the degree of polymerization by melt extrusion become narrower, making stable operation impossible, which is not preferable. Moreover, if it exceeds 10 mol%, it becomes difficult to achieve a high degree of polymerization in a melt extruder, which is not preferable. The relative viscosity (ηr) of the low-order condensate of the present invention is 101-1.
6, preferably 1.01 to 1.
5, more preferably in the range of 1.01 to l4. If the relative viscosity is lower than 101, it may cause the composition ratio to fluctuate during the melt extrusion process to increase the degree of polymerization.
This is not preferable because the conversion to high m synthetic leather is insufficient. Furthermore, if the relative viscosity is greater than 1 or 6, the melt viscosity of the lower-order condensate becomes too high, causing discharge failure, or the lower-order condensate precipitates, causing discharge failure, which is not preferable. There are no particular limitations on the apparatus for producing the lower condensate of the present invention (any known device such as a batch reaction vessel or a 1- to 4-tank continuous reaction apparatus can be used). [ N112] By adding a dicarboxylic acid component to a rich low-order condensate and melt-extruding it, a stable highly polymerized polymer can be obtained very efficiently.As the dicarboxylic acid component, adipic acid, sepanonic acid, etc. aliphatic dicarboxylic acid or terephthalic acid,
Aromatic dicarboxylic acids such as isophthalic acid can be mentioned, but isophthalic acid and terephthalic acid are preferred, and terephthalic acid is particularly preferred. The amount of dicarboxylic acid added is the number of moles corresponding to the excess [N112] of the lower condensate, or [NI+2] -20x I O-'mol
/g. If the amount of dicarboxylic acid added is more than [NI+23] of the low-order condensate or less than [NI+2]-20XICM'■ol/g, it is not preferable because good pellets with a high degree of polymerization cannot be obtained. Further, according to the present invention, the presence of a phosphorus catalyst is essential to obtain pellets with a good degree of polymerization in the melt extrusion process, and the amount added is preferably 0.05 to 2 wt% based on the lower condensate. More preferably 0°1~12W

[%. If the amount added is less than 0.05 wt%, good pellets with a high degree of polymerization cannot be obtained, and if the amount added is more than 2 wt%, the effect will not be improved, which is not preferable. A specific example of a phosphorus compound is H3
P0A+1I3PO3, H3PO2, II 4 P 2
0v, Na11tPOa・21120, Na2HPOa
・12H20, N113P04-121120, Na1
12POa・1120, HatP207 bow 0H20, N
a 2 Ht P 20 ? -61+20,
N15P30+s, Call5P(011)2, C
a11sPO(ONa)2, Cs1sPO(OH)2,
Examples include Mn(II2PO2)2 and (C61+5O)3P. Preferably Hz P Oa, 1l
It is JP207. There are no particular restrictions on the method of adding the phosphorus compound, and methods such as when preparing a low-order condensate, or a method in which it is blended in advance with a low-order condensate and melt-extruded are simple and suitable. The polyamide resin obtained according to the invention is preferably blended with a modified polyolefin. Modified polyolefins include ethylene, propylene, butene-15pentene-1,4-methylpentene-1, isobutylene, I, 4-hexadiene, synclopentadiene, 215-flubornadiene, 5-ethylidenenorbornene, 5-ethyl-2゜5-norbornagene, 5
At least 1 selected from -(1-propenyl)-2-norbornene, butadiene, isoprene, and styrene.
The polyolefin obtained by radical polymerization of the olefin of The intermediate i-form component (hereinafter referred to as
This is a modified polyolefin obtained by introducing a functional group-containing component. Examples of functional group-containing components include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itafonic acid, crotonic acid, methylmaleic acid, methylfumaric acid, mesafonic acid,
Citraconic acid, glutafluoric acid and their carboxylic acid metal salts, methyl hydrogen maleate, methyl hydrogen itafunate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, °(meth)acrylic acid 2-ethylhexyl, hydroxy/ethyl (meth)acrylate, aminoethyl (meth)acrylate, dimethyl maleinoate, methyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endopinochlor [2,2,] -]]5-heptene 2-dicarboxylic acid, endopin claw 12゜2, I]-5-hebutene-
α,β-unsaturated carboxylic acid conductors such as 2,3-dicarboxylic anhydride, α,β-unsaturated carboxylic acids mentioned herein, their esters, their anhydrides, (meth)acrylic acid glyc/nor, Evoquin-containing unsaturated compounds such as (meth)acrylic glycol/nor ether and vinyl glycol norether, ammonia, methyl amine/, ethyl amine, etc.
Butylamine, pechinluamine, dode/luamine, oleylamine, stearylamine, chlorohexylamine, benzylamine, aniline, naphthylamine, trimethylamine, diethylamine, methylethiamine, dibutylamine, distearylamine, dinochloramine, ethylnochlorhexylamine 2min, methylanilino,
Phenylnaphthylamine, melamine, ethanolamine, 3-amino-1-propatol, noethanolamine, morpholine, α-amino-2-pyrrolidone, a-
Amino-ε-caprolactam, α-monomethylamino-ε
N-substituted amide compounds, N-substituted imide compounds, N-[ Examples include converted hydroxy/ethyl compounds. The method of introducing these functional group-containing components is not particularly limited, and methods such as mixing with the main component olefins and copolymerizing them, or grafting them into polyolefin using a radical initiator can be used. can. The introduction of the functional group-containing component (2) is usually 0.001 to 40 mol%, preferably 0.01 to 3 mol%, based on the entire modified polyolefin.
It is suitably within the range of 5 mol%. If the amount of the functional group-containing component is less than 0.001 mol%, the affinity between the modified polyolefin and the copolyamide will be insufficient, and 1IIIi
The impact imparting effect tends to be insufficient. On the other hand, if the amount of functional group-containing components exceeds 40 mol %, side reactions such as gelation tend to occur more easily. Specific examples of modified polyolefins particularly useful in the present invention include ethylene/(meth)acrylic acid copolymers, and some or all of the carboxylic acid moieties in these copolymers replaced with sodium, lithium, zinc, carunium, or potassium. etc., ethylene/methyl(meth)acrylate copolymer, ethylene/methyl(meth)acrylate copolymer, ethylene/ethyl(meth)acrylate-g-fihydromamamaleic acid copolymerg '' represents a graft. Hereinafter, ethylene/methyl(meth)acrylate g-maleic anhydride copolymer, ethylene/methyl(meth)acrylate copolymer, ethylene/ethyl acrylate-g-maleimide copolymer Polymer, ethyl//ethyl acrylate-g-phenylmaleimide copolymer and partially saponified products of these copolymers, ethylene/propylene di-g-anofomaleic acid copolymer, ethylene/phthene-g-maleic anhydride co-t1 copolymer, ethylene/propylene/1,4-1-xanoe/-g-maleic anhydride copolymer, ethylene/propylene/synchropentadiene-g-maleic anhydride copolymer, ethylene/propylene/2,5- Flubornane-g-maleic anhydride copolymer, ethylene/propylene-g-N-phenylmaleimide copolymer, ethylene/buteno-g-N-7-enylmaleimide copolymer, styrene/butanoene-g-maleic anhydride Examples include acid copolymers, styrene/maleino acid anhydride copolymers, etc. The blending amount of the modified polyolefin is 100% of the copolymerized polyamide.
It is 0 to 1 part by weight, preferably 5 to 90f! Within the range of quantitative parts. The blending amount is 1ootr
Exceeding this amount is not preferable because the molded product will lack heat resistance. It is preferable that a filler is further added to the modified polyolefin-containing polyamide according to the present invention. Fillers [C] include glass fibers or beads, talc, kaolin, wollastonite, mica, glue, alumina, diatomaceous earth, clay ceracola, red iron, graphite, titanium dioxide, zinc oxide, copper, stainless steel, etc. powder or plate-like inorganic compounds, other polymer fibers (carbon fibers), etc., and glass fibers are preferable. Particularly preferred glass fibers are glass tyrobuton strands, glass threads, etc. having a diameter of about 3 to 20 μm. The blending ratio of such filler is copolyamide]OO[!
0 to 10011 against Okibe! The amount should be in the range of 10 to 90 parts, preferably 5 to 901 parts, particularly preferably 10 to 90 parts. If the blending amount of the filler exceeds 100 parts by weight, the fluidity during melting will deteriorate, making it difficult to injection mold the molded product, and the appearance of the molded product will deteriorate, which is not preferable. There is no particular restriction on the method of blending the filler and modified polyolefin into the copolyamide of the present invention, and any known method can be used. A specific example of the blending method is a method in which a modified polyolefin and a filler are triblended into a pellet of polyamide, and this is melt-kneaded using a single screw or two-wheel screw extruder. In addition, the polyamide resin composition obtained by the present invention may contain other components such as pigments, dyes, heat resistant agents, catalysts,
Antioxidants, weathering agents, lubricants, crystal nucleating agents, antistatic agents, softeners, other polymers, and the like can be added. <Example> The present invention will be explained in more detail by showing examples below. In addition, various properties in Examples and Comparative Examples were measured by the following methods. l) Melting point (Tm) Using DSC (PERKIN-ELMER7 type),
The temperature at which the maximum value of the melting curve obtained by measuring 8 to 10 mg of the sample at a heating rate of 20° C./min was defined as Tm. 2) End group concentration of polyamide [11+12] Polyamide Ig was mixed with 100 ml of FSN/ethanol (50/
It was determined by dissolving 50 w in a mixed solvent and titrating it with a 175ON aqueous hydrochloric acid solution. 3) End group concentration of polyamide [C00II] Dissolve 0.5 g of polyamide in 50 ml of hot benol alcohol,
It was determined by titration with a methanol solution of 1/50 N-KOH. 4) Appearance of molded product The surface roughness, air bubbles, color tone, gloss, etc. of the molded product were observed. ○: Glossy and smooth surface. △・ The gloss is reduced, but the surface is smooth. ×: The surface is rough and has no luster. 4) Physical properties of the molded product were measured by the following method. Tensile strength: ASTM-D638 bending strength ASTM-D790 bending modulus
: ASTM-D790I zod impact strength
: ASTM-D256 Heat Distortion Temperature (HDT):
ASTM-D648 load 4.6 kgf/e Garden 2 Load Ig, 6 kgf/cm2 <Example>> Hexamethylene ammonium adipate (66 salt)9.
00kg, terephthalic acid 6,47kg. 64.5 wt% aqueous solution of hexamethylene diamine 8.4
1kg and 6.40kg of ion exchange water to 0.05m”
(5 mol% hexamethylene diamine was added in excess of the total number of moles of diamino component units and diamino component units) into a batch-type m-cooker, and after sufficient nitrogen substitution, the water vapor pressure was 17.5 kg/c. Heating was continued under a pressure of 2-G. After raising the temperature to 240°C over 3.5 hours with stirring, and maintaining the temperature at 240°C to 245°C for another 30 minutes to complete the reaction, a differential pressure of 17.0°C was applied from the bottom of the polymerization vessel. 5 kg
/c■2-(H) The lower condensate was discharged into water.The viscosity of this lower condensate was +)r=], ]5, the melting point was 299°C,
[C0OH = 5 2x I O-'mol
/g, [NI+2] = IO5x]
0-"mol/g, 53 x 10-'mo
l/g [)IH2] It was a low-order condensate of Li and Chi. After vacuum drying the obtained low-order condensate at 100°C for 24 hours, 43g of terephthalic acid was triblended with respect to 1 kg of the low-order condensate, and the mixture was heated at a temperature of 260°C to 335°C using a 30mmφ vented twin-screw extruder. Melt extrusion was carried out under the following conditions. A white pellet having a polymer viscosity ηr=2.90 and a polymer melting point of 300°C was obtained. For 100 parts by weight of this pellet, the length is 3 mm and the diameter is 13.
Tri-blend 11 parts of 65mm glass fiber nitride carbonate strut, and use a 30mmφ single-screw extruder to obtain a polymer with a melting point of +
Melt mixing was carried out at a temperature of 20°C. This mixture was molded using an injection molding machine to create a test piece. Table 1 shows the results of evaluating the obtained test piece.
Shown below. <Example 2> 7.21 kg of terephthalic acid, 8.51 kg of 64.5 wt% aqueous solution of hexamethylene diamide 7. Caprolactam 5.25 kg and ion exchange water 6.6
Charge 6 kg into a 0.05 m3 batch type pressure polymerization pot (
Hexamethylene diamine was charged in excess by 3 mol % based on the total number of moles of diamine component units and dicarboxylic acid component units), and after sufficient nitrogen substitution, the water vapor pressure was reduced to 15.
Heating was continued under a pressure of 0 kg/e 2-0. After raising the temperature to 225°C over 5 hours with stirring, the temperature was further increased to 225°C.
After allowing the reaction to proceed at ~232°C for 30 minutes, stirring was stopped and the pressure difference from the bottom of the polymerization vessel was 15. The lower condensate was extracted at 0 kg/ex2-G. The melting point of the obtained lower condensate is 3
02℃, r) r is 1.10, [C00II] = I
14 x l O-'mol/z, [Nl+2]
= + 43 x 10-'mol/g,
[HF1t]=29xlO−'嘗at/g CNl+
2] It was a rich, low-order condensate. This lower condensate 1
Tri-blend 24g of terephthalic acid per kg,
Melt extrusion, molding and molding were carried out by the method of Example 1, and evaluation was made. The results are shown in Table 1. <Example 3> 116.70 kg of terephthal, 3.61 kg of isophthalic acid, 64.5 kg of hexamethylene diamine
12.26 kg of W1% aqueous solution and ion exchange water5.
50 kg was charged into a 0.05 m'' batch type polymerization pot (5 mol% hexamethylene diamine was charged in excess of the total number of moles of diamine component units and nocarboxylic Mff min units), and after sufficient nitrogen substitution, the water vapor pressure 17.
Heating was continued under a pressure of 5 kg/c 2-G. The temperature was raised to 230"C over 5 hours with stirring, and then maintained at 235°C to 240°C for an additional 30 minutes to complete the reaction. The sub-condensate was discharged into water. The viscosity of this low-order condensate is ηr=1.15, and the melting point is 318.
It was ℃. The obtained lower condensate was heated at 100'C for 24 h.
After vacuum drying, 43 g of terephthalic acid was triblended with respect to 1 kg of the low-order condensate, and the mixture was melt-extruded, compounded, and molded using the method of Example 1, and evaluated. The results are shown in Table 1. Examples 4 to 10> Table 1 shows the results of evaluations performed by changing the raw materials and charging amounts, the amount of terephthalic acid added, and the amount of modified polyolefin and glass fiber blended according to the method of Example 1. Comparative Example 1> 1k15.89kg, 66ji
i+o, 00 kg1 A lower condensate was prepared by the method of Example 1 using 6.37 kg of 64.5 wt% aqueous fi of hexamethylene diamine and 6.36 kg of ion-exchanged water. The viscosity of this low-order condensate is ηr=1.16, the melting point is 296°C, [C0OR] = 82 x 1O−
5mol/g, [N112] = 63 x 10-
'mol/g7' J51ri, 19XIO-'■of
/g [CQOI+] It was a rich low-order condensate. The obtained low-order condensate was vacuum-dried at 100"C and 24fir, and then heated to 260℃ using a 30mmφ vented twin-screw extruder.
Melt extrusion was carried out at a temperature of 320"C. Foaming was significant and pelletization was not possible. <Comparative Example 2> 5.30 kg of terephthalic acid, 64.5 wt% aqueous solution of hexamethylene diamine f15. 73 kg, 66
11.00 kg of salt and 6.36 kg of ion exchange water
．． 05m" batch type polymerization reactor, and after purging with nitrogen gas, heating was continued under pressure of water vapor pressure of 1.7.5 kg/e2-G. After reaching 245°C, depressurization was started. ,
Furthermore, it can be heated up to a maximum humidity of 315℃. Next, maintain this maximum temperature and 100 μg after pressure release is completed.
Polymerization was completed under reduced pressure of 5 to 10 minutes. When this polymer was discharged, it foamed significantly due to thermal decomposition, and was an opaque white polymer that could hardly be cut. <Effects of the Invention> The polyamide resin obtained by the present invention has high rigidity and heat resistance that can withstand use in high-temperature atmospheres, is inexpensive, and has good fluidity, so it can be used for thin-walled molding of connectors, coil bobbins, etc. It is treated as a product material.

Claims (1)

[Claims] Repetitive components of the following (I) to (III) (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) ▲ Numerical formulas, There are chemical formulas, tables, etc.▼ (In the formula, R is an aliphatic group with 6 to 18 carbon atoms, and R' is an aliphatic group with 4 carbon atoms.
~18 aliphatic groups, or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and n represents an integer from 5 to 18. ) and containing (I) and/or (II) as essential components, (I)
A diamine component of 0.3 to 10 mol% is added in excess to the total number of moles of the monomer component units constituting ~(III), 150°C to 300°C, 20kg/cm^2-G
Under the following conditions, the relative viscosity (ηr) of 1% sulfuric acid solution at 25°C satisfies 1.01 to 1.6 [NH_2]
1. A method for producing a polyamide resin, which comprises producing a rich low-order condensate, and adding an insufficient dicarboxylic acid component when increasing the degree of polymerization of the low-order condensate using a melt extruder.