JP3367276B2 - Method for producing polyamide resin - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyamide resin, and more particularly to a method for producing a heat-resistant polyamide resin suitable for automobile parts and electric / electronic parts.

[0002]

2. Description of the Related Art Polyamides have been widely used in the fields of automobiles, electric and electronic fields, etc. by utilizing their excellent properties as engineering plastics.

Conventionally, nylon 6 and nylon 66 reinforced with glass fibers have been used for these molded articles (Japanese Patent Laid-Open No. 59-161461), but the temperature rise in the engine room of automobiles due to recent technological innovations and With the progress of microelectronics, there has been a demand for materials for molded products that can withstand use in a higher temperature atmosphere. However, the melting points (Tm) of nylon 6 and nylon 66 are 220 ° C. and 260 ° C., respectively, and even when reinforced with glass fiber, the limits of the heat distortion temperature are only the melting points.

Recently, a number of terephthalic acid- and isophthalic acid-containing copolyamide resin compositions or their glass-reinforced products have been proposed as copolyamide resin compositions that can withstand use under these high-temperature atmospheres (Japanese Patent Laid-open No. Sho 61-187). 5
9-161428, JP-A-59-155426, JP-A-59-53536, JP-A-62-1.
56130). Further, as a method for producing these, a method of polymerizing using a batch type polymerization apparatus (Japanese Patent Laid-Open No. Sho 4)
8-79297) or a method using a continuous polymerization apparatus (JP-A-49-20758), or a method of combining melt polymerization and solid-state polymerization (JP-A-4-502231). ) Or oligomer polymerization and a method of increasing the degree of melt polymerization by means of an extruder (Japanese Patent Laid-Open No. Hei.
Two-process polymerization methods such as JP-A-31070) have been proposed.

[0005]

However, the method of polymerizing the primary condensate and then increasing the degree of polymerization by melting often fails to obtain a sufficient degree of polymerization, or the primary condensate is solidified at the inlet of the melting machine. It was difficult to stably obtain a polymer having a high degree of polymerization, because phenomena such as binding and spouting from the vent portion occurred. Further, the method of solid-phase polymerization after polymerizing the primary condensate also has a problem that the reaction product having a high degree of polymerization is fixed and the reaction cannot be performed uniformly.

[0006]

As a result of studies to solve such problems, the inventors have paid attention to the balance of terminal group concentration of the primary condensate and have completed the present invention. . That is, the present invention provides “the following structural formula (I)

[Chemical 5] A method for producing a polyamide resin having a copolymerized structure containing a structural unit represented by: 150 to 35 in a polymerization tank by adding an end capping agent of an organic acid and / or an organic base.
After the oligomerization polymerization was carried out under the condition of 0 ° C., the oligomer obtained from the polymerization tank was discharged while being in contact with a water stream and continuously pulverized to produce a primary condensate having the following characteristics,
A method for producing a polyamide resin, which comprises increasing the degree of polymerization of a primary condensate. Characteristic of primary condensate Difference in concentration between terminal carboxyl group and amino group is ± 10 ×
10 ^-5 mol / g range Relative viscosity according to JIS-K6810 is 1.04 to 2.5
It consists of "0".

The present invention will be described in detail below.

The hexamethylene terephthalamide unit (hereinafter referred to as 6T) represented by the structural formula (I) used in the present invention has a function of imparting rigidity and heat resistance to the obtained polyamide resin. is there. Further, in terms of heat resistance of the obtained resin, the melting point of the obtained polyamide resin is preferably 230 to 340 ° C, more preferably 260 to 340 ° C. If the melting point is lower than 230 ° C., it is difficult to obtain heat resistance. If the melting point is higher than 340 ° C., a high temperature is required for processing the resin, which causes problems such as heat deterioration, which is not preferable.

In addition to the 6T component, the polyamide resin of the present invention preferably further has one or more structural units selected from the following structural formulas (II) to (IV).

[Chemical 6] (Hexamethylene adipamide unit (hereinafter referred to as 66))

[Chemical 7] (Hexamethylene isophthalamide unit (hereinafter referred to as 6I))

[Chemical 8] (Caproamide unit (hereinafter referred to as 6))

The above 6T-containing copolyamide is 6T / 6I.
The copolymerization ratio of is 45/55 to 80/20, preferably 55/45 to 80/20, more preferably 60 /
It is in the range of 40 to 75/25. Further, the copolymerization ratio of 6T / 66 is 20/80 to 80/20, preferably 30/70 to 70/30, and more preferably 30/70 to 60 by weight.
The range is 60/40. The copolymerization ratio of 6T / 6 is 40/60 to 90/10 by weight, preferably 55/4.
5 to 85/15, more preferably 60/40 to 80/2
The range is 0. The copolymerization ratio of these 6T-containing copolyamides is a crystalline copolyamide having a polymer melting point in the range of approximately 230 to 340 ° C. 6T / 6I, 6T
When the copolymerization ratios of / 66 and 6T / 6 are less than 45/55, 20/80, and 40/60 by weight, respectively, the polymer melting point is lowered when the 6T copolymerization amount is smaller, so that the heat resistance such as heat distortion temperature is low. Is reduced, which is not preferable. Also, 6T
If the 6T, 6T / 66, and 6T / 6 copolymerization ratios are higher than 80/20, 80/20, and 90/10, respectively, the 6T copolymerization amount will increase the polymer melting point and improve the heat resistance. Becomes higher and the polymer is more susceptible to thermal decomposition.

In the present invention, the degree of polymerization of the obtained polyamide resin is not particularly limited, and is usually JIS-K6.
810 (1% sulfuric acid solution 25 ° C.) having a relative viscosity (ηr) of 1.8 to 5.0 can be arbitrarily used.

In the present invention, the starting material for the primary condensate to be first synthesized is generally a monomer such as a cyclic amide, an aminocarboxylic acid, a dicarboxylic acid or a diamine,
Alternatively, a salt composed of dicarboxylic acid and diamine is used. Further, these raw materials can be used as a solution with water or the like. In particular, as a raw material for providing 6T units used in the present invention, terephthalic acid and 1,6-diaminohexane, or a salt of both are generally preferably used.

The oligomerization polymerization reaction for synthesizing the primary condensate of the present invention comprises a raw material giving 6T units and 6 units, 6 units.
One or more kinds selected from raw materials giving 6 units and 6 I units are charged into a pressure type polymerization tank, and stirred at 150 to 350 ° C.
It is obtained by heating to. In order to increase the efficiency of the polymerization tank, the raw material form is 50% or more of the raw material mixed aqueous solution,
It is preferable to concentrate the mixture to 65% or more.
In addition, the method of charging the raw materials is not particularly limited, and it is possible to batch-charge before heating or to separately supply after heating.

There is no particular limitation on the pressure type polymerization tank for the oligomerization polymerization, and a batch type reaction apparatus or a one to three tank type continuous reaction apparatus can be used. The reaction temperature must be 150 to 350 ° C, preferably 180 to 340 ° C, more preferably 190 ° C to 34 ° C.
It is 0 ° C. When the reaction temperature is lower than 150 ° C, the reaction time becomes long, which is not preferable. Further, if the reaction temperature is higher than 350 ° C., foaming or gel-like foreign matter is significantly generated due to thermal decomposition of the primary condensate, which is not preferable.

The pressure for the oligomerization polymerization of the present invention is usually 0.
To 100 kg / cm ² -G (0 to 9800 kPa), preferably ^{2 to} 70 kg / cm ² -G (196 to 6860 kPa), more preferably 5 to 60 kg / cm ² -G (490 to 5880 kPa).
It is operated to keep it at.

In the oligomerization polymerization, an organic acid and / or organic base end-capping agent is added. The organic acid is preferably benzoic acid, stearic acid or acetic acid, more preferably acetic acid. Also, the organic base is
From the point of view of melting point and water absorption of polyamide
Eighteen aliphatic diamines are used. Specific examples thereof include 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane and 1,5-diamino-2.
-Methylpentane, 1,7-diaminoheptane, 1,8
-Diaminooctane, 1,9-diaminononane, 1,1
0-diaminodecane, 1,11-diaminoundecane,
1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-
Diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, etc., among which those having 6 and 12 carbon atoms are preferable, and 1,6-diaminohexane is more preferable. . Those selected from these organic acid components and organic bases may be used alone or in admixture of two or more.

A phosphorus-based catalyst may be used in the production of the polyamide of the present invention. The phosphorus-based catalyst has a catalytic function for the polymerization reaction, and is specifically phosphoric acid, phosphate, hypophosphite, acidic phosphate, phosphate, or phosphite. Examples of hypophosphite include sodium hypophosphite, magnesium hypophosphite,
Examples thereof include potassium hypophosphite, calcium hypophosphite, vanadium hypophosphite, manganese hypophosphite, nickel hypophosphite and cobalt hypophosphite. Examples of acidic phosphates include monomethyl phosphates, dimethyl phosphates, monoethyl phosphates, diethyl phosphates, propyl phosphates, isopropyl phosphates, dipropyl phosphates,
Examples thereof include diisopropyl phosphate ester, butyl phosphate ester, isobutyl phosphate ester, dibutyl phosphate ester, diisobutyl phosphate ester, monophenyl phosphate ester, diphenyl phosphate ester and the like. Examples of phosphoric acid esters include trimethyl phosphate,
Triethylphosphoric acid, tri-n-propylphosphoric acid, tri-
i-propylphosphoric acid, tri-n-butylphosphoric acid, tri-
i-Butylphosphoric acid, triphenylphosphoric acid, tri-n-hexylphosphoric acid, tri-n-octylphosphoric acid, tri (2-
Examples include ethylhexyl) phosphoric acid and tridecylphosphoric acid. Among these, hypophosphite is preferable, and sodium hypophosphite is particularly preferable. When the phosphorus-based catalyst is added, the addition amount thereof is 0.001 to 5 parts by weight, preferably 0.01 to 1 part by weight, based on 100 parts by weight of the polyamide. Further, the addition time may be any time from the time of charging the raw materials to the completion of the oligomerization polymerization step, or may be dividedly charged.
Further, it can be additionally added when the degree of polymerization is increased.

As a method of discharging the oligomer from the polymerization tank, it is preferable to discharge it under a pressure of 1 to 100 kg / cm ² -G (98 to 9800 kPa), and the pressure during the polymerization reaction can be used as it is, or N ₂ can be used. It is suitable to pressurize to an arbitrary pressure with an inert gas such as and then discharge. It is preferable to supply water or steam to the polymerization tank and to discharge under pressure of steam. It is also possible to use a metering pump such as a gear pump to adjust the discharge rate.

The oligomer discharged from the polymerization tank is continuously discharged to a steel belt, a cooling drum, etc., and then water is directly sprayed with a shower nozzle, a spray gun, etc. to cool it, and then it is put into a crusher. Pulverize to obtain a primary condensate. .

As the crusher, a model capable of crushing in a short time is suitable, and a rotary crusher such as a pin type, a blade type or a hammer type can be arbitrarily used. The pulverization temperature is 250 ° C. or lower, preferably 200 ° C. or lower, and if it exceeds 250 ° C., there is a risk of fusion of the primary condensate inside the pulverizer. The crushed particle size is 20 mm
Hereafter, it is preferably 15 mm or less, but fine powder of 0.2 mm or less is not preferable for handling. Furthermore, the primary condensate after crushing can be immediately blown into a storage silo or the like using a blower blower or a cyclone.

The difference in concentration between the carboxyl group (-COOH) and the amino group (-NH ₂ ) is within the range of ± 10 × 10 ^-5 mol / g, preferably within the range of ± 8 × 10 ^-5 mol / g. is there. If the difference in concentration is out of the range of ± 10 × 10 ⁻⁵ mol / g, a sufficient degree of polymerization cannot be obtained at the time of increasing the degree of polymerization by melting.

JIS-K6810 of the primary condensate of the present invention
Relative viscosity (ηr) at (25 ° C of 1% sulfuric acid solution)
Is required to be 1.04 to 2.50, preferably 1.08 to 2.30, and more preferably 1.08.
˜2.10. If the relative viscosity is less than 1.04, the reaction time in the high polymerization degree step becomes long and thermal decomposition occurs, which is not preferable. On the other hand, if the relative viscosity is larger than 2.50, the melt viscosity of the primary condensate becomes too high and ejection failure occurs, which is not preferable.

As the method for increasing the degree of polymerization of the primary condensate of the present invention, a method using a melting machine, a method of solid phase polymerization, a method of using a melting machine or a solid phase polymerization machine in combination, and the like can be used. When using a melting machine, the melting temperature is preferably in the range of 10 to 70 ° C. higher than the melting point of the primary condensate. When a primary condensate having a high terephthalic acid component and a high melting point is used, the upper limit temperature is set to 37 to prevent thermal decomposition or thermal deterioration of the polymer.
The temperature is preferably 0 ° C or lower. Extruder as a melting machine,
A kneader can be used, but a twin-screw extruder and a twin-screw kneader are preferable.

The residence time in the melting machine is not particularly limited, but it is preferably 20 seconds or longer, particularly preferably 30 seconds or longer. If the residence time is short, the degree of polymerization cannot be effectively increased, which is not preferable. It is also effective to connect two or more melting machines in series in order to lengthen the residence time and promote a high degree of polymerization. Further, the polymer having a high degree of polymerization can be subjected to solid phase polymerization as necessary to further increase the degree of polymerization.

As a method for solid-phase polymerization of the primary condensate of the present invention, a method of applying pressure or normal pressure in the presence of an inert gas,
Alternatively, a method under reduced pressure, or a combination thereof may be used. The solid-state polymerization temperature needs to be 130 ° C. to the polymer melting point. Preferably 1
70 ° C. to melting point −10 ° C., more preferably 200 ° C. to melting point −15 ° C. If the solid phase polymerization temperature is lower than 130 ° C., the reaction rate becomes slow, which is not preferable. As the solid phase polymerization time, any time until the relative viscosity of the polyamide used for a usual molded product is reached can be selected. The polymerization apparatus of the present invention is not particularly limited, and any known method can be used. Specific examples of the solid-state polymerization apparatus include a kneader, a twin-screw paddle type, a tower type, a rotating drum type, and a double-cone type solid-state polymerization apparatus.

A filler can be added to the polyamide resin obtained in the present invention. The filler is glass beads, talc, kaolin, wollastonite, mica,
Silica, alumina, diatomaceous earth, clay, gypsum, red iron oxide, graphite, titanium dioxide, zinc oxide, copper,
Powdery or plate-like inorganic compounds such as stainless steel, other polymer fibers (carbon fibers), etc. are preferable, and glass fibers are preferable. As the glass fibers, glass fibers are generally used as a reinforcing agent for thermoplastic resins and thermosetting resins, but particularly preferred are glass rovings and glass chopped strands made from continuous long fiber strands having a diameter of about 3 to 20 μm. , Glass thread, etc. The blending ratio of the filler is 0 to 100 parts by weight of the polyamide.
It is necessary to be in the range of 200 parts by weight, preferably more than 0 and in the range of 150 parts by weight, particularly preferably 10 parts.
~ 100 parts by weight. When the blending ratio of the filler exceeds 200 parts by weight, the fluidity at the time of melting deteriorates, and it becomes difficult to injection-mold a thin-walled molded product, and the appearance of the molded product deteriorates, which is not preferable.

There is no particular limitation on the method of adding the filler to the crystalline polyamide of the present invention, and any known method can be used. Specific examples of the compounding method include a method of dry blending a filler with crystalline copolyamide pellets and melt-kneading the mixture with a single-screw extruder or a twin-screw extruder. When the degree of polymerization is increased with an extruder, a method of side-feeding in the middle of the extruder is preferable because of high production efficiency.

In the present invention, when the primary condensate is produced,
Melt high polymerization degree, solid phase polymerization, compound or molding process, etc., if necessary, catalyst, heat resistance stabilizer, weather resistance stabilizer, plasticizer, mold release agent, lubricant, crystal nucleating agent, pigment, dye, etc. A polymer or the like can be added.

These additives include heat-resistant stabilizers (hindered phenol-based, hydroquinone-based, phosphite-based and substitution products thereof, copper iodide, potassium iodide, etc.), weather-resistant stabilizers (resorcinol-based, salicylate). Type, benzotriazole type, benzophenone type, hindered amine type, etc., mold release agent and lubricant (montanic acid and its salt, its ester, its half ester, stearyl alcohol, stearamide and polyethylene wax etc.), pigment (cadmium sulfide, phthalocyanine type) Compounds, carbon black, etc.), and dyes (such as nigrosine), other polymers (other polyamides, polyesters, polycarbonates, polyphenylene ethers, polycarbonates, polyphenylene ethers, polyphenylene sulfides, Crystal polymers, polyether sulfone, ABS resin, SAN resin, polystyrene, acrylic resins, polyethylene, polypropylene, ethylene, alpha-
Olefin copolymer, ionomer resin, SBS, SE
BS, etc.).

From the viewpoint of productivity, the additive compound is
It is more preferable to perform the polymerization at the same time or continuously in the melter.

The addition of an antioxidant is effective for improving the color tone of the polyamide, and the addition of sodium hypophosphite and a hindered phenol type antioxidant is particularly preferable. Sodium hypophosphite is also effective in promoting a high degree of polymerization of the primary condensate.

The polyamide of the present invention includes switches, microminiature slide switches, DIP switches, switch housings, lamp sockets, binding bands, connectors, connector housings, connector shells, IC sockets,
Coil bobbins, bobbin covers, relays, relay boxes, condenser cases, motor internal parts, small motor cases, gear cams, dancing pulleys, spacers, insulators, fasteners, buckles,
Wire clips, bicycle wheels, casters, helmets, terminal blocks, power tool housings, starter insulation parts, spoilers, canisters, radiator tanks, chamber tanks, reservoir tanks, fuse boxes, air cleaner cases, air conditioner fans,
Typical examples include terminal housings, wheel covers, intake and exhaust pipes, bearing retainers, cylinder head covers, intake manifolds, water pipe impellers, clutch releases, speaker diaphragms, heat-resistant containers, microwave oven parts, rice cooker parts, printer ribbon guides, etc. Electric / electronic related parts, automobile / vehicle related parts,
It is useful for home appliances / office electrical appliances parts, computer related parts, facsimile / copier related parts, machine related parts, and other various applications.

[0033]

The present invention will be described in more detail with reference to the following examples. The properties in the examples and comparative examples were measured by the following methods. 1) Melting point (Tm) Using DSC (PERKIN-ELMER7 type), samples 8 to 10
The temperature showing the maximum value of the melting curve obtained by measuring mg at a temperature rising rate of 20 ° C./min was defined as Tm. 2) Relative viscosity (ηr) According to JIS K6810, 1 g of a sample was dissolved in 100 ml of 98% concentrated sulfuric acid, and the relative viscosity at 25 ° C was measured.

3) YI value Measured according to JIS K7103. The larger the value, the larger the yellow change. 4) Terminal amino group [-NH ₂ ] concentration sample 1 g was added to phenol / ethanol solution 100 ml.
And was titrated with 0.02N hydrochloric acid aqueous solution.

5) 1 g of a sample having a terminal carboxyl group [-COOH] concentration was dissolved by heating in 100 ml of benzyl alcohol, and 0.02 N potassium hydroxide (ethanol solution) was added.
Titrated with. 6) The physical properties of the molded product were measured by the following methods. Tensile strength: ASTM-D638 Bending strength: ASTM-D790 Bending elastic modulus: ASTM-D790

<Example 1> 15.0 kg of hexamethylene ammonium adipate (66 salt), 10.0 k salt of terephthalic acid and hexamethylene diamine (6T salt)
g, 12 g of sodium hypophosphite, 57 g of benzoic acid and 10.0 kg of ion-exchanged water were placed in a 0.1 m ³ batch type reaction tank, and after sufficiently replacing with nitrogen, the steam pressure was 17.5 kg.
Heating was continued under a pressure of / cm ² -G. The temperature was raised to 285 ° C. over 3.5 hours with stirring to complete the reaction. The oligomer was discharged from the lower part of the reaction tank into the atmosphere onto a steel belt having a length of 8 m and a width of 0.5 m at a rate of 50 kg / h. At this time, a spray gun was used to irradiate the oligomer with water at a rate of 30 kg / h. The primary condensate from the steel belt was continuously supplied to a DKA06 type rotary hammer crusher manufactured by Hosokawa Micro Co., Ltd. to obtain a primary condensate composed of white powder having an average particle diameter of 1 mm. Relative viscosity ηr of the obtained primary condensate
= 1.42, the melting point was 284 ° C. After vacuum drying this primary condensate at 100 ° C. for 24 hours, a high degree of polymerization by melt extrusion under a temperature condition of 260 ° C. to 335 ° C. with a 30 mmφ bent type (vacuum degree = −700 to −740 mmHg) twin screw extruder. Was made. As a result, the polymer relative viscosity η
A polyamide resin composed of white pellets having r = 2.65 and a polymer melting point of 282 ° C. was obtained.

Length 3 per 100 parts by weight of this pellet
mm Glass fiber chopped strand 5 with a diameter of 13 μm
0 parts by weight were dry blended, and melt-mixed at a temperature of polymer melting point + 20 ° C. with a 30 mmφ single screw extruder. This mixture was molded by an injection molding machine to prepare a test piece.
Table 1 shows the results of evaluation of the obtained test pieces.

<Example 2> 10.6 kg of 85% by weight ε-caprolactam aqueous solution, 21.0 kg of a salt (6T salt) consisting of terephthalic acid and hexamethylenediamine, 20 g of sodium hypophosphite, 38 g of benzoic acid and ion-exchanged water. 9.0 kg was charged into a 0.1 m ³ batch-type reaction tank, and after sufficient nitrogen substitution, heating was continued under a steam pressure of 40 kg / cm ² -G. After the temperature was raised to 270 ° C. over 2.5 hours with stirring, the ion-exchanged water heated to 240 ° C. was fed to the polymerization tank at a rate of 2 l / h with a metering pump, and further held at 275 ° C. for 1 hour to react. Was completed. At this time, water was emitted to the oligomer at a rate of 40 kg / h using a shower nozzle. This oligomer was continuously supplied to a grinder UG280 of Horai Co., Ltd. to obtain a primary condensate composed of white powder having an average particle diameter of 2 mm. The obtained primary condensate had a relative viscosity ηr = 1.53 and a melting point of 296 ° C. After drying this primary condensate at 100 ° C. for 24 hours, the polymerization degree was increased by melt extrusion in the same manner as in Example 1, molding was performed by a compound and an injection molding machine, and a test piece was prepared and evaluated. The results are shown in Table 1.

Example 3 Hexamethylene ammonium adipate (66 salt) 15.0 kg, terephthalic acid and hexamethylene diamine salt (6T salt) 15.0 kg, sodium hypophosphite 45 g, 65 wt% hexamethylene diamine aqueous solution 394 g, 99% by weight of acetic acid 67 g and ion-exchanged water 6.0 kg were charged into a 0.1 m ³ batch type polymerization tank, and after sufficiently purging with nitrogen, steam pressure was 40 kg / cm ^2.
Heating continued under pressure of -G. 260 with stirring for 3 hours
After the temperature was raised to ℃, the reaction was completed by holding it at 275 ℃ for 2 hours, and then discharge and pulverization were carried out under the same conditions as in Example 1. As a result, a primary condensate of white powder having an average particle size of 1 mm was obtained. Relative viscosity ηr of the obtained primary condensate
= 1.43, the melting point was 293 ° C. The obtained primary condensate was vacuum-dried at 100 ° C. for 24 hours, and then subjected to high polymerization degree by melt extrusion by the method of Example 1, molded by a compound and an injection molding machine, and a test piece was prepared and evaluated. The results are shown in Table 1.

Comparative Example 1 A high degree of polymerization was performed after polymerization of the primary condensate in the same manner as in Example 1 except that benzoic acid was not used. However, the melt abnormally thickened and spouted from the vent portion. The results are shown in Table 1.

Comparative Example 2 A high degree of polymerization was carried out after polymerization of the primary condensate in the same manner as in Example 3 except that the aqueous solution of 65 wt% hexamethylenediamine was 788 g. Erupted from the department. The results are shown in Table 1.

<Comparative Example 3> A primary condensation product was obtained in the same manner as in Example 1 except that 226 g of benzoic acid was used, and then the degree of polymerization was increased, but a sufficient degree of polymerization was not obtained. The highly polymerized pellets were colored yellow. Molded by compound and injection molding machine, test pieces were prepared and evaluated. The mechanical strength of the molded piece decreased. The results are shown in Table 1.

[0043]

[Table 1]

[0044]

The productivity of the terephthalic acid component-containing polyamide is improved by adding the terminal blocking agent of the present invention and adopting the manufacturing method of controlling the concentration balance of the terminal groups.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 69/00-69/50

Claims (6)

(57) [Claims] 1. The following structural formula (I): A method for producing a polyamide resin having a copolymerized structure containing a structural unit represented by: 150 to 35 in a polymerization tank by adding an end capping agent of an organic acid and / or an organic base.
Oligomerization polymerization is performed under the condition of 0 ° C., the oligomer obtained from the polymerization tank is discharged while contacting with a water stream and continuously pulverized to produce a primary condensate having the following characteristics, and then the primary condensate is A method for producing a polyamide resin, which comprises increasing the degree of polymerization. Characteristic of primary condensate Difference in concentration between terminal carboxyl group and amino group is ± 10 ×
10 ^-5 mol / g range Relative viscosity according to JIS-K6810 is 1.04 to 2.5
0 2. The melting point of the polyamide resin is 230 to 340.
The method for producing a polyamide resin according to claim 1, wherein the temperature is in the range of ° C. 3. The method for producing a polyamide resin according to claim 1, wherein the polyamide resin further has one or more kinds of structural units selected from the following structural formulas (II) to (IV). [Chemical 2] [Chemical 3] [Chemical 4] 4. The polyamide resin copolymerization ratio is (I) / (II) = 45 / 55-80 / 20, (I) / by weight.
(III) = 20/80 to 80/20 or (I) / (I
V) = 40 / 60-90 / 10, The manufacturing method of the polyamide resin of Claim 3 characterized by the above-mentioned. 5. The method for producing a polyamide resin according to any one of claims 1 to 4, wherein the organic acid as the end-capping agent is at least one selected from benzoic acid, stearic acid and acetic acid. 6. An organic base as a terminal blocking agent has 4 to 1 carbon atoms.
8. The method for producing a polyamide resin according to claim 1, wherein the method is one or more selected from aliphatic diamines of No. 8.