JP2000063512A - Copolyamide and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolyamide with excellent optical and mechanical properties, and to provide a method for producing the copolyamide. SOLUTION: This copolyamide is such one containing (A) dicarboxylic acid unit with 5-100 wt.% of the dicarboxylic acid consisting of 6-22C branched saturated dicarboxylic acid, (B) diamine unit, and (C) aliphatic polyamide- forming unit; wherein the unit C accounts for 75-99.9 wt.% of this copolyamide. This copolyamide is obtained by producing a prepolymer of 800-5,000 in number- average molecular weight in the 1st stage polymerization followed by bringing the number-average molecular weight to 7,000-50,000 in the 2nd stage polymerization.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyamide copolymer containing a specific dicarboxylic acid as a component and a method for producing the same. More specifically, it relates to a polyamide copolymer having a branched saturated dicarboxylic acid having 6 to 22 carbon atoms as an essential component as an essential component and having excellent optical properties and mechanical properties, and a method for producing the same.

2. Description of the Related Art Generally, polyamide is excellent in rigidity, abrasion resistance, heat resistance, oil resistance, solvent resistance, gas barrier property, and the like, so that it is used for fibers, packaging films, automobile parts, and electrical / electrical materials.
It is used for electronic parts. In recent years, with the diversification of applications, there is a demand for polyamides that have good optical properties such as transparency and gloss in applications such as fibers, monofilaments, films, and molded products without degrading practical mechanical properties. Has been.

[0002] As a method for obtaining nylon having excellent transparency and glossiness (hereinafter sometimes referred to as "polyamide"), a method of suppressing crystallization of polyamide is known. For example, polyamide resin handbook (edited by Osamu Fukumoto, published by Nikkan Kogyo Shimbun, pp. 288-289 (198).
In 8)), a polyamide or polyamide copolymer having a low crystallinity or a low crystallization rate using a specific monomer is described as transparent nylon.

In addition, J. Appl. Polym. Sci., Vol.6
2, No. 13, 2237-2245 (1996), it is reported that a copolymer composed of nylon 6, nylon 66 and / or nylon 12 becomes a transparent nylon in a specific composition ratio. Further, in JP-A-5-310923, a polyamide copolymer made of nylon 6 / 6N (caprolactam, hexamethylenediamine (1,6-diaminohexane) and 2,6-naphthalenedicarboxylic acid as a transparent polyamide is used. ) Is disclosed.

[0004]

Nylon, which is said to have the above-mentioned transparency, has a gradual decrease in transparency during actual use, or a good transparency but a poor glossiness. There was a problem that mechanical properties and thermal properties were not so high. For example, a copolymer of nylon 6, nylon 66, and / or nylon 12 which is said to have transparency is essentially crystalline, so even if it is transparent immediately after its production, it gradually crystallizes during use. It is known that the transparency is reduced and the transparency is reduced. Moreover, the glossiness and mechanical properties are not so high.

Nylon 6 / 6N has transparency immediately after production and has good mechanical properties, but has crystallinity because a change in elastic modulus due to crystals is observed in dynamic solid viscoelasticity measurement. I understand. In fact, there were problems that the transparency gradually decreased during use and the gloss was not so good. Therefore, a polyamide having both good transparency and gloss and practical mechanical strength has been demanded.

An object of the present invention is to provide a polyamide copolymer having good optical properties such as transparency and gloss and mechanical properties, and a process for producing the same.

[0007]

Means for Solving the Problems The present inventors have studied the relationship between the molecular structure of polyamide and the optical and mechanical properties, and as a result, have used a dicarboxylic acid having a branch as a constituent unit of polyamide, and It was found that the polyamide copolymer of the present invention can be obtained by using polyamides as copolymers.

That is, the first aspect of the present invention is (A)
A unit composed of a dicarboxylic acid in which 5 to 100% by weight in the dicarboxylic acid is a branched saturated dicarboxylic acid having 6 to 22 carbon atoms, a unit composed of (B) diamine, and a unit forming (C) an aliphatic polyamide. A polyamide copolymer containing the polyamide copolymer, wherein the unit of forming the aliphatic polyamide (C) is 75 to 99.9% by weight of the polyamide copolymer.

In the second invention, a prepolymer of the polyamide copolymer having a number average molecular weight of 800 to 5,000 is produced by the first stage polymerization, and a high molecular weight is obtained by the second stage polymerization. It is a method for producing a polyamide copolymer by producing a polyamide copolymer having an average molecular weight of 7,000 to 50,000.

A dicarboxylic acid which is a branched saturated dicarboxylic acid having 6 to 22 carbon atoms is used as the dicarboxylic acid, and
It is a feature of the present invention that a polyamide copolymer obtained by copolymerizing polyamides has good optical properties and mechanical strength. Although the reason why the polyamide copolymer of the present invention has good optical properties and mechanical strength is not clear, the branching of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms inhibits the hydrogen bond formation of the polyamide copolymer. It is presumed that, unless the crystallization speed is slowed down and the device is used in a normal state, crystallization hardly progresses and good optical properties are maintained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. The branched saturated dicarboxylic acid having 6 to 22 carbon atoms used in the present invention can be obtained by a known method, for example, oxidation of cyclohexane, hydrolysis of 7-cyanoundecanoic acid, hydroformylation of unsaturated carboxylic acid such as oleic acid, Koch ( Ko
ch) -carboxylation, Reppe-carboxylation and the like. 6-carbon
Specific examples of the branched saturated dicarboxylic acid of 22 include 1,
6-decanedicarboxylic acid (sometimes referred to as "2-butyloctanedioic acid"), 2,3-dibutylbutanedioic acid, 8-ethyloctadecanedioic acid, 8,1
Examples thereof include 3-dimethyleicosadionic acid, 2-octylundecanedioic acid, and 2-nonyldecanedioic acid. These may be used alone or in appropriate combination of two or more. Among these, 1,6-decanedicarboxylic acid is preferably used from the viewpoint of polymerization reactivity. The amount of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms is 5 to 100 of the dicarboxylic acid used in the present invention.
%, Preferably 30 to 100% by weight, more preferably 50 to 100% by weight. If the amount used is less than 5% by weight, the transparency and glossiness will decrease, which is not preferable.

As the dicarboxylic acid other than the branched saturated dicarboxylic acid having 6 to 22 carbon atoms used in the present invention, any known aliphatic dicarboxylic acid, alicyclic dicarboxylic acid or aromatic dicarboxylic acid may be used. You can Specific examples of these include butanedioic acid, pentanedionic acid,
Hexanedioic acid, octanedioic acid, nonanedioic acid, decandioic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid,
Pentadecanedioic acid, hexadecanedioic acid, 1,3
-Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, 2,6
-Naphthalenedicarboxylic acid and 1,4-naphthalenedicarboxylic acid. These dicarboxylic acids can be used alone or in combination of two or more kinds. Of these, hexanedioic acid and octanedioic acid are preferable because they are easy to handle and have good polymerization reactivity.

The diamine used in the present invention includes known diamines such as aliphatic alkylenediamines having 4 to 18 carbon atoms, alicyclic diamines and aromatic diamines. Specific examples of the aliphatic alkylenediamine having 4 to 18 carbon atoms include 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane and 1,8-diaminooctane. , 1,9-diaminononane, 1,10-diaminodecane, 1,11-
Diaminoundecane, 1,12-diaminododecane,
1,13-diaminotridecane, 1,14-diaminotridecane, 1,15-diaminopentadecane, 1,16
-Diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane, 2,2,4
-, 2,4,4-trimethylhexamethylenediamine and the like can be mentioned. Among these, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane and 2,2,4-, 2,4,4-trimethylhexamethylenediamine are easy to handle and can be polymerized. It has good reactivity and can be preferably used.

As the alicyclic diamine, any diamine containing a cyclohexane ring can be used. Specific examples include 1,4-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, bis (4-aminocyclohexyl) methane and bis (3-methyl-4-aminocyclohexyl) methane. Can be mentioned.

As the aromatic diamine, any diamine containing an aromatic ring can be used. Specific examples thereof include paraxylenediamine, metaxylenediamine, paraphenylenediamine, metaphenylenediamine, and 4,4′-diaminodiphenylmethane. Among these, para-xylene diamine and meta-xylene diamine are easy to handle, have good polymerization reactivity, and can be preferably used. These aliphatic alkylenediamines, alicyclic diamines and aromatic diamines may be used alone or in combination of two or more kinds.

In producing the polyamide copolymer of the present invention, 5 to 1 of a branched saturated dicarboxylic acid having 6 to 22 carbon atoms is used.
The dicarboxylic acid and diamine containing 100% by weight may be used as they are, or the dicarboxylic acid and diamine may be dissolved and mixed in water or hot water to adjust the pH, and the synthesized nylon salt may be used. good. The dicarboxylic acid and the diamine are generally used in a molar ratio of 100/95 to 100/105, preferably 100/99 to 100/101. If it is excessively out of this range, the number average molecular weight (hereinafter abbreviated as “Mn”) tends to be small, and the glossiness and mechanical strength may be insufficient.
Incidentally, Mn is a value obtained from the reciprocal of the average value of the terminal amino group concentration and the terminal carboxy group concentration of the obtained polyamide.

The compound serving as a unit for forming the aliphatic polyamide used in the present invention includes aminocarboxylic acid, lactam having 4 to 12 carbon atoms, and equimolar mixture of aliphatic dicarboxylic acid and aliphatic diamine. Specific examples of the aminocarboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminocapric acid, 11-aminoundecanoic acid and 12-aminododecanoic acid. Can be mentioned. As specific examples of lactams, ε-caprolactam (also referred to as “caprolactam”) and ω.
-Enanthlactam, ω-undecane lactam, ω-dodecaractam, α-pyrrolidone, δ-methylpyrrolidone and the like can be mentioned. Specific examples of the equimolar mixture of an aliphatic dicarboxylic acid and an aliphatic diamine include an equimolar mixture of butanedioic acid and 1,4-diaminobutane or a nylon salt thereof, an equimolar mixture of butanedioic acid and 1,6-diaminohexane, or This nylon salt, an equimolar mixture of octanedioic acid and 1,6-diaminohexane, or this nylon salt may, for example, be mentioned. These equimolar mixtures of aminocarboxylic acid, lactam or aliphatic dicarboxylic acid and aliphatic diamine can be used alone or in appropriate combination of two or more kinds. Among these, 6-aminocaproic acid,
12-aminododecanoic acid and ε-caprolactam are easy to handle, have good polymerization reactivity, and can be preferably used.

The amount of the compound serving as a unit forming an aliphatic polyamide is 75 to 99.9% by weight, preferably 90 to 97% by weight based on the total amount of the polyamide copolymer of the present invention.
% By weight. If the amount used is less than 75% by weight, mechanical properties will deteriorate, which is not preferable. On the other hand, when it is more than 99.9% by weight, the transparency is lowered.

As the polymerization method for producing the polyamide copolymer of the present invention, known methods such as a melt polymerization method and a solution polymerization method can be used. These polymerization methods may be used alone or in appropriate combination. Generally, the melt polymerization method is simple and is preferably adopted.

A typical production method is a raw material having 6 to 22 carbon atoms.
A dicarboxylic acid containing 5 to 100% by weight of a branched saturated dicarboxylic acid, a diamine, and / or a nylon salt thereof and a compound serving as a unit forming an aliphatic polyamide, or by adding water thereto, under pressure or Under normal pressure, the first stage polymerization is performed in a molten state, and Mn is 800 to 5,000.
To prepare a prepolymer of the polyamide copolymer, and then carry out a second stage polymerization in a molten state under normal pressure or reduced pressure to highly polymerize the prepolymer so that Mn is 7,000.
It is a production method for obtaining a polyamide copolymer of 0 to 50,000.

When water is used in the present invention, pure water such as ion-exchanged water or distilled water can be used, but the water is dissolved in water by boiling or using another deaerator immediately before use. It is more preferable to use deaerated water from which oxygen has been removed. The amount of water used is the total amount of nylon copolymer raw materials 10
It is generally 1 to 150 parts by weight, preferably 5 to 100 parts by weight, relative to 0 parts by weight. If the amount of water used is too small, the melt viscosity of the polymerization reaction product may increase, the prepolymer may precipitate during the first-stage polymerization reaction, or the prepolymer may adhere to the polymerization vessel. Also,
When the amount of water used increases, the Mn of the resulting prepolymer
Tends to be small, the polymerization time in the second step becomes long, and the balance between the terminal group amino group concentration and the carboxyl group concentration becomes poor, making it difficult to control Mn of the obtained polyamide.

The polymerization temperature in the first step for producing the prepolymer is generally 160 to 320 ° C., preferably 180 to 320 ° C.
The temperature is 280 ° C, more preferably 180 to 250 ° C. When the polymerization temperature is low, the polymerization rate becomes slow and the polymerization time becomes long. Further, when the polymerization temperature is high, a side reaction or a thermal decomposition reaction is likely to occur, and the obtained prepolymer is likely to be colored and impurities such as a gelled product are likely to be generated.

The pressure during the polymerization reaction is determined by the polymerization temperature and the amount of water added to the raw materials and water produced by the polymerization (condensation) reaction. The pressure is adjusted by a pressure control valve directly connected to the polymerization reactor. The pressure during the first-stage polymerization is atmospheric pressure or increased pressure, and generally 0 to 50 kgf / cm ²
G, preferably 0 to 30 kgf / cm ² G. When the polymerization pressure is lower than atmospheric pressure, the diamine may evaporate and be discharged out of the polymerization system, the molar balance with the dicarboxylic acid may be lost, and the polymerization rate may slow down or the desired Mn
It becomes difficult to obtain the prepolymer of On the other hand, when the polymerization pressure is high, the Mn of the obtained prepolymer tends to be small, and the polymerization time of the second stage may be long.

The polymerization time of the first stage depends on the polymerization equipment used,
Influenced by polymerization temperature and polymerization pressure, but usually 5 minutes to 1
0 hours, preferably 10 minutes to 7 hours, more preferably 3
It is from 0 minutes to 5 hours. If the polymerization time is too short, the polymerization will not proceed sufficiently and the Mn of the prepolymer will be small. Further, when the polymerization time is long, a side reaction or a thermal decomposition reaction is likely to occur, the obtained prepolymer is likely to be colored, and impurities such as a gelled product are likely to be generated.

The Mn of the prepolymer obtained in the first stage polymerization reaction is in the range of 800 to 5,000, preferably 10
The range is from 00 to 4,000. The Mn of the prepolymer can be controlled by appropriately adjusting the polymerization temperature, the polymerization pressure, the amino group concentration and the carboxyl group concentration in the polymerization reaction system. When the Mn of the prepolymer is less than 800, the polymerization time in the second step becomes long, and the balance between the terminal group amino group concentration and the carboxyl group concentration becomes poor, so that the final Mn polyamide copolymer is obtained. Is difficult, which is not preferable. On the other hand, when it exceeds 5,000, the melt viscosity of the polymerization reaction mixture becomes high and it becomes difficult to carry out the polymerization reaction in a uniform state, which is not preferable.

The polymerization temperature in the second step for increasing the molecular weight of the prepolymer is the same as or higher than that in the first step.
Usually, 180 to 320 ° C., preferably 200 to 300
C., more preferably 230 to 280.degree. When the polymerization temperature is low, the polymerization rate may be slow, the polymerization time may be long, and it may be difficult to obtain the target Mn polyamide copolymer. Further, when the polymerization temperature is high, side reactions and thermal decomposition reactions are likely to occur, and the obtained polyamide copolymer may be colored and impurities such as gelled products may be generated.

The pressure during the polymerization in the second stage may be atmospheric pressure or reduced pressure, and is generally in the range of 10 to 760 mmHg. When the pressure is higher than atmospheric pressure, it is difficult to discharge water contained in the prepolymer and water by-produced by the polymerization (condensation) reaction of the prepolymer to the outside of the polymerization reaction system, and it is difficult to increase the prepolymer molecular weight. Becomes If the polymerization pressure is excessively low, the depressurization equipment for exhausting will be very expensive, which is not preferable. When reducing the pressure, at least one vent port is provided in the second-stage polymerization reaction device, and the vent port is connected to a known vacuum facility such as a Nash pump, mechanical booster, or steam ejector to forcibly exhaust the gas. Be seen.

The polymerization time in the second stage is influenced by the polymerization equipment used, the polymerization temperature and the polymerization pressure, but is usually in the range of 1 minute to 10 hours. If the polymerization time is too short,
Polymerization does not proceed sufficiently and Mn of the polyamide copolymer becomes low. In addition, when the polymerization time is long, side reactions and thermal decomposition reactions are likely to occur, and the obtained polyamide copolymer may be colored and impurities such as gelation products may be generated.

The Mn of the polyamide copolymer of the present invention produced by the above method is 7,000 to 50,000, preferably 10,000 to 30,000. The Mn of the polyamide copolymer can be controlled by appropriately adjusting the polymerization temperature, the polymerization pressure, the amino group concentration and the carboxyl group concentration in the polymerization system. When Mn is less than 7,000, practical properties such as mechanical strength are deteriorated. Also, Mn is 50,0
When it exceeds 00, the viscosity at the time of melting becomes high and the melt molding becomes difficult, which is not preferable.

The polyamide copolymer of the present invention can be produced using a known polyamide production apparatus, and can be carried out batchwise or continuously. As a device that can be used,
Batch type reaction kettle, one-tank type or multi-tank type continuous reaction device,
A tubular continuous reaction apparatus, a kneading reaction extruder such as a single-screw kneading extruder, a twin-screw kneading extruder, and a multi-screw kneading extruder, and a known second polymerization tank such as a horizontal second polymerization tank described in JP-B-4-32096. A reactor can be used. It is desirable to carry out the polymerization reaction in a state where the raw materials are mixed as uniformly as possible, and from this point, it is desirable to use a polymerization apparatus with good stirring efficiency.

In the method of the present invention, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid are used in the first step or the second step of the polymerization in order to prevent a polymerization accelerator and deterioration during the polymerization, if necessary. , Phosphorus-based compounds such as polyphosphoric acid and their alkali metal salts, alkaline earth metal salts or esters can be added. The addition amount of these phosphorus compounds is usually 5 with respect to the polyamide copolymer to be obtained.
An amount of 0 to 3,000 ppm is preferably used. If the amount added is out of this range, the polymerization rate may not be accelerated or the obtained polyamide copolymer may be colored.

For the purpose of adjusting the molecular weight of the obtained polyamide copolymer and stabilizing the melt viscosity during molding, if necessary, amine or carboxylic acid may be added during the first or second stage polymerization. It can be added as a molecular weight regulator. The amine or carboxylic acid to be added can be used without particular limitation as long as it is monofunctional or difunctional. For example, monoamines such as laurylamine, stearylamine and benzylamine, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1, 11-diaminoundecane, 1,12-diaminododecane, diamines such as metaxylenediamine, paraxylenediamine, acetic acid, benzoic acid, lauric acid,
Suitable monocarboxylic acids such as stearic acid and dicarboxylic acids such as butanedioic acid, pentanedionic acid, hexanedioic acid, octanedionic acid, nonanedioic acid, decanedioic acid, undecanedioic acid, dodecanedioic acid, isophthalic acid and terephthalic acid As. The addition amount of these molecular weight regulators varies depending on the reactivity of the molecular weight regulator used and the polymerization conditions, but the Mn of the polyamide copolymer to be finally obtained is 7,000 to 5
It is appropriately determined so as to be in the range of 50,000.

Further, the polyamide copolymer of the present invention is
During the first-stage or second-stage polymerization, if necessary, a heat-resistant agent, an antioxidant, a weather-resistant agent, a lubricant, an antistatic agent, a pigment,
It is also possible to add a dye, an anti-blocking agent, etc. within a range that does not impair the physical properties of the obtained polyamide copolymer.

The polyamide copolymer of the present invention is preferably used for molded articles such as monofilaments, fibers, films and covers for instruments which are required to have transparency and gloss. These molding methods are not particularly limited and can be manufactured by known molding methods. For example, monofilaments and fibers can be produced by a known melt spinning method or the like. The film can be produced by a method such as T-die method, inflation method, tubular method, solvent casting method or compression molding method using a known extruder. The molded product can be manufactured by a method such as an injection molding method, a blow molding method, or a vacuum molding method. In the case of the melt molding method, the molding temperature is preferably a temperature of not less than the melting point of the obtained polyamide copolymer and not more than 320 ° C.

[0035]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below. Various physical properties of the polyamide copolymers in the following Examples and Comparative Examples were measured by the following methods. The polyamide copolymer used for measurement was freeze-pulverized and then vacuum-dried at 80 ° C. for 2 days.

(1) Relative Viscosity (ηr) According to JIS K6810, the polyamide copolymer was completely dissolved at a concentration of 1% by weight / volume using 98% by weight of concentrated sulfuric acid as a solvent, and then the Uberode It measured using the viscometer.

(2) Terminal amino group concentration ([NH ₂ ]) About 1 g of polyamide copolymer was dissolved in 40 ml of phenol / methanol mixed solvent (volume ratio: 9/1), and the obtained sample solution was used as an indicator. Using thymol blue as
Titrated with / 20 hydrochloric acid.

(3) Terminal carboxyl group concentration ([COO
H]) About 1 g of polyamide copolymer was added with 40 ml of benzyl alcohol, heated and dissolved in a nitrogen gas atmosphere, and the obtained sample solution was mixed with N / 20 potassium hydroxide-ethanol using phenolphthalein as an indicator. Titrated with solution.

(4) Mn (number average molecular weight) The terminal amino group concentration ([NH ₂ ]) determined by the method described in the above item ( ₂ ) and the terminal carboxyl group determined by the method described in the above item (3). It was calculated as the reciprocal of the average value of the concentration ([COOH]).

(5) Haze (H) Haze (H), which is a measure of transparency, is JIS K7105.
According to, the diffuse transmittance (Td) and the total light transmittance (Ti) are measured using an integrating sphere type light transmittance measuring device, and calculated by the expression (1). It is indicated that the smaller the haze value, the better the transparency.

## EQU1 ## H (%) = (Td / Ti) × 100 (1) A test piece whose haze was measured was produced by compression molding under the following conditions. Compression molding temperature: 265 ° C. Compression condition: Hold the sample for 3 minutes in a non-pressurized state, then under a pressure of 10 kgf / cm ² G for 1 minute, 50 k
100 kgf / cm ² for 1 minute under a pressure of gf / cm ² G
Hold for 1 minute under G pressure. Others: The test piece immediately after compression molding was immersed in water at 25 ° C and cooled. Test piece size: 50 mm x 50 mm x 1 mm (thickness)

(6) Glossiness The glossiness was measured in accordance with JIS K7105 by measuring a 60-degree specular glossiness. The test piece used was prepared according to the method described in the above item (5). The larger the value of glossiness, the better the gloss.

(7) Tensile Properties Tensile elastic modulus, tensile strength at break and elongation at tensile break were measured according to ASTM D 882-91. The shape of the test piece was a strip shape of 10 mm (horizontal) × 200 mm (vertical) × 50 μm (thickness), and the distance between grips was 125 mm, and the test speed was 12.5 mm / min. The test piece was cut out from the one prepared by the same method as described in the above (5) and dried under reduced pressure at room temperature for 48 hours or more.

Example 1 300 g of degassed water obtained by boiling high-purity ion-exchanged water (hereinafter abbreviated as "degassed water") was stirred, while 300 g of 1,6-decanedicarboxylic acid was dispersed therein. Then, after maintaining the temperature at 50 ° C. under a nitrogen gas atmosphere, a 50% by weight aqueous solution of 1,6-diaminohexane was added, and when the pH reached 8.10, the addition was stopped and 1,6-diaminohexane was added. A 50% by weight aqueous solution of a nylon salt (hereinafter, abbreviated as “6D salt”) consisting of and 1,6-decanedicarboxylic acid was obtained. 0.28 g of this aqueous solution, ε-caprolactam 13.
A test tube having an outer diameter of 21 mm and a length of 200 mm was charged with 86 g and degassed water 0.597 g. This test tube is a pressure gauge,
It was inserted into a pressure vessel with a capacity of 80 ml equipped with a nitrogen inlet and a pressure release. After sufficiently replacing the inside of the pressure vessel with nitrogen, the temperature is raised in a sealed state at 240 ° C. and the pressure is about 8.3 kgf / cm ^2.
The first stage polymerization was carried out for 4 hours with G to synthesize a prepolymer. Next, after cooling with running water in this pressure vessel,
The pressure vessel is opened, a small amount of the prepolymer is taken, the terminal amino group concentration and the terminal carboxy concentration are measured, and Mn
I asked. The Mn of the prepolymer was 2500. Then, the prepolymer was inserted into a glass cylindrical container having a capacity of 110 ml equipped with a pressure gauge, a nitrogen inlet and a pressure releasing port, and 270 ° C. under atmospheric pressure while flowing a nitrogen gas at a flow rate of 100 ml / min into the container. The second step polymerization was carried out for 4 hours to obtain a polyamide copolymer. Table 1 shows the physical properties of the obtained polyamide copolymer.

Comparative Example 1 The same procedure as in Example 1 was carried out except that 14.00 g of ε-caprolactam and 0.737 g of degassed water were placed in the test tube as raw materials. Table 1 shows the physical properties of the obtained polymer.
Shown in.

Comparative Example 2 300 g of butanedioic acid was dispersed in 300 g of degassed water obtained by boiling high-purity ion-exchanged water with stirring, and the mixture was kept at 40 ° C. in a nitrogen gas atmosphere, and then 1,6-diaminohexane was added. Of 50% by weight of water was added and the addition was stopped when the pH reached 7.50, and a nylon salt composed of 1,6-diaminohexane and butanedioic acid (hereinafter referred to as "AH salt") was added.
Is abbreviated. A 50% by weight aqueous solution of This aqueous solution was kept at 60 ° C. with stirring, and methanol was poured into it in an amount not less than twice the amount of this aqueous solution and then cooled to recrystallize the AH salt. The precipitated AH salt crystals were white plates. AH salt crystals obtained by filtering this off were vacuum dried at 60 ° C. for 3 days. AH salt 0.14 g, ε-caprolactam 1
It carried out by the same method as Example 1 except using 3.86 g and 0.737 g of degassed water, and making the polymerization time of a 2nd step 2 hours. The number average molecular weight of the prepolymer is 3800
Met. Table 1 shows the physical properties of the obtained polymer.

Example 2 The procedure of Example 1 was repeated except that 1.40 g of a 50% by weight aqueous solution of 6D salt, 13.30 g of ε-caprolactam and 0.037 g of degassed water were used. The Mn of the prepolymer was 2370. Table 2 shows the physical properties of the obtained polymer.

Example 3 The procedure of Example 1 was repeated, except that 2.80 g of a 50% by weight aqueous solution of 6D salt and 12.60 g of ε-caprolactam were used. The number average molecular weight of the prepolymer is 230
It was 0. Table 2 shows the physical properties of the obtained polymer.

Comparative Example 3 The same procedure as in Example 1 was repeated except that 1.40 g of AH salt, 12.60 g of ε-caprolactam and 0.737 g of degassed water were used, and the polymerization time in the second stage was 2 hours. Carried out. Table 2 shows the physical properties of the obtained polymer.

Example 4 The procedure of Example 1 was repeated, except that 5.60 g of a 50% by weight aqueous solution of 6D salt and 11.20 g of ε-caprolactam were used. Table 2 shows the physical properties of the obtained polymer.

Comparative Example 4 The procedure of Example 1 was repeated except that 8.4 g of a 50% by weight aqueous solution of 6D salt and 9.80 g of ε-caprolactam were used. Table 3 shows the physical properties of the obtained polymer.

Example 5 2.24 g of 50% by weight aqueous solution of 6D salt, 0.5 AH salt
It carried out by the method similar to Example 1 except having used 6 g and 12.6 g of (epsilon) -caprolactam. Table 3 shows the physical properties of the obtained polymer.

Example 6 1.68 g of a 50% by weight aqueous solution of 6D salt, 1.1 of AH salt
It carried out by the method similar to Example 1 except having used 2 g and 12.6 g of (epsilon) -caprolactam. Table 3 shows the physical properties of the obtained polymer.

Example 7 8-Ethyloctadecanedioic acid 1.12 g, 1,6-
Diaminohexane 0.38 g, ε-caprolactam 1
It carried out by the method similar to Example 1 except having used 3.5 g and 1 g of water. Table 3 shows the physical properties of the obtained polymer.

8,13-Dimethyleicosadiodioic acid 1.
The same procedure as in Example 1 was carried out except that 14 g, 1,6-diaminohexane 0.36 g, ε-caprolactam 13.5 g and water 1 g were used. Table 3 shows the physical properties of the obtained polymer.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

[0058]

[Table 4]

[0059]

[Effect of the Invention] (A) 5-100 in the dicarboxylic acid component
A polyamide copolymer containing, by weight, a unit of a dicarboxylic acid that is a branched saturated dicarboxylic acid having 6 to 22 carbon atoms, a unit of (B) a diamine, and a unit of (C) an aliphatic polyamide. And the unit forming the aliphatic polyamide (C) is 75% of the polyamide copolymer.
The polyamide copolymer, which is ˜99.9% by weight, has good optical and mechanical properties.

Claims (4)

[Claims] 1. A unit composed of a dicarboxylic acid in which 5 to 100% by weight of the (A) dicarboxylic acid is a branched saturated dicarboxylic acid having 6 to 22 carbon atoms, a unit composed of a diamine (B), and a fat (C). A polyamide copolymer containing a group forming a group polyamide, wherein the unit forming the aliphatic polyamide (C) is 75 to 9 of the polyamide copolymer.
A polyamide copolymer characterized by being 9.9% by weight. 2. The polyamide copolymer according to claim 1, wherein 5 to 100% by weight of the dicarboxylic acid of (A) according to claim 1 is a unit composed of 1,6-decanedicarboxylic acid. . 3. The number average molecular weight of the first-stage polymerization is 800.
To 5,000 to produce a prepolymer of the polyamide copolymer according to claim 1, and to increase the molecular weight in the second-stage polymerization to produce a polyamide copolymer having a number average molecular weight of 7,000 to 50,000. The method for producing a polyamide copolymer according to claim 1 or 2, characterized in that 4. A monofilament, a fiber produced from the polyamide copolymer according to claim 1 or 2, or the polyamide copolymer obtained from the production method according to claim 3.
Film or molded product.