JP2000038444A - Polyamide copolymer, its production and fiber and plastic therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide copolymer having excellent mechanical properties, heat resistance and moldability, slightly gelling even holding in molten state such as in polymerization for long time and having excellent heat stability by constituting it of hexamethyleneadipamido units and amide units composed of a diamine and a dicarboxylic acid. SOLUTION: This polyamide copolymer consists of (A) 80-99,5 mol.% hexamethyleneadipamido unit and (B) 0.5-20 mol.% amide unit composed of at least one kind of diamine of the formula: H2N-(CH2)n-NH2 [(n) is a positive integer except 6] and a dicarboxylic acid. This polyamide satisfies a concentration ratio of carboxy group [COOH] (μmol/g) to amino group [NH2] (μmol/g) represented by the formula: 0.7<=[COOH]/[NH2]<=10. This polyamide is preferably obtained by polycondensation of a mixture or a salt of hexamethylenediamine/adipic acid with a mixture or a salt of diamine and a dicarboxylic acid in the presence of a monocarboxylic acid or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a copolymerized polyamide having excellent mechanical properties, heat resistance and moldability. More specifically,
The present invention relates to a copolymerized polyamide which has excellent mechanical properties, generates less gel even when staying in a molten state for a long period of time such as polymerization, melt spinning, and melt molding, and has excellent thermal stability. Also, the present invention relates to a copolymerized polyamide which is less liable to generate gelled matters and spherulites during melt spinning and causes less yarn breakage during melt spinning.

[0002]

2. Description of the Related Art Polyhexamethylene adipamide has high mechanical strength and excellent heat resistance, abrasion resistance and chemical resistance. Is widely used in various fields. However, polyhexamethylene adipamide is liable to form a gel when heated for a long period of time, and this gel reduces heat transfer in the polymerization process, clogging at the discharge port, yarn breakage in the spinning process, and breakage in the polymer. It causes various problems such as deterioration of the appearance of the molded article due to mixing. Further, polyhexamethylene adipamide has a problem that spherulites are easily generated, and particularly, spherulites are generated during melt-spinning, so that yarns are easily broken.

Various methods have been proposed for preventing gelation. Mainly phosphorus compounds,
Addition of an alkali metal compound is performed. For example, a phosphinic acid compound, a mixture of a phosphonous acid compound and an alkali hydroxide, an alkyl alkoxide or an alkali compound (Japanese Patent Publication No. 51-24297), a phosphinic acid compound,
Compounding of a phosphonous acid compound, a phosphonic acid compound, a phosphorous acid compound and an alkali compound selected from an alkali hydroxide, an alkyl alkoxide and an alkyl phenoxide, an alkali carbonate and a dicarboxylic anhydride (Japanese Patent Publication No. 51-2506)
No. 5) is known.

As a method utilizing copolymerization, it is known that a copolymerized polyamide obtained by copolymerizing 2-methylpentamethylenediamine is hardly gelled and, at the same time, hardly generates spherulites (Japanese Patent No. 2726564). No.).

[0005]

However, JP-B-51-24297 and JP-B-51-25065 described above.
In the case of adding a phosphorus compound described in
Although there is an effect of preventing gelation, the effect is small, and there is a problem that increasing the amount of addition promotes gelation. In addition, the copolymerized polyamide obtained by copolymerizing 2-methylpentamethylenediamine described in Japanese Patent No. 2726564 is certainly difficult to gel, and has less spherulite, but its effect is still insufficient. Further, there is a demand for a polyamide that generates less gel and spherulite.

The present inventors have conducted intensive studies on a method for suppressing the generation of gel and spherulite in polyhexamethylene adipamide, and as a result, have found the present invention.

[0007]

That is, the present invention comprises the following. (1) Consisting of 80 to 99.5 mol% of a hexamethylene adipamide unit and 0.5 to 20 mol% of an amide unit composed of at least one diamine represented by the general formula (1) and a dicarboxylic acid. A carboxyl group concentration [COOH] (μmol /
g) and the ratio of amino group concentration [NH2] (μmol / g) is a copolymerized polyamide satisfying the formula (2). H ₂ N— (CH ₂ ) n—NH ₂ (1) (where n represents a positive integer excluding 6) 0.7 ≦ [COOH] / [NH ₂ ] ≦ 10 (2) (2) Carboxyl group concentration [COOH] (μmol /
The copolymerized polyamide according to the above (1), wherein the ratio between g) and the amino group concentration [NH ₂ ] (μmol / g) satisfies the formula (4). 1 ≦ [COOH] / [NH ₂ ] ≦ 3 (4)

(3) When the diamine represented by the general formula (1) is 1,4-diaminobutane, 1,5-diaminopentane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9- The copolymerized polyamide according to the above (1) or (2), which is diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane. (4) The diamine represented by the general formula (1) is 1,4-
Diaminobutane, 1,9-diaminononane, 1,10-
The copolymerized polyamide according to the above (1) or (2), which is diaminodecane or 1,12-diaminododecane. (5) The hexamethylene adipamide unit is 95 to 99.
5 mol%, the amide unit composed of at least one diamine represented by the general formula (1) and a dicarboxylic acid has a content of 0.5 to
The copolymerized polyamide according to any one of the above (1) to (4), which is 5 mol%.

(6) A mixture or salt of 80 to 99.5 mol% of hexamethylenediamine / adipic acid,
When polycondensing 5 to 20 mol% of at least one kind of diamine represented by the general formula (1) with a mixture or salt of dicarboxylic acid, one or two of monocarboxylic acid, dicarboxylic acid, monoamine, and diamine farmland are used. A method for producing a copolymerized polyamide, wherein the copolymerized polyamide according to the above (1) is produced by adding at least one kind. (7) A copolymerized polyamide fiber produced by melt-spinning the copolymerized polyamide according to any of (1) to (5). (8) A copolymerized polyamide molded article produced by melt-molding the copolymerized polyamide according to any one of (1) to (5).

[0010]

Embodiments of the present invention will be described below. Hexamethylene adipamide unit referred to in the present invention, hexamethylene diamine as a diamine component,
An amide unit obtained by dehydration polycondensation using adipic acid as an acid component. A mixture of hexamethylene diamine and adipic acid may be used as a raw material,
A salt formed from hexamethylenediamine and adipic acid may be used as a raw material.

The copolymerized polyamide of the present invention contains an amide unit composed of at least one diamine represented by the general formula (1) and a dicarboxylic acid. _{H 2 N- (CH 2) n} -NH 2 ··· (1) ( wherein n represents a positive integer excluding 6)

Specific examples of the diamine represented by the general formula (1) include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,7 -Diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-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, 1,19-diaminononadecane, 1,20-
Diaminoeicosane and the like;
-Diaminobutane, 1,8-diaminooctane, 1,9
-Diaminononane, 1,10-diaminodecane, 1,1
1-Diaminoundecane and 1,12-diaminododecane are preferred, and in particular, 1,4-diaminobutane, 1,9
-Diaminononane, 1,10-diaminodecane, 1,1
2-Diaminododecane is preferred. These diamines may be used alone or as a mixture.

The dicarboxylic acid constituting the amide unit comprising at least one diamine represented by the general formula (1) and a dicarboxylic acid includes oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, Aliphatic dicarboxylic acids such as suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, prasillic acid, tetradecandioic acid, pentadecandioic acid, octadecandioic acid, and cycloaliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid And aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Adipic acid, sebacic acid, dodecane diacid, terephthalic acid and isophthalic acid are preferred, and adipic acid is particularly preferred. These dicarboxylic acids can be used in a mixture of two or more.

In order to introduce an amide unit comprising at least one diamine represented by the general formula (1) and a dicarboxylic acid, a mixture of at least one diamine represented by the general formula (1) and a dicarboxylic acid is used as a starting material. May be used as
A salt formed from at least one diamine represented by the general formula (1) and a dicarboxylic acid may be used as a raw material.

The copolymerization composition of the copolymerized polyamide of the present invention has a hexamethylene adipamide unit of 80 to 99.5 mol.
1% and at least one diamine represented by the general formula (1) and an amide unit composed of dicarboxylic acid of 0.5 to 20 mo
1%. It is preferably 90 to 99.5 mol% of a hexamethylene adipamide unit and 0.5 to 10 mol% of an amide unit composed of at least one diamine represented by the general formula (1) and a dicarboxylic acid, and more preferably hexamethylene adipamide It is 95 to 99.5 mol% of adipamide units and 0.5 to 5 mol% of amide units composed of at least one diamine represented by the general formula (1) and dicarboxylic acid.
If the hexamethylene adipamide unit is less than 80 mol%, the crystallinity, rigidity and strength become insufficient, and 0.5 mol
%, The gel-suppressing effect and the spherulite-suppressing effect become insufficient.

In the copolymerized polyamide of the present invention, a small amount of a third polyamide unit may be further copolymerized as long as the effects of the present invention are not impaired. The polyamide unit may be any of a polyamide unit derived from a lactam, a polyamide unit derived from an aminocarboxylic acid, and a polyamide unit derived from a diamine and a dicarboxylic acid.
These polyamide units may be used in combination.

Examples of the lactam include valerolactam, caprolactam, enantholactam, caprylactam, undecalactam, laurolactam and the like. Of these, caprolactam, undecalactam and laurolactam are preferred, and caprolactam is particularly preferred. . These lactams can be used in a mixture of two or more.

As a specific example of the aminocarboxylic acid, 6-
Aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like. Acids, 11-aminoundecanoic acid and 12-aminododecanoic acid are preferred, and 6-aminocaproic acid is particularly preferred. These amino acids can be used in a mixture of two or more.

As the diamine, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 2-methyl-1,5-diaminopentane, 1,7
-Diaminoheptane, 1,8-diaminooctane, 1,
9-diaminononane, 1,10-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, 1,
Aliphatic diamines such as 19-diaminononadecane and 1,20-diaminoeicosane, 1,1-diaminocyclohexane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,1 -Di (aminomethyl) cyclohexane, 1,
2-di (aminomethyl) cyclohexane, 1,3-di (aminomethyl) cyclohexane, 1,4-di (aminomethyl) cyclohexane, 1-amino-1-aminomethylcyclohexane, 1-amino-2-aminomethylcyclohexane 1-amino-3-aminomethylcyclohexane, 1-amino-4-aminomethylcyclohexane,
5-amino-1,3,3-trimethylcyclohexanemethylamine (common name: isophoronediamine), di (2-
Aminocyclohexyl) methane, di (3-aminocyclohexyl) methane, di (4-aminocyclohexyl) methane, (2-aminocyclohexyl) (3-aminocyclohexyl) methane, (2-aminocyclohexyl)
(4-aminocyclohexyl) methane, (3-aminocyclohexyl) (4-aminocyclohexyl) methane,
Di (3-methyl-4-aminocyclohexyl) methane,
2,2-di (2-aminocyclohexyl) propane,
2,2-di (3-aminocyclohexyl) propane,
2,2-di (4-aminocyclohexyl) propane,
2,2-di (2-amino-3-methylcyclohexyl)
Propane, 2,2-di (3-amino-5-methylcyclohexyl) propane, 2,2-di (3-methyl-4-aminocyclohexyl) propane, 2,2-di (2-aminocyclohexyl) butane, Alicyclic diamines such as 2,2-di (3-aminocyclohexyl) butane and 2,2-di (4-aminocyclohexyl) butane, and aromatic diamines such as m-xylylenediamine and p-xylylenediamine. Among them, aliphatic diamines are particularly preferable. In particular, when used in combination with a dicarboxylic acid other than adipic acid, 1,6-diaminohexane (hexamethylenediamine) is preferably used.
These diamines can also be used in a mixture of two or more.

The dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
Suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, prasillic acid, tetradecandioic acid,
Aliphatic dicarboxylic acids such as pentadecandioic acid and octadecandioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and aromatic dicarboxylic acids such as naphthalenedicarboxylic acid. , Adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid and isophthalic acid are preferred. In particular,
1,6-diaminohexane (hexamethylenediamine)
If used in combination with other diamines,
Adipic acid is preferred. These dicarboxylic acids can be used in a mixture of two or more.

The preferred amount of copolymerization of the third polyamide unit is from 0.1 to 5 mol%, more preferably from 0.1 to 3 mol%, of the total polyamide unit.

The terminal group concentration of the copolymerized polyamide of the present invention is the carboxyl terminal group concentration [COOH] (μmol /
g) and the amino group concentration [NH ₂ ] (μmol / g) satisfy the expression (2). 0.7 ≦ [COOH] / [NH ₂ ] ≦ 10 (2) If the value of [COOH] / [NH ₂ ] is smaller than 0.7, the effect of suppressing gelation by copolymerization is insufficient, [COO
If the ratio [H] / [NH ₂ ] is more than 10, the dyeing properties and the dispersibility when a matting agent such as titanium oxide is added are reduced.

The preferred value of [COOH] / [NH ₂ ] is in the range represented by the formula (3). 0.7 ≦ [COOH] / [NH ₂ ] ≦ 5 (3) A more preferable value of [COOH] / [NH ₂ ] is represented by the formula (4).
Is the range represented by 1 ≦ [COOH] / [NH ₂ ] ≦ 3 (4)

As a method for controlling the value of [COOH] / [NH ₂ ], a known terminal group concentration control method may be used. For example, at the time of polymerization, it can be controlled by adding one or an arbitrary combination of two or more of monocarboxylic acid, monoamine, dicarboxylic acid, and diamine.

Specific examples of the monocarboxylic acid include acetic acid,
Propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, myristoleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachinic acid Aliphatic monocarboxylic acids such as aliphatic monocarboxylic acids such as cyclohexanecarboxylic acid and methylcyclohexanecarboxylic acid, benzoic acid, toluic acid, ethylbenzoic acid, and aromatic monocarboxylic acids such as phenylacetic acid. .

Specific examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, and tridecanedioic acid. acid,
Aliphatic dicarboxylic acids such as tetradecandioic acid, pentadecandioic acid, and octadecandioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid And the like.

Specific examples of the monoamine include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, dodecylamine and tridecyl. Amine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, nonadecylamine, aliphatic monoamines such as icosylamine, cycloaliphatic monoamines such as cyclohexylamine, methylcyclohexylamine, benzylamine, β-
And aromatic monoamines such as phenylethylamine.

Specific examples of the diamine include 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane and 1,9-diaminononane , 1,10-
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, 1,19-diaminononadecane, 1,2
Aliphatic diamines such as 0-diaminoeicosane, 1,1
-Diaminocyclohexane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,1-di (aminomethyl) cyclohexane, 1,2-di (aminomethyl) cyclohexane, 1,3 -Di (aminomethyl) cyclohexane,
1,4-di (aminomethyl) cyclohexane, 1-amino-1-aminomethylcyclohexane, 1-amino-2
-Aminomethylcyclohexane, 1-amino-3-aminomethylcyclohexane, 1-amino-4-aminomethylcyclohexane, 5-amino-1,3,3-trimethylcyclohexanemethylamine (common name: isophoronediamine), di (2 -Aminocyclohexyl) methane, di (3-aminocyclohexyl) methane, di (4-aminocyclohexyl) methane, (2-aminocyclohexyl) (3-aminocyclohexyl) methane, (2-aminocyclohexyl) (4-aminocyclohexyl) Methane, (3-aminocyclohexyl) (4-aminocyclohexyl) methane, di (3-methyl-4-aminocyclohexyl) methane, 2,2-di (2-aminocyclohexyl) propane, 2,2-di (3- Aminocyclohexyl) propane, 2, - di (4-aminocyclohexyl) propane, 2,2-di (2-amino-3-methylcyclohexyl) propane, 2,2-di (3-amino-5
-Methylcyclohexyl) propane, 2,2-di (3-
Methyl-4-aminocyclohexyl) propane, 2,2
-Di (2-aminocyclohexyl) butane, 2,2-di (3-aminocyclohexyl) butane, 2,2-di (4
-Aminocyclohexyl) butane and the like, and aromatic diamines such as m-xylylenediamine and p-xylylenediamine.

Among them, particularly, the method of controlling the terminal group concentration by adding benzoic acid, adipic acid, hexamethylenediamine, stearylamine or any combination thereof can stably achieve a certain degree of polymerization. preferable.

It is also possible to control the terminal group concentration by adding a compound which reacts with the terminal of polyamide after polymerization. In that case,
Acid anhydrides, lactones and epoxy compounds are used. Of these, acid anhydrides are preferable, and specific examples thereof include:
Examples thereof include acetic anhydride, benzoic anhydride, phthalic anhydride, and succinic anhydride. Among them, cyclic acid anhydrides are particularly preferable, and phthalic anhydride and succinic anhydride are particularly preferable.

Although the absolute value of the terminal group concentration of the copolymerized polyamide resin used in the present invention is not particularly limited, both terminal amino group concentration and terminal carboxyl concentration are preferably 30%.
１５０150 μmol / g, more preferably 50-120 μm
mol / g, particularly preferably 60 to 110 μmol / g
It is. If it is less than 30 μmol / g, it becomes difficult to increase the molecular weight during polymerization. On the other hand, if it is more than 150 μmol / g, the effect of suppressing gelation is reduced.

The copolymerized polyamide of the present invention further has a melting point T
m (° C.), crystallization temperature Tc (° C.), carboxyl group concentration [COOH] (μmol / g), amino group concentration [N
H ₂ ] (μmol / g), a certain relational expression (5),
It is preferable that the expression (6) is satisfied. 1.15 ≦ Tm / Tc ≦ 1.27 (5) 50 ≦ ([COOH] + [NH ₂ ]) / (Tm / Tc) ≦ 100 (6) Further, formula (7) , (8). 1.15 ≦ Tm / Tc ≦ 1.23 (7) 70 ≦ ([COOH] + [NH ₂ ]) / Tm / Tc ≦ 100 (8)

The degree of polymerization of the copolymerized polyamide of the present invention is as follows:
The relative viscosity of a 0.01% g / mL 98% sulfuric acid solution at 25 ° C. is 2.2 to 8.0, preferably 2.2 to 8.0.
7.0, more preferably 2.2 to 6.5, most preferably 2.2 to 6.0. If the relative viscosity is less than 2.2, the mechanical properties are insufficiently developed, and if the relative viscosity is more than 8.0, the melt viscosity is too high and melt spinning and melt molding become difficult.

The copolymerized polyamide of the present invention may contain an antioxidant or a heat stabilizer (a hindered phenol type, a hydroquinone type, a phosphite type or a substituted product thereof, halogen) depending on the use within a range not to impair the effects of the present invention. Copper oxide, iodine compounds, etc.), weathering agents (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), mold release agents and lubricants (aliphatic alcohol, bisurea, polyethylene wax, etc.), pigments (sulfurized Cadmium, phthalocyanine, carbon black, etc., dyes (eg, nigrosine), nucleating agents (eg, talc, silica, kaolin, clay), plasticizers (eg, octyl p-oxybenzoate, N-butylbenzenesulfonamide),
Antistatic agents (alkyl sulfate anionic antistatic agents, quaternary ammonium salt cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agents, etc.), Flame retardants (hydroxide such as red phosphorus, melamine cyanurate, magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene oxide, brominated polycarbonate, brominated epoxy resin, or brominated epoxy resins of these types) Combustion agent and antimony trioxide, etc.), filler (graphite, barium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, antimony oxide, titanium oxide, aluminum oxide, zinc oxide, iron oxide, zinc sulfide, zinc, lead, Nickel, aluminum Copper, iron, stainless steel, glass fiber, carbon fiber, aramid fiber, kaolin, silica, montmorillonite and other particulate, fibrous, needle-like, plate-like fillers), other polymers (other polyamides, polyethylene, polypropylene, Polyester, polycarbonate, polyphenylene ether, polyphenylene sulfide, liquid crystal polymer, polysulfone, polyethersulfone, AB
S resin, SAN resin, polystyrene, modified products thereof, etc.) can be added.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples. Weight means mass. The analysis and measurement described in Examples and Comparative Examples were performed according to the following methods. (1) Relative viscosity 98% of 0.01 g / mL using an Ostwald viscometer
The relative viscosity of the sulfuric acid solution / 25 ° C. was measured.

(2) Carboxyl group concentration [COOH]
(Μmol / g) 0.5 g of sample was added to 20 mL of benzyl alcohol
Dissolve at 5 ° C and use phenolphthalein as an indicator
The carboxyl group concentration [COOH] was determined by titration with a / 50 N potassium hydroxide / ethanol solution.

(3) Amino group concentration [NH ₂ ] (μmol
/ G) 0.5 g sample was phenol / ethanol = 84/1
It was dissolved in 25 mL of a 6% by weight mixed solution, and the amino group concentration [NH ₂ ] was determined using N / 50N hydrochloric acid using thymol blue as an indicator.

(4) Crystallization temperature Tc (° C.) Measured using DSC-7 manufactured by Perkin-Elmer. The peak top temperature of the exothermic peak based on crystallization observed when the temperature of the polymer once melted was lowered at 20 ° C./min was defined as the crystallization temperature Tc.

(5) Melting point Tm (° C.) Measured using DSC-7 manufactured by Perkin-Elmer. After measuring Tc as described above, the peak top temperature of the endothermic peak based on melting observed when the temperature was raised at 20 ° C./min was defined as melting point Tm.

(6) Physical properties of polymer Tensile properties Tensile strength and tensile elongation at break were measured in accordance with ASTM D638. Flexural modulus Measured according to ASTM D790. Izod impact value Measured according to ASTM D256.

(7) Gel Generation Time A 20 g sample was put into a 25 mmφ test tube, and the atmosphere in the test tube was replaced with nitrogen five times. The sample was heated at 290 ° C. under a stream of nitrogen and sampled every 0.5 hour. 0.1 g of the sample taken was added to 19.9 g of 65% sulfuric acid, and 50%
The state of dissolution upon stirring at 15 ° C. for 15 hours was observed. The time at which insolubles began to remain was defined as the gel generation time.

(8) Degree of spherulite A sample was spun from a spinneret having 312 0.28 mm holes at 295 ° C., and the obtained thread was fixed with paraffin and then cut out. This section was placed on a slide glass, and paraffin was dissolved and removed with xylene and dried.
This sample was observed with a polarizing microscope, and the area (%) of the spherulite formed in the cross section was defined as the degree of spherulite generation.

(9) Continuous batch polymerizability When the batch polymerization was repeatedly performed without washing between batches using the 3L polymerization vessel used in Comparative Example 1, a gelled product or a carbide was obviously mixed in the polymer strand. The number of times to begin was recorded.

Comparative Example 1 909 g of a 55% aqueous solution of an equimolar salt of hexamethylenediamine and adipic acid and 1.04 g of benzoic acid were placed in a 3 L stainless steel autoclave.
The pressure is increased to 17.4 kg / cm ² by heating, and then the temperature is raised from 250 ° C. to 289 ° C. while maintaining the pressure at 17.4 kg / cm ² for 1.9 hours. Thereafter, the temperature was maintained at 289 ° C. for 0.6 hours, and then the pressure was released to extrude the polymer into strands to form chips. Table 3 shows polymer characteristic values of the obtained polyamide.

[Examples 1 to 8, Comparative Examples 2 to 6] Tables 1 to 4
The polymerization was carried out in the same manner as in Comparative Example 1 by charging a diamine and a dicarboxylic acid corresponding to the copolymerization amounts shown in Table 2 and other copolymerization components and additives. Tables 1 to 4 show polymer characteristic values of the obtained polyamide.

Example 9 After pelletizing the copolymerized polyamide obtained in Example 1, succinic anhydride was mixed at a ratio shown in Table 3 and supplied to a 35 mmφ twin screw extruder to obtain a resin temperature of 288 ° C. Melt extruded. Table 3 shows the polymer characteristic values of the obtained polyamide.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

[Table 4]

From Example 1 and Comparative Example 1, the copolymerized polyamide obtained by copolymerizing 1,4-diaminobutane / adipic acid unit with polyhexamethylene adipamide has excellent mechanical properties and a long gel generation time. It can be seen that spherulite generation is also suppressed. It can also be seen that the continuous batch polymerizability is greatly improved. Example 2 shows that increasing the copolymerization amount of 1,4-diaminobutane / adipic acid unit further increases the gel generation time and further suppresses the generation of spherulites. Further, it can be seen that the continuous batch polymerizability is further improved. From Examples 3 and 4, the copolymerization of 1,9-diaminononane / adipic acid unit or 1,12-diaminododecane / sebacic acid unit is the same as the copolymerization of 1,4-diaminobutane / adipic acid unit. It can be seen that the effect can be obtained.

According to Example 5, 1,4-diaminobutane /
It can be seen that even when the adipic acid unit and the 1,9-diaminononane / adipic acid unit are simultaneously copolymerized, the same effect as when each unit is copolymerized alone can be obtained. According to Examples 6 and 7, even if 1,4-diaminobutane / adipic acid unit and hexamethylenediamine / terephthalic acid unit or caprolactam unit are simultaneously copolymerized,
It can be seen that the same effect can be obtained as when the diaminobutane / adipic acid unit is copolymerized alone. From Example 8, it can be seen that even if the terminal block was carried out by adding a diamine and the amino group concentration was higher than the carboxyl group concentration, it was effective in suppressing gel formation, spherulite formation and continuous batch polymerization. However, Examples 1 to 4 in which the amino group concentration is lower
The effect is slightly lower than that of 7. From Example 9, it can be seen that even if the terminal amino group is modified into a carboxyl group by post-addition of succinic anhydride, it is effective in suppressing gel formation and spherulite formation.

From Comparative Example 1, when the amide unit obtained from the diamine represented by the general formula (1) and the dicarboxylic acid was not copolymerized, gel generation, spherulite generation, and continuous batch polymerizability were inferior. Understand. Comparative Example 2 shows that the copolymerization of 2-methylpentamethylenediamine / adipic acid unit suppresses the formation of gel, suppresses the formation of spherulites, and improves continuous batch polymerizability, but the effect is small. Comparative Example 3
4 shows that addition of phosphorous acid or phosphorous acid and sodium hydroxide can suppress gel formation, spherulite formation, and improve continuous batch polymerizability, but their effects are small.

According to Comparative Example 5, when the terminal group was blocked with a diamine and the amino group concentration became too large, the gel was obtained even when the polyamide unit obtained from the diamine represented by the general formula (1) and adipic acid was copolymerized. It can be seen that the effects of suppressing generation, suppressing spherulite generation, and improving continuous batch polymerizability are small. From Comparative Example 6, even if a polyamide unit obtained from a diamine and a dicarboxylic acid represented by the general formula (1) is copolymerized, if the amount of copolymerization is small, gel formation suppression, spherulite formation suppression, and continuous batch polymerizability are suppressed. It can be seen that the improvement effect of is small.

[0055]

The copolymerized polyamide of the present invention has excellent mechanical properties and less gel and spherulite generation, so that it is less liable to break even during long-time melt spinning and has excellent continuous batch polymerizability. Further, since the occurrence of gelled matter and black carbide is small, the appearance is not impaired when the molded article is formed.

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Claims (8)

[Claims] 1. 80 to 99.5 mol% of a hexamethylene adipamide unit and 0.5 to 20 mol% of an amide unit composed of at least one diamine represented by the general formula (1) and a dicarboxylic acid. And a carboxyl group concentration [COOH] (μ
mol / g) and amino group concentration [NH2] (μmol / g)
g) a copolymer polyamide satisfying the formula (2). H ₂ N— (CH ₂ ) n—NH ₂ (1) (where n represents a positive integer excluding 6) 0.7 ≦ [COOH] / [NH ₂ ] ≦ 10 (2) ) 2. A carboxyl group concentration [COOH] (μm
ol / g) and amino group concentration [NH ₂ ] (μmol / g)
The copolymerized polyamide according to claim 1, wherein a ratio of the copolymer polyamide and the copolymer satisfies the formula (4). 1 ≦ [COOH] / [NH ₂ ] ≦ 3 (4) 3. A diamine represented by the general formula (1):
1,4-diaminobutane, 1,5-diaminopentane,
3. The copolymer according to claim 1, which is 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, or 1,12-diaminododecane. Polymerized polyamide. 4. A diamine represented by the general formula (1):
1,4-diaminobutane, 1,9-diaminononane,
3. The copolymerized polyamide according to claim 1, which is 1,10-diaminodecane or 1,12-diaminododecane. 5. The method according to claim 1, wherein the hexamethylene adipamide unit is 95 to 95%.
The copolymerized polyamide according to any one of claims 1 to 4, wherein 99.5 mol%, and an amide unit composed of at least one diamine represented by the general formula (1) and a dicarboxylic acid is 0.5 to 5 mol%. 6. A mixture or salt of 80 to 99.5 mol% of hexamethylenediamine / adipic acid, and 0.5 to 2%.
When polycondensation of 0 mol% of at least one kind of diamine represented by the general formula (1) with a mixture or salt of dicarboxylic acid, monocarboxylic acid, dicarboxylic acid, monoamine,
The method for producing a copolyamide according to claim 1, wherein one or more diamine farmland is added. 7. A copolyamide fiber produced by melt-spinning the copolyamide according to claim 1. Description: 8. A copolyamide molded article produced by melt-molding the copolyamide according to claim 1.