JP2001200054A - Preparation method of nylon 6 copolymer and fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for preparing a high quality polymer with reduced white foreign materials in the preparation of a nylon 6 copolymer which uses ε-caprolactam and a dicarboxybenzenesulfonate compound as main raw materials. SOLUTION: In the preparation of a nylon 6 copolymer by polymerizing an ε-caprolactam aqueous solution which contains ε-caprolactam, a dicarboxybenzenesulfonate compound and a diamine compound, the ε- caprolactam aqueous solution contains (1) a salt of the dicarboxylic acid and the diamine and/or (2) an aminocarboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a nylon 6 copolymer and a fiber. More specifically, the present invention relates to a method for producing a uniform nylon 6 copolymer having good dyeing properties for a basic dye and producing no foreign matter during polymerization, and to a fiber.

[0002]

2. Description of the Related Art In general, nylon 6 is used for clothing fibers and industrial fibers by taking advantage of its excellent properties. In addition, nylon 6 is used as an injection molded product in the automotive field, electric / electronic field, etc., and for food packaging. It is widely used mainly as an extruded film and a stretched film. When dyeing these nylon 6, fibers, films, molded articles and the like, acid dyes or disperse dyes are mainly used. But,
These dyes are still unsatisfactory in color clarity as compared with basic dyes, and there is a demand for nylon 6 having an affinity for basic dyes.

[0003] Numerous proposals have been made in the past to increase the affinity of nylon 6 for basic dyes. For example, a method of introducing mono- or dicarboxybenzene having a sulfonate group into polyamide (Japanese Patent Publication No. 37-173).
No. 14646, Japanese Patent Publication No. 37-14647),
A method in which a compound having two sulfonate groups in a naphthalene ring such as di (sodium sulfonate) -naphthalene-2-carboxylic acid is introduced into a polyamide (Japanese Patent Publication No. 44-12 / 1972)
No. 36), mono- or di- (sodium sulfonate)-
A method of introducing a dicarboxylic acid having a sulfonate group into a naphthalene ring such as naphthalene-dicarboxylic acid into a polyamide (Japanese Patent Publication No. 46-6077) or a method of introducing a poly (alkylene ether derivative) having a sulfonate group into a polyamide (see No.46-41016-41
No. 019), and a method of introducing sulfonated polystyrene into polyamide (Japanese Patent Publication No. 43-24229).

However, when the compounds proposed in JP-B-37-14646 and JP-B-44-1236 are introduced into polyamide to such an extent that they have a sufficient affinity for basic dyes, the compounds are converted to ε-caprolactam. There is a disadvantage that the physical and mechanical properties of the polymer are reduced because it acts as a polymerization degree stabilizer. In addition, Japanese Patent Publication No. 46-41016
In the case of obtaining a polyamide fiber having an affinity for a basic dye by the method proposed in JP-A-41019, there is a disadvantage that yarn breakage occurs due to fusion of the yarn in the yarn-making process, and operability is significantly reduced. Further, the product obtained by dyeing the fiber with a basic dye has a drawback that washing fastness is poor. In addition, Tokiko Sho 4
When a polyamide fiber is obtained by the method proposed in JP-A-3-24229, the compatibility between the sulfonated polystyrene and the polyamide is poor, the dispersion of the styrene compound in the polyamide becomes insufficient, and the yarn breakage in the yarn-making process. However, when the obtained fiber is immersed in warm water, sulfonated polystyrene is eluted into the warm water. Although it is possible to obtain polyamide fibers by the method proposed in Japanese Patent Publication No. 46-6077, there is a disadvantage that the sulfonate compound used is expensive and difficult to obtain.

On the other hand, it is possible to obtain a polyamide fiber having an affinity for a basic dye by the method proposed in Japanese Patent Publication No. 37-14647. However, in this case, when polymerizing ε-caprolactam using a dicarboxysulfonate compound, when the water contained in ε-caprolactam decreases during polymerization, white insolubles are mixed in the polymer, resulting in uneven nylon. There is a disadvantage that only 6 can be obtained.

[0006] As a result of exploring the formation mechanism of such a white insoluble matter, it was found that the dicarboxysulfonate compound N
In the process of reducing the water content at the beginning of polymerization, a metal ion such as a or K binds to a carboxyl group of another dicarboxysulfonate compound to form a metal carboxylate, and the metal carboxylate is pure. Na
-Insoluble in caprolactam and nylon 6 polymer and found to be the cause of insoluble white foreign matter.

As methods for suppressing the generation of such white foreign matter, Japanese Patent Application Laid-Open Nos. 53-134896 and 53-1
No. 42499 has been proposed.

First, the method disclosed in JP-A-53-134896 is characterized in that a sulfonate compound is completely dissolved in ε-caprolactam and then polymerized by adding a diamine or the like. Since the exchange reaction occurs regardless of the presence or absence of the diamine, the generation of insoluble white foreign matter cannot be avoided. On the other hand, JP-A-53-1
No. 42499 discloses a polycondensate obtained by previously polycondensing ε-caprolactam and a sulfonate compound,
The method is characterized by further polycondensing a polycondensate obtained by polycondensing caprolactam and a diamine compound, but it is apparent that even this method cannot suppress the formation of white foreign matter.

[0009]

As described above, in the production of a nylon 6 copolymer containing ε-caprolactam and a dicarboxybenzenesulfonate compound as main raw materials,
A practical method capable of producing a high-quality polymer in which the generation of white foreign matter is suppressed has not been known.

Accordingly, it is a main object of the present invention to provide a method for producing a nylon 6 copolymer which solves the above-mentioned problems of the prior art.

[0011]

Means for Solving the Problems In order to solve the above-mentioned problems, the method for producing a nylon 6 copolymer of the present invention mainly has the following constitution. That is, 0.3 to 3 mol% of at least one dicarboxybenzene sulfonate compound represented by the formula (I) is added to ε-caprolactam, and an aqueous solution of ε-caprolactam is polymerized to produce a nylon 6 copolymer. In doing so, the aqueous solution of ε-caprolactam contains (1) a salt of a dicarboxylic acid and a diamine and / or (2) an aminocarboxylic acid in an amount of 0.3 to 5 mol% based on ε-caprolactam. This is a method for producing a copolymer.

[0012]

Embedded image (In the formula, M represents Na or K, X and X ′ represent COOH or RCOOH (where R represents an alkylene group having 1 to 3 carbon atoms).) The fiber of the present invention mainly has the following constitution. Have. That is, it is a fiber obtained by melt-spinning the nylon 6 copolymer obtained by the above production method.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below.
Examples of the dicarboxybenzenesulfonate compound represented by the formula (I) used in the production method of the present invention include 2,5- or 3,5-dicarboxybenzenesulfonic acid, 2,5- or 3,5- Sodium or potassium sulfonates such as dicarboxymethylbenzenesulfonic acid, 2,5- or 3,5-dicarboxyethylbenzenesulfonic acid, and 2,5- or 3,5-dicarboxypropylbenzenesulfonic acid; Compound 1
Although only one kind may be used or two or more kinds may be used in combination, sodium 3,5-dicarboxybenzenesulfonate, which is inexpensive, is particularly preferably used.

In the production method of the present invention, these dicarboxybenzenesulfonate compounds are added in a range of 0.3 to 3 mol% based on ε-caprolactam. Below this range, a sufficient dyeing effect on the basic dye cannot be obtained, and above this range, the physical properties such as heat resistance and mechanical properties of the resulting nylon 6 copolymer tend to decrease.

The addition of the dicarboxybenzenesulfonate compound represented by the formula (I) allows the nylon 6
When the balance between the amino group and the carboxyl group of the copolymer is lost and the polymerization reaction rate is significantly reduced, a diamine compound may be added as needed.

Specific examples of such a diamine compound include:
1,4-diaminobutane, 1,5-diaminopentane,
1,6-diaminohexane, 2-methyl-1,5-diaminopentane (MDP), 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
Aliphatic diamines such as diaminooctadecane, 1,19-diaminononadecane and 1,20-diaminoeicosane, cyclohexanediamine, alicyclic diamines such as bis- (4-aminohexyl) methane, m-xylylenediamine And an aromatic diamine such as p-xylylenediamine, and an aliphatic diamine is particularly preferably used. In addition, these diamine compounds can be used in a mixture of two or more.

The rate of addition of these diamine compounds to ε-caprolactam is not particularly limited, and may be added in consideration of the polymerization rate and the like, but is usually preferably in the range of 0 to 2.0 mol%.

These dicarboxybenzenesulfonate compounds and, if necessary, a diamine compound are added to ε-caprolactam, and water is contained in an amount of 0.5 to 20% by weight based on ε-caprolactam as in ordinary polymerization of nylon 6. It should be done.

In the production method of the present invention, the aqueous solution of ε-caprolactam may comprise (1) a salt of a dicarboxylic acid and a diamine and / or (2) an aminocarboxylic acid in an amount of 0.3 to 5 mol% based on ε-caprolactam. It is essential to contain. When the content of (1) a salt of dicarboxylic acid and diamine and / or (2) aminocarboxylic acid with respect to ε-caprolactam is less than 0.3 mol%, the effect of suppressing the formation of white foreign matter cannot be obtained, and If it exceeds mol%, not only a saturation phenomenon is observed in the effect of suppressing the formation of white foreign substances, but also the physical properties such as heat resistance and mechanical properties of the obtained nylon 6 copolymer tend to decrease.

Surprisingly, when these (1) salts of dicarboxylic acids and diamines and / or (2) aminocarboxylic acids are contained, the formation of the above-mentioned white foreign matter derived from the dicarboxybenzenesulfonate compound can be suppressed. . Although the action of suppressing the formation of white foreign matter is not clear,
When (1) a salt of dicarboxylic acid and diamine and / or (2) aminocarboxylic acid is polymerized, the polymerization reaction rate is improved because these act as an activator of the polymerization reaction,
It is considered that the condensation reaction of nylon occurs preferentially to the binding of the metal ion to the carboxyl group of the dicarboxybenzenesulfonate compound.

The aminocarboxylic acids that can be used in the production method of the present invention include, for example, 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminooctanoic acid and 9-aminooctanoic acid.
-Aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like. Among these, 6-aminocaproic acid, which is a ring-opened product of ε-caprolactam, is preferably used. Further, 6-caprolactam was prepolymerized to give 6-caprolactam.
Those obtained by forming aminocaproic acid or a nylon 6 chain oligomer are also preferably used. In addition, these aminocarboxylic acids can be used in a mixture of two or more.

In the salts of dicarboxylic acids and diamines that can be used in the present invention, specific examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, Aliphatic dicarboxylic acids such as sebacic acid, undecandioic acid, dodecandioic acid, prasillic acid, tetradecandioic acid, pentadecandioic acid, octadecandioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid And aromatic dicarboxylic acids such as terephthalic acid and naphthalenedicarboxylic acid. These dicarboxylic acids can be used in a mixture of two or more. As the diamine, the diamine compounds shown in the above specific examples can be used. These dicarboxylic acids and diamines are added in the form of salts, and salts of adipic acid and hexamethylenediamine are most preferably used.

Using these raw materials, the nylon 6 of the present invention is used.
There is no particular limitation on the reaction apparatus for polymerizing the copolymer, and any apparatus may be used as long as it is a commonly used polymerization apparatus such as a VK tube or an autoclave provided with an external heating jacket. The polymerization conditions are not particularly limited, and ordinary polymerization conditions for nylon 6 may be used.

The polymer obtained in this manner is discharged from a polymerization reactor, cooled and cut into pellets and then subjected to hot water extraction and drying steps in the same manner as in the usual method for producing nylon 6 to obtain nylon. A product of 6 copolymer is obtained.

In the production method of the present invention, for example, an end group amount modifier (e.g., an aliphatic monocarboxylic acid such as acetic acid, propionic acid or butyric acid, a fatty acid such as cyclohexanecarboxylic acid, Cyclic monocarboxylic acids, benzoic acid, toluic acid, ethylbenzoic acid, aromatic monocarboxylic acids such as phenylacetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,
Aliphatic dicarboxylic acids such as pimelic acid, suberic acid, azelaic acid, sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid Such as carboxylic acids and anhydrides thereof, butylamine, pentylamine, hexylamine, heptylamine, octylamine, aliphatic monoamines such as 2-ethylhexylamine, cycloaliphatic monoamines such as cyclohexylamine and methylcyclohexylamine, and benzylamine , Aromatic monoamines such as β-phenylethylamine, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9 −
Aliphatic diamines such as diaminononane, 1,10-diaminodecane, cyclohexanediamine, alicyclic diamines such as bis- (4-aminohexyl) methane, and amine compounds such as aromatic diamines such as xylylenediamine; Antioxidants and heat stabilizers (hindered phenols, hydroquinones, phosphites and their substitutes, copper halides, iodine compounds, etc.), weathering agents (resorcinol, salicylate, benzotriazole, benzophenone, Hindered amines), release agents and lubricants (such as aliphatic alcohols, bisureas and polyethylene waxes), pigments (such as cadmium sulfide, phthalocyanine and carbon black), dyes (such as nigrosine),
Crystal nucleating agent (talc, silica, kaolin, clay, etc.), plasticizer (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.), antistatic agent (alkyl sulfate type amion antistatic agent, quaternary ammonium salt) -Type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine amphoteric antistatic agents, etc., and flame retardants (melamine cyanurate, water such as magnesium hydroxide, aluminum hydroxide, etc.) Oxides, ammonium polyphosphate, brominated polystyrene,
Brominated polyphenylene oxide, brominated polycarbonate, brominated epoxy resin or a combination of these brominated flame retardants with antimony trioxide, etc., fillers (graphite, barium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, antimony oxide, Titanium oxide, aluminum oxide, zinc oxide, iron oxide, zinc sulfide,
Particles such as zinc, lead, nickel, aluminum, copper, iron, stainless steel, glass fiber, carbon fiber, aramid fiber,
Fibrous, needle-like, plate-like fillers), other polymers (other polyamides, polyethylene, polypropylene, polyester,
Polycarbonate, polyphenylene ether, polyphenylene sulfide, liquid crystal polymer, polysulfone, polyethersulfone, ABS resin, SAN resin, polystyrene, etc.) can be added.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 30.0 g of ε-caprolactam (hereinafter abbreviated as LC) and sodium 3,5-dicarboxybenzenesulfonate (hereinafter CB) were placed in a glass test tube.
S) 0.40 g (0.56 mol% based on LC), hexamethylene diamine (hereinafter abbreviated as HD) 0.050
g and 3.0 g of water, and then, as shown in Table 1, a salt of adipic acid and hexamethylenediamine (hereinafter, abbreviated as AH salt) or 6-aminocaproic acid (hereinafter, abbreviated as ACA) is added thereto. To a uniform solution. After attaching a nitrogen gas introduction tube to these test tubes, polymerization was carried out in a silicone oil bath while a small amount of nitrogen gas was flowing. The temperature of the oil bath was raised from 150 ° C. to 240 ° C. at a rate of 15 ° / 10 minutes, and was maintained at 240 ° C. for 6 hours.
After the polymerization, the test tube was pulled out of the oil bath, and the degree of occurrence of white precipitate in the polymer still in a molten state was observed. The result is shown in Table 1. By the addition of the AH salt or ACA of the present invention, the effect of suppressing the formation of white foreign matters was clearly recognized.

[0028]

[Table 1]

Example 2 100 parts by weight of LC and 2.30 parts by weight of CBS were added to a stainless steel autoclave (based on L).
0.97 mol%), 0.34 parts by weight of HD, 8.0 parts by weight of water and 4.50 parts by weight of AH salt (vs. LC).
1.94 mol%), and gradually heated to 250 ° C. for 2 hours.
Polymerization was carried out for hours. Thereafter, the pressure in the autoclave was released, and the mixture was further polymerized in a nitrogen stream for 2 hours. Then, the polymer was extruded into strands, and cooled / cut to obtain pellets. Next, the pellets were extracted with hot water and then dried with a rotary vacuum dryer. The pellets obtained were polymerized using an extruder spinning machine at a polymer temperature of 2.
It was melted at 65 ° C and spun from a die pack (with a die diameter of 0.3 mmφ) equipped with a stainless steel nonwoven fabric filter.
The spun yarn was quenched by passing through a uniflow chimney, a treatment agent was applied to the surface, and then hot drawing was performed using a hot roller. Table 2 shows the frequency of yarn breakage and the rate of increase in the filtration pressure of the pack.
Was as shown in FIG.

[0030]

[Table 2]

Comparative Example 1 The same operation as in Example 2 was carried out except that the AH salt was not added, and polymerization / filament production was carried out.
The frequency of yarn breakage and the rate of increase in the filtration pressure of the pack were as shown in Table 2. Compared to Example 2 of the present invention, the frequency of yarn breakage,
The rate of increase in the filtration pressure of the pack was large.

Example 3 Polymerization / filament production was carried out in the same manner as in Example 2 except that 2.30 parts by weight (based on 1.98 mol% of LC) of ACA was added instead of the AH salt. As shown in Table 2, the frequency of thread breakage and the rate of increase in the filtration pressure of the pack were small and favorable, and the effect of suppressing the generation of white foreign matter was recognized.

[0033]

As described above, by using the production method of the present invention, there is no generation of white foreign matter derived from the dicarboxysulfonate compound during the polymerization, and thus the obtained nylon 6 copolymer is melt-spun. When the filament is used, the breakage of the yarn and the increase in the pressure of the spinning pack are small, and stable continuous operation can be performed for a long time. In addition, the obtained fiber can be clearly dyed with a basic dye,
It is extremely useful for carpets, car interiors, and interiors.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J001 DA01 DB02 DC14 DD18 EA06 EA15 EB08 EC08 FA06 FB06 FC03 FD01 GA01 GA12 HA10 JA10 JB35 JC04 4L035 BB31 BB54 BB59 BB77 EE20 FF01 FF04 GG01

Claims (5)

[Claims] 1. An amount of at least one dicarboxybenzenesulfonate compound represented by the formula (I) of 0.3 to 3 mol% is added to ε-caprolactam, and an aqueous solution of ε-caprolactam is polymerized to form a nylon 6 copolymer. In preparing the union, the aqueous solution of ε-caprolactam is converted into (1) a salt of a dicarboxylic acid and a diamine and / or (2) an aminocarboxylic acid with ε.
-A method for producing a nylon 6 copolymer, comprising 0.3 to 5 mol% based on caprolactam. Embedded image (In the formula, M represents Na or K, X and X ′ represent COOH or RCOOH (where R represents an alkylene group having 1 to 3 carbon atoms).) 2. The method for producing a nylon 6 copolymer according to claim 1, wherein the dicarboxybenzenesulfonate compound is sodium 3,5-dicarboxybenzenesulfonate. 3. The method for producing a nylon 6 copolymer according to claim 1, wherein the aminocarboxylic acid is 6-aminocaproic acid. 4. The method for producing a nylon 6 copolymer according to claim 1, wherein the salt of the dicarboxylic acid and the diamine is a salt of adipic acid and hexamethylenediamine. 5. A fiber obtained by melt-spinning a nylon 6 copolymer obtained by the production method according to claim 1.