JP2001261819A - Nylon 6 or copolymer thereof, and process for preparation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nylon 6 or a copolymer thereof which is excellent in light resistance and viscosity stability and also can be deep color-dyed, and to provide a process for preparation thereof. SOLUTION: The nylon 6 or the copolymer thereof is a polymer in which at least one kind of a piperidine-based compound is chemically bonded to the polymer chain or at the polymer end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to nylon 6 or a copolymer thereof having improved physical properties. Specifically, the present invention relates to nylon 6 or a copolymer thereof, which is excellent in light resistance, dyeability and viscosity stability and can be used as a high-quality fiber or film, and a method for producing the same.

[0002]

2. Description of the Related Art Nylon 6 resin is a versatile engineering plastic excellent in mechanical strength, heat resistance, chemical resistance, workability, etc., and is used in automobiles and home appliances, including tire cords, clothing and packaging films. Widely used as parts of office equipment.

However, the viscosity stability and light resistance of nylon 6 resin are not sufficient for various uses. That is, the nylon 6 resin has a problem that the stability at the time of melt molding is not sufficient and the viscosity increases at the time of molding. As a means for maintaining the viscosity at the time of melting, various methods for blocking the terminal of the nylon 6 molecular chain have been tried. For example, in order to reduce the formation of a gelled product at the time of melting, a carboxyl group terminal with a specific amount of a monoamino hydrocarbon is used. (JP-A-62-252424) and a method of reducing the change in the degree of polymerization by controlling the water content, terminal group concentration, lactam and dimer concentration (JP-A-8-231711), etc. Has been proposed. However, these methods use nylon 6
However, it is difficult to obtain a polymer having a high degree of polymerization, and there is a problem in that the physical properties of a nylon 6 resin molded article using the same are deteriorated.

[0004] Nylon 6 resin also has a disadvantage that the polyamide is easily yellowed due to deterioration of the polyamide under the influence of light, particularly ultraviolet light. Thus, for example, coloring occurs during thermal processing, use, and storage of various fiber products. Also,
Similar problems occur in films and molded products. Therefore, a method of melting and mixing an organic ultraviolet absorber such as a benzophenone compound or a benzotriazole compound has been proposed. However, benzophenone-based compounds have a poor effect of preventing yellowing against ultraviolet rays, and benzotriazole-based compounds are easily decomposed by heat or oxidatively decomposed. There was a problem.

[0005] On the other hand, if the terminal is blocked to stabilize the viscosity of the nylon resin, the dyeability may be reduced. Therefore, it is required to maintain the dyeability while stabilizing the viscosity. When obtaining a dark-colored dyeable type polyamide, a copper salt is used in combination with a halogen or phosphorus compound. However, in this case as well, the product may be colored, or these compounds may be easily extracted in a dyeing process, washing, or the like, and may cause environmental problems. Also, the presence of metal ions in the product can cause additional problems during recycling or incineration of the final product. Therefore, Japanese Patent Application Laid-Open No. 10-504046 discloses the following formula:

Embedded image A polyamide containing an amino compound represented by the formula (1) in a state of being chemically bonded to a polymer chain, maintaining dyeing properties, and being substantially light-stabilized and heat-stabilized is disclosed. Further, JP-A-10-120781 discloses that polymerization or polycondensation of a polyamide-forming monomer is carried out by using 4-amino-2,2,
By performing in the presence of 6,6-tetraalkylpiperidine, an aliphatic or alicyclic diamine having primary and tertiary amino groups, and a 2,6-dialkylphenol having a hydroxyl group at the 4-position, polyamide Methods for improving light fastness are disclosed. However, there is a problem that use of the compound described here increases costs.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and provides nylon 6 or a copolymer thereof having excellent light fastness and excellent viscosity stability while maintaining dyeing properties, and a method for producing the same. Is provided.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that this object can be achieved by chemically bonding a specific piperidine compound to nylon 6. Heading, the present invention has been reached. That is, the gist of the present invention is as follows. (1) Nylon 6 or a copolymer thereof, characterized in that at least one piperidine compound represented by the following formula is chemically bonded to the polymer chain or at the terminal.

Embedded image (2) A method for producing nylon 6 or a copolymer thereof, wherein ε-caprolactam or 6-aminocaproic acid is polymerized as a main component in the presence of at least one piperidine compound represented by the above formula. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The nylon 6 or its copolymer of the present invention needs to have at least one kind of piperidine compound represented by the above formula chemically bonded to the polymer chain or at the terminal. Specific examples of the piperidine-based compound represented by the above formula include 4-ethylamino-2,2,6,6-tetramethylpiperidine, 4-butylamino-2,2,6,6-tetramethylpiperidine, Hexylamino-2,2,6,6-tetramethylpiperidine, 4-dodecylamino-2,2,6,6-tetramethylpiperidine, 4-cyclopentylamino-2,2,6,6-tetramethylpiperidine, 4 -Cyclohexylamino-2,2,6,6-tetramethylpiperidine and the like. The amount of the piperidine compound to be added is preferably 0.0003 to 0.008 mol, and more preferably 0.0006 to 0.008 mol per mol of the amide group of nylon 6.
0.004 mol is more preferred. If the addition amount is further increased, the molecular weight does not increase, and if it is less than this, the effect of light resistance cannot be obtained.

The nylon 6 or its copolymer according to the present invention contains at least 80 mol%, preferably at least 90 mol%, of caproamide units as a main component. Also,
Nylon 6 copolymer refers to ε-caprolactam or 6-aminocaproic acid that forms caproamide units and various other lactams, aminocarboxylic acids, and nylon salts.
It is obtained by copolymerizing in a proportion of less than 10 mol%, preferably less than 10 mol%.

Specific examples of the above-mentioned copolymer components include ω-
Laurolactam, 11-aminoundecanoic acid, 12-aminododecanoic acid, p-aminomethylbenzoic acid, nylon 46 salt,
Nylon 66 salt, Nylon 610 salt, Nylon 6T salt, Nylon 6I salt, Nylon 9T salt, salt of meta-xylylenediamine with adipic acid (nylon MXD salt) and the like.

The relative viscosity of the nylon 6 of the present invention or its copolymer is determined by using 97% by weight concentrated sulfuric acid as a solvent at a temperature of 25%.
It is preferably in the range of 1.5 to 5.0, more preferably in the range of 2.0 to 3.0, at a temperature of 1 ° C. and a concentration of 1 g / dl. If the relative viscosity is less than 1.5, the mechanical strength and formability of the fiber or film are reduced.
Conversely, if it exceeds 5.0, the moldability decreases rapidly.

Next, a method for producing nylon 6 or a copolymer thereof according to the present invention will be described. In the present invention, in the presence of at least one piperidine compound represented by the above formula, ε-caprolactam or 6-
Polymerizes aminocaproic acid. The piperidine-based compound is added to the starting monomer or the polymerization reaction mixture and is chemically bonded to the polymer chain or at the terminal. The polymerization itself of the starting monomer material in the presence of the piperidine compound is carried out by a conventional batch method or a continuous method using a polymerization initiator. At this time, at least one kind of the piperidine-based compound, the polymerization initiator, and the starting monomer material are introduced into the reactor separately or as a mixture, and then subjected to polymerization.

As the polymerization initiator, water, 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, p-aminobenzoic acid and the like are used, but water is preferred. Further, in the present invention, a chain control agent can be used. Specific examples of this chain regulator include acetic acid, propionic acid, benzoic acid and other monocarboxylic acids, adipic acid, azelaic acid, sebacic acid, alkane dicarboxylic acids such as dodecanedioic acid, cyclohexane-1,4-dicarboxylic acid, etc. Aromatic dicarboxylic acids such as cycloalkanedicarboxylic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid and benzenedicarboxylic acid. The type and amount of the chain control agent are determined by the desired amino terminal group concentration (or carboxyl terminal group concentration) and the desired melt viscosity stability as the final product.

The nylon 6 or the copolymer thereof of the present invention contains a heat stabilizer, a weathering agent, an inorganic filler, a reinforcing agent, an antioxidant, an impact modifier, a plasticizer, as long as its physical properties are not impaired. Agents, pigments, lubricants, flame retardants, and the like may be added, and these are added during polymerization, dry blending, melt kneading, or melt molding.

[0015]

The reason why the nylon 6 or the copolymer thereof of the present invention can be expected to be thermally stabilized during the melt spinning, the film forming process, the molding process, etc. is that the specific piperidine compound is
It is presumed that it reacted with the carboxyl group of the polymer being formed by polymerization and was chemically bonded in the polymer chain or at the terminal, and the carboxyl terminal group concentration was reduced. Therefore, it is excellent in light fastness, capable of deep dyeing, and excellent in viscosity stability.

[0016]

Next, the present invention will be described more specifically with reference to examples. In addition, a raw material, a measuring method, and a manufacturing method of a fiber are as follows.

1. Raw materials • ε-caprolactam: manufactured by Ube Industries, Ltd. • 4-butylamino-2,2,6,6-tetramethylpiperidine: H
uls Co., Ltd. ・ Nylon 66 salt: BASF Co., Ltd. ・ 12-aminododecanoic acid: Nacalai Tesque Co., Ltd. ・ Adipic acid: Nacalai Tesque Co., Ltd.

2. Measurement method (a) Relative viscosity Prepare 97% sulfuric acid as a solvent to a concentration of 1 g / dl,
It measured at 25 degreeC using the Ubbelohde viscosity tube. (b) Melt viscosity stability Nylon 6 or a copolymer pellet thereof subjected to viscosity measurement (1) by the method of (a) is dried at 100 ° C. for 12 hours, and is dried in a glass tube at 0.01 Torr or less, 250 ° C. For 5 hours. The melted nylon 6 or its copolymer was freeze-ground in liquid nitrogen, treated with hot water at 100 ° C., dried, and the relative viscosity (2) was determined again by the method (a). The value of (2)-(1) was used as an index of melt viscosity stability. The smaller the value, the better the thermal stability. (c) Amino end group concentration After dissolving 0.5 g of nylon 6 or a copolymer pellet thereof in 20 ml of m-cresol at 60 ° C., the mixture was cooled to room temperature, and 0.1N
It was determined by performing a titration with an aqueous solution of p-toluenesulfonic acid. (d) Concentration of carboxyl end group 0.5 g of nylon 6 or a copolymer thereof was dissolved in 10 ml of benzyl alcohol at room temperature, and titration was performed with a 0.1N potassium hydroxide-benzyl alcohol solution. (e) Strength Measured according to JIS L-1013 7.5.1. (f) Lightfastness Using a Suga Test Machine Fade Meter FAL-3H, irradiate ultraviolet rays at a black panel temperature of 63 ± 3 ° C for a total of 100 hours, and determine the fiber strength before and after irradiation by the method of (e). The strength was measured to determine the strength retention. (g) Dyeing performance After scouring the resulting fiber, Kirinol Gyanine G 1.0 Om
f, leveling agent Liogen P 2.0g / l, pH4, bath ratio 1:50 9
Dye at 8 ° C for 45 minutes.
It was evaluated on a scale. Good: ○ Normal: △ Bad: ×

3. Fiber production method Nylon 6 resin pellets are melt-spun at a spinning temperature of 220 to 320 ° C.
A take-up yarn was obtained at a speed of 0 m / min. Cooling air temperature,
The spraying amount, the take-up speed, the discharge amount, and the number of holes in the base were appropriately adjusted. The obtained yarn was stretched as needed.

Example 1 10 kg of ε-caprolactam, 1 kg of water and 4-butylamino-2,2,6,6-tetramethylpiperidine were mixed in the amounts shown in Table 1, and 30 liters of the mixture were reacted. The mixture was placed in a can, heated to 260 ° C. while stirring, and the pressure was increased to a pressure of 0.5 MPa. Then, release the pressure to normal pressure,
Polymerized for hours. At the time of completion of the polymerization, the reaction product was discharged into a strand, cooled, solidified, and cut to obtain nylon 6 resin pellets. The obtained pellets were treated with hot water of 95 ° C., refined and dried, and the terminal group concentration, relative viscosity and melt viscosity stability were measured.

Example 2 9 kg of ε-caprolactam, 1 kg of 12-aminododecanoic acid
Was mixed with 1 kg of water and 4-butylamino-2,2,6,6-tetramethylpiperidine in the amounts shown in Table 1 and
The mixture was placed in a 0-liter reaction vessel, heated to 260 ° C. while stirring, and the pressure was increased to 0.5 MPa. Thereafter, the pressure was released to normal pressure, and polymerization was performed at 260 ° C. for 3 hours. At the time of completion of the polymerization, the reaction product was discharged into a strand, cooled, solidified, and cut to obtain nylon 6/12 (95: 5) copolymer resin pellets. The obtained pellets were treated with hot water at 95 ° C., refined and dried, and the terminal group concentration, relative viscosity and melt viscosity stability were measured.

Example 3 1 kg of water and 4-butylamino-2,2,6,6-tetramethylpiperidine were added to 9.5 kg of ε-caprolactam and 0.5 kg of nylon 66 salt in the amounts shown in Table 1. , This is 30
The mixture was placed in a liter reaction vessel, heated to 260 ° C. while stirring, and the pressure was increased to 0.5 MPa. Thereafter, the pressure was released to normal pressure, and polymerization was performed at 260 ° C. for 3 hours. At the time of completion of the polymerization, the reaction product was discharged into a strand, cooled, solidified, and cut to obtain nylon 6/66 (95: 5) copolymer resin pellets. The obtained pellets were treated with hot water at 95 ° C., refined and dried, and the terminal group concentration, relative viscosity and melt viscosity stability were measured.

Examples 4-8 Nylon was prepared in the same manner as in Example 1 except that the amounts of 4-butylamino-2,2,6,6-tetramethylpiperidine and adipic acid were changed as shown in Table 1. 6 resin pellets were obtained, and the terminal group concentration, relative viscosity, and melt viscosity stability were measured.

Comparative Example 1 10 kg of ε-caprolactam was mixed with 1 kg of water, placed in a 30 liter reactor, heated to 260 ° C. while stirring, and the pressure was increased to 0.5 MPa. Thereafter, the pressure was released to normal pressure, and polymerization was performed at 260 ° C. for 3 hours. When the polymerization was completed, the reaction product was discharged into a strand, cooled, solidified, and cut to obtain nylon 6 resin pellets. The obtained pellets were treated with hot water at 95 ° C., refined and dried, and the terminal group concentration, relative viscosity and melt viscosity stability were measured.

Comparative Example 2 Nylon 6 resin pellets having different degrees of polymerization by changing the pressure were obtained, and the terminal group concentration, relative viscosity and melt viscosity stability were measured in the same manner as in Comparative Example 1.

Comparative Example 3 Nylon 6 resin pellets were obtained in the same manner as in Comparative Example 1 except that adipic acid was added as shown in Table 1 during polymerization, and the terminal group concentration, relative viscosity and melt viscosity stability were measured. Was.

Table 1 shows the results of Examples 1 to 8 and Comparative Examples 1 to 3.

[0028]

[Table 1]

As is clear from Table 1, the nylon 6 and the copolymers of Examples 1 to 8 were excellent in viscosity stability and maintained dyeability.

Examples 9 to 10 and Comparative Example 4 Fibers were obtained from the nylon 6 resin pellets obtained in Examples 7, 8 and Comparative Example 1, and the light resistance and the dyeing performance were measured. The results are shown in Table 2.

[0031]

[Table 2]

As is clear from Table 2, Examples 9 to 10
The fiber had excellent light resistance with a strong retention rate of 70% or more after ultraviolet irradiation, and the dyeing performance was maintained at the current level.

[0033]

Industrial Applicability The nylon resin of the present invention has excellent light fastness, is free from yellowing by light and coloring due to compounds, is capable of deep dyeing, and has excellent viscosity stability. It is suitable.

Continued on the front page F term (reference) 4J001 DA01 DB01 DB02 DD20 EA06 EA08 EA15 EA16 EA17 EA28 EB08 EB09 EB36 EB37 EC07 EC08 EC09 EC47 EE27C EE28C EE64C FA03 FA05 FB01 FB03 FC01 JA10 JA12 JB35 JB41 JB50

Claims (2)

[Claims] 1. Nylon 6 or a copolymer thereof, characterized in that at least one piperidine compound represented by the following formula is chemically bonded to a polymer chain or at a terminal. Embedded image 2. In the presence of at least one piperidine compound represented by the above formula, ε-
A method for producing nylon 6 or a copolymer thereof, comprising polymerizing caprolactam or 6-aminocaproic acid.