JP2000265366A - Production of polyamide-based fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing polyamide-based fibers having good dimensional stability capable of reducing end breakage and nap generation, stains on rollers and plates in a manufacturing process of fiber and continuously and stably producing the fiber for a long time in producing the polyamide-based fiber having high strength and good dimensional stability. SOLUTION: This production of a polyamide-based fiber is to apply 0.3-1.5 pts.wt. of a spinning oil, which is obtained by blending 0.01-1.0 pts.wt. of an antioxidant comprising DLα-tocopherol (vitamin E) as a main ingredient based on 100 pts.wt. of effective ingredients of the oil, to a melt spun polyamide-based fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyamide fiber, and more particularly to a method for efficiently producing a high-strength polyamide fiber having excellent yarn quality and dimensional stability.

[0002]

2. Description of the Related Art Polyamide fibers have high strength and are excellent in fatigue resistance and impact resistance. Therefore, they are used for various industrial materials such as tire cords, rubber reinforcing cords such as conveyor belts, fishing nets, sewing threads, ropes, and the like. It is used for seat belts, safety nets, etc.

As a method for increasing the strength of polyamide fiber, there is known a method in which a melt-spun fiber is taken and this yarn is subjected to two or more-stage drawing (Japanese Patent Publication No. 4-40449).
No.). Furthermore, in order to obtain a high-strength fiber, a method of using a high-molecular-weight polymer at a high draw ratio is a general yarn-making method.To draw a high-molecular-weight polymer at a high draw ratio, a heating roller or a heating roller is used. It is necessary to perform hot stretching using a plate or the like. In addition, after spinning, heated steam is injected through an orifice and stretched in two steps (Japanese Patent Publication No.
No. 11649) has been proposed and put into practical use.

However, in this method, unless a sufficient amount of heat is applied to the fiber, the fiber-forming property is poor (yarn breakage or fluff is generated), and sufficient drawing cannot be performed, so that a high-strength fiber cannot be obtained. Heating the take-up roller and stretching roller,
The fibers must be preheated and then drawn. In such a case, the aliphatic ester compound or aliphatic ether compound used in the spinning oil and the dispersant or emulsifier used to disperse or emulsify these compounds adhere to the heated roller or plate. And accumulate as tar-like substances and solids, causing thread breaks and fluff,
Tar-like substances and solids deposited on the rollers and plates cannot supply enough heat to the running fiber, which makes it impossible to obtain a stable product.The operation must be stopped and the rollers and plates must be cleaned. There is a problem.

In order to solve these problems, various methods have been proposed for preventing the oil agent from being oxidized by heat.
For example, JP-A-7-25277 and JP-A-4-34088 disclose a method using a specific oil agent and an antioxidant.
No. 1683 discloses a method using a specific emulsifier and an antioxidant, Japanese Patent Publication No. 57-30422 discloses a method using a specific polymer and an antioxidant, and Japanese Patent No. 61-46587 discloses a method using a low surface tension. A method using a compound having the following characteristics and an antioxidant is disclosed. JP-A-63-182416, JP-A-1-111020 and JP-A-2-91225 disclose methods of using an antioxidant in a silicone oil. Further, JP-A-60-9971 and JP-B-61-36115 disclose a method of using a spinning oil containing an organic antioxidant.

However, in any of these methods, it is necessary to increase the temperature of the rollers and plates in accordance with the increase in speed, and the heated rollers and plates become dirty with time, preventing the occurrence of thread breakage and fluff and the dimensional stability. It was not satisfactory enough.

Further, in order to meet the demand for higher performance, a method has been proposed in which the spinning speed is further increased or the high-speed spun yarn is heat-treated (Japanese Patent Publication No. 5-71683). However, it is very difficult to commercialize the cooling to -60 ° C or less in terms of equipment and cost.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, reduces the contamination and fuming properties of rollers and plates subjected to hot stretching and heat treatment in the spinning process, and improves the stability of yarn properties. An object of the present invention is to provide a method for producing a polyamide fiber capable of producing good fibers continuously for a long period of time.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have obtained the following knowledge. The fluff and thread breakage in the spinning process are related to the dirt on the roller and the plate, and it is necessary to minimize the dirt on the roller and plate to prevent fluff and thread breakage. As a method of reducing the contamination of rollers and plates, it cannot be solved by simply adding a specific substance or increasing the thermal decomposition rate of the oil agent as in the past, but by preventing oxidation of the oil agent and adjusting the oil adhesion amount Can be achieved. In other words, if the thermal decomposition of the oil agent is large, the oil agent attached to the roller or the plate is scattered by the thermal decomposition, and the amount of the oil agent remaining on the roller or the plate is reduced. However, in this case as well, it is practically impossible for the oil to decompose 100%, and the remaining oil undergoes an oxidation reaction or thermal decomposition to solidify or become a tar-like substance, and gradually spread on rollers and plates Go accumulate.

On the other hand, when the thermal decomposition property is small, the solidification of the oil agent remaining on the roller or the plate becomes slow, and the liquid oil agent is carried away by the fibers running on the roller surface or the plate surface,
Rollers and plates are always kept in a constant state, but if the amount of oil is too large, more oil than can be carried away by the traveling fiber adheres to the rollers and plates and gradually accumulates on the rollers and plates. This causes problems such as roller contamination and plate contamination. Therefore, in order to reduce roller contamination and plate contamination, it is necessary to increase the thermal stability and stability against oxidative decomposition of the oil agent, and to adjust the oil agent adhesion amount to an appropriate amount.

The present invention has been made on the basis of such findings, and the gist of the present invention is that DL-α-Tocopherol (vitamin-
E) An antioxidant whose main component is 100%
With respect to parts by weight, a spinning oil blended from 0.01 to 1.0 part by weight is
A method for producing polyamide fibers, wherein 0.3 to 1.5 parts by weight is added to 100 parts by weight of the fiber.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, the polyamide fiber is a poly-ε
-Multifilaments composed of caproamide, polyhexamethylene adipamide, polytetramethylene adipamide and polyamides based on the same, and the molecular weight, fineness, number of filaments, cross-sectional shape, yarn properties, fineness of polyamide fibers The structure, the presence or absence of an additive such as a heat-resistant agent or a light-resistant agent, and the properties of the polymer (terminal amino group concentration, terminal carboxyl group concentration) are not limited at all.

In the present invention, after the melt spun fiber is cooled and solidified, first, a spinning oil is applied. The feature of the spinning oil agent used in the present invention is that an antioxidant mainly composed of DL-α-Tocopherol (vitamin-E) is used as an active ingredient of the oil agent.
That is, 0.01 to 1.0 part by weight is added to 00 parts by weight. Antioxidants containing DL-α-Tocopherol as the main component
In general, aliphatic ester compounds and aliphatic ether compounds, which are active ingredients of oil agents, and dispersants and emulsifiers used for dispersing and emulsifying them are oxidatively decomposed on heated rollers or plates. It has the effect of lowering the load.

The antioxidant containing DL-α-Tocopherol as a main component is used in an amount of 0.01 to 100 parts by weight of the active ingredient of the spinning oil.
It must be contained in 1.0 part by weight, DL-α-Tocoph
If the antioxidant containing erol as a main component is less than 0.01 parts by weight,
Roller dirt and plate dirt during heat treatment in the spinning process, and fumes on rollers and plates become intense. Also, DL
-If the antioxidant containing α-Tocopherol as the main component exceeds 1.0 part by weight, roller contamination and plate contamination during heat treatment,
And smoke on rollers and plates is reduced,
It is not preferable because the cost increases. Note that DL-α-To
As the copherol, for example, Uvinul 2000 AO (trademark of BSF Japan Co., Ltd.) can be mentioned. In addition, spinning oils include dispersants, emulsifiers, antistatic agents, heat-resistant agents,
Antioxidants other than L-α-Tocopherol may be blended.

Antioxidants other than DL-α-Tocopherol include “IRGANOX 245”, “IRGANOX259”, and “IRGANOX
565 "," IRGANOX 1010 "," IRGANOX 1010FP "," I
RGANOX 1035FF, IRGANOX 1076, IRGANOX 108
1, IRGANOX 1098, IRGANOX 1222, IRGANOX
1330 '' and other hindered phenolic antioxidants,
Phosphorous processing stabilizers such as "IRGAFOS 168" (all
These are DL-α.
-May be used with Tocopherol.

The main component of the spinning oil used in the present invention is not particularly limited, and may be an aliphatic ester compound obtained by reacting an aliphatic alcohol with an aliphatic carboxylic acid, or an aliphatic alcohol, depending on the purpose. Use of aliphatic ether compounds obtained by reacting propylene oxide, ethylene oxide, and polyoxyethylene with propylene oxide, ethylene oxide, and polyoxyethylene, as well as mineral oil, polydimethyl silicone, and polyoxyethylenated (POE) -modified silicone compounds, alone or in combination can do.

The aliphatic ester obtained by reacting an aliphatic alcohol and an aliphatic carboxylic acid used in a spinning oil agent has an effect of improving the smoothness of the fiber in the spinning process. As the aliphatic alcohol or aliphatic carboxylic acid, those having 6 to 22 carbon atoms are preferable, and those having a sulfur atom, a phosphorus atom, or the like introduced into the molecule for improving heat resistance may be used. Specific examples include dioleyl adipate, oleyl oleate, lauryl oleate, isostearyl oleate, isotridecyl palmitate, diglycerin diolate, dioleyl thiodipropionate, and the like. Since the aliphatic polyester compound is particularly easily oxidized and decomposed by a heated roller or plate, the effect of the present invention is great in an oil agent containing an aliphatic polyester compound as a main component.

An aliphatic ether compound used in spinning oils and obtained by reacting an aliphatic alcohol with propylene oxide, ethylene oxide, or polyoxyethylene has an effect of enhancing the convergence of fibers in the spinning process. Things. Aliphatic ether compounds have an average molecular weight of
Those with less than 6000 are preferred. When the average molecular weight is 6000 or more, the viscosity of the oil agent increases, so that the coefficient of friction between the single yarn and the single yarn, and between the single yarn and the guide increases, and fluff and yarn breakage occur during the yarn making process. The average molecular weight of the aliphatic ether compound may be less than 6000 as long as the final molecular weight is less than 6000, and when a mixture of two or more kinds is used, even if the molecular weight of each aliphatic ether compound is 6000 or more, Should be less than 6000.

Further, when a polydimethyl silicone or a POE-modified silicone compound is blended with the spinning oil agent used in the present invention, it is possible to further reduce roller contamination and plate contamination in the spinning process. The POE-modified silicone preferably has a molecular weight of 2500 or more. Molecular weight 2500
When the viscosity is less than the above, the viscosity is different from that of the aliphatic ester compound or the aliphatic ether compound, and the compatibility becomes poor. As a result, spots of the oil agent attached to the fiber occur, and yarn breakage, fluffing, and stain spots occur. Happens.

The proportion of each component of the spinning oil agent is not particularly limited, but 30 to 80 parts by weight of a smoothing agent, 3
~ 30 parts by weight, emulsifier 10 ~ 50 parts by weight, and other additives in a suitable amount to become 100 parts by weight, this is DL-α-T
It is preferable to add 0.01 to 1.0 part by weight of ocopherol (vitamin-E). Within this range, the intended long-term continuous operation can be achieved without losing the functions of the spinning oil agent inherent in smoothness and convergence.

The spinning oil is applied to the fibers melt-spun by a conventional roller lubrication method or a nozzle lubrication method, and the amount of the spinning oil is 0.3 to 1.5 parts by weight, preferably 0.3 to 1.5 parts by weight, per 100 parts by weight of the fibers. It is necessary to use 0.5 to 1.0 parts by weight. If the applied amount is less than 0.3 parts by weight, the bunching and smoothness inherent in the oil agent will not be obtained, and it will be difficult to form a yarn. On the other hand, if the amount is more than 1.5 parts by weight, the oil agent adhering to the roller cannot be carried away by the running fiber or the cost increases, which is not preferable. The spinning oil is usually applied in the form of a straight oil diluted with a low-viscosity mineral oil or the like, but may be applied in the form of an aqueous emulsion.

The fiber to which the spinning oil has been applied is hot-drawn and relaxed by a conventional method, and then wound as it is, or further applied with a finishing oil to be wound.

[0023]

The spinning oil used in the present invention is DL-α-Toco
Because it contains an antioxidant whose main component is pherol,
This spinning oil agent is suppressed from being oxidized and decomposed with oxygen in the air to become a viscous tar-like substance even under the conditions of hot drawing and heat treatment. As a result, the oil agent adhering to the rollers is carried away by the running fibers without remaining on the rollers, and the rollers are always kept in a constant state. Without doing so, high quality polyamide fibers can be obtained continuously.

[0024]

Next, the present invention will be described specifically with reference to examples. "Parts" means parts by weight, and the measurement and evaluation were performed by the following methods. (a) Yarn-forming property Solid matter of the oil agent is deposited on the stretching roller and the heat treatment roller,
The evaluation was made in the following three stages based on the number of days until the stretching became difficult due to generation of fluff and cleaning was required. ○: 5 days or more, Δ: 2 days to 4 days, ×: less than 2 days (b) Amount of oil adhering The oil was dissolved and extracted with 10 times the sample weight of an ice-cooled fluorine-based organic solvent, and the sample before and after extraction was extracted. The weight was measured and calculated. (c) Using a strong Shimadzu Autograph S-100, sample length 25c
m and a tensile speed of 30 cm / min. (d) Dry heat shrinkage The sample was heat-treated at 150 ° C. for 30 minutes under no tension in accordance with JIS L-1017 and measured.

Example 1 and Comparative Examples 1-2 (a) Preparation of spinning oil agent 50 parts of low viscosity mineral oil was heated to 40 ° C, and the oil agent composition having the composition (parts) shown in Table 1 was heated to 50 ° C. After stirring while slowly adding 50 parts of the heated mixture, the mixture was cooled to room temperature. In addition,
POE means polyethyleneification, and the number in parentheses indicates the number of moles of ethylene oxide added.

[0026]

[Table 1]

(B) Production of polyamide fiber Relative viscosity (1 g of polymer was dissolved in 100 ml of 96% sulfuric acid,
Using a poly-ε-caproamide chip of 3.4,
930 dtex / 210f polyamide fiber was obtained by the melt spinning method in the following manner. After applying the spinning oil prepared by the above method to the undrawn fiber spun from the spinneret and cooled and solidified by the roller lubricating method so that the oil adhering amount becomes 0.7 parts by weight with respect to 100 parts by weight of the fiber, the drawing is performed. I took it. Subsequently, a 3.5-fold stretching is performed between the take-up roller and the first stretching roller heated to 140 ° C. with the separation, followed by the first stretching roller and the second stretching roller heated to 190 ° C. A steam jet nozzle through which steam with a temperature of 360 ° C and a pressure of 294 × 10 ³ Pa is passed (two steam outlets with a yarn diameter of 6 mm and a diameter of 3 mm are formed at an angle of 90 ° with the yarn path) ), And stretched in the second step so that the total stretching ratio becomes 5.3 times. Then, 8% relaxation is applied between the second roller and the third roller heated to 160 ° C. I took it. Table 2 shows the results of measuring the spinning properties and the yarn quality.

[0028]

[Table 2]

As is clear from Table 2, DL-α-Tocoph
Example 1 produced using a spinning oil containing an antioxidant containing erol as a main component is Comparative Examples 1 to 2 using a spinning oil not containing an antioxidant containing DL-α-Tocopherol as a main component. In comparison, even after continuous production for 5 days, there was less occurrence of yarn breakage, fluff, and roller contamination, and the obtained fiber had good elongation and good dimensional stability against heat.

Comparative Example 3 The antioxidant “IRGANOX 1010” was added to the oil of Comparative Example 1
The test was repeated under the same conditions as in Example 1 by adding parts by weight. Although the fuming property was lower than that of Comparative Example 1, thread breakage and fluff occurred on the third day, the strength and elongation decreased, the dimensional stability against heat was poor, and the roller had to be cleaned.

[0031]

According to the present invention, the stains on the stretching roller and the heat treatment roller in the process of producing the polyamide fiber are remarkably reduced, so that stable production can be carried out continuously for a long period of time. The dimensional stability is also good, and brings a great practical effect.

Claims (1)

[Claims] 1. An antioxidant containing DL-α-Tocopherol (vitamin-E) as a main component in an oil agent is added to a melt-spun polyamide fiber in an amount of 0.1 part per 100 parts by weight of an active ingredient of the oil agent.
A method for producing polyamide fibers, comprising adding 0.3 to 1.5 parts by weight of a spinning oil blended in an amount of from 01 to 1.0 part by weight to 100 parts by weight of the fiber.