JPH04209819A - Production of acrylonitrile filament - Google Patents

Abstract

PURPOSE:To produce the filament having good abrasion resistance at a high speed and at a low cost by once extruding a spinning raw solution from a spinneret into air, guiding the spun filament into a flow tube type coagulating bath for the coagulation of the fiber, drawing the coagulated filament in steam, accumulating the filament on an endless net transferred with multi-blade type rollers under heating, and subsequently winding up the filament. CONSTITUTION:A spinning raw solution comprising an acrylonitrile polymer dissolved in a solvent is once extruded from a spinneret 1 disposed at an upper position into air, guided into a flow tube type coagulating bath 2, and freely fallen together with a coagulating solution from the outlet 4a of the flow tube to a direction-changing guide 6 through a flow tube 4 to form the coagulated filament 5. The coagulated filament 5 is washed with water sprayed from washing nozzles 8-10 under a tensed definite length, drawn with a drawing machine 12 in steam supplied from a steam-supplying opening 12a, heated in a heating box 14 using steam, accumulated on a net 1 with multi-blade type rollers 15, 16 in a relaxed state, dried in a drier 12 and subsequently wound up on a winding roller 23 at a high speed to provide the objective filament.

Description

[Detailed description of the invention]

[00011

[Industrial Field of Application] The present invention relates to a high-speed wet spinning method for acrylonitrile long fibers. More specifically, the present invention relates to a method for rapidly and economically producing acrylonitrile long fibers with excellent yarn quality. [0002] [0002] Conventionally, acrylonitrile long fibers have been used in the knitting field because they have a silk-like appearance, luster, and feel, have good dyeability, and have good setting properties at relatively low temperatures. It has been widely used in However, compared to nylon and polyester, acrylonitrile-based long fibers are more expensive and have less than satisfactory yarn quality, so major development cannot be expected. To economically produce acrylonitrile long fibers, it is usually 500 m/min.
It is necessary to finally wind it up at a speed higher than that. [0003] However, when producing by a normal wet spinning method, the take-up speed from the coagulation bath is 5 to 10 m/
Therefore, the final winding speed after washing, stretching, drying, etc. is at most 100 to 150 m/min. For this reason, JP-A No. 49-25228 proposes a method of wet spinning at high speed by increasing the coagulation bath composition higher than the critical concentration and spinning at a high draft. There is. However, increasing the bath composition higher than the critical concentration and spinning at a high draft has the problem of unstable operation, such as uneven fineness and single yarn breakage. . [0004] On the other hand, in Japanese Patent Publication No. 45-9895,
By the so-called dry-wet spinning method, in which the spinning stock solution is once discharged into the air from a spinneret and introduced into a coagulation bath of a normal concentration,
A method is disclosed in which winding speeds of 0 to 400 m/min are possible. However, in the method described in the above-mentioned publication, when the coagulated yarn is introduced into the coagulation bath at a high speed, the surface of the coagulation bath is greatly disturbed, and the distance between the spinneret surface and the surface of the coagulation bath, which affects spinnability It becomes extremely difficult to keep constant. [0005] Generally, in order to impart properties to acrylonitrile long fibers that are resistant to fibrillation, it is necessary to treat the drawn yarns at high temperatures to shrink them by 35% or less, preferably from 20 to 35%. The above-mentioned special public service 1977-
The spinning method described in the 9895 publication discloses relaxation and shrinkage treatment using a plate heater, but this treatment method can only increase the shrinkage rate to about 20%, and heat treatment is required to further increase the shrinkage rate. A problem arises in that the time needs to be significantly increased. [0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-speed wet spinning method that can coagulate and draw acrylonitrile long fibers at high speed, and to improve the quality of the yarn and to manufacture it economically. The goal is to provide a way to do so. [0007]

[Means for Solving the Problems] The present inventors have solved the problems of the conventional acrylonitrile-based long fiber manufacturing method described above, and have developed an acrylonitrile-based long fiber manufacturing method that has excellent gloss, texture, yarn quality, and economical efficiency. The present invention was completed as a result of extensive research into fiber manufacturing methods. That is, in the method of the present invention, a spinning stock solution prepared by dissolving an acrylonitrile-based polymer in a solvent is once discharged into the air from an upper spinneret, guided to a trailing tube type coagulation bath, and further allowed to fall freely to complete coagulation. 1. Next, the material is washed with water under tension, then stretched in steam, and then deposited on an endless net moved by a pair of multi-blade rollers while being heated with steam, dried in a relaxed state, and then rolled up. This is a method for producing acrylonitrile-based long fibers, characterized by the following. [00081 Acrylonitrile-based polymers used in the present invention include polyacrylonitrile and copolymers with one or more vinyl or allyl compounds copolymerizable with acrylonitrile, including at least 85% by weight of acrylonitrile. It is a polymer. Monomers copolymerizable with acrylonitrile include, for example, esters of (meth)acrylic acid such as methyl, ethyl, butyl, octyl, methoxyethyl, phenyl, and cyclohexyl; vinyl such as vinyl acetate, vinyl propionate, vinyl butyrate, etc. Esters: (meth)acrylamide and its derivatives; unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid, itaconic acid and their salts; vinylsulfonic acid, (meth)allylsulfonic acid, P-styrenesulfonic acid, Unsaturated sulfonic acids and their salts such as acrylamide propane sulfonic acid; Vinyl halides and vinylidene halides such as vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, and vinylidene bromide:
Examples include vinyl compounds such as styrene, methyl vinyl ketone, methyl vinyl ether, (meth)allyl alcohol, vinyl pyridine, dimethylaminoethyl methacrylate, vinylidene cyanide, methacrylonitrile, and glycidyl (meth)acrylate. [0009] Solvents for preparing a spinning dope by dissolving such acrylonitrile-based polymers include organic solvents such as dimethylformamide, dimethylacetamide, and dimethyl sulfoxide; rhodan salts such as rhodan soda, rhodan potassium, and rhodan ammonium; and nitric acid. , an inorganic solvent such as an aqueous solution of zinc chloride. Inorganic solvents, especially aqueous solutions of nitric acid, are preferred because they can advantageously achieve the objects of the present invention. [00101 Although no restrictions are recognized regarding the polymer concentration, from an industrial standpoint it is preferably approximately 5 to 30% by weight, and more preferably set within the range of 7 to 20% by weight. Next, a detailed explanation will be given with reference to FIG. 1 showing an example of the manufacturing process according to the present invention. A large number of pores are bored in the spinneret 1, and the spinning dope is forced out into the air under pressure through these pores. [0011] The spinning dope extruded into the air is guided to the flow tube type coagulation bath 2, passes through the flow tube 4, coagulation progresses, and the coagulated thread 5 changes direction from the flow tube outlet 4a together with the coagulation liquid. Guide 6
Free fall until. The detailed structure of the flow tube coagulation device is shown in Figure 2.
As shown in the figure, most of the coagulating liquid supplied to the coagulating bath from the supply port 3 of the coagulating bath passes through the flow tube and falls freely together with the coagulating thread, but a small portion of the coagulating liquid overflows from the coagulating bath. be. Therefore, there is no disturbance in the coagulation bath liquid level, and it is extremely easy to maintain a constant distance between the spinneret surface and the coagulation liquid level. The coagulated thread can complete coagulation without encountering any resistance by freely falling the distance from the outlet of the flow tube to the direction-changing nigite. [0012] The coagulated yarn is taken up by take-up rollers 7a, 7b, 7
C, at a speed of 300 m/min or more, and water washing is performed under tension in a washing nozzle 8.9.10 disposed between washing take-up rollers Lla, llb, llc. The washing water supplied from the washing water supply ports 8a, 9a, and 10a is sprayed toward the threads, and washing can be performed with high efficiency without cutting the threads due to liquid resistance. In particular, when the solvent of the stock solution is a nitric acid aqueous solution, washing with water becomes easy, which is preferable. [0013] The stretching machine 12 includes a steam supply port 12a,
The yarn is drawn in steam between the drawing take-off rollers 13a, 13b, 13c and the washing take-off roller. The degree of stretching is preferably 3 to 6 times. If the stretching ratio is less than 3 times, the strength will be insufficient, and if it is more than 6 times, the stability of the process will be impaired due to single filament breakage. The drawn yarn is heated by steam in a heating box 14 equipped with a steam supply port 14a, and is deposited in a relaxed state on a cloth net 17 by multi-bladed rollers 15,16. The detailed structure of the multi-blade type roller is as shown in Figure 3.A pair of rollers whose blades are alternately and shallowly engaged give a wavy vibrating shape to the stretched yarn, allowing it to be stretched on a cloth net in a relaxed state. It has a depositing action. Although the heating state of the yarn can be changed by changing the amount of steam supplied to the heating box, it is desirable that the yarn temperature is 80° C. or higher. If the yarn temperature is as low as 80° C. or lower, sufficient flexibility cannot be imparted to the yarn, and as shown in FIG. 4, disordered portions 26 are likely to occur in the yarn sheet 25 deposited on the net. If such sheet disorder occurs, when processing a large number of sheets side by side, the disordered portion overlaps the adjacent sheet, which tends to cause problems with cutting threads due to entanglement during winding, making it difficult to wind up at high speeds. It becomes difficult. The yarn is dried in the form of a sheet by a dryer 21. The drying temperature is preferably 100 to 140°C, preferably 110 to 130°C.
is even more preferable. At temperatures below 100°C, sufficient drying shrinkage cannot be obtained, and at temperatures above 140°C, drying spots tend to occur. An oil agent 22 applies an oil agent to the dried yarn, and the yarn is wound at a high speed by a winder 24. [0014] As can be easily imagined from the above description, it can be seen that the method of the present invention can reliably achieve the initial objective of the present invention. [0015]

[Examples] The present invention will be explained below with reference to Examples. In addition, unless otherwise specified, % indicates weight %. Note that the fiber performance was measured by the following method. (1) Tensile strength and elongation Measured according to JIS L 1073 using a Schopper type tensile tester under the following conditions. [0016] Sample length...500mm Tensile speed...
500 mm 7 cans 1n (2) Abrasion resistance The abrasion resistance of the fabric was measured according to JIS L 0849. A chrome plated piece was set in the friction head of a Gakushin type friction tester, and the sample was heated at a pressure of 100 g/cm2 for 50
The sample was rubbed 0 times, and the friction surface of the sample was visually judged. (3) Sumoto shrinkage rate Measured according to JIS L 1042. (4) Fibrillation resistance Sewing thread is sewn with an industrial sewing machine at a needle rotation speed of 500 rpm, and the surface of the sewing thread has three stages: no fibrillation, slight fibrillation, and severe fibrillation. Judging with the naked eye. [0017]

Example 1 A homopolymer having a weight average molecular weight of 70,000 was obtained using acrylonitrile alone according to a conventional method. A polymer concentration of 18% was dissolved in a 69% nitric acid aqueous solution at -3°C to prepare a spinning stock solution. The spinning stock solution is once discharged into the air from a spinneret having 50 holes with a diameter of 0.13 mm,
Using a spinning device equipped with the manufacturing process as shown in Figure 1,
spun. The coagulation bath is a 5% nitric acid aqueous solution and the temperature is 1℃.
And so. The distance between the spinneret surface and the coagulation bath liquid level was set to 15 mm, and the material was introduced into a tapered flow tube having a length of 50 mm and an exit diameter of 5 mm, and coagulation was completed with a free fall length of 1000 mm. Furthermore, it was taken up at a speed of 400 m/min with a take-up roller, and washed with water under constant tension. [0018] The water-washed yarn was stretched 5 times in normal pressure steam, and the yarn was heated to 85°C using steam in a heating box, -
Pair of multi-blade rollers, pitch 20mm, sheet width 17m
m and was deposited on a cloth net at a speed of 2000 m/min. After drying in a relaxed state at a drying temperature of 120°C to give a drying shrinkage of 30% and applying a mineral oil,
The filament was wound at m/min, but there was no trouble in unwinding the sheet, and the sheet could be wound stably for a long time. When the yarn was heated to 70° C., the sheet was disturbed, many threads were cut when the sheet was unwound, and there were problems with stability. [0019] The yarn performance of the obtained filament yarn of 100d and 150f was a strength of 3.5 g/d, an elongation of 38%, and a water conduction shrinkage rate of 0%. 500T/ for this filament thread
Add m first twist (S), then final twist (Z) 500T/m
When processed with double thread, there was no occurrence of fuzz or thread breakage.
A twin yarn with excellent luster was obtained. This twin yarn was dyed using a cationic dye (Astrazon-Blue-FGL) at a dye concentration of 3% owf and a bath ratio of 1:100.130.
When the product was introduced at ℃ for 30 minutes and evaluated as a sewing thread, no fibrillation was observed and a product with beautiful seams was obtained. [00201

[Example 2] 92% of acrylonitrile, 7.5% of methyl acrylate, 0.5% of sodium methallylsulfonate. 5%
A copolymer having a weight average molecular weight of 80,000 was obtained according to a conventional method. The polymer concentration was 15%, and 13% was added to a 69% nitric acid aqueous solution.
The mixture was dissolved at ℃ to prepare a spinning stock solution. Diameter 0.10mm
The spinning stock solution was once discharged into the air from a spinneret having a hole of 60 g IA, and the subsequent steps were performed in the same manner as in Example 1 and wound up. [00211 The yarn properties of the obtained filament yarn of 75 d/10 f were strength of 3.1 g/d, elongation of 37%, and water conduction shrinkage rate of 2.5%. When this filament yarn was used to weave taffeta with a warp density of 110 threads/inch and a weft density of 90 threads/inch, a uniformly textured fabric with no sushi spots was obtained. This taffeta is dyed with cationic dye (
Cath i 1 on-B 1 ack-B
The taffeta was dyed by boiling for 90 minutes at a dye concentration of 5% o w f and a bath ratio of 1 to 0, and the fibrillation resistance of this taffeta was examined in an abrasion test, and no fibrillation was observed. No bleaching phenomenon occurred. [0022] According to the method of the present invention, the solidification process can be completed stably and at a high speed. Furthermore, after washing with water, it is stretched to 2000 m/m i
Extremely high spinning speeds are possible for wet spinning of n or more. Further, by drying in a relaxed state, a large drying shrinkage rate can be advantageously obtained, and acrylonitrile long fibers with excellent abrasion resistance can be produced at high speed and economically.

[Brief explanation of the drawing]

FIG. 1 is a process diagram schematically showing an example of the manufacturing method of the present invention.

FIG. 2 is a cross-sectional view schematically showing a flow tube type coagulation device.

FIG. 3 is an explanatory diagram of a multi-blade roller portion.

FIG. 4 is a plan view schematically showing a sheet of yarn deposited on the net.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Spinneret, 2... Flow tube type coagulation bath, 3... Supply port of coagulation bath, 4... Flow tube, 4a... Flow tube outlet, 5... Coagulated thread, 6... Direction change guide, 7a, 7b, 7cm--Take-up roller, 8.9.10... Washing nozzle, 8a, 9a, 10a... Washing water supply port, 11a, l
lb, 11cm...Water-washing take-off roller, 12...Stretching machine, 12a...Steam supply port, 13a, 13b, 13c--Stretching take-off roller, 1
4... Heating box, 14a... Steam supply port, 1516... Multi-blade roller, 17... Cloth net, 18... Cloth net driving roller, 19... Wire mesh net, 20. ... Driving roller of the wire mesh net, 21 ... Dryer, 22 ... Oil application device, 23 ... Winding package, 24 ... Winder, 25 ... Yarn sheet deposited on the net , 26...
・Disordered parts.

[Figure 1]

Claims (1)

[Claims] [Claim 1] A spinning stock solution prepared by dissolving an acrylonitrile polymer in a solvent is once discharged into the air from an upper spinneret and guided to a wake tube type coagulation bath, and further allowed to fall freely to complete coagulation, It is then washed with water under tension, then stretched in steam, and then deposited on an endless net moved by a pair of multi-blade rollers while being heated with steam, dried in a relaxed state, and then rolled up. A method for producing acrylonitrile-based long fibers.