JPH0684592B2 - Acrylic fiber treatment method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for treating a fiber bundle in a gel swelling state after wet spinning, stretching and washing with water when producing an acrylic synthetic fiber.

(Prior Art) A fiber bundle in a gel swollen state after wet spinning, drawing and washing with water is dried and densified by a hot air dryer. In a gel-swelled fiber bundle running in a hot air dryer, single fibers are in contact with each other, so that the fibers stick to each other, resulting in poor separation property. For this reason, a method is used in which an oil agent, for example, a spinning oil agent is supplied before heat treatment in a hot air dryer.

(Problems to be Solved by the Invention) The oil agent applied to the fiber bundle in the gel-swelling state is uneconomical because a large amount of oil agent is applied to prevent the single fibers from sticking to each other. Since the oil agent contains unnecessary components to prevent the sticking of the single fibers together, the cost is increased, and for the production of many types, the oil agent before the heat treatment by the hot air dryer and the finishing oil agent are added. Because of the same component, the switching frequency of the oil agent increases, the work efficiency decreases, the oil agent loss increases, and it is not only wasteful in terms of resource conservation, but also the COD in the wastewater significantly increases, which is also a problem. ing.

(Means for Solving Problems) As a result of earnest research in view of the present situation, the present inventors have found that a specific oil agent is applied to a fiber bundle in a gel swelling state after wet spinning, stretching, and washing with water, and then hot air is applied. By heat-treating in a dryer, a fiber bundle of acrylic fibers having excellent separation properties, devitrification preventiveness, and luster can be obtained, and no sticking will occur even in the post-drawing and shrinking steps. The inventors have found that spinning properties do not change even when a spinning oil is supplied, and have completed the present invention.

An object of the present invention is to provide an oil agent suitable as an oil agent applied before heat-treating a fiber bundle in a gel-swelled state after wet spinning, stretching and washing with water with a hot air dryer. Another object is to provide an acrylic fiber that does not change the spinnability even when a spinning oil is added, and still another object is to provide an acrylic fiber having excellent properties as described above in a gel swollen state. An object of the present invention is to provide an industrially advantageous method of applying to a bundle.

That is, the present invention provides a fiber bundle of acrylic fibers in a gel swelling state after wet spinning, stretching and washing with water, having an average molecular weight of
2000-7000 and molecular weight distribution is 1000-3500 and 5000-10000
After the addition of propylene oxide / ethylene oxide (PO / EO) block copolymer type polyether having peaks at and, respectively, a roller dryer with a surface temperature of 120 to 160 ° C and / or dry heat of 120 to 180 ° C The method for treating acrylic fibers is characterized in that 0.02 to 0.20% by weight of the polyether is added to the weight of the fibers by heat treatment with a hot air dryer to dry and densify.

The acrylic polymer used in the present invention contains at least 40% by weight of acrylonitrile, and any polymer having a fiber-forming ability can be used. That is, 40% by weight or more of acrylonitrile and other vinyl-based monomers, such as acrylic acid, methacrylic acid, or their alkyl esters, vinyl acetate,
Examples thereof include those obtained by copolymerizing an appropriate combination of vinyl chloride, vinylidene chloride, sodium allyl sulfonate, sodium methallyl sulfonate, sodium vinyl sulfonate, sodium styrene sulfonate, etc. at a ratio of 60% by weight or less. Particularly, a copolymer of acrylonitrile of 80% by weight or more and 20% by weight or less of a vinyl-based monomer and a sulfonic acid group-containing monomer, or a copolymer containing 20 to 60% by weight of vinyl chloride and / or vinylidene chloride and a sulfonic acid-containing monomer. Is preferred. The acrylic polymer may contain a resin that is incompatible with the acrylic polymer such as cellulose acetate, polystyrene, acrylonitrile-styrene copolymer, polyvinyl acetate copolymer, polyvinyl butyral and the like.

Examples of the solvent for the acrylic polymer used in the wet spinning of the present invention include organic and inorganic solvents such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetone, aqueous zinc chloride solution, aqueous rhodan salt solution and concentrated nitric acid.

The propylene oxide / ethylene oxide (PO / EO) block copolymer type polyether used in the present invention has an average molecular weight of 2000 to 7,000 and a molecular weight distribution of 1000 to 3500.
It has a two-peak distribution with peaks at 5,000 and 10,000 to 10,000. If the average molecular weight is less than 2,000, more than 7,000, or one having a peak of molecular weight distribution is applied to the gel swollen fiber bundles and heat-treated to dry and densify, the fineness is inferior. Particularly preferred are those having an average molecular weight in the range of 4000 to 6000, or those having a two-peak distribution having peaks at molecular weight distributions of 1000 to 3000 and 6000 to 8000, respectively.

The PO / EO block copolymer type polyether is, for example, P
It is obtained by copolymerizing at a composition ratio of O / EO = 60 to 80/40 to 20 (hereinafter referred to as PO / EO ratio).

Those copolymerized with a composition other than PO / EO = 60 to 80/40 to 20 tend to be inferior in the separation property even if the fiber bundle in the gel swelling state is oiled and heat treated to dry and densify.

The PO / EO block copolymer type polyether used in the present invention is usually used as an aqueous solution at a temperature of 50 to 70 ° C. for permeation into the fiber bundle at a concentration of 0.2 to 1.0% by weight. Incidentally, in using this oil agent, the purpose of the present invention, namely, the separating property of the fiber bundle dried and densified by heat treatment with a hot air dryer, and within a range that does not affect the devitrification preventive property and gloss, Other components than the above may be added.

Any method may be adopted to apply the oil agent to the fiber bundle in the gel swelling state after wet spinning and stretching the PO / EO block copolymer type polyether, but the fiber bundle may be uniformly applied. It is preferable to attach them, and a dipping method or a shower method is usually adopted.

The amount of the oil agent applied is preferably 0.02 to 0.20% by weight, and more preferably 0.03 to 0.10% by weight, based on the fiber. If the amount of the oil agent applied is less than 0.02% by weight, uneven fiber splitting will occur, while if it exceeds 0.20% by weight, it will be mixed with the spinning oil agent in the finishing step and the spinnability will be deteriorated.

In the present invention, after applying the oil agent, it is heat-treated in a hot air dryer to perform dry densification, but as the condition for dry densification, the surface temperature of the roller dryer is 120 to 160 ° C, preferably 130 to 150 ° C. And / or a hot air dryer having a dry heat of 120 to 180 ° C., preferably 130 to 160 ° C. Drying time is 1
~ 7 minutes is preferred.

If the temperature is lower than the above temperature, the drying and densification will be insufficient, and the fiber physical properties such as whitening of the fiber, defective dyeing and deterioration of strength and elongation will be serious.

Further, if the temperature exceeds the above range, the loss due to the scattering of the oil agent increases, so it must be avoided.

In the present invention, the heat treatment is usually performed after the dry densification, but the heat treatment temperature is usually dry heat 180 ° C. or lower and / or wet heat 130.
Perform at ℃ or below.

(Examples) The present invention will be specifically described below with reference to Examples. In addition, "(%)" in the examples means "% by weight".

A Evaluation of fiber separation property The obtained fiber bundle was cut into 2 mm, and 0.5 g of cut fiber was cut into 500
It was put into an aqueous solution of ml and stirred with a magnetic stirrer for 1 minute at 100 rpm. After 1 minute, the separated fibers were observed for their separated state, and the number of glued fibers (diameter 0.5 mm or more) was counted.

Rating: 0, excellent, 1-10, good, 11-50, acceptable, 51 or more, not acceptable B Evaluation of devitrification resistance Anisole value indicating transparency of fiber is measured as follows. did. Approximately 1 g of dried fiber sample is defibrated and aligned in one direction, cut into pieces with a diameter of approximately 1.5 cm and cut into 3 cm. Next, 0.04 g of the fibers was taken so as not to break the fiber arrangement, placed in a 20 mm glass cell and immersed in anisole for 30 minutes, and the transmittance was measured at 562 mm with 100% anisole as a control, and this was taken as the anisole value.

C Measurement of adhesion amount The adhesion amount of PO / EO block copolymer type polyether fiber was 20 g of fiber bundle, 120 ml of benzene / alcohol = 2/1 (volume) solvent, and extracted for 3 hours with a Soxhlet extractor. The adhesion amount was measured.

D Evaluation of Spinnability (Depending on Card Passability) A dried and densified fiber bundle was continuously stretched, shrunk, applied with a spinning oil agent and mechanically crimped, and then a single yarn 2 denier 51 mm
A cut cotton was prototyped and evaluated by the card passing property.

Example 1 Acrylonitrile (AN) / methyl acrylate (MA) /
Sodium methallyl sulfonate (SMAS) = 91.4 / 8.0 / 0.6 Acrylic polymer concentration 22% by weight Dimethylformamide (DMF) solution was spun into a 55% DMF aqueous solution at 20 ° C, and after a normal stretching water washing step, Average molecular weight of 55 for gel swollen fiber
00, molecular weight distribution has peaks at 8000 and 8000 respectively (PO / EO ratio = 70/30) PO / EO block copolymer type polyether (hereinafter referred to as oil agent A) 0.03, 0.1, 0.3, 0.5, 0.
Apply a 1.5% oil solution and use a roller drier 14
Dry densification was performed at 0 ° C. (Samples 1-6). Table 1 shows the results of the adhesion amount, the fiber splitting property, and the spinnability (card passing property) of these samples.

Example 2 Instead of the oil agent A used in the examples, an average molecular weight of 4500 was used.
PO / EO block copolymer polyethers with peaks at 8000 and 2000 respectively (PO / EO ratio = 80/20) (Sample 7),
PO / E with an average molecular weight of 4500 and a peak (1 peak) at 6500
O-based block copolymer polyether (PO / EO = 70/30)
(Sample 8), each of spinning oil polyoxyethylene (15) cetyl ether phosphate potassium salt (Sample 9) 0.3
Table 2 shows the results of the examination of the fiber splitting property, the spinning property and the devitrification preventive property of the fiber bundle using the% oil agent.

(Effects of the Invention) According to the treatment method of the present invention, it is possible to obtain a fiber bundle of acrylic fibers having excellent splitting property, devitrification preventive property, and gloss. Furthermore, the obtained fiber bundle does not cause sticking even in the stretching and shrinking steps, and even if a spinning oil agent is applied in the finishing step, the spinnability is not lowered, which is a very significant method.

Claims (6)

[Claims] 1. A fiber bundle of acrylic fibers in a gel swelling state after wet spinning, stretching and washing with water has an average molecular weight of 2,000 to 2,000.
After the addition of propylene oxide / ethylene oxide (PO / EO) block copolymer type polyether having a molecular weight distribution of 7,000 and peaks of 1000 to 3500 and 5000 to 10000, respectively, a surface temperature of 120 to 160 ° C. 0.02 to 0.2% by weight based on the weight of the fiber by heat treatment with a roller dryer and / or a hot air dryer with a dry heat of 120 to 180 ° C for dry densification
2. A method for treating an acrylic fiber, characterized in that the above polyether is added. 2. The polyether has an average molecular weight of 4000 to 60.
The method of claim 1, wherein the method is 00. 3. The method according to claim 1, wherein the PO / EO block copolymer type polyether is copolymerized at a composition ratio of PO / EO = 60 to 80/40 to 20. 4. The method according to claim 1, wherein the PO / EO block copolymer type polyether has a molecular weight distribution having peaks at 1000 to 3000 and 6000 to 8000, respectively. 5. The roller dryer has a surface temperature of 130 to 150 ° C.
The method of claim 1 wherein: 6. The method according to claim 1, wherein the temperature of the hot air dryer is 130 to 160 ° C.