JPH03104916A - Production of acrylonitrile-based solution-dyed fiber excellent in spinning property - Google Patents

Abstract

PURPOSE:To obtain the subject fiber without secondary aggregation of a pigment or yarn breakage by adding a solution of a methyl methacrylate-containing acrylic polymer in which the pigment is dispersed in an organic solvent to a spinning solution of an acrylonitrile-based polymer and spinning the resultant mixture solution. CONSTITUTION:A solution of an acrylic polymer containing >=30wt.% methyl methacrylate in which a pigment (e.g. furnace black) is dispersed in an organic solvent (e.g. DMF) is added to a solution prepared by dissolving an acrylonitrile- based polymer in an organic solvent and the resultant mixture solution is then spun to afford the objective fiber. Furthermore, the amount of the added pigment is preferably 0.001-5.0wt.% based on the acrylonitrile-based polymer.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing acrylonitrile-based solution-colored fibers with excellent spinnability, and more specifically, the present invention relates to a method for producing acrylonitrile-based solution-colored fibers with excellent spinnability. This invention relates to a method for producing acrylonitrile-based dyed fibers with improved thread breakability.

(Prior art and its problems) As a method for producing acrylonitrile-based dyed fibers, a pigment is added to a relatively low-viscosity solution of an acrylonitrile-based polymer of the same type as the spinning dope, and the pigment is finely divided using a pulverizer such as a ball mill. A known method is to mix this into a spinning stock solution using a stirrer, mixer, etc., and then perform spinning. However, this method has the problem that the low viscosity solution of the acrylonitrile polymer in which the pigment is dispersed has poor storage stability and becomes colored or gels over time. It is impossible to store and use it for a long period of time, and even if such a pigment dispersion is added and mixed with the spinning stock solution, the atomized pigment will not cause secondary aggregation in the spinning stock solution. As a result, problems occur in the dope process such as filterability and nozzle clogging, as well as thread breakage in the spinning process, making it impossible to stably supply high-quality acrylonitrile dope colored fibers. There is no state.

(Objective of the Invention) Therefore, the object of the present invention is to disperse the pigment in a specific dispersion medium and then add it to the spinning dope, thereby preventing the pigment from secondary agglomeration in the spinning dope, as described above. It is an object of the present invention to provide a method for producing acrylonitrile-based solution-colored fibers, which allows spinning to be carried out in a stable state for a long period of time without causing problems such as passage obstruction in the solution step or yarn breakage in the spinning step.

(Means for Solving the Problems) The present invention has been proposed to achieve the above object, and its gist is to spin a spinning dope in which an acrylonitrile polymer is dissolved in an organic solvent. In this process, an organic solvent solution of an acrylic polymer containing 30% by weight or more of methyl methacrylate in which the pigment has been separated is added to the spinning dope and the spinning process is carried out.

(Description of preferred embodiments of the invention) That is, the greatest technical feature of the present invention is that an organic solvent solution of an acrylic polymer containing 30% by weight or more of methyl methacrylate is used as a dispersion medium for the pigment. be. In the present invention, the acrylic polymer used as a dispersion medium polymer is a homopolymer of methyl methacrylate containing 30% by weight or more of methyl methacrylate or an unsaturated vinyl compound copolymerizable with methyl methacrylate. A copolymer of Copolymerized vine unsaturated vinyl compounds are not particularly limited, but include, for example, acrylonitrile, methacrylic esters, acrylic esters, styrene and styrene derivatives, vinyl ethers, vinyl glycidyl compounds, vinyl sulfonic acids,
Vinylbenzenesulfonic acids, allylsulfonic acids, methallylsulfonic acids, etc. can be mentioned, among which a copolymer of 35 to 70% by weight of methyl methacrylate and 65 to 30% by weight of acrylonitrile is most preferably used. If the methyl methacrylate content of the acrylic polymer is less than 30 tonne percent, the pigment will not be sufficiently dispersed, making it impossible to obtain the effects of the present invention.

The pigment dispersion in the present invention consists of a uniform dispersion of a pigment, the acrylic polymer, and an organic solvent, but in order to improve the dispersibility of the pigment, a small amount of a surfactant may be added. can.

The pigment used in the present invention is not particularly limited as long as it is normally used in the production of acrylonitrile-based solution colored fibers, but examples include carbon black such as furnace black, channel black, thermal black, and acetylene black. Ya Dia Blast, First Yellow HG (manufactured by Mitsubishi Chemical Industries, Ltd.), Variogen Red K3580 (manufactured by BASF), Variotor Black KOO80 (manufactured by DASF), Daimicron PAB-1401 Blue (manufactured by Dainichiseika Industries), Hostabam Brown HFR (manufactured by Hoechst), Monolite Lupine 3B (manufactured by IC1), Thiophyl Red HV-6606 (manufactured by Bayer), Firstgen Super Red R (manufactured by Dainippon Ink), Chromophthal Scallet Examples include various pigments such as RN (manufactured by Ciba Geigy) and Lionol Green 6Y-501 (manufactured by Toyo Ink).

Further, examples of the organic solvent for dissolving the acrylic polymer and using it as a dispersion medium include dimethylformamide, dimethylacetamide, dimethyl sulfoxide, acetone, etc.; Preferably they are the same. The pigment content in the dispersion is not particularly limited, but is usually adjusted to 3 to 25% by weight, preferably 10 to 20% by weight. When the pigment content exceeds 25% by weight, it is difficult to obtain sufficient dispersibility, and when 3% by weight is not swirled, the dispersion becomes dilute, which is unfavorable from the viewpoint of productivity.

The content of the acrylic polymer in the dispersion is usually 20 to 200% by weight, preferably 50 to 150% by weight, based on the pigment in the dispersion. If it is less than 20% by weight, the dispersibility will be insufficient, and if it exceeds 20 OffEffi%, the dispersibility will not improve any further and the physical properties of the resulting fiber will deteriorate, which is not preferable.

There is no specific point in the process to add and mix the pigment dispersion liquid to the spinning dope, but if we consider the workability and efficiency of the procedure when changing types, It is desirable that the

Further, as for equipment for addition and mixing, a normal mixing device is used, but a homomixer is preferably used because homogenization can be achieved in a short time.

The amount of pigment added to the acrylonitrile polymer in the spinning dope is 0.001 to 5.0%, and the concentration of the pigment in the pigment dispersion and the concentration of the acrylonitrile polymer in the spinning dope are calculated. By doing so, mixing within the above range can be easily achieved.

In the present invention, the acrylonitrile-based polymer constituting the spinning dope is a homopolymer of acrylonitrile or a copolymer of an unsaturated vinyl compound copolymerized with acrylonitrile containing 50% by weight or more of acrylonitrile. Examples of unsaturated vinyl compounds copolymerized with acrylonitrile include, but are not limited to, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid, salts thereof, methyl acrylate, and acrylic acid. Methacrylic acid esters such as butyl acid,
Methyl vinyl ketones, vinyl esters such as vinyl formate and vinyl acetate, vinyl ethers such as methyl vinyl ether, acrylamide and its alkyl substituted products, unsaturated sulfonic acids and their salts such as vinyl sulfonic acid and methallyl sulfonic acid, styrene , styrene and its alkyl or halogen substituted products such as α-methylstyrene, allyl alcohol and its esters or ethers, vinyl chloride, vinyl halides or vinylidenes such as vinylidene chloride, and the like.

As the organic solvent used in the spinning dope in the present invention, the organic solvent for the pigment separation medium mentioned above is similarly used.

The colored spinning stock solution obtained by adding and mixing the above-mentioned spinning stock solution and pigment separation solution is spun using a wet, dry or dry-wet method known in the manufacturing process of acrylonitrile-based fiber, and the acrylonitrile-based stock solution colored fiber is will be manufactured.

The colored spinning stock solution of the present invention is constituted as described above, but as long as the purpose of the present invention is not impaired, various fI additives such as light stabilizers and antioxidants, and light additives such as aluminum hydroxide may be added to the spinning stock solution. A non-solvent for the acrylonitrile polymer such as compound water or ethylene glycol can be added.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 Furnace black with a particle size of 20 nm (carbon black #40: manufactured by Mitsubishi Chemical Industries, Ltd.) and various dispersants were added and mixed to dimethylacetamide as shown in Table 1, and then subjected to a separation treatment for about 20 hours in a ball mill. I went. Each carbon black minute rf! The state of dispersion of each carbon black, the decomposition property of the carbon black in the dispersion when the dispersion of each carbon black was left at room temperature (M+) for one week, and the h i# of each portion of acrylonitrile 93. 1wt%, vinyl acetate 6.9wt%
The amount of carbon black added to a spinning stock solution prepared by dissolving an acrylic polymer in dimethylacetamide to a concentration of 2.5 wt% was 3.5 wt% relative to the acrylonitrile polymer.
Table 1 shows the dispersibility of carbon black in the colored spinning dope when it is added and mixed in such a manner as to give Owt%.

From these results, it can be seen that the colored spinning dope according to the present invention exhibits an extremely stable dispersion state.

Example 2 No. 2 in Actual Gallery Example 1. The blue spinning stock solutions No. 4 to 8 were processed at 40'C and 50 wt. % dimethylacetamide water/8
The solution was spun to obtain a 3D androchrome colored fiber. Spinning was carried out for 5 hours, and Table 2 shows the nozzle pressure upper limit and the state of yarn breakage in the spinning bath.

From Table 2, it is clear that the present invention is an excellent method for producing dyed fibers.

Actual gallery example 3 Diaplast Fast Red HF4B (Mitsubishi Chemical Industries, Ltd. ffl) lost% and methyl methacrylate 85w
Copolymer 13 of t% and ethyl methacrylate 15wt%
wt% was added to 5 dimethylformamide, mixed, and subjected to a dissolution treatment in a ball mill for 12 hours to obtain a pigment dispersion.

Next, acrylonitrile 58. 51%, vinylidene chloride 40wt% and sodium methallylsulfonate 15wL%
The pigment dispersion liquid was added to a spinning stock solution in which 23 wt % of an acrylonitrile-based polymer was dissolved in dimethylformamide so that the pigment content was 10 wt % based on the polymer, and mixed to obtain a colored spinning stock solution. 07n+m
, using a 2500-hole spinneret, 30°C, 53wt
% dimethylformamide solution to give 10 d of red stock colored fiber.

Even after 5 hours of spinning, the nozzle pressure increased by 0.3 k.
g/cm", and the number of yarn breakages was as low as 5, proving that the present invention is an excellent method for producing undiluted young colored fibers.

Example 4 Paliotol Green K9781 (BASF'A
) 12wt;% and an acrylic ton combination of 35wt% methyl methacrylate and 65wt% acrylonitrile 10w
t% was added to dimethylacetamide, mixed, and then dispersed in a ball mill for 14 hours to obtain a pigment rtLi liquid.

? Especially acrylonitrile 92. 4wt%, methyl acrinoleate 1. Owt% and methallylsulfonic acid 0.6
Add this pigment separation solution to a spinning stock solution in which 27w% of an acrylonitrile-based aggregate consisting of wL% is dissolved in dimethylacetamide so that the pigment-containing 4i is 1.0% with respect to the acrylonitrile-based aggregate. {1} The blue spinning dope was added to the nozzle hole diameter Q. 15mm. nI: taken out from a 100-hole spinneret and passed through a 4 mm air layer to 20'
C, 65wt. % of dimethylacetamide water (8 liquids), green undiluted blue filament yarn of 300 denier/l 00 filaments was prepared at {1'T. Even after 5 hours of spinning, the nozzle pressure 77 was 0.1 kg/cm
In No. 2, there was no line breakage, and fishing results according to the present invention were confirmed.

According to the present invention, Kao + 4 is allowed to separate into the liquid of a specific polymer, so that even when it is added to the spinning material, secondary agglomeration occurs. There are fewer problems in the manufacturing process, and colored spinning fat in a stable dispersion state can be obtained overnight, making it possible to produce acrylonitrile-based raw solution blue fiber for a long time! Stable production of roof tiles in the fields becomes MuT's ability.

? ■Enter Mitsubishi Rayon Co., Ltd.

Claims (1)

[Claims] (1) When spinning a spinning stock solution in which an acrylonitrile polymer is dissolved in an organic solvent, an organic solvent solution of an acrylic polymer containing 30% by weight or more of methyl methacrylate in which a pigment is dispersed is added to the spinning stock solution. A method for producing acrylonitrile-based solution colored fiber, which comprises adding and spinning.