KR890005271B1 - Process for producing five retardancy acrylic fiber - Google Patents

Abstract

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Description

Manufacturing method of flame retardant acrylic fiber

The present invention relates to a method for producing a flame retardant acrylic fiber. Acrylic fiber has a soft feel similar to wool, excellent physical properties, excellent dyeing fastness and dyeing clarity, and is used in a wide range of applications, but like many other natural fibers and synthetic fibers, it is flammable, so it can be used for carpets, curtains, etc. In particular application fields such as interior decoration use and infant wear, there is a strong demand for imparting flame retardant performance.

In recent years, various attempts have been made on flame retardant means of acrylic fibers. For example, a method of post-processing with a flame retardant, a method of copolymerizing a flame retardant monomer with AN, and the like have been proposed. However, in the post-processing method, there is a problem in washing resistance, the feel of fibers, and in the copolymerization method, although the flame retardancy can be improved by increasing the copolymerization ratio of the flame-retardant monomer, it is only 20 to 25% by weight in order to dissolve in the inorganic solvent. The degree of copolymerization of the flame retardant monomers, and the use of organic solvents can increase the air ratio to about 45% by weight, which can improve the flame retardancy, while the devitrification, coloring, It leads to practically undesirable problems such as unclear dyeing, lack of durability, and heat shrinkage.

Therefore, a number of proposals have also been made for means for reverse-reversing the copolymerization ratio of flame retardant monomers by using a flame retardant improving additive. As such an additive, For example, halogen containing additives, such as bromine and chlorine; Phosphorus Additives; Antimony oxide; Tin oxide; Metal oxides such as zinc oxide; Organometallic compounds such as barium, zinc and tin; Aluminum hydroxide etc. are mentioned.

The flame retardant improving additives are often soluble in organic solvents except for metal oxides and aluminum hydroxides, but are hardly soluble in inorganic solvents. In the manufacturing of the fiber, problems such as clogging in the filtration process, elevated pressure, nozzle clogging in the spinning process, and actual shear are caused.

In addition, since the metal oxide, aluminum hydroxide, and the like are not compatible with any solvent, the above-described problems cause problems such as devitrification of the fiber and unclearness of dyeing. In order to remedy such defects, it has been attempted to reduce the particle diameter. However, even if the primary particles are small, they are aggregated in the spinning stock solution, so that the above defects cannot be avoided, and the metal oxides and the like of the fine particles are expensive. Therefore, it is not suitable for general purpose use.

That is, it is an object of the present invention to provide an industrial production means of acrylic fiber which is excellent in flame retardancy and has no problems in operation, fiber transparency, gloss, dyeing clarity, physical properties, etc. in a stock solution or spinning process.

The object of the present invention described above is industrially advantageously achieved by spinning after adding a salt of soluble aluminum to the inorganic solvent solution of the halogen-containing acrylonitrile (hereinafter referred to as AN) polymer.

The present invention is described in detail below.

First, as the halogen-containing AN polymer, AN, a halogen-containing vinyl monomer and a polymer of one kind or two or more kinds of polymers made of other vinyl monomers, or polymers made of AN and other vinyl monomers and a hologen-containing vinyl Mixtures of polymers with monomers, and the like. In any of the above cases, the polymer may contain 30 to 95% by weight of AN, preferably 60 to 90% by weight, and halogen-containing vinyl monomers of 70 to 5% by weight. As long as it contains in 40 to 10weight% of a range, the objective of this invention can be achieved. The halogen-containing vinyl monomers include vinyl halides and vinylidene halides such as vinyl chloride, vinyl iodide, vinyl fluoride, vinylidene chloride, and vinylidene iodide. Other vinyl monomers include methyl of (meth) acrylic acid, Esters such as ethyl, butyl, octyl, methoxyethyl, phenyl and cyclohexyl; Vinyl esters such as vinyl acetate, vinyl propionate and vinyl butyrate; Acrylamide and alkyl substituents thereof; Unsaturated sulfonic acids such as (meth) acrylic acid, maleic acid and itaconic acid and salts thereof, vinylsulfonic acid, (meth) acrylic sulfonic acid, P-styrene sulfonic acid, acrylamide propanesulfonic acid and the like and salts thereof; And vinyl compounds such as styrene, methyl vinyl ketone, methyl vinyl ether, aryl alcohol, vinyl pyridine, dimethylaminoethyl methacrylate, vinylidene cyanide, methacrylonitrile and glycidyl methacrylate. Moreover, as a manufacturing method of these polymers, well-known emulsion polymerization, aqueous precipitation polymerization, aqueous suspension polymerization, solution polymerization, etc. can be employ | adopted.

Next, as the inorganic solvent of the halogen-containing AN polymer, a thick aqueous solution of a known inorganic solvent, such as rhodansoda, rhodan potassium, rhodanammonium, rhodan calcium, etc., as a solvent for AN polymers; Concentrated aqueous solutions of chlorides such as zinc chloride and calcium chloride; Concentrated aqueous solutions of strong acids such as nitric acid and sulfuric acid; It is also possible to use the mixed solvent which mixed the well-known organic solvent for AN type polymer etc. Among them, the use of rhodan salt rich aqueous solution is preferred because it can provide a polymer solution excellent in flame retardancy and excellent in radioactivity.

As the salt of aluminum, it can be used as long as it can be dissolved in the inorganic solvent. For example, aluminum nitrate, sulfate, hydrochloride, acetate, and the like can be used. Among them, aluminum nitrate significantly improves flame retardancy, and also produces fiber. Since it does not cause various trouble in a process, it is preferable.

In addition, the compounding amount of such a salt is preferably set in the range of 1 to 20%, preferably 2 to 10%, based on the weight of the polymer, and when it is out of the lower limit of the range, the effect of imparting flame retardancy is small and exceeds the upper limit. In addition, the effect not only reaches the limit, but also brings about a decrease in physical properties of the fiber produced using the polymer solution. Moreover, as an addition method of a salt salt, the means which adds and mixes predetermined amount of a salt in the form of an aliquot or an aqueous solution, etc. to the inorganic solvent solution of a halogen-containing polymer is mentioned. If the pH of the solution is high, since the salt does not dissolve, it is preferable to adjust the pH of the solution to 6.0 or less, preferably 4.0 or less. In the case where heating is required at the time of dissolving the polymer, the halogen-containing AN polymer is already deteriorated in such a process. Therefore, it is preferable to add and mix this salt in the so-called slurry state before the heat dissolution of the polymer. The polymer solution thus obtained is subsequently spun to produce a fiber. As the fiber manufacturing method, known spinning and post-treatment means can be employed, and are made of flame-retardant acrylic fibers having excellent performance without problems in lower manufacturing processes.

The reason why the flame retardance of the acrylic fiber of the present invention is remarkably improved cannot be fully understood, but is estimated as follows.

In other words, antimony is said to have an effect of delaying combustion by solid phase reaction during combustion by forming sbocl and sbcl ₃ by combining with halogen. Although it is impossible to maintain, the fiber added with aluminum recommended in the present invention retains its original form even after combustion, so that the aluminum promotes the cyclization reaction caused by the heat of the AN-based polymer, and thus knitted fabrics such as carpets and the like. In particular, it is thought that it contributes to remarkable flame retardancy improvement. In addition, since the salt of aluminum recommended in the present invention is uniformly dissolved and mixed with the polymer at the same time, it can be uniformly present in the fiber, which can effectively improve the flame retardancy, and at the same time, the process of fiber manufacturing, namely, solidification, washing, stretching and the like. By increasing the pH at, it is thought that an acrylic fiber which is water-insoluble and forms fine particulate aluminum hydroxide and remains in the fiber can be improved in flame retardancy without impairing transparency and gloss.

Thus, in the fabric manufacturing process, the resulting fiber has excellent flame retardancy without problems of transparency, gloss, dyeing vividness, physical properties, etc. without any problems such as clogging in the filtration process, pressure raising, nozzle clogging or thread cutting in the spinning process. The point which can be obtained by producing acrylic fiber is an industrial advantage of this invention, and the acrylic fiber obtained in this way shows especially remarkable flame retardance especially in the form of a carpet etc.

EXAMPLE

The following examples have been presented to facilitate understanding of the present invention, which is by way of example only and the gist of the present invention is not limited thereto. In addition, the part and percentage shown in an Example are based on weight unless there is particular notice.

In addition, the reperformance of the fiber was measured or determined as follows.

(A) Deviation

The treatment was carried out in boiling water for 3 hours to determine devitrification.

(B) heat shrinkability

Dry heat treatment at 180 ° C. for 15 minutes determines the presence or absence of shrinkage.

(C) dyeing sharpness

A normal cationic dye is used, and dyeing is carried out according to a conventional method to determine the vividness of the fiber.

(D) Flame Retardant Carpet

Disclosure fiber 60% with a conventional acrylic fiber (X is ^ⓚ K type), and then 1/5's admitted in accordance with the 40% to the conventional method, 1 / 10G, 13.5-cut file on the condition of the stitch: Carr pet (File length 9mm) Was prepared, and flame retardance was measured by the 45 degree ISO burner test method by fire method. The pass rate (%) of this test method was computed from the result measured about 20 pieces of samples.

Example 1

Using a redox-based catalyst, a polymer of 76.5 parts of AN, 9.5 parts of methyl acrylate (MA), 14.0 parts of vinylidene chloride, and 0.3 parts of sodium metalylsulfonate (SMAS) was prepared by a conventional aqueous precipitation polymerization method.

Next, in preparing a polymer of 10% polymer concentration and 45% rhodansoda using a solution of rhodansoda concentrated solution, a predetermined amount of a polymer and a solvent are first mixed, and aluminum nitrate is polymerized before heating and dissolving. After adding 5.0% to, the pH was adjusted to 3.8, and then dissolved at 65 ° C. for 1 hour using a conventional stirrer to prepare a spinning solution.

The obtained solution was spun into a 13% rhodansoda aqueous solution at a temperature of -3 占 폚, and washed with water, stretched, dried, and heat treated according to a conventional method to produce 10 ^d of fiber (1). In the production of the fiber 1, there were no problems such as clogging or boosting in the filtration step, nozzle clogging or thread cutting in the spinning step. Moreover, the fiber 2 was produced as mentioned above except not adding aluminum nitrate as a comparative example. The result of having evaluated the performance of the fiber (1-2) is shown in a 1st table | surface.

[Table 1]

From the above table, it is clearly understood that the present invention has excellent flame retardancy without problems of devitrification, dyeing vividness, and physical properties.

Example 2

Six kinds of fibers (3 to 8) were produced in the same manner as in the fiber 1 of Example 1 except that the addition amount and pH of the aluminum nitrate were changed as shown in the following second table.

The result of having evaluated the flame retardance of a carpet is written together in a 2nd table | surface.

[Table 2]

From the above table, it is understood that the effect of improving the flame retardancy is particularly remarkable within the range of the addition amount of the stabilizer recommended in the present invention and the pH of the spinning solution.

Example 3

As shown in the following Table 3, seven kinds of fibers (9 to 15) were produced in the same manner as in the fiber 1 of Example 1 except for changing the kind of the additive.

We write result of evaluation of flame retardancy in the third table

[Table 3]

From the table above it is understood that the fibers (9-12) using the salts of aluminum recommended in the present invention exhibit excellent flame retardancy.

Claims (3)

A method for producing a flame-retardant acrylic fiber characterized by spinning after adding a salt of aluminum soluble in this solvent to an inorganic solvent solution of a halogen-containing acrylonitrile polymer. The method for producing a flame retardant acrylic fiber according to claim 1, wherein a salt of aluminum is added by 1 to 20% by weight of the polymer. The method for producing a flame retardant acrylic fiber according to claim 1, wherein the pH of the solution is adjusted to 6.0 or less.