KR800001251B1 - Improved process for producing flame-resisting acrylic fiber - Google Patents

Abstract

A spinning solution composed of an acrylonitrile copolymer with the emulsion of an unsaturated halogen monomer or the inorganic solvent solution of an acrylonitrile polymer with a flame-retardant, and with an aqueous solution which particle is below 60 parts and a dispersant were mixed by a mixer, and wetspun for improvement of the flame-retardant property.

Description

Improved manufacturing method of flame retardant acrylic fibers

The present invention relates to an improved method for producing flame retardant acrylic fibers, and more particularly, to an inorganic salt solvent of an acrylonitrile-based polymer composition in which an acrylonitrile-based copolymer copolymerized with a halogen-containing unsaturated monomer or a halogen-containing flame retardant component is blended. In the halogen-containing acrylic spinning stock obtained from the solution, the antimony oxide particles were introduced in an aqueous dispersion using a stirrer having the stirring ability described below under specific conditions, and then the halogen-containing particles obtained by finely and uniformly dispersing the antimony oxide particles thus obtained. By wet spinning the acrylic spinning stock solution according to a conventional method, acrylic fibers having highly flame retardant acrylic fibers having excellent transparency, gloss, and color development without causing gelation or agglomeration of the spinning stock solution are obtained. Industrially beneficial It relates to the law.

Fibers made from conventional acrylonitrile-based polymers or copolymers have a wide range of uses, such as for medical use and upholstery, but because they are inherently lacking in flame retardancy, any particular use, for example, indoor foods such as carpet and catenin, It is not preferable to use it for baby clothes.

In order to overcome such drawbacks of acrylic fibers, conventionally, a method of copolymerizing a flame retardant monomer such as acrylonitrile and a halogen-containing unsaturated monomer, a method of mixing and spinning an acrylonitrile-based polymer and a flame retardant polymer, and a flame retardant containing a halogen are spun. Although a method of mixing and spinning in a stock solution or post-processing with this flame retardant has been adopted, these conventional flame retardant methods are difficult to impart high flame retardancy to acrylic fibers, and therefore, flame retardant synergists such as antimony oxide together with halogen A method of introducing (相乘 劑) into acrylic fibers has been proposed.

As one of the methods of introducing such antimony oxide into the acryl-based fiber together with the halogen, there is a method of dividing the antimony oxide into a pulverizer such as a colloid mill and mixing it in the halogen-containing acrylic spinning stock solution by a stirrer or kneader. However, in the case of a highly viscous solution usually used for spinning of acrylic fibers, it is extremely difficult to obtain a spinning stock solution in which antimony oxide is uniformly dispersed, and also, there is a strong tendency for the antimony oxide particles to easily aggregate and agglomerate in the spinning stock solution. Therefore, it causes various problems such as clogging of the nozzle filter in the spinning process and breaking during drawing. Furthermore, the obtained fibers are markedly devitrified (whitening), and the gloss and color development are also degraded. It is becoming the biggest problem.

As another method, there is a method of adding antimony oxide when the acrylonitrile (co) polymer is dissolved in an aqueous solution of an inorganic salt, but this method still has some drawbacks as described above.

Herein, the present inventors have studied diligently to improve such defects. As a result, antimony oxide is used as an aqueous acid solution, and then introduced into a halogen-containing acrylic spinning stock solution under a specific condition, using a stirrer having a rapid mixing speed. By mixing and stirring, the present inventors have found that the antimony oxide particles can be uniformly mixed in the halogen-containing acrylic spinning stock solution without causing gelation or aggregation at all.

It is a main object of the present invention to provide an improved method for producing flame retardant acrylic fibers.

An object of the present invention is to industrially advantageously produce acrylic fibers having a high flame retardancy and excellent gloss and transparency. It is another object of the present invention to provide an industrial and economical method for dispersing fine and uniformly antimony oxide particles in a halogen-containing acrylic spinning stock solution containing an aqueous inorganic salt solution.

Other objects of the present invention will become apparent from the following detailed description of the invention.

An object of these invention is the antimony oxide particle | grains in the halogen containing acrylic radiation stock solution which consists of the inorganic salt solvent solution of the acrylonitrile-type copolymer which copolymerized the halogen containing unsaturated monomer, or the acrylonitrile-type polymer composition which mix | blended the halogen containing flame-retardant component. Is introduced into a uniform aqueous acid dispersion dispersed in water at a ratio of 60% by weight or less in a ratio of 10 parts by weight to 50 parts by weight of the aqueous dispersion with respect to 1000 parts by weight of the spinning stock solution, After mixing using, it is achieved by wet spinning according to a conventional method.

In the acryl-based spinning stock solution obtained according to the method of the present invention, all the defects exhibited in the conventional methods such as gelation of the spinning stock solution or formation of agglomerates by agglomeration of antimony oxide particles are eliminated, thus making it an industrially useful spinning stock solution. In addition, according to the present invention, it is possible to produce a spinning stock solution in which fine antimony oxide particles are uniformly dispersed, and thus to advantageously eliminate the clogging of the filter or the clogging of the nozzle, which is an extremely serious defect in the fiber manufacturing process. It became. In addition, the acrylic fiber obtained according to the present invention has a high flame retardancy due to the synergistic effect of the halogenated antimony oxide, and furthermore, since there is no void in the fiber, it is excellent in transparency, glossiness and drying after dyeing. The product's value is very high due to the lack of sharpness of color and deterioration of color development.

In the present invention, the antimony oxide ratio in the aqueous dispersion needs to be 60% by weight or less, and when the ratio exceeds 60% by weight, agglomeration due to the coagulation of the antimony oxide particles is formed and the halogen-containing acrylic radiation stock solution is contained. It becomes difficult to finely disperse the antimony oxide particles. The lower limit of the amount of antimony oxide in the aqueous acid solution is preferably about 5% by weight, considering the amount of antimony oxide to be introduced into the fiber.

In addition, such an aqueous solution of antimony oxide needs to be introduced into the spinning stock solution at a ratio of 10 parts by weight to 50 parts by weight with respect to 1000 parts by weight of the spinning stock solution. It is difficult to obtain a stable spinning stock solution by causing gelation of the stock solution, agglomeration of antimony oxide particles, and the like, and on the other hand, in order to impart sufficient flame retardant synergistic effect by the introduction of antimony oxide to the fiber, 1000 parts by weight of spinning stock solution It is necessary to mix at least 10 parts by weight, preferably 15 parts by weight or more of the aqueous dispersion.

In addition, the antimony oxide particles used in the present invention preferably have an average diameter of 50 μm or less, preferably about 10 μm to about 30 μm, and when out of this range, fine and uniform antimony oxide particles are formed in the spinning stock solution. It is difficult to disperse, which is not preferable. In this invention, as a manufacturing method of a halogen-containing acrylic spinning stock solution, the acrylonitrile-type polymer composition which mix | blended the acrylonitrile-type copolymer or halogen containing flame-retardant component which finally copolymerized the halogen-containing unsaturated monomer, and acryl Any method may be used as long as a spinning solution containing a known inorganic salt aqueous solution is obtained as a solvent for the nitrile polymer. For example, (1) A method of dissolving an acrylonitrile copolymer obtained by copolymerizing an acrylonitrile, a halogen-containing unsaturated monomer and, if necessary, another vinyl monomer, in an inorganic saline solution. (2) a method of dissolving an acrylonitrile-based polymer with a homopolymer of a halogen-containing unsaturated monomer or a copolymer of acrylonitrile or another vinyl monomer, followed by dissolving in an inorganic salt aqueous solution or (3) acrylonitrile The method of adding and mixing a halogen containing organic compound to the acryl-type spinning stock solution which melt | dissolves a polymer in inorganic salt aqueous solution, etc. is employ | adopted. At this time, the polymer or copolymer of the halogen-containing unsaturated monomer or the halogen-containing organic compound blended as the halogen-containing flame retardant component is present in the disperse state in addition to being present in the dispersed state.

Here, the halogen-containing unsaturated monomer used in the present invention is an ethylenically unsaturated compound containing a halogen, for example, aryl chloride, allyl bromide, vinyl chloride, vinyl embrittlement, vinylidene chloride, vinylidene embrittlement. Halogenated unsaturated hydrocarbon-based monomers such as: Halogenated alkyl acrylates or methacrylates represented as 2,3-dichloropropyl esters of acrylic acid or methacrylic acid or 2,3-dibromopropyl esters and the like: 2,4 Halogenated aryl acrylates or methacrylates such as, 6-tribromo phenyl acrylate and 2,6-dibromo-4-sulfonicphenyl acrylate and derivatives thereof: halogenated styrene such as dibromo styrene: P- Styrene-substituted halogenated alkyl derivatives such as chloromethyl or P-bromomethyl styrene: chloromethyl vinyl ester, bromomethyl, non Halogenated alkylvinyl ethers such as ether, chloroethyl vinyl ether, bromoethyl vinyl ether, 2,3-dichloro propyl vinyl ether, 2,3-dibromo propyl vinyl ether and the corresponding halogenated alkyl aryl ethers: bis (2- Phosphorus and halogen-containing unsaturated monomers such as chloroethyl) vinyl phosphonate and bis (2-bromoethyl) vinylphosphonate. Among these halogen-containing unsaturated monomers, it is particularly preferable to use halogenated unsaturated hydrocarbon monomers such as vinyl chloride, vinyl embrittlement, and vinylene chloride.

In the present invention, as the halogen-containing organic compound introduced into the acrylic radiation stock solution, conventionally known halogenated organic compounds such as tris (2,3-dibromo propyl) phosphate and tris (2,3-dichloropropyl) are known as flame retardants. ) Phosphate, tris (chloro bromoenyl) phosphate, tris (bromo chloro propyl) phosphate, tris (2-chloro ethyl) phosphate, bisdi bromo propyl dichloro propyl phosphate, bisbromo chloro propyl bromo chloro propyl phospho Halogenated phosphate esters or ananic esters such as nitrate, bis dibromo propyl dibromo propyl phosphonate, bis 2-chloroethyl vinyl phosphonate: telomers made from halo methane and unsaturated phosphates ), Epoxy compounds with phosphorus halides and / or phosphorus oxyhalogenated Halogenated organophosphorus compounds such as reactive substances of: Halogenated aliphatic hydrocarbons such as tetrabromobutane, tetrabromoethane and chlorinated paraffins: Halogenated aromatic hydrocarbons such as hexachlorobenzene, methyl chloride phosphate, methyl + chloride stearate Halogenated aliphatic esters such as acrylate, methyl + lauric ethyl laurate stearate, and halogenated fatty acid amides such as N, N-dimethyldibromo stearamide and N, N-dimethyl tetrabromo stearamide Can be mentioned.

기를 가진 불포화 설폰산 및 그의 염, 예를 들면 아릴설폰산, 메타아릴설폰산, 메타아릴설폰산, 에틸렌설폰산 및 그들의 나트륨염, 칼륨염 : 1개의

기를 가진 불포화 지방족 탄화수소, 예를 들면 이소부틸렌 등 : 및 아크릴로니트릴과 공중합하여 열가소성 공중합체를 만드는 1개의

기를 가진 다수의 다른 비닐, 아크릴 및 화합물이 있다.Moreover, as another vinylic monomer used as needed in this invention, vinyl ester, especially vinyl ester of saturated aliphatic monocarboxylic acid, for example, vinyl acetate, a vinyl propionate, a vinyl butyrate: an aryl alcohol, for example For example, aryl alcohol, metaaryl alcohol, etaaryl alcohol, etc .: aryl, metaaryl, and other unsaturated monohydric alcohol esters of monobasic acids, for example, aryl and methayl acetate, laurene, cyanide, etc .: acrylic acid and alka Alkaacryl acids such as methacrylic acid, etaacrylic acid and the like and esters and amides of such acids, for example acrylates and methacrylates such as methyl, ethyl propyl, butyl, acrylamide, methacrylamide, N -Acrylamide and metaacrylamide, such as methyl, N-ethyl, N-propyl, N-butyl, etc .: methacrylonitrile, etaac Acrylonitrile Ronnie casting reel, and other hydrocarbon-substituted acrylic: 1

Unsaturated sulfonic acids with salts and salts thereof, for example arylsulfonic acid, metaarylsulfonic acid, metaarylsulfonic acid, ethylenesulfonic acid and their sodium salts, potassium salts:

Unsaturated aliphatic hydrocarbons having a group such as isobutylene and the like: and one copolymerized with acrylonitrile to make a thermoplastic copolymer.

There are a number of other vinyls, acrylics and compounds with groups.

The amount of acrylonitrile in these acrylonitrile-based polymers or copolymers is suitably determined to include at least 40% by weight, preferably at least 60% by weight, of bound acrylonitrile in the finally obtained acrylic fiber, and also copolymerization of halogen-containing unsaturated monomers. The amount or the amount of halogen-containing flame retardant component introduced is also appropriately determined so as to contain 3-50% by weight in terms of halogen in the final acrylic fiber.

In addition, in the present invention, any inorganic salt aqueous solution which dissolves the acrylonitrile-based polymer to form a spinning stock solution can be used any conventionally known inorganic salt aqueous solution as the solvent for the acrylonitrile-based polymer. (thiocyanate) Rich aqueous solution of rhodan salts such as soda, rodancali, rhodanammonium, rhodancalcium, and the like. Even if a mixed solvent in which other organic or inorganic compounds are mixed for improvement is used, there is no problem in the practice of the present invention.

(물엿, 조청) 수용액에 요드칼리 수용액(260g·I₂/ℓ, H₂O)을 첨가하여 얻어진 3000센티포이즈(Centipoises)의 청색 균일용액 100중량부에, 이 용액 중에 존재하는 요드의 1.4배 당량에 상당하는 티오 황산소다(Na₂S₂O₃)를 함유하는 수용액 10중량부를 첨가하여 교반한 경우에 있어서, 첨가한 순간부터 이 용액에 청색이 없어질 때까지의 시간이 20초 이하로 되는 교반능력을 가진 교반기를 뜻한다.The acrylic spinning stock solution in which the aqueous acid solution of the antimony oxide obtained according to the present invention is uniformly dispersed is formed into a filament as it is extruded into a coagulating liquid according to a conventional method. In addition, a mixer for finely and uniformly dispersing the aqueous dispersion in the spinning stock solution is suitably used a stirrer with a fast mixing speed having a stirring ability according to the following definition. That is to say that the above-mentioned mixing speed is agitation

(Starch syrup, crude syrup) 1.4 times of iodine present in this solution in 100 parts by weight of a blue uniform solution of 3000 centipoises obtained by adding an aqueous solution of iodide (260 g · I ₂ / l, H ₂ O) to an aqueous solution In the case where 10 parts by weight of an aqueous solution containing an equivalent of sodium thiosulfate (Na ₂ S ₂ O ₃ ) is added and stirred, the time from the time of addition until the color disappears from the solution is 20 seconds or less. Means agitator with agitation ability.

For example, as described in the specification 45-42603 of the application of the present inventors, a high hole stirrer or a commercially available high shear stirrer (i.e., by high-speed rotation of a stirring blade, Mainly increasing shear force to obtain high dispersion effect), for example, "Pipe Line Mixer" manufactured by Shimazaki Factory, and "Pipe Line Homomixer" manufactured by Special Vaporization Co., Ltd. Flomix, In-Line Agitator made by Chemineer (USA), Mixco Line Blender made by Mixing Equipment (USA), Vertex Mixer made by Ashbrook (Miggu), Rietz Mfg (USA) ) "High Shear In-Line Mixer", "In-Line Mixer" by Gifford-Wood (USA), "Recirculating In-Lin Mixer" by Gabb Special product (USA).

The following Examples describe the present invention better and do not limit the scope of the present invention.

In addition, all parts and percentages shown in an Example are based on a weight basis unless there is particular notice.

EXAMPLE

Aqueous 10% aqueous acid solution of the antimony oxide particles having an average particle diameter of 15 mμ was an aqueous solution of 50% rhodansoda of an acrylonitrile copolymer comprising 81% of acrylonitrile, 10% of vinylidene chloride and 9% of methyl acrylate (polymer concentration of 10% ) Is continuously introduced as a ratio of aqueous acid solution / spinning solution = 3/100 (weight ratio), and as a stirrer "Pipe Line Homomixer" (special vaporization: according to the definition of the stirring ability described above, until the blue color disappears) The time of 12 seconds) was used to stably stably obtain an acrylic radiation stock solution having fine and uniformly dispersed antimony oxide particles as the mixture was stirred. The spinning stock solution thus obtained was extremely useful as a spinning stock solution for fiber production, with little lump formation occurring due to gelation and agglomeration even after long standing.

The thus obtained spinning stock solution was coagulated by extruding in a coagulation bath at 0 ° C and 12% in a solution of 12% rodan soda using a spinneret having a pore diameter of 0.15 mm and a hole number of 100, stretched twice at room temperature, washed with water, and washed with hydrogel. The fibers in the film were stretched and removed five times in boiling water, dried in an atmosphere having a dry bulb temperature of 120 ° C. and a wet bulb temperature of 67 ° C., and furthermore, a wet heat relaxation treatment was performed in saturated steam at 127 ° C. A flame retardant acrylic fiber with little gloss, little loss of fiber, and good gloss was obtained. The light transmittance of this fiber was 44.3%.

In addition, in the spinning process, a mantle filter made of gold cloth is used in front of the spinning nozzle. However, there is almost no increase in the pressure applied to the filter, and a problem arises in operability. Did not do it.

On the other hand, as a comparative example, the same experiment was attempted according to the conventional method of adding antimony oxide directly upon dissolution of the acrylonitrile copolymer. In other words, the acrylonitrile copolymer was dispersed (copolymer concentration 26%) in a low concentration rhodansoda aqueous solution (concentration 25%) such that the acrylonitrile copolymer was not dissolved, and then the antimony oxide powder was added, mixed and continued. After adding a high concentration solution of rhodansodium (concentration 60%) and heating, an acrylonitrile copolymer was dissolved to obtain an acryl-based spinning stock solution in which antimony oxide was decomposed.

The spinning spinning solution thus obtained was wet-spun in the same manner as described above. As a result, the aggregate of antimony oxide particles in the spinning spinning solution closed the mantle filter, so that the filter input was raised and continuous operation was difficult for a long time. Moreover, the obtained acrylic fiber has a cavity and is extremely devitrified with a transmittance of 22.3% and has a gloss.

In addition, in the dyeing obtained by dyeing the fiber having a cavity obtained in the comparative example as a cationic dye, the color of the dyeing was changed as part of the cavity in the fiber collapsed and deformed by drying or ironing, but the cation of the fiber obtained according to the present invention. In dye dyeings, this problem was not caused.

As is clear from the above results, according to the present invention, flame retardant acrylic fibers having good gloss and color development with improved devitrification can be obtained without causing any clogging of the clogging filter of the nozzle or the like in the spinning step.

In the present embodiment, light transmittance is a numerical value for measuring light transmittance using a HITACHI-101 Spectrophotometer (manufactured by Hitachi, Ltd.), and the larger the value, the higher the transparency. Specifically, the fiber used for the measurement was cut | disconnected to length of 2 mm, the dimethyl butyrate of refractive index 1.512, the acetophenone of the refractive index 1.529, ethanol of the refractive index 1.358 were mixed, and the liquid adjusted to refractive index 1.506 was put into horizontal X length What was put in a fixed amount in the measuring cell of x height = 1 * 1 * 5cm was prepared, and the transmittance | permeability was measured by putting the light of wavelength 420mmicro at right angles to the cell surface.

Claims (1)

The amount of antimony oxide particles was 60 wt% or less in the halogen-containing acrylic spinning solution containing an inorganic salt solvent solution of an acrylonitrile-based copolymer copolymerized with a halogen-containing unsaturated monomer or an acrylonitrile-based polymer composition containing a halogen-containing flame retardant component. The uniform aqueous dispersion dispersed as a ratio was introduced at a ratio of 10 parts by weight to 50 parts by weight of the aqueous acid solution with respect to 1000 parts by weight of the spinning stock solution, and mixed using a stirrer having a stirring ability as defined in the description of the present invention. Improved manufacturing method of flame retardant acrylic fibers, characterized in that the wet spinning according to the conventional method.