JP2601772B2 - Flame retardant acrylic composite fiber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flame-retardant acrylic composite fiber having excellent flame retardancy and latent crimp development.

(Prior Art) Conventionally, general acrylic fibers have a noble feel similar to wool, excellent physical properties, solid dyeing properties and dyeing clarity, and have been used in a wide range of applications. However, acrylic fibers, like most natural and synthetic fibers, are flammable, so they can be used in clothing, interior products, and industrial and construction applications to help spread fires. Was narrowed.

Flame-retardant acrylic fibers, on the other hand, have the property of flame-retardant self-extinguishing properties, but they do not have the same stiffness, bulkiness, and settling properties as ordinary acrylic fibers, and they are still used in sufficient quantities. That is not the situation. Therefore, as one method of improving the above-mentioned drawbacks in flame-retardant acrylic fiber products, it is common practice to use a blend of fibers having other excellent physical properties such as nylon, polyester, and polyacrylonitrile fibers. The blending causes new disadvantages such as an increase in the number of processing steps, a decrease in dyeability, a change in texture, and a decrease in flame retardancy. In order to improve the bulkiness, stiffness, settling, etc. of products made of flame-retardant acrylic fibers alone, shrinkable cotton with equivalent flame retardancy and fibers with latent crimpability, especially the latter, are necessary It is flame-retardant by mixing and using this flame-retardant acrylic fiber having latent crimping property and ordinary flame-retardant acrylic fiber, and has good waist feeling, bulky property, texture, good dyeing properties, etc. Products can be manufactured.

However, flame-retardant acrylic composite fibers having both good crimpability and flame retardancy have not been obtained, and their studies have not been carried out much.

JP-A-49-68014 discloses that acrylonitrile is 85% by weight.
It is a composite fiber of the polyacrylonitrile polymer contained above, a flame-retardant acrylic polymer and an antimony halide compound, but the fiber obtained here is difficult to use because the polyacrylonitrile polymer is used as one component. Flammability cannot be improved enough. If the vinyl chloride content or antimony halide content in other components is increased to increase the flame retardancy, gelation in the spinneret or clogging of the spinneret due to differences in miscibility and compatibility between both components, Thread breakage occurs, and the coagulation properties of both components are greatly different, so that it is difficult to set coagulation bath conditions that allow both components to coagulate densely. Further, even after spinning, a large drop in operability and a large drop in quality are expected, such as occurrence of troubles due to peeling of both components due to stretching and shrinkage due to insufficient adhesion between the two components. Further, it is expected that the consumption performance of the product, such as dyeability, heat resistance, and gloss, will be reduced, and that the processing performance will be reduced, such as yarn breakage and fluffing during spinning and weaving.

JP-A-59-82410 is a composite fiber obtained by adding a polyurethane polymer to a flame-retardant acrylic polymer and spun.However, the fiber obtained here only increases the cost of the fiber due to the added polyurethane polymer. However, the coloring properties and light resistance after dyeing were not yet satisfactory.

As described above, flame-retardant acrylic composite fibers using a flame-retardant acrylic polymer for both components and having sufficiently good flame retardancy and latent crimpability have not yet been developed. The present inventors have made intensive studies to overcome the above-mentioned drawbacks, and as a result, completed the present invention.

(Problems to be Solved by the Invention) The object of the present invention is to achieve good texture, bulkiness,
An object of the present invention is to provide a flame-retardant acrylic composite fiber having an excellent latent crimping property with a feeling of stiffness.

(Means for Solving the Problems) The present invention relates to a polymer in which both eccentrically bonded components A and B are composed of 40% by weight or more of acrylonitrile and 20 to 60% by weight of a halogen-containing monomer and a sulfonic acid-containing monomer. Yes,
Further, it is a flame-retardant acrylic composite fiber containing 1% by weight or more of vinyl chloride in the A-component polymer as compared with the B-component polymer.

In the polymer of the present invention, examples of the halogen-containing monomer include, but are not limited to, vinyl chloride, vinylidene chloride, vinyl bromide, and vinylidene bromide. Particularly, vinyl chloride and vinylidene chloride are preferable. If the halogen-containing monomer is less than 20% by weight, excellent flame retardancy cannot be obtained, and if it exceeds 60% by weight, not only the quality of the obtained fiber such as heat resistance strength decreases, but also the flame retardancy reaches saturation. Not economic. Therefore, the amount of the halogen-containing monomer is 20 to
The range of 60% by weight is preferable in terms of operability, quality and cost.

The polymer of the component A contains 1% by weight or more, preferably 2% by weight or more of vinyl chloride, and the fiber of the component B contains 1% by weight or more, preferably 2% by weight or more. It is necessary for imparting a high crimping property. If necessary, the component A polymer may contain another halogen monomer, and it is particularly preferable to use vinylidene chloride in combination to improve the flame retardancy and heat resistance of the fiber. The halogen monomer of the component B polymer may not contain vinyl chloride, but when it contains vinyl chloride, it can be contained by 1% or more, preferably 2% or more less than the vinyl chloride content of the component A. It is necessary for imparting good crimping property of the folded fiber. Polymers composed of vinylidene chloride and / or vinyl chloride are preferred because the resulting fibers have good flame retardancy and heat resistance.

When the difference in the vinyl chloride content between the component A polymer and the component B polymer increases, the number of crimping ridges after the boiling water treatment tends to increase, and the spun yarn when the obtained composite fiber is used by blending is used. Since the texture becomes hard, the difference in the content of vinyl chloride is adjusted, and the number of crimping ridges after the boiling water treatment of the obtained conjugate fiber is preferably 5 to 50 / inch, and 10 to 10
It is particularly preferable to set the number to 35 pieces / inch.

In the present invention, examples of the sulfonic acid-containing monomer include sodium allyl sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, and sodium 2-acrylamido-2-methylpropane sulfonate, but are not limited thereto. . Preferably, the sulfonic acid-containing monomer is contained in the polymer in an amount of 0.5 to 5% by weight, particularly preferably 1 to 4% by weight, so that the dyeing property is improved, the coagulation property during spinning is greatly improved, and the dry densification is increased. The fibers can be improved and promoted in a wide range, and fibers having good gloss and dyeability can be obtained.

The polymer used in the present invention can be prepared by any polymerization method such as emulsion polymerization or solution polymerization in an aqueous medium or an aqueous medium containing an organic solvent. When an emulsion polymerization method is employed as the polymerization method, an anionic surfactant is particularly effective as a surfactant to be used, and as the anionic surfactant, a fatty acid salt, a sulfate salt, a sulfonate,
Phosphate salt and the like can be mentioned. The surfactant used may be a small amount of a normal nonionic surfactant in addition to the anionic surfactant. The amount of these surfactants used is 0.1 to 10% by weight based on all monomers.
It is particularly preferable to use 0.2 to 5% by weight. When the solution polymerization method is employed, the solvent used includes dimethylsulfoxide, dimethylformamide, dimethylacetamide and the like, and it is particularly preferable to use dimethylformamide. In addition, as the polymerization medium, a small amount of water or other organic solvent that does not hinder the uniform solubility and the polymerizability of the copolymer can be used in addition to these organic solvents.

Examples of the catalyst used in the polymerization include ordinary radical polymerization initiators, for example, persulfates such as ammonium persulfate and potassium persulfate; or a combination of ammonium persulfate and a persulfate such as sodium acid sulfite and acid sulfite or a salt thereof. Azo compounds such as azobisdimethylvaleronitrile and azobisisobutyronitrile; di (2-
There are peroxides such as (ethylhexyl) peroxydicarbonate, t-butyl peroxypivalate, and lauroyl peroxide, which are appropriately selected and used depending on the polymerization method.

The polymerization temperature is preferably from 30 to 70 ° C, and the monomer concentration is preferably from 10 to 70% by weight based on the whole polymerization system.

In order to obtain a polymer from an aqueous emulsion polymer solution, the polymer is separated by using an aqueous solution of an electrolyte such as sodium chloride, calcium chloride, magnesium sulfate, and aluminum sulfate, which are usually salts for salting out, and further washed with water. , Dehydration and drying to obtain a polymerized powder.

On the other hand, as a method for removing unreacted monomers such as acrylonitrile, vinyl chloride, and vinylidene chloride from a mixture of polymer solutions obtained by a solution polymerization method, vinyl chloride is present as an unreacted monomer. Preferably, first, most of the vinyl chloride is removed under normal pressure, and then monomers such as acrylonitrile and vinylidene chloride are recovered under reduced pressure. The operation conditions for removing the monomer under reduced pressure are preferably 10 to 200 mmHg and 40 to 90 ° C. In this case, in order to adjust the ease of removing unreacted monomers and the final polymer concentration, it is desirable to appropriately add an organic solvent used in the polymerization system as needed in each removal step.

The specific viscosity of the polymer of the present invention (measured at 30 ° C. in a polymer solution of 2 g of polymer / dimethylformamide 1) is
0.13-0.60 is preferred.

As a method for producing fibers from the polymer of the present invention, any of ordinary wet / dry spinning methods can be used. As a solvent for the spinning solution, acetonitrile, acetone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, and the like, which are common solvents for acrylonitrile-based polymers, are used. In addition, the spinning solution or the polymerization system of the solution polymerization method, if necessary, stabilizers such as epoxy compounds and organic tin compounds or organic reducing agents, additives such as titanium compounds and aluminum compounds to improve the texture, or Antimony compounds to further enhance flame retardancy,
Even if a flame retardant such as a tin compound or a bromine compound is contained, there is no problem at all, and the polymer concentration in the spinning solution is 15 to 40.
% By weight. As a spinning method, a spinning solution is extruded through a nozzle into a 10 to 80% by weight aqueous solution of a solvent to form a yarn, and then stretched, washed, dried, and densified to improve crimp development, adjust fiber properties, and texture. Shrinkage, stretching, post-oil, mechanical crimping, crimp setting, etc. may be performed for adjustment, improvement of spinnability, and the like.

(Effect of the Invention) The flame-retardant acrylic composite fiber according to the present invention thus obtained is a fiber having both good flame retardancy and latent crimpability, and has high flame retardancy and bulkiness, and good wind. Bedding, sheets, bedspreads, carpets, curtains, etc. for bedding interior and safety,
It is capable of exerting its performance sufficiently in clothes for children and elderly people who require comfort, especially in pajamas and the like.

(Example) Next, the present invention will be specifically described with reference to examples. still,
Parts and% in Examples are parts by weight and% by weight unless otherwise specified.
Is shown.

 The crimp characteristics were performed according to JIS L-1074.

Flame retardancy was represented by the limiting oxygen index (hereinafter abbreviated as LOI). This is done by cutting the fiber to 51mm, disintegrating it with a hand card, collecting about 0.5g of cotton, stretching it evenly to a length of about 25cm, twisting it 70 times with a twisting machine, and then folding it in half. To make a twist rod. Next, a flame is brought into contact with the upper end of the twisting rod in a mixed gas of nitrogen gas and oxygen gas, and the oxygen gas concentration (volume) in the mixed gas when the sample burns by 5 cm is represented by the following formula.

Example 1 A polymer having a composition of acrylonitrile (hereinafter abbreviated as AN): vinylidene chloride (hereinafter abbreviated as VDC): sodium allyl sulfonate (hereinafter abbreviated as SAS) = 70: 20: 10 (%) was converted to dimethylformamide (hereinafter abbreviated as dimethylformamide). Polymerization was carried out in an autoclave using azobisdimethyl valeronitrile as an initiator using DMF as a solvent. Then, the polymer and A
DMF with N, VDC and / or vinyl chloride (hereinafter abbreviated as VC)
And polymerized in an autoclave at 50 ° C. for 9 hours using azobisdimethylvaleronitrile as an initiator to obtain a polymer shown in Table 1. Unreacted monomers were removed and recovered from the polymerization dope by a rotary evaporator.
After the monomer recovery, the polymer solution was transparent, pale yellow and viscous.

A water / DMF mixed solution was added to the viscous dope to obtain a spinning dope having a polymer concentration of 26% and a water content of 5%. Using these polymers as the A and B components, the spinning solution of the A and B components is a side-by-side type composite spinneret (nozzle hole diameter 0.06 mm, number of holes 4000
) From different entrances, DMF: water = 60:40
(%) Into a coagulation bath. The discharge ratio of A and B components is 1: 1
It is. The spun fiber is subjected to desolvation and primary drawing 4.5 times in two baths where the DMF concentration gradually decreases to 30% and 15%, and then washed thoroughly in a 70 ° C water washing tank before After the oil agent was applied in an oil bath, it was dried and densified with a hot roller at 135 ° C. After drying, the secondary stretching of 1.4 times with 100 ° C steaming and 100%
Under steaming at 90 ° C., the fibers contracted by a factor of 0.95, adhering oil, crimping, and then dried to obtain 3 denier various flame-retardant acrylic composite fibers.

Example 2 Using an autoclave, AN, VC, VDC, sodium styrene sulfonate (hereinafter abbreviated as SSS), a combination of ammonium persulfate and sodium acid sulfite as a polymerization initiator, and sodium lauryl sulfate as a surfactant, Polymeric
Emulsion polymerization was carried out at a reaction temperature of 38 ° C. and a polymerization time of 7 hours by adjusting the pH to 2.3. After recovering the unreacted monomer, a polymer powder was obtained through salting out, filtration, washing with water, dehydration and drying.
Table 2 shows the composition of the obtained polymer.

Dissolve these polymers in acetone and polymer concentration 30%
Was prepared. The spinning solutions of the A and B components were introduced into side-by-side type composite spinnerets from different inlets, respectively, and wet spinning was performed in an acetone: water = 40: 60 acetone aqueous solution. The ratio of the A and B components is 1: 1. The spun fibers are washed with water in a bath where the acetone concentration gradually decreases, and the temperature is 120.
After drying with a hot air dryer at a temperature of 130 ° C., the film was hot-stretched three times at 130 ° C. in a hot air and heat-treated for 3 minutes in hot air at a dry heat of 145 ° C. under tension. Thereafter, a post-oil was applied, a crimp was applied, and then dried to obtain a 3-denier flame-retardant acrylic composite fiber.

Claims (1)

(57) [Claims] An eccentrically joined A and B component is a polymer comprising at least 40% by weight of acrylonitrile, 20 to 60% by weight of a halogen-containing monomer and a sulfonic acid-containing monomer, and the A component polymer A flame-retardant acrylic composite fiber containing 1% by weight or more of vinyl chloride in the B component polymer.