JPS61258073A - Production of synthetic fiber having cavities - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing synthetic fibers having cavities that have excellent texture and water absorption.

(Prior Art) Synthetic fibers such as polyester fibers and polyamide fibers have the waxy and slimy feel characteristic of synthetic fibers, and have the disadvantage of lacking the crisp feel and water absorption properties of linen.

Conventionally, various attempts have been made to overcome this drawback and give synthetic fibers a natural fiber-like feel, water absorption, etc.

A typical method is to include a substance that can be extracted with a solvent during the production of synthetic fibers, and to make the fibers porous by extracting the fibers with a solvent.Many proposals have been made.

(Problems to be Solved by the Invention) However, with the conventionally proposed methods, the spinning properties during the production of synthetic fibers are poor, it is difficult to form holes or cavities of a desired size, and depending on the material, the fiber It has the disadvantage that when it remains in the fiber, it deteriorates the properties of the fiber.

The present invention aims to provide a method for producing synthetic fibers having cavities that do not have these drawbacks.

(Means for Solving the Problems) The present invention provides a method for solving the above problems. Synthetic fibers (A) and [B] in which at least a part of the fiber surface is formed of a composition in which polyarylate (A) is uniformly dispersed in a thermoplastic polymer [B] whose glass transition temperature is lower than that of polyarylate (A) A method for producing synthetic fibers having cavities is characterized in that the synthetic fibers are treated with a solvent that dissolves only one of them or a solvent that has different solubility for both.

As the polyarylate in the present invention, one obtained from a mixture of a terephthalic acid component and an isophthalic acid component and a bisphenol compound component represented by the following general formula is preferably used.

[X is a direct bond, -CH2-+ -c (CH:+
)z-.

-o-, -3ot- or -CO-. ] From the point of view of versatility and spinnability, polyarylate has a molar ratio of 30/70 to 7.
Most preferred are those obtained from a mixture of 0/30 terephthalic acid and isophthalic acid components and bisphenol A component.

Polyarylate can be obtained by conventional methods, for example,
It can be obtained by melt polymerization of a mixture of terephthalic acid and isophthalic acid and an acetate ester of a bisphenol compound, or by solution polymerization or interfacial polymerization of a mixture of terephthalic acid chloride and isophthalic acid chloride and a bisphenol compound.

Further, the polyarylate may contain a small amount of polyester-forming components other than those mentioned above.

The polyarylate used in the present invention has an intrinsic viscosity (measured at 30°C after dissolving it in a mixture of phenol and tetrachloroethane at a weight ratio of 6/4 at a concentration of Ig/dz) of 0.
3 or more, preferably 0.4 or more is a monopolymer [B]
It is desirable because it can be easily dispersed finely.

In addition, the polyarylate in the present invention has a molecular weight of 180 to 200
It has a glass transition temperature of °C.

Next, examples of the polymer [B] having a glass transition temperature lower than that of the polyarylate in the present invention include polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate, and polyesters mainly composed of these, nylon 4. Nylon 6, nylon 12. nylon 4
6. Nylon 66, nylon 610, etc., and polyamides based on these are preferably used. (The glass transition temperature of these polymers is 20 to 90"C.) Among them, when a polyester such as polyethylene terephthalate is used as one polymer [B], it has a moderate affinity with polyarylate and has good thread-spinning properties. is good and preferable.

In the present invention, the synthetic fiber before being treated with a solvent is obtained by slightly melting polyarylate (A) and a thermoplastic polymer [B] having a lower glass transition temperature than polyarylate (A) using a dynamic mixer or a static mixer. It is easily manufactured by mixing and melt spinning.

However, when using polyester as the monopolymer [B], it is desirable to take measures to suppress the reaction with polyarylate, such as phosphoric acid or phosphorous acid.

It is desirable to use a phosphorus compound having the ability to inhibit transesterification such as phosphonic acid and ester thereof in combination.

In the present invention, it is necessary that the polyarylate [A] and the polymer [B] are mixed non-uniformly in the synthetic fiber before solvent treatment, and the polyarylate has a size on the order of several tens of microns or more. The fibers are dispersed in linear, spherical, or long spheroidal shapes, and those dispersed in spherical or long spherical shapes form moderate protrusions on the fiber surface and form large cavities when treated with a solvent. It is preferable because it is easy.

The spinning method for obtaining the synthetic fibers to be subjected to the solvent treatment of the present invention includes (1) melt-spinning the heterogeneous mixture to obtain an undrawn yarn; Method 1+ of stretching at a temperature higher than the glass transition temperature (2) 5000 m/l of the heterogeneous mixture
A method is employed in which highly oriented fibers are obtained by melt spinning at a high speed of approximately 11n or more.

When yarn is spun using this method, the polyarylate portion is difficult to stretch, resulting in fibers in which the polyarylate is non-uniformly dispersed.

The dispersion state of polyarylate (A) and polymer [B] in the fiber is determined not only by the difference in glass transition temperature between the two, the mixing ratio and mixing state before spinning, but also by the temperature below 1 spindle during melt spinning. It is suitably adjusted by the atmospheric temperature, take-up speed, temperature magnification during stretching, etc.

In order to obtain such fibers, polyarylate [A]
The mixing ratio of and polymer [B] was set to 2, taking into consideration the fiber physical properties.
Weight ratio: 3/97~40/60°, preferably 5/95~
30/70 and when using the above phosphorus compound in combination,
It is desirable that the content of the phosphorus compound is 0.01 to 1% by weight, preferably 0.02 to 0.8% by weight.

In addition, the mixing temperature or spinning temperature is 230 to 320°C.
, preferably 250 to 300°C.

Note that the fibers of the present invention include not only single-component fibers, but also
It also includes fibers that are composited with other polymer components in the form of bimetallic, sheath-core, seabird-like, etc. Especially to obtain fibers with good water absorption.

It is preferable to use hollow fibers. Also flame retardant and heat resistant agent.

It may contain various additives such as a light stabilizer, a matte coloring agent, and an antistatic agent.

Next, in the method of the present invention, synthetic fibers (A) and [B] in which at least a part of the fiber surface is formed of a composition in which polyarylate (A) is non-uniformly dispersed in polymer [B] Synthetic fibers with cavities are made by treating them with a solvent that dissolves only one of them, or a solvent that has different solubility for both, and the treatment with a solvent may be carried out in the state of raw yarn or raw cotton. 1 Usually done in the form of cloth.

Examples of solvents for polyarylate include benzene, tetrahydrofuran, dimethylformamide, chloroform, and trichloroethylene. Solvents for polyesters such as polyethylene terephthalate include aqueous alkaline solutions such as sodium hydroxide, hydroxide, and potassium (which decompose and dissolve polyesters). Alkaline aqueous solutions also have solubility for polyarylates, but their solubility is extremely small compared to the solubility for polyesters such as polyethylene terephthalate. Furthermore, examples of the solvent for polyamide include formic acid. In addition, an appropriate solvent may be selected from known solvents depending on the type of polymer [B].

(Function) When spinning a composition in which polyarylate (A) is non-uniformly dispersed in polymer [B], the polyarylate portion has a high glass transition temperature and is difficult to stretch, and cavities are removed by subsequent solvent treatment. It is recognized that this is more likely to occur. That is, [A
] and [B], peeling phenomenon or stress distortion may occur,
It is thought that [A] is not stretched excessively in the fiber axial direction, making it easier for the solvent to penetrate.

If polyarylate (A) is treated with a solvent that dissolves well, part or all of the polyarylate is extracted and cavities are formed, and when treated with a solvent that dissolves the bipolymer [B] well, polyarylate The polymer of the adjacent part [B
] is easily dissolved.

A cavity is formed in that part (part of the polyarylate is removed by dissolving the polymer [B]) (Examples) The present invention will be specifically explained below with reference to Examples. (“
"Parts" indicates parts by weight. ) Example Synthesized by an interfacial polymerization method from an equimolar mixture of terephthalic acid chloride and isophthalic acid chloride and bisphenol A.Essential viscosity 0.7. Intrinsic viscosity of a copolymerized product of 15 parts of polyarylate with a glass transition temperature of 195°C and 1 mol% of 5-sodium sulfoisophthalic acid component (dissolved in an equal weight mixture of phenol and tetrachloroethane and measured at 25°C) 0. 75. 85 parts of a polyethylene terephthalate copolymer having a glass transition temperature of 78°C and 0.05 part of bis(n-butyl) phosphate were melt-mixed at 270°C for 3 minutes using a two-wheel screw mixer.

On the other hand, 1 ordinary polyethylene terephthalate was melted at 280° C. using a melt extrusion device with a single screw.

The above-mentioned two-port melts were introduced into a sheath-core type composite spinning device, and the former was used as a sheath component and the latter was used as a core component, and a composite yarn with a weight ratio of 7:3 was spun at 280° C. at a speed of 1200 m/min. Winding 2 Then, temperature: 90°C, magnification: 3.2x, speed: 7
00 m/mtn.

The obtained drawn yarn has a strength of 3.6 g at 75 d/16 F.
/d.

The elongation was 28%, and there were no problems with thread breakage or fuzz during spinning.

In addition, using the above drawn yarn, a tubular knitted fabric with a density of 80 g/m2 was made, (a) in chloroform at 30°C for 2 hours and (
g) 140g/dj! The sample was treated at 98°C for 20 minutes in an aqueous sodium hydroxide solution having a concentration of .

Figure 1 is a scanning electron micrograph (1000x) of the fibers of the solvent-treated fabric [treated as in (a)]
and FIG. 2 (after processing in (b)).

All of the obtained fabrics had a crisp texture.

Next, these fabrics were immersed in water at 20°C for 30 minutes, and then centrifuged for 2 minutes at 2500 rpm to measure the water retention rate.
) was treated in 17% of the cases. (For fabrics made from ordinary polyethylene terephthalate, it was 6%.) (Effects of the invention) According to the present invention, synthetic fibers having cavities with excellent texture and water absorption can be manufactured with good operability.

[Brief explanation of drawings]

FIGS. 1 and 2 show electron micrographs (1000x magnification) of the fibers obtained in the examples.

Claims (2)

[Claims] (1) A composition in which a polyarylate [A] obtained from a mixture of a terephthalic acid component and an isophthalic acid component and a bisphenol compound component is nonuniformly dispersed in a thermoplastic polymer [B] whose glass transition temperature is lower than that of the polyarylate [A]. [A] and [B] synthetic fibers in which at least a part of the fiber surface is made of
1. A method for producing synthetic fibers having cavities, the method comprising treating with a solvent that dissolves only one of the fibers or a solvent that has different solubility for both. (2) Polyarylate [A] has a molar ratio of 30/70 to 70
/30 obtained from a mixture of terephthalic acid component and isophthalic acid component and bisphenol A component,
The method for producing a synthetic fiber having cavities according to claim 1, wherein the thermoplastic polymer [B] is polyalkylene terephthalate.