JPH11217727A - Polyparaphenylene terephthalamide fiber and method for producing the same - Google Patents

Abstract

(57) [Problem] To provide a para-aramid fiber maintaining the characteristics of high strength and high elastic modulus, and a method for producing the same. A polyparaphenylene terephthalamide fiber after spinning, which has been wound once and before dyeing, has a tensile strength of 15 g / d or more and a crystal size (110 directions) of 3
A dyeable polyparaphenylene terephthalamide fiber having a water content of 0 to 55 angstroms and a moisture content of 6% or less and having no history of drying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a para-aramid fiber maintaining high strength and a high modulus of elasticity and a method for producing the same.

[0002]

2. Description of the Related Art Polyparaphenylene terephthalamide fibers (hereinafter referred to as "para-aramid fibers") have high functionality such as high strength, high elastic modulus, high heat resistance, non-conductivity, and no rust, and are characteristic of organic fibers. It is a synthetic fiber that has both flexibility and lightness. From these features, automobiles and motorcycles,
And reinforcing materials for bicycle tires, toothed belts for automobiles, conveyors, and the like. It is also used for reinforcing optical fiber cables and ropes. In addition, applications are also being made to bulletproof vests, work gloves that use the property of being difficult to cut with blades, protective clothing such as work clothes, and firefighting clothes that use flame resistance.

[0003] In these fields of use, in addition to the above-mentioned properties, it is required to impart dyeing properties. However, it is difficult to dye aramid fibers because of its high crystallinity, strong intermolecular bonding force and a dense structure. there were.

The following means have been proposed as a method for dyeing aramid fibers.

Japanese Patent Application Laid-Open No. 54-59476 discloses a method in which a crimp of 10 crimps / inch or more is applied and dyeing is performed from a buckled portion. Also, Japanese Patent Application Laid-Open No. 2-4
No. 1414 discloses a method of adding an organic pigment into a spinning dope. Also, JP-A-63-145412
The gazette proposes a method in which para-oriented aramid is brought into contact with a dyeing solution by leading to a step of relaxing tension during coagulation immediately after spinning. Further, Japanese Patent Application Laid-Open No. Hei 7-258980 proposes a method in which a para-aromatic polyamide having an intrinsic viscosity of 2.5 dl / g or less is brought into contact with a dye solution in a state of being swollen with water. JP-A-8-260362 discloses that a fiber swelling agent is used, and a cationic dye is used.
A method of dyeing at 0 ° C. or higher is disclosed. Japanese Patent Laid-Open No. 5-
209372 discloses a method of dyeing a copolymerized para-aramid fiber with a disperse dye having a molecular weight of 400 or less at 160 ° C. or more. Also, JP-A-9-8797
8 and JP-A-9-87979 propose a method in which para-aramid fibers are treated with a polar solution such as dimethyl sulfoxide and then subjected to high-pressure dyeing at 200 ° C.

[0006]

However, Japanese Unexamined Patent Publication No.
The method disclosed in Japanese Patent Application Laid-Open No. 4-59476 has a limitation that it is difficult to crimp at a rate of 10 crimps / inch or more industrially with a high-strength rigid para-aramid fiber, and it is limited to staples. JP-A-2-4141
Japanese Unexamined Patent Publication No. 63-145412 proposes a so-called spinning spinning method, which is a method of contacting a dyeing liquid without tension once without spinning immediately after spinning. In each case, the production of each color is premised, and the hue is limited. The method disclosed in JP-A-7-258980 has extremely low fiber strength due to low polymer viscosity, and does not have the characteristics of aramid fiber, which is a high-strength fiber. The method disclosed in Japanese Patent Application Laid-Open No. 8-260362 is a proposal for a spun yarn inferior to a filament yarn in tensile strength and tensile modulus, and is used as a means for dyeing a filament which can utilize the inherent high strength and high modulus functions of aramid fiber. Not be. The methods disclosed in JP-A-5-209372, JP-A-9-87978 and JP-A-9-87979 require special facilities such as a polar solution recovery facility and high-temperature dyeing, and are not general.

Hitherto, a method of post-dyeing, in which a variety of colors can be developed, in the form of a filament maintaining the characteristics of aramid fiber such as high strength and high elastic modulus, that is, into a tube-like material once spun. After the process is terminated by winding or the like, a method of dyeing various hues by transferring to a dyeing process in which individual colors can be dyed cannot be realized.

[0008] In general, the yarn forming process for forming filament fibers and the dyeing process for dyeing the fibers are separate processes, and are carried out by dedicated facilities and specialized engineers.
In order to satisfy the strict customer requirements for the color of dyed textile products, once the fiber is formed, the process is stopped once, the fiber is transported to a dyeing factory, and a specialized dyeing technician dyes it to the color required by the customer. Has important implications.

An object of the present invention is to provide a para-aramid fiber which can maintain a high strength and a high elastic modulus and can be dyed, and a para-aramid fiber dyed in various hues.

[0010]

To achieve the above object, the present invention takes the following measures.

(1) A polyparaphenylene terephthalamide fiber which has been spun and unwound before dyeing, has a tensile strength of 15 g / d or more, a crystal size (110 direction) of 30 to 55 angstroms, A dyeable polyparaphenylene terephthalamide fiber having no history of drying to a water content of 6% or less.

(2) The dyeable polyparaphenylene terephthalamide fiber according to the above (1), which has a crystallinity of 30 to 50%.

(3) The dyeable polyparaphenylene terephthalamide fiber according to (1) or (2), wherein the fiber has no history of drying to a water content of 15% or less.

(4) The fiber described in any of (1) to (3) above is crimped at 4 to 9 ridges / 25 mm,
Staple-like polyparaphenylene terephthalamide fiber that can be dyed and cut to a fiber length of 50 mm.

(5) A floc-shaped polyparaphenylene terephthalamide fiber obtained by cutting the fiber according to any one of the above (1) to (3) into 0.1 to 3 mm.

(6) A dyed polyparaphenylene terephthalamide fiber obtained by dyeing the fiber according to any one of (1) to (3).

(7) A dyed polyparaphenylene terephthalamide fiber obtained by dyeing the fiber according to any one of (1) to (3) with a cationic dye.

(8) Staple-like dyed polyparaphenylene terephthalamide fibers obtained by dyeing the staple-like polyparaphenylene terephthalamide fibers described in (4) above.

(9) A floc-dyed polyparaphenylene terephthalamide fiber obtained by dyeing the floc-like polyparaphenylene terephthalamide fiber according to the above (5).

(10) A dope for spinning is prepared from polyparaphenylene terephthalamide having an intrinsic viscosity (ηinh) of 5 or more and concentrated sulfuric acid, and the dope is once spun into the air through the pores of a spinneret, and immediately into water. In a method in which the step of guiding and coagulating to form a filament having a high strength and a high elastic modulus and the step of dyeing the filament are performed in a separate step without being continuous, the fiber has a tensile strength of 15 g /
d or more, and the crystal size (110 direction) is 30 to 55.
A method for producing dyeable polyparaphenylene terephthalamide fiber, which is angstrom and always maintains the water content of the fiber at 6% or more.

[0021]

DETAILED DESCRIPTION OF THE INVENTION Polyparaphenylene terephthalamide (PPTA) in the present invention is a polymer obtained by polycondensing terephthalic acid and paraphenylenediamine. Polymerized ones can also be used. The polyparaphenylene terephthalamide fiber (hereinafter referred to as para-aramid fiber) of the present invention is prepared by forming an optically anisotropic dope from PPTA having a specific viscosity (ηinh) of 5 or more and concentrated sulfuric acid, and then forming the dope into a spinneret. Once spun into the air through the pores, immediately lead into water and solidify, guided to a Nelson roller, neutralized with sodium hydroxide aqueous solution, passed through a water washing process, slightly dried by a hot roll, and formed into a filament as a filament It is obtained by passing the winding step without interruption.
The wound para-aramid fiber is packaged with a polyethylene film or the like so as not to dry before the dyeing step. The crystallinity of the para-aramid fiber at this time is 5
0% or less. At this stage, the tensile modulus of the fiber is 40
It exceeds 0 g / D and has the performance as a high elastic modulus yarn.
When heat treated at 0 to 400 ° C. for 5 to 10 seconds, the crystallinity becomes 50
Usually it exceeds%.

The intrinsic viscosity of the PPTA used in the present invention (ηin
h) is preferably 5 or more. Below the intrinsic viscosity (ηinh),
It is difficult to obtain fiber properties with high strength and high elastic modulus.

The para-aramid fiber of the present invention must have a crystal size (110 direction) of 30 to 55 angstroms and a water content of at least 6%. When the crystal size is less than 30 angstroms, the densification of the fibers is insufficient and high-strength, high-modulus fiber properties cannot be obtained, and when it exceeds 55 angstroms, dyeing becomes difficult.

The crystallinity of the present invention before dyeing is 30 to
Desirably, it is 50%. If the crystallinity is less than 30%, the tensile strength and tensile modulus of the fiber are inferior, and if it is more than 50%, dyeing becomes difficult.

Here, the condition that the water content is always 6% or more means that 6%
What follows is that it has no dry history. When the moisture content is dried to 6% or less, the structure becomes dense and dyeing becomes difficult. Even if water is added again, the dyeability does not recover.
Preferably, the degree of crystallinity is 35 to 45%, and the water content of the para-aramid fiber is desirably 15 to 100%. In order to achieve such a water content, it is preferable to dry the spun para-aramid fiber at a low temperature of 100 to 150 ° C. for 5 to 20 seconds. If the drying temperature is lower than 100 ° C., it is difficult to remove water, which causes a problem in handling after winding the tube.
If the temperature exceeds 150 ° C., crystallization proceeds and dyeing becomes difficult.

In the present invention, para-aramid fibers having such physical properties are dyed. The staining method is
No special equipment or special method is required, and existing synthetic fiber dyeing equipment can be used. Adjust the pH by adding an appropriate amount of dye, auxiliary and acid, start dyeing at 60 ° C,
This can be achieved by raising the temperature to 130 ° C. in 60 minutes and dyeing for 30 minutes. As the dye, a cationic dye, a disperse dye or the like can be used, but a cationic dye which easily penetrates into a dense structure is preferable. The para-aramid fiber of the present invention is useful for various uses. The dyed para-aramid fiber filament can be a sewing thread, cord, rope, or woven fabric of each color. The color-rich para-aramid fiber woven fabric obtained by the present invention can be used for sports clothing, luggage, work clothes, firefighting clothing, various protective clothing, tent fabric, and the like. The bulletproof vest fabric dyed in an inconspicuous hue is inconspicuous even if the outer skin is torn and the outer skin is torn and the para-aramid fiber fabric as the bulletproof fabric is exposed.

Further, applied products of the dyed para-aramid fiber of the present invention include automobile seat belts, protective clothing for boat racers, Japanese bow strings, tennis gut, fishing line and the like. When the dyed para-aramid fiber of the present invention is used as a transparent or translucent resin fiber reinforcing material, a colored resin product can be seen through the transparent or translucent resin so that a colorful resin product can be obtained. . For example, there are a resin glasses frame, a tennis racket frame, a table tennis racket, a hockey stick, a fishing rod, a golf shaft and the like. When the resin is an elastomer, it is useful for resin transmission belts, resin hoses, bicycle tires, and the like. The para-aramid fiber of the present invention can also be applied to ropes and electric wires indicating the production year by color. In the case where a plurality of electric wires are collected and converged into one, by using them as reinforcing members of different colors, it is possible to reinforce each of the electric wires and identify the terminal. It can also be used as a so-called lip cord that is under the covering of the electric wire and is used to cut the covering and expose the terminal.

The dyed para-aramid fiber filament is crimpered to give a crimp (6 crimps / inch) similar to a commercially available para-aramid fiber, and cut to a length suitable for spinning, ie, 20 to 150 mm. A colored para-aramid fiber staple can be obtained.
By cutting the dyed para-aramid fiber from 0.1 to 3 mm without crimping, a floc for electric flocking can also be obtained. The para-aramid fiber before dyeing of the present invention may be crimped and cut to form staples and then dyed. Similarly, it can be cut and dyed to obtain flocks for electric flocking.

[0029]

The present invention will be described below with reference to examples. The physical properties in the examples were based on the following measurements.

<Crystallinity> A wide-angle X-ray analysis method was used.

X-ray analysis apparatus: 4036A2 type, manufactured by Rigaku Corporation X-ray source: CuKα ray (using Ni filter) <Crystal size> Wide angle X-ray analysis was used.

X-ray analyzer: 4036A2 type, manufactured by Rigaku Corporation X-ray source: CuKα ray Curved crystal monochromator (using graphite) <Intrinsic viscosity> 98.5% by weight of intrinsic viscosity (ηinh)
A solution prepared by dissolving a polymer in concentrated sulfuric acid at a concentration (C) of 0.5 g / dl is measured at 30 ° C. by a conventional method.

Ηinh = (in · ηrel) / C <Strength and elongation characteristics of fiber> Tensile strength and tensile modulus (initial tensile resistance) of the yarn were measured according to JIS L1013.

<Moisture content> The moisture content was measured according to JIS L
According to 1013.

The moisture content (%) = (W−W ′) × 100 / W ′ where W: mass at the time of sampling W ′: mass at the time of absolute drying of the sample <L value> The L value is measured according to JIS. Z 8729. The measuring instrument was Macbe manufactured by Sumika Chemical Analysis Service, Ltd.
th Color Eyes 3000 was used.

Example 1, Comparative Example 1 PPTA (ηinh = 6.5) obtained by a usual method was dissolved in 99.9% concentrated sulfuric acid, and the polymer concentration was 19.0.
%, A spin dope with a temperature of 80 ° C., a small amount of spinning from a die having a number of 1000 pores of 0.06 mm in diameter into the air, and then into water at 4 ° C. for coagulation, leading to a Nelson roller, Neutralizing treatment with 8% aqueous sodium hydroxide solution, washing with water, drying with a hot roller at 110 ° C. for 15 seconds, and winding the film into a plastic tube without interruption, resulting in a total fineness of 1,000 denier comprising 1000 filaments. Para-aramid fiber A (filament yarn) of (absolute dry) was obtained.

Without winding the para-aramid fiber A into a tube, the para-aramid fiber A was subsequently guided to a hot roller provided, and further subjected to a heat treatment at 350 ° C. for 10 seconds. yarn)
I got

Table 1 shows the physical properties of these para-aramid fibers.
It is shown in FIG.

Table 1 Fiber type AB Crystallinity (%) 43 55 Crystal size 110 direction 42 65 Tensile strength (g / D) 23.0 22.2 Tensile modulus (g / D) 565 850 Water content ( %) 60 2.2 These para-aramid fiber filament yarns were dyed dark blue under the following conditions. owf indicates the weight% of the dye based on the weight of the dried fiber. g / l is the prepared dye bath 1
Shows the weight ratio of auxiliaries to liters.

Dye “AY7GLL” (manufactured by Bayer) 0.1% owf “KA.R.GL” (manufactured by Nippon Kayaku) 2.0% owf “TBTBLM” (Hodogaya) 8.0% owf assistant "Neodespon AC" (Morin Chemical Co., Ltd.) 2 g / l Acetic acid 20 g / l Sodium nitrate 20 g / l "Teryl carrier A111" (Meijin Chemical Co., Ltd.) 20 g / l Para-system Aramid fiber yarn was taken in an absolute dry weight of 10 g, dyeing was started at a bath ratio of 1:15, 60 ° C., and 130 minutes in 60 minutes.
C. and the dyeing was carried out for 30 minutes. After dyeing, reduction washing is performed at 80 ° C. for 20 minutes in a bath composed of a nonionic surfactant and a reducing agent
After dehydration and drying, the L value was measured. The L value indicates that the smaller the numerical value, the less the reflection of light and the darker the color. In the case of the same hue, the smaller the numerical value, the better the dyeing. In the dyeing method using the dyeing bath according to the above-mentioned preparation, a level where the L value was 50 or less was determined to be dyed.

The para-aramid fiber A adsorbed the dye well, but the para-aramid fiber B was hardly dyed.

Examples 2 to 4 and Comparative Example 2 Para-aramid fiber A was allowed to stand at room temperature to emit water, and the water content before dyeing was changed. Except for Comparative Example 2 having a water content of 5%, dyeing was well performed.

Comparative Example 3 Para-aramid fiber A was circulated at 100 ° C. with a circulating hot air drier at 6 ° C.
After drying for 0 minutes, the dyeing was performed under the above conditions with the moisture content being 0%. It hardly dyed.

Table 2 shows the results.

Table 2 Fiber type Water content L value Tensile strength Tensile modulus (%) (g / D) (g / D) Comparative Example 1 B 2.2 65.6 22.2 830 Example 1 A 60 45 .4 23.0 565 Example 2 A 45 45.5 23.0 565 Example 3 A 28 45.4 23.0 565 Example 4 A 12 46.0 23.0 565 Comparative example 2 A 5 50.2 23.0565 Comparative Example 3 A 0 65.2 23.0 565 Example 5 Para-aramid fiber A was twisted at a rate of 60 turns / m to prevent the filament from being disordered, and to have an inner diameter of 51 m with many holes.
0.04 g / m in a 25 cm long plastic tube
The cheese was rolled up into a cheese weighing 1 kg in absolute dry weight with a tension of D. This was dyed under the above-mentioned dyeing conditions using a cheese dyeing machine in which a dyeing solution was circulated to the outside of the cheese through a filament thread from a hole formed in the tube. The water content of the para-aramid fiber before dyeing was 52%. The L value of the para-aramid fiber after dyeing was 45.4, which was well dyed. The tensile strength was 23.0 g / D, and the tensile modulus was 565 g / D, which sufficiently satisfied the characteristics as a high-strength, high-modulus para-aramid fiber.

[0046]

According to the present invention, it is possible to provide polyparaphenylene terephthalamide fibers capable of maintaining the characteristics of high strength and high elastic modulus and dyeable, and polyparaphenylene terephthalamide fibers dyed in various hues.

Claims (10)

[Claims] 1. A polyparaphenylene terephthalamide fiber which has been spun and unwound before dyeing, has a tensile strength of 15 g / d or more, a crystal size (110 direction) of 30 to 55 angstroms, and has A dyeable polyparaphenylene terephthalamide fiber, characterized in that it has no history of drying to a content of 6% or less. 2. The polyparaphenylene terephthalamide fiber according to claim 1, wherein the degree of crystallinity is 30 to 50%. 3. A dyeable polyparaphenylene terephthalamide fiber according to claim 1, wherein said fiber has no history of drying to a water content of 15% or less. 4. The fiber according to claim 1, wherein
A staple-like polyparaphenylene terephthalamide fiber that can be dyed and has a crimp of 9 threads / 25 mm and is cut into a fiber length of 20 to 150 mm. 5. The fiber according to claim 1, wherein
Flocked polyparaphenylene terephthalamide fiber cut to 1 to 3 mm. 6. A dyed polyparaphenylene terephthalamide fiber obtained by dyeing the fiber according to claim 1. 7. A dyed polyparaphenylene terephthalamide fiber obtained by dyeing the fiber according to claim 1 with a cationic dye. 8. A staple dyed polyparaphenylene terephthalamide fiber obtained by dyeing the staple polyparaphenylene terephthalamide fiber according to claim 4. 9. A floc dyed polyparaphenylene terephthalamide fiber obtained by dyeing the floc polyparaphenylene terephthalamide fiber according to claim 5. 10. A spinning dope is prepared from polyparaphenylene terephthalamide having an intrinsic viscosity (ηinh) of 5 or more and concentrated sulfuric acid, and the dope is once spun into the air through the pores of a spinneret and immediately led into water. Solidified, high strength,
In a method in which a step of forming a filament having a high elastic modulus and a step of dyeing the filament are performed in separate steps without being continuous, the fiber has a tensile strength of 15 g / d or more and a crystal size (110 direction). A method for producing a dyeable polyparaphenylene terephthalamide fiber, which has a water content of 30 to 55 angstroms and always maintains a water content of 6% or more.