JPS63315669A - Production of conductive fabric fiber - 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 [Technical Field of the Invention] The present invention relates to antistatic monofilament.
) and a special device for carrying out the method. The most preferred equipment is classified as a coating equipment with a solid applicator supporting the thread forming operation. The applicator is movably mounted, rotates, and uses reinforcement or reservoir feed.

[Description of prior art]

The closest prior art patents for this invention are U.S. Pat. No. 3,823,035 and U.S. Pat.
255,487 and U.S. Pat. No. 4,545,835.
issues, and they are included here for reference. These t+, -1r describe a widely common method for producing antistatic filaments that are substantially the same as the filaments made by the method of the present invention. However, these methods differ from the method of the present invention in that different mixtures are applied and different mixture application means are used, as detailed below.

Other patents that are far less relevant to the present invention include U.S. Patent No. 3,582,445;
No. 0,703, U.S. Patent No. 3,749,055, U.S. Patent No. 2,269,150, U.S. Patent No. 2,380
, 422, U.S. Pat. No. 3,971.202 and U.S. Pat. No. 3,401,542. These patents are so closely related to the present invention that no explanation is necessary. Most of these patents describe single mttt coating means that are closely related to the coating means described herein.

SUMMARY OF THE INVENTION The present invention provides an electrically conductive fabric (1) by incorporating a dispersion of fine electrically conductive particles into a non-conductive monofilament polymer substrate. The present invention relates to an improved method of manufacturing fibers.

The particles increase the electrical resistance of the fabric by approximately 10'Ω/cm in a liquid that is a solvent for the substrate but does not react with the conductive particles.
It is applied to the substrate with sufficient strength to bring it below CI-.

Once the desired degree of penetration of the solvent has been achieved into the annular region located at the outer periphery of the filament, the solvent is removed from the substrate before the structural integrity of the substrate is destroyed. The improvement discovered in the present invention is that a dispersion of conductive particles in a liquid solvent is applied to a non-conductive monofilament substrate using a roll-type hot atomizer application machine. The substrate is dissolved and flash evaporated at 150° C. to form a mixture of formic acid and the following groups: (a) amides; or (b) carboxylic acids; or (c) alcohols; or (1) esters; or (1) ether; or (g) carbon (arsenic).

It consists of applying a mixture consisting of a dispersion in a liquid solvent of a mixture with one compound selected from the group consisting of:

With the improved method of the present invention, U.S. Pat.
, 035 Bow, U.S. Pat. No. 4,255,487 and U.S. Pat. can be manufactured. Furthermore, the mixture used in the present invention provides a combination of volatility, surface tension and viscosity that not only allows the process to be carried out at high speeds, but also allows the use of roll-type mixture applicators. .

Roll-type applicators are advantageous in that their use allows for the passage of bulges and knots found in the feed yarn without interrupting the process.

For example, the "splicing end" (t r
a n5fer tail)" can be tied to the tip of another feed yarn package so that a constant supply of feed yarn is maintained. In the case of orifices, knots and bulges create troublesome pressures.

It is an object of the present invention to provide an improved mixture for the production of electrically conductive textile fibers, such that electrically conductive textile fibers can be made at greater speeds than previously possible.

It is an object of the present invention that a roll-type mix applicator can be used in a commercial manner to process feeds with bulges and/or knots in the feed yarn continuously without interruption. The object of the present invention is to provide an improved hot material for the production of conductive fibers.

Yet another object of the present invention is to enable a high speed, substantially horizontal process for manufacturing electrically conductive textile fabrics, p).

Yet another object of the invention is to make it possible to produce supported electrically conductive textile yarns at high speeds, ie at speeds greater than 2000 m/min, the supported yarns comprising a plurality of supporting yarns. Consists of blended conductive textile fibers.

[Details of preferred specific examples]

FIG. 1 is a schematic illustration of a preferred embodiment of carrying out the method of the invention. A bobbin (1) of non-conductive monofilament polymer substrate (2) is placed under the torsion guide 11u (3). The monofilament base material (2) may be, for example, a 20 denier nylon 6 monofilament. The substrate (2) is then moved downwards and passes under the fixed guide rod (4), following which the yarn is directed upwards and in the course (6) of course roll-type coating application 1 (4). 5 shown only in Figs.
) sent inside. Improved; 1. The H6 material (7) is held in the holding tank (8) and pumped through the pump conduit (11
) to the "upper tank" (8). The mixture (7) is then continuously overflowed from the upper tank back to the holding tank (8) via the return conduit (12). is pumped into the upper tank (10) at such a rate that it is filled to the point where the upper tank (10) maintains a constant level (14) of the mixture (7) in it; A constant continuous pressure of the mixture is supplied to the mixture applicator (6) via the supply conduit (13).

The mixture (7) goes into the application fi (6) where it is forced up into the grooves (5 shown only in Figures 4 and 5), which are filled with a roll-type mixture applicator ( 6
> is attached to the grooved roll member (15), which is the most important member. The stator surface (16) (see Figure 2) keeps the mixture (7) wedged in the grooves (5) of the roll member. The substrate is advanced by a pair of drive rolls (17 and 18) at a speed of at least 500 m/min, while the surface speed of the roll member (15) is maintained at about 12+n/min. The roll (15) is driven by a motor (41). The substrate (2) is continuously wiped of the mixture, and the mixture is fed to the point where the substrate (2) contacts j:4 and 111. The base material (2) has a grooved opening.
After leaving the surface of the small part (15), the mixture-covered substrate (2') enters the upstream end of the evaporation tube (19).

The mixture (7) is filled into the mixture-coated substrate (2') while the substrate (2'') enters and travels through the evaporation tube (19).Mixture Volatile constituents within are flashed away from the coated substrate (2') while the coated substrate is exposed to a self-current hot air flow. As indicated by the wavy arrow,
The flow is countercurrent to the direction of yarn movement. A hot air stream is generated by a compressor (20) in conjunction with an electric heater (21), the hot compressed air being pumped around the inner tube (22).

The inner tube (22) is within the evaporation tube (19). Internal tube (2
2) creates a Venturi effect, thereby drawing outside air into the upstream end of the evaporation tube (19). Exhaust blower (
23) and a discharge conduit (24) are connected to the compression R (20), by means of which the solvent-laden air is delivered from the drying tube (19) to an external application. That is, the solvent gas is sent out of the building surrounding the process or to a trap (not shown) for collection.

The downstream end of the drying tube (19) has a small gap (approximately 0.25 inches wide), which is defined by cylindrical rods (25) that are smooth and smooth. It is preferable that the surface of the substrate (2') be drawn out in the form of a line. In FIG. 1, the direction of hot air flow is indicated by wavy arrows. The direction of yarn flow is indicated by straight arrows, which indicate the direction of rotation of the supply rolls (17 and 18).

The base material (2'), which contains almost no solvent, is transferred to the guide rod (2').
5), the substrate (2') passes several times around the supply rolls (18 and 17) and then 90
' through two pairs of guide rods (26 and 27) oriented so that the substrate is properly aligned on the mower to be wound up by the winder forming the bobbin (29). .

FIG. 3 illustrates another embodiment of the process of the invention, in which the monofilamentous polymeric substrate (2 yarns) is treated exactly as in FIG. 1, except that the supporting yarns ( The supporting yarn (30) is fed into the evaporation tube (19) together with, but slightly separated from, the coated monofilament substrate (2') which has passed through the roll member (15). ) does not come into contact with the mixture (7) (i.e. mixture coated substrate 2°) until substantially complete evaporation of the solvent from the coated substrate (2′) occurs. 30) is the base material (2'
) contacts the monofilament substrate (2°) slightly before or at the point where it contacts the first supply roll (17). From here the assembly of substrate (2') and support yarn (30) proceeds in exactly the same manner as illustrated in FIG. (26 and 27)
Blend fabric placed between ll! 1 (31) and is blended with the support yarn (30). Most preferably, the blending machine (31) is supplied with air at a pressure of 11 from a compressor (<32). The direction of gas flow is indicated by arrows near the compressor (32) and blender 31). The blended combination of substrate (2') and support yarn (30) is then wound onto a bobbin.

It has been unexpectedly found that when using a roll coater in the process of the invention, a special series of formulations of the mixtures is highly advantageous. The mixed material allows for higher yarn production rates and/or shorter drying tube lengths due to the higher volatility of the solvate, as well as for longer periods of time. It has been found to be advantageous to carry out the method of the invention in that it allows the use of roll-type hot material applicators. This makes the method advantageous in that it can be performed more nearly completely continuous.

Some of the solvents used in this invention are flammable. Use of these solvents requires expensive detonation equipment. However, many of these flammable solvents have desirable volatility characteristics in that they evaporate very easily.

Some mediums are not easily flammable, so J-ken is also preferred. Part 1 of these solvents are acetic acid, dimethylformamide and dimethylacetamide.

If one of the most preferred solvents is used, it is most preferred that the solvent mixture contains 20-40% formic acid.

Further, when practicing the present method on 7-20 denier filaments, the mixture most preferably contains 20-:3 Q L% formic acid. If the method is carried out on single fibers f, Ii of 20 to 120 denier, it is most preferred that the solvent mixture contains 30 to 40% formic acid.

Furthermore, it is preferred that the mixture contains from 0.1 to 5% of a dissolved polymer that is compatible with the polymer from which the heavy body base material is made. As used herein, the term "compatible polymers" is defined to refer to polymers that are soluble and LPJ to each other in the same solvent. For example, nylon 6.6 weight substrates have been successfully coated with mixtures using fused nylon 6 weights.

It is preferable that the mixture contains 0.1.about.52≦of the “corresponding heavy hexamer”. That is, it is most preferred that the polymer dissolved in the mixture be of the same molecular species as the polymer from which the polymeric substrate is made. The most preferred polymeric substrate is nylon 6
1t from the polymer, and therefore, of course, the most preferred weight for the mixture is nylon 6 polymer.

The roll coater is designed to consistently apply a uniform amount of the mixture to the substrate over an extended period of time without leakage or drying of the mixture on the roll.
Preferably, 51 is provided. As shown in FIG.
15), stator member (40), and roll member (15)
It consists of a motor (14) for rotating the. roll(
15) preferably has a Rulon(TM) surface. Luron is a glass fiber reinforced polytetrafluoroethylene composite that has been found to be highly abrasion resistant in the process described herein. Stator (4
0) is preferably made from a hard metal such as stainless steel. As shown in FIGS. 1 and 3, there is a constant flow of mixture fed to the fluted roll coater. The mixture is applied to the stator support block (42) (
2), through the stator member (40) itself, and finally into the groove of the roll member (15), and finally, It is wiped away by the moving monofilament substrate (not shown in Figure 2).

Figure 2 shows the mixture application machine (6) used in the method of the invention.
) represents a cross-sectional view of The motor (41) is rigid and supported by the upper part (47) of the structural composite.The motor (41) supports the grooved roll member (15) and rotates it. A pneumatic cylinder tank 43) is attached to the lower part (48) of the rigid structural composite. The cylinder (43) has a piston (45) attached to a stator support block (42). The stator support block is attached to a steel stator member (40). In the example shown below, the piston typically exerts a force of approximately 15 bonds on the stator support block (see arrow 46).
, the force is exerted by the stator member (40) on the roll member (15). The surfaces of the stator member (40) and the roll member (15) are connected to the stator support block (42) and the stator member (40).
) so that the mixture (7) flowing through the roll member (15) does not accumulate on the main surface of the roll member (15), i.e. the mixture flows through the surface (5) of the roll member (15) (see Figures 4 and 5, 9). It's smooth, as if it's just going on.

Air under pressure t111 is supplied to the pneumatic cylinder (43) through the pipe (44).

The roll coater (6) should be designed so that the mixture flows just into the grooves without being forced through the channels. If the head is too large or the head pressure is too high, the mixture can literally be forced through the grooves and even squirt out of the head, both of which are highly undesirable. If the groove size is too small, the roll coater will have to rotate too quickly and the mixture will be thrown out of the groove by centrifugal force. Therefore, the groove size, mixture pressure and mixture viscosity are important process factors. Optimizing these factors for a given system can be easily accomplished by applying the old F's principles regarding fluid flow and by examining the examples described herein. Can be done.

FIG. 4 shows a longitudinal side view of the roll member (15). The particular roll member illustrated in Figure 4 has six courses (5) within it. As illustrated in Fig. 4, (c) GS distance; (b) D: roll diameter; (c) L
Several factors are related to the roll member, such as: roll length;

FIG. 5 is an enlarged view of a small portion of the roll member (15).

The surface (5), as illustrated, defines a groove with an apex angle of 60". Also in Figure 5: (a) GD: groove depth; (b)
GW:? M convergence width; factor is determined. The depth of ij4 is
It is believed that a range of 0.010 to 0.030 inches may be acceptable.

The method using a roll coater is to continuously substantially coat the moving substrate or the grooves filled with the mixture as the grooves carry the mixture to the point where the moving substrate comes into contact with the roll. Wipe clean.

The surface speed of the roll along with the cross-sectional area of the roll determines the amount of mixture used to be picked up by the moving substrate. The roll has a small diameter and a large rotation speed (rpm)
should not be necessary. This is because the centrifugal force on the mixture can become so great that the rolls begin to shake the mixture off the rolls.

Additionally, the cross-sectional area of the grooves should be sized such that a suitable amount of nitrogen admixture is applied to the substrate.

The cross-sectional shape of the groove is generally in the shape of ■'. °It is thought that the apex angle of “■” can be changed greatly, but “v”
It has been proven that the apex angle may be in the range of 60 to 90°. A 90° angle is preferred for filaments of 150 to 2000 deniers, while a 60° angle is preferred for filaments of 5 to 150 deniers. 50
Vertical angles of ˜100° are considered effective. However, it is believed that any form of coating may be used as long as it does not exhibit a tendency to block the yarn and it allows sufficient mixture to be applied to the A''- yarn. Preferred roll rotation speeds, roll diameters, roll shapes, and roll sizes are given in the examples below. Roll diameters range from 0.75 to 3.0 inches. )2 It is said that it is okay to keep

The method of the invention was carried out using single fibers of 7 to 2000 denier. However, the method is believed to be operable over a denier range of 5.-5000.

The evaporation tube has a self-current flow of hot air passing through it. Most preferably, the evaporator tube has an internal diameter of 1 to 3 inches;
It may have a length of ~10o feet, but 10
More preferably, the length is ~20 feet 1 ~, about 1
Most preferably, the length is between 5 and 1 feet. Preferably, the hot air supplied to the evaporation tube has a temperature of 100 to 2oO<0>C.

The air blender (31) used to entangle the support yarn (30) with the substrate 2) has a straight, round yarn passage hole having a diameter of 0.125 inches, as schematically shown in FIG. has. The blender has a fluid jet orifice that intersects the passage hole at 90 degrees. The round fluid jet orifice has a diameter of 0.0625 inches. 40-1
Air pressure of 100 psi is available.

Example 1 (Conventional Method) A cold drawn 15 denier nylon 6 monofilament having a round cross-sectional diameter of 42μ was prepared from a source at a rate of 4001+1/min with: (a) Carbon black (30μ) 5% : and (b) Nylon 6 base material 5% 1 and (
c)! %ii acid (80% aqueous solution) 72%: and (d
) Water 18%.

The material was continuously passed through the interface of two opposing surfaces of a polyester band that was in a saturated state.

The monofilaments were passed through a 20 feet long substantially horizontally oriented chamber through which room temperature air was continuously ventilated by an air shed and an exhaust vent. Removal of volatile formic acid was thereby achieved and the filaments were essentially dry. After leaving that long room, take 40 single fibers II.
The package was wound continuously at a speed of 0 m/min.

After 1-2 hours of continuous treatment, it was observed that the pad scraped (actually scraped off) a large amount of the mixture from the filaments. When we investigated this phenomenon, we found the following. The pad saturated with the mixture exposes the mixture to air near the filaments exiting the pad.

At this point, the formic acid evaporates from the mixture and nylon 6 precipitates out of solution. The nylon 6 forms a surface that is effective in substantially completely scraping the mixture off the surface of the monofilament coated with the mixture. The solution to this problem is 7
1 often replaced the Liesdel pad with 2, which was inconvenient, time consuming, and expensive.

Example 2 (Comparative Example) The method illustrated in FIG. 1 was carried out using a 20 denier nylon 6 single fiber. While unwinding the monofilament from the spool at a speed of 2500+n/min, it is passed upwards to the torsion conduit, then downwardly, passed under the guide rod and then upwardly as shown in FIG. A roll-type mix applicator was contacted at 114 filled with the mix as shown. The mixture consisted of:

(a> Carbon black (30μ) 5%; and (b) Powdered nylon hexapolymer 5%; and (c) Formic acid 72%; and (
d) water
The 18% roll had a diameter of 1 inch and the "v" groove had a maximum width of 0.023 inches and a depth of about 0.020 inches. The roll has a steel core and a 0.125 inch thick Luron outer l! It had a tlI layer. The roll was rotated at approximately 150 rpm. The filaments were treated for up to 10 minutes, after which the filaments constantly broke in the drying tube. The evaporator tube had a self-current air flow passed through it, as shown in FIGS. 1 and 3.

The evaporation tube was actually placed horizontally. Air is about 1
It had a temperature of 50°C. The evaporator tube had an internal diameter of 2.5 inches and hot air was pumped into the tube at a rate of 700 feet/minute. Careful inspection of the product revealed that the mixture was very unevenly deposited on the thread. The acid in the mixture dissolved the yarn to such an extent that it resulted in the yarn breaking, as it was surprisingly found that the mixture was very heavily adhered to the areas of the surface of the yarn with sharp edges. It was speculated that. It was believed that the excess acid in these areas weakened the yarn too much.

Example 3 The method was carried out exactly as described in Example 2. However, the mixture contained the following:

(a) Carbon black (30μ) 3.8C'
5; and (b) powdered nylon 6z,
3qs; and (c) formic acid 2
1.1%; and (d) acetic acid 7
2.8% the method is carried out continuously for more than 24 hours;
Meanwhile, the roll coater was able to pass through knots and bulges due to the tethered ends of the monofilaments. Surprisingly, the single fibers were evenly coated with the mixture and there was no accumulation of mixture on the rolls. The resistance value obtained for the single fiber is approximately 5×10
It was 5Ω/cto. The product was considered to have a high r value, which is of concern for antistatic textile purposes.

Example 4 A method similar to that described in Section 4-3 was carried out.

However, the mixture was applied to a 7 denier nylon 6 monofilament polymer substrate. The roll was rotated at approximately 1100 rpm.

A 20 denier/8 monofilament support yarn was passed through a drying tube as shown in FIG.

The substrate first contacted the support yarn at the first supply roll. Both yarns were advanced at approximately 2500 m/min. After both yarns passed through the supply rolls, they passed through a guiding member and then were blended together.

The blending machine has a diameter of 0, 125 inches and a length of 1.25 inches.
The bottom orifice had a diameter of 25 inches. The orifice to air jet 1 intersected the axis of the yarn passage hole at a 90° angle. The air jet orifice was supplied with 901) Si compressed air.

The blended product was then wound up at 2500 m/min. Just like in the 43rd episode, this method was successfully applied for more than 24 hours without interruption.

Example 5 Substantially the same method as shown in FIG. 1 was carried out. However, only] single fiber t: cost for passing the W base material through the core tube
), ten 15 denier filaments were simultaneously coated on one roll coater and sent through -= evaporation tubes. The roll was identical to that described in Example 2, except that it had 10 grooves spaced 1/4" apart. The roll was rotated 100 r 1) I11"'C. The mixture is exactly the same as used in Example 3! )sand.

The mixture was advanced at a speed of 1500+n/min. The single fibers obtained were prepared by the same blending method as described in Example 4.
- Blended together. Next, the blended product was 1.500
+a 0 rolled up in 7 minutes Just as described in Example 3,
The method was run without interruption for more than 24 hours.

Example 6 2000 denier nylon 6.6 monofilament base material Example 3
Advances were made at a rate of approximately 600 feet/minute in the same manner as described in . However, the roll coater is 0.02
It has an anchor that is 5 inches deep and its groove is 0.05 inch deep.
The surfaces forming both sides of the groove met at a 90° angle) with a maximum width of 0 inches. The mixture used was the same as in Example 3. The self-flowing air sent through the evaporator tube had a temperature of approximately 200°C. The air flow rate through the evaporator tube is 600 feet/min;
The inner diameter of the evaporator tube was 2.5 inches. The 2000 denier substrate was processed continuously for a period of 1.5 hours without interruption. The resulting 2000 denier antistatic conductive product had a resistance of 10.000 Ω/can and was considered excellent for applications requiring antistatic filaments of this size.

[Brief explanation of drawings]

FIG. 1 is a longitudinal schematic representation of an apparatus for carrying out the method of the invention. FIG. 2 is a cross-sectional view of a roll-type mixture applicator used in the present invention. FIG. 3 is a schematic longitudinal view of a second embodiment of implementing the method of the invention. FIG. 4 is a longitudinal side view of the chamfered roll used in the method of the present invention. FIG. 5 is an enlarged sectional view of a part of the chamfered roll illustrated in FIG. 4. 2-Single m fibrous polymer base material, 5-Nj4.6-Mixture application machine, 7-Mixture, 8-Cage,
15-R-F roll member, 19-Evaporation (drying) pipe.

Claims (18)

[Claims] (1) A dispersion of finely divided conductive particles is applied to a non-conductive monofilament polymer substrate in an amount sufficient to reduce the electrical resistance of the fabric to approximately 10^9 Ω/cm or less in a solvent relative to the substrate. but after the desired degree of penetration has taken place in the annular region located at the outer periphery of said filament, the structural integrity of the substrate is destroyed. A method for producing electrically conductive textile fibers from a non-conductive monofilament polymer substrate comprising removing said solvent from the substrate before
applying a dispersion of conductive particles in a liquid solvent to the non-conductive monofilament substrate with a grooved roll mixer, the liquid solvent dissolving the substrate and flash evaporating at 150°C;
Formic acid and the following groups: (a) amides; or (b) carboxylic acids; or (c) alcohols; or (d) esters; or (e) ketones; or (f) ethers; or (g) hydrocarbons; An improved manufacturing process comprising applying a mixture consisting of a dispersion in a liquid solvent, the mixture being a mixture with one compound selected from the group consisting of: (2) The solvent is a mixture of formic acid and one compound selected from the group consisting of (a) dimethylformamide, (b) dimethylacetamide, or (c) acetic acid, and the mixture is further dissolved in the solvent. 2. The method of claim 1, comprising 0.1-5% of a compatible polymer. (3) The method according to item 2 above, wherein the solvent is a mixture of formic acid and acetic acid, and the acidic solvent mixture contains 20% to 40% formic acid. (4) The mixture contains the corresponding polymer dissolved in the solvent.
The method according to item 3 above, comprising 1 to 5%. (5) The solvent is a mixture of formic acid and acetic acid, and the solvent mixture is 2
Contains 0% to 30% formic acid, and monofilamentous polymer base material contains 7 to 30% formic acid.
The method according to item 2 above, wherein the fiber is a 20 denier monofilament. (6) The solvent is a mixture of formic acid and acetic acid, and the solvent mixture is 3
Containing 0% to 40% formic acid, the monofilamentous polymer substrate contains 20%
2. The method of item 2, wherein the monofilament is a denier of ~120. (7) The method according to item 4 above, wherein the monofilament polymer base material and the corresponding polymer are nylon 6. (8) The method of paragraph 1, wherein the monofilamentous polymeric substrate is advanced at a speed of at least 900 m/min. (9) The method of item 1, wherein the solvent is removed from the monofilament polymer substrate while the substrate is advanced in a substantially horizontal state. (10) The method according to item 1, wherein the supporting multi-fiber base material is blended with a single fibrous polymer base material. (11) The roll-type mixture applicator has a grooved roll member, both of the grooves having an apex angle of 50 to 100 degrees and a depth of 0.010 to 0.030 inches.
The method described in section. (12) The method according to item 1, wherein the base material has a denier of 5 to 5,000. (13) The method of item 1, wherein an evaporation tube is used to remove the solvent and the countercurrent air flow has a temperature of 100-200°C. (14) At least 2000 m/s of monofilamentous polymer substrate
2. The method of claim 2, wherein the method is advanced at a speed of 1 minute. (15) The method of item 13, wherein the evaporation tube has a length of 10 to 20 feet. 16. The method of claim 1, wherein the roll-type mixture applicator comprises a grooved roll member, the member having an outer surface made from a glass fiber reinforced polytetrafluoroethylene material. (17) The method according to item 16, wherein the roll-type mixture applicator has a steel stator member. 18. The method of claim 11, wherein the grooved roll member has a diameter of 0.75 to 3.0 inches.