JPS6257330B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a carpet having a surface yarn containing novel synthetic filaments having antistatic properties consisting of a continuous non-conductive sheath of synthetic polymer surrounding a conductive polymer core containing carbon black. The use of thin insulated conductive wire with non-conductive synthetic fibers to produce carpets with low static charge is described in U.S. Pat. No. 3,639,807. In carpets containing conductive wire,
The wire is bent and strained, and therefore less effective. For use in antistatic textile products,
The use of conductive carbon black dispersed throughout the fibers is described in U.S. Pat.
Described in No. 3706195. However, these fibers have poor mechanical and physical properties, such as brittleness and low tenacity, and therefore do not have a sufficiently long life during normal consumer handling and use. This is reflected in the U.S. patent describing the application of a conductive coating containing carbon black on synthetic filaments for antistatic purposes.
Recognized by No. 3582448. U.S. Pat. No. 3,475,898 discloses a melt-spun and drawn synthetic polyamide filament having at least about 2% by weight of a polymeric poly(alkylene ether) homogeneously mixed therein as a distinct phase; A relationship in which the poly(alkylene ether) is uniformly distributed throughout the filament structure in the form of extremely fine elongated particles of a specific particle size, and the particles overlap each other in their longest dimension parallel to the major axis of the filament. A synthetic polyamide filament with antistatic and stain resistant properties is disclosed. Also, in U.S. Patent No. 3558149,
at least two polymeric components are arranged in close interrelationship (side-by-side or sheath/core relationship) along the length of the fiber, and at least one of the components is a fiber-forming polyester. A composite fiber with antistatic properties is also described, the other being a specific polyether-polyamide block copolymer consisting of a linear polyamide segment and a polyalkylene ether segment. However, all of these synthetic filaments have the disadvantage that they do not have the ability to reduce the antistatic properties of the filaments and the fabrics made therefrom to a sufficiently satisfactory degree for certain applications. I understood. Furthermore, both of the antistatic filaments described in the above two U.S. patents have antistatic effects that depend to some extent on relative humidity [the polymeric poly(alkylene ether) or polyether-polyamide block copolymer]. Coalescence has the disadvantage that antistatic properties are improved when moisture is absorbed, and furthermore,
Another drawback is that the poly(alkylene ether) is extracted by cleaning fluids and loses its antistatic properties over a period of use. In accordance with the invention, it consists of a continuous non-conductive sheath of synthetic thermoplastic fiber-forming polymer surrounding a synthetic thermoplastic polymer core, said sheath accounting for at least 50% of the cross-sectional area of the filament. , the core is made of a thermoplastic synthetic polymer and 15-50% by weight of conductive carbon black dispersed therein and is electrically conductive, and at a DC voltage of 2KV 0.4×
A carpet characterized in that it has surface threads comprising antistatic synthetic filaments (hereinafter also referred to as filaments of the invention) having a filament core resistance of less than 10 ¹¹ ohms/(10'' ohms/inch) cm. When used in carpets at low concentrations mixed with other filaments, the filaments of the present invention have a core resistance of less than 0.4×10 ⁹ ohms/cm (10 ⁹ ohms/inch) at a DC voltage of 2 KV. Preferably, the filament is subjected to spinning and/or
or have a molecularly oriented sheath as a result of attenuation during stretching. Highly conductive core compositions, ie compositions containing more than 20% by weight of carbon black, are preferably used in filaments having a sheath content of at least 80%. For purposes of the present invention, the sheath comprises at least 90% of the filament, the sheath is matte to partially hide the black core color, and the filament has a light reflectance as described herein. can be greater than 20%. A preferred matte filament contains 2-7% by weight titanium dioxide in the sheath. By appropriate selection of the sheath polymer, the antistatic filaments of the invention can be dyed if desired and can also be co-bulked under various conditions. Surprisingly, the antistatic filaments used in the carpets of the present invention are suitable for antistatic purposes, e.g. (to prevent charge build-up)
As a very small component of carpet thread,
It can be used effectively regardless of relative humidity. When the above-mentioned antistatic filament is used in a yarn on the surface of a carpet, (a) a non-conductive synthetic filament or staple fiber;
(b) Blended yarns comprising less than 20% by weight of filaments or staple fibers according to the invention. Can be used in the form of blended yarns. The proportion of the filaments of the invention in such a mixture provides excellent antistatic properties even when it is present in proportions less than 2%, provided that the mixture contains at least about 0.05% by weight of said filaments. is preferred. In such mixtures the sheath polymer can be dyed together with the non-conductive filaments. In particular, the sheath polymer can be the same type or grade of polymer as the non-conductive filament. The most preferred products of the invention are capable of producing carpets having a static propensity of less than 2.5 kilovolts (KV) as measured by the carpet static propensity test set forth herein. It is a conductive fiber with a specific purpose for which it is designed.
These fibers have a good balance of conductivity and antistatic properties and do not have undesirable colors. The filament of the present invention will be further explained below with reference to the accompanying drawings. In the cross-section 5 of the filament shown in FIG.
and carbon black 3 dispersed therein. In FIG. 2, a filament having a cross section 5 of the type of FIG. The "non-conductive sheath" of the filament of the present invention is comprised of a fiber-formable synthetic polymer. This filament has a surface filament resistance greater than 10 ¹² ohms/inch (0.4 x 10 ¹² ohms/cm), as measured by applying a low DC voltage, e.g. 100 volts or less, to the surface of the filament. It is. The homogeneous fibers of such pod material also
Has a resistance greater than 10 ¹² ohms/inch (0.4 x 10 ¹² ohms/cm). The term "fibre-formable" is used in its conventional sense to refer to linear high molecular weight polymers that can be formed into fibers of sufficient strength and toughness for use. Compared to high-resistance non-conductive sheaths, filament cores have a low resistance, and electrodes can be inserted into the sheath and in direct contact with the core, or electrodes in surface contact can be used to prevent dielectric breakdown of the sheath. Once a high enough voltage is applied to cause the wire to wake up, and once it is brought into electrical contact with the core, it exhibits high conductivity. In the latter case, i.e. when surface contact electrodes are used, when the applied DC voltage is increased to several hundred volts, especially several thousand volts, the current increases rapidly and noticeably, as described in the test method below. A point occurs where the flow begins. Once conductivity is achieved in this way, the current will normally continue to flow even if the voltage is lowered, unless the contact between the filament and the electrodes of the measuring device changes. The low resistance characteristics exhibited by the filament core indicate that the core is electrically continuous throughout the measured length of the filament. Breaking the continuity of the core between the measurement electrodes is
This is demonstrated by the fact that a much larger electrical resistance value is obtained, which is close to that of the sheath. It has been found that occasional breaks in core continuity do not significantly impair the antistatic properties of the filaments of the present invention. However, it is preferred that the core is continuous throughout the length of the fibers and filaments of the invention, whether they are staples or continuous filaments. It is important that the core is continuous over a sufficient length of the filament so that, together with other such antistatic filaments, it forms an effective antistatic network. It has been found that filaments having certain values of core conductivity provide effective antistatic properties when tested using the test method described herein. The filament sheath can be comprised of any extrudable synthetic thermoplastic fiber-forming polymer or copolymer. These include polyolefins with fiber-forming molecular weights such as polyethylene and polypropylene, polyacrylics, polyamides and polyesters. Particularly suitable sheath polymers are condensation polyamides of diamines and dicarboxylic acids and condensation polyamides of amino acids; condensation polyesters, especially terephthalic acid or isophthalic acid and lower glycols such as ethylene glycol, tetramethylene glycol, and hexahydro-p-xylene diol. and poly(acrylonitrile). Such polymers have been developed in the art by, for example, copolymerization to introduce basic or acidic dyeing sites to facilitate blending or interdying with other dyed or dyeable synthetic fibers. It can be modified by known methods to improve its dye receptivity. The strength and other physical properties of the filaments of the present invention are primarily dependent on the sheath polymer. For high strength filaments, high molecular weight polymers and high draw ratio polymers are used in the sheath. Although undrawn filaments of the present invention provide adequate strength for certain purposes, drawn filaments are preferred. The thickness of the sheath must be sufficient to provide the desired protection to the core. For example, it must be thick enough to provide sufficient strength, heat and abrasion resistance, and to hide the core from view where this is important. It is generally desirable for the sheath thickness to be at least 3 microns, with larger thicknesses being used depending on the denier or diameter of the filament available. Suitable sheath thicknesses for normal textile deniers range from 8 to 22 microns. In some applications, where the filament is subjected to high temperature treatments, such as hot fluid jet bulking or texturing operations, sheathing may be required to prevent it from unduly softening or melting under such conditions. must have a sufficiently high melting point. For such applications, high melting point sheath polymers such as poly(hexamethylene adipamide) are preferred over poly(ε-caproamide). The filament core consists of a thermoplastic polymeric matrix material and conductive carbon black dispersed therein. The core material is selected with primary consideration of electrical conductivity and workability. Carbon black in the core can be used in concentrations of 15-50%. It has been found that 20-35% is suitable in order to provide a desirable high conductivity and maintain adequate processability. Preferably, the wick composition used to make the wick has a specific resistance of less than 200 ohms/cm, more preferably less than 50 ohms/cm. More highly conductive carbon blacks made by certain methods known in the art are effective in minimizing the amount required. Because high carbon black loadings tend to strengthen or harden plastic compositions, softer, lower melting point (and lower secondary transition temperature) polymer core matrix materials are generally preferred over harder, higher melting point materials. It is more suitable than The core polymer preferably has a lower melting point than the sheath polymer, and preferably has a lower second order transition temperature than the sheath.
This facilitates processing (e.g., facilitates cutting the core and preventing disruption of the carbon black particle distribution) while preserving the conductivity of the core and the final filament. The core composition does not necessarily need to be capable of being spun into filaments per se; therefore, the core polymer need not be fiber-forming. The core polymer should be thermally stable and extrudable under the conditions necessary to spin the sheath polymer. Suitable core matrix polymers include those selected from polyamides, polyesters, polyacrylics, polyethers, polycaprolactones, and polyolefins (eg, polypropylene, low density and high density polyethylene). The polymers can be blended with other materials such as oils and waxes to facilitate processing. It is also possible to use copolymers, such as poly(ethylene/vinyl acetate) copolymers. The carbon black can be dispersed in the core polymer by mixing methods known per se. Care must be taken to disperse the carbon black sufficiently uniformly in the core polymer to permit extrusion without over-mixing and thus reducing conductivity. For satisfactory spinning, it is important to remove volatile materials from the polymer to which the carbon black is added prior to melt spinning. This can be done during or after combining the carbon black and polymeric matrix material. It is also effective to vacuum dry such polymers at 68° C. for, for example, 16 hours under a slight vacuum. Standard precautions to prevent oxidative degradation during spinning are used, such as passing an inert gas through the polymer line to remove oxygen. The cross-sectional area of the conductive core of the composite filament (which is directly related to the volume of the filament) is sufficient to give it the desired resistance properties and is 0.5
It can be about % by volume. The lower limit is primarily governed by the ability to produce sheath/core filaments of sufficiently uniform quality while at the same time retaining adequate core continuity when the core volume is low. The filament of the present invention can be spun using a conventional sheath/core spinning device for two types of polymers, taking into consideration the differences in properties of the two types of components. These can be easily made using polymers by known spinning methods, e.g. US Pat. No. 2,936,482
It is stated in the number. U.S. Pat. No. 2,969,798 also describes yet another method of performing such spinning using polyamides. Conventional methods of drawing filaments can be used, but care must be taken to avoid sharp corners that tend to cut or damage the core.
Generally, hot drawing, ie, heating the filament auxiliary during drawing, is preferred.
This tends to further soften the core material and facilitates filament drawing. These antistatic filaments can be plyed and co-stretched with conventional synthetic unstretched filaments. This filament can easily be made to have a tenacity of at least 1.5 g/denier, which is very suitable when the filament is blended as a minor component with other filaments. The filament has an elongation at break of at least 10%, but preferably less than 150%. The resulting blended textile properties depend primarily on the properties of the other filaments.
For general applications, the filaments of the present invention have a denier per filament (dpf) of less than 50, preferably less than 25 dpf. The filaments can be in the form of circular or non-circular, eccentric or concentric sheath/core or combinations thereof. Concentric form provides maximum protection and also maximizes wick concealment. A thin core has a significant hiding effect, and filaments with a thin core can be used in dyed or patterned textile products without other hiding factors. If necessary,
The core can be further hidden by the presence in the sheath of an opacifying agent, such as a matting agent, such as titanium dioxide, for example in the form of voids or white solid particles. Non-circular filament forms, such as multilobed forms, tend to further obscure the core. Among the factors that influence the hiding power of the wick are the thickness and dyeability of the pod, the pod/core ratio, the concentration of matting agents such as titanium dioxide present in the pod, and also the relationship between the pod and the core. There is a void created by the separation of the
This void is found in oriented filaments where the sheath and core polymers are dissimilar, such as oriented filaments with a nylon sheath and a polyethylene core. Without a concealing sheath to hide the black color, carbon black filled fibers generally have a light reflectance of less than 5%. Approximately 20% that can be achieved with the present invention
The above light reflectance provides a very significant improvement in eliminating color problems from filaments in lightly dyed products. The filaments of the present invention can provide excellent antistatic properties in all types of textile end uses, including knits, tufted fabrics, wovens, and nonwovens. These filaments may contain conventional additives and stabilizers such as dyes and antioxidants. These filaments can be subjected to all types of textile processing operations, such as crimping, texturing, scoring, bleaching, etc. It can also be combined with staple or filament yarns and used as staple fibers or continuous filaments. The above filament is used during the yarn manufacturing process (e.g. spinning, drawing, texturing, doubling, rewinding,
It can be combined with other filaments or fibers in any suitable step during yarn spinning) or fabric production. Care must be taken to minimize breakage of the antistatic filament. For example, the relative length and shrinkage of the antistatic filament and other filaments during handling must be balanced to provide good processability and the desired loftiness, doubling, twisting or texturing properties. Must be. Test Method Filament Core Resistance Filament core resistance is determined from a current measured at 2 KV on a 2 inch (5.08 cm) long sample. A suitable device is a 15KV Biddle Dielectric Tester.
[James G. Biddle, Plymouth Meeting, Pennsylvania, USA]
Company). A bundle of three filaments is mounted squarely between pairs of electrodes spaced 2 inches (5.08 cm) apart, and a high enough voltage (eg, 1-4 KV) is applied to conduct current. Once the current flows, adjust the voltage to 2KV and the resistance of the yarn is R=
Calculated from the current according to Ohm's law of E/I. For example, if 2KV is 2 inches (5.08cm)
The current is 10μA (microampere) for the sample.
Then, the resistance to the three filaments is
¹⁰⁸ ohms/inch (0.4 x ¹⁰⁸ ohms/cm). Therefore, the resistance per filament is 3×
¹⁰⁸ ohms/inch (1.2× ¹⁰⁸ ohms/cm). In order to flow current as described above, the voltage must be gradually increased to avoid sudden surge currents that would burn out the filament. Burnt filaments are easily detected by eye (by the filaments cutting, fusing, or burning) and such samples must be ignored. Filament resistance of lengths shorter than 2 inches (5.08 cm) can be measured by appropriately adjusting the distance between the electrodes. Reflectance Measure the light reflectance, brightness or whiteness of the sample compared to a magnesium oxide standard using a photoelectric reflectometer. Suitable equipment is 95 Madison Avenue, New York, New York 10016, USA.
(95Madison Avenue New York, New York
Photovolt Corp. (10016)
Model 610 Photoreflectometer, Search Unit Model with a Tristimulus Filter (Cat. No. 6130)
610-Y (search Unit Model 610-Y), and 70
White enamel working standard sample (Cat. No. 6162) calibrated to have ~75% reflectance.
Wrap the conductive filament sample to be measured onto a 2 inch (5.08 cm) x 3 inch (7.62 cm) back mirror card (approximately 6 layers of filament).
Measure the reflectance from the card (average of 10 measurements). Percent Carbon Black in the Core Standard analytical methods can be used to determine the concentration of carbon black in the filament or core material. For example, the concentration of carbon black in ethylene plastics can be determined by the standard method described in ASTM D-1603-68. This method is suitable for quantifying carbon black in polyethylene, which does not contain non-volatile pigments or fillers other than carbon black, and the amount of carbon black is determined by gravimetric analysis after thermally decomposing the sample in a nitrogen atmosphere. This is how to decide. Percentage of Core in the Filament The percent volume of the core is conveniently determined by microscopically measuring the cross-sectional area of the black core and comparing it to the total filament. This is conveniently done at a magnification of approximately 400x. For circular filaments, this value can be easily calculated from the ratio of the average core diameter to the square of the diameters of all filaments. The average of 10 measurements is used to compensate for irregularities. For non-circular cross-sections, calculations are facilitated by photographing and measuring the cross-section of the filament at a known magnification. If the pod polymer is sufficiently different in solubility from the core polymer to be removed by differential solvent action, the proportion of core material should be determined to dissolve the pod and to reduce the weight of the insoluble core to the original sample. It can be determined by gravimetric method by comparing with the weight of . For example, formic acid can be used to dissolve and remove a 66-nylon sheath from a polyethylene core. Resistivity Testing of Core Materials The resistivity of core materials, including carbon black, is measured across a sample film 2 inches (5.08 cm) long, 1 inch (2.54 cm) wide, and 0.01 inches (0.25 cm) thick. Determined by measuring DC resistance. Such films are prepared by sandwiching a powdered or pelleted sample of the core material between two sheets of aluminum foil in a press and applying pressure to 20,000 psig (1407 psig) for 1 to 2 minutes.
It is convenient to produce it by heating above the melting point under a pressure of 1 kg/cm ² ). After cooling, the foil is peeled off from the sample film and a strip of 1 inch (2.54 cm) wide and about 2.5 to 3 inches (6.35 cm) long is removed from the sample film.
Cut out a piece of 7.62 cm). The thickness of the film is measured with a micrometer. Cut a piece into a 2 inch (5.08
sandwich it between copper electrodes with a spacing of cm) and measure its DC resistance with an ohmmeter. The resistivity of the film in ohms ^- cm is calculated from the instrument reading in ohms by multiplying the measured resistance by the width and thickness and dividing by the length of the sample (all in cm). Example 1 A concentric sheath/core filament is made having a sheath of 66-nylon having a relative viscosity of 45 and a core of polyethylene containing 20% by weight of conductive carbon black. Carbon Black is located at 125 High Street, Boston, Massachusetts 02210 (125High).
Oil Furnace Black's superconducting Vulcan XC-72 [fixed carbon: 98.0% by weight, volatile content: 2.0% by weight, available from Cabot Corp., St., Boston, Mass. 02210] %, Negrometer scale:
87, _N2 surface area: 230m ² /g, particle size: 30mμ, DBP
Absorption: 185c.c./100g (fluffy), Electrical Resistance: Lowest when dry - For further details on the properties of this carbon black, please refer to Cabot's
PIGMENT BLACK TECHNICAL REPORT S
-8 and technical data 1518/173]. The dispersion of carbon black is approximately
It is made by mixing with a low density (0.916) polyethylene resin (melt index: 23, Alathon 2821 from DuPont) at 120°C and kneading in a dough mixer. The carbon black is added gradually and the mixture is cast 10 minutes after the addition is complete. The polyethylene resin is selected for its softness; other useful resin compositions include low density (0.916) polyethylene, melt, index: 11.9 (Arathon 20, manufactured by Dupont) alone or in combinations of 40
% of oil or wax]. Melted carbon black mixture 100x
Filter through a 100 mesh screen and extract. The pressed film shows excellent dispersibility,
It has excellent electrical conductivity with a specific resistance of 12.7 ohm ^- cm. When used as a core, a continuous sheath/core filament consisting of three 65 denier monofilaments is spun at 425 ypm (389 m/min), keeping the total denier constant, and the products in Table 1 are spun at 425 ypm (389 m/min). Change the pump speed to reduce the wick volume. The wick volume is determined by the pump speed,
Confirmed by analyzing a cross-section of the filament at 200x magnification. Using a three-hole stainless steel spinneret, the pod and core polymers are fed concentrically and individually until they emerge at the face of the spinneret. An insertion capillary is used to deliver the core polymer composition to a spinneret where it emerges surrounded by the sheath polymer. Spin the filament at approximately 65 dpf. This filament is then heated to 150℃
Approximately 200ypm (183m/
(min) and stretched 3.06 times. The physical and electrical properties of the yarn are shown in Table 1.

[Table] The test carpet shown in Table 1 is made of commercially available 3700 denier/204 filament bulky trilobate.
66—Made from nylon continuous filament carpet yarn with a pile height of 1/2 inch (1.27 cm). A single yarn product of conductive fiber (approximately
0.56% by weight) was coned with the carpet yarn, and then tufted. As the volume of the wick was reduced, the visibility of the conductive filaments in the carpet was significantly reduced. Example 2 Preparation of pod polymer 317.5 kg of aqueous solution containing 50% by weight hexamethylene diammonium adipate (66-nylon salt)
was placed in a stainless steel container, and 10% by weight of manganous hypophosphite [Mn(H ₂ PO ₂ ) ₂ ] was placed in a stainless steel container.
721 g of an aqueous solution, 70 g of a solution containing 25% by weight of acetic acid and 100 ml of silicone antifoam (11.2% strength) are added. The charge is concentrated by evaporation to approximately 75% solids by weight and transferred to a stainless steel autoclave equipped with an agitator. Blow inert gas to drive out the air in the autoclave, heat it to about 200℃, and heat it to 17℃.
Heat to atmospheric pressure. Titanium dioxide
Rutile (Ti-pure Rutile), Titanium dioxide R-
960, manufactured by DuPont] 14.83Kg was added to water at 49% by weight, and the resulting slurry was added to a pressurized autoclave while stirring. Continue heating until the temperature reaches 273°C and gradually reduce the pressure to atmospheric pressure. The polymerization process is as described in Example 1 of US Pat. No. 2,163,636.
Continue like this. After the polymerization reaction is complete, the molten polymer is extruded in the form of approximately 1/4 inch (6.3 mm) strands. After quenching with water, it is cut into 1/4 x 3/16 inch (6.3 x 4.7 mm) chips suitable for remelting in the spinning assembly. The properties of this flake are as follows. Relative viscosity: 43.5 (NH ₂ ): 46.0eg/10 ⁶ g TiO ₂ : 5.04% Mn(H ₂ PO ₂ ) 2: 0.048% Core polymer composition (wt%) Polyethylene: 70% Conductivity of Example 1 Carbon: 30% Polyethylene Arason PE-4318 - Low-density polyethylene for injection molding manufactured by DuPont (density: 0.916, melt index: 23, ASTM-D-1238). It contains 50 ppm antioxidant to improve thermal stability and aging stability. Manufacturing: 1905 g of polyethylene and 816.5 g of carbon black are charged into a 1 gallon (approx. 3.7) capacity double-arm dough mixer. Apply this composition for 30 minutes
Mix at 140°C, extrude, filter through a 100 x 100 mesh screen and pelletize. This product exhibits the following properties. Resistivity: 2.9-4.2 ohm ^- cm (cast film at approx. 180°C) Carbon black: 30.2% Moisture: 0.04% If the moisture content is greater than 0.1%, the pellets should be heated at 70°C for 24 hours before spinning. Vacuum dry. Spinning The sheath and core polymers were co-spun on a screw melt spinning machine using a spinneret assembly for spinning concentric sheath/core filaments according to the method described in US Pat. No. 2,936,482. The pod polymer was fed at a rate of 19.8 g/min (calculated from the pump capacity and speed) and the core polymer was fed at a rate of 0.7 g/min (calculated similarly), with the pod being 96% by volume and the core being 4% by volume.
Create a concentric sheath/core composition of % by volume. The set temperatures of the sheath and core polymer in the screw melter during spinning are shown below.

[Table] The temperature of the spinning block is 293°C. The hopper feeding both the pod and core polymer was purged of air with an inert gas. The relative viscosity of the polymer in the (free-falling) pod emerging from the spinneret is approximately 56, with the relative viscosity increasing as a result of further polymerization of the 66-nylon dried in the screw melter. Spinning speed is 890ypm
(approximately 814m/min). The collected spun yarn is gray in color and has the following properties: Finishing agent on yarn: ~1.0% Percentage of core: 4% by volume Percentage of sheath: 96% by volume Spun denier of bundle: 60 Number of filaments in bundle: 3 Reflectivity: 37-40% Conductive 60-3 Denier spun yarn drawing ratio
Stretched by a stretching twisting machine at a speed of 2.7 times, winding speed of 400 ypm (366 m/min), and shoe temperature of 180°C. The properties of the drawn yarn are as follows. Number of filaments: 3 Strength (gpd): 3.8 Elongation: 35% Modulus: 13 (gpd at 10% elongation) Core resistance (bundle): 4.7 x ¹⁰⁷ ohms/inch (1.8 x ¹⁰⁷ ohms/cm) Reflectance :34% Simultaneous bulking A hollow nylon filament of approximately 3400 denier and 160 filaments with four voids of the type described in British Patent No. 1292388 was spun at one position of a hollow filament spinning machine. It becomes bulky at the same time as the conductive yarn of the book. The two yarns are wound on a final chest roll and brought together in a hot chest under a tension of 10-20 g before being placed in a bulking jet. Cheest roll is
195℃ and yarn speed is 1185ypm
(1084m/min). 120 psig (8.44 Kg/cm ² ) and 240°C as described in Belgian Patent No. 573230
Simultaneous bulking is achieved by passing the yarn through an air jet operated at a temperature of 100 mL to produce a filament with an irregular three-dimensional curvilinear crimp with alternating regions of S and Z twist of the filament. The yarn is then cooled and passed through a winder. The tensile properties of the co-bulked yarn are substantially the same as the unmodified product. Mockdyed level loop carpet made from yarns containing conductive filaments (test) and yarns without conductive filaments (control) [pile height 1/2 inch (1.27 cm), 29.4 Ounce/
square yard (0.996 Kg/m ² ), gauge 5/32 inch (4 mm), 1 inch (2.8 cm) per inch (2.8 cm) with a commercially available non-woven polypropylene lining [Typar manufactured by Dupont] and Latex treated with commercially available latex,
It showed the following electrostatic tendency at a relative humidity of 20% and a temperature of 70°C (21°C). Carpet electrostatic tendency test product: 1.5-2.0KV Reference product: 10.2-11KV The electrostatic property test is based on the AATCC test method, which was modified in September 1971 by the Carpet and Rug Institute. 134-1969. In semi-finished or simulated dyed carpets, 20-3 denier conductive filaments give a very slight bluish trace. Bulky dyed continuous filament carpets containing conductive filaments have no difference in most dark tones;
There was very little difference in certain deep light colors such as yellow, orange and pink compared to the control carpet. If desired, the filaments of the invention can be used in the form of staples, for example in a mixture of 0.5 to 5% by weight with non-conductive staples in carpet yarns. Reference Example 1 This example illustrates the precautions that must be taken when drawing the filament of the present invention to avoid loss of conductivity. 66 with a relative viscosity of 44 and containing 0.3% by weight of _TiO2
- Spinning filaments from a nylon sheath and a 6-nylon core (relative viscosity 45, 31.8 equivalents of NH ₂ end groups/ ¹⁶⁶ g) with 20% by weight of carbon black of the type of Example 1 to produce an eccentric sheath/ I made a core-shaped object. The filament core was 40% by volume. 3
-The spinning denier of filament yarn is approximately 79. Cold draw the yarn using drawing pins. As shown in Table 2, the resistance of the yarn when cold drawn was found to increase as a function of the draw ratio. When the yarn was hot-stretched using a curved plate heated to about 160° C. without using pins, virtually no increase in resistance was observed. It is believed that heating the yarn in the heated zone during drawing softens the core sufficiently to prevent cutting of the core or disruption of the carbon particle distribution necessary for electrical conductivity.

[Table] Calculation.
Reference example 2 Pod polymer Hexafluoroisopropanol at 25℃
Poly(ethylene terephthalate) flakes with a relative viscosity of 23±2 measured in a solution containing 0.8 g of polymer in 20 ml. Core Polymer 6-nylon containing 22% by weight of the conductive carbon black of Example 1. Manufacture 22,680 kg of conductive carbon black (Cabot XC-72), 86,180 kg of caprolactam and 83,910
Prepare a pre-dispersed slurry consisting of Kg distilled water at a temperature of 50
Made in a stirred mixing tank at ~55°C. This slurry is then charged to a stainless steel autoclave equipped with a 500 pound capacity agitator. The contents of the clave are purged with air, filled with inert gas, and heating begins. Clave temperature
The temperature is raised to 258° C., the pressure is set to 250 psig (17.6 Kg/cm ² ), and the initial ring-opening reaction and prepolymerization reaction of caprolactam are carried out. After this heating step, which lasts approximately 6-7 hours, the pressure is increased to 250 psig (17.6 kg/kg) within 1.5 hours.
cm ² ) to atmospheric pressure (depressurization step). The polymer is then extruded at 278°C into a continuous ribbon, which is water quenched and cut into 1/8 inch (3.2 mm) flakes. The flakes are washed with water for about 4 hours in a stirring pot heated to 95°C to remove monomers. This operation was repeated three times, and finally about 6.3% caprolactam was extracted. The polymer is then dried under vacuum [25 inches (635 mm) Hg] until the moisture content is less than 0.3%. The flakes are remelted, extruded, filtered through screen filters of increasing mesh (30-200 mesh), pelletized, and then vacuum dried to a moisture content of less than 0.03%. The specific resistance of the film cast from this polymer is
Varying between 10 and 60 ohm ^- cm. Spinning and drawing Connected spinning - winding speed 1500ypm in drawing machine
(1372 m/min) (calculated from the speed of the take-up rolls) to simultaneously spin and draw the sheath and core polymers. The pod polymer was fed at a rate of 29.7 g/min (calculated from the spun denier and winding speed) and the core polymer was fed at a rate of 6.7 g/min (also calculated), and the pod was 81% by weight.
(calculated from the amount fed) and the core is 19% by weight (calculated from the amount fed) to create a concentric sheath/core composition. The temperature of the screw melter during spinning is set as follows.

[Table] The temperature of the spinning block is 290°C. The yarn is drawn at a draw ratio of 3 times using a steam drawing jet and electrically heated rolls (16 wraps) maintained at 180°C. The drawn yarn is black in color and has the following properties: Number of filaments per bundle 1 Denier 19.02 Total finishing on yarn (%) 1.83 Core resistance 3.3 x 10 ⁹ ohms/inch (1.3 x 10 ⁹ ohms/cm) Tenacity (gpd) 2.5 Elongation (%) 39.9 Modulus 10 gpd at % elongation 13.6 Example 3 Pod Polymer Poly(ethylene terephthalate) flakes with a relative viscosity of 30. Core polymer: Made in Example 2. Spinning The sheath and core polymers are co-spun as in Example 2 at a rate of 860 ypm (787 m/min). Feed the pod polymer at a rate of 36.3 g/min (calculated from pump speed and capacity) and the core polymer at a rate of 1.38 g/min (calculated similarly), determined by the magnification of the wick cross section. This creates a concentric pod/core composition with 96% pod by volume and 4% core by volume. The temperature of the screw melter for the polymer in the sheath during spinning is set as follows.

[Table] The spinning block temperature is 292°C. The yarn is 60 denier/3 filament (60-
3) Spinning. Stretched 60-3 denier sheath/core yarn at 454ypm
(415 m/min), a stretching ratio of 3.8 times, and a high show temperature of 97°C. The properties of the drawn yarn are as follows. Denier 17.2 Number of filaments 3 Core resistance Ohm/inch/filament
6.76× ¹⁰⁸ (ohm/cm/filament) 2.66× ¹⁰⁸ pod/core test yarn Leesona
Co-textured with commercially available 150-34-polyester yarn using 570 false twisting equipment. Co-textured yarns (one 17.2-3 sheath/core and one 150-34 polyester) were woven into a "Suisse Pique" double knit fiber fabric. After washing 30 times, the fabric was tested in an electrostatic tester [Presco
Scientifie Co. electrometer model E525] and compared to a control fabric made from the same polyester yarns and treated under identical conditions. Static Charge on Fabric (Volts) After 0 Seconds After 120 Seconds Test Fabric 400 380 Control Fabric 2750 2550 Good antistatic properties were demonstrated for the test fabric. Example 4 A 60-3 yarn was made from a 66-nylon sheath polymer as in Example 2 and a 6-nylon core polymer containing 28% by weight of carbon black made as in Reference Example 2. Create. 180% filament consisting of 96% volume pod and 4% volume core
Stretch 3 times on a curved hot plate [24 inches (61 cm)] at °C. The properties of the yarn are as follows. Denier of bundle 20.2 Tenacity (gpd) 3.18 Elongation (%) 49.1 Modulus, Mi (gpd) 24.4 Core resistance 4.5×10 ⁸ ohms/inch/filament (1.77×10 ⁹ ohms/cm/filament) Reflectivity 32 Simultaneous bulkiness The conductive yarn was prepared in the same manner as in Example 2.
A 66-nylon core vine (Type 854 Arathon manufactured by Dupont) which can be dyed with a basic dye of 68 was simultaneously made bulky with a continuous filament carpet, tufted as in Example 2, and the pile height was increased.
Make 1/4 inch (6.35 mm), 14 oz/sq yd (0.475 Kg/m ² ) level loop carpet. The reflectance and electrostatic tendency of the simulated dyed carpet was compared to a control carpet containing no conductive yarns.

[Table] The results of visually evaluating the carpet match the measured reflectance of the carpet. Example 5 A filament (spun denier 60, 4 threads of 3 filaments) having a nylon sheath and a polyethylene core substantially the same as in Example 2 was prepared for use in staples having the following properties. Finishing agent on yarn 0.43% Percentage of core 3.5% by weight Percentage of sheath 96.5% by weight Percentage of carbon in bundle 32.3% by weight Reflectivity 39% Resistance of core of bundle (12 filaments)
5× ¹⁰⁷ ohm/(2.0× ¹⁰⁷ ohm/cm) The drawn yarn was drawn using an experimental drawing machine, and the drawing ratio was
The three threads are drawn together at 3.0 times, winding speed of 230 ypm (210 m/min), and high temperature of 180°C.
The properties of the drawn yarn are as follows. Bundle Denier 690 Number of Filaments 96 Tenacity (gpd) 4.72 Elongation (%) 18.5 This conductive yarn bundle is cut to approximately 6.5 inches (16.5 cm) in length and carded in amounts of 0.6, 2, and 5%. On the way, commercially available Dupont T-838,
66 - Blend with nylon carpet staples. The blend is processed under normal stapling conditions to produce a spun yarn of 2.4 cotton count/2 ply, 3.5Z twist/3.5S twist. The yarn was heat set and tufted in an autoclave to produce 35 oz/sq yd (1.19 Kg/ ^m2 ), gauge 5/32" (3.96 mm), pile height 3/4" (1.90
cm), Saxony style cut pile carpet, lined with tieper polypropylene and latex treated with commercially available latex. The carpet is scored and dyed in a conventional manner using a mixture of three commercially available yellow, red and blue acid dyes. dyed carpet at 20% relative humidity and 70% temperature
〓As a result of a shuffle test at (21℃), the following electrostatic tendency is given.

[Table] Reference example 3 Each product has 3 filaments,
The carbon black is the same as that used in Example 1. Product A is substantially the same as that made in Example 2, except that it has a ribbon-shaped filament cross-section. The core composition is a sterically hindered phenolic antioxidant, 1,3,5-trimethyl-2,4,6-tris-(3,5-tris-
t-Butyl-4-hydroxybenzyl)benzene
Contains 0.25% by weight. Product B is the same as Product A except that it has a trilobal cross section and a deformation ratio of 2.50. Products C to H have a circular cross section. Product C has a sheath of 66-nylon containing 5% by weight of titanium dioxide and a core of 40% by weight of polypropylene, 20% by weight of polyethylene and 10% by weight of polyethylene.
Nordel 1500 (a commercially available elastomer based on DuPont's terpolymer of ethylene, propylene and a nonconjugated diene)
30% by weight carbon black in a polyolefin matrix consisting of: Product D has the same core composition as Product A with a sheath of commercially available polypropylene resin (Siel PWD-152). Product E has the same sheath as Product D, but the core is a commercially available polycaprolactone resin containing 30% by weight carbon black [Union Carbide].
Carbide) PCL-700]. Product F contains 5% by weight of titanium dioxide pigment66-
It consists of a nylon sheath and a core of commercially available polypropylene resin (Hercules 8MSR) containing 25% carbon black by weight. Product G uses the same polypropylene sheath as Product D and a core of commercially available polyethylene ether resin [DuPont TLF1681S] containing 26% by weight carbon black. Product H is a non-static control product having the same nylon sheath and the same polyethylene core without carbon black as Product A. The filament properties for these products are shown in Table 3.

【table】 [Brief explanation of the drawing]

1 is a schematic cross-sectional view of a sheath/core filament used in the carpet of the present invention, and FIG. 2 is a schematic cross-sectional view of an antistatic yarn comprising a mixture of the filament of FIG. 1 and a non-conductive synthetic filament. It is a schematic cross-sectional view. In the figure, 1... core material, 2... sheath material, 3
... Carbon black, 4 ... Polymer matrix, 5 ... Cross section of filament.

Claims (1)

[Claims] 1 Consisting of a continuous non-conductive sheath of synthetic thermoplastic fiber-forming polymer surrounding a synthetic thermoplastic polymer core, said sheath accounting for at least 50% of the cross-sectional area of the filament, said core being It is made of a plastic synthetic polymer and 15 to 50% by weight of conductive carbon black dispersed therein, and is conductive.
A carpet characterized in that it has a surface yarn comprising antistatic synthetic filaments having a filament core resistance of less than 0.4×10 ¹¹ ohms/cm at a DC voltage of 2 KV.