Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05F—STATIC ELECTRICITY; NATURALLY-OCCURRING ELECTRICITY
  • H05F1/00—Preventing the formation of electrostatic charges
  • H05F1/02—Preventing the formation of electrostatic charges by surface treatment
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/441—Yarns or threads with antistatic, conductive or radiation-shielding properties
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/73—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with carbon or compounds thereof
  • D06M11/74—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with carbon or compounds thereof with carbon or graphite; with carbides; with graphitic acids or their salts
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/83—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with metals; with metal-generating compounds, e.g. metal carbonyls; Reduction of metal compounds on textiles
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06Q—DECORATING TEXTILES
  • D06Q1/00—Decorating textiles
  • D06Q1/04—Decorating textiles by metallising
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/20—Conductive material dispersed in non-conductive organic material
  • H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2918—Rod, strand, filament or fiber including free carbon or carbide or therewith [not as steel]
  • Y10T428/292—In coating or impregnation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2927—Rod, strand, filament or fiber including structurally defined particulate matter
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2967—Synthetic resin or polymer
  • Y10T428/2969—Polyamide, polyimide or polyester

Definitions

• This invention relates to textiles in general, and in particular to an electrically-conductive textile fiber for use in the fabrication of antistatic fabrics and floor coverings.
• Metallic laminate filaments do not present blending and processing problems, because of 3,823,035 Patented July 9, 1974 their close similarity to ordinary textile fibers, and the hand of the products obtained is consequently not objectionable.
• the cost of such filaments is high when compared with the natural or man-made fibers with which they are blended.
• Textile fiber substrates the surfaces of which have been coated by vapor deposition or electrodeposition, or by the application of adhesive compositions containing finely divided particles of electrically-conductive material, are in some cases less costly than metal fibers and/ or metallic laminate filaments, depending upon the nature of the electrically-conductive material employed.
• such coatings are often found lacking in cohesion and adhesion and are frequently too thick to be practicable in some applicationsespecially when the nature of the electrically-conductive particulate matter is such that a high concentration thereof is required for satisfatcory conductivity. economy is achieved, therefore, only through sacrifices in durability of conductivity of the fiber.
• an electrically-conductive textile fiber which comprises a filamentary polymer substrate having finely-divided, electrically-conductive particles uniformly suffused as a phase independent of the polymer substrate in an annular region located at the periphery of the filament and extending the entire length thereof.
• the electrically-conductive particles are present in an amount sufficient to render the electrical resistance of the textile fiber not more than about 10 ohms/cm.
• the annular suifusion of the present invention is a spreading or diffusion of electrically-conductive particles through the fiber substrate itself.
• the suffusion of the present invention is confined to an annulus located at the periphery of the filament and extending the entire length thereof.
• the filamentary polymer substrate of the present invention is of substantially cylindrical configuration, it has been found especially advantageous if the annular region of suffused electrically-conductive particles extends perpendicularly inwardly from the periphery of the filament up to a distance equal to about ,5 the radius of the filament.
• the electrically-conductive fiber of the present invention is economically produced, has very durable conductive properties, and substantially retains the characteristics of the filamentary polymer substrate, thereby affording a combination of properties unobtainable in the. prior art. That sufficient conductivity could be achieved without substantial sacrifice in the characteristics of the filamentary polymer substrate and without substantial loss of cohesion of polymer in the annular region, is indeed unexpected in view of the prior art.
• the filamentary polymer substrate upon which the electrically-conductive textile fiber of the present invention is based may be prepared from any of the well-known film or fiber forming polymers, such as cellulosics, polyolefins, polyesters, or polyamides, 'by standard techniques wellknown in the art.
• a wide range of deniers viz., from 1 to 100 and above
• Monofilaments of polyamides such as 6 nylon having a denier of between about and 50 have been found especially advantageous in most apparel and floor covering applications.
• the finely-divided, electrically-conductive particles which are suffused in the filamentary polymer substrate are chosen in the light of their electrical conductivity, chemical resistance, weatherability, and resistance to washing, scouring and dyeing treatments, as well as economy. Particularly useful are the metallic powders such as silver and bronze, and the electrically-conductive carbon blacks, all of which are readily available commercially. A wide range of particle sizes has been found acceptable. For electrically-conductive carbon black a particle size of about 20 to 40 m is preferred.
• the concentration of electrically-conductive particles-which is dependent upon the nature and particle size thereof, as well as the nature of the filamentary polymer substrate- is chosen so that the electrical resistance of the fiber will be not more than about ohms/cm., and most advantageously not less than about 10 ohms/cm. (If the fiber has an electrical resistance of between about 10 and 10 ohms/cm, it is most advantageously employed in fabrics for preventing the accumulation of high charges of static electricity while presenting no appreciable electrocution hazard.)
• electrically-conductive carbon black having a particle size between about 20 and 40 mp. is suffused in a denier monofilament of a polyamide such as 6 nylon, for example, a carbon black concentration of between about 2 and percent, based upon the total weight of the electrically-conductive fiber, is preferred.
• the suffusion of finely-divided, electrically-conductive particles in the filamentary polymer substrate is characterized by the existence of a discrete, independent phase of electrically-conductive particles, uniformly dispersed in the polymer substrate in an annular region located at the periphery of the filament and extending inwardly along the entire length of the filament.
• the filamentary polymer substrate is of substantially cylindrical configura tion, which is very common in the art, it has been found of especial advantage if the annular region of suffused electrically-conductive particles extends perpendicularly inwardly from the periphery of the filament up to a distance equal to about the radius of the filament.
• the physical properties of the suffused filamentary substrate still closely approximate those of the unmodified filamentary substrate while the conductivity thereof has been strikingly increased.
• the annular region most advantageously extends perpendicularly inwardly from the periphery of the filament up to a distance equal to about the radius of a circle inscribed within the cross-sectional perimeter of the filament.
• the electrically-conductive textile fiber of the present invention may be prepared from commercially available filamentary polymer substrates using special techniques, the most satisfactory of which comprehend applying to the filamentary polymer substrate a dispersion of the finely-divided, electrically-conductive material in a liquid which is a good solvent for the substrate but does not react with or dissolve the electrically-conductive material. A combination of such liquids maybe used if desired.
• the chosen concentration of electrically-conductive material in the solvent system is dependent upon the desired fiber conductivity and is limited by the viscosity of the dispersion. (Dispersions which are either too viscous or not viscous enough are difficultly applied when certain methods of application are expedient.)
• this dispersion to the filamentary substrate may be by padding, painting, spraying, dipping, rolling, printing, or the like.
• the dispersion may contain dissolved polymer of the same nature as that of the substrate, under which conditions the annular suffusion terminates imperceptibly in an integral coating of the same composition.
• solvent removal from the substrate must be effected before the structural integrity thereof is appreciably destroyed. This is conveniently accomplished by vaporization (for volatile solvents) and/or washing with a non-solvent (for non-volatile solvents) after the desired degree of solvent penetration has taken place (esp. up to about of the radius of substantially cylindrical filamentary substrates).
• the applicable dispersion may be 5 to 15% carbon black in concentrated formic acid, or it may be 5 to 15% carbon black in concentrated sulfuric acid.
• the formic acid solvent may be advantageously removed by continuously passing the dispersion-treated filament through a chamber in which the air is continually exchanged, e.g. by means of air jets and/or means for evacuation.
• the sulfuric acid solvent may be advantageously removed by continuously passing the dispersion-treated filament through a water bath. After removal of solvent has been accomplished, the filament is dried by conventional means and packaged for subsequent use.
• the electrically-conductive textile fiber of the instant invention finds special utility in the production of fabrics the use of which avoids the accumulation of high charges of static electricity while presenting no appreciable electrocution hazard.
• woven fabrics are produced by standard interweaving of the electricallyconductive fiber of the instant invention with ordinary threads made from natural fibers such as cotton or wool, and/or man-made fibers such as nylon, rayon, acrylic, or polyester.
• the electrically-conductive fiber is present in an amount equal to about 0.05-100, and preferably 0.1-5 percent by weight of the woven fabric.
• pile fabrics are produced comprising a backing material having pile loops anchored therein.
• the backing material comprises chain yarns interwoven with filler yarns, as is very well-known in the art. Moreover, the backing material may be constructed from any of the materials commonly employed in the art, such as jute or hemp, among many others.
• the pile loops comprise a yarn made of a plurality of strands twisted together by standard techniques. At least one such strand comprises the electrically-conductive fiber of the present invention.
• the balance of the yarn comprises any commonly-employed natural or man-made fibers. As will be understood by one of skill in the art, it may not be necessary that every end of yarn in the pile contain a strand of the electrically-conductive fiber of the present invention.
• the electricallyconductive fiber of the present invention is present in an amount equal to about 005-100, and preferably 0.1-5 percent by weight of the pile fabric.
• Fabrics such as those of the preparation of which is outlined above when employed in an atmosphere having a relative humidity of 20%, will not generate a static charge above about 3000 volts, which is in proximity to the threshold level of human sensitivity.
• These fabrics moreover, when containing an especially preferred embodiment of the electrically-conductive fiber of the present invention, do not present an electrocution hazard to those contacting them in the event of an accidental and simultaneous contact of such fabrics with a source of essentially unlimited electrical current, as is available from an ordinary electrical outlet, or an electrical appliance short-circuited by insulation failure.
• Example 1 This example specifies detail concerning a method of making an electrically-conductive fiber according to the present invention, and set forth some of the basic properties thereof.
• a cold-stretched 15 denier 6 nylon monofilament having a circular cross-sectional diameter of 42p was continuously directed at a rate of 400 meters/minute from a source of supply through the interface of two opposing surfaces of a polyester pad which was kept saturated with the following dispersion:
• Formic acid 80%, aqueous 90
• the filament was conducted into and through a 20 foot-long, elongated chamber in which the air at room temperature was continuously exchanged by means of air jets and exhaust openings. Removal of the volatile formic acid solvent was thereby accomplished, and the filament was substantially dry. After exiting the elongated chamber, the filament was continuously wound into a package at a rate of 400 meters/minute.
• Microscopic examination of transverse sections of the resulting filament revealed a uniform dispersion of particles of carbon black in an annular region along the length of the filament and extending prependicularly inwardly from the periphery of the filament up to a distance equal to about the radius of the filament.
• the carbon black content of the filament was determined to be 10 percent.
• the total cross-sectional diameter of the filament was not appreciably changed, measuring less than 43 A suifusion, rather than an ordinary coating, had therefore resulted from the specified treatment.
• Example 2 This example specifies detail concerning a modified method of making an electrically-conductive fiber according to the present invention.
• a cold-stretched 15 denier 6 nylon monofilament having a circular cross-sectional diameter of 42 was treated in exactly the same manner as specified in Example 1 above, except that the dispersion had the following contents:
• Example 3 This example specifies detail concerning yet another method of making an electrically-conductive fiber according to the present invention.
• a cold-stretched 15 denier 6 nylon monofilament identical with those employed as the filamentary substrates in Examples 1 and 2 was continuously directed at a rate of 400 meters/minute from a source of supply through the interface of two opposing surfaces of a polyester pad which was kept saturated with the following dispersion:
• Example 4 This example illustrates the integral nature of an electrically-conductive fiber according to the present invention, and shows the surprising cohesion of polymer in the annular region of suffused electrically-conductive particles.
• Unstretched 15 denier 6 nylon monofilament of circular cross-section was treated exactly according to the method of Example 2.
• Microscopic examination of a transverse section of the treated filament revealed a suffusion of particles of carbon black in an annular region extending along the entire length of the filament and perpendicularly inwardly up to a distance equal to about the radius of the filament.
• the resistance of the filament was measured at 3X10 ohms/cm.
• This filament was then cold stretched to 3 times its original length.
• the resistance of the stretched filament was measured at 5X10 ohms/cm, and close scrutiny of the surface of the stretched filament showed no desquamation or other deterioration of the annular suffusion of electrically-conductive particlessubstantial loss of conductivity, excessive flaking, and overall deterioration being generally observed when coated filaments are subjected to such stretching operations.
• Example 1 further illustrates the outstanding durability of electrically-conductive fibers according to the present invention.
• the treated filament of Example 2 was employed in the preparation of a conventional double knit fabric using standard techniques well-known in the art, one end of the treated filament of Example 2 being twisted in or plyed in every ten ends fed to the knitting machine.
• the balance of the fabric consisted of 1 end/ 150 denier polyester filament and 2 ends 28s acrylic staple yarn.
• the fabric was subjected to 135 launderings [utilizing a standard laundry detergent, hot wash (120 F.) and cold rinse (wash and wear cycle)] and tumble dryings (20 minutes at an average temperature of 145 F.), after which the average resistance of the individual electrically-conductive fibers was measured. Resistance before launderings and tumble dryings: 5X ohms/cm. Resistance after 135 launderings and tumble dryings: 5 10 ohms/cm.
• Example 6 This example is illustrative of the utility of an electrically-conductive fiber according to the present invention. Moreover, by comparison with the use of an electrically-conductive fiber of the prior art, the outstanding and unobvious advantages of fibers according to the present invention are further delineated.
• Experiment A (This Invention) A single strand of the electrically-conductive fiber of Example 2 above was twisted with a bulked, continuous filament 6 nylon carpet yarn comprising 136 individual strands and having a total denier of 2600, to produce antistatic yarn A.
• a jute backing material and utilizing a standard tufting machine, an 18 oz./yd. level loop carpet A having a pile height of A" was prepared from antistatic yarn A and a 2600/ 136 bulked, continuous filament 6 nylon carpet yarn; antistatic yarn A being incorporated in every fourth end of the pile.
• the electrically-conductive fiber of Example 2 was present in an amount equal to 0.2 percent by weight of the pile of carpet A.
• An electrically-conductive fiber B exemplary of the prior art, was prepared by coating a cold stretched denier monofilament of 6 nylon with a composition consisting of 25 percent of a crosslinked vinyl polymer adhesive, percent of electrically-conductive carbon black (30 m dispersed therein, and 55 percent of a methyl isobutyl ketone solvent. After the coated filament was passed through a slit to adjust coating thickness, it was then completely cured by heating with an infrared lamp. The average coating thickness of this filament was 12 and the average electrical resistance thereof was l 10 ohms/cm.
• a single strand of this filament was then twisted with a bulked, continuous filament 6 nylon carpet yarn comprising 136 individual strands and having a total denier of 2600, to produce antistatic yarn B.
• a bulked, continuous filament 6 nylon carpet yarn comprising 136 individual strands and having a total denier of 2600
• antistatic yarn B was prepared from antistatic yarn B and a 2600/136 bulked, continuous filament 6 nylon carpet yarn; antistatic yarn B being incorporated in every fourth end of the pile.
• the electrically-conductive fiber B was present in an amount equal to 0.2 percent by weight of the pile of carpet B.
• the fabric to be tested is first cut into sample squares 36 inches on a side. These samples are conditioned for 7 days by being hung from racks in a test room equipped with a rubber floor mat and having an area of at least square feet, wherein the temperature is controlled at 70i2 F. and the relative humidity is controlled at 20%i1%. Free circulation of air over all sample surfaces is effected, but the samples are not allowed to contact each other. A pair of Neolite or PVC-sole test shoes is also conditioned for the same period, under the same conditions.
• Residual static charge on the rubber floor mat is then neutralized by passing twice over its entire surface a polonium wand, which consists of 6 polonium 210 alloy strips mounted end-to-end on a head attached to a handle. A fabric sample is then placed upon the rubber floor mat, and its residual static charge is neutralized in the same manner. The soles of the test shoes are then cleaned by sanding their entire surface with fine sandpaper, followed by a wiping with cheesecloth to remove dust particles.
• the maximum voltage recorded during the walk is the static level of the sample, the average for two operators being
• the unique combination of properties possessed by electrically-conductive fibers according to the present invention renders them especially suitable for use not only in carpets, rugs, and other floor coverings, but also in bed coverings, especially in hospitals; in curtains, especially in hospitals for separation of cubicles; in articles of apparel, especially undergarments such as slips; in hosiery, especially in panty hose and half hose; and as sewing threads.
• An electrically-conductive textile fiber comprising a filamentary polymer substrate having finely-divided, electrically-conductive particles uniformly suffused as a phase independent of the polymer substrate in an annular region located at the periphery of the filament and extending the entire length thereof, the electrically-conductive particles being present in an amount sufiicient to render the electrical resistance of the textile fiber not more than about 10 ohms/cm.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Dispersion Chemistry (AREA)
• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Artificial Filaments (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Multicomponent Fibers (AREA)
• Woven Fabrics (AREA)

Priority Applications (18)

Applications Claiming Priority (2)

Related Child Applications (2)

Publications (1)

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ID=26955138

Family Applications (1)

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Cited By (43)

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• 1972
  • 1972-06-05 CA CA173,238A patent/CA995071A/en not_active Expired
  • 1972-07-14 US US00271837A patent/US3823035A/en not_active Expired - Lifetime
• 1973
  • 1973-07-12 DD DD172250A patent/DD105477A5/xx unknown
  • 1973-07-13 CH CH1029173A patent/CH596350B5/xx not_active IP Right Cessation
  • 1973-07-13 DE DE2335825A patent/DE2335825C3/de not_active Expired
  • 1973-07-13 GB GB3342473A patent/GB1439837A/en not_active Expired
  • 1973-07-13 JP JP48079234A patent/JPS4992400A/ja active Pending
  • 1973-07-13 NL NLAANVRAGE7309799,A patent/NL173776C/xx not_active IP Right Cessation
  • 1973-07-13 FR FR7325827A patent/FR2193103B1/fr not_active Expired
  • 1973-07-13 IE IE1188/73A patent/IE38159B1/xx unknown
  • 1973-07-13 AT AT619373A patent/AT353217B/de not_active IP Right Cessation
  • 1973-07-13 ES ES416899A patent/ES416899A1/es not_active Expired
  • 1973-07-13 CH CH1029173D patent/CH1029173A4/xx unknown
  • 1973-07-13 BE BE133461A patent/BE802321A/xx not_active IP Right Cessation
  • 1973-07-13 IT IT26613/73A patent/IT991291B/it active

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