Conductive composite filaments and methods for producing said composite filaments

Claim 2

A conductive composite filament comprising a conductive component composed of electrically conductive metal oxide particles and at least one polymer selected from the group consisting of thermoplastic polymers and solvent-soluble polymers, bonded to an electrically non-conductive component composed of a fiber-forming polymer, said electrically conductive metal oxide particles comprising a core made of titanium oxide, the surface of said core being coated with an electrically conductive tin oxide.

Claim 3

A filament as claimed in claim 1, wherein the crystallinity of said thermoplastic polymers and said solvent-soluble polymers is at least 40%.

Claim 4

A filament as claimed in claim 1, wherein said thermoplastic polymers are selected from the group consisting of polyamides, polyesters, polyolefins, vinyl polymers, polyethers and polycarbonates.

Claim 5

A filament as claimed in claim 1, wherein said fiber-forming polymer is at least one polymer selected from the group consisting of polyamides, polyesters, polyolefins and vinyl polymers.

Claim 6

A filment as claimed in claim 3, wherein said polyamide is at least one polymer selected from the group consisting of nylon-6, nylon-66, nylon-11, nylon-12, nylon-610, nylon-612 and copolymers thereof, said polyester is at least one polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene oxybenzoate and copolymers thereof, said polyolefin as at least one polymer selected from the group consisting of crystalline polyethylene, polypropylene and copolymers thereof, and said polyether is at least one polymer selected from the group consisting of crystalline polymethylene oxide, polyethylene oxide, polybutylene oxide and copolymers thereof.

Claim 7

A filament as claimed in claim 4, wherein said polyamide is at least one polymer selected from the group consisting of nylon-6, nylon-66, nylon-11, nylon-12, nylon-610, nylon-612 and copolymers thereof, said polyester is at least one polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, polyethylene oxybenzoate and copolymers thereof, said polyolefin is at least one polymer selected from the group consisting of crystalline polyethylene, polypropylene and copolymers thereof, and said polyether is at least one polymer selected from the group consisting of crystalline polymethylene oxide, polyethylene oxide, polybutylene oxide and copolymers thereof.

Claim 8

A filament as claimed in claim 1, wherein said solvent-soluble polymers are selected from the group consisting of acrylic polymers, modacrylic polymers, cellulosic polymers, vinyl alcohol polymers and polyurethanes.

Claim 9

A filament as claimed in claim 7, wherein said acrylic polymer contains at least 85% by weight of acrylonitrile.

Claim 10

A filament as claimed in claim 1, wherein the average grain size of said electrically conductive metal oxide particles is not more than 0.5 μm.

Claim 11

A filament as claimed in claim 1, wherein the specific resistance of said electrically conductive metal oxide particles is not more than 10 2 Ω·cm.

Claim 12

A filament as claimed in claim 1, wherein the light reflectivity of said electrically conductive metal oxide particles is not less than 40%.

Claim 13

A filament as claimed in claim 1, wherein said electrically conductive metal oxide particles comprise 30-85% by weight of the total weight of said electrically conductive component.

Claim 14

A filament as claimed in claim 1, wherein the specific resistance of said electrically conductive component is not more than about 10 7 Ω·cm.

Claim 15

A filament as claimed in claim 1, wherein the conjugate ratio of the electrically conductive component to the electrically non-conductive component is in the range of 3/97 to 60/40.

Claim 16

A filament as claimed in claim 1, wherein said conductive component occupies not more than 30% of the surface area of said filament, and said conductive component comprises one or more relatively thin, elongated layers which extend transversely of the cross section of the filament, each of said layers having at least one exposed end which is exposed on the outer surface of said filament, the thickness of each said layer through substantially all of its length being at least as great as the thickness of said layer at said exposed end so as to prevent separation of said electrically conductive component from said electrically non-conductive component.

Claim 17

A filament as claimed in claim 1, wherein said polymer used to form said electrically conductive component has a crystallinity of not less than 60% and is poor in affinity to said fiber-forming polymer used to form said non-conductive component.

Claim 18

A unitary, elongated, electrically conductive, bi-component filament which is transverse cross section consists essentially of an electrically conductive component in the form of one or more relatively thin, elongated layers which extend transversely of the cross section of the filament and the remainder of the filament being an electrically non-conductive component, said electrically conductive component being made of a mixture of electrically conductive metal oxide particles, said metal oxide particles comprising a core which consists essentially of titanium dioxide, the surface of said core being coated with electrically conductive tin oxide, with at least one polymer selected from the group consisting of thermoplastic polymers and solvent-soluble polymers, said electrically non-conductive component being made of a thermoplastic fiber-forming polymer, at least one exposed end of each said layer being exposed on the outer surface of the filament, the opposite surfaces of each said layer being adhered to said electrically non-conductive component, said layer or layers having a specific resistance of not more than 10 7 ohm·cm, said layer or layers occupying from 1 to 40% of the total cross-sectional area of the filament and the exposed end or ends of said layer or layers occupying from 1 to 30% of the total surface area of the filament.

Claim 19

A unitary, elongated, electrically conductive, bi-component filament which is transverse cross section consists essentially of an electrically conductive component in the form of one or more relatively thin, elongated layers which extend transversely of the cross section of the filament and the remainder of the filament being an electrically non-conductive component, said electrically conductive component being made of a mixture of electrically conductive metal oxide particles, said metal oxide particles comprising a core which consists essentially of titanium dioxide, the surface of said core being coated with electrically conductive tin oxide, with at least one polymer selected from the group consisting of thermoplastic polymers and solvent-soluble polymers, said electrically non-conductive component being made of a thermoplastic fiber-forming polymer, at least one exposed end of each said layer being exposed on the outer surface of the filament, the opposite surfaces of each said layer being adhered to said electrically non-conductive component, said layer or layers having a specific resistance of not more than 10 7 ohm·cm, said layer or layers occupying from 1 to 40% of the total cross-sectional area of the filament and the exposed end or ends of said layer or layers occupying from 1 to 30% of the total surface area of the filament.

Claim 20

A filament as claimed in claim 17, wherein the thickness of each said layer throughout substantially all of its length is at least as great as the thickness of said layer at said exposed end thereof, so as to prevent separation of said electrically conductive component from said electrically non-conductive component.

Claim 21

A filament as claimed in claim 17, wherein said conductive metal oxide particles are formed by firing a mixture of titanium dioxide particles coated with tin oxide and an effective amount of a secondary component capable of imparting said conductive metal oxide particles with a specific resistance of not more than 10 4 ohm·cm, said conductive metal oxide particles having a reflectivity of at least 60%.

Claim 22

A filament as claimed in claim 19, wherein the tin oxide content of said coated titanium dioxide particles is about 12%, said secondary component is antimony oxide, and the amount of secondary component is about 5% based on said coated titanium dioxide particles.

Claim 23

A filament as claimed in claim 19, wherein the tin oxide content of said coated titanium dioxide particles is about 15%, secondary component is antimony oxide, and the amount of said secondary component is about 0.75% based on said coated titanium dioxide particles.

Claim 24

A filament as claimed in claim 19, wherein the crystallinity of said thermoplastic polymers and said solvent-soluble polymers is at least 40%, said thermoplastic polymers are selected from the group consisting of polyamides, polyesters, polyolefins, vinyl polymers, polyethers and polycarbonates, said fiber-forming polymer is at least one polymer selected from the group consisting of polyamides, polyesters, polyolefins and vinyl polymers, said electrically conductive metal oxide particles have an average grain size of not more than 0.5 μm and a specific resistance of not more than 10 2 ohm·cm, said electrically conductive metal oxide particles comprise 30 to 85% by weight of the total weight of said electrically conductive component, and the conjugate ratio of said electrically conductive component to said electrically nonconductive component is in the range of from 3/97 to 60/40.