US5484838A — Thermoplastic compositions with modified electric…

Claim 1

Independent Claim 172 words

A molded thermoplastic article, having a modified electrical conductivity, adapted for electrostatic painting, said article being comprised of a composition comprising: (a) a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 110° C., and (ii) an amorphous or semi-crystalline polymer having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 35 weight percent of said polymer blend and being a continuous phase within said polymer blend; and (b) electrically conductive carbon black (i) comprising between about 2 and about 7.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said article measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -12 S/cm, and the steady surface conductivity at 100 volts applied electric field is greater than about 10 -18 S/cm.

Claim 2

Dependent Claim 172 words

A molded thermoplastic article, having a modified electrical conductivity, adapted for electrostatic painting, said article being comprised of a composition comprising: (a) a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 110° C., and (ii) an amorphous or semi-crystalline polymer having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 35 weight percent of said polymer blend and being a continuous phase within said polymer blend; and (b) electrically conductive carbon black (i) comprising between about 2 and about 7.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said article measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -12 S/cm, and the steady surface conductivity at 100 volts applied electric field is greater than about 10 -18 S/cm.

Claim 3

Dependent Claim 32 words

The article according to claim 1 wherein said crystalline polymer is selected from the group consisting of polypropylene, polybutylene terephthalate, polyethylene, polyethylene terephthalate, nylon, polyphenylene sulfide, polyether ether ketone, and mixtures thereof.

Claim 4

Dependent Claim 51 words

The article according to claim 1 wherein said amorphous polymer is selected from the group consisting of polycarbonate, natural and synthetic polyisoprene rubbers, ethylene-propylene copolymers (EPM), ethylene-propylene diene rubbers (EPDM), chlorinated rubbers, nitrile rubbers, polystyrene, polyphenylene oxides, methylmethacrylate styrene-butadiene block copolymers, polyether sulfones, polysulfones, polyarylates, other impact modifiers, and mixtures thereof.

Claim 5

Dependent Claim 21 words

The article according to claim 1 wherein at least 70 percent of said carbon black is dispersed in said crystalline polymer.

Claim 6

Dependent Claim 20 words

The article according to claim 1 wherein said carbon black has a particle size between about 20 and 50 nanometers.

Claim 7

Dependent Claim 39 words

The article according to claim 5 wherein said carbon black has a pH between about 6.5 and 10, percent volatiles of between about 0.2 and 1.5, and a pore volume between about 150 and 400 cm 3 /100 g.

Claim 8

Dependent Claim 25 words

The article according to claim 1 wherein said carbon black is incorporated into said composition in the form of a concentrate in said crystalline polymer.

Claim 9

Dependent Claim 171 words

A molded thermoplastic automotive article having an electrical conductivity adapted for electrostatic painting, said article being comprised of a composition comprising: (a) a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 140° C., and (ii) an amorphous polymer or semi-crystalline having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 35 weight percent of said polymer blend and being a continuous phase within said polymer blend; and (b) electrically conductive carbon black (i) comprising between about 2.5 and about 7.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said article measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -12 S/cm, and the surface conductivity at 100 volts applied electric field is greater than about 10 -18 S/cm.

Claim 10

Dependent Claim 171 words

A molded thermoplastic automotive article having an electrical conductivity adapted for electrostatic painting, said article being comprised of a composition comprising: (a) a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 140° C., and (ii) an amorphous polymer or semi-crystalline having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 35 weight percent of said polymer blend and being a continuous phase within said polymer blend; and (b) electrically conductive carbon black (i) comprising between about 2.5 and about 7.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said article measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -12 S/cm, and the surface conductivity at 100 volts applied electric field is greater than about 10 -18 S/cm.

Claim 11

Independent Claim 177 words

A method for modifying the electrical conductivity of thermoplastic polymers, which method comprises the steps of: providing a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 110° C., and (ii) an amorphous polymer or semi-crystalline having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 60 weight percent of said polymer blend and being a continuous phase within said polymer blend; and incorporating electrically conductive carbon black within said composition, said carbon black (i) comprising between about 3.0 and about 6.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said carbon black modified thermoplastic polymeric composition measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -10 S/cm, and the surface conductivity at 100 volts applied electric field is greater than about 10 -17 S/cm.

Claim 12

Independent Claim 177 words

A method for modifying the electrical conductivity of thermoplastic polymers, which method comprises the steps of: providing a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 110° C., and (ii) an amorphous polymer or semi-crystalline having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 60 weight percent of said polymer blend and being a continuous phase within said polymer blend; and incorporating electrically conductive carbon black within said composition, said carbon black (i) comprising between about 3.0 and about 6.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said carbon black modified thermoplastic polymeric composition measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -10 S/cm, and the surface conductivity at 100 volts applied electric field is greater than about 10 -17 S/cm.

Claim 13

Dependent Claim 169 words

A molded thermoplastic composition having a modified electrical conductivity and adapted for electrostatic painting, said composition comprising: (a) a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 110° C., and (ii) an amorphous or semi-crystalline polymer having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 35 weight percent of said polymer blend and being a continuous phase within said polymer blend; and (b) electrically conductive carbon black (i) comprising between about 2 and about 7.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said molded composition measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -12 S/cm, and the steady surface conductivity at 100 volts applied electric field is greater than about 10 -18 S/cm.

Claim 14

Dependent Claim 169 words

A molded thermoplastic composition having a modified electrical conductivity and adapted for electrostatic painting, said composition comprising: (a) a polymer blend of at least two polymers comprising: (i) a crystalline polymer having a melting point above about 110° C., and (ii) an amorphous or semi-crystalline polymer having a Tg above about -80° C. and a percent crystallinity between 0 and 20 percent, said crystalline polymer comprising at least about 35 weight percent of said polymer blend and being a continuous phase within said polymer blend; and (b) electrically conductive carbon black (i) comprising between about 2 and about 7.0 weight percent of the total weight of said composition and (ii) at least a portion of said carbon black being dispersed within said crystalline polymer, wherein the internal electrical conductivity of said molded composition measured at an applied field of 1 volt is between about 10 -5 S/cm and 10 -12 S/cm, and the steady surface conductivity at 100 volts applied electric field is greater than about 10 -18 S/cm.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-01-15	1999-07-17	2000-01-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-01-15	2003-07-17	2004-01-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-01-15	2007-07-17	2008-01-16	$7700.00	Window Closed / Lapsed

Thermoplastic compositions with modified electrical conductivity

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag