Electrically conductive pulp and method of making
AssigneeE. I. Du Pont de Nemours and Company
InventorsGary Delmar Jaycox, Jeffrey S. Downey
Life of this patent
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Abstract
An electrically conductive pulp suitable for use as a reinforcement comprises from 60 to 96 weight percent of fibers of aromatic polyamide, aromatic copolyamide or mixtures thereof and from 4 to 40 weight percent of conductive material coated onto the fibers wherein the conductive material comprises (i) a polymer of aniline, or (ii) a random copolymer formed from aniline and one or more substituted aniline co-monomers that exist in the protonated emeraldine salt form.
Claims17
An electrically conductive pulp suitable for use as a reinforcement comprising from 60 to 96 weight percent of fibers selected from the group consisting of aromatic polyamide, aromatic copolyamide and mixtures thereof and from 4 to 40 weight percent of conductive material coated onto the fibers, wherein the conductive material comprises
- (i) a polymer of aniline, or
- (ii) a random copolymer formed from aniline and one or more substituted aniline co-monomers that exist in the protonated emeraldine salt form.
A method of making an electrically conductive fibrous pulp suitable for use as a reinforcement, the fibers being selected from the group consisting of aromatic polyamide, aromatic copolyamide and mixtures thereof, comprising the steps of
- (i) forming a suspension of pulp in an aqueous acid dopant,
- (ii) adding aniline or aniline and at least one substituted aniline co-monomer to the suspension such that the weight percent ratio of the amount of aniline, or the amount of aniline and substituted aniline co-monomers, to the amount of pulp is in the range of from 4 to 40,
- (iii) adding an initiator to the dispersion in the amount of one molar equivalent relative to aniline, or one molar equivalent relative to aniline and substituted aniline co-monomers, to effect polymerization,
- (iv) stirring the pulp suspension for a sufficient time to ensure precipitation of the desired amount of aniline polymer or random copolymer onto the surface of the pulp,
- (v) filtering the suspension to isolate the coated pulp product in a first filtration step,
- (vi) washing the coated pulp product with additional aqueous acid dopant solution, and
- (vii) isolating the washed coated pulp product in a second filtration step.
A substituted polyfunctional aniline co-monomer having the formula
- wherein
- (i) x is an integer of 1 to 4,
- (ii) y is an integer of 2 to 4,
- (iii) A is
- and
- (iv) E is selected from the group consisting of:
- a) CH2n
- when y=2 and where n is an integer from 1 to 200,
- b)
- when y=2 and where m+p is an integer from 1 to 200,
- c) —CH2—CH2—O—CH2—CH2q
- when y=2 and where q is an integer from 1 to 20,
- d)
- when y=3 and where r is an integer from 0 to 5,
- e)
- when y=4 and where s is an integer from 0 to 5,
- f)
- when y=2, and
- g)
- when y=3.
Dependencies are inferred from the claim text.