Exothermic polyphenylene sulfide compounds
View Patent ↗Use of an exothermic additive in a polyphenylene sulfide compound results in an extruded or molded thermoplastic article that is electrically conductive and exothermic when connected to a source of electrical energy. Electronic devices benefit from these articles, particularly where ink must be melted for imaging of commercial graphics on a substrate.
1. A polyphenylene sulfide composition, comprising:
(a) polyphenylene sulfide,
(b) an exothermic additive, and
(c) high density polyethylene,
wherein the composition is exothermic when connected to a source of electrical energy and wherein both the exothermic additive and the high density polyethylene contribute to a given temperature at a given voltage.
2. The composition of claim 1 , wherein the exothermic additive comprises the combination of two different forms of carbon, and wherein one form is more electrically conductive than the other form.
3. The composition of claim 1 , wherein the exothermic additive is a combination of particles of carbon black and particles of graphite, and wherein particles of carbon black are more electrically conductive than particles of graphite.
4. The composition of claim 2 , wherein the more electrically conductive form of carbon is selected from the group consisting of particles of carbon black, single-walled nanotubes, multi-walled nanotubes, nanofibers, and combinations thereof.
5. The composition of claim 1 , wherein the exothermic additive comprises a form of carbon that has a high aspect ratio and is electrically conductive.
6. The composition of claim 1 , wherein the exothermic additive are particles having a size within the nanometric or micrometric region.
7. The composition of claim 1 , wherein the exothermic additive are particles having an aspect ratio ranging from about 1:1 to about 20,000:1.
8. The composition of claim 2 , wherein the weight ratio of more conductive:less conductive forms of carbon can range from 2.2:1 to about 3:1.
9. The composition of claim 1 , wherein the amount of exothermic additive ranges from about 1 to about 75 weight percent of the composition.
10. The composition of claim 3 , wherein the weight ratio of more conductive:less conductive forms of carbon can range from 2.2:1 to about 3:1.
11. The composition of claim 3 , wherein the amount of exothermic additive ranges from about 1 to about 75 weight percent of the composition.
12. The composition of claim 1 , further comprising optional additives selected from the group consisting of fillers, pigments, colorants, processing lubricants, impact modifiers, uv-stabilizers, processing aids, biocides, and flame retardants, wherein the optional additive is present in an amount ranging from 0 to about 25 weight percent of the composition.
13. A method of making the composition of claim 3 , comprising the steps of:
(a) dry mixing the carbon black particles in a mixer;
(b) adding the polyphenylene sulfide into the mixer and continuing dry mixing;
(c) adding the graphite particles into the mixer and continuing dry mixing step to form a dry blend; and
(d) extruding the dry blend in an extruder.
14. A thermoplastic article, comprising the polyphenylene sulfide composition of claim 1 , wherein the article is exothermic throughout the bulk of the article when the article is connected to a source of electrical energy.
15. An electronic device, comprising a thermoplastic article of claim 14 .
16. The composition of claim 2 , wherein the exothermic additive comprises a form of carbon that has a high aspect ratio and is electrically conductive.
17. The composition of claim 2 , wherein the exothermic additive are particles having a size within the nanometric or micrometric region.
18. The composition of claim 2 , wherein the exothermic additive are particles having an aspect ratio ranging from about 1:1 to about 20,000:1.