Antistatic liquid crystalline polymer composition

• US 9,512,293 B2
• Filed: 10/14/2013
• Issued: 12/06/2016
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Ticona LLC (Celanese Corporation)
• Original Assignee: Ticona LLC (Celanese Corporation)
• Inventors: Kim, Young Shin
• Primary Examiner(s): Sample, David
• Assistant Examiner(s): Flores, Jr., Donald M
• Application Number:
  US14/052,790
• Publication Number:
  US 20140272365A1
• Time in Patent Office: 1,149 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B29C 2948/92704 Temperature
• CPC Class Codes: B29C 48/04 Particle-shaped making granules B29B9/00
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/2886 of fibrous, filamentary or filling materials, e.g. thin fibrous reinforcements or fillers
• CPC Class Codes: B29C 48/345 Extrusion nozzles comprising two or more adjacently arranged ports, for simultaneously extruding multiple strands, e.g. for pelletising
• CPC Class Codes: B29C 48/40 using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
• CPC Class Codes: B29C 48/625 characterised by the ratio of the threaded length of the screw to its outside diameter [L/D ratio]
• CPC Class Codes: B29C 48/67 having incorporated mixing devices not provided for in groups B29C48/52 - B29C48/66
• CPC Class Codes: B29C 48/767 through a degassing opening of a barrel
• CPC Class Codes: B29C 48/919 using a bath, e.g. extruding into an open bath to coagulate or cool the material
• CPC Class Codes: B29C 48/92 Measuring, controlling or regulating
• CPC Class Codes: C08J 5/10 characterised by the additives used in the polymer mixture
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C08K 3/346 Clay
• CPC Class Codes: C08K 3/40 Glass
• CPC Class Codes: C08K 5/092 Polycarboxylic acids
• CPC Class Codes: C08K 5/13 Phenols; Phenolates
• CPC Class Codes: C08K 7/02 Fibres or whiskers
• CPC Class Codes: C08L 67/03 the dicarboxylic acids and dihydroxy compounds having the carboxyl- and the hydroxy groups directly linked to aromatic rings
• CPC Class Codes: C09K 19/3809 Polyesters; Polyester derivatives, e.g. polyamides
• CPC Class Codes: C09K 19/52 : characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
• CPC Class Codes: C09K 19/54 : Additives having no specific mesophase characterised by their chemical composition
• CPC Class Codes: C09K 2019/521 : Inorganic solid particles
• CPC Class Codes: H01B 1/20 : Conductive material dispersed in non-conductive organic material organic macromolecular compounds or compositions C08
• CPC Class Codes: H01B 1/24 : the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: Y10T 428/1372 : Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/266 : of base or substrate
• CPC Class Codes: Y10T 428/269 : including synthetic resin or polymer layer or component

Abstract

A liquid crystalline polymer composition that contains a conductive filler (e.g., carbon fibers, ionic liquid, etc.) and a plurality of mineral fibers distributed within a liquid crystalline polymer matrix is provided. Through careful selection of the conductive filler and mineral fibers, as well as the manner in which they are dispersed within the polymer matrix, the present inventors have discovered that a composition can be formed that has a reduced tendency to create a static electric charge during a molding operation, but yet also has good surface characteristics and mechanical properties.

Claims

1. A polymer composition that comprises an electrically conductive filler and plurality of mineral fibers distributed within a liquid crystalline polymer matrix, wherein the mineral fibers have a median width of from about 1 to about 35 micrometers, and wherein conductive fillers constitute from about 0.1 wt. % to about 25 wt. % of the composition and mineral fibers constitute from about 5 wt. % to about 60 wt. % of the polymer composition, wherein the conductive filler includes metal particles metal fibers, carbon particles, carbon nanotubes, carbon fibers, an ionic liquid, or a combination thereof, wherein the composition has a melt viscosity of from about 0.1 to about 80 Pa-s, as determined in accordance with ISO Test No 11443 at a shear rate of 1000 seconds⁻

1 and temperature that is 15°

C. above the melting temperature of the composition.

2. The polymer composition of claim 1, wherein liquid crystalline polymers constitute from about 25 wt. % to about 95 wt. % of the composition.

3. The polymer composition of claim 1, wherein the liquid crystalline polymer matrix is formed from a polymer that contains aromatic ester repeating units.

4. The polymer composition of claim 3, wherein the aromatic ester repeating units are aromatic dicarboxylic acid repeating units, aromatic hydroxycarboxylic acid repeating units, or a combination thereof.

5. The polymer composition of claim 3, wherein the polymer further contains aromatic diol repeating units.

6. The polymer composition of claim 1, wherein the liquid crystalline polymer matrix is formed from a polymer that contains repeating units derived from 4-hydroxybenzoic acid, terephthalic acid, hydroquinone, 4,4′

-biphenol, acetaminophen, 6-hydroxy-2-naphthoic acid, 2,6-naphthalene dicarboxylic acid, or a combination thereof.

7. The polymer composition of claim 1, wherein the conductive filler includes carbon particles, carbon fibers, or a combination thereof.

8. The polymer composition of claim 1, wherein the conductive filler includes an ionic liquid that has a melting temperature of about 400°

C. or more and is a salt that contains a cationic species and counterion.

9. The polymer composition of claim 8, wherein the cationic species is a quaternary onium.

10. The polymer composition of claim 8, wherein the counterion is a halogen, sulfate, sulfonate, sulfosuccinate, amide, imide, borate, phosphate, phosphinate, antimonate, aluminate, fatty acid carboxylate, cyanate, acetate, or a combination thereof.

11. The polymer composition of claim 1, wherein at least about 60% by volume of the mineral fibers have a diameter of from about 1 to about 35 micrometers.

12. The polymer composition of claim 1, wherein the mineral fibers have an aspect ratio of from about 1 to about 50.

13. The polymer composition of claim 1, wherein the mineral fibers have a median width of from about 3 to about 15 micrometers.

14. The polymer composition of claim 1, wherein the mineral fibers include fibers derived from a silicate.

15. The polymer composition of claim 14, wherein the mineral fibers include wollastonite fibers.

16. The polymer composition of claim 1, further comprising a glass filler, clay mineral, or a combination thereof.

17. The polymer composition of claim 1, further comprising a functional compound.

18. The polymer composition of claim 17, wherein the functional compound includes an aromatic compound that is an aromatic dial, aromatic carboxylic acid, or a combination thereof.

19. The polymer composition of claim 17, wherein the functional compound includes a non-aromatic compound that is a hydrate.

20. A molded part comprising the polymer composition of claim 1.

21. The molded part of claim 20, wherein the part exhibits a surface resistivity of about 1×

10¹⁵ ohms or less as determined in accordance with IEC 60093.

22. The molded part of claim 20, wherein the part exhibits a volume resistivity of about 1×

10¹⁵ ohm-m or less as determined in accordance with IEC 60093.

23. A compact camera module that comprises a generally planar base on which is mounted a lens barrel, wherein the base, barrel, or both have a thickness of about 500 micrometers or less and are formed from a part that contains the polymer composition of claim 1.

24. The polymer composition of claim 1, wherein the liquid crystalline polymer contains a liquid crystalline polymer in which the total amount of repeating units derived from naphthenic hydroxycarboxylic and/or naphthenic dicarboxylic acids is no more than about 15 mol. %.

25. The polymer composition of claim 24, wherein the liquid crystalline polymer contains repeating units derived from 4-hydroxybenzoic acid in an amount from about 10 mol. % to about 80 mol. %.

26. The polymer composition of claim 25, wherein the liquid crystalline polymer contains repeating units derived from terephthalic acid and/or isophthalic acid in an amount from about 5 mol. % to about 40 mol. %, as well as repeating units derived from 4,4′

-biphenol and/or hydroquinone in an amount from about 1 mol. % to about 30 mol. %.

27. The polymer composition of claim 26, wherein the liquid crystalline polymer contains repeating units derived from 6-hydroxy-2-naphthoic acid in an amount from about 1 mol. % to about 10 mol. %.

28. The polymer composition of claim 26, wherein the liquid crystalline polymer contains repeating units derived from acetaminophen.