Liquid Crystalline Polymer Composition Containing a Fibrous Filler

• US 20130052447A1
• Filed: 08/27/2012
• Published: 02/28/2013
• Est. Priority Date: 08/29/2011
• Status: Abandoned Application

• Current Assignee: Ticona LLC (Celanese Corporation)
• Original Assignee: Ticona LLC (Celanese Corporation)
• Inventors: Grenci, Joseph J., Nair, Kamlesh P.
• Application Number:
  US13/594,920
• Publication Number:
  US 20130052447A1
• Time in Patent Office: Days
• US Class Current: 428/220
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/395 using screws surrounded by a cooperating barrel, e.g. single 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: C08J 2300/12 Polymers characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity
• CPC Class Codes: C08J 2367/03 the dicarboxylic acids and dihydroxy compounds having the hydroxy and the carboxyl groups directly linked to aromatic rings
• CPC Class Codes: C08J 3/18 Plasticising macromolecular compounds plasticisers C08K
• CPC Class Codes: C08J 3/203 Solid polymers with solid and/or liquid additives
• CPC Class Codes: C08K 5/20 Carboxylic acid amides
• CPC Class Codes: C08K 7/14 Glass
• 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 19/22 linked by a chain containing carbon and nitrogen atoms as chain links, e.g. Schiff bases
• CPC Class Codes: C09K 19/3086 in which at least two rings are linked by a chain containing nitrogen atoms
• CPC Class Codes: C09K 19/322 Compounds containing a naphthalene ring or a completely or partially hydrogenated naphthalene ring
• CPC Class Codes: C09K 19/3444 the heterocyclic ring being a six-membered aromatic ring containing one nitrogen atom, e.g. pyridine
• CPC Class Codes: C09K 19/3809 Polyesters; Polyester derivatives, e.g. polyamides
• CPC Class Codes: C09K 2019/0481 Phenylene substituted in meta position

Abstract

A polymer composition that contains a thermotropic liquid crystalline polymer, fibrous filler (e.g., glass fibers), and a flow aid is provided. The flow aid is in the form of an aromatic amide oligomer which, due to its unique nature and properties, has the ability to dramatically reduce melt viscosity with only a minimal degree of blending with the polymer. More particularly, the fibrous filler is supplied to an extruder in conjunction with the polymer and/or at a location downstream thereof so that the polymer is still in a solid or solid-like state when it initially contacts the filler. In this manner, the fibrous filler and polymer are allowed to mix together while the composition still has a relatively high melt viscosity, which helps to uniformly disperse the fibrous filler within the polymer matrix. After a certain period of time, the aromatic amide oligomer is then supplied to the extruder at a location downstream from the fibrous filler to reduce the melt viscosity of the composition.

Claims

1. A method for forming a polymer composition within an extruder, the extruder containing at least one rotatable screw within a barrel, the method comprising:

supplying a thermotropic liquid crystalline polymer and a fibrous filler to the extruder;

blending the polymer and the fibrous filler within the extruder; and

thereafter, supplying a flow aid to the extruder at a location that is downstream from the polymer and the fibrous filler, wherein the flow aid includes an aromatic amide oligomer.

2. The method of claim 1, wherein the screw has a total length and diameter, wherein the ratio of the total length to the diameter of the screw is from about 15 to about 50.

3. The method of claim 1, wherein the screw has a first blending length that is defined from the point at which the fibrous filler is supplied to the extruder to the end of the screw, wherein the ratio of the first blending length to the diameter of the screw is from about 4 to about 20.

4. The method of claim 3, wherein the screw has a second blending length that is defined from the point at which the flow aid is supplied to the extruder to the end of the screw, wherein the ratio of the second blending length to the diameter of the screw is from about 5 to about 25.

5. The method of claim 1, wherein the aromatic amide oligomer has the following general formula (I):

6. The method of claim 5, wherein ring B is phenyl.

7. The method of claim 1, wherein the oligomer is selected from the group consisting of the following compounds and combinations thereof:

8. The method of claim 1, wherein the oligomer has a molecular weight of about 3,000 grams per mole or less.

9. The method of claim 1, wherein the liquid crystalline polymer is wholly aromatic.

10. The method of claim 1, wherein the liquid crystalline polymer contains monomer repeat units derived from one or more aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic amines, aromatic diamines, or a combination of the foregoing.

11. The method of claim 1, wherein the liquid crystalline polymer contains monomer repeat units derived from 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, terephthalic acid, isophthalic acid, 4,4′

-biphenol, hydroquinone, acetaminophen, or a combination of the foregoing.

12. The method of claim 1, wherein the fibrous filler includes glass fibers.

13. The method of claim 1, wherein the polymer composition has a melt viscosity of from about 0.5 to about 80 Pa-s, determined in accordance with ISO Test No. 11443 at a temperature of 350°

C. and at a shear rate of 1000 s<sup>−

1</sup>.

14. A polymer composition comprising the method of claim 1.

15. A molded part comprising the polymer composition of claim 14.

16. The molded part of claim 15, wherein the part exhibits a blister free temperature of about 250°

C. or greater.

17. The molded part of claim 15, wherein the part contains opposing walls having a width of about 500 micrometers or less.

18. The molded part of claim 15, wherein the part is a planar substrate having a thickness of about 500 micrometers or less.

19. An electronic component that comprises the molded part of claim 15, wherein the electronic component is a cellular telephone, laptop computer, small portable computer, wrist-watch device, pendant device, headphone or earpiece device, media player with wireless communications capabilities, handheld computer, remote controller, global positioning system, handheld gaming device, battery cover, speaker, integrated circuit, electrical connector, camera module, or a combination thereof.

20. A molded part comprising a polymer composition, wherein the polymer composition has a melt viscosity of from about 0.5 to about 80 Pa-s, determined in accordance with ISO Test No. 11443 at a temperature of 350°

C. and at a shear rate of 1000 s<sup>−

1</sup>, the composition comprising from about 30 wt. % to about 95 wt. % of a thermotropic liquid crystalline polymer, from about 2 wt. % to about 40 wt. % of a fibrous filler, and from about 0.1 wt. % to about 10 wt. % of an aromatic amide oligomer, wherein the molded part has a blister free temperature of about 250°

C. or more.

21. The molded part of claim 20, wherein the aromatic amide oligomer has the following general formula (I):

22. The molded part of claim 21, wherein ring B is phenyl.

23. The molded part of claim 20, wherein the oligomer is selected from the group consisting of the following compounds and combinations thereof:

24. The molded part of claim 20, wherein the oligomer has a molecular weight of about 3,000 grams per mole or less.

25. The molded part of claim 20, wherein the liquid crystalline polymer is wholly aromatic.

26. The molded part of claim 20, wherein the liquid crystalline polymer contains monomer repeat units derived from one or more aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic amines, aromatic diamines, or a combination of the foregoing.

27. The molded part of claim 20, wherein the liquid crystalline polymer contains monomer repeat units derived from 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, terephthalic acid, isophthalic acid, 4,4′

-biphenol, hydroquinone, acetaminophen, or a combination of the foregoing.

28. The molded part of claim 20, wherein the fibrous filler includes glass fibers.