Cast molded parts formed from a liquid crystalline polymer

Patent metadata

Field	Value
Publication number	US-9045685-B2
Application number	US-201213594923-A
Country	US
Kind code	B2
Filing date	Aug 27, 2012
Priority date	Aug 29, 2011
Publication date	Jun 2, 2015
Grant date	Jun 2, 2015

Abstract

A molded part having a predetermined shape is provided. The molded part may be formed by casting a liquid crystalline polymer composition into a mold cavity at a relatively low shear rate. Due to the use of a relatively low shear rate, the polymer composition does not generally undergo extensive shear orientation, which can allow the resulting part to be further processed using standard finishing techniques. The ability to use relatively low shear rates during casting is achieved in the present invention through the use of an aromatic amide oligomer. More particularly, the present inventors have discovered that the aromatic amide oligomer can serve as a flow aid by altering intermolecular polymer chain interactions, thereby lowering the overall viscosity of the polymer matrix to “ultralow” levels without having a significant impact on the mechanical properties.

First claim

What is claimed is:

1. A molded part that is formed by casting a polymer composition into a mold cavity, wherein the polymer composition comprises a thermotropic liquid crystalline polymer and an aromatic amide oligomer, and wherein the polymer composition of the molded part has a melt viscosity of from about 0.1 to about 80 Pa-s, as determined at a shear rate of 1000 seconds −1 and temperature of 350° C. in accordance with ISO Test No. 11443.

2. The molded part of claim 1 , wherein the liquid crystalline polymer is wholly aromatic.

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

4. The molded part of claim 3 , 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.

5. The molded part of claim 1 , wherein the aromatic amide oligomer is employed in an amount of from about 0.1 to about 10 parts by weight relative to 100 parts by weight of the liquid crystalline polymer.

6. The molded part of claim 1 , wherein the aromatic amide oligomer has a molecular weight of 3,000 grams per mole or less.

7. The molded part of claim 1 , wherein the oligomer has from 2 to 8 amide bonds per molecule.

8. The molded part of claim 1 , wherein the aromatic amide oligomer has the following general formula (I):

wherein,
ring B is a 6-membered aromatic ring wherein 1 to 3 ring carbon atoms are optionally replaced by nitrogen or oxygen, wherein each nitrogen is optionally oxidized, and wherein ring B may be optionally fused or linked to a 5- or 6-membered aryl, heteroaryl, cycloalkyl, or heterocyclyl;
R 5 is halo, haloalkyl, alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, or heterocyclyl;
m is from 0 to 4;
X 1 and X 2 are independently C(O)HN or NHC(O); and
R 1 and R 2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocyclyl.

9. The molded part of claim 8 , wherein ring B is phenyl, R 1 is phenyl or cyclohexyl, and R 2 is phenyl or cyclohexyl.

10. The molded part of claim 1 , wherein the aromatic amide oligomer has the following general formula (IV):

wherein,
X 1 and X 2 are independently C(O)HN or NHC(O);
R 5 , R 7 , and R 8 are independently selected from halo, haloalkyl, alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, and heterocyclyl;
m is from 0 to 4; and
p and q are independently from 0 to 5.

11. The molded part of claim 1 , wherein the aromatic amide oligomer has the following general formula (V):

wherein,
X 1 and X 2 are independently C(O)HN or NHC(O);
R 5 , R 7 , and R 8 are independently selected from halo, haloalkyl, alkyl, alkenyl, aryl, heteroaryl, cycloalkyl, and heterocyclyl;
m is from 0 to 4; and
p and q are independently from 0 to 5.

12. The molded part of claim 1 , wherein the aromatic amide oligomer is selected from the group consisting of the following compounds:

Structure
Name

N1,N4-diphenylterephthalamide

N1,N4- diphenylisoterephthalamide

N1,N4-bis(2,3,4,5,6- pentafluorophenyl) terephthalamide

N1,N4-bis(4- benzamidophenyl) terephthalamide

N4-phenyl-N1-[4-[[4- (phenylcarbamoyl)benzoyl] amino]phenyl]terephthalamide

N4-phenyl-N1-[3-[[4- (phenylcarbamoyl)benzoyl] amino]phenyl]terephthalamide

N1,N3-bis(4-benzamidophenyl) benzene-1,3-dicarboxamide

N3-phenyl-N1-[3-[[3- (phenylcarbamoyl)benzoyl] amino]phenyl]benzene- 1,3-dicarboxamide

N1,N3-bis(3-benzamidophenyl) benzene-1,3-dicarboxamide

N1,N4-bis(4-pyridyl) terephthalamide

N1,N3-bis(4-phenylphenyl

Assignees

• Nair Kamlesh P
• Gray Steven D
• Grenci Joseph J
• Ticona Llc

Inventors

• Nair Kamlesh P
• Gray Steven D
• Grenci Joseph J

Classifications

• C08L77/12

  Polyester-amides · CPC title

• C09K19/22 Primary

  linked by a chain containing carbon and nitrogen atoms as chain links, e.g. Schiff bases · CPC title

• C08K5/34922

  Melamine; Derivatives thereof · CPC title

• C09K19/3444

  the heterocyclic ring being a six-membered aromatic ring containing one nitrogen atom, e.g. pyridine · CPC title

• C09K19/48

  containing Schiff bases · CPC title