Liquid crystalline polyester composition, method of producing the same and molded product manufactured from the same

• US 8,784,683 B2
• Filed: 12/14/2011
• Issued: 07/22/2014
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Matsubara, Satoshi, Umetsu, Hideyuki, Hase, Takayuki
• Primary Examiner(s): Visconti, Geraldina
• Application Number:
  US13/637,738
• Publication Number:
  US 20130015400A1
• Time in Patent Office: 951 Days
• Field of Search: 252/299.01, 252/299.5, 428/1.1, 349/183, 264/328.14, 264/328.16, 525/418, 524/495
• US Class Current: 252/299.01
• 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 3/201 Pre-melted polymers
• CPC Class Codes: C08J 5/043 with glass fibres
• CPC Class Codes: C08K 7/14 Glass
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• 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 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition

Abstract

A liquid crystalline polyester composition contains at least 100 parts by weight of liquid crystalline polyester having different structural units and 10 to 100 parts by weight of glass fiber, wherein the glass fiber has a weight-average fiber length (Mw) of 200 to 500 μm, and content of specific glass fiber having fiber length of not less than 1500 μm is 0.1 to 5.0 percent by weight to a total amount of the glass fiber.

Claims

1. A liquid crystalline polyester composition, at least containing 100 parts by weight of liquid crystalline polyester having structural units (I), (II), (III), (IV) and (V) shown below and 10 to 100 parts by weight of glass fiber, wherein

the glass fiber has a weight-average fiber length (Mw) of 200 to 500 μ

m and includes specific glass fiber having fiber length of not less than 1500 μ

m, and

content of the specific glass fiber is 0.1 to 5.0 percent by weight to a total amount of the glass fiber

2. The liquid crystalline polyester composition according to claim 1, wherein

the glass fiber has a ratio (D90/D10) of 90%-cumulative-frequency fiber length (D90) to 10%-cumulative-frequency fiber length (D10) in the cumulative weight fiber length distribution curve of not greater than 5.0.

3. The liquid crystalline polyester composition according to claim 1, wherein the glass fiber contained in the liquid crystalline polyester composition has a mode (S) of fiber length in a fiber length frequency distribution that is not less than 0.25 times but less than 0.90 times as much as the weight-average fiber length (Mw).

4. The liquid crystalline polyester composition according to claim 1, wherein

content of the structural unit (I) is 65 to 80 mole percent relative to a total amount of the structural units (I), (II) and (III),

content of the structural unit (II) is 55 to 85 mole percent relative to a total amount of the structural units (II) and (III), and

content of the structural unit (IV) is 50 to 95 mole percent relative to a total amount of the structural units (IV) and (V).

5. A method of producing the liquid crystalline polyester composition according to claim 1 comprising:

melt-kneading at least liquid crystalline polyester having structural units (I), (II), (III), (IV) and (V) shown below and the glass fiber by an extruder having a plurality of supply ports;

supplying the liquid crystalline polyester from a first supply port located on an extruder drive system side;

supplying the glass fiber from a second supply port located downstream of the first supply port; and

controlling melt viscosity of the liquid crystalline polyester at a shear rate of 100 s<sup>−

1</sup> in a glass fiber supply section to 100 to 5000 Pa·

s

6. A molded product manufactured by injection molding the liquid crystalline polyester composition according to claim 1.

7. A connector comprising the molded product according to claim 6.

8. The liquid crystalline polyester composition according to claim 2, wherein the glass fiber contained in the liquid crystalline polyester composition has a mode (S) of fiber length in a fiber length frequency distribution that is not less than 0.25 times but less than 0.90 times as much as the weight-average fiber length (Mw).

9. The liquid crystalline polyester composition according to claim 2, wherein

content of the structural unit (I) is 65 to 80 mole percent relative to a total amount of the structural units (I), (II) and (III),

content of the structural unit (II) is 55 to 85 mole percent relative to a total amount of the structural units (II) and (III), and

content of the structural unit (IV) is 50 to 95 mole percent relative to a total amount of the structural units (IV) and (V).

10. A method of producing the liquid crystalline polyester composition according to claim 2 comprising:

melt-kneading at least liquid crystalline polyester having structural units (I), (II), (III), (IV) and (V) shown below and glass fiber by an extruder having a plurality of supply ports;

supplying the liquid crystalline polyester from a first supply port located on an extruder drive system side;

supplying the glass fiber from a second supply port located downstream of the first supply port; and

controlling melt viscosity of the liquid crystalline polyester at a shear rate of 100 s<sup>−

1</sup> in a glass fiber supply section to 100 to 5000 Pa·

s

11. A molded product manufactured by injection molding the liquid crystalline polyester composition according to claim 2.

12. A connector comprising the molded product according to claim 11.