Liquid crystal polyester resin composition

• US 6,733,691 B2
• Filed: 03/26/2002
• Issued: 05/11/2004
• Est. Priority Date: 03/28/2001
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Nagano, Satoshi, Yamauchi, Hiroyasu
• Primary Examiner(s): Huff, Mark F.
• Assistant Examiner(s): Sadola, Jennifer R
• Application Number:
  US10/105,350
• Publication Number:
  US 20030001139A1
• Time in Patent Office: 777 Days
• Field of Search: 428/1.1, 252/299.01, 252/299.6, 252/299.62, 252/299.64, 252/299.67
• US Class Current: 252/299.67
• CPC Class Codes: C08K 3/01 characterized by their specific function
• CPC Class Codes: C08K 7/00 Use of ingredients characterised by shape
• 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: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence

Abstract

A liquid crystal polyester resin composition having an apparent melt viscosity of 10 to 100 Pa ·sec at a shearing rate of 1000 sec⁻¹ and at a flow temperature +40° C., obtained by compounding 10 to 100 parts by weight of an inorganic filler in the form of fiber and 10 to 100 parts by weight of an inorganic filler in the form of plate based on 100 parts by weight of a liquid crystal polyester resin, wherein the liquid crystal polyester resin contains at least 30% mol of a repeating structural unit of the following formula A₁ and has a flow temperature of 270° C. to 400° C., the inorganic filler in the form of fiber has an average fiber diameter of 0.1 to 10 μm and a number-average fiber length of 1 to 100 μm, the inorganic filler in the form of plate has an average particle size of 5 to 20 μm, and the ratio (F/P) of the compounding amount (F) of the inorganic filler in the form of fiber to the compounding amount (P) of the inorganic filler in the form of plate satisfies the following equation;

0<F/P<0.5 or 1.6<F/P<10.

Claims

1. A liquid crystal polyester resin composition having an apparent melt viscosity of 10 to 100 Pa sec at a shearing rate of 1000 sec⁻

1 and at a flow temperature 40°

C., obtained by compounding 10 to 100 parts by weight of an inorganic filler in the form of fiber and 10 to 100 parts by weight of an inorganic filler in the form of plate based on 100 parts by weight of a liquid crystal polyester resin, wherein the liquid crystal polyester resin contains at least 30% mol of a repeating structural unit of the following formula A₁ and has a flow temperature of 270°

C. to 400°

C., the inorganic filler in the form of fiber has an average fiber diameter of 0.1 to 10 μ

m and a number-average fiber length of 1 to 100 μ

m, the inorganic filler in the form of plate has an average particle size of 5 to 20 μ

m, and the ratio (F/P) of the compounding amount (F) of the inorganic filler in the form of fiber to the compounding amount (P) of the inorganic filler in the form of plate satisfies the following equation;

2. The liquid crystal polyester resin composition according to claim 1, wherein said liquid crystal polyester resin comprises 100 parts by weight of a liquid crystal polyester resin (A) and 10 to 150 parts by weight of a liquid crystal polyester resin (B), the liquid crystal polyester resin (A) has a flow temperature of 310°

C. to 400°

C., the liquid crystal polyester resin (B) has a flow temperature of 270°

C. to 370°

C., and the flow temperature of the liquid crystal polyester resin (A) is higher than the flow temperature of the liquid crystal polyester resin (B) and the difference thereof is 10 to 60°

C.

3. The liquid crystal polyester resin composition according to claim 2, wherein said liquid crystal polyester resins (A) and (B) each comprises the following structural units (I), (II), (III) and (IV), the molar ratio (II)/(I) is 0.2 or more and 1.0 or less, the molar ratio [(III)+(IV)]/(II) is 0.9 or more and 1.1 or less and the molar ratio (IV)/(III) is over 0 and 1 or less, and a ratio of the molar ratio (α

) of (IV)/(III) in the liquid crystal polyester resin (A) to the molar ratio (β

) of (IV)/(III) in the liquid crystal polyester resin (B) is 0.1 or more and 0.5 or less.

4. The liquid crystal polyester resin composition according to any of claims 1, wherein as the inorganic filler in the form of fiber, at least one selected from glass fiber, wollastonite, aluminum borate whisker and potassium titanate whisker is used.

5. The liquid crystal polyester resin composition according to any of claims 1, wherein as the inorganic filler in the form of plate, at least one selected from mica and talc is used.

6. A molded article having a minimum thickness of 0.2 mm or less, obtained by molding the liquid crystal polyester resin composition according to claim 1.

7. A connector having a minimum thickness of 0.2 mm or less, obtained by molding the liquid crystal polyester resin composition according to claim 1.