Wholly aromatic liquid crystalline polyester and method of producing the same

• US 8,440,780 B2
• Filed: 09/14/2012
• Issued: 05/14/2013
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Hamaguchi, Mitsushige, Miyamoto, Kohei, Umetsu, Hideyuki
• Primary Examiner(s): Boykin, Terressa
• Application Number:
  US13/617,677
• Publication Number:
  US 20130012680A1
• Time in Patent Office: 242 Days
• Field of Search: 528/190, 528/191, 528/192, 528/193, 528/271, 528/272
• US Class Current: 528/191
• CPC Class Codes: C08G 63/605 the hydroxy and carboxylic groups being bound to aromatic rings
• CPC Class Codes: C08G 63/78 Preparation processes
• CPC Class Codes: C09K 19/3809 Polyesters; Polyester derivatives, e.g. polyamides

Abstract

A wholly aromatic liquid crystalline polyester contains 2.0 to 15.0 mole percent of a hydroquinone-derived structural unit relative to a total amount of structural units. The wholly aromatic liquid crystalline polyester has sum of an amount (a) of terminal hydroxyl group and an amount (b) of terminal acetyl group in a range of 50 to 350 equivalents/(g·10⁻⁶), and has a ratio [(a)+(b)]/(c) of the sum of the amount (a) of terminal hydroxyl group and the amount (b) of terminal acetyl group to an amount (c) of terminal carboxyl group in a range of 1.05 to 2.00.

Claims

1. A wholly aromatic liquid crystalline polyester comprising 2.0 to 15.0 mole percent of a hydroquinone-derived structural unit relative to a total amount of structural units,

the wholly aromatic liquid crystalline polyester having a sum of an amount (a) of terminal hydroxyl group and an amount (b) of terminal acetyl group of 50 to 350 equivalents/(g·

10<sup>−

6</sup>), and having a ratio [(a)+(b)]/(c) of the sum of the amount (a) of terminal hydroxyl group and the amount (b) of terminal acetyl group to an amount (c) of terminal carboxyl group of 1.05 to 2.00.

2. The wholly aromatic liquid crystalline polyester according to claim 1, wherein the wholly aromatic liquid crystalline polyester has a ratio (a)/[(a)+(b)] of the amount (a) of terminal hydroxyl group to the sum of the amount (a) of terminal hydroxyl group and the amount (b) of terminal acetyl group of 0.30 to 1.00.

3. The wholly aromatic liquid crystalline polyester according to claim 1, wherein the wholly aromatic liquid crystalline polyester has an absolute number-average molecular weight of 5000 to 25000 measured by gel permeation chromatography/light scattering method.

4. The wholly aromatic liquid crystalline polyester according to claim 2, wherein the wholly aromatic liquid crystalline polyester has an absolute number-average molecular weight of 5000 to 25000 measured by gel permeation chromatography/light scattering method.

5. The wholly aromatic liquid crystalline polyester according to claim 1, wherein

the wholly aromatic liquid crystalline polyester comprises structural units (I), (II), (III), (IV) and (V) shown below,

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

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

the total amount of the structural units (II) and (III) is substantially equimolar with the total amount of the structural units (IV) and (V)

6. The wholly aromatic liquid crystalline polyester according to claim 2, wherein

the wholly aromatic liquid crystalline polyester comprises structural units (I), (II), (III), (IV) and (V) shown below, wherein

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

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

the total amount of the structural units (II) and (III) is substantially equimolar with the total amount of the structural units (IV) and (V)

7. A method of producing the wholly aromatic liquid crystalline polyester according to claim 1, comprising:

acetylating a hydroxyl group of a material monomer of the wholly aromatic liquid crystalline polyester with acetic anhydride and subsequently heating a polymerization reaction solution to or above a melting temperature of the wholly aromatic liquid crystalline polyester with removal of acetic acid to enable deacetylation polymerization, thereby producing the wholly aromatic liquid crystalline polyester, wherein

a removal rate obtained by Equation [1] given below is 50 to 80% when a temperature of the polymerization reaction solution reaches about 250°

C.;

removal rate(%)=amount of distillate (g)/[(number of moles of loaded acetic anhydride (mol)−

number of moles of hydroxyl group (mol) in the material monomer)×

molecular weight of acetic anhydride (g/mol)+(number of moles of hydroxyl group (mol) in the material monomer×

2×

molecular weight of acetic acid (g/mol))]×

100 

 

[1].

8. The method according to claim 2, wherein a removal rate obtained by Equation [1] given is 50 to 80% when the temperature of the polymerization reaction solution reaches about 250°

C.

9. A wholly aromatic liquid crystalline polyester resin composition produced by adding 10 to 200 parts by weight of filler relative to 100 parts by weight of the wholly aromatic liquid crystalline polyester according to claim 1.

10. A molded product manufactured by melt molding the wholly aromatic liquid crystalline polyester according to claim 1.

11. A molded product manufactured by melt molding the wholly aromatic liquid crystalline polyester resin composition according to claim 9.