US 7,393,467 B2
Wholly aromatic liquid-crystalline polyester and method for preparing the same
Motoki Asahara, Sanda (Japan); Tetsuhide Sawada, Nishinomiya (Japan); and Hiroyuki Kato, Kawanishi (Japan)
Assigned to Kabushiki Kaisha Ueno Seiyaku Oyo Kenkyujo, Osaka-fu (Japan)
Filed on Jan. 30, 2006, as Appl. No. 11/341,625.
Claims priority of application No. 2005-023415 (JP), filed on Jan. 31, 2005.
Prior Publication US 2006/0186375 A1, Aug. 24, 2006
Int. Cl. C09K 19/52 (2006.01); C09K 19/32 (2006.01); C09K 19/20 (2006.01); C09K 19/38 (2006.01); C08G 63/00 (2006.01)
U.S. Cl. 252—299.01  [252/299.62; 252/299.67; 528/190; 528/193; 528/194] 10 Claims
 
1. A liquid-crystalline polyester, which has a deflection temperature under load (DTUL) of 290-340° C.; the difference between the DTUL and the crystalline melting temperature of the liquid-crystalline polyester determined by differential scanning calorimetry is equal to or less than 40° C.; and which is obtained by subjecting a prepolymer consisting of the repeating units of formulae (I), (II), (III) and (IV):

OG Complex Work Unit Drawing
wherein, p, q, r and s represent relative molar proportions (mol %) of the repeating units in the prepolymer and satisfy the following formulae:
60≤p+q≤78
0.05≤q≤3
11≤r≤20 and
11≤s≤20
to heat treatment in a solid state.