Wholly aromatic liquid crystalline polyester resin, molded article, and electric and electronic components

1. A wholly aromatic liquid crystalline polyester resin comprising,

a polymer prepared by polymerization of monomers giving the following structural units (I), (II), (III), and (IV):

structural unit (I) derived from p-hydroxybenzoic acid,

structural unit (II) derived from 6-hydroxy-2-naphthoic acid,

structural unit (III) derived from an aromatic diol compound,

structural unit (IV) derived from an aromatic dicarboxylic acid, wherein

the composition ratio (mol %) of said structural units (I) to (IV) satisfies the following conditions:

2 mol %≤structural unit (I)≤9 mol %

40 mol %≤structural unit (II)≤75 mol %

9 mol %≤structural unit (III)≤24 mol %

9 mol %≤structural unit (IV)≤24 mol %.

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

the composition ratio (mol %) of said structural units (I) to (IV) satisfies the following conditions:

2 mol %≤structural unit (I)≤9 mol %

48 mol %≤structural unit (II)≤70 mol %

10 mol %≤structural unit (III)≤23 mol %

10 mol %≤structural unit (IV)≤23 mol %.

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

said structural unit (III) is represented by the following formula:

wherein Ar 1 is selected from the group consisting of a phenyl group, a biphenyl group, a naphtyl group, an anthryl group, and a phenanthryl group, optionally having a substituent group.

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

said structural unit (IV) is represented by the following formula:

wherein Ar 2 is selected from the group consisting of a phenyl group, a biphenyl group, a naphtyl group, an anthryl group, and a phenanthryl group, optionally having a substituent group.

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

a draw ratio of a melt strand extruded under the conditions in which a temperature is +20° C. a melting point and a shear rate is 1000 s −1 is 10 times or more.

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

a dielectric tangent in measurement frequency of 10 GHz is 0.85×10 −3 or less.

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

a dielectric tangent in measurement frequency of 82 GHz is less than 3.5×10 −3 .

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

dielectric tangents at 30° C. and 100° C. in measurement frequency of 34 GHz are less than 2.0×10 −3 and less than 4.0×10 −3 respectively.

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

a change rate of a dielectric tangent from 30° C. to 100° C. in measurement frequency of 34 GHz is less than 3.0×10 −5 /° C.

10. The wholly aromatic liquid crystalline polyester resin according to claim 1 , having a melting point of 290° C. or more.

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

a melt viscosity at a shear rate of 1000 s −1 is from 20 to 150 Pa·s.

12. A molded article comprising the wholly aromatic liquid crystalline polyester resin according to claim 1 .

13. The molded article according to claim 12 which is in the form of a film.

14. The molded article according to claim 12 which is in the form of a fiber.

15. The molded article according to claim 12 which is an injection molded article.

16. Electric and electronic components comprising the molded article according to claim 12 .