Method for joining liquid-crystalline polyester resin composition parts and jointed article made of liquid-crystalline polyester resin composition

1. A method for joining liquid-crystalline polyester resin composition parts, characterized in that the melting point of the liquid crystalline polyester resin measured by differential scanning calorimeter is 190-250° C., the resin consisting essentially of the repeating units represented by the following formulae (I), (II), (III) and (IV):

wherein:

Ar 1 and Ar 2 each represents at least one bivalent aromatic group; and

p, q, r and s represent relative molar proportions (mol %) of the repeating units in the liquid-crystalline polyester resin and satisfy the following formulae:

0.4≦p/g≦2.0

2 mol %≦r≦15 mol %

2 mol %≦s≦15 mol %,

and that the parts are jointed by means of welding.

2. The method according to claim 1 , wherein said liquid-crystalline polyester resin consists of the following repeating units:

wherein:

the value below the repeating unit represents mol % of each unit in the liquid-crystalline polyester resin.

3. The method according to claim 1 , wherein said welding is selected from the group consisting of ultrasonic welding, vibration welding, high-frequency welding, electromagnetic induction welding, impulse welding and spin welding.

4. The method according to claim 1 , wherein said welding is ultrasonic welding, vibration welding or spin welding and said liquid-crystalline polyester resin composition parts are welded to form a joint selected from scarf joint and shear joint.

5. The method according to claim 1 , wherein the liquid-crystalline polyester resin composition comprises a filler and/or reinforcement in an amount of 0-100 parts by weight per 100 parts by weight of the liquid-crystalline polyester resin.

6. The method according to claim 5 , wherein the filler and/or reinforcement is at least one selected from the group consisting of glass fiber, silica-alumina fiber, alumina fiber, carbon fiber, aramid fiber, talc, mica, graphite, wollastonite, calcium carbonate, dolomite, clay, glass flake, glass beads, barium sulfate and titanium oxide.

7. The method according to claim 6 , wherein said filler and/or reinforcement is glass fiber.

8. A jointed article made of liquid-crystalline polyester resin composition, which is obtained by joining liquid-crystalline polyester resin composition parts by means of welding, wherein the resin consists essentially of the repeating units represented by the following formulae (I), (II), (III) and (IV):

wherein:

Ar 1 and Ar 2 each represents at least one bivalent aromatic group; and

p, q, r and s represent relative molar proportions (mol %) of the repeating units in the liquid-crystalline polyester resin and satisfy the following formulae:

0.4≦p/q≦2.0

2 mol %≦r≦15 mol %

2 mol %≦s≦5mol %,

and the melting point of the resin measured by differential scanning calorimeter is 190-250° C.

9. The jointed article according to claim 8 , wherein said jointed article is made of parts which are selected from the group consisting of molded article, film, sheet and bonded textile.

10. The jointed article according to claim 8 , wherein said liquid-crystalline polyester resin consists of the following repeating units:

wherein:

the value below the repeating unit represents mol % of each unit in the liquid-crystalline polyester resin.

11. The jointed article according to claim 8 , wherein said welding is selected from the group consisting of ultrasonic welding, vibration welding, high-frequency welding, electromagnetic induction welding, impulse welding and spin welding.

12. The jointed article according to claim 8 , wherein said welding is ultrasonic welding, vibration welding or spin welding and said liquid-crystalline polyester resin composition parts are welded to form a joint selected from scarf joint and shear joint.

13. The jointed article according to claim 8 , wherein the liquid-crystalline polyester resin composition comprises a filler and/or reinforcement in an amount of 0-100 parts by weight per 100 parts by weight of the liquid-crystalline polyester resin.

14. The jointed article according to claim 13 , wherein the filler and/or reinforcement is at least one selected from the group consisting of glass fiber, silica-alumina fiber, alumina fiber, carbon fiber, aramid fiber, talc, mica, graphite, wollastonite, calcium carbonate, dolomite, clay, glass flake, glass beads, barium sulfate and titanium oxide.

15. The method according to claim 14 , wherein said filler and/or reinforcement is glass fiber.

16. A method for manufacturing a jointed article, which comprises:

providing parts made of liquid crystalline polyester resin composition comprising liquid crystalline polyester resin which consists essentially of the repeating units represented by the following formulae (I), (II), (III) and (IV):

wherein:

Ar 1 and Ar 2 each represents at least one bivalent aromatic group; and

p, q, r and s represent relative molar proportions (mol %) of the repeating units in the liquid-crystalline polyester resin and satisfy the following formulae:

0.4≦p/q≦2 0

2 mol %≦r≦15 mol %

2 mol %≦s≦15 mol %, and has a melting point measured by differential scanning calorimeter of 190-250° C.; and

joining said parts by means of welding.

17. The method according to claim 16 , wherein said liquid-crystalline polyester resin consists of the following repeating units:

wherein:

the value below the repeating unit represents mol % of each unit in the liquid-crystalline polyester resin.

18. The method according to claim 16 , wherein said welding is selected from the group consisting of ultrasonic welding, vibration welding, high-frequency welding, electromagnetic induction welding, impulse welding and spin welding.

19. The method according to claim 16 , wherein said welding is ultrasonic welding, vibration welding or spin welding and said liquid-crystalline polyester resin composition parts are welded to form a joint selected from scarf joint and shear joint.

20. The method according to claim 16 , wherein the liquid-crystalline polyester resin composition comprises a filler and/or reinforcement in an amount of 0-100 parts by weight per 100 parts by weight of the liquid-crystalline polyester resin.

21. The method according to claim 20 , wherein the filler and/or reinforcement is at least one selected from the group consisting of glass fiber, silica-alumina fiber, alumina fiber, carbon fiber, aramid fiber, talc, mica, graphite, wollastonite, calcium carbonate, dolomite, clay, glass flake, glass beads, barium sulfate and titanium oxide.

22. The method according to claim 21 , wherein said filler and/or reinforcement is glass fiber.