Wholly aromatic liquid-crystalline polyester and method for preparing the same
AssigneeKabushiki Kaisha Ueno Seiyaku Oyo Kenkyujo
InventorsMotoki Asahara, Tetsuhide Sawada, Hiroyuki Kato
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Abstract
Provided is a liquid-crystalline polyester with good properties obtainable by subjecting a prepolymer consisting of the repeating units represented by formulae to heat treatment in a substantially solid state.
Claims10
A 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 obtainable by subjecting a prepolymer consisting of the repeating units of formulae (I), (II), (III) and (IV):
- 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 substantially solid state.
A liquid-crystalline polyester composition comprising 100 parts by weight of the liquid-crystalline polyester according to claim 1 and 0.1-200 parts by weight of a fibrous, lamellar or particulate filler and/or reinforcement.
A method for preparing liquid-crystalline polyester which comprises the steps of:
- polycondensing monomers which provide the repeating units of formulae (I), (II), (III) and (IV) respectively to give pellets of prepolymer consisting of the repeating units of formulae (I), (II), (III) and (IV):
- wherein, p, q, r and s represent relative molar proportions (mol %) of the repeating units in the resin and satisfy the following formulae:
- 60≦p+q≦78
- 0.05≦q≦3
- 11≦r≦20 and
- 11≦s≦20;
- and
- subjecting the pellets of prepolymer to heat treatment at 250-335° C. in a substantially solid state.
Dependencies are inferred from the claim text.