Aromatic liquid crystalline polyester resin and resin composition thereof

An aromatic liquid crystalline polyester resin obtained by charging 30 to 80 mol % of a compound represented by the following formula (I), 10 to 35 mol % of a compound represented by the following formula (II) and 10 to 35 mol % of a compound represented by the following formula (III) and into a reaction vessel, polycondensing the charged mixture at a temperature from 270 to 350° C. to produce an aromatic liquid crystalline polyester resin having a flow temperature of 210° C. or more and lower than the polycondensation reaction temperature by 30° C. or more, discharging the aromatic liquid crystalline polyester resin in a molten state from the reaction vessel and solidifying the resin, then, pulverizing the solidified resin into particles having a particle size of 3 mm or less and treating the particles at a temperature from 200 to 310° C. still in the solid state under inert gas atmosphere for 1 to 24 hours, and granulating the particles under heat-melted condition into pellets:

• in the formula, R1 represents a hydrogen atom, formyl group, acetyl group, propionyl group or benzoyl group, and R2 represents a hydrogen atom, methyl group, ethyl group, propyl group, benzyl group or phenyl group,
• R3O—Ar—OR3 (II)
• in the formula, Ar represents a divalent aromatic group, and R3 represents a hydrogen atom, acetyl group, propionyl group or benzoyl group,
• in the formula, Ar′ represents two or more selected from
• and the content of
• based on the total of Ar′ is 40-95 mole %,
• and R4represents a hydrogen atom, methyl group, ethyl group, propyl group, benzyl group or phenyl group.

A method for producing an aromatic liquid crystalline polyester resin comprising the steps of charging 30 to 80 mol % of a compound represented by the following formula (I), 10 to 35 mol % of a compound represented by the following formula (II) and 10 to 35 mol % of a compound represented by the following formula (III) and into a reaction vessel, polycondensing the charged mixture at a temperature from 270 to 350° C. to produce an aromatic liquid crystalline polyester resin having a flow temperature of 210° C. or more and lower than the polycondensation reaction temperature by 30° C. or more, discharging the aromatic liquid crystalline polyester resin in a molten state from the reaction vessel and solidifying the resin, then, pulverizing the solidified resin into particles having a particle size of 3 mm or less and treating the powder at a temperature from 200 to 310° C. still in the solid state under inert gas atmosphere for 1 to 24 hours, and granulating the product under heat-melted condition into pellets:

• in the formula, R1 represents a hydrogen atom, formyl group, acetyl group, propionyl group or benzoyl group, and R2 represents a hydrogen atom, methyl group, ethyl group, propyl group, benzyl group or phenyl group,
• R3O—Ar—OR3 (II)
• in the formula, Ar represents a divalent aromatic group, and R3 represents a hydrogen atom, acetyl group, propionyl group or benzoyl group,
• in the formula, Ar′ represents two or more selected from
• and the content of
• based on the total of Ar′ is 40-95 mole %, and R4 represents a hydrogen atom, methyl group, ethyl group, propyl group, benzyl group or phenyl group.

A method for producing an aromatic liquid crystalline polyester resin film, comprising inflation-molding an aromatic liquid crystalline polyester resin comprising 30 to 80 mol % of the following repeating unit (A), 10 to 35 mol % of the following repeating unit (B) and 10 to 35 mol % of the following repeating unit (C):

• in the formula, Ar represents a divalent aromatic group,
• in the formula, Ar′ represents two or more selected from
• and the content of
• based on the total of Ar′ is 40-95% mole %, and having a logarithmic viscosity of 1.5 dl/g or more, a flow temperature of 300° C. or less, and a melt tension measured at a temperature higher than the flow temperature by 25° C. or more of 1.0 or more, and the flow temperature means a temperature (° C.) at which the melt viscosity measured by a capillary type rheometer is 48,000 poise when a resin which has been melted by heating at a temperature raising rate of 4° C./min is extruded through a nozzle having an internal diameter of 1 mm and a length of 10 mm under a load of 100 kgf/cm2, at a blow ratio (TD drawing magnification) of 1.5 to 15 and a draw ratio (MD drawing magnification) of 1.5 to 40.