Flame retardant polybutyleneterephthalate resin

A flame retardant polybutyleneterephthalate resin prepared by:

• (a) performing a transesterification reaction of a dicarboxylic acid or its ester derivative and a 1,4-butanediol to yield an oligomer;
• (b) reacting the oligomer with 0.5 to 30 parts by weight of a phosphorus-based flame retardant represented by the following formula I with respect to 100 parts by weight of the dicarboxylic acid or its ester derivative and
• (c) adding a deposited particle-forming material or an inorganic particle material and performing a polycondensation reaction in the presence of a polycondensation catalyst to prepare a polybutyleneterephthalate:
• wherein R1 and R2 are different or the same and are methyl or butyl including a hydroxyl group.

A flame retardant polybutyleneterephthalate resin composition comprisinig 50 to 90 wt. % of a polybutyleneterephthalate resin and 10 to 50 wt. % of a reinforcing material.

• the polybutyleneterephthalate resin being prepared by:
• (a) performing a transesterification reaction of a dicarboxylic acid or its ester derivative and a 1,4-butanediol to yield an oligomer;
• (b) reacting the oligomer with 0.5 to 30 parts by weight of a phosphorus-based flame retardant represented by the following formula I with respect to 100 parts by weight of the dicarboxylic acid or its ester derivative;
• and
• (c) performing a polycondensation reaction in the presence of a polycondensation catalyst to prepare a polybutyleneterephthalate,
• wherein the polybutyleneterephthalate resin has an Izod impact strength of more than 3 kg·cm/cm, a tensile strength of more than 400 kg/cm2 and a tensile elongation of more than 10%:
• wherein R1 and R2 are different or the same and are methyl or butyl including a hydroxyl group.