| 摘要 |
Disclosed is a method of preparing a polypropylene resin for a secondary battery separating membrane in which all the chemical resistance, a mechanical property, and a thermal property are improved compared to a conventional polypropylene resin as a raw material of a secondary battery separating membrane. The present invention provides a method of preparing a polypropylene resin for a secondary battery separating membrane, the method including the following steps: making a magnesium compound react with alkanediol, substituted or unsubstituted with an alkyl group of 1 to 5 carbon atoms, of 3 to 15 carbon atoms and a benzoyl halide compound to prepare a magnesium compound solution; making the magnesium compound solution react with a first transition metal compound represented by Chemical formula 1, MX_n(OR1)_4-n, to prepare a carrier; performing a synthesis reaction of a propylene monomer in the presence of a solid catalyst prepared by making the carrier react with a second transition metal compound represented by Chemical formula 1 to prepare a polypropylene resin for a secondary battery separating membrane, wherein an internal electron donor and an external electron donor are added when the solid catalyst is prepared in order to obtain a polypropylene resin with 97% or more of stereoregularity, 55% or more of crystallinity, 167°C or higher of a melting temperature, and 1,700MPa or higher of a flexural modulus. In Chemical formula 1, M is selected from the group comprising transition metal elements of Group IVB, VB, and VIB in Periodic Table; X is halogen; R1 is an alkyl group of 1 to 10 carbon atoms; and n is 0 to 4. |
