Poly(amide-imide) copolymer, method of manufacturing the same, poly(amide-imide) copolymer film, window for display device, and display device

A method of manufacturing a poly(amide-imide) copolymer, comprising:

• preparing a poly(amide-amic acid) copolymer comprising an amide structural unit and an amic acid structural unit included in a polymer main chain,
• reacting the poly(amide-amic acid) copolymer with a diisocyanate to prepare a poly(amide-imide) copolymer precursor comprising a moiety cross-linked to an adjacent polymer main chain through an amide bond, and
• imidizing the poly(amide-imide) copolymer precursor to obtain the poly(amide-imide) copolymer,
• wherein the amic acid structural unit comprises a structural unit represented by Chemical Formula 5,
• wherein the amide structural unit comprises a structural unit represented by Chemical Formula 4, and
• wherein the diisocyanate is represented by Chemical Formula 6:
• wherein, in Chemical Formula 5,
• X is the same or different in each structural unit and is independently a substituted or unsubstituted C6 to C20 monocyclic aromatic group, a substituted or unsubstituted C4 to C20 monocyclic non-aromatic group, a substituted or unsubstituted C8 to C20 condensed polycyclic aromatic group, a substituted or unsubstituted C6 to C20 condensed polycyclic non-aromatic group, a substituted or unsubstituted C6 to C20 non-condensed polycyclic aromatic group, a substituted or unsubstituted C6 to C20 non-condensed polycyclic non-aromatic group, or a combination thereof, wherein each of the substituted or unsubstituted C6 to C20 non-condensed polycyclic aromatic group and the substituted or unsubstituted C6 to C20 non-condensed polycyclic non-aromatic group are linked by a single bond or a linking group comprising a substituted or unsubstituted fluorenyl group, O, S, C(═O), OC(═O), S(═O), S(═O)2, C(═O)NH, CRa(OH), SiRbRc, or (CRdRe)p (1≤p≤10), wherein Ra to Re are independently hydrogen, a C1 to C30 alkyl group, a C1 to C30 haloalkyl group, a halogen, or a hydroxy group,
• R11 is the same or different in each structural unit and is independently a divalent organic group comprising a substituted or unsubstituted C6 to C30 aromatic or non-aromatic ring, wherein the aromatic or non-aromatic ring is present as a single ring, two or more aromatic rings are condensed to provide a condensed polycyclic aromatic group, or two or more non-aromatic rings are condensed to provide a condensed polycyclic non-aromatic group;
• or
• two or more aromatic rings, or two or more aromatic and non-aromatic rings, are linked by a single bond or a linking group comprising a substituted or unsubstituted fluorenyl group, O, S, C(═O), OC(═O), S(═O), S(═O)2, C(═O)NH, CRf(OH), SiRgRh, or (CRiRj)p, (1≤p≤10) to provide a non-condensed polycyclic aromatic group, wherein Rf to Rj are independently hydrogen, a C1 to C30 alkyl group, a C1 to C30 haloalkyl group, a halogen, or a hydroxy group;
• wherein, in Chemical Formula 4,
• L is the same or different in each structural unit and is independently a single bond, —CONH—, -Ph-CONH-Ph-, or —NHCO-Ph-CONH—, wherein “Ph” is a substituted or unsubstituted phenylene group,
• R2 is the same or different in each structural unit and is independently a divalent organic group comprising a substituted or unsubstituted C6 to C30 aromatic or non-aromatic ring, wherein the aromatic or non-aromatic ring is present:
• as a single ring;
• as two or more aromatic or non-aromatic rings that are condensed to provide a condensed polycyclic aromatic or condensed polycyclic non-aromatic group, respectively;
• or
• as two or more aromatic, or non-aromatic rings, that are linked by a single bond or a linking group comprising a substituted or unsubstituted fluorenyl group, O, S, C(═O), OC(═O), S(═O), S(═O)2, C(═O)NH, CRk(OH), SiRlRm, or (CRnRo)p, (1≤p≤10) to provide a non-condensed polycyclic aromatic or non-condensed polycyclic non-aromatic group, respectively, wherein Rk to Ro are independently hydrogen, a C1 to C30 alkyl group, a C1 to C30 haloalkyl group, a halogen, or a hydroxy group,
• R6 to R9 are the same or different in each structural unit and are independently a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 haloalkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heterocyclic group, a substituted or unsubstituted silyl group, a halogen, a cyano group, a hydroxy group, a nitro group, or a combination thereof,
• n3 and n4 is the same or different in each structural unit and is independently an integer ranging from 0 to 4,
• n5 and n6 are the same or different in each structural unit and are independently an integer ranging from 0 to 3,
• n3+n5 is the same or different in each structural unit and is independently an integer ranging from 0 to 4,
• n4+n6 is the same or different in each structural unit and is independently an integer ranging from 0 to 4, and
• is a linking point of the polymer main chain;
• Chemical Formula 6
• OCN—Y—NCO
• wherein, in Chemical Formula 6,
• Y is the same or different in each structural unit and is independently a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C3 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C3 to C20 heteroarylene group, or a combination thereof.