Abstract:
A poly(imide-amide) copolymer including a structural unit represented by Chemical Formula 1; a structural unit represented by Chemical Formula 2; and any one of a structural unit represented by Chemical Formula 3, an amic acid precursor of the structural unit represented by Chemical Formula 3, and a combination thereof; wherein a cured material of the poly(imide-amide) copolymer may have a tensile modulus of greater than or equal to about 5.5 GPa, and a yellowness index of less than or equal to about 5: wherein, groups and variables in Chemical Formulae 1 and 3 are the same as described in the specification.
Abstract:
A method of producing a polyimide film, including obtaining a polyamic acid including a repeating unit of Chemical Formula 1: Chemical Formula 1 wherein Ar1 and Ar2 are described in the specification; imidizing the polyamic acid to obtain a partially imidized polyimide; determining a sub-Tg temperature of the partially imidized polyimide; and heating the partially imidized polyimide in at least two steps to obtain a polyimide film, wherein a step transition temperature range is within the sub-Tg temperature±30° C.
Abstract:
A composition for preparing poly(imide-benzoxazole) copolymer is described, where the copolymer include: a tetracarboxylic acid dianhydride represented by Chemical Formula 1, a diamine represented by Chemical Formula 2, and a diamine represented by Chemical Formula 3: wherein definitions of groups and variables in Chemical Formulae 1 to 3 are the same as described in the specification.
Abstract:
A polyimide precursor composition, including a polyamic acid including a repeating unit represented by Chemical Formula 1 and transparent metal oxide nanoparticles coordinated to a ligand represented by RCOOH, wherein R is a linear or branched C1-C4 alkyl or a linear or branched C2-C4 alkenyl: wherein variables Cy, A3, R31, and n34 in Chemical Formula I are described in the specification.
Abstract:
A method of preparing an optical film, preparing a coating composition including an amic acid-containing polymer represented by Chemical Formula 1 and at least one polymerization aid selected from an alkyl phosphite, an aryl phosphite, an alkyl phosphate, and an aryl phosphate; providing the coating composition on a substrate to form a coating layer; and applying heat to the coating layer to prepare a cured film: wherein, in Chemical Formula 1, are the same or different in each repeating unit, and are each independently at least one selected from an aromatic organic group, an aliphatic organic group, and an alicyclic organic group, and 0≦x≦1.
Abstract:
A slot die includes a material distribution chamber configured to distribute a casting solution supplied to the material distribution chamber, and a lip in which a slot including an expansion portion is defined and through which the casting solution distributed in the material distribution chamber is discharged, where a width of the expansion portion taken in a first direction is expanded from one side of the expansion portion to a lip end facing the one side and the one side of the expansion portion is apart from the lip end by a predetermined length taken along a second direction which is perpendicular to the first direction and substantially parallel to a flow direction of the casting solution.
Abstract:
A method of preparing an optical film, preparing a coating composition including an amic acid-containing polymer represented by Chemical Formula 1 and at least one polymerization aid selected from an alkyl phosphite, an aryl phosphite, an alkyl phosphate, and an aryl phosphate; providing the coating composition on a substrate to form a coating layer; and applying heat to the coating layer to prepare a cured film: wherein, in Chemical Formula 1, are the same or different in each repeating unit, and are each independently at least one selected from an aromatic organic group, an aliphatic organic group, and an alicyclic organic group, and 0≦x≦1.