Window for display device and display device including the window

1. A window for a display device comprising:

a plastic substrate and a hard coating layer disposed on at least one side of the plastic substrate,

wherein the plastic substrate has a yield strain of greater than or equal to about 0.8% at about 85 degrees Celsius and 85% relative humidity,

wherein the plastic substrate has a thickness of about 25 micrometers to 80 micrometers, and

wherein the plastic substrate comprises a poly(imide-amide) copolymer including a imide unit and an amide unit,

wherein the imide unit comprises a first repeating unit represented by the following Chemical Formula 1-1 and a second repeating unit represented by the following Chemical Formula 1-2:

wherein A 1-1 is represented by the following formula:

wherein L is a single bond, —O—, —S—, —C(═O)—, —SO 2 —, —Si(CH 3 ) 2 —, or —(CR′ 2 ) p — wherein 1≦p≦10, and R′ is hydrogen, a hydroxy group, a C1 to C3 alkyl group, or a C1 to C3 fluoroalkyl group),

A 1-2 is represented by the following formula:

and

A 2 is represented by the following formula:

wherein the amide unit comprises a moiety represented by Chemical Formula 2:

wherein in Chemical Formula 2,

A 3 is a moiety selected from a substituted or unsubstituted divalent C5 to C24 aliphatic cyclic group, a substituted or unsubstituted divalent C6 to C24 aromatic ring group, a substituted or unsubstituted divalent C4 to C24 hetero aromatic ring group, and -L-SiR 2 —O—SiR 2 -L- wherein L is a single bond or a C1 to C10 alkylene group, wherein the aliphatic or aromatic ring group is present alone; two or more rings are fused to each other to provide a polycyclic aromatic ring; or the two or more aliphatic rings or the two or more aromatic rings are linked through a single bond, —O—, —S—, —CO—, —CH(OH)—, —SO 2 —, —Si(CH 3 ) 2 —, —(CH 2 ) p — wherein 1≦p≦10, —(CF 2 ) q — wherein 1≦q≦10, a C1 to C10 divalent alkylene group having at least one substituent selected from a C1 to C10 linear or branched aliphatic hydrocarbon group, a C1 to C10 fluoroalkyl group, a C6 to C20 aromatic hydrocarbon group, and a C6 to C20 alicyclic hydrocarbon group, or —C(═O)NH—, and

A 4 is a substituted or unsubstituted divalent phenylene residual group, a substituted or unsubstituted divalent naphthalene residual group, or a residual group where two substituted or unsubstituted aromatic rings are linked through a single bond, —O—, —S—, —C(═O)—, —SO 2 —, —Si(CH 3 ) 2 —, —(CR′ 2 ) p — wherein 1≦p≦10, R′ is hydrogen, a hydroxy group, a C1 to C3 alkyl group, or a C1 to C3 fluoroalkyl group), or (CF 2 ) q wherein 1≦q≦10.

2. The window for a display device of claim 1 , wherein the A 1-2 is present in an amount of greater than or equal to about 20% based on a total molar amount of moieties derived from acid anhydrides.

3. The window for a display device of claim 1 , wherein the plastic substrate has a yellow index ASTM E313 of less than or equal to 3.5.

4. The window for a display device of claim 1 , wherein the hard coating layer comprises an acrylate polymer, a polycaprolactone, a urethane-acrylate copolymer, polyrotaxane, an epoxy polymer, polysilsesquioxane, or a combination thereof.

5. The window for a display device of claim 1 , wherein in the formula of the A 1-1 , L is a single bond,

wherein the A 3 is represented by the following formula:

and

wherein the A 4 is a substituted or unsubstituted divalent phenylene residual group.

6. A display device comprising the window of claim 1 .