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[0412] Furthermore, the Re change rate 1 is calculated by the following equation. 

Re change rate !(%)~{(Initial Rel-Rel after stand- ing)/Initial Rel }xl00 

[0413] Furthermore, a comparative optical film was manu› factured without use of an additive of each of Examples and Comparative Examples, and according to the same proce› dure as above, the in-plane retardation Re of the comparative optical film before being left to stand in a wet heat envi› ronment (initial Re2) and the in-plane retardation Re of the comparative optical film after being left to stand in a wet heat environment (Re2 after standing) were compared to each other to calculate a Re change rate 2. 

[0414] Furthermore, the Re change rate 2 is calculated by the following equation. 

Re change rate 2(%)~{(Initial Re2-Re2 after stand› ing)/Initial Re2}x100 

<img src='content_image/924962.jpg'>

[0415] A difference between the Re change rate 2 and the Re change rate 1 (Re change rate 2-Re change rate 1) was evaluated according to the following standard. As the dif› ference is greater, suppression of a change in the retardation is intended. 

[0416] A: The difference is 20% or more. 

[0417] B: The difference is 10% or more and less than 20%. 

[0418] C: The difference is less than 10%. 

[0419] In addition, the initial Rel, the Rel after standing, the initial Re2, and the Re2 after standing are retardations at a wavelength of 550 nm. 

[0420] A presence of the specific acid or a salt thereof in the retardation layer or the alignment layer in the optical film manufactured in each of Examples was confirmed by time› of-flight secondary ion mass spectrometry (TOP-SIMS). 

