PPG Industries, Inc. (NYSE:PPG) reported mixed first-quarter financial results after the bell Thursday. Here's a look at the details.  The Details: PPG reported quarterly adjusted earnings of $1.86 per share, inline with the analyst estimate. Quarterly sales came in at $4.31 billion which missed the analyst consensus estimate of $4.43 billion by 2.69% and represents a 1.58% decrease over sales of $4.38 billion from the same period last year. PPG announced its board of directors authorized the repurchase of $2.5 billion of outstanding common stock, effective immediately ...