Fellow involved in explosion in lab. travels to different time but same person. he is now an unlikeable stage critic about to get divorce from lovely wife. He falls in love with her (of course). She cannot believe the change in him. He is then involved in another accident and thrown back to present day. The rest of movie is about him trying to get back to 'the other time'.
That sounds like an episode of "The Twilight Zone" or "Outer Limits." It is certainly familiar, but for some reason I'm not associating it with a movie. As I read the description, I was sort of 'predicting' what would come next. Man, that rings a bell, but no title at the moment.
Sorry.
Possibly "Quest for Love" (1971) http://www.imdb.com/title/tt0067645/ (http://www.imdb.com/title/tt0067645/)
I never knew that it had been filmed, but I certainly know the short story that served as the source material. "Random Quest" by John Wyndham. The wikipedia article says that it has been filmed and Quest for Love (1971) is one of the dramatizations.