Is it acceptable to publish a paper using an affiliation with a former employer?
If you have written the publication only with the resources and support of the former employer, then it is perfectly acceptable to do what you have written, and list the old address as your address for the "active" affiliations, and include a "present address" affiliation to show your updated physical location.

However, if your new employer does provide financial support, then you should list them accordingly. This is especially important if any of the actual research that makes its way into a publication has been performed while working for the new employer using their resources.