In the older file, use the Attribute Manager ("Options/Attribute Manager"). In Attribute Manager,select open and choose the file containing the fills and materials you want to bring in. Click on append, and OK the creation process. This will then load the fills and make them available for use.
Copying a fill pattern from the new file will also work. Open both the old and new drawings in separate sessions. Place an area of the fill you want to transfer in the new drawing and copy. Paste in the older drawing and the fill will become available.
The attribute manager process would be my recommendation, but both will work.