If you want to make patches from the current work in progress (the files that are checked out in the current folder), you can use cleartool lsco (or cleartool ls) combined with cleartool diff:
cd /path/to/my/view/myfolder
cleartool lsco -s -cview | xargs cleartool diff -pred -diff_format
# for all files:
cleartool ls -s -view-only | xargs cleartool diff -pred -diff_format
The -diff_format option causes both the headers and differences to be reported in the style of the UNIX and Linux diff utility.
You can redirect the output to a file in order to get your patch.
Add -recurse to cleartool ls or cleartool lsco, to get the files in subfolders.
If you know the branch you are in, you can do a diff with a different version than "-pred":
| xargs -0 -i sh -c '`cleartool diff {} {}@@/main/yourBranch/0`'
"xargs : using same argument in multiple commands" proposes another syntax:
| xargs -n1 -I_afile -- sh -c '`cleartool diff _afile _afile@@/main/yourBranch/0`'