I'm not suggesting you publish their IP. However, you've the legal right to learn (utilise and transfer between employers) skills that you learn on the clock.

You are absolutely entitled to publish (in one form or another) your personal learnings. Your contract with your employer may (if you have an extremely restrictive contract) simply prevent you claiming you're using those skills as part of your current role.

If employers had the right to prevent you utilising skills you learned on the clock, you'd have to somehow unlearn skills and start from scratch at every new job - that's not how it works.