Is one considered sinful for using work papers and facilities to print dawah materials for spreading Islam to non-Muslims?

This is an excellent idea, and you can earn a great reward through it because it is a call to Allah and a struggle in His path, in accordance with the Prophet’s (peace be upon him) saying: "Whoever calls to guidance will have a reward like the rewards of those who follow him, without anything being diminished from their rewards." (Narrated by Muslim). However, it is a condition to obtain permission from the employers to use their property and work time, as the noble aim of calling to Allah does not justify using an unlawful means.