**5. Conclusions**

Ultraviolet nanoimprint lithography (UV-NIL) can be used to fabricate nanoscale patterns while ensuring a high throughput and low cost. The high-volume production of nanostructures requires the durability of the release-coated silicon mold to be excellent. Accordingly, the durability of a line-patterned mold was evaluated using a high-hardness release-agent-free resin. Capillary action occurred in the nanoscale line structure. It was observed that the contact angle decreased with repeated transfers and that the water flowed along the lines. Measuring the contact angle in the *x* and *y* directions allowed the prediction of the lifetime of the mold. This prediction method is limited to line-and-space patterns. However, using line-and-space patterns, every release coating or release material can be evaluated. In addition, the minimum number of UV-NIL imprints required to estimate the stamp lifetime is until saturation of the contact angle in the *x* direction occurs. We obtained the contact angles in both *x* and *y* directions vs. the number of imprints. Lifetime can be estimated from the crossing point of the *x* direction (saturated low contact angle value) curve and the corresponding *y* direction curve. This is a facile and labor-saving way. This lifetime prediction could potentially lead to a shortening of the durability evaluation time and prevention of mold breakage. If this comparison of *x* and *y* in L&S patterns, or life prediction, can be utilized, it will be possible to determine which demolding process is best for a smaller number of transfers.

**Author Contributions:** Conceptualization, T.M. and J.T.; methodology, T.M. and J.T.; validation, T.M. and J.T.; investigation, T.M.; materials, S.H.; writing—original draft preparation, T.M.; writing—review and editing, J.T.; project administration, J.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors would like to thank the Toyo Gosei Corporation for providing the UV curable resins (PAK-01-CL).

**Conflicts of Interest:** The authors declare no conflict of interest with this manuscript.
