Staining of the paint film

In such a protective sheet, the weathering stabilizer HMS is included in the layer B disposed on a back side of the substrate , but either is not included in the layer A disposed on the PSA layer side of the substrate or is included in an amount which is one-half or less the amount of HMS in the layer B. By arranging the weathering stabilizer HMS so as to be present in a greater amount on the side away from the PSA layer , hand-painted oil painting it is possible to reduce the amount of HMS present on the PSA layer side surface of the substrate while allowing an amount of HMS sufficient for obtaining the desired weathering resistance to be present in the substrate as a whole.

http://www.oilpaintingsstore.com/hand-painted-animal-oil-painting-leopard.html

Staining of the paint film due to the migration of HMS on the substrate surface to the PSA layer can thus be prevented or minimized. Also, because the weathering stabilizer HMS has a relatively large weight-average molecular weight Mw of at least 1.5×103, portrait oil paintings unlike lower molecular-weight organic weathering stabilizers, the HMS in the layer B does not readily diffuse into the layer A. It is thus possible to stably maintain a low HMS content state at the PSA layer side surface of the substrate. For example, even in a mode of use involving exposure to elevated temperatures after the protective sheet has been affixed, an increase in the amount of HMS present at the PSA layer side surface on account of HMS diffusion into the layer B can be suppressed.

Moreover, disposing the weathering stabilizer HMS so as to be present in a greater amount on the outside of the protective sheet is useful also for increasing the HMS utilization efficiency. Therefore, it is possible with the protective sheet of the invention to both achieve a high weather resistance and minimize staining of the paint film. Preferred use may be made of, for example, discount oil paintings a hindered amine-type light stabilizer which satisfies the Mw as the weathering stabilizer HMS. Hindered amine-type light stabilizers exhibit a high weathering resistance enhancing effect, but in conventional methods of use have tended to give rise to staining of the paint film. In the present invention as constituted above, by disposing a HALS which satisfies the above weight-average molecular weight Mw condition so as to be present in a greater amount on the back side of the substrate, a protective sheet which has a high weather resistance and also minimizes staining of the paint film can be achieved.