National Institute of Advanced Industrial Science and Technology

Haruhisa Akiyama

Hideyuki Kihara

Masaru Yoshida

Aishi Yamashita

Hideki Nagai

Yoko Okuyama

When conventional photo-reactive compounds are to be liquefied with the application of light, liquefaction thereof is time-consuming due to poor sensitivity to ultraviolet light. In the case of conventional photo-reactive compounds, disadvantageously, light does not penetrate through layers to be adhered to each other when such layers are thick. Thus, peeling is not sufficiently performed. Accordingly, it is an object of the present invention to overcome such drawbacks of conventional photo-reactive compounds and provide a photo-reactive adhesive agent exhibiting high sensitivity to light for fluidization and capable of easy peeling. This invention provides a photo-reactive pressure-sensitive adhesive agent comprising, as a main component, a polymeric compound with a weight average molecular weight of 3,000 to 800,000 represented by General Formula (1): wherein A represents a block polymer of monomers represented by Formula (2) below with a molecular weight of 1,000 to 100,000; and B represents a block polymer with a molecular weight of 1,000 to 400,000 having a glass transition point and a melting point of 20&#xb0; C. or lower, which is liquid or plastically deformable at room temperature, provided that B does not absorb light of a wavelength range of 350 to 600 nm by itself: wherein Rrepresents a group having an azobenzene structure represented by Formula (3) below; n is an integer of 2 to 18; m is an integer of 0 to 16; and Rrepresents hydrogen or a methyl group. 

Photoreversible adhesive agent

The invention provides a material having a structure including three or more anthracene structures per molecule as a photosensitive unit. That structure allows the material to remain in a liquid state at room temperature due to its reduced crystallinity. After coated on an application member in a liquid state, it is irradiated with light from outside so that it can be cured by way of photocrosslinking, and when heated, it returns back to the original state as the linkage is cleaved. By use of this material it is possible to form a reversibly detachable layer that serves as an adhesive layer at an interface to an application member and a coating layer at the surface of the application member.

Photocurable composition and anthracene derivative used with the same

This invention provides an adhesive agent with a stronger adhesive force that can adhere and be peeled reversibly with the irradiation of light. With the use of a liquid crystalline polymer compound containing azobenzene or a sugar alcohol derivative containing a hydroxyl group and azobenzene, a photo-reactive adhesive agent that can strongly adhere to and be peeled from a substrate reversibly with the irradiation of light can be obtained.

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Tsukuba, Japan

Haruhisa Akiyama