BONDING METHOD OF CYCLOOLEFIN POLYMER

To provide a method of bonding a plate (first plate) made of a cycloolefin polymer (COP) to a mating material plate (second plate) without additionally applying large pressure and high temperature, and without changing an optical property.SOLUTION: After exposing at least a bonding surface of a first plate to HO plasma, the bonding surface of the first plate and a bonding surface of a second plate are attached to each other under an atmosphere of a temperature (provided that the temperature is 5°C or higher in usual atmosphere) that is 50°C lower than a lower temperature of a glass-transition temperature of a first plate material (COP) or a glass-transition temperature of a second material. In this manner, both of the plates are optically integrated on the bonding surfaces, and thus no bonding surface optically appear. Further, a hydrophilic property on the bonding surface exposed to the HO plasma is maintained.SELECTED DRAWING: Figure 2 【課題】シクロオレフィンポリマー（COP）製の板（第１板）を、大きな圧力や高い温度を付加することなく、また、光学特性を変化させることなく、相手材料の板（第２板）に接合する方法を提供する。【解決手段】少なくとも第１板の接合面をH2Oプラズマに曝した後、第１板の接合面と第２板の接合面を、第１板材料（COP）のガラス転移温度及び第２材料のガラス転移温度のいずれか低い方よりも50℃低い温度以下の温度（ただし、通常の大気中では5℃以上）の雰囲気下で合わせる。これにより、接合面において両板が光学的に一体化し、接合面が光学的に現れなくなる。また、H2Oプラズマに曝された接合面の親水性が維持される。【選択図】図２