| 摘要 |
PURPOSE:To obtain a partially polarizing film with high dimensional accuracy and durability by partially applying a soln. contg. iodide to a uniaxially oriented hydrophilic high molecular film contg. boric acid and an oxidizing agent and by carrying out heat treatment to cause oxidation. CONSTITUTION:A hydrophilic polyvinyl alcohol film is immersed in an aqueous soln. contg. 2% mixture of o-boric acid with ferric chloride as an oxidizing agent for 1min. This film is stretched 4 times in a uniaxial direction, and the oriented film is dried at 70 deg.C for 10min. A gelled aqueous soln. contg. 0.1% KI and 0.5% sodium alginate is applied to the film in the form of streaks each having 10mm. width at 5mm. interval, and the soln. is dried. The film is then allowed to stand at 70 deg.C and 95% relative humidity for 2min to cause oxidation. Thus, a partially polarizing film is formed. The parts with polarizing power have 40% light transmittance and 98% polarizing degree. The boundaries between the parts and other parts with no polarizing power are linear, and high dimensional accuracy and durability are obtd. |
