| 摘要 |
The present invention provides a method for manufacturing a diffusely reflecting polarizer, comprising: extruding and stretching a film containing a first polymer having a birefringence of less than 0.02, with said first polymer being a substantially amorphous nano-composite material, and a second polymer, the first polymer being a major phase, and the second polymer being a dispersed minor phase, wherein said first and second polymers taken together along a first axis for one polarization state of electromagnetic radiation exhibit a diffuse reflectivity R 1d , a specular reflectivity R 1s , a total reflectivity R 1t , a diffuse transmittance T 1d , a specular transmittance T 1s , and a total transmittance T 1t, and along a second axis for another polarization state of electromagnetic radiation exhibit a diffuse reflectivity R 2d , a specular reflectivity R 2s , a total reflectivity R 2t , a diffuse transmittance T 2d , a specular transmittance T 2s , and a total transmittance T 2t , the said first and second axes being orthogonal, wherein the parameters of composition, Tg, and refractive index and the stretch temperature and stretch ratio of the first and second polymers are selected to satisfy the equations:
(1) R 1d is greater than R 1s ; and
(2) T 2 �¢ t / 1 - 0.5 �¢ R 1 �¢ t + R 2 �¢ t > 1.35.
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