| 摘要 |
PURPOSE:To permit control of light transmittance in accordance with change of temp. by using water-contg. polyacrylic acid gel. CONSTITUTION:Water-contg. polyacrylic acid gel used here is obtained by polymerizing methacrylic acid monomer prepared to 12-27vol% aq. soln. in the presence of a polymn. initiator, and the gel is placed in a transparent vessel of glass or the like, and provided for practical use in a sealed state. It is transparent and uniform, transmitting light at low temps., but opacified at higher temps., presumably due to rise of bonding strength among each polymer molecule at higher temps., and causing difference in densities in innumerable parts, resulting in diffused reflection and interception of light transmission. This temps. causing change of light transmittance is affected by the content of gel, and can be finely adjusted by the addition of compds. having a hydrophilic group, such as =O, -OH, or -NH2. Such polyacrylic gel is extremely effective as a stable and highly responsive temp. sensitive light interceptive material. |
