Automatic light valves with polymeric layer containing network of bonds

A layered structure having light reflectivity which is temperature-dependent, said structure comprising:

• first and second cover layers, at least one of which is light transmissive;
• and an inner layer comprising a polymer and a solvent which form a homogeneous solution within a preselected temperature range and which separate into polymer-rich and solvent-rich phases outside said preselected temperature range, said polymer-rich and solvent-rich phases together being substantially more reflective of light than said homogeneous solution;
• where a portion of said polymer is a copolymer of at least two monomers, and said preselected temperature range is bounded by a transition temperature whose value varies with the relative amounts of said monomers, said polymer comprised of individual chains joined together with interchain bonds at points along their length and joined with interface bonds to said first and second cover layers to form a network of said bonds such that stress can travel continuously from one cover layer to the other cover layer.

A layered structure having light reflectivity which is temperature-dependent, said structure comprising:

• first and second cover layers, at least one of which is light transmissive;
• and an inner layer comprising a polymer and a solvent which separate into polymer-rich and solvent-rich phases outside said preselected temperature range, said polymer-rich and solvent-rich phases together being substantially more reflective of light than said homogeneous solution;
• where a portion of said polymer is a random copolymer of at least two monomers, and said preselected temperature range is bounded by a transition temperature whose value varies with the relative amounts of said monomers, said polymer comprised of individual chains joined together with interchain bonds at points along their length and joined with interface bonds to said first and second cover layers to form a network of said bonds such that stress can travel continuously from one cover layer to the other cover layer.

A layered structure comprising a thermochromic layer in between first and second cover layers having light reflectivity which is dependent on temperature, said structure being partially absorptive of varying levels of incident light such that heat generated by incident light so absorbed increases said reflectivity, and in which the light absorption occurs primarily after said incident light passes through said thermochromic layer in the direction of travel of the incident light, said thermochromic layer comprising a polymer and a solvent which form a homogeneous solution within a preselected temperature range and which separate into polymer-rich and solvent-rich phases outside said preselected temperature range, said polymer-rich and solvent-rich phases together being substantially less transmissive of light than said homogeneous solution, individual chains of said polymer being joined together with interchain bonds at points along their length, and interface bonds formed between a portion of said chains and said first and second cover layers to form a network of said bonds such that stress can travel continuously from one cover layer to the other cover layer.

A layered structure comprising a thermochromic inner layer between two polymeric cover layers in which said first and second cover layers are sealed together along lines forming a grid through said inner layer, said thermochromic inner layer comprising a polymer and a solvent which form a homogeneous solution within a preselected temperature range and which separate into polymer-rich and solvent-rich phases outside said preselected temperature range, said polymer-rich and solvent-rich phases together being substantially less transmissive of light than said homogeneous solution;

• individual chains of said polymer being joined together with interchain bonds at points along their length;
• and interface bonds formed between a portion of said chains and said first and second cover layers to form a network of said bonds such that stress can travel continuously from one cover layer to the other cover layer.

A layered structure having light reflectivity which is temperature-dependent, said structure comprising:

• first and second cover layers, at least one of which is light transmissive;
• and an inner layer comprising a polymer and a solvent which form a homogeneous solution within a preselected temperature range and which separate into polymer-rich and solvent-rich phases outside said preselected temperature range, said polymer-rich and solvent-rich phases together being substantially more reflective of light than said homogeneous solution;
• said polymer comprised of individual chains joined together with interchain bonds at points along their length and joined with interface bonds to said first and second cover layers to form a network of said bonds such that stress can travel continuously from one cover layer to the other cover layer in which said first and second cover layers are sealed together by ultrasonic vibrations.

A layered structure in accordance with 34 in which said first and second cover layers are sealed together by passing said inner and first and second cover layers over a drum bearing raised ribs in a grid pattern along the surface thereof and rotating under an ultrasonic horn.

A layered structure having light reflectivity which is temperature-dependent, said structure comprising:

• first and second cover layers, at least one of which is light transmissive;
• and an inner layer comprising a polymer and a solvent which form a homogeneous solution within a preselected temperature range and which separate into polymer-rich and solvent-rich phases outside said preselected temperature range, said polymer-rich and solvent-rich phases together being substantially more reflective of light than said homogeneous solution;
• in which preformed polymer chains are bonded together to form said individual chains joined together with bonds, said polymer comprised of individual chains joined together with interchain bonds at points along their length and joined with interface bonds to said first and second cover layers to form a network of said bonds such that stress can travel continuously from one cover layer to the other cover layer.