Electroluminescent lamp and method

In a thick film, screen printed EL lamp with front conductor layer, a dielectric layer, a phosphor layer, a rear conductor layer and a protective overcoat layer, the improvement comprising the use of a common binder for all of the layers except the rear conductor layer to thereby reduce the susceptibility of the lamp to moisture wherein the phosphor layer comprises by weight:

• (a) copper activated zinc sulfide (50-60%);
• (b) 2-(2-ethoxyethoxy)-ethyl acetate (5-25%);
• (c) 2-butoxyethyl acetate (5-25%);
• and
• (d) polyvinylidene fluoride (2-30%).

In a thick film, screen printed EL lamp with a front conductor layer, a white dielectric layer, a phosphor layer, a rear conductor and a protective overcoat layer, the improvement comprising the use of a common binder for all of the layers except the rear conductor layer to thereby reduce the susceptibility of the lamp to moisture wherein the white dielectric layer comprises by weight:

• (a) titanium dioxide (20-60%);
• (b) silicon dioxide (3-10%);
• (c) aluminum silicate (3-10%);
• (d) 2-(2-ethoxyethoxy)-ethyl acetate (5-25%);
• (e) 2-butoxyethyl acetate (5-25%);
• and
• (f) polyvinylidene fluoride (2-30%).

In a thick film, screen printed EL lamp with front conductor, dielectric, phosphor, rear conductor and protective overcoat layers, the improvement comprising the use of a common binder for all of the layers except the rear conductor layer to thereby reduce the susceptibility of the lamp to moisture wherein the protective overcoat layer comprises by weight:

• (a) Teflon #532-5011 power (15-25%);
• (b) 2-(2-ethoxyethoxy)-ethyl acetate (10-45%);
• (c) 2-butoxyethyl acetate (10-45%);
• and
• (f) polyvinylidene fluoride (20-80%).

A thick film EL lamp comprising:

• .
• a front electrode layer comprising a heat stabilized polyester film with a layer of indium tin oxide in a first fluoropolymer resin binder;
• a phosphor layer in a second fluoropolymer resin binder;
• a dielectric layer in a third fluoropolymer resin binder;
• a rear electrode layer in a binder;
• and
• an overcoat layer in a fourth fluoropolymer resin binder.

A thick film EL lamp comprising:

• a front electrode layer comprising an indium tim oxide sputtered polyester having a sheet resistivity of 300 to 1,000 ohms per square;
• a clear dielectric in a first fluoropolymer resin binder;
• a phosphor layer in a second fluoropolymer resin binder;
• a dielectric layer in a third fluoropolymer resin binder;
• a rear electrode layer in a binder;
• and
• an overcoat layer in a fourth fluoropolymer resin binder.