Protective film and encapsulation material comprising the same
View Patent ↗Disclosed herein is a protective film. The protective film is produced by alternate coating of a polysilazane-based polymer and a flexible polysiloxane-based polymer. The polysilazane-based polymer is cured at low temperature to form silica, thereby achieving high hardness and high light transmittance. The protective film has improved interfacial adhesion between the respective coating films, which prevents permeation of moisture and oxygen. In addition, the protective film can be easily produced by low-temperature wet processes. Also disclosed herein is an encapsulation material comprising the protective film.
1. A protective film comprising one or more pairs of a first coating film and a second coating film,
wherein the first coating film contains a polysilazane-based polymer and the second coating film contains a polysiloxane-based polymer comprising a C 2 to C 10 alkylene group in a backbone thereof,
wherein the first and second coating films form alternating layers in the protective film,
wherein the polysilazane-based polymer is represented by Formula 1:
—(SiH 2 —NH) n — (1)
wherein n is a number from 500 to 1,000,000,
wherein the polysiloxane-based polymer is prepared by hydrolysis and polycondensation of at least one compound represented by Formula 6:
wherein R is C 1 -C 3 alkyl group, X 1 , X 2 and X 3 are each independently a C 1 -C 10 alkoxy group, n is an integer from 3 to 8 and m is an integer from 1 to 10, and
at least one compound represented by Formula 7:
RSiX 1 X 2 X 3 (7)
wherein R is C 1 -C 3 alkyl group, and X 1 , X 2 and X 3 are each independently a C 1 -C 10 alkoxy group, and
wherein the second coating film further comprises
a multi-functional cyclic siloxane compound represented by Formulas 10 or 13,
2. The protective film of claim 1 , wherein the polysiloxane-based polymer is prepared by hydrolysis and polycondensation of at least one compound represented by Formula 6:
wherein R is C 1 -C 3 alkyl group, X 1 , X 2 and X 3 are each a C 1 -C 10 alkoxy group, and
at least one compound represented by Formula 7:
RSiX 1 X 2 X 3 (7)
wherein R is C 1 -C 3 alkyl group, and X 1 , X 2 and X 3 are each a C 1 -C 10 alkoxy group, and
wherein hydrolysis and polycondensation are carried out in an organic solvent in the presence of a catalyst and water.
3. The protective film of claim 1 , wherein the polysiloxane-based polymer is prepared by hydrolysis and polycondensation to provide at least one compound represented by Formula 8:
wherein n is an integer from 3 to 8 and m is an integer from 1 to 10, and
wherein hydrolysis and polycondensation are carried out in an organic solvent in the presence of a catalyst and water.
4. The protective film of claim 1 , wherein the multi-functional cyclic siloxane compound is represented by Formula 13:
5. The protective film of claim 1 , wherein each of the film-forming compositions further comprises at least one additive selected from the group consisting of photoacid generators, photobase generators, and radical initiators.
6. An encapsulation material comprising the protective film of claim 1 .
7. The encapsulation material of claim 6 , wherein the encapsulation material is used as a direct thin film encapsulation for an electronic device, a barrier layer for a substrate, a getter or an airtight anti-corrosion encapsulation material.
8. The protective film of claim 1 , wherein the multi-functional cyclic siloxane compound is a compound represented by Formula 10: