Curable high refractive index compositions and articles prepared from them
Curable compositions include an acrylate of Formula I: Formula I at least one multifunctional (meth)acrylate with fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups, and a photoinitiator. The compositions, when cured, have a refractive index of 1.63 or greater at 532 nanometers, are optically transparent, and have a thermal stability such that upon heating for 1 hour at 250° C. they have a weight loss of 3.5% or less.
1. A curable composition comprising:
an acrylate of Formula I;
at least one multifunctional (meth)acrylate with fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups; and
a photoinitiator;
wherein the composition when cured has a refractive index of 1.63 or greater at 532 nanometers, is optically transparent, and has a thermal stability such that upon heating for 1 hour at 250° C. has a weight loss of 3.5% or less.
2. The curable composition of claim 1 , wherein the aromatic acrylate of Formula I comprises greater than 50% by weight of the curable composition.
3. The curable composition of claim 1 , wherein the at least one multifunctional (meth)acrylate with fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups comprises 10% by weight or less of the curable composition.
4. The curable composition of claim 1 , wherein the at least one multifunctional (meth)acrylate comprises a compound of Formula II:
H 2 C═CR 2 —(CO)—O-A-O—(CO)—R2C═CH 2 Formula II
wherein R2 is hydrogen or methyl;
(CO) is a carbonyl group C═O; and
A is a divalent group comprising fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups.
5. The curable composition of claim 4 , wherein A is a divalent group comprising:
a fused aromatic group selected from a fluorenyl group, or a group with the structure:
-(L-O) m —B—(O-L) m -
wherein B is a phenyl-substituted fluorenyl group, an alkylene-substituted fluorenyl group, a naphthalene group, or an —Ar—Ar— group, wherein each Ar group is a naphthalene group;
L is an alkylene group comprising 2-12 carbon atoms; and
m is an integer ranging from 1-10.
6. The curable composition of claim 5 , wherein the at least one multifunctional (meth)acrylate comprises a compound with the structure of Formula III, IV, or V:
7. The curable composition of claim 1 , wherein the at least one multifunctional (meth)acrylate comprises a compound of Formula HA:
wherein each R2 is independently hydrogen or methyl;
Z is S, or a single bond;
each Q is independently O or S;
L is an alkylene group comprising 2-12 carbon atoms; and
n is an integer ranging from 0 to 10.
8. The curable composition of claim 7 , wherein the at least one multifunctional (meth)acrylate comprises a compound with the structure of Formula VI, VII, or VIII:
9. The curable composition of claim 1 , wherein the composition upon curing is optically clear.
10. An article comprising:
a substrate with a first major surface and a second major surface;
a cured organic layer adjacent to at least a portion of the second major surface of the substrate, wherein the cured organic layer comprises a crosslinked (meth)acrylate-based layer, and has a refractive index of 1.63 or greater at 532 nanometers, and is optically transparent, and has a thermal stability such that upon heating for 1 hour at 250° C. has a weight loss of 3.5% or less.
11. The article of claim 10 , further comprising an inorganic barrier layer in contact with the cured organic layer.
12. The article of claim 10 , wherein the cured organic layer comprises a curable composition that has been disposed and cured on at least a portion of the second major surface of the substrate,
wherein the curable composition comprises:
an acrylate of Formula I;
at least one multifunctional (meth)acrylate with fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups; and
a photoinitiator.
13. The article of claim 10 , wherein the cured organic layer has a thickness of from 1-16 micrometers.
14. The article of claim 10 , wherein the article further comprises a device disposed on the second major surface of the substrate, and adjacent to the cured organic layer.
15. The article of claim 14 , wherein the device comprises an OLED (organic light-emitting diode).
16. A method of preparing an article comprising:
providing a substrate with a first major surface and a second major surface;
providing a curable composition wherein the curable composition comprises:
an acrylate of Formula I;
at least one multifunctional (meth)acrylate with fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups; and
a photoinitiator;
wherein the curable composition when disposed and cured has a refractive index of 1.63 or greater at 532 nanometers, is optically transparent, and has a thermal stability such that upon heating for 1 hour at 250° C. has a weight loss of 3.5% or less;
disposing the curable composition on at least a portion of the second major surface of the substrate to form a curable layer;
curing the curable layer to form a cured organic layer.
17. The method of claim 16 , further comprising depositing an inorganic barrier layer on the cured organic layer.
18. The method of claim 16 , wherein disposing of the curable composition on the second major surface of the substrate to form a curable layer comprises coating to a thickness of from 1-16 micrometers.
19. The method of claim 16 , further comprising providing a device; and
disposing the device on the second major surface of the substrate prior to disposing the curable composition on the second major surface of the substrate to form a curable layer.