Branched polycarbonate compositions having conversion material chemistry and articles thereof

Patent metadata

Field	Value
Publication number	US-9553244-B2
Application number	US-201414278606-A
Country	US
Kind code	B2
Filing date	May 15, 2014
Priority date	May 16, 2013
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

Disclosed herein is a light emitting device, comprising: a lighting element located in a housing, wherein the housing is formed from a plastic composition comprising: a conversion material, and a polycarbonate composition comprising: a flame retardant comprising a sulfonate salt and three polycarbonates. The first polycarbonate has a branching level of greater than or equal to 2%, a weight average molecular weight of 20,000 g/mole to 55,000 g/mole and a peak melt viscosity of greater than or equal to 25,000 poise. The second polycarbonate has a glass transition temperature greater than or equal to 170° C. The third polycarbonate has a branching level of 0 to less than 2% and a molecular weight of 17,000 to 40,000 g/mol.

First claim

The invention claimed is:

1. A light emitting device, comprising:
a lighting element located in a housing, wherein the housing is formed from a plastic composition comprising:
a conversion material, wherein the conversion material comprises yttrium aluminum garnet (YAG) doped with a rare earth element, terbium aluminum garnet doped with a rare earth element, silicate (BOSE) doped with a rare earth element, nitrido silicate doped with a rare earth element; nitride orthosilicate doped with a rare earth element, oxonitridoaluminosilicate doped with a rare earth element or a combination thereof; and a polycarbonate composition
and the polycarbonate composition comprises:
a flame retardant comprising a sulfonate salt;
15 to 50 weight percent of a first polycarbonate, wherein the first polycarbonate comprises structural units of formula (I)

 wherein at least 60 percent of the total number of R 1 groups comprise aromatic groups and the balance thereof are aliphatic or alicyclic groups, and terminal groups derived from an end-capping agent, wherein the first polycarbonate has a branching level of greater than or equal to 2%, a weight average molecular weight of 20,000 to 55,000 g/mol as measured by gel permeation chromatography using polycarbonate standards, and a peak melt viscosity greater than or equal to 25,000 poise when measured using a parallel plate melt rheology test at a heating rate of 10 degrees C./minute at a temperature of 350 to 450 degree C. at a frequency of 3 radians/second and a strain amplitude of 9%;
20 to 50 weight percent of a second polycarbonate having a glass transition temperature greater than or equal to 170° C., wherein the second polycarbonate comprises structural units derived from HO-A 1 -Y 1 -A 2 -OH and structural units derived from HO-A 1 -Y 2 -A 2 -OH wherein each of A 1 and A 2 is a monocyclic divalent aryl group, Y 1 is an aliphatic bridging group or bridging group comprising one to three atoms with the proviso that at least one of the atoms is a hetero atom, and Y 2 is an aromatic group having 6 to 30 carbon atoms, and
15 to 50 weight percent of a third polycarbonate comprising structural units derived from bisphenol A and having a branching level of 0 to less than 2%, and a molecular weight of 17,000 to 40,000 g/mol as measured by gel permeation chromatography using polycarbonate standards, wherein weight percent is based on the combined weight of the first, second and third polycarbonates and the composition has a heat distortion temperature greater than or equal to 145° C., ductility greater than or equal to 90% at 23 degrees C., multi-axial impact greater than or equal to 50 J/m at 23° C., and a molded article of the composition has a UL 94 V0 rating at a thickness of 1.5 mm; and

wherein after the conversion material has been exposed to an excitation source, the conversion material has a luminescence lifetime of less than 10 −4 seconds when the excitation source is removed.

2. The device of claim 1 , wherein the plastic composition comprises 0.1 to 40 pbw of the conversion material based on 100 pbw of polycarbonate composition.

3. The device of claim 1 , wherein the plastic composition comprises 4 to 20 pbw of the conversion material based on 100 pbw of polycarbonate composition.

4. The device of claim 1 , wherein the plastic composition has a 6 min MVR that is less than or equal to 30% greater than a polycarbonate composition 6 min MVR.

5. The device of claim 1 , wherein the conversion material comprises
a conversion material having the formula:
(A 3 ) 2 SiO 4 :Eu 2+ D 1

wherein A 3 is a divalent metal comprising Sr, Ca, Ba, Mg, Zn, Cd, or a combination thereof;
and D 1 is a dopant comprising F, Cl, Br, I, P, S, N, or a combination thereof.

6. The device of claim 1 , wherein the conversion material comprises
a conversion material having formula:
(YA 5 ) 3 (AlB 1 ) 5 (OD 3 ) 12 :Ce 3+

where A 5 is a trivalent metal comprising Gd, Tb, La, Sm, or a combination thereof, or a divalent metal ion comprising Sr, Ca, Ba, Mg, Zn, Cd, or a combination thereof; B 1 is comprises Si, B, P, Ga, or a combination thereof; and D 3 is a dopant comprising F, Cl, Br, I, P, S, N, or a combination thereof.

7. The device of claim 1 , wherein the conversion material comprises
an orange-red silicate-based conversion material having formula:
(SrM1) 3 Si(OD 4 ) 5 :Eu

wherein M1 comprises Ba, Ca, Mg, Zn, or a combination thereof; and D 4 comprises F, Cl, S, N, or a combination thereof.

8. The device of claim 1 , wherein the conversion material comprises
an Eu 2 and/or Dy 3+ doped conversion material having formula:
M 3 MgSi 2 O 8

wherein M comprises Ca, Sr, Ba, or a combination thereof.

9. The device of claim 1 , wherein the conversion material comprises
a rare earth doped a red silicon nitride based conversion material having a formula:
(SrM2) 2 Si 5 N 8

wherein M2 comprises Sr, Ca, Mg, Zn, or a combination thereof.

10. The device of claim 1 , wherein the conversion material comprises
a rare earth doped a red sulfate based conversion material having formula:
(SrM3)S

wherein M3 comprises Ca, Ba, Mg, or a combination thereof.

11. The device of claim 1 , wherein the conversion material is a green sulfate based conversion material having formula:
(SrM3)(GaM4) 2 S 4 :Eu

wherein M3 comprises Ca, Ba, Mg, or a combination thereof; and M4 comprises Al, In, or a combination thereof.

12. The device of claim 1 , wherein the conversion material is comprises a strontium silicate yellow conversion material; a yttrium aluminum garnet doped with rare earth element; a terbium aluminum garnet doped with a rare earth element; a silicate conversion material; nitride conversion material; nitrido silicate; nitride orthosilicate; oxonitridoaluminosilicate; or a combination thereof.

13. The device of claim 1 , wherein the conversion material comprises a combinations of yellow conversion material with a red conversion material; a combinations of green and red conversion material; semiconductor nanocrystals of cadmium sulfide mixed with manganese; or a combination thereof.

14. The device of claim 1 , wherein the conversion material comprises an amorphous silica coating.

15. The device of claim 1 , wherein housing has a transparency of greater than or equal to 30% measured according to ASTM D1003-00, Procedure B, illuminant C, on a spectrophotometer, at a thickness of 1.04 mm.

16. The device of claim 1 , wherein the plastic composition further comprises a light diffusing material selected from crosslinked polymethylmethacrylate (PMMA), polytetrafluoroethylene, and methylsesquioxane, or a combination thereof.

17. The device of claim 1 , wherein the sulfonate salt is Rimar salt, the first polycarbonate comprises structural units derived from bisphenol A, the second polycarbonate comprises structural units derived from PPPBP and bisphenol A and a molded article of the composition has a UL 94 V0 rating at a thickness of 1.0 mm.

18. The device of claim 1 , wherein the sulfonate salt is potassium perfluorobutane sulfonate, the first polycarbonate comprises structural units derived from bisphenol A, the second polycarbonate comprises structural units derived from PPPBP and bisphenol A and a molded article of the composition has a UL 94 V0 rating at a thickness of 1.2 mm.

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Assignees

• Morizur Jean-Francois
• Vollenberg Peter Hendrikus Theodorus
• Sabic Global Technologies Bv

Inventors

• Morizur Jean-Francois
• Vollenberg Peter Hendrikus Theodorus

Classifications

• G02B1/04

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• C08K5/42

  Sulfonic acids; Derivatives thereof · CPC title

• H01L33/501

  Electricity · mapped topic

• C08L69/00

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title

• H01L33/502 Primary

  Electricity · mapped topic