Illuminating devices with color stable thermoplastic light transmitting articles

• US 9,772,086 B2
• Filed: 05/28/2014
• Issued: 09/26/2017
• Est. Priority Date: 05/29/2013
• Status: Active Grant

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: van den Bogerd, Joshua Arie, de Brouwer, Johannes
• Primary Examiner(s): Oh, T. Victor
• Application Number:
  US14/289,253
• Publication Number:
  US 20150070933A1
• Time in Patent Office: 1,217 Days
• Field of Search: 362611, 362555, 362520, 36231102, 36231104, 362127, 362565, 29428
• CPC Class Codes: C08K 5/1515 Three-membered rings
• CPC Class Codes: C08K 5/529 Esters containing heterocyclic rings not representing cyclic esters of phosphoric or phosphorous acids
• CPC Class Codes: C08L 69/00 Compositions of polycarbonates; Compositions of derivatives of polycarbonates
• CPC Class Codes: F21S 41/285 Refractors, transparent cover plates, light guides or filters not provided in groups F21S41/24 - F21S41/2805
• CPC Class Codes: F21V 3/062 the material being plastics
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: G02B 6/0005 the light guides being of the fibre type G02B6/0003 takes precedence
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Illuminating devices are disclosed having plastic light-transmitting article(s) formed from a thermoplastic composition including a polycarbonate having repeating structural carbonate units according to the formula:

in which at least 60 percent of the total number of R¹ groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic. The composition also includes an epoxy additive having at least two epoxy groups per molecule and a phenolic diphosphite derived from pentaerythritol. The thermoplastic composition exhibits a dE (2000 hrs.) value of less than 1.5 after 2000 hours of heat aging at 130° C., measured according ISO 11664-4:2008(E)/CIE S 014-4/E:2007 using CIE illuminant D65 and a 2.5 mm thick molded plaque of the thermoplastic composition.

Claims

1. An illuminating device, comprising:

a light source; and

a light-transmitting article formed from a thermoplastic composition, positioned to provide a light transmission path from the light source through the light-transmitting article, with a distance, d, between the light source and the light-transmitting article of less than 40 mm, the light transmission path extending through the light-transmitting article and optionally through other light-transmitting article(s) comprising the thermoplastic composition such that the total distance, p, of the light transmission path through the light-transmitting article is at least 3 mm;

wherein the thermoplastic composition comprises a polycarbonate;

the polycarbonate having been prepared through an interfacial polymerization process from BPA monomer having an organic purity higher than 99.70% by weight and having a hydroxyl content lower than 150 ppm by weight;

0.01 wt. % to 0.30 wt. %, based on the total weight of the thermoplastic composition, of an epoxy additive having at least two epoxy groups per molecule; and

0.01 wt. % to 0.30 wt. %, based on the total weight of the thermoplastic composition, of a phenolic diphosphite obtained from pentaerythritol;

wherein the thermoplastic composition has a sulfur content lower than 2 ppm; and

wherein the thermoplastic composition exhibits a dE (2000hrs.) value of less than 2.0 after 2000 hours of heat aging at 130°

C., measured according ISO 11664-4;

2008(E)/CIE S 014-4/E;

2007 using CIE illuminant D65 and a 2.5 mm thick molded plaque of the thermoplastic composition.

2. The illuminating device of claim 1, wherein p is at least 5 mm.

3. The illuminating device of claim 1, wherein d is less than 20 mm.

4. The illuminating device of claim 1, wherein d is less than 5 mm.

5. The illuminating device of claim 1, wherein the thermoplastic composition exhibits the dE value of less than 1.50 after 2000 hours of heat aging at 130°

C., measured according ISO 11664-4;

2008(E)/CIE S 014-4/E;

2007 using CIE illuminant D65 and a 2.5 mm thick molded plaque of the thermoplastic composition.

6. The illuminating device of claim 1, wherein the thermoplastic composition exhibits a b* <

0.56 and a L* >

95.65 as measured according ISO 11664-4;

2008(E)/CIE S 014-4/E;

2007 using CIE illuminant D65 and a 2.5 mm thick molded plaque of the thermoplastic composition.

7. The illuminating device of claim 1, wherein the epoxy additive is an aliphatic epoxide having at least two epoxy groups per molecule and a molecular weight less than 600 g/mol.

8. The illuminating device of claim 1, wherein the epoxy additive is a carboxylate epoxy resin.

9. The illuminating device of claim 8, wherein the epoxy additive is a carboxylate epoxy resin comprising a carboxylate diepoxide according to the formula:

10. The illuminating device of claim 1, wherein the phenolic diphosphite is according to the formula:

11. The illuminating device of claim 10, wherein R₂, R₅, R₅, R₇, R₉, and R₁₀ are H and R₁, R₂, R₆, and R₈ each independently represents a C_1-20organic radical.

12. The illuminating device of claim 10 wherein at least 40% of the R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈, R₉, and R₁₀ groups are cumyl.

13. The illuminating device of claim 1, wherein at least 90% of the R¹ groups are obtained from the bisphenol.

14. The illuminating device of claim 13, wherein all of the R¹ groups are obtained from the bisphenol A.

15. The illuminating device of claim 1, wherein the thermoplastic composition comprises from 0.02 wt. % to 0.10 wt. % of the epoxy additive.

16. The illuminating device of claim 1, wherein the light-transmitting article is an illuminant lens, illuminant cover, a light guide, or an optical sheet.

17. The illuminating device of claim 16, wherein the light-transmitting article comprises a light guide wherein p is at least 7 mm.

18. The illuminating device of claim 1, wherein the illuminating device is a display object, a toy, furniture, an art object, or a light.

19. The illuminating device of claim 18, wherein the illuminating device is a motor vehicle headlamp.

20. The illuminating device of claim 1, wherein the light-transmitting article comprises an aspheric lens.

21. The illuminating device of claim 1, wherein the light-transmitting article is a first lens along said light transmission path, and further comprising a second lens along said light transmission path further from the light source than the first lens, said second lens comprises the thermoplastic composition.

22. The illuminating device of claim 1, wherein the light source is a light-emitting diode.

23. The illuminating device of claim 1, wherein the light source is a xenon arc lamp.

24. The illuminating device of claim 1, wherein the light-transmitting article reaches a temperature between 80°

C. and 135°

C. during operation.