OPTICAL SCATTERER COMPRISING A SCATTERING PORTION FORMED FROM A FOAM COMPRISING AT LEAST ONE FLUOROPOLYMER

• US 20160245964A1
• Filed: 09/30/2014
• Published: 08/25/2016
• Est. Priority Date: 10/01/2013
• Status: Abandoned Application

• Current Assignee: Arkema France (Arkema)
• Original Assignee: Arkema France (Arkema)
• Inventors: FINE, Thomas, ZERAFATI, Saeid
• Application Number:
  US15/026,284
• Publication Number:
  US 20160245964A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 5/0247 by means of voids or pores
• CPC Class Codes: G02B 5/0278 used in transmission

Abstract

The present invention relates to an optical scatterer having a scattering portion able to be passed through by the light flux emitted by a point light source, when said optical scatterer is mounted on said point light source. According to the invention, characteristically, said scattering portion is formed from a solid foam comprising at least one fluoropolymer.

Claims

1. An optical diffuser having a diffusing portion capable of being passed through by the luminous flux emitted by a point light source, when said optical diffuser is mounted on said point light source, wherein said diffusing portion is formed from a solid foam comprising at least one fluoropolymer, said fluoropolymer being a copolymer of vinylidene fluoride (VDF) with a fluorinated cornonomer selected from the group consisting of chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene (VF₃), tetrafluoroethylene (TFE) and mixtures thereof.

2. The optical diffuser as claimed in claim 1, wherein said copolymer comprises only VDF and HFP.

3. The optical diffuser as claimed in claim 2, wherein said VDF-HFP copolymer contains at least 50% by weight of VDF.

4. The optical diffuser as claimed in claim 1, wherein said foam contains, in addition, an acrylic polymer, especially polymethyl methacrylate.

5. The optical diffuser as claimed in claim 4, wherein said foam contains a weight fraction of acrylic polymer of between 0.1 and 90%, relative to the total weight of the acrylic polymer-vinylidene fluoride mixture.

6. The optical diffuser as claimed in claim 1, wherein said diffusing portion has a thickness substantially equal to or greater than 100 μ

m and substantially less than or equal to 2 mm and in particular a thickness substantially equal to or greater than 150 μ

m and substantially less than or equal to 1 mm.

7. The optical diffuser as claimed in claim 1, wherein said diffusing portion has a hiding power HP(5.1) % measured according to the integrating sphere method that is substantially equal to or greater than 80% and in particular substantially equal to 90%.

8. The optical diffuser as claimed in claim 1, wherein said diffusing portion transmits, in the wavelengths of the visible spectrum, at least 50% of the light emitted by said point light source.

9. A light-emitting device comprising a point light source, and said optical diffuser as claimed in claim 1.

10. The light-emitting device as claimed in claim 9, wherein said point light source is a light-emitting diode.

11. The light-emitting device as claimed in claim 3, wherein said VDF-HFP copolymer contains at least 75% by weight of VDF.

12. The light-emitting device as claimed in claim 11, wherein said VDF-HFP copolymer contains at least 80% by weight of VDF.

13. The optical diffuser as claimed in claim 8 wherein said diffusing portion transmits, in the wavelengths of the visible spectrum, at least 65% of the light emitted, by said point light source.