US 2019/0169376 A1 · Method to Improve Remote Phosphor Optical Properties in Polycarbonate

Abstract

The disclosure concerns compositions and methods to improve remote phosphor optical properties in polycarbonate. One method includes combining a phosphor component and a polycarbonate component to form a phosphor-polycarbonate composition; and at a fixed phosphor concentration, combining the phosphor-polycarbonate composition with a diffusing agent comprising polytetrafluoroethylene (PTFE), wherein the diffusing agent diffuses light, and wherein the phosphor-polycarbonate composition exhibits an increase in chromaticity coordinate (CIEx) as determined by CIE 1931 or increase in CIE 1976 (u′,v′) of at least about 5% relative to a substantially similar reference composition in the absence of PTFE. Also described are methods to increase yield and reduce product accumulation of an extruded thermoplastic polycarbonate composition through the mixing of PTFE with a phosphor-polycarbonate (PCP) to form a PCP-PTFE component as well as a method forming a phosphor-polycarbonate master batch (PPCMB) composition, and during extrusion, adding PTFE to the PPCMB composition to form a PPCMB-PTFE composition.

Claims20

Dependent claims

A composition comprising:

from about 80.0 wt. % to about 99.5 wt. % of a polycarbonate component;
wherein a melt volume rate of the polycarbonate component is greater than about 15 cm3/10 min as determined according to ISO 1133 at 300° C./1.2 kg, and
wherein a melt flow rate of the polycarbonate component is greater than about 15 g/10 min as determined according to ASTM D 1238 at 300° C./1.2 kgf;
from about 0.3 wt. % to about 2.0 wt. % PTFE,
wherein the PTFE diffuses light;
from about 0 wt. % to about 0.6 wt. % potassium perfluorobutane sulfonate;
from about 0 wt. % to about 0.6 wt. % phosphite stabilizer;
from about 0 wt. % to about 0.2 wt. % hindered phenol anti-oxidant;
and
a phosphor,
wherein the composition exhibits an increase in CIEx when subjected to a blue LED excitation light source and as determined according to CIE 1931 or CIE 1976 (u′,v′) of at least about 5% as compared to a substantially similar reference composition in the absence of PTFE.

8 more elements

A method to improve remote phosphor optical properties in polycarbonate, the method comprising:

combining a phosphor component and a polycarbonate component to form a phosphor-polycarbonate composition;
and
at a fixed phosphor concentration, combining the phosphor-polycarbonate composition with a diffusing agent comprising polytetrafluoroethylene (PTFE) to form a phosphor-polycarbonate-PTFE composition,
wherein the diffusing agent diffuses light, and
wherein the phosphor-polycarbonate-PTFE composition exhibits an increase in CIEx as determined according to CIE 1931 or an increased CIE 1976 (u′,v′) of at least about 5% as compared to a substantially similar reference composition in the absence of PTFE.

2 more elements

Dependencies are inferred from the claim text.

Method to Improve Remote Phosphor Optical Properties in Polycarbonate

Life of this patent

Method to Improve Remote Phosphor Optical Properties in Polycarbonate

Life of this patent

Abstract

Claims20