Talking about the innovative application of PC materials in the field of LED

PC is a colorless, transparent (or pale yellow transparent), rigid and tough material that is non-toxic, tasteless, and looks like plexiglass. The performance of PCs is closely related to the structural characteristics of their macromolecules. The PC macromolecular backbone is a linear macromolecule composed of an isopropanyl group and a carbonate group intercalating with a benzene ring. The molecular structure is symmetrical, regular, and repeating unit length. The benzene ring is rigid, and the carbonate group is a polar water-absorbing group. Although it has flexibility, it forms a conjugated system with two benzene rings, which increases the rigidity and stability of the main chain. The isopropenyl group is a non-polar water-absorbing group, and the symmetrically distributed methyl group hindering is lowered to provide flexibility to the main chain. Therefore, PC macromolecules are mainly rigid and have certain flexibility. The polarity of the polycarbonate group is affected by the aromatic hydrocarbon group, and the water loss rate is not high (about 0.05%), but there is still a disadvantage of easy hydrolysis under high humidity. PC has a regular structure and macromolecules can crystallize. In reality, however, the crystallinity of PC is very low, and it is basically an amorphous polymer, which may be related to its molecular rigidity and too long repeating unit.

In the field of optical materials, as optoelectronic products develop in the direction of “light, thin, short, and small”, people are increasingly demanding the comprehensive performance of some important optical components such as optical lenses, optical brazing, optical disks, and light-emitting diodes. High, optical components are getting smaller and smaller. Compared with inorganic material glass, PC has the advantages of light weight, high strength, high impact resistance, easy processing, high transmittance (up to 90% transmittance), high refractive index and excellent dimensional stability. Features. Various optical lenses made of optical grade PC, whether impact resistance or molding processability, are incomparable with traditional inorganic glass, so they occupy an increasingly important position in the field of optical materials.

At present, light diffusion technology is mainly used in the market to solve the problem of light source glare. The light diffusing agent converts the LED point light source and the line light source into a line light source and a surface light source, so as to achieve a "no glare" effect, it can be added to a transparent resin substrate such as PC, PVC, PS, PMMA, PET, epoxy resin, etc. Increasing the scattering, refraction and transmission of light makes the whole resin emit softer, more beautiful and elegant light, which achieves the opaque comfort of light transmission, and can also increase the brightness of light at a viewing angle, but the absorption of blue light by light scattering agent is minimal. Cannot block blue light.

For the blue-rich phenomenon of white LED light source, the blue substrate is modified by blue light absorber, and the high-energy blue light is absorbed by blue light absorber and converted into heat energy or harmless low-energy radiation to eliminate high-energy blue light in white LED spectrum. Band. As a result, after the surface modification of the PC material by the blue light absorber, the blue light transmittance at each wavelength can be effectively reduced, and the blue light absorption effect is enhanced as the proportion of the blue light absorber is increased. Although this method can effectively reduce the proportion of blue light and reduce the health hazard caused by blue light, there are also some disadvantages.

A product function angle:

The used spectral absorption selectivity of the toner is poor, and the HEV is effectively prevented, and the high-wavelength beneficial blue light and part of the yellow-green light are also absorbed in a large amount. Therefore, compared with the original light diffusing plate, the luminous flux is reduced, the light efficiency is lowered, and the light transmittance is decreased;

B Appearance performance angle:

Due to the excessive absorption of the blue spectrum, the appearance of the product is yellowish and the light absorption is reduced due to the absorption of part of the green and yellow light.

C processing technology angle:

The method needs to blend the toner and the base powder after injection molding, and the toner is easy to agglomerate, and it is difficult to disperse uniformly in the substrate, resulting in uneven distribution of product toner, low blue resistance, product color difference, and optical instability. .

D Economic value perspective:

Since the dispersion effect of the toner is poor, the amount is increased, resulting in an increase in cost.