Abstract: Disclosed is a mono-azo dichroic dye compound represented by the following Chemical Formula 1, a composition for polarizing plate, a polarizing plate, and an optical device. In Chemical Formula 1, Z represents any one selected from the group consisting of CN, COOR11, indanone and 1,3-dioxoindane, wherein R11 is any one selected from the group consisting of alkyl groups, aryl groups, and substituted or non-substituted heteroaryl groups. The mono-azo dichroic dye compound shows excellent dichroic properties, and has excellent heat resistance and photo-resistance, and thus may be used advantageously for a dye-based polarizing plate.

Abstract: Disclosed is a mono-azo dichroic dye compound represented by the following Chemical Formula 1, a composition for polarizing plate, a polarizing plate, and an optical device. In Chemical Formula 1, R3 represents a substituted or non-substituted heterocyclic group having 1-20 carbon atoms. The mono-azo dichroic dye compound shows excellent dichroic properties, and has excellent heat resistance and photo-resistance, and thus may be used advantageously for a dye-based polarizing plate.

Abstract: The present invention relates to an LED encapsulant including rare-earth metal oxide particles and, more particularly, to an LED encapsulant including a compound represented by Chemical Formula 1 below in a polymer resin. Ma(OH)b(CO3)cOd ??[Chemical Formula 1] In Chemical Formula 1, M is Sc, Y, La, Al, Lu, Ga, Zn, V, Zr, Ca, Sr, Ba, Sn, Mn, Bi or Ac, a is 1 or 2, b is 0 to 2, c is 0 to 3, and d is 0 to 3, wherein b, c, and d are not simultaneously zero, and b and c are either simultaneously zero or simultaneously not zero.

Abstract: The present invention relates to an LED package including rare-earth metal oxide particles and, more particularly, to an LED package including an LED chip selected from among a blue LED chip, a green LED chip and a red LED chip, and an LED encapsulant having a compound represented by Chemical Formula 1 below in a polymer resin. Ma(OH)b(CO3)cOd ??[Chemical Formula 1] In Chemical Formula 1, M is Sc, Y, La, Al, Lu, Ga, Zn, V, Zr, Ca, Sr, Ba, Sn, Mn, Bi or Ac, a is 1 or 2, b is 0 to 2, c is 0 to 3, and d is 0 to 3, wherein b, c, and d are not simultaneously zero, and b and c are either simultaneously zero or simultaneously not zero.