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US 7,582,230 B2Granted
Liquid crystal display and colour filter with improved transparency for green light
AssigneeCiba Specialty Chemicals Corporation
InventorsGerardus de Keyzer, Taher Yousaf, Vadiraj Subbanna Ekkundi, Chandrasekhar Dayal Mudaliar
Life of this patent
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Abstract
The invention relates to novel liquid crystal displays comprising a broad backlight emission around 530 nm and a green color filter containing a phthalocyanine colorant, most adequately tetrahydroxy- or tetraalkoxy-substituted but lacking solubilizing groups.
Claims14
A colour filter comprising areas of at least three different colours, wherein at least one area has its maximal visible light transmittance at a wavelength of from 520 to 540 nm and comprises a pigmentary compound of formula
- dispersed in a high molecular weight material,
- in which formula (I) R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are each independently from the others selected from the group consisting of H, OH and
- R17, R18, R19 and R20 are H, m is 0 or 1,
- R21 is 2 H, (CH2)3, (CH2)4, (CH)4, (CH)2CH2, (CH)2(CH2)2 or CH2(CH)2CH2,
- R22 and R23 are independently from each other H, OH, NO2, CONHR24 or NHCOR24, R24 is methyl, ethyl or n-propyl, and
- M is 2 H, Cu, Co or Ni,
- with the proviso that one of R1, R2, R3 and R4, none or one of R5, R6, R7 and R8, none or one of R9, R10, R11 and R12, and none or one of R13, R14, R15 and R16 are selected from the group consisting of OH and
- and all other R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are H.
5 more elements
Dependencies are inferred from the claim text.