Composition for liquid crystal color display

• US 4,555,355 A
• Filed: 11/22/1983
• Issued: 11/26/1985
• Est. Priority Date: 10/03/1980
• Status: Expired due to Term

• Current Assignee: Mitsui Chemicals Incorporated (Mitsui Chemicals)
• Original Assignee: Mitsui Chemicals Incorporated (Mitsui Chemicals)
• Inventors: Tukahara, Ryoichi, Yamada, Yasuyuki, Nishizawa, Tsutomu, Tanaka, Tadaaki
• Primary Examiner(s): Gron, Teddy S.
• Application Number:
  US06/552,302
• Time in Patent Office: 735 Days
• Field of Search: 252/299.1, 350/349
• US Class Current: 252/299.1
• CPC Class Codes: C09B 3/14 Perylene derivatives
• CPC Class Codes: C09K 19/60 Pleochroic dyes
• CPC Class Codes: C09K 19/606 Perylene dyes

Abstract

As dichroic dyes for use in a liquid color display device, compounds of formula (I) ##STR1## such as 4'"'"'-octylphenyl perylene-3,9-dicarboxylate are provided. These compounds have various characteristic properties. For example, (1) they have a sufficient coloring ability in small amounts; (2) they have a high dichroic ratio and show a high contrast by application and non-application of voltage; (3) they have sufficient compatibility with liquid crystals; (4) they have excellent durability, are stable, and do not reduce the performance of a display device even in long-term use.

Claims

1. A composition for liquid crystal color display, said composition comprising at least one nematic liquid crystal and at least one perylenedicarboxylic acid ester dye represented by the following formula (II):

##STR6## wherein R₁ '"'"' and R₁ are identical or different, and each represents a cyclohexyl, bicyclohexyl, cyclohexylphenyl, phenyl or biphenyl group which may be substituted by a halogen atom, an alkyl group having 1 to 15 carbon atoms or alkoxy group having 1 to 15 carbon atoms;

or a group of the formula, Alk--X, wherein Alk represents an alkylene group having 1 to 15 carbon atoms which may be branched and X represents a phenyl group which may be substituted by an alkyl group having 1 to 4 carbon atoms, nitrile group, a halogen atom or a hydroxyl group.

2. The composition of claim 1 wherein said perylenedicarboxylic acid ester dye is represented by the following formula (IV):

##STR7## wherein R₂ '"'"' and R₂ are identical or different and each represents an alkyl group having 1 to 15 carbon atoms which may be branched.

3. The composition of claim 1 or 2 wherein a mixture of said perylenedicarboxylic acid ester dyes is dissolved in at least one nematic liquid crystal.

4. The composition of claim 1 or 2 wherein a mixture of said perylenedicarboxylic acid ester dyes is dissolved in a mixture of nematic liquid crystals.

5. The composition of claim 1 or 2 wherein the concentration of said perylenedicarboxylic acid ester dye is 0.01 to 10 percent by weight based upon the weight of the nematic liquid crystal.

6. The composition of claim 5 wherein said concentration is 0.01 to 5 percent by weight based on the weight of the nematic liquid crystal.

7. The composition of claim 1 or 2 wherein a mixture of said perylenedicarboxylic acid ester dye and at least one anthraquinoic dye is dissolved in said nematic liquid crystal.