Methine dyes

Patent metadata

Field	Value
Publication number	US-10435565-B2
Application number	US-201816197608-A
Country	US
Kind code	B2
Filing date	Nov 21, 2018
Priority date	Nov 24, 2017
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Novel red methine dyes, methods for the preparation thereof, and use thereof for dyeing plastics, especially vinyl polymers, provide red colourings with improved colour strengths and improved colour brilliance.

First claim

What is claimed is:

1. A dye of the formula (I)

wherein:
R 1 is hydrogen, halogen, COOH or COOR 7 ,
R 2 is hydrogen or is C 1 -C 4 -alkyl, optionally mono- to trisubstituted, identically or differently, by halogen and/or hydroxyl,
R 3 is hydrogen, halogen, CN, COOH or COOR 8 ,
R 4 is C 1 -C 4 -alkyl or phenyl,
R 5 and R 6 are each independently C 1 -C 4 -alkyl, and
R 7 and R 8 are each independently C 1 -C 4 -alkyl

wherein R 1 and R 2 are not both hydrogen.

2. The dye of claim 1 , wherein:
R 1 is hydrogen, fluorine, chlorine, COOH or COOR 7 ,
R 2 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl, hydroxymethyl, hydroxyethyl or CF 3 ,
R 3 is hydrogen, fluorine, chlorine, CN or COOR 8 ,
R 4 is methyl or phenyl,
R 5 and R 6 are each independently methyl or ethyl, and
R 7 and R 8 are each independently methyl or ethyl,
wherein R 1 and R 2 are not both hydrogen.

3. The dye of claim 1 , wherein:
R 1 is hydrogen, fluorine, chlorine or COOCH 3 ,
R 2 is n-butyl, isobutyl, tert-butyl or hydroxyethyl,
R 3 is hydrogen, fluorine or chlorine, and
R 4 , R 5 and R 6 are each methyl
wherein R 1 and R 2 are not both hydrogen.

4. The dye of claim 3 , wherein R 1 and R 3 are not both hydrogen.

5. A method for the bulk colouration of plastics, the method comprising coloring plastic with one or more dyes of claim 1 .

6. The method of claim 5 , wherein the plastic is one or more plastics selected from vinyl polymers, polyesters and polycarbonates.

7. The method of claim 6 , wherein the plastic is polystyrene, polymethyl methacrylate (PMMA), polyethylene terephthalate or polycarbonate.

8. The method of claim 5 , wherein the dye is used in an amount from 0.0001 to 1 percent by weight, based on the amount of plastic.

9. A method for the bulk colouration of plastics, the method comprising contacting the dye of claim 1 with one or more plastics, melting the plastic, and homogenizing the plastic and the dye.

10. The method of claim 9 , wherein:
the contacting comprises mixing or grinding the dye with the plastic; and
the plastic is in the form of granules.

11. The method of claim 5 , comprising mixing the one or more dyes of claim 1 with one or more molten plastics, and homogenizing the mixture.

12. The method of claim 5 , wherein the plastic is polymethyl methacrylate (PMMA), and the method comprises mixing or dissolving the dye with one or more methyl methacrylate monomers, and polymerizing the monomers in the presence of one or more polymerization catalysts.

13. A colored plastic composition comprising one or more dyes of claim 1 .

14. The plastic composition of claim 11 , wherein the plastic comprises polystyrene; polymethyl methacrylate, polyethylene terephthalate, or polycarbonate.

15. A moulding comprising one or more plastic compositions of claim 14 .

16. A method for producing the dye according to claim 1 , the method comprising:
contacting one or more aldehydes of the formula (II)

in which R 1 , R 3 , R 4 , R 5 and R 6 have the definitions specified in claim 1 , with one or more compounds of the formula (III)

in which R 2 , R 7 and R 8 have the definitions specified in claim 1 .

17. A dye of the formula (I)

wherein:
R 1 is hydrogen, fluorine, chlorine or COOCH 3 ,
R 2 is n-butyl, isobutyl, tert-butyl or hydroxyethyl,
R 3 is hydrogen, fluorine or chlorine, and
R 4 , R 5 and R 6 are each methyl, and
R 7 and R 8 are each independently alkyl,
wherein R 1 and R 3 are not both hydrogen.

Assignees

• Lanxess Deutschland Gmbh

Inventors

• Borst Hans-Ulrich
• Michaelis Stephan
• Linke Frank

Classifications

• C08K5/0041

  Optical brightening agents, organic pigments · CPC title

• C08K5/3432

  Six-membered rings · CPC title

• C07D401/06

  linked by a carbon chain containing only aliphatic carbon atoms · CPC title

• C08J2333/12

  Homopolymers or copolymers of methyl methacrylate · CPC title

• C08J3/215

  at least one additive being also premixed with a liquid phase · CPC title