VIOLOGEN-BASED ELECTROCHROMIC COMPOSITIONS WHICH CAN BE FORMULATED AND APPLIED AT ROOM TEMPERATURE

• US 20110003070A1
• Filed: 11/13/2008
• Published: 01/06/2011
• Est. Priority Date: 01/31/2008
• Status: Abandoned Application

• Current Assignee: Fundación CIDETEC
• Original Assignee: Fundación CIDETEC
• Inventors: Pomposo Alonso, Jose Adolfo, Salsamendi Telleria, Maitane, Pozo Gonzalo, Cristina, Garcia, Rebeca Marcilla, Grande Telleria, Hans-Jurgen
• Application Number:
  US12/865,669
• Publication Number:
  US 20110003070A1
• Time in Patent Office: Days
• US Class Current: 427/58
• CPC Class Codes: C08K 5/3432 Six-membered rings
• CPC Class Codes: C08L 39/04 Homopolymers or copolymers of monomers containing heterocyclic rings having nitrogen as ring member
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1425 Non-condensed systems
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials

Abstract

The invention relates to electrochromic compositions comprising:

• (a) a viologen derivative of formula (I)
• (b) an electron mediator;
• (c) a polymer compound of formula (II)
• (d) a plasticizer of formula (III): and
• (e) a mixture of at least two miscible solvents which dissolve components (a) to (d) at room temperature, at least one of them being a solvent with a high boiling point.

Said electrochromic compositions can be formulated and applied at room temperature, therefore they allow preparing electrochromic devices with heat-sensitive substrates, particularly with fully plastic substrates, with a high degree of transparency and with a high optical contrast.

Claims

1. Electrochromic composition comprising:

(a) a viologen derivative of formula (I);

2. Composition according to claim 1, characterized in that in the viologen of formula (I), R₁ and R₂ are identical and represent a C₁-C₉ alkyl group.

3. Composition according to claim 2, characterized in that R₁ and R₂ are identical and represent an ethyl group.

4. Composition according to claim 1, characterized in that in the viologen of formula (I), R₁ and R₂ are identical and represent a C₁₀-C₂₀ alkyl group.

5. Composition according to claim 1, characterized in that in the viologen of formula (I), R₁ and R₂ are identical and represent a benzyl, phenyl or p-cyanophenyl group.

6. Composition according to claim 1, characterized in that in the polymer compound of formula (II), R₃ represents a C₁-C₄ alkyl group and X⁻

₁ represents ClO₄⁻

, (CF₃SO₃)⁻

or BF₄⁻

.

7. Composition according to claim 6, characterized in that in the polymer compound of formula (II), R₃ represents ethyl and X⁻

₁ represents BF₄⁻

.

8. Composition according to claim 1, characterized in that in the plasticizer of formula (III), R₄ and R₅ independently represent a C₁-C₄ alkyl group and X⁻

₂ represents ClO₄⁻

, (CF₃SO₃)⁻

or BF₄⁻

.

9. Composition according to claim 8, characterized in that in the plasticizer of formula (III), R₄ represents butyl, R₅ represents methyl and X⁻

₂ represents BF₄⁻

.

10. Composition according to claim 1, characterized in that the electron mediator is selected from among hexacyanoferrate (II), periodate, Fe²⁺ and hydroquinone.

11. Composition according to claim 10, characterized in that the electron mediator is hydroquinone.

12. Composition according to claim 1, characterized in that in the mixture of solvents, the solvent with a high boiling point is selected from among dimethylformamide and 1-hexanol.

13. Composition according to claim 12, characterized in that the mixture of solvents is a mixture of dimethylformamide and acetone.

14. Composition according to claim 1, characterized in that it additionally comprises glass spacers with a diameter of 1-10 μ

m.

15. Method for preparing the electrochromic composition of claim 1, characterized in that components (a) to (e) are mixed at room temperature and with stirring.

16. Electrochromic device comprising the electrochromic composition of claim 1.

17. Method for preparing an electrochromic device, characterized in that it comprises the steps of:

(i) depositing the electrochromic composition of claim 1 on a conductive substrate; and

(ii) depositing another conductive substrate on the assembly.

18. Method according to claim 17, characterized in that the deposition of step (i) is performed by spin-coating, doctor blade coating or dip-coating techniques.