Thermoplastic electrochromic materials

• US 8,323,534 B2
• Filed: 12/18/2009
• Issued: 12/04/2012
• Est. Priority Date: 12/18/2009
• Status: Active Grant

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Percec, Simona, Pollino, Joel M.
• Primary Examiner(s): Ahvazi, Bijan
• Application Number:
  US12/641,449
• Publication Number:
  US 20110147680A1
• Time in Patent Office: 1,082 Days
• Field of Search: 252/586, 252/500, 359/265, 359/267, 359/273, 359/275, 359/359, 359/360, 359/580, 428/437, 428/213, 428/339, 428/141, 428/156, 428/167, 428/172, 428/212, 428/415, 428/426, 428/432, 428/433, 428/436, 428/469, 428/699, 428/701, 428/702, 428/913, 438/69, 438/70, 524/308, 524/306, 524/399, 524/400, 264/211, 264/211.21, 528/378, 528/379, 528/380
• US Class Current: 252/586
• CPC Class Codes: C08K 5/04 Oxygen-containing compounds C08K5/0091 takes precedence
• CPC Class Codes: C08L 29/14 Homopolymers or copolymers of acetals or ketals obtained by polymerisation of unsaturated acetals or ketals or by after-treatment of polymers of unsaturated alcohols
• CPC Class Codes: G02F 1/15165 Polymers

Abstract

Disclosed are electrochromic materials containing a film-forming polymer with a T_g less than 100° C.; a plasticizer; an electrochromophore; an electron mediator; and a salt. Also disclosed are electrochromic devices using such electrochromic materials that can provide light-filtering, color-modulation, or reflectance-modulation in variable transmittance windows, variable-reflectance mirrors and other dynamic glazing applications.

Claims

1. A composition consisting essentially of:

(a) 10-60 wt % of a polymer selected from the group of amorphous, film-forming polymers with T_g less than 100°

C.;

(b) 40-90 wt % of a plasticizer mixture, wherein the plasticizer mixture consists essentially of;

(i) a plasticizer, wherein the plasticizer is soluble in the polymer to at least 45 wt %;

(ii) an electrochromophore, wherein the electrochromophore is soluble in the plasticizer to at least 10 wt % and wherein the concentration of the electrochromophore in the composition is from 1 to 30 wt %;

(iii) an electron mediator selected from the group consisting of ferrocene, butyl ferrocene, ferrocene carboxylic acid, phenazine and its derivatives, carbazole and its derivatives, phenothiazine and its derivatives, and phenanthroline and its derivatives, wherein the concentration of the electron mediator in the composition is from 0.1 to 10 wt %; and

,

(iv) a salt selected from the group consisting of lithium chloride, tetrabutylammonium bromide, lithium bis(trifluoromethanesulfonyl)imide, lithium triflate, and lithium hexafluorophosphate, wherein the concentration of the electron mediator in the composition is from 0.1 to 10 wt %, and

wherein the melting point of the plasticizer is not above about 0°

C., the boiling point of the plasticizer is above about 190°

C. at a pressure of 1 atmosphere, and the solubility in the plasticizer of the electron mediator and the salt are each at least 0.5 mg per mg of plasticizer.

2. The composition of claim 1, wherein the amorphous film-forming polymer is selected from the group consisting of polyvinyl butyral, polyvinyl chloride, polycarbonate, polyvinyl alcohols, acrylate (co)polymers, ethylene-vinyl alcohol copolymers, ethylene-acrylate copolymers, ethylene-CO-acrylate terpolymers, and polyurethanes.

3. The composition of claim 1, wherein the plasticizer is selected from the group consisting of linear carbonates;

cyclic carbonates;

C₇-C₁₀ linear primary alcohols;

linear and branched C₅-C₁₂ aliphatic diols, linear and branched C₅-C₁₂ aliphatic triols;

benzyl alcohol;

1-phenoxy-2-propanol;

linear and cyclic ureas;

linear or cyclic urethanes;

thioureas;

thiourethanes;

linear thio-oxocarbonates;

pyrrolidon-2-ones;

dihydrofuran-2-ones;

piperidin-2-ones;

pyran-2-ones;

substituted imidazolium salts;

3-methanesulfinylmethyl-heptane;

2-(2-butoxyethoxy)ethanol;

bis-cyclics of Structure II,

4. The composition of claim 1, wherein the plasticizer is selected from the group consisting of propylene carbonate;

4-(hydroxymethyl)-1,3-dioxolan-2-one;

carbonic acid dibutyl ester;

1-(3-hydroxypropyl)-2-pyrrolidone;

1-octyl-2-pyrrolidone;

5-dodecanolide;

1-hexyl-3-methylimidazolium chloride;

1-methyl-3-octylimidizolium chloride;

2,2-dimethyl-1,3-hexanediol;

2-methyl-1,3-pentanediol;

1-cyclohexyl-2-methyl-1,3-pentanediol;

2,4-diethyl-1,5-pentanediol;

1,3-nonanediol;

2-butyl-1,3-octanediol;

3-methylpentane-1,3,5-triol;

2-ethyl-1,3-hexanediol;

benzyl alcohol;

3-methyl-1,5-pentanediol;

1-phenoxy-2-propanol;

2-(2-butoxyethoxy)ethanol;

bis(2-ethylhexyl)phosphate;

tributyl phosphate; and

tris(2-ethylhexyl)phosphate.

5. The composition of claim 1, wherein the electrochromophore is a copolymer of 4-4′

-dipyridyl and poly(ethylene glycol).

6. The composition of claim 5, wherein poly(ethylene glycol) has a molecular weight of about 100 to about 2000 Daltons.

7. A composition of claim 1 obtained by mixing:

(a) 10-60 wt % of a polymer selected from the group of amorphous, film-forming polymers with T_g less than 100°

C.;

with

(b) 40-90 wt % of a plasticizer mixture, wherein the plasticizer mixture comprises;

(i) a plasticizer, wherein the plasticizer is soluble in the polymer to at least 45 wt %;

(ii) an electrochromophore, wherein the electrochromophore is soluble in the plasticizer to at least 10 wt %;

(iii) an electron mediator selected from the group consisting of ferrocene, butyl ferrocene, ferrocene carboxylic acid, phenazine and its derivatives, carbazole and its derivatives, phenothiazine and its derivatives, and phenanthroline and its derivatives; and

(iv) a salt selected from the group consisting of lithium chloride, tetrabutylammonium bromide, lithium bis(trifluoromethanesulfonyl)imide, lithium triflate, and lithium hexafluorophosphate,

wherein the melting point of the plasticizer is not above about 0°

C., the boiling point of the plasticizer is above about 190°

C. at a pressure of 1 atmosphere, and the solubility in the plasticizer of the electron mediator and the salt are each at least 0.5 mg per mg of plasticizer.