RU2059974C1 - Electrochrome composition - Google Patents

Abstract

FIELD: devices with electrically controlled value of light absorption. SUBSTANCE: electrochrome composition which have cathode component - di(dicarbaundecaborate)1,1 - dimethyl-4. ,4 - dipyridinium of 0.4-3.6 % or di(dicarbaundecaborate)1.1-dibenzyl-4.4-dipyridinium of 0.5-4.7 %. Anode component is derivative of derrocene 0.3-4.7% or 5.10-dihydro-5.10-dimethylphenasine 0.2-1.4 %, and propylenecarbonat is the rest. EFFECT: improved efficiency. 1 tbl, 6 dwg

Description

 The invention relates to applied electrochemistry-electrochromism of organic compounds. Electrochromic compositions based on organic compounds are mainly used in devices with an electrically controlled amount of light absorption.

 Electrochromic compounds will be widely used in the automotive industry when creating panels to protect the driver’s eyes at night from being blinded by headlights of oncoming cars. At the same time, such compositions can be used to create both interior and exterior automobile rear-view mirrors. Mirrors with an electrochromic electrically controlled filter of variable optical density will protect the driver’s eyes from blinding flashes of headlights from behind a vehicle in the nighttime [1] Such automatically dimming electrochromic mirrors will replace car mirrors with a constant light reflection coefficient.

The principle of creating highly reversible organic electrochromic compositions as well as the compositions based on dipyridinium salts were proposed in [2, 3]. 1,1'-dimethyl-4,4'-dipyridinium diperchlorate or di (tetrafluoroborate) was used as the cathodic component, and as 3-ethyl-2-benzthiazolonazine [2] and 5,10-dihydro-5,10-dimethylphenazine [3] were proposed as anode components
Much later in US Pat. N 4, 902, 108 [4] the range of salts of 4,4'-dipyridinium was expanded and 5,10-dihydro-5,10-dimethylphenazine, in addition to other known organic substances forming reversible redox pairs during electrooxidation, was used as the anode component and its derivatives. The disadvantage of the described analogues is the lack of constancy of the relaxation time of the induced absorption of the composition under prolonged exposure to electric voltage, which is a consequence of the occurrence of the “delamination” of the electrostained state of the composition.

 Close to the proposed solution (prototype) is a composition based on an organic solvent described in ed. testimonial. USSR N 566863 [5] including 1,1'-dimethyl-4,4'-dipyridinium diperchlorate, ferrocene derivative, polyvinyl butyral and dimethylformamide. However, as shown by the values of the limiting currents of the volt-ampere dependences of an electrochromic device with a given composition, the shelf life of such a composition is limited, due to its instability in time. The latter is manifested in a decrease in the value of the limiting currents with time, which indicates an uncontrolled decrease in the concentration of electroactive components or components over time.

 The aim of the invention is the creation of an electrochromic composition having an increased shelf life of its component ratio.

 This problem is achieved by using 1,1'-dimethyl-4,4'-dipyridinium or di (dicarboundecaborate) 1,1'-dibenzyl-4,4'-dipyridinium as the anode components derived ferrocene or 5,10-dihydro-5,10-dimethylphenazine, and as a solvent propylene carbonate in the following ratio of ingredients, wt.

Cathode component
Dee (dicarboundecaborate)
1,1'-dimethyl-4,4'-dipyridinium 0.4-3.6 or
Dee (dicarboundecaborate)
1,1'-dibenzyl-4,4'-dipyridinium 0.5-4.7;
Anode component Ferrocene derivative 0.3-3.0 or 5.10-dihydro-5.10-dimethylphenazine 0.2-1.4; Propylene carbonate Else
A significant difference of the proposed solution is the replacement of the solvent with propylene carbonate, as well as the expansion of the possibly used electroactive components of the composition. Replacing the solvent with propylene carbonate in compositions based on the indicated cathode and anode components gives them a new property of increasing the shelf life.

 Di (dicarboundecaborate) 1,1'-dimethyl-4,4'-dipyridinium and di (dicarboundecaborate) 1,1'-dibenzyl-4,4'-dipyridinium were obtained by a simple exchange reaction of aqueous solutions of 1,1'-dimethyl diiodide -4,4'-dipyridinium or 1,1'-dibenzyl-4,4'-dipyridinium diiodide and potassium dicarboundecaborate. The precipitated precipitate of a water-insoluble product was filtered off, washed with water and recrystallized from a mixture of acetone and ethyl alcohol in an equal ratio.

 The methodology for controlling the shelf life of the composition over time was as follows. Samples were taken from the prepared compositions at certain time intervals and tested in electrochromic devices to assess changes in the content of electroactive components of the composition.

характеризовала изменение содержания электроактивных ингредиентов работающего в электрохромном устройстве состава на период времени его хранения. Величина δ служила критерием срока сохраняемости состава. Близкое к единице значение свидетельствовало о постоянстве состава во времени, а время, в течение которого это значение сохранялось, указывало на срок сохраняемости состава.Electrochromic devices consisted of two glass plates measuring 40x60 mm in size with In ₂ O ₃ semiconductor coatings coated with dopants. The distance between the plates was determined by the thickness of the Teflon gasket, in the middle of which was a hole with a diameter of 18 mm. The thickness of the Teflon gasket was 100-150 μm. The space limited by the plates and the Teflon gasket was filled with the test composition. To seal the device was tightened with clamps. A linear scanning voltage of a triangular shape with a speed of V = 2 mV / s from the PI-50-1 potentiostat connected to the PR-8 programmer was applied to the electrodes. From the current-voltage dependences recorded by the PDA-1 two-coordinate potentiometer, after reaching reproducibility, the value of the limiting current I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ for a freshly prepared composition, and I _before for the composition after its storage over time. The value of the ratio of I _before to I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ δ

characterized the change in the content of electroactive ingredients working in the electrochromic device composition for the period of time of its storage. The value of δ served as a criterion for the shelf life of the composition. A value close to unity testified to the constancy of the composition over time, and the time during which this value was maintained indicated the shelf life of the composition.

Known solution (prototype). In 50 ml of dimethylformamide, 0.5 g (1.0%) of 1,1'-dimethyl-4,4'-dipyridinium diperchlorate, 1.03 g (2.0%) of a mixture of mono-, di-, tri-tert-butylferrocene are dissolved TU 38-103219-88 and 2.57 g (5%) of polyvinyl butyral. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 150 μm. In the initial state, the composition in the layer of the electrochromic device is not colored. When a triangular voltage of V = 2 mV / s is applied to the linear sweep device in the voltage range 0-1.05 V, the composition acquires a blue color and then becomes colorless. The ratio I _before the current-voltage characteristics of an electrochromic device with a composition with a shelf life of 3.7 months and 9 to a value I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ was 0.71, respectively; 0.63; 0.47.

PRI me R 1. In 50 ml of propylene carbonate is dissolved 0.57 g (0.9%) of di (dicarboundecaborate) 1,1'-dimethyl-4,4'-dipyridinium and 0.47 g (0.8% ) a mixture of mono-, di-, tri-tert-butylferrocene TU 38-103219-88. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 150 μm. In the initial state, the composition in the layer of the electrochromic device is not colored. When a triangular-shaped voltage is applied to the linear sweep device at V = 2 mV / s in the voltage range 0-1.05 V, the composition acquires a blue color and then becomes colorless. The ratio of I _before u, I-dependencies measured after the expiration of the storage period of the composition of 1.5; 3; 7; 9 months to the value of I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ is respectively 0.98; 0.97; 0.97; 0.96.

Example 2 0.24 g (0.4%) of di (dicarboundecaborate) 1,1'-dimethyl-4,4'-dipyridinium and 0.12 g (0.20%) are dissolved in 50 ml of propylene carbonate. ) 5,10-dihydro-5,10-dimethylphenazine. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 150 μm. In the initial state, the composition in the layer of the electrochromic device has a weak green color. When a triangular-shaped voltage is applied to the linear sweep device at V = 2 mV / s in the voltage range 0-1.00 V, the composition acquires an intense blue-green color, and then returns to its original state. The ratio of I _before u, I-dependencies of the shelf life of the composition of 1.5; 3 and 7 months to the value of I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ was 0.99, respectively; 0.96; 0.95.

Example 3 3.00 g (4.7%) of di (dicarboundecaborate) 1,1'-dibenzyl-4,4'-dipyridinium and 0.90 g (1.4%) are dissolved in 50 ml of propylene carbonate ) 5,10-dihydro-5,10-dimethylphenazine. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 100 μm. In the initial state, the composition in the layer of the electrochromic device is not colored. When a triangular voltage is applied to the linear sweep device at V = 2 mV / s in the voltage range 0-1.00 V, the composition acquires a blue-green color, and then returns to its original state. The ratio of I _before u, I-dependencies measured after the expiration of the storage period of the composition of 1.5; 3 and 7 months to the value of I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ was 1.01, respectively; 0.98; 0.94.

Example 4. 1.50 g (2.4%) of di (dicarboundecaborate) 1,1'-dibenzyl-4,4'-dipyridinium and 0.50 g (0.8%) are dissolved in 50 ml of propylene carbonate. ) 5,10-dihydro-5,10-dimethylphenazine. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 100 μm. In the initial state, the composition in the layer of the electrochromic device is practically not colored. When a triangular-shaped voltage is applied to the linear sweep device at V = 2 mV / s in the voltage range 0-1.00 V, the composition acquires a blue-green color, and then returns to its original state. The ratio of I _before u, I-dependencies measured after the expiration of the storage period of the composition of 1.5; 3 and 7 months, to the value of I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ was 1.04, respectively; 0.99; 0.96.

Example 5 2.30 g (3.6%) of di (dicarboundecaborate) 1,1'-dimethyl-4,4'-dipyridinium and 1.90 g (3.0%) are dissolved in 50 ml of propylene carbonate ) a mixture of mono-, di-, tri-tert-butylferrocene TU 38-103219-88. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 100 μm. In the initial state, the composition in the layer of the electrochromic device is not colored. When a triangular-shaped voltage is applied to the linear sweep device at V = 2 mV / s in the voltage range 0-1.05 V, the composition acquires a blue color, and then reverts to an unpainted state. The ratio of I _before u, I-dependencies measured after the expiration of the storage period of the composition of 1.5; 3; 7 and 9 months, to the value of I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ was respectively 0.98; 0.96; 0.96 and 0.94.

PRI me R 6. In 50 ml of propylene carbonate dissolved 0.30 g (0.5%) of di (dicarboundecaborate) 1,1'-dibenzyl-4,4'-dipyridinium and 0.19 g (0.3% ) mono-, di-, tri-tert-butylferrocene TU 38-103219-88. The resulting solution is filled in an electrochromic device with a distance between the electrodes of 150 μm. In the initial state, the composition in the layer of the electrochromic device is not colored. When a triangular-shaped voltage is applied to the linear sweep device at V = 2 mV / s in the voltage range 0-1.05 V, the composition acquires a blue color, and then reverts to an unpainted state. The ratio of I _before u, I-dependencies measured after the expiration of the storage period of the composition of 1.5; 3; 7 and 9 months to the value of I $\genfrac{}{}{0ex}{}{\text{out}}{\text{before}}$ obtained immediately after the manufacture of the composition, δ was 1.03, respectively; 1.00; 0.97; 0.97.

The upper concentration limit of the ingredients of the composition was limited by the requirement of uniform staining of the electrochromic device. At higher concentrations compared to those declared due to the finite surface resistance of optically transparent electrically conductive coatings (In ₂ O ₃ ), the unevenness of the current distribution over the surface of the electrodes increases significantly, and, as a result, the uniformity of optical absorption during coloring is significantly impaired. The lower concentration limit was determined by low light absorption in the electrostained state, not suitable for practical use.

As can be seen from the table (see table), the composition of the prototype after 9 months. its storage has δ ≃ 0.5. This value indicates that the limiting current I _before u, I-dependencies, after the specified storage period of the composition, drops by about 2 times. Examples 1-6 with the proposed composition have a value of δ ≃ 1, even with a shelf life of 9 months. and practically do not show signs of aging of the composition over time.

 Thus, the proposed electrochromic composition has an increased shelf life in time and contributes to the implementation on its basis of electrochromic devices with a satisfying consumer service life.

 The data are given in the table.

Claims (1)

 ELECTROCHROMIC COMPOSITION, comprising the cathodic component, the quaternary dipyridinium salt, the anodic component and a solvent, characterized in that 1,1- -dimethyl-4,4'-dipyridinium is used as the cathodic component, a ferrocene derivative is used as the anodic component or 5,10-dihydro-5,10-dimethylphenazine, and the solvent is propylene carbonate in the following ratio of ingredients, wt. Dee (dicarboundecaborate)
1,1 ′ -dimethyl- 4,4 ′ -dipyridinium 0,4 3,6
or
Di (dicarboundecaborate) 1,1′-dibenzyl- 4,4′-dipyridinium 0.5 - 4.7
Ferrocene derivative 0.3 3.0
or
5,10-dihydro-5,10-dimethylphenazine 0.2 1.4
Propylene carbonate Else

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