JP2019172724A - Electrochromic polymer, electrochromic composition and electrochromic display element - Google Patents

Abstract

To provide an electrochromic compound that has high coloring/discoloring repetition durability and excellent memory properties, and can ensure the transparency of an element.SOLUTION: The present invention provides an electrochromic material that contains a polymer containing a structural unit having at least one N-phenyl phenothiazine.SELECTED DRAWING: None

Description

  The present invention relates to an electrochromic polymer, an electrochromic composition, and an electrochromic display element.

  A phenomenon in which a redox reaction occurs reversibly and a color changes reversibly by applying a voltage is called electrochromism. The electrochromic material exhibiting electrochromism is generally formed between two opposing electrodes, and undergoes an oxidation-reduction reaction in a configuration in which an ion conductive electrolyte layer is filled between the electrodes. When a reduction reaction occurs in the vicinity of one of the two opposed electrodes, an oxidation reaction that is a reverse reaction occurs in the vicinity of the other electrode.

  That is, in a device using an electrochromic material, color development occurs at both poles by applying a voltage, and changes in color and optical density.

  In the electrochromic display element using the electrochromic material, when producing a transparent display device, and for full-color display, three color layers of cyan (C), magenta (M), and yellow (Y) are provided. When creating a device having a laminated structure, it is necessary that the device is made of a colorless and transparent material in a decolored state.

  As the electrochromic material, a phenothiazine compound that exhibits an electrochromic phenomenon in which a neutral state is a colorless and transparent state and color develops in an oxidized state is used.

  When the phenothiazine compound is used as the color forming layer of the device, it has been reported that high optical density and high contrast ratio can be realized by using titanium oxide or tin oxide particles as the electrochromic compound-supported particles. (For example, see Non-Patent Document 1)

  Moreover, an electrochromic display element using a polymer electrolyte containing the phenothiazine compound has been proposed (see, for example, Non-Patent Document 2).

J. Phys. Chem. B 2000, 104, 11449-11459 Displays 2010, 31, 150-154

  However, the conventional phenothiazine compound disclosed in Non-Patent Document 1 requires at least the use of supported particles in the electrochromic display device. The light scattering of the supported particles is considered to decrease the transparency, that is, increase the haze value, and is difficult to apply to a transparent display device in which transparency is essential.

  Moreover, in the said nonpatent literature 2, since a phenothiazine compound is dissolved in electrolyte, the use solvent is restricted. Furthermore, since the phenothiazine compound is not immobilized on the electrode surface, it cannot retain electric charge and it is difficult to maintain color development. This memory property greatly affects the power consumption as the area of the element increases, so the memory property is one of important characteristics to be ensured.

  Furthermore, it is more preferable that the above-mentioned problem can be realized in an electrochromic display element manufactured using a simple process.

  Therefore, the present inventor pays attention to a specific structure, that is, a phenothiazine structure, and has an electrodurability equivalent to that of a conventional compound, an electrochromic phenomenon, and excellent transparency and various colors. The material which can be done was examined earnestly.

  That is, the present invention provides an electrochromic material that has high color development / decoloration durability and good memory properties and can ensure the transparency of the device.

  As a result of intensive studies on an electrochromic compound having a phenothiazine structure, the present inventors have found that at least one electrochromic polymer containing at least one N-phenylphenothiazine structural unit has high color-decoloration / repeat durability and good memory properties. And it discovered that the transparency of an element could be ensured and came to complete this invention.

  One embodiment of the present invention provides an electrochromic polymer having at least one structural unit comprising a substituted or unsubstituted N-phenylphenothiazine structure.

  The electrochromic polymer of the present invention may further have a polymerizable functional group.

  Another embodiment of the present invention provides an electrochromic material comprising at least one of the above electrochromic polymers.

Yet another embodiment of the present invention provides:
The electrochromic material,
An electrochromic composition comprising another polymerizable compound different from the electrochromic material is provided.

Yet another embodiment of the present invention provides:
A first electrode;
A second electrode;
An electrolyte filled between the first electrode and the second electrode;
An electrochromic layer comprising one or more selected from the group consisting of the electrochromic polymer, the electrochromic material, and the electrochromic composition, located on the first electrode and on the second electrode side An electrochromic display element is provided.

  According to the embodiments of the present invention, it is possible to provide an electrochromic material that has high color-decoloring / repeatability and good memory properties and can ensure the transparency of the device.

  Hereinafter, embodiments of the present invention will be described in detail.

<Electrochromic polymer>
The electrochromic polymer that is an embodiment of the present invention comprises at least one N-phenylphenothiazine structure.

  Since the electrochromic polymer has high color-decoloring / repeatability and good memory properties, the use of the polymer can provide an electrochromic display element having excellent driving stability. The electrochromic material may further contain other electrochromic polymers in addition to the electrochromic polymer.

  The electrochromic polymer in the present invention may be linear or have a branched structure. The branched structure may be a structure branched in three or more directions, for example. From the viewpoint of easy control of the molecular weight, a linear polymer is preferable, and from the viewpoint of high heat resistance, it preferably has a structure branched in three or more directions. The electrochromic polymer in the present invention may include any one or more of a monovalent structural unit T, a divalent structural unit L, and a trivalent or higher structural unit B. The linear electrochromic polymer only needs to contain the divalent structural unit L1 having a substituted or unsubstituted N-phenylphenothiazine structure, and may contain another divalent structural unit L2. The electrochromic polymer having a structure branched in three or more directions includes the divalent structural unit L1 having the substituted or unsubstituted N-phenylphenothiazine structure, but is substituted or unsubstituted N-phenyl. It may contain a trivalent or higher structural unit B1 having a phenothiazine structure. When the trivalent or higher structural unit B1 having a substituted or unsubstituted N-phenylphenothiazine structure is included, at least the monovalent structural unit T constituting the terminal portion may be included, and the divalent structural unit L may be further included. . Preferably, the specific electrochromic polymer includes at least a trivalent or higher structural unit B1 including a structural unit having a substituted or unsubstituted N-phenylphenothiazine structure, a divalent structural unit L, and a monovalent structure. Unit T is included. In the electrochromic polymer of the present invention, the structural unit having N-phenylphenothiazine is included in at least one of the structural units B, L, and T as the structural units B1, L1, and T1, respectively.

  The electrochromic polymer may contain only one type of each structural unit, or may contain a plurality of types. In the electrochromic polymer, each structural unit is bonded to each other at a binding site of “monovalent” to “trivalent or higher”.

  As described above, the electrochromic material may further include other electrochromic polymers in addition to the electrochromic polymer. The other electrochromic polymer may be linear or have a branched structure. The other electrochromic polymer preferably includes at least a divalent structural unit L2 having a charge transport property and a monovalent structural unit T2 constituting a terminal portion, and a trivalent or higher structural unit constituting a branched portion. B2 may further be included.

(Construction)
Examples of the partial structure contained in the electrochromic polymer having a structure branched in three or more directions include the following. The electrochromic polymer is not limited to a polymer having the following partial structure. In the following partial structures, “B” represents the structural unit B, “L” represents the structural unit L, and “T” represents the structural unit T. “*” Represents a binding site with another structural unit. In the following partial structure, a plurality of L may be the same structural unit as each other or may be different from each other. The same applies to “T” and “B”.

分岐構造を有するエレクトロクロミックポリマー

Linear electrochromic polymer

Electrochromic polymer with branched structure

  Hereinafter, each structural unit will be described more specifically.

(Structural unit B)
The structural unit B is a trivalent or higher structural unit that constitutes the branched portion. The structural unit B is preferably hexavalent or less, more preferably trivalent or tetravalent, from the viewpoint of improving the durability of the electrochromic display element. The structural unit B includes a trivalent or higher structural unit B1 having a substituted or unsubstituted N-phenylphenothiazine structure and a trivalent or higher structural unit B2 having no substituted or unsubstituted N-phenylphenothiazine structure.

(Structural unit B1)
The electrochromic polymer used in the electrochromic material according to the embodiment of the present invention may optionally contain the trivalent or higher valent structural unit B constituting the branched portion described above, but is substituted or unsubstituted N-phenyl. It may contain a trivalent or higher structural unit B1 having a phenothiazine structure.

  The N-phenylphenothiazine structure means a structure in which a hydrogen site on the nitrogen atom of phenothiazine is substituted with a phenyl group. The phenyl group bonded to the nitrogen atom may have a substituent or a linking group, and the substituents may be linked to form a cyclic structure. The aromatic ring constituting the phenothiazine structure may also have a substituent or a linking group.

  When the electrochromic polymer contains a trivalent or higher structural unit B1 having a substituted or unsubstituted N-phenylphenothiazine structure in the molecule, it becomes easy to improve the repetition durability and the memory property of the electrochromic display element. Although details are unknown, it is considered that the electrochromic polymer containing the N-phenylphenothiazine structure in the molecule is excellent in stability.

Specific examples of the structural unit B1 include the following. The structural unit B1 is not limited to the following.

(Structural unit B2)
The electrochromic polymer used in the electrochromic material according to the embodiment of the present invention may optionally contain the trivalent or higher valent structural unit B constituting the branched portion described above, but is substituted or unsubstituted N-phenyl. A trivalent or higher structural unit B2 having no phenothiazine structure may be included. For example, the structural unit B2 is a substituted or unsubstituted aromatic amine structure, carbazole structure, condensed polycyclic aromatic hydrocarbon structure, and one of these from the viewpoint of improving durability of the electrochromic display element It is selected from structures containing two or more.

Specific examples of the structural unit B2 include the following. The structural unit B2 is not limited to the following.

  W represents a trivalent linking group, for example, an arenetriyl group or a heteroarenetriyl group having 2 to 30 carbon atoms. The arenetriyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic hydrocarbon. The heteroarene triyl group is an atomic group obtained by removing three hydrogen atoms from an aromatic heterocyclic ring. Ar each independently represents a divalent linking group, for example, each independently represents an arylene group or heteroarylene group having 2 to 30 carbon atoms. Ar is preferably an arylene group, more preferably a phenylene group. Y represents a divalent linking group. For example, one R atom in the structural unit L (excluding a group containing a polymerizable functional group) has one more hydrogen atom from a group having one or more hydrogen atoms. And divalent groups excluding. Z represents any of a carbon atom, a silicon atom, or a phosphorus atom.

In the structural unit, the benzene ring and Ar may have one or more substituents R. The substituents R each independently include —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ , —SiR ⁶ R ⁷ R ⁸ , a halogen atom, and a polymerizable functional group described later. Selected from the group consisting of groups. R ^{1 to} R ⁸ each independently represents a hydrogen atom; a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms; or an aryl group or heteroaryl group having 2 to 30 carbon atoms (provided that Except when R ¹ is a hydrogen atom).

  The aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. A heteroaryl group is an atomic group obtained by removing one hydrogen atom from an aromatic heterocyclic ring. The alkyl group may be further substituted by an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group is further linear, cyclic or branched having 1 to 22 carbon atoms. It may be substituted with an alkyl group.

  R is preferably an alkyl group, an aryl group, or an alkyl-substituted aryl group.

  Examples of the aromatic hydrocarbon include a single ring, a condensed ring, or a polycycle in which two or more selected from a single ring and a condensed ring are bonded via a single bond. Examples of the aromatic heterocycle include a single ring, a condensed ring, or a polycycle in which two or more selected from a monocycle and a condensed ring are bonded via a single bond.

(Structural unit L)
The structural unit L is a divalent structural unit. The structural unit L is not particularly limited as long as it contains an atomic group having the ability to transport charges. The structural unit L includes a divalent structural unit L1 having a substituted or unsubstituted N-phenylphenothiazine structure and a divalent structural unit L2 having no substituted or unsubstituted N-phenylphenothiazine structure.

(Structural unit L1)
The electrochromic polymer used in the electrochromic material according to the embodiment of the present invention may optionally include the divalent structural unit L shown above, but in one embodiment, at least a substituted or unsubstituted N- The divalent structural unit L1 having a phenylphenothiazine structure may be included.

  When the electrochromic polymer contains the structural unit L1 in the molecule, it becomes easy to improve the repetition durability and the memory property of the electrochromic display element. Although details are unknown, it is considered that when an N-phenylphenothiazine structure is introduced, the stability of the polymer is improved.

Preferred specific examples of the structural unit L1 include the following. The structural unit L1 is not limited to the following.

(Structural unit L2)
The electrochromic polymer used for the electrochromic material according to the embodiment of the present invention may optionally contain the divalent structural unit L shown above, but does not have a substituted or unsubstituted N-phenylphenothiazine structure. The valent structural unit L2 may be included. The structural unit L2 may include an atomic group that extends the ability to transport charges and the conjugate length, and is not particularly limited. For example, the structural unit L2 is a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, biphenyl structure, terphenyl structure, naphthalene structure, anthracene structure, tetracene structure, phenanthrene structure, dihydro Phenanthrene structure, pyridine structure, pyrazine structure, quinoline structure, isoquinoline structure, quinoxaline structure, acridine structure, diazaphenanthrene structure, furan structure, pyrrole structure, oxazole structure, oxadiazole structure, thiazole structure, thiadiazole structure, triazole structure, benzo Thiophene structure, benzoxazole structure, benzooxadiazole structure, benzothiazole structure, benzothiadiazole structure, benzotriazole structure, and one or two of these It is selected from a structure including more.

  In one embodiment, the structural unit L2 has a substituted or unsubstituted aromatic amine structure, carbazole structure, thiophene structure, fluorene structure, benzene structure, pyrrole structure, and 1 thereof from the viewpoint of obtaining excellent durability. It is preferably selected from a species or a structure including two or more, more preferably selected from a substituted or unsubstituted aromatic amine structure, a carbazole structure, and a structure including one or more of these. preferable. Here, the aromatic amine structure is preferably a triarylamine structure, more preferably a triphenylamine structure.

Specific examples of the structural unit L2 include the following. The structural unit L2 is not limited to the following.

Each R independently represents a hydrogen atom or a substituent. Preferably, each R independently represents —R ¹ , —OR ² , —SR ³ , —OCOR ⁴ , —COOR ⁵ , —SiR ⁶ R ⁷ R ⁸ , a halogen atom, and a polymerizable functional group described later. Selected from the group consisting of containing groups. R ^{1 to} R ⁸ each independently represents a hydrogen atom; a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms; or an aryl group or heteroaryl group having 2 to 30 carbon atoms. The aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. A heteroaryl group is an atomic group obtained by removing one hydrogen atom from an aromatic heterocyclic ring. The alkyl group may be further substituted by an aryl group or heteroaryl group having 2 to 20 carbon atoms, and the aryl group or heteroaryl group is further linear, cyclic or branched having 1 to 22 carbon atoms. It may be substituted with an alkyl group. R is preferably a hydrogen atom, an alkyl group, an aryl group, or an alkyl-substituted aryl group. Ar represents an arylene group or heteroarylene group having 2 to 30 carbon atoms. An arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon. A heteroarylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic heterocycle. Ar is preferably an arylene group, more preferably a phenylene group.

  Examples of the aromatic hydrocarbon include a single ring, a condensed ring, or a polycycle in which two or more selected from a single ring and a condensed ring are bonded via a single bond. Examples of the aromatic heterocycle include a single ring, a condensed ring, or a polycycle in which two or more selected from a monocycle and a condensed ring are bonded via a single bond.

(Structural unit T)
The structural unit T is a monovalent structural unit that constitutes the terminal portion of the electrochromic polymer. The structural unit T is not particularly limited. The structural unit T includes a monovalent structural unit T1 having a substituted or unsubstituted N-phenylphenothiazine structure and a monovalent structural unit T2 having no substituted or unsubstituted N-phenylphenothiazine structure.

(Structural unit T1)
The electrochromic polymer used in the electrochromic material according to an embodiment of the present invention may optionally include the monovalent structural unit T shown above, but in one embodiment, at least one substituted or unsubstituted N -A monovalent structural unit T1 having a phenylphenothiazine structure is included.

Specific examples of the structural unit T1 include the following. The structural unit T1 is not limited to the following.

(Structural unit T2)
The electrochromic polymer used for the electrochromic material according to the embodiment of the present invention may optionally contain the monovalent structural unit L shown above, but does not have a substituted or unsubstituted N-phenylphenothiazine structure. The valent structural unit T2 may be included. The structural unit T2 is selected from, for example, a substituted or unsubstituted aromatic hydrocarbon structure, aromatic heterocyclic structure, and a structure including one or more of these. The structural unit T2 may have the same structure as the structural unit L2. In one embodiment, the structural unit T2 is preferably a substituted or unsubstituted aromatic hydrocarbon structure from the viewpoint of imparting durability without degrading electrochromic properties, and a substituted or unsubstituted benzene structure. It is more preferable that In other embodiments, as described later, when the electrochromic polymer has a polymerizable functional group at the terminal portion, the structural unit T2 has a polymerizable structure (for example, a polymerizable functional group such as a pyrrol-yl group). It may be.

Specific examples of the structural unit T2 include the following. The structural unit T2 is not limited to the following.

  R is the same as R in the structural unit L2. When the electrochromic polymer has a polymerizable functional group at the terminal portion, preferably, at least one of R is a group containing a polymerizable functional group.

(Polymerizable functional group)
In one embodiment, the electrochromic polymer preferably has at least one polymerizable functional group from the viewpoint of curing by a polymerization reaction and improving the stability in the device. The “polymerizable functional group” refers to a functional group that can form a bond with each other by applying heat and / or light.

  The polymerizable functional group includes a group having a carbon-carbon multiple bond (for example, vinyl group, allyl group, butenyl group, ethynyl group, acryloyl group, acryloyloxy group, acryloylamino group, methacryloyl group, methacryloyloxy group, methacryloylamino group). Groups, vinyloxy groups, vinylamino groups, etc.), groups having a small ring (eg, cyclic alkyl groups such as cyclopropyl groups, cyclobutyl groups; cyclic ether groups such as epoxy groups (oxiranyl groups), oxetane groups (oxetanyl groups), etc. Diketene group; episulfide group; lactone group; lactam group, etc.), heterocyclic group (for example, furan-yl group, pyrrol-yl group, thiophen-yl group, silole-yl group) and the like. As the polymerizable functional group, a vinyl group, an acryloyl group, a methacryloyl group, an epoxy group, and an oxetane group are particularly preferable, and from the viewpoint of reactivity and characteristics of the organic electronics element, a vinyl group, an oxetane group, or an epoxy group is more preferable. preferable.

  From the viewpoint of increasing the degree of freedom of the polymerizable functional group and facilitating the polymerization reaction, it is preferable that the main skeleton of the electrochromic polymer and the polymerizable functional group are connected by an alkylene chain. In addition, for example, when an organic layer is formed on an electrode, it is connected with a hydrophilic chain such as an ethylene glycol chain or a diethylene glycol chain from the viewpoint of improving the affinity with a hydrophilic electrode such as ITO. preferable. Furthermore, from the viewpoint of facilitating the preparation of the monomer used for introducing the polymerizable functional group, the electrochromic polymer has an alkylene chain and / or a hydrophilic chain end, that is, polymerizable with these chains. You may have an ether bond or an ester bond in the connection part with a functional group and / or the connection part between these chains and the skeleton of the electrochromic polymer. The above-mentioned “group containing a polymerizable functional group” means a polymerizable functional group itself or a group obtained by combining a polymerizable functional group with an alkylene chain or the like. As the group containing a polymerizable functional group, for example, a group exemplified in International Publication No. WO2010 / 140553 can be suitably used.

  The polymerizable functional group may be introduced into the terminal part (that is, the structural unit T) of the electrochromic polymer, or may be introduced into a part other than the terminal part (that is, the structural unit L or B). You may introduce | transduce into both parts other than the terminal. The polymerizable functional group is preferably introduced at least at the terminal portion from the viewpoint of curability, and is preferably introduced only at the terminal portion from the viewpoint of achieving both curability and electrochromic properties. . Further, when the electrochromic polymer has a branched structure, the polymerizable functional group may be introduced into the main chain of the electrochromic polymer or may be introduced into the side chain, and may be introduced into both the main chain and the side chain. It may be introduced.

  From the viewpoint of contributing to the curing rate, it is preferable that a large amount of the polymerizable functional group is contained in the electrochromic polymer. On the other hand, from the viewpoint of not disturbing the electrochromic properties, it is preferable that the amount contained in the electrochromic polymer is small. The content of the polymerizable functional group can be appropriately set in consideration of these.

  For example, the number of polymerizable functional groups per molecule of the electrochromic polymer is preferably 2 or more, more preferably 3 or more from the viewpoint of obtaining a sufficient solubility change. In addition, the number of polymerizable functional groups is preferably 1,000 or less, more preferably 500 or less, from the viewpoint of maintaining electrochromic characteristics.

The number of polymerizable functional groups per molecule of electrochromic polymer is the amount of polymerizable functional group used to synthesize the electrochromic polymer (for example, the amount of monomer having a polymerizable functional group), and each structural unit. It can be determined as an average value using the amount of the corresponding monomer charged, the weight average molecular weight of the electrochromic polymer, and the like. The number of polymerizable functional groups is the ratio of the integrated value of the signal derived from the polymerizable functional group and the integrated value of the entire spectrum in the ¹ H NMR (nuclear magnetic resonance) spectrum of the electrochromic polymer, the weight of the electrochromic polymer The average molecular weight can be used to calculate the average value. Since it is simple, when the preparation amount is clear, a value obtained by using the preparation amount is preferably adopted.

(Ratio of structural units B, L, and T)
The proportion of the structural unit B contained in the electrochromic polymer is preferably 1 mol% or more, more preferably 5 mol% or more, more preferably 10 mol%, based on all structural units, from the viewpoint of improving the durability of the electrochromic display element. The above is more preferable. Further, the proportion of the structural unit B is preferably 50 mol% or less, more preferably 40 mol% or less, from the viewpoint of suppressing the increase in viscosity and satisfactorily synthesizing the electrochromic polymer or obtaining sufficient durability. Preferably, it is 30 mol% or less. The said ratio means the total amount of the structural unit B including the structural unit B1.

  From the viewpoint of obtaining sufficient electrochromic properties, the proportion of the structural unit L contained in the electrochromic polymer is preferably 10 mol% or more, more preferably 20 mol% or more, and more preferably 30 mol% or more based on the total structural unit. Further preferred. Further, the ratio of the structural unit L is preferably 95 mol% or less, more preferably 90 mol% or less, and still more preferably 85 mol% or less in consideration of the structural unit T and the structural unit B introduced as necessary. When the electrochromic polymer includes the structural unit L1, the above ratio means the total amount including the structural unit L1.

  The ratio of the structural unit T contained in the electrochromic polymer is based on the total structural unit from the viewpoint of improving the characteristics of the electrochromic display element or suppressing the increase in viscosity and favorably synthesizing the electrochromic polymer. 5 mol% or more is preferable, 10 mol% or more is more preferable, and 15 mol% or more is still more preferable. The proportion of the structural unit T is preferably 60 mol% or less, more preferably 55 mol% or less, and still more preferably 50 mol% or less, from the viewpoint of obtaining sufficient durability. When the electrochromic polymer includes the structural unit T1, the above ratio means the total amount including the structural unit T1.

  When the electrochromic polymer has a polymerizable functional group, the ratio of the polymerizable functional group is preferably 0.1 mol% or more based on the total structural unit from the viewpoint of efficiently curing the electrochromic polymer. % Or more is more preferable, and 3 mol% or more is still more preferable. The proportion of the polymerizable functional group is preferably 70 mol% or less, more preferably 60 mol% or less, and still more preferably 50 mol% or less from the viewpoint of obtaining good electrochromic properties. The “ratio of polymerizable functional groups” here refers to the ratio of structural units having a polymerizable functional group.

  Considering the balance of electrochromic characteristics, durability, productivity, etc., the ratio (molar ratio) of the structural unit L and the structural unit T is preferably L: T = 100: 70-1 and more preferably 100: 50-3. Preferably, 100: 30-5 is more preferable. When the electrochromic polymer includes the structural unit B, the ratio (molar ratio) of the structural unit L, the structural unit T, and the structural unit B is preferably L: T: B = 100: 10 to 200: 10 to 100. 100: 20-180: 20-90 are more preferable, and 100: 40-160: 30-80 are still more preferable.

The proportion of the structural unit can be determined using the amount of monomer charged corresponding to each structural unit used to synthesize the electrochromic polymer. Moreover, the ratio of a structural unit can be calculated as an average value using the integrated value of the spectrum derived from each structural unit in the ¹ H NMR spectrum of the electrochromic polymer. Since it is simple, when the preparation amount is clear, a value obtained by using the preparation amount is preferably adopted.

  In one embodiment, the electrochromic polymer having a structure branched in three or more directions includes at least a trivalent or higher structural unit B1 having a substituted or unsubstituted N-phenylphenothiazine structure as the trivalent or higher structural unit B. And the structural units L and / or T include structural units L1 and / or T1 having a triphenylamine structure having at least one alkoxy group.

  In another embodiment, the electrochromic polymer includes at least the structural unit L1 and / or T1 as the structural unit B1 and the structural unit L and / or T.

  In still another embodiment, the electrochromic polymer includes the structural unit B1, the structural unit L, and the structural unit T, and the structural unit T has at least the structural unit T1 and a polymerizable functional group. Unit T is included.

  According to the embodiment of the present invention, by using an electrochromic polymer including at least the structural unit B1, the structural unit L1, and / or the structural unit T1, the repetition durability and the memory property of the electrochromic display element are improved. It can be realized. From the viewpoint of effectively obtaining such effects, the proportion of the structural unit B1 contained in the structural unit B is preferably 50 mol% or more, more preferably 60 mol, based on the total amount of the structural unit B. % Or more, more preferably 70 mol% or more.

  When the electrochromic polymer includes the structural unit L1, the structural unit L1 is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more based on the total amount of the structural unit L. .

  Further, when the electrochromic polymer includes the structural unit T1 as the structural unit T, the structural unit T1 is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 50 mol, based on the total amount of the structural unit T. % Or more.

  In particular, from the viewpoint of improving the heat resistance of the electrochromic polymer, the proportion of the structural units L1 and / or T1 is preferably 10 mol% or more, more preferably 20 mol% or more, based on the total constituent units of the polymer. 30 mol% or more is more preferable. When the electrochromic polymer includes the structural units L1 and T1, the above ratio means the total amount of L1 and T1.

(Number average molecular weight)
The number average molecular weight of the electrochromic polymer can be appropriately adjusted in consideration of solubility in a solvent, film formability, and the like. The number average molecular weight is preferably 500 or more, more preferably 1,000 or more, and still more preferably 2,000 or more, from the viewpoint of excellent electrochromic properties. In addition, the number average molecular weight is preferably 1,000,000 or less, more preferably 100,000 or less, more preferably 50,000 from the viewpoint of maintaining good solubility in a solvent and facilitating preparation of an electrochromic composition. 000 or less is more preferable.

(Weight average molecular weight)
The weight average molecular weight of the electrochromic polymer can be adjusted as appropriate in consideration of solubility in a solvent, film formability, and the like. From the viewpoint of excellent durability, the weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, and still more preferably 10,000 or more. Further, the weight average molecular weight is preferably 1,000,000 or less, more preferably 700,000 or less, more preferably 400,000 or less from the viewpoint of maintaining good solubility in a solvent and facilitating the preparation of an electrochromic composition. 000 or less is more preferable.

  The number average molecular weight and the weight average molecular weight can be measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.

(Production method)
The electrochromic polymer can be produced by various synthetic methods and is not particularly limited. For example, known coupling reactions such as Suzuki coupling, Negishi coupling, Sonogashira coupling, Stille coupling, Buchwald-Hartwig coupling and the like can be used. Suzuki coupling causes a cross coupling reaction using a Pd catalyst between an aromatic boronic acid derivative and an aromatic halide. According to Suzuki coupling, an electrochromic polymer can be easily produced by bonding desired aromatic rings together.

  In the coupling reaction, for example, a Pd (0) compound, a Pd (II) compound, a Ni compound, or the like is used as a catalyst. In addition, a catalyst species generated by mixing tris (dibenzylideneacetone) dipalladium (0), palladium (II) acetate and the like with a phosphine ligand can also be used. For the method of synthesizing the electrochromic polymer, for example, the description of International Publication No. WO2010 / 140553 can be referred to.

<Electrochromic composition>
The electrochromic composition of the present invention comprises the above-described electrochromic polymer of the present invention and one or more other polymerizable compounds different from the electrochromic polymer.

[Other polymerizable compounds]
The other polymerizable compound is a compound different from the electrochromic polymer of the present invention and having at least one polymerizable functional group.

  Examples of the other polymerizable compound include, but are not limited to, a monofunctional polymerizable compound, a bifunctional polymerizable compound, a trifunctional or higher functional polymerizable compound, a functional monomer, and a polymerizable oligomer. . Among these, as the other polymerizable compound, a bifunctional or higher functional polymerizable compound is particularly preferable.

  The polymerizable functional group in the other polymerizable compound is the same as the polymerizable functional group in the present invention.

  Examples of the monofunctional polymerizable compound include 2- (2-ethoxyethoxy) ethyl acrylate, methoxypolyethylene glycol monoacrylate, methoxypolyethylene glycol monomethacrylate, phenoxypolyethylene glycol acrylate, 2-acryloyloxyethyl succinate, 2- Ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate , Phenoxytetraethylene glycol Acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, although styrene monomers include, but are not limited to. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the bifunctional polymerizable compound include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1, Examples include, but are not limited to, 6-hexanediol dimethacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, and neopentyl glycol diacrylate. Not. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the tri- or higher functional polymerizable compound include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, and caprolactone-modified trimethylolpropane triacrylate. Acrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified glycerol triacrylate, EO modified glycerol triacrylate, PO modified glycerol triacrylate, tris (acryloxyethyl) ) Isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, and the like, but are not limited thereto. These may be used individually by 1 type and may use 2 or more types together.

  In the above, EO modification represents ethyleneoxy modification, and PO modification represents propyleneoxy modification.

  Examples of the functional monomer include those substituted with fluorine atoms such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, and the like. No.-60503, JP-B-6-45770, acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl poly having 20 to 70 siloxane repeating units Examples include, but are not limited to, vinyl monomers having polysiloxane groups such as dimethylsiloxane diethyl, acrylates and methacrylates. . These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polymerizable oligomer include, but are not limited to, an epoxy acrylate oligomer, a urethane acrylate oligomer, and a polyester acrylate oligomer.

  In one embodiment of the present invention, at least one of the electrochromic polymer of the present invention and another polymerizable compound different from the electrochromic polymer of the present invention has two or more polymerizable functional groups. It is preferable from the point which forms a crosslinked structure.

  In one embodiment of the present invention, the content of the electrochromic polymer of the present invention is preferably 10% by mass or more and more preferably 30% by mass or more and 90% by mass or less with respect to the total amount of the electrochromic composition.

  When the content is 10% by mass or more, the electrochromic function of the electrochromic layer can be sufficiently exhibited, the durability is good by repeated use with applied voltage, and the color development sensitivity is good.

  Even when the content is 100% by mass, an electrochromic function is possible. In this case, the color development sensitivity with respect to the thickness is the highest. On the other hand, the compatibility with the ionic liquid necessary for the transfer of charges may be low, so that repeated use due to applied voltage may cause deterioration of electrical characteristics due to a decrease in durability. Although it cannot be said unconditionally because required electrical characteristics differ depending on the process to be used, it is more preferably 30% by mass or more and 90% by mass or less in consideration of the balance between both the color development sensitivity and the repetition characteristics.

[Polymerization initiator]
The electrochromic composition efficiently initiates a polymerization / crosslinking reaction between the electrochromic polymer of the present invention and another polymerizable compound different from the electrochromic polymer of the present invention. It is preferable to contain an agent.

  Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator, but a photopolymerization initiator is preferable from the viewpoint of polymerization efficiency, and a thermal polymerization initiator is preferable from the viewpoint of simple curing process. .

  The thermal polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, such as t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, etc. Peroxide initiators; azo initiators such as azobisisobutylnitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid, etc. For example, but not limited to. These may be used individually by 1 type and may use 2 or more types together.

  The photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy Cyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-dimethylamino-1- (4-morpholinophenyl) -2-benzyl-1-butanone, 2- Hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o- Acetophenone or ketal photoinitiators such as ethoxycarbonyl) oxime; benzoin, benzoin methyl ether Benzoin ether photopolymerization initiators such as benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl Benzophenone photopolymerization initiators such as ether, acrylated benzophenone, 1,4-benzoylbenzene; 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples thereof include, but are not limited to, thioxanthone photopolymerization initiators such as IRGACURE184, and hydroxyalkylphenone photopolymerization initiators such as IRGACURE184.

  Examples of other photopolymerization initiators that can be used in the embodiment of the present invention include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compounds , Triazine compounds, imidazole compounds, and the like, but are not limited thereto. These may be used individually by 1 type and may use 2 or more types together.

  In addition, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like. It is not limited to these.

  The content of the polymerization initiator is preferably 0.5 parts by mass or more and 40 parts by mass or less, and more preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the total amount of the polymerizable compound.

[Filler]
The electrochromic composition of the present invention may contain a filler. There is no restriction | limiting in particular as a filler, According to the objective, it can select suitably, For example, an organic filler, an inorganic filler, etc. are mentioned.

  Examples of the inorganic filler include metal powders such as copper, tin, aluminum, and indium; silicon oxide (silica), tin oxide, zinc oxide, titanium oxide, aluminum oxide (alumina), zirconium oxide, indium oxide, antimony oxide, Examples include metal oxides such as bismuth oxide, calcium oxide, antimony-doped tin oxide (ATO), tin-doped indium oxide, and metal fluorides such as copper fluoride, calcium fluoride, and aluminum fluoride. It is not limited to these. These may be used individually by 1 type and may use 2 or more types together. Among these, metal oxides are preferable and tin oxide doped with silica, alumina, and antimony (ATO) is particularly preferable in terms of transparency, stability, and ease of surface treatment.

  Examples of the organic filler include, but are not limited to, resins such as polyester, polyether, polysulfide, polyolefin, silicone, and polytetrafluoroethylene, low molecular compounds such as fatty acids, and pigments such as phthalocyanine. These may be used individually by 1 type and may use 2 or more types together. Among these, a resin is preferable from the viewpoint of transparency and insolubility.

  The primary particle size of the filler is preferably 1 μm or less, and more preferably 10 nm or more and 1 μm or less. When the primary particle size of the filler is 1 μm or less, there are no coarse particles, the surface state of the resulting film is good, and the surface smoothness is excellent.

  The content of the filler is preferably 0.3 parts by mass or more and 1.5 parts by mass or less, and preferably 0.6 parts by mass or more and 0.9 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable compound. Part or less is more preferable.

  When the content is 0.3 parts by mass or more, a filler addition effect is sufficiently obtained, the film formability is good, and when the content is 1.5 parts by mass or less, the proportion of the filler is appropriate and the production is completed. Thus, good electrochemical characteristics of the electrochromic display element can be obtained.

[Other optional ingredients]
The electrochromic composition of the present invention may further contain other components, and can be appropriately selected according to the purpose. For example, the solvent, plasticizer, leveling agent, sensitizer, dispersant, surfactant Examples include, but are not limited to, agents and antioxidants.

<Electrochromic display element>
The electrochromic display element according to the present invention includes a first electrode, a second electrode, and an electrolyte filled between the first electrode and the second electrode, and the first electrode The electrochromic layer containing the electrochromic polymer, the electrochromic material, and / or the electrochromic composition is provided on the second electrode side, and other components and members are included as necessary.

  The average thickness of the electrochromic layer is preferably 0.1 μm or more and 30 μm or less, and more preferably 0.4 μm or more and 10 μm or less.

[First electrode and second electrode]
Examples of the material constituting the first electrode and the second electrode include a transparent conductive substrate. As the transparent conductive substrate, for example, a glass or plastic film coated with a transparent conductive thin film is preferable.

The material of the transparent conductive thin film is not particularly limited as long as it is a transparent material having conductivity, and can be appropriately selected according to the purpose. For example, indium oxide doped with tin (hereinafter referred to as “ITO”). Inorganic materials such as tin oxide doped with fluorine (hereinafter also referred to as “FTO”), tin oxide doped with antimony (hereinafter also referred to as “ATO”), zinc oxide, and the like. Not. Among these, InSnO, GaZnO, SnO, In ₂ O ₃ and ZnO are preferable.

  Further, as the material of the transparent conductive thin film, transparent carbon nanotubes, other highly conductive non-permeable materials such as Au, Ag, Pt, Cu, etc. are formed in a fine network shape to increase transparency. You may use the electrode which improved electroconductivity, hold | maintaining.

  The average thickness of each of the first electrode and the second electrode is appropriately adjusted so that an electric resistance value necessary for the oxidation-reduction reaction of the electrochromic layer can be obtained.

  When ITO is used as the material for the first electrode and the second electrode, the average thickness of each of the first electrode and the second electrode is preferably, for example, 50 nm or more and 500 nm or less. As a method for manufacturing each ITO electrode, a vacuum deposition method, a sputtering method, an ion plating method, or the like can be used.

  There is a coating method as another method for forming the first electrode and the second electrode, and there is no particular limitation as long as it can be formed by coating. For example, a spin coating method, a casting method, a micro gravure coating method, a gravure coating Method, bar coating method, roll coating method, wire bar coating method, dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method Various printing methods such as reverse printing and ink jet printing can be used.

[Electrolytes]
The electrolyte is filled between the first electrode and the second electrode. Examples of the electrolyte include inorganic ion salts such as alkali metal salts and alkaline earth metal salts; and supporting salts such as quaternary ammonium salts, acids and alkalis. Specifically, LiClO ₄ , LiBF ₄ , Examples include LiAsF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ COO, KCl, NaClO ₄ , NaCl, NaBF ₄ , NaSCN, KBF ₄ , Mg (ClO ₄ ) ₂ , and Mg (BF ₄ ) ₂ . These may be used individually by 1 type and may use 2 or more types together.

  An ionic liquid can also be used as the electrolyte material. Among these, the organic ionic liquid is preferably used because it has a molecular structure showing the liquid in a wide temperature range including room temperature.

As a molecular structure showing a liquid in a wide temperature range including the room temperature, as a cation component, for example, imidazole such as N, N-dimethylimidazole salt, N, N-methylethylimidazole salt, N, N-methylpropylimidazole salt, etc. Derivatives; pyridinium derivatives such as N, N-dimethylpyridinium salt and N, N-methylpropylpyridinium salt; aliphatic quaternary ammonium salts such as trimethylpropylammonium salt, trimethylhexylammonium salt and triethylhexylammonium salt. As the anionic component, from the viewpoint of stability in the atmosphere, it is preferable to use containing a fluorine compound, for _{^{example, BF 4 -, CF 3 SO}} 3 -, PF 4 -, (CF 3 SO 2) 2 N ^-, and the like. These may be used individually by 1 type and may use 2 or more types together.

  As the electrolyte material, it is preferable to use an ionic liquid in which the cation component and the anion component are arbitrarily combined.

  The ionic liquid may be directly dissolved in any of photopolymerizable monomers, oligomers, and liquid crystal materials. When the solubility is poor, a solution dissolved in a small amount of solvent can be mixed with any of photopolymerizable monomers, oligomers, and liquid crystal materials.

[solvent]
As the solvent, water, an organic solvent, or a mixed solvent thereof can be used. Organic solvents include alcohols such as methanol, ethanol and isopropyl alcohol; alkanes such as pentane, hexane and octane; cyclic alkanes such as cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, tetralin and diphenylmethane; ethylene glycol Aliphatic ethers such as dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, Aromatic ethers such as 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole; ethyl acetate, n-butyl acetate, ethyl lactate, n-butyl lactate Aliphatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate; N, N-dimethylformamide, N, N-dimethylacetamide, etc. Amide solvents; other propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,2-dimethoxyethane, 1,2-ethoxymethoxyethane, polyethylene glycol, Examples include, but are not limited to, acetone, chloroform, methylene chloride and the like.

  The electrolyte need not be a low-viscosity liquid, and can take various forms such as a gel, a polymer cross-linked type, and a liquid crystal dispersed type. By forming the electrolyte in a gel or solid state, it is advantageous from the standpoints of improving element strength and reliability.

  As a solidification method, it is preferable to support an electrolyte and a solvent in a polymer resin from the viewpoint of obtaining high ion conductivity and solid strength.

  As the polymer resin, a photo-curable resin is preferable from the viewpoint that an element can be manufactured at a low temperature and in a short time. Since the process is simple, a thermosetting resin or a method of evaporating a solvent is used. You can also.

[Other parts]
The electrochromic display element of the present invention may have other members and can be appropriately selected depending on the purpose. Examples of other members that can be used in the electrochromic display element of the present invention include, but are not limited to, a support, an insulating porous layer, a deterioration preventing layer, a carrier, and a protective layer.

(Support)
As the support, a known organic material or inorganic material can be used as it is as long as it is a transparent material capable of supporting each layer.

  Examples of the support include glass substrates such as alkali-free glass, borosilicate glass, float glass, and soda lime glass; polycarbonate resin, acrylic resin, polyethylene, polyvinyl chloride, polyester, epoxy resin, melamine resin, phenol resin, Examples include, but are not limited to, resin substrates such as polyurethane resins and polyimide resins.

  The surface of the support may be coated with a transparent insulating layer, a UV cut layer, an antireflection layer or the like in order to improve water vapor barrier properties, gas barrier properties, ultraviolet resistance, and visibility.

  The shape of the support is not particularly limited, and may be rectangular or round.

  The support may be a superposition of a plurality of substrates. For example, by providing a structure in which an electrochromic display element is sandwiched between two glass substrates, the water vapor barrier property and the gas barrier property can be improved.

(Insulating porous layer)
The insulating porous layer has a function of isolating the first electrode and the second electrode so as to be electrically insulated and retaining an electrolyte.

  The material of the insulating porous layer is not particularly limited as long as it is porous, and organic materials, inorganic materials, and composites thereof that have high insulating properties and durability and excellent film forming properties are preferable.

  As the method for forming the insulating porous layer, for example, a sintered soot (by adding a binder or the like, polymer fine particles or inorganic particles are partially fused, and holes generated between the particles are used). Extraction method (dissolves organic or inorganic substances soluble in solvent to obtain pores), foaming foaming method, phase change method (manipulating good solvent and poor solvent to phase-separate polymer mixture) And radiation irradiation method (radiating various types of radiation to form pores).

(Deterioration prevention layer)
The deterioration preventing layer has a chemical reaction opposite to that of an electrochromic layer made of an electrochromic composition, and the first electrode and the second electrode are corroded or deteriorated by an irreversible oxidation-reduction reaction in order to balance the charge. Can be suppressed. The reverse chemical reaction means that the deterioration preventing layer acts as a capacitor in addition to the oxidation-reduction reaction.

  The material for the deterioration preventing layer is not particularly limited as long as it is a material that plays a role of preventing corrosion due to the irreversible oxidation-reduction reaction of the first electrode and the second electrode, and is appropriately selected according to the purpose. For example, antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, or a conductive metal oxide containing a plurality of them, or a semiconductive metal oxide can be used.

  The deterioration preventing layer can be composed of a porous thin film that does not hinder electrolyte injection. For example, conductive metal oxide fine particles or semiconductive metal oxide fine particles such as antimony tin oxide, nickel oxide, titanium oxide, zinc oxide, tin oxide, etc., for example, acrylic, alkyd, isocyanate, urethane, epoxy By fixing to the second electrode with a binder such as phenol, a suitable porous thin film satisfying the electrolyte permeability and the function as a deterioration preventing layer can be obtained.

  As the deterioration preventing layer, when the same conductive nanostructure or semiconducting nanostructure constituting the electrochromic composition is used, the first electrode and the electrochromic composition manufacturing process, the second electrode and This is preferable because a part of the manufacturing process of the deterioration preventing layer can be shared.

(Carrier)
When combining other electrochromic materials with the electrochromic polymer of the present invention, supported particles can be used.

  For example, when an electrochromic compound other than the electrochromic polymer of the present invention has a phosphonic acid, sulfonic acid group, phosphoric acid group, carboxyl group or the like as a bond or adsorption structure, the electrochromic compound is easily separated from the nanostructure. It becomes an electrochromic composition which is compounded and has excellent color image retention. A plurality of the phosphonic acid group, the sulfonic acid group, the phosphoric acid group, and the carboxyl group may be present in the electrochromic compound. In addition, when the electrochromic polymer according to the present invention has a silyl group, a silanol group or the like, the bond becomes strong by being bonded to the nanostructure through a siloxane bond, and a stable electrochromic composition Can be obtained. The siloxane bond refers to a chemical bond through a silicon atom and an oxygen atom. In addition, the electrochromic composition only needs to have a structure in which the electrochromic polymer and / or the electrochromic compound and the nanostructure are bonded via a siloxane bond, and the bonding method and form thereof are not particularly limited. .

  The conductive nanostructure or semiconducting nanostructure refers to a structure having nanoscale irregularities such as a nanoparticle or a nanoporous structure.

  Examples of the material constituting the conductive nanostructure or semiconducting nanostructure include metal oxides from the viewpoint of transparency and conductivity.

  Examples of the metal oxide include titanium oxide, zinc oxide, tin oxide, zirconium oxide, cerium oxide, yttrium oxide, boron oxide, magnesium oxide, strontium titanate, potassium titanate, barium titanate, calcium titanate, and oxidation. Examples include calcium, ferrite, hafnium oxide, tungsten oxide, iron oxide, copper oxide, nickel oxide, cobalt oxide, barium oxide, strontium oxide, vanadium oxide, aluminosilicate, calcium phosphate, and aluminosilicate. It is not limited to these. These may be used individually by 1 type and may use 2 or more types together. Among these, titanium oxide, zinc oxide, tin oxide, zirconium oxide, iron oxide, magnesium oxide, indium oxide, and tungsten oxide are preferable from the viewpoint of electrical characteristics such as electrical conductivity and physical characteristics such as optical properties. Titanium oxide is more preferable. When the metal oxide or a mixture of the metal oxides is used, the response speed of color development and decoloration is excellent.

As the shape of the metal oxide, metal oxide fine particles having an average primary particle diameter of 30 nm or less are preferable. As the average primary particle size is smaller, the light transmittance with respect to the metal oxide can be improved, and a shape having a larger surface area per unit volume (hereinafter referred to as “specific surface area”) is used. By having a large specific surface area, the electrochromic polymer and / or the electrochromic composition can be more efficiently supported, and a multicolor display having an excellent display contrast ratio for color development and decoloration can be achieved. There is no restriction | limiting in particular in the specific surface area of a nanostructure, According to the objective, it can select suitably, 100 m < ² > / g or more is preferable.

(Protective layer)
The protective layer can protect the electrochromic display element from external stresses and chemicals used in the cleaning process, can prevent leakage of the electrolyte, and can be electrochromic such as moisture and oxygen in the atmosphere. Since the display element operates stably, entry of unnecessary objects can be prevented.

  There is no restriction | limiting in particular as average thickness of the said protective layer, Although it can select suitably according to the objective, 1 micrometer or more and 200 micrometers or less are preferable.

  As the material of the protective layer, for example, an ultraviolet curable resin, a thermosetting resin, or the like can be used. Specific examples include an acrylic resin, a urethane resin, and an epoxy resin.

<Method for manufacturing electrochromic display element>
The method for producing an electrochromic display element of the present invention includes a coating step of coating the electrochromic polymer and / or electrochromic composition of the present invention on the first electrode, and the applied electrochromic polymer and / or electrochromic composition. And a crosslinking step of crosslinking by applying heat or light energy to the product.

[Coating process]
The coating step is a step of coating the electrochromic polymer of the present invention and / or the electrochromic composition of the present invention on the first electrode. The coating solution is applied by diluting with a solvent as necessary. As the solvent, the above solvents can be used.

[Crosslinking process]
The crosslinking step is a step of heating or applying light energy to the applied electrochromic polymer and / or electrochromic composition for crosslinking.

  After applying the electrochromic polymer and / or electrochromic composition on the first electrode, energy is applied from the outside and cured to form an electrochromic layer. Examples of the external energy include heat, light, and radiation. The heat energy is applied by heating from the coating surface side or the support side using a gas such as air, nitrogen, steam, various heat media, infrared rays, or electromagnetic waves. The heating temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 60 ° C. or higher and 170 ° C. or lower.

  As the energy of the light, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp having an emission wavelength mainly in ultraviolet light (UV) can be used, but visible light is matched to the absorption wavelength of the polymerizable substance or the photopolymerization initiator. A light source can also be selected.

Irradiation dose of UV is not particularly limited and may be appropriately selected depending on the intended purpose, 5 mW / cm ² or more 15,000 MW / cm ² or less.

[Other processes]
As other processes, for example, a process of forming a first electrode, a process of forming a second electrode, an insulating porous layer forming process, a deterioration preventing layer forming process, a protective layer forming process, a bonding process, etc. Is mentioned.

<Application>
Since the electrochromic display element of the present invention is capable of stable operation and excellent in response speed and light durability, for example, an electrochromic display, a large display board such as a stock price display board, an antiglare mirror, It can be suitably used for dimming elements such as optical glass, low-voltage driving elements such as touch panel key switches, optical switches, optical memories, electronic paper, and electronic albums.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<I> Synthesis of monomer (Synthesis of monomer (PT-1) having N-phenylphenothiazine structure)
In a three-necked flask, phenothiazine (19.8 g, 0.1 mol), 4-bromobutylbenzene (21.3 g, 0.1 mol), palladium (II) acetate (0.225 g, 1 mmol), NaOtBu (14.4 g, 0.1 mol). 15 mol) and o-xylene (300 mL) were added, and the flask was moved into the glove box. The solution was bubbled with nitrogen gas for 20 minutes and degassed. P (t-Bu) ₃ (0.606 g, 3 mmol) was added and sealed. The flask was taken out of the glove box, a cooling pipe was attached, and heating and refluxing were performed at 150 ° C. for 5 hours under a nitrogen flow. After cooling the solution, the solution was filtered through Celite and concentrated with an evaporator to obtain a black solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (9: 1) as a developing solution, and 25.3 g of a pale yellow solid of N- (4-butylphenyl) phenothiazine was obtained. Obtained. Yield 76.3%.

N- (4-Butylphenyl) phenothiazine (2.14 g, 6.46 mmol) was added to the three-necked flask and dissolved in N, N-dimethylformamide (100 mL). N-Bromosuccinimide (4.02 g, 22.6 mmol) was added little by little under stirring, and then stirred for 6 hours. After concentrating the reaction solution with an evaporator, ethyl acetate and pure water were added to perform extraction and washing with water. The obtained organic layer was concentrated with an evaporator to obtain a dark red solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (4: 1) as a developing solution, and 2.68 g of a monomer (PT-1) having an N-phenylphenothiazine structure was obtained. Obtained. Yield 84.7%.

(Synthesis of monomer (PT-2) having N-phenylphenothiazine structure)
In a three-necked flask, phenothiazine (19.8 g, 0.1 mol), bromobenzene (15.7 g, 0.1 mol), palladium (II) acetate (0.225 g, 1 mmol), NaOtBu (14.4 g, 0.15 mol), o-Xylene (300 mL) was added and the flask was moved into the glove box. The solution was bubbled with nitrogen gas for 20 minutes and degassed. P (t-Bu) ₃ (0.606 g, 3 mmol) was added and sealed. The flask was taken out of the glove box, a cooling pipe was attached, and heating and refluxing were performed at 150 ° C. for 5 hours under a nitrogen flow. After cooling the solution, the solution was filtered through Celite and concentrated with an evaporator to obtain a black solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (9: 1) as a developing solution to obtain 17.3 g of a light yellow solid of N-phenylphenothiazine. Yield 63.0%.

N-phenylphenothiazine (1.07 g, 3.88 mmol) was added to the three-necked flask and dissolved in N, N-dimethylformamide (100 mL). N-bromosuccinimide (3.45 g, 19.4 mmol) was added little by little under stirring, and then stirred for 6 hours. After concentrating the reaction solution with an evaporator, ethyl acetate and pure water were added to perform extraction and washing with water. The obtained organic layer was concentrated with an evaporator to obtain a dark red solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (2: 1) as a developing solution to obtain 1.45 g of a monomer (PT-2) having an N-phenylphenothiazine structure. Obtained. Yield 73.2%.

(Synthesis of monomer (PT-3) having N-phenylphenothiazine structure)
In a three-necked flask, PT-1 (48.9 g, 0.1 mol), bispinacolatodiboron (55.9 g, 0.22 mol), Pd (dppf) Cl ₂ (2.2 g, 3 mmol), potassium acetate (39. 3 g, 0.4 mol) and dimethoxyethane (500 mL) were added, and the flask was moved into the glove box. The solution was bubbled with nitrogen gas for 20 minutes, degassed and sealed. The flask was taken out of the glove box, a condenser tube was attached, and heating under reflux was performed for 24 hours under a nitrogen flow. After cooling the solution, water (500 mL) and ethyl acetate (500 mL) were added, and the solution was filtered. The filtered solution was extracted with ethyl acetate (200 mL × 2), the organic layer was washed with saturated brine (400 mL × 2), magnesium sulfate was added, and the mixture was allowed to stand for a while and dried. Magnesium sulfate was filtered and concentrated by an evaporator to obtain a black solid. The obtained solid was dissolved in toluene and purified by silica gel column chromatography using hexane: ethyl acetate (9: 1) as a developing solution to obtain 30.9 g of a light yellow solid of PT-3. Yield 53.0%.

<II> Preparation of electrochromic polymer (Preparation of Pd catalyst)
Tris (dibenzylideneacene) dipalladium (73.2 mg, 80 μmol) was weighed into a sample tube at room temperature in a glove box under a nitrogen atmosphere, anisole (15 mL) was added, and the mixture was stirred for 30 minutes. Similarly, tris (t-butyl) phosphine (129.6 mg, 640 μmol) was weighed in a sample tube, anisole (5 mL) was added, and the mixture was stirred for 5 minutes. These solutions were mixed and stirred at room temperature for 30 minutes, and then used as a Pd catalyst solution. All solvents were used after being degassed with a nitrogen bubble for at least 30 minutes.

(Electrochromic polymer 1 having N-phenylphenothiazine structure)
To the three-necked round bottom flask, the following monomer PT-1 (4.0 mmol), the following monomer L2-1 (5.0 mmol), the following monomer T2-1 (2.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was added. After stirring this reaction liquid for 30 minutes, 10 mass% tetraethylammonium hydroxide aqueous solution (20 mL) was added to the said reaction liquid. All raw materials were used after being degassed with nitrogen bubbles for more than 30 minutes. The mixture was heated to reflux for 2 hours. The operation so far was performed under a nitrogen stream.

  After completion of the reaction, the organic layer was washed with water, and the organic layer was poured into methanol-water (9: 1). The resulting precipitate was collected by suction filtration and washed with methanol-water (9: 1). The resulting precipitate was dissolved in toluene and reprecipitated from methanol. The resulting precipitate was collected by suction filtration, dissolved in toluene, and a metal adsorbent (“Triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer” manufactured by Strem Chemicals, 200 mg for 100 mg of the precipitate) was added. Stir overnight. After completion of the stirring, the metal adsorbent and insoluble matter were removed by filtration, and the filtrate was concentrated with a rotary evaporator. The concentrate was dissolved in toluene and then reprecipitated from methanol-acetone (8: 3). The resulting precipitate was collected by suction filtration and washed with methanol-acetone (8: 3). The obtained precipitate was vacuum-dried to obtain an electrochromic polymer 1.

  The obtained electrochromic polymer 1 had a number average molecular weight of 5,300 and a weight average molecular weight of 8,600.

The number average molecular weight and the weight average molecular weight were measured by GPC (polystyrene conversion) using tetrahydrofuran (THF) as an eluent. The measurement conditions are as follows.
Liquid feed pump: L-6050 Hitachi High-Technologies Corporation UV-Vis detector: L-3000 Hitachi High-Technologies Corporation Column: Gelpack (registered trademark) GL-A160S / GL-A150S Hitachi Chemical Co., Ltd. Eluent: THF (HPLC Wako Pure Chemical Industries, Ltd. Flow rate: 1 mL / min
Column temperature: Room temperature Molecular weight standard: Standard polystyrene

(Electrochromic polymer 2 having N-phenylphenothiazine structure)
To the three-necked round bottom flask, the following monomer PT-2 (2.0 mmol), the following monomer L2-1 (5.0 mmol), the following monomer T2-1 (4.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the electrochromic polymer 2 was synthesized in the same manner as the synthesis of the electrochromic polymer 1.

  The obtained electrochromic polymer 2 had a number average molecular weight of 15,800 and a weight average molecular weight of 78,200.

(Electrochromic polymer 3 having N-phenylphenothiazine structure)
To the three-necked round bottom flask, the following monomer PT-1 (5.0 mmol), the following monomer L2-2 (4.0 mmol), the following monomer T2-1 (2.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the electrochromic polymer 3 was synthesized in the same manner as the synthesis of the electrochromic polymer 1.

The obtained electrochromic polymer 3 had a number average molecular weight of 5,600 and a weight average molecular weight of 10,400.

(Electrochromic polymer 4 having N-phenylphenothiazine structure)
The monomer PT-2 (2.0 mmol), the following monomer L2-3 (5.0 mmol), the monomer T2-1 (4.0 mmol) and anisole (20 mL) were added to a three-necked round bottom flask, The prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the electrochromic polymer 4 was synthesized in the same manner as the synthesis of the electrochromic polymer 1.

The obtained electrochromic polymer 4 had a number average molecular weight of 12,500 and a weight average molecular weight of 63,900.

(Electrochromic polymer 5 having N-phenylphenothiazine structure)
To a three-necked round bottom flask, the following monomer PT-3 (5.0 mmol), the following monomer T2-2 (4.0 mmol), the following monomer PT-2 (2.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the electrochromic polymer 5 was synthesized in the same manner as the synthesis of the electrochromic polymer 1.

The obtained electrochromic polymer 5 had a number average molecular weight of 10,700 and a weight average molecular weight of 59,400.

(Electrochromic polymer 6 having N-phenylphenothiazine structure)
To the three-necked round bottom flask, the following monomer PT-3 (5.0 mmol), the following monomer PT-1 (4.0 mmol), the following monomer T2-2 (2.0 mmol) and anisole (20 mL) were added. The prepared Pd catalyst solution (7.5 mL) was added. Thereafter, the electrochromic polymer 6 was synthesized in the same manner as the synthesis of the electrochromic polymer 1.

  The obtained electrochromic polymer 6 had a number average molecular weight of 6,600 and a weight average molecular weight of 12,800.

  The monomers used for the preparation of electrochromic polymers 1-6 are summarized in the following table.

Example 1
<Preparation of electrochromic display element 1>
<Formation of electrochromic layer on first electrode>
In order to form an electrochromic layer on the first electrode, an electrochromic composition having the following composition was prepared.

<Composition>
Electrochromic polymer 5 having an N-phenylphenothiazine structure: 50 parts by mass α-hydroxyalkylphenone (IRGACURE184, BASF Japan Ltd.): 5 parts by mass PEG400 diacrylate having bifunctional acrylate (hereinafter PEG400DA, Japan) Kayaku Co., Ltd.): 50 parts by mass Methyl ethyl ketone: 900 parts

  The obtained electrochromic composition was applied by spin coating on an ITO glass substrate (40 mm × 40 mm, thickness 0.7 nm, ITO film thickness: about 100 nm) as a first electrode, and the obtained coating film was applied. A cross-linked electrochromic layer having an average thickness of 400 μm was formed by irradiating with UV irradiation apparatus (SPUS CURE, manufactured by USHIO INC.) For 60 seconds at 10 mW and annealing at 60 ° C. for 10 minutes.

<Formation of deterioration preventing layer on second electrode>
As a second electrode, a titanium oxide nanoparticle dispersion was applied as a deterioration preventing layer to an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) by spin coating, and annealed at 120 ° C. for 15 minutes. By performing the treatment, a nanostructured semiconductor material made of a titanium oxide particle film having a thickness of 1.0 μm was formed.

<Electrolyte filling>
An electrolyte solution having the following composition was prepared.
Α-hydroxyalkylphenone (IRGACURE183, manufactured by BASF Japan Ltd.): 5 parts by mass PEG400DA (manufactured by Nippon Kayaku Co., Ltd.): 100 parts by mass 1-ethyl-3-methylimidazolium tetracyanoborate (manufactured by Merck) ): 50 parts by mass

  30 mg of the obtained electrolyte solution was measured with a micropipette and dropped onto the ITO glass substrate having the deterioration preventing layer. An ITO glass substrate having a cross-linked electrochromic layer was bonded so that there was an electrode lead portion thereon, and a bonded element was produced.

  The obtained bonded element was irradiated for 60 seconds at 10 mW with a UV (wavelength 250 nm) irradiation device (USHIO Corporation, SPOT CURE). Thus, the electrochromic display element 1 was produced.

<Color generation / erasing drive>
The color generation / decoloration of the produced electrochromic display element 1 was confirmed. Specifically, when a voltage of −2 V is applied for 5 seconds between the lead portion of the first electrode layer and the lead portion of the second electrode layer, the first electrode layer and the second electrode layer A red color derived from the electrochromic polymer of the present invention of the electrochromic crosslinked layer was confirmed in the overlapping portion of the electrode layer.

  Next, when a voltage of +2 V is applied for 5 seconds between the lead portion of the first electrode layer and the lead portion of the second electrode layer, the first electrode layer and the second electrode layer It was confirmed that the overlapping portion of the color disappeared and became transparent.

<Test 1: Repeated durability test>
With respect to the produced electrochromic display element 1, the above-described −2 V, 5 s, +2 V, and 5 s color development driving was repeated 500 times. The absorption maximum in the visible region (400 to 800 nm) at that time was λmax (in this case, 550 nm). The change in absorbance at that time was measured with a USB4000 manufactured by Ocean Optics and evaluated according to the following criteria.

<Evaluation criteria>
A: When the absorbance at λmax is 90% or more compared to the initial state. ○: When the absorbance at λmax is 80% or more and less than 90% compared to the initial state. Δ: The absorbance at λmax is 50% compared to the initial state. When it is less than 80% x: When the absorbance at λmax is less than 50% compared to the initial state

<Test 2: Memory evaluation>
About the produced electrochromic display element 1, -2V and 5s were applied, and it was made to color, and it was set as the open circuit. The transmittance in the visible region when the circuit was opened was measured with a USB4000 manufactured by Ocean Optics, and the memory property was evaluated according to the following criteria.

<Evaluation criteria>
A: When the absorbance at λmax is 90% or more compared to the initial state. ○: When the absorbance at λmax is 80% or more and less than 90% compared to the initial state. Δ: The absorbance at λmax is 50% compared to the initial state. When it is less than 80% x: When the absorbance at λmax is less than 50% compared to the initial state

<Test 3: Haze value measurement>
About the produced electrochromic display element 1, the haze value measurement of the decolored state was performed according to JIS specification using Nippon Denshoku NDH5000. The haze value was evaluated according to the following criteria.

<Evaluation criteria>
○: When haze value is 2% or less ×: When haze value is larger than 2%

  The results of tests 1 to 3 are shown in the table.

(Example 2)
An electrochromic display element 2 was produced in the same manner except that the electrochromic polymer 5 in Example 1 was changed to the electrochromic polymer 6. In the same manner as in Example 1, repeated durability, memory property, and haze value were evaluated.

(Comparative Example 1)
An electrochromic display element was produced using a compound represented by the following formula described in Non-Patent Document 1. A tin oxide nanoparticle dispersion is applied to an ITO glass substrate (40 mm × 40 mm, thickness 0.7 mm, ITO film thickness: about 100 nm) as a first electrode by spin coating, and annealed at 120 ° C. for 15 minutes. Thus, a nanostructured semiconductor material composed of a tin oxide particle film having a thickness of 1.0 μm was formed. Here, 0.15 mL of a 2% by mass of the following compound aqueous solution was dropped, the dye was adsorbed by spin coating (1500 rpm (1500 min ⁻¹ )), and 0.15 mL of pure water was simultaneously spin-coated and rinsed. Other than this, the electrochromic display element 3 was produced in the same manner as in Example 1. In the same manner as in Example 1, repeated durability, memory property, and haze value were evaluated.

(Comparative Example 2)
An electrochromic display element was produced by the method described in Non-Patent Document 2 using a compound represented by the following structural formula. In the same manner as in Example 1, repeated durability, memory property, and haze value were evaluated.

As described above, when the conventional comparative compound is used, an electrochromic display element satisfying repeated durability, memory property and transparency is not provided, whereas the electrochromic polymer and / or electrochromic of the present invention is not provided. It was found that an electrochromic display element having the above characteristics can be provided by using the composition.

Claims (5)

  An electrochromic polymer having at least one structural unit containing a substituted or unsubstituted N-phenylphenothiazine structure.   The electrochromic polymer according to claim 1, further comprising a polymerizable functional group.   An electrochromic material comprising at least one electrochromic polymer according to claim 1 or 2. An electrochromic material according to claim 3;
An electrochromic composition comprising: another polymerizable compound different from the electrochromic material. A first electrode;
A second electrode;
An electrolyte filled between the first electrode and the second electrode;
The electrochromic polymer according to claim 1, the electrochromic material according to claim 3, and the electrochromic according to claim 4, wherein the electrochromic polymer is located on the first electrode and on the second electrode side. An electrochromic display element comprising: an electrochromic layer including at least one selected from the group consisting of compositions.