JP6136532B2 - Suspension for variable electromagnetic wave adjustment element and variable electromagnetic wave adjustment element - Google Patents

Description

  The present invention relates to a suspension for a variable electromagnetic wave adjustment element and a variable electromagnetic wave adjustment element.

  From the viewpoints of energy saving, privacy protection, anti-glare and the like, there is an increasing interest in electromagnetic wave adjusting elements that can electrically control the transmittance or scattering intensity of electromagnetic waves such as visible light and near infrared rays. Up to now, as electromagnetic wave adjusting elements, types using electrochromic, liquid crystal, particle suspension and the like have been put into practical use. Among them, the type using electrochromic has a problem that it is difficult to increase the area. Further, the type using liquid crystal switches between a light transmission state and a light scattering state, and there is a problem that light cannot be blocked.

  On the other hand, the type using a particle suspension controls the transmittance of electromagnetic waves by changing the dispersion state of particles and the alignment state or alignment state, and can increase the area. Application to aircraft, building windows, etc. is advancing. There are two types of electromagnetic wave adjustment methods using particle suspensions. The first method is a method of increasing electromagnetic wave transmittance by orienting rod-shaped particles in the electric field direction by applying a voltage. The second method is a method of increasing the electromagnetic wave transmittance by aligning particles in the electric field direction like an electrorheological fluid by applying a voltage.

  As a first method for controlling the orientation of rod-like particles, Patent Document 1 describes a method using needle-like particles containing iodine. In addition, the second method for controlling the alignment state and the dispersion state of the particles can be expected as an electromagnetic wave adjustment method that has a relatively wide range of particle choices and can easily meet various requirements (for example, see Patent Document 2). ). Further, in the second method, a method using charged particles has been proposed as a method for electrically dispersing the particles once aligned (see, for example, Patent Document 3).

JP 2002-189123 A Japanese Patent No. 3339266 Japanese Patent No. 4633793

  However, in the first method described in Patent Document 1, since there are few examples of usable rod-like particles having dichroism, it is difficult to arbitrarily change the type of particles. Therefore, various electromagnetic wave adjustment elements expected to change the color tone at the time of shading or scattering, or to give a function of controlling heat ray permeability using particles having a heat ray reflection function, depending on the application. It is difficult to meet the demand.

  In the second method described in Patent Document 2, the change from the dispersed state to the aligned state of the particles can be performed in a short time by applying an electric field, whereas the change from the aligned state to the dispersed state is performed by applying an applied electric field. It is necessary to wait for the particles to diffuse by Brownian motion. Therefore, it has been difficult to change from the electromagnetic wave transmission state to the shielding or scattering state in a practical time as an electromagnetic wave adjusting element. Furthermore, the speed of particle diffusion is easily affected by temperature, and when the temperature is low, the problem is that particle diffusion becomes even slower. In the method described in Patent Document 3, the selection range of particles is narrow, and it is difficult to meet various requirements.

  An object of the present invention is to provide a variable electromagnetic wave adjusting element that adjusts the transmission state of electromagnetic waves using a suspension of particles, and is capable of electrically controlling the alignment state and the dispersion state of particles in the suspension. It is intended to provide a suspension for a variable electromagnetic wave adjustment element capable of shortening the time required for bidirectional change between the two states, and a variable electromagnetic wave adjustment element using the same.

Specific means for solving the above problems are as follows.
<1> Electromagnetic wave adjusting particles, a first compound having an amide structure and a hydrophobic structure, and at least one compound selected from the group consisting of a second compound having an ester structure, an amine structure and a hydrophobic structure; Is a suspension for a variable electromagnetic wave adjusting element.

<2> The first compound is a compound represented by the following general formula (I), a salt of a compound represented by the following general formula (I), a compound represented by the following general formula (II), and the following The suspension for a variable electromagnetic wave adjusting element according to <1>, including at least one selected from the group consisting of salts of compounds represented by the general formula (II).

(In the formula, R ¹ and R ¹¹ each independently represent a hydrocarbon group. R ² , R ³ , R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group or a hydroxyalkyl group. R ¹⁴ represents a divalent hydrocarbon group.)

<3> The second compound includes at least one selected from the group consisting of a compound represented by the following general formula (III) and a salt of a compound represented by the following general formula (III). > Or <2>. The suspension for a variable electromagnetic wave adjusting element according to <2>.

(In the formula, R ²¹ represents a hydrocarbon group. R ²² and R ²³ each independently represents a hydrogen atom, an alkyl group or a hydroxyalkyl group. R ²⁴ represents a divalent hydrocarbon group.)

<4> The variable electromagnetic wave adjusting element suspension according to any one of <1> to <3>, further including an organic acid.

<5> The electromagnetic wave adjusting particle is a suspension for a variable electromagnetic wave adjusting element according to any one of <1> to <4>, wherein the number average particle diameter is 20 μm or less.

<6> The electromagnetic wave adjusting particle is a suspension for a variable electromagnetic wave adjusting element according to any one of <1> to <5>, which is a colored particle.

<7> The electromagnetic wave adjusting particle is a suspension for a variable electromagnetic wave adjusting element according to any one of <1> to <6>, including a metal oxide.

<8> The suspension for a variable electromagnetic wave adjusting element according to any one of <1> to <7>, which is disposed between the two conductive substrates and the two conductive substrates. A variable electromagnetic wave adjusting element having an electromagnetic wave adjusting layer containing a liquid.

<9> The electromagnetic wave adjusting layer has an electromagnetic wave transmission state in which the electromagnetic wave adjusting particles are aligned in the electric field direction depending on the strength of the electric field applied to the two conductive substrates, and the electromagnetic wave adjusting particles are The variable electromagnetic wave adjusting element according to <8>, wherein the electromagnetic wave transmission suppression state dispersed irregularly is controlled.

<10> The variable electromagnetic wave adjusting element according to <9>, wherein the electric field applied in the electromagnetic wave transmission suppression state is a stronger electric field than the electric field applied in the electromagnetic wave transmission state.

<11> The electromagnetic wave adjusting particles in the electromagnetic wave adjusting layer are irregular by changing an electric field applied to the conductive base material of the variable electromagnetic wave adjusting element according to any one of <8> to <10>. An electromagnetic wave adjusting method including switching between an electromagnetic wave transmission suppressing state dispersed in the electromagnetic wave and an electromagnetic wave transmitting state in which the electromagnetic wave adjusting particles are aligned in the electric field direction.

  According to the present invention, in a variable electromagnetic wave adjusting element that adjusts the transmission state of electromagnetic waves using a suspension of particles, the alignment state and dispersion state of particles in the suspension can be electrically controlled. It is possible to provide a suspension for a variable electromagnetic wave adjustment element capable of performing a bidirectional change between these states in a short time and a variable electromagnetic wave adjustment element using the same.

It is a conceptual diagram which shows an example of the electromagnetic wave transmission suppression state in the variable electromagnetic wave adjustment element concerning this embodiment. It is a conceptual diagram which shows an example of the electromagnetic wave transmission state in the variable electromagnetic wave adjustment element concerning this embodiment.

  In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. . Moreover, the numerical range shown using "to" shows the range which includes the numerical value described before and behind "to" as a minimum value and a maximum value, respectively. Furthermore, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. . In addition, in the present specification, the term “layer” includes a configuration of a shape formed in part in addition to a configuration of a shape formed on the entire surface when observed as a plan view.

<Suspension for variable electromagnetic wave adjusting element>
The suspension for a variable electromagnetic wave adjusting element of the present invention (hereinafter also simply referred to as “suspension”) has electromagnetic wave adjusting particles (hereinafter also simply referred to as “particles”), an amide structure and a hydrophobic structure. One compound and at least one compound selected from the group consisting of a second compound having an ester structure, an amine structure and a hydrophobic structure. The variable electromagnetic wave adjusting element suspension may further contain other components as required, such as a dispersion medium.
The suspension in which the electromagnetic wave adjusting particles are dispersed contains at least one compound selected from the group consisting of a first compound having a specific structure and a second compound (hereinafter also referred to as “specific compound”). Thus, when the variable electromagnetic wave adjusting element is configured using the suspension, it is possible to shorten the time required for bidirectional change between the aligned state and the dispersed state of the electromagnetic wave adjusting particles in the suspension. .

This can be considered as follows, for example.
When the specific compound has a hydrophilic structure including an amide structure, or a hydrophilic structure including an ester structure and an amine structure, and a hydrophobic structure, for example, a surface active action is expressed on the surface of the particle. As a result, the dispersibility of particles in the suspension and the polarization effect due to the electric field are improved, and the time required for bidirectional change between the aligned state and the dispersed state of the particles in the suspension can be shortened. It is done.

  Furthermore, in the variable electromagnetic wave adjustment element formed by disposing the electromagnetic wave adjustment layer containing the suspension between two conductive substrates, in the state where no electric field is applied, Since the particles irregularly Brownianly move and are in a dispersed state (hereinafter also referred to as “first dispersed state”), electromagnetic wave transmission is suppressed. Here, when an electric field is applied to the two conductive substrates and the applied electric field strength is changed from the low electric field side to the high electric field side, the suspension exhibits the properties of an electrorheological fluid, and the predetermined electric field strength is obtained. When it reaches, due to the polarization action of the particles, the particles are aligned in the direction of the electric field, and the electromagnetic wave can be transmitted. In an ordinary electrorheological fluid, the alignment state is maintained even when an electric field of higher strength is applied. However, when the variable electromagnetic wave adjusting element is configured using the suspension for the variable electromagnetic wave adjusting element of the present invention, it is possible to apply a stronger electric field than the electric field in which the particles are aligned in the electric field direction. The aligned state is quickly eliminated, and the particles change to a dispersed state in which the particles move irregularly in the dispersion medium (hereinafter also referred to as “second dispersed state”).

  Although the mechanism of this phenomenon is not clear, for example, it can be considered as follows. Considering the case where a high DC voltage is applied to the electromagnetic wave adjusting element, electrons are emitted from the particles by a strong electric field, and the particles are positively charged. Positively charged particles migrate towards the cathode. When the particles reach the cathode, they receive electrons from the cathode and are negatively charged. The negatively charged particles migrate toward the anode, but during the migration to the anode or after reaching the anode, electrons are released by the action of the electric field and become positively charged again. By repeating this, each particle independently reciprocates between the cathode and the anode. Therefore, it is considered that when the electric field strength is increased, the particles move irregularly. Actually, when a high DC voltage is applied, a phenomenon in which particles move irregularly can be observed. On the other hand, it is considered that the same phenomenon occurs when an alternating high voltage is applied, but it is considered that it works more effectively at low frequencies. If the frequency is low, the switching of the electric field direction becomes slow, and the moving distance or moving time of the particles to the anode or the cathode is sufficiently secured, and the phenomenon of irregular movement is more effectively expressed. On the other hand, when high-frequency alternating current is applied, the magnitude of the dielectric polarization of the particles does not decrease so much even at high frequencies, so that the action of the polarization of the particles becomes stronger, and a sufficient alignment state can be achieved. This phenomenon is a phenomenon that occurs when the suspension contains the specific compound, and does not occur when the specific compound is not included. Therefore, as long as the suspension contains the specific compound, the type of the electromagnetic wave adjusting particles is not particularly limited, and the options of the electromagnetic wave adjusting particles are widened, and it is considered that various requirements can be met.

  Next, the operation of the variable electromagnetic wave adjusting element according to the present embodiment will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing the first dispersed state or the second dispersed state in the variable electromagnetic wave adjusting element 100. FIG. 2 is a conceptual diagram showing an example of a state in which an electric field is applied to the two conductive substrates 2 by the power source 10 and the electromagnetic wave adjusting particles 4 are aligned in the electric field direction. The variable electromagnetic wave adjusting element 100 includes two conductive substrates 2 connected to a power source 10, electromagnetic wave adjusting particles 4 and a dispersion medium 6, and is disposed between the two conductive substrates 2. And an electromagnetic wave adjusting layer 8. Further, the electromagnetic wave adjusting layer 8 contains a specific compound (not shown) in addition to the electromagnetic wave adjusting particles 4 and the dispersion medium 6. Alternatively, a specific compound may be used as the dispersion medium 6.

In a state where an electric field is not applied to the electromagnetic wave adjustment layer 8 by the power supply 10, as shown in FIG. 1, the first dispersion state in which the particles 4 move irregularly in the dispersion medium in the electromagnetic wave adjustment layer 8 Become. In this case, the incident electromagnetic wave 12 is suppressed from being reflected or scattered by the electromagnetic wave adjusting particles 4 moving irregularly and passing through the electromagnetic wave adjusting layer 8.
Here, when an electric field having a predetermined intensity is applied to the electromagnetic wave adjustment layer 8 by the power source 10, the electromagnetic wave adjustment particles 4 are aligned with each other along the electric field direction as shown in FIG. In this case, the incident electromagnetic wave 12 is transmitted as a transmitted electromagnetic wave 14 on the opposite side of the electromagnetic wave adjustment layer 8 from the incident side of the electromagnetic wave by passing between the aligned electromagnetic wave adjusting particles 4.
Further, the electric field strength applied to the electromagnetic wave adjusting layer 8 in a state where an electric field having a predetermined intensity is applied to the electromagnetic wave adjusting layer 8 as shown in FIG. 2 and the particles 4 are aligned in the electric field direction and the incident electromagnetic wave 12 can be transmitted. Is further increased, the alignment state of the electromagnetic wave adjusting particles 4 is canceled, and the electromagnetic wave adjusting particles 4 as shown in FIG. 1 are changed to a second dispersed state in which the electromagnetic wave adjusting particles 4 are moving irregularly. In this case, the incident electromagnetic wave 12 is suppressed from being reflected or scattered by the irregularly moving particles 4 and passing through the electromagnetic wave adjustment layer 8.

In the variable electromagnetic wave adjustment element 100 of the present embodiment, an electric field having a predetermined intensity is applied to the electromagnetic wave adjustment layer 8 by applying a predetermined voltage from the power source 10 to the two conductive base materials 2, and the electromagnetic wave adjustment particles 4. Can be aligned. As a result, the variable electromagnetic wave adjusting element 100 enters an electromagnetic wave transmission state. Further, in the variable electromagnetic wave adjustment element 100 of the present embodiment, the two conductive substrates 2 are powered so that a stronger electric field is applied to the electromagnetic wave adjustment layer 8 than the electric field in which the electromagnetic wave adjustment particles 4 are aligned. By applying an electric field by 10, the electromagnetic wave adjusting particles 4 can be in a second dispersed state in which the particles are moving irregularly. As a result, the variable electromagnetic wave adjusting element 100 enters an electromagnetic wave transmission suppressed state.
In this way, by changing the strength of the electric field applied to the electromagnetic wave adjustment layer 8, it is possible to switch between the electromagnetic wave transmission state and the electromagnetic wave transmission suppression state in a short time.

[Specific compounds]
The suspension for a variable electromagnetic wave adjusting device of the present invention is a group consisting of a first compound having an amide structure and a hydrophobic structure, and a second compound having an ester structure, an amine structure, and a hydrophobic structure. It contains at least one compound (specific compound) selected from the above. The specific compound may be contained singly or in combination of two or more.
Here, the hydrophobic structure means a structural portion having a low affinity for water, for example, from a group consisting of an aliphatic hydrocarbon group having 4 to 30 carbon atoms and an aromatic hydrocarbon group having 6 to 30 carbon atoms. It is composed of one or more selected hydrocarbon groups.

The first compound is not particularly limited as long as it is a compound having at least one amide structure and at least one hydrophobic structure in one molecule. Among these, the first compound is represented by the following general formula (I) from the viewpoint of the state change rate between the aligned state and the dispersed state of the particles in the suspension (hereinafter also simply referred to as “state change rate”). At least selected from the group consisting of a salt of a compound represented by the following general formula (I), a compound represented by the following general formula (II), and a salt of a compound represented by the following general formula (II) One type is preferable.
Examples of the salt include salts obtained from a compound represented by the general formula (I) or the general formula (II) and having basicity and an acid. Specifically, the salt may be represented by the general formula (II). The amine salt obtained from the compound and amine which have the amine structure represented by these can be mentioned. In the present invention, the amine salt means a salt obtained from an amine compound which is a basic substance and an acid. The acid may be an inorganic acid or an organic acid, and is preferably an organic acid. Specific examples of the organic acid described below can be given as the organic acid.
Hereinafter, the compound represented by the general formula (I) or the salt of the compound represented by the general formula (I) is also referred to as “a compound represented by the general formula (I) or a salt thereof”. A compound represented by formula (II) or a salt of the compound represented by formula (II) is also referred to as “a compound represented by formula (II) or a salt thereof”.

In the formula, R ¹ and R ¹¹ each independently represent a hydrocarbon group. R ² , R ³ , R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group or a hydroxyalkyl group. R ¹⁴ represents a divalent hydrocarbon group.

In the compound represented by the general formula (I) or a salt thereof, R ¹ represents a hydrocarbon group. The hydrocarbon group represented by R ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. From the viewpoint of the rate of state change, the hydrocarbon group represented by R ¹ is preferably an aliphatic hydrocarbon group. The number of carbon atoms of the hydrocarbon group represented by R ¹ is not particularly limited. When the hydrocarbon group is an aliphatic hydrocarbon group, the number of carbon atoms of the hydrocarbon group represented by R ¹ is preferably 4 to 30 and preferably 8 to 24 from the viewpoint of the state change rate. More preferred. Further, when the hydrocarbon group is an aromatic hydrocarbon group, the hydrocarbon groups represented by R ^1, from the viewpoint of state change rate is preferably 6 to 30, is 6 to 24 It is more preferable. Further, the hydrocarbon group represented by R ¹ is preferably an aliphatic hydrocarbon group having 4 to 30 carbon atoms, and more preferably an aliphatic hydrocarbon group having 8 to 24 carbon atoms. The aliphatic hydrocarbon group for R ¹ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group.

The hydrocarbon group for R ¹ may further have a substituent. Examples of the substituent include an alkoxy group having 1 to 24 carbon atoms and an alkyloxycarbonyl group having 2 to 24 carbon atoms.

In the general formula (I), R ² and R ³ each independently represent a hydrogen atom, an alkyl group or a hydroxyalkyl group. The number of carbon atoms of the alkyl group in R ² and R ³ is not particularly limited. Among these carbon number of the alkyl group in ^{R 2} and ^{R 3} is preferably 1 to 12, and more preferably 1-8. Further, the number of carbon atoms of the hydroxyalkyl group in R ² and R ³ is not particularly limited. Among these it is preferable that the carbon number of the hydroxyalkyl group in ^{R 2} and ^{R 3} are 1-12, more preferably 1-8. Furthermore, the substitution position of the hydroxy group in the hydroxyalkyl group is not particularly limited.

In general formula (I), at least one of R ² and R ³ is preferably an alkyl group or a hydroxyalkyl group, and R ² and R ³ are each independently more preferably an alkyl group or a hydroxyalkyl group. .

The compound represented by the general formula (I) or a salt thereof is preferably a compound that can be dissolved in a dispersion medium to be described later or a dispersible compound, and is a compound that is liquid at room temperature (25 ° C.). Is more preferable. When the compound represented by the general formula (I) or a salt thereof can function as a dispersion medium, the compound represented by the general formula (I) may be used as the dispersion medium.
The compound represented by the general formula (I) or a salt thereof is preferably a compound in which R ¹ is a saturated or unsaturated aliphatic hydrocarbon group, and more preferably a mixture thereof. Such compounds are available as fatty acid amides such as coconut oil and palm oil. Here, in this specification, that the compound is soluble in the dispersion medium means that the solubility of the compound at 25 ° C. is 10 g or more with respect to 100 g of the dispersion medium. Further, that the compound is dispersible in the dispersion medium means that when 10 g of the compound is dispersed in 100 g of the dispersion medium, phase separation is not visually observed at 25 ° C. for 24 hours or more and the dispersion state is maintained. .

When the suspension for a variable electromagnetic wave adjusting element contains the compound represented by the general formula (I) or a salt thereof, the content is the structure of the compound represented by the general formula (I) or a salt thereof, necessary Depending on the type of dispersion medium contained, the type of electromagnetic wave adjusting particles, etc., are selected as appropriate. For example, when R ² and R ³ in the general formula (I) are both a hydrogen atom or an alkyl group, the content of the compound represented by the general formula (I) or a salt thereof in the suspension is 20% by mass to 99% by mass. %, And more preferably 40% by mass to 99% by mass. When the content of the compound represented by the general formula (I) or a salt thereof in which R ² and R ³ are both hydrogen atoms or alkyl groups is 20% by mass or more, the alignment state of particles when a strong electric field is applied There is a tendency that the state change speed from the state to the dispersed state is improved.

For example, when at least one of R ² and R ³ in the general formula (I) is a hydroxyalkyl group, the content of the compound represented by the general formula (I) or a salt thereof in the suspension is 0.1. It is preferable that it is mass%-40 mass%, and it is more preferable that it is 0.5 mass%-20 mass%. Electromagnetic wave adjustment when a strong electric field is applied when the content of the compound represented by the general formula (I) or the salt thereof, in which at least one of R ² and R ³ is a hydroxyalkyl group is 0.1% by mass or more There is a tendency that the state change speed from the aligned state to the dispersed state of the particles is further improved. Moreover, when it is 40 mass% or less, there exists a tendency for the electromagnetic wave adjustment particle alignment state to be obtained with lower electric field strength.

In the compound represented by the general formula (II) or a salt thereof, R ¹¹ represents a hydrocarbon group. The hydrocarbon group represented by R ¹¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. From the viewpoint of the rate of state change, the hydrocarbon group represented by R ¹¹ is preferably an aliphatic hydrocarbon group. The number of carbon atoms of the hydrocarbon group represented by R ¹¹ is not particularly limited. When the hydrocarbon group is an aliphatic hydrocarbon group, the number of carbon atoms of the hydrocarbon group represented by R ¹¹ is preferably 4 to 30 and preferably 8 to 24 from the viewpoint of the state change rate. More preferred. Further, when the hydrocarbon group is an aromatic hydrocarbon group, the hydrocarbon groups represented by R ^11, from the viewpoint of state change rate is preferably 6 to 30, is 6 to 24 It is more preferable. Furthermore, the hydrocarbon group represented by R ¹¹ is preferably an aliphatic hydrocarbon group having 4 to 30 carbon atoms, and more preferably an aliphatic hydrocarbon group having 8 to 24 carbon atoms. In addition, the aliphatic hydrocarbon group in R ¹¹ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group.

The hydrocarbon group for R ¹¹ may further have a substituent. Examples of the substituent include an alkoxy group having 1 to 24 carbon atoms and an alkyloxycarbonyl group having 2 to 24 carbon atoms.

In the general formula (II), R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group or a hydroxyalkyl group. The number of carbon atoms of the alkyl group in R ¹² and R ¹³ is not particularly limited. Among these carbon number of the alkyl group in ^{R 13} and ^{R 13} is preferably 1-12, more preferably 1-8. The number of carbon atoms of the hydroxyalkyl group in R ¹² and R ¹³ is not particularly limited. Among these it is preferable that the carbon number of the hydroxyalkyl group in ^{R 12} and ^{R 13} is 1-12, more preferably 1-8. Furthermore, the substitution position of the hydroxy group in the hydroxyalkyl group is not particularly limited.

In general formula (II), at least one of R ¹² and R ¹³ is preferably a hydroxyalkyl group, and R ¹² and R ¹³ are more preferably each independently a hydrogen atom or a hydroxyalkyl group.

In the general formula (II), R ¹⁴ represents a divalent hydrocarbon group. The divalent hydrocarbon group for R ¹⁴ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. From the viewpoint of the state change rate, the divalent hydrocarbon group represented by R ¹⁴ is preferably an aliphatic hydrocarbon group, and more preferably an alkylene group. The number of carbon atoms of the divalent hydrocarbon group represented by R ¹⁴ is not particularly limited. Among them, the number of carbon atoms of the hydrocarbon group represented by R ¹⁴ is preferably 1 to 10 and more preferably 1 to 6 from the viewpoint of the state change rate. Further, the divalent hydrocarbon group represented by R ¹⁴ is preferably a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms. An alkylene group having 1 to 6 carbon atoms is more preferable.

In the compound represented by the general formula (II) or a salt thereof, R ¹¹ is an aliphatic hydrocarbon group having 8 to 24 carbon atoms, R ¹⁴ is an alkylene group having 1 to 10 carbon atoms, R ¹² and R It is preferable that at least one of ¹³ is a hydroxyalkyl group.

The compound represented by the general formula (II) or a salt thereof is preferably a compound that can be dissolved in a dispersion medium to be described later, or a dispersible compound, and is a compound that is liquid at room temperature (25 ° C.). Is more preferable. In the case where the compound represented by the general formula (II) or a salt thereof can function as a dispersion medium, the compound represented by the general formula (II) may be used as the dispersion medium.
The compound represented by the general formula (II) or a salt thereof is preferably a compound in which R ¹¹ is a saturated or unsaturated aliphatic hydrocarbon group, and more preferably a mixture thereof. Such compounds are available as fatty acid amides such as coconut oil and palm oil.

  When the suspension for a variable electromagnetic wave adjusting element contains the compound represented by the general formula (II) or a salt thereof, the content is the structure of the compound represented by the general formula (II) or a salt thereof, necessary Depending on the type of dispersion medium contained, the type of electromagnetic wave adjusting particles, etc., are selected as appropriate. For example, the content of the compound represented by the general formula (II) or a salt thereof in the suspension is preferably 0.1% by mass to 10% by mass, and 0.2% by mass to 5% by mass. Is more preferable. When the content of the compound represented by the general formula (II) or a salt thereof is 0.1% by mass or more, the electric field strength required for the state change from the aligned state to the dispersed state of the electromagnetic wave adjusting particles tends to be further reduced. is there. Further, when the content is 10% by mass or less, the alignment state of the electromagnetic wave adjusting particles tends to be easily obtained at a lower electric field strength.

  The first compound may include at least one compound represented by the general formula (I) or a salt thereof, or may contain at least one compound represented by the general formula (II) or a salt thereof. Even if it contains, it includes both at least one compound represented by the general formula (I) or a salt thereof and at least one compound represented by the general formula (II) or a salt thereof. Also good.

The second compound is not particularly limited as long as it is a compound having at least one ester structure, at least one amine structure, and at least one hydrophobic structure in one molecule. Above all, the second compound is at least one selected from the group consisting of a compound represented by the following general formula (III) and a salt of the compound represented by the following general formula (III) from the viewpoint of the state change rate. Preferably there is.
Examples of the salt include salts obtained from a compound represented by the general formula (III) and showing basicity and an acid, and specifically, an amine structure represented by the general formula (III). And an amine salt obtained from a compound having an acid and an acid. The acid may be an inorganic acid or an organic acid, and is preferably an organic acid. Specific examples of the organic acid described below can be given as the organic acid.
Hereinafter, the compound represented by the general formula (III) or the salt of the compound represented by the general formula (III) is also referred to as “a compound represented by the general formula (III) or a salt thereof”.

In the formula, R ²¹ represents a hydrocarbon group. R ²² and R ²³ each independently represents a hydrogen atom, an alkyl group or a hydroxyalkyl group. R ²⁴ represents a divalent hydrocarbon group.

In the compound represented by the general formula (III) or a salt thereof, the hydrocarbon group represented by R ²¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. From the viewpoint of the rate of state change, the hydrocarbon group represented by R ²¹ is preferably an aliphatic hydrocarbon group. The number of carbon atoms of the hydrocarbon group represented by R ²¹ is not particularly limited. When the hydrocarbon group is an aliphatic hydrocarbon group, the number of carbon atoms of the hydrocarbon group represented by R ²¹ is preferably 4 to 30 and preferably 8 to 24 from the viewpoint of the state change rate. More preferred. Further, when the hydrocarbon group is an aromatic hydrocarbon group, the hydrocarbon groups represented by R ^21, from the viewpoint of state change rate is preferably 6 to 30, is 6 to 24 It is more preferable. Furthermore, the hydrocarbon group represented by R ²¹ is preferably an aliphatic hydrocarbon group having 4 to 30 carbon atoms, and more preferably an aliphatic hydrocarbon group having 8 to 24 carbon atoms. In addition, the aliphatic hydrocarbon group in R ²¹ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group.

The hydrocarbon group for R ²¹ may further have a substituent. Examples of the substituent include an alkoxy group having 1 to 24 carbon atoms and an alkyloxycarbonyl group having 2 to 24 carbon atoms.

In the general formula (III), R ²² and R ²³ each independently represent a hydrogen atom, an alkyl group or a hydroxyalkyl group. The number of carbon atoms of the alkyl group in R ²² and R ²³ is not particularly limited. Among these carbon number of the alkyl group in ^{R 22} and ^{R 23} is preferably 1-12, more preferably 1-8. Further, the number of carbon atoms of the hydroxyalkyl group in R ²² and R ²³ is not particularly limited. Among these it is preferable that the carbon number of the hydroxyalkyl group in ^{R 22} and ^{R 23} is 1-12, more preferably 1-8. Furthermore, the substitution position of the hydroxy group in the hydroxyalkyl group is not particularly limited.

In general formula (III), at least one of R ²² and R ²³ is preferably a hydroxyalkyl group, and both R ²² and R ²³ are more preferably a hydrogen atom or a hydroxyalkyl group.

The compound represented by the general formula (III) or a salt thereof is preferably a compound that can be dissolved in a dispersion medium described later, or a dispersible compound, and is a compound that is liquid at room temperature (25 ° C.). Is more preferable. When the compound represented by the general formula (III) or a salt thereof can function as a dispersion medium, the compound represented by the general formula (III) may be used as the dispersion medium.
The compound represented by the general formula (III) or a salt thereof is preferably a compound in which R ²¹ is a saturated or unsaturated aliphatic hydrocarbon group, and more preferably a mixture thereof. Such compounds are available as fatty acid esters such as coconut oil and palm oil.

  When the suspension for a variable electromagnetic wave adjusting element contains the compound represented by the general formula (III) or a salt thereof, the content is the structure of the compound represented by the general formula (III) or a salt thereof, necessary Depending on the type of dispersion medium contained, the type of electromagnetic wave adjusting particles, etc., are selected as appropriate. For example, the content of the compound represented by the general formula (III) or the salt thereof in the suspension is preferably 0.1% by mass to 10% by mass, and preferably 0.2% by mass to 5% by mass. Is more preferable. When the content of the compound represented by the general formula (III) or a salt thereof is 0.1% by mass or more, the electric field strength required for the state change from the aligned state to the dispersed state of the electromagnetic wave adjusting particles tends to be further reduced. is there. Further, when the content is 10% by mass or less, the alignment state of the electromagnetic wave adjusting particles tends to be obtained with lower electric field strength.

[Organic acid]
The suspension for a variable electromagnetic wave adjusting element preferably further contains at least one organic acid in addition to the specific compound, and further contains an organic acid having at least one hydroxy group in addition to the acidic group. Is more preferable. The acidic group in the organic acid is not particularly limited, and examples thereof include a carboxylic acid group, a sulfonic acid group, and a phosphoric acid group. Among these, an organic acid having a carboxylic acid group or a sulfonic acid group is preferable, and an organic acid having a hydroxy group and a carboxylic acid group or a sulfonic acid group is more preferable.

Specific examples of organic acids include acetic acid, methanesulfonic acid, propionic acid, butyric acid, hexanoic acid, octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, stearic acid, lactic acid, 3-hydroxypropionic acid, 2- Hydroxybutanoic acid, 2-hydroxyisobutyric acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid, 3-hydroxy-2-methylbutanoic acid, 3-hydroxy-3-methylbutanoic acid, 2-hydroxyhexanoic acid, 3-hydroxyhexane Acid, 6-hydroxyhexanoic acid, 2-hydroxyoctanoic acid, 3-hydroxyoctanoic acid, 8-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 3-hydroxydecanoic acid, 10-hydroxydecanoic acid, 2-hydroxydodecanoic acid, 3-hydroxydodecanoic acid, 12-hydroxydodecane Acid, 2-hydroxytetradecanoic acid, 3-hydroxytetradecanoic acid, 14-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 3-hydroxyhexadecanoic acid, 16-hydroxyhexadecanoic acid, 2-hydroxystearic acid, 3-hydroxystearic acid, Examples thereof include 12-hydroxystearic acid, 18-hydroxystearic acid, 9,10,16-trihydroxyhexadecanoic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid and the like. Among these, an organic acid having at least one hydroxy group in addition to an acidic group is preferable, an organic acid having 2 to 18 carbon atoms having at least one hydroxy group in addition to an acidic group, Lactic acid, 3-hydroxypropionic acid, 2-hydroxybutanoic acid, 2-hydroxyisobutyric acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid, 3-hydroxy-2-methylbutanoic acid, 3-hydroxy-3-methylbutanoic acid, 2-hydroxyhexanoic acid, 3-hydroxyhexanoic acid, 6-hydroxyhexanoic acid, 2-hydroxyoctanoic acid, 3-hydroxyoctanoic acid, 8-hydroxyoctanoic acid, 2-hydroxydecanoic acid, 3-hydroxydecanoic acid, 10- Hydroxydecanoic acid, 2-hydroxydodecanoic acid, 3-hydroxydodecanoic acid, 12- Roxide decanoic acid, 2-hydroxytetradecanoic acid, 3-hydroxytetradecanoic acid, 14-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 3-hydroxyhexadecanoic acid, 16-hydroxyhexadecanoic acid, 2-hydroxystearic acid, 3-hydroxystearic acid More preferably, it is at least one organic acid selected from the group consisting of 12-hydroxystearic acid, 18-hydroxystearic acid, and 9,10,16-trihydroxyhexadecanoic acid.
The organic acid may be a polymer compound having an acidic group. Examples of the polymer compound having an acidic group include those used as an anionic surfactant. Specifically, DISPER BYK-111 (manufactured by BYK-Chemie) can be used.

  When the suspension for variable electromagnetic wave adjusting element contains an organic acid, the content thereof is not particularly limited, and is appropriately selected according to the structure of the specific compound. For example, when the specific compound is a compound represented by the general formula (II) or the general formula (III) or a salt thereof, the content of the organic acid is represented by the general formula (II) or the general formula (III). It is preferable that the equivalent ratio with respect to the basic group of the compound or its salt is 0.2 to 10.0, and it is more preferable that the equivalent ratio is 0.5 to 8.0. . When the equivalent ratio of the organic acid to the basic group of the specific compound is 0.2 or more, the electric field strength required to shift from the aligned state to the dispersed state of the electromagnetic wave adjusting particles tends to be further reduced. Moreover, when the equivalence ratio is 10.0 or less, there is a tendency that a state change to an aligned state of the electromagnetic wave adjusting particles can be obtained with a lower electric field strength.

[Electromagnetic wave adjusting particles]
The suspension for variable electromagnetic wave adjusting element includes at least one kind of electromagnetic wave adjusting particles. The electromagnetic wave adjusting particles are particles for adjusting the transmission state of the electromagnetic wave, and the alignment state and the dispersion state are electrically controlled in the suspension. As long as the electromagnetic wave adjusting particles are particles that can reflect or absorb electromagnetic waves, the material, particle diameter, and shape thereof are not particularly limited, and are appropriately selected according to the purpose and the like.
The electromagnetic wave in the present invention is not particularly limited as long as it is an electromagnetic wave having a wavelength of 300 nm to 2500 nm, and is appropriately selected according to the purpose of the electromagnetic wave adjusting element. For example, when it is desired to control visible light, it is 300 nm to 800 nm, and when it is desired to control near infrared light, it is 700 to 2500 nm.

  In general, as particles applicable to an electrorheological fluid, it is considered necessary to use particles whose dielectric constant is somewhat larger than the dielectric constant of the dispersion medium. However, the present inventors have found that the restriction on the dielectric constant of the particles used is relaxed by including the specific compound in the suspension. Therefore, in the suspension for a variable electromagnetic wave adjusting element of the present invention, it is possible to use even the types of particles that were conventionally considered difficult to use for electrorheological fluids. The width is greatly expanded.

  The electromagnetic wave adjusting particles used in the suspension for the variable electromagnetic wave adjusting element include resin particles such as silicone particles, melamine / formaldehyde condensate particles, polymethyl methacrylate particles, polyacrylonitrile particles; alumina, boehmite, ITO (Indium Tin Oxide), metal oxide particles such as zinc oxide, iron oxide, cerium oxide, and titanium oxide; various inorganic oxide pigment particles; carbon particles such as carbon black and carbon nanotubes; These can be appropriately selected from commercially available ones. Moreover, you may manufacture newly according to the objective.

  Among these, when the variable electromagnetic wave adjusting element is used for adjusting visible light, the change in visible light transmittance between the aligned state and the dispersed state is large. More preferably, it is brown colored particles. From the same viewpoint, the electromagnetic wave adjusting particles are preferably oxide particles, more preferably metal oxide particles, and still more preferably black or brown metal oxide particles.

When the electromagnetic wave adjusting particles are metal oxide particles, a black or brown oxide pigment containing at least one metal element selected from the group consisting of Cu, Fe and Mn is excellent in terms of weather resistance. Moreover, since the black thing does not have the coloring of transmitted light, when it applies to an electromagnetic wave adjustment element, it is visually excellent. Furthermore, among black or brown oxide pigments, (Bi, Mn) ₂ O ₃ , (Y, Mn) ₂ O ₃ , (Co, Fe) (Fe, Cr) ₂ O ₄ , Cr ₂ O ₃ : Fe A composite oxide having a composition such as ₂ O ₃ : CoO, Cr ₂ O ₃ : Fe ₂ O ₃ , or CuO: MgO has a property of reflecting near infrared rays. When a variable electromagnetic wave adjustment element using particles that reflect near-infrared rays is applied to a window that is exposed to sunlight, the near-infrared transmittance can be controlled and the temperature of the suspension rises due to absorption of near-infrared rays. There is an advantage that it can be reduced and deterioration of characteristics can be reduced.

  The particle diameter of the electromagnetic wave adjusting particles is not particularly limited. The particle diameter of the electromagnetic wave adjusting particles is preferably 20 μm or less as the number average particle diameter. In general, the number average particle diameter of the electromagnetic wave adjusting particles is preferably 10 μm or less from the viewpoint of obtaining a sufficient electromagnetic wave transmission suppressing effect (for example, colorability) and sufficiently suppressing electromagnetic wave scattering. The following is more preferable. Further, the number average particle diameter of the electromagnetic wave adjusting particles is preferably 0.05 μm or more, and more preferably 0.1 μm or more, from the viewpoint of the state change speed from the dispersed state to the aligned state of the electromagnetic wave adjusting particles. The number average particle diameter of the electromagnetic wave adjusting particles is calculated by calculating the equivalent circle diameter (geometric average of major axis and minor axis) of 50 particles by observing the particles using a scanning electron microscope, and calculating the arithmetic average value thereof. Desired.

  The shape of the electromagnetic wave adjusting particles is not particularly limited and can be appropriately selected depending on the purpose and the like. Examples of the shape of the electromagnetic wave adjusting particles include a rod shape, a substantially spherical shape, a flat shape, a block shape, a plate shape, and a scale shape. The shape of the electromagnetic wave adjusting particles is preferably substantially spherical, flat or rod-shaped from the viewpoints of dispersibility and radio wave transmittance controllability. The shape of the electromagnetic wave adjusting particles can be determined by observation using, for example, a scanning electron microscope.

  The content of the electromagnetic wave adjusting particles in the suspension is not particularly limited, and is appropriately selected depending on the purpose and the like. The content of the electromagnetic wave adjusting particles in the suspension is 1% by mass to 40% by mass from the viewpoint of obtaining a sufficient change in electromagnetic wave transmittance when the dispersed state and the aligned state of the electromagnetic wave adjusting particles are switched. Preferably, it is 3 mass%-20 mass%.

[Dispersion medium]
The suspension for variable electromagnetic wave adjusting element contains at least one dispersion medium as required. The dispersion medium is not particularly limited as long as it can disperse the electromagnetic wave adjusting particles at a temperature at which the electromagnetic wave adjusting element is operated. In general, the dispersion medium is preferably a liquid and insulating organic compound. Specific examples include aromatic hydrocarbons, aliphatic hydrocarbons, carboxylic acid esters, carboxylic acid amides, ketones, polyethers, silicone oils, acrylic oligomers, and the like, and at least one selected from the group consisting of these It is preferable that In particular, when the dispersion medium has a functional group having an affinity for the electromagnetic wave adjusting particles, the dispersibility of the electromagnetic wave adjusting particles can be further improved, and sedimentation or aggregation of the electromagnetic wave adjusting particles can be reduced. The functional group having affinity for the electromagnetic wave adjusting particles is appropriately selected according to the type of the electromagnetic wave adjusting particles, and examples thereof include a hydroxy group, a carbonyl group, and an amino group.

  The physical properties such as the freezing point (melting point) of the dispersion medium can be appropriately selected according to the use of the variable electromagnetic wave adjusting element. For example, when there is a possibility of using the electromagnetic wave adjusting element in a low temperature environment, it is preferable to select a dispersion medium having a low freezing point (melting point), and the freezing point of the dispersion medium is preferably −10 ° C. or lower, and −20 ° C. The following is more preferable, and −30 ° C. or lower is further preferable. By using a dispersion medium having a low freezing point, electromagnetic wave adjustment at a low temperature can be more easily performed, and aggregation of particles due to solidification of the suspension can be prevented.

As a low freezing point dispersion medium, hexyldecyl isostearate, isocetyl myristate, isopropyl isostearate, isostearyl palmitate, ethyl linoleate, isopropyl linoleate, 2-octyldodecyl neopentanoate, butyl octyl salicylate, diglyceryl triisostearate , Propylene glycol monocaprylate, propylene glycol dicaprylate, trimethylolpropane triethylhexanoate, trimethylolpropane triisostearate, glyceryl tri-2-ethylhexanoate, 2-butyl-2-ethyl-1,3-ethylhexanoate -Propanediol, dialkyl carbonate (C14,15), di-2-ethylhexyl phthalate, diisopropyl adipate, diisodecyl adipate, dibasic sebacate Chiruokuchiru, diisostearyl malic acid, citric acid tri-ethylhexyl, hydrogenated polyolefins, hydrogenated polydecene, mention may be made of phosphoric acid trioleyl, dimethyl silicone oil, diphenyl silicone oil, a dimethyl diphenyl silicone oil.
Among them, those having a freezing point of −20 ° C. or less include hexyldecyl isostearate, butyl octyl salicylate, propylene glycol monocaprylate, trimethylolpropane triethylhexanoate, trimethylolpropane triisostearate, 2-butyl 2-ethylhexanoate 2-ethyl-1,3-propanediol, dialkyl carbonate (C14,15), di-2-ethylhexyl phthalate, diisodecyl adipate, dibutyloctyl sebacate, triethylhexyl citrate, hydrogenated polyolefin, hydrogenated polydecene, dimethyl silicone Examples thereof include oil, diphenyl silicone oil, and dimethyl diphenyl silicone oil.
Further, those having a freezing point of −30 ° C. or lower include dialkyl carbonate (C14,15), di-2-ethylhexyl phthalate, diisodecyl adipate, dibutyloctyl sebacate, triethylhexyl citrate, hydrogenated polyolefin, hydrogenated polydecene, dimethyl Examples thereof include silicone oil, diphenyl silicone oil, dimethyldiphenyl silicone oil, and the like.
Here, the dialkyl carbonate (C14, 15) means a mixture containing a dialkyl carbonate ester having two alkyl groups having 14 or 15 carbon atoms.
These dispersion media may be used alone or in combination of two or more. It is also possible to adjust the viscosity of the dispersion medium by mixing two or more kinds.

  As an index of the insulating property of the dispersion medium, electric resistivity can be mentioned. The dispersion medium preferably has an electric resistivity of 100 MΩ · m or more, more preferably 10,000 MΩ · m or more. The use of a dispersion medium having a high resistivity can more effectively suppress the occurrence of a short circuit due to deterioration with time and the like, and the reliability and durability of the variable electromagnetic wave adjusting element tend to be further improved.

  The viscosity of the dispersion medium is not particularly limited and can be appropriately selected depending on the purpose and the like. Generally, the viscosity of the dispersion medium is 1 mPa · s to 30000 mPa · s at 25 ° C. The viscosity of the dispersion medium is measured at 25 ° C. using a rotational viscometer such as an E-type viscometer.

  When the dispersion stability of the electromagnetic wave adjusting particles in the suspension is good and the sedimentation of the electromagnetic wave adjusting particles is not a problem, and the state change speed between the dispersed state and the aligned state of the electromagnetic wave adjusting particles is to be set faster. The viscosity of the dispersion medium is preferably low. Specifically, it is preferably 1 mPa · s to 600 mPa · s at 25 ° C., more preferably 50 mPa · s to 400 mPa · s. When the viscosity of the dispersion medium is 600 mPa · s or less at 25 ° C., the state change rate can be sufficiently increased.

  Specific examples of the low-viscosity dispersion medium include aromatic hydrocarbons, aliphatic hydrocarbons, carboxylic acid esters, carboxylic acid amides, ketones, polyethers, and silicone oils, and are selected from the group consisting of these. It is preferable to use at least one kind.

  Moreover, when it is desired to impart memory properties to the variable electromagnetic wave adjusting element, it is preferable that the viscosity of the dispersion medium is high. Specifically, it is preferably 1000 mPa · s to 20000 mPa · s at 25 ° C., and more preferably 1500 mPa · s to 10000 mPa · s. When the dispersion medium has a viscosity of 1000 mPa · s or more at 25 ° C., the alignment state of the electromagnetic wave adjusting particles can be maintained for a desired time even when the application of the electric field is stopped when the electromagnetic wave adjusting particles are in the aligned state. And the property of maintaining the transmission state of electromagnetic waves (memory property) can be exhibited. Such a memory property that can maintain the transmission state of electromagnetic waves even when the application of an electric field is stopped is useful because it becomes fail-safe when the variable electromagnetic wave adjusting element is applied to a window of an automobile, train, aircraft, or the like. In the suspension of the present invention, it is possible to change the state to the second dispersion state by applying a higher electric field to the aligned electromagnetic wave adjusting particles, so even if a high viscosity dispersion medium is used. Thus, it is possible to avoid the slow state change from the aligned state of particles to the dispersed state of particles as in a conventional suspension.

  Specific examples of the high-viscosity dispersion medium include silicone oil and acrylic oligomer, and it is preferable to use at least one selected from the group consisting of these.

  As the acrylic oligomer, a (meth) acrylic acid ester oligomer having an alkyl group having 4 to 24 carbon atoms and a hydroxyl group is preferable, and a (meth) acrylic acid ester oligomer containing a structural unit having an alkyl group and a structural unit having a hydroxyl group is further included. preferable. When such a (meth) acrylate oligomer is used as a dispersion medium, a structural unit having a hydroxyl group is oriented toward the particle side, and a structural unit having an alkyl group is oriented toward the dispersion medium side. For this reason, the dispersibility of the particle | grains in suspension improves, and there exists a tendency to disperse | distribute more uniformly. Moreover, as for carbon number of an alkyl group, 6-20 are more preferable. In addition, the description with (meth) acrylic acid ester means containing at least one of methacrylic acid ester and acrylic acid ester.

  Examples of the (meth) acrylic acid ester oligomer having an alkyl group and a hydroxyl group include those obtained by copolymerizing a mixture containing at least one alkyl group-containing monomer and one hydroxyl group-containing monomer. Specific examples of the (meth) acrylic acid ester oligomer having an alkyl group and a hydroxyl group include: (meth) butyl acrylate / (meth) acrylic acid 2-hydroxyethyl copolymer, (meth) acrylic acid hexyl / (meth) acrylic Acid 2-hydroxyethyl copolymer, octyl (meth) acrylate / (meth) acrylic acid 2-hydroxyethyl copolymer, (meth) acrylic acid decyl / (meth) acrylic acid 2-hydroxyethyl copolymer, ( (Meth) acrylic acid dodecyl / (meth) acrylic acid 2-hydroxyethyl copolymer, (meth) acrylic acid tetradecyl / (meth) acrylic acid 2-hydroxyethyl copolymer, (meth) acrylic acid hexadecyl / acrylic acid 2- Hydroxyethyl copolymer, octadecyl (meth) acrylate / (meth) acrylate 2-H Roxyethyl copolymer, 3,5,5-trimethylhexyl (meth) acrylate / 2-hydroxyethyl (meth) acrylate, butyl (meth) acrylate / 2-hydroxypropyl (meth) acrylate And (meth) acrylic acid 3,5,5-trimethylhexyl / (meth) acrylic acid 2-hydroxypropyl copolymer, (meth) acrylic acid dodecyl / (meth) acrylic acid 2-hydroxypropyl copolymer, etc. Can be mentioned.

  The content of the structural unit having an alkyl group in these (meth) acrylic acid ester oligomers is preferably 80 mol% to 99 mol%, and more preferably 90 mol% to 98 mol%. When the content of the constituent unit having alkyl is 80 mol% or more, the refractive index of the dispersion medium is suppressed from being excessively increased, and the light transmittance tends to be further improved. Moreover, it is preferable that it is 1 mol%-20 mol%, and, as for the content rate of the structural unit which has a hydroxyl group in these (meth) acrylic acid ester oligomers, it is more preferable that it is 2 mol%-10 mol%. When the content of the structural unit having a hydroxyl group is 20 mol% or less, the refractive index of the dispersion medium is suppressed from being excessively increased, and the light transmittance tends to be further improved.

  The molecular weight of the (meth) acrylic acid ester oligomer is not particularly limited and can be appropriately selected depending on the purpose and the like. The molecular weight of the (meth) acrylic acid ester oligomer used as a high-viscosity dispersion medium is preferably a weight average molecular weight of 1,000 to 80,000 in terms of standard polystyrene measured by gel permeation chromatography, More preferably, it is 000-50,000.

  Examples of the silicone oil include dimethyl silicone oil, dimethyl diphenyl silicone oil, polyether-modified silicone oil, and ester-modified silicone oil. The molecular weight of the silicone oil is not particularly limited and can be appropriately selected according to the purpose. As for the molecular weight of the silicone oil used as the high-viscosity dispersion medium, the weight average molecular weight in terms of standard polystyrene measured by gel permeation chromatography is preferably 4,000 to 100,000, and 8,000 to 80,000. It is more preferable that

  As such silicone oil, TSF451, TSF437, TSF4300, TSF410, TSF4440 (above, manufactured by Momentive Performance Materials), KF-96, KF-50, KF-352A (above, manufactured by Shin-Etsu Chemical Co., Ltd.) Etc.

  When the suspension for variable electromagnetic wave adjusting element contains a dispersion medium, the content thereof is appropriately selected according to the type and content of the electromagnetic wave adjusting particles, the type and content of the specific compound, and the like. In general, the content of the dispersion medium is preferably 60% by mass to 99% by mass, and more preferably 70% by mass to 97% by mass.

[Other ingredients]
The suspension for a variable electromagnetic wave adjusting element may further contain other components other than the electromagnetic wave adjusting particles, the specific compound, and the dispersion medium contained as necessary. Examples of other components include a pour point depressant, a viscosity index improver, a coupling agent, a dispersant, an emulsifier, and an anticorrosive.

  For example, when the variable electromagnetic wave adjusting element is used in a low temperature environment, the suspension for the variable electromagnetic wave adjusting element preferably contains a pour point depressant. When the suspension for the variable electromagnetic wave adjusting element contains the pour point depressant, the fluidity at a low temperature is further improved. Pour point depressants include polyalkyl methacrylates, polyalkyl acrylates, alkylated aromatic compounds, fumarate-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, and the like.

  The viscosity index improver means an additive capable of reducing the temperature dependence of the viscosity of the suspension for a variable electromagnetic wave adjusting element. By reducing the temperature dependency of the viscosity of the suspension for the variable electromagnetic wave adjustment element, the temperature dependency of the responsiveness of the variable electromagnetic wave adjustment element is reduced, and the handleability tends to be further improved. Examples of the viscosity index improver include polyalkyl methacrylate, olefin copolymer, polyisobutylene and the like.

  The method for preparing the suspension for the variable electromagnetic wave adjustment element is not particularly limited as long as the components constituting the suspension for the variable electromagnetic wave adjustment element can be sufficiently mixed, and can be prepared by a commonly used method. it can. For example, after blending particles, specific compound, dispersion medium included as necessary and other components included as necessary, using an automatic mortar, three rolls, ball mill, bead mill, homogenizer, ultrasonic disperser, etc. A method for obtaining a suspension can be mentioned.

<Variable electromagnetic wave adjustment element>
The variable electromagnetic wave adjusting element of the present invention includes two conductive base materials and an electromagnetic wave adjusting layer including the variable electromagnetic wave adjusting element suspension disposed between the two conductive base materials. Have. The variable electromagnetic wave adjusting element may further include other components as necessary. When the electromagnetic wave adjusting layer includes the suspension for the variable electromagnetic wave adjusting element, it becomes possible to electrically control the alignment state and the dispersed state of the particles in the suspension, and bidirectional between these states. It becomes possible to shorten the time required for the change.

[Conductive substrate]
The conductive substrate is not particularly limited as long as it has a conductive layer on at least one surface of the substrate. The conductive substrate may be light transmissive or light non-transmissive (light reflective). In general, the conductive substrate is preferably a light transmissive transparent conductive substrate. By configuring the variable electromagnetic wave adjusting element using the transparent conductive base material, for example, it is possible to configure a light control element capable of variably adjusting the light transmittance. When the conductive substrate has light transmittance, the light transmittance of the conductive substrate is preferably 80% or more. The light transmittance of the transparent conductive substrate is defined as the transmittance at a wavelength of 550 nm measured with an ultraviolet-visible near-infrared spectrophotometer.

The base material constituting the conductive base material is not particularly limited as long as a conductive layer can be formed on at least one surface thereof, and can be appropriately selected from commonly used base materials according to the purpose. Specific examples of the substrate include a glass plate, a resin plate, a glass film, and a resin film. Examples of the resin film include polyester films such as polyethylene terephthalate, polyolefin films such as polypropylene, polyvinyl chloride, acrylic resin films, polyether sulfone films, polyarylate films, polycarbonate films, and the like. . Among them, a polyethylene terephthalate film is preferable because the substrate is excellent in transparency and excellent in moldability, adhesiveness, workability, and the like.
The thickness in particular of a base material is not restrict | limited, According to the objective etc., it can select suitably. The thickness of a base material can be 30 micrometers-300 micrometers, for example.

The conductive layer formed on the surface of the substrate is preferably a light transmissive conductive layer. Specific examples of the material for the light-transmitting conductive layer include metal oxide films such as ITO, SnO ₂ , and In ₂ O ₃ , organic conductive films, carbon nanotubes, and silver nanowires. The thickness of the conductive layer is not particularly limited and can be appropriately selected according to the purpose. In general, the thickness of the conductive layer is preferably 10 nm to 5,000 nm. The thickness of the conductive layer can be measured using an optical film thickness meter.
The surface resistance value of the conductive layer is not particularly limited and can be appropriately selected depending on the purpose. In general, the surface resistance value of the conductive layer is preferably 3Ω / □ to 10000Ω / □. The surface resistance value of the conductive layer is measured at 25 ° C. using a four-probe method. In addition, the surface resistance value of the conductive layer is preferably 1000Ω / □ to 10000Ω / □ from the viewpoint of electromagnetic wave permeability near gigahertz (GHz). By having electromagnetic wave permeability in the vicinity of gigahertz, it is possible to transmit electromagnetic waves used in mobile phones and the like.

  The conductive substrate may further have an insulating layer (preferably a transparent insulating layer) having a thickness of about several nm to 1 μm on the conductive layer. By further including an insulating layer, it is possible to suppress the occurrence of a short-circuit phenomenon that may occur due to mixing of foreign substances. When the variable electromagnetic wave adjusting element of the present invention is used as a reflective electromagnetic wave adjusting element (for example, a rear-view mirror for an automobile), a conductive metal thin film such as aluminum, gold, or silver as a conductive layer is used as a conductive layer. It may be used.

[Electromagnetic wave adjustment layer]
The variable electromagnetic wave adjusting element of the present invention has an electromagnetic wave adjusting layer disposed between the two conductive substrates. The structure of the electromagnetic wave adjusting layer is a structure in which a space between conductive substrates maintained at a constant interval by a spacer or the like is filled with a suspension, and a network structure is formed by partition walls on the conductive layer surface of the conductive substrate. A structure in which the space partitioned by suspension is filled with suspension, a structure in which fine capsules containing the suspension are arranged between conductive substrates, a structure in which droplets of suspension are dispersed in a matrix of resin, etc. Is mentioned. The thickness of the electromagnetic wave adjusting layer is not particularly limited and is appropriately selected depending on the purpose and the like. In general, the thickness of the electromagnetic wave adjusting layer is preferably 20 μm to 200 μm. The thickness of the electromagnetic wave adjusting layer can be measured by measuring the thickness including the substrate using a micrometer and subtracting the thickness of the substrate measured in advance.

  In the variable electromagnetic wave adjustment element of the present invention, the two conductive layers are an electromagnetic wave transmission suppression state in which particles in the electromagnetic wave adjustment layer are irregularly dispersed and an electromagnetic wave transmission state in which the particles are aligned in the electric field direction. It is preferably controlled by the strength of the electric field applied to the conductive substrate or the frequency. When controlling by the strength of the electric field, the electric field applied in the electromagnetic wave transmission suppression state is preferably a stronger electric field than the electric field applied in the electromagnetic wave transmission state. In the case of controlling with the frequency level, the frequency of the electric field applied in the electromagnetic wave transmission suppressed state is preferably lower than the frequency applied in the electromagnetic wave transmission state. Moreover, it is also possible to control by both the strength of the electric field and the level of the frequency as required. In that case, it is preferable that the electric field and the frequency applied in the electromagnetic wave transmission suppression state are stronger and lower in frequency than the electric field applied in the electromagnetic wave transmission state.

  In a conventional electromagnetic wave adjustment element using an electrorheological fluid, particles in the suspension are aligned in the direction of the electric field by applying an electric field so that the electromagnetic wave can be transmitted, and in the suspension by applying no electric field. These particles were irregularly dispersed to obtain a state in which the transmission of electromagnetic waves was suppressed. However, since the state change from the aligned state to the dispersed state of the particles is governed by the Brownian motion of the particles, it is difficult to change from the aligned state to the dispersed state at a practical state change rate. In the present invention, the electromagnetic wave transmission can be suppressed by applying a stronger electric field and / or an electric field having a lower frequency than the electric field applied in the electromagnetic wave transmission state. The state and the electromagnetic wave transmission suppression state can be switched.

  In the variable electromagnetic wave adjusting element, the electric field strength applied to the electromagnetic wave adjusting layer in the electromagnetic wave transmitting state is appropriately selected according to the configuration of the suspension. Generally, it is preferably 0.2 MV / m to 2 MV / m, and more preferably 0.4 MV / m to 1.5 MV / m. In addition, the electric field strength applied to the electromagnetic wave adjusting layer in the electromagnetic wave transmission suppressed state that is the second dispersion state is preferably 1 MV / m to 4 MV / m, and more preferably 1.5 MV / m to 3 MV / m. Is more preferable.

In the variable electromagnetic wave adjusting element, the voltage V1 applied to the two conductive substrates in the electromagnetic wave transmission state is appropriately selected according to the configuration of the suspension, the distance between the two conductive substrates, and the like. The For example, when the distance between the conductive substrates is 50 μm, the voltage V1 for aligning the particles is preferably 10V to 100V, and more preferably 20V to 75V. On the other hand, the voltage V2 applied to the electromagnetic wave adjusting layer in the electromagnetic wave transmission suppressed state which is the second dispersion state is preferably 50V to 200V, and more preferably 75V to 150V.
In the variable electromagnetic wave adjusting element, V2 is preferably larger than V1, and a voltage difference (V2−V1) between V2 and V1 is more preferably 50V to 100V.

  In the variable electromagnetic wave adjusting element, the applied electric field may be a DC electric field or an AC electric field. In general, the electric field applied to the electromagnetic wave adjusting layer in the electromagnetic wave transmitting state is preferably an alternating electric field. The frequency of the alternating electric field is not particularly limited as long as the electromagnetic wave transmission state and the electromagnetic wave transmission suppression state of the particles in the suspension can be controlled. For example, when the frequency is constant and the electromagnetic wave transmission state and the electromagnetic wave transmission suppression state are controlled by the strength of the electric field, 0 Hz to 100 Hz is preferable, and 1 Hz to 60 Hz is more preferable. Moreover, when controlling an electromagnetic wave transmission state and an electromagnetic wave transmission suppression state by making the electric field intensity constant and by controlling the frequency, the frequency for controlling the electromagnetic wave transmission state is preferably 200 Hz to 500 kHz, and more preferably 500 Hz to 100 kHz. The frequency for setting the electromagnetic wave transmission suppressed state is preferably 0 Hz to 100 Hz, and more preferably 1 Hz to 60 Hz. The electric field strength at this time is preferably 1 MV / m to 4 MV / m, and more preferably 1.5 MV / m to 3 MV / m.

As a method for controlling the electromagnetic wave transmission state and the electromagnetic wave transmission suppression state, a method of setting the electromagnetic wave transmission state at a weak electric field strength and high frequency and setting the electromagnetic wave transmission suppression state at a strong electric field strength and low frequency can be selected. The electric field intensity in the electromagnetic wave transmission state is preferably 0.2 MV / m to 2 MV / m, more preferably 0.4 MV / m to 1.5 MV / m, and the frequency at this time is 200 Hz to 500 kHz. Is preferable, and 500 Hz to 100 kHz is more preferable. The electric field strength in the electromagnetic wave transmission suppressed state is preferably 1 MV / m to 4 MV / m, more preferably 1.5 MV / m to 3 MV / m, and the frequency is preferably 0 Hz to 100 Hz, and 1 Hz to 60 Hz. More preferred. These control methods are preferably selected from the viewpoint of the cost of the control circuit and the speed of switching between the electromagnetic wave transmission state and the electromagnetic wave transmission suppression state. In general, the method of making the frequency constant can further reduce the cost of the drive power supply. The speed of change from the electromagnetic wave transmission suppression state to the electromagnetic wave transmission state is the fastest in the case of strong electric field strength and high frequency, and then the fast in the case of weak electric field strength and high frequency. Therefore, when the change from the electromagnetic wave transmission suppression state to the electromagnetic wave transmission state is sufficiently fast even at a low electric field strength and at a low frequency, a method in which the frequency is constant and the electric field intensity is controlled is more preferable.
After the voltage is applied to make the electromagnetic wave transmission suppressed state, the electromagnetic wave transmission suppressed state is maintained even if the voltage application is stopped. For this reason, it is preferable to quickly stop the application of voltage from the viewpoints of energy saving and durability of the electromagnetic wave adjusting element. Further, it is preferable from the viewpoint of energy saving and durability of the electromagnetic wave adjusting element that the voltage is intermittently applied within a range in which the transmittance can be maintained even after the transmission state is obtained by applying the voltage. When a high-viscosity dispersion medium is used, the voltage application interval can be increased because the change to the electromagnetic wave transmission suppression state is slow when the application of voltage is stopped.

  The variable electromagnetic wave adjusting element of the present invention includes an indoor / outdoor partition; a window glass for a building, a skylight, etc .; various flat display elements used in electronic equipment or video equipment; various instrument panels and existing liquid crystal displays Substitutes for elements; optical shutters; various indoor and outdoor advertisements; various information signs; window glass for aircraft, railway vehicles, ships, etc .; window glass for automobiles, rearview mirrors, sunroofs, etc .; glasses; sunglasses; sun visor; It can use suitably for the use of.

<Electromagnetic wave adjustment method>
The electromagnetic wave adjustment method of the present invention is an electromagnetic wave transmission suppression state in which the electric field applied to the conductive substrate of the variable electromagnetic wave adjustment element is changed, and the electromagnetic wave adjustment particles in the electromagnetic wave adjustment layer are irregularly dispersed. And switching between the electromagnetic wave transmitting particles in which the electromagnetic wave adjusting particles are aligned in the electric field direction. When the electromagnetic wave adjusting layer includes the suspension for the variable electromagnetic wave adjusting element of the present invention, the electromagnetic wave transmission state and the electromagnetic wave transmission suppression state can be switched at an excellent state change speed.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Production Example 1)
Copolymer 1 which is a methacrylate ester copolymer having a hydroxyl group was prepared as follows. Toluene (reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.) 164 g, dodecyl methacrylate 231.4 g (produced by Kyoeisha Chemical Co., Ltd.), 2-hydroxyethyl methacrylate (reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.) 7.56 g, 18.40 g of n-hexyl mercaptan (first grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added to a three-necked flask and heated to 60 ° C. with stirring under a nitrogen atmosphere. After 1 hour, 1.84 g of azoisobutyronitrile (reagent special grade, manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 80 g of toluene, and then the whole amount was dropped. After stirring for 21 hours as it was, the temperature was raised to 115 ° C. and the mixture was further stirred for 2 hours. Then, the pressure was reduced and the solvent was distilled off. 200 g of methanol was added to this, transferred to a separatory funnel, shaken vigorously, and allowed to stand for 30 minutes. The lower layer of the reaction solution separated into the upper layer and the lower layer was transferred to a separating funnel. After adding 200 g of methanol to the separatory funnel and shaking vigorously, it was left for 30 minutes. The lower layer of the reaction solution separated into the upper layer and the lower layer was transferred to a separating funnel. After adding 200 g of methanol to the separatory funnel and shaking vigorously, it was left for 30 minutes. After the solvent was distilled off from the lower layer collected from the reaction solution separated into the upper layer and the lower layer under reduced pressure, short-path distillation purification was performed under conditions of 110 Pa and 200 ° C. to obtain a copolymer 1. The molar ratio of the structural unit having a hydroxyl group (structural unit derived from 2-hydroxyethyl methacrylate) and the structural unit having an alkyl group (structural unit derived from dodecyl methacrylate) was 6:94.
It was 3,500 when the weight average molecular weight of the obtained copolymer 1 was measured by GPC. It was 2000 mPa * s when the viscosity in 25 degreeC was measured with the E-type viscosity meter (the Tokimec Co., Ltd. make, VISCONIC EHD). Hereinafter, the viscosity of the dispersion medium was measured in the same manner.

In addition, the measuring method of the weight average molecular weight of the copolymer 1 is as follows. The weight average molecular weight of the copolymer 1 was converted from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using five standard polystyrene sample sets (PStQuick MP-H, PStQuick B [trade name, manufactured by Tosoh Corporation)]. The GPC conditions are shown below.
Apparatus: (Pump: L-2130 type [manufactured by Hitachi High-Technologies Corporation]),
(Detector: L-2490 type RI [manufactured by Hitachi High-Technologies Corporation]),
(Column oven: L-2350 [manufactured by Hitachi High-Technologies Corporation])
Column: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R400M (3 in total) (manufactured by Hitachi Chemical Co., Ltd., trade name)
Column size: 10.7mm ID x 300mm
Eluent: Tetrahydrofuran Sample concentration: 10 mg / 2 mL
Injection volume: 200 μL
Flow rate: 2.05 mL / min Measurement temperature: 25 ° C

<Example 1>
A complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm, amorphous) is 10.0% by mass, and a specific compound represented by the general formula (II) 1.0 mass% of alkylolaminoamide (trade name: DISPERBYK-109 (manufactured by BYK-Chemie)), which is a compound represented by the formula: 0.2 mass% of lactic acid as an organic acid, and a hydroxyl group as a dispersion medium A copolymer of methacrylic acid ester (Copolymer 1, viscosity 2000 mPa · s (25 ° C.)) was blended so as to be 88.8% by mass and dispersed in a mortar to obtain a suspension. Note that alkylolaminoamide and lactic acid were previously diluted with a dispersion medium.
The number average particle size of the complex oxide pigment of Fe and Cr was calculated as an arithmetic average value of 50 particle sizes measured using a photograph taken with a scanning electron microscope. Hereinafter, the number average particle diameter of the particles was measured in the same manner.

As a conductive substrate, two glass plates (average thickness 0.7 mm) having an ITO film (average thickness 17 nm, surface resistance 200 Ω / □) on one side were prepared. The light transmittance of the conductive substrate was 88%. The average thickness of the ITO film was measured with an optical film thickness meter (F20 manufactured by Filmmetrics). The thickness of the glass plate was measured with a micrometer. The light transmittance of the conductive substrate was measured at a wavelength of 550 nm using an ultraviolet-visible near-infrared spectrophotometer (trade name V-670, manufactured by JASCO Corporation). In addition, the blank in the light transmittance measurement was air.
The suspension obtained above was dropped on the surface of the glass plate on which the ITO film was formed, and another glass plate was placed around the glass plate so that the ITO film was in contact with the suspension. After overlapping with a polyimide adhesive tape having a thickness of 50 μm, it was further fixed with a clip to produce a variable electromagnetic wave adjusting element.

(Evaluation)
The following evaluation was performed in an environment of 25 ° C.
About the variable electromagnetic wave adjusting element obtained above, when a power source is connected to the ITO film, the voltage is gradually increased from 0 V at a frequency of 50 Hz, the light transmittance is increased to a maximum voltage, and the voltage is further increased. The voltage at which the light transmittance was reduced to a state close to the light transmittance before voltage application was recorded. A constant frequency and constant voltage power source (trade name: CVFT1-200H, manufactured by Tokyo Seiden Co., Ltd.) was used as the power source.
In addition, after the light transmittance was close to that before the voltage application, the applied voltage was raised and lowered to confirm the reversible operation of the light transmittance change. The change in light transmittance was confirmed visually. Whether or not the light transmittance was restored was confirmed by comparing with the light transmittance of the region outside the electrode.

  As a result of the evaluation, the applied voltage at which the light transmittance was maximum was 80 V, the applied voltage at which the light transmittance was the same as that before voltage application was 120 V, and a reversible operation was possible in a short time. When the applied voltage was 80V, it was colorless and transparent, and when the applied voltage was 120V, it became black, and good contrast was obtained. The results are shown in Table 1.

  Next, the applied voltage was set to 80 V and kept in a transparent state for about 1 minute, and then the application was stopped and left standing. As a result, the transparent state was maintained even after 30 minutes. Further, the applied voltage was set to 120 V to make it black, and then the application was stopped and left as it was. As a result, the black state was maintained even after one day.

  Black 6350 is a near-infrared reflective pigment, and it is considered that the temperature rise of the suspension can be reduced when irradiated with sunlight. For this reason, it is considered that the deterioration of the characteristics of the variable electromagnetic wave adjusting element due to the temperature rise can be reduced.

<Example 2>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.3 mass% of alkylolaminoamide (trade name: DISPERBYK-109 (manufactured by BYK-Chemie)), an anionic dispersant (trade name: DISPERBYK-111 (manufactured by BYK-Chemie) )) Was blended to 0.6% by weight and copolymer 1 to 88.1% by weight as a dispersion medium, and dispersed in a mortar to obtain a suspension. The alkylolaminoamide and the anionic dispersant were previously diluted with a dispersion medium. DISPERBYK-111 is a copolymer having a carboxylic acid or sulfonic acid that is an acidic group.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 70 V, the voltage at which the light transmittance was the same as before voltage application was 150 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 70V, it was colorless and transparent, and when the applied voltage was 150V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 3>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.9% by mass of a compound such as cocamidopropyldimethylamine (propyldimethylamine coconut oil), 2.2% by mass of an anionic dispersant (trade name: DISPERBYK-111 (manufactured by BYK-Chemie)), As a dispersion medium, the copolymer 1 was blended so as to be 85.9% by mass and dispersed in a mortar to obtain a suspension. Cocamidopropyldimethylamine and an anionic dispersant were previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 100 V, the voltage at which the light transmittance was the same as that before voltage application was 200 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 100V, it was colorless and transparent, and when the applied voltage was 200V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 4>
A composite pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, and is represented by the general formula (I) as a specific compound. A compound, fatty acid diethanolamide (trade name: Aminone PK-02S (manufactured by Kao Corporation)), 2.9% by mass, and copolymer 1 as a dispersion medium to 87.1% by mass were blended, and a mortar Dispersion treatment was performed to obtain a suspension. The fatty acid diethanolamide was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 50 V, the voltage at which the light transmittance was the same as that before voltage application was 150 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 50V, it was colorless and transparent, and when the applied voltage was 150V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 5>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (I) as a specific compound The compound 1 is fatty acid diethanolamide (trade name: Aminone PK-02S (manufactured by Kao Corporation)), 5.1% by mass, and the copolymer 1 as a dispersion medium is compounded to 84.9% by mass, Dispersion treatment was performed in a mortar to obtain a suspension. Fatty acid diethanolamide was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 100V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 6>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (I) as a specific compound The compound fatty acid methyl ethanolamide (trade name: Aminone C-11S (manufactured by Kao Corporation)) is 8.6% by mass, and the copolymer 1 as a dispersion medium is compounded to 81.4% by mass, Dispersion treatment was performed in a mortar to obtain a suspension. Fatty acid methylethanolamide was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 50 V, the voltage at which the light transmittance was the same as that before voltage application was 150 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 50V, it was colorless and transparent, and when the applied voltage was 150V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 7>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (I) as a specific compound N, N-diethyldodecanamide (manufactured by Wako Pure Chemical Industries, Ltd.), 44.0% by mass, and copolymer 1 as a dispersion medium in an amount of 46.0% by mass. Dispersion treatment was performed to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 50 V, the voltage at which the light transmittance was the same as before voltage application was 120 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 50V, it was colorless and transparent, and when the applied voltage was 120V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

<Example 8>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (I) as a specific compound N, N-diethyldodecanamide (manufactured by Wako Pure Chemical Industries, Ltd.) was blended so as to be 90.0% by mass and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 35 V, the voltage at which the light transmittance was the same as that before voltage application was 70 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 35V, it was colorless and transparent, and when the applied voltage was 70V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

<Example 9>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.7% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt of a compound of 2-hydroxybutanoic acid and 88 of copolymer 1 as a dispersion medium. The mixture was blended so as to be 3% by mass and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 100V, it became black and good contrast was obtained. The results are shown in Table 1.
As a result of visually observing the change in transmittance using the same element, the change from the electromagnetic wave transmission suppression state to the electromagnetic wave transmission state when 30 V was applied was about 60 seconds, and the electromagnetic wave transmission suppression from the electromagnetic wave transmission state when 100 V was applied. The change to the state was about 1-2 seconds. As a result of measuring the transmittance using a spectrophotometer, the transmittance at a wavelength of 550 nm was 14% in the electromagnetic wave transmission state and 2% in the electromagnetic wave transmission suppression state.

<Example 10>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 5.0 mass%, and is represented by the general formula (II) as a specific compound. 2.0% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt of a compound of 2-hydroxybutanoic acid and 93 of copolymer 1 as a dispersion medium It mix | blended so that it might become 0.0 mass%, and it disperse-processed with the mortar, and obtained suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 20 V, the voltage at which the light transmittance was the same as before voltage application was 70 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 20V, it was colorless and transparent, and when the applied voltage was 70V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

<Example 11>
10.0% by mass of titanium oxide particles (trade name: JR-1000 (manufactured by Teika Co., Ltd.), number average particle size 1 μm), a compound represented by the general formula (II) as a specific compound and 2-hydroxybutanoic acid 1.0 mass% of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) and 89.0 mass% of copolymer 1 as a dispersion medium. The mixture was mixed and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as before voltage application was 70 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 70V, it became cloudy. The results are shown in Table 1.

(Example 12)
10.0 mass% of CuO particles (number average particle size 0.4 μm) prepared by hydrothermal synthesis, an amine salt that is a salt of a compound represented by general formula (II) and 2-hydroxybutanoic acid as a specific compound Type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) and 1.0% by weight of copolymer 1 as a dispersion medium were mixed and dispersed in a mortar. To obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 40 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 40V, it was colorless and transparent, and when the applied voltage was 100V, it turned brown, and good contrast was obtained. The results are shown in Table 1.

<Example 13>
A composite oxide pigment of Fe, Co, Cr (trade name: Brown # 9290 (manufactured by Dainichi Seika Kogyo Co., Ltd.), number average particle size 0.6 μm) is 10.0% by mass, a specific compound represented by the general formula (II ) 1.0% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)), which is a salt of a compound represented by 2) and 2-hydroxybutanoic acid, Blend 1 was blended to 89.0% by mass and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium. Brown # 9290 is a near infrared reflective pigment.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as before voltage application was 150 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30 V, it was colorless and transparent, and when the applied voltage was 150 V, it became brown and good contrast was obtained. The results are shown in Table 1.

<Example 14>
10.0% by mass of Fe oxide particles (trade name: HR-390H (manufactured by Toda Kogyo Co., Ltd., number average particle size 0.2 μm)), a compound represented by the general formula (II) as a specific compound and 2 -1.0% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco)) which is a salt with hydroxybutanoic acid, and 89.0% by mass of copolymer 1 as a dispersion medium A suspension was obtained by dispersing in a mortar, and an amine salt type cationic surfactant previously diluted with a dispersion medium was added.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, and the voltage at which the light transmittance was the same as that before the voltage application was 100 V, and reversible operation was possible. It was. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 100V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 15>
10.1% by mass of silicone particles (trade name: Tospearl 120 (manufactured by Momentive Performance Materials), number average particle size 2 μm), a compound represented by the general formula (II) as a specific compound and 2-hydroxybutane Amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) that is a salt with an acid is 1.0 mass%, and copolymer 1 is 88.9 mass% as a dispersion medium. And dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 50 V, the voltage at which the light transmittance was the same as that before voltage application was 150 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 50V, it was colorless and transparent, and when the applied voltage was 150V, it became cloudy. The results are shown in Table 1.

<Example 16>
4.9% by mass of melamine / formaldehyde condensate particles (trade name: Eposter S6 (manufactured by Nippon Shokubai Co., Ltd.), number average particle size 0.4 μm), a compound represented by the general formula (II) as a specific compound; Amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt with 2-hydroxybutanoic acid is 2.0% by mass, and 93.1% of copolymer 1 is used as a dispersion medium. %, And dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 50 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. At an applied voltage of 50V, it was colorless and transparent, and at an applied voltage of 100V, it became cloudy. The results are shown in Table 1.

<Example 17>
9.8% by mass of black polymethyl methacrylate particles (trade name: C-12 (manufactured by Toyobo Co., Ltd.), number average particle size 12 μm), a compound represented by the general formula (II) as a specific compound and 2 -Amine salt type cationic surfactant (trade name: NOPCOSPERTH 092 (manufactured by San Nopco Co., Ltd.)), which is a salt with hydroxybutanoic acid, is 2.0% by mass, and the copolymer 1 is 88.2% by mass as a dispersion medium. Were mixed and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as before voltage application was 120 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 120V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 18>
9.8% by mass of barium carbonate (trade name: BW-K (manufactured by Sakai Chemical Industry Co., Ltd.), number average particle size 0.5 μm), a compound represented by the general formula (II) as a specific compound, and 2- 1.9% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco)) which is a salt with hydroxybutanoic acid, and 88.3% by mass of copolymer 1 as a dispersion medium. The mixture was mixed and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 100V, it became cloudy. The results are shown in Table 1.

<Example 19>
9.7% by mass of barium sulfate (trade name: B-54 (manufactured by Sakai Chemical Industry Co., Ltd.), number average particle size 0.9 μm), a compound represented by the general formula (II) as a specific compound, and 2- Amine salt type cationic surfactant which is a salt with hydroxybutanoic acid (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) is 2.2% by mass, and copolymer 1 is 88.1% by mass as a dispersion medium. The mixture was mixed and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 100V, it became cloudy. The results are shown in Table 1.

<Example 20>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.0 mass% of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt of a compound of 2-hydroxybutanoic acid and triisodecyl trimellitic acid (viscosity) as a dispersion medium 500 mPa · s (25 ° C.)) was blended so as to be 89.0% by mass and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 50 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 50V, it was colorless and transparent, and when the applied voltage was 100V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 21>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.3 mass% of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)), which is a salt of a compound of 2-hydroxybutanoic acid, and a polyether-modified dimethyl silicone (as a dispersion medium) Product name: TSF4440 (made by Momentive Performance Materials Co., Ltd.), viscosity 160 mm ² / s (25 ° C.)) was blended so as to be 88.7% by mass and dispersed in a mortar to obtain a suspension. . The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 40 V, the voltage at which the light transmittance was the same as that before voltage application was 100 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 40V, it was colorless and transparent, and when the applied voltage was 100V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

<Example 22>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.8% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt of a compound of 2-hydroxybutanoic acid and ester-modified dimethyl silicone (product) Name: TSF410 (manufactured by Momentive Performance Materials), viscosity 30 mm ² / s (25 ° C.) was blended to 88.2% by mass, and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 30 V, the voltage at which the light transmittance was the same as before voltage application was 70 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 30V, it was colorless and transparent, and when the applied voltage was 70V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 23>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.7% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt of a compound of 2-hydroxybutanoic acid and methylphenyl silicone (trade name) : TSF437 (manufactured by Momentive Performance Materials Co., Ltd.) and a viscosity of 22 mm ² / s (25 ° C.) were blended so as to be 88.3% by mass and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 70V, the voltage at which the light transmittance was the same as before voltage application was 130V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 70V, it was colorless and transparent, and when the applied voltage was 130V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

<Example 24>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, represented by the general formula (II) as a specific compound 1.8% by mass of an amine salt type cationic surfactant (trade name: Nop Cosperth 092 (manufactured by San Nopco Co., Ltd.)) which is a salt of a compound of 2-hydroxybutanoic acid and methylphenyl silicone (trade name) : TSF4300 (manufactured by Momentive Performance Materials Co., Ltd.) and a viscosity of 140 mm ² / s (25 ° C.) were mixed so as to be 88.2% by mass and dispersed in a mortar to obtain a suspension. The amine salt type cationic surfactant was previously diluted with a dispersion medium.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 70V, the voltage at which the light transmittance was the same as before voltage application was 130V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 70V, it was colorless and transparent, and when the applied voltage was 130V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

(Example 25)
4.0 mass% CuO particles (number average particle size 0.4 μm) prepared by hydrothermal synthesis, alkylolaminoamide (trade name: DISPERBYK-109) which is a compound represented by the general formula (II) as a specific compound (BYK-Chemie)) is 2.5% by mass, lactic acid is 0.5% by mass as an organic acid, and triisodecyl trimellitic acid is 93.0% by mass as a dispersion medium, and dispersed in a mortar. To obtain a suspension. Alkyrolaminoamide and lactic acid previously diluted with a dispersion medium were added.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 80 V, the voltage at which the light transmittance was the same as before voltage application was 180 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 80V, it was colorless and transparent, and when the applied voltage was 180V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

(Example 26)
Complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.1% by mass, represented by the general formula (III) as a specific compound 1.9% by mass of hydroxyl group-containing carboxylic acid ester (trade name: DISPERBYK-108 (manufactured by BYK-Chemie)), 1.1% by mass of lactic acid, and 86.9% by mass of copolymer 1 as a dispersion medium. The mixture was mixed and dispersed in a mortar to obtain a suspension. The specific compound and lactic acid previously diluted with a dispersion medium were added.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 70 V, the voltage at which the light transmittance was the same as before voltage application was 150 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 70V, it was colorless and transparent, and when the applied voltage was 150V, it became black and good contrast was obtained. The results are shown in Table 1.

<Example 27>
A composite oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.9% by mass, represented by the general formula (III) as a specific compound 1.9% by mass of a hydroxyl group-containing carboxylic acid ester (trade name: DISPERBYK-108 (manufactured by BYK-Chemie)), an anionic dispersant (trade name: DISPERBYK-111 (manufactured by BYK-Chemie)) as an organic acid Was blended in an amount of 2.1% by mass and copolymer 1 as a dispersion medium in an amount of 85.1% by mass, and dispersed in a mortar to obtain a suspension. Specific compounds and anionic dispersants previously diluted with a dispersion medium were added.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, the applied voltage at which the light transmittance was maximized was 80 V, the voltage at which the light transmittance was the same as before voltage application was 180 V, and the reversible operation was performed in a short time. It was possible. When the applied voltage was 80V, it was colorless and transparent, and when the applied voltage was 180V, it was in a black state, and good contrast was obtained. The results are shown in Table 1.

(Comparative Example 1)
Silicone particles (trade name: Tospearl 120 (made by Momentive Performance Materials Co., Ltd.), number average particle diameter 2 μm) are blended so as to be 9.7% by mass, and copolymer 1 is 90.3% by mass as a dispersion medium. And dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, no change in transmittance was observed even when the applied voltage was increased to 200V. The results are shown in Table 2.

(Comparative Example 2)
Melamine / formaldehyde condensate particles (trade name: Eposter S6 (manufactured by Nippon Shokubai Co., Ltd.), number average particle size 0.4 μm) are 5.0 mass%, and copolymer 1 is 95.0 mass% as a dispersion medium. The mixture was mixed and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, no change in transmittance was observed even when the applied voltage was increased to 200V. The results are shown in Table 2.

(Comparative Example 3)
Black polymethyl methacrylate particles (trade name: C-12 (manufactured by Toyobo Co., Ltd.), number average particle size 12 μm) are 10.5% by mass, and copolymer 1 is 89.5% by mass as a dispersion medium. Were mixed and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, no change in transmittance was observed even when the applied voltage was increased to 200V. The results are shown in Table 2.

(Comparative Example 4)
9.6% by mass of barium carbonate particles (trade name: BW-K (manufactured by Sakai Chemical Industry Co., Ltd., number average particle size 0.5 μm)) and 90.4% by mass of copolymer 1 as a dispersion medium And dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, white turbidity was slightly increased at an applied voltage of about 100 V, and no further change was observed even when the voltage was increased to 200 V. That is, a transparent state with an increased light transmittance was not achieved, and no reversible operation occurred even when the applied voltage was raised or lowered. The results are shown in Table 2.

(Comparative Example 5)
Barium sulfate particles (trade name: B-54 (manufactured by Sakai Chemical Industry Co., Ltd.), number average particle size 0.9 μm) are 9.5% by mass, and copolymer 1 is 90.5% by mass as a dispersion medium. Were mixed and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

  As a result of evaluation in the same manner as in Example 1, white turbidity was slightly increased at an applied voltage of about 100 V, and no further change was observed even when the voltage was increased to 200 V. That is, a transparent state with an increased light transmittance was not achieved, and no reversible operation occurred even when the applied voltage was raised or lowered. The results are shown in Table 2.

(Comparative Example 6)
Complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, and copolymer 1 is 90.0 as a dispersion medium. It mix | blended so that it might become mass%, and it disperse-processed with the mortar, and obtained suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

As a result of evaluation in the same manner as in Example 1, the transmittance increased with increasing voltage up to about 100 V applied voltage, and thereafter became saturated, but the light transmittance reached a maximum at 200 V applied voltage.
Thereafter, the applied voltage was turned off and the mixture was allowed to stand, but the state where the light transmittance was high was maintained even after 5 minutes. Further, no reversible operation occurred even when the applied voltage was raised or lowered. The results are shown in Table 2.

(Comparative Example 7)
Complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, dodecylbenzenesulfonic acid (Tokyo Kasei Kogyo) as an organic acid Co., Ltd.) was blended so that the content of copolymer 1 was 88.5% by mass and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

As a result of evaluation in the same manner as in Example 1, the transmittance increased with increasing voltage up to about 100 V applied voltage, and thereafter became saturated, but the light transmittance reached a maximum at 200 V applied voltage.
Thereafter, the applied voltage was turned off and the mixture was allowed to stand, but the state where the light transmittance was high was maintained even after 5 minutes. Further, no reversible operation occurred even when the applied voltage was raised or lowered. The results are shown in Table 2.

(Comparative Example 8)
Complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, polyethylene glycol monolaurate (10E as a surfactant) O.) (manufactured by Wako Pure Chemical Industries, Ltd.) 1.5% by mass, copolymer 1 as a dispersion medium to 88.5% by mass, dispersed in a mortar, suspension Got.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

As a result of evaluation in the same manner as in Example 1, the transmittance increased with increasing voltage up to about 100 V applied voltage, and thereafter became saturated, but the light transmittance reached a maximum at 200 V applied voltage.
Thereafter, the applied voltage was turned off and the mixture was allowed to stand, but the state where the light transmittance was high was maintained even after 5 minutes. Further, no reversible operation occurred even when the applied voltage was raised or lowered. The results are shown in Table 2.

(Comparative Example 9)
Complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm) is 10.0% by mass, N-butyldiethanolamine (Wako Pure) 2.0% by mass of Yaku Kogyo Co., Ltd.), 2.0% by mass of an anionic dispersant (trade name: DISPERBYK-111 (manufactured by BYK-Chemie)) as an organic acid, and copolymer 1 as a dispersion medium Was mixed so as to be 86.0% by mass and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

As a result of evaluation in the same manner as in Example 1, the transmittance increased with increasing voltage up to about 100 V applied voltage, and thereafter became saturated, but the light transmittance reached a maximum at 200 V applied voltage.
Thereafter, the applied voltage was turned off and the mixture was allowed to stand, but the state where the light transmittance was high was maintained even after 5 minutes. Further, no reversible operation occurred even when the applied voltage was raised or lowered. The results are shown in Table 2.

(Comparative Example 10)
10.0% by mass of complex oxide pigment of Fe and Cr (trade name: Black 6350 (manufactured by Asahi Kasei Kogyo Co., Ltd.), number average particle size 0.5 μm), lauryltrimethylammonium chloride (Tokyo Kasei) as a surfactant Kogyo Co., Ltd.) was blended in an amount of 1.5% by mass and copolymer 1 as a dispersion medium at 88.5% by mass, and dispersed in a mortar to obtain a suspension.
Using the obtained suspension, a variable electromagnetic wave adjusting element was produced in the same manner as in Example 1.

In the produced variable electromagnetic wave adjusting element, the transmittance became maximum at 30 V and became black at 100 V, but thereafter, the transmittance did not change even when the voltage was changed, and reversible operation was not possible. The results are shown in Table 2.
The reason for the black color at 100 V is unknown, but it is considered that the dissolution of the ITO film of the conductive substrate is involved.

  From the above, it is possible to shorten the switching time between the electromagnetic wave transmission state and the transmission suppression state by configuring the variable electromagnetic wave adjustment element using the suspension for variable electromagnetic wave adjustment element of the present invention. I understand. In addition, because of the wide selection of particles to be used, it is possible to change the color tone and increase the area when applied to a light adjustment element, and it is a variable electromagnetic wave suitable for automobiles, trains, aircraft, building windows, etc. An adjustment element can be provided.

  2: conductive substrate, 4: electromagnetic wave adjusting particles, 6: dispersion medium, 8: electromagnetic wave adjusting layer, 10: power supply, 12: incident electromagnetic wave, 14: transmitted electromagnetic wave, 100: variable electromagnetic wave adjusting element

Claims (11)

Electromagnetic wave adjusting particles;
At least one compound selected from the group consisting of a first compound having an amide structure and a hydrophobic structure, and a second compound having an ester structure, an amine structure and a hydrophobic structure;
Only including,
The first compound includes a compound represented by the following general formula (I), a salt of a compound represented by the following general formula (I), a compound represented by the following general formula (II), and the following general formula ( II) Suspension for variable electromagnetic wave adjusting element comprising at least one selected from the group consisting of salts of compounds represented by II) .


(In the formula, R ¹ and R ¹¹ each independently represent a hydrocarbon group. R ² , R ³ , R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group or a hydroxyalkyl group. R ¹⁴ Represents a divalent hydrocarbon group.) Electromagnetic wave adjusting particles;
At least one compound selected from the group consisting of a first compound having an amide structure and a hydrophobic structure, and a second compound having an ester structure, an amine structure and a hydrophobic structure;
Only including,
The second compound includes at least one selected from the group consisting of a compound represented by the following general formula (III) and a salt of a compound represented by the following general formula (III) . Suspension.


(In the formula, R ²¹ represents a hydrocarbon group. R ²² and R ²³ each independently represents a hydrogen atom, an alkyl group or a hydroxyalkyl group. R ²⁴ represents a divalent hydrocarbon group.) Electromagnetic wave adjusting particles;
At least one compound selected from the group consisting of a first compound having an amide structure and a hydrophobic structure, and a second compound having an ester structure, an amine structure and a hydrophobic structure;
A suspension for a variable electromagnetic wave adjusting element , comprising an organic acid . The suspension for a variable electromagnetic wave adjusting element according to any one of claims 1 to 3 , wherein the electromagnetic wave adjusting particles have a number average particle diameter of 20 µm or less. The variable electromagnetic wave adjusting element suspension according to any one of claims 1 to 4 , wherein the electromagnetic wave adjusting particles are colored particles. The said electromagnetic wave adjustment particle | grains are suspensions for variable electromagnetic wave adjustment elements of any one of Claims 1-5 containing a metal oxide. Two conductive substrates;
An electromagnetic wave adjusting layer comprising the variable electromagnetic wave adjusting element suspension according to any one of claims 1 to 6 , which is disposed between the two conductive substrates,
A variable electromagnetic wave adjusting element. The electromagnetic wave adjusting layer has an electromagnetic wave transmission state in which the electromagnetic wave adjusting particles are aligned in the electric field direction, and the electromagnetic wave adjusting particles are irregular depending on the strength of the electric field applied to the two conductive substrates. The variable electromagnetic wave adjusting element according to claim 7 , wherein the electromagnetic wave transmission suppression state in motion is controlled. The variable electromagnetic wave adjusting element according to claim 8 , wherein the electric field applied in the electromagnetic wave transmission suppression state is a stronger electric field than the electric field applied in the electromagnetic wave transmission state. A variable electromagnetic wave adjustment element comprising two conductive substrates and an electromagnetic wave adjustment layer comprising a suspension for variable electromagnetic wave adjustment elements disposed between the two conductive substrates,
The suspension for variable electromagnetic wave adjusting element is selected from the group consisting of electromagnetic wave adjusting particles, a first compound having an amide structure and a hydrophobic structure, and a second compound having an ester structure, an amine structure and a hydrophobic structure. And at least one compound
The electromagnetic wave adjusting layer has an electromagnetic wave transmission state in which the electromagnetic wave adjusting particles are aligned in the electric field direction, and the electromagnetic wave adjusting particles are irregular depending on the strength of the electric field applied to the two conductive substrates. The electromagnetic wave transmission suppression state in motion is controlled,
The variable electromagnetic wave adjusting element, wherein the electric field applied in the electromagnetic wave transmission suppression state is a stronger electric field than the electric field applied in the electromagnetic wave transmission state.   The electric field applied to the conductive substrate of the variable electromagnetic wave adjustment element according to any one of claims 8 to 10 is changed, and the electromagnetic wave adjustment particles in the electromagnetic wave adjustment layer are irregularly dispersed. An electromagnetic wave adjustment method comprising: switching between an electromagnetic wave transmission suppression state that is present and an electromagnetic wave transmission state in which the electromagnetic wave adjustment particles are aligned in an electric field direction.