JP2006343600A - Method for manufacturing particle moving type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a particle moving type display device having improved display characteristics, display stability and memory properties. <P>SOLUTION: The method for manufacturing a particle moving type display device, having at least one pixel composed of at least one substrate, a barrier wall disposed on the substrate surface, one or more particles disposed in the space enclosed by the barrier wall and the substrate, and at least two electrodes, includes a step of forming a polymer layer, comprising a polymer compound obtained by living polymerization in at least a part of the pixel face to be in contact with the particle of the pixel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a particle movement type display device that performs display by moving particles in a medium.

  In recent years, with the development of information equipment, there has been an increasing need for lower power consumption and thinner display devices, and reduced burden on the eyes, and research and development of display devices that meet these needs has been actively conducted. ing. As one of the methods, there is known a particle movement type display device that obtains a display effect by moving a plurality of particles in a medium and changing the distribution thereof.

  Various types of methods have been proposed for this display device. For example, colored particles (hereinafter referred to as electrophoretic particles) dispersed in an insulating liquid (hereinafter referred to as dispersion medium) are moved by an electrophoresis phenomenon. An electrophoretic display device that obtains a display effect by a distribution change is known.

  In addition, a toner display that uses toner used in a copying machine or the like as particles and moves it in a gas, and a magnetophoretic display that moves magnetized particles (hereinafter referred to as magnetic particles) are known. There is also known an Electric Twisting Ball (Electric Twisting Ball) display device in which particles having dipoles color-coded for each hemisphere are rotated by an electric field to change the display.

  These display methods have features such as a memory property of an image that can continue to display a still image without supplying any energy after moving the particles, and a wide image viewing angle corresponding to a normal printed matter.

  Various proposals have been made to further improve the characteristics of these particle movement type display devices. First, in an image display device using static electricity in which particles are encapsulated between opposing substrates, at least one of which is transparent, and an electric field is generated between the substrates to move the particles to display an image, the particles on at least one substrate are A display device in which a contact surface is coated with a resin containing a fluororesin is disclosed. (Patent Document 1) This display device can achieve both improvement in stability and reduction in driving voltage during repeated display or storage of images.

Also, in an image display device that encloses particles between opposing substrates that are transparent at least one and moves the particles to display an image, the surface of the substrate that the particles contact for the purpose of improving stability and reducing driving voltage An example of coating a thin film with an insulator is disclosed. (Patent Document 2)
JP 2003-248247 A JP 2004-29759 A

  A common problem of these particle movement type display devices is that particles adhere to the surface (hereinafter abbreviated as inner wall) where the particles and the medium are in contact with each pixel, and the display characteristics are remarkably deteriorated. is there. In order to realize low power consumption of the display device, it is necessary to provide display memory properties.

  The present invention has been made in view of such background art, and provides a method for manufacturing a particle movement type display device with improved display characteristics, display stability and memory performance.

  In order to achieve the above object, the inventors pay attention to the inner wall among the physical and chemical interactions at the interfaces of the particles, the medium, and the inner wall, and control the physical properties of the inner wall surface to display characteristics and display. The inventors have found that stability and memory performance can be controlled, and have completed the present invention.

  That is, the present invention comprises at least one substrate, partition walls disposed on the substrate surface, one or more particles disposed in a gap surrounded by the partition walls and the substrate, and at least two or more particles. A method for manufacturing a particle movement type display device having at least one pixel formed by an electrode, the polymer layer comprising a polymer compound obtained by living polymerization on at least a part of a surface of the pixel in contact with the particle A method for manufacturing a particle movement type display device.

It is preferable to form a polymer layer by applying a polymer compound obtained by living polymerization to at least a part of the surface in contact with the particles of the pixel.
It is preferable to form a polymer layer by reacting at least a part of the functional group on the surface in contact with the pixel particles with the functional group of the polymer compound obtained by the living polymerization.

  A layer containing a polymerization initiating group is formed on at least a part of the surface in contact with the pixel particles, a monomer is brought into contact with the layer containing the polymerization initiating group, and the monomer is grafted by living polymerization from the polymerization initiating group to form a polymer. It is preferable to form a polymer layer made of a compound.

Preferably, the polymer layer made of the polymer compound is made of at least two different polymer compounds having different repeating structures.
The polymer compound preferably has at least two different repeating structures.

The living polymerization is preferably living radical polymerization, living cation polymerization, or living anion polymerization.
The particle movement type display device is preferably an electrophoretic display device.

  According to the present invention, a particle movement type display device having improved display characteristics, display stability, and memory properties by forming a polymer layer made of a polymer compound obtained by living polymerization on at least a part of an inner wall. A manufacturing method can be provided.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic view showing an embodiment of an electrophoretic display device as an example of a particle movement display device manufactured by the method of the present invention. The pixel is composed of at least electrophoretic particles 13 and 20, a dispersion medium 18, a partition wall 14, and electrodes 12 and 17, and a surface portion in contact with the electrophoretic particle 13 and the dispersion liquid 18 is an inner wall 15. At least a part of the inner wall 15 has a polymer layer 16 made of a polymer compound obtained by living polymerization.

  The living polymerization in the present invention includes living radical polymerization, living cationic polymerization, and living anion polymerization. The polymer compound produced by these polymerization methods has a controlled structure such as the molecular weight, molecular weight distribution, stereoregularity, and monomer arrangement in the polymer. By forming a polymer layer of such a polymer compound on the pixel surface, the physical and chemical properties of the pixel surface can be controlled throughout the pixel, improving display characteristics, display stability, and memory performance. To do. The living polymerization includes living ring-opening polymerization.

  In addition, the molecular weight distribution index, molecular weight, stereoregularity, and structure of the monomer sequence in the polymer in the polymer compound obtained by living polymerization in the present invention are required display characteristics, display stability, memory, etc. Since it is appropriately selected depending on the kind of the monomer for imparting the property and the structure of the polymer chain, there is no limitation. Therefore, it may be a polymer composed of a single monomer, a block polymer composed of a plurality of types of monomers and having a plurality of types of repeating structures, or a random polymer not having a repeating structure.

  The polymer compound obtained by living polymerization in the present invention is not particularly limited as long as a material that can be produced by living polymerization of various methods is used. In general, in order to produce by living polymerization, various vinyl monomers can be used. Specifically, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-propylstyrene, 3-propylstyrene, 4-propyl Styrene, 2-isopropylstyrene, 3-isopropylstyrene, 4-isopropylstyrene, 4-tert-butylstyrene, 2,3-dimethylstyrene, 3,4-dimethylstyrene, 2,4-dimethylstyrene, 2,6-dimethyl Styrene, 2,3-diethylstyrene, 3,4-diethylstyrene, 2,4-diethylstyrene, 2,6-diethylstyrene, 2-methyl-3-ethylstyrene, 2-methyl-4-ethylstyrene, α- Methylstyrene, 4-phenylstyrene, acetoxystyrene, methoxystyrene Styrenic monomers such as ethoxystyrene and butoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate ( (Meth) acrylate monomers, vinyl ether monomers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl ketone monomers such as vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, N-vinyl pyrrole, N-vinyl carbazole, N-vinyl compound monomers such as N-vinylindole and N-vinylpyrrolidone, vinyl hydrocarbon monomers such as ethylene, butylene and hexene, vinyl acetate, (meth) acrylonitrile, (meth) acrylamide, and the above monomers -Halogenated monomers. In addition, it does not affect living polymerization like ethyl 2- (vinyloxy) ethoxyacetate, 2- (tert-butyldimethylsiloxy) ethyl vinyl ether, 2- (trimethylsiloxy) ethyl vinyl ether, 2-vinyloxyethyl phthalamide, etc. A monomer that introduces a substituent (protecting group) and converts the protecting group into a hydroxyl group, a carboxyl group, an amino group, or the like after living polymerization can also be used. You may use the above monomers individually or in mixture of 2 or more types.

  Moreover, you may use a crosslinking agent together as needed. In this case, the polymer obtained by living polymerization is preferably used within a range that does not affect the properties obtained by living polymerization, such as crosslinking after living polymerization. Specific examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and trimethylolpropane. Examples include compounds such as triacrylate, allyl (meth) acrylate, 1,3-butanediol di (meth) acrylate, N, N-divinylaniline, divinyl ether, etc., and these are used alone or in admixture of two or more. May be.

  The polymer compound obtained by this living polymerization is chemically and physically bonded to the inner wall 15. That is, it is sufficient that the polymer compound and the inner wall 15 are bonded by a covalent bond or a non-covalent bond, and the bonding mode is not particularly limited.

In order to form the polymer layer 16 of the polymer compound obtained by living polymerization, the method differs depending on whether it is chemically bonded or physically bonded. That is, when chemically bonding,
1) A method of coating the inner wall surface with a polymer compound by chemically reacting the inner wall 15 with a functional group in the polymer compound previously prepared by living polymerization,
2) A method in which a layer of a polymerization initiating group is provided on the inner wall 15 and a polymer is grafted by living polymerization from the polymerization initiating group,
There is.

As a method of physically bonding, 3) a method in which a polymer compound produced by living polymerization is applied to the inner wall 15 and an interaction between a functional group of the inner wall 15 and a functional group in the polymer compound is generated. It is done.

Hereinafter, these methods will be described in detail.
In the method 1), it is essential that there are reactive functional groups in the inner wall 15 and the polymer compound produced by living polymerization, and that these reactive functional groups react with each other.

  The reactive functional group is not particularly limited as long as it is a chemically reactive substituent, but preferably a hydroxyl group, a carboxylic acid, an amino group, an isocyanate group, a halogen group, a vinyl group, an epoxy group. And halogenated carbonyl group. Of these, reactive functional groups are appropriately selected so as to react with each other. The material of the inner wall 15 is not particularly limited, but if there is no reactive functional group such as metal, a substance having a reactive functional group may be coated as an intermediate layer. In addition, a reactive functional group may be formed on the inner wall surface by oxidation treatment such as UV ashing.

  When introducing a reactive functional group into the inner wall, the polymer compound made by living polymerization can be selectively introduced in the pixel by selecting the introduction position, and each of the particles, medium, and inner wall It is possible to control the physical and chemical interaction at the interface of the liquid crystal display, leading to improvements in stability, display characteristics, and memory performance of the electric display device.

  Further, by introducing two or more types of reactive functional groups on the pixel side surface of the inner wall 15, it becomes possible to bond two or more types of polymer compounds, and the physical interface of each of the particles, the medium, and the inner wall. , Allowing further control of chemical interactions.

  It is essential that at least one and at least one type of reactive functional group is introduced into the polymer compound obtained by living polymerization. In this case, the introduction position in the polymer compound is not limited, but it is preferably at the end of the polymer compound. In addition, when a plurality of reactive functional groups and / or a plurality of types of functional groups are introduced into one polymer chain, the polymer compound includes a reactive functional group and a non-reactive functional group. Is preferably a polymer compound arranged so as to have a constant repeating structure, that is, a block polymer. When these plural and / or plural kinds of reactive functional groups are introduced, there is a possibility that the reactivity in one polymer chain is increased.

  As specific methods for these production methods, a polymer compound produced by living polymerization and an inner wall are brought into contact with each other by a coating method such as a dip coating method, a spin coating method, a spray coating method, a bar coating method, etc. It is possible to react by irradiating energy such as heat and ultraviolet light. Here, in order to adjust the viscosity, a polymer compound produced by living polymerization may be dissolved or dispersed in a solvent or the like.

  In the method 2), a compound having a polymerization initiating group is used on the inner wall surface in advance, and a monomer, a catalyst, a solvent, or the like is brought into contact therewith and reacted by irradiating energy such as heat or ultraviolet rays from the outside. In this case, the monomer, catalyst, solvent and the like may be those described above or known ones. It is essential that the polymerization initiating group is capable of initiating living polymerization from that group, and any known material may be used without particular limitation. The material of the inner wall 15 is not particularly limited, but when there is no reactive functional group such as a metal, the polymerization initiating group may be introduced after the introduction of the intermediate layer or the surface treatment of the inner wall.

  When introducing a compound having a polymerization initiating group into the inner wall 15, by selecting the introduction position, a polymer compound obtained by living polymerization can be selectively introduced within the pixel, and particles, media, inner walls It is possible to control physical and chemical interactions at each interface, leading to improvements in stability, display characteristics, and memory performance in an electric display device.

  Further, by introducing a compound having two or more kinds of polymerization initiating groups into the pixel side surface of the inner wall 15, it becomes possible to bind a polymer compound obtained by two or more kinds of living polymerization, and the particles, medium, inner wall Further control of the physical and chemical interactions at each interface is possible.

In method 3),
It is essential that there are non-covalent functional groups on the pixel side surface of the inner wall 15 and the polymer compound obtained by living polymerization, and that these non-covalent functional groups are non-covalently bonded to each other. Become.

  Non-covalent bonds include ionic bonds, coordination bonds, hydrophilic-hydrophobic bonds, hydrogen bonds, acid-base bonds, and the like. The non-covalent functional group is not particularly limited as long as it is a functional group capable of forming each of the above bonds. The material of the inner wall 15 is not particularly limited, but if there is no non-covalent functional group such as a metal oxide, a material having a non-covalent functional group may be coated as an intermediate layer. Further, a non-covalent functional group may be formed on the inner wall surface by oxidation treatment such as UV ashing.

  When introducing a non-covalent functional group into the inner wall, the polymer compound obtained by living polymerization can be selectively introduced within the pixel by selecting the introduction position, and particles, media, inner wall It is possible to control the physical and chemical interaction of each interface, leading to improvement in stability, display characteristics, and memory performance in the electric display device.

  In addition, by introducing two or more types of non-covalent functional groups into the inner wall 15, it becomes possible to bind a polymer compound obtained by two or more types of living polymerization, and the interface between particles, media, and inner walls. It is possible to further control the physical and chemical interactions.

  It is essential that at least one and at least one non-covalent functional group is introduced into the polymer compound obtained by living polymerization. In this case, the introduction position in the polymer compound is not limited, but is preferably at the end of the polymer compound. In addition, when plural and / or plural kinds of non-covalent functional groups are introduced, a repeating structure of a portion having a non-covalent functional group and a portion not having a non-covalent functional group Is preferably a block polymer. In the case where a plurality and / or a plurality of types of non-covalent functional groups are introduced, it is preferable because the bondability in one polymer chain is increased.

  As a specific method by these production methods, a polymer compound obtained by living polymerization and an inner wall are brought into contact with each other by a coating method such as a dip coating method, a spin coating method, a spray coating method, a bar coating method, and the like. It is possible to bond them by irradiating energy such as heat or ultrasonic waves. Here, in order to adjust the viscosity, the polymer compound obtained by living polymerization may be dissolved or dispersed in a solvent or the like.

Hereinafter, the present invention will be described in more detail with reference to examples of the electrophoretic display device.
Example 1
[Production of polymer compounds by living polymerization]
In a 500 ml flask thoroughly dried and purged with nitrogen inside, 300 ml of hexane as a solvent, 0.27 g of acetic acid adduct (AcOVE-HOAc) of 2-acetoxyethoxyvinyl ether represented by the following chemical formula (1) as a functional initiator, 10 g of isobutyl vinyl ether, 30 g of dodecyl vinyl ether, 0.25 g of ethylaluminum dichloride, and 18 g of ethyl acetate were added, the polymerization reaction was carried out at 0 ° C. for 8 hours, the number average molecular weight was about 20,000, and the molecular weight distribution index was 1.10. Thus, 37 g of a random copolymer of isobutyl vinyl ether and dodecyl vinyl ether having an acetoxy group at the terminal is obtained.

  Subsequently, the terminal acetoxy group is deprotected to a hydroxyl group by treatment under alkaline conditions, and a random copolymer of isobutyl vinyl ether and dodecyl vinyl ether having a terminal hydroxyl group is obtained.

[Production of electrophoretic display device]
The electrophoretic display device shown in FIG. 1 is manufactured.
A pattern of Al having a thickness of about 0.2 μm is formed on the glass substrate 19 having a thickness of 1 mm as the electrode 17. Then, an insulating thin film (not shown) is formed by spin-coating a thermosetting resin (Optomer, manufactured by JSR Corporation) and curing by heating. Thereafter, a photosensitive epoxy resin is applied to the entire surface, and then a partition 14 having a width of 7 μm and a height of 15 μm is formed between the pixels by photolithography, and this is used as a first substrate.

  Separately, as a second substrate, an indium-titanium oxide (hereinafter abbreviated as ITO) with a thickness of about 0.2 μm is patterned as an electrode 12 on a glass substrate 11 with a thickness of 1 mm, and a thermosetting resin is formed. An insulating thin film (not shown) is formed by spin-coating (Optomer, manufactured by JSR Corporation) and curing by heating.

  A polyvinyl alcohol aqueous solution is spin-coated on each of the first substrate and the second substrate, and an intermediate layer (so as to cover the pixel surface (not shown) and the inner wall 15 of the first substrate and the insulating layer surface of the second substrate). (Not shown). Then, the 1st board | substrate and 2nd board | substrate which have an isocyanate group on the surface are produced by spin-coating hexamethylene diisocyanate.

  Then, the first substrate and the second substrate are immersed in a solution in which α-picoline is dissolved in toluene as a random copolymer of isobutyl vinyl ether and dodecyl vinyl ether having a terminal hydroxyl group and as a catalyst for 8 hours. Thus, the terminal hydroxyl group and the isocyanate group react to produce a substrate for an electrophoretic display device having a polymer layer 16 made of a polymer compound obtained by living polymerization.

  Next, an electrophoretic dispersion liquid containing electrophoretic particles and a dispersion medium is prepared. Isopar M (manufactured by ExxonMobil) is used as a dispersion medium, and two types of particles are used as electrophoretic particles: carbon black particles grafted with polyethylene and polystyrene particles containing titanium oxide. These two kinds of particles and a surfactant (Olonite Japan Co., Ltd., OLAA1200) are mixed in a dispersion medium at 10% by weight and 0.5% by weight, respectively, to obtain an electrophoretic dispersion. The electrophoretic liquid can be injected into the first substrate thus prepared, the second substrate can be adhered and sealed, and an electrophoretic display device can be manufactured by providing voltage application means.

  When the electrophoretic display device thus manufactured is driven by applying a voltage between the electrodes, black-white display is performed with high contrast corresponding to the pixel. Further, even if the application of voltage is stopped in the white display state or the black display state, no change in the display state is observed, and good memory performance can be realized.

Example 2
[Production of polymer compounds by living polymerization]
In a 500 ml flask sufficiently dried beforehand and purged with nitrogen inside, 300 ml of hexane as a solvent, 0.27 g of acetic acid adduct (AcOVE-HOAc) of 2-acetoxyethoxyvinyl ether represented by the above chemical formula (1) as a functional initiator, 10 g of isobutyl vinyl ether, 0.25 g of ethylaluminum dichloride, and 18 g of ethyl acetate are added, and a polymerization reaction is performed at 0 ° C. for 8 hours. Next, 40 g of dodecyl vinyl ether was added and the polymerization reaction was carried out for 10 hours. A block copolymer of isobutyl vinyl ether and dodecyl vinyl ether having a number average molecular weight of about 20,000, a molecular weight distribution index of 1.18, and having an acetoxy group at the terminal. 45 g are obtained.

  Subsequently, the terminal acetoxy group is deprotected to a hydroxyl group by treatment under alkaline conditions, and a block copolymer of isobutyl vinyl ether and dodecyl vinyl ether having a terminal hydroxyl group is obtained.

[Production of electrophoretic display device]
The electrophoretic display device shown in FIG. 2 is manufactured.
A pattern of Al having a thickness of about 0.2 μm is formed on the glass substrate 19 having a thickness of 1 mm as the electrode 17. Then, spin coating a thermosetting resin in which titanium oxide is dispersed and heat-curing, spin coating a white scattering film (not shown) and thermosetting resin (Optomer, manufactured by JSR Corporation) Then, an insulating thin film (not shown) is formed by heating and curing. Thereafter, a photosensitive epoxy resin is applied to the entire surface, and a partition wall 14 having a width of 7 μm and a height of 15 μm is formed between the pixels by photolithography. An electrode 12 made of titanium is formed on the surface of the partition wall 14 by a vacuum deposition method, and a thermosetting resin (Optomer, manufactured by JSR Co., Ltd.) is spin-coated and heat-cured, whereby an insulating thin film ( (Not shown). This is the first substrate.

  Separately, as a second substrate, a thermosetting resin (Optomer, manufactured by JSR Co., Ltd.) is spin-coated on a glass substrate 11 having a thickness of 1 mm and heat-cured, whereby an insulating thin film (FIG. Not shown). Then, an aqueous polyvinyl alcohol solution is spin-coated on the first substrate and the second substrate, and an intermediate layer (not shown) is formed so as to cover the pixel surface (not shown) of the first substrate and the insulating layer surface of the second substrate. Form). Then, the 1st board | substrate and 2nd board | substrate which have an isocyanate group on the surface are produced by spin-coating hexamethylene diisocyanate.

  Then, the first substrate and the second substrate are immersed in a solution in which α-picoline is dissolved in toluene as a block copolymer of isobutyl vinyl ether and dodecyl vinyl ether having a terminal hydroxyl group and as a catalyst for 8 hours. Thus, the terminal hydroxyl group and the isocyanate group react to produce a substrate for an electrophoretic display device having a polymer layer made of a polymer compound obtained by living polymerization.

  Next, an electrophoretic dispersion liquid containing electrophoretic particles and a dispersion medium is prepared. Isopar M (manufactured by ExxonMobil) is used as a dispersion medium, and carbon black particles grafted with polyethylene are used as electrophoretic particles. These electrophoretic particles and a surfactant (Olonite Japan Co., Ltd., OLAA1200) are mixed in a dispersion medium at 10 wt% and 0.5 wt%, respectively, to obtain an electrophoretic dispersion. The electrophoretic liquid can be injected into the first substrate thus prepared, the second substrate can be adhered and sealed, and an electrophoretic display device can be manufactured by providing voltage application means.

  When the electrophoretic display device thus manufactured is driven by applying a voltage between the electrodes, black-white display is performed with high contrast corresponding to the pixel. Further, when the pixel is observed in detail with a microscope, since there is no electrophoretic particle adhered to the substrate without being able to follow the change in the electric field, the polymer layer formed by living polymerization is the first substrate and It can be seen that sticking to the surface of the second substrate is suppressed. Further, even if the voltage application is stopped in the white display state or the black display state, no change in the display state is observed, and a good memory performance can be realized.

Example 3
[Production of electrophoretic display device]
In the same manner as in Example 2, an electrode 12 made of titanium was formed on the surface of the partition wall 14 by vacuum evaporation, and a thermosetting resin (Optomer, manufactured by JSR Corporation) was spin-coated and heat-cured. Then, an insulating thin film (not shown) is formed to be a first substrate. Similarly to Example 2, a polyvinyl alcohol aqueous solution is spin-coated as the second substrate, and an intermediate layer (not shown) is formed so as to cover the insulating layer surface of the second substrate.

  Next, a toluene solution in which a compound having an atom transfer radical polymerization initiating group represented by the following chemical formula (2) is dissolved on the second substrate is spin-coated, and a second substrate having an atom transfer radical polymerization initiating group on the surface is spin coated. A substrate is produced.

  Then, the second substrate is immersed in toluene, octadecyl methacrylate is added, the reaction system is replaced with nitrogen gas, and atom transfer radical polymerization is performed at 70 ° C. for a predetermined time. Further, ethyl 2-bromoisobutyrate is added in advance to the reaction system so as to serve as an index of the molecular weight and molecular weight distribution of the polymer compound to be grafted on the second substrate. After completion of the polymerization, a substrate for an electrophoretic display device having a polymer layer made of a polymer compound obtained by living polymerization can be produced through washing and drying processes.

  When the molecular weight and molecular weight distribution of the polymer produced from ethyl 2-bromoisobutyrate added as a free polymerization starting species were measured, the number average molecular weight was about 110,000 and the molecular weight distribution index was 1.07. From this, it can be confirmed that the polymer chain grafted on the pixel surface of the second substrate is a polymer chain having a uniform chain length.

Until the subsequent electrophoretic display device is manufactured, it is manufactured in the same steps as in the second embodiment.
When the electrophoretic display device thus manufactured is driven by applying a voltage between the electrodes, black-white display is performed with high contrast corresponding to the pixel. Further, when the pixel is observed in detail with a microscope, since there is no electrophoretic particle adhered to the substrate without following the change in the electric field, the polymer layer formed by living polymerization is the first substrate and It can be seen that sticking to the surface of the second substrate is suppressed. Further, even if the voltage application is stopped in the white display state or the black display state, no change in the display state is observed, and a good memory performance can be realized.

Example 4
[Production of polymer compounds by living polymerization]
In a 500 ml flask thoroughly dried and purged with nitrogen inside, 300 ml of hexane as a solvent, 0.3 g of 1-isobutoxyethyl acetate as a functional initiator, 30 g of isobutyl vinyl ether, 0.25 g of ethyl aluminum dichloride, and ethyl acetate 17 g is added, and a polymerization reaction is performed at −40 ° C. for 8 hours. Next, 10 g of ethyl 2- (vinyloxy) ethoxyacetate was added and the polymerization reaction was carried out for 8 hours, so that isobutyl vinyl ether and ethyl 2- (vinyloxy) having a number average molecular weight of about 30,000 and a molecular weight distribution index of 1.19 were obtained. A block copolymer of ethoxy acetate is obtained.

  Subsequently, the block copolymer of isobutyl vinyl ether and vinyloxyethyl carboxylic acid is obtained by hydrolyzing the acetoxy of 2-acetoxyethyl vinyl ether into a carboxyl group by treatment under alkaline conditions.

[Production of electrophoretic display device]
Until each of the first substrate and the second substrate is spin-coated with an aqueous polyvinyl alcohol solution and an intermediate layer is formed so as to cover the pixel surface and partition wall surface of the first substrate and the insulating layer surface of the second substrate, respectively. The same process as in Example 1 is performed.

  A polymer compound is obtained by immersing the first substrate and the second substrate in a liquid in which the block copolymer of isobutyl vinyl ether and vinyloxyethyl carboxylic acid is dispersed in tetrahydrofuran and irradiating with ultrasonic waves. A polymer layer made of a polymer compound produced by living polymerization, wherein a carboxyl group on the side and a hydroxyl group on the first substrate side and a hydroxyl group on the second substrate side are physically bonded by a hydrophilic-hydrophobic bond and / or a hydrogen bond; A substrate for an electrophoretic display device can be manufactured.

Until the subsequent electrophoretic display device is manufactured, it is manufactured in the same process as in Example 1.
When the electrophoretic display device thus manufactured is driven by applying a voltage between the electrodes, black-white display is performed with high contrast corresponding to the pixel. Further, even if the application of voltage is stopped in the white display state or the black display state, no change in the display state is observed, and good memory performance can be realized.

Example 5
[Production of polymer compounds by living polymerization]
In a 200 ml flask thoroughly dried and purged with nitrogen inside, 80 ml of hexane as a solvent, 0.9 g of AcOVE-HOAc shown in the above chemical formula (1) as a functional initiator, 10 g of isobutyl vinyl ether, 0.8 g of ethylaluminum dichloride, And 4 g of ethyl acetate were added and the polymerization reaction was carried out at 0 ° C. for 8 hours, the number average molecular weight was about 25,000 and the molecular weight distribution index was 1.10. 9 g of coalescence is obtained. Subsequently, the terminal acetoxy group is deprotected to a hydroxyl group by treatment under alkaline conditions to obtain a polymer of isobutyl vinyl ether having a terminal hydroxyl group.

  Separately from the above, in a 300 ml flask thoroughly dried and purged with nitrogen inside, 160 ml of hexane as a solvent, 1.3 g of AcOVE-HOAc shown in the above chemical formula (1) as a functional initiator, 20 g of dodecyl vinyl ether, ethyl dichloride When 1.2 g of aluminum and 8.8 g of ethyl acetate are added and a polymerization reaction is performed at 0 ° C. for 8 hours, the number average molecular weight is about 15,000 and the molecular weight distribution index is 1.3. 18 g of a dodecyl vinyl ether polymer having a group is obtained. Subsequently, the terminal acetoxy group is deprotected to a hydroxyl group by treatment under alkaline conditions to obtain a polymer of dodecyl vinyl ether having a terminal hydroxyl group.

[Production of electrophoretic display device]
The first and second substrates having an isocyanate group on the surface are prepared by spin coating with hexamethylene diisocyanate, and the steps are the same as those in Example 1.

  Then, by immersing the first substrate and the second substrate in a solution in which a polymer of isobutyl vinyl ether having a terminal hydroxyl group and a polymer of dodecyl vinyl ether are dissolved in toluene, the terminal hydroxyl group and the isocyanate group are changed. By reacting, a substrate for an electrophoretic display device having a layer in which polymer compounds prepared by two kinds of living polymerization are mixed can be manufactured.

Until the subsequent electrophoretic display device is manufactured, it is manufactured in the same process as in Example 1.
When the electrophoretic display device thus manufactured is driven by applying a voltage between the electrodes, black-white display is performed with high contrast corresponding to the pixel. Further, even if the application of voltage is stopped in the white display state or the black display state, no change in the display state is observed, and good memory performance can be realized.

Example 6
[Production of polymer compounds by living polymerization]
Into a 2 liter flask thoroughly dried in advance and purged with nitrogen, 1.2 L of tetrahydrofuran as a solvent and 4.2 ml of n-butyllithium 2.2M hexane solution as a polymerization initiator were charged and mixed to -78 ° C. After cooling, 10 g of pt-butoxystyrene is added and a polymerization reaction is carried out for 2 hours. Next, 90 g of styrene was added and the polymerization reaction was carried out for 2 hours with stirring. After adding methanol as a reaction stopper to the resulting reaction solution to stop the polymerization reaction, the solution was poured into methanol. The obtained polymer is precipitated, separated and dried to obtain a white polymer.

  Next, this polymer was dissolved in acetone, a small amount of hydrochloric acid was added, and the mixture was stirred at 60 ° C. for 8 hours, whereby p-hydroxystyrene having a number average molecular weight of about 20,000 and a molecular weight distribution index of 1.10. A styrene block copolymer can be obtained.

[Production of electrophoretic display device]
The first and second substrates having an isocyanate group on the surface are prepared by spin coating with hexamethylene diisocyanate, and the steps are the same as those in Example 1.

  Then, by immersing the first substrate and the second substrate in a solution in which the p-hydroxystyrene-styrene block copolymer is dissolved in toluene, the terminal hydroxyl group and the isocyanate group react with each other, thereby living polymerization. Thus, an electrophoretic display device substrate having a layer in which the polymer compound prepared by the method is mixed can be manufactured.

Until the subsequent electrophoretic display device is manufactured, it is manufactured in the same process as in Example 1.
When the electrophoretic display device thus manufactured is driven by applying a voltage between the electrodes, black-white display is performed with high contrast corresponding to the pixel. Further, even if the application of voltage is stopped in the white display state or the black display state, no change in the display state is observed, and good memory performance can be realized.

  The present invention provides a particle movement type display device having improved display characteristics, display stability and memory properties by forming a polymer layer made of a polymer compound obtained by living polymerization on at least a part of an inner wall. The particle movement type display device can be used for electronic paper, advertising media, POP (Point Of Purchase advertising) display devices, and the like.

It is the schematic which shows one embodiment of the electrophoretic display device manufactured by the method of this invention. It is the schematic which shows the other embodiment of the electrophoretic display device manufactured by the method of this invention.

Explanation of symbols

11, 14 Substrate 12 Electrode 13 Electrophoretic particles (black)
14 Partition 15 Inner wall 16 Polymer layer 17 Electrode 18 Dispersion medium 19 Substrate 20 Electrophoretic particles (white)
21 Observer

Claims (8)

  Formed by at least one substrate, a partition wall disposed on the substrate surface, one or more particles disposed in a space surrounded by the partition wall and the substrate, and at least two electrodes. A method for manufacturing a particle movement type display device having at least one pixel, comprising a step of forming a polymer layer made of a polymer compound obtained by living polymerization on at least a part of a surface in contact with the particles of the pixel. A method for manufacturing a particle movement type display device.   2. The method for manufacturing a particle movement type display device according to claim 1, wherein a polymer layer is formed by applying a polymer compound obtained by living polymerization to at least a part of a surface in contact with the particles of the pixel.   3. The polymer layer is formed by reacting at least a part of a functional group on a surface in contact with a particle of the pixel with a functional group of a polymer compound obtained by the living polymerization. The manufacturing method of the particle movement type display apparatus of description.   A layer containing a polymerization initiating group is formed on at least a part of the surface in contact with the pixel particles, a monomer is brought into contact with the layer containing the polymerization initiating group, and the monomer is grafted by living polymerization from the polymerization initiating group to form a polymer. The method for producing a particle movement type display device according to claim 1, wherein a polymer layer made of a compound is formed.   5. The particle movement type display device according to claim 1, wherein the polymer layer made of the polymer compound is made of at least two different polymer compounds having different repeating structures. 6. Production method.   The method for producing a particle movement type display device according to any one of claims 1 to 5, wherein the polymer compound has at least two or more different repeating structures.   The method for producing a particle movement type display device according to any one of claims 1 to 6, wherein the living polymerization is living radical polymerization, living cation polymerization, or living anion polymerization.   The method for manufacturing a particle movement type display device according to any one of claims 1 to 7, wherein the particle movement type display device is an electrophoretic display device.

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