JP2005302387A - Solid formed el sheet and el integrated resin formed product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an EL sheet formed in a solid manner without causing interlayer delamination and a rupture of a layer. <P>SOLUTION: The EL sheets includes a solid formed portion formed in the solid manner, and an EL light-emitting portion 1 is formed at the solid formed portion. Of each layer constituting the EL light-emitting portion 1, a light-emitting layer 7, a dielectric layer 8, a back electrode layer 9 and an insulating layer 11 are formed using a binder of which main component is polycarbonate resin, by which there exists no cracks in each layer of the EL light-emitting portion 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an EL (electroluminescence) sheet used as a light-emitting component and an EL integrated resin molded product, and more particularly to an EL sheet and an EL integrated resin molded product in which a portion including an EL element is three-dimensionally molded. .

  A method of providing an EL sheet on a display screen of various devices such as a portable electronic terminal or an operation component such as a keypad and illuminating the display screen and the operation component is widely used. A conventional EL sheet is a sheet-like light-emitting component that includes one or more light-emitting parts each formed of an EL light-emitting part formed in a flat shape. This EL sheet is usually provided as a frame of the display screen, as a backlight of the display screen, or as a backlight of operation parts. The light emitted from the backlight provided on the back side of the display screen and operation parts is visible through the parts.

  However, when an EL sheet is provided on the back side of a display screen or the like as described above, a loss of light intensity is large while light is transmitted to the surface. Therefore, the light emitting portion needs to emit light having sufficient intensity to compensate for the loss of light.

  On the other hand, with the spread of mobile phones and portable electronic terminals, the design of these devices is diversified. For this reason, it is necessary to form the light-emitting component, which has conventionally been formed in a planar shape, in a three-dimensional manner by embossing or the like.

  Thus, attempts have been made to form three-dimensionally the light-emitting components used in electronic devices and the like (see, for example, Patent Document 1). The EL light emitting unit of Patent Document 1 includes a transparent electrode layer, a light emitting layer, a dielectric layer, a back electrode layer, and an insulating layer. In view of the problem that when an ITO (indium tin oxide) film is used for the transparent electrode layer, the ITO film is broken due to the load applied when the EL sheet is bent, this document describes that conductive powder is used instead of the ITO film. An EL device using a transparent electrode layer dispersed in molecules is disclosed.

Furthermore, Patent Document 2 discloses an EL sheet that is three-dimensionally formed using a polythiophene-based conductive polymer for a transparent conductive film.
JP 2000-285760 A JP2004-6105

  However, even when any EL sheet described in the above patent document was manufactured, the EL element was damaged by cracks and delamination during the three-dimensional molding of the EL sheet. Furthermore, the breakage of the EL element is caused by the elongation during processing of each layer constituting the EL element, the followability between each layer and between the EL element layer and the base material, and between the layer material and the base material. It was found to be caused by a number of factors, such as the suitability of. In further tests on the three-dimensional molding of EL light emitting parts, if the conventionally used high dielectric constant cyanoresin or fluororesin is used as a binder for each layer such as the light emitting layer and dielectric layer constituting the EL light emitting part, the EL light emitting part will crack. And delamination are likely to occur.

  Accordingly, an object of the present invention is to provide an EL sheet that is three-dimensionally formed without causing delamination or layer breakage.

In the following, means for achieving the above object and its operational effects are described.
The invention according to claim 1 is an EL light-emitting part that is formed on a base material 2 and the base material 2 and includes a transparent electrode layer 5, a light-emitting layer 7, a dielectric layer 8, a back electrode layer 9, and an insulating layer 11. The light emitting layer 7, the dielectric layer 8, the back electrode layer 9, and the insulating layer 11 contain a binder whose main component is polycarbonate resin, and the EL sheet has a portion having the EL light emitting unit 1. The gist is that at least a part of is three-dimensionally molded.

  The EL sheet refers to a sheet-like light-emitting component that includes one or more light-emitting portions made of EL elements. In claim 1, the EL sheet has at least a part of a three-dimensionally shaped three-dimensionally formed portion, and the EL light emitting portion 1 is formed in the three-dimensionally formed portion. Among the layers constituting the EL light emitting unit 1, the light emitting layer 7, the dielectric layer 8, the back electrode layer 9, and the insulating layer 11 are formed using a binder whose main component is polycarbonate resin. The layer 1 does not crack in the layer.

  The gist of the invention according to claim 2 is that, in the EL sheet according to claim 1, the EL light emitting unit 1 further includes a transparent electrode compensation electrode layer 6 and a back electrode compensation electrode layer 11 containing a binder. A compensation electrode layer is provided to allow the EL light emitting unit 1 to emit light uniformly.

  The invention according to claim 3 is the EL sheet according to claim 1 or 2, wherein the polycarbonate resin is represented by the following formula (I):

式中、Ｒ^１，Ｒ^２は相互に独立して水素、ハロゲン、Ｃ_１〜Ｃ_８アルキル、Ｃ_５〜Ｃ_６シクロアルキル、Ｃ_６〜Ｃ_１０アリールアルキルを表し、ｍは４〜７の整数であり、Ｒ^３，Ｒ^４は各Ｘに対して個々に選択可能であり、かつ相互に独立して水素またはＣ_１〜Ｃ_６アルキルを表し、Ｘは少なくとも１個の炭素原子を表し、Ｒ^３，Ｒ^４は共にアルキルである、二官能性カーボネート構造単位を含む芳香族カーボネートである
１，１−シクロアルキル骨格、または下記式（ＩＩＩ）

In the formula, R ¹ and R ² each independently represent hydrogen, halogen, C _{1 to} C ₈ alkyl, C _{5 to} C ₆ cycloalkyl, C _{6 to} C ₁₀ arylalkyl, and m is an integer of 4 to 7 R ³ and R ⁴ are individually selectable for each X and independently of each other represent hydrogen or C ₁ -C ₆ alkyl, X represents at least one carbon atom, R ³ and R ⁴ are both alkyl, 1,1-cycloalkyl skeleton which is an aromatic carbonate containing a difunctional carbonate structural unit, or the following formula (III)

式中、Ｒ^１，Ｒ^２は各々独立してアルキル基、アルコキシ基、アリール基、アリール置換アルケニル基、及び縮合多環式炭化水素基から選ばれる一価の置換基を示し、ｙ／（ｘ＋ｙ）＝５〜７０重量％であり、ｌは１〜１０の整数、ｍは１〜５０の整数を示す
ポリオルガノシロキサン骨格を分子鎖に備える、ことを要旨とする。立体成形に好適なポリカーボネート樹脂をバインダに使用することによって、立体成形後においても層にクラックを生じないＥＬ発光部１が製造される。

In the formula, each of R ¹ and R ² independently represents a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl group, and a condensed polycyclic hydrocarbon group, and y / (x + y ) = 5 to 70% by weight, l is an integer of 1 to 10, and m is a polyorganosiloxane skeleton showing an integer of 1 to 50 in the molecular chain. By using a polycarbonate resin suitable for three-dimensional molding as a binder, the EL light emitting unit 1 that does not cause cracks in the layer even after three-dimensional molding is manufactured.

  According to a fourth aspect of the present invention, in the EL sheet according to any one of the first to third aspects, the EL sheet further includes a colored layer 3 printed on the substrate 2 to display a sign, and the EL sheet The gist is that the light emitting unit 1 is laminated on the base material 2 so that the marker is visually recognized through the EL light emitting unit 1. A colored layer 3 is provided between the EL light emitting unit 1 and the base material 2 for giving letters and figures to the EL sheet or coloring the EL sheet. The marker of the colored layer 3 is illuminated by the EL light emitting unit 1 and can be visually recognized.

  The invention according to claim 5 is an EL integrated molded product obtained by integrally molding an EL sheet and a resin molded body, and the EL sheet has a base material and an EL light emitting portion formed on the base material. And a part of the EL sheet is three-dimensionally formed, and the EL light emitting portion includes a transparent electrode layer, a light emitting layer, a dielectric layer, a back electrode layer, and an insulating layer, and the light emitting layer, the dielectric layer, The gist of the back electrode layer and the insulating layer is an EL integrated molded product containing a binder mainly composed of polycarbonate resin. An EL integrated resin molded product such as a key top in which the resin molded body 4 is further integrally formed with the EL sheet can be obtained.

  The invention according to claim 6 is the EL integrated resin molded product according to claim 5, wherein the EL light emitting part further includes a transparent electrode compensation electrode layer and a back electrode compensation electrode layer containing the binder. To do. A compensation electrode layer is provided to enable the EL light emitting unit 1 to emit light uniformly.

  The invention according to claim 7 is the EL integrated resin molded article according to claim 5 or 6, wherein the polycarbonate resin is represented by the following formula (I):

式中、Ｒ^１，Ｒ^２は相互に独立して水素、ハロゲン、Ｃ_１〜Ｃ_８アルキル、Ｃ_５〜Ｃ_６シクロアルキル、Ｃ_６〜Ｃ_１０アリールアルキルを表し、ｍは４〜７の整数であり、Ｒ^３，Ｒ^４は各Ｘに対して個々に選択可能であり、かつ相互に独立して水素またはＣ_１〜Ｃ_６アルキルを表し、Ｘは少なくとも１個の炭素原子を表し、Ｒ^３，Ｒ^４は共にアルキルである、二官能性カーボネート構造単位を含む芳香族カーボネートである
１，１−シクロアルキル骨格または下記式（ＩＩＩ）

In the formula, R ¹ and R ² each independently represent hydrogen, halogen, C _{1 to} C ₈ alkyl, C _{5 to} C ₆ cycloalkyl, C _{6 to} C ₁₀ arylalkyl, and m is an integer of 4 to 7 R ³ and R ⁴ are individually selectable for each X and independently of each other represent hydrogen or C ₁ -C ₆ alkyl, X represents at least one carbon atom, R ³ , R ⁴ are both alkyl, 1,1-cycloalkyl skeleton, which is an aromatic carbonate containing a difunctional carbonate structural unit, or the following formula (III)

式中、Ｒ^１，Ｒ^２は各々独立してアルキル基、アルコキシ基、アリール基、アリール置換アルケニル基、及び縮合多環式炭化水素基から選ばれる一価の置換基を示し、ｙ／（ｘ＋ｙ）＝５〜７０重量％であり、ｌは１〜１０の整数、ｍは１〜５０の整数を示す
ポリオルガノシロキサン骨格を分子鎖に備え、ことを要旨とする。立体成形に好適なポリカーボネート樹脂をバインダに使用することによって、立体成形後においても層にクラックを生じないＥＬ発光部１が製造される。

In the formula, each of R ¹ and R ² independently represents a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl group, and a condensed polycyclic hydrocarbon group, and y / (x + y ) = 5 to 70% by weight, l is an integer of 1 to 10, and m is a polyorganosiloxane skeleton showing an integer of 1 to 50 in the molecular chain. By using a polycarbonate resin suitable for three-dimensional molding as a binder, the EL light emitting unit 1 that does not cause cracks in the layer even after three-dimensional molding is manufactured.

  The invention according to claim 8 is the EL integrated resin molded product according to any one of claims 5 to 7, wherein the EL sheet further includes a colored layer 3 printed on a base material for displaying a sign. The gist is that the EL light emitting part is laminated on the base material so that the marker is visually recognized through the EL light emitting part.

  By using the three-dimensional molded EL sheet and the EL integrated resin molded product of the present invention, for example, a light emitting portion can be provided along the surface layer of a three-dimensionally molded resin component such as a casing or cover component of an electronic device or a key top. It becomes possible.

Hereinafter, embodiments of the present invention will be described in more detail.
FIG. 1 shows a perspective view of an EL sheet having an EL light emitting unit 1 on the surface. In the embodiment of FIG. 1, an operation button that is three-dimensionally formed is provided on a part of the EL sheet.

  As shown in FIG. 2, the three-dimensionally formed EL sheet of the present embodiment is a three-dimensionally formed base material 2 in a state in which an EL light emitting unit 1 mainly composed of a polycarbonate resin is laminated on the base material 2. is there.

  More specifically, the transparent electrode layer 5, the transparent electrode compensation electrode layer 6, the light emitting layer 7, and the dielectric layer shown in FIG. 8. The back electrode layer 9, the back electrode compensation electrode layer 10, and the insulating layer 11 are sequentially formed. Thereby, the EL light emitting unit 1 is formed on the substrate 2. Then, a three-dimensional EL sheet is manufactured by forming the base material 2 into a three-dimensional shape. As the three-dimensional forming process, a vacuum forming process, a press forming process, a hydroforming forming process, or the like can be used. As shown in FIG. 3B, before the transparent electrode layer 5 is formed, the colored layer 3 for displaying characters, graphics, and the like is formed by screen printing, and the colored layer 3 is illuminated by the lower EL light emitting unit 1. You may make it do.

  4 and 5 show an embodiment in which an EL integrated resin molded product is manufactured by integrally forming a resin molded body 4 such as a key top on the back side of a three-dimensional molded EL sheet by injection molding or the like. For the resin molded body 4, for example, a thermoplastic resin such as a polycarbonate resin, an acrylic resin, a polyethylene terephthalate resin, or an ABS resin, or a thermoplastic elastomer such as a styrene, olefin, polyester, or urethane can be used.

  The EL light emitting unit 1 shown in FIG. 2 is formed into a three-dimensional shape together with the base material 2 after being formed on the base material 2, but breakage or peeling from the base material 2 occurs in the curved portion or the bent portion. Absent. Accordingly, good light emission can be obtained from the three-dimensionally formed EL light emitting unit 1.

  Such a three-dimensional shape can be obtained by using a material with good processability as the base material 2 and also using a material excellent in followability to the base material 2 and flexibility in the EL light emitting part 1. Can do. Furthermore, in order not to cause peeling between the base material 2 and the EL light emitting portion 1, it is also important that there is compatibility between these materials.

  As the base material 2 having good processability, a polycarbonate film having excellent flexibility is preferably used. Examples of polycarbonate-based materials include materials consisting only of polycarbonate, materials consisting of an alloy of polycarbonate and polybutylene terephthalate, materials consisting of an alloy of polycarbonate and polyethylene terephthalate (PET), and polycarbonate and acrylonitrile butadiene styrene (ABS). The material which consists of an alloy with, etc. is mentioned. Among these, since a bending fatigue property is lowered in a sheet stretched with an alloy with PET, it is desirable to use an unstretched material when using an alloy with PET. Further, the alloy with ABS has a disadvantage that the base material 2 after molding is easily damaged. Therefore, a material made only of polycarbonate and a material made of an alloy of polycarbonate and polybutylene terephthalate are more preferable.

  The base material 2 shown in FIG. 2 is a translucent resin film, and may be colorless or colored, and may be transparent or translucent. Although the thickness of a film is not specifically limited, The thing of 50-200 micrometers is suitable.

  Next, the structure of the EL light emitting unit 1 will be described in detail. As shown in FIG. 5, the EL light emitting unit 1 includes a transparent electrode layer 5, a light emitting layer 7, a dielectric layer 8, a back electrode layer 9, and an insulating layer 11 stacked. In order to make the light emission from the EL light emitting unit 1 uniform throughout, the transparent electrode compensation electrode layer 6 and the back electrode compensation electrode layer 10 may be further provided.

  In the present invention, the EL light emitting unit 1 has a good followability with respect to the base material 2 and does not cause delamination or breakage between the respective layers constituting the EL light emitting unit 1. Used. Moreover, the material which was excellent in workability is used so that each layer which comprises EL light emission part 1 can each be shape | molded flexibly.

  It is preferable to use a polythiophene-based conductive polymer for the transparent electrode layer 5. For example, 3,4-polyalkylenedioxythiophene can be mentioned. Among them, 3,4-polyethylenedioxythiophene (PEDOT), which has low resistance and excellent transparency, is optimal. The polythiophene-based conductive polymer can form a coating film by printing or painting as a polystyrene sulfonic acid solution.

  The light emitting layer 7, the dielectric layer 8, the back electrode layer 9, the insulating layer 11, and the compensation electrode layers 6 and 10 laminated on the transparent electrode layer 5 are mixed with particles that cause the function of each layer in the binder. Is formed by. The binder of each layer may be the same or different, but it is desirable to use the same binder from the viewpoint of compatibility and followability of each material.

  The present invention is characterized in that a polycarbonate resin having excellent flexibility is used for the binder. This is because the polycarbonate resin has good elongation when heated to the glass transition point or more for three-dimensional molding, and has good followability to a polycarbonate substrate having good workability.

Conventionally, in order to increase the luminance of the EL element, cyanoresin or fluorine resin having a high dielectric constant has been used as a binder. Polycarbonate resin has a dielectric constant of only about 1/5 compared to these conventional binders. When a material having such a low dielectric constant is used, the luminance of the EL element is lowered. It was not used. However, since three-dimensional molding is performed in the present invention, the polycarbonate resin is used as a binder with a focus on good processability of the polycarbonate resin. As a result, a three-dimensional molding without delamination and cracks was realized. Furthermore, since it is possible to provide a light emitting layer on the outermost surface of the display surface by making the light emitting surface into a three-dimensional shape, the function as an EL sheet is not adversely affected even if the luminance of the EL light emitting unit 1 is somewhat reduced. And gained knowledge. Further, it has been found that the lifetime of an EL element using a polycarbonate resin as a binder is almost the same as that of an EL element using a conventional cyanoresin or fluorine resin as a binder.

  The polycarbonate resin capable of three-dimensional molding used in the present invention will be described in detail below. First, the polycarbonate resin has a skeleton that can be used as an ink when forming an EL element by printing, that is, a skeleton that improves solubility in solvents generally used in inks such as toluene and cyclohexanone. It is necessary to have. Therefore, a material that does not dissolve in a solvent, such as bisphenol-A type polycarbonate resin, or dissolves only in methylene chloride, which is not normally used as a solvent for ink, cannot be used in the present invention. Good solubility in the ink solvent means that it dissolves in the ink solvent, and when dissolved, neither gelation nor crystallization occurs.

  A further requirement for use in the present invention is that the heat distortion temperature (or glass transition point Tg) of the ink resin is within an appropriate temperature range. When the heat distortion temperature is high, the molding temperature becomes a high temperature exceeding the heat distortion temperature. Furthermore, a polycarbonate resin having a heat deformation temperature higher than the heat deformation temperature of the base material does not become flexible by heating at a temperature at which the base material can be deformed, and causes the EL element to break.

  In particular applications, it should also be taken into account that the modulus of elasticity of the ink resin produced is in the desired range. If the elasticity modulus of resin is too high, there arises a problem that the load at the time of an input operation increases in certain applications such as operation buttons.

  Considering the above, as the polycarbonate resin, for example, a resin having a cycloalkyl group in which carbon existing between two phenyl groups, represented by the formula (I), can be used. It is desirable to use a polycarbonate resin having a 1,1-cycloalkyl skeleton in the molecular chain and having a weight average molecular weight of at least 10,000. The resin having the structure represented by the chemical formula (I) is dissolved in toluene, cyclohexanone, or the like, and does not gel and crystallize.

上記式（Ｉ）中、Ｒ^１，Ｒ^２は相互に独立して水素、ハロゲン、Ｃ_１〜Ｃ_８アルキル、Ｃ_５〜Ｃ_６シクロアルキル、Ｃ_６〜Ｃ_１０アリールアルキルを表し、ｍは４〜７の整数であり、Ｒ^３，Ｒ^４は各Ｘに対して個々に選択可能であり、かつ相互に独立して水素またはＣ_１〜Ｃ_６アルキルを表し、Ｘは少なくとも１個の炭素原子を表し、Ｒ^３，Ｒ^４は共にアルキルである、二官能性カーボネート構造単位を含む芳香族カーボネートである。

In the above formula (I), R ¹ and R ² each independently represent hydrogen, halogen, C ₁ -C ₈ alkyl, C ₅ -C ₆ cycloalkyl, C ₆ -C ₁₀ arylalkyl, m is 4 An integer of ˜7, R ³ , R ⁴ are individually selectable for each X and independently of each other represent hydrogen or C ₁ -C ₆ alkyl, where X is at least one carbon atom Wherein R ³ and R ⁴ are both an alkyl carbonate containing a bifunctional carbonate structural unit, which is alkyl.

On the other hand, in the chemical formula (I), when R ^{1 to} R ⁴ are hydrogen and X = 6, that is, a polycarbonate resin having a cyclohexyl group has high solubility in toluene or the like, but has a very high glass transition point. Since it exceeds 170 ° C., the molding temperature becomes high. Therefore, when an alloy film such as polycarbonate resin, polycarbonate / polybutylene terephthalate, polycarbonate / polyethylene terephthalate, polycarbonate / ABS resin is used as the base material, the heat distortion temperature of these materials is 105 ° C. to 135 ° C. Therefore, when the molding is performed at the heat deformation temperature of the substrate, the EL element is broken. Furthermore, the elastic modulus of the produced resin is very high (4.9 × 10 ⁹ Pa), and when used as a film key sheet unit, the load during the input operation becomes heavy as described above.

  The binder includes a monomer having a structure represented by the chemical formula (I) and other units such as bisphenol-type polycarbonate and polyorganodimethylsiloxane which are added to lower the thermal deformation temperature and elastic modulus of the resin. It is also possible to use a copolymer obtained by copolymerizing a monomer. By using a skeleton containing bisphenol-type polycarbonate or polyorganodimethylsiloxane, the heat distortion temperature and elastic modulus of the resin can be lowered. If only the elastic modulus is lowered, it is possible to improve the properties of the resin relatively easily by adding a rubber component.

  More specifically, a copolymer of 1,1-bis- (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane of formula (II) and bisphenol A may be used.

また、１，１−シクロアルキル骨格を有する樹脂の代わりに、式（ＩＩＩ）のようなポリオルガノシロキサン骨格を有するポリカーボネート樹脂を用いることもできる。

Further, instead of the resin having a 1,1-cycloalkyl skeleton, a polycarbonate resin having a polyorganosiloxane skeleton as represented by the formula (III) can also be used.

式中、Ｒ^２，Ｒ^３は各々独立してアルキル基、アルコキシ基、アリール基、アリール置換アルケニル基及び縮合多環式炭化水素基から選ばれる一価の置換基を示し、ｙ／（ｘ＋ｙ）＝５〜７０重量％であり、ｌは１〜１０の整数、ｍは１〜５０の整数を示す。

In the formula, R ² and R ³ each independently represents a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl group and a condensed polycyclic hydrocarbon group, and y / (x + y) = 5 to 70% by weight, l is an integer of 1 to 10, and m is an integer of 1 to 50.

  The table which compared about the characteristic of polycarbonate resin which can be used for the present invention, and other polycarbonate resin is shown.

表１において、共重合体１〜５はそれぞれ以下の骨格を有する。

In Table 1, copolymers 1 to 5 each have the following skeleton.

    Copolymer 1

共重合体２

Copolymer 2

式中、Ｒ^２，Ｒ^３は各々独立してアルキル基、アルコキシ基、アリール基、アリール置換アルケニル基及び縮合多環式炭化水素基から選ばれる一価の置換基を示し、ｙ／（ｘ＋ｙ）＝５〜７０重量％であり、ｌは１〜１０の整数、ｍは１〜５０の整数を示す。

In the formula, R ² and R ³ each independently represents a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl group and a condensed polycyclic hydrocarbon group, and y / (x + y) = 5 to 70% by weight, l is an integer of 1 to 10, and m is an integer of 1 to 50.

    Copolymer 3

式中、Ｒ^１，Ｒ^２，Ｒ^３は各々独立してアルキル基、アルコシキ基、アリール基、アリール置換アルケニル及び縮合多環式炭化水素基から選ばれる一価の置換基を示し、（ｙ＋ｚ）／（ｘ＋ｙ＋ｚ）＝５〜７０重量％であり、ｌは１〜１０の整数、ｍは１〜５０の整数、ｎは０〜４の整数である。

In the formula, R ¹ , R ² , and R ³ each independently represent a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl, and a condensed polycyclic hydrocarbon group, and (y + z) / (X + y + z) = 5 to 70% by weight, l is an integer of 1 to 10, m is an integer of 1 to 50, and n is an integer of 0 to 4.

    Copolymer 4

式中、ｍ，ｎはそれぞれ整数である。

In the formula, m and n are each an integer.

    Copolymer 5

上記のようなバインダを使用して形成された、発光層７、誘電層８、背面電極層９、絶縁層１１、および補償電極層６，１０の構成をより詳細に説明する。

The configuration of the light emitting layer 7, the dielectric layer 8, the back electrode layer 9, the insulating layer 11, and the compensation electrode layers 6 and 10 formed using the above binder will be described in more detail.

The light-emitting layer 7 is formed by using a light-emitting ink containing ZnS-based phosphor powder in a binder as the transparent electrode layer 5.
Form by printing on top. Although the magnitude | size of fluorescent substance powder is not specifically limited, Preferably it is about 20 micrometers-35 micrometers of average particle diameters. The smaller the phosphor powder, the higher the luminance compared to the larger one, but the luminance life is inferior. Moreover, the brightness becomes higher when the particle diameters are uniform. The filling amount of the phosphor powder is preferably about 2 to 3 times the solid content of the binder although it varies depending on the type of binder. If the filling amount is too small, the number of light emitters is reduced with respect to the binder, resulting in uneven light emission. Moreover, when there is too much filling amount, light-emitting bodies will contact directly and it will become difficult to apply a high electric field stably.

  The emission color of the phosphor ZnS is determined by the type of activator element added. Typical activators are Cu and Cl, and blue-green light emission based on a recombination transition between DA pairs in which Cu is an acceptor (A) and Cl is a donor (D) is obtained. When Cu and Al are used, green light emission is obtained. When Mn is further added to the Cu and Cl, the transition energy between the D-A pair is transmitted to Mn to excite it, and orange-yellow light emission from the Mn center is extracted to the outside. Further, by mixing phosphor particles having different emission colors to form a light emitting layer, the color tone of light extracted to the outside becomes a mixed color thereof. For example, white light emission can be obtained by mixing orange, blue-green, and blue phosphors.

The dielectric layer 8 is formed by applying a dielectric ink containing a high dielectric material such as barium titanate or titanium oxide in a binder onto the light emitting layer 7 by printing. The dielectric layer 8 is an important component for ensuring the stability of the EL light emitting unit 1. In order to stably apply a high electric field necessary for EL light emission to the light emitting layer 7 without causing dielectric breakdown in the EL light emitting unit 1, the material of the dielectric layer 8 is made as high as possible. It is desirable to have _B. The particle size of the high dielectric is not particularly limited, but is preferably about 1 μm. When the particle size of the high dielectric material is large, the thickness of the printed dielectric layer 8 becomes thick, and when it is too small, the particles aggregate and it is difficult to obtain a uniform coating film. The filling amount varies depending on the type of the binder, but is preferably about 2 to 3 times the solid content of the binder. If the filling amount is too small, the dielectric constant of the dielectric layer 8 is lowered and the luminance is lowered. On the other hand, if the filling amount is too large, the viscosity becomes high and good printing cannot be performed.

  The back electrode layer 9 may be formed from the same material as the transparent electrode layer described above. The back electrode layer 9 and the compensation electrode layers 6 and 10 may be formed by printing conductive ink. The conductive ink at this time is obtained by containing a conductive powder in a binder. As the conductive powder, for example, non-metallic powder such as carbon black powder can be used. In addition, noble metal powders such as gold, silver and palladium, base metal powders such as copper and nickel, or metal powders such as alloys made of these metals can be used. The average particle size of the conductive powder needs to be 0.3 to 10 μm. When the average particle size of the conductive powder exceeds 10 μm, it is necessary to contain a large amount of the conductive powder, and therefore, it becomes easy to cause a conduction failure and it is difficult to use it as a conductor. When the average particle size of the conductive powder is less than 0.3 μm, the particles tend to aggregate and it is difficult to print uniformly. The conductive powder is formed by, for example, a mechanical pulverization method, an atomization method, a reduction method, an electrolysis method, a gas phase method, or the like. The shape of the conductive powder may be any shape, but a flake-shaped or flake-shaped conductive powder having a large aspect ratio is preferable because it has a lower resistance when forming wiring than a spherical shape. The filling amount varies depending on the type of the binder, but is preferably about 100 to 300 parts by weight with respect to 100 parts by weight of the ink. If the filling amount is too small, the resistance becomes high and the function as an electrode is not exhibited. Moreover, when there is too much filling amount, since the amount of binders will decrease too much, the crack of a coating film may arise at the time of shaping | molding.

An additive such as a silane coupling agent may be added to the above three inks, the light emitter ink, the dielectric ink, and the conductor ink. Although the silane coupling agent is not particularly limited, it has an organic functional group and a hydrolyzable group in one molecule, so that the inorganic substance and the organic resin can be combined, and the above filler is stably dispersed in the binder. It is a molecule that makes it possible to

  The insulating layer 11 is formed using the same kind of binder as the compensation electrode layers 6 and 10, the light emitting layer 7, the dielectric layer 8, and the back electrode layer 9. This is to improve the subsequent molding process. The insulating layer is formed by using only a binder, or is formed by filling a filler such as silica, alumina, or acrylic beads that adds insulation to the binder.

Examples of the printing method for each layer include screen printing, but other printing methods may be used.
The thickness of the EL light emitting portion formed as described above is as follows: the transparent electrode layer 5, the transparent electrode compensation electrode layer 6, the light emitting layer 7, the dielectric layer 8, the back electrode layer 9, the back electrode compensation electrode layer 10, and the insulating layer 11. The total thickness is 5 to 200 μm, preferably 50 to 100 μm.

  The EL light emitting unit 1 may be partially formed on an EL sheet formed as a three-dimensional molded body as shown in FIG. 3A or may be formed entirely as shown in FIG. In the example shown in FIG. 3B, the colored layer 3 is further provided in the EL light emitting unit 1 or separately from the EL light emitting unit 1. The colored layer 3 is provided to display characters, figures, symbols, or the like on a part or the whole of the molded body or to color the molded body. The colored layer 3 is formed by printing or painting using a light-transmitting or light-shielding pigment ink, fluorescent coloring ink, glitter pigment ink containing pearl pigment, dye ink, or the like. Moreover, you may form by laminating | stacking metal foil.

  When the colored layer 3 is formed so as to overlap the EL light emitting portion 1, a cutout portion is provided in the light-shielding ink layer according to the shape of a pattern such as a character, and the cutout portion is notched when viewed from the substrate 2 side. It is good also as a structure where light emission is visually recognized from a part. Moreover, you may form the colored layer 3 directly on the base material 2 as another structure. After printing the colored layer 3 in the shape of a pattern on the base material 2, by providing the EL light emitting unit 1, it can be seen as if the pattern is placed on the key that emits light entirely when viewed from the base material 2. Is done. Further, as a different structure, a layer formed by printing the EL light emitting unit 1 and the colored layer 3 may be a pattern layer provided in the EL light emitting unit. In this structure, both the colored layer and the EL layer are printed on the substrate 2 as a picture. In order to maintain the adhesion between the colored layer 3 and the EL light emitting unit 1 provided adjacent thereto, a resin binder such as a polycarbonate resin having good adhesion may be appropriately selected.

  Below, the Example of EL light emission part 1 using the polycarbonate resin of this invention and the comparative example using an acrylic resin are described.

  A polycarbonate film was used as the base material 2, and as shown in FIG. 3B, a colored layer 3 such as letters and figures was formed on the back surface of the base material 2 with a polycarbonate ink by screen printing. Next, on the back surface of the resin film provided with the colored layer 3, the transparent electrode layer 5 (polythiophene-based ink, manufactured by Nippon Agfa) shown in FIG. Then, the light emitting layer 7, the dielectric layer 8, the back electrode layer 9, the back electrode compensation electrode layer 10, and the insulating layer 11 were sequentially formed, and the EL light emitting unit 1 was formed. Thereafter, it was molded into a three-dimensional shape by press molding.

  The moldability of the EL light-emitting portion 1 was good, and no breakage occurred in each layer, and the EL light-emitting portion 1 could be formed with good reproducibility.

Comparative example

A film made of an alloy of a polycarbonate resin and a polybutylene terephthalate resin was used as the base material 2, and a colored layer 3 for displaying characters, graphics, and the like was formed by screen printing on the back surface of the film using an ink mainly composed of a polycarbonate resin. Next, a transparent electrode compensation electrode layer 6 in which Dotite FA-312 manufactured by Fujikura Kasei Co., Ltd. was dispersed in a binder having a polyester skeleton was printed on the back surface of the resin film of the base material 2 provided with the colored layer 3. Next, transparent electrode layer 5 (ITO ink, manufactured by Sumitomo Osaka Cement Co., Ltd.), light emitting layer 7 (Dotite FEL-125, manufactured by Fujikura Kasei Co., Ltd.), dielectric layer 8 (Dotite FEL-615, Fujikura) by screen printing. Kasei Co., Ltd.), back electrode layer 9 (Dotite FEC-198, manufactured by Fujikura Kasei Co., Ltd.), back electrode compensation electrode layer 10 (Dotite FA-312, manufactured by Fujikura Kasei Co., Ltd.), insulating layer 11 (XB-101G, Fujikura Kasei Co., Ltd.) were sequentially formed to form the EL light emitting unit 1. Here, as a binder for the transparent electrode layer 5, the light emitting layer 7, the dielectric layer 8, the back electrode compensation electrode layer 10, and the insulating layer 11, a fluorine-based resin was used. After that, when the three-dimensional shape is formed by press molding, the ink breaks mainly in the layers from the colored layer 3 to the insulating layer 11, and the EL display layer can emit light with good reproducibility even when the power is connected. There wasn't.

  From the above, in Examples using a polycarbonate resin binder, moldability was good, while in Comparative Examples, cracks occurred in the molded product. The luminance of the light emitted from the EL light emitting unit 1 was also better in the example.

The perspective view which shows a solid molded EL sheet. The longitudinal cross-sectional view of a solid molded EL sheet. (A) The longitudinal cross-sectional view of a solid molded EL sheet. (B) The longitudinal cross-sectional view of a solid molded EL sheet. The longitudinal cross-sectional view of EL integral resin molding. The longitudinal cross-sectional view which shows the layer structure of EL light emission part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... EL light emission part, 2 ... Base material, 3 ... Colored layer, 4 ... Resin molded object, 5 ... Transparent electrode layer, 6 ... Transparent electrode compensation electrode layer, 7 ... Light emitting layer, 8 ... Dielectric layer, 9 ... Back electrode Layer 10, back electrode compensation electrode layer 11, insulating layer.

Claims (8)

In an EL sheet having a base material and an EL light emitting part formed on the base material and having a transparent electrode layer, a light emitting layer, a dielectric layer, a back electrode layer, and an insulating layer,
The light emitting layer, the dielectric layer, the back electrode layer, and the insulating layer contain a binder mainly composed of polycarbonate resin,
The EL sheet is an EL sheet in which at least a part of a portion having an EL light emitting portion is three-dimensionally formed.   The EL sheet according to claim 1, wherein the EL light emitting unit further includes a transparent electrode compensation electrode layer and a back electrode compensation electrode layer containing the binder. The polycarbonate resin has the following formula (I)

^Wherein, R 1, ^{R 2} represents hydrogen, _halogen, C 1 -C _{8 alkyl,} C 5 -C _{6 cycloalkyl,} C 6 _{-C 10} arylalkyl independently of one another, m is 4-7 integer R ³ and R ⁴ are individually selectable for each X and independently of each other represent hydrogen or C ₁ -C ₆ alkyl, X represents at least one carbon atom, R ³ and R ⁴ are both alkyl, 1,1-cycloalkyl skeleton which is an aromatic carbonate containing a difunctional carbonate structural unit, or the following formula (III)

In the formula, each of R ¹ and R ² independently represents a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl group, and a condensed polycyclic hydrocarbon group, and y / (x + y The EL sheet according to claim 1, wherein the molecular chain includes a polyorganosiloxane skeleton in which 5 is an integer of 1 to 10 and m is an integer of 1 to 50.   The EL sheet further includes a colored layer printed on a base material for displaying the sign, and the EL light emitting part is laminated on the base material, whereby the sign is visually recognized through the EL light emitting part. The EL sheet according to any one of claims 1 to 3. An EL integrated resin molded product obtained by integrally molding an EL sheet and a resin molded body,
The EL sheet has a base material and an EL light emitting part formed on the base material, and a part of the EL sheet is three-dimensionally formed. The EL light emitting part includes a transparent electrode layer, a light emitting element. An EL integrated resin molded product comprising a layer, a dielectric layer, a back electrode layer, and an insulating layer, wherein the light emitting layer, the dielectric layer, the back electrode layer, and the insulating layer contain a binder mainly composed of a polycarbonate resin.   The EL integrated resin molded product according to claim 5, wherein the EL light emitting unit further includes a transparent electrode compensation electrode layer and a back electrode compensation electrode layer containing the binder. The polycarbonate resin has the following formula (I)

In the formula, R ¹ and R ² each independently represent hydrogen, halogen, C _{1 to} C ₈ alkyl, C _{5 to} C ₆ cycloalkyl, C _{6 to} C ₁₀ arylalkyl, and m is an integer of 4 to 7 R ³ and R ⁴ are individually selectable for each X and independently of each other represent hydrogen or C ₁ -C ₆ alkyl, X represents at least one carbon atom, R ³ and R ⁴ are both alkyl, a 1,1-cycloalkyl skeleton that is an aromatic carbonate containing a difunctional carbonate structural unit, or a compound represented by the following formula (III)

In the formula, R ¹ and R ² each independently represents a monovalent substituent selected from an alkyl group, an alkoxy group, an aryl group, an aryl-substituted alkenyl group, and a condensed polycyclic hydrocarbon group, and y / (x + y) The EL integrated resin molded article according to claim 5 or 6, wherein the molecular chain includes a polyorganosiloxane skeleton in which 5 is an integer of 1 to 10 and m is an integer of 1 to 50.   The EL sheet further includes a colored layer printed on a base material for displaying the sign, and the EL light emitting part is laminated on the base material, whereby the sign is visually recognized through the EL light emitting part. The EL integrated resin molded product according to any one of claims 5 to 7.

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