JP5239127B2 - Display element substrate - Google Patents

Description

  The present invention relates to a display element substrate. More specifically, the present invention relates to a display element substrate used for a display such as a flexible display.

  The display element substrate is used for a display element. The display element is used for a display such as a flexible display. The flexible display is a flexible display that can be installed on a curved surface of a device or the like, and examples thereof include a flexible display using an organic EL element as a display element and a flexible display using a liquid crystal element as a display element. Further, as a display element substrate, Patent Document 1 discloses a film in which a gas barrier layer made of an inorganic oxide film and a resin layer are laminated in this order on a base film.

JP 2003-89163 A (pages 1 to 3)

  However, the conventional display element substrate does not have sufficient gas barrier properties, and the durability of the display element using the substrate is not sufficient. An object of the present invention is to provide a display element substrate that can provide a display element with better gas barrier properties and better durability.

  As a result of intensive studies to solve the above problems, the present inventor has completed the present invention.

That is, the present invention provides the following display element substrate and display element.
<1> A display element substrate having two or more resin layers, wherein at least one of the two or more resin layers is functionally reactive with (A) liquid crystal polyester and (B) the liquid crystal polyester. A liquid crystal polyester resin layer substantially composed of a copolymer having a group, wherein at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer. substrate.
<2> A display element substrate having two or more resin layers, wherein at least one of the two or more resin layers is functionally reactive with (A) liquid crystal polyester and (B) the liquid crystal polyester. A liquid crystal polyester resin layer substantially composed of a copolymer having a group, wherein at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer, and at least of the liquid crystal polyester resin layer One layer and at least one layer of the resin layer other than the liquid crystal polyester resin layer are in contact with each other, and the surface average roughness (Ra) on the resin layer side other than the liquid crystal polyester resin layer is 5 nm or less. Substrate.
<3> A display element substrate having two or more resin layers, wherein at least one of the two or more resin layers is functionally reactive with (A) liquid crystal polyester and (B) the liquid crystal polyester. A liquid crystal polyester resin layer substantially composed of a copolymer having a group, wherein at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer, and further from an inorganic layered compound and a resin At least one layer of the liquid crystalline polyester resin layer is in contact with the layer composed of the inorganic layered compound and the resin, and at least one of the layer composed of the inorganic layered compound and the resin and the resin layer other than the liquid crystalline polyester resin layer. A substrate for a display element, which is in contact with one layer and has a surface average roughness (Ra) on the resin layer side other than the liquid crystal polyester resin layer of 5 nm or less.
<4> The display element substrate according to any one of <1> to <3>, wherein the resin used for the resin layer other than the liquid crystal polyester resin layer is a resin having a glass transition temperature (Tg) of 150 ° C. or higher.
<5> The display element substrate according to any one of <1> to <4>, further including an inorganic layer, wherein the resin layer other than the liquid crystal polyester resin layer is in contact with the inorganic layer.
<6> The display element substrate described above, wherein the inorganic layer is made of one or more inorganic substances selected from the group consisting of metals, metal oxides, metal nitrides, metal carbides, and metal oxynitrides.
<7> The display element substrate according to any one of <3> to <6>, wherein the inorganic layered compound is an inorganic layered compound having a particle size of 5 μm or less and an aspect ratio of 50 to 5000.
<8> The display element substrate according to any one of <1> to <4>, further including a conductive layer, wherein the resin layer other than the liquid crystal polyester resin layer is in contact with the conductive layer.
<9> The display element substrate according to any one of <5> to <7>, further including a conductive layer, wherein the inorganic layer and the conductive layer are in contact with each other.
<10> For the display element according to any one of <1> to <9>, wherein the water vapor permeability is 0.2 g / m ² / day or less and the oxygen permeability is 0.1 cc / m ² / day or less. substrate.
<11> The display element according to any one of <1> to <10>, wherein an average linear expansion coefficient in a temperature range of 20 ° C. to 150 ° C. is −10 ppm / ° C. to 25 ppm / ° C. Substrate.
<12> A flexible display substrate, comprising the display element substrate according to any one of <1> to <11>.
<13> A display element having the following (a) to (e).
(A) The substrate according to any one of <1> to <7>.
(B) A layer having conductivity.
(C) An organic layer that exhibits at least one function selected from light absorption, light scattering, optical rotation, and light emission by applying an electric field.
(D) A layer having transparent conductivity.
(E) Transparent encapsulant.
<14> A display element obtained by a production method including the following steps (a ′) to (d ′).
(A ′) A step of forming a conductive layer on the surface of the substrate on the side of the resin layer other than the liquid crystal polyester resin layer according to any one of <1> to <7>.
(B ′) A step of forming, on the surface of the conductive layer obtained in the step (a ′), an organic layer in which at least one function selected from light absorption, light scattering, optical rotation and light emission is manifested by applying an electric field. .
(C ′) A step of obtaining a laminate by forming a layer having transparent conductivity on the surface of the organic layer side in the step (b ′).
(D ′) A step of obtaining a display element by sealing part or all of the surface of the laminate obtained in the step (c ′) with a transparent sealing material.
<15> A flexible display using the display element according to <13> or <14>.

  The display element substrate of the present invention has flexibility and better gas barrier properties. In addition, since the display element using the display element substrate of the present invention has flexibility, better gas barrier properties, and better durability, the display element substrate of the present invention is more suitable for a flexible display. The present invention is industrially extremely useful because it can be used suitably, particularly for a flexible display using an organic EL element as a display element.

The present invention will be described below.
The display element substrate of the present invention is a display element substrate having two or more resin layers, wherein at least one of the two or more resin layers is (A) liquid crystal polyester and (B) the liquid crystal polyester. A liquid crystal polyester resin layer substantially comprising a copolymer having a functional group having reactivity with at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer Features. By setting it as such a structure, the board | substrate for display elements of this invention can show more favorable gas barrier property.

  Next, the liquid crystal polyester resin layer included in the display element substrate of the present invention will be described. The liquid crystal polyester resin layer is substantially composed of (A) liquid crystal polyester and (B) a copolymer having a functional group reactive with the liquid crystal polyester.

(A) As liquid crystal polyester, for example,
(1) What is obtained by polymerizing aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, and aromatic diol,
(2) those obtained by polymerizing the same or different aromatic hydroxycarboxylic acids,
(3) those obtained by reacting an aromatic hydroxycarboxylic acid with a polyester such as polyethylene terephthalate,
Etc.

  Further, these ester-forming derivatives may be used in place of these aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, and aromatic diols.

  Here, as the ester-forming derivative of carboxylic acid, for example, a carboxyl group is a highly reactive derivative such as an acid chloride or an acid anhydride that promotes a polyester forming reaction, and a carboxyl group is And those that form esters with alcohols, ethylene glycol, or the like that form polyesters by transesterification.

  In addition, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids and aromatic diols are halogen atoms such as chlorine atoms and fluorine atoms, alkyl groups such as methyl groups and ethyl groups, phenyl groups, and the like, as long as they do not inhibit ester formation. It may be substituted with an aryl group such as a group.

  As the repeating structural unit of the liquid crystal polyester, the following (1) repeating structural unit derived from aromatic dicarboxylic acid, (2) repeating structural unit derived from aromatic diol, and (3) derived from aromatic hydroxycarboxylic acid. A repeating structural unit can be illustrated.

上記の繰り返し構造単位は、ハロゲン原子、アルキル基またはアリール基で置換されていてもよい。 (1) Repeating structural unit derived from aromatic dicarboxylic acid:

The above repeating structural unit may be substituted with a halogen atom, an alkyl group or an aryl group.

上記の繰り返し構造単位は、ハロゲン原子、アルキル基またはアリール基で置換されていてもよい。 (2) Repeating structural unit derived from aromatic diol:

The above repeating structural unit may be substituted with a halogen atom, an alkyl group or an aryl group.

上記の繰り返し構造単位は、ハロゲン原子、アルキル基またはアリール基で置換されていてもよい。 (3) Repeating structural unit derived from aromatic hydroxycarboxylic acid:

The above repeating structural unit may be substituted with a halogen atom, an alkyl group or an aryl group.

  (A) The liquid crystalline polyester has 30 repeating structural units represented by the above formula (A) with respect to the total number of moles of repeating structural units in (A), from the viewpoint of balance between heat resistance, mechanical properties, and workability. It is preferable to contain more than mol%.

  Moreover, as a combination of the repeating structural unit of (A) liquid crystal polyester containing the repeating structural unit represented by the above formula (a), those shown in any one selected from the following (I) to (VI) are more preferable. . In addition, the wholly aromatic polyester of (I), (II), (III), (V) or (VI) is more preferable in order to further improve the gas barrier property. Particularly preferred are wholly aromatic polyesters having the structures (I) to (III).

(I)

(II)

(III)

(IV)

(V)

(VI)

  The (A) liquid crystal polyesters in the combinations (I) to (VI) are, for example, Japanese Patent Publication No. 47-47870, Japanese Patent Publication No. 63-3888, Japanese Patent Publication No. 63-3891, and Japanese Patent Publication No. 56-18016. And can be produced according to the method described in JP-A-2-51523. Among these, preferred combinations include (I), (II) or (IV), more preferably (I) or (II).

  Moreover, (A) liquid crystalline polyester in this invention is 30 to 80 mol% of repeating structural units derived from the said aromatic hydroxycarboxylic acid, and 25 repeating structural units derived from the said aromatic dicarboxylic acid from a heat resistant viewpoint. It is preferable to contain 35 to 10 mol% of repeating structural units derived from the aromatic diol.

  Next, (B) a copolymer having a functional group reactive with liquid crystal polyester will be described. The functional group having reactivity with the liquid crystalline polyester may be any functional group reactive with the liquid crystalline polyester, but is preferably an oxazolyl group, an epoxy group, or an amino group, and more preferably an epoxy group. These functional groups may exist as a part of other functional groups, and examples thereof include a glycidyl group.

  In the copolymer (B), as a method of introducing a functional group having reactivity with the above liquid crystal polyester into the copolymer, for example, in the synthesis step of the copolymer, the monomer having the functional group is copolymerized. It is possible to introduce by polymerization, or it is possible to graft copolymerize a monomer having the functional group with a copolymer.

（式中、Ｒは、エチレン系不飽和結合を有する炭素数２〜１３の炭化水素基を表し、Ｘは、−Ｃ(Ｏ)Ｏ−、−ＣＨ₂−Ｏ−または

を表す。）
で示される不飽和カルボン酸グリシジルエステル、不飽和グリシジルエーテルが好ましく用いられる。 As the monomer having a functional group having reactivity with the liquid crystal polyester, a monomer containing a glycidyl group is preferably used. As a monomer containing a glycidyl group, for example, the following general formula

(In the formula, R represents a hydrocarbon group having 2 to 13 carbon atoms having an ethylenically unsaturated bond, and X represents —C (O) O—, —CH ₂ —O— or

Represents. )
An unsaturated carboxylic acid glycidyl ester or an unsaturated glycidyl ether represented by formula (1) is preferably used.

  Examples of the unsaturated carboxylic acid glycidyl ester include glycidyl acrylate, glycidyl methacrylate, itaconic acid diglycidyl ester, butenetricarboxylic acid triglycidyl ester, and p-styrene carboxylic acid glycidyl ester.

  Examples of the unsaturated glycidyl ether include vinyl glycidyl ether, allyl glycidyl ether, 2-methylallyl glycidyl ether, methacryl glycidyl ether, and styrene-p-glycidyl ether.

  The copolymer (B) is preferably a copolymer containing 0.1 to 30% by weight of unsaturated carboxylic acid glycidyl ester units and / or unsaturated glycidyl ether units.

  Further, the copolymer (B) may be a thermoplastic resin, a rubber, or a mixture of a thermoplastic resin and rubber. Rubber is more preferable in terms of thermal stability and flexibility of the display element substrate of the present invention.

  As a method for introducing a functional group having reactivity with the liquid crystalline polyester into the rubber, for example, at the rubber synthesis stage, a monomer having the functional group can be introduced by copolymerization. It is also possible to graft copolymerize a monomer having a functional group.

  Specific examples of rubbers having functional groups that are reactive with liquid crystalline polyesters include rubbers having epoxy groups such as (meth) acrylic acid ester-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer. Examples include polymer rubber.

  Here, the (meth) acrylic acid ester is an ester obtained from acrylic acid or methacrylic acid and an alcohol. As the alcohol, an alcohol having 1 to 8 carbon atoms is preferable. Specific examples of (meth) acrylic acid esters include methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and the like. be able to. In addition, as (meth) acrylic acid ester, you may use said 2 or more types together.

  In terms of the thermal stability and mechanical properties of the obtained liquid crystal polyester resin layer, the rubber composition is preferably (meth) acrylic acid ester units exceeding 40% by weight and less than 97% by weight, more preferably 45 to 45%. 70% by weight, preferably 3 to 50% by weight of ethylene units, more preferably 10 to 49% by weight, preferably 0.1 to 30 unsaturated carboxylic acid glycidyl ether units and / or unsaturated glycidyl ether units % By weight, more preferably 0.5 to 20% by weight.

The rubber can be produced, for example, by bulk polymerization, emulsion polymerization, solution polymerization or the like using a free radical initiator. Typical polymerization methods are those described in JP-A-48-11388, JP-A-61-127709, etc., and in the presence of a polymerization initiator that generates free radicals, a pressure of 500 kg / It can be produced under conditions of cm ² or more and a temperature of 40 to 300 ° C.

  As rubbers other than the above rubber, acrylic rubber having a functional group reactive with liquid crystal polyester, and vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber having a functional group reactive with liquid crystal polyester Can be illustrated.

The acrylic rubber here is preferably a formula (1) to (3).
_{CH 2 = CH-C (O} ) -OR 1 (1)
_{CH 2 = CH-C (O} ) -OR 2 OR 3 (2)
^{_{CH 2 = CR 4 H-C}} (O) -O (R 5 (C (O) O) nR 6 (3)
(Wherein R ¹ represents an alkyl group having 1 to 18 carbon atoms or a cyanoalkyl group, R ² represents an alkylene group having 1 to 12 carbon atoms, and R ³ represents an alkyl group having 1 to 12 carbon atoms. R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 30 carbon atoms, R ⁶ represents an alkyl group having 1 to 20 carbon atoms or a derivative thereof, and n represents an integer of 1 to 20. .)
The main component is at least one monomer selected from the compounds represented by:

  Specific examples of the alkyl acrylate ester represented by the above formula (1) include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl. Examples include acrylate, dodecyl acrylate, cyanoethyl acrylate, and the like.

  Examples of the acrylic acid alkoxyalkyl ester represented by the above formula (2) include methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, and ethoxypropyl acrylate. One or more of these can be used as the main component of the acrylic rubber.

As such an acrylic rubber composition, an unsaturated monomer copolymerizable with at least one monomer selected from the compounds represented by the above formulas (1) to (3) is used as necessary. it can.
Examples of such unsaturated monomers include styrene, α-methyl styrene, acrylonitrile, halogenated styrene, methacrylonitrile, acrylamide, methacrylamide, vinyl naphthalene, N-methylol acrylamide, vinyl acetate, vinyl chloride, chloride. Examples include vinylidene, benzyl acrylate, methacrylic acid, itaconic acid, fumaric acid, maleic acid and the like.

  As a preferable composition of the acrylic rubber, 40.0 to 99.9% by weight of at least one monomer selected from the compounds represented by the above formulas (1) to (3), an unsaturated carboxylic acid glycidyl ester, and / or Or unsaturated glycidyl ether 0.1 to 30.0% by weight, unsaturated monomer copolymerizable with at least one monomer selected from the compounds represented by the above general formulas (1) to (3) 0.0-30.0 wt%. By setting the composition of the acrylic rubber in this way, the polyester resin layer tends to have good heat resistance, impact resistance, and moldability.

  As a method for producing the acrylic rubber, for example, a well-known production method as described in, for example, JP-A-59-111010, JP-A-62-64809, JP-A-3-160008, or WO95 / 04764. And can be produced by emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization in the presence of a radical initiator.

  Examples of the vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber include (i) a sequence mainly composed of vinyl aromatic hydrocarbon compounds and (ii) a sequence mainly composed of conjugated diene compounds. And a rubber obtained by epoxidizing a block copolymer comprising the above, a rubber obtained by epoxidizing a hydrogenated product of the block copolymer, and the like.

Examples of the vinyl aromatic hydrocarbon compound include styrene, vinyl toluene, divinyl benzene, α-methyl styrene, p-methyl styrene, vinyl naphthalene, and styrene is preferable.
Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 3-butyl-1,3-octadiene, and butadiene or isoprene is preferable.

  Such a vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer or a hydrogenated product thereof is obtained by a method described in, for example, Japanese Patent Publication No. 40-23798, Japanese Patent Application Laid-Open No. 59-133203, and the like. Can be manufactured.

  Furthermore, (meth) acrylic acid ester-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber is preferably used as the rubber used for the copolymer (B).

The rubber used for the copolymer (B) can be used as a vulcanized rubber after being vulcanized as necessary.
Vulcanization of the above (meth) acrylic acid ester-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber includes, for example, polyfunctional organic acid, polyfunctional amine compound, imidazole This is achieved by using a compound or the like.

  In addition, specific examples of the thermoplastic resin having a functional group having reactivity with the liquid crystal polyester, the thermoplastic resin having an epoxy group includes (I) an ethylene unit of 50 to 99% by weight, and (II) an unsaturated carboxylic acid. Epoxy group comprising 0.1 to 30% by weight, preferably 0.5 to 20% by weight of glycidyl ester unit and / or unsaturated glycidyl ether unit, and (III) 0 to 50% by weight of ethylenically unsaturated ester compound unit Examples thereof include an ethylene copolymer.

  Examples of the ethylenically unsaturated ester compound (III) include vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and other carboxylic acid vinyl esters, α , Β-unsaturated carboxylic acid alkyl ester and the like, and vinyl acetate, methyl acrylate, and ethyl acrylate are preferable.

  Specific examples of the epoxy group-containing ethylene copolymer include a copolymer comprising an ethylene unit and a glycidyl methacrylate unit, a copolymer comprising an ethylene unit, a glycidyl methacrylate unit and a methyl acrylate unit, an ethylene unit and a glycidyl methacrylate unit, and Examples include a copolymer composed of ethyl acrylate units, a copolymer composed of ethylene units, glycidyl methacrylate units, and vinyl acetate units.

  The epoxy group-containing ethylene copolymer is usually an unsaturated epoxy compound and ethylene in the presence of a radical generator at 500 to 4000 atm and 100 to 300 ° C. in the presence or absence of a suitable solvent or chain transfer agent. It can be produced by a high-pressure radical polymerization method for copolymerization. It can also be produced by a method in which an unsaturated epoxy compound and a radical generator are mixed with polyethylene and melt graft copolymerized in an extruder.

  The liquid crystal polyester resin layer in the present invention preferably contains (A) liquid crystal polyester as described above as a continuous phase. Moreover, it is preferable that the liquid crystalline polyester resin layer of this invention contains the copolymer which has the above (B) functional group which has reactivity with this liquid crystalline polyester as a dispersed phase. By setting the liquid crystal polyester resin layer to such a configuration, the gas barrier property and heat resistance of the liquid crystal polyester resin layer can be further improved.

As one embodiment of the composition of the liquid crystal polyester resin layer, (A) is 56.0 to 99.9% by weight, preferably 65.0 to 99.9% by weight, more preferably 70 to 98% by weight, And (B) 44.0 to 0.1% by weight, preferably 35.0 to 0.1% by weight, more preferably 30 to 2% by weight.
When (A) is less than 56.0% by weight, the water vapor barrier property and heat resistance of the obtained liquid crystal polyester resin layer may be lowered. On the other hand, if (A) exceeds 99.9% by weight, the molding processability of the liquid crystal polyester layer may be lowered, and the price becomes expensive.

  As a method for producing a liquid crystal polyester resin comprising (A) and (B) constituting such a liquid crystal polyester resin layer, for example, (A) and (B) are mixed in a solution state and the solvent is evaporated. And a method of precipitation in a solvent. From an industrial standpoint, a method of kneading the above (A) and (B) in a molten state is preferable. For this melt-kneading, a kneading apparatus such as a uniaxial or biaxial extruder or various uniaxial or biaxial kneaders can be used. Among these, a biaxial kneader is preferable. In the melt-kneading, the cylinder setting temperature of the kneading apparatus is preferably in the range of 200 to 360 ° C, more preferably 230 to 350 ° C.

  In kneading, (A) and (B) may be uniformly mixed in advance with an apparatus such as a tumbler or a Henschel mixer, or the mixing may be omitted and a fixed amount may be separately supplied to the kneading apparatus.

  If necessary, further organic fillers, antioxidants, heat stabilizers, light stabilizers, flame retardants, lubricants, antistatic agents, inorganic or organic colorants, rust preventives, crosslinking agents, foaming agents, fluorescent Various additives such as an agent, a surface smoothing agent, a surface gloss improving agent, and a mold release improving agent such as a fluororesin can be added during the manufacturing process of the resin (A) and (B) or in the subsequent processing process. .

  The liquid crystal polyester resin layer in the present invention is preferably formed by inflation molding capable of biaxial stretching at the same time. That is, the resin comprising (A) and (B) is supplied to a melt-kneading extruder equipped with a die having an annular slit, and melt-kneaded at a cylinder set temperature, preferably 200 to 360 ° C, more preferably 230 to 350 ° C. Next, the molten resin is extruded upward or downward from the annular slit of the extruder (this direction (longitudinal direction) is the MD direction, and the direction perpendicular to it in the film plane is the TD direction). The interval between the annular slits is usually 0.1 to 5 mm, preferably 0.5 to 2 mm, and the diameter of the annular slit is usually 20 to 1000 mm, preferably 50 to 300 mm.

In inflation molding, a preferable blow ratio is usually 1.5 to 10, and a preferable MD stretch ratio is 1.5 to 40.
If the setting conditions at the time of inflation molding are out of the above range, it may be difficult to obtain a high-strength liquid crystal polyester resin layer having a uniform thickness and no wrinkles.
The expanded liquid crystal polyester resin layer is air-cooled or water-cooled around the circumference, and then taken through a nip roll.

In the inflation molding, conditions can be selected such that the melt liquid crystalline polyester resin layer expands to a smooth surface with a uniform thickness according to the resin composition.
If the method is other than inflation molding, the liquid crystal polyester resin layer may not be biaxially stretched and the strength may not be sufficient. Further, biaxial stretching by a method other than inflation molding may cause a problem in terms of cost.

  The thickness of the liquid crystal polyester resin layer in the present invention is 3 μm or more and less than 500 μm, more preferably 5 μm or more and less than 300 μm, and still more preferably 8 μm or more and less than 200 μm in terms of gas barrier properties and flexibility. When the thickness is less than 3 μm or 500 μm or more, flexibility may be impaired.

  The display element substrate of the present invention is a display element substrate having two or more resin layers, wherein at least one of the two or more resin layers is the above-described liquid crystal polyester resin layer, and two or more layers. At least one of the resin layers is a resin layer other than the liquid crystal polyester resin layer. Here, the liquid crystal polyester resin layer is preferably a single layer in terms of production. Moreover, as resin used for resin layers other than this liquid crystal polyester resin layer, resin with high heat resistance is mentioned. The resin preferably has a glass transition temperature (Tg) of 150 ° C. or higher. Specific examples of resins having a glass transition temperature (Tg) of 150 ° C. or higher include ethylene-norbornene copolymers and ethylene-monone. Polyolefin resins such as copolymers; Polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; Nylon-6, nylon-6,6, metaxylenediamine-adipic acid condensation polymer; polymethylmethacrylamide, etc. Amide resins; acrylic resins such as polymethylmethacrylate; styrene-acrylonitrile resins such as polystyrene, styrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene copolymer, polyacrylonitrile; cellulose triacetate Hydrophobized cellulose resins such as cellulose diacetate; Halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polytetrafluoroethylene; Hydrogen such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, and cellulose derivatives Binding resin: polycarbonate resin, polysulfone resin, polyether sulfone resin, polyether ether ketone resin, polyphenylene oxide resin, polymethylene oxide resin, and among these resins, ethylene-norbornene copolymer, ethylene- One or more resins selected from the group consisting of a domon copolymer, polyethylene naphthalate, polycarbonate resin, polysulfone resin or polyethersulfone resin are more preferable. Further, it is more preferable to use a resin having a glass transition temperature (Tg) of 180 ° C. or higher, and it is particularly preferable to use a resin having a glass transition temperature of 190 ° C. or higher.

  The display element substrate of the present invention is a display element substrate having two or more resin layers, wherein at least one of the two or more resin layers comprises (A) liquid crystal polyester and (B) the A liquid crystal polyester resin layer substantially composed of a copolymer having a functional group reactive with liquid crystal polyester, and at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer And at least one layer of the liquid crystal polyester resin layer is in contact with at least one layer of the resin layer other than the liquid crystal polyester resin layer, and the surface average roughness (Ra) on the resin layer side other than the liquid crystal polyester resin layer is 5 nm or less. It is characterized by being. When the surface average roughness (Ra) exceeds 5 nm, it is not preferable from the viewpoints of adhesion to a conductive layer to be combined when the display element substrate is used for a display element, or gas barrier properties of the substrate. Moreover, since the said adhesiveness can be improved more, it is preferable that surface average roughness (Ra) is 3 nm or less. Here, the surface average roughness is a value corresponding to the arithmetic average roughness described in paragraph [4.2.1] of JIS B 0601 (revised on January 20, 2001) issued by the Japanese Standards Association, This is a value obtained from the average line of the cross-sectional curve on the surface of the resin layer, and specifically, a value that can be calculated using a device such as Nanopics manufactured by Seiko Instruments Inc.

  What is necessary is just to use said thing as this liquid crystal polyester resin layer. Moreover, what is necessary is just to use said thing as resin layers other than this liquid crystal polyester resin layer.

  In addition, when the liquid crystal polyester resin layer is in contact with a resin layer other than the liquid crystal polyester resin layer, the surface of the liquid crystal polyester resin layer can be subjected to surface treatment in advance for the purpose of improving adhesion. Examples of the surface treatment method include corona discharge treatment, plasma treatment, flame treatment, sputtering treatment, solvent treatment, ultraviolet treatment, polishing treatment, infrared treatment, and ozone treatment.

  The display element substrate of the present invention is a display element substrate having two or more resin layers, wherein one of the two or more resin layers is (A) liquid crystal polyester and (B) the liquid crystal. A liquid crystal polyester resin layer substantially comprising a copolymer having a functional group reactive with polyester, wherein at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer; Furthermore, it has a layer composed of an inorganic layered compound and a resin, and at least one layer of the liquid crystalline polyester resin layer is in contact with a layer composed of the inorganic layered compound and resin, and the layer composed of the inorganic layered compound and resin and the liquid crystalline polyester resin The surface average roughness (Ra) on the resin layer side other than the liquid crystal polyester resin layer is in contact with at least one layer other than the resin layer, and is 5 nm or less. When the surface average roughness (Ra) exceeds 5 nm, it is not preferable from the viewpoints of adhesion to a conductive layer to be combined when the display element substrate is used for a display element, or gas barrier properties of the substrate. Moreover, since the said adhesiveness can be improved more, it is preferable that surface average roughness (Ra) is 3 nm or less. The surface average roughness can be obtained by the same method as described above.

  What is necessary is just to use said thing as this liquid crystal polyester resin layer. Moreover, what is necessary is just to use said thing as resin layers other than this liquid crystal polyester resin layer.

Moreover, as an inorganic layered compound used for the layer which consists of an inorganic layered compound and resin, the aspect-ratio measured by the method mentioned later is 50 or more and 5000 or less, and an average particle diameter of 5 micrometers or less is preferable. If the aspect ratio is less than 50, the gas barrier property tends to decrease. On the other hand, an inorganic layered compound having an aspect ratio exceeding 5000 may not be easily manufactured. From the viewpoint of production, the aspect ratio is more preferably from 50 to 2,000, and even more preferably from 100 to 1,000. Here, the aspect ratio (Z) is calculated by the formula Z = L / a. L is an average particle diameter measured by a dynamic light scattering method in a solvent, and a is an average unit thickness of the inorganic layered compound. The unit thickness a is a value that can be calculated from the diffraction peak of the inorganic layered compound obtained by powder X-ray diffraction measurement.
Furthermore, the size of the inorganic layered compound, that is, the average particle diameter measured by the dynamic light scattering method in a solvent is 5 μm or less, more preferably in the range of 50 nm to 3 μm, and still more preferably in the range of 100 nm to 2 μm. It is. When the average particle size of the inorganic layered compound exceeds 5 μm, the dispersion of the inorganic layered compound in the resin may not be easy, and when the average particle size is less than 50 nm, the gas barrier property may be deteriorated.

  As the inorganic layered compound, a clay mineral can be preferably used. Specific examples of clay minerals include kaolinite, dickite, nacrite, halloysite, antigolite, chrysotile, pyrophyllite, montmorillonite, hectorite, tetrasilic mica, sodium teniolite, muscovite, margarite, talc, Examples include vermiculite, phlogopite, xanthophyllite, chlorite. In view of ease of handling, kaolinite, montmorillonite, hectorite, talc and the like are preferable.

  Moreover, as resin used for the layer which consists of an inorganic layered compound and resin, resin with high heat resistance is mentioned. Specifically, polyolefin resins such as ethylene-norbornene copolymer and ethylene-monone copolymer; polyester resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; nylon-6, nylon-6,6, Metaxylenediamine-adipic acid condensation polymer; Amide resin such as polymethylmethacrylamide; Acrylic resin such as polymethylmethacrylate; Polystyrene, Styrene-acrylonitrile copolymer, Styrene-acrylonitrile-butadiene copolymer, Polyacrylonitrile, etc. Styrene-acrylonitrile resins; Hydrophobized cellulose resins such as cellulose triacetate and cellulose diacetate; Polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polytetrafluoro Halogen-containing resins such as ethylene; hydrogen-bonding resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, cellulose derivatives; polycarbonate resins, polysulfone resins, polyether sulfone resins, polyether ether ketone resins, polyphenylene oxide resins, poly A methylene oxide resin is mentioned.

  Moreover, as resin used for the layer which consists of an inorganic layered compound and resin, the weight ratio of an inorganic layered compound and resin is the range whose weight ratio of an inorganic layered compound / resin is 5 / 95-90 / 10 normally. The weight ratio is preferably in the range of 5/95 to 50/50. When the weight ratio of the inorganic layered compound / resin is smaller than 5/95, the gas barrier property tends to decrease, and when it is larger than 90/10, the film forming property may not be good.

  Moreover, as resin used for the layer which consists of an inorganic layered compound and resin, 10 micrometers or less are preferable, More preferably, it is 2 micrometers or less. If it exceeds 10 μm, the flexibility of the display element substrate may be lowered.

  In addition, the display element substrate of the present invention further has a conductive layer, and a resin layer other than the liquid crystal polyester resin layer may be in contact with the conductive layer. This conductive layer may be an anode or a cathode of a display element described later, or may be patterned.

  As the conductive layer, a conductive metal oxide film, a metal thin film, or the like is used. Specific materials include indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide, gold, platinum, silver, copper, etc., vacuum deposition, sputtering, A conductive layer can be formed by ion plating or plating. Alternatively, an organic conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the conductive layer.

  From the viewpoint of gas barrier properties, the display element substrate of the present invention preferably further comprises an inorganic layer, and the resin layer other than the liquid crystal polyester resin layer is preferably in contact with the inorganic layer. The inorganic layer is preferably a layer made of one or more inorganic materials selected from the group consisting of metals, metal oxides, metal nitrides, metal carbides or metal oxynitrides. , Titania, indium oxide, tin oxide, titanium oxide, zinc oxide, aluminum nitride, silicon nitride, silicon carbide, silicon oxynitride, aluminum, copper, nickel and combinations thereof. More preferred are alumina, aluminum nitride, silicon nitride, silicon oxynitride, and still more preferred is silicon oxynitride.

  The thickness of the inorganic layer is preferably 1 nm or more and 1000 nm or less, more preferably 10 nm or more and 500 nm or less. If it is less than 1 nm, film formation is difficult, and if it is thicker than 1000 nm, cracks tend to occur. Moreover, the display element substrate in which the liquid crystal polyester resin layer and the inorganic layer are in contact is not preferable from the viewpoint of gas barrier properties.

  The display element substrate of the present invention may further have a conductive layer, and the inorganic layer and the conductive layer may be in contact with each other. This conductive layer may be an anode or a cathode of a display element described later, or may be patterned. Examples of the conductive layer include those described above.

  In addition, the display element substrate of the present invention can be used by laminating films such as an antireflection film and an abrasion-resistant film. Moreover, an ultraviolet absorber, a coloring agent, antioxidant, etc. may be contained in the range which does not impair the effect of this invention.

Next, the manufacturing method of the display element substrate of the present invention will be described.
Examples of the production method of the liquid crystal polyester resin layer include the production methods described above.
Examples of a method for contacting a liquid crystal polyester resin layer with a resin layer other than the liquid crystal polyester resin layer, or a method for contacting an inorganic layered compound and resin layer with a resin layer other than the liquid crystal polyester resin layer include, for example, a liquid crystal polyester resin layer Alternatively, a coating solution containing a resin other than the liquid crystalline polyester resin layer is applied to the surface of the layer composed of an inorganic layered compound and a resin, which will be described later, dried, and subjected to a heat treatment for coating, or other than the liquid crystalline polyester resin layer It can be formed by a method of laminating a layer made of this resin later. Specific methods include a direct gravure method; a reverse gravure method; a micro gravure method; a roll coating method such as a two-roll beat coat method or a bottom feed three-pin reverse coat method; a doctor knife method; a die coating method; a dip coating method; A bar coating method; and a combination thereof. When laminating, the surface to be contacted may be treated with a corona treatment or an anchor coating agent.

  In addition, as a method for contacting the layer composed of the inorganic layered compound and the resin, it can be formed by a method commonly used in industry, and a mixture of the inorganic layered compound, the resin and the solvent is applied to the surface of the liquid crystal polyester resin layer. Then, it can be formed by a method of coating by drying and heat treatment, or a method of laminating a layer composed of an inorganic layered compound and a resin. As a coating method, a direct gravure method; a reverse gravure method; a micro gravure method; a roll coating method such as a two-roll beat coat method or a bottom feed three-reverse coat method; a doctor knife method; a die coating method; a dip coating method; A coating method; and a combination thereof. When laminating, the surface to be contacted may be treated with a corona treatment or an anchor coating agent.

  Here, in the inorganic layered compound, many of the respective particles are aligned so that the maximum surface of the particles is substantially parallel to the surface of the display element substrate of the present invention (this is referred to as “orientation in the plane direction”). Preferably). When the inorganic layered compound is oriented, the gas barrier property of the display element substrate tends to be improved. Therefore, as a coating method, a roll coating method or a doctor knife method, which is a method of applying a force (shear) acting in a direction parallel to the substrate so as to orient the particles of the inorganic layered compound in the plane direction, is preferable.

  A mixture of an inorganic layered compound, a resin and a solvent is obtained by using the above-mentioned inorganic layered compound and resin, for example, a solution obtained by dissolving a resin in a solvent, and swelling and cleaving the inorganic layered compound with a solvent. A method of mixing the resulting dispersion with the resin, a method of adding the dispersion to the resin and mixing, a method of adding the inorganic layered compound to the solution and mixing while swelling and cleaving, and heating the resin and the inorganic layered compound The kneaded product obtained by kneading can be produced by a method of mixing a solvent, and the former three are preferred. As the solvent, those capable of swelling and cleaving the inorganic layered compound are preferable, and examples thereof include water, alcohols such as methanol, dimethylformamide, dimethyl sulfoxide, dichloromethane, chloroform, toluene, acetone, N-methylpyrrolidone and the like. Can be mentioned. Moreover, when manufacturing the said dispersion liquid, in order to improve the dispersibility of an inorganic layered compound, it is preferable to surface-treat an inorganic layered compound. As the surface treatment agent, a quaternary ammonium salt or the like is used.

  Examples of the method for contacting the inorganic layer include a vacuum deposition method, a CVD method, a sputtering method, a sol-gel method, and the like that are usually used industrially.

  Examples of a method for contacting the conductive layer include a vacuum deposition method, a CVD method, a sputtering method, a sol-gel method, and the like that are usually used industrially.

In addition, since the durability of the display element using the display element substrate of the present invention is improved, the gas barrier property of the display element substrate of the present invention is such that the water vapor permeability is 0.2 g / m ² / day or less and When the oxygen permeability is preferably 0.1 cc / m ² / day or less, when the water vapor permeability is 0.1 g / m ² / day or less and the oxygen permeability is 0.05 cc / m ² / day or less Is more preferable.

  Moreover, since the adhesiveness of the display element using the display element substrate of the present invention is improved, the display element substrate of the present invention has an average coefficient of thermal expansion in the temperature range of 20 ° C. to 150 ° C. of −10 ppm / ° C. The case of 25 ppm / ° C. or less is preferable, and the range of −5 ppm / ° C. to 20 ppm / ° C. is more preferable.

Next, a display element having the display element substrate of the present invention will be described.
Examples of the display element having the display element substrate of the present invention include those having the following (a) to (e).
(A) The display element substrate according to any one of <1> to <7>.
(B) A layer having conductivity.
(C) An organic layer that exhibits at least one function selected from light absorption, light scattering, optical rotation, and light emission by applying an electric field.
(D) A layer having transparent conductivity.
(E) Transparent encapsulant.

Examples of the display element using the display element substrate of the present invention include those obtained by a production method including the following steps (a ′) to (d ′).
(A ′) A step of forming a conductive layer on the surface on the resin layer side other than the liquid crystal polyester resin layer of the substrate for display elements of the present invention according to any one of <1> to <7>.
(B ′) A step of forming, on the surface of the conductive layer obtained in the step (a ′), an organic layer in which at least one function selected from light absorption, light scattering, optical rotation and light emission is manifested by applying an electric field. .
(C ′) A step of forming a layer having transparent conductivity on the surface of the organic layer obtained in step (b ′) to obtain a laminate.
(D ′) A step of obtaining a display element by sealing part or all of the surface of the laminate obtained in the step (c ′) with a transparent sealing material.

Examples of the conductive layer include those described above, and examples of the method for forming the conductive layer include the above-described methods. In addition, the conductive layer may be patterned. Examples of the patterning method include sputtering using a mask and a resist work method.
In the step (a ′), the surface on the resin layer side other than the liquid crystal polyester resin layer is not the surface of the liquid crystal polyester resin layer but the surface of the resin layer other than the liquid crystal polyester resin layer or the surface of the inorganic layer. is there. In addition, the conductive layer serves as a cathode or an anode described later in the display element.

  The layer having transparent conductivity is a layer having transparency and conductivity, and may be patterned. Examples of a method for forming a layer having transparent conductivity include a vacuum vapor deposition method, a CVD method, a sputtering method, a sol-gel method, and the like that are usually used industrially, and a mask is used as a patterning method. Examples of such methods include sputtering and resist work. In addition, the transparent conductive layer serves as a cathode or an anode described later in the display element. When the conductive layer serves as a cathode, the transparent conductive layer serves as an anode. When the conductive layer plays a role as an anode, the transparent conductive layer plays a role as a cathode.

  In the case where the layer having transparent conductivity becomes the anode, a conductive metal oxide film, a metal thin film, or the like is used as the layer having transparent conductivity. Specific materials include indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide, gold, platinum, silver, copper, etc., vacuum deposition, sputtering, A layer having transparent conductivity can be formed by an ion plating method or a plating method. Alternatively, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the layer having transparent conductivity.

  When the transparent conductive layer is a cathode, specific materials include, for example, lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, and zinc. , Yttrium, indium, cerium, samarium, europium, terbium, ytterbium, an alloy selected from two or more of these metals, or one or more of these metals, and gold, silver, platinum, An alloy with one or more selected from copper, manganese, titanium, cobalt, nickel, tungsten, tin, graphite or a graphite intercalation compound is used, and transparent conductivity is obtained by vacuum deposition, sputtering, or lamination by thermocompression bonding. The It is possible to form a layer. In addition, when these materials are opaque, in order to make these materials transparent, the layer thickness may be thinned, or in order to reduce the resistance value, the above-mentioned materials for the anode are laminated. May be.

The organic layer that exhibits at least one function selected from light absorption, light scattering, optical rotation, and light emission by applying an electric field is between the conductive layer and the transparent conductive layer, that is, the above-described layer. It is formed between electrodes consisting of a cathode and an anode.
In the step (b ′), the surface on the conductive layer side is the surface of the conductive layer in the step (a ′), or when the conductive layer is patterned, a display element This means that the organic layer is formed on the surface of the substrate (for example, the surface of the resin layer other than the liquid crystal polyester resin layer or the surface of the inorganic layer).

Examples of the organic compound used for the organic layer that exhibits a light absorption function when an electric field is applied include a liquid crystal composition containing a dichroic dye.
Examples of the organic compound used in the organic layer that exhibits a light scattering function when an electric field is applied include polymer-dispersed liquid crystals.
Examples of the organic compound used in the organic layer that exhibits the function of optical rotation when an electric field is applied include a cholesteric liquid crystal composition.

In addition, the organic layer that exhibits the function of light emission when an electric field is applied is an organic layer that essentially includes a light-emitting layer and may further include an electron transport layer and / or a hole transport layer.
Examples of the structure of the anode, the cathode, and the organic layer exhibiting the function of light emission include a structure in which an electron transport layer is provided between the cathode and the light emitting layer (anode / light emitting layer / electron transport layer / cathode) (here, “/” Indicates that each layer is laminated adjacently.), A structure in which a hole transport layer is provided between the anode and the light emitting layer (anode / hole transport layer / light emitting layer / cathode), cathode And a structure in which an electron transport layer is provided between the light emitting layer and a hole transport layer between the anode and the light emitting layer (anode / hole transport layer / light emitting layer / electron transport layer / cathode). It is done.

As the organic compound used in the light emitting layer, a low molecular compound or a high molecular compound can be used, and a high molecular compound is preferably used from the viewpoint of easy coating. Examples of the low molecular weight compounds include, for example, naphthalene derivatives, anthracene or derivatives thereof, perylene or derivatives thereof, polymethine series, xanthene series, as described in JP-A-57-51781 and 59-194393. , Pigments such as coumarins and cyanines, metal complexes of 8-hydroxyquinoline or derivatives thereof, aromatic amines, tetraphenylcyclopentadiene or derivatives thereof, or tetraphenylbutadiene or derivatives thereof are used.
Examples of the polymer compound include poly (p-phenylene vinylene) and polyfluorene (Japanese Journal of Applied Physics, Volume 30, L1941 (1991)), Polyparaphenylene derivatives (Advanced Materials (Adv. Mater.) Vol. 4, page 36 (1992)), etc. are used.
The light-emitting layer can be formed by a vacuum deposition method from a powder of these organic compounds, a method of forming a solution of an organic compound and drying, an inkjet method, a spin coating method, or the like.

  Examples of the organic compound used for the hole transport layer include polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a derivative thereof, polythiophene or a derivative thereof, poly (P-phenylene vinylene) or a derivative thereof, or poly (2,5-thienylene vinylene) or a derivative thereof is used, and the hole transport layer is a mixture of an organic compound used for the hole transport layer and a polymer binder. The solution is applied and dried to form.

  Organic compounds used for the electron transport layer include oxadiazole derivatives, anthraquinodimethane or its derivatives, benzoquinone or its derivatives, naphthoquinone or its derivatives, anthraquinone or its derivatives, tetracyanoanthraquinodimethane or its derivatives, fluorenone derivatives , Diphenyldicyanoethylene or a derivative thereof, a diphenoquinone derivative, or a metal complex of 8-hydroxyquinoline or a derivative thereof, polyquinoline or a derivative thereof, polyquinoxaline or a derivative thereof, polyfluorene or a derivative thereof, It is formed by applying a vacuum deposition method from an organic compound powder used for the layer, or applying a solution of the organic compound used for the electron transport layer and drying.

  Moreover, the transparent sealing material plays the role which seals a part or all of the laminated body obtained at process (a '), (b'), and (c '). Moreover, the laminated body before sealing may further have a protective layer for the purpose of protecting a layer having transparent conductivity.

  The transparent encapsulant is a translucent encapsulant as long as the object of the present invention is not impaired, and is a material that does not reduce the flexibility of the display element obtained. Specifically, what consists of resin etc. are mentioned. Specific examples of the resin include polyethylene (low density, high density), ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, ethylene-norbornene copolymer. Polymers, ethylene-domon copolymers, polypropylene, ethylene-vinyl acetate copolymers, ethylene-methyl methacrylate copolymers, polyolefin resins such as ionomer resins; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate Resin; Nylon-6, Nylon-6,6, Metaxylenediamine-Adipic acid condensation polymer; Amide resin such as polymethylmethacrylamide; Acrylic resin such as polymethylmethacrylate; Polystyrene, Styrene-acrylonite Copolymers, styrene-acrylonitrile-butadiene copolymers, styrene-acrylonitrile resins such as polyacrylonitrile; hydrophobic cellulose resins such as cellulose triacetate and cellulose diacetate; polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride Halogen-containing resins such as polytetrafluoroethylene; hydrogen-bonding resins such as polyvinyl alcohol, ethylene-vinyl alcohol copolymers and cellulose derivatives; polycarbonate resins, polysulfone resins, polyethersulfone resins, polyetheretherketone resins, polyphenylene Examples thereof include engineering plastic resins such as oxide resins and polymethylene oxide resins.

  The transparent sealing material is a film having a thickness in the range of 20 μm to 1000 μm (1 mm), and the thickness is more preferably in the range of 20 μm to 500 μm, and further in the range of 20 μm to 300 μm. preferable.

  As a method of providing a transparent sealing material, a method of applying a coating liquid containing the above resin to a laminate, drying, performing a heat treatment, and a method of laminating a layer made of the resin later Can be formed. As a coating method, a direct gravure method; a reverse gravure method; a micro gravure method; a roll coating method such as a two-roll beat coat method or a bottom feed three-reverse coat method; a doctor knife method; a die coating method; a dip coating method; A coating method; and a combination thereof. When laminating, the surfaces to be joined may be subjected to treatment such as corona treatment or anchor coating agent.

  The display element having the display element substrate of the present invention can be used as a display such as a flexible display by emitting light in various patterns depending on the arrangement of the anode and the cathode. In order to obtain planar light emission, the planar anode and cathode may be arranged so as to overlap each other. Further, in order to obtain a specific pattern of light emission, a method in which a mask having a specific pattern window is provided on the surface of the planar display element, either the anode or the cathode, or both electrodes There is a method of forming a specific pattern. A segment type display element capable of displaying numbers, letters, simple symbols, etc. can be obtained by forming a pattern by any of these methods and arranging several electrodes so that they can be turned ON / OFF independently. Further, in order to obtain a dot matrix element, both the anode and the cathode may be formed in stripes and arranged so as to be orthogonal to each other. Partial color display and multi-color display can be achieved by using a method in which a plurality of light-emitting layers having different emission colors are separately applied, or by using a color filter or a fluorescence conversion filter. The dot matrix element may be passively driven or may be actively driven in combination with a TFT or the like.

  A display such as a flexible display using the display element having the display element substrate of the present invention can be used as a display for a computer, a television, a mobile terminal, a mobile phone, a car navigation, a video camera viewfinder, and the like. Furthermore, it is self-luminous and can be made thin, and can be suitably used as a planar light source for backlight of a liquid crystal display device or a planar illumination light source. The display element substrate of the present invention can also be used for curved light sources and display devices.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

またＡ−１は偏光顕微鏡で観察した際、加圧下で２８０℃以上の温度で光学異方性を示した。 Comparative Example 1
(1) Production of liquid crystalline polyester (A) 16.6 kg (12.1 mol) of p-hydroxybenzoic acid, 8.4 kg (4.5 mol) of 6-hydroxy-2-naphthoic acid and 18.6 kg of acetic anhydride (18 .2 mol) was charged into a polymerization tank equipped with a comb-shaped stirring blade, heated while stirring in a nitrogen gas atmosphere, and polymerized at 320 ° C. for 1 hour and further under a reduced pressure of 2.0 torr at 320 ° C. for 1 hour. . During this time, acetic acid produced as a by-product continued to be distilled out of the system. Then, it cooled gradually and took out at 180 degreeC and obtained the polymer.
The obtained polymer was pulverized with a hammer mill manufactured by Hosokawa Micron Co., Ltd. to obtain particles of 2.5 mm or less. This was further treated in a rotary kiln under a nitrogen gas atmosphere at 240 ° C. for 5 hours to obtain a liquid crystal polyester having the following repeating units and ratios. Hereinafter, the liquid crystal polyester is abbreviated as A-1. A-1 had a flow start temperature of 270 ° C. and was in the form of particles.

A-1 showed optical anisotropy at a temperature of 280 ° C. or higher under pressure when observed with a polarizing microscope.

(2) Copolymer (B)
According to the method described in Example 5 of JP-A-61-127709, a rubber of methyl acrylate / ethylene / glycidyl methacrylate = 59.0 / 38.7 / 2.3 (weight ratio) was obtained. Hereinafter, this rubber is abbreviated as B-1.

(3) Manufacture of liquid crystal polyester resin layer A-1 (95 wt%) and B-1 (5 wt%) are melt-kneaded using a TEX-30 type twin screw extruder manufactured by Nippon Steel Co., Ltd. The composition was obtained at a cylinder set average temperature of 300 ° C. and a screw rotation speed of 250 rpm. This composition exhibited optical anisotropy at 265 ° C. or higher under pressure. The composition was melt extruded using a single screw extruder of 60 mmφ equipped with a cylindrical die at a cylinder setting temperature of 290 ° C. and a screw rotation speed of 60 rpm, a diameter of 50 mm, a lip interval (annular slit interval) of 1.0 mm, a die A cylindrical molten resin was extruded from above a cylindrical die having a set temperature of 305 ° C. Dry air was pressed into the hollow portion of the tubular molten resin, expanded, then cooled, and then passed through a nip roll to obtain a film AB-1. The blow ratio was 2.5, the drawdown ratio (MD draw ratio) was 10, and the measured average thickness of the film AB-1 was 40 μm.
The surface average roughness (Ra) of the film AB-1 was 8.6 nm (10 μm □). Moreover, it was 0.29 g / m < ² > / day when the water-vapor permeability of film AB-1 was measured at 40 degreeC. The oxygen permeability at 23 ° C. was 0.84 cc / m ² / day or less.

Example 1
A polyethersulfone (hereinafter referred to as “PES”) (manufactured by Sumitomo Chemical Co., Ltd., PES5200p (trade name), Tg was 230 ° C.) 15 g and N-methylpyrrolidone (hereinafter referred to as “NMP”) 45 g were added and stirred at 80 ° C. for 3 hours to prepare a solution C which is a 25 wt% NMP solution of PES.
A PES layer (resin layer) having a thickness of 15 μm was applied to the surface of the film AB-1 obtained in Comparative Example 1 using a bar coater (manufactured by Tester Sangyo Co., Ltd., SA-203 type) to produce a substrate 1. . The surface average roughness (Ra) on the PES layer side of the obtained substrate 1 was 0.2 nm (10 μm □). The average linear expansion coefficient in the temperature range of 20 ° C. to 150 ° C. of the substrate 1 was −1.8 ppm / ° C.

Example 2
On the surface of the substrate 1 obtained in Example 1 on the PES layer side, Al ₂ O ₃ was formed to a thickness of 150 nm under the condition of 120 ° C. by sputtering to produce the substrate 2. It was 0.12 g / m < ² > / day when the water-vapor permeability of the board | substrate 2 was measured at 40 degreeC. The oxygen permeability at 23 ° C. was 0.01 cc / m ² / day or less.

Example 3
Formation of Layer Consisting of Inorganic Layered Compound and Resin 100 g of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA117H (trade name)) is added to 3000 g of ion-exchanged water, and 95 under low-speed stirring conditions (1500 rpm, peripheral speed about 4 m / sec). The solution was obtained by heating to 0 ° C. and stirring for 1 hour to dissolve. Subsequently, the temperature of the solution D was lowered to 65 ° C. with stirring, and then an aqueous alcohol solution obtained by previously mixing 1600 g of ion-exchanged water and 376 g of 1-butanol was dropped into the solution D. After completion of dropping, 50 g of high purity natural montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia G (trade name), aspect ratio is 200 to 1000 nm) as powder is added as an inorganic layered compound in powder form, and stirring conditions are set. The mixture E was obtained by switching to high-speed stirring conditions (3000 rpm, peripheral speed of about 8 m / sec) and stirring and dispersing for 90 minutes. Next, the liquid mixture E is passed through an ultrahigh pressure homogenizer (manufactured by Microfluidics Corporation, M110-E / H type) and treated once at 1.750 kgf / cm ² to obtain a coating liquid F in which the inorganic layered compound is dispersed. It was. A layer made of an inorganic layered compound and a resin having a thickness of 1.4 μm was formed on the surface of the film AB-1 using a bar coater (manufactured by Tester Sangyo, SA-203 type) to obtain a substrate 3. Further, a PES layer (resin layer) having a thickness of 15 μm was formed on the substrate 3 in the same manner as in Example 1 by using the solution C obtained in Example 1 using a bar coater (SA-203 type, manufactured by Tester Sangyo). As a result, a substrate 4 was obtained. The surface average roughness (Ra) on the PES layer side of the substrate 4 was 1.7 nm (10 μm □). The average linear expansion coefficient of the substrate 4 in the temperature range of 20 ° C. to 150 ° C. was −1.1 ppm / ° C.

Example 4
On the surface of the substrate 4 obtained in Example 3 on the side of the PES layer, Al ₂ O ₃ was formed to a thickness of 150 nm under the conditions of 120 ° C. by sputtering to produce the substrate 5. It was 0.16 g / m < ² > / day when the water-vapor permeability of the board | substrate 5 was measured at 40 degreeC. The oxygen permeability at 23 ° C. was 0.01 cc / m ² / day or less.

Comparative Example 2
A 200 μm PES film was prepared, a 150 nm inorganic layer made of silicon oxynitride was formed on the surface by sputtering, and the water vapor transmission rate was measured at 40 ° C., which was 0.6 g / m ² / day. The oxygen permeability at 23 ° C. was 2.9 cc / m ² / day.

Example 5
A 150 nm inorganic layer made of silicon oxynitride was formed by sputtering on the surface of the substrate 1 obtained in Example 1 on the PES layer side, and a substrate 5 was produced. It was 0.22 g / m < ² > / day when the water-vapor permeability of the board | substrate 5 was measured at 40 degreeC. The oxygen permeability at 23 ° C. was 0.01 cc / m ² / day or less.

Claims (14)

  A display element substrate having two or more resin layers, wherein at least one of the two or more resin layers has (A) a liquid crystal polyester and (B) a functional group reactive with the liquid crystal polyester. A liquid crystal polyester resin layer substantially composed of a copolymer, wherein at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer, and at least one of the liquid crystal polyester resin layers; A display element substrate, wherein at least one resin layer other than the liquid crystal polyester resin layer is in contact with each other, and the surface average roughness (Ra) on the resin layer side other than the liquid crystal polyester resin layer is 5 nm or less.   A display element substrate having two or more resin layers, wherein at least one of the two or more resin layers has (A) a liquid crystal polyester and (B) a functional group reactive with the liquid crystal polyester. A liquid crystal polyester resin layer substantially comprising a copolymer, wherein at least one of the two or more resin layers is a resin layer other than the liquid crystal polyester resin layer, and further comprises a layer comprising an inorganic layered compound and a resin. And at least one layer of the liquid crystalline polyester resin layer and the layer composed of the inorganic layered compound and the resin are in contact with each other, and the layer composed of the inorganic layered compound and the resin and at least one layer of the resin layer other than the liquid crystalline polyester resin layer; And a surface average roughness (Ra) on the resin layer side other than the liquid crystal polyester resin layer is 5 nm or less. The display element substrate according to claim 2 , wherein the inorganic layered compound is an inorganic layered compound having a particle size of 5 μm or less and an aspect ratio of 50 or more and 5000 or less.   The display element substrate according to claim 1, wherein the resin used for the resin layer other than the liquid crystal polyester resin layer is a resin having a glass transition temperature (Tg) of 150 ° C. or higher.   The display element substrate according to claim 1, further comprising an inorganic layer, wherein the resin layer other than the liquid crystal polyester resin layer is in contact with the inorganic layer.   The display element substrate according to claim 5, wherein the inorganic layer is made of at least one inorganic material selected from the group consisting of metals, metal oxides, metal nitrides, metal carbides, and metal oxynitrides.   Furthermore, it has a layer which has electroconductivity, The resin layer other than liquid crystal polyester resin layer and the layer which has electroconductivity contact | connect the display element substrate in any one of Claims 1-4. Further comprising a layer having conductivity, a display device substrate according to claim 5 or 6 and a layer having an inorganic layer and the electrically conductive contacts. Display element substrate according to any one of claims 1-8 water vapor permeability and oxygen permeability than 0.2g / m2 / day is not more than 0.1cc / m2 / day. The average linear expansion coefficient in the temperature range of 20 ° C. to 150 DEG ° C. is, display element substrate according to any one of claims 1 to 9, characterized in that not more than -10 ppm / ° C. or higher 25 ppm / ° C.. Substrate for a flexible display, characterized by comprising using the substrate for a display device according to any one of claims 1 to 1 0. A display element having the following (a) to (e):
(A) The substrate according to any one of claims 1 to 6 .
(B) A layer having conductivity.
(C) An organic layer that exhibits at least one function selected from light absorption, light scattering, optical rotation, and light emission by applying an electric field.
(D) A layer having transparent conductivity.
(E) Transparent encapsulant. A display element obtained by a manufacturing method including the following steps (a ′) to (d ′):
(A ') The process of forming the layer which has electroconductivity in the surface by the side of resin layers other than the liquid crystalline polyester resin layer of the board | substrate in any one of Claims 1-6 .
(B ′) A step of forming, on the surface of the conductive layer obtained in the step (a ′), an organic layer in which at least one function selected from light absorption, light scattering, optical rotation and light emission is manifested by applying an electric field. .
(C ′) A step of obtaining a laminate by forming a layer having transparent conductivity on the surface of the organic layer side in the step (b ′).
(D ′) A step of obtaining a display element by sealing part or all of the surface of the laminate obtained in the step (c ′) with a transparent sealing material. Flexible display characterized by comprising using the display device according to claim 1 2 or 1 3, wherein.