JP2007237466A - Resin sheet and electroluminescence display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sheet obtained by laminating an inorganic protective film on an epoxy resin base material and excellent in the adhesion of the inorganic protective film even under a severe environment of an in-vehicle use or the like. <P>SOLUTION: In the resin sheet constituted by laminating the inorganic protective film on an epoxy resin base material, a plasma polymerization film, which is obtained by the plasma polymerization of an epoxy group-containing material, is provided between the epoxy resin base material and the inorganic protective film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin sheet in which an inorganic protective film for improving gas barrier properties is laminated on an epoxy resin base material, and an electroluminescence display device using the resin sheet as a substrate.

  In recent years, in the field of electronic devices such as liquid crystal display devices and electroluminescent elements, plastic substrates are being used instead of glass substrates as substrates on which electronic devices are formed in order to reduce weight and thickness.

  As a substrate for this type of electronic device, heat resistance, chemical resistance, surface hardness, optical isotropy, low water absorption, and the like are required. Epoxy resins are preferable for such necessary characteristics. Therefore, various epoxy resin substrates have been proposed as the substrate (see, for example, Patent Documents 1 to 6).

  However, since electronic devices dislike foreign impurities (for example, water, oxygen, etc.), plastics have low shielding properties (gas barrier properties), and epoxy resins are no exception, so electronic devices are formed. When an epoxy resin is used as the substrate, it is necessary to laminate a protective film that improves gas barrier properties on the epoxy resin base material.

  By the way, as a protective film for improving the gas barrier property of the substrate, an inorganic protective film is excellent, and conventionally, various inorganic protective films used for glass substrates have been proposed (Patent Documents 7 to 12 below).

  However, the inorganic protective film described in Patent Documents 1 to 12 has low adhesion to the epoxy resin. For example, in a state where thermal stress is applied under high temperature and high humidity conditions, the inorganic protective film is protected from the epoxy resin substrate. There may be a problem that the film peels easily.

  As a technique for solving this problem, Patent Document 13 discloses a method of inserting a carbon nitride plasma polymerized film between an epoxy resin substrate and an inorganic protective film, and UV ozone treatment on the surface of the epoxy resin substrate. The method to perform and the combination thereof are described, and it is shown that a resin sheet can be obtained which does not cause any abnormality even if it is allowed to stand at 65 ° C. and a humidity of 95% RH for 1000 hours.

JP 63-144041 A JP-A-2-169620 Japanese Patent Laid-Open No. 3-16171 JP-A-6-337408 JP 7-28043 A Japanese Patent Laid-Open No. 13-59015 JP 63-259994 A JP 7-161474 A JP-A-4-73886 Japanese Patent Laid-Open No. 5-101885 JP-A-5-335080 Japanese Patent Application Laid-Open No. 8-96955 JP 2005-14599 A

  However, even in the method described in Patent Document 13, an epoxy resin is used under conditions required for automobile use, for example, more severe environmental conditions such as a pressure cooker test in an environment of 120 ° C., humidity 100% RH, and 0.2 MPa. There may be a problem that the carbon nitride plasma polymerized film or the inorganic protective film easily peels from the substrate.

  The present invention relates to a resin sheet in which an inorganic protective film is laminated on an epoxy resin base material, a resin sheet having excellent adhesion of the inorganic protective film even under severe environments such as in-vehicle use, and the resin sheet as a substrate for an electroluminescence element The electroluminescence display device used.

  The present invention relates to an epoxy resin base material, a plasma polymerized film obtained by plasma polymerizing an epoxy group-containing material laminated on the epoxy resin base material, and an inorganic protection laminated on the plasma polymerized film. A resin sheet having a film.

（前記式（１）中、Ｒ_１〜Ｒ_４はそれぞれ独立して水素原子または置換基を表す。） Moreover, in the resin sheet, the material containing the epoxy group is preferably a compound represented by the following formula (1).

(In the formula (1), R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent.)

  In the resin sheet, the material containing the epoxy group may be 1,2-epoxybutane, 2,3-epoxybutane, 1,2,3,4-diepoxybutane, 1,2-epoxyhexane, 1, 2,5,6-diepoxyhexane, 1,2,7,8-diepoxyoctane, 1,2-epoxydecane, 1,2-epoxy-3-butene, 1,2-epoxy-5-hexene, , 2-epoxy-7-octene, 1,2-epoxy-9-decene, 1,2-epoxy-2-methylpropane, 1,2-epoxy-3-methylbutane, 3,3-dimethyl-1,2- Epoxybutane, 2,3-epoxy-1-propanol, 2,3-epoxypropyl methyl ether, ethyl 2,3-epoxy-3-phenylbutyrate, 1,2-epoxy-3,3,3-trifluoropro 1,1,1-trifluoro-3,4-epoxybutane, 3- (2-biphenylyloxy) -1,2-epoxypropane, 1,2-epoxy-4-vinylcyclohexane One is preferred.

  Moreover, in the resin sheet, it is preferable that the layered surface of the epoxy resin substrate is subjected to UV ozone treatment.

  In the resin sheet, the inorganic protective film preferably includes at least one of an inorganic oxide and an inorganic nitride.

  In the resin sheet, it is preferable that the laminated surface of the epoxy resin substrate is washed with an organic solvent containing at least one of a cyclic ether organic solvent and a chlorine organic solvent.

  Furthermore, the present invention is an electroluminescence display device in which the resin sheet is used as a substrate of an electroluminescence element.

  In the present invention, in a resin sheet in which an inorganic protective film is laminated on an epoxy resin base material, a plasma polymerization film obtained by plasma polymerizing a material containing an epoxy group between the epoxy resin base material and the inorganic protective film is provided. By providing, the resin sheet which is excellent in the adhesiveness of an inorganic protective film can be provided even in severe environments, such as a vehicle-mounted use.

  In addition, by using the resin sheet as a substrate of an electroluminescence element, an electroluminescence display device that can be used even under severe environments such as in-vehicle applications can be provided.

  Embodiments of the present invention will be described below.

<Resin sheet>
In the resin sheet in which an inorganic protective film is laminated on an epoxy resin base material, the present inventors have provided a predetermined film between the epoxy resin base material and the inorganic protective film, so that the environment under on-vehicle conditions is reduced. The present inventors have found that the adhesion of the inorganic protective film below is improved and have completed the present invention.

  In FIG. 1, an example of schematic sectional structure of the resin sheet which concerns on embodiment of this invention is shown. The resin sheet 1 according to the present embodiment is laminated in a state of being in close contact with the epoxy resin base material 10 and the upper surface of the epoxy resin base material 10 as a layered surface (a state in which the resin sheet 1 is directly adhered without using other materials). The plasma polymerized film 12 obtained by plasma polymerizing the material containing the epoxy group and the inorganic protective film 14 laminated in close contact with the upper surface of the plasma polymerized film 12 are provided. In the resin sheet 1 having such a configuration, the plasma polymerized film 12 exhibits good adhesion to the epoxy resin substrate 10 and the inorganic protective film 14, and thus the inorganic protective film 14 is difficult to peel off.

  In the present embodiment, the action is considered as follows. In general, the low adhesion between the organic material, which is an epoxy resin, and the inorganic material of the protective film is due to the weak chemical bond strength between the two materials, so the bond strength at the interface depends on the van der Waals force and This is because the van der Waals force acting on the interface itself is not so large because the density of the resin is relatively low. In addition, poor wettability between organic and inorganic substances is also a cause of low adhesion. Furthermore, in addition to the internal stress contained in the formed protective film, stress generated by the difference in expansion coefficient from the epoxy resin base material is applied under severe environments such as high temperature and high humidity conditions, It becomes easier to peel off.

  On the other hand, the plasma polymerized film 12 formed by plasma polymerizing a material containing an epoxy group has good wettability with an organic substance and improves adhesion. Further, the radicals and ions generated during the plasma polymerization cause a polymerization reaction between the epoxy group present on the surface of the epoxy resin substrate 10 and the epoxy group present in the plasma polymerized material, and the chemistry between the two. The bond becomes stronger and the adhesion is improved. In addition, since the plasma polymerized film 12 has a relatively high density, a large van der Waals force works between the plasma polymerized film 12 and the surface of the plasma polymerized film 12 because many dangling bonds are included. The chemical bond with the inorganic protective film 14 becomes strong, and the adhesion can be improved. Therefore, as described above, the inorganic protective film 14 is difficult to peel off.

  Further, in the above configuration, since the plasma polymerization is performed by the vapor phase growth method, it becomes easy to form a film on a substrate having various shapes.

  Further, in the above configuration, the plasma polymerized film 12 obtained by plasma polymerizing a material containing an epoxy group is often higher in stress relaxation than the inorganic protective film 14, and the thermal stress of the inorganic protective film 14, When an element is formed on the inorganic protective film 14, the thermal stress of the element can be reduced, and the gas barrier property and the element characteristic can be reduced less.

  Further, in the above configuration, the thickness of the inorganic protective film 14 having high gas barrier properties but low bending stress resistance is reduced to increase the bending stress resistance, and the gas barrier properties that are reduced accordingly are excellent in stress relaxation and bending stress. The plasma polymerized film 12 having high resistance can be supplemented by the lamination (particularly, multilayer lamination). For this reason, the resin sheet 1 of this embodiment can also have a high bending stress tolerance and a high gas barrier property.

  In this embodiment, the epoxy resin substrate 10 is a single-layer or multi-layer sheet-like body containing an epoxy resin, and the epoxy resin substrate 10 usually has an average thickness of 100 to 800 μm. The range is preferably set in the range of 150 to 700 μm.

  Examples of the epoxy resin constituting the epoxy resin base material 10 include bisphenol A type, bisphenol F type, bisphenol S type and bisphenol types such as water addition thereof, novolak types such as phenol novolac type and cresol novolac type, Nitrogen-containing ring type such as triglycidyl isocyanurate type and hydantoin type, alicyclic type and aliphatic type, aromatic type such as naphthalene type, glycidyl ether type, low water absorption type such as biphenyl type, dicyclo type and ester type And ether ester types, and modified types thereof. These may be used alone or in combination. Among the various epoxy resins, it is preferable to use a bisphenol A type epoxy resin, an alicyclic epoxy resin, or a triglycidyl isocyanurate type from the viewpoint of discoloration prevention.

  As such an epoxy resin, generally, an epoxy equivalent having an epoxy equivalent of 100 to 1000 and a softening point of 120 ° C. or less is preferably used in view of physical properties such as flexibility and strength of the obtained resin sheet. Furthermore, from the point of obtaining an epoxy resin-containing liquid that is excellent in coating property, developability to a sheet shape, etc., a two-component mixed type that exhibits a liquid state at a temperature equal to or lower than the coating temperature, particularly at room temperature, can be preferably used.

  In addition, epoxy resins are conventionally known as curing agents, curing accelerators, and anti-aging agents, modifiers, surfactants, dyes, pigments, anti-discoloring agents, ultraviolet absorbers and the like that have been conventionally used as necessary. These various additives can be appropriately blended.

  There is no limitation in particular also about the said hardening | curing agent, The 1 type (s) or 2 or more types of suitable hardening | curing agents according to an epoxy resin can be used. Examples include tetrahydrophthalic acid and methyltetrahydrophthalic acid, organic acid compounds such as hexahydrophthalic acid and methylhexahydrophthalic acid, ethylenediamine and propylenediamine, diethylenetriamine and triethylenetetramine, their amine adducts and Examples include amine compounds such as phenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone.

  In addition, amide compounds such as dicyandiamide and polyamide, hydrazide compounds such as dihydragit, methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, 2,4-dimethylimidazole, phenylimidazole, undecyl Examples of the curing agent include imidazole compounds such as imidazole, heptadecylimidazole, and 2-phenyl-4-methylimidazole.

  Furthermore, imidazolines such as methyl imidazoline, 2-ethyl-4-methyl imidazoline, ethyl imidazoline, isopropyl imidazoline, 2,4-dimethyl imidazoline, phenyl imidazoline, undecyl imidazoline, heptadecyl imidazoline, 2-phenyl-4-methyl imidazoline. Examples of the curing agent include compounds, other phenolic compounds, urea compounds, and polysulfide compounds.

  In addition, acid anhydride compounds and the like are also mentioned as examples of the curing agent, and such an acid anhydride curing agent can be preferably used from the viewpoint of discoloration prevention. Examples include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, nadic anhydride, glutaric anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, Examples include methylhexahydrophthalic acid anhydride, methylnadic acid anhydride, dodecenyl succinic acid anhydride, dichlorosuccinic acid anhydride, benzophenone tetracarboxylic acid anhydride, and chlorendic acid anhydride.

  Particularly, an acid anhydride curing agent having a molecular weight of about 140 to about 200 and having a colorless or light yellow color, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Can be preferably used.

  The mixing ratio of the epoxy resin and the curing agent is such that when an acid anhydride curing agent is used as the curing agent, the acid anhydride equivalent is 0.5 to 1.5 equivalents per 1 equivalent of the epoxy group of the epoxy resin. It is preferable to mix | blend so that it may become, More preferably, 0.7-1.2 equivalent is good. When the acid anhydride is less than 0.5 equivalent, the hue after curing is poor, and when it exceeds 1.5 equivalent, the moisture resistance tends to decrease. In addition, also when using another hardening | curing agent individually or in combination of 2 or more types, the usage-amount can be based on said equivalent ratio.

  Examples of the curing accelerator include tertiary amines, imidazoles, quaternary ammonium salts, organometallic salts, phosphorus compounds, urea compounds, etc., particularly tertiary amines and imidazoles. It is preferable to use it. These can be used alone or in combination.

  It is preferable that the compounding quantity of the said hardening accelerator is 0.05-7.0 weight part with respect to 100 weight part of epoxy resins, More preferably, 0.2-3.0 weight part is good. When the blending amount of the curing accelerator is less than 0.05 parts by weight, a sufficient curing accelerating effect cannot be obtained, and when it exceeds 7.0 parts by weight, the cured body may be discolored.

  Examples of the anti-aging agent include conventionally known compounds such as phenol compounds, amine compounds, organic sulfur compounds, and phosphine compounds.

  Examples of the modifier include conventionally known ones such as glycols, silicones and alcohols.

  The surfactant is added to smooth the surface of the base material when the epoxy resin base material 10 is molded by touching the epoxy resin with air by a casting method or the like. Examples of the surfactant include silicones, acrylics, and fluorines, and silicones are particularly preferable.

  In the present embodiment, when the epoxy resin base material 10 is formed by applying an epoxy resin on a support such as a glass plate or a stainless steel endless belt, as shown in FIG. On the back surface of the epoxy resin substrate 10 (the surface opposite to the surface on which the plasma polymerized film 12 and the inorganic protective film 14 are laminated), a resin layer (usually an epoxy resin group) that improves the peelability from the support A hard coat layer 16) harder than the material 10, that is, formed by previously forming a hard coat layer 16 on a support and applying an epoxy resin on the hard coat layer 16. Is preferred.

  Examples of the material for forming the hard coat layer 16 include urethane resins, acrylic resins, polyester resins, and silicone resins. Among these resins, urethane resins are preferable, and urethane acrylate is particularly preferably used. For the formation of the hard coat layer 16, two or more blends of suitable resins can be used.

  The average thickness of the hard coat layer 16 is usually in the range of 1 to 10 μm, and more preferably in the range of 2 to 5 μm. When the average thickness is less than 1 μm, the peelability when the hard coat layer 16 is applied to a support such as a glass plate or a stainless steel endless belt is peeled off, and when it exceeds 10 μm, the hard coat layer is smooth. This is because it may be difficult to obtain 16.

  The plasma polymerized film 12 is adhered to the upper surface of the epoxy resin substrate 10 by plasma-polymerizing a material containing an epoxy group on the epoxy resin substrate 10 to form a film on the epoxy resin substrate 10. It is laminated in a state.

  As a preferable method for forming a film by plasma polymerization, a gas pressure of 1 to 1400 Pa, more preferably 10 to 300 Pa, a substrate temperature of 0 to 200 ° C., and more preferably 10 to 100 ° C. from the point of using a resin substrate. A method of glow discharge (usually using high-frequency power) while passing a monomer component at a relatively low temperature can be used.

The average thickness of the plasma polymerized film 12 is usually set in the range of 0.001 to 10 μm, preferably in the range of 0.005 to 1 μm. In the present specification, the average thickness of the film is measured by cross-sectional SEM observation. Specifically, the measured values at five arbitrary points in an area of 1 cm ² are taken, and the average value is taken as the average thickness. If the interface of the plasma polymerized film 12 is unclear, the composition of the cross section is analyzed with an EDX (energy dispersive X-ray analysis) apparatus attached to the SEM apparatus, and the measured value is obtained after clarifying the interface. Can be sought.

  The material containing the epoxy group is preferably a compound represented by the following formula (1).

（前記式（１）中、Ｒ_１〜Ｒ_４はそれぞれ独立して水素原子または置換基を表す。）

(In the formula (1), R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent.)

Examples of the substituent include a linear, branched, and cyclic alkyl group having 1 to 10 carbon atoms, a linear, branched, and cyclic alkenyl group having 2 to 10 carbon atoms, and a linear, branched, and cyclic group having 1 to 10 carbon atoms. Hydroxyalkyl group, straight chain, branched or cyclic alkoxyalkyl group having 2 to 10 carbon atoms, alkoxycarbonylalkyl group having 3 to 10 carbon atoms, straight chain, branched or cyclic fluorinated alkyl group having 1 to 10 carbon atoms , An aryl group having 6 to 10 carbon atoms, an epoxyalkyl group having 2 to 10 carbon atoms, a biphenylyloxy group, etc., and an alkyl group having 1 to 5 carbon atoms from the point that a high-density plasma polymerization film can be formed. An alkenyl group having 2 to 5 carbon atoms is preferred. R ₁ or R ₂ and R ₃ or R ₄ may be bonded to each other to form a ring.

  Among the compounds represented by the above formula (1), those having a boiling point of 150 ° C. or lower are preferable, and those having a boiling point of 100 ° C. or lower are more preferable. Since a material having a boiling point of 150 ° C. or lower can be vaporized at a relatively low temperature, plasma polymerization can be performed using a relatively low cost apparatus.

  Among them, 1,2-epoxybutane, 2,3-epoxybutane, 1,2,3,4-diepoxybutane, 1,2-epoxyhexane, 1,2,5,6-diepoxyhexane, 1,2 , 7,8-diepoxyoctane, 1,2-epoxydecane, 1,2-epoxy-3-butene, 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene, 1,2- Epoxy-9-decene, 1,2-epoxy-2-methylpropane, 1,2-epoxy-3-methylbutane, 3,3-dimethyl-1,2-epoxybutane, 2,3-epoxy-1-propanol, 2,3-epoxypropyl methyl ether, ethyl 2,3-epoxy-3-phenylbutyrate, 1,2-epoxy-3,3,3-trifluoropropane, 1,1,1-trifluoro-3,4- Epoxy tube And at least one selected from 3- (2-biphenylyloxy) -1,2-epoxypropane and 1,2-epoxy-4-vinylcyclohexane, and among them, 1,2-epoxybutane, 2,3-epoxybutane, 1,2,3,4-diepoxybutane, 1,2-epoxy-3-butene, 1,2-epoxy-2-methylpropane, 1,2-epoxy-3-methylbutane, Preference is given to at least one selected from 3,3-dimethyl-1,2-epoxybutane, 2,3-epoxy-1-propanol, 2,3-epoxypropyl methyl ether.

  According to such a material, it is easy to handle because the form of the material is in a liquid state at room temperature, and can be vaporized at a relatively low temperature, so that plasma polymerization can be performed using a relatively low cost apparatus. Is possible.

  When plasma polymerization is performed using a material containing an epoxy group as a monomer, an additive gas or another carbon-containing material may be mixed. Examples of the additive gas include argon, neon, helium, nitrogen, and ammonia, and examples of the material containing carbon include methane, ethane, propane, butane, and ethylene.

  Further, a second plasma polymerized film 18 obtained by plasma polymerizing a material containing carbon atoms as shown in FIG. 3 is formed between the plasma polymerized film 12 obtained by plasma polymerizing a material containing an epoxy group and the inorganic protective film 14. It may be inserted.

  The second plasma polymerized film 18 using a material containing carbon atoms as a monomer includes amorphous carbon nitride, amorphous carbon, hetero five-membered ring organic compound plasma polymer such as furan and pyrrole, methyl methacrylate plasma polymer, acrylonitrile plasma. Acrylic organic compound plasma polymer such as polymer, Fluorine organic compound plasma polymer such as tetrafluoroethylene plasma polymer, Chlorine organic compound polymer such as dichloroethylene plasma polymer, Tetraethoxysilicon plasma polymer, Hexamethyl Any film of a silicon-based organic compound plasma polymer such as a disilazane plasma polymer, or a film containing at least one of these can be employed. Among these, a film made of a plasma polymer of a hetero atom-containing compound, particularly an amorphous carbon nitride film is preferable. According to such a film, the chemical bonding force with the inorganic substance is further increased by the heteroatoms present in the film, so that the adhesion with the inorganic protective film 14 is further improved. The second plasma polymerized film 18 is usually set to an average thickness in the range of 0.001 to 10 μm, preferably in the range of 0.005 to 1 μm.

  When a 1,2-epoxybutane plasma polymerized film is employed as the plasma polymerized film 12, it can be formed by plasma polymerization using vaporized 1,2-epoxybutane as a raw material. In addition, at the time of film-forming of the plasma polymerization film | membrane 12 by a plasma polymerization method, a base-material temperature can be performed as room temperature, and the damage to the epoxy resin base material 10 by a heat | fever can be reliably prevented at the time of film-forming.

  The inorganic protective film 14 is formed on the plasma polymerization film 12 so as to be in close contact with the upper surface of the plasma polymerization film 12.

  In general, the inorganic protective film 14 has an average thickness per layer of 0.01 to 10 μm, and preferably 0.02 to 2 μm.

As the inorganic protective film 14, an inorganic film having a gas barrier property as compared with the epoxy resin as the epoxy resin substrate 10 can be adopted. Specifically, nitrides such as silicon nitride (SiNx), aluminum nitride, and nitride nitride, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ , TiCO, etc.), etc. A material made of any of oxide, amorphous silicon, diamond-like carbon (DLC), or a material containing at least one of them can be employed. These inorganic protective films 14 may be a single layer or a plurality of layers.

  Moreover, these inorganic protective films 14 can be formed by a method such as a vacuum deposition method, a sputtering method, or a vapor phase growth method. Examples of the vapor deposition method include a plasma CVD (chemical vapor deposition) method, an ALE (atomic layer epitaxial growth) method, and a Cat (catalyst) -CVD method. Among them, the plasma CVD method is preferable from the viewpoint that low-temperature film formation is possible, and preferable conditions for forming a film by the plasma CVD method include a gas pressure of 1 to 1400 Pa, more preferably 10 to 300 Pa, and a substrate temperature of 0 to 0. From the point which uses 200 degreeC and a resin base material, More preferably, it is 10-100 degreeC. Note that the conditions of the normally used high-frequency power are appropriately determined based on the device to be used.

When a silicon oxide film is used as the inorganic protective film 14, as an example, it can be formed by an RF sputtering method using a SiO ₂ target and using a mixed gas of argon and oxygen. In the case of using a silicon nitride film, for example, it can be formed by a plasma CVD method using silane gas, nitriding gas, and ammonia gas as raw materials.

  As described above, a laminated protective film of the plasma polymerization film 12 obtained by plasma polymerization of a material containing an epoxy group and the inorganic protective film 14 formed by a plasma CVD method or the like is formed on the epoxy resin substrate 10. Thereby, the resin sheet excellent in moisture resistance can be obtained. In addition, since a thin protective film having a thickness of 20 μm or less is formed on the epoxy resin substrate 10 having a surface as flat as glass, a plastic substrate with a protective film having excellent surface flatness can be obtained. Furthermore, since the resin sheet according to the present embodiment has both moisture resistance and flatness, it is weak against gas such as moisture and oxygen in the atmosphere, and is very thin in electroluminescence elements such as organic EL elements. It can be suitably used as a substrate. Further, by providing a plasma polymerized film 12 obtained by plasma polymerizing a material containing an epoxy group between the epoxy resin base material 10 and the inorganic protective film 14, the plastic base material which is an organic material and a high moisture-proof property are provided. Since adhesion with an inorganic protective film such as silicon nitride (SiNx) can be improved, sufficient moisture resistance can be ensured even under harsh environments such as in-vehicle conditions. And although the inorganic protective film 14 is laminated | stacked on the epoxy resin base material 10, the inorganic protective film 14 may become difficult to peel.

  The resin sheet according to the present embodiment includes an epoxy resin substrate 10 and a plasma polymerized film 12 formed by plasma polymerization of a material containing an epoxy group, which is laminated in close contact with the epoxy resin substrate 10; It is preferable that the inorganic protective film 14 laminated | stacked in the state closely_contact | adhered to this plasma polymerization film | membrane 12 is provided, and the to-be-laminated surface of the epoxy resin base 10 is UV ozone processed. That is, it is preferable that the surface to be laminated which is the surface on which the plasma polymerized film 12 and the inorganic protective film 14 of the epoxy resin substrate 10 are laminated is subjected to UV ozone treatment before lamination.

  Here, the UV ozone treatment means that the epoxy resin base material 10 is placed in an oxygen atmosphere and irradiated with ultraviolet rays to generate ozone, and the epoxy resin base material 10 has a synergistic effect of ozone and ultraviolet rays. It means a method of cleaning the surface dry.

  By performing the UV ozone treatment, it is possible to further improve the adhesion with the plasma polymerized film 12 and further reduce the possibility of peeling off the inorganic protective film 14 while suppressing the deterioration of the original performance of the epoxy resin substrate 10. It can be a resin sheet.

  In other words, UV ozone treatment and plasma treatment are conventionally known as treatment methods for improving surface adhesion. However, when UV ozone treatment or plasma treatment is performed on a general plastic substrate, oxidation or the like deepens from the surface to the inside. In particular, when plasma treatment is performed with an oxidizing gas such as oxygen mixed in the discharge gas, ashing is further performed from the surface of the base material, and the original flatness of the base material is also impaired. However, in this embodiment, since the epoxy resin has a characteristic excellent in oxidation resistance, even if exposed to ozone and ultraviolet rays, only the surface properties are modified without being modified to the inside. Further, while maintaining the original performance of the base material sufficiently, the adhesion with the plasma polymerized film 12 becomes better, and the possibility of peeling off the inorganic protective film 14 can be reduced.

In addition, from the viewpoint of sufficiently modifying the surface while suppressing the modification inside the epoxy resin substrate 10, UV ozone treatment conditions include low-pressure mercury having a strong line spectrum at 185 nm and 254 nm in an atmosphere containing oxygen. It is preferable to irradiate the light of the lamp onto the substrate, the intensity of the irradiated light is 0.01 to 10 mW / cm ² , the oxygen concentration in the processing atmosphere is 20 to 100% by volume, and the irradiation time is 30 seconds to 60 minutes. . Under such conditions, the epoxy resin base material is hardly modified to the inside.

  In the present embodiment, instead of the UV ozone treatment, plasma treatment that exposes to plasma such as argon gas, oxygen gas, nitrogen gas, or the like may be performed. Before the lamination, the epoxy resin substrate 10 is exposed to plasma such as argon gas, oxygen gas, nitrogen gas, etc., so that only the surface is modified and the adhesion with the plasma polymerized film 12 is further improved.

  Moreover, as for the epoxy resin base material 10 in this embodiment, that whose surface roughness Ra of a to-be-laminated surface is 0.8 nm or less is preferable. As a substrate of an electronic device, in particular, an electroluminescent element, high flatness is required for reasons of preventing element short-circuiting and ensuring fine workability. The formed plasma polymerized film 12 and inorganic protective film 14 can be made flat, and can be a resin sheet that can be used sufficiently as a substrate of an electronic device. Here, the surface roughness of the epoxy resin substrate 10 is measured by AFM (Atomic Force Microscopy).

  As a method for adjusting the surface roughness Ra of the surface to be laminated of the epoxy resin substrate 10 to 0.8 nm or less, for example, a resin layer (hard coat) that improves the peelability on a support having a smooth surface such as a mirror surface. While the layer 16) is formed, an epoxy resin coating liquid is spread on the resin layer in the form of a sheet to form a film and peeled off from the support.

  In this method, the coating liquid is developed by, for example, applying a fluid such as a roll coating method, a spin coating method, a wire bar coating method, an extrusion coating method, a curtain coating method, a spray coating method, or a dip coating method. An appropriate method that can be formed into a sheet shape can be employed. Surface smoothness can be remarkably enhanced by forming a free surface by such flow development. From the viewpoint of coating efficiency and production efficiency, roll coating method, wire bar coating method, curtain coating method, extrusion coating method and the like are preferable, especially an extrusion coating method in which a coating liquid is fluidly developed through a die. Is preferred.

  In the present embodiment, it is preferable that the epoxy-based resin base material 10 has a surface to be laminated washed with an organic solvent before the plasma polymerization film 12 is laminated.

  A general plastic substrate is easily eroded by chemicals such as organic solvents, acids, and alkalis and cannot be sufficiently cleaned. However, since the epoxy resin substrate 10 has excellent solvent resistance, it is cleaned with an organic solvent. be able to. Therefore, by removing dirt and dust on the surface of the epoxy resin substrate 10, it can be excellent in adhesion to the plasma polymerized film 12 and the inorganic protective film 14, and is generated when dust or the like is interposed therebetween. Unevenness on the surface of the plasma polymerization film 12 and the inorganic protective film 14 can be prevented, and flatness that can be sufficiently used as a substrate of an electronic device, in particular, an electronic device formed very thin on the inorganic protective film 14. The resin sheet can be provided.

  In particular, in the case where the epoxy resin base material 10 has a release sheet for surface protection attached thereto via glue (adhesive), the glue cannot be completely removed even if the release sheet is peeled off. Since the paste hinders surface flatness, cleaning with an organic solvent is more preferable when such an epoxy resin substrate 10 is used.

  As the organic solvent, any of cyclic ether organic solvents such as THF (tetrahydrofuran) and 1,4-dioxane, chlorinated organic solvents such as dichloromethane, chloroform, carbon tetrachloride, methylene chloride, and trichloroethylene, or these A mixed solvent with another organic solvent containing one or more of the above can also be employed. Further, methyl ethyl ketone, ethyl acetate or the like may be used as the organic solvent. Furthermore, it is preferable to use a saturated hydrocarbon solvent such as hexane together with a cyclic ether organic solvent such as THF (tetrahydrofuran) from the viewpoint of improving the cleaning effect.

  As a cleaning method, a method is adopted in which the epoxy resin substrate 10 is immersed in the organic solvent, and in some cases, the organic solvent is heated, and dirt or the like is removed by ultrasonic cleaning or mechanical scrubbing. Can do. Furthermore, it is preferable to perform the same cleaning with acetone, ethyl alcohol, isopropyl alcohol or the like after cleaning with these organic solvents having strong degreasing power.

  In addition, after washing with an organic solvent, in order to remove dirt such as heavy metals, for example, ultrasonic washing with an organic alkaline detergent (for example, trade name “Semico Clean”, manufactured by Furuuchi Chemical Co., Ltd.) In order to remove completely, it is preferable to wash with running pure water and then dry. As a drying method, for example, a method of heating and drying at 150 ° C. or more for 2 hours or more in an environment free from dust and particles using a clean oven can be employed.

  In the present embodiment, it is preferable to perform at least one of the UV ozone treatment and organic solvent cleaning on the epoxy resin substrate 10, and it is more preferable to perform UV ozone treatment and organic solvent cleaning. In that case, it is better to perform UV ozone treatment after organic solvent cleaning.

  Since the epoxy resin is excellent in chemical resistance, solvent resistance, etc., dirt and particles adhering to the surface can be completely removed by washing as described above. Also, dry surface treatment such as UV ozone treatment can modify the surface without causing damage to the inside, so there are almost no defects such as dirt and particle-induced pinholes, and excellent lamination protection. A film can be formed on the epoxy resin substrate 10.

  Furthermore, in this embodiment, it is preferable that the said epoxy resin base material 10, the plasma polymerization film | membrane 12, and the inorganic protective film 14 are transparent. If it is the resin sheet of such a structure, it can be used also as a board | substrate of an optical element and a light emitting element with which adoption of an opaque metal film, Si film, etc. is difficult.

  The resin sheet according to the present embodiment is preferably used as a substrate for an electronic device such as a liquid crystal display device or an electroluminescence element such as an organic EL element and an inorganic EL element. It is preferably used as an element substrate.

<Electroluminescence display device>
Next, an organic EL element will be described as an example of an electroluminescence display device using the resin sheet according to the present embodiment as a substrate of an electroluminescence element.

  FIG. 4 shows a schematic cross-sectional structure of the organic EL element 30 according to this embodiment. A transparent electrode 34 is formed on the transparent substrate 32 which is the resin sheet using ITO (indium tin oxide) or the like. Here, the transparent electrode 34 functions as an anode. At least one organic layer 44 is formed on the transparent electrode 34. In addition to ITO, the transparent electrode 34 may be an electrode such as IZO (indium zinc oxide), AZO (indium aluminum oxide), or GZO (indium gallium oxide).

  The organic layer 44 includes at least the light emitting layer 40, and the layer structure differs depending on the function of the organic compound used. In addition to the single layer structure of the light emitting layer, a multilayer structure such as a hole transport layer / light emitting layer, a light emitting layer / electron transport layer, a hole transport layer / light emitting layer / electron transport layer, or the like can be adopted. In this embodiment, a hole injection layer 36 / a hole transport layer 38 / a light emitting layer 40 / an electron transport layer 42 are stacked in this order from the transparent electrode 34 side.

  A metal electrode 50 is formed on the organic layer 44. Here, the metal electrode 50 functions as a cathode. The metal electrode 50 can be constituted by, for example, a stacked body of an electron injection layer 46 such as a LiF layer and an electron injection electrode 48 such as an Al electrode as shown in FIG. In addition, the metal electrode 50 can be constituted by a single layer of the electron injection electrode 48. In addition to Al, for example, an Mg—Ag alloy, an Al—Li alloy, or the like can be used. Although not shown, a hole blocking layer may be formed between the light emitting layer 40 and the electron transport layer 42 in order to prevent holes from flowing from the light emitting layer 40 to the electron transport layer 42. The organic EL element that is actually applied does not have to have such a structure. For example, various structures such as a structure without the hole injection layer 36, the electron injection layer 46, and the electron transport layer 42 are conceivable.

  A conventionally well-known thing can be used for the material used in each said layer.

  In the organic EL element 30 according to this embodiment, when holes and electrons are injected into the organic layer 44 from the transparent electrode 34 functioning as an anode and the metal electrode 50 functioning as a cathode, the holes are injected into the hole injection layer 36 and the hole. Through the transport layer 38, electrons are transported through the electron transport layer 42, reach the light emitting layer 40, and holes and electrons recombine. Due to the recombination of holes and electrons, the light emitting material in the light emitting layer 40 is excited, and light emission such as fluorescence and phosphorescence occurs when it returns to the ground state.

  An electroluminescence display device such as an organic EL element and an inorganic EL element according to this embodiment includes a display element, a display such as a computer, a television, a mobile phone, a digital camera, a PDA, and a car navigation, a light source such as a backlight, illumination, and interior. It can be suitably used for signs, traffic lights, signboards, and the like.

  By using the resin sheet according to the present embodiment as a substrate of an electroluminescence element, it can be used even in harsh environments such as in-vehicle use.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Preparation of epoxy resin substrate>
100 parts by weight of a liquid epoxy resin represented by the following formula (2) and 80 parts by weight of a solid epoxy resin represented by the following formula (3) were mixed, stirred while heating at 90 ° C., and completely dissolved. The mixture was allowed to cool until the main composition was obtained. Next, 100 parts by weight of methylhexahydrophthalic anhydride represented by the following formula (4) and 12 parts by weight of a modifying agent represented by the following formula (5) are mixed as a curing agent and heated and stirred at 120 ° C. After performing the esterification reaction, it is cooled to 80 ° C. and allowed to cool to room temperature, and tetra-n-butylphosphonium o, o-diethyl phosphorodithioate represented by the following formula (6) is used as a curing accelerator. 2 parts by weight were stirred and mixed to obtain a curing agent. 120 parts by weight of the curing agent and 100 parts by weight of the main agent were mixed by stirring to prepare an epoxy resin-containing liquid.

Further, a 17 wt% toluene solution (including a photoinitiator) of urethane acrylate represented by the following formula (7) was cast on a stainless endless belt having a running speed of 1.0 m / min, air-dried, and then toluene. Then, it was cured using a UV curing device to form a urethane acrylate layer having an average thickness of 2.0 μm. Subsequently, on the urethane acrylate layer having a running speed of 1.0 m / min, the prepared epoxy resin-containing liquid was cast-coated at a rate of 360 mm ³ / min, and heated at 150 ° C. using a heating device. An epoxy resin layer having an average thickness of 400 μm was formed by heat curing at 190 ° C. for 20 minutes. Next, the laminate composed of the urethane acrylate layer and the epoxy resin layer was peeled off from the stainless steel endless belt to prepare an epoxy resin substrate in a state where the urethane acrylate layer (hard coat layer) was laminated.

(Production and evaluation of resin sheet)
<Example 1>
The resin sheet of Example 1 was produced using a sputtered silicon oxide film having a gas barrier property as the inorganic protective film and using a 1,2-epoxybutane plasma film as the plasma polymerization film.

Specifically, an average thickness of 0.1 μm is obtained by plasma polymerization using vaporized 1,2-epoxybutane as a raw material on the prepared epoxy resin base material (not cleaned with an organic solvent or the like). A 1,2-epoxybutane plasma polymerized film was formed. At this time, the pressure in the film formation chamber was 376 mTorr (1 Torr≈133 Pa), the 1,2-epoxybutane flow rate was 20 sccm, the plasma input power was 150 W, and the substrate temperature was room temperature (25 ° C.). Next, an RF magnetron sputtering method using a silicon oxide film as an inorganic protective film on this 1,2-epoxybutane plasma polymerized film, using an Ar ₂ / O ₂ mixed gas (mixing ratio 7: 3) with an SiO ₂ target. A resin sheet of Example 1 was produced by forming a film with an average thickness of 0.2 μm under the conditions in which the pressure was 3 mTorr and the substrate temperature was room temperature (25 ° C.).

<Example 2>
The resin sheet of Example 2 was produced in the same manner as Example 1 except that a silicon nitride film formed by a gas barrier plasma CVD method was used as the inorganic protective film.

Specifically, on a 1,2-epoxybutane plasma polymerized film, a mixed gas of SiH ₄ gas, NH ₃ gas, and N ₂ gas (mixing ratio 1: 1: 50) is used as a raw material, and the pressure during film formation is changed. A silicon nitride film having an average thickness of 0.2 μm was formed by plasma CVD at 400 mTorr (1 Torr≈133 Pa), a plasma input power of 40 W, a substrate temperature of 100 ° C., and a resin sheet of Example 2 was produced.

<Example 3>
The resin sheet of Example 3 uses a 2,3-epoxy-1-propanol plasma polymerized film as a plasma polymerized film, and a silicon nitride film formed by a plasma CVD method having a gas barrier property as an inorganic protective film. Produced.

  Specifically, an average thickness of 0. 0 is obtained by plasma polymerization using vaporized 2,3-epoxy-1-propanol as a raw material on the produced epoxy resin base material (one not washed with an organic solvent). A 1 μm 2,3-epoxy-1-propanol plasma polymerized film was formed. At this time, the pressure in the film forming chamber was 376 mTorr (1 Torr≈133 Pa), the 2,3-epoxy-1-propanol flow rate was 20 sccm, the plasma input power was 150 W, and the substrate temperature was room temperature (25 ° C.). Next, a silicon nitride film was formed on the 2,3-epoxy-1-propanol plasma polymerization film in the same manner as in Example 2 to produce a resin sheet of Example 3.

<Example 4>
The resin sheet of Example 4 uses, as a plasma polymerization film, an epoxy resin base material in which the surface of the base material is treated with ozone generated by irradiating ultraviolet rays in an oxygen atmosphere (UV ozone treatment). , 2-Epoxybutane plasma film, a silicon nitride film formed by plasma CVD as an inorganic protective film, and a plasma polymerized film and an inorganic protective film are sequentially laminated on the surface of the epoxy resin substrate. did.

Specifically, first, a UV ozone cleaner (Nippon Laser, NL-UV253) using a low-pressure mercury lamp as a light source was used for the epoxy resin substrate produced (not washed with an organic solvent). UV ozone treatment was performed. In UV ozone treatment, an epoxy resin substrate is placed in an apparatus in which the internal air is replaced with oxygen (oxygen concentration: 100% by volume), irradiated with ultraviolet rays, and the generated ozone and irradiated ultraviolet rays are epoxy-based. A method of cleaning the resin base material surface was adopted. In addition, the intensity | strength of the ultraviolet-ray on the base-material surface was 1 mW / cm < ² >, and irradiation time was 20 minutes. After the UV ozone treatment, a 1,2-epoxybutane plasma film and a silicon nitride film were sequentially formed on the epoxy resin substrate in the same manner as in Example 2.

<Comparative Example 1>
A resin sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that no plasma polymerization film was formed.

<Comparative example 2>
A resin sheet of Comparative Example 2 was produced in the same manner as in Example 2 except that no plasma polymerization film was formed.

<Comparative Example 3>
A resin sheet of Comparative Example 3 was produced in the same manner as in Example 2 except that an amorphous carbon nitride film formed by plasma polymerization was used as the plasma polymerization film.

  The amorphous carbon nitride film has a pressure in the film forming chamber of 200 mTorr (1 Torr≈) by plasma polymerization using methane gas and nitrogen gas as raw materials on the produced epoxy resin substrate (not cleaned with an organic solvent). 133 Pa), a methane gas flow rate of 10 sccm, a nitrogen gas flow rate of 5 sccm, a plasma input power of 20 W, and a substrate temperature of room temperature (25 ° C.) were formed to an average thickness of 0.1 μm.

<Test Example 1>
[Flatness]
Using the produced resin sheets of Examples 1 to 4 and Comparative Examples 1 to 3, the surface morphology was observed with an AFM (atomic force microscope, manufactured by Digital Instruments) in a tapping mode. In a 5 μm square region, the number of protrusions due to foreign matters having a height of about 5 nm or more was counted and evaluated according to the following criteria. The results are shown in Table 1.
A: Number of projections 0: Δ: Number of projections 1 to less than 10 ×: Number of projections 10 or more

  In the resin sheets of Examples 1 to 4, no protrusions having a height of about 5 nm or more were observed. Also in the resin sheets of Comparative Examples 1 and 3, no protrusion having a height of about 5 nm or more was observed. However, in the resin sheet of Comparative Example 2, as many as 20 or more protrusions of about 5 nm or more on which silicon nitride abnormally grew was observed with the segregation portion of the component of the epoxy resin base material as a nucleus.

  When the inorganic protective film is grown by the plasma CVD method, if there is a segregated portion of the component on the base material, the film grows abnormally with this as a nucleus. In the resin sheets of Examples 2 and 3, In this case, since the plasma polymerized film formed on the epoxy resin substrate covers the segregated portion of the component on the substrate, a flat gas barrier inorganic protective film is formed on the plasma polymerized film. It is recognized that

  Moreover, in the resin sheet of Example 4, since the whole surface of the substrate surface is activated by UV ozone treatment of the substrate surface, the adhesion of the plasma polymerized film is improved. It can be seen that the flattest gas barrier inorganic protective film is formed.

  As can be seen from this, when a very thin element such as an organic EL element is formed on a resin sheet, the protruding portion causes the leakage current of the element, but it is formed by a plasma polymerization method. A resin sheet in which an inorganic protective film is formed on an epoxy resin base material without forming a plasma polymerized film has a large number of projections, making it unsuitable as a substrate for an organic EL element.

<Test Example 2>
[Adhesion]
Using the resin sheets of Examples 1 to 4 and Comparative Examples 1 to 3, the adhesion of the inorganic protective film was tested by a tape peeling method. Each resin sheet is cut into 2 mm square grids with a cutter knife to form 100 2 mm square grids, Permacel Kapton tape (P-221) is applied to the tape, the tape is peeled off, and evaluated according to the following criteria: did. The results are shown in Table 1.
A: Number of peeled lattices 0: Δ: Number of peeled lattices 1 or more and less than 10 ×: Number of peeled lattices 10 or more

  In the resin sheets of Examples 1 to 4 and Comparative Example 3, the silicon oxide film and the silicon nitride film did not peel from the plastic substrate. However, in Comparative Examples 1 and 2, the number of peeled lattices was 50 or more.

  Furthermore, each resin tape was allowed to stand at 120 ° C., humidity 100% RH, and pressure 0.2 MPa for 500 hours (pressure cooker test), a peel test was performed in the same manner, and evaluation was performed based on the same criteria as described above. The results are shown in Table 1.

  In the resin tapes of Examples 1 to 4, no abnormality such as peeling was observed, whereas in the resin tapes of Comparative Examples 1 to 3, the interface between the inorganic protective film or the plasma polymerized film and the epoxy resin substrate was used. Peeling was observed.

  Resin sheets are used, for example, as substrates for electronic devices such as liquid crystal display devices and organic EL elements. However, in these electronic devices, deterioration of the elements rapidly progresses when moisture and oxygen from the substrate permeate, so that the gas barrier property is increased. It must be protected by an inorganic protective film such as a silicon oxide film or a silicon nitride film. However, as can be seen from the tape peeling test and the pressure cooker test using the resin sheets of Comparative Examples 1 to 3, a resin sheet in which an inorganic protective film is directly laminated on a base material, or a plasma polymerization film of a material not containing an epoxy group In the formed resin sheet, since sufficient adhesion of the inorganic protective film cannot be realized, the gas barrier property may be lowered, and it is not suitable as a substrate for an in-vehicle electronic device. On the other hand, a plasma polymerization film of a material containing an epoxy group between an epoxy resin base material and a gas barrier inorganic protective film such as a silicon oxide film or silicon nitride as in the resin sheets of Examples 1 to 4 The resin sheet that has been surface-modified by forming a film has high adhesion between an inorganic protective film such as a silicon oxide film or a silicon nitride film and an epoxy-based resin base material, and is suitable as a substrate for an in-vehicle electronic device. .

<Example 5>
After the protective sheet was peeled off from the prepared epoxy resin base material with a protective sheet laminated via glue, the epoxy resin base material was made of tetrahydrofuran (THF), hexane, acetone, isopropyl alcohol (IPA). It was immersed in this order and subjected to ultrasonic cleaning for 10 minutes. Thereafter, the substrate was immersed in a semi-clean glass substrate (manufactured by Furuuchi Chemical) and subjected to ultrasonic cleaning for 10 minutes, and then rinsed with pure water for 30 minutes or more. After pulling up the epoxy resin base material from pure water, it was kept in a clean oven at 150 ° C. for 2 hours and sufficiently dried. After drying, a 1,2-epoxybutane plasma polymerization film having an average thickness of 0.1 μm is formed on the substrate surface by plasma polymerization as a plasma polymerization film, and 0.2 μm by plasma CVD as an inorganic protective film. The silicon nitride film was formed on a 1,2-epoxybutane plasma polymerized film to produce a resin sheet of Example 5. In forming a 1,2-epoxybutane plasma polymerized film, the pressure in the film forming chamber is 376 mTorr (1 Torr≈133 Pa), the 1,2-epoxybutane flow rate is 20 sccm, the plasma input power is 150 W, and the substrate temperature is room temperature ( 25 ° C.). In forming a silicon nitride film, plasma CVD using a mixed gas of SiH ₄ gas, NH ₃ gas, and N ₂ gas (mixing ratio 1: 1: 50) as a raw material is performed in a consistent vacuum process without exposure to the atmosphere. The law was adopted. Further, the pressure during film formation was 400 mTorr (1 Torr≈133 Pa), the plasma input power was 40 W, and the substrate temperature was 100 ° C.

<Example 6>
A resin sheet of Example 6 was produced in the same manner as in Example 5 except that trichloroethylene was used instead of tetrahydrofuran (THF) and hexane in Example 5.

<Example 7>
A resin sheet of Example 7 was produced in the same manner as Example 5 except that tetrahydrofuran and hexane were not used and ethyl alcohol was used instead of isopropyl alcohol.

<Test Example 3>
[Flatness]
Using the resin sheets of Examples 5, 6, and 7, the surface morphology was observed with an AFM (atomic force microscope) and evaluated in the same manner as in Test Example 1. The results are shown in Table 1.

  In Examples 5 and 6, the number of protrusions was zero. On the other hand, in Example 7, the number of protrusions was 6, and one large residue having a height of about 10 nm was observed.

  When using an epoxy resin base material with a protective sheet laminated, in order to completely remove the dirt after the protective sheet is peeled off, a cyclic ether organic solvent or a chlorinated organic solvent such as tetrahydrofuran or trichloroethylene with strong degreasing power is used. It is recognized that it needs to be used. Epoxy resin base materials are excellent in resistance to these organic solvents, and it is recognized that a flat and clean surface can be obtained without damaging the surface by washing with the organic solvent.

<Test Example 4>
[Adhesion]
The adhesion of the inorganic protective film in the resin sheets of Examples 5, 6, and 7 was tested by a tape peeling method. Each resin sheet is cut into 2 mm square grids with a cutter knife to form 100 2 mm square grids, and Permacel Kapton tape (P-221) is applied thereto, the tape is peeled off, and the same as above Evaluated by criteria. The results are shown in Table 1.

  In any of Examples 5, 6, and 7, the inorganic protective film did not peel from the epoxy resin substrate. In Example 7, although projections of foreign matters are observed on the surface due to contamination of the epoxy resin substrate, the 1,2-epoxybutane plasma polymerization film formed by the plasma polymerization method works as an adhesion layer, The adhesion of the inorganic protective film was sufficient.

  Furthermore, each resin sheet was allowed to stand for 500 hours under a pressure of 120 ° C., a humidity of 100% RH and a pressure of 0.2 MPa (pressure cooker test), a peel test was performed in the same manner, and evaluation was performed based on the same criteria as described above. The results are shown in Table 1.

  In the resin sheets of Examples 5 and 6, no abnormality such as peeling was observed, whereas in the resin sheet of Example 7, peeling was slightly observed. In the resin sheet of Example 7, protrusions of about 10 nm or more were observed from the AFM observation, and moisture penetrated and peeled from the portion that was not completely covered with the silicon nitride film formed thereon. It is recognized that it has occurred. Since the resin sheets of Examples 5 and 6 are sufficiently washed so that there are no foreign substances on the epoxy resin base material, a stable resin sheet that maintains sufficient gas barrier properties even under the severe conditions of the pressure cooker test It is recognized that

(Production and evaluation of organic EL elements)
<Examples 8 to 14 and Comparative Examples 4 to 6>
Organic EL elements were produced on the resin sheets produced in Examples 1 to 7 and Comparative Examples 1 to 3. Specifically, an ITO (indium tin oxide) film was formed as a hole injection electrode on a resin sheet, an organic EL element was formed thereon, and an element sealed with a protective film was produced. The sealing method is not limited to protective film sealing, and a bonding method such as a can, glass, or a resin sheet with a barrier film may be used. The ITO film was formed by RF magnetron sputtering. A sintered target in which indium oxide was doped with 10 wt% tin oxide was used, an Ar—O ₂ mixed gas was used as a sputtering gas, and the substrate temperature was formed at room temperature (25 ° C.). The film thickness was 150 nm and the resistivity was about 500 μΩcm. The ITO film is preferably formed by a sputtering method, but is not limited to this method, and various methods such as a reactive sputtering method, a reactive vapor deposition method, a CVD method, a sol-gel method, and a spray method can be used. The substrate temperature is not limited to room temperature, but is preferably a temperature below the glass transition point of the resin sheet.

The organic electroluminescence device used in this example and the comparative example is as shown in FIG. 4 in which a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and an electron injection electrode are stacked on the ITO film. The structure was In this example and comparative example, copper phthalocyanine (CuPc) shown below as the hole injection layer 36, triphenylamine tetramer (TPTE) as the hole transport layer 38, and N, N′-dimethylquinacridone (MeQd) as the light emitting layer 40. ) Is doped with 1 mol% of quinolinol aluminum complex (Alq ₃ : Tris (8-hydroxyquinolinato) aluminum (III)), Alq ₃ as the electron transport layer 42, lithium fluoride (LiF) as the electron injection layer 46, electron injection electrode 48 Aluminum (Al) was used. Film formation was performed in-situ by a vacuum deposition method (vacuum degree 5 × 10 ⁻⁷ Torr; 1 Torr≈133 Pa). The thickness of each layer is as follows: hole injection layer 36: 10 nm, hole transport layer 38: 50 nm, light emitting layer 40: 20 nm, electron transport layer 42: 40 nm, electron injection layer 46: 0.5 nm, electron injection electrode 48: 100 nm. did. In addition, as a protective film, SID2003 DIGEST, Vol. 34, p. 559 (2003), a SiNx / a-CNx: H laminated protective film is used, and the structure is a-CNx: H / SiNx / a-CNx: H / SiNx in order from the surface, and each film thickness is SiNx. The layer was 200 nm, and the a-CNx: H layer was 500 nm. In order to prevent erosion due to moisture in the atmosphere from the formation of the organic EL element to the formation of the protective film, they were all formed without being exposed to the atmosphere.

Table 2 shows half the organic EL elements produced on the resin sheets produced in Examples 1 to 7 and Comparative Examples 1 to 3 when driven at a constant current at an initial luminance of 2400 cd / m ² in a room temperature (25 ° C.) environment. Indicates the lifetime (the time during which the luminance is halved from the initial value). In Comparative Example 5 using the resin sheet of Comparative Example 2 having many protrusions, the half-life is less than 200 hours, which is unsuitable for organic EL device applications. Similarly, Example 14 using the resin sheet of Example 7 having protrusions had a half life of 200 hours or more, but it was shorter than other examples. On the other hand, the half-life of Example 11 using the resin sheet of Example 4 in which the flattest surface was obtained is the longest, and as the resin sheet for an organic EL element, it is preferable that it is flat without a protrusion. I understood.

It is a figure which shows schematic sectional structure of an example of the resin sheet which concerns on embodiment of this invention. Figure. It is a figure which shows schematic sectional structure of the other example of the resin sheet which concerns on embodiment of this invention. It is a figure which shows schematic sectional structure of the other example of the resin sheet which concerns on embodiment of this invention. It is a figure which shows schematic sectional structure of the organic EL element which concerns on this embodiment.

Explanation of symbols

1, 3, 5 resin sheet, 10 epoxy resin base material, 12 plasma polymerized film, 14 inorganic protective film, 16 hard coat layer, 18 second plasma polymerized film, 30 organic EL element, 32 transparent substrate, 34 transparent electrode, 36 hole injection layer, 38 hole transport layer, 40 light emitting layer, 42 electron transport layer, 44 organic layer, 46 electron injection layer, 48 electron injection electrode, 50 metal electrode.

Claims (7)

An epoxy resin substrate;
A plasma polymerized film formed by plasma polymerizing a material containing an epoxy group, laminated on the epoxy resin substrate;
An inorganic protective film laminated on the plasma polymerized film;
A resin sheet characterized by comprising: The resin sheet according to claim 1,
The resin sheet characterized in that the material containing the epoxy group is a compound represented by the following formula (1).

(In the formula (1), R _{1 to} R ₄ each independently represents a hydrogen atom or a substituent.) The resin sheet according to claim 1 or 2,
The material containing the epoxy group is 1,2-epoxybutane, 2,3-epoxybutane, 1,2,3,4-diepoxybutane, 1,2-epoxyhexane, 1,2,5,6-diene. Epoxy hexane, 1,2,7,8-diepoxyoctane, 1,2-epoxydecane, 1,2-epoxy-3-butene, 1,2-epoxy-5-hexene, 1,2-epoxy-7- Octene, 1,2-epoxy-9-decene, 1,2-epoxy-2-methylpropane, 1,2-epoxy-3-methylbutane, 3,3-dimethyl-1,2-epoxybutane, 2,3- Epoxy-1-propanol, 2,3-epoxypropyl methyl ether, ethyl 2,3-epoxy-3-phenylbutyrate, 1,2-epoxy-3,3,3-trifluoropropane, 1,1,1-tri Fluoro Resin sheet characterized by being at least one selected from 3,4-epoxybutane, 3- (2-biphenylyloxy) -1,2-epoxypropane, and 1,2-epoxy-4-vinylcyclohexane . The resin sheet according to any one of claims 1 to 3,
A laminated sheet of the epoxy resin substrate is subjected to UV ozone treatment. The resin sheet according to any one of claims 1 to 4,
The said inorganic protective film contains at least 1 among inorganic oxide and inorganic nitride, The resin sheet characterized by the above-mentioned. The resin sheet according to any one of claims 1 to 5,
The laminated surface of the epoxy resin substrate is washed with an organic solvent containing at least one of a cyclic ether organic solvent and a chlorine organic solvent.   An electroluminescence display device, wherein the resin sheet according to any one of claims 1 to 6 is used as a substrate of an electroluminescence element.

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