JP2013154550A - Transparent composite substrate and display element substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a transparent composite substrate excellent in an optical characteristic; and a display element substrate with a high reliability that is provided with the transparent composite substrate.SOLUTION: A transparent composite substrate 1 includes: a composite layer 4 that includes a glass cloth 2, and a resin material 3 that is impregnated to the glass cloth 2, and whose Abbe number is at least 45; and a gas barrier layer 5 that is disposed on the composite layer 4 and consists of an inorganic material, wherein when the melting point of the inorganic material is assumed to be Tm [°C], and the 5% weight reduction temperature of the principal ingredient of the resin material is assumed to be Td [°C], the relation of 1,200°C<(Tm-Td)<1,400°C is satisfied. Moreover, the inorganic material is shown by SiOxNy, and it is desirable that x satisfies the relation of 1≤x≤2 and y satisfies the relation of 0≤y≤1.

Description

  The present invention relates to a transparent composite substrate and a display element substrate.

  Glass plates are widely used for color filter substrates used for display elements such as liquid crystal display elements and organic EL display elements, display element substrates such as active matrix substrates, and substrates for solar cells. However, in recent years, substrates made of plastic materials (plastic substrates) have been studied as substitutes for glass plates because they are easily broken, cannot be bent, and are not suitable for weight reduction.

  Here, as a plastic substrate, the glass fiber composite resin sheet for printed circuit boards has been proposed until now (for example, refer patent document 1). The glass fiber composite resin sheet is obtained by impregnating a glass fabric containing glass fibers with a transparent resin material. By including the glass fiber, the glass fiber composite resin sheet can particularly enhance mechanical properties (such as bending strength and low linear expansion coefficient).

  In recent years, attempts have been made to make this glass fiber composite resin sheet transparent to substitute for a glass plate.

  However, since the conventional glass fiber composite resin sheet has been optimized specifically for printed circuit board applications, there has been a problem that it does not have optical characteristics suitable for the above-described applications.

Japanese Patent Laid-Open No. 5-147979

  An object of the present invention is to provide a transparent composite substrate having excellent optical characteristics and a highly reliable display element substrate including the transparent composite substrate.

Such an object is achieved by the present inventions (1) to (9) below.
(1) a composite layer comprising a glass fabric and a resin material having an Abbe number of 45 or more impregnated in the glass fabric;
A gas barrier layer provided on the composite layer and made of an inorganic material,
When the melting point of the inorganic material is Tm [° C.] and the 5% weight reduction temperature of the main component of the resin material is Td [° C.], the relationship of 1200 ° C. <(Tm−Td) <1400 ° C. is satisfied. A transparent composite substrate characterized by

  (2) The transparent composite substrate according to (1), wherein the inorganic material includes a silicon compound.

  (3) The transparent composite substrate according to (2), wherein the silicon compound contains an oxygen atom and a nitrogen atom.

  (4) The silicon compound is represented by SiOxNy, wherein x satisfies a relationship of 1 ≦ x ≦ 2 and y satisfies a relationship of 0 ≦ y ≦ 1 (2) or (3 ) Transparent composite substrate.

  (5) The transparent composite substrate according to any one of (1) to (4), wherein the gas barrier layer has an average thickness of 10 to 500 nm.

(6) The water vapor transmission rate defined in JIS K 7129 B is 0.1 [g / m ² / day / 40 ° C., 90% RH] or less, according to any one of (1) to (5) above Transparent composite substrate.

  (7) The transparent composite substrate according to any one of (1) to (6), wherein the resin material has an alicyclic epoxy resin as a main component.

  (8) The transparent composite substrate according to any one of (1) to (7), wherein the transparent composite substrate is provided between the composite layer and the gas barrier layer and has an intermediate layer made of a resin material.

  (9) A display element substrate comprising the transparent composite substrate according to any one of (1) to (8).

  According to the present invention, since a resin material having a predetermined Abbe number is used and a gas barrier layer composed of a silicon compound having a predetermined composition is provided, a decrease in optical characteristics over time can be suppressed. A transparent composite substrate capable of maintaining uniform and excellent optical characteristics over a wide range is obtained.

  In addition, according to the present invention, a display element substrate with high reliability can be obtained by including the transparent composite substrate as described above.

It is a top view which shows the glass cloth which concerns on embodiment of the transparent composite substrate of this invention. It is sectional drawing which shows embodiment of the transparent composite substrate of this invention.

  Hereinafter, the transparent composite substrate and the display element substrate of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  The transparent composite substrate of the present invention includes a composite layer having a glass fabric and a resin material having an Abbe number of 45 or more impregnated in the glass fabric, and a gas barrier layer provided on the composite layer and made of an inorganic material. , Has. When the melting point of the inorganic material is Tm [° C.] and the 5% weight loss temperature of the main component of the resin material is Td [° C.], the relationship of 1200 ° C. <(Tm−Td) <1400 ° C. is satisfied. It is configured.

  In the present invention, the term “transparent” refers to a state having translucency, and may have a chromatic color, but is preferably colorless.

  The transparent composite substrate of the present invention uses a resin material having a predetermined Abbe number, is provided with a gas barrier layer composed of an inorganic material, and has a melting point of the inorganic material and a 5% weight reduction temperature of the main component of the resin material. By optimizing the difference, it is possible to reliably suppress the temporal deterioration of the optical characteristics. For this reason, the transparent composite substrate of the present invention can maintain uniform and excellent optical characteristics over a long period of time.

<Transparent composite substrate>
First, an embodiment of the transparent composite substrate of the present invention will be described.

  FIG. 1 is a plan view showing a glass cloth according to an embodiment of the transparent composite substrate of the present invention, and FIG. 2 is a cross-sectional view showing an embodiment of the transparent composite substrate of the present invention.

  A transparent composite substrate 1 shown in FIG. 2 includes a composite layer 4 including a glass cloth (glass fabric) 2 and a resin material (matrix resin) 3, and a gas barrier layer 5 provided on the composite layer 4. is there. Hereinafter, each component will be described.

(Glass cloth)
Examples of the glass cloth 2 used in the present invention include fabrics such as woven fabrics and nonwoven fabrics containing glass fibers. In FIG. 1, the case where the glass cloth 2 is a woven fabric is illustrated as an example. A glass cloth 2 shown in FIG. 1 includes a longitudinal glass yarn (warp) 2a and a transverse glass yarn (weft) 2b. The longitudinal glass yarn 2a and the transverse glass yarn 2b are substantially orthogonal to each other. . Examples of the woven structure of the glass cloth 2 include a plain weave, a woven weave, a satin weave, and a twill weave.

  Examples of the inorganic glass material constituting the glass fiber include E glass, C glass, A glass, S glass, T glass, D glass, NE glass, quartz, low dielectric constant glass, and high dielectric constant glass. Among them, E glass, S glass, T glass, and NE glass, which have few ionic impurities such as alkali metals and are easily available, are preferably used. Especially, S glass having an average linear expansion coefficient of 5 ppm or less at 30 ° C. to 250 ° C. T glass is more preferably used.

  Moreover, although the refractive index of an inorganic type glass material is suitably set according to the refractive index of the resin material to be used, it is preferable that it is about 1.4-1.6, for example, about 1.5-1.55. It is more preferable that Thereby, the transparent composite substrate 1 which shows the outstanding optical characteristic in a wide wavelength range is obtained.

  The average diameter of the glass fibers contained in the glass cloth 2 is preferably about 2 to 15 μm, more preferably about 3 to 12 μm, and further preferably about 3 to 10 μm. Thereby, the transparent composite substrate 1 which can make mechanical characteristics, optical characteristics, and surface smoothness highly compatible is obtained. In addition, the average diameter of glass fiber is calculated | required as an average value of the diameter of 100 glass fibers measured from the observation image by observing the cross section of the transparent composite substrate 1 with various microscopes.

  On the other hand, the average thickness of the glass cloth 2 is preferably about 10 to 200 μm, and more preferably about 20 to 120 μm. By making the average thickness of the glass cloth 2 within the above range, the transparent composite substrate 1 can be made thin, and sufficient flexibility and translucency can be secured, while suppressing the deterioration of mechanical properties. it can.

  When a bundle (glass yarn) made of a plurality of glass fibers is woven to form a woven fabric, the glass yarn preferably contains about 30 to 300 single fibers of glass fiber, and about 50 to 250. More preferably it is included. Thereby, the transparent composite substrate 1 which can make mechanical characteristics, optical characteristics, and surface smoothness highly compatible is obtained.

  Such a glass cloth 2 is preferably subjected to a fiber opening treatment in advance. By the fiber opening process, the glass yarn is widened and the cross section is formed into a flat shape. Also, the so-called basket hole becomes smaller. As a result, the smoothness of the glass cloth 2 is increased, and the smoothness of the surface of the transparent composite substrate 1 is also increased. Examples of the opening process include a process of spraying a water jet, a process of spraying an air jet, and a process of performing needle punching.

  Moreover, you may make it provide a coupling agent to the surface of glass fiber as needed. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent, and a silane coupling agent is particularly preferably used. As the silane coupling agent, those containing an epoxy group, a (meth) acryloyl group, a vinyl group, an isocyanate group, an amide group or the like as a functional group are preferably used.

  The content of such a coupling agent is preferably about 0.01 to 5 parts by mass, more preferably about 0.02 to 1 part by mass with respect to 100 parts by mass of the glass cloth. More preferably, it is about 02 to 0.5 parts by mass. If the content rate of a coupling agent is in the said range, an optical characteristic can be improved, for example, the transparent composite substrate 1 suitable as a display element substrate is obtained.

  Further, as the glass cloth 2, one having a difference between the maximum value and the minimum value of the refractive index of 0.01 or less is preferably used. By using the glass cloth 2 having such a refractive index distribution, light interference associated with the refractive index difference can be suppressed, and the optical characteristics of the transparent composite substrate 1 can be particularly enhanced. Since the refractive index distribution is considered to reflect the microstructure (atomic arrangement) of the glass fiber, the glass cloth 2 having such a refractive index distribution has characteristics based on this microstructure, such as weather resistance. It is thought that it has uniformity. That is, the glass cloth 2 as described above can change its optical characteristics uniformly even in an environment where deterioration over time is unavoidable. Therefore, the transparent composite substrate 1 including the glass cloth 2 can maintain uniform and excellent optical characteristics over a long period of time.

  Further, the difference between the maximum value and the minimum value of the refractive index in the glass cloth 2 is more preferably 0.008 or less, and further preferably 0.005 or less.

  When the glass cloth 2 used in the present invention is a woven fabric, the cross-sectional area of the glass component in the lateral glass yarn (second glass fiber bundle) 2b per unit width is set to 1 in this woven fabric. The ratio of the cross-sectional areas of the glass components in the longitudinal glass yarn (first glass fiber bundle) 2a per unit width is preferably 1.04 or more and 1.40 or less, and 1.21 or more and 1. It is more preferably 39 or less, and further preferably 1.25 or more and 1.35 or less. Thereby, while the uniformity of the linear expansion coefficient of the vertical direction and a horizontal direction can be aimed at in the transparent composite substrate 1, the further improvement of a light transmittance can be aimed at.

  When the longitudinal glass yarn 2a and the transverse glass yarn 2b are the same glass yarn, that is, when the cross-sectional areas of the glass components are substantially equal to each other, the transverse glass yarn per unit width (second glass When the number of fiber bundles) is 1, the ratio of the number of longitudinal glass yarns (first glass fiber bundles) per unit width is preferably 1.02 or more and 1.18 or less, and 1.10 or more. It is more preferably 1.18 or less, and further preferably 1.12 or more and 1.16 or less. Thereby, while the uniformity of the linear expansion coefficient of the vertical direction and a horizontal direction can be aimed at in the transparent composite substrate 1, the further improvement of a light transmittance can be aimed at.

  When the glass cloth 2 is a woven fabric, when manufacturing this woven fabric, the longitudinal glass yarn 2a faces the MD direction (flow direction), and the transverse glass yarn 2b faces the TD direction (vertical direction). It is set in the manufacturing device so that it faces. Here, when weaving the longitudinal glass yarn 2a and the transverse glass yarn 2b, equal force is not applied to both, but changes depending on the yarn feeding direction. Therefore, in the present invention, in consideration of the influence of the difference in force applied during weaving on the optical characteristics of the final transparent composite substrate 1, the cross-sectional area of the glass component and the glass as described above are optimized in order to optimize the optical characteristics. It is preferable to make the number of yarns anisotropic.

On the other hand, when the glass cloth 2 has anisotropy as described above, anisotropy also occurs in a dimensional change due to a change in heat and humidity environment, and there is a risk of causing deformation or the like. On the other hand, in the present invention, by providing the gas barrier layer 5 made of an inorganic material on the composite layer 4, the dimensional change of the transparent composite substrate 1 can be greatly suppressed. According to the present invention as described above, it is possible to suppress the uneven distribution of internal stress that causes a dimensional change, and it is possible to suppress a decrease in optical characteristics, warpage, deformation, and the like of the transparent composite substrate 1. That is, according to the present invention, it is possible to solve the problem that is unavoidable when the glass cloth 2 is a woven fabric.
The “unit width” is a width of 1 inch.

  Further, the number of twists of the first glass fiber bundle and the second glass fiber bundle is preferably 0.2 to 2.0 / inch, and more preferably 0.3 to 1.6 / inch. preferable. When the number of twists of the glass fiber bundle is in this range, the transparent composite substrate 1 having a small haze value can be obtained.

(Resin material)
The resin material 3 used in the present invention has an Abbe number after curing of 45 or more, preferably 50 or more.

Here, the Abbe number (ν _d ) indicates the wavelength dependency of the refractive index, that is, the degree of dispersion, and can be obtained by ν _d = (n _D −1) / (n _F −n _C ). . n _C , n _D , and n _F are refractive indexes of the Fraunhofer line with respect to C line (wavelength 656 nm), D line (589 nm), and F line (486 nm), respectively. The refractive index of the resin material 3 having a small Abbe number varies greatly depending on the wavelength. That is, since a general glass fiber has an Abbe number of 50 or more, when the Abbe number of a resin material combined with such a glass fiber is as small as less than 45, the refractive indexes of both are combined at a wavelength of 589 nm. Even at a wavelength of 400 nm or less, the refractive index is greatly different, and the light transmittance of 400 nm or less is lowered. In the present invention, by using the resin material 3 having an Abbe number of 45 or more, the refractive index can be matched with a general glass fiber in a wide wavelength range. For example, excellent light transmission even at a wavelength of 400 nm or less. Rate can be realized. Therefore, the transparent composite substrate of the present invention has uniform and excellent optical characteristics in a wide wavelength range.

  In addition, when the Abbe number of the resin material 3 is less than 45, the deviation from the Abbe number of the glass constituting the glass fiber is further caused by the Abbe number change when the resin material 3 is affected by moisture absorption or oxidation. As a result, the haze value increases. On the other hand, when the Abbe number is 45 or more, even if there is a change in the Abbe number, the difference in the Abbe number from the glass is small, so the change in haze value is also small. When the gas barrier layer 5 is present, the effect of suppressing the change in haze value becomes more remarkable.

  Examples of the resin material 3 used in the present invention include epoxy resins, oxetane resins, isocyanate resins, acrylate resins, olefin resins, cycloolefin resins, diallyl phthalate resins, polycarbonate resins, and diallyl carbonate resins. Examples include resins, urethane resins, melamine resins, polyimide resins, aromatic polyamide resins, polystyrene resins, polyphenylene resins, polysulfone resins, polyphenylene oxide resins, silsesquioxane compounds, and the like. Among these, an epoxy resin or an acrylic resin is preferably used, and an alicyclic epoxy resin or an alicyclic acrylic resin is more preferably used.

  Examples of the epoxy resin used in the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, or hydrogenated products thereof, epoxy resin having a dicyclopentadiene skeleton, and triglycidyl isocyanurate. Epoxy resin having skeleton, epoxy resin having cardo skeleton, epoxy resin having polysiloxane structure, alicyclic polyfunctional epoxy resin, alicyclic epoxy resin having hydrogenated biphenyl skeleton, alicyclic having hydrogenated bisphenol A skeleton An epoxy resin etc. are mentioned, The 1 type (s) or 2 or more types of mixture of these epoxy resins can be used.

  In addition, the above-mentioned epoxy resin is a glycidyl ether type epoxy resin containing a glycidyl group and an ether bond, a glycidyl ester type epoxy resin containing a glycidyl group and an ester bond, and a glycidyl amine type epoxy resin containing a glycidyl group and an amino group. Type epoxy resin and alicyclic epoxy group having an alicyclic epoxy group can be broadly classified. In the present invention, an alicyclic epoxy resin having two or more epoxycyclohexane rings in the molecule is preferably used. Specifically, the main component is various alicyclic epoxy resins such as alicyclic polyfunctional epoxy resins, alicyclic epoxy resins having a hydrogenated biphenyl skeleton, and alicyclic epoxy resins having a hydrogenated bisphenol A skeleton. A resin material is used.

  More specifically, as the alicyclic epoxy resin, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy- 6-methylcyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro- (3,4-epoxy) cyclohexane-m-dioxane, 1,2: 8,9-diepoxy limonene, di Cyclopentadiene dioxide, cyclooctene dioxide, acetal diepoxyside, vinylcyclohexane dioxide, vinylcyclohexylene monooxide 1,2-epoxy-4-vinylcyclohexane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3 , 4-epoxy- -Methylcyclohexylmethyl) adipate, exo-exobis (2,3-epoxycyclopentyl) ether, 2,2-bis (4- (2,3-epoxypropyl) cyclohexyl) propane, 2,6-bis (2,3 -Epoxypropoxycyclohexyl-p-dioxane), 2,6-bis (2,3-epoxypropoxy) norbornene, diglycidyl ether of linoleic acid dimer, limonene dioxide, 2,2-bis (3,4-epoxy) Cyclohexyl) propane, o- (2,3-epoxy) cyclopentylphenyl-2,3-epoxypropyl ether, 1,2-bis [5- (1,2-epoxy) -4,7-hexahydromethanoindanxyl] Ethane, cyclohexanediol diglycidyl ether and diglycidyl hexahydride Examples include phthalate and ε-caprolactone oligomers in which both ends of 3,4-epoxycyclohexylmethanol and 3,4-epoxycyclohexylcarboxylic acid are ester-bonded, and epoxidized hexahydrobenzyl alcohol. A seed or a mixture of two or more is used.

  In the present invention, an alicyclic epoxy resin having two or more epoxycyclohexane rings in the molecule is particularly preferably used. Of these, alicyclic epoxy structures represented by the following chemical formulas (1), (2), and (3) are particularly preferably used.

［上記式（２）中、−Ｘ−は−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ_２−、−ＣＨ_２−、−ＣＨ（ＣＨ_３）−、または−Ｃ（ＣＨ_３）_２−を表す。］

[In the above formula (2), -X- is _{-O -, - S -, -} SO -, - SO 2 -, - CH 2 -, - CH (CH 3) -, or -C _{(CH 3) 2} -Represents. ]

  On the other hand, as the alicyclic epoxy resin having one epoxycyclohexane ring in the molecule, alicyclic epoxy resins represented by the following chemical formulas (4) and (5) are particularly preferably used.

  Since such an alicyclic epoxy resin is excellent in curability at low temperature, it can be cured at low temperature. Thereby, since it becomes unnecessary to make the resin material 3 high temperature at the time of hardening, even if it returns a hardened | cured material to room temperature after that, the amount of change of temperature can be suppressed. As a result, the transparent composite substrate of the present invention can suppress the generation of thermal stress accompanying a temperature change, and has excellent optical characteristics.

  Moreover, since the alicyclic epoxy resin as described above has a low coefficient of linear expansion after curing, in the transparent composite substrate 1 obtained using a resin material containing the alicyclic epoxy resin, a glass cloth 2 and a resin are used. The interfacial stress at the interface with the material 3 is particularly small at room temperature. For this reason, the said transparent composite substrate 1 with a small interface stress can be obtained, and this transparent composite substrate 1 becomes a thing with small optical anisotropy. Furthermore, since the linear expansion coefficient is low, the transparent composite substrate 1 is prevented from being deformed such as warpage and swell.

  In addition, these alicyclic epoxy resins are excellent in transparency and heat resistance, and thus contribute to the realization of the transparent composite substrate 1 having excellent light transmittance and high heat resistance.

  The resin material 3 is preferably a resin material mainly composed of an alicyclic epoxy resin. In the present invention, the main component means a component occupying more than 50% by mass of the resin material 3, and the content of the alicyclic epoxy resin in the resin material 3 is preferably 70% by mass or more, and 80% by mass. The above is more preferable.

  For the resin material 3, a glycidyl type epoxy resin is preferably used together with an alicyclic epoxy resin. By using these together, the refractive index of the resin material 3 can be easily adjusted while suppressing a decrease in optical properties in the transparent composite substrate 1. That is, the refractive index of the resin material 3 can be set to a desired value by appropriately adjusting the mixing ratio of the alicyclic epoxy resin and the glycidyl type epoxy resin. As a result, a transparent composite substrate 1 having a high light transmittance is obtained.

  In this case, the addition amount of the glycidyl type epoxy resin is preferably about 0.1 to 10 parts by mass and more preferably about 1 to 5 parts by mass with respect to 100 parts by mass of the alicyclic epoxy resin. .

  Examples of the glycidyl type epoxy resin include a glycidyl ether type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, and the like.

  Of the glycidyl type epoxy resins to be used, glycidyl type epoxy resins having a cardo structure are preferably used. That is, by adding a glycidyl type epoxy resin having a cardo structure to an alicyclic epoxy resin and using it, a large number of aromatic rings derived from the bisarylfluorene skeleton are included, so the optical characteristics of the transparent composite substrate 1 In addition, the heat resistance can be further increased.

  Examples of the glycidyl type epoxy resin having such a cardo structure include Oncoat EX series (manufactured by Nagase Sangyo Co., Ltd.), Ogsol (manufactured by Osaka Gas Chemical Co., Ltd.), and the like.

  In addition, a silsesquioxane compound is also preferably used as the resin material 3 together with the alicyclic epoxy resin, and among these, a silsesquioxane compound having a photopolymerizable group such as an oxetanyl group or a (meth) acryloyl group. A compound is more preferably used. By using these together, the refractive index of the resin material 3 can be easily adjusted while suppressing a decrease in optical characteristics in the transparent composite substrate 1. Moreover, since the silsesquioxane-based compound having an oxetanyl group is rich in compatibility with the alicyclic epoxy resin, uniform mixing is possible, and as a result, the refractive index is more reliably adjusted, A transparent composite substrate 1 having excellent optical characteristics is obtained.

  Examples of such silsesquioxane compounds having an oxetanyl group include OX-SQ, OX-SQ-H, OX-SQ-F (all manufactured by Toagosei Co., Ltd.) and the like.

  In this case, the addition amount of the silsesquioxane-based compound is preferably about 1 to 20 parts by mass and more preferably about 2 to 15 parts by mass with respect to 100 parts by mass of the alicyclic epoxy resin. .

  On the other hand, as the alicyclic acrylic resin, for example, tricyclodecanyl diacrylate, its hydrogenated product, dicyclopentanyl diacrylate, isobornyl diacrylate, hydrogenated bisphenol A diacrylate, cyclohexane-1,4- Examples include dimethanol diacrylate, and specifically, Hitachi Chemical's Optretz series, Daicel Cytec's acrylate monomer, and the like.

  Furthermore, the resin material 3 used in the present invention preferably has a glass transition temperature of 150 ° C. or higher, more preferably 170 ° C. or higher, and further preferably 180 ° C. or higher. Thereby, even if various heat treatments are performed when the transparent composite substrate 1 is manufactured and then processed into a display element substrate, it is possible to prevent the transparent composite substrate 1 from being warped or deformed.

  The resin material 3 preferably has a heat distortion temperature of 200 ° C. or higher, and preferably has a coefficient of thermal expansion of 100 ppm / K or lower.

  The refractive index of the resin material 3 is preferably as close as possible to the refractive index of the glass cloth 2 and is preferably substantially the same refractive index. Specifically, the refractive index difference between the two is preferably 0.01 or less, and more preferably 0.005 or less. Thereby, the transparent composite substrate 1 with high light transmittance is obtained.

(Other ingredients)
The transparent composite substrate of the present invention may contain a filler in the resin material 3 in addition to the above.

  As a filler, the glass filler comprised, for example with the fiber piece or particle | grains, etc. of the inorganic type glass material is mentioned. Dispersing the glass filler in the resin material 3 can enhance the mechanical characteristics without inhibiting the light transmittance of the transparent composite substrate 1.

  Specific examples of the glass filler include glass chopped strands, glass beads, glass flakes, glass powder, and milled glass.

  As the inorganic glass material, the same material as that of the glass cloth described above is used.

  The content of the filler is preferably about 1 to 90 parts by mass, more preferably about 3 to 70 parts by mass with respect to 100 parts by mass of the glass cloth.

  In addition, it is preferable that the diameter of a filler is 100 nm or less. Since such a filler hardly causes scattering at the interface, the transparency of the transparent composite substrate 1 becomes relatively high.

  Further, the coupling agent described above may be added to the resin material 3. Thereby, the stress concentration described above can be further relaxed, and the optical characteristics of the transparent composite substrate 1 can be further enhanced. When adding a coupling agent in the resin material 3, it is preferable that the addition amount is about 0.01-5 mass parts with respect to 100 mass parts of resin materials, and is about 0.05-2 mass parts. Is more preferable.

(Gas barrier layer)
A gas barrier layer 5 is provided on the composite layer 4 provided in the transparent composite substrate of the present invention.

  The constituent material of the gas barrier layer 5 may be an inorganic material, for example, from the group consisting of Si, Al, Ca, Na, B, Ti, Pb, Nb, Mg, P, Ba, Ge, Li, K, Zr, and the like. The oxide, fluoride, nitride, oxynitride, or the like of at least one selected oxide or a mixture of two or more types can be given.

  Among these, the inorganic material preferably includes a plurality of types of oxides, and more preferably includes a glass material including a plurality of types of oxides. Thereby, the gas barrier property of the gas barrier layer 5 can be improved by a layer made of an amorphous and dense glass material.

  Here, silicon oxide, aluminum oxide, magnesium oxide and boron oxide are preferably used as the oxide contained in the inorganic material, and among these, silicon oxide which is a silicon compound is particularly preferably used. By containing silicon oxide, the gas barrier property can be remarkably improved.

  In addition, as the silicon compound, those containing silicon nitride in addition to silicon oxide (hereinafter, those containing both are referred to as “silicon oxynitride”) are preferably used. By including silicon oxynitride, which is a silicon compound containing oxygen atoms and nitrogen atoms, the inorganic material has excellent surface hardness as well as gas barrier properties. That is, the gas barrier layer 5 can achieve both gas barrier properties and protective properties.

  Here, when the melting point of the inorganic material constituting the gas barrier layer 5 is Tm [° C.] and the 5% weight reduction temperature of the main component of the resin material 3 is Td [° C.], the transparent composite substrate 1 is 1200 ° C. <( Tm−Td) <1400 ° C. Such a transparent composite substrate 1 is rich in gas barrier properties by optimizing the properties between the inorganic material and the resin material 3, and also has surface protection properties. For this reason, moisture absorption, oxidation, warpage, deformation, etc. of the transparent composite substrate 1 are suppressed, the optical characteristics of the transparent composite substrate 1 are maintained uniformly over a long period of time, and the surface is reliably prevented from being scratched. Can do.

  The 5% weight reduction temperature Td [° C.] can be measured, for example, by thermogravimetric analysis (TGA) as the temperature at which a 5% weight reduction occurs with heating in the atmosphere. On the other hand, when the inorganic material does not have a melting point and is thermally decomposed, the thermal decomposition start temperature can be set to the above Tm [° C.].

  The value of Tm−Td is preferably 1250 ° C. <(Tm−Td) <1400 ° C., more preferably 1300 ° C. <(Tm−Td) <1400 ° C.

  The silicon compound is represented by SiOxNy, and it is preferable that x and y satisfy the relationship of 0.3 <x / (x + y) ≦ 1, and 0.35 <x / (x + y) ≦ 0. It is more preferable to satisfy the relationship of .95, and it is even more preferable to satisfy the relationship of 0.4 <x / (x + y) ≦ 0.9. The gas barrier layer 5 composed of such a silicon compound can achieve both gas barrier properties and surface protection properties. For this reason, moisture absorption and oxidation of the composite layer 4 can be suppressed, the optical characteristics of the transparent composite substrate 1 can be maintained uniformly over a longer period, and the surface of the transparent composite substrate 1 can be more reliably protected from scratches and the like. Can do. As a result, the wear resistance is further improved, and the transparent composite substrate 1 that can withstand use in a particularly severe environment is obtained.

  Moreover, since the linear expansion coefficient of the gas barrier layer 5 is optimized with respect to the composite layer 4 by providing the gas barrier layer 5 made of such a silicon compound, it is transparent while providing gas barrier properties. Warpage or deformation of the composite substrate 1 can be suppressed. As a result, the optical characteristics of the transparent composite substrate 1 can be made more uniform. Further, since the refractive index of the gas barrier layer 5 is close to that of the composite layer 4, the light transmittance of the transparent composite substrate 1 can be improved.

  In addition to this, the gas barrier layer 5 made of the silicon compound has a function of suppressing moisture absorption and oxidation of the composite layer 4 and suppressing a change in the Abbe number of the resin material 3 as described above. For this reason, even if the transparent composite substrate 1 is used in a harsh environment, the resin material 3 can maintain a high Abbe number. Therefore, even when used in a harsh environment, the transparent composite substrate 1 showing uniform and excellent optical characteristics in a wide wavelength range can be obtained.

  If the value of x / (x + y) is below the lower limit value, the abundance ratio of oxygen atoms with respect to nitrogen atoms is remarkably reduced, so that the light transmittance of the gas barrier layer 5 is reduced and flexibility is increased. May also decrease. Furthermore, the difference in Abbe number between the gas barrier layer 5 and the resin material 3 becomes too large, and the wavelength range showing uniform and excellent optical characteristics becomes narrow.

  In SiOxNy, x preferably satisfies the relationship of 1 ≦ x ≦ 2, and y preferably satisfies the relationship of 0 ≦ y ≦ 1, and 1.2 ≦ x ≦ 1.8 and 0.2 ≦ y ≦ It is more preferable to satisfy the relationship of 0.8. Such SiOxNy can achieve a high degree of compatibility between gas barrier properties and protective properties, and its refractive index is particularly optimized with respect to the composite layer 4, thereby improving the light transmittance of the transparent composite substrate 1. Contribute.

  In addition, when x is less than the lower limit, the light transmittance and flexibility of the gas barrier layer 5 may be reduced, and when x exceeds the upper limit, the surface protection of the gas barrier layer 5 may be reduced. Moreover, when y exceeds the said upper limit, there exists a possibility that the surface protection of the gas barrier layer 5 may fall.

  The average thickness of the gas barrier layer 5 is not particularly limited, but is preferably about 10 to 500 nm. Within this range, the gas barrier layer 5 having sufficient gas barrier properties and protective properties and excellent flexibility can be obtained.

The gas barrier layer 5 preferably has a water vapor permeability of 0.1 [g / m ² / day / 40 ° C., 90% RH] or less as defined in JIS K 7129 B. When the water vapor transmission rate is within the above range, the transparent composite substrate 1 has excellent optical characteristics over a long period of time by suppressing alteration and deterioration of the glass cloth 2 and the resin material 3 due to moisture absorption and suppressing the change in the refractive index associated therewith. Is obtained.

In addition, the gas barrier layer 5 preferably has an oxygen permeability defined by JIS K 7126 B of 0.1 [cm ³ / m ² / day / 1 atm / 23 ° C.] or less. When the oxygen permeability is within the above range, the transparent composite substrate 1 having excellent optical characteristics over a long period of time can be obtained by suppressing alteration and deterioration of the resin material 3 due to oxidation and suppressing the change in the refractive index.

  An intermediate layer may be interposed between the composite layer 4 and the gas barrier layer 5 as necessary. Examples of the intermediate layer include a functional layer, which will be described later, and a layer composed of a resin material such as an epoxy resin or an acrylic resin is preferably used. By interposing such an intermediate layer, the flatness and smoothness of the surface of the transparent composite substrate 1 can be enhanced, and the optical characteristics can be enhanced. At the same time, the adhesion between the composite layer 4 and the gas barrier layer 5 can be enhanced, and the gas barrier layer 5 can be reliably prevented from peeling off. As a result, the durability of the transparent composite substrate 1 is improved, and the transparent composite substrate 1 capable of maintaining uniform and excellent optical characteristics over a long period of time is obtained.

  As the resin material constituting the intermediate layer, the same material as the resin material 3 included in the composite layer 4 is used, and preferably the same material as the resin material 3 is used. Thereby, it becomes difficult to peel off the intermediate layer, and the adhesion between the composite layer 4 and the gas barrier layer 5 can be further improved.

(Characteristics of transparent composite substrate)
The total light transmittance at a wavelength of 400 nm of the display element substrate is preferably 70% or more, more preferably 75% or more, and further preferably 78% or more. If the total light transmittance at a wavelength of 400 nm is less than the lower limit, the display performance of the display element may not be sufficient.

  Moreover, although the average thickness of a transparent composite substrate is not specifically limited, It is preferable that it is about 40-200 micrometers, and it is more preferable that it is about 50-100 micrometers.

  Moreover, it is preferable that the average linear expansion coefficient in 30 to 150 degreeC of the transparent composite substrate of this invention is 40 ppm or less, More preferably, it is 20 ppm or less, More preferably, it is 10 ppm or less. Such a transparent composite substrate having an average coefficient of linear expansion has a sufficiently small dimensional change due to a temperature change. For example, when it is used for an active matrix display device substrate, various problems such as warping and wire breakage occur. It will be difficult.

In addition, the transparent composite substrate of the present invention preferably has a water vapor permeability of 0.1 [g / m ² / day / 40 ° C., 90% RH] or less as defined in JIS K 7129 B. If the water vapor transmission rate is within the above range, the amount of water vapor passing through the inside of the transparent composite substrate is suppressed, and moisture absorption of the glass cloth 2 and the resin material 3 is suppressed. Thereby, the quality change and deterioration of the resin material 3 can be suppressed, and the change in the Abbe number of the resin material 3 can be particularly suppressed. As a result, the resin material 3 can maintain a high Abbe number, and even when used in a harsh environment, a transparent composite substrate 1 that exhibits uniform and excellent optical characteristics in a wide wavelength range is obtained.

  Further, when the difference between the maximum value and the minimum value of the refractive index of the glass cloth 2 is 0.01 or less, the microstructure is uniform, and the refractive index variation due to moisture absorption is further uniform, and the transparent composite substrate 1 is uniform. With this, excellent optical characteristics can be maintained for a longer period of time. Moreover, if the water vapor permeability is within the above range, the fluctuation of the linear expansion coefficient of the transparent composite substrate 1 due to moisture absorption is also suppressed. For this reason, it is possible to reliably suppress the deterioration of the optical characteristics accompanying the dimensional change. Furthermore, when the water vapor permeability is within the above range, when the transparent composite substrate of the present invention is used as a display element substrate, it is possible to suppress deterioration of the display element due to moisture absorption and to improve the reliability of the display element over a long period of time. it can.

The transparent composite substrate of the present invention preferably has an oxygen permeability specified by JIS K 7126 B of 0.1 [cm ³ / m ² / day / 1 atm / 23 ° C.] or less. When the oxygen permeability is within the above range, when the transparent composite substrate of the present invention is used as a display element substrate, deterioration of the display element due to oxidation can be suppressed, and the reliability of the display element can be improved over a long period of time.

  From the above, according to the present invention, even when used in a harsh environment, it is possible to obtain the transparent composite substrate 1 exhibiting uniform and excellent optical characteristics in a wide wavelength range.

<Display element substrate>
The transparent composite substrate of the present invention includes, for example, various display element substrates such as a liquid crystal display element substrate, an organic EL element substrate, a color filter substrate, a TFT substrate, an electronic paper substrate, and a touch panel substrate. In addition to the display element substrate, it is also applied to a solar cell substrate and the like.

  The display element substrate of the present invention includes the transparent composite substrate of the present invention, and has a functional layer formed on the surface of the transparent composite substrate as necessary.

  Examples of such a functional layer include a transparent conductive layer composed of indium oxide, tin oxide, an oxide of tin-indium alloy, a metal conductive layer composed of gold, silver, palladium, or an alloy thereof, or an epoxy resin. Smooth layer composed of acrylic resin, rubber or gel cured silicone, polyurethane, epoxy resin, acrylic resin, polyethylene, polypropylene, polystyrene, vinyl chloride resin, polyamide resin, polycarbonate resin, polyacetal resin, polyether An impact buffer layer composed of sulfone, polysulfone or the like can be used.

  Among these, the smooth layer preferably has heat resistance, transparency, and chemical resistance, and, for example, a material having the same composition as that of the resin material contained in the composite layer is preferably used. The average thickness of the smooth layer is preferably about 0.1 to 30 μm, and more preferably about 0.5 to 30 μm.

  In addition, as a layer configuration, a smooth layer is provided on at least one side of the transparent composite substrate, and an impact buffer layer is further provided thereon, or an impact buffer layer is provided on at least one side of the transparent composite substrate, and a smooth surface is further provided thereon. The structure etc. which provide a layer are mentioned.

  The display element substrate of the present invention is originally superior in impact resistance by a falling ball test than a glass substrate, but the impact resistance is further improved by providing the impact buffer layer as described above.

  As described above, according to the present invention, a display element substrate capable of realizing a display element with high quality and high reliability can be obtained.

<Method for producing transparent composite substrate>
As described above, the transparent composite substrate of the present invention is obtained by impregnating a glass cloth with an uncured resin material, forming into a plate shape in this state, and then curing.

  Specifically, in the transparent composite substrate of the present invention, a glass cloth is impregnated with a resin varnish, the resin varnish is cured while being molded, and a composite layer is obtained, and a gas barrier layer is formed on the composite layer. And a process. Hereinafter, the manufacturing process will be described in detail.

  [1] First, a surface treatment is performed by applying a coupling agent to the glass cloth. This step may be performed as necessary and may be omitted. The application of the coupling agent is performed by, for example, a method of immersing a glass cloth in a liquid containing the coupling agent, a method of applying the liquid to the glass cloth, a method of spraying the liquid on the glass cloth, or the like.

  [2] Next, a resin varnish is prepared. The resin varnish contains the above-mentioned uncured resin material, other components such as a filler, an organic solvent, and the like, and also contains a curing agent, an antioxidant, a flame retardant, an ultraviolet absorber, and the like as necessary.

(Curing agent)
Examples of such curing agents include acid anhydrides, crosslinking agents such as aliphatic amines, cationic curing agents, anionic curing agents, and the like, and one or a mixture of two or more thereof is used.

  Among these, a cationic curing agent is particularly preferably used. According to the cationic curing agent, since the resin material can be cured at a relatively low temperature, it is not necessary to set the resin varnish to a high temperature at the time of curing, and generation of thermal stress accompanying a temperature change can be suppressed. As a result, a transparent composite substrate with low optical anisotropy is obtained.

  Further, by using a cationic curing agent, a transparent composite substrate having high heat resistance (for example, glass transition temperature) can be obtained. This is considered to be because the crosslinking density of the cured epoxy resin is increased by using a cationic curing agent.

  The cationic curing agent releases a substance that initiates cationic polymerization by heating, for example, an onium salt cationic curing agent, an aluminum chelate cationic curing agent, or a substance that initiates cationic polymerization by active energy rays. For example, an onium salt cationic curing agent. Among these, a photocationic curing agent is preferable. Thereby, the presence or absence of hardening can be easily selected only by selecting the irradiation region of light.

  The cationic photocuring agent is not particularly limited as long as it can cause a polycationic cationically polymerizable compound and a monofunctional cationically polymerizable compound to undergo a cationic photopolymerization reaction. For example, Lewis acid diazonium salt, Lewis acid iodonium salt, Lewis acid And onium salts such as sulfonium salts. Specifically, boron difluoride phenyldiazonium salt, phosphorus hexafluoride diphenyliodonium salt, antimony hexafluoride diphenyliodonium salt, arsenic hexafluoride tri-4-methylphenylsulfonium salt, antimony tetrafluoride And tri-4-methylphenylsulfonium salt.

  Depending on the type of resin monomer, a radical photocuring agent such as Irgacure series (manufactured by Ciba Japan) may also be used.

  On the other hand, examples of the thermal cationic curing agent include aromatic sulfonium salts, aromatic iodonium salts, ammonium salts, aluminum chelates, and boron trifluoride amine complexes.

  Although content of such a cationic hardening | curing agent is not specifically limited, It is preferable that it is about 0.1-5 mass parts with respect to 100 mass parts of alicyclic epoxy resins, and 0.5-3 weight part is especially preferable. Is preferred. If the content is less than the lower limit, the curability may be lowered, and if the content exceeds the upper limit, the transparent composite substrate may become brittle.

  In the case of photocuring, a sensitizer, an acid proliferating agent, and the like can be used together to accelerate the curing reaction as necessary.

(Antioxidant)
As the antioxidant, for example, a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and the like are used, and a hindered phenol-based antioxidant is particularly preferably used.

  Examples of the hindered phenol antioxidant include BHT and 2,2'-methylenebis (4-methyl-6-tert-butylphenol).

  The content of the antioxidant is preferably 0.01% by mass or more and 5% by mass or less, more preferably about 0.1% by mass or more and 3% by mass or less of the resin varnish. By setting the content of the antioxidant within the above range, a transparent composite substrate having a low optical anisotropy can be obtained, and a transparent composite substrate having a small deterioration in optical anisotropy can also be obtained in a reliability test.

  Moreover, it is preferable that the weight average molecular weight of antioxidant is 200-2000, It is more preferable that it is 500-1500, It is further more preferable that it is 1000-1400. When the weight average molecular weight of the antioxidant is within the above range, the volatility of the antioxidant is suppressed and compatibility with the alicyclic epoxy resin is ensured. Such an antioxidant can continue to remain even after a reliability test such as wet heat treatment, thereby realizing a transparent composite substrate capable of suppressing deterioration of optical anisotropy.

  Examples of phenolic antioxidants other than hindered phenolic antioxidants include, for example, semi-hindered phenolic antioxidants in which one of the substituents located so as to sandwich the hydroxyl group is substituted with a methyl group or the like. And a hindered phenolic antioxidant in which both of two substituents sandwiching a hydroxyl group are substituted with a methyl group or the like. These are added in a smaller amount than the hindered phenolic antioxidant.

  Examples of phosphorus antioxidants include tridecyl phosphite and diphenyl decyl phosphite.

  In addition, by using a hindered phenolic antioxidant and a phosphorus-based antioxidant in combination, their synergistic effect is exhibited, the alicyclic epoxy resin is antioxidant, and the optical anisotropy of the transparent composite substrate is suppressed. Becomes more prominent. This is probably because hindered phenolic antioxidants and phosphorus antioxidants have different antioxidant mechanisms, so they both work independently and have a synergistic effect. .

  The addition amount of antioxidants (particularly phosphorus antioxidants) other than such hindered phenolic antioxidants is preferably about 30 to 300 parts by mass with respect to 100 parts by mass of hindered phenolic antioxidants. And more preferably about 50 to 200 parts by mass. Thereby, a hindered phenolic antioxidant and other antioxidants can exhibit each effect, without burying, and can bring about a synergistic effect.

In addition, the resin varnish may contain an oligomer or a monomer agent of a thermoplastic resin or a thermosetting resin as necessary as long as the characteristics are not impaired. In addition, when using these oligomers and monomers, the composition ratio is appropriately set so that the overall refractive index matches the refractive index of the glass cloth.
The resin varnish is obtained by mixing the above components.

  [3] Thereafter, the obtained resin varnish is impregnated into a glass cloth. When impregnating the resin varnish into the glass cloth, for example, a method of immersing the glass cloth in the resin varnish, a method of applying the resin varnish to the glass cloth, or the like is used. Further, after impregnating the resin varnish into the glass cloth, the resin varnish may be further applied from above after the resin varnish is uncured or cured.

  Thereafter, the resin varnish is defoamed as necessary. Furthermore, the resin varnish is dried as necessary.

  [4] Next, the glass cloth impregnated with the resin varnish is heated while being formed into a plate shape. Thereby, the resin material is cured and a transparent composite substrate is obtained.

  As heating conditions, the heating temperature is preferably about 50 to 300 ° C. and the heating time is about 0.5 to 10 hours, more preferably the heating temperature is about 170 to 270 ° C. and the heating time is about 1 to 5 hours. Is done.

  Moreover, you may make it change heating temperature on the way. For example, it may be initially heated at about 50 to 100 ° C. for about 0.5 to 3 hours, and then heated at about 200 to 300 ° C. for about 0.5 to 3 hours.

  Moreover, a polyester film, a polyimide film, etc. are used for shaping | molding of a resin varnish, for example. And the surface of a resin varnish can be smooth | blunted and planarized by pressing a film from both sides so that the glass cloth impregnated with the resin varnish may be pinched | interposed.

  In addition, when a resin varnish has photocurability, a resin varnish is hardened by irradiating the ultraviolet-ray etc. with a wavelength of about 200-400 nm.

Light energy applied (integrated quantity of light) is preferably at 5 mJ / cm ² or more 3000 mJ / cm ² or less, more preferably 10 mJ / cm ² or more 2000 mJ / cm ² or less. If the integrated light quantity is within the above range, it can be cured uniformly and reliably without unevenness.

[5] Thereafter, a gas barrier layer is formed on the surface of the composite layer.
For forming the gas barrier layer, for example, various liquid phase film forming methods such as sol-gel method, vacuum vapor deposition method, ion plating method, sputtering method, various gas phase film forming methods such as CVD method, etc. are used. It is done. Among these, a vapor deposition method is preferably used, and a sputtering method or a CVD method is more preferably used. In addition, for example, for forming a gas barrier layer containing silicon oxynitride, an RF sputtering method using silicon oxide and nitride as raw materials, or a reactive gas such as oxygen or nitrogen is used during the process using a target containing silicon. A DC sputtering method or the like to be introduced is used.
The transparent composite substrate 1 is obtained as described above.

  Although the present invention has been described above, the present invention is not limited to this. For example, an arbitrary component may be added to the transparent composite substrate and the display element substrate.

Next, specific examples of the present invention will be described.
1. Production of transparent composite substrate (Example 1)
(1) Preparation of Glass Cloth First, a 100 mm square NE glass-based glass cloth (average thickness 95 μm, average wire diameter 9 μm, refractive index 1.511) was prepared. And after immersing this in benzyl alcohol (refractive index 1.54), acetoxyethoxyethane (refractive index 1.406) is added little by little to the benzyl alcohol, and whenever the refractive index of benzyl alcohol is changed, glass The cloth was held over a fluorescent lamp, and it was confirmed whether or not the glass cloth became substantially transparent. Then, the refractive index of the liquid mixture when the first substantially transparent portion appears and the refractive index of the liquid mixture when the substantially transparent portion finally appears are measured. The value was the refractive index difference of the glass cloth. Moreover, the refractive index of the liquid mixture when the area of the transparent part was the largest was made into the average refractive index. The results are shown in Table 1.

  Further, in this glass cloth, the number of longitudinal glass yarns per inch width in the MD direction was 58, and the number of lateral glass yarns per inch width in the TD direction was 50. That is, when the number of transverse glass yarns per inch width in the TD direction was 1, the ratio of the number of longitudinal glass yarns per inch width in the MD direction was 1.16.

  Further, in this glass cloth, when the cross-sectional area of the glass component in the glass yarn per inch width in the TD direction is 1, the ratio of the cross-sectional area of the glass component in the glass yarn per inch width in the MD direction is 1.35.

  Further, the number of twists of the glass fiber bundle of the glass cloth was 1.0 per 1 inch length in the MD direction and 1.0 per 1 inch length in the TD direction.

(2) Preparation of Resin Varnish Next, an alicyclic epoxy resin having the structure of the above chemical formula (2), wherein “—X—” is “—C (CH ₃ ) ₂ —” (Daicel Chemical) Kogyo Co., Ltd., E-DOA, Tg:> 250 ° C.), silsesquioxane (manufactured by Toagosei Co., Ltd., OX-SQ-H), and photocationic polymerization initiator (manufactured by ADEKA, SP-170) ) And a solvent (methyl isobutyl ketone) were mixed at a ratio shown in Table 1 to prepare a resin varnish. The refractive index after crosslinking of E-DOA is 1.513, and the refractive index after crosslinking is 1.47.
The Abbe number of the resin varnish was measured as follows.

First, a resin varnish was applied to a release-treated glass plate to form a liquid film, and then the release-treated glass plate was placed on the liquid film, and the liquid film was sandwiched between the glass plates. At this time, spacers having a thickness of 200 μm were arranged on the four sides between the glass plates. The liquid film was irradiated with ultraviolet rays of 1100 mJ / cm ^{2 with} a high-pressure mercury lamp. Furthermore, a 200 μm-thick resin film (matrix resin) was obtained by heating at 250 ° C. for 2 hours. Thereafter, the Abbe number of the resin film was measured using an Abbe refractometer (DR-A1 manufactured by Atago Co., Ltd.). The results are shown in Table 1.

(3) Impregnation / curing of resin varnish Next, the obtained resin varnish was impregnated into a glass cloth, then subjected to defoaming treatment, and the resin varnish was further dried.

Subsequently, the glass cloth impregnated with the resin varnish in this way was sandwiched between two glass plates subjected to a release treatment, and irradiated with ultraviolet rays of 1100 mJ / cm ^{2 with} a high-pressure mercury lamp. Furthermore, the composite layer of average thickness 97micrometer (glass cloth content 60 mass%) was obtained by heating at 250 degreeC for 2 hours.

(4) Formation of smooth layer (intermediate layer) Alicyclic epoxy resin having the structure of the above chemical formula (2), wherein “—X—” is “—C (CH ₃ ) ₂ —” Daicel Chemical Industries, Ltd., E-DOA, Tg:> 250 ° C.) 100 parts by mass and photocationic polymerization initiator (ADEKA, SP-170) 1 part by mass are mixed to prepare a coating material. did. Subsequently, after apply | coating to both surfaces of a composite layer with a bar coater, the ultraviolet ray of 1100 mJ / cm < ² > was irradiated with the high pressure mercury lamp. Further, a smooth layer having an average thickness of 5 μm was formed by heating at 250 ° C. for 2 hours.

(5) Formation of Gas Barrier Layer Next, the composite layer having the smooth layer formed thereon was placed in the chamber of the RF sputtering apparatus. Then, after reducing the pressure in the chamber, Ar gas was introduced at 0.5 Pa and O ₂ gas was introduced at a partial pressure of 0.005 Pa. Subsequently, an RF power of 0.3 kW was applied between the Si ₃ N ₄ target placed in the chamber and the composite layer for discharge. When the discharge was stabilized, the shutter provided between the target and the composite layer was opened, and the film formation of the gas barrier layer composed of SiOxNy was started. Thereafter, when the average thickness of the gas barrier layer reached 100 nm, the shutter was closed to complete the film formation. The chamber was opened to the atmosphere to obtain a manufactured transparent composite substrate.

  Tm-Td is calculated when the 5% weight loss temperature of the alicyclic epoxy resin that is the main component of the resin material is Td [° C.] and the melting point of the inorganic material constituting the gas barrier layer is Tm [° C.]. And shown in Table 1.

(Examples 2 to 10, Comparative Examples 1 to 7)
A transparent composite substrate was obtained in the same manner as in Example 1 except that the production conditions were changed as shown in Table 1.

  Moreover, the hydrogenated biphenyl type alicyclic epoxy resin used in Examples 2, 3, 4, 8 and Comparative Examples 2, 4, 7 (Daicel Chemical Industries, E-BP, Tg:> 250 ° C.) And having the structure of the chemical formula (1). The refractive index after crosslinking of E-BP is 1.522.

  Moreover, the T glass-type glass cloth used in Examples 3 and 8 and Comparative Example 4 has an average thickness of 95 μm, an average wire diameter of 9 μm, and a refractive index of 1.522.

  Further, the S glass-based glass cloth used in Example 5 has an average thickness of 95 μm, an average wire diameter of 9 μm, and a refractive index of 1.510.

  Moreover, the E glass-type glass cloth used in Comparative Examples 6 and 7 has an average thickness of 95 μm, an average wire diameter of 9 μm, and a refractive index of 1.558.

  In addition, the alicyclic acrylic resin (IRR-214K, manufactured by Daicel-Cytec Corp.) used in Example 5 has a refractive index after crosslinking of 1.529. When the resin varnish was cured, the glass cloth impregnated with the resin varnish was irradiated with ultraviolet rays having a wavelength of 365 nm.

  Moreover, in Comparative Examples 6 and 7, bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, Epicoat 828) was used.

  Further, Irgacure 184 manufactured by Ciba Japan Co., Ltd. was used as the radical photopolymerization initiator used in Example 5 and Comparative Examples 6 and 7.

  Moreover, the average thickness of the gas barrier layer in Example 2 is 50 nm, and the average thickness of the gas barrier layer in Example 8 is 250 nm.

2. 2.1 Evaluation of transparent composite substrate 2.1 Evaluation of dimensional change due to humidity A test piece of 100 mm × 100 mm was cut out from the transparent composite substrate obtained in each Example and each Comparative Example, and a non-contact image measuring device S-QVH606 (Mitutoyo Corporation) The dimensions of the four sides of the sample were measured in an environment of temperature 25 ° C./apparatus humidity 50%. Next, after the sample was treated under the conditions of temperature 25 ° C./relative humidity 90% / 24 hours, the dimensions of the four sides were similarly measured, and the dimensional change rate of the test piece accompanying the moisture absorption treatment was measured. In addition, the measurement of the dimensional change rate was performed for each of the MD direction and the TD direction in accordance with the woven structure of the glass cloth. The measurement results are shown in Table 1.

2.2 Evaluation of Haze For the transparent composite substrates obtained in each Example and each Comparative Example, a test piece of 100 mm × 100 mm was cut out, and nine points were uniformly dispersed in an environment of temperature 25 ° C./relative humidity 50%. The haze was measured for each point using a turbidimeter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH2000) under conditions based on JIS K7136. And the average value of the measured value was made into haze.

2.3 Evaluation of Haze Change Rate Next, after the sample was processed under the conditions of temperature 25 ° C./relative humidity 90% / 24 hours, the haze of the same part as the measurement part described in 2.2 was changed to the method described in 2.2. The difference from the haze measured in 2.2 was obtained.

2.4 Evaluation of Gas Barrier Properties With respect to the transparent composite substrates obtained in each Example and each Comparative Example, the water vapor permeability specified in JIS K 7129 B and the oxygen permeability specified in JIS K 7126 B were measured. Measurement conditions are as shown in Table 1.

2.5 Evaluation of Abrasion Resistance For the transparent composite substrates obtained in each example and each comparative example, the test method for the mechanical properties of the coating film specified in JIS K 5600-5-4 (scratch hardness (pencil method)) ) To evaluate the wear resistance. The abrasion resistance was evaluated according to the following evaluation criteria.

<Evaluation criteria for wear resistance>
A: Scratch hardness is harder than 2H B: Scratch hardness is F or H C: Scratch hardness is softer than B Table 1 shows the above evaluation results.

  As is clear from Table 1, the transparent composite substrates obtained in each Example had a low haze, and even when the moisture treatment was performed, the haze change rate was small. Moreover, the difference (anisotropy) of the dimensional change by the weaving direction was small in the transparent composite substrate obtained in each Example. In addition, the value of Tm-Td is within a predetermined range, and the wear resistance of the transparent composite substrate can be improved by optimizing the abundance ratio of oxygen atoms and nitrogen atoms in the silicon compound constituting the gas barrier layer. Was recognized. Therefore, it became clear that the transparent composite substrate obtained in each example has excellent optical characteristics and can maintain excellent optical characteristics over a long period of time even in a harsh environment.

  On the other hand, the transparent composite substrate obtained in each comparative example contained a large haze. Moreover, it became clear that a haze changes a lot with moisture treatment. Furthermore, it has been clarified that the transparent composite substrates obtained in the respective comparative examples are rapidly deteriorated by performing an accelerated test such as moisture treatment even if the haze is small immediately after production. The transparent composite substrates obtained in the respective comparative examples include those in which the value of Tm−Td is out of the predetermined range, and those in which the glass cloth has a large refractive index difference, water vapor permeability, or linear expansion coefficient. It is speculated that these have led to deterioration of haze. Further, it was confirmed that the wear resistance was lowered when a gas barrier layer other than the silicon compound was used.

  From the above, it became clear that according to the present invention, a transparent composite substrate capable of maintaining uniform and excellent optical characteristics over a long period of time can be obtained.

DESCRIPTION OF SYMBOLS 1 Transparent composite substrate 2 Glass cloth 2a Longitudinal direction glass yarn (1st glass fiber bundle)
2b Transverse glass yarn (second glass fiber bundle)
3 Resin material 4 Composite layer 5 Gas barrier layer

Claims (9)

A composite layer having a glass cloth and a resin material having an Abbe number of 45 or more impregnated in the glass cloth;
A gas barrier layer provided on the composite layer and made of an inorganic material,
When the melting point of the inorganic material is Tm [° C.] and the 5% weight reduction temperature of the main component of the resin material is Td [° C.], the relationship of 1200 ° C. <(Tm−Td) <1400 ° C. is satisfied. A transparent composite substrate characterized by   The transparent composite substrate according to claim 1, wherein the inorganic material contains a silicon compound.   The transparent composite substrate according to claim 2, wherein the silicon compound contains an oxygen atom and a nitrogen atom.   4. The transparent composite according to claim 2, wherein the silicon compound is represented by SiOxNy, wherein x satisfies a relationship of 1 ≦ x ≦ 2 and y satisfies a relationship of 0 ≦ y ≦ 1. 5. substrate.   The transparent composite substrate according to any one of claims 1 to 4, wherein an average thickness of the gas barrier layer is 10 to 500 nm. The transparent composite substrate according to any one of claims 1 to 5, wherein the water vapor permeability specified in JIS K 7129 B is 0.1 [g / m ² / day / 40 ° C, 90% RH] or less.   The transparent composite substrate according to claim 1, wherein the resin material is mainly composed of an alicyclic epoxy resin.   The transparent composite substrate according to any one of claims 1 to 7, further comprising an intermediate layer provided between the composite layer and the gas barrier layer and made of a resin material.   A display element substrate comprising the transparent composite substrate according to claim 1.

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