JP2022137418A - Waveform conversion paste, substrate, display, and method for manufacturing substrate - Google Patents

Abstract

To stably apply a paste excellent in heat resistance and light resistance by a nozzle application method.SOLUTION: A waveform conversion paste contains (A) a siloxane resin, (B) a waveform conversion material, and (C) a solvent. (A) the siloxane resin is represented by the following general formula (1) and (A) the siloxane resin has a weight average molecular weight of 10,000 or more and 1,000,000 or less and a viscosity at a temperature of 20°C and a shear rate of 1 sec-1 of 10,000 mPa s or more and 200,000 mPa s or less. (R1 and R2 each individually represent an alkyl group or an aromatic group having 1-12 carbon atoms and may be the same or different, R3 represents an organic group having 1-20 carbon atoms, R4 represents any one of a methyl group, an ethyl group, and hydrogen, and x, y, z in the formula satisfy the conditions of 0.1≤x≤0.3, 0≤y, 0≤z, and x+y+z=1.)SELECTED DRAWING: None

Description

The present invention relates to a wavelength conversion paste, a substrate, a display and a method for manufacturing the substrate.

In recent years, with the development of information terminal devices such as smartphones and tablets, and the high definition of flat panel displays such as televisions, the demand for higher performance of displays is increasing. Among them, wavelength-converting OLED displays and LED displays are attracting attention as high-performance displays. These displays use active matrix-driven organic light-emitting diodes (hereinafter sometimes referred to as OLEDs) and light-emitting diodes (hereinafter sometimes referred to as LEDs) as light sources, and at least part of the light is converted by wavelength conversion materials. It is a display that displays full color by changing the color, and has excellent contrast and color reproducibility.

As a method of using an OLED as a light source, a method of using an OLED that emits blue light is known (Patent Document 1). In this case, the blue sub-pixel transmits and scatters the light from the OLED without wavelength conversion, and the green and red sub-pixels convert the blue light from the OLED to green and red by the wavelength conversion material, respectively. I am letting it pass through.

As for the method of using an LED as a light source, in addition to the method of using a blue-emitting LED similar to an OLED and converting part of the light into red and green with a wavelength conversion material, an ultraviolet-emitting LED is used and a wavelength conversion material is used. A method of converting into blue, green, and red is known (Patent Document 2).

These wavelength-converted displays require a patterned arrangement of wavelength-converting materials with sizes corresponding to the sub-pixels of the OLED or LED light sources. A photolithography method and an inkjet method (Patent Document 3) are known as methods of patterning a wavelength conversion material.

Special Table No. 2006-501617 Special table 2016-523450 WO2018/123103

However, in the photolithography method, the wavelength conversion material is applied to the entire surface, and after a predetermined position is exposed to light, most of the material is removed by development, so the loss of the wavelength conversion material is large. It was a necessary and complicated task. In addition, the inkjet method is excellent in material efficiency because the wavelength conversion layer can be formed only at the desired position. There was a problem that the particle components such as the wavelength conversion material settled in the ink, and the ink jet nozzle was easily clogged.

On the other hand, as a paste application method, a nozzle application method is known in which paste is applied while being continuously ejected from ejection holes of a die. FIG. 1 is a schematic diagram showing a method of applying a paste using a die having a plurality of ejection holes by a nozzle coating method. The nozzle coating method has a space (manifold) for storing the paste 2 inside the nozzle 1, and controls the pressure through a pressure pipe 4 connected to the space while moving relatively to face the substrate 3. In this method, the paste 2 is discharged from the discharge holes 5 by introducing compressed air, and the paste 2 is applied in the form of stripes. The paste 2 ejected from the ejection holes 5 fills the spaces separated by the partition walls 6 on the substrate. At this time, the paste liquid transfer method is not limited to the introduction of compressed air, and other methods such as using a liquid transfer pump may be used. In the nozzle coating method, the viscosity of the paste can be adjusted from low to high as compared with the ink jet method. Therefore, by designing the paste to have a high viscosity, it is possible to suppress the clogging of the ejection hole nozzles due to sedimentation of the particle components. However, when the design of the paste containing the wavelength conversion material for the wavelength conversion type display is the same as that of the existing ink for the ink jet method, there is a problem that the paste cannot be discharged normally from the discharge holes. In addition, even if ejection is possible with a nozzle having ejection holes larger than 80 μm in diameter as in conventional PDP (plasma display panel) applications, ejection accuracy is high when a nozzle having minute ejection holes with a diameter of 50 μm or less is used. There was a problem that it could not be applied stably. In addition, there is a problem that the heat resistance and light resistance of resins used in conventional wavelength conversion pastes are insufficient.

Therefore, the present invention uses a nozzle coating method to enable stable coating with good discharge accuracy and heat resistance and light resistance even when using a nozzle having minute discharge holes with a hole diameter of φ50 μm or less. An object of the present invention is to provide a paste having excellent properties.

In order to solve the above problems, the wavelength conversion paste of the present invention has the following configuration. i.e.
(A) a siloxane resin, (B) a wavelength conversion material, and (C) a solvent; ,000 or more and 1,000,000 or less, and a viscosity of 10,000 mPa s or more and 200,000 mPa s or less at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ . be.

(R ¹ and R ² each independently represent an alkyl group or aromatic group having 1 to 12 carbon atoms and may be the same or different; R ³ represents an organic group having 1 to 20 carbon atoms; ^R4 represents a methyl group, an ethyl group, or hydrogen, and x, y, and z in the formula satisfy the conditions of 0.1≦x≦0.3, 0≦y, 0≦z, and x+y+z=1 .)
The substrate of the present invention has the following configuration. i.e.
A substrate comprising at least one of the wavelength conversion paste and a cured product of the wavelength conversion paste, a support plate, partition walls provided on the support plate, and cells partitioned by the partition walls, wherein the wavelength conversion paste or A substrate having at least one of the cured wavelength conversion paste in the cell.

The display of the present invention has the following configuration. i.e.
A display comprising the above substrate and an organic light-emitting diode or light-emitting diode as a light source.

The substrate manufacturing method of the present invention has the following configuration. i.e.
The wavelength conversion paste according to any one of claims 1 to 4 is applied in the cells of a semi-finished substrate comprising a support plate, partition walls provided on the support plate, and cells partitioned by the partition walls, by a nozzle coating method. A method for manufacturing a substrate, comprising a step of coating.

In the wavelength conversion paste of the present invention, the (B) wavelength conversion material is preferably an inorganic phosphor and/or an organic phosphor.

In the wavelength conversion paste of the present invention, the (B) wavelength conversion material is preferably an inorganic phosphor.

The wavelength conversion paste of the present invention preferably satisfies the following relationship (i) with respect to _Dω defined by the following formula (1).

(1) D _ω = G″ _ω /G′ _ω
D _ω : Loss tangent tan δ at measurement temperature 5° C. and angular velocity ω
G′ _ω : Storage modulus at a measurement temperature of 5° C. and an angular velocity ω G″ _ω : Loss modulus at a measurement temperature of 5° C. and an angular velocity ω (i) 0.7≦D _ω ≦2.0 (100≦ω≦500 rad/ sec, 5°C)

ADVANTAGE OF THE INVENTION This invention can apply|coat the wavelength conversion paste excellent in heat resistance and light resistance stably by the nozzle coating method.

It is a schematic diagram showing a paste coating method by a nozzle coating method. FIG. 2 is a cross-sectional view showing one embodiment of the substrate of the present invention having patterned barrier ribs and cured paste.

The wavelength conversion paste of the present invention contains (A) a siloxane resin, (B) a wavelength conversion material, and (C) a solvent. By containing the (A) siloxane resin having the above-mentioned molecular weight and specific structure, the viscosity of the wavelength conversion paste is 10,000 mPa s or more and 200,000 mPa s or less at a temperature of 20 ° C. and a shear rate of 1 sec ^-1 . A wavelength conversion paste having excellent properties and light resistance can be stably applied by a nozzle coating method.

(A) siloxane resin
(A) The siloxane resin is a hydrolysis/dehydration condensate of organosilane, and in the present invention, it is characterized by being represented by the following general formula (1).

R ¹ and R ² each independently represent an alkyl group or aromatic group having 1 to 12 carbon atoms and may be the same or different; R ³ represents an organic group having 1 to 20 carbon atoms; ⁴ represents a methyl group, an ethyl group, or hydrogen, and x, y, and z in the formula satisfy the conditions of 0.1≦x≦0.3, 0≦y, 0≦z, and x+y+z=1. Here, if x is less than 0.1, excessive cross-linking reaction during polymerization cannot be controlled, making it difficult to obtain a solvent-soluble siloxane resin. On the other hand, if x is more than 0.3, the dehydration condensation reaction cannot be promoted, making it difficult to obtain a high-molecular-weight siloxane resin. If the range of y and z is less than 0, the dehydration condensation reaction cannot be promoted, making it difficult to obtain a high-molecular-weight siloxane resin.

Here, the structural units represented by x, y, and z in general formula (1) correspond to general formulas (2) to (4), respectively, and consist of alkoxysilane compounds.

Examples of alkoxysilane compounds represented by general formula (2) include methylpropyldimethoxysilane, ethylpropyldimethoxysilane, methylbutyldimethoxysilane, ethylbutyldimethoxysilane, methylpentyldimethoxysilane, methylhexyldimethoxysilane, and methylheptyldimethoxysilane. , methyloctyldimethoxysilane, methylnonyldimethoxysilane, methyldecyldimethoxysilane, methylpropyldiethoxysilane, methylbutyldiethoxysilane, methylpentyldiethoxysilane, methyloctyldiethoxysilane, methyldodecyldiethoxysilane, methylpropyldipropoxysilane Silane, methylbutyldipropoxysilane, methylpentyldipropoxysilane, methyldecyldipropoxysilane, methyldodecyldipropoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, and two or more of these may be used.

Examples of alkoxysilane compounds represented by formula (3) include methyltrimethoxysilane, phenyltrimethoxysilane, naphthyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, propyltrimethoxysilane, and butyltrimethoxysilane. , pentyltrimethoxysilane, hexyltrimethoxysilane, heptyltrimethoxysilane, octyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, undecyltrimethoxysilane, dodecyltrimethoxysilane, propyltriethoxysilane, butyltriethoxysilane Silane, pentyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, propyltripropoxysilane, butyltripropoxysilane, pentyltripropoxysilane, octyltripropoxysilane, decyltripropoxysilane, dodecyltripropoxysilane Silane, 4-trimethoxysilylbutyrate, 4-triethoxysilylbutyrate, 5-trimethoxysilylvalerate, 5-triethoxysilylvalerate, 3-trimethoxysilylpropylsuccinic anhydride, 3-triethoxysilylpropyl Succinic anhydride, 3-trimethoxysilylpropylcyclohexyldicarboxylic anhydride, 3-triethoxysilylpropylcyclohexyldicarboxylic anhydride, 3-trimethoxysilylpropyl phthalic anhydride, 3-triethoxysilylpropyl phthalic anhydride and carboxyl group-containing alkoxysilane compounds such as , and two or more of these may be used.

Examples of alkoxysilane compounds represented by general formula (4) include tetramethoxysilane and tetraethoxysilane.

(A) The siloxane resin can be obtained by hydrolyzing the aforementioned organosilane compound and then subjecting the hydrolyzate to a dehydration condensation reaction in the presence of a solvent.

Various conditions for hydrolysis can be set according to physical properties suitable for the intended use, taking into consideration the reaction scale, the size and shape of the reaction vessel, and the like. Various conditions include, for example, acid concentration, reaction temperature, and reaction time.

Acid catalysts such as hydrochloric acid, acetic acid, formic acid, nitric acid, oxalic acid, hydrochloric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, polyvalent carboxylic acids and their anhydrides, and ion exchange resins can be used for the hydrolysis reaction. Among these, acidic aqueous solutions containing formic acid, acetic acid and/or phosphoric acid are preferred.

When an acid catalyst is used for the hydrolysis reaction, the amount of the acid catalyst added is 0.05 parts by weight with respect to 100 parts by weight of all the alkoxysilane compounds used in the hydrolysis reaction, from the viewpoint of making the hydrolysis proceed more rapidly. part or more is preferable, and 0.1 part by weight or more is more preferable. On the other hand, from the viewpoint of appropriately adjusting the progress of the hydrolysis reaction, the amount of the acid catalyst to be added is preferably 20 parts by weight or less, more preferably 10 parts by weight or less with respect to 100 parts by weight of all the alkoxysilane compounds. Here, the total amount of alkoxysilane compound means the amount including all of the alkoxysilane compound, its hydrolyzate and its condensate, and the same shall apply hereinafter.

A hydrolysis reaction and a dehydration condensation reaction are performed in an organic solvent. The organic solvent can be appropriately selected in consideration of the stability, wettability, volatility, etc. of the wavelength conversion paste. Organic solvents include, for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, 4-methyl-2-pentanol, 3-methyl-2-butanol, 3-methyl-3- Alcohols such as methoxy-1-butanol and diacetone alcohol; Glycols such as ethylene glycol and propylene glycol; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monoethyl Ethers such as ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol mono-t-butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether; methyl ethyl ketone, acetylacetone, methyl propyl ketone, Ketones such as methyl butyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, 2-heptanone; amides such as dimethylformamide and dimethylacetamide; ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether Acetates such as acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate; aromatic or aliphatic such as toluene, xylene, hexane, cyclohexane group hydrocarbon; γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylsulfoxide and the like. You may use 2 or more types of these.

The amount of the organic solvent used in the hydrolysis reaction to be added is preferably 3 parts by weight or more, more preferably 6 parts by weight or more with respect to 100 parts by weight of all the alkoxysilane compounds, from the viewpoint of suppressing gel formation. On the other hand, the amount of the organic solvent to be added is preferably 300 parts by weight or less, more preferably 200 parts by weight or less with respect to 100 parts by weight of all the alkoxysilane compounds, from the viewpoint of accelerating the hydrolysis reaction.

Moreover, ion-exchanged water is preferable as the water used for the hydrolysis reaction. Although the amount of water can be set arbitrarily, it is preferably 1.0 to 4.0 mol with respect to 1 mol of all alkoxysilane compounds.

Examples of the dehydration-condensation reaction method include a method of directly heating a silanol compound solution obtained by a hydrolysis reaction of an organosilane compound. The heating temperature is preferably 50° C. or higher and the boiling point of the solvent or lower, and the heating time is preferably 1 to 100 hours. Further, reheating or addition of a base catalyst may be performed in order to increase the degree of polymerization of the siloxane resin. Also, depending on the purpose, after hydrolysis, an appropriate amount of the alcohol produced may be distilled off under heating and/or under reduced pressure, and then a suitable solvent may be added.

The weight average molecular weight (Mw) of (A) the siloxane resin in the present invention is 10,000 or more, preferably 100,000 or more. (A) If the weight-average molecular weight Mw of the siloxane resin is less than 10,000, the nozzle coatability will be poor. On the other hand, the Mw of (A) the siloxane resin should be 1,000,000 or less, preferably 500,000 or less. (A) When the weight average molecular weight Mw of the siloxane resin exceeds 1,000,000, nozzle clogging is likely to occur. (A) The Mw of the siloxane resin can be controlled by optimizing the hydrolysis and dehydration condensation reaction conditions described above. Here, the Mw of the (A) siloxane resin in the present invention refers to a polystyrene conversion value measured by gel per emission chromatography (GPC).

In the wavelength conversion paste of the present invention, the content of (A) the siloxane resin can be arbitrarily set depending on the desired viscosity, but is generally 10 to 90% by weight in the wavelength conversion paste. Moreover, 20 weight% or more is preferable in solid content of a wavelength conversion paste, and, as for content of (A) siloxane resin, 25 weight% or more is more preferable. On the other hand, the content of (A) the siloxane resin is preferably 85% by weight or less in the solid content of the wavelength conversion paste.

Further, the wavelength conversion paste of the present invention has a viscosity of 10,000 to 200,000 mPa·s at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ . If the paste has a viscosity of less than 10,000 mPa s at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ , particle components such as phosphors used as wavelength conversion materials tend to settle when the paste is stored for a long period of time after preparation. . The viscosity of the paste at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ is preferably 15,000 mPa·s or more, more preferably 20,000 mPa·s or more. Moreover, if the viscosity of the paste exceeds 200,000 mPa·s at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ , it becomes difficult to select a liquid feeding pressure suitable for ejection. The viscosity of the paste at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ is preferably 180,000 mPa·s or less, more preferably 150,000 mPa·s or less.

(B) Wavelength conversion material In the present invention, the wavelength conversion material refers to a material having wavelength conversion properties that absorbs electromagnetic waves and emits electromagnetic waves having a wavelength different from the wavelength of the absorbed electromagnetic waves. A full-color display can be obtained by applying and patterning the paste of the present invention having a wavelength conversion material, producing a substrate having a wavelength conversion layer, and combining it with an OLED light source or an LED light source.

(B) As the wavelength conversion material, it is preferable to use an inorganic phosphor and/or an organic phosphor. For example, in the case of a display in which an OLED that emits blue light and a substrate having a wavelength conversion layer are combined, a region corresponding to a red sub-pixel contains red light that emits red fluorescence when excited by blue excitation light. A phosphor is preferably used as the wavelength conversion material, and a green phosphor that emits green fluorescence when excited by blue excitation light is preferably used as the wavelength conversion material in the region corresponding to the green subpixel, Preferably, no wavelength converting material is used in the regions corresponding to the blue subpixels. Similarly, the substrate of the present invention can also be used for a display that uses blue LEDs or ultraviolet light emitting LEDs corresponding to each sub-pixel as a backlight. Light emission of each sub-pixel can be turned ON/OFF by active matrix driving of OLEDs and LEDs.

Inorganic phosphors emit light in colors such as green and red. Examples of inorganic phosphors include those that are excited by excitation light with a wavelength of 400 to 500 nm and have an emission spectrum with a peak in the region of 500 to 700 nm, and the above-mentioned quantum dots, which are called quantum dots and have unique optical properties according to quantum mechanics. Inorganic semiconductor fine particles of scale and the like can be mentioned. Examples of the shape of the former inorganic phosphor include a spherical shape and a columnar shape. Examples of such inorganic phosphors include YAG-based phosphors, TAG-based phosphors, sialon-based phosphors, Mn ⁴⁺ -activated fluoride complex phosphors, and the like. You may use 2 or more types of these.

(C) Solvent (C) The solvent is the solid content concentration/viscosity of the wavelength conversion paste regardless of whether the (A) siloxane resin contains/does not contain the solvent used in the hydrolysis reaction and the dehydration condensation reaction obtained by the above method. can be added for the purpose of adjusting the From the viewpoint of coating stability, the solid content concentration of the wavelength conversion paste in the present invention is preferably 70 to 90 wt %. If the solid content concentration of the wavelength conversion paste is less than 70 wt %, the liquid swells due to the influence of the solvent component in the coating liquid during coating, and pulsation is likely to occur, making it difficult to maintain stability during coating. On the other hand, when the solid content concentration is higher than 90 wt %, the fluidity of the coating liquid due to the solvent component is low, and the ejection and coating properties are deteriorated. Further, by setting the solid content concentration within the above range, the coating liquid is leveled in the step of drying the solvent component after coating, and a uniform film can be formed. Further, by setting the solid content concentration within the above range, when the liquid is applied to the openings surrounded by the partition walls, it is possible to fill a thick film with a small amount of volatile components. Examples of the (C) solvent used in the present invention include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, 4-methyl-2-pentanol, 3-methyl-2- alcohols such as butanol, 3-methyl-3-methoxy-1-butanol, diacetone alcohol; glycols such as ethylene glycol and propylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene Ethers such as glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol mono-t-butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether; Ketones such as methyl ethyl ketone, acetylacetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, 2-heptanone; amides such as dimethylformamide and dimethylacetamide; ethyl acetate, propyl acetate, butyl acetate, Acetates such as isobutyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate; toluene, xylene, hexane , aromatic or aliphatic hydrocarbons such as cyclohexane; γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylsulfoxide and the like. You may use 2 or more types of these.

In describing the present invention, evaluation indices in the prior art, evaluation indices in the present invention, the significance of viscoelasticity parameters and methods for measuring them, and properties required to achieve the effects of the present invention, namely fluidity, rigidity, and ejection properties, will be described. I will explain in order.

When applying the wavelength conversion paste by the nozzle coating method, as described above, the wavelength conversion paste is filled in the manifold in the nozzle and discharged from the discharge hole by compressed air introduced through the pressurized pipe. At this time, the property that the apparent viscosity, which appears as the ratio of the shear stress applied to the wavelength conversion paste to the shear rate, decreases as the shear stress increases is called thixotropy. Thixotropy is generally used as a parameter that influences ejection properties of nozzle coating. An index representing thixotropy is the TI value (Thixotropic Index) shown in the following formula (2), where η _a and η _b are the viscosities at arbitrary shear rates a and b (here, a < b). expressed.

(2) TI= _ηa / _ηb
In general, when the TI value is less than 1, the viscosity of the wavelength conversion paste does not decrease even when shear stress is applied. A problem arises that it is not ejected. Also, even if the TI value is greater than 1, if a ballast effect occurs when the paste is ejected from the ejection hole, the wavelength conversion paste will expand and will not be ejected normally, or the paste will run on the top of the barrier ribs of the base substrate during application. may cause defects. Here, the ballast effect means that when a polymer solution or polymer melt is extruded through a fine hole, the molecular chains do not relax completely, and some shearing energy is stored as elastic deformation, which relaxes as soon as it exits the hole. A phenomenon in which a liquid expands by being

Hitherto, the TI value as described above has been emphasized as an index for evaluating ejection performance of nozzle coating. However, with the increasing definition of displays, when using a nozzle having ejection holes with a minute hole diameter of φ50 μm or less, the possibility of ejection depends on the type of wavelength conversion paste even if the TI value is the same. Therefore, it has become clear that the ejection accuracy of the wavelength conversion paste cannot be evaluated only by thixotropy as in the past. In addition, even when the paste can be discharged normally, if the wavelength conversion paste discharge property during application is not stable, the application becomes unstable, the wavelength conversion paste pulsates, and the uniformity of the formed pixel film thickness is impaired. At the same time, it has become clear that the applicability cannot be evaluated only by the ejection property. A new evaluation index is necessary for the wavelength conversion paste used for higher resolution displays for coating using a nozzle having ejection holes with a smaller hole diameter than before, and we have been earnestly studying it. Finally, we found that the viscoelasticity of the wavelength conversion paste can be used to evaluate the dischargeability and coating properties.

In the present invention, it is found that the change behavior of the loss tangent of the wavelength conversion paste is important as a factor that determines whether or not nozzle coating can be discharged and the applicability in a state where a high shear stress is applied (hereinafter referred to as a high shear region). It was used as an indicator of the possibility of ejection in a state of vertical ejection while maintaining a constant shape suitable for nozzle coating (hereinafter referred to as a columnar flow) and the coating stability.

The viscoelasticity of the wavelength conversion paste in the present invention can be represented by the loss elastic modulus G″ and the storage elastic modulus G′ for the viscous component and the elastic component, respectively, and the ratio of the storage elastic modulus to the loss elastic modulus as the loss tangent tan can be represented.

These viscoelastic parameters can be measured using a rheometer (HAAKE MARS; manufactured by Thermo Fisher Scientific Co., Ltd.). Specifically, the rheometer was equipped with Plate P35 Ti L manufactured by the same company, the temperature was set in the range of 5 to 25 ° C., the gap between the plate and the sample stage was set to 100 to 200 µm, and the angular velocity was set to 1 to 200 µm. G′, G″ and tan δ are measured when changing to 500 rad/s. In addition, when measuring the viscoelasticity of a high-viscosity wavelength conversion paste like the present invention, since the resistance of the sample during measurement is large, It is preferable to use a parallel plate.When measured using a parallel plate, the shear rate differs from the center of the plate to the edge of the plate, and the low shear rate and high shear rate during nozzle application and viscoelasticity are described below. Since it is difficult to precisely match the shear rate at the time of measurement, the angular velocity at the time of measurement is used here instead of the shear rate.

Next, the viscoelastic properties of the wavelength conversion paste necessary for achieving the effects of the present invention will be described.

The wavelength conversion paste of the present invention has fluidity at room temperature and in a state in which no shear is applied or a weak shear is applied (hereinafter referred to as a low shear region). Specifically, at a measurement temperature of 25 ° C., the loss elastic modulus G″ _ω at the angular velocity ω and the storage elastic modulus G′ _ω at the angular velocity ω are G″ _ω >G when the angular velocity ω is in the range of 1 rad / s to 100 rad / s. It is preferable that the relationship ' _ω is satisfied, in other words, the viscosity of the wavelength conversion paste is always higher than the elasticity. When the above relationship is satisfied, the loss tangent _Dω obtained from the above formula (1) becomes a value greater than 1. Here, assuming that the minimum value of D _ω at a measurement temperature of 25° C. and an angular velocity ω in the range of 1 rad/s to 100 rad/s is D _{MIN (25° C.)} , in order to satisfy the relationship G″ _ω >G′ _{ω . _ _} easier. In addition, when the above relationship is satisfied, the coating liquid becomes fluid after being applied to the substrate, so that the openings can be neatly filled and the pixels can be formed normally. As an index of sufficient fluidity required for nozzle coating, the viscosity of the coating liquid in the low shear region is preferably higher than the elasticity.

Moreover, the wavelength conversion paste of the present invention preferably has rigidity in addition to fluidity at room temperature and a low shear region. This is because, if the coating liquid does not have rigidity, the wavelength conversion paste swells into droplets when discharged from the discharge holes, making it difficult to apply the paste with high accuracy. More specifically, the loss elastic modulus G″ _{1 (25° C.)} at a measurement temperature of 25° C. and an angular velocity ω of 1 rad/s preferably exceeds 10 Pa, more preferably 20 Pa or more.

The above characteristics are various characteristics that are prerequisites for exhibiting the effects of the wavelength conversion paste in the present invention.

When the wavelength conversion paste of the present invention satisfies the above condition (i), swelling of the wavelength conversion paste is suppressed when the wavelength conversion paste is discharged from the discharge hole, forming a columnar flow, which enables accurate application. It becomes possible. When the coating liquid filled in the manifold of the nozzle is pressurized, shear stress is applied to the wavelength conversion paste when it is ejected from the ejection hole, and the speed of deformation of the wavelength conversion paste in the state where the shear stress is applied is the shear rate can be expressed as The shear stress and shear rate are determined by the length and diameter of the discharge hole and the volumetric flow rate of the wavelength conversion paste during application. Minutes need to be corrected. As an example, the apparent shear rate without the above correction is shown by the following formula (3). In addition, since the shear rate applied to the wavelength conversion paste changes depending on the structure of the nozzle and the ejection hole, the calculation of the shear rate is not necessarily limited to the formula defined below.

(3) γ=4Q/πR ³
γ: shear rate (sec ⁻¹ )
Q: volumetric flow rate (mm ³ /sec)
R: discharge hole radius (mm)
From the formula (3), it can be said that the smaller the diameter of the discharge nozzle hole, the higher the shear rate when the volume flow rate during application is assumed to be the same. According to the above formula, the shear rate is about 1,000 to 200,000 sec ⁻¹ when nozzle coating is performed using a nozzle having ejection holes with a hole diameter of about 20 μm to 50 μm. In the present invention, in a state where a high shear stress is applied (hereinafter referred to as a high shear region) as described above, the more the loss tangent tan δ asymptotically approaches 1, the more stable the wavelength conversion paste becomes a columnar flow when ejected from the ejection hole. It was found that it can be applied to

The loss tangent tan δ is the ratio of the loss elastic modulus G″ _ω , which indicates the strength of the viscous component of the coating liquid, to the storage elastic modulus _G′ω , which indicates the strength of the elastic component, and is 1 when both are equal. When the tan δ is higher than 1, the loss elastic modulus, that is, the ratio of the viscous component, is increased, and droplets are likely to be ejected. In some cases, the coating liquid is difficult to be deformed, so that it is difficult to be discharged from the discharge hole.

The angular velocity ω for measuring the viscoelasticity at room temperature is preferably about 0.1 to 500 sec ⁻¹ , and a higher angular velocity makes stable measurement difficult. Assuming nozzle application in the present invention, in order to evaluate the viscoelasticity in the high shear region of about 1,000 to 200,000 sec ^-1 as described above, a synthetic curve based on the temperature/frequency conversion rule described later is used. can be evaluated.

In general, when measuring the viscoelasticity of materials containing polymers, the temperature-frequency conversion rule (Williams-Randell-Ferry formula) holds true, so by changing the temperature and performing measurements, the storage modulus at each measurement temperature is , the loss modulus and the loss tangent, it is possible to create a composite curve (master curve) and evaluate the viscoelasticity when the frequency is changed. Further, since the frequency can be converted into angular velocity, it is possible to evaluate the viscoelasticity when the angular velocity is changed. In the present invention, by lowering the measurement temperature from room temperature 25 ° C. to 5 ° C., the viscoelasticity in the shear region higher than the angular velocity in the measurement at room temperature was evaluated. It has been found that a wavelength conversion paste having a loss tangent tan δ in the range of 0.7 to 2.0 can be stably nozzle-coated in a nozzle having minute ejection holes with a hole diameter of φ50 μm or less, which is preferable. In other words, when the maximum value of the loss tangent at a measurement temperature of 5° C. and an angular velocity of 100 to 500 rad/sec is D _{MAX (5° C.)} and the minimum value is D _{MIN (5° C.)} , D _{MIN (5° C.)} ≧0. .7, preferably D _{MAX(5° C.)} ≦2.0.

When the loss tangent tan δ at a measurement temperature of 5° C. and an angular velocity of 100 to 500 rad/sec is 0.7 or more, it is easy to stably eject even a die having ejection holes with a hole diameter of φ50 μm or less. Also, when the loss tangent tan δ at a measurement temperature of 5° C. and an angular velocity of 100 to 500 rad/sec is 2.0 or less, it is easy to eject columnar particles even from a die having ejection holes with a hole diameter of φ50 μm or less.

When the paste of the present invention contains a dispersant, the dispersant may be, for example, "Disperbyk" (registered trademark) 106, 108, 110, 180, 190, 2001, 2155, 140, 145 (trade name, BYK-Chemie Co., Ltd.) and the like are preferably mentioned.

The substrate of the present invention can be produced by applying the wavelength conversion paste of the present invention and curing it. The substrate of the present invention comprises at least one of the wavelength conversion paste and the cured wavelength conversion paste, a support plate, partition walls provided on the support plate, and cells partitioned by the partition walls. In this case, it is preferable to prepare by applying the wavelength conversion paste of the present invention to cells partitioned by partition walls and curing the paste. In particular, nozzle coating is preferable as the coating means.

The barrier ribs preferably have a pattern corresponding to sub-pixels in pixels of the display. The number of pixels of the display is, for example, 2,000 vertically and 4,000 horizontally. The number of pixels affects the resolution (fineness) of the displayed image. Therefore, it is necessary to form the number of pixels according to the required image resolution and the screen size of the display, and it is preferable to determine the pattern formation dimensions of the barrier ribs accordingly.

The support plate that constitutes the substrate of the present invention functions as a support in the substrate with partition walls. Examples of the support plate include a glass plate, a resin plate, and a resin film. Non-alkali glass is preferable as the material of the glass plate. Polyester, (meth)acrylic polymer, transparent polyimide, polyethersulfone and the like are preferable as materials for the resin plate and the resin film. The thickness of the glass plate and the resin plate is preferably 1 mm or less, more preferably 0.8 mm or less. The thickness of the resin film is preferably 100 μm or less.

When a wavelength conversion paste is applied and cured between adjacent partition walls to form subpixels containing the cured wavelength conversion paste, the partition walls prevent color mixing of light from a certain subpixel to adjacent subpixels. It is preferable to have a function to prevent it.

FIG. 2 shows a cross-sectional view of one embodiment of the substrate of the present invention. A patterned partition 6 is provided on a support plate 3, and a cured product 7 of the wavelength conversion paste of the present invention is provided in cells partitioned by the partition.

The barrier ribs preferably have a reflectance of 60 to 90% per 10 μm thickness at a wavelength of 550 nm. By setting the reflectance to 20% or more, the luminance of the display can be improved by utilizing the reflection on the side surfaces of the partition walls. On the other hand, the reflectance is preferably 90% or less from the viewpoint of improving the partition pattern formation accuracy. Here, the thickness of the partition refers to the length of the partition in the vertical direction (height direction) with respect to the substrate. In the case of the substrate with partition walls shown in FIG. 2, the thickness of the partition walls 6 is represented by symbol H. Note that the horizontal length of the partition with respect to the substrate is the width of the partition. In the case of the substrate with partition walls shown in FIG. 2, the width of the partition walls 6 is represented by L.

The thickness of the barrier ribs is preferably larger than the thickness of the cured wavelength conversion paste when the cells of the substrate with barrier ribs contain the cured wavelength conversion paste. Specifically, the thickness of the partition wall 6 is preferably 0.5 μm or more, more preferably 5 μm or more. On the other hand, the thickness of the partition is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 20 μm or less, from the viewpoint of extracting light emitted from the bottom of the layer containing the color-converting luminescent material more efficiently. In addition, the width of the partition walls should be sufficient to improve brightness by utilizing light reflection on the side surfaces of the partition walls and to suppress color mixture of emitted light from adjacent cured products of the wavelength conversion paste due to light leakage. Specifically, the width of the partition wall is preferably 5 μm or more, more preferably 10 μm or more. On the other hand, the width of the partition wall is preferably 50 μm or less, more preferably 30 μm or less, from the viewpoint of securing a large filling area of the cured product 7 of the wavelength conversion paste and further improving the luminance.

In the case of producing a high-resolution display with the number of pixels as described above, the smaller the diameter of the ejection holes used for nozzle coating, the easier it is to handle high resolution. It is preferred to use a mouthpiece with certain discharge holes. The hole diameter is preferably 20 μm or more from the viewpoint of hole workability and variations in processing accuracy for each hole, and the hole diameter is preferably 50 μm or less for coating pixels with small opening areas corresponding to high definition.

Next, the display of the present invention will be explained. A display of the present invention has the substrate and a light source. As the light source, a light source selected from blue OLEDs, blue LEDs, and ultraviolet light emitting LEDs capable of active matrix driving is preferable.

The method of manufacturing the display of the invention will now be described with reference to an example of a display having the substrate of the invention and a blue OLED. A photosensitive polyimide resin is applied onto a glass support plate having a TFT pattern capable of active matrix driving, and an insulating film is formed by photolithography. After sputtering aluminum as a back electrode layer, patterning is performed by a photolithography method to form a back electrode layer in the openings where there is no insulating film. Subsequently, tris(8-quinolinolato)aluminum (hereinafter abbreviated as Alq3) was deposited as an electron-transporting layer by a vacuum vapor deposition method, and then Alq3 as a light-emitting layer. ,2-diphenylvinyl)biphenyl to form a white light-emitting layer. Next, N,N'-diphenyl-N,N'-bis(α-naphthyl)-1,1'-biphenyl-4,4'-diamine is deposited as a hole transport layer by vacuum deposition. Finally, ITO (Indium Tin Oxide) is deposited as a transparent electrode by sputtering to fabricate an OLED having a blue light-emitting layer. A display can be produced by making the OLED thus obtained face the above-described substrate and bonding them with a sealant.

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited thereto. In addition, the following abbreviations were used for the following compounds.
DPM: dipropylene glycol monomethyl ether The solid content concentration of the siloxane resin solutions in Synthesis Examples 1 to 6 was obtained by the following method. 1.5 g of siloxane resin solution or acrylic resin solution was put into an aluminum cup and heated at 250° C. for 30 minutes using a hot plate to evaporate the liquid component. The weight of the solid content remaining in the aluminum cup after heating was weighed, and the solid content concentration of the siloxane resin solution or acrylic resin solution was obtained from the ratio to the weight before heating.

The weight-average molecular weight of the siloxane resins in Synthesis Examples 1 to 6 is the weight-average molecular weight in terms of polystyrene, obtained by the calibration curve method from the measurement results of gel permeation chromatography analysis under the following measurement conditions.
<Measurement conditions>
Measuring device: GPC measuring device with RI detector manufactured by Waters (2695)
Column: PLgel MIXED-C column (manufactured by Polymer Laboratories, 300
mm) x 2 (connected in series)
Measurement temperature: 40°C
Flow rate: 1 mL/min
Solvent: Tetrahydrofuran (THF) 0.1% by mass solution Standard substance: Polystyrene The content ratio of each repeating unit in polysiloxane in Synthesis Examples 1 to 6 was obtained by the following method. A polysiloxane solution is injected into a “Teflon” (registered trademark) NMR sample tube with a diameter of 10 mm and ²⁹ Si-NMR measurement is performed, and the Si derived from a specific organosilane is compared with the integrated value of the entire Si derived from the organosilane. The content ratio of each repeating unit was calculated from the ratio of the integrated value of. ²⁹ Si-NMR measurement conditions are shown below.

Apparatus: Nuclear magnetic resonance apparatus (JNM-GX270; manufactured by JEOL Ltd.)
Measurement method: Gated decoupling method Measurement nucleus frequency: 53.6693 MHz ( ²⁹ Si nucleus)
Spectrum width: 20000Hz
Pulse width: 12 μs (45° pulse)
Pulse repetition time: 30.0 seconds Solvent: Acetone-d6
Reference substance: Tetramethylsilane Measurement temperature: 23°C
Sample rotation speed: 0.0 Hz.

Synthesis Example 1 Siloxane resin (A-1) solution In a 1,000 mL three-necked flask, 214.35 g (0.874 mol) of methyltrimethoxysilane, 119.06 g (0.345 mol) of dimethyldimethoxysilane, phenyltrimethoxysilane 41.48 g (1.081 mol) of DPM and 149.28 g of DPM were charged, and an aqueous solution of phosphoric acid was prepared by dissolving 1.874 g of phosphoric acid (0.5% by weight relative to the charged monomers) in 118.12 g of water while stirring at room temperature. was added over 30 minutes. After that, the flask was immersed in an oil bath at 70° C. and stirred for 90 minutes, and then the oil bath was heated to 120° C. over 30 minutes. After 1 hour from the start of heating, the solution temperature (internal temperature) reached 100° C., and the solution was heated and stirred for 1 hour (internal temperature: 100 to 110° C.) to obtain a siloxane resin solution. A mixed gas of 95% by volume of nitrogen and 5% by volume of oxygen was flowed at 0.05 liter/min during the temperature rise and heating and stirring. A total of 269.08 g of methanol and water, which are by-products, were distilled during the reaction. DPM was added to the resulting siloxane resin solution so that the solid content concentration was 60% by weight to obtain a siloxane resin (A-1) solution. The weight average molecular weight of the obtained siloxane resin (A-1) was 11,000 (converted to polystyrene). Further, from the measurement results of ²⁹ Si-NMR, the molar ratios of repeating units derived from methyltrimethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane in the siloxane resin (A-1) were 38.0 mol% and 15.0 mol%, respectively. 0 mol % and 47.0 mol %.

Synthesis Example 2 Siloxane Resin (A-2) Solution The procedure was carried out in the same manner as in Synthesis Example 1, except that the DPM was changed from 149.28 g to 95.97 g, and the resulting siloxane resin solution had a solid content concentration of 70% by weight. DPM was added to obtain a siloxane resin (A-2). The weight average molecular weight of the obtained siloxane resin (A-2) was 100,000 (converted to polystyrene). Further, from the measurement results of ²⁹ Si-NMR, the molar ratios of repeating units derived from methyltrimethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane in the siloxane resin (A-2) were 38.0 mol% and 15.0 mol%, respectively. 0 mol % and 47.0 mol %.

Synthesis Example 3 Siloxane Resin (A-3) Solution The procedure was carried out in the same manner as in Synthesis Example 1 except that the DPM was changed from 149.28 g to 55.98 g, and the resulting siloxane resin solution had a solid content concentration of 80% by weight. DPM was added to obtain a siloxane resin (A-3). The weight average molecular weight of the obtained siloxane resin (A-3) was 500,000 (converted to polystyrene). Further, from the measurement results of ²⁹ Si-NMR, the molar ratios of repeating units derived from methyltrimethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane in the siloxane resin (A-3) were 38.0 mol% and 15.0 mol%, respectively. 0 mol % and 47.0 mol %.

Synthesis Example 4 Siloxane resin (A-4) solution Synthesis except that 1.874 g of phosphoric acid (0.5% by weight relative to the charged monomer) was changed to 3.748 g (1.0% by weight relative to the charged monomer) DPM was added to the siloxane resin solution obtained in the same manner as in Example 3 so that the solid content concentration was 80% by weight, to obtain a siloxane resin (A-4). The weight average molecular weight of the resulting siloxane resin (A-4) was 900,000 (converted to polystyrene). Further, from the measurement results of ²⁹ Si-NMR, the molar ratios of repeating units derived from methyltrimethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane in the siloxane resin (A-4) were 38.0 mol% and 15.0 mol%, respectively. 0 mol % and 47.0 mol %.

Synthesis Example 5 Siloxane resin (A-5) solution DPM from 149.28 g to 39.52 g, phosphoric acid 1.874 g (0.5 wt% relative to charged monomer) 3.748 g (1 relative to charged monomer .0% by weight), DPM was added to the obtained siloxane resin solution so that the solid content concentration was 85% by weight, and siloxane resin (A-5) was obtained. rice field. The weight average molecular weight of the resulting siloxane resin (A-5) was 1,600,000 (converted to polystyrene). Further, from the ²⁹ Si-NMR measurement results, the molar ratios of repeating units derived from methyltrimethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane in the siloxane resin (A-5) were 38.0 mol% and 15.0 mol%, respectively. 0 mol % and 47.0 mol %.

Synthesis Example 6 Siloxane resin (A-6) solution In a 1,000 mL three-necked flask, 214.35 g (0.874 mol) of methyltrimethoxysilane, 119.06 g (0.345 mol) of dimethyldimethoxysilane, phenyltrimethoxysilane 41.48 g (1.081 mol) of and 149.28 g of DPM were charged, and an aqueous solution of phosphoric acid was prepared by dissolving 0.7496 g of phosphoric acid (0.2% by weight relative to the charged monomers) in 118.12 g of water while stirring at room temperature. was added over 30 minutes. After that, the flask was immersed in an oil bath at 70° C. and stirred for 90 minutes, and then the oil bath was heated to 110° C. over 30 minutes. One hour after the start of heating, the temperature of the solution (internal temperature) reached 100° C., and the solution was heated and stirred for one hour (internal temperature: 95 to 105° C.) to obtain a siloxane resin solution. A mixed gas of 95% by volume of nitrogen and 5% by volume of oxygen was flowed at 0.05 liter/min during the temperature rise and heating and stirring. A total of 269.08 g of methanol and water, which are by-products, were distilled during the reaction. DPM was added to the obtained siloxane resin solution so that the solid content concentration was 60% by weight to obtain a siloxane resin (A-6) solution. The weight average molecular weight of the resulting siloxane resin (A-6) was 3,700 (converted to polystyrene). Further, from the measurement results of ²⁹ Si-NMR, the molar ratios of repeating units derived from methyltrimethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane in the siloxane resin (A-6) were 38.0 mol% and 15.0 mol%, respectively. 0 mol % and 47.0 mol %.

Table 1 shows the raw material composition, catalyst, molecular weight, and solid content concentration of the resin solution of Synthesis Examples 1 to 6.

(Raw material for wavelength conversion paste)
The raw materials used for preparing the wavelength conversion paste are as follows.
Siloxane resin solution: A-1 to A-6
Wavelength conversion material A: Ce _0.63 Tb _0.37 MgAl ₁₁ O ₁₉ (green-emitting inorganic phosphor material, manufactured by SIGMA-ALDRICH)
Solvent: DPM (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)
(Preparation of wavelength conversion paste)
Each material was weighed into a flask at the weight fraction shown in Table 2, defoamed with a hybrid mixer ARE-310 (manufactured by THINKY Co., Ltd.) for 15 minutes, and a SHP-400 filter ( Roki Techno Co., Ltd.) to obtain a wavelength conversion paste.

(Adjustment of acrylic resin solution for partition walls)
A 500 mL three-necked flask was charged with 3 g of 2,2′-azobis(isobutyronitrile) and 50 g of propylene glycol monomethyl ether. After that, 30 g of methacrylic acid, 35 g of benzyl methacrylate, and 35 g of tricyclo[5.2.1.0 ^2,6 ]decan-8-yl methacrylate were charged, stirred at room temperature for a while, and after replacing the inside of the flask with nitrogen, The mixture was heated and stirred at ℃ for 5 hours. Next, 15 g of glycidyl methacrylate, 1 g of dimethylbenzylamine, 0.2 g of p-methoxyphenol, and 100 g of propylene glycol monomethyl ether acetate are added to the resulting solution, and the mixture is heated and stirred at 90° C. for 4 hours to remove the solid content. An acrylic resin solution for partition walls having a concentration of 40% by weight was obtained.
(Adjustment of partition wall resin composition)
As a white pigment, titanium dioxide pigment R-960 (manufactured by BASF Japan Co., Ltd.) 5.00 g, and as a resin, zirconia beads mixed with 5.00 g of an acrylic resin solution Dispersed using a mill-type dispersing machine. , to obtain a pigment dispersion.

Next, 10.00 g of pigment dispersion, 1.15 g of acrylic resin solution, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (“Irgacure” ( 907 (manufactured by BASF Japan Ltd.) 0.100 g, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (“Irgacure” (registered trademark) 819 (manufactured by BASF Japan Ltd.) 0.100 g. 200 g, as a photopolymerizable compound, pentaerythritol acrylate "light acrylate" (registered trademark) PE-3A (manufactured by Kyoeisha Chemical Co., Ltd.) 1.50 g, photopolymerizable fluorine-containing compound "Megafac" (registered trademark) RS- 1.00 g of a 40% by weight PGMEA diluted solution of 76-E (manufactured by DIC Corporation), 0.500 g of a 20% by weight diluted PGMEA solution of a silane coupling agent, 3′,4′-epoxycyclohexylmethyl-3,4- Epoxy cyclohexane carboxylate (“Celoxide” (registered trademark) 2021P (manufactured by Daicel Corporation) 0.200 g, ethylene bis (oxyethylene) bis [3-(5-tert-butyl-4-hydroxy-m-tolyl) propionate ] (“Irganox” (registered trademark) 1010 (manufactured by BASF Japan Co., Ltd.) 0.300 g, acrylic surfactant “BYK” (registered trademark) 352, (manufactured by BYK Chemie Japan Co., Ltd.) PGMEA 10% by weight 0.100 g of the diluted solution (equivalent to a concentration of 500 ppm) was dissolved in a mixed solvent of 1.000 g of DAA and 4.200 g of PGMEA, stirred, and then filtered through a 5.0 μm filter to obtain a negative photosensitive coloring composition. Obtained.
(Fabrication of substrate)
A 10 cm square, 0.5 mm thick non-alkali glass support plate (manufactured by AGC Techno Glass Co., Ltd.) was spin-coated with the partition wall resin composition, and a hot plate (SCW-636, SCREEN Semiconductor Solutions Co., Ltd.) was applied. A dry film was prepared by drying at a temperature of 90° C. for 2 minutes. The prepared dry film is exposed through a photomask with an exposure amount of 200 mJ/cm ² (i-line) using a parallel light mask aligner (PLA-501F, manufactured by Canon Inc.) using an ultra-high pressure mercury lamp as a light source. did. Then, using an automatic developing device (AD-2000, manufactured by Takizawa Sangyo Co., Ltd.), shower development was performed using a 0.045% by weight potassium hydroxide aqueous solution for 100 seconds, and then rinsed with water for 30 seconds. Furthermore, using an oven (IHPS-222, manufactured by Espec Co., Ltd.), it was heated in the air at a temperature of 230 ° C. for 30 minutes, and a partition wall having a height of 20 µm and a width of 20 µm was formed on the glass support plate, with a short side of 100 µm and a width of 20 µm. A substrate having barrier ribs patterned in a grid pattern was formed in a 7 cm square range with a pitch of 300 μm on the long side.
(Method for evaluating viscosity)
A rheometer (HAAKE MARS; manufactured by Thermo Fisher Scientific Co., Ltd.) was equipped with Plate P35 Ti L manufactured by the same company, the measurement temperature was set to 25 ° C., the gap was set to 200 μm, and the wavelength conversion of each example and each comparative example was performed. The paste was measured for viscosity at a shear rate of 1 sec ⁻¹ . Also, the viscosity η 1 at shear rate a=1 sec ⁻¹ and the viscosity η ₁₀₀ at shear rate b= ₁₀₀ sec ⁻¹ were measured and substituted into equation (5) to calculate the TI value.
(Method for evaluating viscoelasticity)
Using a rheometer (HAAKE MARS; manufactured by Thermo Fisher Scientific Co., Ltd.), a Plate P35 Ti L manufactured by the same company was mounted in the same manner as viscosity evaluation, the measurement temperature was set to 5 to 25 ° C., and the gap was set to 100 μm. The storage elastic modulus G′, the loss elastic modulus G″ and the loss tangent tan δ in the angular velocity range of 100 to 500 rad/sec were measured for the wavelength conversion pastes of Examples and Comparative Examples.

A maximum value D _{MAX (5° C.)} and a minimum value D _{MIN (5° C.)} were obtained from the measurement results D _ω at a measurement temperature of 5° C. and an angular velocity of 100 to 500 rad/sec.
(Method for evaluating liquidity)
In a room temperature (25° C.) environment, 15 g of the wavelength conversion paste was weighed into a 100 mL container, the container was tilted and held for 1 minute, and the fluidity of the wavelength conversion paste in the low shear region was visually observed. Based on the observation results, fluidity was evaluated based on the following criteria.

A: The wavelength conversion paste flows easily.

B: The wavelength conversion paste flows slightly.

C: Flow cannot be visually confirmed.
(Rigidity evaluation method)
In a room temperature (25° C.) environment, 15 g of the wavelength conversion paste was weighed into a 100 mL container, and the rigidity of the wavelength conversion paste in the low shear region was evaluated by the resistance when a dropper was inserted into the wavelength conversion paste.

In addition, evaluation was performed based on the following criteria as evaluation criteria.

A: There is resistance when the dropper is inserted.

B: There is weak resistance when the dropper is inserted.

C: Almost no resistance like water when a dropper is inserted.
(Applying method of wavelength conversion paste)
As a coating device, a multi-lab coater (manufactured by Toray Engineering Co., Ltd.) was used. While applying a pressure of 500 to 1500 kPa with air and changing the traveling speed with respect to the substrate within the range of 10 to 300 mm/s to eject the wavelength conversion paste, the substrate having the partition walls is coated in a direction parallel to the long side direction of the partition walls. After filling the wavelength conversion paste by nozzle coating, it was dried on a hot plate at 100° C. for 10 minutes, and then cured by heat treatment at 230° C. for 30 minutes using an oven.
(Applicability evaluation method)
The evaluation criteria for applicability are as follows: The wavelength conversion paste is discharged while varying the air pressure to the substrate having the barrier ribs, and the substrate immediately after application is examined with a laser microscope (color 3D laser microscope VK-9710, manufactured by Keyence Corporation). ), an optical microscope image was observed in camera mode from above. In addition, the vicinity of the nozzle hole immediately after application was visually observed to confirm liquid adhesion in the vicinity of the nozzle hole, and evaluation was made based on the following criteria.

A: There is no adhesion of the wavelength conversion paste to the vicinity of the nozzle hole, and the wavelength conversion paste can be applied linearly without pulsating.

B: There is no adhesion of the wavelength conversion paste to the vicinity of the nozzle hole, and the paste can be applied linearly, but the wavelength conversion paste pulsates repeatedly by expansion and contraction.

C: The paste adheres to the vicinity of the nozzle hole, and the wavelength conversion paste is applied so as to rub against the substrate without being ejected in a columnar flow.

D: No wavelength conversion paste was applied.

Table 3 shows the evaluation results. Examples 1 to 4 have good fluidity and rigidity, and as for the coatability, although Example 1 can be applied in a straight line, the wavelength conversion paste pulsates repeatedly by expanding and contracting, but the For 2 to 4, it was possible to apply with high accuracy. In Comparative Example 1, the wavelength conversion paste came out only slightly at the time of ejection and was applied only intermittently, resulting in poor applicability. In Comparative Example 2, the wavelength conversion paste was discharged in the form of droplets, adhered to the vicinity of the nozzle hole, and was applied by rubbing against the substrate, resulting in poor applicability.

Reference Signs List 1 Base 2 Wavelength conversion paste 3 Support plate 4 Processing pipe 5 Discharge hole 6 Partition 7 Cured product of wavelength conversion paste H Partition thickness L Partition width

Claims (8)

(A) a siloxane resin, (B) a wavelength conversion material, and (C) a solvent; ,000 or more and 1,000,000 or less, and a viscosity of 10,000 mPa·s or more and 200,000 mPa·s or less at a temperature of 20° C. and a shear rate of 1 sec ⁻¹ .

(R ¹ and R ² each independently represent an alkyl group or aromatic group having 1 to 12 carbon atoms and may be the same or different; R ³ represents an organic group having 1 to 20 carbon atoms; ^R4 represents a methyl group, an ethyl group, or hydrogen, and x, y, and z in the formula satisfy the conditions of 0.1≦x≦0.3, 0≦y, 0≦z, and x+y+z=1 .) 2. The wavelength conversion paste according to claim 1, wherein the (B) wavelength conversion material is an inorganic phosphor and/or an organic phosphor. 3. The wavelength conversion paste according to claim 2, wherein the (B) wavelength conversion material is an inorganic phosphor. The wavelength conversion paste according to any one of claims 1 to 3, wherein the following relationship (i) holds for D _ω defined by the following formula (1).
(1) D _ω = G″ _ω /G′ _ω
D _ω : Loss tangent tan δ at measurement temperature 5° C. and angular velocity ω
G′ _ω : Storage modulus at a measurement temperature of 5° C. and an angular velocity ω G″ _ω : Loss modulus at a measurement temperature of 5° C. and an angular velocity ω (i) 0.7≦D _ω ≦2.0 (100≦ω≦500 rad/ sec, 5°C) A substrate comprising at least one of the wavelength conversion paste or the cured wavelength conversion paste according to any one of claims 1 to 4, a support plate, partition walls provided on the support plate, and cells partitioned by the partition walls. A substrate comprising at least one of the wavelength conversion paste and a cured product of the wavelength conversion paste in the cell. A display comprising a substrate according to claim 5 and an organic light-emitting diode or light-emitting diode as a light source. The wavelength conversion paste according to any one of claims 1 to 4 is applied in the cells of a semi-finished substrate comprising a support plate, partition walls provided on the support plate, and cells partitioned by the partition walls, by a nozzle coating method. A method of manufacturing a substrate, comprising the step of coating. 8. The method for manufacturing a substrate according to claim 7, wherein nozzle coating is performed using a nozzle having ejection holes with a hole diameter ranging from 20 μm to 50 μm.

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