TW202219203A - Curable composition for inkjet coating and LED protection, LED module, manufacturing method of LED module, and LED display device - Google Patents

Abstract

Provided is a curable composition for inkjet coating and LED protection with which it is possible to satisfactorily maintain the shape of the edge portion of an applied material when the curable composition is applied, by an inkjet method, to a gap between a plurality of LED chips and/or to the upper sections of the plurality of LED chips in order to form an LED protection layer. The curable composition for inkjet coating and LED protection according to the present invention: contains a first polyfunctional (meth)acrylate compound having a plurality of (meth)acryloyl groups and having an aliphatic cyclic skeleton, a second polyfunctional (meth)acrylate compound having a plurality of (meth)acryloyl groups and having an alkylene oxide skeleton, and a photopolymerization initiator; and has a viscosity at 25 DEG C of 80-2000 mPa.s (inclusive).

Description

Curable composition for inkjet coating and LED protection, LED module, manufacturing method of LED module, and LED display device

The present invention relates to a curable composition for inkjet coating and LED protection which is used by coating by an inkjet method and used to protect a light emitting diode (LED). Moreover, this invention relates to the LED module using the said curable composition for inkjet coating and LED protection, the manufacturing method of an LED module, and an LED display apparatus.

Light emitting diode (LED) wafers are used in various electronic machine applications. For example, an LED package in which a lead frame and an LED chip are arranged on a substrate, and the lead frame and the LED chip are sealed with resin, is widely used in the industry. As said LED package, a cannonball type LED package, and a surface mount type (SMD) LED package are mentioned.

In recent years, large-scale display devices have been used for advertisements, guide plates, and the like. As a large-scale display device, there is known a display device obtained by arranging a plurality of the above-mentioned LED packages to form a small module, and then connecting the modules. In this display device, for example, LEDs can be lit in red, blue, green, or the like for display.

However, in a display device using an LED package, since the distance between the LED chips cannot be shortened, it is difficult to realize a high-resolution display.

In order to improve the above-mentioned problems, the industry is studying a COB (Chip on Board, chip on board) method which directly encapsulates LED chips on a printed substrate or a glass substrate with TFT (Thin Film Transistor) wiring. Or COG (Chip On Glass, chip on glass) display device. In these methods, since the LED chips are directly packaged on the printed circuit board or the glass substrate, the distance between the LED chips can be shortened, and the display resolution can be increased.

The following Patent Document 1 discloses a silicone material, which is an element on the surface of the silicone material obtained by X-ray photoelectron spectroscopy (ESCA), as a sealant for an LED chip used in a COB-type display device The composition percentage satisfies at least one of (i) and (ii) below.

(i) The elemental composition percentage of carbon atoms is 50.0 to 70.0 atom% (ii) The ratio of the elemental composition percentage of carbon atoms to the elemental composition percentage of silicon atoms (C/Si) is 2.0 to 5.0

In addition, the following Patent Document 2 discloses a photocurable and thermosetting composition for inkjet containing (A) an acid anhydride, (B) a liquid compound having a cyclic ether group, and (C) a photoreactive composition A diluent and (D) a photopolymerization initiator, and the viscosity is 150 mPa·s or less at 25°C. [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2016-191038 Patent Document 2: Japanese Patent Laid-Open No. 2005-068280

[Problems to be Solved by Invention]

As in the conventional sealant described in Patent Document 1, since the viscosity of the material is high, unevenness is likely to occur on the surface after coating. When such an encapsulant is used as a protective material for an LED chip, there is a problem in that it is difficult to ensure the surface flatness of the LED protective layer after curing for a COB method or a COG method display device.

Moreover, as the curable composition described in patent document 2, in order to reduce a viscosity, a low molecular polymerizable compound (so-called reactive diluent) is used as a diluent. Therefore, there is a problem that the curing shrinkage becomes large, a problem that the substrate is warped, or that the adhesion between the LED protective layer and the substrate is lowered. Furthermore, when an LED module is produced by using the composition as described in Patent Document 2 as a protective material for an LED chip, and a plurality of the LED modules are connected to produce a large-scale LED display device, LED The display quality of the connection part of the module is deteriorated.

The inventors of the present invention found that the conventional curable composition had a large shrinkage during curing, so that the substrate warped after curing, or the adhesion between the LED protective layer and the substrate was lowered. Furthermore, the present inventors found that when the previous curable composition was applied, dripping occurred at the edge portion of the coated object, and the shape of the edge portion of the obtained LED module deteriorated, thereby causing the connection of the LED modules. Some display quality deteriorates.

An object of the present invention is to provide a curable composition for inkjet coating and LED protection, wherein the curable composition is applied to a gap between a plurality of LED chips and a plurality of LEDs by an inkjet method in order to form an LED protective layer. When at least one of the upper portions of the wafer is used, the shape of the edge portion of the coating can be maintained relatively well. Furthermore, an object of the present invention is to provide a curable composition for inkjet coating and LED protection, which can improve the surface flatness of the LED protection layer after forming the LED protection layer, suppress the warpage of the substrate, and can Improve the adhesion between the substrate and the LED protective layer. Moreover, the objective of this invention is to provide the LED module using the said curable composition for inkjet coating and LED protection, the manufacturing method of an LED module, and an LED display apparatus. [Technical means to solve problems]

According to a broader aspect of the present invention, there is provided a curable composition for inkjet coating and LED protection (hereinafter, sometimes referred to as a curable composition) comprising: a first polyfunctional (meth)acrylate compound , which contains a plurality of (meth)acryloyl groups and has an aliphatic cyclic skeleton; the second polyfunctional (meth)acrylate compound contains a plurality of (meth)acryloyl groups and has an alkylene oxide skeleton; and a photopolymerization initiator; and the viscosity at 25°C is 80 mPa·s or more and 2000 mPa·s or less.

In a specific aspect of the curable composition of this invention, the said 1st polyfunctional (meth)acrylate compound has a dicyclopentadiene skeleton.

In one specific aspect of the curable composition of this invention, the said 2nd polyfunctional (meth)acrylate compound has a bisphenol skeleton.

In a specific aspect of the curable composition of the present invention, when the curable composition is irradiated with light with a wavelength of 365 nm for 1 second at an illuminance of 1000 mW/cm ² to obtain a cured product with a thickness of 50 μm, the above The total light transmittance of the cured product is above 90%.

In one specific aspect of the curable composition of this invention, the glass transition temperature of the homopolymer of the said 1st polyfunctional (meth)acrylate compound is 100 degreeC or more.

In one specific aspect of the curable composition of this invention, the glass transition temperature of the homopolymer of the said 2nd polyfunctional (meth)acrylate compound is 50 degrees C or less.

In a specific aspect of the curable composition of the present invention, the content of the first polyfunctional (meth)acrylate compound in 100% by weight of the curable composition is 10% by weight or more and 70% by weight or less.

In a specific aspect of the curable composition of the present invention, the content of the second polyfunctional (meth)acrylate compound in 100% by weight of the curable composition is 15% by weight or more and 75% by weight or less.

In a specific aspect of the curable composition of the present invention, the content of the second polyfunctional (meth)acrylate compound is 50 parts by weight relative to 100 parts by weight of the first polyfunctional (meth)acrylate compound. more than 130 parts by weight.

According to a broader aspect of the present invention, there is provided an LED module comprising: a substrate having a plurality of LED chips on its upper surface; and an LED protection layer disposed between the plurality of the LED chips and the plurality of the LED chips At least one of the upper parts; and the above-mentioned LED protective layer is a cured product of the above-mentioned curable composition.

According to a broader aspect of the present invention, a method for manufacturing an LED module is provided, which includes the following steps: a coating step, wherein the above-mentioned inkjet coating and LED protection are applied to a substrate having a plurality of LED chips on the upper surface. The curable composition is coated on at least one of the gaps of the plurality of the above-mentioned LED chips and the upper part of the plurality of the above-mentioned LED chips by an inkjet method; and a curing step, which is applied to the above-mentioned inkjet coating and LED protection. The curable composition is irradiated with light to cure the curable composition for inkjet coating and LED protection, thereby forming an LED protection disposed at least one of the gaps between the plurality of the above-mentioned LED chips and the upper part of the plurality of the above-mentioned LED chips Floor.

According to a broader aspect of the present invention, an LED display device is provided, which includes a plurality of LED modules, and the plurality of the LED modules are connected together, and the LED module includes: a substrate having a plurality of LEDs on its upper surface a chip; and an LED protective layer, which is disposed in at least one of the gaps between the plurality of the above-mentioned LED chips and the upper part of the plurality of the above-mentioned LED chips; and in the above-mentioned LED module, the above-mentioned LED protective layer is formed of the above-mentioned curable composition. hardened material. [Effect of invention]

The curable composition of the present invention contains a plurality of (meth)acrylate compounds and a photopolymerization initiator. The curable composition of the present invention includes: a first polyfunctional (meth)acrylate compound containing a plurality of (meth)acryloyl groups and having an aliphatic cyclic skeleton; and a second polyfunctional (meth)acrylate compound An acrylate compound containing a plurality of (meth)acryloyl groups and having an alkylene oxide skeleton. The viscosity of the curable composition of the present invention at 25°C is 80 mPa·s or more and 2000 mPa·s or less. In the present invention, since the above-mentioned configuration is provided, when the curable composition is applied to at least one of the gaps between the plurality of LED chips and the upper portion of the plurality of LED chips by the inkjet method to form the LED protective layer, it is possible to The shape of the edge portion of the coating is maintained relatively well. Furthermore, in the present invention, since the above-mentioned configuration is provided, after the LED protective layer is formed, the surface flatness of the LED protective layer can be improved, the warpage of the substrate can be suppressed, and the adhesion between the substrate and the LED protective layer can be improved.

Hereinafter, the present invention will be described in detail.

(Curable composition for inkjet coating and LED protection) The curable composition for inkjet coating and LED protection of the present invention (hereinafter, it may be described as curable composition) is used for inkjet coating. The curable composition of the present invention is used to protect light emitting diodes (LEDs).

The curable composition of this invention contains the following components (A)-(C).

The first polyfunctional (meth)acrylate compound (A) containing a plurality of (meth)acryloyl groups and having an aliphatic cyclic skeleton The second polyfunctional (meth)acrylate compound (B) which contains a plurality of (meth)acryloyl groups and has an alkylene oxide skeleton Photopolymerization Initiator (C)

The viscosity of the curable composition of the present invention at 25°C is 80 mPa·s or more and 2000 mPa·s or less.

When the previous encapsulant described in the above-mentioned Patent Document 1 is used as a protective material for a directly packaged LED chip, the surface after coating is likely to be uneven, and it may be difficult to ensure that the surface of the LED protective layer after curing is flat. sex.

Moreover, the curable composition described in the said patent document 2 has the problem that a board|substrate is warped, or the adhesiveness of an LED protective layer and a board|substrate becomes low. Furthermore, when the composition described in Patent Document 2 is used as a protective material for an LED chip to produce an LED module, and a plurality of the LED modules are connected to produce a large-scale LED display device, the LED module may be damaged. The display quality of the linked part of the group is deteriorated. The inventors of the present invention found that the conventional curable composition had a large shrinkage during curing, so that the substrate warped after curing, or the adhesion between the LED protective layer and the substrate was lowered. In addition, the inventors of the present invention conducted intensive research and found that when the conventional curable composition was applied, dripping occurred at the edge portion of the coating material, and the shape of the edge portion of the obtained LED module deteriorated, resulting in The display quality of the connecting part of the LED module deteriorates.

In addition, in order to suppress the warpage of the substrate and keep the adhesiveness from being lowered, the curable composition and its cured product using only a material with a low glass transition temperature may cause a decrease in brightness after the high temperature and high humidity test. the problem.

In the present invention, since the above-mentioned configuration is provided, when the curable composition is applied to at least one of the gaps between the plurality of LED chips and the upper portion of the plurality of LED chips by the inkjet method to form the LED protective layer, it is possible to The shape of the edge portion of the coating is maintained relatively well. In the present invention, it is difficult to form irregularities on the surface of the coating material. In addition, in the present invention, the thickness of the edge portion of the coating object can be prevented from being reduced, and the missing of the edge portion of the coating object can be avoided, for example, the shape of the edge portion of the coating object can be made close to a right angle. Furthermore, in the present invention, since the above-described configuration is provided, after the LED protective layer is formed, the surface flatness of the LED protective layer can be improved, the warpage of the substrate can be suppressed, and the adhesion between the substrate and the LED protective layer can be improved.

In addition, in the present invention, since the leakage of the edge portion of the LED protective layer can be avoided, the display quality of the LED module and the LED display device can be improved. Moreover, in the case where a large-scale LED display device is obtained by connecting a plurality of LED modules, the connecting portion of the LED modules can be made inconspicuous.

Furthermore, in the present invention, the LED module and the LED display device on which the LED protective layer is formed can have good luminance retention after the high-temperature and high-humidity test.

The said curable composition can be apply|coated by the inkjet system. The above-mentioned curable composition can be well coated on the gap between the LED chips on the substrate body and the upper part of the LED chips by the inkjet method. When applying the above curable composition by an ink jet method, an ink jet apparatus is used. The above-mentioned inkjet apparatus has an inkjet head. The above-mentioned ink jet head has ink jet nozzles.

The above-mentioned curable composition is used to protect an LED chip. The above curable composition is suitable for forming an LED protective layer. The above-mentioned curable composition is suitable for forming a protective layer for protecting an LED chip. The LED chip can be well protected by arranging the LED protective layer formed of the curable composition in at least one of the gap between the LED chips on the substrate body and the upper part of the LED chips. The above-mentioned curable composition is suitable for forming an LED protective layer in the gap between the LED chips on the substrate body and on the upper part of the LED chips. The above curable composition can be used to form an LED protective layer between the LED chips on the substrate body, and can also be used to form an LED protective layer on the top of the LED chips on the substrate body. The above-mentioned curable composition can also be used to form an LED protective layer at the gap between the LED chips on the substrate body and the upper part of the LED chips on the substrate body.

The said curable composition is especially suitable for use in the LED module of COB system or COG system. The above curable composition is preferably used as a sealant for LED chips. The above curable composition is more preferably used as an LED chip encapsulant in a COB type or COG type LED module.

The said curable composition is a liquid state at 25 degreeC from a viewpoint of apply|coating a curable composition more favorably by an inkjet system. The liquid state also includes the paste state.

The viscosity (η25) of the curable composition at 25°C is 80 mPa·s or more and 2000 mPa·s or less from the viewpoint of further favorable application of the curable composition by the inkjet method. The above-mentioned viscosity (η25) can be appropriately adjusted by the types and amounts of the ingredients to be prepared.

The above-mentioned viscosity (η25) is preferably 150 mPa·s or more, more preferably 300 mPa·s or more, still more preferably 400 mPa·s or more, particularly preferably 500 mPa·s or more, and more preferably 1500 mPa·s Hereinafter, it is more preferably 1200 mPa·s or less, and still more preferably 1000 mPa·s or less. If the said viscosity (η25) is more than the said minimum and below the said upper limit, the said curable composition can be apply|coated more favorably by the inkjet method. Moreover, when the said viscosity (η25) is more than the said lower limit and less than the said upper limit, when apply|coating the said curable composition on a board|substrate by an inkjet method, it becomes difficult to form unevenness|corrugation on the surface of a coating material. Moreover, when the said viscosity (η25) is more than the said lower limit and less than the said upper limit, the shape of the edge part of a coating material can be maintained more favorable. As a result, an LED protective layer with a better shape of the edge portion can be formed. Moreover, when the said viscosity (η25) is more than the said lower limit and less than the said upper limit, since the stickiness of the surface of a curable composition can be suppressed, powders, such as dirt, can be prevented from adhering to the surface.

The above-mentioned viscosity (η25) can be measured at 25° C. and 1 rpm using, for example, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

The glass transition temperature (Tg) of the curable composition is preferably 25°C or higher, more preferably 60°C or higher, and preferably 200°C or lower, more preferably 170°C or lower. If the glass transition temperature of the said curable composition is more than the said minimum and below the said upper limit, it becomes easy to adjust the viscosity at 25 degreeC of the said curable composition to the said preferable range.

The above-mentioned glass transition temperature can be measured under the conditions of a temperature increase rate of 10° C./min using a differential scanning calorimeter in accordance with JIS-K7121. As said differential scanning calorimeter, "DSC7020" by Hitachi High-Tech Science Corporation, etc. are mentioned.

In recent years, a method is also being studied in which a cover member is provided over the LED chip without coating the protective material on the LED chip, thereby protecting the LED chip. However, when the cover member is used, since the difference in refractive index between the LED chip and the air is large, the light transmittance of the LED light is reduced, resulting in problems of poor display and increased power consumption.

On the other hand, according to the present invention, the LED protective layer for protecting the LED is formed in contact with the LED chip, thereby suppressing the reduction of the transmittance of the LED light. As a result, the display of the LED module and the LED display device can be improved, and power consumption can be reduced.

From the viewpoint of improving the display of the LED module and the LED display device and suppressing power consumption more effectively, the visible light transmittance of the curable composition at a thickness of 200 μm is preferably 60% or more, more preferably It is 90% or more, more preferably 95% or more, and particularly preferably 99% or more. The upper limit of the visible light transmittance is not particularly limited. The above visible light transmittance may be 100%. The visible light transmittance in the thickness of 200 μm of the curable composition can be set to the above-mentioned preferable range by selecting the material.

The said visible light transmittance can be measured by the following method.

The visible light transmittance of the curable composition at a wavelength of 380 nm to 780 nm was measured in accordance with JIS R3211:1998 using a spectrophotometer (“U-4100” manufactured by Hitachi High-Technologies Corporation).

The curable composition was irradiated with light with a wavelength of 365 nm for 1 second at an illuminance of 1000 mW/cm ² to obtain a cured product X with a thickness of 50 μm (cumulative light intensity 1000 mJ/cm ² ). From the viewpoint of improving the display of the LED module and the LED display device and suppressing power consumption more effectively, the total light transmittance of the cured product X is preferably 60% or more, more preferably 80% or more, and further Preferably it is 90% or more, and particularly preferably 95% or more. The upper limit of the above-mentioned total light transmittance is not particularly limited. The above-mentioned total light transmittance may be 100%. The total light transmittance of the above-mentioned cured product X can be set to the above-mentioned preferable range by the selection of the material. Furthermore, when actually using the above-mentioned curable composition, the above-mentioned curable composition can be cured under the condition of irradiating light with a wavelength of 365 nm at an illuminance of 1000 mW/cm ² for 1 second, or other The above-mentioned curable composition is cured under the conditions.

The total light transmittance of the cured product X can be measured in the following manner.

The total light transmittance of the cured product X was measured in accordance with JIS K7361-1 using a spectroscopic hazemeter (“SH7000” manufactured by Nippon Denshoku Kogyo Co., Ltd.).

Hereinafter, the detail of each component which can be used for the curable composition of this invention is demonstrated. In addition, in this specification, "(meth)acrylate" means one or both of "acrylate" and "methacrylate".

<The first polyfunctional (meth)acrylate compound (A) containing a plurality of (meth)acryloyl groups and having an aliphatic cyclic skeleton> The said curable composition contains the following 1st polyfunctional (meth)acrylate compound (A), and this 1st polyfunctional (meth)acrylate compound (A) contains plural (meth)acryloyl groups, and Has an aliphatic cyclic skeleton.

The first polyfunctional (meth)acrylate compound (A) may be a bifunctional (meth)acrylate compound, a bifunctional or more (meth)acrylate compound, or a trifunctional (meth)acrylate compound. The acrylate compound may be a trifunctional or higher (meth)acrylate compound. The functional number corresponds to the number of (meth)acryloyl groups. The said 1st polyfunctional (meth)acrylate compound (A) may use only 1 type, and may use 2 or more types together.

As a bifunctional (meth)acrylate compound having an aliphatic cyclic skeleton, for example, ethoxylated cyclohexanemethanol di(meth)acrylate, tricyclodecane di(meth)acrylate, 1 , 3-adamantanediol di(meth)acrylate and propoxylated cyclohexanemethanol di(meth)acrylate etc.

As a trifunctional (meth)acrylate compound which has an aliphatic cyclic skeleton, a pentaerythritol triacrylate-isophorone diisocyanate-urethane prepolymer etc. are mentioned, for example.

It is preferable that the said 1st polyfunctional (meth)acrylate compound (A) has a dicyclopentadiene skeleton from a viewpoint of suppressing the curvature of a board|substrate more effectively. In addition, in the said dicyclopentadiene skeleton in the said 1st polyfunctional (meth)acrylate compound (A), the double bond part of dicyclopentadiene can react. For example, the said dicyclopentadiene skeleton in the said 1st polyfunctional (meth)acrylate compound (A) may be the skeleton represented by following formula (1). In the following formula (1), the right end portion and the left end portion are bonding sites with other groups.

[hua 1]

The first polyfunctional (meth)acrylate compound (A) preferably contains ethoxylated cyclohexanemethanol di(meth)acrylate or tricyclodecanedimethanol di(meth)acrylate, more preferably It contains tricyclodecane dimethanol di(meth)acrylate. The first polyfunctional (meth)acrylate compound (A) preferably contains ethoxylated cyclohexanemethanol di(meth)acrylate or tricyclodecane dimethanol diacrylate, more preferably contains tricyclic Decane dimethanol diacrylate. Tricyclodecane dimethanol di(meth)acrylate has a skeleton represented by the above formula (1). Moreover, it is preferable that the said 1st polyfunctional (meth)acrylate compound (A) has a tricyclodecane skeleton from a viewpoint of suppressing the curvature of a board|substrate more effectively.

The glass transition temperature (Tg) of the homopolymer of the first polyfunctional (meth)acrylate compound (A) is preferably 100°C or higher, more preferably 150°C or higher, further preferably 190°C or higher, and more Preferably it is 250 degrees C or less, More preferably, it is 220 degrees C or less. When the glass transition temperature of the homopolymer of the first polyfunctional (meth)acrylate compound (A) is equal to or higher than the lower limit and lower than the upper limit, the adhesiveness between the substrate and the LED protective layer can be easily improved, and the high temperature can be increased. Brightness retention after the wet test became good.

The glass transition temperature of the homopolymer of the above-mentioned first polyfunctional (meth)acrylate compound (A) and the glass transition temperature of the homopolymer of the following second polyfunctional (meth)acrylate compound (B) are respectively It represents the glass transition temperature of a homopolymer with a degree of polymerization of 3000 to 4000 (preferably about 3500, and most preferably 3500).

The above-mentioned glass transition temperature can be measured under the conditions of a temperature increase rate of 10° C./min using a differential scanning calorimeter in accordance with JIS-K7121. As said differential scanning calorimeter, "DSC7020" by Hitachi High-Tech Science Corporation, etc. are mentioned.

In 100% by weight of the curable composition, the content of the first polyfunctional (meth)acrylate compound (A) is preferably 10% by weight or more, more preferably 20% by weight or more, and preferably 70% by weight % or less, more preferably 60% by weight or less. When content of the said 1st polyfunctional (meth)acrylate compound (A) is more than the said minimum and below the said upper limit, the brightness retention after a high temperature and high humidity test can be made favorable. In addition, when the content of the second polyfunctional (meth)acrylate compound (A) is more than or equal to the above lower limit and less than or equal to the above upper limit, the viscosity of the curable composition at 25° C. can be adjusted to the above preferred range, The above-mentioned curable composition can be further favorably applied by an inkjet method.

<The second polyfunctional (meth)acrylate compound (B) containing a plurality of (meth)acryloyl groups and having an alkylene oxide skeleton> The said curable composition contains the following 2nd polyfunctional (meth)acrylate compound (B), and this 2nd polyfunctional (meth)acrylate compound (B) contains a plurality of (meth)acryloyl groups, and Has an alkylene oxide skeleton.

In addition, in the present specification, the second polyfunctional (meth)acrylate compound (B) does not include a plurality of (meth)acryloyl groups and those having an aliphatic cyclic skeleton and an alkylene oxide skeleton. Functional (meth)acrylate compounds. In this specification, the polyfunctional (meth)acrylate compound containing a plurality of (meth)acryloyl groups and having an aliphatic cyclic skeleton and an alkylene oxide skeleton is classified as the first polyfunctional (meth)acrylate compound. In the acrylate compound (A).

In the present specification, the "alkylene oxide skeleton" refers to a skeleton derived from a glycol-based material such as ethylene glycol (EG), propylene glycol (PG), or 1,4-butanediol (TMG). Specifically, the "alkylene oxide skeleton" is preferably a skeleton in which a diol-based material has reacted, and preferably a skeleton in which a diol-based material has undergone a polymerization reaction. As said alkylene oxide skeleton, the skeleton etc. which are represented by following formula (11) are mentioned, for example.

-(RO) _n - (11)

In the said formula (11), as R, a C1-C4 alkylene group etc. are mentioned, for example. Examples of the alkylene group having 1 to 4 carbon atoms include a CH ₂ group, a CH ₂ CH ₂ group, a CH ₂ CH ₂ CH ₂ group, a CH ₂ (CH ₃ )CH group, and a CH ₂ CH ₂ CH ₂ group. CH ₂ base, etc. The number of carbon atoms in the alkylene group is preferably 2 or more, and preferably 3 or less. The carbon number of the above-mentioned alkylene group may be 2 or 3. In the above formula (11), n preferably represents 1 or more, more preferably 2 or more, still more preferably 4 or more, preferably 12 or less, more preferably 9 or less.

Since the said curable composition contains a 2nd polyfunctional (meth)acrylate compound (B), after forming an LED protective layer, the warpage of a board|substrate can be suppressed, and the adhesiveness of a board|substrate and an LED protective layer can be improved.

The second polyfunctional (meth)acrylate compound (B) may be a bifunctional (meth)acrylate compound, a bifunctional or more (meth)acrylate compound, or a trifunctional (meth)acrylate compound. The acrylate compound may be a trifunctional or higher (meth)acrylate compound, or a tetrafunctional (meth)acrylate compound. The said 2nd polyfunctional (meth)acrylate compound (B) may be a tetrafunctional or more (meth)acrylate compound. The functional number corresponds to the number of (meth)acryloyl groups. Only 1 type may be used for the said 2nd polyfunctional (meth)acrylate compound (B), and 2 or more types may be used together.

As a bifunctional (meth)acrylate compound having an alkylene oxide skeleton, for example, polyethylene glycol di(meth)acrylate, polypropylene glycol diacrylate, and ethylene glycol di(meth)acrylate may be mentioned. , ethylene oxide modified bisphenol A di(meth)acrylate, and propylene oxide modified bisphenol A di(meth)acrylate, etc.

As a trifunctional (meth)acrylate compound which has an alkylene oxide skeleton, the alkylene oxide modification|denaturation tri(meth)acrylate of trimethylolpropane etc. are mentioned, for example.

As an alkylene oxide which comprises an alkylene oxide skeleton, ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc. are mentioned. By reacting an alkylene oxide, an alkylene oxide skeleton can be formed.

From the viewpoint of further effectively suppressing the warpage of the substrate and further improving the adhesion between the substrate and the LED protective layer, the above-mentioned alkylene oxide is preferably ethylene oxide or propylene oxide. From the viewpoint of further effectively suppressing the warpage of the substrate and further improving the adhesion between the substrate and the LED protective layer, the second polyfunctional (meth)acrylate compound (B) preferably has an ethylene oxide skeleton or an epoxy resin. Propane skeleton. From the viewpoint of further effectively suppressing the warpage of the substrate and further improving the adhesion between the substrate and the LED protective layer, the second polyfunctional (meth)acrylate compound (B) preferably has a polyalkylene oxide skeleton, more preferably It has a polyethylene oxide skeleton or a polypropylene oxide skeleton. From the viewpoint of further effectively suppressing the warpage of the substrate and further improving the adhesiveness between the substrate and the LED protective layer, the second polyfunctional (meth)acrylate compound (B) preferably has an alkylene oxide that has undergone a polymerization reaction. The skeleton is more preferably a skeleton in which ethylene oxide has been polymerized or a skeleton in which propylene oxide has been polymerized.

As a polyfunctional (meth)acrylate compound which has an ethylene oxide skeleton, ethylene oxide modified bisphenol A di(meth)acrylate etc. are mentioned.

As a polyfunctional (meth)acrylate compound which has a propylene oxide skeleton, a propylene oxide modified bisphenol A di(meth)acrylate, a propylene glycol di(meth)acrylate, etc. are mentioned.

It is preferable that the said 2nd polyfunctional (meth)acrylate compound (B) has a bisphenol skeleton from a viewpoint of further improving the adhesiveness of a board|substrate and an LED protective layer. As a polyfunctional (meth)acrylate compound which has an alkylene oxide skeleton and a bisphenol skeleton, ethylene oxide modified bisphenol A di(meth)acrylate etc. are mentioned.

Furthermore, ethylene oxide-modified bisphenol A di(meth)acrylate is a polyfunctional (meth)acrylate compound having an ethylene oxide skeleton and a bisphenol skeleton. From the viewpoint of further effectively suppressing the warpage of the substrate and further improving the adhesion between the substrate and the LED protective layer, the second polyfunctional (meth)acrylate compound (B) preferably contains ethylene oxide-modified bisphenol. A di(meth)acrylate.

The glass transition temperature (Tg) of the homopolymer of the second polyfunctional (meth)acrylate compound (B) is preferably -50°C or higher, more preferably -40°C or higher, and further preferably -30°C or higher , and preferably 50°C or lower, more preferably 40°C or lower. When the glass transition temperature of the homopolymer of the said 2nd polyfunctional (meth)acrylate compound (B) is more than the said minimum and below the said upper limit, the warpage of a board|substrate can be suppressed more effectively.

The content of the second polyfunctional (meth)acrylate compound (B) in 100% by weight of the curable composition is preferably 15% by weight or more, more preferably 20% by weight or more, and still more preferably 30% by weight % or more, and preferably 75% by weight or less, more preferably 70% by weight or less, and still more preferably 60% by weight or less. When content of the said 2nd polyfunctional (meth)acrylate compound (B) is more than the said minimum and below the said upper limit, the warpage of a board|substrate can be suppressed more effectively, and the adhesiveness of a board|substrate and an LED protective layer can be improved further. Moreover, if the content of the second polyfunctional (meth)acrylate compound (B) is more than the aforementioned lower limit and less than or equal to the aforementioned upper limit, the viscosity of the curable composition at 25° C. can be adjusted to the aforementioned preferable range, The above-mentioned curable composition can be further favorably applied by an inkjet method.

The content of the second polyfunctional (meth)acrylate compound (B) is preferably 50 parts by weight or more, more preferably 60 parts by weight relative to 100 parts by weight of the first polyfunctional (meth)acrylate compound (A). part by weight or more, and preferably not more than 130 parts by weight, more preferably not more than 120 parts by weight. When content of the said 2nd polyfunctional (meth)acrylate compound (B) is more than the said minimum and below the said upper limit, the warpage of a board|substrate can be suppressed more effectively, and the adhesiveness of a board|substrate and an LED protective layer can be improved further.

The total content of the first polyfunctional (meth)acrylate compound (A) and the second polyfunctional (meth)acrylate compound (B) is preferably 50 weight % in 100% by weight of the curable composition. % or more, more preferably 70% by weight or more, preferably 95% by weight or less, more preferably 90% by weight or less. When the total content of the first polyfunctional (meth)acrylate compound (A) and the second polyfunctional (meth)acrylate compound (B) is more than the above lower limit and less than or equal to the above upper limit, the photocurability is excellent, The shape of the edge portion can be maintained better.

<Photopolymerization initiator (C)> The said curable composition contains the said photopolymerization initiator (C).

Since the said curable composition contains the said photopolymerization initiator (C), the said curable composition can be hardened by irradiating light.

As said photopolymerization initiator (C), a photoradical polymerization initiator, a photocationic polymerization initiator, etc. are mentioned. The above-mentioned photopolymerization initiator (C) is preferably a photoradical polymerization initiator. Only one type of the above-mentioned photopolymerization initiator (C) may be used, or two or more types may be used in combination.

、2,4-二乙基9-氧硫𠮿

、2-氯9-氧硫𠮿

、2,4-二異丙基9-氧硫𠮿

等9-氧硫𠮿

化合物；苯乙酮二甲基縮酮、苄基二甲基縮酮等縮酮化合物；2,4,6-三甲基苯甲醯基二苯基氧化膦、雙(2,4,6-三甲基苯甲醯基)-苯基氧化膦等醯基氧化膦化合物；1,2-辛二酮、1-[4-(苯硫基)-2-(鄰苯甲醯基肟)]、乙酮、1-[9-乙基-6-(2-甲基苯甲醯基)-9H-咔唑-3-基]-1-(鄰乙醯基肟)等肟酯化合物；雙(環戊二烯基)-二-苯基-鈦、雙(環戊二烯基)-二-氯-鈦、雙(環戊二烯基)-雙(2,3,4,5,6-五氟苯基)鈦、雙(環戊二烯基)-雙(2,6-二氟-3-(吡咯-1-基)苯基)鈦等二茂鈦化合物；等。上述光自由基聚合起始劑可僅使用一種，亦可併用兩種以上。The above-mentioned photoradical polymerization initiator is a compound for generating a radical by irradiating light and starting a radical polymerization reaction. Examples of the above-mentioned photoradical polymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl Propiophenone Isobenzophenone compounds; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloro Acetophenone compounds such as acetophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-𠰌olinylpropan-1-one, 2-benzyl-2-dimethylamino -1-(4-𠰌olinylphenyl)-butan-1-one, 2-benzyl-2-dimethylamino-1-(4-𠰌olinylphenyl)-butanone-1, 2 -(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone, phenylbis(2, 4,6-trimethylbenzyl) phosphine oxide, N,N-dimethylaminoacetophenone and other aminoacetophenone compounds; 2-methylanthraquinone, 2-ethylanthraquinone, 2- Anthraquinone compounds such as tert-butyl anthraquinone; 2,4-dimethyl 9-oxothio

, 2,4-diethyl 9-oxothio

, 2-chloro-9-oxysulfur

, 2,4-diisopropyl 9-oxothio

Wait for 9-oxysulfur 𠮿

Compounds; ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal; 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis(2,4,6- Trimethylbenzyl)-phenylphosphine oxide and other acyl phosphine oxide compounds; 1,2-octanedione, 1-[4-(phenylthio)-2-(o-benzyl oxime)] , ethyl ketone, oxime ester compounds such as 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-1-(o-acetyloxime); (Cyclopentadienyl)-di-phenyl-titanium, bis(cyclopentadienyl)-di-chloro-titanium, bis(cyclopentadienyl)-bis(2,3,4,5,6 -Titanocene compounds such as pentafluorophenyl)titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl)titanium; etc. Only one type of the above-mentioned photoradical polymerization initiator may be used, or two or more types may be used in combination.

The above-mentioned photopolymerization initiator (C) preferably contains phenylbis(2,4,6-trimethylbenzyl)phosphine oxide, 2-dimethylamino-2-[(4-methylbenzene yl)methyl]-1-[4-(4-𠰌olinyl)phenyl]1-butanone, 2-hydroxy-2-methylpropiophenone or 1-hydroxycyclohexyl phenyl ketone. It is more preferable that the said photopolymerization initiator (C) contains 1-hydroxycyclohexyl phenyl ketone. By using these preferable photopolymerization initiators (C), the shape of the edge portion can be maintained better, and the visible light transmittance can be improved.

A photopolymerization initiator may also be used together with the above-mentioned photoradical polymerization initiator. As the photopolymerization starting aid, N,N-dimethylaminobenzoic acid ethyl, N,N-dimethylaminobenzoic acid isoamyl, 4-dimethylaminobenzoic acid amyl , triethylamine and triethanolamine, etc. Photopolymerization initiation aids other than these may also be used. Only one kind of the above-mentioned photopolymerization initiation aids may be used, or two or more kinds thereof may be used in combination.

In addition, a titanocene compound such as CGI-784 (manufactured by Ciba Refinery Co., Ltd.) having absorption in the visible light region can also be used to promote the photoreaction.

As said photocationic polymerization initiator, perylene salt, iodonium salt, metallocene compound, benzoin tosylate, etc. are mentioned. Only one type of the above-mentioned photocationic polymerization initiators may be used, or two or more types may be used in combination.

In 100% by weight of the curable composition, the content of the photopolymerization initiator (C) is preferably 5% by weight or more, more preferably 8% by weight or more, and preferably 15% by weight or less, more preferably 12% by weight or less. If the content of the above-mentioned photopolymerization initiator (C) is more than the above-mentioned lower limit and below the above-mentioned upper limit, the shape of the edge portion can be maintained more favorably, and the brightness retention rate after the high-temperature and high-humidity test can be further improved.

Content of the above-mentioned photopolymerization initiator (C) with respect to 100 parts by weight of the total of the above-mentioned first polyfunctional (meth)acrylate compound (A) and the above-mentioned second polyfunctional (meth)acrylate compound (B) It is preferably 6 parts by weight or more, more preferably 10 parts by weight or more. Content of the above-mentioned photopolymerization initiator (C) with respect to 100 parts by weight of the total of the above-mentioned first polyfunctional (meth)acrylate compound (A) and the above-mentioned second polyfunctional (meth)acrylate compound (B) It is preferably 18 parts by weight or less, more preferably 14 parts by weight or less. If the content of the above-mentioned photopolymerization initiator (C) is more than the above-mentioned lower limit and below the above-mentioned upper limit, the shape of the edge portion can be maintained more favorably, and the brightness retention rate after the high-temperature and high-humidity test can be further improved.

＜Other ingredients＞ The above curable composition may contain: colorants, fillers, defoaming agents, hardeners, hardening accelerators, mold release agents, surface treatment agents, flame retardants, viscosity modifiers, dispersants, dispersing aids, surface modifiers Quality agent, plasticizer, antibacterial agent, antifungal agent, leveling agent, stabilizer, coupling agent, anti-sag agent or phosphor, etc.

As said filler, titanium oxide, silicon dioxide, calcium oxide, etc. are mentioned. In 100% by weight of the curable composition, the content of the filler is preferably 0.1% by weight or more, more preferably 1.0% by weight or more, and preferably 5.0% by weight or less, more preferably 3.0% by weight or less.

As said dispersing agent, an alkylammonium salt, a high molecular weight copolymer, etc. are mentioned. In 100% by weight of the curable composition, the content of the dispersant is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, and preferably 4.0% by weight or less, more preferably 2.0% by weight or less.

The said curable composition may contain the 3rd polyfunctional (meth)acrylate other than the said 1st polyfunctional (meth)acrylate compound (A) and the said 2nd polyfunctional (meth)acrylate compound (B), Acrylate compound.

As the third polyfunctional (meth)acrylate compound, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and dipropylene glycol may, for example, be mentioned. Di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, trimethylolpropane tris((meth)acrylooxypropyl) ether, sorbitol Tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, sorbitol tetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)propionate base) acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate and the like.

(LED module and manufacturing method of LED module) The LED module of the present invention includes: a substrate having a plurality of LED chips on its upper surface; and an LED protective layer disposed on the substrate. In the LED module of the present invention, the LED protective layer is disposed on at least one of the gaps between the plurality of the LED chips and the upper portion of the plurality of the LED chips. In the above-mentioned LED module, the above-mentioned LED protective layer can be arranged only in the gaps of the plurality of the above-mentioned LED chips, can also be arranged only on the upper part of the plurality of the above-mentioned LED chips, and can also be arranged in the gaps of the plurality of the above-mentioned LED chips and the plurality of the above-mentioned LED chips. Above the LED chip. From the viewpoint of further exerting the effects of the present invention, the LED protective layer in the LED module is preferably disposed between the plurality of the LED chips and above the plurality of the LED chips. In the LED module of the present invention, the LED protective layer is a cured product of the curable composition.

In addition, the manufacturing method of the LED module of the present invention includes the following coating step: in the substrate having a plurality of LED chips on the upper surface, the above-mentioned curable composition is coated on the gaps between the plurality of the above-mentioned LED chips by an inkjet method and At least one of the upper parts of the plurality of LED chips. The manufacturing method of the LED module of the present invention includes the following curing step: irradiating the coated curable composition with light to cure the curable composition, thereby forming gaps arranged in the plurality of the LED chips and the plurality of the above-mentioned An LED protective layer on at least one of the upper parts of the LED chip.

The LED module and the manufacturing method of the LED module of the present invention can improve the surface flatness of the LED protective layer, and can keep the shape of the edge portion of the LED module relatively well. Moreover, the warpage of the substrate can be suppressed, and the adhesion between the substrate and the LED protective layer can be improved.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an LED module obtained by using the curable composition for inkjet coating and LED protection according to one embodiment of the present invention.

The LED module 1 shown in FIG. 1 includes an LED protective layer 11 . The LED protective layer 11 is formed of the above-mentioned curable composition, and is a cured product of the above-mentioned curable composition. The said curable composition contains the said 1st polyfunctional (meth)acrylate compound (A), the said 2nd polyfunctional (meth)acrylate compound (B), and a photoinitiator (C). In this embodiment, the said curable composition has a specific viscosity.

The LED module 1 has an LED protective layer 11 and a substrate 12 . The substrate 12 includes a substrate body 12A, a plurality of LED chips 12B, and a plurality of electrodes 12C. In the LED module 1, the substrate 12 having the LED chip 12B on the upper surface is used. The LED chip 12B is mounted on the substrate body 12A via the electrodes 12C. In the substrate 12, a plurality of LED chips 12B are arranged side by side at intervals. A plurality of LED chips 12B are arranged on the substrate body 12A.

The LED protective layer 11 is formed to cover the gaps between the plurality of LED chips 12B arranged on the substrate body 12A and the upper portion of the plurality of LED chips 12B. The side surface and the upper surface of the LED chip 12B are covered by the LED protective layer 11 .

The above-mentioned LED chips may be red LED chips, blue LED chips, green LED chips, or a combination of these LED chips.

The number of the above-mentioned LED chips per substrate is preferably more than 10,000, more preferably more than 20,000, and preferably less than 80,000, more preferably less than 60,000.

In the manufacturing method of the LED module of the present invention, preferably, the above-mentioned curable composition is applied to the gaps between the plurality of LED chips and the upper portion of the plurality of LED chips. The curable composition described above is ejected from an ink jet head of an ink jet apparatus.

An LED protective layer can be formed by irradiating light to the said curable composition to apply|coat, and hardening the said curable composition. As a light source for photohardening the said curable composition, the irradiation apparatus which emits active energy rays, such as an ultraviolet-ray and a visible ray, is mentioned. As said light source, an ultra-high pressure mercury lamp, a deep ultraviolet lamp, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, and an excimer laser can be mentioned, for example. These light sources are appropriately selected according to the photosensitive wavelengths of the components of the curable composition. The irradiation energy of light is appropriately selected according to the required layer thickness or the constituents of the curable composition. The irradiation energy of light is generally in the range of 10 mJ/cm ² to 3000 mJ/cm ² .

With regard to the manufacturing method of the LED module of the present invention, after the curable composition is applied to a specific area, the entirety of the applied curable composition can be irradiated with light to form an LED protective layer. Regarding the manufacturing method of the LED module of the present invention, after applying a plurality of drops of the curable composition each time, light can be irradiated to the applied curable composition to form an LED protective layer. About the manufacturing method of the LED module of this invention, the application|coating of a curable composition and the irradiation of light can also be performed several times.

In the manufacturing method of the LED module of the present invention, the coating step can be performed only once in the thickness direction of the substrate, so that the curable composition does not overlap in the thickness direction of the substrate. In the manufacturing method of the LED module of the present invention, the above-mentioned coating step may be performed multiple times in the thickness direction of the substrate so that the curable composition overlaps in the thickness direction of the substrate. The thickness of the LED protective layer can be increased by carrying out the above-mentioned coating step several times in the thickness direction of the substrate so that the curable composition is overlapped in the thickness direction of the substrate.

From the viewpoint of improving the display of the LED module and the LED display device and reducing power consumption, the thickness of the above-mentioned LED protective layer on the upper part of the LED chip is preferably 10 μm or more, more preferably 20 μm or more, and more preferably It is 100 micrometers or less, More preferably, it is 80 micrometers or less.

The shape of the above-mentioned LED module is not particularly limited. The shape of the above-mentioned LED module can be circular, rectangular or triangular.

(LED display device) The LED display device of the present invention includes a plurality of the above-mentioned LED modules. In the LED display device of the present invention, a plurality of the above-mentioned LED modules are connected together.

Since the LED display apparatus of this invention has the said structure, the reduction of the light transmittance of LED light can be suppressed. As a result, the display of the LED display device can be improved, and the power consumption can be reduced.

2 is a partial cross-sectional view schematically showing an LED display device obtained by using the curable composition for inkjet coating and LED protection according to one embodiment of the present invention.

The LED display device 21 shown in FIG. 2 includes a plurality of LED modules 1 . A plurality of LED modules 1 are connected together. A plurality of LED modules 1 are connected at the side. In FIG. 2 , a plurality of LED modules 1 are connected side by side in the left-right direction. In FIG. 2 , a plurality of LED modules 1 can also be connected side by side in the near-far direction. In this case, the size of the LED display device 21 can be increased.

In the LED display device 21, the electrodes 12C on the substrate bodies 12A of the connected LED modules 1 are electrically connected to each other.

As a method of connecting the above-mentioned LED modules to obtain an LED display device, a method of arranging a plurality of the obtained modules, etc. may be mentioned. As a method of connecting the above-mentioned LED modules, a method of using an adhesive, a method of using a connecting member, and a method of fitting the arrayed LED modules can be mentioned.

In the above LED display device, the number of the connected LED modules is preferably 3 or more, more preferably 5 or more. If the number of the above-mentioned LED modules is more than the above-mentioned lower limit, further enlargement of the LED display device can be realized. In the above LED display device, the number of the connected LED modules is preferably 35 or less, more preferably 30 or less. If the number of the above-mentioned LED modules is equal to or less than the above-mentioned upper limit, the weight of the LED display device can be reduced.

The shape of the above-mentioned LED display device is not particularly limited. The shape of the above-mentioned LED display device may be circular, rectangular or triangular. By connecting a plurality of LED modules, various shapes of LED display devices can be obtained.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these embodiments.

Prepare the following materials.

1st polyfunctional (meth)acrylate compound (A): Tricyclodecane dimethanol diacrylate ("IRR-214K" manufactured by DAICEL-ALLNEX, glass transition temperature of homopolymer: 190°C) Ethoxylated cyclohexanemethanol diacrylate ("HBPE-4" manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., glass transition temperature of homopolymer: 50°C)

Second polyfunctional (meth)acrylate compound (B): Ethylene oxide-modified bisphenol A diacrylate ("Viscoat #700HV" manufactured by Osaka Organic Chemical Industry Co., Ltd., glass transition temperature of homopolymer: -3°C) Polyethylene glycol (200) diacrylate ("Light acrylate 4EG-A" manufactured by Kyōeisha Chemical Co., Ltd., glass transition temperature of homopolymer: 50°C) Polyethylene glycol (400) diacrylate ("Light acrylate 9EG-A" manufactured by Kyōeisha Chemical Co., Ltd., glass transition temperature of homopolymer: 3°C) Polyethylene glycol (600) diacrylate ("Light acrylate 14EG-A" manufactured by Kyōeisha Chemical Co., Ltd., glass transition temperature of homopolymer: -42°C) Polypropylene glycol diacrylate ("APG-700" manufactured by Shin-Nakamura Chemical Co., Ltd., glass transition temperature of homopolymer: 32°C)

Other polyfunctional (meth)acrylate compounds (third polyfunctional (meth)acrylate compounds other than the first and second polyfunctional (meth)acrylate compounds (A) and (B)): 1,6-Hexanediol diacrylate ("Viscoat #230" manufactured by Osaka Organic Chemical Industry Co., Ltd., glass transition temperature of homopolymer: 105°C)

Photopolymerization initiator (C): 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone (manufactured by IGM Resins "Omnirad379EG") Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide ("Omnirad819" manufactured by IGM Resins) 1-Hydroxycyclohexyl phenyl ketone ("Omnirad184" manufactured by IGM Resins)

Filler: Titanium oxide ("TTO-55(E)" manufactured by Ishihara Sangyo Co., Ltd.)

Dispersant: Wetting and dispersing agent ("BYK9076" manufactured by BYK Corporation)

(Examples 1 to 19 and Comparative Examples 1 to 8) The components shown in following Tables 1-6 were mix|blended by the compounding quantity (unit is weight part) shown in following Tables 1-6, and a curable composition was obtained.

(Evaluation) (1) Viscosity of curable composition at 25°C (η25) The viscosity (η25) of the obtained curable composition at 25°C was measured. The above-mentioned viscosity (η25) was measured under the conditions of 25° C. and 1 rpm using an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

(2) Inkjet ejectability The discharge test of the obtained curable composition was performed from the inkjet head of the piezoelectric inkjet printer with an ultraviolet irradiation device, and it judged based on the following criteria.

[Criteria for Judgment of Inkjet Dischargeability] 〇〇: The curable composition can be continuously discharged from the nozzle for more than 10 hours ○: Although the curable composition can be continuously ejected from the nozzle for 10 hours or more, a little unevenness in ejection occurs during the continuous ejection period of 10 hours △: Although the curable composition can be continuously discharged from the nozzle, it cannot be continuously discharged for more than 10 hours ×: Unable to eject the curable composition at the initial stage of ejection from the ejection head

(3) Visible light transmittance of curable composition The obtained curable composition was put into a quartz cell of 0.5 mm optical path length so that the thickness would be 200 μm. Using a spectrophotometer (“U-4100” manufactured by Hitachi High-Technologies Corporation), according to JIS R3211:1998, the visible light transmittance of the curable composition at a thickness of 200 μm was measured at a wavelength of 380 nm to 780 nm. The visible light transmittance of the curable composition was determined according to the following criteria.

[Criteria for determination of visible light transmittance of curable composition] 〇〇: Visible light transmittance is more than 95% in all regions with wavelengths from 380 nm to 780 nm 〇: Does not meet 〇〇, and the visible light transmittance is 90% or more in all regions with wavelengths from 380 nm to 780 nm ×: Visible light transmittance does not reach 90% in at least a part of the wavelength range from 380 nm to 780 nm

(4) Total light transmittance of the cured product of the curable composition The curable composition was irradiated with light with a wavelength of 365 nm for 1 second at an illuminance of 1000 mW/cm ² to obtain a cured product X with a thickness of 50 μm (cumulative Light quantity 1000 mJ/cm ² ). The total light transmittance of the obtained cured product X was measured according to JIS K7361-1 using a spectroscopic hazemeter (“SH7000” manufactured by Nippon Denshoku Kogyo Co., Ltd.). The total light transmittance of the cured product X was determined according to the following criteria.

[Criteria for the determination of the total light transmittance of the cured product of the curable composition] 〇〇: Total light transmittance is 90% or more 〇: Total light transmittance is 80% or more and less than 90% ×: Total light transmittance less than 80%

(5) Surface flatness, and (6) Shape of edge portion On a glass substrate (5 cm x 5 cm in size), from the ink jet head of a piezoelectric ink jet printer equipped with an ultraviolet irradiation device, the curable composition was repeatedly ejected, and the curing process was carried out by irradiating ultraviolet rays. hardened to obtain a hardened product having a thickness of 150 μm. Using a laser microscope ("OLS4100" manufactured by Olympus Corporation), the surface flatness of the obtained cured product and the shape of the edge portion of the obtained cured product were confirmed. The surface flatness and the shape of the edge portion were determined according to the following criteria, respectively.

[Criteria for Judgment of Surface Flatness] 〇: There is no unevenness on the surface of the hardened object, or the height difference of the unevenness on the surface of the hardened object is less than 10 μm △: The height difference of the unevenness on the surface of the cured product is 10 μm or more and less than 15 μm ×: The height difference of the unevenness on the surface of the cured product is 15 μm or more -: Unable to judge because ink jet ejection cannot be performed

[Criteria for determining the shape of the edge portion] 〇〇: The difference between the height position of the edge portion of the cured product and the height position of the center of the cured product is less than 60 μm 〇: The difference between the height position of the edge portion of the cured product and the height position of the center of the cured product is 60 μm or more and less than 120 μm △: The difference between the height position of the edge portion of the cured product and the height position of the center of the cured product is 120 μm or more and less than 200 μm ×: The difference between the height position of the edge portion of the cured product and the height position of the center of the cured product is 200 μm or more -: Unable to judge because ink jet ejection cannot be performed

(7) Warpage of the substrate On a polyethylene terephthalate film (PET) (5 cm × 5 cm in size, 50 μm in thickness), from the ink jet head of a piezoelectric ink jet printer equipped with an ultraviolet irradiation device, the procedure was repeated. The obtained curable composition was ejected and cured by irradiation with ultraviolet rays to obtain a cured product with a thickness of 150 μm. The PET film with the hardened object was placed on a flat table, one side part was pressed, and the height of the other side part from the table was measured. The height of the other side part of the PET film with a hardened|cured material from a stage was evaluated as the curvature of a board|substrate. The warpage of the substrate was judged according to the following criteria.

[Criteria for Judgment of Warpage of Substrate] 〇〇: Warpage less than 300 μm ○: Warpage is 300 μm or more and less than 600 μm ×: Warpage is 600 μm or more -: Unable to judge because ink jet ejection cannot be performed

(8) Adhesion between substrate and protective layer On a glass substrate (5 cm x 5 cm in size), from the ink jet head of a piezoelectric ink jet printer equipped with an ultraviolet irradiation device, the curable composition was repeatedly ejected, and the curing process was carried out by irradiating ultraviolet rays. hardened to obtain a hardened product having a thickness of 150 μm. For the obtained hardened product, slits were cut in the longitudinal and transverse directions at intervals of 1 mm, and 100 grids were produced. The adhesion between the substrate and the protective layer was judged according to the following criteria.

[Adhesion between substrate and protective layer] 〇: The number of grids where the protective layer is peeled off is 0 to 10 △: The number of grids with the protective layer peeled off is 11 to 15 ×: The number of grids with the protective layer peeled off is 16 or more -: Unable to judge because ink jet ejection cannot be performed

(9) Brightness retention after high temperature and high humidity test Prepare a substrate on which three blue light-emitting elements with a main emission peak of 460 nm are mounted on the substrate body. On the substrate, ejection of the obtained curable composition and curing by irradiation with ultraviolet rays were repeated from an ink jet head of a piezoelectric ink jet printer equipped with an ultraviolet irradiation device to obtain a thickness. A hardened product with a thickness of 150 μm was obtained, thereby obtaining an LED display device.

The initial luminance of the obtained LED display device was measured using "OL770" manufactured by Optronic Laboratories. Then, in a state where the three light-emitting elements emit light at 20 mA at the same time, the LED display device is placed in a high-temperature and high-humidity oven at 85°C and 85 RH%, and the high-temperature and high-humidity test for 100 hours and 300 hours are measured. Brightness after the high temperature and high humidity test. After the test, the rate of decrease in luminance was obtained from the initial luminance. The brightness retention after the high-temperature and high-humidity test was judged according to the following criteria.

[Judgment criteria for brightness retention after high temperature and high humidity test] 〇〇: The brightness drop rate is less than 3% 〇: The brightness reduction rate is more than 3% and less than 10% △: The luminance decrease rate is 10% or more and less than 40% ×: The luminance drop rate is 40% or more -: Unable to judge because ink jet ejection cannot be performed

The compositions and results are shown in Tables 1 to 6 below.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 1st polyfunctional (meth)acrylate compound (A) Tricyclodecane dimethanol diacrylate parts by weight 50 50 50 60 Ethoxylated cyclohexane methanol diacrylate parts by weight 50 Second polyfunctional (meth)acrylate compound (B) Ethylene oxide modified bisphenol A diacrylate parts by weight 30 30 40 20 Polyethylene glycol (200) diacrylate parts by weight 30 Polyethylene glycol (400) diacrylate parts by weight Polyethylene glycol (600) diacrylate parts by weight Polypropylene glycol diacrylate parts by weight 10 10 10 10 Other polyfunctional (meth)acrylate compounds 1,6-Hexanediol diacrylate parts by weight Photopolymerization Initiator (C) 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone parts by weight 10 Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide parts by weight 1-Hydroxycyclohexyl phenyl ketone parts by weight 10 10 10 10 filler Titanium oxide parts by weight Dispersant Wetting and dispersing agent parts by weight Evaluation (1) Viscosity (η25) mPa·s 450 550 600 400 320 (2) Inkjet ejectability 〇〇 〇〇 〇〇 〇〇 〇〇 (3) Visible light transmittance of curable composition 〇〇 〇 〇〇 〇〇 〇〇 (4) Total light transmittance of the cured product X of the curable composition 〇〇 〇 〇〇 〇〇 〇〇 (5) Surface flatness 〇 〇 〇 〇 〇 (6) Shape of the edge portion 〇〇 〇〇 〇〇 〇〇 〇 (7) Warpage of the substrate 〇〇 〇〇 〇〇 〇〇 〇 (8) Adhesion between substrate and protective layer 〇 〇 〇 〇 〇 (9) Brightness retention after high temperature and high humidity test 〇〇 〇〇 〇〇 〇〇 〇

[Table 2] Example 6 Example 7 Example 8 Example 9 Example 10 1st polyfunctional (meth)acrylate compound (A) Tricyclodecane dimethanol diacrylate parts by weight 25 65 Ethoxylated cyclohexane methanol diacrylate parts by weight 50 50 50 Second polyfunctional (meth)acrylate compound (B) Ethylene oxide modified bisphenol A diacrylate parts by weight 20 50 15 Polyethylene glycol (200) diacrylate parts by weight Polyethylene glycol (400) diacrylate parts by weight 30 Polyethylene glycol (600) diacrylate parts by weight 30 Polypropylene glycol diacrylate parts by weight 10 10 15 10 10 Other polyfunctional (meth)acrylate compounds 1,6-Hexanediol diacrylate parts by weight Photopolymerization Initiator (C) 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone parts by weight Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide parts by weight 1-Hydroxycyclohexyl phenyl ketone parts by weight 10 10 15 15 10 filler Titanium oxide parts by weight Dispersant Wetting and dispersing agent parts by weight Evaluation (1) Viscosity (η25) mPa·s 340 370 600 700 320 (2) Inkjet ejectability 〇〇 〇〇 〇〇 〇〇 〇〇 (3) Visible light transmittance of curable composition 〇〇 〇〇 〇〇 〇〇 〇〇 (4) Total light transmittance of cured product X of curable composition 〇〇 〇〇 〇〇 〇〇 〇〇 (5) Surface flatness 〇 〇 〇 〇 〇 (6) Shape of the edge portion 〇 〇 〇 〇 〇〇 (7) Warpage of the substrate 〇 〇 〇 〇〇 〇 (8) Adhesion between substrate and protective layer 〇 〇 〇 〇 〇 (9) Brightness retention after high temperature and high humidity test 〇 〇 〇 〇〇 〇〇

[table 3] Example 11 Example 12 Example 13 Example 14 Example 15 1st polyfunctional (meth)acrylate compound (A) Tricyclodecane dimethanol diacrylate parts by weight 15 54 50 50 Ethoxylated cyclohexane methanol diacrylate parts by weight 15 Second polyfunctional (meth)acrylate compound (B) Ethylene oxide modified bisphenol A diacrylate parts by weight 65 65 30 30 Polyethylene glycol (200) diacrylate parts by weight Polyethylene glycol (400) diacrylate parts by weight 30 Polyethylene glycol (600) diacrylate parts by weight Polypropylene glycol diacrylate parts by weight 10 10 10 10 10 Other polyfunctional (meth)acrylate compounds 1,6-Hexanediol diacrylate parts by weight Photopolymerization Initiator (C) 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone parts by weight Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide parts by weight 10 1-Hydroxycyclohexyl phenyl ketone parts by weight 10 10 6 10 filler Titanium oxide parts by weight Dispersant Wetting and dispersing agent parts by weight Evaluation (1) Viscosity (η25) mPa·s 1200 1500 400 520 240 (2) Inkjet ejectability 〇 〇 〇〇 〇〇 〇〇 (3) Visible light transmittance of curable composition 〇〇 〇〇 〇〇 〇 〇〇 (4) Total light transmittance of the cured product X of the curable composition 〇〇 〇〇 〇〇 〇 〇〇 (5) Surface flatness 〇 〇 〇 〇 〇 (6) Shape of the edge portion 〇〇 〇 〇 〇〇 〇〇 (7) Warpage of the substrate 〇〇 〇 〇〇 〇〇 〇 (8) Adhesion between substrate and protective layer 〇 〇 〇 〇 〇 (9) Brightness retention after high temperature and high humidity test 〇 〇 〇〇 〇〇 〇

[Table 4] Example 16 Example 17 Example 18 Example 19 1st polyfunctional (meth)acrylate compound (A) Tricyclodecane dimethanol diacrylate parts by weight 50 50 70 Ethoxylated cyclohexane methanol diacrylate parts by weight 50 Second polyfunctional (meth)acrylate compound (B) Ethylene oxide modified bisphenol A diacrylate parts by weight 30 30 Polyethylene glycol (200) diacrylate parts by weight 20 Polyethylene glycol (400) diacrylate parts by weight Polyethylene glycol (600) diacrylate parts by weight 30 Polypropylene glycol diacrylate parts by weight 10 10 10 Other polyfunctional (meth)acrylate compounds 1,6-Hexanediol diacrylate parts by weight Photopolymerization Initiator (C) 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone parts by weight Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide parts by weight 1-Hydroxycyclohexyl phenyl ketone parts by weight 10 10 10 10 filler Titanium oxide parts by weight 1 1 Dispersant Wetting and dispersing agent parts by weight 0.1 0.1 Evaluation (1) Viscosity (η25) mPa·s 580 300 500 120 (2) Inkjet ejectability 〇〇 〇〇 〇〇 〇〇 (3) Visible light transmittance of curable composition 〇〇 〇〇 〇〇 〇〇 (4) Total light transmittance of the cured product X of the curable composition 〇〇 〇〇 〇〇 〇〇 (5) Surface flatness 〇 〇 〇 〇 (6) Shape of the edge portion 〇 〇〇 〇〇 〇 (7) Warpage of the substrate 〇〇 〇〇 〇〇 〇 (8) Adhesion between substrate and protective layer 〇 〇 〇 〇 (9) Brightness retention after high temperature and high humidity test 〇 〇〇 〇〇 〇

[table 5] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 1st polyfunctional (meth)acrylate compound (A) Tricyclodecane dimethanol diacrylate parts by weight 50 Ethoxylated cyclohexane methanol diacrylate parts by weight 40 40 50 Second polyfunctional (meth)acrylate compound (B) Ethylene oxide modified bisphenol A diacrylate parts by weight 65 35 30 Polyethylene glycol (200) diacrylate parts by weight Polyethylene glycol (400) diacrylate parts by weight Polyethylene glycol (600) diacrylate parts by weight Polypropylene glycol diacrylate parts by weight 25 10 Other polyfunctional (meth)acrylate compounds 1,6-Hexanediol diacrylate parts by weight 40 50 Photopolymerization Initiator (C) 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone parts by weight 25 Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide parts by weight 1-Hydroxycyclohexyl phenyl ketone parts by weight 10 10 10 10 filler Titanium oxide parts by weight Dispersant Wetting and dispersing agent parts by weight Evaluation (1) Viscosity (η25) mPa·s 1000 320 2400 240 280 (2) Inkjet ejectability 〇 〇〇 × 〇〇 〇〇 (3) Visible light transmittance of curable composition 〇〇 〇〇 〇 〇〇 〇〇 (4) Total light transmittance of the cured product X of the curable composition 〇〇 〇〇 〇 〇〇 〇〇 (5) Surface flatness 〇 〇 - 〇 〇 (6) Shape of the edge portion △ 〇〇 - 〇 〇 (7) Warpage of the substrate 〇 × - × 〇 (8) Adhesion between substrate and protective layer × × - × × (9) Brightness retention after high temperature and high humidity test × 〇〇 - 〇 ×

[Table 6] Comparative Example 6 Comparative Example 7 Comparative Example 8 1st polyfunctional (meth)acrylate compound (A) Tricyclodecane dimethanol diacrylate parts by weight 5 Ethoxylated cyclohexane methanol diacrylate parts by weight 50 Second polyfunctional (meth)acrylate compound (B) Ethylene oxide modified bisphenol A diacrylate parts by weight 30 Polyethylene glycol (200) diacrylate parts by weight 89 Polyethylene glycol (400) diacrylate parts by weight Polyethylene glycol (600) diacrylate parts by weight Polypropylene glycol diacrylate parts by weight 10 Other polyfunctional (meth)acrylate compounds 1,6-Hexanediol diacrylate parts by weight Photopolymerization Initiator (C) 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-𠰌olinyl)phenyl]-1-butanone parts by weight Phenylbis(2,4,6-trimethylbenzyl)phosphine oxide parts by weight 1-Hydroxycyclohexyl phenyl ketone parts by weight 10 10 6 filler Titanium oxide parts by weight Dispersant Wetting and dispersing agent parts by weight Evaluation (1) Viscosity (η25) mPa·s 190 340 60 (2) Inkjet ejectability 〇〇 〇〇 〇〇 (3) Visible light transmittance of curable composition 〇〇 〇〇 〇〇 (4) Total light transmittance of the cured product X of the curable composition 〇〇 〇〇 〇〇 (5) Surface flatness 〇 〇 〇 (6) Shape of the edge portion × × × (7) Warpage of the substrate 〇 〇 〇 (8) Adhesion between substrate and protective layer × × 〇 (9) Brightness retention after high temperature and high humidity test × × 〇〇

1: LED module 11: LED protective layer 12: Substrate 12A: Substrate body 12B: LED chip 12C: Electrode 21: LED display device

FIG. 1 is a cross-sectional view schematically showing an LED module obtained by using the curable composition for inkjet coating and LED protection according to an embodiment of the present invention. 2 is a partial cross-sectional view schematically showing an LED display device obtained by using the curable composition for inkjet coating and LED protection according to one embodiment of the present invention.

1: LED module

11: LED protective layer

12: Substrate

12A: Substrate body

12B: LED chip

12C: Electrode

Claims (12)

A curable composition for inkjet coating and LED protection, comprising: a first polyfunctional (meth)acrylate compound containing a plurality of (meth)acryloyl groups and having an aliphatic cyclic skeleton; a second polyfunctional (meth)acrylate compound containing a plurality of (meth)acryloyl groups and having an alkylene oxide skeleton; and a photopolymerization initiator; and The viscosity at 25°C is above 80 mPa·s and below 2000 mPa·s. The curable composition for inkjet coating and LED protection according to claim 1, wherein the first polyfunctional (meth)acrylate compound has a dicyclopentadiene skeleton. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein the second polyfunctional (meth)acrylate compound has a bisphenol skeleton. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein when the curable composition is irradiated with light with a wavelength of 365 nm for 1 second at an illuminance of 1000 mW/cm ² , a 50 μm thick sheet is obtained. In the case of a cured product, the total light transmittance of the cured product is 90% or more. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein the glass transition temperature of the homopolymer of the first polyfunctional (meth)acrylate compound is 100°C or higher. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein the glass transition temperature of the homopolymer of the second polyfunctional (meth)acrylate compound is 50°C or lower. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein in 100% by weight of the curable composition, the content of the first polyfunctional (meth)acrylate compound is 10% by weight or more 70% by weight or less. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein in 100% by weight of the curable composition, the content of the second polyfunctional (meth)acrylate compound is 15% by weight or more 75% by weight or less. The curable composition for inkjet coating and LED protection according to claim 1 or 2, wherein the second polyfunctional (meth)acrylate compound is 100 parts by weight of the first polyfunctional (meth)acrylate compound. The content of the compound is 50 parts by weight or more and 130 parts by weight or less. An LED module, comprising: a substrate, the upper surface of which has a plurality of LED chips; and The LED protective layer is disposed on at least one of the gaps between the plurality of the LED chips and the upper portion of the plurality of the LED chips; and The above-mentioned LED protective layer is a cured product of the curable composition for inkjet coating and LED protection according to any one of claims 1 to 9. A method for manufacturing an LED module, comprising the following steps: a coating step, wherein a substrate having a plurality of LED chips on the upper surface is used for inkjet coating and LED protection according to any one of claims 1 to 9. The curable composition is applied to at least one of the gaps of the plurality of the above-mentioned LED chips and the upper part of the plurality of the above-mentioned LED chips by an inkjet method; and A curing step of irradiating light to the applied curable composition for inkjet coating and LED protection to cure the above-described curable composition for inkjet coating and LED protection, thereby forming a plurality of LED chips arranged on the The gap and the LED protective layer on at least one of the upper parts of the plurality of LED chips. An LED display device is provided with a plurality of LED modules, and A plurality of the above-mentioned LED modules are connected together, The above-mentioned LED module includes: a substrate having a plurality of LED chips on its upper surface; and an LED protection layer disposed at least one of the gaps between the plurality of the above-mentioned LED chips and the upper portion of the plurality of the above-mentioned LED chips; and In the above-mentioned LED module, the above-mentioned LED protective layer is a cured product of the curable composition for inkjet coating and LED protection according to any one of claims 1 to 9.

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