KR20180085181A - Photocurable composition and photocurable layer formed from the same - Google Patents

Abstract

The present invention provides a photocurable composition, comprising: a difunctional or multi-functional allyl ether compound; a monofunctional to trifunctional (meta) acrylate compound; a (meta) acrylate compound including at least one fluoroalkyl group; a monomer containing a carboxyl groupl; and a photoinitiator. According to the present invention, the allyl ether compound and the (meta) acrylate compound have interaction such that the composition having improved low viscosity, reactivity, and coating performance, and the photocurable film with excellent oxygen or moisture blocking property can be realized.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a photocurable composition and a photocurable composition formed therefrom,

The present invention relates to a photocurable composition and a photocurable film formed therefrom. To a photocurable composition comprising photopolymerizable monomers and to a photocurable film formed therefrom.

For example, a photosensitive composition is used to form various photocurable insulating patterns such as photoresist, insulating film, protective film, black matrix, column spacer, etc. of a display device. After the photosensitive composition is applied, a photocuring pattern of a predetermined shape can be formed in a desired area through an exposure process and / or a development process. The photosensitive composition has, for example, high sensitivity to ultraviolet ray exposure, polymerization reactivity, and a pattern formed therefrom needs to have improved heat resistance, chemical resistance, and the like.

For example, in an organic light emitting diode (OLED) display device, an organic light emitting layer is formed for each pixel, and an encapsulation layer for protecting the organic light emitting layer from external impurities or moisture may be formed.

An inorganic insulating layer containing silicon oxide, silicon nitride, and / or silicon oxynitride may be formed as the encapsulation layer. However, deterioration of the display element due to external moisture may not be sufficiently blocked by the inorganic insulating layer alone.

Therefore, a protective film containing an organic component needs to be employed. In this case, it may be considered to form an encapsulation layer using the photosensitive organic composition.

In recent years, as the resolution of an OLED device increases, patterns and pixel sizes also become finer. Therefore, the photosensitive organic composition also needs to have physical properties suitable for fine application or fine patterning.

For example, Korean Patent Registration No. 10-1359470 discloses a photoresist composition comprising an alkali-soluble resin, a photocurable monomer, a photopolymerization initiator, an aminoacetophenone-based or aminobenzaldehyde-based hydrogen donor and a solvent and activating an alkyl radical generated in the photopolymerization initiator Discloses a photosensitive resin composition capable of improving photoreactivity.

However, when an alkali-soluble resin is included, the viscosity of the composition is increased, which limits the desired implementation of fine patterning.

Korean Patent No. 10-1359470

An object of the present invention is to provide a photocurable composition having low viscosity and improved polymerization reactivity.

An object of the present invention is to provide a photocurable film formed from the photocurable composition and having improved strength, hardness and stability, and excellent moisture or oxygen shielding property.

An object of the present invention is to provide an image display device including the photocurable film.

1. bifunctional allyl ether compound; 1 to 3 functional (meth) acrylate compounds; (Meth) acrylate compounds comprising at least one fluoroalkyl group; Carboxylic acid-containing monomers; And a photoinitiator.

2. The photocurable composition according to 1 above, wherein said bifunctional allyl ether compound comprises at least one selected from compounds represented by the following formulas 1-1 to 1-3:

[Formula 1-1]

[Formula 1-2]

(In the formula (1-2), R ₁ is hydrogen, an alkyl having 1 to 3 carbon atoms, or a hydroxyl group)

[Formula 1-3]

.

.

3. The photocurable composition according to item 1 above, wherein the (meth) acrylate compound of the first to third functional groups comprises at least one selected from compounds represented by the following general formulas (2-1) to (2-5)

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Chemical Formula 2-4]

[Chemical Formula 2-5]

(In the formulas (2-1) to (2-5), R ₂ is each independently hydrogen or a methyl group, R ₃ is a non-cyclic or cyclic alkyl group having 1 to 20 carbon atoms, R ₄ is hydrogen or an alkyl group having 1 to 3 carbon atoms , R ₅ is hydrogen, an alkyl group having 1 to 3 carbon atoms, a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms, m is an integer of 1 to 10, and n is independently an integer of 1 to 5).

4. The photocurable composition according to 1 above, wherein the (meth) acrylate compound of the first to third functional groups comprises two or more (meth) acrylate compounds having different functional numbers.

5. The composition according to item 4 above, wherein said (meth) acrylate compound is a combination of a monofunctional (meth) acrylate compound and a trifunctional (meth) acrylate compound, (Meth) acrylate compound, and a tricompatible meta (acrylate) compound.

6. The photocurable composition according to item 1 above, wherein the (meth) acrylate compound comprising at least one fluoroalkyl group comprises a compound represented by the following formula (3):

(3)

(Wherein R ₆ is hydrogen or a methyl group, o is an integer of 1 to 10, and p is an integer of 1 to 5).

7. The photocurable composition according to 1 above, wherein the carboxylic acid-containing monomer comprises a monofunctional carboxylic acid-containing (meth) acrylate monomer.

8. The photocurable composition according to 7 above, wherein the carboxylic acid-containing monomer comprises a monomer represented by the following Formula 3:

[Chemical Formula 4]

(Wherein X is an alkylene, cyclohexyl, cyclohexenyl, or phenyl group having 1 to 3 carbon atoms, and R _a and R _b are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms).

9. The photocurable composition of 1 above, wherein the photoinitiator comprises an oxime ester-based compound.

10. The composition according to 1 above, wherein, in the total weight of the composition, 10 to 50% by weight of the bifunctional or higher allyl ether compound; 20 to 60% by weight of the (meth) acrylate compound having from 1 to 3 functional groups; 10 to 40% by weight of a (meth) acrylate compound comprising the at least one fluoroalkyl group; 1 to 5% by weight of the carboxylic acid-containing monomer; And 1 to 10% by weight of the photoinitiator.

11. The photocurable composition according to item 1, further comprising a polyfunctional thiol compound.

12. The photocurable composition of claim 1, wherein the photocurable composition is prepared in a non-solvent type.

13. The photocurable composition of any preceding claim, wherein the polymer or resin component is not included.

14. The photocurable composition as in 1 above, having a viscosity of 20 cp or less at room temperature.

15. A photocurable film formed from any one of the photocurable compositions of any one of claims 1 to 14 above.

16. An image display device comprising a photocurable film formed from any one of the photocurable compositions 1 to 14 above.

17. The system of claim 16, further comprising: a base substrate; And organic light emitting devices disposed on the base substrate, wherein the photocurable film is provided as an encapsulation layer of the organic light emitting devices.

Photocurable compositions according to embodiments of the present invention include polymeric monomers and may not include resin or polymer components. Therefore, a composition of low viscosity can be realized, and fine patterning can be effectively carried out, for example, through an inkjet process. The photo-curing composition may, for example, be prepared as a solvent-free solventless form containing an allyl ether compound as a diluent. A low viscosity composition can be realized without solvent by the above-mentioned allyl ether compound.

In addition, the photocurable composition may include a (meth) acrylate compound having an appropriate functional group in consideration of the reactivity of the allyl ether compound. Therefore, damage to the surface profile due to oxygen inhibition can be suppressed while ensuring desired polymerization or curing reactivity.

Also, the photo-curable composition includes a (meth) acrylate compound containing at least one fluoroalkyl group, and can realize a coating film or a photo-curable pattern having excellent strength and improved moisture or oxygen shielding property.

In addition, the photo-curable composition further includes a carboxyl group-containing compound, thereby improving the adhesion to the substrate or the object, thereby improving the mechanical stability of the coating film or the photo-curable pattern.

According to embodiments of the present invention, the photocurable film formed using the photocurable composition has excellent moisture barrier properties and can be utilized, for example, as an encapsulation film of an organic light emitting diode device.

FIGS. 1, 2 and 3 are schematic cross-sectional views showing an image display apparatus including a photocurable film according to embodiments of the present invention.
Figs. 4 to 6 are images for explaining the evaluation criteria of the photocurable coating properties of the examples and the comparative examples. Fig.
Figs. 7 and 8 are images for explaining the criteria for evaluating the oxygen inhibition effect on the photocurable film of the examples and the comparative examples. Fig.

Examples of the present invention include a (meth) acrylate compound having at least two functionalities, at least one functional group-containing (meth) acrylate compound, at least one fluoroalkyl group, a carboxylic acid-containing monomer and a photoinitiator A photocurable composition having a low viscosity and having improved coating properties, adhesiveness, and curing properties, and a photocurable film formed therefrom.

Hereinafter, embodiments of the present invention will be described in detail.

< Photocurable  Composition>

Allyl ether ( allyl  ether) compound

The allyl ether compound contained in the photocurable composition according to the embodiments of the present invention substantially functions to lower the viscosity of the composition and can function as a diluent. The above-mentioned allyl ether compound can replace the solvent included in the compositions for forming a general photosensitive organic film. Thus, according to exemplary embodiments, the photocurable composition may be prepared and utilized in a substantially solvent-free or non-solvent type.

The allyl ether compound may have high solubility for other components of the composition described below and may have reactivity to participate in polymerization or curing together.

According to exemplary embodiments, an allyl ether compound having two or more functional groups (for example, two or more allyl ether groups) may be utilized as the allyl ether compound.

When a monofunctional allyl ether compound is used, the polymerization reactivity of the composition and the degree of curing of the photocurable film may be excessively lowered. For example, bifunctional, trifunctional or tetrafunctional allyl ether compounds may be used, and one or more of these may be used in combination.

Preferably, the allyl ether compound may use a trifunctional or higher functional compound in consideration of polymerization reactivity. For example, the allyl ether compound may include at least one of the compounds represented by the following formulas 1-1 to 1-3.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

In formula (1-2), R ₁ may be hydrogen, an alkyl having 1 to 3 carbon atoms, or a hydroxyl group (-OH). When R &lt; _{1 &gt;} is an alkyl group, it may preferably be a methyl group for low viscosity implementation. In one embodiment, preferably, R ₁ is a hydroxyl group, and in this case, adhesion and developability of the cured film to the substrate can be further improved.

According to exemplary embodiments, the content of the allyl ether compound in the total weight of the photocurable composition may be about 10 to 50 wt%. When the content of the allyl ether compound is less than about 10% by weight, the viscosity of the composition may be excessively increased, resulting in failure to realize a desired microfabrication process and excessively lowering the solubility to other components. If the content of the allyl ether compound exceeds about 50% by weight, the curing and polymerization reactivity of the composition may be excessively decreased, and the curing degree and mechanical properties of the cured film may be deteriorated. Preferably, the content of the allyl ether compound may be about 20 to 40% by weight.

( Meta ) Acrylate  compound

The photocurable composition according to embodiments of the present invention may include a (meth) acrylate compound as a polymerizable monomer. The (meth) acrylate compound may be included as a main component, for example, by participating in a radical polymerization reaction by an ultraviolet exposure process to secure a desired hardness or degree of curing.

The term " (meth) acrylic- " as used in the present application is used to refer to "methacryl-", "acryl-" or both.

According to exemplary embodiments, the photocurable composition may comprise from one to three functional (meth) acrylate compounds. When a tetrafunctional or higher (meth) acrylate compound is used, the viscosity of the composition may be excessively increased, making it difficult to achieve the desired low viscosity composition.

Examples of the monofunctional (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl Acrylate, stearyl (meth) acrylate, octadecyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, (Meth) acrylate having a straight chain or branched, or acyclic or cyclic alkyl group of 1 to 20 carbon atoms such as isopropyl (meth) acrylate, isodecyl (meth) acrylate or isobornyl (meth) .

For example, the monofunctional (meth) acrylate compound may be represented by the following formula (2-1).

[Formula 2-1]

In the formula (2-1), R ₂ may be hydrogen or a methyl group (-CH ₃ ). R ₃ may be a linear or branched (having 3 to 20 carbon atoms when branched) carbon atoms of 1 to 20 carbon atoms, or an acyclic or cyclic alkyl group.

Examples of the bifunctional (meth) acrylate compound include 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 3-methylpentanediol di (Meth) acrylate, triethylene glycol di (meth) acrylate, and the like.

For example, the bifunctional (meth) acrylate compound may be represented by the following formula (2-2) or (2-3).

[Formula 2-2]

In the formula (2-2), R ₂ may be hydrogen or a methyl group (-CH ₃ ). and m may be an integer of 1 to 10.

[Formula 2-3]

In formula (2-3), R ₂ may be hydrogen or a methyl group (-CH ₃ ). R ₄ may be hydrogen or an alkyl group having 1 to 3 carbon atoms. and n may be an integer of 1 to 5.

Examples of the trifunctional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) And pentaerythritol tri (meth) acrylate.

For example, the trifunctional (meth) acrylate compound may be represented by the following formula 2-4 or 2-5.

[Chemical Formula 2-4]

[Chemical Formula 2-5]

In formulas 2-4 and 2-5, R ₂ may be hydrogen or a methyl group (-CH ₃ ). R ₅ may be hydrogen, an alkyl group having 1 to 3 carbon atoms, a hydroxyl group (-OH), or an alkoxy group having 1 to 3 carbon atoms. and n may be an integer of 1 to 5.

The above-mentioned compounds may be used alone or in combination of two or more. In some embodiments, two or more (meth) acrylate compounds having different functional numbers may be used together.

For example, a monofunctional meta (acrylate) compound and a trifunctional meta (acrylate) compound may be used together. Or a bifunctional meta (acrylate) compound and a trifunctional meta (acrylate) compound may be used together. The combination of the number of functional groups of the meta (acrylate) compounds can be selected in view of the viscosity of the composition, the coating properties and the sufficient hardness of the photocurable film.

Generally, the greater the number of unsaturated double bonds participating in the polymerization reaction, the faster the cure density increases and the desired physical properties can be reached within a short period of time. However, as the number of double bonds and reactive functional groups increases, the viscosity may increase due to intermolecular interactions due to the carbonyl structure of the ester group.

As described above, a polyfunctional allyl ether compound may be used to lower the viscosity of the composition and to obtain a desired degree of polymerization and reactivity by using a (meth) acrylate compound together to achieve a desired low viscosity composition.

In addition, the allyl ether compound can function as a regulator for suppressing, for example, partial unbalance in reaction rate of radical polymerization and adverse effect of remaining sticky on the surface of the coating film, and thereby, by oxygen inhibition The surface defects of the cured film can be suppressed or buffered.

The sum of the functional numbers of the allyl ether compound and the (meth) acrylate compound can be adjusted to, for example, 4 or more. It is possible to secure the desired hardness of the cured film while suppressing an increase in viscosity in the functional water range. When a plurality of allyl ether compounds and (meth) acrylate compounds are used, the total number of functional groups of the allyl ether compound and the (meth) acrylate compound is preferably in the range of (Meth) acrylate compound having the highest number of functional groups.

For example, when a bifunctional allyl ether compound is used, a bifunctional or trifunctional (meth) acrylate compound may be used. When a trifunctional allyl ether compound is used, a (meth) acrylate compound having from 1 to 3 functionalities may be used.

In view of low viscosity and hardness realization, the sum of the functional numbers of the allyl ether compound and the (meth) acrylate compound may preferably be in the range of 4 to 7.

According to exemplary embodiments, the content of the (meth) acrylate compound in the total weight of the photocurable composition may be about 20 to 60% by weight. If the content of the (meth) acrylate compound is less than about 20% by weight, the hardness and mechanical properties of the cured film may deteriorate. If the content of the (meth) acrylate compound exceeds about 60 wt%, the viscosity of the composition may be excessively increased. Preferably, the content of the (meth) acrylate compound may be about 30 to 45% by weight.

Fluoroalkyl group  contain ( Meta ) Acrylate  compound

The photocurable composition according to embodiments of the present invention comprises a (meth) acrylate compound comprising at least one fluoroalkyl group, whereby the photocurable composition can ensure stabilization of the crosslinking network, It is possible to form a photocurable film or a coating film excellent in shielding property and strength.

The (meth) acrylate compound comprising at least one fluoroalkyl group according to an embodiment of the present invention may improve the hydrophobicity of the composition, and may be a sphere having a curing network with a dense, high crosslink density and a low solubility parameter (SP) It is possible to prevent water from adhering to the surface of the photocurable film or diffusing through the inside of the photocured film. Therefore, the photocurable film or the coating film formed of the photocurable composition is excellent in the moisture or oxygen shielding property, and can effectively prevent deterioration of the photocured film or a part to be protected inside the image display device, for example, a light emitting element.

In addition, the (meth) acrylate compound containing at least one fluoroalkyl group according to the embodiments can enhance the stabilization and strength of the curing network of the photocurable film due to the steric effect of the fluorine (F) atoms contained therein.

According to some embodiments, the (meth) acrylate compound comprising at least one fluoroalkyl group may comprise a compound represented by the following formula (3).

(3)

In the above formula (3), R ₆ is hydrogen or a methyl group, o is an integer of 1 to 10, and p is an integer of 1 to 5.

For example, the (meth) acrylate compound comprising at least one fluoroalkyl group may include at least one of the compounds represented by the following general formulas (III-1) to (III-3).

[Formula 3-1]

 [Formula 3-2]

[Formula 3-3]

According to exemplary embodiments, the content of the (meth) acrylate compound comprising the at least one fluoroalkyl group in the total weight of the photocurable composition may be from about 10 to 40% by weight. When the content is less than about 10% by weight, the effect of improving the hardness and mechanical properties of the cured film may not be sufficient. If the content exceeds about 40% by weight, the coating property of the composition may deteriorate and the coating film or the photocurable film may be unevenly formed . Preferably, the content of the (meth) acrylate compound comprising the at least one fluoroalkyl group may be about 15 to 30 wt%.

Carboxylic acid  Containing monomer

The photocurable composition according to embodiments of the present invention includes a carboxylic acid-containing monomer, and thus the coating property and the adhesion property of the cured film can be improved. In some embodiments, the carboxylic acid containing monomer may comprise a carboxylic acid containing (meth) acrylate monomer.

Through the combination of the allyl ether compound and the (meth) acrylate compound described above, the viscosity of the composition can be lowered while securing the degree of curing and hardness, but the coating property or adhesion with the substrate may become insufficient.

According to embodiments of the present invention, as the carboxylic acid-containing monomer is included in the composition, adhesion with the base material through hydrogen bonding, for example, can be improved. Further, as the high polarity substituent is introduced, the wettability with the substrate increases, and the adhesion can be further improved.

According to exemplary embodiments, monofunctional carboxylic acid containing (meth) acrylate monomers may be used. When the number of functional groups of the (meth) acrylate in the carboxylic acid-containing (meth) acrylate monomer is increased to two or more functional groups, the viscosity of the composition increases due to the interaction between the allyl ether compound and the (meth) Can be excessively increased.

In some embodiments, the carboxylic acid containing (meth) acrylate monomer may be represented by the following formula (4).

[Chemical Formula 4]

In Formula 4, X may be alkylene having 1 to 3 carbon atoms, cyclohexyl, cyclohexenyl, or a phenyl group. R _a and R _b may each independently be hydrogen or an alkyl group having 1 to 3 carbon atoms.

For example, the carboxylic acid-containing (meth) acrylate monomer may include at least one of the compounds represented by the following formulas (4-1) or (4-3).

[Formula 4-1]

[Formula 4-2]

[Formula 4-3]

According to exemplary embodiments, the carboxylic acid containing (meth) acrylate monomers may be included in minor amounts which may act, for example, as a wetting agent. For example, the content of the carboxylic acid-containing (meth) acrylate monomer in the total weight of the photocurable composition may be about 1 to 5 wt%. When the content of the carboxylic acid-containing (meth) acrylate monomer is less than about 1% by weight, the coating property of the composition and the adhesion of the cured film may not be sufficiently secured. If the content of the carboxylic acid-containing (meth) acrylate monomer exceeds about 5% by weight, the viscosity of the composition may be excessively increased.

ore Initiator

According to exemplary embodiments, the photoinitiator is not particularly limited as long as it can induce a crosslinking reaction or a polymerization reaction between the allyl ether compound and the (meth) acrylate compound by generating a radical by an exposure process . For example, the photoinitiator may be at least one compound selected from the group consisting of an acetophenone-based compound, a benzophenone-based compound, a triazine-based compound, a nonimidazole-based compound, a thioxanthone-based compound and an oxime ester-based compound Oxime ester-based compounds may be preferably used.

As the oxime ester-based photoinitiator, at least one of the compounds represented by the following formulas (5-1) to (5-3) may be used.

[Formula 5-1]

[Formula 5-2]

[Formula 5-3]

In formulas (5-1) to (5-3), R _7, R _9, R ₁₀ and R ₁₁ each independently represents hydrogen or an alkyl group having 1 to 10 carbon atoms. R ₈ may be an alkyl group, a cycloalkyl group or an aryl group having 1 to 10 carbon atoms.

According to exemplary embodiments, the content of the photoinitiator in the total weight of the photocurable composition may be about 0.1 to 10 wt%, and preferably about 1 to 10 wt%. The resolution of the exposure process and the hardness of the cured film can be improved without raising the viscosity of the composition within the above range.

additive

Additional agents may be further included to improve the polymerization, cure and surface properties of the cured film formed from the photo-curable composition. For example, additives may further be included within a range that does not impair the low viscosity and curing properties of the photocurable composition according to the embodiments of the present invention.

In some exemplary embodiments of the present invention, a polyfunctional thiol compound may be further included as an initiator aid. As the polyfunctional thiol compound is included, the curing reaction is further promoted, and oxygen inhibition on the surface of the cured film can be suppressed.

Examples of the polyfunctional thiol compound include 2-mercaptobenzothiazole, 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) 1,3,5-triazine-2,4,6 (1H, 3H, 5H) -thione, trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis ), Pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), and tetraethylene glycol bis (3-mercaptopropionate).

In some embodiments, the polyfunctional thiol compound may include at least one of the compounds represented by the following formulas (6-1) to (6-5).

[Formula 6-1]

(In the formula (6-1), m is an integer of 1 to 12)

[Formula 6-2]

[Formula 6-3]

[Formula 6-4]

[Formula 6-5]

In formulas (6-1) to (6-5), R ₁₂ and R ₁₃ each independently may be hydrogen or a methyl group.

According to exemplary embodiments, about 0.1 to 10% by weight of the polyfunctional thiol compound in the total weight of the photocurable composition may be, and preferably about 1 to 5% by weight. The resolution of the exposure process and the hardness of the cured film can be improved without raising the viscosity of the composition within the above range.

In some embodiments, the photocurable composition may further comprise a surfactant. As described above, the wettability and adhesiveness with the base material can be improved through the carboxylic acid-containing monomer. In addition, the above surfactant may be further added to improve the coating uniformity of the composition and the surface uniformity of the cured film.

The surfactant is not particularly limited, and nonionic surfactants, cationic surfactants, anionic surfactants, and the like used in the art can be used. For example, the surfactant may be included in an amount of about 0.01 to 1% by weight of the total weight of the photocurable composition.

On the other hand, additives such as an antioxidant, a leveling agent, a curing accelerator, an ultraviolet absorber, an anti-aggregation agent and a chain transfer agent may be further added to further improve the properties such as hardenability, smoothness, adhesiveness, solvent resistance and chemical resistance have.

The photocurable compositions according to the exemplary embodiments of the present invention described above may be prepared in a substantially non-solvent or solvent-free type. In addition, the photocurable composition may be substantially composed of monomers, and may not include a polymer or a resin component.

Therefore, an allyl ether compound having a low self-viscosity can be used as a diluent, for example, and a low-viscosity composition capable of performing a coating process without a solvent can be realized. In addition, through the combination of the functional group between the (meth) acrylate compound and the allyl ether compound, it is possible to secure polymerization reactivity capable of suppressing oxygen inhibition while maintaining a low viscosity.

According to exemplary embodiments, the viscosity of the photocurable composition may be 20 cP or less at room temperature (e.g., 25 캜), and preferably 15 cP or less.

The photocurable composition according to the embodiments of the present invention can be produced as a solvent-free type composed of monomers, for example, fluctuations in the content / composition due to the volatilization of the solvent can be prevented. Further, by using an allyl ether compound together as a diluent and a reactive agent, a high-resolution composition that satisfies a low viscosity and a desired degree of curing and can realize, for example, an inkjet process can be produced.

< Photocuring  Membrane and image display device>

The present invention provides a photocurable film produced from the above-mentioned photocurable composition and an image display device including the photocurable film.

The photocurable film may be used as various film structures or patterns of an image display device, such as an adhesive layer, an array planarizing film, a protective film, an insulating film pattern, etc., and may be a photoresist, a black matrix, a column spacer pattern, But it is not limited thereto.

In the photocurable film formation, the above-described photocurable composition can be applied on a substrate to form a coating film. Examples of the application method include ink jet printing, spin coating, flexible coating, roll coating, slit-and-spin coating, and slit coating.

Thereafter, an exposure process may be performed to form a photocurable film, and a post exposure baking (PEB) process may be further performed. In the exposure process, an ultraviolet light source such as a UV-A region (320 to 400 nm), a UV-B region (280 to 320 nm) and a UV-C region (200 to 280 nm) of a high pressure mercury lamp may be used. A development process may be further performed as needed to pattern the photocurable film.

In exemplary embodiments, an ink-jet coating using the photocurable composition may be used to form an encapsulation layer of the light-emitting layer included in the OLED device.

FIGS. 1, 2 and 3 are schematic cross-sectional views showing an image display apparatus including a photocurable film according to embodiments of the present invention. For example, Figs. 1 to 3 illustrate an image display apparatus utilizing the photocurable film as an encapsulation layer of an organic light emitting element.

Referring to FIG. 1, the image display device may include a base substrate 100, a pixel defining layer 110, an organic light emitting diode 120, and an encapsulation layer 140.

The base substrate 100 may be provided as a support substrate or a back-plane substrate of an image display apparatus. For example, the base substrate 100 may be a glass or plastic substrate, and, in some embodiments, may comprise a flexible resin material such as polyimide. In this case, the image display device may be provided as a flexible OLED display.

A pixel defining layer 110 is formed on the base substrate 100 to expose each pixel in which a color or an image is realized. A thin film transistor (TFT) array may be formed between the base substrate 100 and the pixel defining layer 110, and an insulating structure covering the TFT array may be formed. The pixel defining layer 110 is formed on the insulating structure and may expose a pixel electrode (for example, an anode) which penetrates the insulating structure and is electrically connected to the TFT.

The organic light emitting diode 120 may be formed in each pixel region exposed by the pixel defining layer 110. The organic light emitting diode 120 may include, for example, the pixel electrode, the organic light emitting layer, and the counter electrode sequentially stacked.

The organic light emitting layer may include organic light emitting materials known in the art for red, green, and blue light emission. A hole transport layer (HTL) may be further formed between the pixel electrode and the organic light emitting layer, and an electron transport layer (ETL) may be further formed between the organic light emitting layer and the counter electrode. The counter electrode may be provided, for example, as a cathode. The counter electrode may be patterned for each pixel region, or may be provided as a common electrode for a plurality of organic light emitting elements. The organic light emitting layer or the organic light emitting device 120 may be formed, for example, through an inkjet printing process.

The encapsulation layer 140 may partially cover the pixel defining layer 110 while covering the organic light emitting diode 120. The encapsulation layer 140 may function, for example, in a moisture barrier pattern of the organic light emitting element 120. [

Can be formed using the photocurable composition according to the exemplary embodiments of the present invention. As described above, the photo-curable composition is solvent-free and can have a low viscosity capable of ink-jet printing. For example, the photocurable composition may have a viscosity of about 20 cp, preferably about 15 cp or less.

1, the encapsulation layer 140 may be patterned for each pixel, and the organic light emitting device 120 may be patterned with the wettability and adhesion by the carboxylic acid-containing monomer contained in the photo- . In addition, the interaction of the allyl ether compound, bismaleimide compound and (meth) acrylate compound described above can form an encapsulation layer 140 having improved hardness while preventing oxygen inhibition at the surface.

Additional structures such as a polarizing film, a touch sensor, a window substrate, and the like may be stacked on the encapsulation layer 140.

Referring to FIG. 2, the encapsulation layer 143 may be formed as a film that commonly covers the pixel defining layer 110 and the plurality of organic light emitting devices 120.

Referring to FIG. 3, the encapsulation layer may have a multi-layer structure including a first encapsulation layer 130 and a second encapsulation layer 145.

The first encapsulation layer 130 may be formed of an inorganic insulating material, such as, for example, silicon oxide, silicon nitride, and / or silicon oxynitride. A second encapsulation layer 145 may be formed using the photo-curable composition according to exemplary embodiments of the present invention. Accordingly, the encapsulation layer may be provided in the form of an organic or inorganic hybrid film.

Even when the second encapsulation layer 145 is formed on the inorganic insulating layer, the coating property for the inkjet printing process can be ensured by the wetting property enhanced by the carboxylic acid-containing monomer.

Hereinafter, exemplary embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the present invention is not limited to the following claims, It will be apparent to those skilled in the art that various changes and modifications can be made in the embodiment within the scope of the category and the scope of the invention, and such variations and modifications are within the scope of the appended claims.

Example  And Comparative Example

The photocurable compositions according to Examples and Comparative Examples were prepared by the ingredients and contents shown in Table 1 below.

Category (% by weight) Example Comparative Example One 2 3 4 5 One 2 3 4 5 6 The allyl ether compound (A) A-1 29.4 29.4 29.4 - 29.4 30.0 - 36.7 48.4 - - A-2 - - - 29.4 - - - - - - - A-3 - - - - - 29.4 - The vinyl ether compound (A ') - - - - - - - - - - 29.4 (Meth) acrylate compound (B) B-1 39.2 39.2 39.2 39.2 - 40.0 55.6 48.7 - 39.2 39.2 B-2 - - - - 39.2 - - - - - - The fluoroalkyl group-containing compound (C) C-1 19.6 - - 19.6 19.6 20.0 27.8 - 32.2 19.6 19.6 C-2 - 19.6 - - - - - - - - - C-3 - - 19.6 - - - - - - - - The carboxylic acid-containing monomer (D) D-1 2.0 2.0 2.0 2.0 2.0 - 2.8 2.4 3.2 2.0 2.0 Photoinitiator (E) E-1 4.9 4.9 4.9 4.9 4.9 5.0 6.9 6.1 8.1 4.9 4.9 Initiation aid (F) F-1 4.9 4.9 4.9 4.9 4.9 5.0 6.9 6.1 8.1 4.9 4.9

A-1: Trifunctional allyl ether compound containing hydroxyl group

A-2: tetrafunctional allyl ether compound

A-3: Monofunctional allyl ether compound (allyl ethyl ether)

A ': Trifunctional vinyl ether compound

B-1: Trimethylolpropane triacrylate (A-TMPT: Shin-Nakamura Chemical Co., Ltd.)

B-2: Ethoxylated trimethylolpropane triacrylate (A-TMPT-3 EO: Shin-Nakamura Chemical Co., Ltd.)

C-1: (meth) acrylate compound containing a fluoroalkyl group

C-2: (meth) acrylate compound containing a fluoroalkyl group

C-3: (meth) acrylate compound containing a fluoroalkyl group

D-1: Methacryloyloxyethyl succinate (NK ESTER A-SA: Shin-Nakamura Chemical Co., Ltd.)

E-1: Oxime ester compound

F-1: pentaerythritol tetrakis [3-mercaptopropionate] (PEMP: manufactured by SC Chemical Co., Ltd.)

G-1: SH8400 Fluid (manufactured by Dow-Corning-Toray)

Experimental Example

The compositions of Table 1 or the coating film formed therefrom, the viscosity of the photocured film, the coating property, the pencil hardness, the oxygen inhibition and the moisture permeability were evaluated through the evaluation methods described below. The evaluation results are shown in Table 2 below

(1) Viscosity measurement

The viscosity of each composition according to Examples and Comparative Examples was measured using a viscosity meter (DV3T, manufactured by Brookfield) (measurement conditions: number of revolutions 20 rpm / 25 ° C)

(2) Coating property  evaluation

Each composition according to Examples and Comparative Examples was spin-coated on a silicon (Si) wafer cut into 50 mm X 50 mm to form a coating film having a thickness of 3.0 탆. The coating was allowed to stand for 5 minutes after the spin coating, and the coating properties were evaluated as follows.

&Lt; Evaluation criteria of coating property &

?: The coating film was evenly spread and the surface uniformity (see Fig. 4)

DELTA: The composition is stretched but the surface is uneven Visually observed (see Fig. 5)

X: no surface wetting occurs and liquid curling occurs, and the coating film is not substantially formed (see Fig. 6)

On the other hand, FIGS. 4 to 6 are reference images for explaining evaluation criteria of coating properties, and are not used as images showing actual experimental results of Examples and Comparative Examples in this Experimental Example.

(3) Pencil hardness measurement

The coating films formed during the evaluation of coating properties were subjected to UV curing to form a photocurable film. Specifically, ultraviolet rays were irradiated for 120 seconds at an illuminance of 150 mW / cm 2 (in the UV-A region of 320 to 400 nm) using a UV curing apparatus (Lichtzen, Model No. LZ-UVC-F402-CMD). The pencil hardness of the formed light-cured film was measured using a pencil hardness tester. Specifically, after a pencil (manufactured by Mitsubishi) was brought into contact with the photocurable film, the surface was scratched with a load of 1 kg and a speed of 50 mm / sec to measure the surface hardness.

(4) Evaluation of oxygen inhibition effect

The compositions of Examples and Comparative Examples were spin-coated to form a coating film having a thickness of 3.0 탆. After standing for 5 minutes after spin coating, ultraviolet rays were irradiated for 60 seconds at an illuminance of 150 mW / cm 2 (based on 320-400 nm of UV-A region) using a UV curing device (Lichtzen, Model No. LZ-UVC-F402-CMD) (No nitrogen substitution)

The surface of the formed photocured film was scratched lightly with a metal tool, and then the state of the surface of the coated film was observed. The composition which is not influenced by oxygen inhibition hardens the surface and hardly scratches or scratches (see FIG. 7). However, when the surface hardening progresses slowly due to the oxygen inhibition, (See FIG. 8). As a result, the influence of oxygen inhibition was evaluated as follows.

<Evaluation Criteria for Oxygen Inhibition Effect>

X: no scratches due to surface hardening

○: Omission occurs on the surface due to oxygen inhibition

7 and 8 are reference images for illustrating an evaluation criterion for determining the oxygen inhibition effect, and the images used as the images showing the actual experimental results of the examples and the comparative examples in this example no.

(5) Evaluation of breathability

Each composition according to the examples and comparative examples was coated on a polyimide (PI) film cut into a thickness of 40 탆 and a size of 70 mm × 70 mm and allowed to stand for 5 minutes on a plate, and then placed in an acrylic case And then irradiated for 120 seconds at an illuminance of 150 mW / cm ² using a UV curing device (LZ-UVC-F402-CMD, manufactured by Lichtzen) to obtain a cured coating film.

Thereafter , the amount of moisture passing through the cured coating film was measured to calculate the moisture permeability. Specifically, a cylindrical glass container (diameter: 0.058 m) filled with a calcium chloride mass was prepared, the coating film was placed on the glass container inlet so as to be positioned below the polyimide film side, and the molten paraffin and the glass container , And this was stored in a chamber having a humidity of 90% and a temperature of 40 캜 for 24 hours. The moisture permeability was evaluated according to the following equation (1) related to the change in the weight of calcium chloride in the container.

[Equation 1]

(G / m ² ) = [(weight of calcium chloride after the test) - (weight of calcium chloride before the test)] / (area of the bottom surface of the container)

division Viscosity (cp) Coating property Pencil hardness Oxygen inhibition effect Water vapor permeability (g / m ² ) Example 1 13.4 ○ 5H × 445 Example 2 12.9 ○ 4H × 477 Example 3 12.5 ○ 3H × 601 Example 4 13.8 ○ 4H × 690 Example 5 13.6 ○ 3H × 597 Comparative Example 1 17.1 ○ Not measurable ○ Not measurable Comparative Example 2 26.1 × 2H Not measurable 796 Comparative Example 3 14.1 × 2H ○ 1310 Comparative Example 4 13.6 ○ HB ○ 847 Comparative Example 5 8.6 △ Not measurable
(Uncured) Not measurable
(Uncured) 1562 Comparative Example 6 12.1 △ 5B ○ 1477

As shown in Table 2, the practice of the present invention includes a bifunctional or higher allyl ether compound, a (meth) acrylate compound having one to three functional groups, a (meth) acrylate compound having at least one fluoroalkyl group, a carboxylic acid containing monomer and a photoinitiator In the examples, excellent coating properties and pencil hardness were obtained while ensuring low viscosity characteristics as a whole, and it was observed that they were not greatly influenced by oxygen inhibition, and moisture permeability was excellent due to low moisture permeability.

In Comparative Example 1 in which the carboxylic acid-containing monomer was not contained, the coating film was not formed substantially due to lack of wettability. In Comparative Example 2, which did not contain the allyl ether compound, the viscosity exceeded 20 cp and the hardness And the measurement was impossible.

In the case of Comparative Example 3 which did not contain a fluoroalkyl group-containing (meth) acrylate compound, the moisture-permeability was too high, the water-shielding property was very poor, the hardness and coating properties were excessively decreased, 4, the moisture permeability was high and the hardness and coating properties were deteriorated.

In Comparative Example 5 in which a vinyl ether compound was used instead of an allyl ether compound and Comparative Example 6 in which a monofunctional allyl ether compound was used, the viscosity was reduced to less than 15 cp, but the viscosity was reduced to less than 15 cp. However, And the dilution of the composition and the retardation of the reaction rate were excessively increased, so that a substantially cured coating film could not be obtained.

100: base substrate 110: pixel defining film
120: organic light emitting device 130: first encapsulation layer
140, 143: encapsulation layer 145: second encapsulation layer

Claims (17)

Bifunctional allyl ether compounds;
1 to 3 functional (meth) acrylate compounds;
(Meth) acrylate compounds comprising at least one fluoroalkyl group;
Carboxylic acid-containing monomers; And
A photocurable compound comprising a photoinitiator.
The photocurable composition according to claim 1, wherein the bifunctional allyl ether compound comprises at least one selected from compounds represented by the following formulas (1-1) to (1-3):
[Formula 1-1]

[Formula 1-2]

(In the formula (1-2), R ₁ is hydrogen, an alkyl having 1 to 3 carbon atoms, or a hydroxyl group)
[Formula 1-3]

.
The photocurable composition according to claim 1, wherein the (meth) acrylate compound of the first to third functional groups comprises at least one selected from compounds represented by the following general formulas (2-1) to (2-5)
[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Chemical Formula 2-4]

[Chemical Formula 2-5]

(In the formulas (2-1) to (2-5), R ₂ is each independently hydrogen or a methyl group, R ₃ is a non-cyclic or cyclic alkyl group having 1 to 20 carbon atoms, R ₄ is hydrogen or an alkyl group having 1 to 3 carbon atoms , R ₅ is hydrogen, an alkyl group having 1 to 3 carbon atoms, a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms,
m is an integer of 1 to 10, and n is independently an integer of 1 to 5).
The photocurable composition according to claim 1, wherein the (meth) acrylate compound of the first to third functional groups comprises two or more (meth) acrylate compounds having different functional numbers.
[4] The method according to claim 4, wherein the (meth) acrylate compound is a combination of a monofunctional (meth) acrylate compound and a trifunctional (meth) acrylate compound, Methacrylate &lt; / RTI &gt; compounds.
The photocurable composition of claim 1, wherein the (meth) acrylate compound comprising at least one fluoroalkyl group comprises a compound represented by the following Formula 3:
(3)

(Wherein R ₆ is hydrogen or a methyl group, o is an integer of 1 to 10, and p is an integer of 1 to 5).
The photocurable composition according to claim 1, wherein the carboxylic acid-containing monomer comprises a monofunctional carboxylic acid-containing (meth) acrylate monomer.
The photocurable composition according to claim 7, wherein the carboxylic acid-containing monomer comprises a monomer represented by the following formula (3):
[Chemical Formula 4]

(Wherein X is an alkylene, cyclohexyl, cyclohexenyl, or phenyl group having 1 to 3 carbon atoms,
R _a and R _b are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms.
The photocurable composition of claim 1, wherein the photoinitiator comprises an oxime ester compound.
The composition according to claim 1,
10 to 50% by weight of the bifunctional or higher allyl ether compound;
20 to 60% by weight of the (meth) acrylate compound having from 1 to 3 functional groups;
10 to 40% by weight of a (meth) acrylate compound comprising the at least one fluoroalkyl group;
1 to 5% by weight of the carboxylic acid-containing monomer; And
And 1 to 10% by weight of the photoinitiator.
The photocurable composition of claim 1, further comprising a polyfunctional thiol compound.
The photocurable composition of claim 1, wherein the photocurable composition is produced in a solventless type.
The photocurable composition of claim 1, which does not comprise a polymer or resin component.
The photocurable composition according to claim 1, having a viscosity of 20 cp or less at room temperature.
A photocurable film formed from the photocurable composition of any one of claims 1 to 14.
An image display device comprising a photocurable film formed from the photocurable composition according to any one of claims 1 to 14.
18. The method of claim 16,
A base substrate; And
Further comprising organic light emitting devices disposed on the base substrate,
Wherein the photocurable film is provided as an encapsulation layer of the organic light emitting elements.

Images