KR20180085182A - Photocurable composition and photocurable layer formed from the same - Google Patents

Abstract

Provided is a photocurable composition composed of an allyl ether compound having at least two functional groups, a (meth)acrylate compound having one to three functional groups, a polyfunctional epoxy compound, a carboxylic acid-containing monomer, a radical photoinitiator, and a photoacid generator. According to the present invention, it is possible to produce photocurable films and compositions with enhanced flexibility, hardness, coating properties, and low viscosity through an interaction of the allyl ether compound, the (meth)acrylate compound, and the epoxy compound.

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 hardness, flexibility and stability.

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; Polyfunctional epoxy compounds; Carboxylic acid-containing monomers; Radical photoinitiators; And a photoacid generator.

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 polyfunctional epoxy compound comprises a bifunctional or trifunctional epoxy compound.

5. The photocurable composition according to 4 above, wherein said polyfunctional epoxy compound comprises at least one selected from compounds represented by the following formulas (3-1) to (3-3):

[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms , p, q and r are each independently an integer of 1 to 5).

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

7. The photocurable composition according to 6 above, wherein said carboxylic acid-containing monomer comprises a monomer represented by the following formula (4):

[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).

8. The photocurable composition of 1 above, wherein said radical photoinitiator comprises an oxime ester compound.

9. The photocurable composition of 1 above, wherein said photoacid generator comprises a sulfonium borate or an alkyl fluoride-containing sulfone compound.

10. The composition of claim 1, wherein,

10 to 50% by weight of the bifunctional or higher allyl ether compound; 20 to 40% by weight of the (meth) acrylate compound having 1 to 3 functional groups; 20 to 40% by weight of the polyfunctional epoxy compound; 1 to 10% by weight of the carboxylic acid-containing monomer; 1 to 10% by weight of the radical photoinitiator; And 1 to 10% by weight of the photoacid generator.

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. Photopolymerizable film formed from the photocurable composition of any one of claims 1-13.

15. In the above 14, 200 N / mm < ² > Of Martens Hardness and indentation modulus of 8 GPa or less.

16. An image display comprising a photocurable film formed from the photo-curable composition of any one of items 1 to 13 above.

17. The image display apparatus of 16 above, further comprising a base substrate and organic light emitting elements disposed on the base substrate, wherein the photo-curing film is provided as an encapsulation layer of the organic light emitting elements.

18. The image display apparatus of claim 17, wherein the base substrate comprises a resin material and is provided as a flexible display.

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.

In addition, the photo-curable composition may contain a polyfunctional epoxy compound. As a result, a photocurable film having a matrix structure formed by epoxy ring-opening polymerization mixed with a (meth) acrylate matrix and simultaneously having improved hardness and flexibility can be formed.

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.

In accordance with embodiments of the present invention, a photocurable film formed using a photocurable composition has excellent gas and moisture barrier properties and has improved flexibility, for example, as an encapsulation layer of a flexible organic light emitting diode (OLED) device Can be utilized.

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.
7 and 8 are images for explaining the film surface according to the influence of oxygen inhibition.

Embodiments of the present invention are directed to a resin composition containing a bifunctional or higher functional allyl ether compound, a (meth) acrylate compound having one or more functional groups, a polyfunctional epoxy compound, a carboxylic acid containing monomer, a photoinitiator and a photoacid generator, A photocurable composition having improved hardness, flexibility and adhesion, and a photocurable film formed therefrom.

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

≪ Photocurable composition >

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 < _{1 >} 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 10 to 30% by weight.

(Meth) 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 40% 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 40% by weight, the viscosity of the composition may be excessively increased.

Polyfunctional epoxy compound

The photocurable composition according to embodiments of the present invention may further include a polyfunctional epoxy compound as a polymerizable monomer. As the polyfunctional epoxy compound participates in the photo-curing, an epoxy derived network can be produced together with the hydrocarbon matrix produced by the above-described one to three functional (meth) acrylate compounds.

The epoxy-derived network may be intermixed with the hydrocarbon matrix to form an inter-penetration network (IPN). Thus, it is possible to obtain a photocured film having increased flexibility (for example, having a low modulus) while having a hardness higher than a certain level.

According to exemplary embodiments, a bifunctional or trifunctional epoxy compound may be used, in view of ensuring flexibility and realizing composition low viscosity.

For example, the epoxy compound may include at least one of the compounds represented by the following formulas (3-1) to (3-3).

[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

In formulas (3-1) to (3-3), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. p, q and r each independently may be an integer of 1 to 5.

According to exemplary embodiments, the content of the polyfunctional epoxy compound in the total weight of the photocurable composition may be about 20 to 40% by weight. If the content of the polyfunctional epoxy compound is less than about 20% by weight, the flexibility of the photocurable film may deteriorate, and the modulus value may exceed the desired range. If the content of the polyfunctional epoxy compound exceeds about 40 wt%, the viscosity of the composition may be excessively increased, and the hardness of the photocurable film may be deteriorated.

The 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, the (meth) acrylate compound and the epoxy compound, the viscosity of the composition can be lowered while securing the hardness and flexibility, but the coating property or the adhesion property 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 monomer in the carboxylic acid-containing (meth) acrylate monomer is increased to two or more functional groups, the viscosity of the composition is excessively increased due to the increase in interaction with the allyl ether compound and the polymerizable monomers .

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) to (4-3).

[Formula 4-1]

[Formula 4-2]

[Formula 4-3]

According to exemplary embodiments, the carboxylic acid containing 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 monomer in the total weight of the photocurable composition may be about 1 to 10% by weight. When the content of the carboxylic acid-containing 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 monomer exceeds about 10% by weight, the viscosity of the composition may be excessively increased.

Photoinitiator

According to exemplary embodiments, the photoinitiator can be used without particular limitation 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 ₆ , R _8, R ₉ , R ₁₀ and R ₁₁ each independently represents hydrogen or an alkyl group having 1 to 10 carbon atoms. R ₇ 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.

Photoacid generator

The photocurable composition according to embodiments of the present invention may further include a photo-acid generator (PAG). The above-mentioned photoinitiator may initiate radical polymerization to induce polymerization of the (meth) acrylate compound. On the other hand, the cationic polymerization reaction of the polyfunctional epoxy compound can be initiated by the photoacid generator.

For example, a proton generated from the photoacid generator may bond with an oxygen atom of an epoxy ring to initiate a chain reaction by epoxy ring opening. Thus, an epoxy derived network can be generated as described above.

Therefore, the flexibility of the photocurable film can be improved by reducing the modulus while satisfying the predetermined hardness by the hydrocarbon matrix produced from the (meth) acrylate compound and the interpenetrating network (IPN) of the network derived from the epoxy.

The photoacid generator is not particularly limited as long as it is a photoreactive compound known in the art capable of generating acid (H ⁺ ) upon ultraviolet exposure, for example. In some embodiments, the photoacid generator may include, for example, a sulfonium borate-based compound represented by the following formula (6-1).

[Formula 6-1]

R ₁₂ , R ₁₃ and R ₁₄ are each independently selected from the group consisting of halogen, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, acetoxy, an aromatic ring having 1 to 10 carbon atoms, Of an aromatic ring substituted alkyl group.

In some embodiments, the photoacid generator may include, for example, a fluorinated alkyl group-containing sulfone compound represented by the following formula (6-2).

[Formula 6-2]

In formula (6-2), R ^a , R ^b , R ^c , R ^d , R ^e and R ^f may each independently be hydrogen, an alkyl group having 1 to 5 carbon atoms, a halogen or an alkoxy group having 1 to 4 carbon atoms. s may be an integer from 0 to 8;

According to exemplary embodiments, the content of the photoacid generator in the total weight of the photocurable composition may be about 0.1 to 10% by weight, and preferably about 1 to 10% by weight. The resolution of the exposure process and the production efficiency of the epoxy derived network can be improved without increasing the viscosity of the composition in the above range.

additive

Further formulations may be further included to improve the polymerization properties, hardenability and surface properties, etc. 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 characteristics, hardness and flexibility 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 (7-1) to (7-5).

[Formula 7-1]

(In the formula (7-1), m ₁ is an integer of 1 to 12)

[Formula 7-2]

[Formula 7-3]

[Chemical Formula 7-4]

[Formula 7-5]

In formulas (7-1) to (7-5), R ⁷ and R ⁸ each independently may be hydrogen or a methyl group.

According to exemplary embodiments, the content of the polyfunctional thiol compound in the total weight of the photocurable composition may be about 0.1 to 10 wt%, and preferably about 1 to 5 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.

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 Film 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 inkjet 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.

According to exemplary embodiments, the Martens Hardness of the photocurable film may be greater than or equal to about 200 N / mm &lt; ² &gt;. Martens hardness value of about 200 N / mm ² , The strength and mechanical durability of the photocured film may be lowered. In one embodiment, the Martens hardness value may be about 200 to 250 N / mm &lt; ² &gt; to prevent an excessive increase in the brittle characteristics of the photocured film.

In addition, the indentation modulus of the photocurable film may be about 8 Gpa or less, for example, about 3 to 8 Gpa. Preferably, the indentation modulus of the photocurable film may be less than about 7.5 GPa. As a result, it is possible to secure flexibility that enables the characteristics such as folding and bending to be achieved while satisfying a predetermined hardness value.

In exemplary embodiments, the encapsulation layer of the light emitting layer included in the OLED device can be formed through inkjet printing using the photocurable composition.

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. Therefore, the encapsulation layer 140 having excellent leveling properties can be obtained.

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- . Also, the interaction of the allyl ether compound and the hydrocarbon-based (meth) acrylate compound can form an encapsulation layer 140 having improved hardness while preventing oxygen inhibition at the surface. In addition, the encapsulation layer 140 can be formed, which is improved in flexibility by a polyfunctional epoxy compound and can be effectively applied to, for example, a flexible OLED device.

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.

Examples and Comparative Examples

The photocurable compositions according to Examples and Comparative Examples were prepared by the components and contents shown in Tables 1 and 2 below.

Category (% by weight) Example One 2 3 4 5 6 7 8 9 10 Allyl ether
The compound (A) A-1 26.2 26.2 26.2 25.1 27.4 27.4 - 27.9 28.7 27.4 A-2 - - - - - - 27.4 - - - A-3 - - - - - - - - - - (Meth) acrylate compound
(B) B-1 21.8 21.8 21.8 - - - - - - - B-2 - - - 25.1 - 27.4 27.4 27.9 28.7 - B-3 - - - - 27.4 - - - - - B-4 - - - - - - - - - 27.4 Epoxy compound
(C) C-1 34.9 - - - - - - - - - C-2 - 34.9 - - - - - - - - C-3 - - 34.9 - - - - - - - C-4 - - - 33.4 - - - - - - C-5 - - - - 27.4 27.4 27.4 27.9 28.7 27.4 C-6 - - - - - - - - - - The carboxylic acid-containing monomer (D) 8.7 8.7 8.7 8.4 9.1 9.1 9.1 9.3 9.6 9.1 Photoinitiator
(E) 1.3 1.3 1.3 1.3 1.4 1.4 1.4 1.4 1.4 1.4 Photoacid generator
(F) F-1 2.6 2.6 2.6 2.5 2.7 2.7 2.7 - 2.9 2.7 F-2 - - - - - - - 0.9 - - Initiator
(G) 4.5 4.5 4.5 4.2 4.6 4.6 4.6 4.7 - 4.6

Category (% by weight) Comparative Example One 2 3 4 5 6 7 8 Allyl ether
The compound (A) A-1 - 30.2 27.8 28.2 27.4 27.4 27.4 - A-2 - - - - - - - - A-3 - - - - - - - 26.2 (Meth) acrylate compound
(B) B-1 - - - - 27.4 - 27.4 21.8 B-2 37.7 30.2 27.8 28.2 27.4 - - - B-3 - - - - - - - - B-4 - - - - - - - - Epoxy compound
(C) C-1 - - - - - - - 34.9 C-2 - - - - - - - - C-3 - - - - - 27.4 - - C-4 - - - - - - - - C-5 37.7 30.2 27.8 28.2 - 27.4 - - C-6 - - - - - - 27.4 - The carboxylic acid-containing monomer (D) 12.6 - 9.3 9.4 9.1 9.1 9.1 8.7 Photoinitiator
(E) 1.9 1.5 - 1.4 1.4 1.4 1.4 1.3 Photoacid generator
(F) F-1 3.8 3.0 2.8 - 2.7 2.7 2.7 2.6 F-2 - - - - - - - - Initiator
(G) 6.3 4.9 4.5 4.6 4.6 4.6 4.6 4.5

A-1: tetrafunctional allyl ether compound

A-2: Trifunctional allyl ether compound containing hydroxyl group

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

B-1: Ethoxylated trimethylolpropane triacrylate (NK ESTER A-TMPT-3 EO: Shin-Nakamura Chemical Co., Ltd.)

B-2: 1,6-hexanediol diacrylate (NK ESTER A-HD-N: Shin-Nakamura Chemical Co., Ltd.)

B-3: 2-hydroxy-1-acryloxy-3-methacrylate (NK ESTER 701A: Shin-Nakamura Chemical Co., Ltd.)

B-4: Lauryl acrylate (NK ESTER LA: Shin-Nakamura Chemical Co., Ltd.)

C-1: Propylene glycol diglycidyl ether (Epolite 70P: manufactured by Kyowa Chemical Co., Ltd.)

C-2: Diethylene glycol diglycidyl ether (Epolite 100E: manufactured by Kyowa Chemical Co., Ltd.)

C-3: 1,6-hexanediol diglycidyl ether (Epolite 1600, manufactured by Kyowa Chemical Co., Ltd.)

C-4: neopentyl glycol diglycidyl ether (Epolite 1500NP: manufactured by Kyowa Chemical Co., Ltd.)

C-5: Trimethylolpropane triglycidyl ether (Epolite 100MF: manufactured by Kyowa Chemical Co., Ltd.)

C-6: Dodecyl alcohol glycidyl ether (ED-503, manufactured by Kyowa Chemical Co., Ltd.)

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

E: oxime ester compound

F-1: photoacid generator (Irgacure PAG103, manufactured by BASF)

F-2: Photo acid generator (SANEID SI-B5: manufactured by Samsin Chemical Industry Co., Ltd.)

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

Experimental Example

The coating compositions, coating properties of the photocured film, pencil hardness, martens hardness, indentation modulus and oxygen inhibition effects of the compositions shown in Tables 1 and 2 or the coating films formed therefrom were evaluated through evaluation methods described below.

The evaluation results are shown in Table 3 below

(One) 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.

(2) 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.

(3) Martens  Hardness (Martens Hardness) and Indentation Modulus (Indentation Modulus) measurement

The coating films formed during the evaluation of coating properties were subjected to UV curing to form a photocurable film. Specifically, the coating film was placed in an acrylic case and replaced with a nitrogen atmosphere, and irradiated for 60 seconds at an illuminance of 150 mW / cm ² (UV-A region) using a UV curing device (Model No. LZ-UVC-F402-CMD) A photocured film was formed.

The photocurable film formed was measured for martens hardness and indentation modulus using a nanoindenter (manufactured by Fischer Technology, Inc.). Specifically, the load section which is not influenced by the lower substrate was confirmed by using the equipment equipped with Vickers indenter according to the international standard ISO 14577-1. That is, Martens hardness (N / mm ²⁾ after the indenter displacement (Depth) press the film coming through the data of the section is minimized check the loading value, and by using this set to 0.5mN against the formed spectacle hwamak And the modulus of indentation (GPa) were measured.

(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. Compositions which are not affected by oxygen inhibition harden the surface hardly to leave scratches or scratched marks, but when the surface hardening progresses slowly due to the effect of oxygen inhibition, marks remain on the uncured portions remaining sticky. As a result, the influence of oxygen inhibition was evaluated as follows.

<Evaluation Criteria for Oxygen Inhibition Effect>

X: no marks occurred due to surface hardening (see FIG. 7)

○: Mark on the surface of the loose surface due to oxygen inhibition (see FIG. 8)

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.

division Coating property pencil
Hardness Martens hardness
(N / mm ² ) Indentation
Modulus (GPa) Oxygen inhibition effect Example 1 ○ 5H 236 6.88 × Example 2 ○ 4H 212 7.13 × Example 3 ○ 6H 242 7.19 × Example 4 ○ 4H 213 7.13 × Example 5 ○ 6H 270 7.32 × Example 6 ○ 5H 217 6.92 × Example 7 ○ 5H 237 6.54 × Example 8 ○ 5H 217 7.73 × Example 9 ○ 4H 226 6.17 × Example 10 ○ HB 222 7.49 × Comparative Example 1 △ H 237 8.66 ○ Comparative Example 2 × Not measurable Not measurable Not measurable Not measurable Comparative Example 3 ○ Not measurable
(Uncured) Not measurable
(Uncured) Not measurable
(Uncured) Not measurable
(Uncured) Comparative Example 4 ○ Not measurable
(Uncured) Not measurable
(Uncured) Not measurable
(Uncured) Not measurable
(Uncured) Comparative Example 5 ○ 7H 319 8.65 × Comparative Example 6 ○ 4H 260 8.07 ○ Comparative Example 7 ○ 2H 250 8.16 × Comparative Example 8 ○ Not measurable
(Uncured) Not measurable
(Uncured) Not measurable
(Uncured) Not measurable
(Uncured)

As shown in Table 3, in the examples including the bifunctional or higher functional allyl ether compound, the (meth) acrylate compound, the polyfunctional epoxy compound, the photoinitiator and the photoacid generator, Modulus was obtained and it was observed that it was not greatly influenced by oxygen inhibition. Therefore, it can be seen that the photocurable film having a uniform surface is obtained in the embodiments, while ensuring mechanical durability and flexibility.

In the case of Comparative Example 1 which did not contain the allyl ether compound, the coating property was poor, the modulus of the impregnation was excessively increased (more than 9 GPa), the flexibility was decreased, and the compound was vulnerable to oxygen inhibition. On the other hand, in the case of Comparative Example 8 in which the monofunctional allyl ether compound was used, the composition dilution and the reaction rate delay were excessively increased, and a substantially cured coating film could not be obtained.

In Comparative Example 2 in which the carboxylic acid-containing monomer was not included, Comparative Example 3 in which no photoinitiator was included, and Comparative Example 4 in which the photoacid generator was not included, a coating film was not substantially formed due to lack of wettability.

In the case of Comparative Example 5 in which the polyfunctional epoxy compound was not included, the hardness of the martens was excessively increased and the indentation modulus also increased, resulting in a brittle structure lacking in flexibility. In the case of Comparative Example 6 in which the (meth) acrylate compound was not included, oxygen inhibition occurred due to lack of curing. In the case of Comparative Example 7 in which the monofunctional epoxy compound was used, the increase of the indentation modulus and the weakening of the flexibility were observed due to the lack of a sufficient epoxy derived network.

Embodiments commonly measured hardness of the indentation modulus of less than 8 GPa and the Martens hardness of more than 200 N / mm ² to obtain cured films that satisfied the desired strength and flexibility.

However, in Example 10 in which the monofunctional meta (acrylate) compound alone was used, the pencil hardness was somewhat lowered and the modulus of indentation was slightly increased (in excess of 7.5 GPa) compared with the other Examples,

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 (18)

Bifunctional allyl ether compounds;
1 to 3 functional (meth) acrylate compounds;
Polyfunctional epoxy compounds;
Carboxylic acid-containing monomers;
Radical photoinitiators; And
And a photoacid generator.
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 polyfunctional epoxy compound comprises a bifunctional or trifunctional epoxy compound.
5. The photocurable composition according to claim 4, wherein the polyfunctional epoxy compound comprises at least one selected from compounds represented by the following general formulas (3-1) to (3-3):
[Formula 3-1]

[Formula 3-2]

[Formula 3-3]

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently hydrogen, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms ,
p, q and r each independently represent 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 of claim 6, wherein the carboxylic acid-containing monomer comprises a monomer represented by the following formula (4):
[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 radical photoinitiator comprises an oxime ester compound.
The photocurable composition of claim 1, wherein the photoacid generator comprises a sulfonium borate or an alkyl fluoride-containing sulfone compound.
The composition according to claim 1,
10 to 50% by weight of the bifunctional or higher allyl ether compound;
20 to 40% by weight of the (meth) acrylate compound having 1 to 3 functional groups;
20 to 40% by weight of the polyfunctional epoxy compound;
1 to 10% by weight of the carboxylic acid-containing monomer;
1 to 10% by weight of the radical photoinitiator; And
And 1 to 10% by weight of the photoacid generator.
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.
A photocurable film formed from the photocurable composition of any one of claims 1 to 13.
The method according to claim 14, 200 N / mm ² Of Martens Hardness and indentation modulus of 8 GPa or less.
An image display device comprising a photocurable film formed from the photocurable composition according to any one of claims 1 to 13.
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.
18. The image display apparatus according to claim 17, wherein the base substrate comprises a resin material and is provided as a flexible display.

Images