KR20180070903A - Thermosetting resin composition - Google Patents

Abstract

The present invention relates to a thermosetting resin composition. More specifically, the present invention relates to a thermosetting resin composition containing (a1) at least one compound selected from the group consisting of unsaturated carboxylic acid and unsaturated carboxylic anhydride, (a2) an epoxy group-containing unsaturated compound, and (a3) an olefin-based unsaturated compound [A]. The thermosetting resin composition may further contain (b1) an alicyclic epoxy compound and (b2) an oxetane compound as a multifunctional curable compound [B]. By using the (b1) alicyclic epoxy compound and the (b2) oxetane compound together, it is possible to effectively increase curing density, leading to improvement in mechanical properties without deterioration in heat resistance and chemical resistance in cured films.

Description

TECHNICAL FIELD The present invention relates to a thermosetting resin composition,

The present invention relates to a thermosetting resin composition and a cured film (protective film) for an optical device manufactured from the composition, and more particularly, to a specific composition of a thermosetting resin composition for effectively improving the curing density.

An optical device such as a liquid crystal display device (LCD) is immersed in an organic solvent, an acid, an alkali solution or the like during the manufacturing process, or the wiring electrode layer is subjected to severe treatment such as being subjected to high temperature locally heated by sputtering . Therefore, a protective film may be provided on the surface of these devices in order to prevent deterioration at the time of manufacturing.

The protective film serves to protect the colored layer and to flatten the color filter. Therefore, the protective film must be able to withstand such a severe treatment as described above, and must be excellent in adhesion to the substrate or the underlayer, and has excellent heat resistance and light resistance without deterioration such as high flatness, surface hardness, transparency, coloration, yellowing, Is required. In addition, excellent chemical resistance, such as solvent resistance, acid resistance and alkali resistance, and excellent water resistance are required. When such a protective film is applied to a color filter of a color liquid crystal display device, it is preferable that a step of a general color filter can be planarized with a substrate.

The protective film composition is prepared in the form of a curable resin composition and satisfactorily classified into thermosetting and photocurable (photosensitive). When a pattern of a protective film is required, a photosensitive resin composition is required. Otherwise, a thermosetting resin composition is used. This is because it is convenient in the process and can increase the crosslinking density and is excellent in mechanical properties and heat resistance.

Japanese Patent Laying-Open No. 2007-277540 discloses a thermosetting resin composition as a composition constituting a protective film. That is, a composition comprising a thermosetting resin containing a carboxyl group or an epoxy group, organic fine particles, and a fluorine-containing polyether, and a thermosetting resin containing an alicyclic epoxy is used. When a protective film is prepared using these compositions, the mechanical properties are not excellent, and in particular, yellowing phenomenon is often observed due to poor heat resistance at high temperatures.

Japanese Patent Application Laid-Open No. 2007-277540

(B1) an alicyclic epoxy compound and (b1) a polyfunctional curing compound [B] in order to improve the mechanical properties and the heat resistance at a high temperature by improving the curing density, b2) oxetane compound at the same time as the thermosetting resin composition.

Another object of the present invention is to provide a cured film for an optical device made of the above-mentioned thermosetting resin composition.

(A1) at least one compound selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride, (a2) an epoxy group-containing unsaturated compound, and (a3) (B1) an alicyclic epoxy compound and (b2) an oxetane compound as a multifunctional curable compound [B], wherein the thermosetting resin composition comprises a copolymer [A] of an olefinically unsaturated compound.

In the thermosetting resin composition according to another embodiment of the present invention, the (b2) oxetane compound includes at least one compound selected from the group consisting of compounds represented by the following general formula (1).

≪ Formula 1 >

(Wherein n is 0 or an integer of 1 to 3, which represents a repeating unit in the main chain.)

In the thermosetting resin composition according to another embodiment of the present invention, the [B] polyfunctional curing compound may be contained in an amount of 1 to 40 parts by weight based on 100 parts by weight of the [A] alkali-soluble resin.

In the thermosetting resin composition according to another embodiment of the present invention, the (b1) alicyclic epoxy compound and the (b2) oxetane compound may be contained in a weight ratio of 3 to 7: 7 to 3.

In the thermosetting resin composition according to another embodiment of the present invention, the thermosetting resin composition may further comprise [C] an unsaturated ethylenic monomer and a thermal radical polymerization initiator.

A cured film for an optical device according to another embodiment of the present invention is manufactured by using the thermosetting resin composition.

The thermosetting resin composition of the present invention improves the curing density and thus has excellent mechanical properties and excellent heat resistance at a high temperature, so that the yellowing of the cured film can be prevented.

Further, the optical device can be effectively protected while being excellent in adhesion, planarizing property, UV resistance, and chemical resistance to withstand severe treatment at the time of manufacture.

1 is an example of the alicyclic epoxy compound (b1) that can be used in the present invention.

The present inventors have completed the present invention by confirming that the curing degree, the mechanical properties and the heat resistance at high temperature of the resin composition are increased when the alicyclic epoxy and the oxetane compound are simultaneously used as the polyfunctional curing compound.

The thermosetting resin composition of the present invention is prepared by dissolving the [A] alkali-soluble resin, [B] the polyfunctional curing compound, optionally the [C] unsaturated ethylenic monomer and the thermal radical polymerization initiator in a solvent, [B] is characterized by containing both (b1) alicyclic epoxy and (b2) oxetane compound at the same time.

(A1) at least one compound selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride, (a2) an epoxy group-containing unsaturated compound and (a3) an olefin-based unsaturated compound (B1) an alicyclic epoxy compound and (b2) an oxetane compound as a multifunctional curable compound [B], wherein the thermosetting resin composition comprises an alkali-soluble resin [A] which is a copolymer resin of an unsaturated compound.

 [A] Alkali-soluble resin

The alkali-soluble resin (A) used in the present invention is at least one compound selected from the group consisting of (a1) unsaturated carboxylic acid and unsaturated carboxylic anhydride, (a2) an epoxy group- It may be a cohesive resin.

Examples of the compound (a1) selected from the group consisting of unsaturated carboxylic acid and unsaturated carboxylic acid anhydride include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, and dicarboxylic acid Or anhydrides thereof. Of these, acrylic acid, methacrylic acid, maleic anhydride and the like are preferable in view of copolymerization reactivity, heat resistance and availability. The monomer (a1) is preferably contained in an amount of 1 to 15% by weight in the [A] alkali-soluble resin.

Examples of the epoxy group-containing unsaturated compound (a2) include glycidyl methacrylate, glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α-n-propyl acrylate ,? -n-butyl acrylate glycidyl ester, acrylic acid-3,4-epoxybutyl ester, methacrylic acid-3,4-epoxybutyl ester, acrylic acid-6,7-epoxyheptyl ester, methacrylic acid- Vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, and the like are copolymerizable and / or non-reactive. It is preferably used because it increases the heat resistance and hardness of the obtained thin film. These compounds may be used alone or in combination. The monomer (a2) is preferably contained in an amount of 1 to 15% by weight in the [A] alkali-soluble resin.

Examples of the olefinic unsaturated compound (a3) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinyl chloride Acrylamide, acrylamide, methacrylamide, vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and dicyclopentyl acrylate. The monomer (a3) is preferably contained in an amount of 1 to 30% by weight in the [A] alkali-soluble resin.

The alkali-soluble resin [A] of the present invention may have a solid content of 10 to 70% by weight, more preferably 20 to 50% by weight, based on the weight of the component [A]. When the solid content is less than 10% by weight, the polymer containing both the storage stability of the copolymer [A] and the constituents of [a1] to [a3] tends to be solidified due to poor polymerization control during production, %, The developability, heat resistance and surface hardness of the copolymer [A] tends to be lowered.

The alkali-soluble resin [A] of the present invention is preferably contained in an amount of 10 to 80% by weight in the composition. When the content of the [A] alkali-soluble resin is within the above range, there is an effect of improving water resistance, heat resistance, developability and coating property.

Examples of the solvent used in the synthesis of the copolymer and the alkali-soluble resin [A] of the present invention include alcohols such as methanol and ethanol; Ethers such as tetrahydrofuran, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; And propylene glycol alkyl ether acetates such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate and propylene glycol butyl ether acetate. The solvent is preferably contained in an amount of 60 to 70% by weight in the [A] alkali-soluble resin.

As the polymerization initiator used in the synthesis of the copolymer alkali-soluble resin [A], any polymerization initiator generally known as a radical polymerization initiator can be used without limitation, and examples thereof include 2,2'-azobisisobutyronitrile, 2 Azo compounds such as 2'-azobis- (2,4-dimethylvaleronitrile) and 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile); Organic peroxides such as benzoyl peroxide, t-butyl peroxypivalate, and 1,1'-bis- (t-butylperoxy) cyclohexane; And hydrogen peroxide. When a peroxide is used as a radical polymerization initiator, the peroxide may be used as a redox initiator together with a reducing agent. The polymerization initiator is preferably contained in an amount of 1 to 10% by weight in the [A] alkali-soluble resin.

The [A] alkali-soluble resin of the present invention preferably has a weight average molecular weight of 5,000 to 40,000 g / mol. When the weight average molecular weight of the alkali-soluble resin falls within the above range, it can have excellent coating properties and developability.

[B] Multifunctional curing compound

The [B] multifunctional curable compound of the present invention can act as a curing agent for the [A] alkali-soluble resin.

The [B] multifunctional curable compound includes (b1) an alicyclic epoxy and (b2) an oxetane compound simultaneously. When the alicyclic epoxy and the oxetane compound are used at the same time, the cured film can secure a high cured density, and the mechanical properties can be increased without deteriorating the heat resistance and chemical resistance of the cured film.

Specific examples of the alicyclic epoxy compound (b1) of the present invention include CELLOXIDE 3000, CELLOXIDE 2021P, CELLOXIDE 2081, EHPE 3150, and EPOLEAD GT401 commercially available from Daicel Chemical Co. (Fig. 1).

The oxetane compound (b2) of the present invention may contain any one or more selected from the group consisting of compounds represented by the following general formula (1).

≪ Formula 1 >

(B2) a specific example of the oxetane compound is 1,4-Bis {[(3-ethyloxetane-3-yl) methoxy] methyl } benzene, 3-Ethyl-3 - {[(3-ethyloxetane-3-yl) methoxy] methyl} oxethane.

The [B] multifunctional curing compound of the present invention is preferably contained in an amount of 1 to 50 parts by weight, more preferably 1 to 40 parts by weight, per 100 parts by weight of the [A] alkali-soluble resin. When the content of the [B] polyfunctional curing compound is less than 1 part by weight based on 100 parts by weight of the copolymer [A], it is difficult to obtain a protective film having a sufficiently high crosslinking density and various resistance of the protective film may be deteriorated . On the other hand, if it exceeds 50 parts by weight, a large amount of unreacted polyfunctional curing compound [B] remains in the film of the obtained protective film, which makes the properties of the protective film unstable, the residual film ratio reduced, and the adhesion property easily deteriorated.

(B1) an alicyclic epoxy compound and (b2) an oxetane compound are simultaneously contained in the [B] polyfunctional curing compound, and the (b1) alicyclic epoxy compound and the (b2) To 3 by weight. If it exceeds the above range, the effect of improving surface hardness and heat resistance becomes small.

As another embodiment of the present invention, the thermosetting resin composition of the present invention may further contain [C] unsaturated ethylenic monomer in addition to the [A] alkali-soluble resin and the [B] polyfunctional curing compound.

[C] unsaturated ethylenic monomer

The (C) unsaturated ethylenic monomer of the present invention is preferably a (mon) acrylate having a monofunctional, bifunctional or trifunctional or more functionality from the viewpoint of good polymerizability and improved heat resistance and surface hardness of a protective film to be obtained later.

Examples of the monofunctional (meth) acrylate include 2-hydroxyethyl (meth) acrylate, carbitol (meth) acrylate, isobonyl (meth) acrylate, 3-methoxybutyl And 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate.

Examples of the bifunctional (meth) acrylate include ethylene glycol (meth) acrylate, 1,6-hexanediol (meth) acrylate, 1,9-nonanediol (meth) acrylate, propylene glycol Tetraethylene glycol (meth) acrylate, bisphenoxy ethyl alcohol fluorene diacrylate, and the like.

Examples of the above (meth) acrylate having three or more functional groups include (meth) acrylic acid esters such as trishydroxyethylisocyanurate tri (meth) acrylate, trimethylpropanetri (meth) acrylate, pentaerythritol tri (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like.

The [C] unsaturated ethylenic monomer of the present invention may be used alone or in combination of two or more selected from the above monofunctional, bifunctional or trifunctional (meth) acrylates.

The [C] unsaturated ethylenic monomer of the present invention is preferably contained in an amount of 150 parts by weight or less, more preferably 120 parts by weight or less, based on 100 parts by weight of the copolymer [A]. When the content of the [C] unsaturated ethylenic monomer exceeds 150 parts by weight based on 100 parts by weight of the [A] alkali-soluble resin, the adhesion of the resulting protective film tends to deteriorate.

In another embodiment of the present invention, the thermosetting resin composition of the present invention may further include a thermal radical polymerization initiator. The amount of the thermosetting resin composition may be 20 parts by weight or less, more preferably 15 parts by weight or less based on 100 parts by weight of the [A] By weight. If the amount of the thermal radical polymerization initiator exceeds 20 parts by weight, the heat resistance and planarizing property of the protective film, which will be obtained later, are liable to be lowered.

As the thermal radical polymerization initiator, those generally known as radical polymerization initiators may be used, and a polymerization initiator used for polymerization of the above-mentioned [A] alkali-soluble resin may be used.

The thermosetting resin composition of the present invention can be produced by dissolving the [C] unsaturated ethylenic monomer and the thermal radical polymerization initiator together with the above-mentioned [A] alkali-soluble resin and [B] polyfunctional curing compound in a solvent. The solvent used here is one which does not react with any one component. For example, from the viewpoints of solubility, reactivity, and convenience of forming a film, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and propylene glycol methyl Ether acetate is preferred. It is also possible to use a high boiling point solvent together with the above-mentioned solvent. Examples of the high boiling point solvent include N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, And the like. When such a high boiling point solvent is used in combination, it is preferable that the mixing ratio with the above solvent (the above solvent): (high boiling point solvent) is 50 to 100: 50 to 0.

In addition, the thermosetting resin composition of the present invention may contain other components as needed within the technical scope of the present invention. Other components herein include surfactants for improving the coating properties, for example. Examples of the surfactant include fluorine or silicone surfactants, and examples thereof include FC-129, FC-170C and FC-430 of 3M Company. It may be used in an amount of 5 parts by weight or less, more preferably 2 parts by weight or less, based on 100 parts by weight of the [A] alkali-soluble resin. When the surfactant is used in an amount exceeding 5 parts by weight based on 100 parts by weight of the [A] alkali-soluble resin, bubbling tends to occur during application.

The thermosetting resin composition thus mixed can be used after filtration using a filter having a diameter of about 0.1 to 5 탆.

The cured film for an optical device according to another embodiment of the present invention is manufactured using the thermosetting resin composition.

In the thermosetting resin composition of the present invention, for example, a protective film can be formed by the following method. A protective film can be obtained by applying a thermosetting resin composition to a substrate and removing the solvent to form a coating film of the thermosetting resin composition, followed by heat treatment.

As the substrate, glass, quartz, silicon, resin, or the like can be used, and examples of the resin include polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, polyimide, and ring- And hydrogenated products thereof.

The method of applying the thermosetting resin composition solution is not particularly limited, and for example, a spray method, a roll coating method, a spin coating method, or the like can be used.

The removal of the solvent is preferably performed by a heat treatment (preliminary firing). The conditions of the preliminary firing are preferably baked at 60 to 120 DEG C for 0.5 to 20 minutes though they vary depending on the kind, ratio, and the like of each component of the composition solution.

The protective film for optical devices can be manufactured by treating the substrate at a temperature of 150 to 300 DEG C for 10 to 100 minutes.

The thickness of the protective film formed as described above is preferably 0.1 to 6.0 占 퐉. In the case where the protective film has unevenness on the substrate, the value should be understood as a value at the uppermost surface of the unevenness.

Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention and Comparative Examples which are not based on the present invention, but the scope of the present invention is not limited by the following Examples.

≪ Preparation Example 1 > Preparation of alkali-soluble resin

10 parts by weight of 2,2'-azobisisobutyronitrile as a photopolymerization initiator was dissolved in 200 parts by weight of a solvent propylene glycol monomethyl ether acetate in a reaction vessel equipped with a cooling tube and a stirrer. Subsequently, 65 parts by weight of styrene, 15 parts by weight of methacrylic acid, and 20 parts by weight of glycidyl methacrylate were charged, purged with nitrogen, and gently stirred. The temperature of the solution was raised to 70 캜 and maintained at this temperature for 4 hours to obtain a polymer solution containing the copolymer. The solid concentration of the obtained polymer solution was 35% by weight. This was called an alkali-soluble resin.

≪ Examples 1 to 5 and Comparative Examples 1 to 3 >

(B1) an alicyclic epoxy compound and (b2) an oxetane compound as a polyfunctional multifunctional curing compound were added to the alkali-soluble resin obtained in the above-mentioned Production Example, a propylene glycol monomethyl ether acetate and a surfactant as a solvent, , The thermosetting resin was blended while varying the content.

division [A] Alkali-soluble resin (b1) alicyclic epoxy (b2) Oxetane compound menstruum Surfactants Example 1 45 2.5 2.5 49.9 0.1 Example 2 40 5 5 49.9 0.1 Example 3 35 7.5 7.5 49.9 0.1 Example 4 40 3 7 49.9 0.1 Example 5 40 7 3 49.9 0.1 Example 6 40 One 9 49.9 0.1 Example 7 40 9 One 49.9 0.1 Comparative Example 1 40 10 0 49.9 0.1 Comparative Example 2 40 0 10 49.9 0.1 Comparative Example 3 30 10 10 49.9 0.1

(Unit: wt%)

1) (b1) The alicyclic epoxy is Cel-2021P (Daicel).

2) (b2) The oxetane compound is OXT-221 (Toagosei).

3) The surfactant is 3M FC430.

≪ Formation of cured film &

The above-mentioned thermosetting resin composition was coated on a glass substrate so as to have a film thickness of 2 탆 by using a spin coater and then fired in a clean oven at 220 캜 for 30 minutes to form a cured film on the glass substrate.

The properties of the compositions prepared in the above Examples and Comparative Examples were evaluated as follows, and the results are shown in Table 2 below.

(1) Adhesiveness

According to a checkerboard tape method, 11 lines of cuts having a spacing of 1 mm were cut out to a depth of the upper surface of the glass substrate using a cutter knife using a cutter knife, After forming a checkerboard pattern, an adhesive tape (Elcometer Co., Part Number K0001539M001) was placed on the checkerboard pattern and peeled off. The number of peeled checkerboard patterns was measured and the adhesion of the cured film was evaluated according to the following criteria.

○: Number of peeled checkered patterns No more than 5

B: Number of peeled checkered patterns 6 to 49

X: Number of peeled checkered patterns 50 or more

(2) Surface hardness

The cured film was subjected to the pencil hardness test according to the pencil hardness method (test standard: ASTM D3363) to evaluate the surface hardness.

(3) Transparency

The transmittance of the cured film in a wavelength range of 400 to 700 nm was measured using a spectrophotometer (UV-3101PC, manufactured by Shimadzu Corporation) and the transparency of the cured film was evaluated according to the following criteria.

○: Minimum transmittance of 95% or more

?: Minimum transmittance of 90% or more and less than 95%

×: Minimum transmittance less than 90%

(4) Flatness

The surface irregularities of the cured film were irradiated using an? Step (manufacturer: KLA Tencor, equipment name: AS-500) and the step height of the substrate was measured.

(5) Heat resistance (thickness change)

The film thickness was measured using a Profiler. Separately, the cured film was heated in a clean oven at 240 캜 for 60 minutes, and the film thickness was measured in the same manner. The heat resistance of the protective film was evaluated from the thickness change after each additional heat treatment by the following criteria.

◎: Thickness change within 2%

○: Thickness change within 3%

Δ: Thickness change within 5%

X: Thickness change exceeded 5%

(6) Chemical resistance

The glass substrate on which the cured film was formed was immersed in a 25 wt% hydrochloric acid aqueous solution at 30 DEG C for 20 minutes, and then the appearance change of the cured film was observed to evaluate the acid resistance.

(7)

Each of the thermosetting resin compositions prepared on Glass was spin-coated and preliminarily dried on a hot plate under the conditions of 100 DEG C and 100 seconds to form a 2 mu m film. The glass on which the film was formed was subjected to strong baking at 220 DEG C for 30 minutes . The film thickness at the time of preliminary drying and the thickness of the film after baking were measured, and the residual film ratio was measured by the ratio measurement.

The evaluation results are shown in Table 2 below.

Adhesiveness Surface hardness Transparency Heat resistance Planarization property Chemical resistance Remaining film ratio (%) Example 1 ○ 6H ○ ○ 0.1 μm or less No change 92 Example 2 ○ 6H ○ ◎ 0.1 μm or less No change 92 Example 3 ○ 6H ○ ○ 0.1 μm or less No change 91 Example 4 ○ 6H ○ ○ 0.1 μm or less No change 92 Example 5 ○ 6H ○ ○ 0.1 μm or less No change 92 Example 6 ○ 5H ○ △ 0.1 μm or less No change 90 Example 7 ○ 5H ○ △ 0.1 μm or less No change 90 Comparative Example 1 ○ 4H ○ × 0.1 μm or less No change 89 Comparative Example 2 ○ 4H ○ × 0.1 μm or less No change 89 Comparative Example 3 × 6H ○ ○ 0.1 μm or less No change 86

According to the above Table 2, the thermosetting resin compositions prepared in the compositions of Examples 1 to 7 according to the present invention are excellent in adhesion, transparency, flatness, residual film ratio, and chemical resistance, and have excellent surface hardness and excellent heat resistance .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

A thermosetting resin composition comprising (a1) at least one compound selected from the group consisting of an unsaturated carboxylic acid and an unsaturated carboxylic acid anhydride, (a2) an epoxy group-containing unsaturated compound and (a3) an olefinically unsaturated compound, A thermosetting resin composition comprising (b1) an alicyclic epoxy compound and (b2) an oxetane compound as the polyfunctional curable compound [B]. The thermosetting resin composition according to claim 1, wherein the oxetane compound (b2) comprises at least one compound selected from the group consisting of compounds represented by the following formula (1).
≪ Formula 1 >

(Wherein n is 0 or an integer of 1 to 3, which represents a repeating unit in the main chain). The thermosetting resin composition according to claim 1, wherein the [B] polyfunctional curing compound is contained in an amount of 1 to 40 parts by weight based on 100 parts by weight of the [A] alkali-soluble resin. The thermosetting resin composition according to claim 1, wherein the alicyclic epoxy compound (b1) and the oxetane compound (b2) are contained in a weight ratio of 3 to 7: 7 to 3. The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition further comprises a [C] unsaturated ethylenic monomer and a thermal radical polymerization initiator. A cured film for an optical device made from the thermosetting resin composition according to any one of claims 1 to 5.

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