KR101897212B1 - Pigment dispersion and colored photosensitive resin composition comprising same - Google Patents

Abstract

The present invention relates to a pigment dispersion and a colored photosensitive resin composition containing the same, wherein the pigment dispersion of the present invention comprising an acrylic binder resin obtained by polymerizing the compounds represented by Chemical Formulas 1 to 5 and a colored photosensitive resin composition containing the same, It is possible to form a cured film having excellent adhesiveness as well as various physical properties such as light shielding property, electrical insulating property, elastic recovery rate and chemical resistance, and it is possible to provide a black matrix, a column spacer and a black column spacer for a liquid crystal display device, And can be usefully used for the production of black banks and the like.

Description

 TECHNICAL FIELD [0001] The present invention relates to a pigment dispersion and a colored photosensitive resin composition containing the pigment dispersion.

The present invention relates to a pigment dispersion (mill base) and a method of manufacturing the same, which are used for manufacturing a black matrix for a liquid crystal display, a column spacer, a black column spacer (BCS, light blocking spacer) To a colored photosensitive resin composition.

2. Description of the Related Art Liquid crystal displays (LCDs) are gaining popularity as display devices for use in mobile devices, computer monitors, and HDTV. A column spacer formed by using a photosensitive resin composition is applied in order to keep the interval between the upper and lower transparent substrates constant in the liquid crystal cell of the liquid crystal display (LCD). Such a column spacer is prepared by applying a photosensitive resin composition on a substrate, exposing an active line or the like using a mask, developing, and curing.

Recently, a black column spacer (BCS) in which a column spacer and a black matrix are integrated into a single module has been developed to simplify the process procedure.

In order to improve the reliability and durability of a liquid crystal display device, black matrix, column spacer, and black column spacer are required to have excellent optical density and viscosity stability as well as excellent adhesion in the formation of fine patterns.

Thus, studies have been made on a positive-type photosensitive resin composition capable of realizing a fine pattern using an organosiloxane-based polymer compound (Korean Patent Publication No. 10-2002-0021005). However, such a colored photosensitive resin composition has a problem in that the dispersibility and dispersion stability of the colored pigment are low, the stability with time is poor, and the compatibility with the alkali-soluble resin is low.

On the other hand, it is possible to efficiently reduce the external light reflection without using a polarizing film for a smart device such as a smart phone or a tablet using a flexible organic light emitting diode (OLED) There is an increasing need to develop materials and processes that make a bank that can improve black color. Such a black bank improves the visibility of the organic light emitting device and can serve as a black matrix as well as a bank of the organic light emitting device, Thereby simplifying the manufacturing process. As a result, it is possible to secure price competitiveness by using the black bank, and the technology applying the black bank is attracting attention as a new technology useful in the OLED market.

Korean Patent Publication No. 10-2002-0021005

Therefore, an object of the present invention is to provide a black matrix for a liquid crystal display, a liquid crystal display device, and a liquid crystal display device, which are excellent in various physical properties such as optical density, light shielding property, electrical insulation property, elastic recovery rate, and chemical resistance, And a black column spacer, and a black bank for an organic light emitting device, and a colored photosensitive resin composition containing the pigment dispersion.

In order to achieve the above object,

A pigment dispersion comprising a pigment, a binder, a dispersant and a solvent, wherein the binder comprises an acrylic resin obtained by polymerizing the compounds of the following formulas (1) to (5).

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

The present invention also

There is provided a colored photosensitive resin composition comprising the above pigment dispersion, a photopolymerization compound, a photopolymerization initiator and a solvent.

The present invention also

There is provided a black column spacer for a liquid crystal display, which is prepared by curing the colored photosensitive resin composition.

The present invention also

And a black bank for an organic light emitting device manufactured by curing the colored photosensitive resin composition.

The pigment dispersion of the present invention and the colored photosensitive resin composition containing the same can form a cured film having excellent various properties such as optical density, light shielding property, electrical insulation property, elastic recovery rate, and chemical resistance as well as excellent adhesion, A black matrix for a device, a column spacer and a black column spacer, and a black bank for an organic light emitting device.

Therefore, a liquid crystal display device comprising a black matrix, a column spacer and / or a black column spacer manufactured from the pigment dispersion and the colored photosensitive resin composition containing the same, as well as the pigment dispersion and the colored photosensitive resin composition containing the same The organic light emitting device including the black bank has far superior reliability and durability than the conventional one.

The pigment dispersion (mill base) of the present invention comprises a pigment, a binder, a dispersant, and a solvent, wherein the binder (compound 1) (glycidyl methacrylate, GMA), the compound of formula 2 (methacrylic acid, MAA) , An acrylic resin obtained by polymerizing a compound of formula (3) (phenylthioethyl acrylate, PTEA), a compound of formula (4) (vinyltoluene monomer, VTM) and a compound of formula (5) (tetrahydrofurfuryl methacrylate, THFMA) do.

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

The acrylic binder resin is an alkali developable polymer that realizes developability in the development step, and also serves as a base for realizing a base role and a final pattern for forming a coating film after coating.

(1) to (5) derived from each of the monomer compounds represented by the general formulas (1) to (5), based on the total number of moles of the repeating units constituting the acrylic resin, is from 1:10 to 2:20 to 1: 20 to 2: 30 to 1. Specifically, the acrylic resin is a copolymer of repeating units (1) to (5) in a ratio of 1: 3 to 2: 6 to 1: 5 to 2: 6 to 1 based on the total number of moles of repeating units constituting the acrylic resin Molar ratio. Within the above range, adhesion to the substrate can be improved while maintaining developability.

The compounds of the formulas (1) to (5) may be polymerized according to a conventional method to produce the desired acrylic binder resin. For example, the compound of the general formula (2) to (5) is first polymerized at 60 to 120 ° C in a nitrogen atmosphere, then the compound of the general formula (1) is added and further polymerized at 60 to 100 ° C to prepare the desired acrylic binder resin .

The acrylic binder resin thus obtained may have a weight average molecular weight (Mw) of 3,000 to 20,000, specifically 5,000 to 15,000 or 6,000 to 12,000. The acrylic binder resin may have an acid value of 50 to 80 KOH mg / g, specifically 60 to 70 KOH mg / g.

The pigment dispersion of the present invention can be prepared by mixing the acrylic binder resin with a pigment, a dispersant, and a solvent and then milling.

The pigment dispersion may contain the pigment in an amount of 5 to 25% by weight based on the total weight of the dispersion. The pigment dispersion may also contain 1 to 80 parts by weight of the dispersant, 1 to 80 parts by weight of the binder and 10 to 150 parts by weight of the solvent based on 100 parts by weight of the pigment.

Then, the raw material mixture in which the raw materials are mixed in the above-mentioned content range is mixed with a bead mill, an attriter, a super mill, a homomixer, a paint shaker, a ball mill, a sand mill or a horizontal mill It can be milled using. For example, the raw mixture is homogenized (primary dispersion process) in the raw material mixture by primary milling using relatively large beads of 0.5 to 1.2 mm (primary dispersion process), and the primary milled raw material mixture is aged 0.3 to 0.05 mm The particles in the raw material mixture can be refined by secondary milling using the fine beads of the second mill (secondary dispersion process) (equipment: paint kneader).

In addition, the dispersion of the pigment dispersion may be aged for a predetermined period of time, for example, 24 to 168 hours to stabilize the dispersion.

As the pigment, dispersant and solvent, those conventionally used may be used.

Specific examples of the pigment include carbon black, titanium black, Cu-Fe-Mn-based oxide, synthetic iron black, aniline black, lactam black, perylene black, CI Pigment Blue, CI Pigment Red, CI Pigment Green, and mixtures thereof.

Specific examples of the dispersing agent include acrylate dispersants such as butyl (meth) acrylate and N, N-dimethylaminoethyl (meth) acrylate; Styrene-maleic acid ester resin, styrene-maleic acid ester resin, methacrylic acid-methacrylic acid ester resin, acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-acrylic acid- An ethylene double bond-containing resin such as an acrylic ester resin, an isobutylene-maleic acid resin, and a vinyl-ester resin; (Meth) acrylic acid-styrene copolymers, (meth) acrylic acid- (meth) acrylate ester copolymers, polyvinyl alcohol, polyvinylpyrrolidone, Resin type dispersants such as ralidon, polyester, modified polyacrylate, phosphoric acid ester, and polycarboxylic acid; , And mixtures thereof.

Specific examples of the solvent include (poly) alkylene glycol monoalkyl ethers such as diethylene glycol monoethyl ether, propylene glycol monomethyl ether and propylene glycol monoethyl ether; (Poly) alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; Ethers such as diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether and tetrahydrofuran; Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-heptanone and 3-heptanone; Alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, diethylene glycol, and glycerin; , And mixtures thereof.

If necessary, the pigment dispersion may further include a dispersing aid which serves to shorten the dispersing time of the pigment dispersion and to maintain the viscosity of the pigment dispersion more stably, by facilitating the action of the dispersing agent. As the dispersion aid, those conventionally used may be used. The pigment dispersion may contain the dispersion aid in an amount of 1 to 10 parts by weight based on 100 parts by weight of the pigment.

The pigment dispersion according to the present invention can have an average particle size of 90 to 250 nm, and can form a smooth cured film with a later surface roughness (roughness). Also, the pigment dispersion exhibits a viscosity of 2 to 8 cps at 25 캜 (room temperature), and can exhibit a viscosity change rate of 105% or less, specifically 95 to 105% when maintained at 25 캜 (room temperature) for 7 days.

The colored photosensitive resin composition of the present invention comprises the above pigment dispersion, a photopolymerization compound, a photopolymerization initiator and a solvent, and may further contain an alkali developing binder resin, a surfactant, a silane coupling agent, an antioxidant, a stabilizer, As shown in FIG.

The colored photosensitive resin composition of the present invention containing the above components can be produced by a conventional method of uniformly mixing the above components. The kind and content of the above components can also be appropriately selected within the range usually used.

The colored photosensitive resin composition is cured to prepare a column spacer, a black matrix, a black column spacer, and a black bank for an organic light emitting device for a liquid crystal display device.

The column spacer, the black matrix, the black column spacer, or the black bank may be manufactured according to a conventional method, for example, through a film forming step, an exposure step, a development step, and a heat treatment step.

In the step of forming a coating film, the colored photosensitive resin composition according to the present invention is coated on a predetermined pretreated substrate to a desired thickness using a spin or slit coating method, a roll coating method, a screen printing method, an applicator method, or the like The coating film can be formed by removing the solvent by pre-bake at a temperature of 70 to 100 ° C for 1 to 10 minutes.

In order to form a pattern on the obtained coating film, a mask of a predetermined type is interposed, and an active line of 200 to 500 nm is irradiated. At this time, in order to manufacture the integrated black column spacer, a mask having a pattern with a different transmittance may be used so that a column spacer and a black matrix can be simultaneously realized. As the light source used for the irradiation, a low pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, an argon gas laser, and the like can be used.

Following the above exposure step, an unnecessary portion is dissolved and removed by using an alkaline aqueous solution of sodium carbonate, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, or the like as a developer, so that only the exposed portion is left to form a pattern. The image pattern obtained by development can be post-baked at 180 ° C to 250 ° C for 10 minutes to 60 minutes to obtain a desired final pattern.

The cured film (black column spacer or black bank) formed from the colored photosensitive resin composition may have an optical density of 1.0 to 3.5 / 탆. In terms of adhesion, the existing cured film has a minimum fine pattern size of 30 mu m or more, whereas the cured film (black column spacer or black bank) formed from the colored photosensitive resin composition of the present invention has a fine pattern with a size of 30 mu m or less, It is possible to maintain a minimum fine pattern of a size of 18 mu m to 30 mu m.

The black column spacer or the black bank thus manufactured can be usefully used in electronic parts such as LCD and OLED display due to its excellent physical properties. Accordingly, the present invention provides an electronic component including the black column spacer or the black bank.

As described above, the pigment dispersion of the present invention and the colored photosensitive resin composition containing the pigment dispersion of the present invention are excellent in various physical properties such as optical density, light shielding property, electrical insulation property, elastic recovery rate, and chemical resistance and also form a cured film having excellent adhesion And can be usefully used for manufacturing black matrixes for liquid crystal displays, column spacers and black column spacers, and black banks for organic light emitting devices.

Therefore, a liquid crystal display device comprising a black matrix, a column spacer and / or a black column spacer manufactured from the pigment dispersion and the colored photosensitive resin composition containing the same, as well as the pigment dispersion and the colored photosensitive resin composition containing the same The organic light emitting device including the black bank has far superior reliability and durability than the conventional one.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

Manufacture of binders

Production Example 1

122 g of propylene glycol monomethyl ether acetate (PGMEA) as a solvent and 1 g of 1-methoxypropane-2-yne as a polymerization initiator were placed in an internal volume 1.0 liter round flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen- (PGME) were added and stirred. To this were added 100 g of phenylthioethyl acrylate (PTEA), 101 g of vinyltoluene monomer (VTM), 80 g of tetrahydrofurfuryl methacrylate (THFMA) and 74 g of methacrylic acid (MAA) To obtain a copolymer having a carboxyl group.

Then, 42 g of glycidyl methacrylate (GMA) was added to the obtained copolymer and reacted at 80 DEG C for 8 hours to prepare a copolymer (binder) solution (solid concentration 29.27% by weight). The reaction was carried out in a nitrogen atmosphere. The obtained copolymer (binder) was analyzed and found to have an acid value of 63 KOH mg / g, a weight average molecular weight (Mw, GPC result) of 12,000 and a dispersion degree of 2.21.

Production Example 2

A copolymer (binder) solution having a solid concentration of 28.90% by weight was prepared by carrying out the same processes as in Preparation Example 1, except that the degree of polymerization was controlled by changing the amount of the polymerization initiator used and the reaction temperature. The resulting copolymer (binder) was analyzed and found to have an acid value of 60 KOHmg / g, a weight average molecular weight (Mw, GPC result) of 9,000 and a dispersion degree of 2.31.

Production Example 3

A copolymer (binder) solution having a solid concentration of 28.27% by weight was prepared by carrying out the same processes as in Preparation Example 1, except that the degree of polymerization was controlled by changing the amount of the polymerization initiator used and the reaction temperature. The resulting copolymer (binder) was analyzed and found to have an acid value of 64 KOH mg / g, a weight average molecular weight (Mw, GPC result) of 6,500 and a degree of dispersion of 2.38.

The copolymers (binders) prepared in Preparation Examples 1 to 3 contained repeating units derived from each of GMA, MAA, PTEA, VTM and THFMA in a molar ratio of 1: 3: 1.5: 3: 1.6.

Preparation of pigment dispersion

Example 1

(Step 1) Pre-mixing process

, 150 parts by weight of propylene glycol monomethyl ether (PGME) as a solvent, 80 parts by weight of a dispersant (Disperbyk-2001 by BYK), and 80 parts by weight of a binder prepared in Preparation Example 1, based on 100 parts by weight of a pigment (BASF Co. Black 582) And 1 part by weight of a dispersion aid (Solsperse 22000) were mixed and premixed at 1000 rpm for 60 minutes to prepare a raw material mixture.

(Step 2) The primary dispersion step

The raw material mixture prepared in the step 1 was first milled using relatively large beads of 0.5 to 1.2 mm to homogenize the large agglomerated particles in the raw material mixture.

(Step 3) Secondary dispersion step

The primary milled raw material mixture obtained in the above step 2 was subjected to secondary milling using fine beads of 0.3 to 0.05 mm to make the particles in the raw material mixture finer (equipment: paint kneader).

(Step 4) The dispersion stabilization process

The secondary milled raw material mixture obtained in the step 3 was aged at room temperature for 36 hours to prepare a desired pigment dispersion.

Examples 2 and 3

A pigment dispersion was prepared by following the same procedure as in Example 1, except that the binders prepared in Preparation Examples 2 and 3 were used in place of the binders prepared in Preparation Example 1, respectively.

Comparative Example 1

The procedure of Example 1 was repeated to prepare a pigment dispersion except that a commercially available binder (SPCO-823X, Showa Denko KK) was used in place of the binder prepared in Production Example 1.

Preparation of colored photosensitive resin composition

Examples 4 to 6 and Comparative Example 2

6 wt% of a photopolymerization compound, 1 wt% of a photopolymerization initiator, 0.4 wt% of an additive (leveling agent) was added to 44 wt% of the pigment dispersion based on the solid content of the pigment dispersion prepared in Examples 1 to 3 and Comparative Example 1, By weight and 48.6% by weight of a solvent were added, and stabilization was carried out at 3 to 10 캜 for 1 hour or more to obtain a desired colored photosensitive resin composition.

DIC F-554 (DIC KOREA) as an additive and propylene glycol monomethyl ether acetate (PGMEA) as a solvent were used as a photopolymerization initiator, dipentaerythritol hexaacrylate (DPHA, MIC Corporation) as a photopolymerization initiator, OXE- ) Was used.

<Test Example>

Test Example 1: Optical density evaluation

The colored photosensitive resin compositions prepared in Examples and Comparative Examples were coated on a glass substrate using a spin coater, respectively, and then cured at 95 캜 to form a coating film having a thickness of 1 탆. The optical density of the coating was measured using a 361T densitometer from X-Rite.

Test Example 2: Evaluation of surface roughness (roughness)

The surface of the coating film prepared in Test Example 1 was observed with a VHX-1000E optical microscope of Keynece at a magnification of 500 to evaluate the surface roughness (roughness).

Test Example 3: Evaluation of adhesion

The colored photosensitive resin compositions prepared in the above Examples and Comparative Examples were coated on a glass substrate using a spin coater, respectively, and then cured by heating at 95 DEG C for 1 minute to form a coating film having a thickness of 1 mu m. Next, a photomask was applied to the coating film, and energy of 50 mJ / cm 2 was irradiated under a mercury lamp. The exposed coating film was developed with a 0.05 wt% KOH aqueous solution at room temperature by a spray method and then washed with distilled water. The remaining minimum fine pattern size was measured by observing the fine pattern (pattern line width: 1 to 40 탆) remaining on the glass substrate at 200 magnification with a VHX-1000E optical microscope of Keynece.

The evaluation criteria of the average particle diameter of the pigment dispersion and the surface roughness of the coating film are shown in Table 1 below. Weight average molecular weight (Mw) of the binder; Initial viscosity (25 占 폚), viscosity change rate (degree of change in viscosity when maintained at 25 占 폚 for 7 days) and average particle size of the pigment dispersion; And the optical density, surface roughness and minimum fine pattern size of the coating film are shown in Table 2, respectively.

standard × △ ○ Average particle diameter 300nm or more 250 nm or more, less than 300 nm 90 nm or more, less than 250 nm Surface roughness rough surface Smooth surface

bookbinder Pigment dispersion Coat Mw Initial viscosity Viscosity
Rate of change Average particle diameter Optical density Surface roughness Minimum fine pattern (탆) Example 1
(Example 4) 12,000 3.37 100% ○ 1.63 ○ 25 Example 2
(Example 5) 9,000 3.42 101% ○ 1.62 ○ 23 Example 3
(Example 6) 6,500 3.63 100% ○ 1.64 ○ 18 Comparative Example 1
(Comparative Example 2) 12,000 3.52 102% ○ 1.62 ○ > 30

From the experimental results shown in the above Table 2, the pigment dispersions of Examples containing specific binders and the coating films prepared therefrom exhibited comparable physical properties in terms of viscosity stability, optical density and surface roughness, And it shows excellent fine pattern adhesion.

Claims (10)

A pigment dispersion comprising a pigment, a binder, a dispersant and a solvent, wherein the binder comprises an acrylic resin obtained by polymerizing the compounds of the following formulas (1) to (5)
Wherein the acrylic resin has a weight average molecular weight (Mw) of 6,000 to 12,000 and the repeating units (1) to (5) derived from each of the compounds of the formulas (1) to (5), based on the total moles of the repeating units constituting the acrylic resin ) In a molar ratio of 1: 3 to 2: 6 to 1: 5 to 2: 6 to 1.6.
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

delete The method according to claim 1,
Wherein the acrylic resin has an acid value of 50 to 80 KOH mg / g.
delete The method according to claim 1,
Wherein the pigment dispersion comprises from 5 to 25% by weight of the pigment based on the total weight of the dispersion and from 1 to 80 parts by weight of the dispersant, from 1 to 80 parts by weight of the binder and from 10 to 150 parts by weight of the solvent By weight based on the total weight of the pigment dispersion.
The method according to claim 1,
Wherein the pigment dispersion has an average particle size of 90 to 250 nm.
The method according to claim 1,
Wherein the pigment dispersion exhibits a viscosity of 2 to 8 cps at 25 占 폚 (room temperature) and exhibits a viscosity change rate of 95 to 105% when maintained at 25 占 폚 (room temperature) for 7 days.
A colored photosensitive resin composition comprising the pigment dispersion, the photopolymerizable compound, the photopolymerization initiator and the solvent according to any one of claims 1, 3 and 5 to 7.
A black column spacer for a liquid crystal display, which is prepared by curing the colored photosensitive resin composition of claim 8.
A black bank for an organic light emitting device, which is prepared by curing the colored photosensitive resin composition of claim 8.