A weak alkaline developer composition for color filter

Abstract

The invention discloses a weak base developer composition for color filters, belongs to the field of wet electronic chemicals, is mainly used in the field of microelectronic material technology, and is used for the development of negative photoresists in display panels. The key lies in 8-15% of a special nonionic surfactant, 5-10% of an inorganic weak base, 1-5% of a solubilizer, and the balance is water. The special nonionic surfactant is selected from the following structure:; wherein n is an integer of 5-15; wherein R is selected from any one of hydrogen atoms, halogen atoms, saturated alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, carboxyl groups, ester groups, acyl groups, cyano groups, nitro groups, amino groups, hydroxyl groups, alkoxy groups, and styryl groups. The weak base developer composition has the characteristics of low alkalinity, low foam, no photoresist residue after development, no substrate corrosion, clear development pattern, and long service life of the developer.

Description

Technical Field

[0001] The invention belongs to the field of wet electronic chemicals and is mainly used for developing negative photoresist in the process of color filter manufacturing in TFT-LCD, in particular to a weak alkaline developer composition for color filter. Background Art

[0002] TFT-LCD has the characteristics of good use characteristics, good environmental protection characteristics, wide application range, high degree of automation of manufacturing technology, and good large-scale industrial production characteristics. TFT-LCD is easy to integrate and upgrade, and is a perfect combination of large-scale semiconductor integrated circuit technology and light source technology, with great potential for continued development. The process of liquid crystal display (TFT-LCD) includes array, color filter (CF), cell and module. Among them, the color filter includes glass substrate, black matrix, red / green / blue primary color resistance, flat layer, ITO and columnar spacer. The production of each layer of film on the entire color film glass substrate can be roughly divided into three steps: the first is BM process; the second is color resistance process; the third is OC and PS process. The color resistance layer is the key material for the colorization of liquid crystal flat panel display. The coloring methods of photoresist usually include dyeing method and pigment dispersion method. The pigment dispersion method is currently the mainstream method for coloring color resists. It is to disperse the pigment representing a certain color in the solvent of the photoresist, and then coat the photoresist on a glass substrate with a black matrix prepared. After a series of exposure and development processes, the required pattern is prepared.

[0003] The photoresist used in the CF process is a negative photoresist. The development process is a process in which an alkaline developer reacts chemically with the photoresist, in which the unexposed part reacts and dissolves, and the exposed part remains, that is, the transparent area pattern on the mask is transferred to the photoresist. In high-generation line processes, development is often carried out by spraying. The main components of color photoresist include adhesive polymers (mostly acrylates), cross-linking agents, photoinitiators, solvents, dispersants and pigment molecules. In the color filter manufacturing process, the matching of the black matrix BM and RGB photoresist and the developer is very important. During the development process, the photoresist and the developer must react quickly and completely, and no photoresist residue can be left.

[0004] The CF developer currently used on the market is mainly a strong alkali system represented by KOH, which mainly includes a strong alkali, a surfactant and deionized water. The strong alkali developer has a significant dissolving effect on the photoresist, but the alkalinity is too high, which is quite dangerous in the production process. Strong alkaline substances are extremely harmful to the skin. The weak alkali developer is relatively safe in the production process, with a low alkalinity, will not cause serious irritation to the skin, and will not volatilize seriously. Among them, some patents have mentioned the use of organic strong alkalis instead of inorganic strong alkalis to avoid the harm caused in the production process. Patent CN101872136A discloses a developer for flat panel displays, which adds organic alkalis and inorganic alkalis for compounding, and uses organic alkalis such as monomethylamine, dimethylamine, and triethylamine. It can increase the alkalinity of the developer to a certain extent, so that the concentration is greatly increased, but organic solvents will bring uncertainties, such as excessive foam, reduced development speed, and development residues. Patent US2006 / 0166147A1 mentions a high-concentration color filter developer, which contains a surfactant with a special structure, organic acetic acid or carboxylate and water. However, the developer has problems such as incomplete development, residues during development and a short service life. Summary of the invention

[0005] The main technical problem solved by the present invention is to provide a weak alkaline developer for color filters, which has low alkalinity, a relatively safe production process, and no harm to the environment. It uses a special surfactant that can effectively reduce surface tension, has an excellent cleaning effect, and can effectively reduce problems such as incomplete development and residues in development, and effectively improve the service life of the developer. At the same time, a solubilizer is added to ensure that the developer is a uniform and stable system without stratification, and can also effectively improve the development effect.

[0006] The solution adopted by the present invention to solve the technical problem is:

[0007] A weak base developer composition for color filters comprises the following components by mass percentage: 5-10% inorganic weak base, 8-15% special nonionic surfactant, 1-5% solubilizer, and the balance water.

[0008] The structure of the special nonionic surfactant is:

[0009]

[0010] Wherein, n is an integer of 5-15; wherein R is selected from any one of a hydrogen atom, a halogen atom, a saturated alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a carboxyl group, an ester group, an acyl group, a cyano group, a nitro group, an amino group, a hydroxyl group, an alkoxy group, and a styryl group.

[0011] The preparation method of the special nonionic surfactant comprises the following steps:

[0012] (1) Synthesis of Intermediate I

[0013]

[0014] Compound 2 is placed in a reactor and heated, a catalyst (a complex of sulfonic acid macroporous cationic resin and aluminum phenol is used as the catalyst) is added, and compound 1 is added dropwise with stirring, and the conversion amount of compound 2 is checked by thin layer chromatography. The reaction temperature is 35-40°C, and the reaction time is 2h. After the reaction is completed, the catalyst is removed, and the reduced pressure distillation is performed, and the 200-220°C fraction (4-6.7kPa) is collected as intermediate I;

[0015] (2) Synthesis of Intermediate II

[0016]

[0017] Dissolve compound 3 in tetrahydrofuran and add it to a three-necked flask with a condenser. Then place the three-necked flask on a SZCL-digital display intelligent temperature control magnetic stirrer and put in a rotor, heat to 70°C, then add an equal amount of intermediate I dissolved in tetrahydrofuran to the three-necked flask using a constant pressure dropping funnel (drop rate is 20 drops / min), stir and react at 70°C for 1 hour, add two drops of catalyst dibutyltin dilaurate, and continue to react for 1 hour to obtain intermediate II;

[0018] (3) Synthesis of special nonionic surfactant A

[0019]

[0020] A large amount of solvent (tetrahydrofuran) was evaporated using a rotary evaporator, and a large amount of cyclohexane was added. A relatively pure solid intermediate product II was obtained by suction filtration and placed in a 60°C oven for 24 hours. Then, the intermediate product I was dissolved in a solvent (tetrahydrofuran) under stirring and then dripped into 70°C polyethylene glycol 1000 (PEG1000) (drip rate of 20 drops / min), and stirred at a constant temperature of 60°C for 2.0 hours to finally obtain a nonionic surfactant A.

[0021] Further, the inorganic weak base is selected from any one or more of the following groups, including: sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium silicate, ammonium carbonate, sodium phosphate, sodium hydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, sodium hypochlorite, potassium hypochlorite, sodium hypobromite, potassium hypobromite, aluminum hydroxide, and sodium dihydrogen sulfate.

[0022] Furthermore, the solubilizing agent is selected from any one or more of the following groups, including: Tween-80, Tween-20, sodium dodecylbenzene sulfonate, polysorbate 80, poloxamer, polyoxyethylene laurate, sodium lauryl sulfate, sodium dodecyl sulfate, sodium taurocholate, polyoxyethylene castor oil, polyoxyethylene hardened castor oil, polyglycerol fatty acid esters, fatty alcohol polyoxyethylene ethers, and fatty alcohol polyoxyethylene-polyoxypropylene ethers.

[0023] Furthermore, the water is high-purity water with a resistance value greater than 18 MΩ / cm.

[0024] The preparation method of the weak base developer composition for color filters comprises: adding an inorganic weak base to water, and then adding a special nonionic surfactant and a solubilizer to form a uniform system at a stirring speed of 200 rpm to obtain a uniform, stable, clear and transparent composition.

[0025] The significant advantages of the present invention are:

[0026] A special nonionic surfactant is used, which is connected to p-phenylene diisocyanate with p-cumylphenol as the head group and ethylene oxide. The benzene ring can effectively dissolve and disperse the photoresist through the principle of similar compatibility with the benzene ring in the photoresist. The introduction of amide groups makes it easier for the surfactant molecules in the adsorption layer to be arranged more closely through the interaction of intermolecular hydrogen bonds or dipole moments, thereby increasing the viscosity and elasticity of the adsorption layer, enhancing the stability of the adsorption film, and improving the foam stabilization performance of the surfactant; at the same time, it reduces irritation, is conducive to biodegradation, greatly reduces the discharge pressure, and is green and environmentally friendly. The introduction of ethylene oxide can effectively improve the dispersibility and wettability of the developer to the photoresist. The use of special nonionic surfactants greatly reduces the surface tension, small foam, improves the solubility of the photoresist, effectively reduces the problems of incomplete development and residue in development, and has a significant effect on improving the service life of the developer, and can obtain a substrate with clear graphics, complete edges, and no photoresist residue. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The exemplary implementation modes of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0028] The preparation method of the special nonionic surfactant is as follows:

[0029] Step 1: Synthesis of Intermediate I

[0030] The reaction is carried out at a molar ratio of resorcinol: methyl styrene = 2:1. Phenol is placed in a reactor and heated, and a complex of sulfonic acid type macroporous cationic resin and phenol aluminum is added as a catalyst. Stir and drip styrene, and the conversion amount of phenol is checked by thin layer chromatography technology. The reaction temperature is 35-40°C and the reaction time is 2h. After the reaction is completed, the catalyst is removed, and the reduced pressure distillation is performed to collect the 200-220°C fraction (4-6.7kPa) as the intermediate I p-cumylphenol.

[0031]

[0032] Step 2: Synthesis of Intermediate II

[0033] The reaction was carried out at a molar ratio of p-phenylenediisocyanate: p-cumylphenol = 1:1. P-phenylenediisocyanate was dissolved in tetrahydrofuran and added to a three-necked flask with a condenser, and then the three-necked flask was placed on a SZCL-digital display intelligent temperature control magnetic stirrer and a rotor was placed, and heated to 70°C. Then, an equal amount of intermediate I dissolved in tetrahydrofuran was added to the three-necked flask using a constant pressure dropping funnel (the dropping rate was 20 drops / min), and the reaction was carried out at a constant temperature for 1 hour under stirring, and two drops of catalyst (dibutyltin dilaurate) were added, and the reaction was continued for 1 hour to obtain intermediate II.

[0034] Step 3: Preparation of specific nonionic surfactant

[0035] A large amount of solvent (tetrahydrofuran) was evaporated using a rotary evaporator, and a large amount of cyclohexane was added. A relatively pure solid intermediate product I was obtained by suction filtration and placed in a 60°C oven for 24 hours. Then, the intermediate product I was dissolved in a solvent (tetrahydrofuran) under stirring and then dripped into 70°C polyethylene glycol 1000 (PEG1000) (drip rate of 20 drops / min), the mass ratio of the two drugs was 1.0:1.0, and the mixture was stirred at a constant temperature for 2.0 hours to finally obtain nonionic surfactant A.

[0036] according to 1 HNMR (δ, DMSO, 300MHz) analysis, the chemical shift is (δ): 1.69 (s, 3H, -CH3); 3.52 (m, 18H, O-CH2-CH2); 4.20 (t, 2H, O-CH2-CH2); 6.60 (s, 1H, -CH); 6.73 (d, 1H, -CH=CH-C-); 7.18 (d, 2H, C-CH=CH); 7.29 (t, 2H, -CH-CH-CH-); 7.62 (d, 1H, C-CH=CH); 9.86 (s, 1H, O=C-NH-C).

[0037] according to 13C NMR (δ, DMSO, 300 MHz) analysis showed that the chemical shift δ was 31.2; 36.2; 61.3; 70.4; 109.8; 114.7; 121.8; 126.4; 128.2; 133.6; 150.0; 150.2; 153.8; 155.7.

[0038] According to HRMS analysis, its molecular formula is C 33 H 42 N2O 10 , m / z:626.28.

[0039] Proved the successful synthesis of non-ionic surfactants with R as hydrogen atom and n as 5

[0040] Similarly, intermediate I was synthesized using phenol and 1-isopropenyl-4-methylbenzene in a molar ratio of 2:1 as raw materials, and the subsequent synthesis method was the same as above.

[0041] according to 1 HNMR (δ, DMSO, 300 MHz) analysis, the chemical shift is (δ): 1.69 (s, 6H, -CH3); 2.19 (s, 3H, -CH3); 4.20 (t, 4H, CH2-CH2); 3.52 (m, 18H, -CH2-CH2); 5.40 (s, 1H, -OH); 6.60 (s, 1H, -CH-); 6.73 (d, 2H, -CH-CH-); 7.05 (m, 6H, -CH-CH-); 7.62 (d, 4H, -CH-CH-); 9.86 (s, 1H, -O=C-NH-C-).

[0042] according to 13 C NMR (δ, DMSO, 300MHz) analysis showed chemical shifts δ of 21.3; 31.2; 36.2; 61.3; 70.4; 109.8; 121.8; 126.4; 129.5; 133.6; 135.9; 150.0; 153.8; 155.7

[0043] According to HRMS analysis, its molecular formula is C 34 H 44 N2O 10 ,m / z:640.30

[0044] The nonionic surfactant with R as methyl and n as 5 was successfully synthesized.

[0045] Examples and Comparative Examples: Weak alkaline developer composition for color filters.

[0046] The weak base developer compositions of the examples and comparative examples were prepared according to the compositions and mass percentages shown in Table 1. The bridging groups of the test polyether nonionic surfactant are hydrogen atoms, G m The addition number of ethylene oxide (EO) is n, the polyether nonionic surfactant A, and the weak base developer composition is mainly prepared by adding different component raw materials and mixing them uniformly to obtain different embodiments.

[0047] Table 1

[0048]

[0049]

[0050] Experimental example: Experiment on measuring the developing performance of developer

[0051] In order to evaluate the developing performance of the weak alkaline developers of Examples 1-5 and Comparative Examples 1-5, the developing performance of the developers was measured by the following experiment:

[0052] 1. Preparation of glass substrate

[0053] In order to evaluate the developing performance of the developer composition on the photoresist, the present invention prepares the developer according to the above-mentioned embodiment and comparative example respectively, prepares the glass substrate sample, and spin-coats a layer of 1.0 μm BM negative photoresist or R, G, B photoresist on each glass substrate. The preparation process is as follows: After the glass substrate is cleaned with a special detergent, it is rinsed with ultrapure water and blown dry with nitrogen. Spin the photoresist with a spin coater, vacuumize and extract most of the solvent, pre-bake at 110°C in an oven for 100s, and then expose it with a pattern mask to transfer the pattern on the mask to the glass substrate.

[0054] 2. Development test

[0055] The developer composition was diluted 20-60 times with ultrapure water, the liquid temperature was controlled to be 23°C, and the diluted developer was sprayed on the glass substrate coated with photoresist with a constant pressure for 50 seconds, and then washed with ultrapure water and dried with nitrogen. An optical microscope and an electron microscope were used to observe whether the developed pattern was clear, whether the photoresist remained, whether the pattern edge was complete, whether there was a burr phenomenon, how many glass substrates would have obvious photoresist residues after spraying, and how long the developer had a service life. The results are shown in Table 2.

[0056] Table 2

[0057]

[0058]

[0059] As can be seen from Table 1, compared with Example 1, the difference of Comparative Example 1 is that under the same ethylene oxide number, the addition amount is different. The difference between Comparative Example 2 and Example 2 is the difference in the ethylene oxide number. The difference between Comparative Example 3 and Example 3 is that the surfactant of Comparative Example 3 is TX-10. The difference between Comparative Example 4 and Example 3 is that the surfactant of Comparative Example 4 is AES. The difference between Comparative Example 5 and Example 3 is the difference in the content of inorganic weak base.

[0060] It can be seen from Table 1 and Table 2 that after the development test of Examples 1-5, the graphics on the glass substrate are clear and complete, there is no photoresist residue, there is no burr phenomenon on the edge of the graphics, and the service life of the developer is relatively long. When the EO value of the polyether in Comparative Example 1 is equal to 5, it cannot make the photoresist graphics uniform when diluted at a higher multiple, the graphics are not completed, and there are burrs. Comparative Example 2 increases the ethylene oxide number to 8, and a clearer graphic can be obtained, but there will be burrs. Comparative Examples 3 and 4 select the commonly used nonionic surfactant TX-10 and anionic surfactant AES. It can be seen that the nonionic surfactant TX-10 has poor development performance, cannot obtain a clearer graphic, and is prone to photoresist residue; the anionic surfactant AES has general alkali resistance and poor development performance. Comparative Example 5 significantly increases the ethylene oxide number, but at the same dilution multiple, it has large bubbles during the spraying process, and there is burrs at the same development time. In summary, the positive progress of the present invention is that by adding a special non-ionic surfactant and adjusting the addition amount of different ethylene oxide numbers, the developing performance of the developer can be significantly improved, with a moderate developing speed, clear graphics, complete edges, no photoresist residue, little foam, and a long service life.

[0061] The above embodiments describe the present invention in detail, but they are only examples and do not limit the patent scope of the present invention. Any equivalent modification and substitution of the present invention using the present description is also within the scope of the present invention and is included in the patent protection scope of the present invention.

Claims

1. A weak base developer composition for color filters, comprising the following components by mass percentage: 5-8% of an inorganic weak base, 10-11% of a special nonionic surfactant, 2-4% of a solubilizer, and the balance of water; The special nonionic surfactant is selected from the following structures: ； in, n is an integer of 5-15; wherein R is selected from any one of a hydrogen atom and a saturated alkyl group; The inorganic weak base is selected from any one or more of the following groups, including: sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate; The solubilizing agent is selected from any one or more of the following groups, including: Tween-80, Tween-20, sodium dodecylbenzene sulfonate, and polysorbate 80.

2. The weak alkaline developer composition for color filters according to claim 1, characterized in that: The specific preparation method is: adding an inorganic weak base to water, and then adding a special non-ionic surfactant and a solubilizer to form a uniform system at a stirring speed of 200 rpm to obtain a uniform, stable, clear and transparent composition.

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