Quantitative analysis method for monomer of photoresist binder

Abstract

A quantitative analysis method for a monomer of a color filter (CF) photoresist (PR) binder for a thin film transistor-liquid crystal display (TFT-LCD), performs quantitative analysis on a monomer of a CF PR binder for a RFT-LCD by using a Py-GC/MS used for qualitative analysis.

Claims

1. A method for quantitative analysis of monomers in a photoresist (PR) binder obtained by polymerization of four or more monomers, comprising: (1) preparing a binder as a standard obtained by polymerization of same kind of monomers as those comprised in the PR binder; (2) subjecting each of the standard prepared in the step (1) and the PR binder into Py-GC/MS analysis to obtain analysis results; and (3) normalizing the analysis results of the step (2) to determine weight ratios of the two or more monomers in the PR binder, wherein the normalizing comprises measuring area % of each of the monomers and substituting the area % of the monomers into a calibration curve, wherein the four or more monomers are selected from benzyl methacrylate (BzMA), Nphenylmaleimide (N-PM), styrene, lauryl methacrylate (LMA), cyclohexyl methacrylate (CHMA), methyl methacrylate (MMA), and 2-hydroxypropane-1,3-diylbis(2-methylacrylate)(reactive methacrylate, RMA).

2. The method of claim 1, wherein the Py-GC/MS analysis is performed at a pyrolyzer temperature of 500 to 700° C.

3. The method of claim 1, wherein during the performing of the Py-GC/MS analysis, a GC oven temperature is maintained at 50 to 60° C. for 3 to 10 minutes, and then increased to 300 to 350° C. at a rate of 10 to 15° C./min, and finally maintained at 300 to 350° C. for 5 to 20 minutes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the kind of monomers contained in a linear binder among photoresist (PR) binders.

(2) FIG. 2 shows the kind of monomers contained in a reactive binder among the PR binders.

(3) FIG. 3 shows a calibration curve of normalized area (%) versus the feeding ratio of monomers in binder A (consisting of benzyl methacrylate (BzMA). N-phenylmaleimide (N-PMI) and styrene) in accordance with the present invention.

BEST MODE

(4) Hereinafter, the present invention will be described in detail.

(5) It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation.

(6) The present invention relates to an analysis method which comprises analysis of a photoresist (PR) binder via Py-GC/MS by using a standard having the same two or more monomers as the PR binder to be analyzed and each contend thereof being confirmed and normalization of the analyzed results to quantitatively identify the weight ratios of the two or more monomers in the PR binder.

(7) Generally, the Py-GC/MS has been applied only in qualitative analysis to determine the composition of several pyrolysates produced by the pyrolysis mechanism of polymers and to determine monomer components constituting polymers. The composition of monomers in the binder has been analyzed by using NMR, which has limitations as the monomer components are complicated.

(8) The present invention investigates the Py-GC/MS in quantitative aspect and attains information on pyrolysis efficiency to develop a method for analyzing the content of monomers in a photoresist binder, which can be variously utilized in general laboratories.

(9) Therefore, the present invention provides a method for quantitative analysis of monomers in a PR binder obtained by polymerization of two or more monomers, which comprises the steps of: (1) preparing a binder obtained by polymerization of the same monomers as the PR binder as a standard; (2) analyzing the standard prepared in the step (1) and the PR binder by using Py-GC/MS; and (3) normalizing the analysis results of the step (2) to determine the weight ratios of the two or more monomers in the PR binder.

(10) In one embodiment, the monomers in the PR binder may comprise acrylate monomer or methacrylate monomer, for example two or more monomers selected from the group consisting of ethyl hexyl acrylate (EHA), butyl acrylate (BA), methyl acrylate (MA), ethyl acrylate (EA), ethyl hexyl methacrylate (EHMA), butyl methacrylate (BMA), methyl methacrylate (MMA), ethyl methacrylate (EMA), benzyl methacrylate (BzMA), N-phenylmaleimide (N-PMI), styrene, lauryl methacrylate (LMA), cyclohexyl methacrylate (CHMA), methyl methacrylate (MMA), and 2-hydroxypropane-1,3-diyl bis(2-methylacrylate) (reactive methacrylate, RMA).

(11) In one embodiment, a linear binder among the PR binders is subject to radical polymerization by a single step reaction, and a reactive binder reacts a part of MMA in the linear binder with the epoxy of glycidyl methacrylate (GMA) by a 2-step reaction to introduce a reactive site.

(12) In the standard prepared in the step (1), its ratios of two or more monomers may be the same or different from that of the PR binder to be analyzed.

(13) The Py-GC/MS analysis in the step (2) is not particularly limited if it is performed by an analyzer being conventionally used for gas chromatography and mass spectrometry. The Py-GC/MS analysis in the step (2) may be performed at a pyrolyzer temperature of 500 to 700° C. according to one embodiment, or 550 to 650° C. according to other embodiment. In the Py-GC/MS analysis in the step (2), the temperature of a GC oven may be maintained at 50 to 60° C. for 3 to 10 minutes, and then increased to 300 to 350° C. at a rate of 10 to 15° C./min, and finally maintained at 300 to 350° C. for 5 to 20 minutes.

(14) The pyrolysis mechanism of the PR binder is divided into depolymerization, chain cleavage, elimination and the like. Particularly, when the methacrylate binder is subject to depolymerization, its monomer components decomposed can be detected to analyze the composition of the binder resin.

(15) The pyrolysis rate obtained by depolymerization as the pyrolysis mechanism of the PR binder to be analyzed may varied depending on the ratios of two or more monomers constituting the PR binder.

(16) Considering the above matters, the quantitative analysis of monomers in a PR binder according to the present invention uses a PR binder having the same two or more monomers as the PR binder to be analyzed as a standard and obtains the precise content ratio of the monomers by using Py-GC/MS analysis.

(17) Hereinafter, the present invention will be described in more detail with reference to Examples. It will be apparent to those skilled in the art that the following examples are intended to be illustrative of the present invention and not to be construed as limiting the scope of the invention.

EXAMPLE

(18) 1. Composition of Monomers in PR Binder Samples

(19) In this example, 3 linear binders and 3 reactive binders having monomer compositions as shown in Table 1 below were analyzed.

(20) TABLE-US-00001 TABLE 1 Information of PR 6 binders Monomer feeding ratio (wt %) Analysis Bzma.sup.1) N-PMI.sup.2) Styrene LMA.sup.3) CHMA.sup.4) MMA.sup.5) RMA.sup.6) Linear Binder A 78.0 12.8 9.3 — — — — binder Binder B 56.7 9.3 6.7 27.3 — — — Binder C — — — — 71.6 28.4 — Reactive Binder D 86.2 — — — — — 13.8 binder Binder E 17.2 32.3 19.4 — — 9.8 20.4 Binder F — — — — 48.9 4.4 45.6 .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide, .sup.3)lauryl methacrylate, .sup.4)cyclohexyl methacrylate .sup.5)methyl methacrylate, .sup.6)2-hydroxypropane-1,3-diyl bis(2-methylacrylate)

(21) The structures of monomers constituting the PR binder were shown in Table 2 below and FIGS. 1 and 2.

(22) TABLE-US-00002 TABLE 2 # Structure 1 BzMA 2 N-PMI 3 Styrene 4 RMA 5 LMA 6 CHMA 7 MMA

(23) 2. Preparation of Samples

(24) For each of PR binders A to F, three different standards 1, 2 and 3 were prepared by using the same kinds of monomers in their different contents. Three standards for each PR binder were exhibited to have monomer compositions and contents shown in Tables 3 to 8 below.

(25) TABLE-US-00003 TABLE 3 Monomer feeding ratio (wt %) in Standard for Binder A BzMA.sup.1) N-PMI.sup.2) styrene 1 64 21 15 2 78 13 9 3 88 7 6 .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide

(26) TABLE-US-00004 TABLE 4 Monomer feeding ratio (wt %) in Standard for Binder B BzMA.sup.1) N-PMI.sup.2) styrene LMA.sup.3) 1 29 14 9 47 2 57 9 7 27 3 78 6 3 13 .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide, .sup.3)lauryl methacrylate

(27) TABLE-US-00005 TABLE 5 Monomer feeding ratio (wt %) in Standard for Binder C CHMA.sup.1) MMA.sup.2) 1 84 16 2 72 28 3 43 57 .sup.1)cyclohexyl methacrylate, .sup.2)methyl methacrylate

(28) TABLE-US-00006 TABLE 6 Monomer feeding ratio (wt %) in Standard for Binder D BzMA.sup.1) RMA.sup.2) 1 79 21 2 87 13 3 94 6 .sup.1)benzyl methacrylate, .sup.2)2-hydroxypropane-1,3-diyl bis(2-methylacrylate)

(29) TABLE-US-00007 TABLE 7 Monomer feeding ratio (wt %) in Standard for Binder E BzMA.sup.1) N-PMI.sup.2) Styrene MMA.sup.3) RMA.sup.4) 1 34 25 16 17 9 2 17 32 20 10 20 3 51 12 8 4 25 .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide, .sup.3)methyl methacrylate, .sup.4)2-hydroxypropane-1,3-diyl bis(2-methylacrylate)

(30) TABLE-US-00008 TABLE 8 Monomer feeding ratio (wt %) in Standard for Binder F CHMA.sup.1) MMA.sup.2) RMA.sup.3) 1 47 14 39 2 49 5 46 3 44 31 26 .sup.1)cyclohexyl methacrylate, .sup.2)methyl methacrylate, .sup.3)2-hydroxypropane-1,3-diyl bis(2-methylacrylate)

(31) 3. Analysis Methods and Conditions

(32) (1) NMR (Nuclear Magnetic Resonance) Analysis

(33) Bruker AvanceIII HD 700 MHz NMR spectrometer equipped with 5 mm PABBO probe was used for proton NMR experiments. As the pretreatment, 10 mg of the sample was put in a vial and 0.75 mL of acetone-d6 as a solvent was added thereto to dissolve the sample. The resultant solution was transferred into an NMR tube for experiments. The experiments were performed under the conditions of zg30 pulse sequence and 32 times scan with 5 seconds of relaxation delay time. An elemental analysis was carried out by accurately measuring 1.3 to 1.5 mg of each sample into a Sn sample cup and using Flash 2000 (Thermo Fisher Scientific) as an elemental analyzer under the operation conditions of 1060° C. as a furnace temperature, 65° C. as an oven temperature, and 140 ml/min as a flow rate.

(34) (2) Py-GC/MS (Pyrolysis-Gas Chromatography/Mass Spectrometry) Analysis

(35) For Py-GC/MS, the pyrolysis of the sample was performed in a furnace being maintained to 600° C., and then the sample was analyzed by using Ultra ALLOY-5 (5% diphenyl-95% dimethylpolysiloxane) metal column (0.25 mm I.D.×30 m L., 0.25 μm of coated film thickness, Frontier Laboratories) connected to Agilent 7890A GC system equipped with a pyrolyzer and 5975C inert XL mass selective detector (MSD). Specifically, the sample was left on a GC oven set at 50° C. for 5 minutes and the temperature of the oven was increased to 320° C. at a rate of 10° C./min to give chromatograms under the conditions: 1 mL/min of flow rate of He (carrier gas); 1/50 of split ratio of injector; 300° C. of injector, oven and interface temperature of GC/MS; 320° C. of interface temperature of the pyrolyzer and 20 to 600 m/z of MSD scan mode. The 3 standards for each PR binder were tested and a calibration curve for each monomer was given. About 1 mg of the binder was measured with a micro-balance, transferred to a sample cup, and subjected to Py-GC/MS analysis.

(36) The area % of the detected monomers was substituted into the calibration curve, and the content of each monomer was determined and normalized to obtain the weight ratios of the monomers.

(37) (3) Elemental Analysis by EA (Elemental Analyzer)

(38) An elemental analysis was carried out by accurately measuring 1.3 to 1.5 mg of each sample into a Sn sample cup and using Flash 2000 (Thermo Fisher Scientific) as an elemental analyzer under the operation conditions of 1060° C. as a furnace temperature, 65° C. as an oven temperature, and 140 ml/min as a flow rate.

Example 1

(39) For a PR binder containing benzyl methacrylate (BzMA), N-phenylmaleimide (N-PMI) and styrene monomers, 3 standards and a sample of binder A were taken in the amount of 0.5 mg, 1 mg, 1.5 mg and 2 mg, respectively, and then tested after accurately weighing their weight up to 0.1 mg unit. By using Py-GC/MS (pyrolyzer temperature: 600° C.), the area % of each monomer was measured and the measured values were substituted into the calibration curve to normalize the values. The results thereof were shown in Tables 9 and 10 below.

(40) TABLE-US-00009 TABLE 9 Result of Normalization for Monomers in Binder A Normalization Area % styrene BzMA.sup.1) N-PMI.sup.2) Standard 1 26.69 72.45 0.86 Standard 2 15.76 82.83 1.41 Standard 3 1.48 96.71 1.81 .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide

(41) TABLE-US-00010 TABLE 10 Results of Feeding Ratio in Binder A Styrene BzMA.sup.1) N-PMI.sup.2) Feeding Normal- Feeding Normal- Feeding Normal- Ratio ization Ratio ization Ratio ization Standard 1 15 26.69 64 72.45 21 0.86 Standard 2 9 15.76 78 82.83 13 1.41 Standard 3 6 1.48 88 96.71 7 1.81 .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide

(42) Based on FIG. 3 showing a calibration curve of normalized area (%) versus the feeding ratio of the monomers, the 3 standards were subject to quantitative analysis to obtain recovery ratios and errors for the samples of PR binder whose feeding ratios were confirmed. As shown in Table 11 below, the error range between the recovery ratios of BzMA, N-PMI and styrene which are monomers of the PR binder A and the feeding ratios thereof was found to be from 0.4% to maximum 8.1%.

(43) TABLE-US-00011 TABLE 11 Error between Recovery Ratio and Feeding Ratio in PR Binder Styrene BzMA.sup.1) N-PMI.sup.2) Recovery Ratio 10.0% 77.7% 12.3% Feeding Ratio 9.2% 78.0% 12.8% Error 8.1% 0.4% 3.7% .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide

Example 2: Results of Quantitative Analyses by Using Py-GC/MS. NMR and NMR+EA Methods

(44) This example performed quantitative analyses for total 6 samples of linear binders and reactive binders, and the results from each analysis method were shown in Table 12 below. For the binders C, D and F, it was confirmed that the NMR method provided less error than the Py-GC/MS method. For the binders A, B and E, it was confirmed that the Py-GC/MS method provided less error than the NMR method.

(45) From these results, it can be seen that the Py-GC/MS method is more suitable for a binder containing four or more monomers. The EA method was used to calibrate the content of N in NMR calculations (NMR+EA method).

(46) TABLE-US-00012 TABLE 12 Recovery Ratio and Error of Monomers in 6 Binder Samples by Analysis of Py-GC/MS, NMR and NMR + EA Analysis Monomer (wt %) (deviation) Sample Method Bzma.sup.1) N-PMI.sup.2) Styrene LMA.sup.3) CHMA.sup.4) MMA.sup.5) RMA.sup.6) Binder Feeding 78.0 12.8 9.2 — — — — A Ratio Py-GC/MS 77.7 (0.4) 12.3 (3.7) 10.0 (8.1) — — — — NMR 76.4 (2.0) 16.2 (27.1) 7.4 (20.5) — — — — NMR + EA 77.0 (1.3) 14.5 (13.5) 8.5 (7.8) — — — — Binder Feeding 56.7 9.3 6.7 27.3 — — — B Ratio Py-GC/MS 61.5 (8.5) 9.4 (1.2) 7.3 (8.3) 21.8 (20.1) — — — NMR 56.2 (0.8) 12.9 (39.3) 7.8 (15.9) 23.1 (15.5) — — — NMR + EA 56.1 (0.9) 13.0 (39.7) 7.7 (14.9) 23.2 (15.2) — — — Binder Feeding — — — — 71.6 28.4 — C Ratio Py-GC/MS — — — — 67.6 (5.5) 32.4 (14.0) — NMR — — — — 71.5 (0.2) 28.5 (0.4) — Binder Feeding 86.2 — — — — — 13.8 D Ratio Py-GC/MS 85.4 (1.0) — — — — — 14.6 (6.1) NMR 86.6 (0.4) — — — — — 13.4 (2.7) Binder Feeding 17.4 32.6 19.5 — — 9.9 20.6 E Ratio Py-GC/MS 17.5 (0.5) 32.6 (0.0) 20.7 (5.7) — — 8.9 (9.5) 20.3 (1.4) NMR 17.0 (2.3) 39.9 (22.5) 17.3 (11.5) — — 7.9 (20.1) 17.9 (13.0) NMR + EA 17.4 (0.1) 34.8 (6.9) 21.3 (8.8) — — 8.0 (18.8) 18.5 (10.1) Binder Feeding — — — — 49.4 4.5 46.1 F Ratio Py-GC/MS — — — — 52.4 (6.1) 4.8 (6.3) 42.8 (7.1) NMR — — — — 52.3 (5.9) 4.4 (2.7) 43.3 (6.1) .sup.1)benzyl methacrylate, .sup.2)N-phenylmaleimide, .sup.3)lauryl methacrylate, .sup.4)cyclohexyl methacrylate .sup.5)methyl methacrylate, .sup.6)2-hydroxypropane-1,3-diyl bis(2-methylacrylate)

(47) While the present invention has been particularly shown and described with reference to figures and embodiments thereof, it will be understood by those of ordinary skill in the art that the scope of the present invention is not limited thereby and that various changes and modifications may be made therein. Therefore, the actual scope of the present invention will be defined by the appended claims and their equivalents.