Nitro-containing bisoxime ester photoinitiator and preparation method and use thereof

Abstract

This present invention discloses a nitro-containing bisoxime ester photoinitiator having a structure represented by general formula (I). This photoinitiator has excellent application performances in terms of storage stability, photosensitivity, developability, pattern integrity, etc., and it has good adaptability to single-wavelength UV-LED light sources and exhibits a photosensitive property, which is obviously superior to those of existing photoinitiators, under the irradiation of UV-LEDs. ##STR00001##

Claims

1. A nitro-containing bisoxime ester photoinitiator, having a structure represented by general formula (I): ##STR00028## wherein X and Y each independently represent a carbonyl (CO) or a single bond; Z is blank, a single bond, or a C.sub.1-C.sub.5 alkylene group; A is O, S, or a R.sub.5N group, wherein R.sub.5 represents hydrogen, a C.sub.1-C.sub.20 linear or branched alkyl group, a C.sub.3-C.sub.20 cycloalkyl group, a C.sub.4-C.sub.20 cycloalkylalkyl group, or a C.sub.4-C.sub.20 alkylcycloalkyl group; R.sub.1 represents hydrogen, halogen, a nitro group, a hydroxy group, a carboxyl group, a sulfonic acid group, an amino group, a cyano group, or an alkoxy group, or a C.sub.1-C.sub.20 linear or branched alkyl group, a C.sub.3-C.sub.20 cycloalkyl group, a C.sub.4-C.sub.20 cycloalkylalkyl group, or a C.sub.4-C.sub.20 alkylcycloalkyl group optionally substituted with one or more group selected from the group consisting of halogen, a nitro group, a hydroxy group, a carboxyl group, a sulfonic acid group, an amino group, a cyano group, and an alkoxy group; R.sub.2 and R.sub.3 each independently represent hydrogen, a C.sub.1-C.sub.20 linear or branched alkyl group, a C.sub.3-C.sub.20 cycloalkyl group, a C.sub.4-C.sub.20 cycloalkylalkyl group, a C.sub.4-C.sub.20 alkylcycloalkyl group, or a C.sub.7-C.sub.20 aralkyl group, and optionally, hydrogen in the above groups may be substituted with a group selected from the group consisting of halogen, a nitro group, a hydroxy group, a carboxyl group, a sulfonic acid group, an amino group, a cyano group, and an alkoxy group; R.sub.4 represents a C.sub.1-C.sub.20 linear or branched alkyl group, a C.sub.3-C.sub.20 cycloalkyl group, a C.sub.4-C.sub.20 cycloalkylalkyl group, a C.sub.4-C.sub.20 alkylcycloalkyl group, a C.sub.3-C.sub.20 heteroaryl group, or a C.sub.6-C.sub.20 aryl group, and optionally, hydrogen in the above groups may be substituted with a group selected from the group consisting of halogen, a phenyl group, a nitro group, a hydroxy group, a carboxyl group, a sulfonic acid group, an amino group, a cyano group, and an alkoxy group.

2. The nitro-containing bisoxime ester photoinitiator according to claim 1, wherein Z is blank, a single bond, a methylene group, an ethylene, or a propylene group.

3. The nitro-containing bisoxime ester photoinitiator according to claim 1, wherein A is O, S, or a R.sub.5N group, wherein R.sub.5 represents hydrogen, a C.sub.1-C.sub.10 linear or branched alkyl group, a C.sub.3-C.sub.15 cycloalkyl group, or a C.sub.4-C.sub.15 cycloalkylalkyl group.

4. The nitro-containing bisoxime ester photoinitiator according to claim 1, wherein R.sub.1 represents hydrogen, halogen, a nitro group, or a C.sub.1-C.sub.15 linear or branched alkyl group.

5. The nitro-containing bisoxime ester photoinitiator according to claim 1, wherein R.sub.2 and R.sub.3 each independently represent hydrogen, a C.sub.1-C.sub.15 linear or branched alkyl group, a C.sub.3-C.sub.15 cycloalkyl group, a C.sub.4-C.sub.15 cycloalkylalkyl group, a C.sub.4-C.sub.15 alkylcycloalkyl group, or a C.sub.7-C.sub.15 aralkyl group, and optionally, hydrogen in the above groups may be substituted with a group selected from the group consisting of halogen, a nitro group, and an alkoxy group.

6. The nitro-containing bisoxime ester photoinitiator according to claim 1, wherein R.sub.4 represents a C.sub.1-C.sub.10 linear or branched alkyl group, a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.4-C.sub.10 cycloalkylalkyl group, a C.sub.4-C.sub.10 alkylcycloalkyl group, a C.sub.3-C.sub.10 heteroaryl group, or a C.sub.6-C.sub.10 aryl group.

7. The nitro-containing bisoxime ester photoinitiator according to claim 1, wherein the nitro-containing bisoxime ester photoinitiator is selected from the group consisting of the following structures: ##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035##

8. A preparation method for the nitro-containing bisoxime ester photoinitiator of claim 1, comprising the step of: performing an esterification reaction between a compound containing a nitro-bisoximino group structure and an acid anhydride or acid halide containing a R.sub.4 group to obtain the nitro-containing bisoxime ester photoinitiator, the reaction shown as follows: ##STR00036## wherein B represents halogen.

Description

DESCRIPTION OF EMBODIMENTS

(1) Hereafter, this invention will be further illustrated in conjunction with specific Examples, but it is not to be understood that the scope of this invention is limited thereto.

PREPARATION EXAMPLE

Example 1

Preparation of 1-nitro-3-(1-oxime acetate)propyl-6-(1-oxime acetate-3-cyclohexyl)propyl-9-ethyl-carbazole

(2) ##STR00012##

(3) 23.2 g of 1-nitro-3-(1-ketoxime)propyl-6-(1-ketoxime-3-cyclohexyl)propyl-9-ethyl-carbazole, 100 g of dichloromethane, and 5.1 g of triethylamine were added into a 250 mL four-neck flask and were stirred at room temperature for 5 min, and then 11.3 g of acetic anhydride was dropped within about 30 min. Stirring was continued at room temperature for 2 h, and then 5% NaHCO.sub.3 aqueous solution was added to adjust pH value to become neutral. An organic layer was separated with a separation funnel, followed by washing twice with 200 mL of water and drying with 50 g of anhydrous MgSO.sub.4, and the solvent was evaporated by rotation to obtain a viscous liquid. Recrystallization with methanol obtained a white solid powder, which was filtered to obtain a product of 24.7 g with a yield of 90% and a purity of 99%.

(4) The structure of the product was determined by hydrogen nuclear magnetic resonance spectroscopy, and the specific characteristic result is as follows:

(5) .sup.1H-NMR(CDCl.sub.3, 500 MHz): 0.9015-1.0102 (3H, t), 1.3918-1.4714 (13H, m), 1.5073-1.5932 (3H, t), 2.1022 (6H, s), 2.5468-2.7029 (4H, m), 3.8210-3.9421 (2H, m), 7.0301-7.8127 (3H, m), 8.4301-8.6127 (2H, s).

Example 2

Preparation of 1,8-dinitro-3-(1,2-dione-2-oxime-O-benzoate-3-cyclobutyl)propyl-6-(1,2-dione-2-oxime-O-benzoate)propyl-9-ethyl-carbazole

(6) ##STR00013##

(7) 24.8 g of 1,8-dinitro-3-(1,2-dione-2-oxime-3-cyclobutyl)propyl-6-(1,2-dione-2-oxime)propyl-9-ethyl-carbazole, 100 g of dichloromethane, and 5.1 g of triethylamine were added into a 250 ml four-neck flask and were stirred at room temperature for 5 min, and then 14.3 g of benzoyl chloride was dropped within about 30 min. Stirring was continued at room temperature for 2 h, and then 5% NaHCO.sub.3 aqueous solution was added to adjust pH value to become neutral. An organic layer was separated with a separation funnel, followed by washing twice with 200 mL of water and drying with 50 g of anhydrous MgSO.sub.4, and the solvent was evaporated by rotation to obtain a viscous liquid. Recrystallization with methanol obtained a white solid powder, which was filtered to obtain a product of 20.9 g with a yield of 87% and a purity of 99%.

(8) The structure of the product was determined by hydrogen nuclear magnetic resonance spectroscopy, and the specific characteristic result is as follows:

(9) .sup.1H-NMR(CDCl.sub.3, 500 MHz): 1.4908-1.5193 (3H, t), 1.9037-2.1823 (7H, m), 2.5099-2.7629 (5H, m), 3.90732-4.0231 (2H, m), 7.4309-7.7098 (6H, t), 8.1067-8.2319 (4H, d), 8.3980-8.6678 (4H, s).

Examples 3-15

(10) Referring to the method illustrated in Example 1 or 2, compounds 3-15 shown in Examples 3-15 were prepared from a corresponding compound containing a nitro-bisoximino group structure

(11) ##STR00014##
and an acid halide compound or an acid anhydride.

(12) The structures of compounds of interest and .sup.1H-NMR data thereof were listed in Table 1.

(13) TABLE-US-00001 TABLE 1 Examples Compounds .sup.1H NMR [ppm] Example 3 1.4302-1.5547(12H,m) 2.1391(9H,s) 2.5349-2.6819(2H,d) 3.8790-3.9908(2H,m) 8.4450-8.7612(4H,s) Example 4 1.3908-1.5546(21H,m) 2.1987(6H,s) 2.6571-2.8719(4H,d) 3.7690-3.9908(2H,m) 8.3998-8.6971(4H,s) Example 5 0.9982-1.1034(6H,t) 1.3998-1.5051(13H,m) 1.7903-1.8234(2H,m) 2.0789 (6H,s) 2.6501-2.7836(4H,m) 3.7651-3.8957(2H,t) 8.2198-8.7891(4H,s) Example 6 1.0556-1.1239(6H,m) 1.4034-1.4689(11H,m) 1.7349-1.9734(3H,m) 2.1038(6H,s) 2.5987-2.8038(5H,m) 3.8890-3.9802(2H,d) 7.5298-8.6781(5H,m) Example 7 1.4098-1.5103(11H,m) 1.5203-1.7239(16H,m) 2.3452-2.4985(2H,m) 2.5617-2.8793(5H,m) 3.7721(3H,s) 7.4827-8.6723(5H,m) Example 8 0 1.3907-1.4572(11H,m) 1.5321-1.5932(3H,m) 2.4598-2.7893(5H,m) 3.8742-3.9804(2H,m) 7.4890-7.7693(9H,m) 8.0927-8.2186(4H,d) 8.4984-8.6739(2H,s) Example 9 1.4560-1.5237(14H,m) 2.5602-2.8739(5H,m) 3.8047-3.9901(2H,m) 7.4038-7.6566(6H,m) 8.0802-8.2231(4H,d) 8.3301-8.6902(4H,s) Example 10 1.4290-1.5545(14H,m) 2.5692-2.7178(5H,t) 3.8094-3.9842(2H,m) 7.4590-7.7345(9H,m) 8.0342-8.6783(6H,m) Example 11 1.4905-1.7037(24H,m) 2.3290-2.4012(2H,m) 2.4532(3H,s) 2.5632-2.7778(4H,m) 7.3089-8.5523(6H,m) Example 12 1.4880-1.7112(9H,m) 2.1998(6H,s) 2.5779-2.7691(5H,m) 8.7099-8.9067(4H,s) Example 13 0.9987-1.1592(21H,m) 1.2308-1.3376(6H,m) 1.5065-1.5539(2H,m) 1.6450-1.8390(5H,m) 2.5609-2.7765(8H,m) 3.3011-3.4087(5H,m) 7.1028-8.5692(6H,m) Example 14 0.9982-1.1022(6H,t) 2.0899(6H,s) 2.6758-2.7746(4H,m) 8.5344-8.7892(4H,s) Example 15 0.9896-1.9212(6H,t) 2.1221(6H,s) 2.7636-2.7659(4H,m) 7.0344-8.6548(5H,m)
Performance Evaluation

(14) By formulating exemplary photocurable compositions, respective application performances of the photoinitiators represented by the formula (I) of this invention, were evaluated, including aspects of storage stability, photosensitivity, developability, pattern integrity, etc.

(15) 1. Formulation of Photocurable Compositions

(16) (1) Uncolored Photocurable Composition A

(17) TABLE-US-00002 Acrylate copolymer 100 (Benzyl methacrylate/methacrylic acid/hydroxyethyl methacrylate (molar ratio of 70/10/20) copolymer (Mw: 10,000)) Trimethylolpropane triacrylate (TMPTA) 100 Photoinitiator 2 Butanone (solvent) 25

(18) (2) Colored Photocurable Composition B

(19) TABLE-US-00003 Acrylate copolymer 100 (Benzyl methacrylate/methacrylic acid/methyl methacrylate (molar ratio of 50/15/30) copolymer (Mw: 15,000)) Dipentaerythritol hexaacrylate 100 Photoinitiator 2 Butanone (solvent) 25 Dye blue 15 5

(20) In the compositions A and B described above, the photoinitiator was a nitro-containing bisoxime ester compound represented by the general formula (I) of this invention or a photoinitiator known in the prior art as a comparison, and the respective components were represented in parts by mass.

(21) 2. Development by Exposure

(22) (1) Development by Exposure after Film Coating Under Mercury Lamp Light Source

(23) The photocurable compositions A and B described above were stirred, respectively, under protection from light. Materials were taken on a PET template, film coating was performed with a wire bar, the solvent was removed by drying at 90 C. for 5 min, and a coating film with a film thickness of about 2 m was formed. The substrate on which the coating film was formed was cooled to room temperature, a mask plate was attached thereon, and a long wavelength irradiation was achieved with a high pressure mercury lamp 1PCS light source through a FWHM color filter. Exposure was performed on the coating film through a seam of the mask plate under an ultraviolet having a wavelength of 370-420 nm. Subsequently, development was performed by soaking in a 2.5% sodium carbonate solution at 25 C. for 20 s, followed by washing with ultra-pure water and air drying. The pattern was fixed by hard baking at 220 C. for 30 min, and the obtained pattern was evaluated.

(24) (2) Development by Exposure after Film Coating Under UV-LED Light Source

(25) The photocurable compositions A and B described above were stirred, respectively, under protection from light. Materials were taken on a PET template, film coating was performed with a wire bar, the solvent was removed by drying at 90 C. for 5 min, and a coating film with a film thickness of about 2 m was formed. The substrate on which the coating film was formed was cooled to room temperature, a mask plate was attached thereon, irradiation was performed with an LED point light source (model: UVEL-ET, Shenzhen Lamplic Technology Co., Ltd.), and exposure was performed on the coating film through a seam of the mask plate under a wavelength of 395 nm. Subsequently, development was performed by soaking in a 2.5% sodium carbonate solution at 25 C. for 20 s, followed by washing with ultra-pure water and air drying. The pattern was fixed by hard baking at 220 C. for 30 min, and the obtained pattern was evaluated.

(26) 3. Performance Evaluation of Photocurable Compositions

(27) (1) Storage Stability

(28) After naturally storing a liquid-state photocurable composition at room temperature for 1 month, the degree of precipitation of substances was visually evaluated according to the following criteria:

(29) A: No precipitation was observed;

(30) B: Precipitation was slightly observed;

(31) C: Significant precipitation was observed.

(32) (2) Photosensitivity

(33) Upon exposure, the minimum exposure amount of the irradiated region having a residual film rate of 90% or more after development in the step of exposure was evaluated as the demand of exposure. A smaller exposure demand represents a higher sensitivity.

(34) (3) Developability and Pattern Integrity

(35) The pattern on the substrate was observed using a scanning electron microscope (SEM) to evaluate the developability and the pattern integrity.

(36) The developability was evaluated according to the following criteria:

(37) : No residue was observed in unexposed portions;

(38) : A small amount of residue was observed in unexposed portions, but the residue is acceptable;

(39) .circle-solid.: Significant residue was observed in unexposed portions.

(40) The pattern integrity was evaluated according to the following criteria:

(41) : No pattern defects were observed;

(42) : A few defects were observed in some portions of the pattern;

(43) .diamond-solid.: A number of defects were significantly observed in the pattern.

(44) Evaluation results were as shown in Tables 2-5:

(45) TABLE-US-00004 TABLE 2 Performance evaluation of photocurable composition A(Measurement of demand of exposure, developability, and pattern integrity under irradiation condition of mercury lamp light source) Demand of Storage exposure Devel- Pattern Photoinitiator stability mJ/cm.sup.2 opability integrity Example Compound 1 A 52 Compound 2 A 51 Compound 5 A 51 Compound 6 A 39 Compound 9 A 33 Compound 10 A 32 Compound 12 A 35 Compound 15 A 40 Comparative Comparative A 65 Example compound 1 Comparative A 60 compound 2 Comparative A 70 compound 3 Comparative B 105 .diamond-solid. compound 4 Comparative B 85 .diamond-solid. compound 5 Comparative C 160 .diamond-solid. compound 6

(46) TABLE-US-00005 TABLE 3 Performance evaluation of photocurable composition A(Irradiation of LED light source) Demand of exposure Devel- Pattern Photoinitiator mJ/cm.sup.2 opability integrity Example Compound 1 49 Compound 2 36 Compound 5 47 Compound 6 47 Compound 9 30 Compound 10 29 Compound 12 30 Compound 15 34 Comparative Comparative 270 .diamond-solid. Example compound 1 Comparative 254 .diamond-solid. compound 2 Comparative 300 .diamond-solid. compound 3 Comparative 368 .diamond-solid. compound 4 Comparative 312 .diamond-solid. compound 5 Comparative >500, still .diamond-solid. compound invalid 6

(47) TABLE-US-00006 TABLE 4 Performance evaluation of photocurable composition B(Measurement of demand of exposure, developability, and pattern integrity under irradiation condition of mercury lamp light source) Demand of Storage exposure Devel- Pattern Photoinitiator stability mJ/cm.sup.2 opability integrity Example Compound 1 A 57 Compound 2 A 42 Compound 5 A 54 Compound 6 A 53 Compound 9 A 36 Compound 10 A 35 Compound 12 A 36 Compound 15 A 39 Comparative Comparative A 72 Example compound 1 Comparative A 68 compound 2 Comparative A 88 compound 3 Comparative B 117 .diamond-solid. compound 4 Comparative B 98 .diamond-solid. compound 5 Comparative C 176 .diamond-solid. compound 6

(48) TABLE-US-00007 TABLE 5 Performance evaluation of photocurable composition B(Irradiation of LED light source) Demand of exposure Devel- Pattern Photoinitiator mJ/cm.sup.2 opability integrity Example Compound 1 50 Compound 2 37 Compound 5 48 Compound 6 48 Compound 9 30 Compound 10 30 Compound 12 32 Compound 15 35 Comparative Comparative 282 .diamond-solid. Example compound 1 Comparative 267 .diamond-solid. compound 2 Comparative 302 .diamond-solid. compound 3 Comparative 372 .diamond-solid. compound 4 Comparative 314 .diamond-solid. compound 5 Comparative >500, still .diamond-solid. compound invalid 6

(49) In Tables 2-5, Comparative compound 1 represents a photoinitiator, 1-{4-[4-(2-thiophenecarbonyl)phenylthio]phenyl}-(3-cyclopentyl)-propane-1-ketoxime-O-acetate, disclosed in CN102492060A; Comparative compound 2 represents a photoinitiator, 1-[6-(2-thiophenecarbonyl)-9-ethylcarbazol-3-yl]-3-cyclopentyl-propane-1,2-dione-2-oxime-O-acetate, disclosed in CN103130919A; Comparative compound 3 represents a photoinitiator, 1-(6-o-methyl benzoyl-9-ethylcarbazol-3-yl)-(3-cyclopentylacetone)-1-oxime-acetate, disclosed in CN101508744A; Comparative compound 4 represents a photoinitiator, 1-(4-phenylthio-phenyl)-octan-1,2-dione-2-oxime-O-benzoate, disclosed in CN1241562A; Comparative compound 5 represents a photoinitiator, 1-(6-o-methyl benzoyl-9-ethylcarbazol-3-yl)-(3-ethanone)-1-oxime-acetate, disclosed in CN1514845A; and Comparative compound 6 represents a commonly-used photoinitiator, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-propane-1-one (commonly known as Irgacure907).

(50) It can be seen from the results of Tables 2-5 that the photocurable compositions comprising the nitro-containing bisoxime ester photoinitiator represented by the general formula (I) of this invention have good storage stability, and either under the condition of conventional high-pressure mercury lamp light source or under the condition of UV-LED light source, these photocurable compositions (including colorless systems and pigment systems) exhibit extremely good photosensitivity, developability, and pattern integrity, and have excellent application effects. However, the six existing photoinitiators as comparisons have obvious shortages. They not only have no advantage under the excitation condition of mercury lamps, but also can be hardly matched with UV-LED light sources. Therefore, it is not possible to initiate polymerization or the efficiency for initiating polymerization is particularly low. The nitro-containing bisoxime ester photoinitiator represented by the general formula (I) of this invention has a photosensitive property, which is obviously superior to those of existing photoinitiators, under the irradiation of UV-LEDs having single wavelengths.

(51) In summary, the nitro-containing bisoxime ester photoinitiator represented by the general formula (I) disclosed by this invention has excellent application performances and has good adaptability to UV-LED light sources, which can greatly improve performances of photocured products and has good promotion effects on the generalization and application of UV-LED light sources in the field of photocuring.