Dibutylfluorene derivative and application thereof as photoinitiator

Abstract

The present invention provides a dibutylfluorenyl derivative, an application of same as a photoinitiator, and a preparation method therefor. The present invention provides a photocuring composition including the compound and a photocuring method using the composition.

Claims

1. A photocuring composition, comprising: (a) a photoinitiator compound having the following formula: ##STR00008## and (b) a photopolymerizable carbon-carbon double bond unsaturated compound.

2. The photocuring composition according to claim 1, wherein the photoinitiator compound accounts for 0.5-10% by weight of the composition.

3. The photocuring composition according to claim 1, wherein the carbon-carbon double bond unsaturated compound is an ester of ethylenically unsaturated carboxylic acid and a polyol or an ester of ethylenically unsaturated carboxylic acid and polyepoxide.

4. The photocuring composition according to claim 1, further comprising a reactive amine co-initiator wherein the amine co-initiator accounts for 0.5-10% by weight of the composition.

5. The photocuring composition according to claim 1, comprising: TABLE-US-00007 epoxy acrylate about 35% reactive amine co-initiator about 7% trimethylolpropane triacrylate about 55% and photoinitiator about 3%, wherein the percentage is the weight ratio of said component in the composition.

6. The photocuring composition according to claim 1, wherein the photocuring composition is used for manufacturing colored and non-colored paints and varnishes, a powder coating, a printing ink, a printing plate, an adhesive, a dental composition, a gel coating, a photoresist for electronics, an electroplating resist, liquid and dry films, a solder resist, a resist for a color filter for display application, a structural resist produced in a manufacturing process for a plasma display panel, an electroluminescent display, and an LCD, an LCD spacer, used for holographic data storage, used as a composition for encapsulating electrical and electronic elements, used for manufacturing a magnetic recording material, a micromechanical component, an optical switch, an electroplating mask, an etching mask, a color proofing system, a glass fiber cable coating, and a screen printing stencil, used for generating a three-dimensional object by means of stereolithography, used as an image recording material, used for holographic recording, used for manufacturing a microelectronic circuit and a decolorizing material, and used for an image recording material using microcapsules.

7. The photocuring composition according to claim 1, comprising coating the photocuring composition on a substrate, and performing irradiation with light having a wavelength of 150-600 nm.

8. A photoinitiator compound having the following formula: ##STR00009##

9. A method for preparing the compound of the following formula: ##STR00010## comprising the following steps: ##STR00011##

10. The method according to claim 9, wherein step (5) comprises: mixing 2-methyl-l-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide and morpholine; undergoing a reflux reaction for about 20 hours while stirring; reducing the pressure to distill off excess morpholine; adding methanol to dissolve the residue; and after heating and dissolving, standing and cooling.

11. The photocuring composition according to claim 2, further comprising a reactive amine co-initiator wherein the amine co-initiator accounts for 0.5-10% by weight of the composition.

12. The photocuring composition according to claim 3, further comprising a reactive amine co-initiator wherein the amine co-initiator accounts for 0.5-10% by weight of the composition.

13. The photocuring composition according to claim 2, wherein the photocuring composition is used for manufacturing colored and non-colored paints and varnishes, a powder coating, a printing ink, a printing plate, an adhesive, a dental composition, a gel coating, a photoresist for electronics, an electroplating resist, liquid and dry films, a solder resist, a resist for a color filter for display application, a structural resist produced in a manufacturing process for a plasma display panel, an electroluminescent display, and an LCD, an LCD spacer, used for holographic data storage, used as a composition for encapsulating electrical and electronic elements, used for manufacturing a magnetic recording material, a micromechanical component, an optical switch, an electroplating mask, an etching mask, a color proofing system, a glass fiber cable coating, and a screen printing stencil, used for generating a three-dimensional object by means of stereolithography, used as an image recording material, used for holographic recording, used for manufacturing a microelectronic circuit and a decolorizing material, and used for an image recording material using microcapsules.

14. The photocuring composition according to claim 13, wherein the photoinitiator compound accounts for 0.5-10% by weight of the composition.

15. The photocuring composition according to claim 13, wherein the carbon-carbon double bond unsaturated compound is an ester of ethylenically unsaturated carboxylic acid and a polyol or an ester of ethylenically unsaturated carboxylic acid and polyepoxide.

16. The photocuring composition according to claim 13, further comprising a reactive amine co-initiator wherein the amine co-initiator accounts for 0.5-10% by weight of the composition.

17. The photocuring composition according to claim 13, comprising: TABLE-US-00008 epoxy acrylate about 35% reactive amine co-initiator about 7% trimethylolpropane triacrylate about 55% and photoinitiator about 3%, wherein the percentage is the weight ratio of said component in the composition.

18. The photocuring composition according to claim 2, comprising coating the photocuring composition on a substrate, and performing irradiation with light having a wavelength of 150-600 nm.

19. The photocuring composition according to claim 2, wherein the photoinitiator compound accounts for 3% by weight of the composition.

20. The photocuring composition according to claim 4, wherein the reactive amine co-initiator comprises a water-soluble tertiary amine, and the amine co-initiator accounts for 7% by weight of the composition.

Description

DETAILED DESCRIPTION

(1) The following embodiments help to further understand the present invention, but are not used to limit the content of the present invention.

Embodiment 1 Synthesis of 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone

(2) The synthesis route of 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone is as follows:

(3) ##STR00006##

Step (1) Synthesis of 9,9-dibutylfluorene

(4) 12 mmol (1.99 g) of fluorene, 0.5 mmol (0.16 g) of phase transfer catalyst tetra-n-butylammonium bromide, 4.5 mL of 50% aqueous sodium hydroxide solution, 29 mmol (3.1 mL) of n-butyl bromide, and 50 mL of butanone are respectively added to a 100 mL three-necked flask. Heating and reflux are performed for 3-4 hours, and the reaction is followed by means of thin-layer chromatography until the reaction is ended. After the solvent butanone is distilled off, extraction is performed with dichloromethane (10 mL×3 times). Organic layers are combined, drying is performed with anhydrous sodium sulfate, and the solvent is removed by rotary evaporation to obtain a target product.

Step (2) Synthesis of 2-(2-methylpropionyl)-9,9-dibutylfluorene

(5) 0.01 mol (1.0 mL) of isobutyryl chloride, 0.01 mol (2.78 g) of 9,9-dibutylfluorene, and 40 mL of dichloromethane are respectively added to a 250 mL three-necked flask. Mixing is performed uniformly while magnetically stirring, and cooling is performed in an ice bath. Under magnetic stirring, a total of 0.012 mol (1.58 g) of aluminum trichloride is added in two portions at 10° C. or less, then the temperature is raised to room temperature and stirring is performed for 3 hours, and then the temperature is raised to 40° C. and stirring is continued for 1 hour. The reaction mixture is slowly poured into 100 g of ice water while stirring. After standing and layering, the water layer is separated and removed, and the organic layers are washed with ice water (30 mL×3 times), and is basically neutral. After drying, dichloromethane is removed to obtain a target product.

Step (3) Synthesis of 2-(2-bromo-2-methylpropionyl)-9,9-dibutylfluorene

(6) 50 mL of methylene chloride, 15 mL of 80% sulfuric acid, 0.20 mol of hydrogen peroxide, and 0.10 mol (34.85 g) of 2-(2-methylpropionyl)-9,9-dibutylfluorene are added to a 250 mL three-necked flask. The temperature is controlled at 25-30° C., and 0.07 mol (3.6 mL) of bromine is added dropwise within 1.0-1.5 hours. After bromine is added dropwise for 20 minutes, HPLC detects that 2-(2-methylpropionyl)-9,9-dibutylfluorene reacts completely. Under cooling, 30% sodium hydroxide solution is added dropwise while stirring to neutralize the reaction mixture until the pH value is neutral. Standing and layering are performed. The water layer is extracted with dichloromethane (20 mL×2 times). Organic layers are combined, and drying and rotary distillation are performed to remove the solvent methylene chloride to obtain a target product.

Step (4) Synthesis of 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide

(7) 50 mL of anhydrous methanol and 0.12 mol (2.76 g) of sodium metal are added to a 250 mL three-necked flask to prepare a methanol solution of sodium methoxide. The temperature is controlled at 25-30° C., and 0.10 mol (4.27 g) of 2-(2-bromo-2-methylpropionyl)-9,9-dibutylfluorene is added in three batches within 1.5-2.0 hours. After the addition is ended, the reaction is continued for 1 hour. After HPLC detects that 2-(2-bromo-2-methylpropionyl)-9,9-dibutylfluorene reacts completely, rotary distillation is performed at 60° C. to remove the solvent methanol and cooling is performed to obtain a white solid. The product is not purified and directly undergoes further reaction.

Step (5) Synthesis of 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone

(8) Method 1: 3.67 g (10.0 mmol) of the product 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide of the reaction in step (4) is added to a 100 mL reaction flask, 2.61 g (30.0 mmol) of morpholine is added, reaction is undergone for 20 hours while stirring at 120-130° C. After the tracking of the reaction by means of thin-layer chromatography is ended, the pressure is reduced to distill off excess solvents such as morpholine, and then separation and purification are performed by means of column chromatography by using petroleum ether-ethyl acetate as a mobile phase to obtain 3.63 g of the target compound 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone, with the yield being 83.7%. 1H NMR (400 MHz, CDCl.sub.3) δ: 8.74 (d, J=0.8 Hz, 1H), 8.48 (dd, J1=8.0 Hz, J2=0.8 Hz, 1H), 7.78-7.73 (m, 2H), 7.39-7.37 (m, 3H), 3.74 (t, J=4.8 Hz, 4H), 2.66-2.64 (m, 4H), 2.05-2.00 (m, 4H), 1.59 (s, 6H), 1.13-1.06 (m, 4H), 0.69-0.60 (m, 10H); 13C NMR (100 MHz, CDCl3) δ: 202.9, 151.9, 149.8, 145.2, 140.0, 129.6, 128.1, 127.0, 125.0, 123.0, 120.6, 119.0, 76.9, 67.4, 55.0, 47.1, 40.1, 26.0, 23.0, 20.4, 13.8. ESRMs m/z=434.3 [M+H]+.

(9) According to nuclear magnetic resonance spectrum (hydrogen spectrum and carbon spectrum) and mass spectrometry results, the product is determined as the target product, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone.

(10) Method 2: 7.33 g (20.0 mmol) of the product 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide of the reaction in step (4) is added to a 100 mL reaction flask, 4.35 g (50.0 mmol) of morpholine is added, and reflux reaction is undergone for 20 hours while stirring. After the tracking of the reaction by means of thin-layer chromatography is ended, the pressure is reduced to distill off the excess morpholine, methanol is added to dissolve the residue, heating is performed to completely dissolve the residue, and standing and cooling are performed to obtain 7.14 g of the target product, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone, with the yield being 82.3%.

(11) Nuclear magnetic resonance spectrum (hydrogen spectrum and carbon spectrum) and mass spectrometry results are the same as those in Synthesis Method 1, i. e., the product is the target product, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone.

(12) Method 3: 7.33 g (20.0 mmol) of the product 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide of the reaction in step (4) is added to a 100 mL reaction flask, 1.74 g (20.0 mmol) of morpholine and 10 mL of N,N-dimethylformamide are added, and reflux reaction is undergone for 20 hours while stirring.

(13) Post-treatment is the same as that in Synthesis Method 2.5.04 g of the target product, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone is obtained, with the yield being 58.1%.

(14) Method 4: 7.33 g (20.0 mmol) of the product 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide of the reaction in step (4) is added to 100 mL reaction flask, 1.74 g (100.0 mmol) of morpholine is added, and a reflex reaction is undergone for 20 hours while stirring. Post-treatment is the same as that in Synthesis Method 2.7.32 g of the target product, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone is obtained, with the yield being 84.4%.

(15) The product yield (83.7%) of Method 1 is slightly higher than the product yield (82.3%) of Method 2. In Method 2, it is not required to separate and purify the product by means of column chromatography, and Method 2 is more suitable for industrial production.

(16) In Method 3, when the molar ratio of the reaction raw material, 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide to the reaction raw material, morpholine, is 1:1, and the yield is low and is only 58.1%; and because 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide is solid at room temperature, the two reaction raw materials are slightly inadequate to dissolve each other.

(17) In Method 4, when the molar ratio of the reaction raw material, 2-methyl-1-methoxy[2-(9,9-dibutylfluorenyl)]propylene oxide to the eaction raw material, morpholine, is 1:5, the product yield (84.4%) does not increase significantly compared with the yield (82.3%) of Synthesis Method 2. However, the amount of morpholine at the molar ratio is increased from 2.5 to 5.0, and the amount of morpholine is increased significantly.

Embodiment 2 Preparation of Photocuring Varnish Formulation

(18) The photocuring varnish formulation is configured according to the following formulation.

(19) The specific formulation is as follows:

(20) TABLE-US-00002 % by weight of the total Components weight of the composition epoxy acrylate 35% Active amine P115  7% trimethylolpropane triacrylate 55% Photoinitiator  3%

(21) According to the formulation, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone is used as a photoinitiator to prepare the invention formulation.

(22) Comparative formulations prepared by other photoinitiators are prepared and tested by preparing photocuring varnish formulations having only different photoinitiator contents and other formulations with the same composition.

(23) The comparative formulations include:

(24) Comparative formulation 1 prepared by using 2-methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-acetone as a photoinitiator; and

(25) Comparative formulation 2 prepared by using 2-methyl-1-(4-biphenyl)-2-morpholinyl-1-acetone as a photoinitiator.

Embodiment 3 Curing Effect Test

(26) The varnish formulation prepared in Embodiment 2 is coated on blank paper with a thickness of about 15 microns by using a printability tester, an ultraviolet lamp with an adjustable filter with the power of 50 W/CM line power is used in the wavelength range of 360-420 to perform curing at a speed of 100 m/min, and the number of passes under the lamp required to obtain a good surface and perform complete curing is recorded. The results are shown in Table 1 below.

(27) TABLE-US-00003 TABLE 1 Results of measurement of the effect of curing by irradiation with UV Varnish Number of passes required formulation Photoinitiator for complete curing Invention 2-methyl-1-(2-(9,9- 2 formulation dibutylfluorenyl))-2- (N-morpholinyl)-1-acetone Comparative 2-methyl-1- 4 formulation (4-biphenyl)-2- 2 morpholinyl-1-acetone

Embodiment 4 VOC Emission Analysis

(28) The emissions of VOCs in the cured film prepared with the photoinitiator of the present invention in Embodiment 3 are measured by using headspace gas chromatography.

(29) The results are shown in Table 2 below.

(30) TABLE-US-00004 TABLE 2 Results of measurement of emissions of harmful VOCs in the cured layer of a coating by means of headspace gas chromatography Serial Measured value Index value number VOC (Unit: PPm) (Unit: PPm) 1 Ethanol 543.4  / 2 Acetone 1.3 200 3 Isopropyl 5.6 200 alcohol 4 Butanone 0.2 100 5 Ethyl 5.7 / acetate 6 Benzene  /   4 7 Isopropyl 0.3 / acetate 8 Propylene glycol  /  500 monomethyl ether 9 N-butyl  /  100 alcohol 10 N-propyl 12.3  / acetate 11 4-methyl-  /  200 2-pentanone 12 Methylbenzene 0.2 100 13 N-butyl 1.5 100 acetate 14 Ethylbenzene 0.8  50 15 Dimethylbenzene 3.3  50 16 Cyclohexanone  1   50

Embodiment 5 Solubility, Yellowing and Odor Analysis

(31) A solid photoinitiator (the compound, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone, of the present invention, and a comparative photoinitiator, 2-methyl-1-[4-methylthiophenyl]-2-morpholinyl-1-propanone and 2-methyl-1-(4-biphenyl)-2-morpholinyl-1-acetone

(32) ##STR00007##
are dissolved in a liquid polymerized monomer, (1,6-hexanediol diacrylate (HDDA) or tripropylene glycol diacrylate (TPGDA)), heating is performed to 50-60° C. and mixing is performed uniformly. The liquid obtained after dissolving should be stored at room temperature. The solubility of the compound is measured. The degree of yellowing is observed and the odor is manually evaluated. The results are shown in Table 3 below.

(33) TABLE-US-00005 TABLE 3 Results of analysis and measurement of solubility, yellowing and odor 2-methyl-1-(2-(9,9- 2-methyl-1- dibutylfluorenyl)) [4-methylth 2-methyl-1-(4- 2-(N-morpholinyl)- iophenyl]-2- biphenyl)-2- 1-acetone Initiator morpholinyl- morpholinyl-1- (the present compound 1-acetone acetone patent compound) Solubility, Polymerized 35 20 50 % (mass monomer 1: fraction) HDDA Polymerized 22 15 40 monomer 2: TPGDA Yellowing after curing Yellowing No No yellowing yellowing Odor after curing Stench No No odor odor

Embodiment 6 Stability Analysis

(34) The varnish formulation prepared in Embodiment 2 is applied to 12×12 cm paperboard with a 15-micron wire rod applicator, and cured with a medium-pressure mercury arc lamp with the power of 80 W/cm at a speed of 20 m/min. The cardboard is cut to a size of 10×10 cm, is completely immersed in two analog solutions, i. e., 100 ml distilled water and 3% acetic acid aqueous solution, sealing is performed well, and placement is performed at 40° C. for 10 days. The printed matter is taken out, and after standing, the contents of the initiator compounds in the analog solutions are directly analyzed by means of HPLC. Calculation is performed by packaging 1 kg of food in a printing area of 600 cm.sup.2, the measurement result of mobility is expressed in g/Kg of food, and the results are shown in Table 4.

(35) TABLE-US-00006 TABLE 4 Stability analysis results Mobility ug/kg 3% acetic Initiator compound Water acid Comparative 2-methyl-1- 1000 4000 formulation [4-methylthiophenyl]-2- 1 morpholinyl-1-acetone Comparative 2-methyl- 80 98 formulation 1-(4-biphenyl)-2- 2 morpholinyl-1-acetone Invention 2-methyl-1-(2-(9,9- 50 60 formulation dibutylfluorenyl))-2- (N-morpholinyl)-1-acetone

(36) The present inventor has surprisingly found that the innovative compound, 2-methyl-1-(2-(9,9-dibutylfluorenyl))-2-(N-morpholinyl)-1-acetone, has good performance in photopolymerization and can effectively produce polymerization initiation groups when irradiated with UV light, for example. Moreover, the production costs of the photoinitiator compound and the curing composition provided by the present invention are low, the production processes are simple, post-treatment is simple, and the requirements for environmental protection are satisfied. The photoinitiator provided by the present invention can effectively reduce the release of various VOCs, including benzene or toluene, in products and is suitable for packaging and printing industries such as food, tobacco, and cosmetics.