阅读说明：本技术 一种新型苯甲酰甲酸甲酯类光引发剂及其制备方法 (Novel benzoyl formic acid methyl ester photoinitiator and preparation method thereof ) 是由 朱晓群 李阳 聂俊 于 2020-05-20 设计创作，主要内容包括：本发明涉及有机合成技术领域,尤其涉及一种新型苯甲酰甲酸甲酯类光引发剂及其制备方法。目前市面上所使用的LED光源的发射波长范围均在365nm以上,而传统的光引发剂MBF的最大吸收波长为255nm,与LED光源的发射波长不相匹配,为了使得MBF光引发剂的最大吸收波长与LED光源的主要发射波长范围相匹配,本发明提供一种新型苯甲酰甲酸甲酯类光引发剂,其由含有双αH的羰基官能化的苯甲酰甲酸甲酯衍生物与酮类化合物发生缩合反应得到,其最大吸收波长可以达到365nm以上,与市面上使用的LED光源相匹配,具有良好的商业应用前景。(The invention relates to the technical field of organic synthesis, in particular to a novel benzoyl formic acid methyl ester photoinitiator and a preparation method thereof. The emission wavelength range of the LED light source used in the market at present is more than 365nm, the maximum absorption wavelength of the traditional photoinitiator MBF is 255nm and is not matched with the emission wavelength of the LED light source, in order to ensure that the maximum absorption wavelength of the MBF photoinitiator is matched with the main emission wavelength range of the LED light source, the invention provides a novel methyl benzoylformate photoinitiator which is obtained by condensation reaction of carbonyl functionalized methyl benzoylformate derivatives containing double alpha H and ketone compounds, the maximum absorption wavelength of the novel methyl benzoylformate photoinitiator can reach more than 365nm and is matched with the LED light source used in the market, and the novel methyl benzoylformate photoinitiator has good commercial application prospect.)

1. A novel benzoyl formate photoinitiator is characterized by having the following chemical structural general formula:

in the general chemical structure formula, n is 1-2, and in the general formula I: 4R₂Represents a substituent on 4 arbitrary vacant positions on a benzene ring; r₁And R₂Is one of hydrogen atom, alkyl, alkenyl, alkoxy, alkynyl, hydroxyl, nitro, halogen, sulfonic group and alkyl, alkenyl, alkoxy and alkynyl which are substituted by hydroxyl, halogen, nitro, sulfonic group, cyano and amino; r₃Is one of alkyl, alkenyl, alkynyl, aryl and heterocyclic aryl.

2. The novel methyl benzoylformate photoinitiator as claimed in claim 1, having the following formula:

3. a preparation method of a novel benzoyl formate photoinitiator is characterized by comprising the following steps:

(1) first, a carbonyl-functionalized methyl benzoylformate derivative containing a bis-alphaH is prepared;

(2) the carbonyl functionalized methyl benzoylformate derivative containing double alpha H and aldehyde compounds are subjected to condensation reaction, and after the reaction is finished, the obtained solid product is purified to obtain the novel methyl benzoylformate photoinitiator.

4. The method for preparing the novel methyl benzoylformate photoinitiator according to claim 3, wherein the method comprises the following steps: the carbonyl-functionalized methyl benzoylformate derivative containing a bis alphaH has the following formula:

5. the method for preparing the novel methyl benzoylformate photoinitiator according to claim 3, wherein the method comprises the following steps: the aldehyde compound is 1-methyl-2-pyrrole formaldehyde, terephthalaldehyde, furfural, p-tolualdehyde, 2, 5-diformylfuran, 1-methyl-1H-pyrrole-2, 5-dicarboxaldehyde or benzaldehyde.

6. The method for preparing the novel methyl benzoylformate photoinitiator according to claim 3, wherein the method comprises the following steps: the molar ratio of the carbonyl functionalized methyl benzoylformate derivative containing bis alpha H to the aldehyde compound in the condensation reaction is 1-2: 1.

7. The method for preparing the novel methyl benzoylformate photoinitiator according to claim 3, wherein the method comprises the following steps: the condensation reaction is carried out at the temperature of 0-80 ℃ for 0.05-6h, and the pH value is 8-13.

8. The method for preparing the novel methyl benzoylformate photoinitiator according to claim 3, wherein the method comprises the following steps: the solvent of the condensation reaction is methanol, ethanol, isopropanol, tert-butanol, tetrahydrofuran, dimethylformamide or dimethyl sulfoxide.

9. The method for preparing the novel methyl benzoylformate photoinitiator according to claim 3, wherein the method comprises the following steps: the catalyst for the condensation reaction is sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, sodium bicarbonate, diisopropylamine, pyridine, lithium diisopropylamide, triethanolamine, methyldiethanolamine or lithium hexamethyldisilazide.

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a novel benzoyl formic acid methyl ester photoinitiator and a preparation method thereof.

Background

The photoinitiator MBF is also called methyl benzoylformate. Methyl benzoylformate is colorless or light yellow liquid, can be dissolved in organic solvents such as toluene, ethanol, diethyl ether and the like, is a photoinitiator developed in recent years, is often used together with a mercury lamp, has the advantages of high initiation efficiency, good thermal stability, low odor and the like, and has an important position in a photopolymerization system.

With China signing water good for the convention, mercury lamps will be prohibited from use. The LED light source is a novel low-power light source, and has many advantages over the mercury lamp, such as high efficiency, no ozone generation, no mercury pollution, and long life, and has been widely used in the field of photopolymerization in recent years. However, due to packaging technology and other reasons, the LED light source cannot continuously and stably emit ultraviolet light with short wavelength, and the main emission wavelength is concentrated in 365nm-400nm, while the main absorption wavelength of the conventional photoinitiator MBF is 255nm and 325 nm. When the LED light source is used to provide energy for photopolymerization, and MBF is used as a photoinitiator for photopolymerization, the conversion rate of double bonds of the polymerized monomers in photopolymerization is relatively low. Therefore, the development of long wavelength photoinitiators that match the emission wavelength of the LED light source is of great commercial value.

Disclosure of Invention

Aiming at the problems in the prior art, the technical problems to be solved by the invention are as follows: how to improve the maximum absorption wavelength of the traditional photoinitiator MBF to enable the maximum absorption wavelength to be adapted to the main emission wavelength of an LED light source and improve the double bond conversion rate in photopolymerization reaction.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the invention provides a novel benzoyl formic acid methyl ester photoinitiator, which has the following chemical structural general formula:

in the general chemical structure formula, n is 1-2, and in the general formula I: 4R₂Represents a substituent on 4 arbitrary vacant positions on a benzene ring; r₁And R₂Is one of hydrogen atom, alkyl, alkenyl, alkoxy, alkynyl, hydroxyl, nitro, halogen, sulfonic group and alkyl, alkenyl, alkoxy and alkynyl which are substituted by hydroxyl, halogen, nitro, sulfonic group, cyano and amino; r₃Is one of alkyl, alkenyl, alkynyl, aryl and heterocyclic aryl.

Specifically, the novel methyl benzoylformate photoinitiator is characterized by having the following chemical formula:

specifically, the preparation method of the novel benzoyl formate photoinitiator comprises the following steps:

(1) first, a carbonyl-functionalized methyl benzoylformate derivative containing a bis-alphaH is prepared;

(2) the carbonyl functionalized methyl benzoylformate derivative containing double alpha H and aldehyde compounds are subjected to condensation reaction, and after the reaction is finished, the obtained solid product is purified to obtain the novel methyl benzoylformate photoinitiator.

Specifically, the carbonyl-functionalized methyl benzoylformate derivative containing a bis α H has the following formula:

specifically, the aldehyde compound is 1-methyl-2-pyrrole formaldehyde, terephthalaldehyde, furfural, p-tolualdehyde, 2, 5-diformylfuran, 1-methyl-1H-pyrrole-2, 5-dicarboxaldehyde or benzaldehyde.

Specifically, the molar ratio of the carbonyl functionalized methyl benzoylformate derivative containing bis alpha H to the aldehyde compound in the condensation reaction is 1-2: 1.

Specifically, the condensation reaction is carried out at the temperature of 0-80 ℃ for 0.05-6h at the pH of 8-13.

Specifically, the solvent of the condensation reaction is methanol, ethanol, isopropanol, tert-butanol, tetrahydrofuran, dimethylformamide or dimethyl sulfoxide.

Specifically, the catalyst for the condensation reaction is sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, sodium bicarbonate, diisopropylamine, pyridine, lithium diisopropylamide, triethanolamine, methyldiethanolamine or lithium hexamethyldisilazide.

The invention has the beneficial effects that:

(1) the maximum absorption wavelength of the novel methyl benzoylformate photoinitiator prepared by the invention can reach more than 356nm, and the novel methyl benzoylformate photoinitiator is matched with the emission wavelength of an LED light source commonly used in the field of photopolymerization, so that the novel methyl benzoylformate photoinitiator has more excellent performance and stronger marketability.

(2) The method for preparing the novel benzoyl formic acid methyl ester photoinitiator is simple, the product can be obtained by one-step condensation reaction, the preparation cost is low, and the industrial production is easy to carry out.

Drawings

FIG. 1: uv absorption spectrum of traditional commercial MBF photoinitiators.

FIG. 2: example 1 uv absorption spectra of the long wavelength photoinitiator prepared.

FIG. 3: example 2 uv absorption spectra of the long wavelength photoinitiator prepared.

FIG. 4: example 3 uv absorption spectra of the long wavelength photoinitiator prepared.

FIG. 5: example 4 uv absorption spectra of the long wavelength photoinitiator prepared.

FIG. 6: example 5 ultraviolet absorption spectra of the long wavelength photoinitiator prepared.

FIG. 7: example 6 ultraviolet absorption spectra of the long wavelength photoinitiator prepared.

FIG. 8: example 7 uv absorption spectra of the long wavelength photoinitiator prepared.

FIG. 9: example 8 ultraviolet absorption spectra of the long wavelength photoinitiator prepared.

FIG. 10: example 9 ultraviolet absorption spectra of the long wavelength photoinitiator prepared.

FIG. 11: example 10 ultraviolet absorption spectra of the long wavelength photoinitiator prepared.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings.