A kind of preparation method of photoinitiator bis (2,4,6-trimethylbenzoyl) phenyl phosphine oxide

Abstract

The invention discloses a preparation method of a photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide, comprising the steps of enabling diethyl benzylphosphonate and an excessive vitride solution to react in argon under the temperature of 60-70 DEG C, so as to generate phenyl phosphine, enabling the phenyl phosphine and 2,4,6-trimethylbenzoyl chloride to react, so as to obtain a methylbenzene solution of diphenyl(2,4,6-trimethylbenzoyl)phosphine, and oxidizing the diphenyl(2,4,6-trimethylbenzoyl)phosphine into 2 phenyl bis(2,4,6-trimethylbenzoyl)-phosphine oxide by hydrogen peroxide without separating. According to the process, dangerous metal sodium or potassium is not used, the process is advanced, the operation is simple and safe, the product yield is high, the quality is good, and large-scale production is easy.

Description

technical field [0001] The invention relates to a photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, in particular to diethyl phenylphosphonate and excess red aluminum solution at a temperature of 70°C to 80°C Under the reaction in an inert gas, after the reaction is completed, remove excess red aluminum to obtain a toluene solution of phenylphosphine; then react with 2,4,6-trimethylbenzoyl chloride under the action of a basic compound to obtain an intermediate The body is then oxidized with hydrogen peroxide to obtain bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, which belongs to the field of chemical synthesis. Background technique [0002] Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide is a bisacyl oxide, and the photoinitiator decomposes to produce two benzoyl radicals and one phosphonodiradical with four active centers , its photochemical speed is fast, because it has been widely used in the fields of coatings, inks, adhesives, resists, soldering ag...

AI Technical Summary

Problems solved by technology

[0004] 1. Using phenylphosphine dichloride as the starting material, react with lithium under the catalysis of naphthalene lithium to form a phosphine lithium salt intermediate, then react with acid chloride, and finally obtain (2,4,6-trimethylbenzene Formyl) phenylphosphine oxide (WO 00 / 32612), the method has harsh reaction conditions and is not suitable for industrial production

[0005] 2. Using tertiary amines (such as triethylamine) as acid-binding agents, aryl phosphine reacts directly with acid chlorides, and then oxidizes to obtain (2,4,6-trimethylbenzoyl)phenylphosphine oxide (US 4,737,593), this method reaction selectivity is poor, and impurity is many, and yield is low (generally below 40%), is not suitable for industrialized production

[0006] 3. In the presence of active lithium reagent, aryl phosphine and acid chloride are reacted and then oxidized to obtain bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (US 6,020,528, US 5,723,512), metal lithium price More expensive, difficult to achieve industrialization

[0007] 4. Phenylphosphine dichloride reacts with metal lithium, sodium or potassium in a solvent and in the presence of a catalyst (activator) to obtain a phenylphosphine metal compound, and then reacts with 2,4,6-trimethylbenzoyl chloride, Obtain the intermediate, obtain the target object (CN99813713.8, CN200480022027.5) through hydrogen peroxide oxidation, because phenylphosphine dichloride and metal lithium, sodium or potassium are easy to form ring polyphosphine compounds in the reaction process and cannot obtain independent Sodium phenylphosphine, so the yield is low, and the use of potassium and sodium has caused a fire

[0008] 5. After the reaction of phenylphosphine dichloride with metal sodium or potassium, tert-butanol is added for protonation, and then reacted with 2,4,6-trimethylbenzoyl chloride to obtain bis(2 , 4,6-trimethylbenzoyl) phenylphosphine oxide (CN200480020599.X), this method needs to use extremely active metal sodium or potassium, and has higher requirements on reaction equipment and various raw materials, and the safety of the reaction process The property is also low, and it is easy to cause fire during alcoholysis or hydrolysis, and the yield of this process is also low

However, this method needs to use extremely active metal sodium or potassium, which requires high reaction equipment and various raw materials, and the safety of the reaction process is also low. It is easy to cause fire during alcoholysis or hydrolysis, and the yield is also low.