Benzomethane is a white crystal mainly used in perfumes, mordants, galvanizing brighteners, organic synthesis and the like.
The benzylideneacetone is also known as 4-phenyl-3-buten-2-one, benzalacetone, methylcinnamyl ketone, benzylideneacetone, methylstyryl ketone. The one obtained by vacuum distillation was a colorless to pale yellow lustrous flake crystal. It has aromas of sweet peas and is spicy and irritating. It is light and dark, flammable, and easily decomposed by heat for a long time.
The main uses of benzylideneacetone are as follows
Aromatic organic substances, the most widely used bright additive in acid galvanizing process, can obtain bright coating in a wide current density and temperature range in potassium chloride and ammonium plating process, internal stress and corrosion protection of coating Sex can have a good effect. This product can also be used as an anti-volatile agent for perfumes, a mordant for dyeing industry, a fixing agent, and a flavoring and flavoring agent.
For example, benzylideneacetone as a spice
As a flavoring agent, benzylideneacetone is used to prepare fragrant peas, cocoa, nuts, cherries, fruits and other flavors. It is also used as a conditioner and anti-volatile agent for floral fragrances. It is irritating to the skin. Not for cosmetics.
In addition, benzalkonium ketone can also be used as a mordant, a fixing agent and a galvanizing brightener in the dyeing industry. A brightener is an organic compound that produces a brightening and leveling action.
Generally containing aromatic aldehydes or aromatic ketones and certain heterocyclic aldehydes, namely coumarin, vanillin, benzalkonium, etc., the molecular structure of which contains a carbonyl group, as long as the structure remains unchanged, replacing various substituents, Many types of compounds that produce a brilliant effect can be produced. Among them, benzylidene-acetone is the best, and most of these additives are commercially available as benzylideneacetone as the main brightener.
Method for preparing benzylideneacetone
At present, the commonly used preparation method is to use a benzaldehyde and acetone as a raw material to carry out a Claisen reaction, and in the presence of a base (sodium hydroxide or sodium carbonate), the aldehyde and ketone are condensed, and after the reaction is completed, the mixture is neutralized by dilute hydrochloric acid to adjust the pH. =6～7, standing layering, separating the upper yellow oil layer. In order to increase the yield as much as possible, the lower layer is extracted with benzene. After extracting the benzene, the extract is combined with the oil layer, then washed with water, and the oil layer is separated and decolorized with activated carbon. Filtration, purification under reduced pressure steam distillation, cooling, and crystallization to obtain crude benzylideneacetone.
It is obtained by condensation of benzaldehyde with acetone. Acetone and benzaldehyde, water mixed, slowly add 10% sodium hydroxide solution after cooling, the temperature is controlled at 25-31 ° C, and stirring is continued for 1 h after the addition. It was then neutralized to pH 6-7 with dilute hydrochloric acid and allowed to stand for 1 h to isolate a yellow oil. The lower layer is extracted with benzene, the extract and the oil are combined, washed twice with water, and the aqueous layer is separated, and then benzene is recovered, dried with calcium chloride, added to dry decolorized carbon, filtered, and the filtrate is distilled under reduced pressure to obtain a finished product. Raw material consumption quota: 1700kg/t for benzaldehyde, 2900kg/t for acetone, and 500kg/t for liquid alkali (40%).
The above is the main manufacturing method and application of benzylideneacetone.