Novel method for synthesizing SBQ sensitizer

Abstract

The invention discloses a novel SBQ sensitizer synthesizing method. 4-bromomethyl pyridine synthesis and Wittig reagent synthesis are separately carried out. Under the protection of N2, NaOH aqueous solution is added in a reaction container. The Wittig reagent and terephthalaldehyde undergo magnetic stirring and 12-hour circumfluence at 25 DEG C. HCL solution is added. A claret-red solution is obtained after filtration. reduced pressure distillation is carried out to remove the HCL solution. Brick red solid, i.e. 4-[2-4-formoxphenyl] vinyl] pyridine, i.e. SBQ sensitizer is obtained after drying. SBQ sensitive glue can be prepared from the SBQ sensitizer together with accessory agents such as polyvinyl alcohol, colorant and the like according to different proportions. According to tests, 15,000 times of printing can be stood by the SBQ sensitive glue, and the printing absolution is as high as 96 percent, which is equal to an imported product.

Description

technical field [0001] The invention belongs to a method for synthesizing a polymer material, in particular to a method for synthesizing a novel SBQ photosensitive agent. Background technique [0002] SBQ photosensitive glue relies on the singlet photocycloaddition reaction to crosslink PVA, so it has strong stability when it is not exposed to light, without any dark reaction, and it is being widely used in the printing industry and photoresist. SBQ photosensitive adhesive is divided into two categories: solvent-resistant type and water-resistant type. Solvent-resistant photosensitive adhesive is suitable for solvent-based inks, such as solder resist inks, embossed inks, flocking inks, instant inks, foaming inks, etc., mainly used for PCBs, circuit boards, instruments, advertising signs, various trademarks, ceramic decals Screen printing of paper, plastic, glass, enamel, metal products, etc. Water-resistant photosensitive adhesive is suitable for printing and dyeing, ceram...

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Problems solved by technology

[0004] A problem that must be faced during the synthesis of monomers according to the above scheme is: how to better control the reaction, so that only one aldehyde group on the terephthalaldehyde reacts, while retaining the other

[0005] For the acid-catalyzed method, the dehydration condensation in acetic anhydride to prepare the product will produce many colored condensation impurities, which are not easy to separate from the product; in order to remove excessive terephthalaldehyde, a large amount of dilute hydrochloric acid should be used to dissolve the product, so that the terephthalaldehyde Diformaldehyde precipitates, and extracts terephthalaldehyde in the water phase with benzene, which is not conducive to the recovery of terephthalaldehyde; in the process of alkali neutralization, the generated product and many colored impurities are precipitated together, in the form of colloid, filtered It is very difficult, the product is difficult to dry, and it also produces a lot of waste water; in addition, the acid-catalyzed reaction is two steps, which increases the loss in the reaction

[0006] For the base-catalyzed method, because it is a one-step reaction, the reaction is greatly reduced compared with the acid-catalyzed method, but when dealing with a large excess of raw material terephthalaldehyde, a large amount of ethanol and acetone must be used to precipitate the product, so the excessive The recovery of terephthalaldehyde is also very difficult

This method of preparing SBQ sensitizer is still feasible in the laboratory to prepare a small amount of products, but it is not suitable for industrial production

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