What do you know about the role of anhydrous sodium sulfite

Anhydrous sodium sulfite is used as a photographic development protective agent, textile bleaching cloth, leather decalcification agent, food preservative, and reducing agent in the production of preparations.

Application examples are as follows:

1) Preparation of acidic textile dyes containing anhydrous sodium sulfite and polydimethylsiloxane quaternary ammonium salt, which belongs to the technical field of textile dyes. Acid textile dyes include acid dyes 15-30 parts, anhydrous sodium sulfite 5-10 parts, sodium dihydrogen phosphate 4-8 parts, sodium laurate sarcosinate 2-5 parts, polyvinyl alcohol 3-11 parts, wetting agent 1-5 parts, dimethicone diquaternium 8-13 parts. M salt, 3-9 parts polymethylcyclotetrasiloxane, 2-9 parts sodium fatty acid. 1-6 parts of acetic acid. The invention ensures the dyeing ability of natural dyes on textiles, the dyed fabric has uniform color, good soaping fastness, sunlight fastness and good bacteriostatic property.

2) Preparation of a monocyclic aromatic hydrocarbon superplasticizer. Monocyclic aromatic hydrocarbon superplasticizer is composed of anhydrous sodium sulfite, sodium sulfate, acetophenone, bisphenol A and formaldehyde monomers.

First, under alkaline conditions, acetophenone condenses with part of formaldehyde, using sodium hydroxide produced by the hydrolysis of partly anhydrous sodium sulfite as a catalyst, and reacts with a composite sulfonating agent (sodium sulfate + anhydrous sodium sulfite hydrolysate). Introduce amino and sulfonic acid groups into the benzene ring to form sulfonated formaldehyde phenethyl. Ketone condensation product intermediate.

Then, under alkaline conditions, bisphenol A reacts with another part of formaldehyde to synthesize bisphenol A-formaldehyde intermediate through methylation, and the remaining hydrolysate of anhydrous sodium sulfite and formaldehyde are added to bisphenol A-formaldehyde -In phenolic intermediates. Sulfonate.

Finally, using sulfonated formaldehyde-acetophenone condensation intermediate and sulfonated bisphenol A-formaldehyde intermediate as raw materials, monocyclic aromatic hydrocarbon-type superplasticizer was synthesized.

3) Preparation of foamed phenolic resin, especially the synthesis of high-performance dehydrated foamed phenolic resin. Polyacetal and phenol are used as raw materials, and anhydrous sodium sulfite is used as a catalyst for polycondensation reaction. The weight ratio of polyoxymethylene to phenol is 0.38-0.64:1, the weight ratio of anhydrous sodium sulfite to phenol is 0.03-0.08:1, and the weight ratio of water to phenol is 0.06-0.12:1. Then water and ethyl p-toluenesulfonate. The weight ratio of p-toluenesulfonic acid to phenol in the neutralizer is 0.03-0.05:1, the weight ratio of ethylene glycol or diethylene glycol or polyethylene glycol to phenol is 0.04-0.12:1, and the weight ratio of water to phenol It is 0.015-0.022:1. The invention avoids the dehydration process in the synthetic production process, the whole production process has no waste water discharge, environmental protection and energy saving, high product performance, and is suitable for producing high-quality phenolic foam.

4) Preparation of dispersion stabilizer from paper sludge, including adding NaOH solution to raw materials without treatment, adding anhydrous sodium sulfite at 90°C for 1.5-2 hours, reacting hydrogen peroxide, formaldehyde solution and anhydrous sodium sulfite, and FIN. Add monochloroacetic acid and stir for 2-3 hours to obtain sodium lignosulfonate-sodium carboxymethyl cellulose dispersion stabilizer. The product has good dispersion stability. When used in coal water slurry, the concentration of coal water slurry can reach 67%, and the viscosity is less than 1100 MPa. S, no heavy precipitation after 72 hours. It has good liquidity. The process of the invention is simple, the reaction conditions are mild, and the recycling of waste is realized, and the invention can be used in industries such as preparation of coal water slurry, oil field, cement processing and the like.