Hydroquinone_Kain Industrial Additives

Hydroquinone is also known as hydroquinone (English: Hydroquinone), quinone, gallinol, 1,4-dihydroxybenzene, 1,4-benzenediol, In 1820, the world first used distillation to prepare hydroquinone from quinic acid. It is white crystal or nearly white crystalline powder at room temperature. It is flammable, with a melting point of 173~174°C, a boiling point of 285°C (750 mmHg), and a density of 1.328 g/cm3 (15℃), soluble in hot water, ether and ethanol, slightly soluble in benzene. It has reducing properties. After mild oxidation, brown p-benzoquinone (C6H4O2) is obtained, and p-benzoquinone is reduced to obtain hydroquinone. The p-benzoquinone-hydroquinone redox couple exists in many biomolecules, such as coenzyme Q and so on.
The phenolic hydroxyl hydrogen of hydroquinone is weakly acidic and can lose one or two protons to generate the corresponding phenoxide anion. Mainly used as reducing agent, developer (reducing silver halide to silver), polymerization inhibitor of monomers (acrylic acid, methyl methacrylate), and skin whitening agent. Hydroquinone ether is a raw material in the production of dyes and spices.

Use and function
Toxicity
First aid measures
Operational Precautions
Storage Precautions
Production methods
Implementation standards
Domestic production technical difficulties have been overcome
Tert-butylhydroquinone
Shipping Information
---Dangerous goods number
---UN number
---Packaging category
---Packaging method
---Transportation Notes

Purpose and function

Used in the fields of dyes, pharmaceutical intermediates, photographic developers, antioxidants, plastic resin polymerization inhibitors and other fields.
It can interfere with the formation of melanin, and clinically has a fading effect on freckles, age spots, and liver spots induced by oral contraceptives.
Black auto-developer for producing photographic film, quinone dyes and azo dyes, auxiliary solvents for syngas desulfurization process, antioxidants and view blockers for rubber limb processing, stabilizers and antioxidants for food and coatings. In addition, it can also be used as Petroleum anticoagulant, Taicheng ammonia catalytic agent, etc.

Toxicity

Hydroquinone is very toxic. It is carcinogenic and mutagenic. Adults who take 1g by mistake can cause headache, dizziness, tinnitus, pale complexion, cyanosis, nausea and vomiting. , abdominal pain, feeling of suffocation, dyspnea, tachycardia, tremor, muscle twitching, convulsions, delirium and collapse. In severe cases, hematemesis, hematuria and hemolytic jaundice may occur. Urine is cyan or brownish-green. Skin can cause dermatitis due to primary irritation and allergic reactions, which can cause skin depigmentation. Eye contact with the dust or vapor of this product may cause conjunctivitis and keratitis.

First aid measures

Skin contact: Take off contaminated clothing immediately and rinse with plenty of running water. Seek medical attention.
Eye contact: Immediately lift eyelids and rinse thoroughly with plenty of running water or saline for at least 15 minutes. Seek medical attention.
Inhalation: Move quickly to fresh air. Keep your airway open. If breathing is difficult, give oxygen. If breathing stops, perform artificial respiration immediately. Seek medical attention.
Ingestion: Give 15 to 30 mL of vegetable oil immediately. Induces vomiting. Seek medical attention.

Operation Precautions

Closed operation to provide sufficient local exhaust. Isolate as much as possible. Operators must undergo special training and strictly abide by operating procedures. It is recommended that operators wear self-priming filter dust masks, chemical safety glasses, anti-toxic substance penetration overalls, and rubber gloves. Keep away from fire and heat sources. Smoking is strictly prohibited in the workplace. Use explosion-proof ventilation systems and equipment. Avoid dust generation. Avoid contact with oxidants, acids, and alkalis. When handling, load and unload with care to prevent damage to packaging and containers. Equipped with corresponding varieties and quantities of fire-fighting equipment and leakage emergency treatment equipment. Empty containers may be harmful residues.

Storage Notes

Stored in a cool, ventilated warehouse. Keep away from fire and heat sources. The packaging must be sealed and must not come into contact with air. They should be stored separately from oxidants, acids, alkalis, and food chemicals, and avoid mixed storage. Equipped with the appropriate variety and quantity of fire equipment. Suitable materials should be available in the storage area to contain spills. The "five pairs" management system for extremely toxic substances should be strictly implemented.

Production method

1. In general industry, aniline is used as raw material to generate hydroquinone. In sulfuric acid medium, aniline is oxidized with manganese dioxide to p-benzoquinone, and then reduced with iron powder to obtain hydroquinone.
2. Use nitrobenzene as raw material, hydrogenate and heat to obtain hydroquinone.

Implement standards

Q/320583 W&M303－2004

Domestic production technical difficulties have been overcome

Since the 1960s, many countries have successively developed production processes for dihydric phenols. Due to the complexity of its separation process and the difficulty of engineering, so far, there are only 20,000 tons/year high-concentration hydrogen peroxide phenol hydroxylation device of French Rhône-Poulenc Company in the world and a 10,000-ton/year high-concentration hydrogen peroxide phenol hydroxylation device of Italian company Bridgema. The annual high-concentration hydrogen peroxide phenol hydroxylation method device and the 5000 tons/year device of Japan Ube Kosan Co., Ltd. are in operation.

Our country began to develop new processes for the production of dihydric phenols more than ten years ago. From the "Seventh Five-Year Plan" to the "Ninth Five-Year Plan", it has continuously initiated projects on diphenol technology and developed many types of catalysts, and the reaction technology is becoming increasingly mature, but due to the hydroxylation liquidThe separation and product purification technology is not up to standard, and industrial production has never been formed. my country is completely dependent on imports of catechol, which has seriously hindered the production of downstream products of dihydric phenols and the development of related industries. Our country also intended to introduce dihydric phenol production technology from Rhône-Poulenc, but it failed to materialize due to high costs and other reasons.

In this context, the Institute of Chemical Engineering of Tianjin University relied on the solid foundation accumulated over the years in distillation theory and high-efficiency packed tower technology, combined with the characteristics of the benzene system, to carry out the distillation process Basic research and energy-saving technology development, and in view of the technical problems of high viscosity of tar contained in the system and easy deformation and expansion when heated, an efficient decoking separation system and equipment suitable for this feature have been developed.

Tert-butylhydroquinone

It is white to off-white or reddish brown crystalline powder at room temperature. It has a very light special fragrance. It is almost insoluble in water (about 5‰) and soluble in ethanol and isopropyl alcohol. , acetic acid, ethyl ester, ethyl acetate, ether, vegetable oil, lard, etc. The boiling point is 295℃ and the melting point is 126.5~128.5℃. It has anti-corrosion and anti-septic effects on most oils and fats, especially vegetable oils. It does not change color when exposed to iron or copper, but can turn pink if alkali is present. It has superior antioxidant properties and is more powerful than BHT (2,6-di-tert-butyl-p-cresol), BHA (tert-butyl-4-hydroxyanisole), PG (propyl gallate) and VE. Ability to effectively inhibit the growth of bacteria such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Brevibacterium aerogenes, and microorganisms such as Aspergillus niger, Aspergillus versicolor, and Aspergillus flavus.

Shipping information

Dangerous goods number

61725

UN number

2662

Packaging category

O53

Packaging method

Fibreboard barrels, plywood barrels, cardboard barrels outside plastic bags or two-layer kraft paper bags; ordinary wooden boxes outside plastic bags or two-layer kraft paper bags; screw-top glass bottles and iron caps Ordinary wooden boxes outside glass bottles, plastic bottles or metal barrels (cans); outside full-floor grate boxes, fiberboard boxes or plywood boxes outside screw-top glass bottles, plastic bottles or tin-plated sheet steel barrels (cans).

　
Transportation precautions

During railway transportation, the dangerous goods assembly table in the "Dangerous Goods Transport Rules" of the Ministry of Railways should be strictly followed. Before transportation, check whether the packaging container is complete and sealed. During transportation, make sure that the container does not leak, collapse, fall, or be damaged. It is strictly prohibited to mix with acids, oxidants, food and food additives. During transportation, they should be protected from exposure to the sun, rain, and high temperatures.