Phthalic anhydride (PA)

I. Production composition

Phthalic anhydride is white scaly or crystalline powder, the purity of which is greater than 99.5%, and other impurities are free acid (including phthalide, lime bran anhydride, O-Toluic acid, etc.).

II. Product production process

The Company takes the production process of O-xylene method: O-xylene is mixed with the air, generating phthalic anhydride and by-products with the reaction through the reactor catalyst bed layer. The mixed gas goes through the switching condenser and carries on trapping, and tail gas is released by bath tower spraying absorption, while the trapped phthalic anhydride materials, after the processed continuous distillation process, enter the flaking packaging after reaching qualified products.

III. Product quality index (GB/T15336-94)

IV. Product physical security
1. Product characteristics
Phthalic acid generates phthalic anhydride after the removal of a molecular water, referred to as the phthalic anhydride (PA)
Formula: C8H4O3
Molecular weight: 148.12
Freezing point: 130.7℃
Melting point: 130-131 ℃
Boiling point: 284 ℃
Density: solid phase: 1.527Kg/m3, liquid phase: 1.181. 527Kg/m3
Autoignition temperature: 580 ～ ℃
The phthalic anhydride flash point of molten liquid: open-cup: 165℃, closed-cup: 151℃
Maximum allowable concentration: 1mg/m3

2. Transportation
During transportation, it shall get away from fire source and shall be handled with care, away from the sun and rain. Anhydride phtalique is irritating to eyes and skin, wear protective equipment during handling, pay strict attention to safety, do not contact with the skin and prevent from being inhaled.

3. Storage conditions

Anhydride phtalique shall be stored in a clean, cool and dry warehouse, away from sunlight and fire source, and storage temperature shall not exceed 40℃. The preservation period of the anhydride phtalique products is three months, during which time the products shall conform to the grade requirements in the national standards.

4. Rescue measures

Phthalic anhydride has no severe toxicity. At present, no reports about carcinogenicity and sudden induced mutation have been reported. Personnel in contact with a large number of phthalic anhydride must keep the skin dry, wear overalls, etc., and maintain good ventilation indoors. The flushing device and shower shall be arranged around the workplace, eyes and skin shall be washed with plenty of water after the contact of phthalic anhydride.

5. Methods for fire protection

Phthalic anhydride is flammable, and fire can be extinguished with water and carbon dioxide agent after ignition.

V. Product application functions
Phthalic anhydride is a kind of important organic raw materials, with more than 60% used for the manufacture of PVC plasticizers, 30% for polyester resin and alkyd resin, and the remaining 10% for dye, medicine and pesticide, etc.
1. Plasticizer: Phthalic anhydride reacts with two molecular mass alcohols and generates phthalate esters, as plasticizers, with good plasticity, solubility, good gloss, and good thermal stability.
2. Unsaturated polyester resin: Phthalic anhydride, together with another unsaturated dicarboxylic acid or anhydride, after the condensation polymerization with dihydric alcohol in high temperature, shall be added with crosslinking agent, while the thermosetting resin generated after the cross-linking and solidity of polymerization inhibitor and antiager is used for processing glass steel, very extensive in use.
3. Alkyd resin: It is made by grease or oleic acid modification with the reaction from phthalic anhydride and polyols, alkyd resin is the resin widely used in coating, used for surface protection and decoration, and used in ink and adhesive as well
4. Dyes and pigments: Phthalic anhydride is an important raw material for making vat dyes, disperse dyes, reactive dyes and organic dyes.
5. Medicine and pesticide: It is the raw material for making antibiotics, food additives, (preservatives and saccharin), gastrointestinal drugs, sedatives, and disinfection mercurochrome in medicine; it is used for making herbicide, fungicide, insecticide and others in pesticide.