Phthalic anhydride CAS#85-44-9

Phthalic anhydride, Promotion Season Now in Store and Free Sample for Testing with Factory Price
  • Appearance: White flake solid or powder
  • Assay: 99.9% min
  • Packaging: 25kg/bag
  • Sample: Available

Quality Control of Phthalic anhydride

Chemical Structure
Packing of Bretazenil

Description of Phthalic anhydride

Phthalic anhydride is the organic compound with the formula C6H4(CO)2O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the worldwide production volume was estimated to be about 3 million tonnes per year.

Basic Info of Phthalic anhydride

Basic Info

Chemical Name

phthalic anhydride


phthallic anhydride;1,3-dihydroisobenzofuran-1,3-dione;2,3-Dihydroimidazole-2-one;2,3-dihydro-1H-imidazol-2-one;1,3-dihydro-2h-imidazol-2-on;Expand



Molecular Formula


Molecular Weight







Safety Info



Hazard Class


Safety Statements


HS Code


Packing Group


WGK Germany



UN 2214

Risk Statements

R22; R37/38; R41; R42/43

Hazard Codes




Appearance & Physical State

white crystalline solid with choking odour



Boiling Point


Melting Point


Flash Point


Refractive Index


Water Solubility

6 g/L (20 ºC)


Stable. Combustible. Incompatible with strong oxidizing agents, strong bases, moisture, strong acids. Dust may form an explosive mixture with air.

Storage Condition

Store at RT.

Vapor Density

5.1 (vs air)

Vapor Pressure

<0.01 mm Hg ( 20 °C)


Numbering system

EINECS number


MDL number



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What is Phthalic anhydride?

Part I: Introduction

With the progress of science and technology and the development of society, chemical products have invariably permeated our daily lives, in medicine, food, cosmetics, electronics, industry, and other areas, becoming an essential part of our lives. One such product is Phthalic anhydride which has developed particularly rapidly in recent years. Do you know about Phthalic anhydride?

The official answer: Phthalic anhydride is an organic compound with the molecular formula C8H4O3, a cyclic anhydride formed by dehydration within the phthalic acid molecule. Phthalic anhydride is a white solid and is an important raw material in chemicals, especially in the manufacture of plasticizers.

What’s the application of Phthalic anhydride?

Part 2: In-depth development

  1. Phthalic anhydride is one of the most important organic chemical raw materials, its main derivatives are dibutyl phthalate; dioctyl ester and diisobutyl ester, etc., used as plasticizers for PVC, etc.; also used in the production of unsaturated polyester resins; alkyd resins; dyes and pigments; a variety of paints; food additives; phenolphthalein, a laxative in medicine; imitation in pesticides; methoprene and sodium saccharin, etc.
  2. This product is used as a curing agent for epoxy resin. It is an important organic chemical raw material, mainly used in the production of phthalate plasticizers, paints, saccharin, dyestuff, and important intermediates of organic compounds, insecticides, fungicides, rubber processing aids, photosensitive materials, etc.
  3. Used as analytical reagents. Organic synthesis intermediates. Used in dyestuff industry to prepare anthraquinone, 2-chloro anthraquinone, 1,4-dihydroxy anthraquinone, and other important intermediates and phthalocyanine blue BS, phthalocyanine blue BX, phthalocyanine blue B, and other dyestuffs.
  4. used as curing agent for epoxy resin, reference dosage 30-50 mass, 100g resin compound applicable period rt/6h, 120℃/1.5h. curing conditions: 100/2h+150℃/5h or 100℃/12h, 140℃/8h, 200℃/6h. small heat generation during curing, cured products have good electrical properties and mechanical strength, heat deflection temperature 110~152℃.
  5. It is an important organic chemical raw material. In the synthetic resin industry for the production of polyester resin, amino resin, unsaturated polyester resin, alkyd resin, etc… In the dyestuff industry, it is used to produce anthraquinone, chloroanthracene dihydroxyanthraquinone, and other dyestuff intermediates and phthalocyanine blue BS, phthalocyanine blue BX, phthalocyanine blue B, and other dyestuffs. The plastics industry is used to prepare plasticizers such as dibutyl phthalate, dioctyl phthalate, and its mixed esters. It is also an important intermediate in the manufacture of many kinds of drugs, paints, and organic compounds.
  6. Used in the manufacture of plasticizers, dibutyl benzodicarboxylate, resins, and dyes, etc.


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