Tetrachlorophthalic Anhydride CAS 117-08-8

What Tetrachlorophthalic Anhydride Is

Tetrachlorophthalic anhydride is phthalic anhydride with all four aromatic hydrogens replaced by chlorine, a white to off-white needle crystal or powder that melts above 250 °C. The anhydride group reacts with alcohols and amines to form esters and imides, and the chlorine bound on the ring stays in the finished polymer, so the material works as a reactive rather than additive flame retardant. It is almost insoluble in cold water but hydrolyzes to tetrachlorophthalic acid in hot water or damp air, so dry handling and sealed storage matter. UATChem supplies standard industrial crystals and powder, with assay and moisture confirmed on the COA for each lot.

Flame Retardant Resins and Other Uses

• Reactive flame retardant. Esterified into the backbone of unsaturated polyester, epoxy and alkyd resins to give durable, non-migrating flame resistance in high temperature composites, electronic potting and flame retardant coatings.
• Dyes, pigments and agrochemicals. An intermediate for dyes, organic pigments and pesticide syntheses, and a feed for chlorinated plasticizers and resin modifiers.
• Fine synthesis. The tetrachlorophthaloyl (TCP) group serves as an amine protecting reagent in peptide and pharmaceutical intermediate work.
• Coatings and molding compounds. Used as a chlorinated monomer in flame retardant alkyd and polyester coatings, molding compounds and elastomer formulations.

Typical Specifications

Industrial and higher grades differ in assay and moisture; values are reported on the COA for each lot, and the physical constants below identify the material.

Packaging, Documents and Ordering

• Packed in 25 kg paper bags or fiber drums with sealed liner on pallets; material is kept strictly dry, sealed, cool and away from strong oxidizers to prevent hydrolysis, with transport classification shown on the SDS.
• The anhydride irritates and may burn the skin, eyes and respiratory tract and may sensitize skin or airways, so gloves, goggles, a dust mask and ventilation are used, and the chlorinated powder is kept out of waterways. Every lot carries a COA with assay, melting point, moisture and free acid, together with TDS and SDS, and samples are supported.
• For a quote, UATChem needs the grade (industrial or refined), form (crystals, flakes or powder), quantity, packing and destination port.

FAQ

Q: What is tetrachlorophthalic anhydride used for?

A: It is a reactive chlorinated monomer for flame retardant polyester and epoxy resins, and a dye and plasticizer intermediate.

Q: Is TCPA an additive or a reactive flame retardant?

A: It is reactive; ring chlorine and the anhydride bond it into cured resin, so the flame resistance does not migrate or bloom.

Q: Why must tetrachlorophthalic anhydride be kept dry?

A: It is moisture sensitive and hydrolyzes in hot water or damp air to tetrachlorophthalic acid, so packs stay sealed and dry.