Phthalic Anhydride 99.5% Resin Grade

Phthalic Anhydride 99.5% Resin Grade (CAS 85-44-9, molecular formula C8H4O3) is a coatings raw material used by paint, ink and adhesive formulators who need consistent dispersion, opacity and rheology from drum to drum. China Chemicals supplies it at 99.5% min in pack sizes from 1 kg through to 1000 kg Bulk Bag, so laboratory trial quantities and full production volumes can be sourced from the same specification.

It is also traded as PA, 1,2-Benzenedicarboxylic Anhydride, Phthalandione. Every consignment ships with a batch-specific Certificate of Analysis and the current Safety Data Sheet, and material is stored and picked under stock rotation so you receive product well inside its shelf life.

Typical applications

Alkyd resin manufacture for decorative paint
Unsaturated polyester resin for composites
Plasticiser production for flexible PVC
Dye and pigment intermediate synthesis
Curing agent in epoxy systems

Technical specification

Chemical name	Phthalic Anhydride 99.5% Resin Grade
Synonyms	PA, 1,2-Benzenedicarboxylic Anhydride, Phthalandione
CAS number	85-44-9
Molecular formula	C8H4O3
Appearance	White flakes or molten liquid
Purity	99.5% min
Solidification point	130.5°C min
Free acid as phthalic acid	0.3% max
Colour (molten, APHA)	20 max
Ash	0.1% max
Maleic anhydride	0.05% max

Values above are typical and are confirmed on the Certificate of Analysis issued against each batch. Tighter specifications can be quoted where a process requires them.

Packaging and supply

Available in 1 kg, 5 kg, 25 kg Bag, 1000 kg Bulk Bag. Bulk, road tanker and export drum quantities are quoted on request, including FOB and CIF terms for international shipment. Pricing shown is per pack in USD, exclusive of freight and any applicable duties.

Handling and safety

Transport classification: UN2214 · Harmful, causes serious eye damage. Store in the original closed container in a cool, well-ventilated area away from incompatible materials, and handle using appropriate personal protective equipment. Read the Safety Data Sheet in full before use — it is issued with every order and is available on request before purchase.

Supply to industry only. Products are sold for legitimate industrial, laboratory and manufacturing use. We may request end-use details and business registration before releasing an order.