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Tetrahydrophthalic anhydride

CAS Number
85-43-8
EC Number
201-605-4
Chemical Formula
C8H8O3
Molecular Weight
152.15 g/mol

Description

Tetrahydrophthalic anhydride (CAS 85-43-8 ), commonly abbreviated as THPA, is a cyclic dicarboxylic anhydride used as a curing agent and reactive intermediate in polymer manufacturing. It functions as a hardener for epoxy systems and a building block for polyester and alkyd resins. This chemical is utilized across the coatings, adhesives, and plastics industries. In epoxy coating formulations, THPA acts as a stoichiometric curing agent, producing crosslinked networks with good mechanical performance and chemical resistance. These properties make it ideally suited to industrial and protective coatings. Alkyd and unsaturated polyester resin producers use it as a monomer to control flexibility and reactivity in the final resin product. In adhesive and sealant systems, THPA-cured epoxy formulations deliver the bond strength and thermal stability required for structural and assembly applications. This ensures long-term durability in demanding environments. Printing ink manufacturers incorporate THPA-based resins where controlled cure response and adhesion to packaging substrates are required. This versatility makes it a staple in modern chemical manufacturing and processing. THPA is supplied as a white to off-white crystalline solid or powder. Technical grade is the standard commercial form, with purity specifications typically at 98% or above to meet industrial requirements. Bulk supply is available in bags or drums, with packaging options scaled to industrial procurement volumes. Our logistics network ensures reliable delivery for large-scale manufacturing operations and specialized chemical facilities. Contact us for supply of Tetrahydrophthalic anhydride Request Quote

Other Names (Synonyms)

3a,4,7,7a-tetrahydroisobenzofuran-1,3-quinone | 3a,4,7,7a-tetrahydro-2-benzofuran-1,3-dione | 1,2,3,6-tetrahydrophthalic anhydride | Rikacid TH | Tetrahydrophthalic acid anhydride | Memtetrahydro phtalic anhydride | 4-Cyclohexene-1,2-dicarboxylic acid anhydride | 1,3-Isobenzofurandione, 3a,4,7,7a-tetrahydro- | THPA

Key Technical Features

  • High Purity Grade standard
  • Consistent Batch Quality
  • Full Regulatory & REACH Support
  • Global Logistics Network enabled

Physical Properties

Melting Point102 °C
Boiling Point195 °C @ Press: 50 Torr
Density1.20 g/cm³ @ Temp: 105 °C
Flash Point157°C
ColorOff-White to Light Tan
FormSolid
Water Solubility29.4g/L at 20℃
Vapor Pressure0.021Pa at 20℃
Refractive Index1.4810 (estimate)
pH2.1 (20°C, 10g/L in H2O)
Log P1.29 at 40℃

Safety & Handling

Danger
GHS05· CorrosiveGHS08· Health HazardGHS07· Irritant

Hazard Statements

H302Harmful if swallowed
H315Causes skin irritation
H317May cause an allergic skin reaction
H318Causes serious eye damage
H334May cause allergy or asthma symptoms or breathing difficulties if inhaled
H335May cause respiratory irritation
H412Harmful to aquatic life with long lasting effects

Precautionary Statements

P233Keep container tightly closed.
P260Do not breathe dust/fume/gas/mist/vapours/spray.
P261Avoid breathing dust/fume/gas/mist/vapours/spray.
P264Wash … thoroughly after handling.
P270Do not eat, drink or smoke when using this product.
P271Use only outdoors or in a well-ventilated area.
P272Contaminated work clothing should not be allowed out of the workplace.
P273Avoid release to the environment.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P284In case of inadequate ventilation wear respiratory protection.
P317Get emergency medical help.
P319Get medical advice/attention if you feel unwell.
P321Specific treatment (see … on this label).
P330Rinse mouth.
P403Store in a well-ventilated place.
P405Store locked up.
P501Dispose of contents/container in accordance with local regulations.
P265Wash … thoroughly after handling.
P317Get emergency medical help.
P352IF ON SKIN: Wash with plenty of water.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P317Get emergency medical help.
P317Get emergency medical help.
P316Get emergency medical help immediately.
P364Take off contaminated clothing and wash it before reuse.
P233Store in a well-ventilated place. Keep container tightly closed.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.