Phthalic Acid (C6H4(COOH)2, CAS 88-99-3) is a white crystalline aromatic dicarboxylic acid that is only slightly soluble in cold water. It is more commonly handled as phthalic anhydride. It is an intermediate for phthalate plasticizers used in flexible PVC, alkyd and polyester resins, dyes and pigments. Phthalic acid solutions are mildly acidic and typically stored warm or dilute. Use the compatibility ratings to choose the right tank resin, fittings and gaskets.
Polypropylene is the most economical tank material for Phthalic Acid, rated Excellent. PVDF (Kynar®), HDPE and nylon are also rated Good or better. Avoid Buna-N gaskets.
How Phthalic Acid works with the plastics used to make our storage tanks.
| Material | Rating |
|---|---|
| HDPE | |
| Polypropylene | |
| Nylon | |
| PVDF (Kynar®) |
How Phthalic Acid works with the plastics used for tank fittings.
| Material | Rating |
|---|---|
| HDPE | |
| PVC | |
| CPVC | |
| Polypropylene | |
| PVDF |
How Phthalic Acid works with gasket and O-ring materials.
| Material | Rating |
|---|---|
| Buna-N | |
| EPDM | |
| Viton® |
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