PIA
Isophthalic acid is one of Isomers of Phthalic acid, also called m-Phthalic acid, an organic compound with the formula m-C6H4(COOH)2, two carboxyl groups in the meta position of the benzen. Isophthalic acid is an important copolymer material for bottle grade polyester chips, low melting fiber, coating resin.
Metaxylene (MX), which produced from Aromatic Unit, is the raw material of Purified Isophthalic Acid (PIA). During the production process, Acetic Acid is used as the solvent. The oxidation reaction is conducted with catalyst and Oxygen, in order to produce Crude Isophthalic Acid (CIA). With the process of hydrogenation, the impurity would be removed. After Crystallization, Separation and Drying, Crude Terephthalic Acid (CIA) is processed into Purified Isophthalic Acid (PIA).
PIA has been used widely in chemical industry. If conducting with Purified Terephthalic Acid (PTA) during copolymerization, it could produce bottle chip and low melting fiber. Adding Purified Isophthalic Acid (PIA) into Alkyd coating resins, or unsaturated polyester resins, could strengthen the weather resistance. The resins could be used as outdoor products. With the sulfonation reaction, Purified Isophthalic Acid (PIA) apply to produce polyester textile dyeing modifier (SIPM). After the copolymerization, polyester fiber could be dyed by cationic dyestuff. It is not only used to improve the dyeing properties of polyester textile, but lower the temperature during the dyeing process.
Product Features
- Molecular weight 166.14; white solid fine-grained powder; insoluble in water, chloroform, ether and acetic acid; slightly soluble in alcohol.
Application：
- (1) Copolyester products (polyester bottle、low melting point polyester fiber, etc.).
- (2) Polyester coating resin.
- (3) Unsaturated polyester resin.
- (4) Cationic dyeable polyester fiber dying modifier.
- (5) Polyurethane adhesive.
Quality specification
| Item | Specification | Product (Typical) |
| Purity(wt%) | Min 99.8% | Min 99.9% |
| Acid nmber(mg KOH/gm) | 675±2 | 675±2 |
| 3-CBA(ppm w/w) | Max 25 | Max 25 |
| m-Toluic acid(ppm w/w) | Max 150 | Max 150 |
| Moistur(wt%) | Max 0.15 | Max 0.10 |
| b*(colour) | Max 1.0 | Max 1.0 |
| APHA colour(2N KOH) | Max 15 | Max 10 |
| Aah(ppm w/w) | Max 15 | Max 9 |
| Metals(ppm w/w) | None greater than 2 and in total max 10 | None greater than 1.0 and in total max 6 |
| Median particle size(um) | - | 120±30 |
