Generally, it is formed by direct esterification of phthalic acid and monohydric alcohol. By using different monohydric alcohols, various phthalates can be obtained. For example, combining phthalic acid and 2ethylhexanol at a molecular ratio of 1:2.4, MS at a concentration of 0.3%urgeChemistry at 150℃Esterification can produce di(2-ethylhexyl phthalate). Industrially it is called dioctyl phthalate, o- Esterification of phthalic acid is generally carried out under the action of an acidic catalyst. The reaction temperature is 130~150 ℃reaction. It can be carried out under normal pressure or under reduced pressure, depending on the boiling point of the alcohol used.
In order to save raw material alcohol. Also availableα-eneHydrocarbonWith phthalic acidAnhydridereaction, currently一Generally use Jue and phthalic acidSameUsed in the same way, first make the monoester, and then In the presence of perchloric acid, combine the monoester with ‘;letter-spacing: 0;font-size: 16px”>α-Olefin The reaction proceeds to produce phthalate esters. This can reduce the production cost of plasticizer.
Most phthalates are not comprehensive performance,ais generally used as the main plasticizer. The most commonly used one isDOP (dioctyl phthalate), and DBP (dibutyl phthalate) is also widely used. However, due to its high volatility and poor durability, the development of RP is subject to certain restrictions.
DOP and PVC resin can Very good blend. Because of their good electrical properties and low temperature resistance, low volatility, low exudation and toxicity, and many other advantages, they are often used in various formulations, such as cables, films, etc.”
DMP (dimethyl phthalate) and DEP (phthalate) Diethyl formate] is commonly used as the phthalate ester of higher linear alcohols in nitrocellulose and ester-based fibers. Solid plasticizers such as DNOP (monobutyl phthalate) have good properties with many polymers. It has compatibility, low volatility, good durability and low-temperature flexibility. It has more outstanding advantages than esters of branched chain alcohols, but the price is high. In recent years, mixed straight alcohols have been used to synthesize phthalate esters. Such as 79 phthalate, 610ester, with good performance and low price.
Esters of higher alcohols with branched chains, such asDTDP (diisodecyl phthalate), DTDP (di(tridecyl) phthalate), low volatility, small migration, water extraction resistance, and Excellent heat and electricityAbsolutelyGood thermal conductivity, widely used in high-temperature cables, but miscibility and plasticization The effect is worse than DOP.
Asymmetric phthalates are called intramolecular mixed esters, their plasticizing properties are better than the mechanical mixability of the corresponding symmetric diesters of alcohols, and the role of plasticizers can achieve a good balance of performance and cost. For example, butyl octyl ester The performance of (B()P) is between DBP and DCP. The mixing performance is better than DQP, the volatility is smaller than DEP, and the cost is lower than DOP. When there are aromatic groups in the mixed ester, the volatility and mobility can be improved. Commonly used mixed esters include butyl-octyl ester, butyl-butyl ester, butyl-butyl ester, etc.
