Properties and Applications of Phthalic Anhydride (PA)

What is Phthalic Anhydride (PA)

Phthalic anhydride, also known as ortho-phthalic anhydride (PA), is an important organic chemical raw material. It serves as a general-type anti-scorching agent for natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, and nitrile rubber. It can prevent scorching and improve operational safety with minimal impact on curing time and product aging performance. It is particularly effective with compounds containing azo-guanidine and thiazole-sulfenamide accelerator systems, as well as those mixed with alkaline accelerators, but it is not suitable for sulfur-free sulfenamide curing systems.

Phthalic Anhydride Properties

It is easy to disperse, does not bloom, and has low contamination, but white compounds may exhibit slight discoloration upon exposure to light, making it generally unsuitable for white compounds. Benzene

When used with sodium carbonate in high-accelerated sponge product compounds, phthalic anhydride PA can enhance the foaming action.

The largest application of phthalic anhydride PA is as an organic intermediate in the production of plasticizers, coatings, and unsaturated polyester resins.

Phthalic anhydride PA is also a widely used anhydride-type epoxy resin curing agent. It is inexpensive and generates low heat during curing, making it particularly suitable for large castings and laminates.

The cured product has good electrical properties and mechanical strength, excellent chemical resistance, and a heat deflection temperature of 110-147°C. The typical dosage is 30-50 parts, with curing conditions of 100°C for 2 hours followed by 150°C for 5 hours.

Phthalic anhydride PA has a relatively high melting point, is sublimable, and has a short service life (3.5 hours at 110°C).

Phthalic Anhydride Uses

Phthalic anhydride PA is one of the most important organic chemical raw materials. Its main derivatives include dibutyl phthalate, dioctyl phthalate, and diisobutyl phthalate, which are used as plasticizers for PVC, among other applications. It is also used in the production of unsaturated polyester resin; alkyd resin; dyes and pigments; various paints; food additives; laxatives such as phenolphthalein in medicine; pesticides such as benomyl and metribuzin; and sodium saccharin.

Phthalic anhydride PA can be used as an epoxy resin curing agent. This product is an important organic chemical raw material mainly used in the production of phthalate ester plasticizers, coatings, saccharin, dyes, and organic compounds as an intermediate, insecticides, fungicides, rubber processing aids, and photosensitive materials.

In the dye industry, it can be used to prepare important intermediates such as anthraquinone, 2-chloroanthraquinone, and 1.4-dihydroxyanthraquinone, as well as dyes like phthalocyanine blue BS, phthalocyanine blue BX, and phthalocyanine blue B.

It can be used as a curing agent for epoxy resins, with a reference dosage of 30-50 parts by weight. It generates low heat during curing, and the cured product has good electrical properties and mechanical strength, with a heat deflection temperature of 110-152°C.

Phthalic anhydride PA is an important organic chemical raw material used in the synthetic resin industry for the production of polyester resins, amino resins, unsaturated polyester resins, and alkyd resins.

In the plastics industry, it is used to prepare dibutyl phthalate, dioctyl phthalate, and mixed esters as plasticizers. It is also an important intermediate for manufacturing various drugs, paints, and organic compounds.

In summary, phthalic anhydride has a wide range of applications and is an extremely important organic chemical raw material. As a professional phthalic anhydride manufacturer, Douwin provides customers with phthalic anhydride with excellent performance, which can be effectively applied in multiple fields.