m-benzene unsaturated polyester resin is one of the main varieties of corrosion-resistant unsaturated polyester resin, because of its easy manufacturing, low cost, resistance to weak acids and a variety of solvents. Become a more general medium corrosion-resistant resin. The basic raw materials of isophthalic unsaturated polyester resins are isophthalic acid, maleic anhydride, and propylene glycol. Changing the ratio of the three raw materials will result in a certain change in corrosion resistance. Using neopentyl alcohol instead of propylene glycol has Better weather resistance and water resistance.
In the main chain of the m-benzene type unsaturated polyester resin molecule, because the two ester groups are far apart, the space effect is small, and it has excellent physical and chemical properties. They have high strength, good toughness, water resistance, weather resistance, and corrosion resistance. At present, in the international market, m-benzene unsaturated polyester resin has become a general-purpose resin, such as American EASTMAN company, REICHOLD company, British SCOT BADER company, Dutch DSM company, Japanese catalyst company, these companies have produced m-benzene polyester It accounts for 1/4 of the total polyester. The resin grades introduced by Nanjing Insulation Material Factory from the United States, among which polyester grades resistant to chemical corrosion account for 80% of the isophthalic type and 50% of the gel coat resins.
The unsaturated polyester resins produced by manufacturers of various sizes in our country are mainly o-phthalic polyesters, with less m-benzene type. One of the reasons is that the synthesis time of isophthalic polyester is longer, and the raw material isophthalic acid contains a certain amount of terephthalic acid, which is extremely difficult to react without catalyst. Tang Siding and others used a mixed catalyst of organometallic salts and organometallic compounds to synthesize m-benzene-type unsaturated polyester resin in a relatively short time. The resin has good resistance to boiling water, chemical corrosion and physical and mechanical properties.
The m-benzene type unsaturated polyester resin is widely used in industries such as ships, sanitary ware, urban water supply facilities and sewage treatment equipment. In some special industries, the application of m-benzene type unsaturated polyester resin is also under study.