Study On Synthesis And Anticorrosion Properties Of Uv-cured Metal Coating

In the field of metal anticorrosive coating research and development, UV curing technology, with advantages of high curing rate, none VOC and lower energy cost ect, is attracting more and more attention. Because of its renewable resources and nature special molecule structure, the vegetable oil-based coating material was payed much interest.The two kinds of coating preparation methods mentioned above were integrated to develop an UV-cured metal anticorrosive coating material in this paper. Synthesis of Tong Oil modified phenolic aldehyde epoxy resin (TMPE) and the performances of UV-cured coating containing TMPE were studied. The optimal reaction or conversion rates for preparing TAP were achieved at the reaction temperature of 110℃with 0.75%wt oxalic acid as catalyst. The TMP viscosity at 70℃was about 45 mPa·s, which is synthetic product of TAP and formaldehyde reacting for 5.5 hours at 80℃with pH range of 1.0～1.5. The TMPE was produced by TMP, ECH and NaOH, and its epoxy number is 4.4 according to the preparing condition as the amount of ECH and NaOH respectively 6 and 1 time as amount of phenol, the ring-opening and ring-closing reaction temperatures are 70℃and 85℃respectively.The coating adhesion of UV-cured coating was enhanced by TMPE, but which reduced the coating film pencil rigidity. The optimal proportion of TMPE to E-44 is 1/3, the coating pencil rigidity and adhesion can reach 3H and rank 0 with the mixure of TMPE and E-44 as its prepolymer.The pencil rigidity and adhesion of cation-radical hybrid coating were 3H and rank 0, respectively, which prepolymer was prepared by bisphenol-A epoxy acrylate and 2 times quality of epoxy resin mixture, composed of TMPE and E-44. Zinc powder was brought to strengthen the anticorrosive ability for the coating. The results showed that the anticorrosive property of the coating added zinc powder by 4%wt comparing to 0, 2%, 6% and 8% was first rank in ammonium nitrate solution and the general properties of the coating with 30%wt zinc is optimal among those with 10%, 20% and 40% in brine.The pencil rigidity and the coating film adhesion, which composed of synthesis product from epoxy resin synthesized with Tong Oil and excessive phenol and E-44, were 3H and rank 0 when amount of E-44 is half of the synthesis polymer. The saline soaking test results indicated that the anticorrosive ability of the coating film with thickness 120μm comparing to 80μm and 40μm is excellent. And the appearance tinct of the above synthesis product was more colorless when part of phenol is replaced by p-tert-butylphenol.