| 摘要 |
543,401. Treating wood; rot-proofing. IRSA, G. L. DE. Aug. 23, 1940, No. 13401. [Class 140] Wood is impregnated first with a rot- and insect - proofing substance and then with a solution of a neutral or synthetic resin under pressure. Logs are first dried in an evacuated vessel at a temperature not exceeding 100‹C., then impregnated with corrosive sublimate or Tanalith (a mixture of sodium fluoride, sodium arsenate, potassium dichromate and dinitrophenol to which a neutral soft soap may be added and the water removed by a vacuum treatment. A solvent for the resin is then introduced and excess pumped off. A solution of resinit or coumarone resin in a mixture of ethylene tri-chloride and alcohol is then introduced into the vessel by utilizing the vacuum and pressure is applied. The pressure is subsequently reduced to atmospheric, excess solution removed and the temperature slowly increased to remove the solvent. If desired this temperature may be increased to 140‹C, to harden the resin. Paraffin wax may be added to the resin solution. Specification 352,272 is referred to.
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