Patented Oct. 8, 1940 2,217,265

UNITED STATES PATENT OFFICE 2,2,265 WOOD PROTECTION Francis E. Cisak, Indianapolis, Ind., assignor to Peter C. Reilly No Drawing. Application September 16, 1938, Serial No. 230,208 5 Claims. (CL 21-45) My invention is directed generally to the pres- phenol-formaldehyde resins of the thermo-Setting ervation or protection of wood, and has for its type and use a suitable acid as a catalyst. object the obtaining jointly of the advantages in- The nature of a paint or varnish embodying my dividually resulting from creosote-impregnation invention may vary considerably. It may be a and a surface coating with paint or varnish. simple varnish comprising the phenol-formalde- is 5 More specifically, it is the object of my invention hyde resin in a suitable volatile solvent, with or to provide a coating for creosoted wood, which without a catalyst; or it may be a paint made effectively protects the surface, conceals and cov- Similarly to the varnish but including a filler and ers the creosote, and through which the creosote a pigment to impart the desired color. 0 will not penetrate. As an example of a resin suitable for use in 10 I use the term creosote generically, to desig- practicing my invention, I may employ the resin nate the wood-preservative oils which are derived produced by the following process. A solution of from tars and pitches of all sorts, including eS. 648 gms. of cresol (for example, m-p-cresol con pecially coal-tar creosote, wood-tar creosote, and taining about 12% o-cresol), 15 petroleum productS. 584 gms. of 37% aqueous formaldehyde, and Creosote has highly valuable Wood-preserving 1.62 gms. of sodium hydroxide dissolved in 16 cc. properties; but it imparts a distinctive Color and of water m oiliness to wood which because of their persist ence and objectionable character limit the uses Atis refluxedthe conclusion on Water of thispath operation, for about the35 minutes. sodium 20 considerof creosoted it highly wood. unsuitable For instance, for frame most dwelling- people hydroxide ls neutralized, as by the addition of 2.7 2 cc. of glacial acetic acid, and the water removed houses, because it has been substantially impoSSi- by vacuum distillation, about 242 hours being re ble heretofore to coat it over with any coating a. s o quired for this removal. The yield of resin is 780 material through which it Will not penetrate or gms. This resin may be dissolved in 260 gms. of 95 25 “bleed.” d enatured alcohol for further processing. I am aware that many previous attempts have To produce a Sinple warnish from the above been made to cover and hide the CreoSOte in Creo- . Solution, it may be thinned further, preferably , soted wood, and to prevent the creosote from With a less volatile solvent, to improve its spread bleeding' through subsequently applied coatingS ing qualities. About 40 gn.S. of butyl alcohol 30 ofthe various removal kinds. of the Sometimescreosote from this the has superficial involved added to the Sotion produced by the aboye POC 3. portions of the wood, as by dissolving it out With ess will give satisfactorya - results. A warnish thus various solvents. Sometimes alcoholic Solutions prepared, wnen applied to creosoted Wood, Wi. of shellac have been applied. But so far as I am adhere Satisfactorily thereto,- and the creosote m 35 aware, no one heretofore has succeeded1 a in paint Willwill notnot "bleed'set quickly, through but it.will However,remain tacky the varnish for an 8. ing over creosoted Wood With a coating that is - impervious to the creosote as well as the elementS. ErieE. b i.e.Sting St. My present invention overcomes the objections EE, ed E. tellie which have heretofore applied to creosoted Wood. acid which, when added to the above E. in 4. By my invention, for example, it becomes possible quantity of about of gm., will cause the varnish to 40 to use creosote to preserve Wood in and around a Set in 24 to 48 hours. dwelling house, and to cover the creoSoted Wood To make a paint from the resin solution pro with a coating which completely conceals the duced as above described a filler and a pigment Creosote and permits any desired final color to be giving the desired color are added. To produce a 45 obtained. yellow paint, for example, I may add the follow- 46 In accordance with my invention, the creosote ing ingredients to 225 parts of the resin solution: may be applied to the WOOd in any usual or Con- Parts venient manner, preferably by impregnation un- Chrome yellow------80 50 der pressure; and when the creosote is sufficiently Talc (200 mesh)------20 50 dry SO that there is no free liquid Creosote on the Denatured alcohol------45 surface, the creosoted wood is coated with a paint Butyl alcohol------30 or varnish comprising a phenol-formaldehyde Oxalic acid hydrate------6 resin and, desirably, a catalyst acting to promote This entire mixture is ground in a ball mill for the Setting of Such resin, Freferably employ about 10 hours. The resulting paint may be ap 55 2 2,217,265 plied to creosoted wooden articles, such as creo A phenol-formaldehyde resin incorporated in soted telegraph poles, creosoted wood-block floors, a paint or varnish in accordance with my inven creosoted lumber, etc., by means of a brush. Two tion is, when the resin has set, insoluble in Creo coats are generally applied, allowing 24 to 48 sote; and as a result, the creosote does not hours between coats. “bleed.' Its weathering qualities adapt it for 5 As another example of a phenol-formaldehyde use on exposed surfaces and its wearing quali suitable for use in practicing my invention, I may ties for use on floors. Further, since it can be employ a phenol-formaldehyde resin produced by produced in a wide variety of colors, its field of refluxing for 60 minutes a solution embodying application is wide. O 470 gms. of phenol, 488 gms. of 37% aqueous form I claim as my invention: 10 aldehyde, and 4 gms. of sodium hydroxide, neu 1. A wood article having a creosote-impreg tralizing the sodium hydroxide at the end of the nated surface coated with a solution in a volatile reflux period with 6.2 gms. glacial acetic acid, solvent of a thermo-setting phenol-formaldehyde and removing the Water by Vacuum distillation as resin, and a catalyst accelerating setting of such 15 before. resin. The periods of refluxing and distillation will 2. A wood article having a creosote-impreg vary somewhat with operating conditions and nated surface coated with a paint comprising a quantities. They are controlled with regard to solution of a phenol-formaldehyde resin in a the desired viscosity of the paint or varnish in volatile solvent, a pigment, and a catalyst pro 20 which the resin is to be embodied and such con moting setting of such resin. 20 trol usually results in a resin which is approach 3. The process of protecting wood, which corn ing insolubility in the solvent in which it is sub prises impregnating the wood with creosote and sequently to be dissolved. then applying to the Creosote-impregnated Sur It is to be understood that my invention is not face of the wood a coating comprising a Solution 25 limited to the Specific examples set forth above. of a phenol-formaldehyde resin in a volatile Suitable catalysts other than the oxalic acid solvent. mentioned specifically above include acetic acid, 4. The process of protecting wood, which Com tartaric acid, stannous chloride, and other sub prises impregnating the wood with creosote and stances. Even a mineral acid might be used; . then applying to the creosote-impregnated Slil 30 but I find, in general, that the common mineral face of the wood a coating comprising a Solution () acids may have a tendency to result in alteration of a phenol-formaldehyde resin in a volatile of any pigment employed. The pigment used will solvent, and a pigment. of course depend upon the color desired. In ad 5. The process of protecting wood, which com dition to the chrome yellow mentioned above, I prises impregnating the wood with creosote and 35 have used chrome green, Venetian red, burnt then applying to the creosote-impregnated sur umber, cadmium red, cadmium Sulphide, and face of the wood a coating comprising a solution carbon black, as well as mixtures of those pig of a phenol-formaldehyde resin in a volatile ments. Suitable fillers, in addition to talc, are solvent, and a catalyst promoting setting of Such wood flour, ground silica, asbestos floats, diato resin. 40 maceous earth, various clays, powdered mica, FRANCIS E. CISLAK. etc. 40