Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N61/00—Biocides, pest repellants or attractants, or plant growth regulators containing substances of unknown or undetermined composition, e.g. substances characterised only by the mode of action
  • A01N61/02—Mineral oils; Tar oils; Tar; Distillates, extracts or conversion products thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
  • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
  • B27K3/34—Organic impregnating agents
  • B27K3/36—Aliphatic compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
  • B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
  • B27K3/52—Impregnating agents containing mixtures of inorganic and organic compounds

Definitions

• This invention relates to wax-containing compositions. More particularly, the invention relates to Waxand oilcontaining compositions which are very useful for the treating and preservation of wood.
• wood of any commercial importance is subject to deterioration after cutting, and the degree and kind of deterioration depends on the type of use to which the wood is put.
• wood deterioration There are, of course, a number of natural agencies of wood deterioration, among which are wood-destroying (decay-producing) fungi, wood-staining fungi, molds, wood-boring insects such as termites, powder-post beetles and carpenter ants, marine borers such as ship worms, martesia, limnoria, sphaeroma and chelura, and the different kinds of deterioration which are normally referred to as weathering.
• Coaltar creosote is produced by distillation of coal tar which consists of the condensable liquids made by carbonization of bituminous coal at elevated temperatures. It is comprised principally of liquid and solid aromatic hydrocarbons and contains appreciable quantities of tar acids (e.g., pyridines, quinolines, acridines) and tar bases (e.g., phenols, cresols).
• tar acids e.g., pyridines, quinolines, acridines
• tar bases e.g., phenols, cresols
• Creosote usual-1y has a boiling range Width of at least 125C, the initial boiling point being in the range of ISO-200C, the final boiling point being in the range 300450C.
• the higher boiling portions of creosote may contain appreciable amounts of fluorene, anthracene and phenanthrene.
• Creosote-coal tar solutions are frequently used in place of creosote alone primarily to reduce the preservative cost.
• Such solutions may be either a solution of coal tar in distillate oil (creosote) or a so-called coal-tar distillate oil. They are comprised of at least 50% coal tar and should contain no more than 3 by volume water and no more than 24% weight benzene insolubles, this amount being directly related to the amount of coal tar in the solution.
• wood preservatives there are, of course, many other closely related wood preservatives.
• water-gas tar and watergas tar creosote which is produced by distillation of water-gas tar, a by-product in the manufacture of watergas from petroleum oils.
• Water-gas tar and water-gas tar creosote are not, however, considered to be as effective as coal-tar creosote.
• Wood-tar creosote produced by distillation of wood tar, is an effective wood preservative.
• it is more expensive than coal-tar creosote and not quite as effective as coal-tar creosote.
• Petroleum oils have occasionally been tried as wood preservatives; however, they possess very low toxic properties when used alone. Consequently, their use has been limited to diluents for other preservative oils such as coal-tar creosote and solvents for toxic chemicals such as pentachlorophenol.
• creosote preservatives are applied to wood by a wide variety of processes.
• non-pressure processes are used as brushing, spraying, dipping, steeping and cold soaking.
• the most widely used processes for treating wood with preservatives are those which are conducted under pressure. In such pressure processes,
• the wood is impregnated in a closed vessel with the preservative, usually in the liquid form, at pressures up to, say, 250 psi. and temperatures on the order of 180- 220F.
• the preservative usually in the liquid form
• the pressure process for example, the wood may first be subjected to a vacuum before pressure impregnation to exhaust air from the wood.
• air is deliberately forced into the wood prior to impregnation in order to facilitate removal of excess preservative and to reduce bleeding and dripping of the preservative upon the completion of the treatment.
• retention In the treatment of wood with preservatives, it is important that retention of the preservative in the wood be high in order to provide a reserve against depletion by leaching and evaporation.
• retention is meant the net amount of treating solution which is retained in the wood after impregnation. Retention is usually measured at the time of treatment by determination of the consumption of treating solution, allowing, of course, for any other known non-retentive losses.
• the minimum amount of retention depends on many factors-the type of wood, the type of service to which the wood is to be put, and the kind of preservative used. Illustrative of the required minimum retention, however, is 5-10 pounds per cubic foot which is specified by the railroads for impregnation of railroad ties with coal-tar creosote-containing compositions.
• Penetration is usually measured by making incremental borings or hit holes in the wood a sufiicient distance from the end of the treated piece of wood to escape the effect of end penetration. Such borings are observed as to penetration promptly after boring.
• the degree of penetration is determined by visual observation of the depth of color change in the wood.
• reagents are used to induce color-producing reactions with the oil, thereby facilitating visual observation of the penetration of the preservative.
• wood-preservative composition consists essentially of 15 to by volume normally liquid creosote, 0 to 45% by volume normally liquid coal tar, the volumetric ratio of creosote to coal tar being at least 1.0:1, 7 to 66.5% by volume Wax and 0.5 to 21.0% by volume of a high-boiling paraffinic petroleum oil, the volumetric ratio of wax-to-oil being from about 2.3:1 to about 19: 1.
• the volumetric ratio of creosote to coal tar be at least about 1.5 :1 and the volumetric ratio of wax to oil from about 4:1 to about 9:1.
• the wax component of the preservative composition it is preferred to use a low-melting-point petroleum paraffinic distillate wax such as that obtained from the dewaxing of petroleum lubricating oil stocks.
• low melting point is meant an ASTM D87 wax melting point of less than 135 F. and preferably no greater than 120 F. The minimum melting point will not, however, be lower than 95 F.
• the wax or the wax-oil mixture which is used in the invention may not have a distinct melting point, in which case its point of phase change is measured by the ASTM D938 Congeal Point.
• Such oily waxes and wax-oil mixtures have been found to be particularly suitable in the composition of the invention.
• the wax contain no substantial amounts of microcrystalline or amorphous wax, which is normally present in all except certain specially refined residual waxes. It is also preferred that the preservative composition contain at least 10% by volume wax and, still more preferably, at least by volume wax.
• oil component of the composition of the invention it is preferred to employ a high-boiling paraflinic petroleum oil, preferably one containing at least 80% paratfinic hydrocarbons and less than aromatic hydrocarbons.
• High-boiling oils containing at least 90% parafiinic hydrocarbons are preferred, especially those oils the paraffins in which contain a high degree of side-chain branching.
• high-boiling oil is meant an essentially hydrocarbon oil no more than about 5% of which boils below 600 F. when heated at one atmosphere pressure.
• oils Within the boiling and viscosity range of distillate lubricating oils which, of course, are substantially vaporizable at 600 F. only at below atmospheric pressures.
• both the oil and wax be of comparatively low average molecular weight, i.e., from 280 to no more than 420 and still more preferably no more than about 340.
• Both the wax and the oil may be fully or only partially refined. They may also be obtained from either the same or different crude oil fractions. Not infrequently, it is possible to obtain the wax and oil in the correct proportions from the same fraction.
• the soft wax product obtained by solvent de-oiling of crude wax obtained by solvent dewaxing of high-viscosity-index distillate lubricating oils is particularly suitable without further adjustment of composition.
• certain crude or slack waxes obtained by dewaxing distillate lubricating oils are likewise frequently suitable. More rarely, certain undewaxed distillate lubricating oil stocks containing very high amounts of wax can also be used.
• highly refined waxes and oils can likewise be employed.
• the customary refining treatments of such Waxes and oils e.g., hydrotreating, acid treating, percolation, etc. have no adverse effect on their efiicacy in the compositions of the invention.
• Example I Four charges of wooden railroad crossties, each containing over 500 ties, were treated with Wood preservative in a commercial scale pressure-treating facility. Two of the charges were treated with a conventional woodpreservative composition consisting of 60% creosote and 40% coal tar. The remaining two charges were treated under the same operating conditions with a waxand oilcontaining wood-preservative composition in accordance with the invention.
• the waxand oil-containing preservative consisted of by volume of 60/40 creosote-coal tar mixture and 15 by volume of soft wax byproduct produced from the solvent dewaxing of a H.V.I. distillate lubricating stock oil.
• the soft wax contained about 29% by volume oil.
• the over-all composition of the waxand oil-containing preservative was therefore as follows:
• Example 11 Two charges of railroad crossties containing an equal number of crossties made from Engelmann spruce were treated separately at the same operating conditions. One charge was treated with a standard solution of pentachlorophenol in petroleum oil, the other was treated with the creosote-Wax-oil composition of Example I. Upon examination of the treated crossties it was found that the pentachlorophenol-oil solution had penetrated an average of only inch, whereas the creosote-Wax-oil composition had penetrated an average of greater than /2 inch.
• the Engelmann spruce ties used in this test were of particularly close grain and dense cell structure, hence the low penetrations.
• the hydrocarbon material is dissolved in a 60/ 40 (by volume) mixture of methyl ethyl ketone and toluene and cooled to 0 F.
• the cooled material is then filtered.
• the resultant filter cake is redissolved in warm fresh solvent and recrystallized by cooling again to 0 F. and filtered.
• the recrystallized cake is washed with additional solvent and repulped but not redissolved by mixing the washed cake with cold (0 F.) solvent and filtered to remove the solvent. Additional cold solvent is finally used to wash the repulped and filtered wax, and the wax is washed.
• Each of the oil fractions is then recombined, either before or after solvent removal if the properties and weight of the oil are to be determined.
• the solvent to feed volumetric ratios employed are as follows:
• a wood preservative composition comprising (a) at least about 51% by volume of coal tar creosote, (b) at least about 34% by volume of coal tar, (c) at least about 10% to 66.5% by volume of low melting point parafiinic wax obtained by solvent deoiling of crude wax obtained by solvent dewaxing of high viscosity index petroleum distillate lubricating oil stocks, said wax being further characterized as having no substantial amounts of microcrystalline or amorphous wax, an ASTM D87 wax melting point of between about F. and F.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Plant Pathology (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Pest Control & Pesticides (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Agronomy & Crop Science (AREA)
• Dentistry (AREA)
• General Health & Medical Sciences (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Environmental Sciences (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)

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Citations (11)

• 1964
  • 1964-03-12 US US351527A patent/US3278377A/en not_active Expired - Lifetime
• 1965
  • 1965-03-10 NL NL6503028A patent/NL6503028A/xx unknown
  • 1965-03-10 DE DE19651266479 patent/DE1266479C2/de not_active Expired
  • 1965-03-10 BE BE660876D patent/BE660876A/xx unknown
  • 1965-03-10 CH CH343065A patent/CH468874A/de unknown
  • 1965-03-10 FI FI0592/65A patent/FI41600B/fi active
  • 1965-03-10 FR FR8637A patent/FR1426615A/fr not_active Expired
  • 1965-03-10 GB GB10227/65A patent/GB1080916A/en not_active Expired
  • 1965-03-10 SE SE3111/65A patent/SE301869B/xx unknown

Patent Citations (11)

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