FI59355C - FOERFARANDE FOER KONSERVERING AV TRAEVARA MOT ROETSVAMP OCH SKADEINSEKTER - Google Patents

Description

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Patent raeJdelat VTV (51) Kv.lk?/lnt.ci.3 B 27 K 3/52 FINLAND — FINLAND (21) —PKmtamMcnlits 760172 CT 26.oi.76 v 7 (23) Primary cloud · —GlMglMttdag 26.01.76 ( 41) Tullut | ulklMk »l - Bllvlt offandif 27.07.77

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Patent- och raglstarstyralaan AntOktn utlafd och utl. * Krtft * n pubitcarad 30.Ou.8l (32) (33) (31) Pyyd «« y «Motkow. B «|« rd priority (71) Kemira Oy, Malminkatu 30, 00100 Helsinki 10, Finland-Finland (FI) (72) Mikko Aarne Anton Kuusamo, Vaasa, Bo Göran Berg, Koivulahti,

The present invention relates to a method for protecting wood against rot fungi and insect fungi, and to a method for protecting wood against rot fungi and insect fungi, and to a method for protecting wood against rot fungi and insect fungi. the wood is impregnated under overpressure with a decay and insect repellent dissolved in a non-combustible organic liquid boiling at 30-100 ° C, such as a hydrocarbon substituted by several halogen atoms, preferably chlorine atoms, the excess solution is removed and the wood is heated under normal pressure with an oily heating medium having a flash point above 55 ° C, preferably above 70 ° C and in which the solvent used for impregnation dissolves in the solvent for distillation from the heating medium and recovery by condensation.

It is previously known to impregnate wood by immersing it in a treatment solution in a pressure vessel containing a wood modifier dissolved in a halogenated hydrocarbon boiling at 35-100 ° C, after which the excess treatment solution is removed and the impregnated wood is heated with steam or a halogenated hydrocarbon solvent.

59355 In this process, the impregnation solvent must be purified from time to time by mixing the rock oil with it and distilling the solvent away from the oil and the modifier remaining in the oil.

If water vapor is used in this method to heat impregnated wood, the water can cause the wood to swell and deform, and if hot halogenated hydrocarbon vapors are used, it is difficult to control solvent recovery without spreading to the work area. The thermal economy of the process is also poor, because steam has to be used to heat the wood and, in addition, the solvent still has to be distilled separately.

A method is also known in which, after impregnation, the wood is dried at high temperature in a solvent-immiscible liquid and under reduced pressure at a temperature such that the solvent boils off, preferably at 60-90 ° C, after which the drying medium is removed from the vessel. According to this method, a considerable vacuum must be applied to evaporate and remove the solvent from the timber quickly enough and at such a low temperature that the timber is not damaged.

Finnish patent 45626 discloses a method for treating wood by impregnating it with a solution containing a preservative and, after impregnation, drying it with a liquid boiling in a mixture immiscible with a solvent medium and under reduced pressure at a temperature such that the solvent boils off. As the drying medium, a high-boiling oil has been used, to which wax or resin has been added to improve the water-repellent effect and other additives.

Finnish patent application 753217 further discloses a treatment method of the above-mentioned type, in which wood impregnated with a preservative solution is treated in a warm, high-boiling oil under vacuum so that the solvent evaporates from the wood, and the oils are then removed from the treatment vessel under vacuum.

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The method according to the present invention, the main features of which appear from the appended claim 1, differs from these previously known methods in that the drying is carried out at normal pressure with a heating medium in which the impregnation solvent dissolves, which promotes the removal of impregnation solvent from the wood during drying. the surface treatment of the timber is considerably enhanced when the still hot timber is immediately brought into contact with the colder treatment solution. Namely, it has been found that the greater the temperature difference between the hot timber and the colder treatment solution, the better the treatment solution is absorbed on the surface of the wood.

This is apparently due to the fact that the volume of air and gases in the pores of the wood decreases as the wood cools, creating a suction on the surface of the wood which draws the treatment solution onto the surface of the wood.

According to the invention, the wood products are impregnated in a limited, pressure-resistant state at an overpressure (approx. 2-12 kp / cm) with a solution of the polychlorinated hydrocarbons of the preservative. As the preservative, copper thallate, copper naphthenate, tetrachlorophenol, heptachlor, lindane or other known rotting insecticides can be used. As the solvent, methylene chloride, trichlorethylene, carbon tetrachloride or other low-boiling (b.p. 30-100 ° C), non-combustible organic liquids can be used.

The solution is made to penetrate deep into the wood, up to the heartwood, using overpressure, whereby the pressure time is relatively short.

In thin wood, the solution penetrates completely under overpressure in just a few minutes, but even in heavier wood, the impregnation time is often not longer than 60 minutes.

The solution is then removed back to its storage tank so that it is recovered as accurately as possible. Excess solvent in wood products is removed by heating with medium. As the medium, linseed oil, varnish, alkyd resins or other high-boiling oily substances having a Lei flash point of more than 55 ° C, for example more than 100 ° C, can be used.

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Distillation takes place without vacuum and contrary to previous data, very quickly. The solvents in the wood are removed quite completely (recovery is over 90%) and with a distillation time of about one hour with a distillation temperature between 80-140 ° C.

Drying oil is partially left on the surface of hot wood products and if the wood is taken out of the cylinder to cool, the oil on its surface dries in a few days into a film on which any translucent paint or paint can be painted.

According to the invention, this step is also carried out surprisingly quickly, in just a few minutes, by removing the hot timber from the pressure vessel and immediately immersing it in a room temperature treatment solution, whereby the drying oil on the wood surface is suddenly completely absorbed into the wood. When an acrylate-latex emulsion is used as the treatment solution, to which various dyes can also be mixed, this too is caused to be absorbed on the surface of the wood on top of the drying oil, whereby the wood products are uniformly colored throughout as desired. Organic preservative solutions can also be used as the treatment solution.

The immersion treatment takes place in about 1-60 seconds, preferably in 5 seconds. The excess is immediately drained back into the basin. The wood is already dry to dry after a few minutes.

The treatment can thus save expensive thermal energy and use it to provide efficient absorption. As the treatment takes place quickly and the timber remains hot even after that, it in turn increases the post-drying and evaporation of water from the surface of the wood.

The total time of the process will be short and the production capacity of the equipment will be large.

The invention is described in more detail below by way of example.

Example

By impregnating a thin pine surface wood and using a copper thallate-naphthenate mixture dissolved as a impregnating agent

Claims (2)

5 59355 to methylene chloride with a copper content of 3 g / l and linseed oil as drying oil and an aqueous emulsion of acrylate latex with * brown color pigment as treatment solution gave the following time and consumption values: 2 Pressure impregnation time (7-8 kp) and a solvent distillation time of 90 min and a distillation temperature of 80-110 ° C, and a color treatment time of 5 sec. The timber was dry after 20 minutes. Consumption rates were 3 Impregnant concentrate 17 kg / m Drying oil 20 kg / m3 Solvent 25 kg / m3 3 Color latex 15 1 / m A method for protecting wood against decaying fungi and insect pests, wherein the wood is impregnated under elevated pressure with a decay and insect repellent dissolved in a non-combustible organic liquid boiling at 30-100 ° C, such as a hydrogenate substituted with several halogen atoms, preferably a chlorine atom, and the wood is heated at normal pressure by contacting it with a hot high-boiling oily heating medium having a flash point above 55 ° C, preferably above 70 ° C and in which the impregnation solvent dissolves in the solvent to distill from the heating medium and recover by condensation, characterized in that contact with a colder treatment solution, possibly containing a dye and / or a water-repellent agent, to absorb this on the surface of the wood. Process according to Claim 1, characterized in that an aqueous emulsion of a latex, such as acrylic latex, is used as the water-repellent agent.