BE433253A

BE433253A -

Info

Publication number: BE433253A
Authority: BE

Description

       

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  Procédé pour produira des mélanges de sels protecteurs, contenant du fluor, pour la conservation du bois. 



   11 est connu d'employer pour la conservation du bois des sels de fluor et leurs mélanges avec d'autres sels fongicides ou insecticides. On rencontre cependant la difficulté que la vitesse avec laquelle la solution imprégnante s'infiltre dans le bois diminue selon la nature du bois à traiter et que la durée de traitement   s'en   trouve notablement prolongée. Par suite de cette absorption ralentie de l'agent d'imprégnation il se développe une formation correspondante de boue, dont les causes ne sont pas élucidées à ce jour de façon bien nette. 



   Or on a trouvé qu'on peut écarter ou réduire notable- ment ces difficultés en ajoutant aux sels ou mélanges salins 

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 d'imprégnation à employer, des polyphosphates des alcalis ou des métaux   alcalino-terreux.   Il se manifeste alors l'effet surprenant que non seulement la vitesse d'infiltration de la solution imprégnante dans le bois est augmentée, mais encore que la formation de boue indésirable, et redoutée pour diverses raisons, est empêchée. Cet effet de l'addition de poly phosphates demeure encore inexpliqué. 



   On a trouvé en outre qu'on peut ajouter les polyphos- phates au dissolvant (eau) et y mélanger ensuite les sels d'im- prégnation, ou bien mélanger les poly phosphates immédiatement au sel d'imprégnation solide. On peut ainsi produire ,des mélan- ges de sels protecteurs à teneur en fluor, dont on peut adapter la composition, dans une large mesure, à l'essence de bois à traiter dans chaque cas considéré, à condition de choisir la valeur pH de la solution aqueuse de ces mélanges salins de manière qu'elle ne dépasse pas 6,9. 



   Cette réserve s'applique notamment aux mélanges salins se composant de fluorures ou silicofluorures des alcalis, des métaux alcalino-terreux ou des métaux lourds, aux sels de fluor, aux sels de fluor et chrome, aux mélanges salins se composant de sels de fluor et chrome et de phénols nitrés ou leurs sels,ou /et de phénols chlorés ou leurs sels,aux mé- langes salins à teneur en fluor et chrome et en arsenic, et aux mélanges salins se composant de sels d'arsenic et de phénols nitrés. 



   Le présent procédé procure l'avantage que les agents d'imprégnation mis en oeuvre sont désormais complètement et intégralement utilisés et que la durée d'imprégnation   lest'nota-   blement abrégée. En outre une imprégnation uniforme du bois est assurée du fait que la formation de boue est empêchée.



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  Process to produce mixtures of protective salts, containing fluorine, for the preservation of wood.



   It is known to use fluorine salts and their mixtures with other fungicidal or insecticidal salts for preserving wood. However, there is the difficulty that the speed with which the impregnating solution infiltrates into the wood decreases depending on the nature of the wood to be treated and that the duration of treatment is thereby significantly prolonged. As a result of this slowed absorption of the impregnating agent, a corresponding formation of sludge develops, the causes of which have not yet been clearly understood.



   Now it has been found that these difficulties can be avoided or considerably reduced by adding to salts or salt mixtures

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 impregnation to be used, polyphosphates of alkalis or alkaline earth metals. There then arises the surprising effect that not only the rate of infiltration of the impregnating solution into the wood is increased, but also the formation of unwanted sludge, and feared for various reasons, is prevented. This effect of the addition of polyphosphates still remains unexplained.



   It has further been found that one can add the polyphosphates to the solvent (water) and then mix the impregnation salts therein, or else the polyphosphates can be mixed immediately with the solid impregnation salt. It is thus possible to produce mixtures of protective salts with a fluorine content, the composition of which can be adapted to a large extent to the species of wood to be treated in each case considered, on condition that the pH value of the aqueous solution of these salt mixtures so that it does not exceed 6.9.



   This reservation applies in particular to salt mixtures consisting of fluorides or silicofluorides of alkalis, alkaline earth metals or heavy metals, to fluorine salts, fluorine and chromium salts, to salt mixtures consisting of fluorine salts and chromium and nitrated phenols or their salts, or / and chlorinated phenols or their salts, to salt mixtures containing fluorine and chromium and arsenic, and to salt mixtures consisting of arsenic salts and nitrated phenols.



   The present process provides the advantage that the impregnating agents used are now completely and completely used and that the impregnation time is considerably shortened. In addition, a uniform impregnation of the wood is ensured because the formation of sludge is prevented.

Claims

CLAIMS EMI3.1 --------------------------- 1.- Process for making mixtures of protective salts, containing fluorine, for preserving wood, characterized by the addition of polyphosphates of alkalis or alkaline earth metals.

2.- A method according to claim 1, characterized in that, when using mixtures of protective salts with fluorine content, consisting of fluorides or silicofluorides of alkalis, alkaline earth metals or heavy metals, the pH value of the aqueous solution of these salt mixtures does not exceed 6.9.

3. A process according to claim 1, characterized in that, when fluorine salts are used, the pH value of the aqueous solution of these salt mixtures does not exceed 6.9.

4. - Process according to claim 1, characterized in that, when fluorine and chromium salts are used, the pH value of the aqueous solution of these salt mixtures does not exceed 6.9.

5.- Process according to. Claim 1, characterized in that, when salt mixtures consisting of fluorine and chromium salts and nitrated phenols or their salts, or / and chlorinated phenols or their salts, are employed, the pH value of the. saline solution of these saline mixtures does not exceed 6.9.

6. - Process according to claim 1, characterized in that, when using salt mixtures with fluorine and chromium content and arsenic, the pH value of the aqueous solution of these salt mixtures does not exceed 6.9.

7. A process according to claim 1, characterized in that, when using salt mixtures consisting of arsenic salts and nitrated phenols, the pH value of the so- <Desc / Clms Page number 4> aqueous lution of these salt mixtures does not exceed 6.9.

8. - Process for producing mixtures of protective salts, containing fluorine., For preserving wood, substantially as described above.