DE1218136B - Wood preservatives - Google Patents

Description

Wood preservatives The present invention relates to a new one Wood preservative made from liquid, water-based ammonium fluorates with a The atomic ratio of boron to fluorine is about 1: 1.

The exact composition of these ammonium fluoroborates is not known, however, it should roughly correspond to the formula (Am) 2 (B4F405) '4 H20, where Am is the Ammonium or an organic ammonium cation, e.g. B. triethylammonium, trimethylbenzylammonium and ethanol ammonium. They are obtained by mixing e.g. B. 1 Moles of ammonium bifluoride with 2 moles of boric acid with the addition of a little water and optionally some excess ammonia or excess ammonium compound. Instead of from ammonium bifluoride can optionally also from ammonium fluoride or from Mixtures of hydrofluoric acid with ammonia or nitrogenous ammonium bases and in place of boric acid, partially dehydrated boric acid or boric anhydride go out. You can also add a little urea if necessary.

The ammonium fluorates stand out compared to known wood preservatives characterized by an extremely high solubility in water. Dissolve at 20 ° C about 900 parts (based on solid starting materials) in 100 parts of water.

This has the consequence that wood or wood-containing materials such as Wood chips that are processed into chipboard through a one-time treatment with the wood preservative, e.g. B. by dipping once or by brushing or spray, absorb so much wood preservative that it becomes flame retardant. As a result of the fungicidal and insecticidal properties of the ammonium fluorate is the wood also largely protects against attack by biological destroyers, like mushrooms and insects, protected.

The new wood preservative also has the further advantage that it does not affect the gluing properties of the wood treated with it. A special Drying of the wood or wood-containing materials before gluing is a consequence not necessary due to the low water content.

A good protection of the wood can usually be achieved by about 50 to 250 g and in particular about 100 to 200 g (based on the solids content of the agent) on 1 m2 of wood or with an addition of about 3 to 10 percent by weight, based on atro wood for wood-based materials. If necessary, the liquid, water-containing ammonium fluorates and other flame-retardant substances, e.g. B. ammonium sulfate, can be added.

Wood preservatives containing boron and fluorine are already known correspond to the general formula Me (I) (BF2-4 (OH) 0-2), in which the atomic ratio Boron to fluorine is 1: 2 to 1: 4 and where Me (I) is a monovalent cation. However, such boron fluorides are less soluble than the ammonium fluorates according to the invention. Their concentration in the wood is therefore usually much too low for them to be Could make wood flame retardant. Rather, their importance lies in protection of wood against biological destroyers, especially if they are used together with chromates and / or Arsenates are used, so they work well with a suitable choice of additives form fixing precipitates in the wood.

Also compared to the well-known "phosphate combinations", mostly ammonium phosphate with an addition of fluorides or borates or boric acid, primarily as flame retardants the ammonium fluoborates are significantly superior in terms of their solubility in water. The "phosphate combinations" only dissolve in about 50 to 70 parts at 20 ° C 100 parts of water. To ensure that the wood is sufficiently flame-retardant with them To achieve this, it takes several treatments of the wood with these agents. In addition, the wood treated with such "phosphate combinations" must be glued be dried, which, as mentioned, when using the ammonium fluorate according to The present invention does not apply.

Example 1 570 g of ammonium bifluoride are mixed with 1260 g of boric acid with the addition of 255 g of 25% ammonia solution and receives one Solution, the 925 parts by weight, based on the solid starting materials, to 100 parts by weight Contains water.

With this solution, rough sawn spruce boards with a thickness of 20 mm are made impregnated by painting it once with an amount of approx. 170 g / m2. That Wood treated in this way is flame retardant after drying and against wood-destroying Fungi, such as Poria vaporaria, and wood-destroying insects, e.g. B. Longhorn beetle larvae, protected. Example 2 6 moles of boric acid and 3 moles of ethanolamine are mixed and added 6 mol hydrofluoric acid (as 40% aqueous Solution). This gives a highly concentrated solution of the wood preservative, which is ready to use without further dilution and used for impregnation can be. If necessary, the solution can still be removed by evaporation of water constrict.

Claims (2)

Claims: 1. Wood preservatives made from liquid, water-based Ammonium fluorates, characterized in that they are used for their production Ammonia, boron trioxide and hydrofluoric acid or corresponding ammonium fluorides, organically substituted ammonium compounds or hydrates of boron trioxide in atomic ratio 1N: 2B: 2F, if necessary with excess ammonia or excess organic substituted ammonium. 2. Wood preservative according to spoke 1, characterized in that they also contain other (lamb-retardant substances). Documents considered: German Patent No. 675 400; German Auslegeschriften Nos. 1019 817, 1107 923; U.S. Patent No. 2,823,145.