DE2014118A1 - Fungicidal and insecticidal bonding agent for wood work - Google Patents

Abstract

Fungicidal and insecticidal bonding agent comprising urea-formaldehyde- and/or melamine-formaldehyde glue and an inorganic wood preservative is used for the prepn. of wood-working materials. The wood preservative consists of an insecticidal anion, the pH being adjusted to produce the desired gelling time (pref. below pH 8) by the addn. of a hydroxycarboxylic acid capable of forming a Cu complex or a mixture of such acid or its Na salt with an inorganic acid. The hydroxycarboxylic acid may be a mono, di or tri acid e.g. lactic. tartaric or citric acid. The fungicidal anion is specif. borate, fluoride or arsenate and the inorg. acid may be H2SO4 or HCl which may be partly replaced by NH4-or alkali hydrogen sulphate or by (NH4)2SO4 or NH4Cl.

Description

Fungicidal and insecticidal binding agent for the production of wood-based materials.

The invention relates to a fungicidal and insecticidal binder from urea-formaldehyde and / or melamine-formaldehyde glue and an inorganic one Wood preservatives for the production of wood-based materials.

It is known to use wood-based materials, in particular chipboard and plywood, to protect against wood-destroying fungi and insects by removing the shavings or veneers either with a water-insoluble, organic wood preservative or impregnated with water-soluble, inorganic wood preservatives or the to manufacture these wood-based materials use glues poisoned with wood preservatives.

These known designs have some serious disadvantages that can be remedied by the invention.

Water-insoluble wood preservatives poison the glue, but they are not inatande due to their insolubility in water, in the chips of a chipboard (Veneers of a plywood sheet, etc.) to diffuse into it. It has therefore been suggested to add organic solvents to the glue in addition to these wood preservatives, which penetrate more or less deeply into the wooden parts and the protective agent more or take less. However, since it is used for the production of e.g. chipboard The amount of glue in relation to the surface of these chips is very small, the chip surface becomes only partially wetted by the poisoned binder. Large parts of the chips preserved no wood preservative. In addition, most of the previously used for the production Fungus and insect resistant wood preservatives proposed are not sufficient Effect against the pathogens of the so-called "Modder rot", a putrefaction that in particular Hardwood, e.g. the hardwood portion of chipboard, beech veneer and the like, in can destroy in a short time. To the wood preservatives effective against mold rot pathogens belongs to the pentachlorophenol.

However, organic wood preservatives work at the high press temperatures a noticeable vapor pressure, as a result of which there are losses due to evaporation or Sublimation, which e.g. with pentachlorofhenol more than 50CA of the poisoning of The amount of pentachlorophenol used against wood destroyers and on the other hand there are hygienic concerns because noticeable amounts of poison get into the air.

The wood preservatives mentioned generally do not act as hardeners.

So far, the inorganic wood preservatives are highly soluble borates, boric acid, bifluorides and arsenates or mixtures of these substances have been proposed. These inorganic wood preservatives do not have a sufficient effect against mold rot and can also be used with arsenates and similarly strong poisons glued without hesitation at most for the gluing the inner layer of multi-layer panels, against the gluing of the outer layers of panels, there are considerable hygienic concerns because, for example, chipboard after the crimping are sanded, with large amounts of sanding dust that arise contaminate the air we breathe. Furthermore, it must be taken into account that bifluorides also not suitable because they split off at the high press temperatures can be largely converted by hydrogen fluoride into neutral alkali fluorides.

Among the inorganic wood preservatives that also protect against mold rot are highly effective and at the press temperatures in question, no ins Weight falling vapor pressure include compounds of copper. Incorporation copper compounds in urea-melamine-formaldehyde condensates, however, succeed nio-ht, because the copper reacts with constituents of these glues, thereby reducing their ability to bind is severely affected.

In addition, the glues become unstable.

In order to efficiently add wood preservatives to the glue and to provide a To achieve a uniform distribution of the wood preservative in the board is not possible Üolzsohutzmittel have a high solubility. But the higher the solubility of wood preservatives containing copper is all the faster and more complete these glues are destroyed.

Copper compounds are highly effective against mold rot pathogens; against some other important wood-destroying fungi, e.g. against brown rot Poria and Merulius species, however, copper has a relatively low effectiveness Disadvantage due to the addition of other suitable wood preservatives with fungicidal anions fix, such as boric acid, fluoride, and arsenates, failed because mixtures of copper salts with such wood preservatives in the one in question here pH range no longer have sufficient solubility. Above about pil 4.5 some of the copper is in the form of insoluble more or less finely dispersed If such dispersions are used, urea-melamine-formaldehyde condensates are used then these glues become unstable and their setting capacity is impaired.

The gel times are influenced in a confusing way.

Own attempts to prematurely destroy the glue mentioned Addition of ammoniacal solutions from copper salts and anionic wood preservatives to avoid failed because the gel times increased too much because the Alkalinity of these ammoniacal solutions or those mixed with these solutions Glues too big. It proved impossible to check the alkalinity of this ammoniacal Reduce copper salt solutions by adding inorganic acids to such an extent that Sufficient, reproducible gel times can be achieved. The solubility was also improved severely impaired.

It has been found that the difficulties mentioned are avoided if you check the pH value of ammoiacal or ammonium salt-containing copper solutions in the presence of an oxy acid, in particular an oxymonocarboxylic acid, an oxydicarboxylic acid or an oxytricarboxylic acid or a salt of an oxy acid and these Mixes solution in a urea-melamine-formaldehyde glue.

The invention thus culminates in the knowledge that copper is present of oxyacid, especially those mentioned above, the Do not glue destroyed and their ability to set is not reduced.

The acids bind copper in a complex way, so it also works with pH values remains in solution, which would otherwise be in the form of copper hydroxide or in the form of a other poorly soluble copper compounds, e.g. in the form of copper oxide or basic ones Copper connections, etc., would fail.

Surprisingly, the pH of these solutions and the The glue dispensed with it can be lowered far below the neutral point without precipitating As a result, all gel times that are usual in practice can be set without to impair the quality of the gluing. It is easily possible, e.g. the transverse tensile strength and wet strength values required for V 7o gluing reach and even exceed the latter.

Contains to increase the effectiveness against copper-insensitive fungi the binders according to the invention preferably boric acid or borates, because these are for Warm-blooded animals are practically non-toxic.

However, other known substances such as fluoride, arsenate and the like can be added.

The invention is explained in more detail below using a few examples.

Example 1 Production of a fungicidal glue.

1 a) Wood preservative used.

57.5 parts of crystalline copper sulfate, 42.5 parts of boric acid 1 b) glue formulation for the production of a V 70-glued chipboard, consisting of a middle layer and a top layer.

A commercially available glue made of 70.00 parts is used as the starting product Urea-formaldehyde resin and 3 o, o parts of melamine-formaldehyde resin in 65% strength aqueous solution used.

To glue the top layer, 139 parts of glue are used with a solution of 4.6 parts of the above wood preservative and 2.4 parts of crystalline Citric acid in 41 parts of water, 3'7 Share ammonia (25%) and 4.3 parts of 10% sulfuric acid mixed.

This mixture is sprayed onto 808 parts of chips. The gel time of this The glue / protective agent mixture takes about 90 seconds to glue the middle layer 185 parts of glue with a solution of 9.2 parts of the wood preservative mentioned under 1b) and 4.8 parts of crystall. Citric acid in 55 parts of water, 7.3 parts of ammonia (25%) and 5.5 parts of sulfuric acid (30%) mixed. This mixture is made up of 1616 parts of wood shavings bloated.

The gel time is about 60 seconds.

Press data; Duration: 8 min.

Pressing pressure: 25/5-kp / cm2 Pressing temperature 1600 ¢, the bulk density of the finished chipboard is 650 kg / m3.

Example 2 Production of a fungicidal glue.

2a) Wood preservative used: 57.5 parts of crystalline copper sulphate, 42.5 parts Parts boric acid.

2b) Glue recipe for the production of a V 70-glued chipboard, consisting of from top layer and middle layer.

The concentrated product described under Example 1b) is used as the starting product Urea-melamine-formaldehyde glue.

139 parts of glue are mixed with a solution of 4.6 parts of the above mentioned wood preservative and 1.7 parts of crystalline citric acid in 41 parts of water, 3 Parts of ammonia (25% g) and 4.2 parts of 10% sulfuric acid mixed. This mixture is sprayed onto 8e8 parts of the chips used to produce the top layer is about 9o se ¢. To produce the middle layer, 185 parts of glue are used with a Solution of 9.9 parts of the mentioned wood protection agent and 3.6 parts of crystalline. citric acid in 55 parts of water, 6 parts of ammonia (25%) and 14.3 parts of 30% sulfuric acid mixed. This ao obtained mixture is sprayed onto 1616 parts of wood chips.

The gel time is about 60 seconds.

Press data: as in example 1 The bulk density of the finished chipboard is 650 kg / m3.

Example 3 Production of a fungicidal glue 3a) Wood preservative used: 40 parts of crystall. Copper sulfate 30 parts boric acid 30 parts ammonium sulfate 3b) glue formulation for the production of a V 20-glued chipboard The starting product is a commercially available Urea formaldehyde glue used in the above aqueous concentration.

For gluing, 37 parts of this glue are mixed with a solution of 2.5 parts of the above wood preservative and 0.8 parts of crystalline. citric acid mixed in 28 parts of water and 1.05 parts of ammonia (25%).

The gel time is about 75 seconds.

This mixture is applied to 300 parts of chips. Then the Plate produced using an extrusion process.

Press data: temperature: 1600 C feed rate: 0.8 m / min.

The gross density of the finished chipboard is 660 kg / m3 Example 4 Production of a fungicidal glue 4a) Wood preservative used: 47 parts of crystalline. Copper sulfate 53 parts crystall. Sodium tetraborate 4b) glue recipe for the production of a V 20 glue The starting product is a commercially available urea-formaldehyde glue used in 65% concentration.

To produce the fungicidal glue, 100 parts of the above are used commercial glue with a solution of 5.0 parts of the above Wood preservative and 2.5 parts of crystalline. Citric acid in 30 parts of water, 2.2 parts Ammonia (25%) and 6.5 parts of hydrochloric acid (10 Zig) mixed.

The glue takes about 70 seconds to gel.

Example 5 Production of a fungicidal glue 5a) Wood preservative used: 48.5 parts of crystall. Copper sulfate 43.0 parts crystall. Sodium Tetraborate 8.5 Xeile Boric Acid 5b) Glue formulation for the production of a V 20 glue The starting product is a commercial urea-formaldehyde glue in 25% aqueous solution used.

100 parts of this commercially available glue are used to produce the fungicidal glue Glue with a solution of 4.6 parts of the aforementioned wood preservative, 1.9 parts of tri-sodium citrate-2-hydrate and 3.0 parts of ammonium chloride in 30 parts Water mixed.

The glue takes about 70 seconds to gel.

Example 6 Production of a fungicidal glue 6a) Wood preservative used: as in example 5.

6b) Glue formulation for the production of a V 70 glue as a starting product The commercially available aqueous urea-melamine-formaldehyde glue described in Example 1 is used.

100 parts of this commercially available glue are used to produce the fungicidal glue Glue with a solution of 4.6 parts of the wood preservative given in Example 5 and 1.9 parts of tri-sodium citrate-2-hydrate and 3.0 parts of ammonium chloride in 30 parts Water mixed.

The gelling time of this glue is about 60 seconds.

Example 7 Production of a fungicidal glue 7a) Wood preservative used: 57.5 parts of crystall. Copper sulfate 42.5 parts boric acid.

7b) Glue recipe for the production of a V 20 glue As a starting product was a commercially available urea-formaldehyde glue in 65% aqueous solution used.

154 parts of the commercially available glue were used to produce the fungicidal glue Glue with a solution of 5.9 parts of the aforementioned wood preservative and 2.0 parts of tartaric acid in 50 parts of water mixed with 2.75 parts of ammonia (25%).

The gel time of this glue was about 75 seconds.

Example 8 Production of a fungicidal glue 8a) Wood preservative used: as in example 7 8b) glue formulation for the production of a fungicidal V 70 glue The commercially available aqueous solution described in Example 1 is used as the starting product Urea-melamine-formaldehyde glue.

154 parts of this commercially available glue were used to produce the fungicidal glue Glue with a solution of 5.9 parts of the Holz8chutzmittel8 given in Example 7 and 2.0 parts of tartaric acid in 50 parts of water and 2.75 parts of ammonia solved.

The gel time is about 70 seconds.

Example 9 Production of a fungicidal glue 9a) Wood preservative used: as in Example 7-9b) glue formulation for the production of a V 20 glue.

The starting product is the commercially available, described in Example 1 aqueous urea-formaldehyde glue.

154 parts of the above were used to produce the fungicidal glue commercially available glue with a solution of 5.9 parts of that given in Example 7 Wood preservative and 4.0 parts of lactic acid (90%) in 50 parts of water and 2.75 Parts of ammonia (25%) mixed together.

The gel time was about 70 seconds.

The above application examples are only intended to illustrate the invention explain. The invention is not limited to these examples.

Citric acid, lactic acid and tartaric acid were only selected because because they are typical representatives of oxymono-, oxydi- and oxytricarboxylic acids. the The invention can of course also be used with other oxyacids from the groups mentioned carry out.

You can also use mixtures of such oxyacids and their alkali salts work. Finally, the mixing ratio of oxyacids or their Alkali salt to inorganic acid can be varied. The content of oxyacid or of However, its alkali salt must be at least as high as the copper component at the pH that remains in solution, which is necessary to set the desired gel time is required. A generally binding gel time wsrd cannot be specified because the gel time in different manufacturing plants of wood-based materials is different can be chosen and because it is ultimately also dependent on the composition the melamine-formaldehyde glue or the urea-formaldehyde glue.

The determination of the addition of acid, i.e. of oxyacid and inorganic Acid or mixtures of the salts of this oxyacid with inorganic acid, the pH value required for setting the required gel time is required can be determined in a known manner by simple preliminary tests.

When ammonia is mixed with acid, the ammonium folds are formed the acid in question. As a result, one can use both the aforementioned organic Acids as well as the inorganic acid in whole or in part by the ammonium salts Replace these acids and reduce the ammonia content accordingly. That has Advantage that part of the claimed agent is then produced in solid form and can be delivered.

Finally, you can also increase the crystallized content Replace polybasic inorganic acids with their acidic salts. The ones in the examples 1 and 2 mentioned sulfuric acid can be replaced by the equivalent amount of sodium bisulfate be replaced or by a salt that, when dissolved in water, becomes an acidic salt forms; so sulfuric acid can also be replaced by alkali pyrosulphate.

Mixtures composed according to the invention of copper compounds, an oxymonocarboxylic acid, oxydicarboxylic acid or oxytricarboxylic acid or their salts and boric acid or borates are well below the neutral point even without addition resistant to ammonia and ammonium salts.

The fungicidal binders according to the invention can therefore also be used in such a way that these solutions are free of ammonia and ammonium salts Admits glue and the gelling time of the glue only immediately before it is used adjusts to the desired value with the help of ammonia or ammonium salts. Examples for this one obtains if one adds ammonium chloride in the application examples 5 and 6 omits or only makes it immediately before gluing.

To determine the content of fungicidal and insecticidal copper, boron (or fluorine or arsenic) compounds, one can also use a copper compound as a target Borate (or arsenate or fluoride) of copper with the addition of the oxycarboxylic acid mentioned Dissolve directly in ammonia and this ammoniacal solution Bring the pH value required to set the desired gel time. The copper connection can also be a copper as the oxycaric acid in question.

The amount of fungicidal and insecticidal to be introduced into the wood-based material Wood preservatives depends on the intended use of the wood-based material. The one to be introduced The amount of wood preservative can be greater or less than indicated in the examples.

Claims (9)

Claims 1.) Fungicidal and insecticidal binders made from urea-formaldehyde and / or Melamine-formaldehyde glue and an inorganic wood preservative for the production of wood-based materials, characterized in that the binder is a copper compound, ammonia and / or ammonium salt and an oxycarboxylic acid capable of forming copper complexes or contains a salt of this acid. 2.) Binder according to claim 1, characterized in that there is a Wood preservative contains a copper and a fungicidal or insecticidal anion containing ammoniacal or ammonium salt-containing solution is added, the pH by adding an oxycarboxylic acid or a mixture of an oxycarboxylic acid or a sodium salt of an oxycarboxylic acid with an inorganic acid or a an inorganic acid hydrolytically splitting off sals on the to achieve the desired gel time required pH value, preferably to pH values below pH 8th ! is set. 3.) Binder according to claim 1 and 2, characterized in that the oxycarboxylic acid is an oxymonocarboxylic acid. 4.) Binder according to claim 1 and 2, characterized in that the oxycarboxylic acid is an ocydioarboxylic acid. 5.) Binder according to claim 1 and 2, characterized in that the oligoarboxylic acid is an oxytricarboxylic acid. 6.) Binder according to claim 1 and 2, characterized in that the inorganic acid is sulfuric acid or hydrochloric acid. 7.) Binder according to claim 1 and 2, characterized in that the inorganic acid of the wood preservative contained in the binding agent or completely partially replaced by ammonium or alkali metal hydrogen sulfate or by alkali metal pyrosulfate is. 8.) Binder according to claim 1 and 2, characterized in that the inorganic acid of the wood preservative contained in the binding agent or completely partially replaced by ammonium sulfate or ammonium chloride. 9.) Binder according to claim 1 and 2, characterized in that the fungicidal and insecticidal anion of the wood preservative contained in the binder is a borate. lo.) Binder according to claim 1 and 2, characterized in that the fungicidal anion of the wood preservative contained in the binder is a fluoride or Areenat is.