SE461773B - PROCEDURES FOR THE PREPARATION OF FIRE PROTECTED CHIPPING OR TREATMENT PARTS - Google Patents

Description

The processing requires special tools and special extraction systems must be installed, since specifically relatively heavy dust is formed on such materials with inorganic binders, e.g. cement.

In a similar process (DE-OS 30 44 861), in a one-step process, acid is added, namely sulfuric acid or phosphoric acid, but this is not done to set the adhesive resin on an acid reaction, but to remove from the boron mineral colemenite, a calcium borate, produce free boric acid, which then acts as a fire retardant. If you work with sulfuric acid, boric acid and gypsum are formed. If you work with phosphoric acid, boric acid and calcium phosphate are formed. Admittedly, in this way the introduction of the in principle relatively expensive boric acid into the material becomes computationally favorable, but the possibility of total introduction of fire protection substances is still insufficient. In addition, the chips here are suitably pretreated with alkaline additives and are thus neutralized in advance, which, however, reduces their impregnability. On the other hand, it is per se known in other types of processes for the production of artificial wood pulps (DE-PS 966 041) to digest wood waste by prehydrolysis with an organic acid, so that the adhesive substance can penetrate deeper into the cells.

In all previously known processes, the problem remains that the preferably used adhesive resins have a tendency to cure prematurely as soon as they come into contact with common fire protection substances, especially boric acid. The object of the present invention is therefore to provide a method with which an excellent fire protection can be achieved, while the technological properties of the wood chip materials are mainly maintained, so that these wood chip plates and wood chip mold parts can be further processed and further processed in the same way. as non-fire-protected plates and moldings. The invention thus relates to a process which comprises that the adhesive resin is made strongly acidic by mixing acidic fire retardants before being added to the wood chips and that the wood chips pre-glued with adhesive resin are mixed with fillers which likewise prevent the development of fire, whereby the adhesive resin wood neutralized at least to a large extent.

The method according to the invention has several surprising effects. If you add the adhesive resins in question, for example melamine resins, with only a small amount of acid, the acid first acts as a hardener. The resin / acid mixture is not very stable and cures even at room temperature so fast that a subsequent gluing with the chips can hardly take place. However, if, according to the invention, the adhesive resin is set to a strongly acidic reaction by mixing in the fire protection substances, a stable, cationic adhesive resin solution is obtained, which remains viscosity stable for a sufficiently long time for the gluing of the chips to be carried out without problems. In addition, this adhesive resin solution has a very high impregnation ability for the chips. In this first step, a considerable part of the fire protection substances can thus be introduced into the material without problems. An additional part of fire protection substances and substances which prevent the development of fire are introduced according to the invention by mixing these fillers with the wood chips pre-glued with the adhesive resin solution, which can be carried out without problems and above all homogeneously, since the gluing of the wood chips in advance usually powder-filled fillers are not again separated, especially during the later spreading. The neutralization by means of these fillers, which also prevents the development of fire, also reduces the curing time to the extent required by the process. In this way, a highly fire-protected end product is obtained, mainly while maintaining the technological properties of a wood chip product, in conjunction with the strength values and processing possibilities obtained primarily through the use of ordinary 461,773 adhesive resins for chipboard production. No pre-treatment of the chip is otherwise required. The procedure can be carried out with only insignificant changes in ordinary chipboard plants. It has been found that despite the filler content, which provides very good fire protection and which necessarily leads to a certain reduction of the wood chip content in the final product, this process requires practically only the same amount of binder as for an unprotected plate, which indicates a certain filling effect of the salts and the additives. Despite the filler content, the end products also have a surprisingly good strength and at the same time a very low flue gas density during combustion. It has also been found that some of the known technological properties of non-fire-protected wood chipboard are even significantly improved, especially with regard to water absorption, swelling and smoke development. Experiments have thus shown that plates prepared according to this procedure showed a swelling after 2 hours of about 2% and after 24 hours of about 3 to 4%. The smoke density was about 10%.

Fire tests carried out showed considerable residual strength values. After a fire test for 20 minutes at 700 ° C, the flexural strength of the specimens decreased to only about 1/3 of the flexural strength of the original plate.

The tiles produced according to the process of the invention with their high strength values, especially in the area of the outer layer, can be refined without problems, for example veneered, or coated with resin-impregnated paper, in the same way as non-fire-protected chipboard. The machining of the coated or veneered slabs can be done with tools known from the chipboard machining. Special extraction devices are not required at the processing site.

The plates manufactured according to the process can be produced with the usual pressing factors and the usual pressing temperatures for chipboard. According to this method, it is possible to produce both single-layer and multi-layer plates 461 773 as well as corresponding molded parts without any problems.

Further preferred embodiments of the method according to the invention are characterized in that they mainly relate to the use of certain selected fire protection agents to be added to the adhesive resin, as well as the use of certain selected fillers which prevent the development of fire, and the appropriate proportions of the various the components.

As the adhesive resin, ie as a binder, melamine-formaldehyde condensation products, urea-formaldehyde condensation products or melamine-urea-phenol-formaldehyde condensation products or mixtures thereof can be used.

It is further possible to add up to 25% of isocyanates, such as, for example, diphenylmethane-4,4'-diisocyanate.

In this case, the amine resins are suitably charged with hardeners, for example an addition of 2-10% of ammonium chloride, ammonium sulphate or diammonium peroxide disulphate in the form of a 10-30% aqueous solution. Phosphoric acid, boric acid and aluminum sulphate are suitably added as fire retardants which lead to strong acidification of the adhesive resin-fire retardant mixture. Phosphoric acid is of particular importance for this very strong acidification of the mixture.

The weight ratio of adhesive resin to especially phosphoric acid can be varied within relatively wide limits and ranges from 4: 1 to 1: 4, preferably at 1: 2 to 2: 1.

The concentration of the adhesive resin batches and the fire protection substances is preferably adjusted so that at a starting humidity of the chips of about 4% a humidity of the glued chip mixture, which is mixed with fillers which prevent the development of fire, of about 10-25% is achieved. As a result, the concentration of the sizing additives can have a solids content which varies from 55 to 80%.

As inorganic fillers, which prevent the development of 461,773 fires, alumina hydrate, aluminum sulfate, dolomite, daolin, diatomaceous earth and tungsten as well as mixtures of these substances in weight percentages from about 10 to about 50% have been found to be suitable.

According to these data, a chipboard, which is highly fire-protected, consists of approximately one third of the wood chip, the binder-fire protection substance mixture and the inorganic fillers that prevent the development of fire.

Various embodiments of raw material mixtures for the process according to the invention are given in more detail in the following. s! Example 1 1,200 g of wood shavings with a thickness of 0.2 to 0.6 mm and a length of 1 to 15 mm are mixed at a residual moisture of 4-5% with 390 g of melamine resin (60%), molar ratio of melamine formaldehyde hyd 1: 2.0, 8 g ammonium chloride (25% aqueous solution) and 410 g phosphoric acid (60%).

Then the pre-glued chips are added with a mixture of: 500 130 340 360 and g aluminum sulphate, g boric acid, g diatomaceous earth and g tongue spatula are further mixed.

The chip mixture is then spread on a chip web and pressed into a leveling press.

The resulting plate is sanded and then coated with decorative paper impregnated with melamine resin.

Exemgel 2 1,200 g wood shavings, thickness 0.2-0.6 mm, length l-35 mm, moisture content 4-5%, mixed with a mixture of 600 g melamine resin (60%), molar ratio melamine formaldehyde l : 1.6, 60 g of diammonium peroxide disulfate (10%), 400 g of phosphoric acid (60%) and 130 g of boric acid.

Then 500 g of aluminum sulphate, 340 g of kieselguhr and 360 g of heavy spatula are added. 461 773 The chip mixture Spread out on a chipboard and press in a floor press. The wood chipboard is glued with a 60% melamine resin solution after sanding, coated with a wood veneer and pressed in a floor press. The chipboard thus veneered is removed hot from the mold, the veneer is easily sanded and then treated with a fire protection varnish.

Example gel 3 l.200 g wood shavings, thickness 0.2-0.6 mm, length l-l5 mm, moisture content 4-5%, mixed with 800 g melamine urea resin (60%), molar ratio melamine urea l: 1. Melamine / urea molar ratio: formaldehyde 1: 1.4, 400 g phosphoric acid (60%) and 80 g boric acid.

Then the pre-glued chips are added with 500 g diatomaceous earth and 700 g heavy spatula and mixed further until a uniform distribution has been achieved.

The chips are further processed as described in Example 1.

Example gel 4 1,200 g wood shavings, thickness 0.2-0.6 mm, length l-15 mm, moisture content 4-5%, mixed with 400 g melamine resin, molar ratio melamine formaldehyde 1: 1,4, which is added with 50 g ammonium sulphate , 30%, as hardener and 800 g of phosphoric acid (60%), and 250 g of boric acid and then added with 250 g of alumina hydrate, 300 g of kieselguhr and 700 g of heavy spatula and mixed further. 461 775 The chips thus treated are further processed as described in Example 1.

Exemgel 5 1,200 g wood shavings, thickness 0.4-0.8 mm, length 5-25 mm, moisture content 4-5%, treated with a mixture of 600 g melamine resin (60%), molar ratio melamine: mold aldehyde 1: 1.6, 150 g phosphoric acid (602-ug) and 200 g boric acid.

Then the pre-glued chips are added with a mixture of 400 g tongue spatula, 400 g kaolin and 400 g diatomaceous earth and mixed further.

The chips were used for the intermediate layer.

Example 6 l.200 g wood chip, thickness 0.2-0.6 mm, length 2-8 mm, moisture about 5%, glued with a mixture of 600 g melamine resin (60%), molar ratio melamine formaldehyde 1: 1, 6, 100 g of boric acid, 400 g of phosphoric acid (60%) and 200 g of aluminum sulphate and then mixed further with 500 g of kaolin and 500 g of kieselguhr.

The chips were used for the cover layer. o 461 775 10 Exemgel 7 l.200 g wood shavings, thickness 0.2 - 0.6 mm, length 2-8 mm, moisture about 5%, glued with a mixture of 400 g melamine resin (60%), molar ratio melamine: formaldehyde 1: 8, 400 g phosphoric acid (60%) and 200 g aluminum sulphate and then mixed further with 500 g heavy tongue, 500 g kaolin and 400 g boric acid.

The further processing of the treated wood chips takes place in the manner described in Example 1.

Example gel 8 1,200 g wood shavings, thickness 0.2-0.6 mm, length 2-15 mm, humidity 4-5%, mixed with 400 g melamine resin (60%), molar ratio melamine formaldehyde 1: 1, 8,100 g of phosphoric acid (60%) and 150 g of boric acid and then mixed further with 400 g of heavy spatula and 400 g of alumina hydrate.

The processing is carried out in the manner described in Example 1.

Example gel 9 1,200 g wood chip, thickness 0.2-0.6 mm, length l-l5 mm, moisture content 4-5%, treated with a mixture of 200 g melamine resin (60%), molar ratio melamine formaldehyde l : 2.0, 200 g of phosphoric acid and 200 g of aluminum sulphate.

The pre-glued chip mixture is then further mixed with 46 g of boric acid, 120 g of kieselguhr, 40 g of kaolin and 45 g of dolomite.

The chips are further processed in the manner described in Example 1.

Example gel l0 l.200 g wood chips, thickness 0.2-0.6 mm, moisture content 4-5%, length l-l5 mm, mixed with 400 g melamine resin (60%), molar ratio melamine: formaldehyde l: 1.6, 200 g of boric acid and 400 g of phosphoric acid and then added with a mixture of 400 g of heavy spatula, 400 g of aluminum sulphate and 400 g of dolomite and mixing further.

The chips thus treated are further processed as described in Example 1.

Example gel ll l.200 g wood chip, thickness 0.2-0.6 mm, length l ~ l5 mm, humidity about 4%, glued with a mixture of 400 g melamine urea formaldehyde resin, 60 g diphenylmethane-4,4'-diisocyanate , 460 g of phosphoric acid (60%), 40 g of diammonium peroxide disulphate (10%) and 640 g of aluminum sulphate and then add 450 g of kieselguhr, in iso g of kaolin, 150 g of dicyandiamide and 450 g of boric acid and mix completely. The chips thus treated are further processed in the manner described in Example 1. 461 773 12 Exemggl l2 1,200 g wood shavings, thickness 0.2-0.6 mm, length 1-15 mm, moisture content 5%, mixed with 200 g diphenylmethane-4,4'-diisocyanate, 400 g phosphoric acid (60% 400 g of aluminum sulphate and 200 g of water and then add a mixture of 400 g of kieselguhr, 150 g of dolomite, 100 g of kaolin and 400 g of boric acid and mix further.

The treated chips are further processed in the manner described in Example 1.

Example L3 1,200 g wood shavings, thickness 0.2-0.6 mm, length l ~ l5 mm, moisture content 4%, mixed with 450 g melamine-urea-phenol-formaldehyde resin (60%), 200 g water, 370 g boric acid and 15 g of sodium hydroxide solution (50%) and then added with a mixture of 300 g of aluminum sulphate, 100 g of kaolin, 250 g of kieselguhr and 120 g of dolomite and further mixing.

The chips thus treated are further processed in the manner described in Example 1.

All the characteristics stated in the documentation are considered essential for the invention, insofar as they are new in relation to the state of the art.

M; N /

Claims (9)

461 773 13 PATENT REQUIREMENTS 1. l. Process for the production of fire-protected chipboard or wood chipboard parts by mixing the wood chips with fire retardants, adhesive resins and fillers, spreading the wood chips thus treated and pressing them, characterized in that the adhesive resin is made strongly acidic by admixture with acidic the addition to the wood chips and that the wood chips pre-glued with said adhesive resin are mixed with fillers before spreading, which likewise prevent the development of fire, whereby the adhesive resin-wood chip mixture is neutralized at least to a large extent. 2. A method according to claim 1, characterized in that the concentration of the adhesive resin and the fire protection substances is adjusted so that an initial moisture of the wood chips of about 4% results in a moisture of the pre-glued and with fillers, which prevents the development of fire, loaded the chip mixture of about 10-25%. 3. A method according to claim 1 or 2, characterized in that the adhesive resin is mixed with phosphoric acid. 4. A method according to claim 3, characterized in that the adhesive resin is mixed with phosphoric acid in a weight ratio of 4: 1 to 1: 4. 5. A method according to claim 1, 2 or 3, characterized in that the adhesive resin is mixed with boric acid. 6. A method according to claim 3 or 5, characterized in that the adhesive resin is mixed with aluminum sulphate. Process according to Claim 1, characterized in that the fillers are inorganic substances, for example alumina hydrate, aluminum sulphate, dolomite, kaolin, kieselguhr, tungsten or mixtures of these materials. 8. A method according to claim 7, characterized in that the fillers are preferably mixed in in parts by weight between 10 and 50%, calculated on the weight of the plate. 9. A method according to claim 7, characterized in that the pre-glued wood chips are additionally added with phosphoric acid and / or boric acid together with the fillers.