Insulating wood fibre board.

(42) Date of commencement of the patent: 15.10.1992 (45) Date of issue: 25. 6.1993

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>DE-OS 2034208 EP-A2 0107155 US-PS 4256491</td><td>LEITGEB AKTIENGESELLSCHAFT A-9125 KÜHNSDORF, CARINTHIA (AT).</td>

<td></td><td>(72) Inventor:</td>

<td></td><td>DLASKA HUBERT DIPL.ING. DR. KLAGENFURT, CARINTHIA (AT).</td>

(54) WOOD FIBER INSULATION PLATE (57) For the production of hydrophobized wood fiber insulation panels by wet processes, a bitumen-free hydrophobizing agent is added to the wood fibers in an amount of not more than 5% by weight, preferably 2% by weight, based on the wood fiber in the form of an aqueous dispersion of reinforced natural resins 45% solids content mixed. In order to fix the hydrophobizing agent to the individual wood fibers, a fixing agent is then added in the form of an aqueous solution and mixed with the wood fibers and the hydrophobing agent. Optionally, after an intermediate storage a fiber mat is formed from the hydrophobized wood fibers, which, as is customary, further processed to Holzfaserdämmplatte.

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AT 396 137

Π / R 0070013

AT 396 137 B

The invention relates to a wood fiber insulation board, which is made waterproof by bitumen-hydrophobic water repellent

Known Holzfaserdämmplatten be hydrophobic by adding bitumen emulsion (see DIN 68752 or ÖNORM 3006) (bituminous plate). The wood fiber insulation board contains 12% bitumen additive, based on the wood fiber mass (atro).

From DE-OS 2034 208 a bitumen-free hydrophobing and swelling protection agent for chipboard is known.

A disadvantage of the known plates is not only in terms of the environmental concern of adding bitumen, but also the dark brown to black color of the plate and finally the limited wet strength.

The invention has for its object to provide a hydrophobized Holzfaserdämmplatte available, which does not have the disadvantages described.

According to the invention this is achieved with a wood fiber insulation board with the features of claim 1

Preferred embodiments of the invention Holzfaserdämmplatte are the subject of Unteranspriiche.

The wood fiber insulation board according to the invention surpasses the known wood fiber insulation panels rendered hydrophobic by bitumen emulsion additions in several properties. Thus, the wood fiber insulation board according to the invention has a higher bending strength, wherein the higher bending strength is given even after 24 hours of storage in water. In addition, the water absorption of the wood fiber insulation board according to the invention over the known wood fiber insulation panels, which have been rendered hydrophobic by adding a bitumen emulsion, reduced

Another advantage of the wood fiber insulation board according to the invention is that it is no longer dark brown to black as the bitumen plates, but rather normal, not impregnated by Bitumenbeigabe Holzfaserdämmplatten resembles.

In the table below, the essential properties of the panel according to the invention (BVR panel) are compared with the corresponding properties of wood fiber insulation panels rendered bituminous by bitumen addition (bituminous panels).

table

<td>property</td><td>Bitumen board 15%</td><td>BVR plate</td>

<td>Water absorption: (after 24 hours water storage)</td><td>53.16%</td><td>26.13%</td>

<td>Bending strength dry:</td><td>10.43 kp / cm ^</td><td>11.40 kp / cm ^</td>

<td>Flexural strength wet:</td><td>2.25 kgf / cm⁷</td><td>8.44 kp / cm ^</td>

Hereinafter, the operation in the production of wood fiber insulation board according to the invention will be explained with reference to the flow chart shown in the accompanying drawing

The process for the production of wood fiber insulation board according to the invention does not differ from fiber production to blending from that of the known, modified by bitumen emulsion addition (hydrophobized) Holzsfaserdämmplatten (bituminous panels).

In Mischhollander first the hydrophobing agent, for example, reinforced natural resins (for example, the products of the reaction of rosin or tall resin with dienophilic compounds), in the form of an aqueous Disperson with 45% solids content (trade name: Furtin BVR 50, manufacturer: Chemische Werke Franz v. Furtenbach Ges. m. b. H. in Wr. Neustadt). After a mixing time of 10 minutes, the fixing agent, for example an oligomeric aluminum DiziandiamidKondensat, in the form of an aqueous solution (trade name: FURTOFIX B3, manufacturer: Chemische Werke Franz v. Furtenbach Ges. m. b. H. in Wr. Neustadt) to fix the hydrophobing agent to the wood fibers.

-2AT 396 137 B

Overall, up to 1.5%, preferably 0.5 to 0.8% of hydrophobing agent and up to 1.0%, preferably 0.8% of fixing agent were added, based on the wood fiber content.

After a suitable mixing time, for example 15 min, the finished pulp is pumped down and stored in the vat until it has been processed.

From this chest of so prepared material reaches the dewatering machine and is then formed into an endless plate. The further operation, such as the pressing and drying of the wood fiber insulation panels produced again corresponds to the operation in the production of bituminous panels.

A significant advantage of the use of bitumen-free hydrophobing agents, such as the water repellent mentioned as an example, compared to the use of bitumen emulsions is the pH at which to work. When adding a bitumen emulsion, the pH value is adjusted to 4.5 to 4.7, ie to the acidic range, by adding aluminum sulfate.

In the hydrophobizing agent used according to the invention, the improved physical properties achieved according to the invention are achieved at a pH range from 5.5 to 7.0, that is to say in the almost neutral range. Thus, the return water from the fourdrinier and the press can again be used as a diluent without neutralization. or production water can be used, as indicated in the attached flow chart

Below are some examples of inventive, made waterproof by bitumen-free water repellents Holzfaserdämmplatten. The respective physical values ​​obtained are also mentioned here

<td colspan="2">Example j;</td>

<td>Solid pulp freeness 68</td><td>180 g of atro (450 g)</td>

<td>+ 9% BVR-50 (45 percent)</td><td>36 g</td>

<td>+ 1.9% aluminum sulfate pH 5.3</td><td>3.4 g</td>

<td>Density: 260 kg / m³Flexural strength: 17.7 kp / cm²Water absorption: 19.9%</td><td>Thickness: 13.5 mm</td>

<td colspan="2">Example 2:</td>

<td>Solid pulp freeness 68</td><td>180 g atro</td>

<td>+ 9% BVR-50</td><td>36 g</td>

<td>+ 0.8% aluminum sulfate</td><td>1.5 g</td>

<td>+ 0.5% Furtofix P3 (50%) pH 6.0</td><td>1.8 g</td>

<td>Density: 242 kg / m³Flexural strength: 133 kp / cm²Water absorption: 26.5%</td><td>Thickness: 11.5 mm</td>

<td colspan="2">Example 3;</td>

<td>Solid pulp freeness 68</td><td>180 g atro</td>

<td>+ 6% BVR-50</td><td>24 g</td>

<td>+ 1.9% aluminum sulfate</td><td>3.4 g</td>

<td>+ 1% Furtofix P3 = binder pH 5.3</td><td>3.6 g</td>

<td>Density: 259 kg / m³Bending strength: 18.6 kp / crr3 Water absorption: 25.1%</td><td>Thickness: 13.6 mm</td>

<td colspan="2">Example 4:</td>

<td>Solid pulp freeness 68</td><td>220 g atro</td>

<td>+ 3.3% BVR-50</td><td>16 g</td>

<td>+ 0.8% Furtofix P3</td><td>3.6 g</td>

<td>+ 0.5% aluminum sulfate pH 6.0</td><td>1.5 g</td>

<td>Density: 253 kg / m³Bending strength: 10.9 kp / cm ^ Water absorption: 10.8%</td><td>Thickness: 17.0 mm</td>

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Example 5:

Solid pulp Freeness 68 220 g atro + 3.3% BVR-50 16 g + 0.8% Furtofix P3 3.6 g pH 6.0

Density: 236 kg / m³ Thickness: 16.0 mm

Flexural strength: 13.5 kp / cm²Water absorption: 18.0%

Example 6:

Solid pulp freeness 68 +1.6% BVR-50 + 0.5% Furtofix P3 + 0.35% aluminum sulfate pH 6.5

Density: 226 kg / m³Flexural strength: 143 kp / cm²Water absorption 18.6%

Example 7:

Solid pulp Freeness 38 +1.6% BVR-50 + 0.5% Furtofix P3 pH 6.5

Density: 266 kg / m³Flexural strength: 16.0 kp / cm²Water absorption: 14.1%

Example 8:

Solid pulp Freeness 38 + 1.6% BVR-50 + 0.5% Furtofix P3 + 0.35% aluminum sulfate pH 6.3

Density: 249 kg / m³Flexural strength: 12.1 kp / cm²Water absorption: 11.7%

Example 9:

Solid pulp Freeness 38 + 13% BVR-50 + 0.6% Furtofix P3 pH 6.5

Density: 236 kg / m³Bending strength: 10.6 kp / cm2 Water absorption: 11.6%

Example 10:

Solid pulp Freeness 29 + 1.6% BVR-50 + 0.5% Furtofix P3 pH returned water 5.6 pH 5.3

Density: 245 kg / m³Bending strength: 10.6 kp / cm2 Water absorption: 46.5%

220 g. 8g. 2.7 g. 0,75 g

Thickness: 16.1 mm

260 g of atro (620 g) 935 g

2.6 g

Thickness: 20.3 mm

260 g., 9.25 g, 2.6 g, 0.91 g

Thickness: 20.9 mm

260 g., 6.93 g, 3.12 g

Thickness: 23.5 mm

260 g. aro (620 g) 8.26 g 2.6 g

Thickness: 26.8 mm

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<td colspan="2">Example 11:</td>

<td>Solid pulp freeness 29</td><td>173 g of atro (</td>

<td>+ 1.6% BVR-50</td><td>5.51 g</td>

<td>+ 0.5% Furtofix P3 pH returned water: 5.6 pH 5.4</td><td>1.73 g</td>

<td>Density: 224 kg / m³Flexural strength: 14.1 kp / cm²Water absorption: 21.9%</td><td>Thickness: 17.3 mm</td>

<td colspan="2">Example 12:</td>

<td>Solid pulp freeness 32</td><td>190 g of oil</td>

<td>+1.6% BVR-50</td><td>6.76 g</td>

<td>+ 0.5% Furtofix P3 pH returned water 5.1 pH 4.7</td><td>1.9 g</td>

<td>Density 250 kg / m³Flexural strength: 12 kp / cm²Water absorption: 268.1%</td><td>Thickness: 20.5 mm</td>

<td colspan="2">Example 13:</td>

<td>Solid pulp freeness 32</td><td>190 g atro</td>

<td>+ 2.0% BVR-50</td><td>8.45 g</td>

<td>+ 0.5% Furtofix P3 pH returned water 5.1 pH 4.7</td><td>1.9 g</td>

<td>Density: 280 kg / m³Bending strength: 6.7 kp / cm²Water absorption: 239.9%</td><td>Thickness: 22.9 mm</td>

<td colspan="2">Example 14:</td>

<td>Solid pulp freeness 32</td><td>190 g atro</td>

<td>+1.6% BVR-50</td><td>6.76 g</td>

<td>+ 0.5% Furtofix P3 pH returned water 6.5 pH 6.5</td><td>1.9 g</td>

<td>Density: 237 kg / m³Bending strength: 8.5 kp / cm²Water absorption: 19.8%</td><td>Thickness: 22.3 mm</td>

<td colspan="2">Example 15:</td>

<td>Solid pulp freeness 42</td><td>190 g atro</td>

<td>+ 2.0% BVR-50</td><td>8.45 g</td>

<td>+ 0.5% Furtofix P3 pH returned water 5.7 pH 5.1</td><td>1.9 g</td>

<td>Density: 250 kg / m³Flexural strength: 18.5 kp / cm²Water absorption: 27.7%</td><td>Thickness: 15.4 mm</td>

<td colspan="2">Example 16:</td>

<td>Solid pulp freeness 42 </td><td>190 g atro</td>

<td>+ 2.0% BVR-50</td><td>8.45 g</td>

<td>+ 0.5% Furtofix P3 pH returned water 5.2 pH 4.9</td><td>1.9 g</td>

<td>Density: 247 kg / m³Flexural strength: 19.5 kp / cm²Water absorption: 184 3%</td><td>Thickness: 17.6 mm</td>

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<td colspan="2">Example 17:</td>

<td>Solid pulp freeness 42</td><td>190 g atro</td>

<td>+ 2.0% BVR-50</td><td>8.45 g</td>

<td>+ 0.5% Furtofix P3 pH returned water 6.5 pH 6.4</td><td>1.9 g</td>

<td>Density: 243 kg / m³Flexural strength: 16.4 kp / cm²Water absorption: 21.6%</td><td>Thickness: 17.1 mm</td>

<td colspan="2">Example 18:</td>

<td>Solid pulp freeness 42</td><td>190 g atro</td>

<td>+1.6% BVR-50</td><td>6.76</td>

<td>+ 0.5% Furtofix P3 pH returned water 6.5 pH 6.5</td><td>1.9 g</td>

<td>Density: 249 kg / m³Flexural strength: 16.9 kp / cm²Water absorption: 27.7%</td><td>Thickness: 17.8 mm</td>

<td colspan="2">Β? Ϊ§ρφ 19;</td>

<td>Solid pulp freeness 42</td><td>190 g atro</td>

<td>+1.6% BVR-50</td><td>6.76 g</td>

<td>+ 0.5% Furtofix P3 pH returned water; 5.7 pH 5.2</td><td>1.9 g</td>

<td>Density: 250 kg / m³Flexural strength: 18.4 kp / cm²Water absorption: 15.3%</td><td>Thickness 17.1 mm</td>

It should also be noted in the above examples that in the examples 10 to 19, as indicated in the attached flow chart, work was done with return water.

The hydrophobized wood-fiber insulation panels given in Examples 12 to 19 have different and sometimes high water absorption values, since the pulp mixture consists of 50% spruce, wood chips in bark (foreign), 40% spruce, wood chips in bark and 10% larch, and could not be avoided that the accumulation of larch was partly high and this resulted in increased water absorption values.