DE1653268A1 - Improved flame-retardant or flame-retardant chipboard and / or fibreboard - Google Patents

Description

2092

Eeichhold-Albert-Chemie Aktiengesellschaft, 2000 Hamburg 70, Iversstrasse 57

Improved flame retardant or flame retardant chipboard and / or fibreboard

The present invention relates to an improved flame-retardant or flame-retardant chipboard, which is characterized in that it is flame-retardant or flame-retardant in a special way and can nonetheless be produced by conventional methods. The production of chipboard is described in the book "Holzspanwerkstoffe" by Prof Dr Franz Kollmann, Springer Verlag Berlin / Heidelberg / New York 1966. One only has to, based on the wood chip material, 5-25 wt # powdered cured aminoplasts in feinverteil- 'ter form, preferably having a particle size of μ m or below 100, admixing the chip material.. This mixture is processed into a chipboard in the usual way. As special firing tests have shown, the burn-through time of the chipboard produced according to the present invention is at least doubled, so that it has significantly improved properties. Chipboard with such improved flame-retardant or flame-retardant properties are

Documents (Art. 7 g I Ai- *. A No. I Sr.tz 3 dos Amendment Ges. Of 4.9.1967)

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of particular interest for shipbuilding, residential construction and prefabricated house construction

Powder-like aminoplasts that are retained according to the invention are preferably to be understood as: condensation products of urine-formaldehyde which have undergone complete curing and drying and are present in finely divided form, preferably around or below 100 U. The preparation of these powdered cured aminoplasts can be done in that aqueous urea-formaldehyde resin with the aid of catalysts at room temperature or elevated temperature curing, for example, pre-comminuted, at about 130-140 ⁰ C dried and then by grinding to the desired fineness crushed. However, it is also possible to process liquid urea resins with the addition of catalysts in a spray dryer or on a drum dryer. The work steps of hardening, drying and grinding are carried out in one work step.

The usual organic binders are used as binders for the chipboard according to the invention used by phenolic resins, urea resins or melamine resins. It is noteworthy that according to the invention added powdery aminoplast behaves as an inert substance during gluing and pressing, and the mechanical Properties of the chipboard are not impaired in any Y / oiso. Considerable technical progress has been made in the manufacture of the new flame-retardant or flame-retardant chipboard is seen as the organic binder that is used for particleboard production is used in the usual way, neither has to be modified nor used in increased amounts. Farther

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the use according to the invention of the powdered or pulverulent aminoplasts is possible in a simple manner without any significant change in the customary technological processes for the production of chipboard. How out. As can be seen from the comparisons and examples, chipboard with a content of 10 $ urea resin, which has been used in the usual way as a soluble binder, does not increase the burn-through time after hardening compared with chipboard that has been bound, for example, with phenolic resin. In contrast, a chipboard according to the invention, ie a chipboard which contains % aminoplasts in the form of an otherwise inert filler with a grain size of around or less than 100 y, shows a considerable increase in the burn-through time. The effect of the hardened pulverulent urea resin contained in the chipboard, in the form described in this invention, is therefore surprising and provides a considerable technical advance.

For the examples and comparisons, three-layer chipboard was produced in which the proportion of both Top layers with around 35 wt. # And the middle layer was chosen to be approximately 65% by weight. The plate thickness, was uniformly set at 20 mm, the bulk density was between 640 and 660 kg / m.

Comparison 1:

Urea resin-bonded chipboard top layer: 10 $ urea resin on atro chip

0.5 # paraffin emulsion dry to dry

Chip

Middle layer: 8 $ urea resin atro on atro chip

0.5 $ paraffin emulsion dry to dry Chip

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Comparison 2:

Phenolic resin bonded chipboard

Top layer s 10 $ phenolic resin dry on dry chip

0.5 $ paraffin emulsion dry to dry

Chip

Middle layer: 8 $ phenolic resin dry on dry chip

0.5 $ paraffin emulsion dry to dry Chip

Example 1:

Addition of 10 $ according to the invention "described powdery Aminoplasts for the cover layer Analogous to comparison 2, a chipboard was produced, "with the one in the cover layer instead of the pure wood shavings, a mixture of 90 parts by weight of wood shavings and 10 parts by weight of powdered material cured urea resin was used.

Example 2:

A particle board was produced analogously to comparison 2, in which both the top layer and the middle layer instead of the pure wood shavings, a mixture of 90 parts by weight of wood shavings and 10 parts by weight of powdered material cured urea resin was used.

Firing sample:

Chipboard was cut to size approx. 25 x 50 cm, set up vertically and exposed to a Teclu burner flame, which had a length of approx. 18 cm and a flame cone of approx. 5 cm length. The distance from the burner mouth to the chipboard was 13 cm. The axis of the burner tube pointed perpendicular to the plate surface. The time was measured from the beginning of the flame application to the first continuous exposure, i.e. also from the rear

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visible cracking of the plate. The evaluation of the comparison tests gave the following picture:

Comparison 1:

(Urea resin bonded chipboard)? 30 min.

Comparison 2:

(Phenolic resin bonded chipboard): 28 min.

Example 1:

(inventive equipment of

two outer layers): 53 min · etc.

Example 2:

(equipment according to the invention over the entire panel cross-section, i.e. both top layers and the middle layer): 76 min.

The chipboard obtained according to the invention is shown by way of example in the drawings.

FIG. 1 shows a section through a multilayer flat pressed chipboard according to the invention, here the top layers with the number 1 and the middle layer ( 2 with the powdery hardened aminoplasts provided in finely divided form.

FIG. 2 illustrates a section through a single-layer chipboard according to the flat press process, in which all layers merge steplessly into one another and into the powdery hardened aminoplasts thus finely divided over the entire cross-section Form.

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FIG. 3 shows a section through a multilayer flat pressed chipboard again, with only one top layer the powdery hardened aminoplasts 3 contains.

FIG. 4 shows a section of a multilayer flat press chipboard represents, in which both cover layers contain the powdery hardened aminoplasts 3.

The production and use of aminoplasts, especially urine resin, are described in the book: "Ullmann's Encyclopedia of Technical Chemistry" 3rd volume, Verlag Urban & Schwarzenberg 1953, pages 475-494.

The powdery, hardened aminoplast material on the base, denoted by number 3 in the figures of condensation products of urea and formaldehyde was made as follows:

1150 g 37 # ig6S formaldehyde, containing methanol, is mixed with

Sodium hydroxide adjusted to a pH of 7.0 - 7.2. This solution becomes at room temperature
450 g of urea are added, which is brought to a solution in the formaldehyde ^{at approx. 30 0 O.} At a temperature around 9O ⁰ C, the mixture is kept at pH 7.3 7.5 long turbid until the resin at 50 ⁰ C. As soon as the cloud point is reached, the pH value is adjusted to 5> 6 - 5.7 with formic acid. The batch is to be kept at 90 ^° C. until the Gardner viscosity, measured directly, is approx. When the viscosity B is reached, the batch must be cooled and

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6.2 g iriethanolamine and 0.16 g sodium thiosulfate dissolved in Add 0.65 g of water and 0.56 g of dibutyl phthalate.

The pH value should now be 7.7 - 7.9, if necessary, is this pH value with formic acid or sodium hydroxide to adjust.

Manufacture of the hardener:

15 parts by weight of urea

22 parts by weight of hexamethylenetetramine ™

12 parts by weight of ammonium chloride 57 parts by weight of water

Before spray drying, the liquid urea resin must be mixed with 10 $ hardener. This mixture is sprayed in a spray-drying plant "at temperatures of about 100 ⁰ O. In this case, at the same time the curing occurs.

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Claims (4)

Claims 1. Flame-retardant, bound with organic binders Chipboard, characterized in that between the glued chipboard 5 to 25 wt. $ Based on the chip material cured aminoplasts in powder form in finely divided form, preferably with a Grain size around or below 100 μ are arranged. 2. Particle board according to claim 1, characterized in that the powdery cured aminoplasts . Are contained in at least one top layer. 3. Particle board according to claim 2, characterized in that that the powdery cured aminoplasts are contained in at least both cover layers. 4. Particle board according to one of claims 1 to 3, characterized in that the powdery cured Aminoplast material consists of condensation products of formaldehyde with urea. (Art. ~ Γ Λ ..:.:, ..R. Ι L ,: - '.. iz- Är-erun ^ es. V. 9/9/1967) 109883/0239 QRlGMAL INSPECTED