DE2124811A1 - Fireproof foam panels made from panels coated with silicate foam - Google Patents

Description

2124811 FARBENFABRIKEN BAYER AG

LEVERK US EN-Bayerwerk

Central area

Patents, trademarks and licenses

GM / KK / HG

1 8, Hai 1971

Fireproof foam panels made with silicate foam coated PU panels

The invention relates to fire-resistant foam panels, consisting of a flame-retardant polyurethane panel, which one or both sides with a syntactic foam made of hollow beads made of vinyl chloride-ethylene copolymers and one are coated with silicate-containing structural substance.

According to British patent specification 1,170,999, it is known to process hollow beads made of vinyl chloride-ethylene copolymers into a flame-retardant foam. If such a foam is exposed to a flame, the hollow pearls melt away and the flame can penetrate the resulting hole. In this specification and the sticking of the hollow microspheres is described with a water glass solution to a heat-% stable foam. After drying, a syntactic foam is created from hollow beads and the silicate-containing structural substance. Syntactic foams are foamed materials with a low volume weight, which consist of a coherent phase of any binder in which hollow, spherical structures are embedded, which in turn have a cohesive self-supporting membrane.

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A syntactic foam resembles a closed, cellular foam, in the case of the one at the interface A thin membrane made of the material of the hollow beads is made of solid phase and trapped gas. During a setting process the membrane prevents the trapped gases from escaping or from forming larger pores. The with help Foam panels produced by water glass according to British Patent 1,170,999 have high flame resistance with an exceptionally long burn through time of over 30 minutes.

However, their high density of 100 to 300 kg / m 2 is disadvantageous. It is true that an increased proportion of Hollow beads also foam sheets with a low density can be produced, but such sheets have shorter ones Burn through times. The compressive strength also decreases with a lower volume weight. To with polystyrene or polyurethane foams to obtain comparable thermal insulation values, these panels would have to be in thick layers of more than 5 cm can be used. The hardening of a Syntactic waterglass foam in thick layers causes difficulties, however, because the remaining water passes through thick layers are difficult to remove.

Furthermore, in the German patent application P 20 32 174.8 described to produce flame-retardant rigid polyurethane foams, which when exposed to a flame in a pass thermoplastic state and melt away without burning or developing smoke gases. It can the flame penetrates the foam, but the organic material eludes the flame, and the otherwise dangerous smoke gas development does not occur.

It has now been found that one can use fire-resistant foam boards can produce which, when exposed to a flame,

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Burn, emit still flammable and smoking gases, at the same time have a good thermal insulation effect with a low density if panels made of flame-retardant polyurethane foams are coated on one or both sides with a syntactic foam consisting of hollow beads made of special vinyl chloride-ethylene copolymers and a silicate-containing structural substance . The syntactically foamed silicate layer is usually 0.5 to 5 cm thick, the polyurethane sheet is usually 2 to 10 cm thick. The density of the laminated board is generally between 20 and 80 kg / nP i, and thus significantly lower than the density of a foamed silicate reineα syntactically plate of the same thickness. For example, the density of a pure silicate board is 100 kg / m, whereas that of a 2 cm thick polyurethane board coated on one side with the same material in a 1 cm thick layer is 50 kg / in. The composite panel has a thermal conductivity of approx. 0.025, whereas the pure silicate panel is 0.050.

A 7.5 cm thick silicate board corresponds to a 3 cm thick composite board with the same thermal insulation. Using the composite panel results in considerable weight savings, i

The present invention relates to a fire-resistant board, consisting of a flame-retardant polyurethane foam board, which is covered on one or both sides with a syntactic foam consisting of 1 to 20 parts by weight of hollow beads made from a copolymer of 92-85% by weight vinyl chloride and 8-15% by weight. -Ji ethylene and 80 to 99 parts by weight of a silicate-containing structural substance, has been coated.

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According to the invention, panels are made of flame-retardant Polyurethane foams used. The production of such polyurethane foams is known per se and is e.g. the German Offenlegungsschrift 1 929 034, in the Belgian patents 761 626 and 752 261, in the Dutch published patent application 7 102 524 and French patent 7 017 514. In addition, the production of such foams is also e.g. in the Kunststoff-Handbuch, Volume VII, Polyurethane, published by R. Vieweg and A. Höchtlen, Carl Hanser Verlag, Munich, 1966, e.g. on pages 513 - 520 and 475 described. Hard foams are preferably used.

The polyurethane foam can optionally be flame-retardant Substances have been added. Generally halogen, phosphorus, Antimony, boron and optionally nitrogen-containing organic compounds should be mentioned.

The density of the polyurethane foam sheets is usually 10 to 60 kg / m 2. You can make the panels out of blocks cut to the desired thickness.

The hollow beads used consist of 8 to 15 percent by weight Ethylene and 85 to 92 percent by weight vinyl chloride in copolymerized form. For example, after the British Patent 1,187,667. The diameter of the hollow pearls is usually 50 to 2000 u. It is advisable to use the hollow pearls in water-moist form, as they arise immediately after the expansion process, to use, but dried hollow beads can also be used will. It is advantageous to mix the silicate containing

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212481Ί

Binder before the expansion process in the polymerization or a second mixing autoclave. If you want to mix in the silicate-containing binders after the expansion process, this can be done happen on augers, mixers, kneaders. The silicate-containing binders are in the form of their aqueous Solutions or used as hydrosols. A silicate-containing binder is understood to mean alkali silicates known per se, such as, for example, by treating quartz, glasses, silicate-containing minerals, silicic acid derivatives with Alkali solutions are formed and are known as "water glasses". There are also monomers or polymers Silicic acid, silicic acid with aliphatic or cyclo- "

aliphatic alcohols, hydrated silicic acid, so-called hydrosols in question, as described in Gmelin, Handbuch der inorganic Chemie, 8th Edition, Vol. 15, p. 408 484 are described.

The silicate-containing binders are used as 10 to 80% by weight solutions or brine in water with the hollow beads mixed or added to the finely divided, blowing agent-containing polymer particles before the expansion process. On 1 to 20 parts by weight of hollow beads or finely divided unfoamed polymer are 99 to 80 parts by weight of silicate-containing Binder used. The hollow pearls have a bulk density of 4 to 60 kg / m in the bound state. The mixes You can also add additives such as pigments, stabilizers, thickeners, lubricants, elasticizers and other binders such as organic polymer emulsions or water-soluble adhesives as described in British Patent 1170 999, contain. Such additives can be in 1 to 50 parts by weight, based on 100 parts by weight of silicate-containing binder can be used. Through aging, removal of water, either thermally or through acids or bases or bases

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the foam mixtures gel, and solid foam structures are formed. The aging "can be done by additives accelerated, e.g. by latent acids. These are compounds that acids can set free, which in turn cause gelation or polycondensation of the silicic acid derivatives. Such connections are for example azodicarbonamides, percarbonates, carbonic acid esters, ammonium carbonate, ammonium oxalate, ammonium carbamate, Formats. When exposed to temperature, these compounds split off carbon dioxide, which binds the alkali and thus causes gelling of the foam masses.

You can also use amine hydrochlorides such as aniline hydrochloride, Ammonium salts such as ammonium acetate, inorganic and organic acids or polycarboxylic acids gel. the Catalysts are in 0.5 to 50 parts by weight, based on 100 parts by weight of silicate-containing binder added. The silicate-hollow bead mixture is e.g. with slot extruders, Rolling, doctor blade, scraper on the polyurethane plates discontinuously or continuously in 0.5 to 5 cm thick layer applied. To improve the adhesion, the polyurethane plate can previously be coated with an adhesion promoter such as water glass solution or an adhesive can be sprayed or brushed on.

The composite panels dry at room temperature or at an elevated temperature in ovens or by blowing with them heated air. Heating by infrared or microwave heating has proven to be very useful. The foam layer is brought to temperatures of 40 to 130 °, for example. To accelerate the setting process, the plates can also be blown with carbon dioxide, hydrochloric acid, nitrogen oxides, formic acid, acetic acid, sulfur dioxide. Of the

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Advantage of the claimed foam sheets "is that When exposed to flaram, the hollow beads do not contain any flammable gases split off, as is known, for example, when using foamed polystyrene balls. The vast majority Part in the decomposition gases of the hollow beads consists of hydrochloric acid, which is partly from the alkaline silicate structure is absorbed. When exposed to a flame, the minimal organic fraction burns completely without developing smoke to carbon dioxide and water. The remaining almost closed-cell Silicate framework resists the effects of flame and also prevents the flames from spreading. The polyurethane layer to be used with preference according to the invention melts away at the point of exposure to the flame, without to burn yourself. The remaining silicate layer also prevents the flame from penetrating, so that the Stressed panels are of particular interest as fire protection panels. Such fire protection panels are used to Facade insulation, for the erection of partition walls, for flat roof insulation, whereby the high compressive strength of 5 up to 10 kg / m is advantageous. Possibilities for the production of composite panels are described below.

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Comparative example

10 000 ecm of moist hollow pearls with a water content are mixed of 50% by weight, a particle diameter of up to 600 u of the composition 13.5% by weight of ethylene and 86.5% by weight of vinyl chloride with 1000 ecm of a 10% strength aqueous citric acid solution. 4000 g of a 25% by weight waterglass solution are quickly mixed with the hollow beads pretreated in this way and spreads the mass into a siliconized mold measuring 40 χ 40 χ 7.5 cm. The mix will stored under a carbon dioxide atmosphere for 1 hour at 50 ° C in a heating cabinet, and then the gelled plate demolded. Stored at room temperature, it takes about 3 weeks to achieve constant weight. The density of the Plate is now 100 g / l. The coefficient of thermal conductivity is 0.050.

example 1

A polyurethane sheet of dimensions 40 40 χ 2 with a density of 25 g / l, produced by foaming a mixture of 100 g of a propylene oxide polyether started on bisphenol A, which has been modified at the end with 13 wt .-? 6 ethylene oxide and an OH number of 24θ, 1.5 g of water, 0.8 g of triethylamine and 30 g of monofluorotrichloromethane and 105 g. a biuret polyisocyanate prepared according to French patent specification 7017 514, Example 1 A, with an NCO content of 34.6% by weight, is brushed on one side with a 25 % waterglass solution, placed in a 40 × 40 × 3 cm frame and with coated the mixture described in the comparative example. After 1 hour of gelling in a heating oven under a carbon dioxide atmosphere, it is removed from the mold and the plate is stored at room temperature.

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stores. A constant weight is achieved after approx. 3 days. The plate has a density of 50 g / l with a coefficient of thermal conductivity of 0.025. The compressive strength on the silicate foam side is 7 kg / cm. The plate will in the middle with a forced draft burner that is fed with air and natural gas and produces a 10 cm long flame, flamed on the side of the silicate layer. When the flame is applied there is no development of smoke, and no flames emerge from the plate. After about 3 minutes the polyurethane layer on the back begins to melt away. After 10 minutes the polyurethane side shows

Hole 7 cm in diameter. Even after 30 minutes the *

Flame not yet penetrated through the silicate layer.

Example 2

Example 1 is repeated, but instead of the polyurethane plate described, a plate which is produced by foaming a mixture of 100 g of a sucrose-started propylene oxide polyether with an OH number of 380, 1 g of silicone stabilizer, 1.5 g of triethylamine, 0.5 g Water, 10 g of trichloroethyl phosphate and 40 g of monofluorotrichloromethane and 110 g of a polyphenyl-polymethylene polyisocyanate (produced by condensation of aniline a with formaldehyde and subsequent phosgenation) with an NCO content of 31.2% by weight.

The dimensions of the frame are again 40 χ 40 χ 3 cm, the density 30 g / l. After a constant density of the layered plate of 40 g / l had been reached, the Thermal conductivity 0.023. After exposure to a flame, the polyurethane side had a hole 8 cm in diameter after 5 minutes, the silicate layer was still intact after 30 minutes.

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Example 3

The laminated plate described in Example 1 is after Setting process coated on the uncoated side with the same silicate mixture in a 40 χ 40 χ 4 cm frame and dried as described in Example 1 to constant weight. The density is now 62.3 g / l with a coefficient of thermal conductivity of 0.03. When exposed to a flame, the plate was externally still intact after 30 minutes. The plate was cut apart, it showed a cavity about 9 cm in diameter inside.

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Claims (1)

Claim Fireproof board, consisting of a flame-retardant polyurethane foam board, which is covered on one or both sides with a syntactic foam, consisting of 1 to 20 parts by weight of hollow beads made of a copolymer of 92-35% by weight of vinyl chloride and 8-15% by weight of ethylene, 80 to 99 parts by weight has been coated with a silicate-containing structural substance. Le A 13 75 1 - 1 * - 209649/0960