MATERIAL MIXTURES FOR FORMING A COMPLEX FIRE-PROTECTION SYSTEM AND THE APPLICATION THEREOF

Abstract: Material mixture suitable for forming a complex fire-protection system, in particular for the fire-protection of electric cables with synthetic insulation and other combustible materials and equipments, which comprises a material composed of a coating material preventing combustion resp. propagation of fire and optionally a material being suitable for forming an independant wall, and the coating material inhibiting occurance of combustion and propagation of fire, respectively, contains mineral fibres of high melting point, a mineral expanding in water and being able to form a micellular structure, furtheron a synthetic dispersion which can be diluted with water and forming a stable aqueous dispersion and water, as well as optionally colouring agent, i.e. a material being suitable for forming an independent wall or for thickening the coat on an already existing coating layer, containing flocculated mineral fibres, a mineral fine-grist with a high melting point, furtheron a fine material-grist with good water absorption properties and tending to foaming and slippery to the touch in a wet state, expanded pearlite in the required quantity, containing furtheron aqueous water-glass solution sufficient for obtaining the proper consistency, an additive for accelerating binding of the water-glass and foaming agent being insensitive to alkaline reaction in an expedient quantity.

Description: Material mixtures for forming a complex fire-protection system and the application thereof Technical Field The invention relates to a complex fire-protection system, in particular to material mixtures " being suitable for coatings and/or wallings, as well as to the appli¬ cation thereof, One of the fundamental requirements to he met " by materials used for fire-protection is to prevent in¬ flammation of combustible objects, constructions and equipments under momentary or permanent heat influence and to prevent propagation of fire i.e. flames, A further requirement is that materials serving for fire- protection should increase the mass and size of the objects, constructions and equipments to be protected to the possibly least extent without reducing effect of fire-protection. It is of utmost importance that application of protective materials should be simple and could be realized subsequently, furtheron it could be applied to surfaces - even with the most complicated design and shape - in an equal quality and should ad¬ here well thereon. It is also essential that materials to be used for coatings and/or wallings could be pro¬ cessed easily and economically. Background Art For meeting the multiple and severe require¬ ments in respect of safety and application technics in course of using said materials, several solutions have been developed for protecting different objects, electric cable systems, steel structures and other equipments. However, known solutions meet only partly the requirements mentioned above. With complicated overcrowded cable systems, intricately divided steel structures etc. protection cannot be realized at all and if, only with an irreally high expenditure. In general, known materials having been developed for the purpose of fire-protection contain some fire-resistant mineral fibre /e.g. basalt-wool/ and some binding material, mostly cements; heat- insulating properties used to be improved by admixing proper additives, so e.g. expanded pearlite. The mixture processed with water is either sprayed or applied manually onto the surface to be protected. Such a type of coating is specified e.g. in the GDR Patent No. 67345, which serves for the protection of structures made of reinforced concrete and steel; efficient layer thickness of the coating amounts to about 20 cm and it is fire-resi3tant up to 1200 C , Fire-resistant materials containing also pear- lite are dealt with in the German Patents DE-OS 1 243 574, 1 095 187 and DE-AS 818 749. The solutions described serve mainly for shaping solid profiles and insulating bodies. In the German Patent DE-OS 2 051 513 a mixture is disclosed, which contains - in addition to the above mentioned components - maximally 65 % silicate, thus silica or ground kieselguhr; said mixture is well suitable for the protection of steel structures in form of an about 3 cm thick coating which is applied by spraying. The Hungarian Patent HU-PS 163 291 related to a process for producing sheets made of mineral fibres which can be used for fireproof partition walls, thermal insulation of furnaces and for making casting dies. Sheets are made of slag-wood, mineral wool, asbestos and expanded pearlite, as binding material magnesia and solid sodium silicate are used. Sodium silicate is used instead of water-glass solution, generally used for producing heat-resistant materials /as e.g. DE-PS 843 222 and 965 227/, which makes processing rather difficult, however activation of sodium silicate requires a complicated technology, it is not suitable for local application. Wallings and coatings containing cement as binding material are to be constantly wetted up to reaching proper strength of the cement. Water retaining properties of mixtures containing mineral fibres are insufficient, accordingly these do not reach proper strength values without duly performed subsequent wetting. Known material mixtures used for fire-resistant walls are available as prefabricated products only because of their wearisome technology, for local pro¬ cessing - in compliance with prevailing circumstances - they cannot be used at all. Disclosure of the Invention The aim of our invention is to develop material mixtures for making coatings and/or wallings, i.e. a complex fire-protection system, which are free of all the disadvantageous features of known products and which meet requirements relating to safety and application technics as much as possible. Primary - but not exclusive - aim of our invention is directed to the efficient fire-protection of electric cables with synthetic coating and the environment thereof. Electric cables coated with a synthetic insulation - mostly polyvinyl chloride /FVC/ - represent most critical materials from the point of view of fire- protection. In case of a defect involving overheating /e.g. short-circuit, overload etc./ but also under the influence of any external thermal effect, the synthetic insulation catches fire easily and the flames propagate with a considerable speed along the insulation of the inflamed cable, as blasting fuse and the fire is spread through the whole object. Localization of fire - in particular in closed spaces, as e.g. in tunnels for railways, underground railways, tunnels of public works, power plants - is most difficult, moreover, in the majority of cases it is absolutely impossible. Fire-protection of electric cables represent an utmost complex task, as in addition to general points of view of fire-protection - fire- resistance, small mass etc, - special requirements are to be complied with, so e.g. fire-resistant coating should not be excessively heat-insulating so as to be able to avoid overheating in course of operation. Furtheron, it is of utmost importance, that the coating could be applied safely and in a good quality onto the cables already installed, the more, being under operation. Further requirement is that cable fires must not spread to confining rooms, buildings and equip¬ ments from the centre of fire, accordingly path of fire is to be closed; possibility of quick exchanging of damaged cables is to be ensured; it is to be rendered possible to break up the wall without damaging existing cables, as exchange of cables and subsequent pulling-in of cables are frequently occuring activities in practice, We found that a material mixture containing mineral fibres, mineral fine-grist with a high melting point, a mineral expanding in water and being able to form a micellular structure, a synthetic solution forming a stable aquaeous dispersion and water is excellently suitable for forming a thin-layer fire- protecting coating on incendiary and combustible objects, equipments and apparatuses - in particular on electric cables -, which mixture can be applied by spraying, it forms an even layer and meets fully all the require- ments previously mentioned. It was found to be expedient, if the material mixture is applied in two layers; in this case the mixture being suitable for forming one or both, layers should be of different colours to ensure safety of application, in the top layer the synthetic material forming the dispersion can be contained in a larger proportion, than in the priming coat. As mineral fibres short asbestos fibres, chopped glass-wool or rock-wool, as mineral fine-grist with a high melting point e.g. kaolin or siliceous kaolin can be used; illite grist can be added as a mineral being able to form a micellular structure and expanding in water; for forming dispersion polyvinylidene chloride dis¬ persion can be admixed. The mixture contains at least 10 weight- - maximally 30 weight-% short mineral fibre, 0.5 to 30 weight- - preferably 2 to 15 weight-% mineral fine- grist with a high melting point, 1 to 40 weight-%, preferably 4 to 25 weight-%, expediently 5 to 15 weight-% mineral expanding in water and 2 to 50 weight-%, preferably 10 to 35 weight-% synthetic dispersion; in case, if the mixture is applied in two layers, the top layer may contain synthetic dispersion in a higher percentage but not more, than by 10 weight-%. With the coating mixture a coat of an approximate thickness of 0,8 to 1,6 mm is to be formed. In order to obtain the mixture we simply mix the single components into a homogeneous mixture and apply it onto the object to be protected in a suitable manner, expediently by spraying. In case, if two layers are applied, the top layer should be applied into the already dry priming coat. Mixture can be manipulated in a most simple manner, as in course of storing it does not precipitate due to the pulp-like, permanently homogeneous consistency, When agitated it becomes thin, when sprayed it does not cause clogging in the spraying gun, it β — can be applied both cn horizontal and vertical surfaces evenly and permanently. The thin coat thus formed in¬ creases the mass of the cables only to a slight extent, it does not cause a heat-insulating and electric load- ability reducing effect. It resists to the effect of a jet flame of 1800 C° for a longer period. Otherwise, the coating material is well suit¬ able for the fire-protection of other combustible objects and equipments. As already mentioned before, the scope of the invention includes - connected thereto organically - a ' walling and coating material, respectively, which is suitable partly to produce the fire-protective coat previously described, for thickening such coats and/or for producing heat-resistant solids and for performing local walling. This coating or wall-making material, respectively, contains flocculated fibres, mineral grist preferably with a grain size less, than 0,1 mm, a fine-grist with a foaming charachter with a high water-absorbing capacity and slippery to the touch in a wet state, furtheron expanded pearlite and aquaeous water-glass solution in a sufficient quantity for adjusting consist¬ ency, an additive accelerating binding of water-glass and chemically reacting therewith, as well as - according to necessity - a foaming agent being insensitive to alkaline reaction. As flocculated mineral fibres chopped mineral fibrous material, maximally 10 mm long, preferably in a length of 3 to 8 mm, e,g, asbestos fibres or rock- wool fibres can be used; as a mineral grist we may admix a fire-proof fine-grist with a grain-size less, than 0,1 mm with a high melting point, so e.g. kaoline or siliceous kaoline, as material grist illite, as additive sodium silico-fluoride and as a foaming agent fatty alcohol sulfate. Amount of flocculated mineral fibres should be "" at least 10 weight-%, preferably 10 to 25 weight-%, that of mineral grist 0.5 to 4 weight-%, preferably 1 to 2 weight-%, quantity of material grist should equal to at least 1.0 weight-%, preferably 1 to 6 weight-%, expanded pearlite is 1 to 3 weight-%, additive accelerating binding of water-glass, e.g, sodium- silico-fluoride is needed in a quantity of 0.1 to 1,5 weight-%, Proportion of water-glass and water lies in the range between 1:1 and 1:5; prior to use, foaming agent to be used according to necessity is to be dis¬ solved in the aquaeous water-glass solution. Quantity of foaming agent amounts to 0.2 - 3 weight-%, prefer- ably 1 to 1,5 weight-%. In order to prepare the coat or wall , we mix the components, thereafter desired consistency is adjusted with the mixture of water and water-glass, while the mixture is well agitated. In course of agitating the mixture becomes foamy, it can be easily charged mechanically and it is well suitable for being transported in a pipeline. he foamy material can be forwarded with a screw pump without suffering any damage; when applied onto a surface to be protected or when forming a wall, he desired spongy structure can be maintained. In dependence of demands, layer thickness of the coat or walling, respectively, may amount to 15 to 30 mm, however, a thickness of 80 mm is also possible. This thickness enables full fire-protection, Solids may be produced from the mixture, it is suitable for filling locally cradled spaces. Heat- insulating ability of the coat or walling, respectively, is mediocre. The aforementioned thin coating material and the latter coating resp, wall-forming material can be combined for the purpose of fire-protection yielding a high technical level. Fire-protecting effect of the coat-system thus formed is considerable, so the so- called cables of vital importance, /emergency stop, fire-extinguishers, escape routes, supply of elevators with current, etc./ are kept in safe operational state inspite of a fire-effect lasting several hours. Without restricting the scope of invention we give some examples for the material mixture accord¬ ing to the invention, A material mixture being suitable for forming a thin coating may have the following composition: /Quantities are given in weight-%/. Priming coat: 10 % short asbestos fibre 8 % kaoline fine-grist 6 % illite fine-grist 20 % polyvinylidene chloride dispersion 0.5 % red dyestuff 30 % water Top layer: 10 % short asbestos fibre 8 % kaoline fine-grist 6 % illite fine-grist 25 % polyvinylidene chloride dispersion 0.5 % yellow powdered dyestoff 30 % water, Another example for forming the thin coating according to the invention: /quantities in weight-%/ Priming coat: 10 % short-fibre chopped rock-wool 8 % kaoline fine-grist 7 % illite fine-grist 20 % polyvinyliiene chloride dispersion 0,5 % red powdered dyestcff 35 % water. Top layer: 10 % short-fibre chopped rock-wool 8 % kaoline fine-grist 6 % illite fine grist 25 %. polyvinylidene chloride dispersion 0.5 % yellow powdered dyestoff 30 % water. Composition of a material mixture being suitable for thick coating and wall-making, respectively: /quantities in weight-%/ 10 % asbestos fibre in a length of 4 to 5 m 2 % expanded pearlite /grain size 1 to 2 mm/ 3 % illite fine-grist 0.8 % sodiumsilico-fluoride fine-grist. In order to obtain consistency needed for pro¬ cessing, to the dry mixture described above a mixture is admixed consisting of sodium-water-glass and water in a ratio of 1:3, Another example for the composition of the material mixture for preparing thick coating and wall- making, respectively: /quantities in weight-%/ 10 % chopped rock-wcol /fibre length: 3 to 3 mm/ 2 % kaoline fine-grist 2 % illite fine-grist 2 % expanded pearlite /grain size: 1 to 3 mm/ 0.3 % sodiumsilico-fluoride 1.0 % foaming agent /e.g. fatty alcohol sulfonate/ In order to obtain proper consistency, to the dry mixture the mixture of sodium-water-glass and water is added in a ratio of 1:3.

Claims: What we claim is: 1. Material mixture suitable for forming a complex fire-protection system, in particular for the fire-protection of electric cables with synthetic insulation and other combustible materials and equip¬ ments, w h i c h c o m p r i s e s a material composed of a coating material preventing combustion resp. propagation of fire and ' optionally a material being suitable for forming an independent wall, and the coating material inhibiting occurance of combustion and propagation of fire, respectively, containsmineral fibres, mineral fine-grist of high melting point, a mineral expanding in water and being able to form a micellular structure, furtheron a synthetic dispersion which can be diluted with water and forming a stable aquaeous dispersion and water, as well as optionally colouring agent, i.e. a material being suitable for forming an independent wall or for thickening the coat on an already existing coating layer, containing flocculated mineral fibres, a mineral fine-grist with a high melting point, furtheron a fine material-grist with good water absorption properties and tending to foaming and slippery to the touch in a wet state, ex- panded pearlite in the required quantity, containing furtheron aquaeous water-glass solution sufficient for obtaining the proper consistency, an additive for accelerating binding of the water-glass and foaming agent being insensitive to alkaline reaction in an expedient quantity. 2. Thin coating material as claimed in claim 1 for forming a thin coat i c c o m p r i s e s at least 10 weight-% but expediently maximally 30 weight-% short mineral fibres, preferably asbestos fibres and/or chopped glass-wool and/or chopped rock-wool; 0.5 to 30 weight-%, preferably 2 to.15 weight-% kaoline or siliceous kaoline fine-grist; 1 to 40 weight-%, preferably 4 to 25 weight-% illite fine-grist; 2 to 50 weight-%, preferably 10 to 35 weight-% aquaeous synthetic dispersion, expediently polyvinylidene chloride dispersion as well as water in the required quantity; if the mixture is applied in two layers dyestuff can also be contained; the material for thickening the coat i.e. for forming a wall contains preferably at least 10 weight-% floccu- lated mineral fibres, expediently chopped rock-wool, preferably 1 to 4 weight-% kaoline fine-grist, 1 to 5 weight-% illite fine-grist, preferably 1 to 4 weight-% expanded pearlite; in order to obtain proper consistency, the mixture of water-glass and water is added in a proportion of 1:1 - 1:5, as well as an additive to accelerate binding of water-glass, first - - of all sodiumsilico fluoride and optionally foaming agent expediently selected. 3. Complex fire-protection system, w h i c h c o m p r i s e s forming a coat prior to installation, meanwhile or after on the surface to the elements, equipments to be coated from the mixture/s/ as claimed in claim 1 and 2, optionally we form a wall therefrom. 4. Complex fire-protection system, w h i c h c o m p r i s e s ensuring undisturbed operation of the system having been developed for the protection of cables, cable bundles, escape routes etc. being consi¬ dered as of vital importance in case of an enviromental or general fire.

Inventors: KENDERI LASZLO, KENDERI TIBOR, KENDERI, LASZLO, KENDERI, TIBOR
Applicants: KENDERI LASZLO, KENDERI TIBOR, KENDERI, LASZLO, KENDERI, TIBOR
Application year: 1984
Main classification: C09D5
IPC codes: C08K7, C09D5, C09D7, H01B3, H01B7