CS249121B2 - Retardation and extinguishing powder - Google Patents

Abstract

1. Anti-catalytic additives, optionally with a content of 1 or more adsorbent(s) and/or any inert material(s) for increasing the efficacy of fire retarding and fire extinguishing powders of the basis of 1 or more salt(s) and/or their mixed crystals with urea, characterized in that they contain a) 1 or more inclusion complex(ex) of 1 or more mineral acid(s) with 1 or more cyclodextrine(s) and/or b) 1 or more inclusion complex(es) of 1 or more organic halide(s) with 1 or more cyclodextrine(s) and/or c) 1 or more inclusion complex(es) of 1 or more organic acid(s) with 1 or more cyclodextrine(s) and/or d) 1 or more inner salt(s) of 1 or more amino acid(s) with 1 or more mineral acid(s) with an average particle size below 10 mu m.

Description

The invention relates to a retarding and extinguishing powder which is based on acid salts and optionally mixed crystals formed with urea.

There are known substances and mixtures of substances that slow the outbreak of fire or extinguish fire. These are mainly inorganic acid salts and mixed crystals thereof formed with organic substances.

Most commonly used are alkali metal acid salts, acid ammonium salts and mixed urea crystals of these compounds. In addition to these substances (active substances), the extinguishing powders contain other additives which primarily improve the storage capacity. The effect of retarding and extinguishing powder depends essentially on three factors:

Heat treatment causes a chemical reaction which leads, on the one hand, to reaction products having an extinguishing effect, and on the other hand removes heat from the fire compartment due to the endothermic nature;

- the combustion process as such consists of a chain of processes and the chain is interrupted by the absorption of initiating radicals;

The reaction rate is a function of the specific surface area of the active substance contained in the extinguishing powder.

According to these three aspects, bicarbonates are particularly suitable. KHCO3, Na.NCO3, NHiHCO3, but also Na2PO4 and (NH2 H2PO4) are most used.

It is a well-known phenomenon that the extinguishing effect of a powder depends on the way it is prepared, for example, from which raw materials and by what technology the salt was prepared. This particularly affects crystal size and particle size distribution. By reducing the particle size, the specific surface area is increased and the extinguishing effect is enhanced. However, this is only possible to a certain extent since, at a certain particle size, the ballistic properties of the powder deteriorate so that they can only be shot by carriers.

The object of the invention was to improve the efficiency of the extinguishing powder based on the acid salts and optionally their mixed carbamide crystals.

First, the mode of action of the extinguishing powder was taken into account more closely. Flame fire can basically be conceived as a gaseous fire. Acid salts get into the flame, decompose by heat, and the acid radicals released by the heat act as "radical scavengers" for initiating radicals, interrupting the chain. As is known, weaker acids are displaced by stronger acids from their salts. The distribution of the acid salts and hence the rate of action is therefore increased by allowing them to be treated with a strong acid in the flame.

SUMMARY OF THE INVENTION It is therefore an object of the invention to find substances which are pulverulent, well mixed with, do not react with, extinguish, contact with metals, for example during storage, cause no corrosion and behave abruptly as a strong acid at elevated temperature.

It has now been found that certain anticatalytic additives correspond to these requirements, whose admixture in the extinguishing powder increases its extinguishing effect in many cases by more than double.

The object of the invention is therefore a salt-based retarding and extinguishing powder, in particular alkali metal and alkaline earth metal acid salts and possibly mixed urea crystals thereof, characterized in that it contains from 2 to 20% of a closed mineral acid complex formed with cyclodextrin in molar ratio of i: 0.5 to 2 and optionally 2 to 20% of the closed alkyl halide complex having up to 5 carbon atoms with cyclodextrin in a molar ratio of 1: 0.5 to 2 and optionally 2 to 20% of the alkanecarboxylic acid complex with 2 to 18 carbon atoms and cyclodextrin and optionally 0.5 to 25% of an internal salt of C 3 -C 9 amino acids in the alkyl moiety formed with mineral acids and optionally 0.5 to 25% alkyl halides of up to 5 carbon atoms and optionally 0.5 to 25% chemisorption complexes alkyl halides or 2 carbon atoms, based on the total weight of the powder.

Anticatalytic additives are used with average particle sizes below 10 μm, together with adsorbents such as activated oxides and zeolite.

In preparing the retarding and extinguishing powders, the alkali metal and optionally alkaline earth metal phosphates, hydrogen phosphates, and optionally the alkaline earth metal phosphates, and optionally the respective ammonium salts and optionally mixed crystals of these salts formed with carbamide are mixed with the anticatalytic additives mentioned above.

Cyclodextrins are cyclic oligosaccharides. Ring systems comprising 6,7 or 8 glucopyrancs units are referred to as α-, β- or γ-cyclodextrins. The diameter of the cavity formed from the ring is about 0.68 or even nm. Cyclodextrins form crystalline complexes with molecules of appropriate size and polarity. For example, complexes of certain mineral acids are known [J. Szejtli and Zs. Budai: Acta. Chim. Hung. 94 (4), 383-390 (i977)]. Particularly suitable are the orthophosphoric, hydrochloric and hydrobromic acid complexes formed with the cyclodextrin.

Among the other possible substances, in particular, the internal amino acid salts formed with strong acids can be mentioned. It is generally known that amino acids form with stronger ones. mineral acids are inner salts from which mineral acids are released only well above i00 ° C. The betaacid (betaine hydrochloride) only releases hydrochloric acid above i40 ° C. The same also applies to halogenated paraffins, the effect of which extinguishing powder is superior to that of cyclodextrin.

The fire-extinguishing powders according to the invention do not cause any corrosion, although they contain a relatively strong acid. Their effect is twice as great as that of the extinguishing powder containing no anticatalytic additive. They are not limited to individual classes of flammable substances, but can be used to extinguish all classes of flammable substances (A, B, C, D, E) .The powders can be safely stored below 100 ° C.

The invention will be explained in more detail on the basis of the following examples.

Example 1 x parameters in the quality test. The powder to be examined belongs to the BCE class and contains 42.5% NaHCO3 as active substance. Samples are taken from this powder ("Antipiro-100") and an anticatalytic additive is added for the purposes of the invention. It is homogenized by conventional machines (ball mill, screw).

The powder according to the invention thus obtained is subjected to the same quality test as that produced in the factory. The extinguishing efficiency measured in kg / m2 is calculated as a percentage and is shown in the following table. The extinguishing effect of the extinguishing powder containing no additive was assumed to be 10%.

In the extinguishing powder factory, Table I

Amount

Antipiro- (100%)

Quantity and type of ingredient

Increase in extinguishing efficiency (%)

90 10 BCD-H3PO4 100—150 95 5 BCD-H3PO4 50— 70 85 15 Dec BCD-H3PO4 150—200 80 20 May BCD-H3PO4 180—300 95 5 BCD-HBr 100—150 90 10 BCD-HBr 180—200 85 15 Dec BCD-HBr 200—230 95 5 BCD-HCl 70—100 90 10 BCD-HCl 100—150 85 15 Dec BCD-HCl 150—180 80 20 May BCD-HCl 180—200 95 5 Betacid 60- 80 90 10 Betacid 100—150 85 15 Dec Betacid 200—250 90 10 chlorinated paraffin 200—250 80 20 May chlorinated paraffin 250—300 95 5 alanine 90—100 98 2 cysteine 100—120 95 5 phenylalanine 120—150 98 2 glycine 60—100 80 20 May 10 wt% glycol on Al 2 O 3 support 80—100 80 20 May 10% by weight, acetic acid on AI2O3 carrier 100—150 80 20 May 10 wt% propionic acid on Al 2 O 3 support 80—100 80 20 May 10% by weight of palmitic acid on AI2O3 carrier 20— 30 50 50 25 wt. CzFáBra on Al2O3 carrier 100—200 50 50 25 wt. CF2Cl Br on Al2O3 support 100—200 70 30 25 wt. CH2Cl2 on Al2O3 support 100—150 80 10 10 BCD-H5PO4 in Al2O3 CF2ClBr carriers 200—300

BCD = β-cyclodextrin Betacid = Betaine.HCl

Example 2

Extinguishing powder consisting of 90% NaHCCh (average particle size 45 μ),

7.5% active gamma-alumina (10 μm) and 2.5% calcium stearate (as a hydrophobic agent) were added with various anticatalstic additives and then tested as in Example 1. The results are shown in the following table.

Quantity of basic extinguishing powder (%)

100 ALIGN!

Table II

Quantity and type of ingredient Increase in extinguishing efficiency (%) 5 BCD-H3PO4 100—200 10 BCD-H3PO4 170—200 15 Dec BCD-H3PO4 200—220 2.5 chlorinated paraffin instead of calcium stearate 80—100 5.0 chlorinated paraffin 120—150

instead of calcium stearate

Example 3

Example 4% NaHCO 3% (NH 4) 3 HPO 4% Al (0H) 3% Gamma-AlaOs

5 to 20% cyclodextrin complex with mineral acids is added to this ABC class extinguishing powder, thereby increasing the extinguishing effect by 50 to 200%.

% NaHC13% CO (NH2) 2% NH4H2PO4% A1 (OH) 3% A1 (H2PO4) 3% cyclodextrin-H3PO4 complex

The above composition has a retarding powder for the treatment of wood, textiles and plastics. If these treated substances ignite, they either do not burn or smolder without flame.

Claims (1)

Retarding and extinguishing powder based on salts, in particular alkali metal and alkaline earth metal acid salts and possibly mixed urea crystals thereof, characterized in that it contains from 2 to 20% of a closed mineral acid complex formed with cyclodextrin in a molar ratio of 1: 0, 5 to 2 and optionally 2 to 20% of a closed complex of 1 to 5 carbon atoms with cyclodextrin in a molar ratio of 1: 0.5 to 2 and optionally 2 to 20 VYNALEZU Salt-based retarding and extinguishing powder, percentage of C 2 -C 18 alkanecarboxylic acid complex and cyclodextrin, and optionally 0.5 to 25% of the C 3 -C 9 internal amino acid salt in the alkyl moiety formed with mineral acids and optionally 0.5 to 25% 25% of alkyl halides having 1 to 5 carbon atoms and optionally 0.5 to 25% of chemisorption complexes of alkyl halides having 1 or 2 carbon atoms, based on the total weight of the powder.