US 3342614: "FIRE4 RESISTANT ASPHALTIC COMPOSITIONS Russell E. Koons, St. Louis, Mo., mignor to Monsanto Company, April corporation of Delaware November Drawing. (OCR)"



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Patent Title: FIRE4 RESISTANT ASPHALTIC COMPOSITIONS Russell E. Koons, St. Louis, Mo., mignor to Monsanto Company, April corporation of Delaware November Drawing. (OCR)
Patent Number: 3342614 Filing Date: Dec 08, 1961
Application Number: Issue Date: Sep 19, 1967
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FIP8501 XR 34342t6l4 3 2 3 4 2 , 6 1 4 United States Patent Office .,tented Sept. 19, 1967 3,342,614 FIRE4 RESISTANT ASPHALTIC COMPOSITIONS Russell E. Koons, St. Louis, Mo., mignor to Monsanto Company, a corporation of Delaware No Drawing. Filed Dec. 8, 1961, Ser. No. 158,130 5 2 Claims. (Cl. 106-15) The present invention relates to a new composition of matter. More particularly, the present invention relates to a fire resistant asphaltic composition which may be 10 utilized in preparing mastics, roofing, wire coatings, im- pregnated paper or other cellulosic material, plastic ce- inent and the like. The use of asphalt and other bituminous materials in the preparation of mastics, roofing, wire coatings, - impreg- 15 nated paper, etc., is well known. Due to the combustible nature of such materials, however, their use has been severely limited in many areas. Even in the areas where they are frequently used, it is desirable and, in many in- stances, necessary to reduce their combustibility. The cOm- 20 mon method of reducing this combustibility is by the addition of chemicals and materials such as certain chlo- rinated organic compounds and/or non-combustible fillers. Examples of bituminous compositions containing fire re- tardant materials are found in U.S. Patent Nos. 2,861,012 25 and 1, 167,195. The chemicals used with asphalts, tars, etc., to impart fire resistant properties to the finished product are usually rather expensive and must be used in relative- ly large quantities. In addition, many of these chemicals are rather toxic and for this reason dangerous and unde- 30 sirable. There is then a need for fire retardant bituminous compositions wherein the bituminous material itself has improved fire retardant properties. Such compositions would have fire retardant properties at least equivalent to the prescntly k@own fire retardant bituminous composi- 35 tions and yet would need less fire retardant additives to impart these properties. It is then an object of the present invention to provide a new and novel asphaltic composition. A more particular object of the present invention is to provide an asphaltic 40 composition having significantly improved fire retardant properties. Another particular object of the present inven- tion is to provide an asphaltic composition prepared from a particular asphalt, the asphaltic composition having significantly improved fire retardant properties. Addi- 45 tional objects will become apparent from the following de- scription of the invention herein disclosed. In fulfillment of these and other objects, it has been found that an asphaltic composition comprised of as high as 97 and as low as 80 percent by weight of a particular 50 low pqnetration asphalt and 3 to 20 weight percent of a fire retardant chemical possesses fire retardant properties substantially superior to those of known fire retardant bituminous compositions. The particular low penetration asphalt which is the basic component of the present fire 55 retardant composition is one having the following proper- ties: A penetration of 3 to 35 at 71' F., a softening point of 130 to 300' F. Asphalts having these properties .n-iay be obtained by the vacuum reduction, solvent treat- ment, air blowing or a combination of these of the residium 60 from the "topping" of a crude petroleum. This residium material is generally known as a topped crude oil and is that which remains after the atmospheric distillation of cnide petroleum to remove gas, gasoline, haphthas, kero- sene, distillates or diesel oil and gas oil. The most pre- 65 ferred asphalts of the present invention are those which have been obtained by (1) The solvent extraction of a topped crude oil withnormally gaseous hydrocarbons such as butane and/or propane to obtain an asphalt of less than 20 penetration at 77' F. or (2) The solvent extraction 70 or vacuum reduction of such residium to obtain an asphalt of less than 70 penetration at 77' F. with subsequent 2 air blowing to less than 35 penetration. The asphalts obtained by the first method above have a enetration of 0 p to 20 at 77' F., and a softening point of 150 to 250' F. while those obtained by the second method have a penetration of 0 to 35 at 77' F. and a softening point of 130 to 250' F. The fire retardant chemicals which are a part of the herein disclosed composition should be stable up to temperatures of 250' F. or higher. Further, these chemicals must be compatible with the asphalt and not exude from the composition on heating or under the exposure of service for which the composition is intended. Also, the fire retardant chemicals must have a low volatility to prevent their evaporation from the composition at the elevated temperatures generated by approaching or nearby fires as well as under more normal service conditions. Preferred fire retardant chemicals are halogen containing organic compounds such as chlorinated paraffins and polychlorinated polyphenyls and also certain organic phosphorus containing compounds. Non-limiting examples of halogenated organic compounds are such compounds as Aroclor 1248, 1254 and 1260, marketed by Monsanto Chemical Company, which are polychlorinated polyphenyls, Clorowax 40 and 70, marketed by Diamond Alkali Company, hexachlorodiphenyl oxide and hexabromodiphenyl oxide. Particularly preferred fire retardant chemicals for the present composition are the organic phosphates. Several non-limiting examples of fire retardant organic phosphates which may be utilized in the present coating compositions are tricresylphosphate, triphenylphosphate, cresyldip-henyl phosphate, tri-o-chlorophenyl phosphate and tris(2, 3-dibromopropyl)phosphate. As previously stated, the amount of fire retardant chemical added as a part of the present composition may range from 3 to 30 percent by weight of the asphalt-fire retardant additive mixture. It is somewhat preferred, however, that the amount of fire retardant chemical in the new composition disclosedherein be within the range of approximately 5 to 15 percent by weight. If fillers, solvents, or other additives are used in asphaltic fbrmulations, this percentage is correspondingly reduced by dilution. In many of the applications of the present fire-retardant asphaltic blend, such as the preparation of masties, it will be desirable in many instances to use a vehicle. If the use of the present fire retardant asphalt is such that its fire retardant properties are needed only after c-uring of the asphalt, virtually any of the conventional hydrocarbon vehicles such as petroleum napht-ha may be used. However, if the fire retardant properties are needed from the outset prior to curing, then a vehicle with low flammability and self extinguismng properties must be used. It has been found that vehicle mixtures particularly effective in this respect are those containing 0 to 60 percent by wei,-ht of an aromatic naphtha within the boiling range of 80-3 60' F. and I 00 to 40 percent by weight of a volatile halogenated organic compound such as perchloroethylene. A preferred vehicle is one containing 50 percent by weight of an aromatic naphtha boiling from 300 to 360' F. and 50 percent by weight of perchloroethylene. In addition to fire retardant additives, asphalt and sol- vents, it is often desirable and necessary to have present in the compositions of the present invention a mineral filler to impart certain properties necessary for a given end use. These fillers, in many instances, are resistant to fire themselves and therefore decrease to some extent the flammable properties of the total mixture. The amount of filler used will generally range from as low as 1 percent by weight and lower to as high as 50 percent by weight and higher of the total composition. More often, however, the amount of filler when used will range from 10 to 35 percent by weight of the compositions. Usable fillers include all of the fillers known to the art for inclusion in


3 asphaltic compositions. Such fillers include various asbestos fibers, granular asbestos, slate flour, diatomaceous earth, clay, powdered mica, powdered silica, unexpanded and expanded vermiculite, and unexpanded and expanded perlite. The choice of typ,- and amount of mineral filler will be generally dependent upon the particular end use. For example, a particularly tou-h, tear resistant asphaltic mastic is obtained when the cured product contains, in addition to asphalt and fire retardant chemical, approximately 20 weight percent of 7T asbestos and 12 weight percent of slate flour. The latter, being finely .-round, bas been found to increase the viscosity of the asphaltic composition, reducing its tendency to flow when subjected to hi,-h temperatures or mechanical blows. The fire retardant asphaltic compositions prepared in accordance with the present invention find excellent utility in a host of applications. They may beused in the preparation of mastics, roofing materials, wire coatin.-s, impregnated paper and other cellulosic material, plastic cement and the like. Re.-ardless of the application, however, the present composition is significantly improved in fire retardant properties over the known asphaltic compositions. This is well illustrated by the series ol tests described below. Several asphaltic mastics were prepared. Fire tests on these mastics are given in the table below. The asphaltic mastics were spread 3,,3, inch thick on calcium silicate blocks and cured in an oven at 140' F. for one week to evaporate all volatile solvents from the blend. The resultin.- panels were then subjected to a fire test by expos@ure to a standard flame. After 200 seconds' exposure to the flame, the percent of the panel burning was recorded and the flame removed. The time between the removal of the flame and complete self-extin.-uishment of the burning asphalt was also recorded. The percent of the asphalt panel buming after 200 seconds' exposure to a standard flame and the rate at which the burning asphalt selfextinguishes are indicative of the fire resistance of the asphalt composition. Percent Sec c,nds Composition of the A.spbaltie-fire of Panel Until Self- Retardant Mixture Burning Extinglish- at 200 ing Occurred Seconds A ---- A vacuum reduced aspbalt of 90 40 300+ penetration at 771 F. B ---- A vacuum reduced asphalt of 90 31 68 penetration at 771 F. containing 10 ii,eight percent of Aroolor 1262.* C ---- A vacuum reduced asphilt of 90 14 15 Penetration at 771 F. wbich was air blown to 18 penetration at 77' F. contaiiaing 17 Nveight percent of Aroclor 1254.- * --- The asphalt of 0 containing 17 14 12 weight percent of trieresyl phos- phate. * ---- Propane extracted residue of 39 8 I penetration at 77' F. which %vas air blow-n to I penetration at 77' F. containing 14 weight percent trieresyl phospbate. F---- Propaneextractedresiducof3pene- 3 1 tration at 77' F. containing 8 weight percent of trieresyl phos- phate. G---- Propane extracted residue of 33 pen- 1 0 etration at 771 F. Nvhich Nvas air blowil to I penetration at 771 F. containing 13.5 percent of trieresyl phosphate. The Aroclor compounds are polychlorinated polyphenyls. Compositions C, D, E, F and G above represent compositions prepared in accordance with the present invention. The E, F and G compositions represent the preferred compositions of the present invention. A comparison of- compositions B and F dramatically illustrates the supetio'rity of the asphaltic compositions disclosed herein over a more ganerally known composition in regard to their fire retardant ptoperties. There is in the F composition greater than a 900 percent decrease in the percent 3,342,614 4 of the panel burning after 200 seconds and a 5700 percent decrease in the time necessary for self-extin,-Uishment. This improvement with the asphalt of the present invention is obtained wh-ile -usir.,- 2 percent less of a fire retardant chemical than th-- other asphalt. The- unexpectedness o@.1 such results was made more appareiit with the determinalion that while a reduction in pe:,etration of only 87 at 77' F. brou.-ht about th.- above startlin.- results, a reduction in pe@ietration of approximately 120 at 10 77' F. caused an increase in the flash point of only 16' C., or from approximately 333' C. to approximately 349' C. The following examples illustrate the use of th.- here,.n disclosed asphaltic compositions. 15 1. A fire retardaiit mastic with low permeability to water vapor: Components- Percent by wt. 35 peiietration propane extracted asphalt, air blown at 500' F. to 1 penetration at 77' 20 F - ---------------------------------- 43.6 Tricresyl phosphate --------------------- 5.9 \\-Petroleum naphtha, 300/360' F. boiling range ------------------------------- 26.6 Slate flolir- ---------------------------- 9.3 25 7T asbestos ---------------------------- 14.6 100.0 This mastic was sprayed on a prepared surface and al- 30 lowed to cure free of the petroleum solvent, and it was found to htve the following properties: (1) It gave excellent protection to steel in the prevention of corrosion. (2) It was very durable with respect to outside weath- 35 ering conditions. (3) The permeability to water vapor was found to be very low (.002 perm.-inch). (4) It had excellent resistance to abrasion. (5) In a comparative fire test, as described previous- 40 ly in this specification, it had exce]Jent fire retardant properties. 11. A fire retardant mastic with bi.-h permeability to water vapor: Components- Percent by wt. 45 35 penetration propane extracted asphalt, air blown at 500' F. to I penetration at 77' F - - ------------------------------ 25.0 Tricresyl phosphate --------------------- 3.4 Aromatic naphtha, 300 to 360' F. boilin.- 50 range ------------------------------- 27.9 Perchloroethylene ----------------------- 27.9 Expanded vermiculite (Zonolite No. 4) ----- 5.3 7M asbestos ---------------------------- 10.5 r:,,5 100.0 This fire retardant mastic was found to be suitable for- application over damp insulation material. It was also found to be self extinguishing in the uncured state. Orl 60 curing, it was found to possess the same desirable properties listed under I above. The major difference in the cured film was the permeability. A permeability of 0.027 perm.-inch allowed the escape of water vapor from the underlayin@ insulatioii materials without the formation 65 of blisters, and yet prevented water on the outside surface from penctraing the film in the liquid form. Any number of other similar useful compositions may be prepared and found to have the same properties as those described above. However, a particularly effective 70 -roup of such compositions containing vehicle and filler are those containing 20 to 55 percent by wei@ht of the special asphalts of the present invention, I to 10 percent by weight of a fire retardant organic chemical, 10 to 35 percent by wei.-ht mineral fili'er and 20 to 60 pereciit by 75 weight of a volatile solvent.


3,342,614 5 Those skilled in the art wilj readily appreciate that numerous asphaltic compositioris having a host of end uses as yet undeveloped may be prepared in accordance with the present iiivention. Regardless to what end @use the compositions disclosed herein are put, such use is within the spirit and scope of the present invention. 1 claim: 1. A fire resistant composition consisting essentially of 80 to 97 percent by weight of an a@.phalt havi-i.- a penetration of 0 to 35 at 77' F. and a softening point of 130 to 300' F. and 3 to 20 percent by weigbt of a fire retardant chemical, wherein the fire retardant cbemical is a chlorinated paraffin. 2. A fire resistant composition consisting essentially of 80 to 97 percent by weight of an asphalt having a penetra'Lion of 0 to 35 at 77' F. and a softening point of 130 to 300' F. and 3 to 20 percent by weight of a fire retardant chemical, wherei-@i the fire retardant chemical is selected from the group consisting of polychlorinated polyphenyls and polybTOMinated polyphenyls, 6 References Cited UNITED STATES PATENTS 2,025,929 12/1935 Young ---------- 106-16 XR 2,693,425 1111954 Hardman ---------- 106-273 2,926,096 2/1960 Sakornbut ----------- 106-15 3,035,930 5/1962 Talley ------------- 106-273 3,053,714 9/1962 Edwards -------- 106-281 XR OTHER REFERENCES 10 Zimmerman et al.: Handbook of Material Trade Names, 1953 edition (page 65, Aroclor, relied upon). The Condensed Chemical Dictionary, sixth edition, Reinhold Print. Corp., New York (page 108, Aroclor, re- 15 lied upo@i). ALEXANDER H. BRODMERKEL, Pritizary Examiner. MORRIS LIEBMAN, J. B. EVANS, 4ssistant Exatniners, 20

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