Compositions – Fire retarding – For solid synthetic polymer and reactants thereof
Patent
1996-10-01
1999-03-16
Kelly, C. H.
Compositions
Fire retarding
For solid synthetic polymer and reactants thereof
524107, C09K 2100, C08K 515
Patent
active
058825509
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to fire retardant agents which, when added to a material during its manufacture, provide a fire resistant or fire retardant characteristic to that material. Of special interest from the point of view of the invention are polymers, especially polyurethanes.
BACKGROUND OF THE INVENTION
It is well known to use certain chemicals and mixtures of chemicals as fire retardants for materials such as fabrics, rigid and flexible plastics foamed and non-foamed, timber, particle board and the like. The kinds of fire retardant agents employed vary with the material of interest and thus fire retardant agents considered suitable for application to one type of material may be completely unsuitable for another.
In the polyurethane industry, inorganic fire retardants which are soluble in nature are generally disregarded because they will leach from the polyurethane foam with deleterious results. For example, it is known from the literature the difficulties encountered with the soluble nature of ammonium monophosphate.
U.S. Pat. No. 3,423,343 assigned to Monsanto Company also discloses the above problem with ammonium monophosphate and ammonium orthophosphates in general and discusses the additional problem encountered with loss of physical properties such as compressive strength and closed cell content.
The above patent proposes the use of phosphorus and nitrogen compounds in the form of substantially water insoluble ammonium polyphosphates, having P--O--P type linkages and the general formula: between about 0.7 and about 1.1 and the maximum value of m is equal to n+2.
Now, this compound sold under the trade name PHOSCHEK 30 by Monsanto Company is certainly less soluble than ammonium monophosphate or ammonium diphosphate and is described by Lewin, Atlas & Pearce, Vol 1, "Polyurethane Structure and Flame Resistance" to have flame spread of 36% after 7 days immersion in water, as opposed to 33% before immersion. However, Miles, C. E and Lyons, J. W report in "Properties of Rigid Urethane Foams Containing Fire Retardants based on Phosphorus", Journal of Cellular Plastics, p 539, December 1967 that polyurethane rigid foams containing this ammonium polyphosphate require a chlorofluorinated compound (CFC) blowing agent, trichlorofluoromethane in manufacture, and demonstrated an average weight loss of 10.0% upon ignition.
Leaving aside the issue of the use of a CFC blowing agent, in itself undesirable, for the present further disadvantage may occur in that the decomposition temperature is such that a reduced amount of char is formed. This results in either reduced fire protection or the increased expense of using more material to achieve adequate protection.
Thus, present development in the art favours the use of organic fire retardants for use in polyurethane applications.
For example, U.S. Pat. No. 4,623,672, assigned to Bayer AG, discloses flame retardant isocyanate addition products made by reacting an isocyanate with a compound selected from the group consisting of 1-phosphonoethane-2-carboxylic acid-tri-C.sub.1 -C.sub.4 -alkyl esters, 1-phosphonopropane-2-carboxylic acid-tri-C.sub.1 -C.sub.4 -alkyl esters and mixtures thereof. Blowing agents may include CFC agents, the examples particularly specify the use of trichlorofluoromethane, and foams prepared in accordance with this patent are ignitable.
Australian Patent No. 591089 assigned to Ciba-Geigy Limited employs as fire retardant a salt formed by reaction between dimethyl methyl phosphonate, monomethyl methyl phosphonate and a compound of the general formula (I): ##STR1## in which X is O,S or NH, R.sup.1 is H, alkyl with 1 to 4 carbon atoms, alkenyl of up to 4 carbon atoms, CN, CONH.sub.2 or NH.sub.2, R.sup.2 is H, alkyl with 1 to 4 carbon atoms or alkenyl of up to 4 carbon atoms or R.sup.1 and R.sup.2 together with the nitrogen atom to which they are attached form a heterocyclic ring of up to 6 carbon atoms which may optionally contain another heteroatom and R is H, an alkyl group with 1 to 8 carbon atoms, an aryl group with
REFERENCES:
patent: 4246146 (1981-01-01), Wood et al.
patent: 4254177 (1981-03-01), Fulmer
patent: 4349494 (1982-09-01), Fulmer
patent: 4680324 (1987-07-01), Malwitz
patent: 4816186 (1989-03-01), Acitelli
patent: 4871477 (1989-10-01), Dimanshteyn
patent: 5268393 (1993-12-01), Blount
patent: 5344855 (1994-09-01), Narita et al.
Bains Harding Limited
Kelly C. H.
LandOfFree
Fire retardant agents suitable for plastics does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fire retardant agents suitable for plastics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fire retardant agents suitable for plastics will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-814193