Abstract:
The effectiveness of combinations comprising an antimony compound and a halogen-containing compound for reducing the flammability of polyolefins is increased significantly by the addition of certain organometallic compounds and/or compounds which are used as metal deactivators and which contain the chemical structure of either a substituted hydrazine or a substituted 3-amino-1,2,4-triazole amide.

Description:
BACKGROUND OF THE INVENTION 
     Flame resistant polyolefin compositions have been obtained heretofore by incorporating various additives. To be effective, an additive must promote suitable levels of flame resistance without causing inordinate sacrifices in the appearance, processing, mechanical properties, and economics of the flame resistant composition. Additives disclosed by the prior art include, halogenated organic compounds, and various combinations thereof. One such additive combination is described by Monroe in U.S. Pat. No. 3,216,960 (1965) wherein an organic pyrophosphate, a halogenated organic compound, and an inorganic additive are intimately mixed, in specified concentrations, with polypropylene to produce a flame resistant composition. 
     The prior art has also disclosed a flame resistant composition which is produced by mixing with polypropylene, an inorganic compound containing antimony and a halogenated organic compound in fixed proportions to each other and to the polypropylene. Such combinations have found wide use in flame resistant polypropylene compositions, in part because there is a synergistic action within such combinations. Said synergistic action is shown by a greater increase in oxygen index (hereinafter defined) when said combination is used than is achieved when the halogenated organic compounds or inorganic compounds are used alone. Antimony trioxide is commonly used as the inorganic component of such combinations. Examples of polyhalogenated organic compounds that are known to be useful in combination with an antimony compound so as to impart flame retardancy to resinous polyolefin compositions containing them are to be found in U.S. Pat. No. 3,275,596 (1966), U.S. Pat. No. 3,403,036 (1968), U.S. Pat. No. 3,419,518 (1968), and U.S. Pat. No. 3,738,958 (1973). These form part of a class to be later referred to as a flame retardant package containing an antimony compound such as Sb 2  O 3 . Typical of such halogenated organic compounds are hexabromocyclododecane (HBCD), chlorinated paraffins, tetrabromophthalic anhydride (TBPA), and tetrabromoterephthalic acid (TBTA). 
     The greatest problem associated with the use of the aforesaid prior art additives involves the high additive concentrations necessary to effect suitable degrees of flame resistance. It is not uncommon for a flame resistant polypropylene composition to contain, by weight, 40% additives. In addition to the high cost of such flame resistant compositions, the use of high additive concentrations is generally accompanied by processing difficulties. For example, aliphatic and cycloaliphatic compounds containing bromine require lower extrusion temperatures (400° F maximum) than for brominated aromatic compounds. Although aromatic compounds containing bromine can be processed at higher temperatures, they are less effective than aliphatic compounds as flame retardants. Chlorine containing additives tend to decompose, liberating hydrochloric acid which corrodes processing equipment. 
     BRIEF DESCRIPTION OF THE INVENTION 
     We have found that the effectiveness of flame retardent combinations, comprising an antimony compound such as Sb 2  O 3  and halogen-containing compounds such as HBCD, chlorinated paraffins, TBPA, and TBTA, is significantly increased by the addition of certain organometallic compounds and/or compounds which act as metal deactivators and which contain the chemical structure of either substituted hydrazines or substituted 3-amino-1,2,4-triazole amides. Metal deactivators are compounds which, when added to resins used to coat a particular metal such as copper wire, tend to inhibit the breakdown of said resin when ions from the metal diffuse into said coating. Said metal deactivators do not themselves contain any metal and are generally purely organic in nature, with an ability to chelate with said metal ions or in some other way inhibit the metal&#39;s otherwise present ability to catalyze the degradation of the polypropylene resin coating. 
     Experimentally, the effectiveness of an additive in reducing a plastic&#39;s flammability may be determined by using the Oxygen Index Method, ASTM D-2863-70. The oxygen index of a material is defined to be the minimum gas volume percent concentration of oxygen in a slowly rising mixture of oxygen and nitrogen that will just support combustion of the material. The higher is the oxygen index of a material, the lower is that material&#39;s flammability. 
     In sum, certain organometallic compounds both covalent and ionic in nature and/or metal deactivator compounds (hereinabove defined) have been found to increase substantially the oxygen index of polypropylene resins, copolymer resins of propylene and ethylene, polystyrene and polyethylene when such resins contain antimony compounds and halogen containing compounds. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Several combinations of halogenated organic compounds and at least one antimony compound (hereinafter referred to as a flame retardant package containing an antimony compound) have been found to become more efficient flame retardants as measured by the oxygen index method when our discovered additives are incorporated. Several typical flame retardant packages containing an antimony compound which were investigated are given in Table 1. It should be noted that these are merely particular examples which indicate the genus of flame retardant packages which as a class employ Sb 2  O 3 , and that the examples of Table 1 employ a three component system comprising: 
     1. an antimony compound such as antimony trioxide; 
     2. a brominated organic compound; and 
     3. a chlorinated organic compound. 
     However, two component systems employing just Sb 2  O 3  and a halogenated organic compound are known also to be effective U.S. Pat. No. 3,419,518 (1968). From a cost point of view chlorinated organic compounds are preferred over brominated organic compounds; but from an effectiveness point of view, brominated organic compounds are preferred over chlorinated organic compounds. In general, a trade-off is practiced wherein a mixture of brominated and chlorinated organic compounds are employed, such as utilized herein. 
     The main attributes of these halogenated organic compounds are: 
     a. a substantial non-volatility from the polymer matrix at the approximate melting point of the flammable polymer composition into which the flame retardant package is blended to insure the presence of these halogenated compounds in the final extruded product; 
     b. a gram molecular weight above 200; and 
     c. a halogen content in percent by weight of the halogenated compound in the range 35-93%. 
     
                       Table 1______________________________________                         Designated                         Hereinafter      Percent by Weight  as______________________________________Sb.sub.2 O.sub.3        3HBCD         4                    AChlorowax 70S        2Sb.sub.2 O.sub.3        3TBPA         10                   BChlorowax 70S        2Sb.sub.2 O.sub.3        3TBTA         10                   CChlorowax 70S        2Sb.sub.2 O.sub.3        3HBCD         4                    DDechlorane Plus 25        2______________________________________ 
    
     To retard oxidation and degradation by light, all flame resistant polymer compositions were equally stabilized with a stabilization package E, of approximately .80% by weight based upon the total composition. 
     
         ______________________________________0.10% Butylated hydroxytoluene (BHT)0.36% Argus Q328                E0.15% Epon 1002 (epoxy resin)0.15% Calcium Stearate______________________________________ 
    
     Some raw material used hereinafter in the various formulations are: 
     Polypropylene powder having an average molecular weight of approximately 450,000, and flow rate of 2-4 grams/10 minutes as determined per ASTM D-1238 following Procedure A and Condition L; 
     Chlorowax 70S, a chlorinated paraffin sold by Diamond Shamrock Chemical Company containing approximately 69% chlorine, having a ball and ring softening point of 102° C, and a specific gravity of 1.63; 
     Dechlorane Plus 25 obtained from Hooker Chemical Corporation having approximately 65.1% chlorine, a density of 1.80 gm./cc., a melting point of 350° C, and a vapor pressure at 197° C equal to .006 mm of Hg; 
     GI09-367 (to be discussed in more detail hereinafter) obtained from Ciba-Geigy; 
     Mark 1475 (to be discussed in more detail hereinafter) obtained from Argus; 
     BHT obtained from Eastman Kodak; 
     Argus Q328 obtained from Argus being a mixture of distearyl thiodipropionate and the three to one condensate of 3 methyl-6 tertiary butyl phenol with crotonaldehyde; 
     Epon 1002 obtained from Shell being an epoxy resin having a melting point of from 75 to 85° C and an epoxide equivalent, in grams of resin containing one gram equivalent epoxy, of 600 to 700; 
     Mark QED obtained from Argus having a percent by weight of Ca, Zn, C, and H of 0.06, 4.7, 57.94, and 8.15%, respectively; 
     Advastab CZ-19 obtained from Cincinnati Milacron having a percent by weight of Ca, Zn, C and H of 0.89, 3.1, 64.49 and 10.52%, respectively; and 
     Advastab CZ-22 obtained from Cincinnati Milacron having a percent by weight of Ca, Zn, C and H of 1.00, 2.10, 72.78 and 11.87%, respectively. 
     All resin compositions were prepared by weighing out a stabilization package, various fire retardant additives, and polypropylene powder, and by mixing in a Waring Blendor. Each batch was extruded on a one inch pelletizing screen extruder having a 1/8 inch strand die maintained at a temperature of 400° F. Incidentally, it was here found that additives containing any water of hydration could not be extruded. Test specimens were molded on a Frohring Minijector at 400°-420° F. 
     The Oxygen Index of various specimens were determined following ASTM D-2863-70. 
     EXAMPLE 1 -- Zinc Compounds 
     The effectiveness of zinc compounds as additives to increase the oxygen index substantially of stabilized polymer compositions utilizing flame retardant packages containing an antimony compound is demostrated by examples involving zinc stearate, zinc borate, zinc dibutyl dithiocarbamate, zinc pentamethylene dithiocarbamate, Advastab CZ-19, Advastab CZ-22, and Mark QED. 
     An effect upon oxygen index of some zinc compound additives is observable when concentrations as low as .01% in weight percent are used. Zinc compounds having concentrations in weight percent as high as 10% are of practical effectiveness. In practice, concentrations of approximately 5% are preferred. 
     Table 2 consists of compositions tested in the manner hereinabove described. As a guide to evaluating the significance in changes to oxygen index, there are provided several reference compositions containing A, B, C, or D but without any additives. 
     
                       Table 2______________________________________Zinc Compounds                  Flame Retardant         Polypro- Package Containing         pylene   an Antimony Com-         and E,   pound DesignatedZinc Compound and         % by     by letter and % by                                Oxygen% by Weight   Weight    Weight       Index______________________________________O              73.0%     A 27%       31.7O              91%       A 9%        27.90.8% Zinc Stearate          90.2%     A 9%        35.1O              85%       B 15%       25.30.8% Zinc Stearate          84.2%     B 15%       26.1O              85%       C 15%       25.80.8% Zinc Stearate          84.2%     C 15%       26.10.8% Zinc Borate          90.2%     A 9%        34.41.0% Zinc Dibutyl          90.0%     A 9%        34.4Dithiocarbamate1.0% Zinc Pentamethyl-          90.0%     A 9%        35.9ene DithiocarbamateO              91%       D 9%        28.41.0% Advastab CZ-19          90%       A 9%        30.01.0% Advastab CZ-22          90%       A 9%        30.01.0% Mark QED  90%       A 9%        29.4______________________________________ 
    
     EXAMPLE 2 -- Cobalt Compounds 
     The effectiveness of cobalt compounds as additives to increase the oxygen index substantially of polymer compositions utilizing flame retardant packages containing an antimony compound is demonstrated by examples involving cobalt stearate, cobalt naphthenate, and cobalt (III) acetylacetonate. 
     An effect upon oxygen index of some cobalt compound additives is observable when concentrations as low as .01% in weight percent are used. Concentrations of cobalt compounds in weight percent as high as 10% are of  practical effectiveness. In practice, concentrations of approximately 5% are preferred. 
     Table 3 consists of compositions tested in the manner hereinabove described. Recourse to Table 2 is useful to gauge the significance in changes to oxygen index. 
     
                       Table 3______________________________________Cobalt Compounds                  Flame Retardant         Polypro- Package Containing         pylene   an Antimony Com-         and E,   pound DesignatedCobalt Compound and         % by     by Letter and % by                                Oxygen% by Weight   Weight   Weight        Index______________________________________0.8% Cobalt Acetyl-         90.2%    A 9.0%        30.0acetonate1.0% Cobalt (III)         90.0%    A 9.0%        32.4Acetylacetonate0.8% Cobalt Naphthen-         90.2%    A 9.0%        31.2ate0.8% Cobalt Stearate         90.2%    A 9.0%        30.00.8% Cobalt (III)         84.2%    B 15%         26.5Acetylacetonate0.8% Cobalt (III)         84.2%    C 15%         26.5Acetylacetonate0.8% Cobalt (III)         90.2%    D 9.0%        31.7Acetylacetonate______________________________________ 
    
     EXAMPLE 3 -- Lithium, Molybdenum and Aluminum Compounds 
     The effectiveness of lithium, molybdenum, and aluminum compounds as additives to increase the oxygen index substantially of polypropylene compositions utilizing flame retardant packages containing an antimony compound is demonstrated by examples involving lithium stearate, molybdenum (VI) acetylacetonate, and aluminum palmitate. 
     Table 4 consists of compositions tested in the manner hereinabove described. 
     
                                           Table 4__________________________________________________________________________Aluminum, Lithium, and Molybdenum                Flame Retardant                Package Containing                an Antimony Com-        Polypropylene                pound DesignatedCompound and %        and E, % by                by Letter and % by                           Oxygenby Weight    Weight  Weight     Index__________________________________________________________________________1% Aluminum Palmitate        90.0%   A 9.0%     29.41% Lithium Myristate        90.0%   A 9.0%     28.41% Molybdenum (VI)        90.0%   A 9.0%     28.4AcetylacetonateO            91.0%   A 9.0%     27.9O            73.0%   A 27%      31.7__________________________________________________________________________ 
    
     EXAMPLE 4 -- Other Resin Systems: Polystyrene, Polyester, Polyethylene, Copolymers of Ethylene and Propylene 
     Although having the ability to act as effective flame retardant additives by significantly increasing the oxygen index of polypropylene compositions containing polypropylene and A, B, C, or D, metal additives may not have a similar effect in other polymeric resin systems. This is demonstrated by the fact that neither zinc nor cobalt salts were effective in polystyrene, polyester, or polyethylene. The result with respect to polyethylene is particularly striking in that the chemical similarity of polyethylene to polypropylene is such as might lead one to expect a priori that there would be a similar effectiveness as to oxygen index in each with respect to a particular flame retardant additive. Note, however, that in crystalline propylene dominated propylene-ethylene copolymers comprising a propylene homopolymer attached to a copolymer, metal additives of zinc, cobalt, lithium, aluminum, or molybdenum are effective. 
     The metal deactivator GI09-367 was found to be effective as a flame retardant additive in polystyrene, polyethylene, polypropylene, and copolymers of propylene and ethylene; but ineffective in polyester. 
     These results are summarized in Table 5. 
     The polystyrene of Table 5 had a number average molecular weight in the range 45,000-48,000, an average of weight average molecular weight of approximately 225,000, a melt flow of approximately 4.5g/10 min. 
     The polyethylene of Table 5 had a weight average molecular weight of approximately 80,000, a number average molecular weight of approximately 9,000, and a flow rate of approximately 5.5g/10 min. 
     The ethylene-propylene copolymer of Table 5 is a crystalline propylene dominated ethylene-propylene copolymer comprising a propylene homopolymer attached to a copolymer containing approximately 4% ethylene, and having a weight average molecular weight in the range 500,000-550,000, a number average molecular weight of approximately 80,000, and a melt flow index in the range of 4.0-6.5g/10 min. 
     Hytrel 4055 polyester (Du Pont) has the following physical properties: 
     
         __________________________________________________________________________Property      ASTM Test                  Unit      Value__________________________________________________________________________Shore Hardness A/D         D-2240   --        92/40Specific Gravity         D-792    --        1.17Bulk Density (as Pellets)                  lbs/ft.sup.3                            43.7Tensile Strength         D-412    lbs/in.sup.2 (Kg/cm.sup.2)                            5900 (415)Elongation at Breat         D-412    %         805Stress at 10% Elongation         D-638    lbs/in.sup.2 (Kg/cm.sup.2)                            650 (45.5)Stress at 100% Elongation         D-412    lbs/in.sup.2 (Kg/cm.sup.2)                            925 (65)Stress at 300% Elongation         D-412    lbs/in.sup.2 (Kg/cm.sup.2)                            1200 (84)Tear Strength, Graves         D-624    lbs/in (Kg/cm)                            700 (124)Tear Strength, Split         D-470    lbs/in (Kg/cm)                            170 (30)Abrasion Resistance         D-1630   % of Std. 800Compression Set         D-395    %22 Hrs./70° C         Method B           60Melting Point D-2117   ° F (° C)                            334 (168)Melt Index    D-1238*  8/10 min. 4.8         *200° C/2160g.__________________________________________________________________________ 
    
     All melt flow indexes, unless otherwise expressly stated, were determined per ASTM D-1238 following Procedure A and Condition L. 
     Number average molecular weight (Mn) is defined by the formula: 
     
         Mn = W/N 
    
     where 
     W = total weight of the sample, and 
     N = number of individual molecules present in said sample. 
     Weight average molecular weight (Mw) is defined by the formula: 
     
         Mw = ΣMi.sup.2 Ai/ΣAi 
    
     where 
     Mi = molecular weight of species i, and 
     Ai = number of molecules belonging to species i. 
     Note only the ethylene-propylene copolymer composition contains the stabilization package E. 
     
                       Table 5______________________________________The Effect of Metal Salts and Metal Deactivatorson the Fire Retardancy of Polystyrene, Polyester,Polyethylene and Copolymers of Propylene and Ethylene______________________________________       A              AdditivePolystyrene %              %           Oxygen% by weight by weight      by weight   Index______________________________________91          9              0           20.990.2        9              Zinc Stearate                                  20.9                      .890.2        9              Cobalt Stearate                                  20.2                      .890          9              GI09-367    22.3                      1Hytrel 4055                            OxygenPolyester (Du Pont)       A              Additive    Index91          9              0           27.990.2        9              Cobalt Stearate                                  27.0                      .890          9              GI09-367    26.5                      1                                  OxygenPolyethylene       A              Additive    Index91          9              0           23.890.2        9              Cobalt Stearate                                  23.8                      .890          9              GI09-367    25.8                      1Ethylene-PropyleneCopolymer100         0              0           18.291          9              0           28.490.2        9              Zinc Stearate                                  32.4                      0.890.2        9              Cobalt Stearate                                  31.2                      0.890.2        9              GI09-367    30.5                      1.0______________________________________ 
    
     EXAMPLE 5 
     The effectiveness of metal deactivators as additives to increase the oxygen index substantially of polypropylene compositions utilizing flame retardant packages containing an antimony compound is demonstrated by the following metal deactivators: GI09-367 and Mark 1475 as shown in Table 6. 
     
                       Table 6______________________________________Metal Deactivators                 Flame Retardant                 Package Containing                 an Antimony Com-      Polypropylene                 pound DesignatedMetal Deactivator      and E, % by                 by Letter and % by                                Oxygenand % by Weight      Weight     Weight         Index______________________________________1% GI09-367      90%        A 9.0%         29.41% Mark 1475      90%        A 9.0%         30.00          91%        A 9.0%         27.90          73%        A 27%          31.7______________________________________ 
    
     EXAMPLE 6 
     That a metal deactivator and a metal additive (as heretofore defined) may be used together to substantially increase the oxygen index of polymer resins utilizing a flame retardant package containing an antimony compound is shown by Table 7. The polypropylene, E, and A are in weight percent approximately 90.04%, 0.76%, and 9%, respectively. 
     
                       Table 7______________________________________Metal Deactivator andCobalt (III) AcetylacetonateCo (III) Acetyl-       Polypropylene                              Oxygenacetonate    GI09-367  and E + A   Index______________________________________0.2%         0%        99.8%       28.40.2%         0.2%      99.6%       30.00.4%         0%        99.6%       30.00.4%         0.2%      99.4%       31.20.6%         0%        99.4%       30.50.6%         0.2%      99.2%       31.70.8%         0%        99.2%       30.00.8%         0.2%      99%         32.4______________________________________ 
    
     The structure of GI09-367 has been determined to be: ##STR1## 
     A chemical name for this compound is N,N&#39;-diacetyl-adipic acid dihydrazide. 
     Other compounds having a similar usefulness as flame retardant additives are: 
     N,n&#39;-bis-β-naphthoyl-sebacic acid dihydrazide, 
     N,n&#39;-dipropionyl-terephthalic acid dihydrazide, 
     N,n&#39;-dipelargonyl-terephthalic acid dihydrazide, 
     N,n&#39;-di-2-ethylhexanoyl-terephthalic acid dihydrazide, 
     N,n&#39;-dilauroyl-terephthalic acid dihydrazide, 
     N,n&#39;-distearoyl-terephthalic acid dihydrazide, 
     N,n&#39;-di-p-(tert.-octyl)-benzoyl-terephthalic acid dihydrazide, 
     N,n&#39;-di-p-(octoxy)-benzoyl-terephthalic acid dihydrazide, 
     N,n&#39;-di-tridecanoyl-terephthalic acid dihydrazide, 
     N,n&#39;-dipalmitoyl-terephthalic acid dihydrazide, 
     N,n&#39;-divaleroyl-terephthalic acid dihydrazide, 
     N,n&#39;-dibutyroyl-isophthalic acid dihydrazide, 
     N,n&#39;-dipelargonyl-isophthalic acid dihydrazide, 
     N,n&#39;-dicyclohexanoyl-isophthalic acid dihydrazide, 
     N,n&#39;-di-2-chlorobenzoyl-oxalic acid dihydrazide, 
     N,n&#39;-bis-2,4-dichlorobenzoyl-sebacic acid dihydrazide, 
     N-benzoyl-N&#39;-butyroyl-oxalic acid dihydrazide, 
     N-benzoyl-N&#39;-pelargonyl-oxalic acid dihydrazide, 
     N,n&#39;-bis-(3,5-di-tert.-butyl-4-hydroxybenzoyl)-oxalic acid dihydrazide, 
     N,n&#39;-bis-[3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionyl]-adipic acid dihydrazide, 
     N,n&#39;--dipropionyl-oxalic acid dihydrazide, 
     N,n&#39;-dibutyroyl-oxalic acid dihydrazide, 
     N,n&#39;-dipelargonyl-oxalic acid dihydrazide, 
     N,n&#39;-diacetyl-carbohydrazide, 
     N,n&#39;-dicyclohexanoyl-oxalic acid dihydrazide, 
     N,n&#39;-diphenylacetyl-oxalic acid dihydrazide, 
     N,n&#39;-dibenzoyl-oxalic acid dihydrazide, 
     N,n&#39;-di-α-naphthoyl-oxalic acid dihydrazide, 
     N,n&#39;-di-o-toluoyl-oxalic acid dihydrazide, 
     N,n&#39;-di-p-methoxybenzoyl-oxalic acid dihydrazide, 
     N,n&#39;-dicaproyl-oxalic acid dihydrazide, 
     N,n&#39;-dicapryloyl-oxalic acid dihydrazide, 
     N,n&#39;-diacetyl-succinic acid dihydrazide, 
     N,n&#39;-dipropionyl-adipic acid dihydrazide, 
     N,n&#39;-diacetyl-sebacic acid dihydrazide, and 
     N,n&#39;-dibenzoyl-sebacic acid dihydrazide. 
     These compounds have the formula: ##STR2## in which R 1  and R 2  independent of one another represent: an alkyl with 1 to 17 carbon atoms, cyclohexyl, arylalkyl possibly substituted by one or two alkyl groups with 1 to 4 carbon atoms in each case and/or a hydroxyl group; phenyl, chlorophenyl, dichlorophenyl, phenyl possibly substituted by one or two alkyl groups with 1 to 4 carbon atoms in each case 
     and/or a hydroxyl group, alkylphenyl with 7 to 14 carbon atoms, alkoxy phenyl with 7 to 24 atoms or naphthyl, 
     R 3  represents: the direct bond, an alkylene group with 1 to 8 carbon atoms, a phenylene group or a naphthylene group and 
     n is 0 or 1. 
     Compounds useful as flame retardant additives are: 
     
         __________________________________________________________________________                             MeltingName of Compound followed by Structure                             Point (° C)__________________________________________________________________________N-(1,2,4-triazol-3-yl)salicylamide [Mark 1475] ##STR3##                         307-3095,5&#39;-(Methylene bis-N,N&#39;-(1,2,4-triazol-3-yl) disalicylamide ##STR4##                         &gt; 3304-t-octyl-N-(1,2,4-triazol-3-yl)-salicylamide ##STR5##                         316-321N-(5-(2-(3,5-di-t-butyl-4-hydroxyphenyl)-ethyl 1,2,4-triazol-3-yl)-salicylamide ##STR6##                             264-267N-(1,2,4-triazol-3-yl)-o-anisamide ##STR7##                         263-265Methyl 3-(3-salicylamido-1H-1,2,4-triazol-3-yl) propionate ##STR8##                         155-158Thiodi-3,3&#39;-bis(N&#39;-salicyloyl hydrazide) of propionic acid ##STR9##                         225-2275,5&#39;-(methylenebis(salicyloyldiiminocarbonyl-1,2-ethylidenethio-1,2-ethylidene carbonyl)) disalicyloyl hydrazide                             212-218 ##STR10##3-(3-salicylamido-1H-1,2,4-triazol-4-yl) pentanoic acid ##STR11##__________________________________________________________________________ ##STR12## where R.sub.1 is either a hydrogen or a monovalent alkyl radical of up to 10 carbon atoms, 
    
     R 2  is either a divalent alkyl radical of up to 10 carbon atoms, when n is 2, or monovalent alkyl radical of up to 10 carbon atoms when n is 1, 
     R 3  is either a hydrogen, a monovalent alkyl radical, alkyl acid, or alkyl ester, wherein all alkyl groups are connected so as to form a nitrogen to carbon bond and wherein all alkyl groups contain up to 10 carbon atoms, 
     R 4  is an alkyl radical containing up to 10 carbon atoms or a phenyl radical substituted with no more than three alkyl groups containing up to 10 carbon atoms, and no more than one hydroxy group, and 
     n is 1 or 2. 
     The specific examples of this invention are illustrative only and should not be limiting in the light of the variations thereon which are within the intended scope of this invention and apparent to one skilled in the relevant art once this disclosure is made known.