United States Patent [19] [111 3,888,822 Gilleo Et Al

United States Patent [19] [111 3,888,822 Gilleo et al. [451 June 10, 1975

[54] PROCESS FOR INCREASING FLAME [56] References Cited RESISTANCE OF NYLON AND RESULTING UNITED STATES PATENTS FLAME RESISTANT NYLON 3,250,772 5/1966 Dexter et a1 ...... 260/45.8 NT COMPOSITION 3,293,249 12/1966 Biland et al...... 260/45.8 NT [75] Inventors: Kenneth B. Gilleo, Depew; Francis 3,415,824 12/1968 Biland et a1...... , 260/45.8 NT E. Evans, Hamburg; Allen W. Sogn, 3,444,142 5/1969 Kolyer et al...... 260/458 NT Williamsville, all of NY. 3,538,092 11/1970 Dexter et al...... 260/45.8 NT 3,709,883 l/l973 Dexter et al...... ,. 260/45.8 NT [73]. Assignee: Allied Chemical Corporation, New 3,793,289 2/1974 Koch et al...... 260/45.8 NT York, NY. 1221 Filed: Dec. 17, 1973 Primary Examiner-Melvyn l. Marquis Attorney, Agent, or Firm—Michael L. Dunn; Jay P. [21] Appl. No.: 425,488 Friedenson

[52] US. Cl ...... 260/45.8 NT.260/45.75 R, [57] ABSTRACT 260/45.75 C, 260/45.8 N A process for increasing the ?ame resistance of nylon [51] Int. Cl...... C08f 45/58 comprising treating the nylon with a heterocyclic ring [53] Field of Search 260/45.8 NT, 45.8 N, 45.75 R, compound which contains both sulfur and nitrogen 260/45.75 C and the resulting ?ame resistant nylon composition. 41 Claims, No Drawings 3,888,822 1 2 PROCESS FOR INCREASING FLAME RESISTANCE bonded to a carbon atom and no phosphorous or arse OF NYLON AND RESULTING FLAME RESISTANT nic. NYLON COMPOSITION ‘ The novel composition in accordance with the inven tion comprises nylon containing from about 0.5 to This invention relates to nylons exhibiting improved 5 about 25 weight percent of a compound or a mixture ?ame resistance. More speci?cally, this invention re of compounds having the above formula. lates to nylon treated with compositions which impart improved ?ame resistance thereto and. to the process of DETAILED DESCRIPTION OF THE INVENTION so treating the nylon. In accordance with this invention nylon is treated In the prior art numerous compounds have been used with at least about 0.5 weight percent and preferably at as additives to carbon containing polymers, including least about 2 weight percent of a compound or a mix nylon (polycarbonamides), to reduce ?ammability of ture of compounds falling within the above formula. the polymers. For example inorganic and organic tin Generally less than about 25 weight percent, preferably compounds and halogen containing compounds have less than about 16 weight percent, and most preferably been used to reduce ?ammability of nylon. These com 15 less than about 8 weight percent of the compound or pounds have not, however, been entirely successful. mixture of compounds is used since generally greater In addition to the tin containing compounds and hal percentages do not materially increase ?ame resistance ogen containing compounds, some. compounds, con and can sometimes cause undesirable effects such as taining nitrogen and sulfur have been employed to im ?aking on the surface of the nylon. prove ?ame resistance. For example thiourea and com 2O The nylon may be treated by wetting the surface with pounds containing non-cyclic imine groups have been a solution or emulsion containing one or more of the used. Thiourea, while being an improvement over the above compounds or one or more of the compounds tin and halogen compounds, still does not create as may be added to the nylon polymerization reactants or much ?ame resistance as is desired, or necessary, and to the nylon melt prior to the formation of polymeric the compounds containing imine groups do not give the 25 products, eg a nylon ?ber. desired ?ame resistance and, due to the imine group, The compounds which are added to the nylon poly hydrolize when contacted with water thus preventing merization reactants should of course be stable under the formation of a permanent application of the com the conditions of polymerization, should not interfere pounds to the nylon or other carbon containing poly with the polymerization and should be stable in the mers. 30 nylon melt. An example of such a compound is: Other compounds containing both sulfur and nitro gen which have been suggested to impart ?ame resis tance to nylon have been found to be inadequate since HS N s'm” they contain too much carbon in relation to the amount \ of other elements present in the compound or the car Y Y bon is present in a single ?ammable chain of excessive NYN length, which chain will easily burn. S II BRIEF DESCRIPTION OF THE INVENTION In accordance with the process of this invention it has 40 now been discovered that nylon can be treated with Compounds added to the nylon melt should be stable certain additive compounds containing sulfur and ni in the melt and should not deleteriously affect the ny trogen to give a ?ame resistance which is superior to lon. Examples of such compounds are: the ?ame resistance obtainable by any known prior art compound or method. 45 The additive compounds, with which the nylon is treated, have the formula:

wherein Q is a saturated or unsaturated heterocyclic ring structure, which may be substituted or unsubsti tuted, containing at least one sulfur or nitrogen atom in the ring; R1 is independently at each occurrence a mon ovalent radical containing at least one sulfur or nitro gen atom; R2 is independently at each occurrence a di 55 valent radical containing at least one sulfur or nitrogen atom; n is O or an integer of 1 through 6 and m is 0 or an integer of 1 through 3 and the sum of n and 2m is no greater than six with the proviso that said compound contains at least one nitrogen atom and at least one sul 60 fur atom, contains no non-cyclic imine group, and the ratio of the number of carbon atoms in the compound to the total number of atoms having an atomic number greater than 2 other than carbon in the compound being 2:1 or less, said compound including no carbon Q in the above formula for the compounds may be chain containing over six and preferably not over ?ve any substituted or unsubstituted heterocyclic ring con carbon atoms, no hexavalent sulfur which is directly taining at least one sulfur or nitrogen atom in the ring. 3,888,822 3 4 The substituents e.g. —COOH or —OHupon the ring be hexavalent only if it is not directly connected to a should of course not contribute to ?ammability al carbon atom, and the compound contains no halogen though hydrogen and small amounts of carbon can be or phosphorous since halogen or phosphorous tends to: tolerated. The heterocyclic ring, exclusive of substitu degrade nylon and since it is believed that the presence ents, contains from four through six atoms; and con of phosphorous and halogen tends to form toxic prod tains either sulfur or nitrogen, preferably both. Three ucts‘ during combustion. Arsenic is also not used be membered rings are unsuitable and not included in that cause of possible toxic products. they are unstable. Examples of some preferred R1 radicals are —SH; Examples of suitable heterocyclic rings, O, which -NR3R., wherein R3 and R4 are independently at each may be saturated or unsaturated, are: six membered occurrence hydrogen or methyl; rings containing nitrogen including azine, diazine, tri azine, tetrazine and pentazine rings; six membered rings containing sulfur including dithiin and thiopyran -SgCH3;i-ilECll3; 4i N112; sing; —iiiCI-lg, rings; six membered rings containing both nitrogen and sulfur including thiatriazine, thiadiazine, dithiadiazine, 15 dithiazine and thiazine rings; ?ve membered rings con taining nitrogen including azole, diazole, triazole and tetrazole rings; ?ve membered rings containing sulfur --SCH3; —SCN; or —SM wherein M is an ion having including thiole and dithiole rings; five membered rings a single positive charge preferably selected from simple containing both nitrogen and sulfur including thiazole or complex ions of ammonium, Li, Na, K, Cs, Mg, Sn, and thiadiazole rings; four membered rings containing Ni, Cu, Ti, Zr, Cr, Mn, Fe, Co, Zn and Al. As used nitrogen including azete, diazete and triazete rings; herein “complex ion” means an ion formed by the four membered rings containing sulfur including thie~ combination of an ion of one of the above listed metals tane rings and four membered rings containing both with another ion or with an atom or molecule. Exam sulfur and nitrogen including thiazete rings. 25 ples of complex ions contemplated by this invention Preferably Q is triazine, diazine, thiatriazine, thiadia are: *CaA, +MgA, +SnA, +SnA3, *NiAz, +CuA, +TiA2, zine, triazole, diazole, thiazole' and thiadiazole rings, +TiA3, +ZrA3, +CrAz, +CrA, +MnA, +MnA2, *FeA, since the ?ve and six membered rings are generally +FeAz, *CoA, +CoA2, +ZnA, +AlAz, +SnAD‘, +NiD, more stable than the four membered rings and since the *TiD, *TiAD, +ZrAD, +CrD, +MnD, *FeD, *CoD, rings containing more nitrogen and sulfur atoms in rela 30 *AlD, +SnPO4, +TiPO, and +ZrPO, where A indepen tion to the number of carbon atomsrprovide less fuel for dently at each occurrence is halogen‘, BOfor combustion. The heterocyclic rings containing both sulfur and ni trogen in themselves impart good ?ame resistance in 51%???“ accordance with this invention but may be even further 35 improved through the addition of appropriate substitu where R,, R2, n, m and Q are as de?ned herein; and ent groups R, and R2. The heterocyclic rings in accor where D is independently ‘at each occurrence CO3l=or dance with this invention which contain only nitrogen S=. . or sulfur require at least one substituent group contain The most preferred R1 radicals are —SI-l, —Nl-l2 and ing sulfur or nitrogen respectively so that the com 40 —SM where M is ammonium, Li, or the complex ions pound as a whole will contain both sulfur and nitrogen. ofrCa or Mg. Rl may also be a carbon containing radi The compound preferably contains at least some dis cal which must also contain sulfur, nitrogen or both sul~ valent or tetravalent sulfur since hexavalent sulfur is fur ‘and nitrogen and which is free from non~cyclic completely oxidized and cannot react to stop decompo- ‘ imine groups and which carbon containing radical con sition and combustion. The most preferred compounds 45 tains no more than 55 weight percent carbon. “Non are those containing no hexavalent sulfur. cyclic imine group,” as used herein, means that‘ the Substituent groups R, and R2 have essentially the imine group double bond does not form part of a heter same characteristics except R, is a monvalent radical ocyclic ring. , other than hydrogen and is attached to a single atom The R1 group may be or may contain ‘any additional within the heterocyclic ring and R2 is polyvalent and 50 heterocyclic ring containing sulfur, nitrogen or both may be attached to one or more atoms‘within the heter sulfur and nitrogen joined to Q by a single bond. ocyclic ring. The R, and R2 groups must contain sulfur, An advantage of using -—SH as an R1 radical is that nitrogen or both sulfur and nitrogen and should prefer the —SH group seems to prevent the formation of vola tile and combustible products. Reduction of volatiles ably contain only a sufficient number of carbon atoms 55 to maintain chemical stability. The fewer carbon atoms seems to be evidenced by dif?cult ignition of nylon in the R1 and R2 groups, the less fuel is available for which has been exposed to Q containing a —SH radical combustion. In general, unless a polymeric material at elevated temperatures. ' containing sulfur and nitrogen is used to impart ?ame —S‘NI-l,+ as a R, radical seems to function in a man resistance, each of the R1 and R2 groups contains fewer ner similar to —SH; however, the ionic character of the than 10 total atoms, other than hydrogen to simplify —S-Nl-L,+ radical also enhances solubility characteris synthesis of the compound. tics. ‘ The compound preferably contains at least some di —SM as an R1 radical seems to operate in a manner valent or tetravalent sulfur since hexavalent sulfur is somewhat dissimilar to the —SH and —S‘NHJ groups in that Q containing a —SM group seems to form an es completely oxidized and is believed unable to react to 65 stop combustion or decomposition of the nylon. The sentially non-combustible insulating char which results most preferred compounds are those containing no during combustion of the nylon. This char is particu hexavalent sulfur and in general the sulfur, if any may larly advantageous in reducing ?ammability of carpet 3,888,822 5 6 ing by insulating the carpet backing and the nylon ?ber dried. The product is 4-methyl-2-mercapto-l,3 from an ignition source. thiazole. —-Nl-I2 groups in the R1 position seem to act synergis tically with sulfur containing groups thus reducing the amount of the composition which is required to provide increased ?ame resistance. In addition, a -—Nl-l2 group Ill in the R1 position seems to increase the substantivity of CH3 the compound added to the nylon thus increasing dura methylaminothiazole bility. A —-NH2 group in the R1 position can also be re Preparation: Equimolar amounts of thiourea and acted upon the nylon with a reactant such as formalde monochloroacetone are heated on a steam bath. Heat hyde to form a resin upon the nylon surface which in ing is maintained for 5 hours. The solid residue'is crease flame resistance. washed with water and dried to yield 4-methyl-2 Examples of some preferred R2 groups are =6, and amino-l ,3-thiazole. any heterocyclic rings containing sulfur, nitrogen or both sulfur and nitrogen, such as

3 ,5 -diamino- I ,2 ,4-thiadiazole 20 which heterocyclic ring is fused with one or more Preparation: A solution of ~10 g. of amidinothiourea atoms in Q. Examples of particular compounds which have been found useful in forming ?ame resistant nylon composi S NH n n tions with a suggested method for preparation are as 25 follows:

SH in 100 ml water is treated with 10 ml of 30% H202. The N A. solution is heated at 50°C. for 1 hour. Solvent is re 30 moved by evaporation to give 8 g. of 3,5-diamino g 1,2,4-thiadiazole. - as ‘SH trithio-s-triazine (trithiocyanuric acid) 35 Preparation: Add 0.1 mole of cyanuric chloride to a re ?uxing solution of 0.3 mole of thiourea in 200 ml ace HST ST SH N"'— N tone and heat for 1 hour. Filter solid and hydrolyze with 10% NaOH solution. Neutralize with 10% HCl and 2,5 -dimercapto-l ,3 ,S-thiadiazole ?lter the resulting precipitate. 40

SCN Preparation: To a cold solution of 10 g. hydrazine hy drate in 100 ml ethanol saturated with NH3, 17 g. car bon disul?de is added. The mixture is evaporated on a steam bath. The resulting residue is dissolved in boiling NCS water and ?ltered. An equal volume of ethanol is added trithiocyano-s-triazine to the ?ltrate, which is then acidi?ed with concentrated HCl until crystals form. On cooling, 18 g. of product Preparation: A mixture of 0.1 mole of cyanuric chlo are formed. ride and 0.3 mole of KSCN is heated at re?ux for 20 hr. 0

in 200 ml of acetone. Filtration gives 35 g. of orange II o solid product. I HN-C-Cl-l3 " rm-c-cu3 8 SH / 55 N T u s u 21% u k " ' l N -C-N \ N-c-cn3 H3C-C-NH N H... U II I o O methylmercaptothiazole - " di(2,4-diacetylmelaminyDN ,N '-thiourea 60 Preparation: Equimolar amounts of ammonium di Preparation: A ?ask is charged with 38 g. of KOH, 42 thiocarbamate ml of CS2, 600 ml of 95% ethanol, and 90 ml of water. 75.6 grams of melamine is then added and the mixture is heated for 3 hours. Activated charcoal is then added 65 to clarify the resulting solution. The mixture is then ?l tered to give an amber solution. The solution is then and monochloroacetone are heated on a steam bath for heated at 60°~70°C. with 600 ml of water and 50 ml of 3 hours. The resulting solid is washed with water and acetic acid in 100 ml of water for 5 minutes. The solu 3,888,822 7 tion is then cooled in an ice bath which results in crys tals of the desired product which are ?ltered from the as / a i liquid. The product has a melting point of over 360°C. / C \ (l/ \ 1120 c 2 > H r“ EL ] u_ thione _ 1,2 _ diazole S 5 N N It

N/ N s 1 HS H N-C-NI‘ k N /]\N H 10 \ CH 2 H 2 / \ aminodithiourea-s-triazine HI‘, Z-mercapto-lH-l,3,ll-triazole Preparation: The dihydrochloride of melamine is pre HZC ——N pared by adding 55 ml of HCl to 37.8 g. (0.3 mole) of 15 melamine in 300 ml of warm water. 50 g. (0.66 mole) of ammonium thiocyanate are then added to the mix ture. The mixture is then heated on a steam bath for about 1 hour to evaporate the liquid. The solid is then HS S SH redispersed in 350 ml of water and the water is again 20 T v 2 ,S-dimercapto-l ,3~th1azo1e evaporated. 300 additional ml of water are then added, the mixture is ?ltered and the solid product is recov ered. The product has a melting point of over 360°C.

S 25 /c\II Hr ‘1H thiohydantoin o=c\ /cn2 C H2 30 SH s-triazinetrithioureide N \ N\ NR2 (trithiourea-s-triazine) I j 6 -am1no-2,1l ,dimercaptopteridine / / Preparation: Melamine hydrochloride is prepared by 35 H N adding 87 ml of concentrated HCl to 37.8 g. (0.03 mole) of melamine in 300 ml of water. 75 g. (0.99 mole) of NH4SCN is then added and the solution is evaporated on a hot plate at 120°C. The solids are then powdered and redispersed in 350 ml of water. The mix ture is then again evaporated to dryness. The solids are 40 f2 again redispersed in 250 ml of water and the resulting . N/ f slurry is ?ltered to obtain the product which has a melt-' \ A 2-mercaptodiam1no-s-triazine ing point over 360°C. as N NH2 45 S

/ C\ Hal l“ SH H2O _—" CH2 Z-mercapto-H ,S-diamino l ,3-diazine butyrothiolactam Preparation: A flask is charged with 2 moles of butyro lactam and 1.4 moles of water. The mixture is then heated to 55°—60°C. to form a solution. 0.64 mole of SCH3 phosphorous pentasul?de is then added in small incre ments over a 2 hour period while maintaining the tem 'N ¢kN Z-methylthio-ll ,G-diamino perature between 60° and 100°C. A thick paste forms M 1 , 3-diaz1ne which is then heated to 115°C. for 20 minutes. The. 60 H2"’ NH2 paste is then poured into 1,100 ml of water at 80°C. and is stirred while the mixture is heated to 90°C. until most solids dissolve. The mixture is then cooled to room temperature‘ and the resulting butyrothiolactam crys SH tals are ?ltered from the mixture. 65 Other compounds, known and available in the prior art, which have now been found to impart ?ame resis Z-mercapto-N,G-dihydroxy (XI. 1,3-d1az1ne tant properties to nylon are: OH

3,88 8,822 1 1 2,ll-dimercapto-5 ,6 ,-diam1no S Sll-l 1,3-diazine HN)J\NHI I > N/ \I 2-mercapto-14-hydroxy_ ___, q l ,3-diazole “2 \\ 0 '\ OH HS 8 / SH

2,5-dimercapto—l ,3 ,ll SH thiadiazole I]_ N ‘II II 2-mercapto-l ,3-ll-triazole

as \I/S /NH2 15 2-am1no-5- mercaptothiadiazole H N l W 2 \\ \ N N_—- N I B-arnino-l ,2,3,l4—th1atr1azo1e

N -—-— N

H N\/ S 1,2,5-thiadiazole I I/ Pithiouracil NH 25

mtgv l /N\\ SH N /NHNH H2C I I N 141,2,3-thiadiazole ,5 dihydro HZC — S T I 2 35 s \ 110/ CH 1 ,3 thiazete Two of the most preferred compounds are: \\I/ 2

40 SR3

N A/ N “38, I, - I ' and

s ‘ gcocn Z-acetoamidothiazole k A ' 3 N SR 1 \N 45 R38 3 wherein R3 is H or M, and M is ammonium, Li or a complex ion of Ca or Mg. 2 H In practicing this invention a sulfur-nitrogen contain n/ I N \f 51'! 8-mercapto-6-amino pyrazolopyrimi ing compound as described herein, is dissolved in sol K // ' dine 1 vent, usually water to make a solution of about 0.5 to N about 12 weight percent, more preferably from about 2 to about 8 weight percent and most preferably from 5 SH about 4 to about 6 weight percent. A fabric or carpet 55 is then soaked by the solution which may contain other additives commonly used in ?nishing baths to improve Z-mercapto-U ,6-dihydroxy 1,3-d1azine properties such as penetration or water repellency. The fabric or carpet is then squeezed with any suitable ap~ 0 H2 0 HO OH paratus such as pad rollers, to remove excess solution. The squeezing apparatus, such as the rollers, is adjusted to give from about 25 to about 300 weight percent, preferably from about 50 to 200 weight percent and most preferably from about 75m about 150 weight percent wet pick up. The fabric or carpet material is l-mercaoto-3,5-d1hydroxy-s 65 then dried in air or in a dryer or oven at temperatures triazine up to about 150°C. but preferably less than about 125°C. 3,888,822 13 14 The solution may be applied to the material in nu EXAMPLE 1 merous ways. For example the material may be im :A pad bath of the following composition is prepared: mersed in the solution or the solution may be sprayed upon the material or applied to the material by means 5 g. of trithiocyanuric acid, 20 g. ethylene glycol (as of pad rolls. wetting and swelling agent), 7 g. of ammonium hydrox ide and 170 g. water. A piece of 16 oz./yd. nylon-6 up The dry material can be tested for ?ame retardancy by several methods. In the case'of apparel fabric, the holstery fabric 3 X 10 inches is dipped into the solution Children’s Sleepwear Standard is used. A 1% inch and squeezed through a wringer (laboratory padder) to obtain a wet pick up (weight increase) of 164% corre ?ame from a bunsen burner is applied to the lower edge sponding to a dry chemical add-on of about 4% trithi of a vertically supported fabric. Untreated (control) ocyanuric acid. The sample is dried in a horizontal po fabric may burn completely while fabrics composed of 10 sition in a circulating oven at 140°C. for 1 hour. the nylon compositions of this invention usually stop The sample is placed in a desicator containing CaSO4 burning when the bunsen burner ?ame is removed indi drying agent and allowed to cool for 15 min. The sam cating that in the absence of an externally applied ele ple is tested by the New York Port Authority (NYPA) vated temperature which may be in the form of a ?ame, test whereby it is clamped in a vertical position and a the material is usually Self eXtingui$hlng-_ 15 11/2 inch bunsen ?ame is applied to the lower edge for Upholstery, tapestfy and drapery fabncs are tested 12 seconds. After removal of the ?ame, the fabric by holdmg the fabrlc Over a 1% Inch bu_nsen burner burns for 1.2 seconds and has a char length of 2%. ?ame for up to 12 seconds. Untreated fabr1cs may burn inches. for several minutes, while fabrics made from the nylon ‘ compositions of this invention usually extinguish in 20 EXAMPLES 2 — 9 from 0 to 5 seconds after removal of the burner ?ame. The procedure of Example 1 is followed for Exam_ The additive compounds of this invention are gener- ples 2 — 9 except different compositions and concentra ally more durable to laundering and .dry cleaning than tlons are used. thiourea and are generally much more effective than 25 The results are set forth in Table I.

TABLE I

EXAMPLE TREATING AGENT % ADD ON AREA DESTROYED (inz) AFTER FLAME (sec) CHAR LENGTH (in)

2 None — 1O 49 6.35 511114 NA N 3 )\N,L5H 2.7 2.4 18.3 2.65 H4NS

4 do. 3.6 1.7 9.4 2.5 5 do. 3.7 1.0 4.5 2.1 6 do. 5.9 .98 0.14 2.5 N-‘N I \ 7 HS ‘45 )_ 5H 5.5 1.2 0.9 3.0

H2N 1 S ‘ NH2 3 N- N 5.5 5.75 31 3.75

S \\c/N\r= ° 9 g __ CH2 6.2 2.75 9.6 3.25

prior art compounds. For example as little as 0.5 dry EXAMPLES 1.0 — 17 weight percent of those compounds described above The procedure of Example 1 is followed except the particularly those containing two or three —SH or —S_NH.,1L groups effectively reduces the ?ammability fabric is a 4 inch X 4 inch piece of nylon 6 carpet 55 backed with jute and the ?ame test used is a modified of nylon upholstery fabric while as much as 50 - 100 weight percent of prior art phosphorous or halogen United States Department of Commerce Test DOC containing ocmpounds may be required to accomplish FFl-70 wherein a 250 watt heat lamp is positioned 5 the same result. Nylon compositions containing from inches from the carpet surface and is controlled by a Variac. The lamp is turned on for 5 minutes at a pre-set about 2 to about 16 dry weight percent of an additive 60 voltage on the Variac in order to provide a more vigor compound of this invention usually pass most generally recognized ?ammability tests for synthetic fabrics. As ous test. The higher the voltage applied to the heat lamp the greater the heat applied to the carpet prior to much as about 25 dry weight percent can be used to ob burning the carpet. The carpet is burned by placing a tain even better ?ame resistant properties. 150 mg. methinamine pill in the center of the carpet. The following examples serve to illustrate the process 65 The pill is then ignited. The carpet passes the test if the and composition of the invention. Unless otherwise in carpet self extinguishes within 60 seconds after the pill dicated all parts and percentages are by weight. has ?nished burning. 3,888,822 15 16 The higher the voltage which can be applied to the 475 g. of a 4 to 1 weight ratio solution of water and eth heat lamp before the carpet fails, the better the flame ylene glycol for 1 minute. The fabric is then run resistant properties of the carpet. through a small laboratory padder to remove excess liq The following Table II shows the highest voltage ap uid. The wet pick up (weight of increase due to weight plied to the heat lamp before the carpet fails the test, of absorbed solution) is 110%, corresponding to 5.8% the additive used, the burn area resulting from the test dry add on of tri-thio cyanuric acid. The fabric is dried and the percentages of additive on the carpet. in a horizontal position in a ll0° oven. The fabric is

TABLE II

HIGHEST BURN VOLTAGE EXAMPLE ADDlTIVE % ADD ON BEFORE FAILURE AREA

HS SNH4+ 10 TN 2.31 60 1.25" /

SH

HS SH 5 11 Y 10.2 60 _ N——-N

"" m HS S_ Mg++ 12 W 15 7 120 1.0"

.._ FYNH J 2

-— T Cu++

13 N N 1 0 . 9 90 l . 25 " L In _ 2

, _ TSnH

14 HSWS - 10.2 90 1.0" N / N

__ SH 2

HS S- L i + 15 | N 9 6 120 1.0 H

SH

Br H3 / \ l6 0 =c (! CH3 100 .0 complete _ burn l ‘Q B.’ l 7 None - 0 complete burn

EXAMPLE 18 65 then tested by the Federal Children’s Sleepwear Flam Lightweight nylon 6 woven apparel fabric is dipped mability Test (FF-3-7l ). This consists of holding a 1% into a bath composed of 25 g. tri-thio-cyanuric acid and inch bunsen burner ?ame at the lower edge of verti 3,888,822 17 18 cally supported fabric for 3 seconds. The tested sample 10. The composition according to claim 7 wherein Q has an after ?ame (burning time after ?ame is re is a diazine ring. moved) of 0 seconds and a char length of 3.9 inches. 11. The composition according to claim 7 wherein Q A control (untreated) piece of fabric has an after ?ame is a triazine ring. of 26 seconds and burned 8.6 inches. (Tests are done 12. The composition according to claim 7 wherein Q in quintuplicate and numbers reported are in aver is a tetrazine ring. ages). 13. The composition according to claim 7 wherein Q What is claimed is: is a pentazine ring. ‘ 1. A composition comprising nylon and from about 14. The composition according to claim 8 wherein Q 0.5 to about 25 weight percent of a compound of the 10 is a thiatriazine ring. formula 15. The composition according to claim 8 wherein Q is a dithiadiazine ring. (R1)n_Q=(R2)m 16. The composition according to claim 8 wherein Q wherein Q comprises a heterocyclic ring structure is a dithiazine ring. which may be substituted and contains at least one sul- 15 17. The composition according to claim 3 wherein m fur or nitrogen atom in the ring; R, is independently at is O, Q contains from four to six atoms in the ring, at each occurrence a monovalent radical containing no least one of which is a nitrogen atom and R, is indepen more than 55 weight percent carbon and at least one dently at each occurrence —SH, —Nl-lz, —SM or a car sulfur or nitrogen atom; R2 is independently at each oc bon and sulfur containing radical. currence a divalent radical containing fewer than 10 20 18. The composition of claim 17 wherein the nitro atoms other than hydrogen and at least one sulfur or gen containing ring is a triazine. nitrogen atom; 11 is O or an integer 1 through 6 and m 19. The composition of claim 17 wherein the nitro is 0 or an integer of 1 through 3 and the sum of n + 2m gen containing ring is a thiadiazole.v is O or an integer of 1 through 6, with the proviso that 20. The composition of claim 17 wherein at least one said compound contains at least one nitrogen atom and 25 R1 radical is —SH, or —SM and M is NH4, Li, or a com at least one sulfur atom, contains no non-cyclic imine plex ion of Ca or Mg. group, and the ratio of the number of carbon atoms in 21. The composition of claim 18 wherein at least one the compound to the total number of atoms having an Rl radical is —SH. atomic number greater than two other than carbon in 22. A composition according to claim 17 wherein the compound being 2:1 or less, said compound includ- 30 said compound has the formula: ' ing no carbon chain containing over six carbon atoms and being free of phosphorous, arsenic, halogens, and SR3 hexavalent sulfur which is directly bonded to a carbon atom. N A 2. The compositions according to claim 1 wherein R2 35 \ k is selected from R38 N R3 H / N =5 and >5“ 40 wherein R3 is H or M, where M is ammonium, Li or a \ u complex ion of Ca or Mg. 23. The composition according to ‘claim 22 wherein 3. The compositions according to claim 1 wherein R1 R3 is hydrogen. is selected from —SH, —NR3R4 wherein R3 and R4 are 24. The composition according to ‘claim 3 wherein m each independently hydrogen or methyl; is O, Q is a sulfur containing ring radical having from

c u u

—SCH3; —SCN or —SM wherein M is an ion having a four to 6 atoms in the ring and at least one R1 radical single positive charge selected from simple or complex contains nitrogen. ions of ammonium, Li, Na, K, Cs, Ca, Mg, Sn, Ni, Cu, 25. The composition according to claim 24 wherein Ti, Zr, Cr, Mn, Fe, Co, Zn and Al. 4. The composition according to claim 3 wherein Q 55 at least one R1 radical is —NH2. is a heterocyclic ring containing nitrogen. 26. The composition according to claim 3 wherein at 5. The composition according to claim 4 wherein Q least one R2 radical is =S. is a heterocyclic ring containing both sulfur and nitro 27. The composition according to claim 26 wherein gen. the compound is: 6. The composition according to claim 3 wherein Q 6 is a six membered ring. 7. The composition according to claim 6 wherein Q contains a nitrogen atom in the ring. 8. The composition according to claim 7 wherein Q contains both nitrogen and a sulfur atom in the ring. 9. The composition according to claim 7 wherein Q is an azine ring. 3 ,8 88,822 19 20 28. The composition according to claim 26 wherein a single positive charge selected from simple or com the compound is: plex ions of ammonium, Li, Na, K, Cs, Ca, Mg, Sn, Ni, Cu, Ti, Zr, Cr, Mn, Fe, Co, Zn and Al. S 33. The process according to claim 32 wherein Q is A a four to six membered heterocyclic ring containing ni trogen.

/ ‘.\ 34. The process according to claim 33 wherein the O HUB O “2 compound is: 10 29. The composition according to claim 26 wherein SH the compound is: N / J ns \N \ SH

35. The process according to claim 33 wherein the compound is:

30. A process for forming a nylon composition hav ing improved flame resistance comprising treating 20 nylon with a compound of the formula wherein Q is a heterocyclic ring structure which may be substituted or unsubstituted and contains at least one sulfur or nitrogen atom in the ring; R1 is independently 36. The process according to claim 33 wherein the at each occurrence a monovalent radical containing no compound is: more than ‘55 weight percent carbon and at least one sulfur or nitrogen atom; R2 is independently at each oc currence a divalent radical containing fewer than 10 SH atoms other than hydrogen and at least one sulfur or nitrogen atom; n is 0 or an integer of 1 through 6 and the sum of n and 2m is no greater than six with the pro k N/kNI-IZ viso that said compound contains at least one nitrogen atom and at least one sulfur atom, contains no non cyclic imine group and the ratio of the number of car~ bon atoms in the compound to the total number of atoms having an atomic weight number greater than two other than carbon in the compound being 2:1 or 40' 37. The process according to claim 30 wherein the less, said compound including no carbon atom chain nylon composition comprises nylon ?ber. containing over six carbon atoms and being free of phosphorous, arsenic, halogens, and hexavalent sulfur 38. A process according to claim 37 wherein the which is directly bonded to a carbon atom. nylon fiber is treated by wetting the ?ber with a solu 31. The process according to claim 30 wherein R2 is tion of from about 0.5 to about 16 weight percent of selected from =S, and compound. / 39. A process according to claim 37 wherein said compound is stable in nylon melt and from about 0.5 to about 16 weight percent said compound is incorpo rated into the nylon prior to spinning. 32. The process according to claim 31 wherein R1 is selected from —SH; -—NR3R4 wherein R3 and R4 are 40. A process according to claim 30 wherein the each independently at each occurrence hydrogen or nylon is treated by incorporating from about 0.5 to methyl; about 8 weight percent of compound into the nylon po 55 lymerization reaction. 41. A process according to claim 30 wherein said compound is‘ stable in nylon melt and the nylon is H9 treated by incorporating from about 0.5 to about 16 aroma ; weight percent of compound into the nylon prior to molding. —SCl-la; —SCN; or —SM wherein M is an ion having

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