US3654274A - Phosphorus-containing triazines - Google Patents

Abstract

NEW PROCESSES FOR PREPARING AMINOALKOXYPHOSPHINYL1,3,5-TRIAZINES AND PROCESSES FOR PRODUCING FLAME RESISTANT CELLULOSIC MATERIALS BY TREATING THE CELLULOSIC MATERIALS WITH THE FORMALDEHYDE DERIVATIVES OF THE AMINOALKOXYPHOSPHINYL TRIAZINES.

Description

Zine-Meme United 3,654,274 PHOSPHORUS-CONTAINING TRIAZINES Leon H. Chance and Jerry P. Moreau, New Orleans, La.,

assignors to the United States of America as represented by the Department of Agriculture No Drawing. Filed June 9, 1970-, Ser. No. 44,864 Int. Cl. C07d 55/20 US. Cl. 260249.8 2 Claims ABSTRACT OF THE DISCLOSURE New processes for preparing aminoalkoxyphosphinyl- 1,3,5-triazines and processes for producing flame resistant cellulosic materials by treating the cellulosic materials with the formaldehyde derivatives of the aminoalkoxyphosphinyl triazines.

derivatives as fia ne retardant, finishes. for cellulosic textiles. W

The main object of the instant invention is to disclose new methods of preparing aminoalkoxyphosphinyl triazmes.

A second object of the instant invention is to provide a process for preparing the formaldehyde derivatives of the compounds prepared by methods of the instant invention.

A third object of the instant invention is to provide a process for imparting to cotton and other cellulosic material, improved flame resistance, using the formaldehyde derivatives of the compounds prepared by methods of the instant invention.

Searching the prior art we find that Gaetano F. DAlelio claims to have prepared aminoalkoxyphosphinyl triazines by the reaction of chloroamino-triazines with trial-kyl phosphites by way of the well known Arbusov reaction. [Gaetano F. DAlelio, U.S. Pat. 3,011,998, Dec. 5, 1961, and U8. Pat. 3,210,350, Oct. 5, 1965.] We were unable to duplicate DAlelios method. When we tried to duplicate DAlelios Example 1 which states:

In a suitable reactor equipped with stirrer and reflux condenser a mixture of 145.5 parts of 2,4-diamino-6- monochloro-l,3,5 triazine and 200 parts of'triethyl phosphite and 200 parts of benzene are heated at reflux for eight hours, at which time no more ethyl chloride is released from the reactionYFhe reactionis then cooled and the solid 'bon, 28.1% nitrogen, 5.35% hydrogen, and 12.2% phosphorous, and a molecular weight of 246.1, which values are in close agreement with'the'theoretical'values. When 165 parts of the corresponding monoamino-dichlorotri- 'azine are'reactedinstead of themonoch'lorotriazine with 380 parts of'triethyl phosphite, and the reaction product isolated, there is obtained an almostquantitative yield of 3,654,274 Patented Apr. 4, 1972 which on analysis gives values of 35.16% carbon, 5.89% hydrogen, 15.35% nitrogen, and 17.21% phosphorus, and a molecular weight of 367.1, which values are in close agreement with the theoretical values. When this diester is allowed to stand at room temperature with aniline, the corresponding is obtained. These compounds are very effective as fire retardants when impregnated into wood, etc. according to standard methods, and are also effective as tanning agents for leather.

When halotriazines of the formula (A) (C N )Cl, or

Zo Nsol or A(C N )Cl are used instead of the halotriazines of the preceding example, the corresponding triazine derivatives are obtained. These products show very good fire retardant properties We obtained none of the expected product when either triethyl phosphite or trimethyl phosphite was allowed to react with 2,4-diamino-6-chloro-1,3,5-triazine. The latter compound was recovered unchanged in yields up to 92%. We have found new methods of preparing aminoalkoxyphosphinyl triazines which are an improvement over the methods of the prior art. We have also found that it is advantageous to carry out the reaction of formaldehyde with aminoalkoxyphosphinyl triazines under acidic conditions at temperatures of 95 C. for periods of time less than 30 minutes. When the reaction is carried out at 859 5 C. for less than 30 minutes condensation of the formaldehyde derivative is minimized, producing a Water soluble further polymerizable product which is suitable for application to cellulosic textiles.

We have found that when the aminoalkoxyphosphinyl triazines are heated with alkaline aqueous formaldehyde the solutions become acidic due to hydrolysis. Thus, we were not able to prepare formaldehyde derivatives suitable for cellulose textile application by boiling the aminoalkoxyphosphinyl triazines with aqueous formaldehyde under alkaline conditions as described by DAlelio in Example 2 of U8. Pat. 3,011,998, said example states:

Twenty-one parts of ICI) za( a :)P 0, 02 and 32 parts of aqueous formaldehyde (approximately 37% H-CHO) are heated together with 0.02 part of sodium hydroxideunder reflux at the boiling point of 'the mixture, ,for 30 minutes, yielding a resinous reaction product that curesto an insoluble, infusible mass when a sample is heated on a hot plate at 150C. A satisfactory molding compound that shows adequate flow characteristics during molding is produced by mixing a portion of the resinous syrup with a weight of alpha cellulose equal to'the solids content of the syrup followed by drying at low temperature to remove the excess water. A well-cured molded piece is obtained by molding a sample of the dried and ground molding compound for 3 minutes at C. under a pressure of 5000 pounds per square inch. Instead. of heating the reactants under reflux, as described above, the mixture is stirred for a longer period, 72 hours, atroom temperautre to effect reaction between the components and to obtain a soluble, fusible reaction product which is heathardenable.

Other alkaline condensation catalysts that can be used include sodium carbonate, ammonia, triethanol amine, hexamethylene tetramine, etc., and acidic curing catalysts include acetic acid, phthalic acid, ammonium chloride, ammonium phosphate, glycine, chloroacetamide, chloroacetyl urea, etc., or substances which under the influence of the reaction or heat produce such acidic substances.

When instead of 2)2( :s s)- CKHQZ there is used an equivalent amount of (113N028 C6II4NID2C3N3" (O (ll-I9 etc., heat convertible condensation products are obtained.

Formaldehyde derivatives prepared by DAlelios method form condensation products which make cellulosic materials too stiff and boardy for textile uses.

Compounds of this invention comprise triazine derivatives of the general formula: 3 c

H N-( 1 i lP (0) (OR):

where R represents an alkyl radical or a haloalkyl radical, X represents NH or P(O) (OR) where R is an alkyl radical or a haloalkyl radical.

We have found that the compounds of this invention can be prepared by new improved methods according to the following equations: )2

+HOP(OR) where R represents an alkyl radical or a haloalkyl radical. )2

+2HOP(OR) where R represents an alkyl or a haloalkyl radical.

Specific examples of the reactions of this invention are represented by the following equations:

I- ZNH:

IITIIz In accordance with the present invention a 2,4,6-tris (dialkoxyphosphinyl) 1,3,5-triazine (represented by Equation 2) or a 2-arnino-4,6-bis(dialkoxyphosphinyl)-l,3,5- triazine (represented by Equation 1) is allowed to react with ammonia. Triazines particularly suitable for the invention are 2,4,6-tris(diethoxyphosphinyl)-l,3,5-triazine, 2,4,6-tris(dirnethoxphosphinyl) 1,3,5-triazine, 2,4,6-tris(fichloroethoxyphenosphinyl)1,3,5triazine, and 2-amino-4, 6-bis(diethoxyphosphinyl)-l,3,5-triazine. The preferred compounds are 2,4,6-tris(diethoxyphosphinyl)1,3,5-triazine and 2-amino-4,6-bis(diethoxyphosphinyl)l,3,5-triazine, Solvents suitable for the reaction are polar solvents such as water or ethanol and non-polar solvents such as benzene. While other organic solvents may be used, the preferred solvent is ethanol.

The reaction of the phosphinyl triazines with ammonia may be carried out at temperature about from 0 C. to 40 C. The reaction is preferably carried out by dissolving the triazines in the solvent and then adding the ammonia. The preferred temperature for adding the ammonia is about from 0 C. to 15 C. After the addition of the ammonia is complete the reaction is allowed to take place at room temperature for about from 24 hours to 72 hours. The preferred time is about 72 hours.

Theoretically, 4 moles of formaldehyde can react with one mole of a diaminoalkoxyphosphinyl triazine and 2 moles of formaldehyde can react with aminobis(alkoxy-- phosphinyl) triazines. In practice, however, it is advantageous to use formaldehyde in excess of the theoretical amount in order to insure as complete a reaction as possible. A typical reaction of formaldehyde with a triazine is represented by the following equation:

It is not likely, however, that a tetramethylol derivative is actually produced in the acidic media employed in the reaction. Apparently, low molecular weight water soluble condensation products of the formaldehyde derivatives are formed which are capable of polymerizing further to crosslinked polymers which are insoluble in water and most organic solvents. The formaldehyde derivaties are preferably formed by mixing the aminoalkoxyphosphinyl triazine with aqueous formaldehyde in a mole ratio of 1:4 to 1:65. The preferable ratio of triazine to formaldehyde is 1:5. The initial pH of the mixture. is 3.3, but at the end of the heating period drops to about from. 2.6 to 3.0. The mixture is then placed in a suitable preheated bath and the reaction mixture brought as quickly as possible to 85 95 C. A water bath was used but any suitable heating device may be used. The heating time may be varied about from minutes to 27 minutes. The preferable time is about from 15 to 17 minutes.

After the heating period is completed, the solution is cooled to room temperature quickly and adjusted to the desired pH with aqueous sodium hydroxide for applica' tion to cellulosic materials. Other suitable bases may be.

used.

The polymerization on cellulosic materials may be carried out by impregnating the cellulosic material with a solution of the further. polymerizable formaldehyde deriva tives, drying, and curing at temperatures ranging about from 150 to 170 C. for periods of time about from 5 to 7 minutes. Latent acid catalysts such as magnesium chloride or zinc nitrate may be used in the application to cellulosic materials, but it is preferable to use no catalyst.-Tex tile lubricants or softening agents may be added to the treating baths to improve thestrength and abrasion resistance of the treated textiles. A pad bath pH of 6.5-6.6 is preferred for best fabric strengthand abrasion resistance and flame resistance.

Cotton fabrics treated by the processes of this invention possess good flame resistance which is durable to repeated laundering. Fabric strength and abrasion resistance properties are also good.

Cotton fabrics which have been treated by the processes of this invention were tested by the standard methods of the American Society for Testing Materials, Philadelphia, Pa., Committee D-13. Wrinkle recovery was determined by the Monsanto Method. AST M designation, Dl295-53T; breaking strength by the one-inch strip method, D39-59; tearing strength by the Elmendorf Method, D1295-60T; flex abrasion resistance by the Stoll Method, D1175-65T. Flame resistance was determined by the standard vertical method, U.S; Federal Supply Service Textile Test Methods, Federal Specification CCC-T- 191b, Method 5902. Durability of the flame resistant finish to laundering was determined by washing in an agitator-type washing machine under normal washing conditions for cotton, using a commercialdetergentaEach laundering cycle was followed by tumbledryin gfor 2O minutes.

The following examples illustrate the methods of carrying out the invention, but the inventionis not restricted to these examples. In the examples the following abbreviations will be used: 2,4,6-tris(diethoxyphosphinyl)triazine will be referred to as TEPT; 2,4-diamino-6-diethoxyphosphinyl triazine, as DAPT; 2-amino-4,6-bis(diethoxyphosphinyl)triazine, as ADPT; the formaledhyde derivative DAPT, as N-methylol DAPT or M DAPT.

EXAMPLE 1 2,4-diamino 6 diethoxyphosphinyl triazine (DAPT): DAPT was prepared by the reaction of TEPT with ammonia in (a) ethanol, (b) benzene, and (c) Water.

Ethanol procedure: 2,4,6-tris(diethoxyphosphinyl)-1,3, S-triazine (TEPT) (97.9 grams, M.P. 93-95 C.) was dissolved in 400 ml. of absolute ethanol. The solution was cooled in an ice-salt bath to approximately 0 C., and then saturated with ammonia gas. The addition was regulated so that the reaction temperature did not rise above 15 C. The solution was allowed to stand for three days. After cooling, the precipitated white solid was removed by filtration, washed thoroughly with water then acetone and dried to give 41.2 grams (83% yield) of DAPT.

When the above reaction was carried out without cool ing during the ammonia addition the temperature rose from 22 to 40 C. in 5-10 minutes. After standing at room temperature for 24 hours, the DAPT was isolated as above in yields of only 30%. Diethyl hydrogen phosphite was recovered by vacuum distillation as the major byproduct in 75% yield.

A sample of DAPT, recrystallized from boiling water, had a M.P. of 273 C. with decomposition. The IR spectrum showed absorption bands at 2.99, 3.12 microns (s.) (NH stretching); 6.00, 6.14 microns (s.) (NH deformation); 6.46, 6.56 microns (s.) (ring stretching); 8.18 microns (s.) (P=O); 9.77, 13.47 microns (s.) (w.) (POC); and 12.24, 12.59 microns (w.) (ring bend ing). The PMR spectrum (DMSO) gave a triplet at 4.17 p.p.m. (J =J =7 cps.) and a singlet at 7.00 p.p.m. The spectrum integrated 3:212, respectively.

Analysis.-Calcd. for C H N O P (percent): C, 34.01; H, 5.71; N, 28.33; P, 12.53. Found (percent): C, 34.00; H, 5.66; N, 28.38; P, 12.60.

Benzene procedure: TEPT (0.023 mole, 11.4 grams) was dissolved in 35 ml. of benzene, the solution cooled and then saturated with ammonia. After cooling overnight, the white precipitate was removed by filtration to give 0.93 gram (0.004 mole, 17.4% yield) of DAPT. The filtrate was concentrated and diethyl hydrogen phos phite (0.022 moles, 3.1 grams) removed by vacuum dis= tillation. The residue, which solidified overnight, was triturated in petroleum ether, filtered and dried to give 6.21 grams of a white crystalline compound. A sample of this compound, after recrystallization from diethyl ether, had elemental analyses and melting point consistent with an authentic sample of 2-amino-4,6-bisdiethoxyphosphinyl-1,3,5-triazine (ADPT) as prepared by DAlelio [U. S. Pat. 3,210,350 (1965)]. This constitutes a new method for preparing ADPT.

Water procedure: TEPT (0.05 mole, 24.5 grams) was added in' increments to 75.5 grams of NH; (28% NH;;). The reaction temperature rose spontaneously to 34 C. After standing at room temperature for five days, the white precipitate was removed by filtration, washed thoroughly with water then acetone and dried to give 2.11 grams (0.009 mole,'18% yield) of DAPT.

EXAMPLE 2 DAPT was also prepared by the ethanol procedure described in Example 1 except that ADPT was used instead of TEPT. (see Equation 5 of specification.)

EXAMPLE 3 Preparation of N-methylol DAPT (MDAPT) MDAPT was prepared by the following typical pro cedure, DAPT (49.4 g., 0.2 mole), formaldehyde (83.0

g. of 36.6% HCHO, 1.0 mole), and water (43.0 g.) were placed in a 300 ml. flask equipped with a reflux con denser, stirrer, and thermometer (immersed in the liquid). This was a mole ratio of DAPTzHCHO of 1:5. The flask was immersed in a water bath which had been preheated to boiling. After approximately minutes of heating and stirring, the DAPT dissolved completely forming a clear solution. At this point the solution temperature was about 9495 C. Heating and stirring at this temperature were continued for an additional 6 minutes, for a total heating time of about 16 minutes. If possible, the total heating time should not exceed 16 minutes. If the solution is heated too long, excessive condensation of MDAPT apparently occurs. Even under the conditions described, it is believed that some condensation occurs, but the prod uct is of low molecular weight and hence very water soluble.

After the heating was completed, the flask was immediately cooled by immersing the flask in cold water. The pH of the resulting solution was 2.7. The solution was adjusted to the desired pH with sodium hydroxide solution and served as a stock solution.

In one experiment crude MDAPT was isolated as a clear colorless, very viscous material by evaporation of the water under high vacuum at about 50 C. This material was not as stable upon storage as the water solution, and set to a gel in two or three weeks.

Analysis.Calculated for C H N O P (percent) (tetramethylol derivative of DAPT): C, 35.97; H, 6.04; N, 19.07; P, 8.43. Found (percent): C, 37.68; H, 6.44; N, 18.29; P, 8.29.

Solutions of the formaldehyde derivatives of DAPT were also prepared in a similar manner as above in which the heating time was varied from 15 minutes to 27 minutes. Heating periods of 16-17 minutes were considered optimum. Temperatures as low as 85 C. were used for heating periods above 20 minutes.

Solutions were also prepared in a similar manner in which the DAPT to formaldehyde ratio was 1:4 and 1:6. When the ratio was 1:4 a longer heating period minutes) was needed to solubilize the DAPT.

EXAMPLE 4 Fabric treatment with MDAPT The fabric used in the experiments was an 8.5 oz. white cotton sateen.

The stock solutions prepared as described above are stable for several days without any loss of efliciency when applied to cotton fabric. (A solution stored for 2 months at room temperature [27 C.] did not get, and when applied to cotton fabric had an efficiency 1718% less than a freshly prepared solution.) The pH of the solutions shifts downward during storage. Therefore, it is necessary to adjust to the desired pH just prior to treating cotton fabrics. All of the pad baths used in this report contained 0.1% wetting agent and 1.5% softener (dry solids basis). The solution as prepared above, after addition of the wetting agent and softener, contained approximately 27% DAPT (or MDAPT calculated as the tetramethylol derivatives). These values were based on the total weight of the solution. Just prior to fabric treatment, the solution was diluted to the desired concentration, and finally adjusted to the desired pH with aqueous sodium hydroxide solution.

In some of the experiments, magnesium chloride hexahydrate was used as a catalyst. The percent catalyst (as the hexahydrate) was based on the total weight of the solution as it was applied to the fabrics.

The solutions were applied to the fabrics by padding procedures to give a wet pickup of about 80% on sateen. The fabrics were dried for 5 minutes at 85 C. and cured for 37 minutes at temperatures ranging from 150 C. 170 C. The fabrics were finally rinsed in hot water and dried.

Table I shows the properties of white 8 oz. cotton sateen containing polymer add-ons of 14.7%, 17.6%, and 19.5%.

These add-ons were obtained by using pad bath concentrations approximately 20%, 24%, and 27%, respectively, based on actual DAPT content. The ratio of DAPT to formaldehyde in the pad baths was 1:5. The fabrics were dried for 5 minutes at C. and cured for 7 minutes at 160 C.

TABLE I.-PIIYSICAL PROPERTIES OF COTTON SATEEN Resin add-on, percent Untreated Fabric properties control 14. 7 17. 6 19. 5

Phosphorus, percent 1. 70 1. 76 1.86 Nitrogen, percent... 3. 46 3. 61 4. 00 Char length, inches... 3. 1 3. 4 3. 1 Flex abrasion (F), cycles.. 1, 505 .2, 215 2,264 Tear strength (F), gms... 3,400 3,400 3,107 Breaking strength (F), lbs 84. 4 80. l 82. 5

The fabric samples shown in Table I were subjected to repeated laundering cycles followed by tumble drying. The flame resistance as measured by char length in the standard vertical flame test were as follows: at 14.7% add-on the char length was 5.3 inches after 15 launderings; at the 17.6% add-on the char length was 5.0 inches after 30 launderings; and at the 19.5% add-on the char length was 5.5 inches after 35 launderings.

EXAMPLE 5 Add-on=weight gain of cotton after curing and rinsing Wet pickup=weight of cotton+solution before drying DAPT conc.=concentration of DAPT in pad bath TABLE II.-INFLUENCE OF MOLE RATIO OF DAP'IzIIClIO Pad bath eone., per- Resin add- Etficiency, Mole ratio, DAPTzHCHO cent DAPT on, percent percent No'rE.Sateen fabric; dried 5 min. at 85 0., cured 7 min. at C EXAMPLE 6 Table III shows the influence of curing time on the resin add-on and efficiency. They increase with increasing temperature.

TABLE IIL-INFLUENCE OF CURING TEMPERATURE Resin add-on Etliciency (luring tein1)., C. percent percent.

EXAMPLE 7 Table IV shows the influence of curing time on some fabric properties. Highest add-on and flame resistance are obtained at the 7 minute cure time.

TABLE IV.INFLUENCE OF CURING TIME l lex abrasion Resin Efli- Char addon, ciency, length, (W), Curing time, min. percent percent warp cycles (F), irls 3 7. 7 51 2 BEL 2, 800

12.2 81 5. 1 2,020 4,800 7. 14.0 02 4.0 1,136 3,000 Control. 833

1 Over capacity of machine. 2 J3EL=bnrned entire length. Norm-"Sateen fabric; pad bath c0110., 20% DAPT cure tciup., 100

9 10 EXAMPLE 8 We claim: l

Table V shows the influence of pad bath pH on some Process prepgrmg fabric properties. Although higher add-ons were obtained phosp h1r.1y1 1.35'tnaZme i 9 process fii 3 5 at pH values of 3.0 and 4.5 the strength losses were (a) ls.solving msmlethoxyphosphmy excessive. of 6.6 Was considered optimum for flame 5 tnazme m a Solvent Selected from t 6 group consisting of ethyl alcohol and benzene, (b) cooling the solution from (a) and saturating with ammonia gas,

resistance versus strength and abrasion resistance.

TABLE V.INFLUENCE ON PAD BATH pH R Abrasion Tearing (c) allowing the reaction mixture from (b) to stand S I Pad bath pH on j p r iit 523? 10 fgi ggig zgg fi gg z hours at a tempera $35 3 2? (d) mechanically removing the 2,4 diaminoethoxy- 1,150 5, phosphinyl-1,3,5-triazine.

Q88; 2. A process for preparing 2,4-diamino-6-diethoxyphosp-hinyl-1,3,5-triazine which process comprises: EXAMPLE 9 (a) dissolving 2 amino 4,6 bis(diethoxyphosphinyl)l,3,5-triaz ine in ethanol, (b) cooling the solution from (a) and saturating with ammonium gas, (c) allowing the reaction mixture from (b) to stand for a period of about 24 to 72 hours at a temperature of not more than 15 C Table VI shows a comparison of fabric properties resulting from treatments in which no catalyst was used with those in which magnesium chloride was used. It is clear that the best strength and abrasion properties are obtained with no catalyst. The only advantage in using the catalyst is that slightly higher wrinkle recovery is (d) mechanically removing the 2,4 diaminoethoxy obtained. phosphinyl-1,3,5-triazine.

TABLE VI.-INFLUENCE OF CATALYST, MgClgfiHgO Wrinkle re) R Eir- T B k A y MECIQ-GI'IZO, add iif ciency streng t li sisting t ii res is t afi i c e difi j percent percent percent (F), gms. (W), lbs. (W), cycles degrees 1 14. 5 94 3, 4.00 84. 4 1,136 238 10.8 70 2, s33 68. 1 601 254 10. 9 72 2, 500 65. 0 478 249 11.7 76 2, 317 60. 9 347 25 1 14.1 94 1, 617 48. 2 138 258 Control 5, 300 105. 0 833 173 1 Cured 7 min. at 160 C. Norm-Sateen fabric; pad bath conc., 20% DAPI; cured 5 min. at 150 0.

EXAMPLE 10 40 References Cited A typical procedure for preparing a formulation for UNITED STATES PATENTS application to cotton fabric using 2-amino-bis(diethoxy- 3,165 513 1/1965 DAlelio 2 .249 8 X phosphinyl)triazine (ADPT) consisted of (l) refluxing 3,210,350 1O/1965 DAlelio 249 X ADPT in aqueous formaldehyde (mole ratio 1:2) for 30 3,2133) 10/1965 Papp et 49 g minutes, (2) adding a softening agent and a wetting agent, and "(3) adding trimethylolrnelamine (TMM) (mole ratio of TMM:ADPT of 2:1) previously dissolved in Water, and (4) diluting to 40% reactive solids (total Weight ADPT, HCHO, and TMM). White 8 oz. cotton sateen was padded to approximately wet pickup, 50 dried for 5 minutes at C., and cured for 7 minutes 8 at C. After rinsing and drying, the weight gain of the fabric was 20%. The fabric had good flame resistance as determined by a char length of 2.7 inches.

45 3,305,348 2/1967 Schwarze et a1. 260249.8 X

JOHN M. FORD, Primary Examiner US. Cl. X.R.

116.3; 106l5 FP; l17l36; 2528.8; 260249.5