Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/244—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing sulfur or phosphorus
  • D06M13/282—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing sulfur or phosphorus with compounds containing phosphorus
  • D06M13/288—Phosphonic or phosphonous acids or derivatives thereof

Definitions

• This invention relates to flame-retardant cellulosic textiles and to methods for their production. More particularly this'invention relates to cellulosic fabrics which compound and the amide and the melamine compounds amount of nitrogen which is required increases as the phosphorus content decreases.
• organo-nitrogen compounds having high nitrogen contents such as the poly(oxymethyl)melamines
• One problem with the use of such organonitrogen compounds has been their tendency to cross-link the cellulose and thereby adversely affect properties such as hand, strength and the like. It has been discovered in accordance with the present invention that a desirable degree of flame retardance can be obtained without adverse effect on cellulosic properties when an N-(oxymethyD phosphonopropionamide is employed as the phosphorus-containing are applied to the cellulose in a specific sequence.
• the method of the present invention comprises treating cellulose with an N-(oxymetihyl)phosphonopro pionamide in an amount suificient to provide the desired have been rendered filame-retardant with little adverse effect on the physicalproperties of the fabric.
• oxymethyl as employed in the present. application, is meant hydroxymethyl or lower alkoxy-' methyl.
• lower alkyl and lower alkoxy are examples of lower alkyl and lower alkoxy
• linear or branched chain alkyl and alkoxy groups containing up to about 6 carbons, and preferably up to about 2 carbons, such as methyl, ethyl, isopropyl, tert-butyl, methoxy, ethoxy, isopropoxy, tert-butoxy and the like.
• lower alkenyl alkenyl' groups of up to 6 carbons, preferably allyl.
• halogen is meant a halogen having an atomic number of 17 to 53, inclusive, with chlorine being preferred.
• organophosphoru's compounds have been developed in an effort to provide flame retardance Without concurrent damage to the cellulose and to render the phosphorus-containing agent -resistant to removal during laundering. Although many of these-treatments are commercial-use today, none has been completely successful due to the high cost of the or'ganophosphorus compound and the high degree ofadd-on of organophosphorus compound required to provideflanie-retardant properties.” 7
• organic nitrogen is a synergist for phosphorus-induced flame retardance in cellulose, and thus allows the use of reduced amountslof organophosphorus compound.
• organophosphorus compound little or no flame-retardant eifect is observed until at least about 1.5 weight percent phosphorus, based on cellulose, is present, and acceptable flame-retardant properties are not achieved until the phosphorus content is'at least about 2 percent.
• sufiicient organic nitrogen into the treatment, however, excellent flame-retardant properties can be obtained at phosphorus contents as low as about 0.2 weight percent, despite thefact that organic nitrogen compounds alone are not flame-retardant agents.
• the lower alkyl or lower alkenyl; R is and R are preferaby hydrogen.
• Illustrative compounds include:
• the amides of Formula I are readily produced by 5 reaction of the corresponding N-unsubstituted amide with formaldehyde, optionally in the presence of an alcohol,
• R is lower alkyl or halogen-substituted lower alkyl; R is hydrogen or lower alkyl; and R? is hydrogen,-
• alkyl and R amide in turn, can be obtained by the reaction of a dialkylphosphite with acrylamide in the presence of a basic catalyst as described in U.S. Pat. 2,754,319.
• poly(oxymethyl)melam-ines which are employed in accordance with the present invention contain at least two oxyrnethyl groups and are represented by the formula:
• C N represents the s-triazine nucleus
• each of x, y and z is an integer having a value of from 0 to 3, with the proviso that the sum of x, y and z is 3 and the compound contains at least two oxymethyl groups
• R is hydrogen or lower alkyl, preferably hydrogen.
• P Illustrative of the poly(oxymethyl)melamines are:
• cellulose is treated with the N-(oxymethynphosphonopro pionamide and an acidic catalyst to promote reaction of the phosphonopropionamide with the cellulose.
• Suitable acidic catalysts include hydrochloric acid, sulfuric acid and formic acid.
• the phosphonopropionamide and acid catalyst are preferably applied to the cellulosic substrate in aqueous solution, and when aqueous media are employed suitable catalysts include salts of strong acids and weak bases which upon hydrolysis yield acids.
• Ammonium halide e.g., chloride, and various amine hydrohalides (hydrochlorides) are preferred.
• Other suitable catalysts are ammonium sulfate, zinc nitrate, zinc tetrafluoroborate,
• phosphonopropionamide and catalyst present in the aqueous solution are not critical to this invention, and will depend upon the desired phosphorus content of the treated cellulose and the quantity of solution applied to the cellulose. In general, however, solutions containing from about to about 35 weight percent propionamide and from about 0.5 to about 5 weight percent catalyst have been found suitable.
• Insolubilization of the propionamide is elfected by subjecting the thus-treated cellulose to conditions under which the propionamide reacts with the cellulose, as by heating the treated cellulose at an elevated temperature, for example, a temperature of about 150 C. to about 200 C. The heating is carried out for a period of time sufficient to effect insolubilization, usually 1 to 10 minutes.
• the solvent is preferably evaporated oif prior to effecting insolu'bilization.
• the fabric After insolubilization of the propionamide, the fabric is washed to remove unreacted amide, and in particular, to remove the acidic catalyst which, if left on the cellulose, would promote cross-linking of the cellulose by the poly(oxymethyl)melamine. Such cross-linking adversely affects the properties of cellulosic materials such as strength, hand and the like.
• the washed fabric is then treated with the poly(oxymethylhnelamine compound and a peroxide, preferably hydrogen peroxide.
• This treatment like the treatment of the first step, is preferably carried out by the use of aqueous solutions of melamine and peroxide.
• concentration of melamine compound in such a solution is not narrowly critical, but should be enough to provide sufficient nitrogen to the cellulose to impart flame-retardant properties thereto, and concentrations of from about 2 to about 25 weight percent have been found useful.
• Catalytic amounts of peroxide are normally in the range of from about 0.1% to about 0.5%.
• Insolubilization of the melamine compound is ordinarily effected by means of Wet fixation of the thus-treated material.
• the cellulose already modified in the first step is padded to 100% i30%-wet pick-up with an aqueous solution containing both melamine compound and hydrogen peroxide, partially dried to a moisture content of about 10 to about 30 weight percent and then treated with steam for a period of time sufiicient to insolubilize the melamine compound. Ordinarily-times of from about 1 minute to about 1 hour are required.
• N is the 'weight percent nitrogen, based upon expression because chlorine assists the nitrogen-phosphorus synergism with respect to flame retardance. Be-.
• the treatmentof this invention when applied to textile products it has been found that air permeability decreases with increasing phosphorus content, and when preservation of air permeability is desired, the phosphorus content should not be in excess of about 1.8 Weight percent and is desira-bly less than 1.2%. To provide effective flame re" tardance without excessive add-on of melamine cornpound, the cellulose should contain at least about 0.2%
• the nitrogen content of the cellulose should be in the range of from 10% to about 1.7%, and preferably from about 8% to about 5%
• the cellulose which is treated in accordance with'this invention can be from any of various sources, for instance, from seed hairs, as native cotton, from bast fabrics, as flax (linen), ramie, juteand hemp, and from regenerated cellulose, as viscose rayon.
• This invention also can be applied to yarns and to fabrics which are cellu s losic blends, as cotton-rayon blends containing from about 10% to about 60% cotton and from about to about 1 40% rayon. Furthermore, the invention is applicable to'.
• Chlorine Saponi'fication by means of potassium A hydroxide in ethylene glycol, followed by'argentometric titration of chloride ion.
• Phosphorus Kjeldahl digestion followed by colorimetricanalysis employing acetone-water to intensify the phosphornolybdate color [Bernha'rt ,et al., Anal. Chem.,
• weight of the fabric (OWF) resulting immediately after padding are shown in thetable. After padding, .the samples were framed to the original dimensions, dried at 60 C., heated at 165 C. for 5 minutes to insolubilize the amide, washed, dried and conditioned as before. Weight gains were measured, and were .corrected for moisture regain.
• N ,N ,N -tris (hydroxymethyl)melamine s m s s) was applied in a second step to increase the nitrogen content of the fabric by padding the samples resulting from the first step with aqueous solutions which contained both tris(hydroxymethyl)melamine (in varying amounts) and 0.3% hydrogen peroxide. Then the samples were dried to 20-30% moisture content, steamed in a laboratory steamer for 8 minutes (to hasten wet fixation), washed, dried and conditioned as before.By the procedure of wet fixation, tris(hydroxymethyl)melaminewas insolubilized substantially quantitatively.
• Examples A-G are U summarized in Table I, together with the results of an (6) Laundering: AATCC 88A-1964T, Test III, hometype washer, S-pound load, full cycle, 60 0., synthetic experiment in which the cotton sheeting was treated with a mixture of the amide and the melamine compound employing Catalyst XRF to insolubilize the reagents (Sample H). The pad-cure procedure was used in applying the mixture in a single step.
• EXAMPLE 4 I erties which are typical of the two-step process are ob- Employing the two-step procedure of Example 1, several 5 samples were prepared and then laundered repeatedly with tained without loss in char length or whiteness in comparison with those of the single-step process.
• Example 1 The general procedure "of Example 1 was followed to compare the eflects on fabric properties resulting from the two-step process and from the simultaneous treatment with N-(hydro'xymethyl)+3 (diethylphosphono)propionamide and t'ris(hydroxyrnethyl) melamine.
• R is lower alkyl or halogen-substituted lower alkyl; R is hydrogen or lower alkyl; and R is hydrogen, lower alkyl, or lower alkenyl, and said melamine is represented by the formula:
• C N represents a triazine ring
• each of x, y and g is an integer having a value of from to 3 with the proviso that the sum of x, y and z is 3, and there are at least two oxymethyl groups
• R is hydrogen or lower alkyl
• propionamide is N-(hydroxymethyl) 3 (dimethylphosphono) propionamide and said melamine is N N N -tris(hydroXymethyDmelamine.
• propionamide is N-(hydroxymethyl) 3 (diethylphosphono) propionamide and said melamine is N N N -tris(hydroxymethyl)melarnine.
• propionamide is N-(hydroxymethyl) 3 [bis(2 chloroethyl) phosphono]propionamide and said melamine is N N N -tris(hydroxymethyl)melamine.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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Cited By (6)

Family Cites Families (2)

• 1968
  • 1968-03-15 US US713317A patent/US3556840A/en not_active Expired - Lifetime
• 1969
  • 1969-03-14 GB GB1258652D patent/GB1258652A/en not_active Expired
  • 1969-03-14 DE DE19691913137 patent/DE1913137A1/de active Pending
  • 1969-03-17 FR FR6907505A patent/FR2004039A1/fr not_active Withdrawn

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