RU2041301C1 - Method of modification of stained cotton fabric - Google Patents

Abstract

Flame retardant cellulosic fabrics having reduced shrinkage are obtained by treatment of fabric with a tetrakis hydroxymethyl phosphonium compound or condensate and then curing with ammonia, followed by treatment involving reaction of the fabric with a non self-condensing methylolamide under aqueous acid conditions. The order of treatment can also be reversed.

Description

 The invention relates to the chemical technology of materials, in particular to methods for treating dyed flame retardant cotton fabrics.

 A known method of modifying tissue by impregnating with an aqueous solution of a polymer compound tetrakis- (oxymethyl) phosphonium (THP) and a polyfunctional nitrogen compound, for example trimethylomelamine (TMM), used as a curing agent, followed by drying and heat curing.

 A known method of impregnating tissue with an aqueous solution of the precondensate of the THP salt, a carbamic acid derivative, for example urea, and ammonia, followed by curing with an aqueous solution of ammonia.

 A process is known in which the fabric is impregnated with an aqueous solution of P-containing N-hydroxymethylamide (and possibly a THP compound) and a curing agent, for example methylomelamine and a weak acid catalyst such as zinc nitrate, followed by drying and heat curing.

 There is also known a method of impregnating tissue with an aqueous solution of a partially neutralized salt of THP and various di- (hydroxymethyl) amides (DMU), in the preferred embodiment, it is dimethylol urea, but possibly di (hydroxymethyl) di (hydroxy) ethylene urea (DMDHEU), followed by drying and curing with ammonia gas with or without heat. It should be noted that DMDHEU either does not pass the fire test at all or barely withstands them (see Tables 1 and 2).

 Closest to the invention is a method of modifying dyed tissue by impregnation with an aqueous solution of the precondensate of tetrakis (oxymethyl) phosphonium chloride and urea chloride. The fabric is dried and cured in a stream of ammonia gas.

 Fabrics obtained using these known methods have insufficiently good properties, for example, the duration of fire retardancy with respect to shrinkage during washing and recoverability when wrinkled. In known processes, a joint reaction of the THP compound, methylolamide and / or tissue takes place.

 The technical problem to which this invention is directed is to eliminate the above disadvantages.

 The problem is solved due to the fact that in the known method of modifying dyed cotton fabric by impregnation with an aqueous solution of THP chloride precondensate by drying and curing in a stream of ammonia gas before impregnation or after curing, the fabric is further treated with an aqueous solution of di-1,3-N, N'-hydroxymethyl -4,5-dihydroxy ethylene urea in the presence of a mineral acid, providing a pH of not more than 1.7.

The following is a description of examples of the invention in which the following test methods are used. In each case the fabric before the tests was maintained for 24 hours ^at 20 ° C and humidity 65% (related).

 1. Crush resistance.

 Measurement of the crease angle was measured in the direction of the base for the treated and untreated fabric, folded with the front side out, in a dry and wet state, using a (MONSANTO WRINKLE RECOVERY TESTER with a load of 500 g and 3-minute load-recovery intervals.

 2. Assessment of crush resistance (DP).

 In Examples 1-15, the fabric was evaluated by Test Method N 88 AATCC (American Association of Fabric Dyes Specialists) in accordance with the standard for washing and wear, and DP in terms of fabric smoothness at a glance in accordance with Standards 1-5 (1 worst) , and in examples 16-26 by the method 124 AATCC.

 3. Shrinkage.

Shrinkage on the basis and weft was measured according to the method of BS 4923 after 40 washes (for examples 1-15) or after 50 washes (for examples 16-27) (soft water according to DLN 53920) at a temperature of 93 ^about C.

 4. Strength.

 The tensile strength was measured according to BS 2756, and the tear strength in the direction of the weft according to Elmendorf.

5. The flame retardant properties of the fabric was determined after 12 washes at 93 ^C and after 40 washes at 93 ^{° C} (for Examples 1-15) or 50 washes (for Examples 16-26) (soft water by DIN 53920 standard) for BS 3119 standard methodology.

 6. Tissue analysis.

After final treatment, P, N and formaldehyde content were determined in parts per million. P and N were also determined after 12 and 40 washes (for examples 1-15) or 50 washes (for examples 16-29) at a temperature of 93 ^about C. Then the atomic ratio N: P was calculated.

 7. Wear resistance.

 Accelerated tests were carried out according to method A of the AATCC-99-1984 standard. Depreciation was checked by weight loss after friction against a fabric-based hide with a 250 mesh net for 3 minutes at a rotation speed of 3000 rpm.

 Fabric treated with THR.

 Fabric A (comparative).

The fabric for use in examples 1-13, 15 and 27 was obtained by impregnating a cotton teak 3111 having a mass of 0.285 kg / m ² and dyed previously with bright orange azo dye without sensing, an aqueous solution of THR chloride and urea precondensate at a molar ratio of 1: 0.5 and pH 4-5. Equivalent solution relative to THP ion of 25% was impregnated fabric to a moisture content of about 80% was dried for 1 minute at ¹²⁰ ° C, and then cured in a forced stream of ammonia gas according to U.S. patent N 4145463. The cured fabric was oxidized with hydrogen peroxide, neutralized with sodium carbonate solution, washed and dried.

 Fabric B, C, D and E.

The procedure described for fabric A was used for the remaining four cotton fabrics with the following changes. Wash water contained tissue plasticizer ("Alkamine" FPS) in an amount of 2% of the weight of the treated THP fabric, and each sample of the treated THP fabric was subjected to mechanical shrinkage by compression in accordance with the "Sanforization" process. Mercerized satin fabric for work clothes weighing 0.270 kg / m ² , pre-stained with cubic blue dye (fabric B), stained with azo dye teak 3111 weighing 0.346 kg / m ² (fabric C), dyed with red azo dye, was used as fabric samples. satin teak weighing 0.28 kg / m ² (fabric D), as well as optically clarified twill weighing 0.192 kg / m ² (fabric E).

PRI me R 1. A sample of treated THP tissue A was stuffed to 80% humidity with an impregnating solution containing 250 ml / l of a 45% aqueous solution of 1,3-N, N'-hydroxymethyl-4,5- DMDHEU dihydroxyethylene urea (trademark EIxapret CPN) and 50 ml / l of 98% sulfuric acid, the pH of the solution is less than 1, and the acid concentration in the bath is 1.88 n. A damp cloth with a total moisture content of about 68% (based on the weight of the treated THP fabric) was neatly folded, placed in a plastic bag, which was sealed, and kept in a free state (i.e., without tension) for 22 hours at room temperature for curing . The fabric was then removed and washed successively with cold water, aqueous sodium carbonate at a concentration of 10 g / L, an aqueous solution of sodium carbonate at a concentration of 2 g / L and supplemented with 2 g / L of detergent at ⁵⁰ ° C, hot water at ⁶⁰ ° C and cold water. After that, the tissue was dried and tested together with comparative samples of tissue treated with THP (Comp. A).

 The results are shown in table. 1. Slow combustion was measured after 40 washes.

PRI me R 2. The process of example 1 was repeated with the following changes: a wetting agent in the amount of 0.5 g / l was added to the impregnation solution, which is a mixture of non-ionic and anionic agents with the brand WA 100 sold by Brookstone Chemicals staffordshire "(England), and after curing the fabric was washed with cold water, neutralized with sodium carbonate solution, washed with cold water and dried at 100 ^C. The cut of this fabric squares, and the squares of the original THP cured fabric were washed in a washing machine for 10 minutes at ⁶⁰ ° C, then washed three times with cold water and centrifuged for 4 minutes at a speed of 1000 rev / min. Thereafter, the fabric squares were dried on the rope at room temperature or in the drum for 15 minutes with a final maximum temperature of 70 ° ^C.

 These tissue squares, together with comparative samples of THP-treated tissue (Comparative Example B), were tested to evaluate crush resistance. The results are shown in table. 2.

 PRI me R 3. For example 3, the process was repeated as in example 1 with the following changes: the impregnation solution with a pH of less than 1 contained 70 ml / l of concentrated 35% hydrochloric acid (instead of sulfuric) with a concentration of 0.82 N. as well as 0.5 ml / l of the wetting agent of Example 2, the fabric was cured for 16 hours. The tissue moisture at the beginning of the curing process was about 72% (by weight of the treated THP fabric).

 The test results of this tissue, as well as the test results of a comparative sample of treated THP tissue (comparative example C) are given in table. 3, 4, 5 and 6.

 PRI me R s 4-12. The process of Example 1 was repeated with various quantitative hardeners and added concentrated sulfuric acid. In all cases, the humidity at the exit from the bath with the impregnating resin was maintained at about 80% and the humidity at the beginning of the curing process was about 63-72% (by weight of the tissue treated with THP). The results are shown in table. 7.

 The flammability of all fabrics meets the requirements of standard B 3120.

PRI me R 13. The process according to examples 7-9 was repeated with the replacement of sulfuric acid with concentrated hydrochloric acid in an amount of 100 ml (about 30 wt.), The pH of the solution was less than 1, and the acid concentration of 1.17 N. The moisture content of the tissue at the beginning of the curing process was about 71% (by weight of the tissue treated with THP). The treated fabric was subjected to an accelerated wear test, the weight loss was 10.6% Other tests gave the following results: shrinkage of 3.5% based on the angle wrinkle resistance in the wet state ^about 150, tear strength (Elmendorf, weft) 1.10 kg average characteristic length of GR after 40 washes of 68 mm.

 PRI me R 14. The process according to examples 7-9 was repeated with the following changes: used processed THP fabric B, the sulfuric acid content in the impregnation bath 140 ml / l (acid concentration of 5.25 N.), curing time 3 h The moisture content of the tissue at the beginning of the curing process is about 57% (by weight of the tissue treated with THP). The test results of this tissue and a comparative sample of treated THP tissue (Comp. B) are given in table. 8.

 PRI me R 15. The process according to example 14 was repeated with processed THP fabric A. The test results of this fabric together with the results of comparative sample A are shown in table. nine.

PRI me R s 16-19. Sections of fabric A 20 m long, fabric C 30 m long, fabric D 50 m long and fabric E 30 m long were sewn together and passed twice through a solution containing 350 g / l of an aqueous DMDHEU solution according to Example 1, 90 g / l 98% sulfuric acid and 2 g / l wetting agent according to example 2. The acid concentration in the solution was 1.84 N. and pH less than 1. The excess solution was squeezed out of the swollen tissue, which was then wound around a roll, wrapped with a plastic sheet and continued to slowly rotate the roll at a moisture content of about 52-60% (by weight of the treated THR fabric) and a minimum tension sufficient to prevent sagging for 22 hours at room temperature (18 ° ^C) before curing DMDHEU. The trapping of the solution with a cloth for fabric A 72% C 59% D 72% and E 70%. All cured fabrics were then washed with water, neutralized and washed again with water in a roll dyeing machine. Then, a plasticization operation was performed, during which each of the four tissues was passed through a bath containing 10 g / l of a derivative of a nonionic fatty acid ester as a plasticizer (trademark CPOSOFT XME manufactured by Crosfield Textile Chemicals). The wet tissue was dried by suction, and then heated in a stretch at a temperature of 150 ^about C.

 Thus obtained four tissues were tested, and the test results of untreated and processed tissues are given in table. 10-16.

 1. Shrinkage.

 Base shrinkage and weft were determined as described above, but after 50 washes.

 2. Tear strength in the direction of the duck along Elmendorf.

3. Tensile Strength according to BS 2756 standards, and the treated fabric only treated fabric C after 50 washes at 93 ^{° C} (soft water on standard DIN 53920).

 4. Burn retardation tests were performed as described above, but after 50 washes.

 5. Corrosion resistance.

6. Evaluation of crease resistance (DP) was carried out as described above on the tissues after one wash at a temperature of 95 ^about C and with drying according to example 2.

7. The results of the analysis of the treated tissue before and after 50 washes at a temperature of 93 ^about (soft water according to DIN 53920).

 8. Lightfastness of coloring.

 The xenon arc light resistance was measured in accordance with BS 02 B 1006 standards. No difference was found between untreated and untreated fabrics A, C, D and E, respectively.

 9. Operational properties.

 A noticeable difference between the performance properties of untreated and treated fabrics A, C, D and E, respectively, was not found.

 10. Humidity.

Humidity of treated and untreated fabric A, CE, respectively, were determined after incubation for 24 hours at 65% relative humidity by weighing the fabrics before and after drying for 2 hours at a temperature of 105 ^° C Humidity fabrics was about 0.5% less than moisture treated fabrics. Thus, the treatment increases moisture absorption at a relative humidity of 65%
11. Absorption of water.

 Untreated and treated tissues A and C-E were washed with HL CCI, after which the amount of residual water was determined after centrifugation of wet tissues for 4 min at a speed of 1000 rpm. Treated tissues retained less water than untreated and, therefore, DHDMEU treatment reduces water absorption.

 PRI me R s 20-26.

 The cloth.

Two pieces of cotton teak 3111 up to 100 m long and weighing 0.295 kg / m ² were subjected to enzymatic purification, washed with alkali and bleached with hydrogen peroxide in an alkaline medium. The fabric was taken directly from the loom.

Bleached fabric weighing 0.27 f / m ² was cut into 4 pieces of 50 m each, which were subjected to processing operations V, X, Y and Z, respectively. These operations are various combinations of the following treatments: DHDMEU treatment with curing, treatment by combining THP with curing and shrinkage by mechanical compression. These combinations are shown in table. 17.

 Curing THR for operations V, X, Y, and Z.

 The tissue treatment procedure was as described for fabric A. The moisture content of the tissue upon exiting the impregnation solution during operation V was about 80% (by weight of the cured tissue treated with DHDMEU tissue) and 100% by operations X, Y and Z (based on the weight of the bleached tissue) .

 DHDMEU curing treatment for operations V, Y, and Z.

 The tissue treatment procedure was as described in examples 16-19, except that the impregnation solution contained 325 g / l of an aqueous solution of DHDMEU, 90 g / l of 98% sulfuric acid, 2 g / l of a wetting agent used in example 2, and 18 g / l of an acid resistant fluorescent brightening agent known as Sandor Lencophor HRV fluid. The moisture content of the tissue upon leaving the solution was 100% for operation V (based on the weight of the bleached tissue) and 75% for operations Y and (based on the weight of the tissue treated with THP), and the moisture content of the tissue at the beginning of the curing process was about 60% for examples 20-24 (by weight of tissue treated with THP) and 79% for examples 25 and 26 (by weight of the starting tissue).

 Compression mechanical shrinkage.

 The process of mechanical shrinkage by compression was carried out on a classic Sanforizer machine in accordance with the description (see Textile Bulletin Dyeing (Printing / Finishing 2/86). The process included the operations of steam treatment, width adjustment, pressing against the stretched rubber tape, which relieves tension shrinkage of the fabric, drying by compression between the heated metal cylinder and the absorbent layer, and rolling, while the machine was set to shrink 5% for operations V, X, Y and Z.

 Optical brightening.

 An optical brightener was introduced into the DHDMEU impregnation solution for operations V, Y, and Z and into the wash water after treatment with THP for operation X.

 Results.

 The properties of the treated tissues were checked at the fourth stage of operations, V, Y and Z, and some of the properties at the last stage of operation X and the early stages of operations X, Y and Z.

 In the table. 18 is a summary of operations for Examples 20-26 and Comparative Examples D-C.

 1. Shrinkage.

 In the table. 19 shows the results of shrinkage tests according to the method described in examples 16-19, after 1 and 50 washes.

 2. Tear strength in the direction of the duck along Elmendorf.

 3. Tensile strength in accordance with standard B 2756.

 4. Slowing combustion after 50 washes (procedure described above).

 5. Corrosion resistance.

6. Evaluation of crease resistance (DP) after 1 washing at a temperature of 95 ^about C and drying according to example 2 (the method is described above).

 7. Humidity.

The determination of tissue moisture was carried out in accordance with the description of examples 16-19. The moisture content of the fabrics in examples 23, 24, and 26 was 0.5-1% higher than for comparative example D (when drying in an oven). Therefore, treatment with DHDMEU increases the equilibrium humidity at a relative humidity of 65%
8. The absorption of water.

 Checking the residual moisture after centrifugation was carried out in the same way as in examples 16-19 for fabrics in examples 23, 24 and 26 and in comparative example D. The fabrics in examples 23, 24 and 26 retained 22% less moisture than the fabric in comparative Example D. Consequently, treatment with DHDMEU reduces water absorption.

PRI me R 27. Treated with THP tissue A was impregnated in a solution containing 250 ml / l of the 45% DHDMEU solution used in example 1 and 20 g / l of 98% sulfuric acid, the pH of the solution was 1, 7, and the acid concentration of 0.2 N. The impregnated cloth was squeezed to a moisture content of 75% and then heated for 3 minutes in an oven at ⁹⁰ ° C to obtain a moisture content of 10% The fabric was immediately sealed in a plastic bag to maintain its moisture content and was aged for 22 hours at room temperature without strain . Thereafter, the fabric was taken out and washed as in Example 1, dried and subjected to 50 washes at 93 ^° C Shrinkage thus treated fabric was based on 5% compared with 10% for the washed fabrics same manner THP cured fabric A before treatment DHDMEU .

Claims (2)

 1. METHOD OF MODIFICATION OF THE COLORED COTTON FABRIC by impregnation with an aqueous solution of precondensate of tetrakis (oxymethyl) phosphonium chloride and urea chloride, drying and curing in a stream of gaseous ammonia, characterized in that the fabric is additionally treated with 1,3-water, before impregnation or after curing with N-water, N ′ hydroxymethyl-4,5-dihydroxyethylene urea in the presence of a mineral acid providing a pH of not more than 1.7.  2. The method according to claim 1, characterized in that the additional processing is carried out on a fabric containing 57-80% moisture.

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