FLAME RETARDANT TREATED FABRICS WITH LOW FORMALDEHYDE CONTENT

Abstract

The instant invention relates to a textile article comprising a flame-retardant treated fabric including an oxidized polymer obtained from an ammonia curing of a condensate of (i) a tetrakis (hydroxyorgano) phosphonium salt; and (ii) urea or thiourea; followed by an oxidation into phosphine oxide groups of at least one part of the phosphonium groups present on the cured condensate, wherein said flame-retardant treated fabric: is intended to be used as a stable substrate in which the formation of formaldehyde over the time is inhibited; and contains less than 1% by weight of phosphorus present in phosphonium groups, based on the total weight of the flame-retardant treated fabric.

Claims

1. A textile article comprising at least one flame-retardant treated fabric including an oxidized polymer obtained from an ammonia curing of a condensate of (i) a tetrakis (hydroxyorgano) phosphonium salt; and (ii) urea and/or thiourea; followed by an oxidation into phosphine oxide groups of at least one part of the phosphonium groups present on the cured condensate, wherein said flame-retardant treated fabric: is intended to be used as a stable substrate in which the formation of formaldehyde over the time is inhibited; and contains less than 1% by weight of phosphorus present in phosphonium groups, based on the total weight of the flame-retardant treated fabric.

2. The textile article according to claim 1 wherein the flame-retardant treated fabric contains less than 0.9% by weight of phosphorus present in phosphonium groups, based on the total weight of the flame-retardant treated fabric.

3. The textile article according to claim 1 intended to be in indirect contact with the skin, with a clothing between the treated surface and the skin, that comprises less than 300 ppm.

4. The textile article according to claim 1 intended to be in direct contact with the skin, that comprises less than 75 ppm of free formaldehyde.

5. The textile article according to claim 1, wherein the tetrakis (hydroxyorgano) phosphonium salt is tetrakis (hydroxyorgano) phosphonium chloride (THPC).

6. The textile article according to claim 1, wherein the tetrakis (hydroxyorgano) phosphonium salt is tetrakis (hydroxyorgano) phosphonium sulfate (THPS).

7. The textile article according to claim 1, wherein the oxidized polymer is obtained from an ammonia curing of a condensate of (i) a tetrakis (hydroxyorgano) phosphonium salt; (ii) urea and/or thiourea, together with an aliphatic amine having 12 carbon atoms or more; followed by an oxidation into phosphine oxide groups of at least one part of the phosphonium groups present on the cured condensate.

8. A process for preparing a textile article as defined in claim 1, the process comprising: (a) a flame retardant treatment of the fabric, including: (a1) an impregnation of said fabric with the condensate of (i) a tetrakis (hydroxyorgano) phosphonium salt; and (ii) urea or thiourea, optionally together with an aliphatic amine having 12 carbon atoms or more, (a2) a curing with ammonia of the impregnated condensate; (a3) an oxidation of the polymer resulting from the curing, (b) an analysis of the content of the phosphonium groups in the fabric, followed by a repetition of the sequence of the steps (a3) and (b) if the analysis shows that the fabric contains 1% or more of phosphorus present in phosphonium groups, based on the total weight of the flame-retardant treated fabric.

9. The process of claim 8, wherein in step (b), the analysis is followed by a repetition of the sequence of steps (a3) and (b) if the analysis shows that the oxidized polymer contains 0.9% or more of phosphorus present in phosphonium groups, based on the total weight of the flame-retardant treated fabric.

10. A process for preparing a textile article as defined in claim 1, the process comprising the following steps: step 1: an impregnation of said fabric with the condensate of (i) a tetrakis (hydroxyorgano) phosphonium salt; and (ii) urea or thiourea; step 2: a curing with ammonia of the impregnated condensate; step 3: an oxidation of the polymer resulting from the curing, said oxidation including and/or being followed by a treatment with a metabisulfite salt at a pH of below 4.

11. A method, comprising using a flame-retardant treated fabric including an oxidized polymer obtained from an ammonia curing of a condensate of (i) a tetrakis (hydroxyorgano) phosphonium salt; and (ii) urea and/or thiourea; followed by an oxidation into phosphine oxide groups of at least one part of the phosphonium groups present on the cured condensate, wherein said flame-retardant treated fabric contains less than 1% by weight of phosphorus present in phosphonium groups, based on the total weight of the flame-retardant treated fabric, as a substrate stabilized against formation of formaldehyde.

12. The method according to claim 11, wherein the flame-retardant treated fabric is used for a long term contact with the skin.

13. The method according to claim 12, wherein the long term contact with the skin is for more than one year after the synthesis of the oxidized polymer.

14. The method according to claim 13, wherein the long term contact with the skin is for more than two years after the synthesis of the oxidized polymer.

15. The method according to claim 14, wherein the long term contact with the skin is for more than three years after the synthesis of the oxidized polymer.

16. The textile article according to claim 3, comprising less than 200 ppm of free formaldehyde.

17. The process according to claim 8, wherein, in (a3), the oxidation of the polymer resulting from the curing is with H.sub.2O.sub.2.

18. The process according to claim 8, wherein, in (b), the analysis of the content of the phosphonium groups in the fabric is by .sup.31P NMR.

19. The process according to claim 10, wherein, in step 3, the treatment with a metabisulfite salt is at a pH below 3.

Description

EXAMPLE 1

[0040] Two treated fabrics having a total content of phosphorus of 2% based on the total weight of the flame-retardant treated fabric have been compared: [0041] Fabric 1: Comparative [0042] containing trivalent phosphorus at a content more than 1% of based on the total weight of the flame-retardant treated fabric [0043] Fabric 2: according to the invention [0044] containing trivalent phosphorus at a content of 0.9% of based on the total weight of the flame-retardant treated fabric

[0045] The free HCOH content on the fabric has been measured and are reported in the table below:

TABLE-US-00001 Free HCOH content (pppm) time Fabric 1 Fabric 2 (years) (comparative) invention) 0 100 100 0.5 125 100 1 150 100 2 205 100 3 305 100

EXAMPLE 2

[0046] In order to illustrate the advantages of the succession of step 1 to step 3 of the process of the invention, a comparison test has been conducted on fabric treated with PERFORM chemical, ammonia cured and oxidised with hydrogen peroxide according to the standard industry procedure, using sodium metabisulfite (SMBS) at a pH of 5, and the same but using sodium metabisulfite (SMBS) at a pH of 2

[0047] More precisely, a fabric treatment has been carried out as follows: [0048] Impregnation [0049] 514 g of a fabric was immersed in a bath having the following composition: 481 g of PERFORM CC (available at Solvay) in 519 g of water as a solvent. [0050] The fabric was then immediately passed through a pad mangle and into an oven for drying at 120 C. for approximately 1 minute. [0051] Ammonia curing [0052] The PERFORM CC treated fabric was then subjected to an ammonia atmosphere for 15 seconds by passing through an ammonia cure unit. [0053] After sampling this resulted in 577 g of impregnated and cured fabric. [0054] H.sub.2O.sub.2 Oxidation [0055] The 577 g of cured fabric was then immersed for 10 minutes in a bath with the following composition: 2 L of 35% hydrogen peroxide in 8 L of water as a solvent. [0056] The fabric was then immersed for 15 minutes in another bath with the following composition: 100 g of soda ash in 10 L of water as a solvent. [0057] The fabric was then immersed for 45 minutes in another bath with the following composition: 10 L of water. [0058] The fabric was then immersed for 5 minutes in another bath with the following composition: 10 L of water, whereby a bulk oxidised fabric (BOF) is obtained. [0059] Sodium metabisulfite treatment [0060] As a comparative test, a first sample (Sample 1) of the BOF as obtained after the treatment steps as defined above was treated at a pH of 5. [0061] As an illustration of the instant invention, the same treatment has been carried out on a second Sample of the BOF (Sample 2), in exactly the same conditions as for Sample 1, but with a treatment at a pH of 2. [0062] Sample 1 (Comparative test) [0063] 13.4 g of the BOF (=Sample 1) was immersed in a bath with the following composition: 27.4 g of 40% sodium metabisulfite in 1 L of water as a solvent, with a resulting pH of 5, for 5 minutes at 70 C. [0064] Sample 1 was then immersed for 5 minutes in another bath with the following composition: 1 L of water at 80 C. [0065] Sample 1 was then immersed for 5 minutes in another bath with the following composition: 1 L of water at 80 C. [0066] Sample 1 was then immersed for 5 minutes in a bath with the following composition: 1 L of water at 20 C. [0067] Sample 2 (Illustrative) [0068] 13.9 g of the BOF (=Sample 2) was immersed in a bath with the following composition: 27.4 g of 40% sodium metabisulfite plus 40 g of 1M HCl in 1 L of water as a solvent, with a resulting pH of 2 for 5 minutes at 70 C. [0069] Sample 2 was then immersed for 5 minutes in another bath with the following composition: 1 L of water at 80 C. [0070] Sample 2 was then immersed for 5 minutes in another bath with the following composition: 1 L of water at 80 C. [0071] Sample 2 was then immersed for 5 minutes in another bath with the following composition: 1 L of water at 20 C.

[0072] As a result, a trivalent phosphorus content of less than 1% (0.84%) has been obtained when SMBS is used at pH=2 according to the invention (Sample 2).

[0073] On the other hand, a content of more than 1% (1.26%) has been obtained in the standard conditions using SMBS is used (sample 1)

[0074] With the content of less than 1% as obtained according to the invention, the free content of HCOH remains very low and stable over the time (Sample 2), when it increases with the time with the standard conditions of treatment (sample 1).