CZ38803U1 - A coating to treat textiles with fire resistant properties and a textile with fire resistant properties - Google Patents

Description

The technical solution relates to the field of non-flammable textile treatments, specifically a coating for treating textiles with fire-retardant properties and textiles with fire-retardant properties.

State of the art

Reducing the flammability of textile materials is currently a significant trend in their refinement. The market for flame retardants and non-flammable textile materials has been growing significantly in recent years, mainly due to increasingly stringent national and international safety requirements. Given the increasing use of non-flammable textiles in many fields, such as protective clothing - PPE (CLOTHTECH, PROTECH), automotive industry (MOBITECH), furniture and interior materials (HOMETECH), technical textiles (INDUTECH) or healthcare (MEDTECH), the importance of research into their impact on the environment and human health is growing.

In addition to flame-retardant textile fibers such as meta-aramid-based Nomex, p-aramid-based Kevlar, Viscose FR, modacrylic (acrylic fiber modified with vinylidene chloride), poly-benzimidazole (PBI)-based fibers, carbonized carbon fiber (Zylon), polyphenylene sulfide (PPS), polyester with flame-retardant chain modification (Trevira-CS), and synthetic polymers modified with flame-retardant additives in the mass (PA66 Nexylon), the use of flame retardants applied to natural and synthetic materials as part of final treatments is increasing.

The increased risk of negative effects, including proven accumulation in living tissues, is pointed out primarily in flame retardants based on brominated derivatives of organic compounds and in systems with a risk of formaldehyde emissions, which is why the rules and regulations related to the use of these agents are being significantly tightened at the European level.

The most commonly used commercial flame retardants can be divided into three main categories. The first are primary flame retardants, which are based on phosphorus with a condensed phase mechanism, and halogens with a gas phase mechanism. The second are synergistic substances that have only a small retarding effect on their own, but significantly increase the non-flammable effect of primary flame retardants. These are substances based on Sb/halogens or nitrogen/phosphorus N/P. And the third category is adduction retardants, which show activity through physical effects, these are usually borates, alumina, alumina carbonate, intumescent systems.

The choice of retardants depends on the type of textile material being treated and the requirement for stability of the flame retardant effect under conditions of use and maintenance according to the end application.

Flame retardants for the final flame retardant treatment of cellulose and blends with polyester Cel/PES up to 25% polyester content are most often based on organic chemical systems combining phosphorus and nitrogen P/N, which react with the fiber to form permanent crosslinked structures. The basic ingredient of the PROBAN treatment is tetrakis-(hydroxymethyl)phosphonium chloride (THPC) produced from phosphine, formaldehyde and hydrochloric acid. Another commercial approach to achieving permanent flame retardant treatment of cellulose is the PYROVATEX system based on the use of N-methylol dimethylphosphonopropionamide in combination with trimethylmelamine and phosphoric acid as a catalyst in the pad-dry-cure process. Both of these systems are associated with significant formaldehyde emissions during production and with an increased formaldehyde content in fabrics, which represents a significant toxicological risk. In addition, both of the above treatments are accompanied by a high loss of strength, up to 30%, and a change in color shade. Mixtures with a polyester content higher than 30% cannot be made flame retardant using these treatments.

- 1 CZ 38803 U1

Commercial flame retardants for polyester treatments are based on compounds based on cyclic phosphates and phosphonates, applied by a thermosol process involving impregnation and high-temperature processing or as part of high-temperature dyeing together with a dye. These are often chlorinated compounds with a higher level of risk, efforts are growing to limit their use, the concentration of the active substance in the product is limited to 30% for applications within the EU, which causes complications in the actual treatment of textiles, such as a demanding neutralization process, high dosage.

In addition to the above bath processes, flame-retardant treatments can be applied to textiles using a coating technique. Textile coatings represent a special technique of one-sided application of a polymer formulation with a suitably adjusted rheology using a doctor blade. For this method of flame-retardant treatment, brominated organic derivatives have proven themselves in terms of functionality and the resulting soft feel of textiles, and are usually used for this purpose in combination with dispersible antimony oxides with a synergistic effect. However, brominated derivatives, such as the previously used HBCD (hexabromociclodecane) or Deca BDE (decabromodiphenyl ether), pose high toxicological risks due to toxic effects on living organisms, deposition in the environment and accumulation in animal tissues. Their combustion also results in the emission of toxic volatile organic compounds (VOCs). The increased risk of negative effects, including proven accumulation in living tissues, is pointed out primarily in the case of flame retardants based on brominated derivatives of organic compounds and in systems with a risk of formaldehyde emissions, which is why the rules and regulations related to the use of these agents at the European level are being significantly tightened. A number of these compounds for textile treatments are already banned in the EU and the process of legislative restriction and gradual elimination of treatments based on halogen derivatives, mainly bromine, and recently also chlorine, from the market on a global scale continues. Therefore, their replacement with safer halogen-free and antimony-free alternatives is highly topical.

The aim of intensive research is to formulate and verify new halogen-free flame retardants or inhibitors and their application using environmentally friendly technological processes, which are mainly focused on reducing VOC emissions, especially formaldehyde, during production and final treatments, as well as on minimizing the content or eliminating these components in treated textiles. These are mainly systems based on functional nanomaterials, phosphorus and nitrogen compounds, carbonizing and intumescent systems applied by impregnation and coating techniques. Examples of halogen-free flame retardants based on inorganic and organic compounds, often based on natural sources, are inorganic phosphorus compounds (ammonium polyphosphate) for wash-resistant treatments, organic phosphorus compounds (esters, phosphonates, phosphinates, polyphosphonates), inorganic hydroxides releasing water (Al(OH)3, AUO3.3H2O, Mg(OHŘ), nitrogen and phosphorus compounds (synergistic effect), e.g. mixtures of melamine, melamine cyanurate and guanidine phosphate, Zr compounds (for wool treatment), Co and Sn compounds, boron compounds, e.g. borax, boric acid, melamine borate, which are not permitted by legislation, bio-based retardants based on natural compounds containing phosphorus and nitrogen, e.g. phytic acid from agricultural waste, aminopolysaccharides (chitosan), amino acids (casein, zein), deoxyribonucleic acid (DNA), eggshells and ground crustacean shells (content CaCO3), polysaccharides and other polyols and lignin as a carbon source for intumescent systems in combination with sodium polyphosphate, phosphorylated lignin phloroglucinol, layered hydroxides and (nano)clays: nanoLDH, organomodified montmorillonite in combination with ammonium polyphosphate, SiO2, clays, sepolite, halloysite, DOPO (9,10-dohydro-9-oxy-10-phosphaphenanthrene-10-oxide from castor oil grafted to jaconic acid: flame retardant for polyamide, MWCTS: multi-walled carbon nanotubes for thermoplastic polymers, PPMA - poly(piperazinyl phosphatide, phosphazene derivatives and polyethylemimine (PEI) and sodium polyphosphate - application using the layer by layer (LbL) technique.

The reduction of flammability of textiles is assessed using relevant standards according to the target applications of the treated fabrics, where in addition to the flame-retardant effect, the stability of the treatments in prescribed maintenance systems is also tested.

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Functionalization of textiles by coating technique is used mainly for technical textiles, e.g. construction, automotive, furniture. When a polymer layer is applied on one side, flexibility, breathability and vapor permeability are reduced, therefore the use of these treatments for clothing textiles is limited to special protective clothing (PPE) or zone treatments of exposed parts of clothing. The aim of coating treatments is usually stabilization and reinforcement, achieving water impermeability, dirt resistance, resistance to blowing through, thermal reflectivity, e.g. aluminum coatings, anti-slip effect or prevention of light penetration. Coating formulations are usually applied from paste or foam to textiles with a hydrophobic pre-treatment, which is carried out to prevent penetration of the applied coating into the textile material and to ensure localization of the coating on the surface of the textile (prevention of seepage, homogeneous applied layer). When applied using an air knife or a knife against a roller, the applied coating formulation must have suitable properties in terms of rheology, homogeneity and stability. The dispersed particles contained must not agglomerate, the quality of the applied formulation must be stable to ensure a homogeneous, high-quality coating. Therefore, various auxiliary agents must usually be added to the coating formulation during preparation, e.g. thickener, deaerator, defoamer, and in the case of powdered functional additives also wetting agents, etc. These are usually organic materials, which, including the hydrophobic pre-treatment, represent a flammable component and therefore counteract the non-flammable effect.

The mere addition of a flame retardant to the coating mixture is often insufficient, and in addition, some compounds tend to migrate to the surface in the polymer matrix or are directly washed out of this matrix upon contact with water. Products for flame-retardant treatments tend to be hydrophilic, and therefore tend to worsen water repellency, the so-called repellent effect, and water impermeability, the so-called water column, when combined with hydrophobic treatments. Even a combination of different types of flame retardants, e.g. when treating mixed materials, does not usually lead to a flame-retardant effect, because different retardants have different mechanisms of flammability suppression that do not show a synergistic effect. Textiles with multifunctional treatments are therefore often more demanding in terms of ensuring a reliable flame-retardant effect, and it is therefore necessary to find suitable solutions to ensure the required properties even with combined treatments.

The task of the technical solution is therefore to create such a coating for treating textiles with fire-retardant properties and textiles with fire-retardant properties that would eliminate the above-mentioned shortcomings. The aim of the technical solution is therefore to create such a coating that would be stable, in which there would be no washing out and migration of individual components outside the textile itself and which would provide long-term multifunctional treatment of the textile against burning, soiling and creasing while maintaining a long-term flame-retardant effect.

The essence of the technical solution

The task is solved by means of a coating for treating textiles with fire-retardant properties according to this technical solution. The coating contains a supporting polymer matrix based on aliphatic polyurethane of the polyether type and a flame retardant.

The essence of the technical solution is that the flame retardant is a monomer based on diol or diamine with a phosphorus content of at least 8 wt. % or an oligomer containing polyphosphate diol in its structure. The coating further contains a modified polyurethane-based polymer component, which is in the form of an aqueous dispersion with a concentration of 43 wt. % of the modified polymer component in water with a viscosity of 5 to 15 Pa.s, where the weight ratio of polymer dry matter between the modified polymer component and the supporting polymer matrix in the coating is 1:3 to 4:1. The modified polymer component is contained in the coating in a concentration of 16 to 35 wt. % and has a viscosity of 2 to 15 Pa.s.

The synthesis of the modified polymer component is carried out in a dimethyl formamide or dimethyl sulfoxide environment to a constant molecular weight characterized by viscosity measurement at a defined concentration of the modified polymer component in the solution. For application to the coating, it is subsequently necessary to convert this modified polymer component into an aqueous dispersion. Procedure

- 3 CZ 38803 UI transferring the modified polymer component into water consists of isolating the modified polymer component by precipitation from the reaction mixture using water and salts of a suitable concentration, preferably 4.5 to 15.0% by weight NaCl and subsequent dispersion of the modified polymer component into a dilute solution in water (approx. 8 to 10% by weight, dry matter) and concentration of the aqueous dispersion using a rotary vacuum evaporator to a concentration of the modified polymer component of 16 to 35% by weight, dry matter in water, thereby obtaining a homogeneous aqueous dispersion of the modified polymer component with a viscosity of 2 to 15 Pa.s.

In a preferred embodiment, the flame retardant is selected from the group: diethyl N,N-bis(2-hydroxyethyl)aminomethayl phosphate with a phosphorus content of 12.1%, phenyl diaminophosphate containing 18.0% phosphorus, bis(3-hydroxyphenyl)phenyl phosphate containing 8.7% phosphorus, bis(3-hydroxypropyl) isobutylphosphine oxide or another oligomeric phosphate diol, oligomeric phosphonate diol or polyphosphate diol.

The flame retardant, which has the character of a monomer, is incorporated in the polymer component, preferably bound by a chemical or urethane bond with a diisocyanate. Since the modified polymer component is based on polyurethane and the flame retardant is based on a diol or diamine, diisocyanate is used in the preparation of the modified polymer component. Polyurethane is a polymer that is produced by polyaddition of diisocyanates with dihydric or polyhydric alcohols to form a carbamate or urethane bond. The diisocyanate is selected from the group: isophorone diisocyanate, hexamethylene diisocyanate, methylene diphenyl diisocyanate.

After reaction with a suitable diisocyanate, a modified polymer component of the following structure can then be prepared. The reaction is presented in a general manner with general formulas for clarity.

ho--r ₂ —OH

O^=C^=N--R,--N^=C^=O + |

X

where R 1 is -(CH ₂ ) 6 -, -C ₆ H ₇ (CH ₃ ) ₃ CH 2 - or -(C ₆ H 4 )CH ₂ (C ₆ H 4 )-;

R ₂ is -(C ₂ H 4 )(O(P=O)(OC 2 _{H 5} )(OC 2 H 4 )) 4 -, -(C ₂ H ₄ )N(CH ₂ )(P=O)(OC ₂ H ₅ ) ₂ (C ₂ H ₄ )- or -(CH ₂ )C(CH ₃ )(CH ₂ )-;

X is -COOH and n is the number of polymer units in units to tens of thousands.

In terms of suitable application properties, industrial coatings must have an appropriate viscosity so that the resulting coating has a honey-like character and suitable rheological behavior ensuring uniform application of the squeegee paste to the carrier fabric on the coating equipment. It seems appropriate to mix the modified polymer component, i.e. an aqueous polyurethane emulsion with a polymer-incorporated flame retardant, with the carrier polymer matrix, i.e. with commercially available materials based on aliphatic polyurethane of the polyether type in a ratio of 1:3 to 4:1 according to the requirements for the level of non-flammable treatment and the mechanical properties of the coating layer, especially elasticity, stiffness and strength.

In a preferred embodiment, the modified polymer component comprises a hydrophilic group based on a polyether diol with a molecular weight of 1000 to 2000 g/mol and a diol with a dissociable carboxylic acid to increase the dispersibility of the modified polymer component in water. The hydrophilic group is preferably polyethylene glycol (PEG) or polypropylene glycol (PPG), which is added to the polymerization reaction, and the diol with a dissociable carboxylic acid is preferably 2,2-bis(hydroxymethayl)propanoic acid (DMPA), which is also added as a monomer to

-4CZ 38803 U1 polymerization reaction. The optimal properties of the modified polymer component are determined by the correct ratio of individual monomers, which leads to products with different dispersibility and stability in water.

The coating in a preferred embodiment contains from 0.6 to 1.1 wt. % phosphorus and from 1.2 to 2.1 wt. % nitrogen

The subject of the technical solution is also a textile with fire-retardant properties according to this technical solution. The essence of the technical solution lies in the fact that the textile includes on its surface an impregnating semi-permanent non-flammable coating based on ammonium salts of aliphatic phosphonates of diammonium phosphate or organic complex phosphates and further includes the above-described coating arranged on the impregnating semi-permanent non-flammable coating.

The coating mixture itself only makes up part of the total weight of the treated textile and the content of nitrogen and phosphorus atoms is insufficient in terms of flame retardancy. For this reason, the coating is applied to a textile with a semi-permanent flame-retardant treatment based on, for example, ammonium salts of aliphatic phosphonates, diammonium phosphate or organic complex phosphonates, which is applied by an impregnation process. The coating itself then stabilizes this flame-retardant treatment, there is no migration or washing out, and we can speak of a long-term multifunctional treatment protecting the textile from burning, soiling and creasing. A conventional coating without flame-retardant modification would represent an increase in the proportion of the flammable component and its application to a textile with a flame-retardant treatment would result in a loss of the flame-retardant effect. Modification of the coating polyurethane polymer with groups containing phosphorus and nitrogen is therefore necessary and ensures the preservation of the flame-retardant effect.

The advantages of the coating for treating textiles with fire-retardant properties and textiles with fire-retardant properties according to this technical solution lie mainly in the fact that it is stable, does not wash out and does not migrate individual components outside the textile itself, and thus provides long-term multifunctional treatment of the textile against burning, soiling and wrinkling while maintaining a long-term flame-retardant effect.

Example of implementing a technical solution

Determination of non-flammable properties according to the ČSN ISO 3795 standard for vehicle interiors

The tests were carried out in accordance with ČSN ISO 3795 (300577:1994), Road vehicles, tractors, agricultural and forestry machinery. Determination of the flammability of materials used in the interior of vehicles. This standard specifies a method for determining the horizontal burning rate of materials used in the passenger compartment of road vehicles (e.g. passenger cars, vans, buses), tractors, agricultural and forestry machinery after exposure to a small flame. The sample is held horizontally in a U-shaped holder and exposed to a defined flame for 15 s in a combustion chamber, with the flame acting on the free end of the sample. The test determines whether and when the flame extinguishes, or the time it takes for the flame to travel a measured distance. If the sample does not start to burn or does not continue to burn after the burner is switched off, or if the flame goes out before reaching the first measuring point so that the burning time has not been measured, the test report shall state that the burning rate is 0 mm/min. The measurement of the burning time shall begin when the flame reaches the first measuring point. The burning rate shall be measured up to the second measuring point. The burning rate in mm/min shall be calculated from the time and distance values.

Determination of non-flammable properties according to DIN 4102 for building materials (DIN 4102-1 procedure for class B2)

The tests are described in DIN 4102-1, Flammability of building materials and building components - Part 1: Building materials, terminology, requirements and testing (5/1998, +01:8/1998) Procedure for class B2. This standard is important for product safety. It evaluates whether a material burns,

- 5 CZ 38803 U1 smoldering or dripping molten material. This is almost as dangerous from a safety point of view as burning with a flame. The speed of flame spread is also measured, which is important so that a person has a chance to extinguish the fire or enough time to escape.

For the determination according to DIN 4102-1, a burner flame defined in accordance with DIN 4102-1 is applied to the surface or lower edge of textile test samples placed in a vertical position. In the case of determining the burning rate, the flame propagation time in seconds required for the flame front to pass between marking threads placed above the surface of the test sample at three distances from the ignition flame is recorded.

For class B2, it is assessed whether the flame tip reaches a distance of 150 mm from the ignition point, and if so, in what time. Furthermore, the standard monitors the occurrence of fallen parts burning for more than 2 seconds and whether these parts ignite the control filter paper placed under the sample.

Determination of flammability - limiting oxygen number ČSN EN ISO 4589-2

Standard ČSN ISO 4589-2 (640756:1998), Plastics - Determination of flammability by the oxygen number method - Part 2: Test at ambient temperature. This part of the standard prescribes methods for determining the minimum concentration of oxygen in a mixture with nitrogen that is still capable of sustaining the burning of small test specimens in a vertical position under the prescribed test conditions. The results are defined as oxygen number values (% oxygen in the mixture).

Resistance to water penetration ČSN EN ISO 811

Determination according to ČSN EN ISO 811 (800818:2018), Textiles - Determination of resistance to water penetration - Water pressure test. This standard specifies a method for determining the resistance of flat textiles to water penetration using hydrostatic pressure. The method is suitable for all types of flat textiles that are intended to be resistant to water penetration, with or without a water-resistant or water-repellent treatment. The result directly expresses the behavior of flat textile products exposed to short-term or medium-term water pressure.

Example 1 - Synthesis procedure of a modified polyurethane-based polymer component with built-in flame retardant diethyl N,N-bis(2-hydroxyethyl)aminomethyl phosphate and bound polypropylene glycol and its conversion into an aqueous dispersion

In a 3-necked reaction vessel equipped with a mechanical stirrer and an argon supply, 9.3 g (0.069 mol) of (2,2-bis(hydroxymethyl)propanoic acid) was first dissolved in 133 ml of dimethyl sulfoxide at a temperature of 25 °C. Then 11.5 g (0.012 mol) of polypropylene glycol PPG (Mw = 1000 g/mol) was added and at 30 °C 10.5 g (0.069 mol) of diazobicycloundene base (DBU) was added to neutralize the -COOH groups. After the addition of 38.3 g (0.15 mol) of pre-dried diol phosphorus flame retardant diethyl N,N-bis(2-hydroxyethyl)aminomethyl phosphate with a phosphorus content of 12.1 wt. %. 1.5 g (0.01 mol) of DBU catalyst is added and then 59.0 g (0.265 mol) of isophorone diisocyanate is added in portions. The mixture is allowed to react for 5 hours at 60 °C until a reaction mixture of the modified polymer component with a viscosity of 10 Pa.s is obtained. The polymerization is terminated by the addition of a terminating agent of 4.2 g (0.069 mol) of 2-aminoethanol at 60 °C and after 1 hour the heating is terminated and the pH of the reaction mixture is adjusted by the addition of 2.1 g (0.035 mol) of acetic acid.

To 250 g of the reaction mixture of the modified polymer component with a built-in flame retardant, a 43% wt. solution in dimethyl sulfoxide, 800 g of deionized water is added at a temperature of 25 °C with intensive stirring. Then 36 g of NaCl (9% wt. in water) is gradually added and after the product precipitates, the resulting precipitate of the modified polymer component is washed by decantation twice with 200 ml of water with the addition of 18 g of NaCl (9% wt.). Subsequently, the polymer component is dispersed in 1,000 ml of deionized water with intensive stirring to a concentration of approximately 10% wt., thereby creating a homogeneous

- 6 CZ 38803 U1 dispersion of the modified polymer component in water, which is concentrated using a rotary vacuum evaporator to a concentration of 16 wt.%.

Example 2 - Synthesis procedure of a modified polyurethane-based polymer component with built-in flame retardant diethyl N,N-bis(2-hydroxyethyl)aminomethyl phosphate and bound polyethylene glycol and its conversion into an aqueous dispersion

In a 3-necked reaction vessel equipped with a mechanical stirrer and an argon supply, 18.6 g (0.138 mol) of 2,2-bis(hydroxymethyl)propanoic acid was first dissolved in 293.9 ml of dimethyl sulfoxide at a temperature of 25 °C. Then 46.2 g (0.023 mol) of polyethylene glycol (Mw = 2000 g/mol) was added and at 30 °C 21.1 g (0.138 mol) of DBU (diazobicycloundenedene) base was added to neutralize the -COOH groups. After the addition of 76.6 g (0.30 mol) of pre-dried diol phosphorus flame retardant diethyl N,N-bis(2-hydroxyethyl)aminomethyl phosphate with a phosphorus content of 12.1 wt. 1.5 g (0.01 mol) of DBU catalyst is added and then 118.0 g (0.531 mol) of isophorone diisocyanate is added in portions. The mixture is allowed to react for 5 hours at 60 °C until a reaction mixture of the modified polymer component with a viscosity of 5 Pa.s is obtained. The polymerization is terminated by the addition of a terminating agent of 8.5 g (0.138 mol) of 2-aminoethanol at 60 °C and after 1 hour the heating is terminated and the pH of the reaction mixture is adjusted by the addition of 4.2 g (0.069 mol) of acetic acid.

To 250 g of the reaction mixture of the modified polymer component with a built-in flame retardant, a 43% wt. solution in dimethyl sulfoxide, 800 g of deionized water is added at a temperature of 25 °C with intensive stirring. Then 36 g of NaCl (9% wt. in water) is gradually added and after the product has precipitated, the resulting precipitate of the modified polymer component is washed by decantation twice with 200 ml of water with the addition of 18 g of NaCl (9% wt.). Subsequently, the modified polymer component is dispersed in 1,000 ml of deionized water with intensive stirring to a concentration of approximately 10% wt., thereby creating a homogeneous dispersion of the modified polymer component with a built-in flame retardant in water, which is concentrated using a rotary vacuum evaporator to a concentration of 35% wt.

Example 3 - Synthesis procedure of a modified polyurethane-based polymer component with an incorporated flame retardant oligomeric phosphate diol with a phosphorus content of P 18.0 wt. % and its conversion into an aqueous dispersion

In a 3-necked reaction vessel equipped with a mechanical stirrer and an argon supply, 7.0 g (0.052 mol) of DMPA (2,2-bis(hydroxymethyl)propanoic acid) was first dissolved in 321.6 ml of dimethyl sulfoxide at 25 °C. Then 5.3 g (0.052 mol) of triethylamine base was added at 30 °C to neutralize the -COOH groups. 33.3 g (0.15 mol) of IPDI (isophorone diisocyanate) and 0.6 g (0.004 mol) of DBU catalyst were added and the reaction mixture was heated for 1 h at 60 °C. Then 52.5 g (0.078 mol) of diol phosphorus flame retardant oligomeric phosphate diol with the structure shown below with a phosphorus content of P 18.0 wt.% were added at 40 °C. and then 8.8 g (0.058 mol) of DBU catalyst is added. The mixture is allowed to react for 1 hour at 60 °C until a reaction mixture of the modified polymer component with a built-in flame retardant with a viscosity of 15 Pa.s is obtained. The polymerization is terminated by adding a terminating agent of 3.0 g (0.049 mol) of 2-aminoethanol at 60 °C and after 1 hour the heating is terminated and the pH of the reaction mixture is adjusted by adding 1.8 g (0.029 mol) of acetic acid.

To 400 g of the reaction mixture of the modified polymer component with a built-in flame retardant, a 20% wt. solution in dimethyl sulfoxide, 400 g of deionized water is added at a temperature of 25 °C with intensive stirring. Then 45 g of NaCl (11.3% wt. in water) is gradually added and the resulting precipitate of the modified polymer component is washed by decantation twice with 100 ml of water with the addition of 11.1 g of NaCl (10% wt.). 149.6 g of an aqueous dispersion of the modified polymer component (paste) with a dry matter of 52.6% wt. is obtained, which is further dispersed in water to a concentration of 16% wt.

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Structure of a flame retardant, i.e. oligomeric phosphate diol (P content 18.0 wt. %; x=3; tetramer with 4 P atoms).

OO ho—c ₂ h ₄ -o-[-p—o—c ₂ h ₄ -o]—P—O—C ₂ H ₄ -OH oc ₂ h ₅ oc ₂ h ₅

Example 4 - Synthesis procedure of a modified polyurethane-based polymer component with an incorporated flame retardant oligomeric phosphonate diol with a phosphorus content of P 12.0% by weight and bound polyethylene glycol and its conversion into an aqueous dispersion

In a 3-necked reaction vessel equipped with a mechanical stirrer and an argon supply, 9.3 g (0.069 mol) DMPA - (2,2-bis(hydroxymethyl)propanoic acid) and 23.1 g (0.012 mol) PEG polyethylene glycol (Mw = 2,000 g/mol) were first dissolved in 145.9 ml of dimethyl sulfoxide at 25 °C. Then, 37.4 g (0.15 mol) of a diol phosphorus flame retardant oligomeric phosphonate diol with the structure below and a phosphorus content of 12.0 wt% P were added at 30 °C. 59.0 g (0.265 mol) IPDI (isophorone diisocyanate) and 12.0 g (0.079 mol) DBU were added. The mixture is allowed to react for 1 hour at a temperature of 60 °C until a reaction mixture of a modified polymer component with a built-in flame retardant with a viscosity of 10 Pa.s is obtained. The polymerization is terminated by adding a terminating agent of 4.2 g (0.069 mol) of 2-aminoethanol at 60 °C and after 1 hour the heating is terminated and the pH of the reaction mixture is adjusted by adding 2.1 g (0.035 mol) of acetic acid.

To 250 g of the reaction mixture of the modified polymer component with a built-in flame retardant, a 43% wt. solution in dimethyl sulfoxide (DMSO) is added 400 g of deionized water at a temperature of 25 °C with intensive stirring. Then 18 g of NaCl (4.5% wt. in water) is gradually added and the resulting precipitate of the modified polymer component is washed by decantation twice with 100 ml of water with the addition of 4.5 g of NaCl (4.5% wt. in water). 325.5 g of an aqueous dispersion of the modified polymer component (paste) with a dry matter of 31.2% wt. is obtained.

Structure of a flame retardant, i.e. an oligomeric phosphonate diol (P content 12.0 wt. %; x=2, y=2).

O ho4c ₂ h ₄ -o|-p4o-c ₂ h4oh ¹ 1χ I ^{1 J} y ch ₃

Example 5 - Procedure for preparing a coating containing a modified polymer component with a built-in flame retardant and a supporting polymer matrix for adjusting the mechanical properties of the coating layer in a ratio of 3:1 polymer dry matter

605.2 g of an aqueous dispersion of a modified polymer component with a built-in flame retardant diethyl N,N-bis(2-hydroxyethylaminomethyl phosphate) with a concentration of 17% by weight, with a phosphorus content of 0.71% by weight in the dispersion; with a nitrogen content of 1.41% by weight in the dispersion prepared according to Example 1, are introduced into a container equipped with a mechanical stirrer. Subsequently, a carrier polymer matrix for adjusting mechanical properties in the form of 85.5 g of an aqueous dispersion of aliphatic polyurethane of the polyether type with a concentration of 40% by weight is added with intensive stirring. 690.6 g of a coating with a concentration of 19.8% by weight of the modified polymer component and a viscosity of 3 Pa.s is obtained. The phosphorus content in the coating is 0.62% by weight and the nitrogen content in the coating is 1.23% by weight.

-8CZ 38803 U1

Example 6 - Procedure for preparing a coating containing a modified polymer component with a built-in flame retardant and a supporting polymer matrix for adjusting the mechanical properties of the coating layer in a ratio of 3:1 polymer dry matter

225.3 g of an aqueous dispersion of a modified polymer component with a built-in flame retardant diethyl N,N-bis(2-

- hydroxyethyl)aminomethyl phosphate with a concentration of 22.5% by weight with a phosphorus content of 0.95% by weight in the dispersion and a nitrogen content of 1.87% by weight in the dispersion prepared according to Example 1. Subsequently, a carrier polymer matrix for adjusting the mechanical properties in the form of 42.2 g of an aqueous dispersion of aliphatic polyurethane of the polyether type with a concentration of 40% by weight is added with intensive mixing. After adding 15.3 g of water for viscosity adjustment, 282.8 g of a coating with a concentration of 23.9% by weight of the modified polymer component and a viscosity of 12.7 Pa.s is obtained. The phosphorus content in the coating is 0.75% by weight and the nitrogen content in the coating is 1.49% by weight.

Example 7 - Procedure for preparing a coating containing a modified polymer component with a built-in flame retardant and a supporting polymer matrix for adjusting the mechanical properties of the coating layer in a ratio of 4:1 polymer dry matter

320.5 g of an aqueous dispersion of a modified polymer component with a built-in flame retardant diethyl N,N-bis(2-

- hydroxyethyl)aminomethyl phosphate with a concentration of 32.7% by weight with a phosphorus content of 1.25% by weight in the dispersion and a nitrogen content of 2.46% by weight in the dispersion prepared according to Example 2. Subsequently, a carrier polymer matrix for adjusting mechanical properties in the form of 65.5 g of an aqueous dispersion of aliphatic polyurethane of the polyether type with a concentration of 40% by weight is added with intensive mixing. 386.0 g of a coating with a concentration of 34.0% by weight of the modified polymer component and a viscosity of 6 Pa.s is obtained. The phosphorus content in the coating is 1.03% by weight and the nitrogen content in the coating is 2.04% by weight.

Example 8 - Procedure for preparing a coating containing a modified polymer component with a built-in flame retardant and a supporting polymer matrix for adjusting the mechanical properties of the coating layer in a 1:1 ratio of polymer dry matter

153.7 g of an aqueous dispersion of a modified polymer component with a built-in flame retardant diethyl N,N-bis(2-

- hydroxyethyl)aminomethyl phosphate with a concentration of 33.0% by weight with a phosphorus content of 1.26% by weight in the dispersion and a nitrogen content of 2.48% by weight in the dispersion prepared according to Example 2. Subsequently, a supporting polymer matrix for adjusting the mechanical properties in the form of 126.6 g of an aqueous dispersion of aliphatic polyurethane of the polyether type with a concentration of 40% by weight is added with intensive mixing. 280.3 g of a coating with a concentration of 36.1% by weight is obtained. The phosphorus content in the coating is 0.69% by weight and the nitrogen content in the coating is 1.36% by weight.

Example 9 - Applying a coating to cotton twill

The coating prepared according to Example 6 was applied to 100% cotton fabric - twill 2/1, 160 g/m ² . The fabric was subjected to a non-flammable pre-treatment with an impregnating semi-permanent non-flammable coating using the ammonium salt of aliphatic phosphonate TEXAFLAM CU (INOTEX) and with a hydrophobic sub-treatment based on silicone-acrylate copolymer TEXAFOB DRO (INOTEX) to prevent penetration of the coating paste into the textile structure and ensure uniform localization of the coating on the surface of the fabric. The process was carried out on a continuous line with a filler, a coating head and a Werner-Mathis drying/fixing chamber with a width of 45 cm. A single-sided coating was carried out with an air squeegee (Werner-Mathis line), followed by heat treatment with two passes: 1) drying at 110 °C for 2 min. at a line speed of 1 m/min, 2) fixation at 150 °C for 4 min. at a line speed of 0.5 m/min.

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The textile thus treated had the following parameters: dry weight gain 10 g/m ² , phosphorus content: 1.97% by weight of the textile, nitrogen content: 2.01% by weight of the textile, resistance to water penetration: 25.7 cm vs (centimeters of water column).

Example 10 - Applying a coating to polyester canvas

The coating prepared according to Example 6 was applied to 100% polyester canvas 1/1, 155 g/m ² . The fabric was subjected to a non-flammable pre-treatment with an impregnating semi-permanent non-flammable coating using the ammonium salt of aliphatic phosphonate TEXAFLAM CU (INOTEX) and with a hydrophobic sub-treatment based on silicone-acrylate copolymer TEXAFOB DRO (INOTEX) to prevent penetration of the coating paste into the textile structure and ensure uniform localization of the coating on the surface of the fabric. The process was carried out on a continuous line with a gown, a coating head and a Werner-Matais drying/fixing chamber with a width of 45 cm. A single-sided coating was carried out with an air squeegee (Werner-Matais line), followed by a heat treatment with two passes: 1) drying at 110 °C for 2 min. at a line speed of 1 m/min, 2) fixation at 150 °C for 4 min. at a line speed of 0.5 m/min.

The textile thus treated had the following parameters: dry weight gain 10 g/m ² , phosphorus content: 2.52% by weight of the textile, nitrogen content: 2.59% by weight of the textile, resistance to water penetration: 21.3 cm vs (centimeters of water column).

Example 11 - Application of coating on mixed fabric - cotton/polyester 52/48

The coating prepared according to Example 6 was applied to a mixed textile canvas consisting of 52% cotton and 48% polyester, 135 g/m ² . The textile was subjected to a non-flammable pre-treatment with an impregnating semi-permanent non-flammable coating using the ammonium salt of aliphatic phosphonate TEXAFLAM CU (INOTEX) and with a hydrophobic sub-treatment based on the silicone-acrylate copolymer TEXAFOB DRO (INOTEX) to prevent penetration of the coating paste into the textile structure and ensure uniform localization of the coating on the surface of the textile. The process was carried out on a continuous line with a gown, a coating head and a Werner-Matais drying/fixing chamber with a width of 45 cm. A single-sided coating was carried out with an air squeegee (Werner-Matais line), followed by a heat treatment with two passes: 1) drying at 110 °C for 2 min. at a line speed of 1 m/min, 2) fixation at 150 °C for 4 min. at a line speed of 0.5 m/min.

The textile thus treated had the following parameters: dry weight 12 g/m ² , phosphorus content: 3.56% by weight of the textile, nitrogen content: 3.68% by weight of the textile, resistance to water penetration: 22.1 cm vs (centimeters of water column).

Example 12 - Determination of flammability according to standards

Determination of flammability of materials in the vehicle interior according to ČSN ISO 3795

Example Surface weight [g/ ^m2 ] dry weight [g/m ² ] burning length [mm] burning time N burning rate [mm/min] 9 185.21 10.09 5 7 23 10 183.77 9.91 3 6 30 11 172.42 11.98 0 0 0

All tested samples meet the standard requirement, i.e. burning rate < 100 mm/min.

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Determination of the flammability of building materials and their components - Part 1, procedure for class B2 according to DIN 4102

spontaneous combustion time (s) the flame tip reached 150 mm time to reach 150 mm (s) occurrence of fallen parts burning for more than 2s Example 9 0 no - no

The tested sample complies with the standard requirement.

Example 13 - Determination of multifunctional barrier effect reduced flammability/water impermeability

Textiles Limiting oxygen number ČSN ISO EN 4589-2 [%] Resistance to water penetration ČSN EN ISO 811 [cm h.s.] 100% Untreated Cotton 18.5 < 10 100% Cotton — treatment according to Example 9 28.2 25.7 100% PES without treatment 19.0 < 10 100% PES - modification according to Example 10 24.1 22.1 52/48 BA/PES without adjustment 19.2 < 10 52/48 BA/PES modification according to Example 11 26.5 21.3

An oxygen number value higher than 24% demonstrates reduced flammability of the tested material, taking into account the fact that the oxygen content in the atmosphere is around 21%. A water column height higher than 20 cm represents the achievement of a barrier effect - resistance to water penetration (water impermeability). A multifunctional barrier effect, reduced flammability and water impermeability were achieved for all treated textiles.

Industrial applicability

The coating for treating textiles with fire-retardant properties and textiles with fire-retardant properties according to this technical solution can be used for the production of non-flammable textiles in many fields, such as protective clothing, automotive textiles, furniture and interior materials, technical textiles or medical textiles.

Claims (8)

1. A coating for treating textiles with fire-retardant properties comprising a carrier polymer matrix based on aliphatic polyurethane of the polyether type and a flame retardant, characterised in that the flame retardant is a monomer based on a diol or diamine with a phosphorus content of at least 8% by weight or an oligomer containing polyphosphate diol in its structure, and the coating further comprises a modified polymer component based on polyurethane, which is in the form of an aqueous dispersion with a concentration of 43% by weight of the modified polymer component in water with a viscosity of 5 to 15 Pa.s, where the weight ratio of polymer dry matter between the modified polymer component and the carrier polymer matrix in the coating is 1:3 to 4:1, the modified polymer component being contained in the coating in a concentration of 16 to 35% by weight. and has a viscosity of 2 to 15 Pa.s. 2. Coating according to claim 1, characterized in that the flame retardant is selected from the group: diethyl N,N-bis(2-hydroxyethyl)aminomethyl phosphate, phenyl diaminophosphate, bis(3-hydroxyphenyl)phenyl phosphate, bis(3-hydroxypropyl)isobutylphosphine oxide, oligomeric phosphate diol, oligomeric phosphonate diol or polyphosphate diol. 3. Coating according to claim 1 or 2, characterized in that the flame retardant in the polymer component is bound by a chemical or urethane bond with a diisocyanate, wherein the diisocyanate is selected from the group: isophorone diisocyanate, hexamethylene diisocyanate, methylene diphenyl diisocyanate. 4. Coating according to any one of claims 1 to 3, characterized in that the modified polymer component contains a hydrophilic group based on a polyether diol with a molecular weight of 1000 to 2000 g/mol and a diol with a dissociable carboxylic acid. 5. The coating according to claim 4, characterized in that the hydrophilic group is polyethylene glycol or polypropylene glycol. 6. The coating according to claim 4, characterized in that the diol with a dissociable carboxylic acid is 2,2-bis(hydroxymethyl)propanoic acid. 7. A coating according to any one of claims 1 to 6, characterized in that it contains from 0.6 to 1.1 wt. % phosphorus and from 1.2 to 2.1 wt. % nitrogen. 8. A textile with fire-retardant properties, characterized in that it comprises on its surface an impregnating semi-permanent non-flammable coating based on ammonium salts of aliphatic phosphonates, diammonium phosphate or organic complex phosphates and further comprises a coating according to any one of claims 1 to 7 arranged on the impregnating semi-permanent non-flammable coating.