Modified flame retardant, flame-retardant modified coating adhesive, composite cloth, and preparation methods therefor

Abstract

The present disclosure belongs to the technical field of flame retardants. Provided are a modified flame-retardant compound, a modified flame retardant, a flame-retardant modified coating adhesive, composite cloth, and preparation methods therefor. The structure of the modified flame-retardant compound is as below: formula (I). The compound as represented by formula (I) is obtained by introducing an Si-(OMe)3 group into a compound as represented by formula (II). The structure of the compound as represented by formula (II) is as below: formula (II). P and Si in the compound as represented by formula (I) have good flame-retardant capability, and after the compound is blended with blending agents such as phosphoric acid, an ammonium salt, a magnesium salt and melamine, the flame-retardant capability and binding strength of fabric fibers can be improved.

Description

Modified flame retardant, flame retardant modified coating adhesive, composite cloth and preparation method thereof Technical Field

[0001] The present disclosure belongs to the technical field of flame retardants, and in particular relates to a modified flame retardant compound, a modified flame retardant, a flame retardant modified coating adhesive, a composite cloth and a preparation method thereof. Background Art

[0002] Cotton, polyester, and other fiber fabrics are widely used around the world and across various industries, including clothing, curtains, fabric furniture, and interior decoration in shopping malls, airports, entertainment venues, and transportation. While these fabrics bring convenience to people's lives, their flammability also poses a fire hazard. Current flame-retardant fabrics, such as those used in firefighter uniforms, while flame-retardant, have poor thermal insulation properties and cannot effectively block or insulate fires.

[0003] Therefore, it is of great significance to develop fabrics with good flame retardancy and thermal insulation.

[0004] Summary of the Invention

[0005] One aspect of the present disclosure provides a modified flame retardant compound, the specific structure of which is shown in formula (I):

[0006] The compound represented by formula (I) is obtained by introducing a Si-(OMe)3 group into the compound represented by formula (II);

[0007] Wherein, the structure of the compound represented by formula (II) is as follows:

[0008] As a second aspect of the present disclosure, there is provided a method for preparing a compound represented by formula (I) in a modified flame retardant compound, comprising:

[0009] Compound A With B compound Reaction to obtain the compound shown in formula (I)

[0010] As a third aspect of the present disclosure, there is provided a modified flame retardant, comprising:

[0011] A mixture of a compound represented by formula (I) and a compound represented by formula (II); and

[0012] A co-agent blended with the mixture, the co-agent being selected from one or more of phosphoric acid, ammonium salt, magnesium salt, and melamine;

[0013] Wherein, the structures of the compounds represented by formula (I) and formula (II) are as follows:

[0014] The ammonium salt is ammonium chloride, and the magnesium salt is selected from one or more of magnesium chloride and magnesium sulfate.

[0015] As a fourth aspect of the present disclosure, a flame retardant modified coating adhesive is provided, comprising the following components in parts by weight:

[0016] The sum of the weight parts of all components is 100, and the modifier is selected from one or more of graphite, fiber, silicon oxide, calcium oxide, and titanium oxide.

[0017] As a fifth aspect of the present disclosure, a method for preparing a flame retardant modified coating adhesive is provided, comprising:

[0018] Adding a diluent to a reactor containing aqueous polyurethane and stirring until a vortex appears at the center of the liquid surface;

[0019] After slowly adding the wetting agent, defoaming agent and dispersant into the reactor, add the ammonium polyphosphate flame retardant and carbonizing agent into the reactor and mix them evenly;

[0020] The modifier is then added to the mixed liquid, and the mixture is dispersed and stirred evenly again to obtain a flame retardant modified coating adhesive.

[0021] As a sixth aspect of the present disclosure, a method for preparing a flame retardant and heat-insulating composite fabric is provided, comprising:

[0022] At 30-45°C, multiple pieces of fabric to be treated are immersed in an aqueous solution of a modified flame retardant, pre-dried at 55-65°C, and dried at 100-120°C to obtain multiple pieces of flame retardant fabric, wherein the mass ratio of the modified flame retardant to water is 1:10-30;

[0023] Applying flame retardant modified coating adhesive on both sides of each flame retardant fabric as a heat insulation layer to obtain flame retardant heat insulation fabric;

[0024] Multiple pieces of flame-retardant heat-insulating fabrics are stacked in sequence, bonded together using the adhesiveness of the flame-retardant modified coating adhesive, and dried to obtain a flame-retardant heat-insulating composite fabric;

[0025] The fabric to be treated includes any one of cotton, non-woven, polyester, nylon, and fiber cloth, and the multiple flame-retardant and heat-insulating fabrics stacked in sequence are different;

[0026] The thickness of the thermal insulation layer is 0.1-3.5 mm.

[0027] As a seventh aspect of the present disclosure, a flame retardant and heat insulating composite cloth is provided, which is produced by the above-mentioned method for producing the flame retardant and heat insulating composite cloth.

[0028] Based on the above technical solution, the present disclosure provides a modified flame retardant compound, a modified flame retardant, a flame retardant modified coating adhesive, a composite cloth and a preparation method thereof, which have at least one of the following beneficial effects:

[0029] (1) According to the embodiments of the present disclosure, Si-(OMe)3 is introduced into the compound represented by formula (II) to obtain the compound represented by formula (I). The P and Si elements in the compound represented by formula (I) have good flame retardancy and can be used as a flame retardant.

[0030] (2) According to the embodiments of the present disclosure, the P and Si elements in the compounds represented by formula (I) and formula (II) have good flame retardancy, and the selected melamine and magnesium elements also have good flame retardancy. Formula (I) and formula (II) are mixed with at least one blending agent selected from phosphoric acid, ammonium salt, magnesium salt, and melamine to obtain a modified flame retardant. The modified flame retardant thus prepared improves the flame retardancy of the fabric and the bonding strength between the flame retardant and the fabric.

[0031] (3) According to the embodiments of the present disclosure, by mixing graphite, fiber and other modifiers with certain high temperature resistance and flame retardancy, and water-based polyurethane with good expansion ability, heat insulation ability, adhesion ability and strong compatibility with ammonium polyphosphate flame retardant, carbonizing agent, wetting agent, defoaming agent, etc., the flame retardant modified coating glue prepared has good heat insulation ability and good flame retardancy.

[0032] (4) According to the embodiment of the present disclosure, a plurality of fabrics to be treated are immersed in a modified flame retardant, and a flame retardant modified coating adhesive is applied on both sides of the fabric containing the modified flame retardant, and then the plurality of fabrics are stacked and assembled in sequence to obtain a series of composite fabrics. The composite fabric formed has flame retardant properties while basically maintaining its softness. When the flame continues to burn, the composite fabric will not burn within a certain period of time, and the composite fabric will not smolder after leaving the fire. On the other hand, the modified coating adhesive in the composite fabric can absorb a large amount of heat and undergo phase change when directly burned by the flame, and at the same time foam and expand to form a porous carbonized layer that is dozens of times thicker than the original coating layer. It absorbs a large amount of heat during the foaming process, so that the porous carbonized layer formed has high thermal insulation performance and can form a thermal insulation barrier, so that the composite fabric has flame retardancy and thermal insulation capabilities, and is expected to be used in scenes such as flame retardancy and thermal insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is an infrared spectrum of a modified flame retardant compound in an embodiment of the present disclosure;

[0034] FIG2 is an infrared spectrum of the modified flame retardant in an embodiment of the present disclosure;

[0035] FIG3 is a thermogravimetric-differential thermal scanning curve of the modified flame retardant in an embodiment of the present disclosure;

[0036] FIG4 is an infrared spectrum of the flame retardant modified coating adhesive in an embodiment of the present disclosure;

[0037] FIG5 is a thermogravimetric-differential thermal scanning curve of the flame retardant modified coating adhesive in an embodiment of the present disclosure;

[0038] FIG6 is a schematic diagram of vertical flame spraying of a flame-retardant and heat-insulating composite fabric according to an embodiment of the present disclosure;

[0039] FIG7 is a graph showing the temperature variation of the back side of the composite fabric under a 1300° C. flame over time in Example 1 of the present disclosure;

[0040] FIG8 is a graph showing the change in quality of the composite fabric over time using a cone calorimeter in Example 1 of the present disclosure;

[0041] FIG9A is a scanning electron microscope image of a 5-micron-scale block region of a thick carbonized portion of the flame-retardant modified coating adhesive of the composite cloth in Example 1 of the present disclosure after spraying;

[0042] FIG9B is a scanning electron microscope image of a 5-micron-scale porous region of a flame-retardant modified coating adhesive of the composite cloth in Example 1 of the present disclosure after spraying and carbonizing;

[0043] FIG9C is a scanning electron microscope image of a 10-micrometer-scale region of a thick carbonized layer structure of the flame-retardant modified coating adhesive of the composite cloth in Example 1 of the present disclosure after spraying. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0045] In response to the problem that existing fabrics cannot achieve high flame retardancy and heat insulation properties at the same time, the present disclosure proposes a modified flame retardant compound, a modified flame retardant, a flame retardant modified coating adhesive, a composite cloth and a preparation method thereof, wherein a compound represented by formula (I) is obtained by introducing a Si-(OMe)3 group on the basis of the original compound represented by formula (II), and the P and Si elements in the compound represented by formula (I) have good flame retardancy. The compounds represented by formula (I) and formula (II) are blended with co-admixtures such as phosphoric acid, ammonium salt, magnesium salt, and melamine to obtain a modified flame retardant. At the same time, a water-based polyurethane with good foaming expansibility, flame retardancy and compatibility is reacted with a modifier, ammonium polyphosphate flame retardant, carbonizing agent, defoaming agent, etc. to obtain a modified coating adhesive with flame retardancy. Finally, the modified flame retardant and flame retardant modified coating adhesive are used to treat the fabric to be treated, so that the fabric has both flame retardancy and heat insulation properties.

[0046] Specifically, the first aspect of the present disclosure provides a modified flame retardant compound, the specific structure of which is shown in formula (I): The compound represented by formula (I) is obtained by introducing a Si-(OMe)3 group into the compound represented by formula (II); wherein the structure of the compound represented by formula (II) is as follows:

[0047] In the embodiments of the present disclosure, Si-(OMe)3 is introduced into the compound represented by formula (II) to obtain the compound represented by formula (I). The P and Si elements in the compound represented by formula (I) have good flame retardant properties and can be used as a flame retardant.

[0048] According to an embodiment of the present disclosure, a second aspect of the present disclosure provides a method for preparing a compound represented by formula (I) in a modified flame retardant, comprising: compound A With B compound Reaction to obtain the compound shown in formula (I)

[0049] Specifically, the method for preparing the compound represented by formula (I) is as follows: Compound A and Compound B are mixed in the presence of an organic solvent and a catalyst to form a flame-retardant mixed liquid; a pH adjuster is added to the flame-retardant mixed liquid, and the mixture is reacted at a predetermined temperature to obtain the compound represented by formula (I). The organic solvent is selected from methanol, the catalyst is selected from calcium oxide, the molar ratio of Compound A to Compound B is 1:1 to 1:1.2, such as 1:1.02, the predetermined reaction temperature is 50-70°C, such as 60°C, and the pH adjuster is used to adjust the pH of the flame-retardant mixed liquid to a neutral pH of 6-7.

[0050] For example, Compound A (91.7 mL, 1 mol) and CaO (16.8 g, 0.3 mol) were placed in a reactor and stirred. Then, 300 mL of methanol solvent was added, and the mixture was placed in a water bath equipped with a condenser and a thermometer and preheated to 50°C. Compound B (242 mL, 1.02 mol) was then added dropwise to the reactor. During the addition, the reaction temperature was controlled at 65°C. The reaction was stopped after 30 minutes. After filtration and washing with methanol, the compound represented by formula (I) was obtained. The infrared spectrum of the compound represented by formula (I) is shown in Figure 1. The specific reaction formula for obtaining the compound represented by formula (I) is as follows:

[0051] The third aspect of the present disclosure provides a modified flame retardant, comprising: a mixture of a compound represented by formula (I) and a compound represented by formula (II); and a co-blending agent blended with the mixture, wherein the co-blending agent is selected from one or more of phosphoric acid, an ammonium salt, a magnesium salt, and melamine; the ammonium salt is ammonium chloride, and the magnesium salt is selected from one or more of magnesium chloride and magnesium sulfate, wherein the structures of the compound represented by formula (I) and the compound represented by formula (II) are respectively as follows:

[0052] According to the embodiments of the present disclosure, the Si and P elements in the compounds represented by formula (I) and formula (II) have good flame retardancy, and the selected melamine and magnesium elements also have good flame retardancy. The compounds represented by formula (I) and formula (II) are mixed with at least one blending agent selected from phosphoric acid, ammonium salt, magnesium salt, and melamine to obtain a modified flame retardant. The modified flame retardant thus prepared improves the flame retardancy of the fabric while utilizing the solubility between the blending agents such as phosphoric acid, ammonium chloride, and magnesium sulfate and the compounds represented by formula (I) and formula (II), thereby improving the bonding strength between the flame retardant and the fabric.

[0053] According to an embodiment of the present disclosure, the blending mass ratio of the co-admixture and the mixture (including the compounds represented by formula (I) and formula (II)) is 1:20-50, and the mass ratio of the compound represented by formula (I) to the compound represented by formula (II) is 1:1-3. The modified flame retardant formed within this ratio range has good flame retardancy, wherein the blending mass ratio can be selected as 1:20, 1:30, 1:40, 1:50, etc., and the mass ratio of the compounds represented by formula (I) and formula (II) can be 1:1, 1:2, 1:3, etc.

[0054] FIG2 is an infrared spectrum of the modified flame retardant in the embodiment of the present disclosure, and FIG3 is a thermogravimetric-differential thermal scanning curve of the modified flame retardant in the embodiment of the present disclosure.

[0055] From Figure 3, we can see that as the temperature gradually increases, there is a certain amount of mass loss and an obvious endothermic peak, which indicates that the modified flame retardant has a certain heat absorption capacity.

[0056] According to an embodiment of the present disclosure, the fourth aspect of the present disclosure provides a flame retardant modified coating adhesive, comprising the following components in parts by weight: 1-10 parts of a modifier, 20-50 parts of an aqueous polyurethane, 20-50 parts of an ammonium polyphosphate flame retardant, 10-30 parts of a carbonizing agent, 0.1-0.5 parts of a wetting agent, 0.1-0.5 parts of a defoaming agent, 0.1-0.5 parts of a dispersant, 0.1-0.5 parts of an anti-settling agent, and 10-30 parts of a diluent; wherein the sum of the parts by weight of all components is 100, and the modifier is selected from at least one of graphite, fiber, silicon oxide, calcium oxide, and titanium oxide; the infrared spectrum of the obtained flame retardant modified coating adhesive is shown in Figure 4.

[0057] In the embodiments of the present disclosure, the selected water-based polyurethane is easily expanded, heat-insulated, and adhered during the reaction process, and has good compatibility with the compounds represented by formula (I) and formula (II) and other components. The selected modifier has a porous structure, high temperature resistance and flame retardancy, and the ammonium polyphosphate flame retardant has good flame retardancy and can be mixed with the modifier and water-based polyurethane. The water-based polyurethane is doped with the modifier, ammonium polyphosphate flame retardant, carbonizing agent, etc. to prepare a flame-retardant modified coating adhesive. The flame-retardant modified coating adhesive has flame retardancy and heat insulation, and the various components in the coating adhesive are evenly dispersed.

[0058] According to an embodiment of the present disclosure, the wetting agent is a combination of one or more of BYK-306, BYK-S706, BYK-361, BYK-359, and SN-4727A; the defoaming agent is a combination of one or more of SN-6710, silicone defoaming agent, mineral oil, and polyether; the charring agent is a combination of one or more of glucose, starch, sucrose, cyclodextrin, pentaerythritol, and dipentaerythritol; the dispersant is BYK-2150, BYK-330, BYK-341, BYK-307, BYK -2155, BYK-104S, SN-1728A, SN-1728, SN-1729, SN-1776, SN-1760, SN-1790A, SN-1791, SN-1790, SN-1792, and SN-1798; the anti-settling agent is a combination of one or more of polyamide wax, bentonite, and polyethylene wax; the diluent is a combination of one or more of gasoline, water, methanol, xylene, isopropyl alcohol, ethanol, ethyl acetate, and propylene glycol dimethyl ether.

[0059] FIG5 is a thermogravimetric-differential thermal scanning curve of the flame retardant modified coating adhesive in an embodiment of the present disclosure.

[0060] It can be seen from Figure 5 that there is a certain amount of mass loss in the process of gradual temperature increase, and there are three obvious endothermic peaks, which shows that the flame retardant modified coating adhesive has a strong heat absorption capacity.

[0061] According to an embodiment of the present disclosure, a fifth aspect of the present disclosure provides a method for preparing a flame-retardant modified coating adhesive, comprising: adding a diluent to a reactor containing aqueous polyurethane and stirring until a vortex appears at the center of the liquid surface to fully dissolve the aqueous polyurethane; slowly adding a wetting agent, a defoaming agent, and a dispersant to the reactor to uniformly mix the added wetting agent, defoaming agent, and dispersant; adding an ammonium polyphosphate flame retardant and a charring agent to the reactor and mixing them uniformly; then adding the modifier to the mixed solution and dispersing and stirring again to uniformly obtain a flame-retardant modified coating adhesive. The above order of addition allows the aqueous polyurethane, modifier, ammonium polyphosphate flame retardant, charring agent, defoaming agent, etc. to be uniformly dispersed, thereby facilitating the production of a flame-retardant modified coating adhesive with moderate viscosity and uniform dispersion of the flame retardant.

[0062] According to an embodiment of the present disclosure, a sixth aspect of the present disclosure provides a method for preparing a flame retardant and heat-insulating composite cloth, comprising: soaking multiple pieces of fabric to be treated in an aqueous solution of the modified flame retardant in the above embodiment at 30-45°C, pre-baking at 55-65°C after the immersion treatment, and drying at 100-120°C to obtain multiple pieces of flame retardant fabric; applying the flame retardant modified coating adhesive in the above embodiment on both sides of each piece of flame retardant fabric as a heat insulation layer to obtain a flame retardant and heat-insulating fabric; then, stacking the multiple pieces of flame retardant and heat-insulating fabric in sequence, connecting the multiple pieces of flame retardant and heat-insulating fabric to each other using the viscosity of the flame retardant modified coating adhesive, and obtaining a flame retardant and heat-insulating composite cloth after drying, wherein the soaking treatment time is 10-40min, the pre-baking time is 20-60min, the drying time is 10-40min, and the mass ratio of the modified flame retardant to water is 1:10-30.

[0063] According to an embodiment of the present disclosure, the thickness of the thermal insulation layer is 0.1-3.5 mm, preferably 0.1-2 mm, so that the composite cloth has high thermal insulation and air permeability while maintaining the softness of the composite cloth.

[0064] According to embodiments of the present disclosure, the fabric to be treated includes any one of cotton, non-woven, polyester, vinyl, and fiber fabric, and the multiple stacked flame-retardant and thermal-insulating fabrics are different. For example, a flame-retardant and thermal-insulating composite fabric can be obtained by stacking cotton, non-woven, and polyester in sequence, or by stacking cotton, vinyl, and polyester in sequence.

[0065] In an embodiment of the present disclosure, soaking multiple pieces of fabric to be treated at 30-45°C helps to wet the fabric and evenly disperse the modified flame retardant on the fabric to be treated; then pre-drying at 55-65°C helps the modified flame retardant to penetrate into the fabric to be treated; finally, drying at 100-120°C removes excess moisture from the fabric to be treated.

[0066] According to an embodiment of the present disclosure, in a seventh aspect, a flame retardant and thermal insulation composite cloth is provided. The flame retardant and thermal insulation composite cloth is obtained by the preparation method of the thermal insulation composite cloth in the above embodiment.

[0067] In an embodiment of the present disclosure, a series of different flame-retardant and heat-insulating composite fabrics are obtained by synergistically using a modified flame retardant and a flame-retardant modified coating adhesive, and then assembling different fabrics to be treated. The flame-retardant and heat-insulating composite fabric formed has flame-retardant properties while basically maintaining its softness. When the flame continues to burn, the composite fabric will not burn for a period of time, and the composite fabric will not smolder after leaving the fire, indicating that the composite fabric has good flame-retardant properties. In addition, when the flame is directly burned, the composite fabric can absorb a large amount of heat to undergo a phase change, and at the same time foam and expand to form a porous carbonized layer that is dozens of times thicker than the original flame-retardant modified coating adhesive. The porous structure of the carbonized layer is used to improve its heat insulation performance, forming a heat insulation barrier. The fabric treated with the above-mentioned flame-retardant modified coating adhesive and flame-retardant modifier effectively reduces the possibility of fire caused by the fabric. At the same time, the composite fabric is made into firefighting clothing with good heat insulation to ensure the safety of firefighters.

[0068] Example 1

[0069] The preparation process of cotton cloth-fiber cloth-non-woven flame retardant thermal insulation composite cloth is as follows:

[0070] (1) The actual modified flame retardant needs to be compounded with a certain proportion of water when used. The mass ratio of the modified flame retardant to water is 1:10-30. The cotton was soaked in the modified flame retardant aqueous solution for 20 minutes, the soaking temperature was controlled at 30℃, after the soaking treatment was completed, it was pre-baked at 60℃ for 20 minutes, and then dried in a 100℃ oven for 15 minutes; the fiber was soaked in the modified flame retardant solution for 40 minutes, the soaking temperature was controlled at 45℃, after the soaking treatment was completed, it was pre-baked at 60℃ for 60 minutes, and then dried in a 120℃ oven for 30 minutes; the non-woven fabric was soaked in the modified flame retardant solution for 10 minutes, the soaking temperature was controlled at 30℃, after the soaking treatment was completed, it was pre-baked at 60℃ for 20 minutes, and then dried in a 100℃ oven for 10 minutes, to obtain three different flame retardant fabrics. The modified flame retardant aqueous solution comprises: 5 parts by weight of the compound represented by formula (I), 10 parts by weight of the compound represented by formula (II), 0.04 parts by weight of phosphoric acid, 0.1 parts by weight of melamine, and 200 parts by weight of water.

[0071] (2) The steps of heat-insulating the corresponding flame-retardant fabric are as follows: a flame-retardant modified coating adhesive with a thickness of 0.1-1.0 mm is coated on both sides of cotton cloth, fiber cloth and non-woven fabric containing a modified flame retardant. The flame-retardant modified coating adhesive is prepared from the following raw materials in parts by weight: 7 parts by weight of a modifier (expanded graphite), 45 parts by weight of an aqueous polyurethane emulsion (E11 (product model) of Jiangsu Xingfeng Chemical Technology Co., Ltd.), 23 parts by weight of ammonium polyphosphate, 12 parts by weight of a carbonizing agent (pentaerythritol), 0.8 parts by weight of a wetting agent (BYK-S706 (product model) of a German BYK brand), 0.3 parts by weight of a defoaming agent (mineral oil), 0.4 parts by weight of a dispersant (BYK-2150 (product model) of a German BYK brand), 0.5 parts by weight of an anti-settling agent (bentonite), and 11 parts by weight of a diluent (water). At the same time, the adhesion of the flame retardant modified coating adhesive is utilized to adhere the cotton cloth-fiber cloth-non-woven fabric in the order of adhesion to obtain the cotton cloth-fiber cloth-non-woven fabric flame retardant heat insulating composite cloth.

[0072] In order to further improve its thermal insulation performance, flame retardant modified coating glue can be applied on the front and back of the composite cloth with a thickness of 1-2mm. After the coating is completely dry, the composite cloth has high adhesion, will not fall off, will not crack, and has good flexibility.

[0073] The flame retardant and heat insulating properties of the flame retardant and heat insulating composite fabric prepared in Example 1 were tested. The specific process is as follows:

[0074] First, the flame retardant fabric prepared in step (1) of the embodiment is directly measured by the vertical method, wherein the schematic diagram of vertical flame spraying of the flame retardant and heat-insulating composite fabric is shown in FIG6 .

[0075] Cotton fabric flame retardancy test: At 20°C, in an atmosphere, a 300 cm × 80 cm cotton fabric was placed in a vertical combustion tester and ignited. The afterflaming time, smoldering time, and carbonization length were tested. Five parallel experiments were conducted. The specific experimental results are shown in Table 1.

[0076] Table 1. Vertical burning test of cotton flame retardant fabric

[0077] As shown in Table 1, the average afterflame time of the cotton flame retardant fabric is less than 0.1s, the average smoldering time is 0.8s, and the average carbonization length is 3.0mm.

[0078] Fiber cloth flame retardancy test: At 20°C, in an atmosphere, a 300cm × 80cm fiber cloth was placed in a vertical combustion tester and ignited. The afterflaming time, smoldering time, and damage length were tested. Five parallel experiments were conducted. The specific experimental results are shown in Table 2.

[0079] Table 2. Vertical burning test of fiber cloth flame retardant fabric

[0080] As shown in Table 2, the average afterflame time of the fiber cloth flame retardant fabric is less than 0.1s, the average smoldering time is less than 0.1s, and the average carbonization length is 1mm.

[0081] Non-woven fabric flame retardancy test: At 20°C, in an atmosphere, a 300cm × 80cm cotton fiber was placed in a vertical combustion tester and ignited. The afterflaming time, smoldering time, and damage length were tested. Five parallel experiments were conducted. The specific experimental results are shown in Table 3.

[0082] Table 3. Vertical burning test of non-woven flame retardant fabrics

[0083] As shown in Table 3, the average afterflame time of the non-woven flame retardant fabric is less than 0.1 s, the average smoldering time is 1.0 s, and the average carbonization length is 4.0 mm.

[0084] Testing of flame-retardant and thermally insulating composite fabric: At 20°C, in ambient air, a 30 cm x 30 cm flame-retardant and thermally insulating composite fabric with a 1.0 mm outermost insulation layer was placed vertically on a safety countertop in a fume hood, secured with two metal clips. Its thermal insulation properties were tested using a 1300°C flame for 5 minutes, with five parallel runs. Data were obtained. When a 1200-1300°C butane torch flame was directed at the front of the composite fabric, with the surface falling within the outer flame region, where the flame had the highest temperature, the coating foamed. The foaming height was 30 times higher than the original coating, and a phase transition occurred, transforming the coating into a porous carbonized layer. This foaming process absorbed a significant amount of heat, resulting in a final backside temperature of only 55°C. The temperature changes on the backside of the composite fabric during combustion are shown in Figure 7. After the composite fabric was removed from the flame, the average afterburning time on the front side of the composite fabric was less than 0.1 second, and the average smoldering time was less than 0.1 second. Specific experimental results are shown in Table 4.

[0085] Table 4. Flame retardant composite fabric combustion test

[0086] Furthermore, the mass loss of the composite fabric was measured using a cone calorimeter. The specific steps were as follows: at 25°C, in an atmosphere, a flame retardant and thermal insulation composite fabric of size 12cm×12cm was heated at 50kw / m 2 After 15 minutes of testing under radiation intensity, the mass loss was 1.5g, and the mass loss rate per unit area was 0.116g / m 2 / s, the specific experimental results are shown in Figure 8.

[0087] Comparative experimental results show that composite fabrics prepared by modifying cotton, non-woven fabrics, polyester, nylon, and fiber fabrics using modified flame retardants and flame-retardant modified coating adhesives exhibit excellent flame retardancy and heat insulation properties. Upon exposure to fire, the composite fabric's surface undergoes an immediate phase transition, absorbing heat and forming a carbonized layer (as shown in Figures 9A, 9B, and 9C). This carbonized layer exhibits excellent thermal insulation properties. If applied to textile fiber-related applications, it could effectively prevent the occurrence and spread of fires, significantly reducing the incidence and damage caused by plant fiber fires. Furthermore, its excellent heat absorption and insulation properties could be used as raw materials for protective equipment and firefighting rescue equipment, particularly in the production of fireproof and heat-insulating firefighting uniforms. The composite fabric is highly flexible, lightweight, and features a comfortable inner non-woven fabric layer. When heated, its outer surface foams to isolate the majority of the heat, providing a relatively insulated system for firefighters during rescue operations and maximizing their safety.

[0088] Example 2

[0089] The steps for preparing polyester-vinyl alcohol-fiber cloth flame retardant and heat-insulating composite cloth are as follows:

[0090] (1) Soak polyester in a modified flame retardant aqueous solution for 30 minutes, control the soaking temperature at 35°C, pre-bake at 60°C for 25 minutes after the soaking treatment is completed, and then dry in an oven at 100°C for 20 minutes; soak viren in a modified flame retardant solution for 15 minutes, control the temperature at 40°C, pre-bake at 60°C for 25 minutes after the soaking treatment is completed, and then dry in an oven at 100°C for 25 minutes; soak the fiber arrangement in a modified flame retardant solution for 40 minutes, control the temperature at 45°C, pre-bake at 60°C for 60 minutes after the soaking treatment is completed, and then dry in an oven at 120°C for 30 minutes. Three different flame retardant fabric fibers are obtained. The modified flame retardant comprises: 5 parts by weight of the compound represented by formula (I), 10 parts by weight of the compound represented by formula (II), 0.04 parts by weight of phosphoric acid, 0.1 parts by weight of melamine, and 200 parts by weight of water.

[0091] (2) The steps of heat-insulating the corresponding flame-retardant fabric are as follows: coating the polyester, nylon and fiber cloth with a flame-retardant modified coating adhesive with a thickness of 0.1-1.0 mm on both sides. The flame-retardant modified coating adhesive is prepared from the following raw materials in parts by weight: 7 parts by weight of a modifier (expanded graphite), 45 parts by weight of an aqueous polyurethane emulsion (E11 (product model) of Jiangsu Xingfeng Chemical Technology Co., Ltd.), 23 parts by weight of ammonium polyphosphate, 12 parts by weight of a carbonizing agent (pentaerythritol), 0.8 parts by weight of a wetting agent (BYK-S706 (product model) of a German BYK brand), 0.3 parts by weight of a defoaming agent (mineral oil), 0.4 parts by weight of a dispersant (BYK-2150 (product model) of a German BYK brand), 0.5 parts by weight of an anti-settling agent (bentonite), and 11 parts by weight of a diluent (water). At the same time, the adhesion of the flame retardant modified coating adhesive is utilized to adhere the polyester-vinyl alcohol-fiber cloth in the order of adhesion to obtain the polyester-vinyl alcohol-fiber flame retardant heat insulation composite cloth.

[0092] Flame-retardant and thermally insulating composite fabric testing: At 20°C, in ambient air, a 30 cm x 30 cm flame-retardant and thermally insulating composite fabric with a 1.0 mm outermost insulation layer was placed vertically on a safety countertop in a fume hood, secured with two metal clips. Its thermal insulation properties were tested using a 1300°C flame for 5 minutes, with five parallel runs. Data were obtained. When a 1200-1300°C butane torch flame was directed at the front of the composite fabric, with the surface falling within the outer flame zone (where the flame had the highest temperature), the coating foamed, reaching a height 30 times that of the original coating. Simultaneously, a phase transition occurred, transforming the coating into a porous carbonized layer. This foaming process absorbed significant heat, resulting in a final backside temperature of only 67°C. After the composite fabric was removed from the flame, the average afterflame time on the front side of the composite fabric was less than 0.1 second, and the average smoldering time was less than 0.1 second. Detailed experimental results are shown in Table 5.

[0093] Table 5. Flame retardant composite fabric combustion test

[0094] In order to further improve its thermal insulation performance, flame retardant modified coating glue can be applied on the front and back of the composite cloth. The thickness can be 1-2mm. After the coating is completely dry, it has high adhesion, will not fall off, will not crack, and has good flexibility.

[0095] Example 3

[0096] (1) Soak cotton in a modified flame retardant aqueous solution for 20 minutes, control the soaking temperature at 30°C, and after the soaking treatment is completed, pre-bake at 60°C for 20 minutes, and then dry in a 100°C oven for 15 minutes; soak nylon in a modified flame retardant solution for 15 minutes, control the soaking temperature at 40°C, and after the soaking treatment is completed, pre-bake at 60°C for 25 minutes, and then dry in a 100°C oven for 25 minutes; soak polyester in a modified flame retardant solution for 30 minutes, control the soaking temperature at 35°C, and after the soaking treatment is completed, pre-bake at 60°C for 25 minutes, and then dry in a 100°C oven for 20 minutes. Three different flame retardant fabric fibers are obtained. The modified flame retardant comprises: 5 parts by weight of the compound represented by formula (I), 10 parts by weight of the compound represented by formula (II), 0.04 parts by weight of phosphoric acid, 0.1 parts by weight of melamine, and 200 parts by weight of water.

[0097] (2) The steps of heat-insulating the corresponding flame-retardant fabrics are as follows: the cotton cloth, the vinylon and the polyester are coated with a flame-retardant modified coating adhesive with a thickness of 0.1-1.0 mm; at the same time, the flame-retardant modified coating adhesive is used to bond them together in the order of cotton cloth-vinylon-polyester, thereby obtaining a cotton cloth-vinylon-polyester flame-retardant heat-insulating composite cloth. Among them, the flame retardant modified coating adhesive is prepared from the following raw materials in parts by weight: 7 parts by weight of modifier (expanded graphite), 45 parts by weight of aqueous polyurethane emulsion (E11 (product model) of Jiangsu Xingfeng Chemical Technology Co., Ltd.), 23 parts by weight of ammonium polyphosphate, 12 parts by weight of carbonizing agent (pentaerythritol), 0.8 parts by weight of wetting agent (BYK-S706 (product model) of German BYK brand), 0.3 parts by weight of defoaming agent (mineral oil), 0.4 parts by weight of dispersant (BYK-2150 (product model) of German BYK brand), 0.5 parts by weight of anti-settling agent (bentonite), and 11 parts by weight of diluent (water).

[0098] Flame-retardant and thermal insulation composite fabric testing: At 20°C, in ambient air, a 30cm x 30cm flame-retardant and thermal insulation composite fabric with a 1.0mm outermost insulation layer was placed vertically on a safety countertop in a fume hood, secured with two metal clips. Its thermal insulation properties were tested using a 1300°C flame for 3.0 minutes, with five replicated experiments. Data were obtained. When a 1200-1300°C butane torch flame was directed at the front of the composite fabric, with the surface falling within the outer flame zone (where the flame had the highest temperature), the coating foamed, reaching a height 30 times that of the original coating. Simultaneously, a phase transition occurred, transforming the coating into a porous carbonized layer. This foaming process absorbed significant heat, resulting in a final backside temperature of only 84°C. After removal from the flame, the composite fabric maintained an average afterburning time of less than 0.1s on the front and an average smoldering time of less than 0.1s on the back. Detailed experimental results are shown in Table 6.

[0099] Table 6. Flame retardant composite fabric combustion test

[0100] In order to further improve its thermal insulation performance, flame retardant modified coating glue can be applied on the front and back of the composite cloth. The thickness can be 1-2mm. After the coating is completely dry, it has high adhesion, will not fall off, will not crack, and has good flexibility.

[0101] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A modified flame retardant compound, the specific structure of which is shown in formula (I): The compound represented by formula (I) is obtained by introducing Si-(OMe)3 group into the compound represented by formula (II); in, The structure of the compound shown in formula (II) is as follows:

2. A method for preparing the compound of formula (I) as claimed in claim 1, comprising: Compound A Compound B Reaction to obtain the compound shown in formula (I) 3. The method according to claim 2, wherein: The method comprises: In the presence of an organic solvent and a catalyst, compound A and compound B are mixed to form a flame retardant mixed liquid, a pH regulator is added to the flame retardant mixed liquid, and the mixture is reacted at a preset temperature to obtain a compound represented by formula (I); in: The organic solvent is selected from methanol, and the catalyst is selected from calcium oxide; The molar ratio of the compound A to the compound B is 1:1 to 1:1.2; The preset reaction temperature is 50-70°C; The pH regulator adjusts the pH of the flame retardant mixed solution to be neutral, with the pH being 6-7.

4. A modified flame retardant comprising: A mixture of a compound represented by formula (I) and a compound represented by formula (II); as well as A blending agent blended with the mixture, wherein the blending agent is selected from one or more of phosphoric acid, ammonium salt, magnesium salt, and melamine; Wherein, the structures of the compounds represented by formula (I) and formula (II) are as follows: The ammonium salt is ammonium chloride, and the magnesium salt is selected from one or more of magnesium chloride and magnesium sulfate.

5. The modified flame retardant according to claim 4, wherein The blending mass ratio of the blending agent to the mixture is 1:20-50, and the mass ratio of the compound represented by formula (I) to the compound represented by formula (II) is 1:1-3.

6. A flame retardant modified coating adhesive, comprising the following components in parts by weight: in, The sum of weight parts of all components is 100, and the modifier is selected from one or more of graphite, fiber, silicon oxide, calcium oxide, and titanium oxide.

7. The flame retardant modified coating adhesive according to claim 6, wherein: The wetting agent is a combination of one or more of BYK-306, BYK-S706, BYK-361, BYK-359, and SN-4727A; The defoamer is a combination of one or more of SN-6710, silicone defoamer, mineral oil, and polyether; The carbon-forming agent is a combination of one or more of glucose, starch, sucrose, cyclodextrin, pentaerythritol, and dipentaerythritol; The dispersant is a combination of one or more of BYK-2150, BYK-330, BYK-341, BYK-307, BYK-2155, BYK-104S, SN-1728A, SN-1728, SN-1729, SN-1776, SN-1760, SN-1790A, SN-1791, SN-1790, SN-1792, and SN-1798; The anti-settling agent is a combination of one or more of polyamide wax, bentonite, and polyethylene wax; The diluent is a combination of one or more of gasoline, water, methanol, xylene, isopropanol, ethanol, ethyl acetate, and propylene glycol dimethyl ether.

8. A method for preparing the flame retardant modified coating adhesive according to any one of claims 6 to 7, comprising: Adding a diluent to a reactor containing aqueous polyurethane and stirring until a vortex appears at the center of the liquid surface; After slowly adding a wetting agent, a defoaming agent, and a dispersant into the reactor, an ammonium polyphosphate flame retardant and a carbon-forming agent are added into the reactor and mixed evenly; The modifier is then added into the mixed solution, and the mixture is dispersed and stirred evenly again to obtain the flame retardant modified coating adhesive.

9. A method for preparing a flame retardant and heat insulating composite fabric, comprising: At 30-45° C., multiple pieces of fabric to be treated are immersed in an aqueous solution of the modified flame retardant according to any one of claims 4-5, and after the immersion treatment, they are pre-dried at 55-65° C. and dried at 100-120° C. to obtain multiple pieces of flame-retardant fabric, wherein the mass ratio of the modified flame retardant to water is 1:10-30; Applying the flame retardant modified coating adhesive according to any one of claims 6 to 7 as a heat insulation layer on both sides of each piece of the flame retardant fabric to obtain a flame retardant heat insulation fabric; Stacking a plurality of the flame-retardant heat-insulating fabrics in sequence, bonding them together by utilizing the stickiness of the flame-retardant modified coating adhesive, and obtaining the flame-retardant heat-insulating composite fabric after drying; Wherein, the fabric to be treated includes any one of cotton cloth, non-woven fabric, polyester, nylon, and fiber cloth, and the flame-retardant and heat-insulating fabrics stacked in sequence are different from each other; The thickness of the heat insulation layer is 0.1-3.5 mm.

10. The method according to claim 9, wherein: The thickness of the heat insulation layer is 0.1-2 mm.

11. A flame retardant heat insulating composite fabric, wherein: The flame retardant and heat insulating composite fabric is prepared by the method described in any one of claims 9 to 10.

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