阅读说明：本技术 一种阻燃剂及其制备方法和应用 (Flame retardant and preparation method and application thereof ) 是由 王敬伟 纪发达 于 2021-07-20 设计创作，主要内容包括：本发明提供一种阻燃剂及其制备方法和应用。本发明提供的阻燃剂为核壳结构,其中,以含有二氧化硅和氢氧化铝的组分为核结构,以表面活性剂、季戊四醇磷酸酯三聚氰胺盐和第一偶联剂为形成壳的原料反应后得到磷氮系壳结构。本发明提供的阻燃剂能够提高聚酯纤维的阻燃性和抗熔滴性能。(The invention provides a flame retardant, and a preparation method and application thereof. The flame retardant provided by the invention is of a core-shell structure, wherein a component containing silicon dioxide and aluminum hydroxide is used as the core structure, and a surfactant, pentaerythritol phosphate melamine salt and a first coupling agent are used as raw materials for forming a shell, so that a phosphorus-nitrogen shell structure is obtained after reaction. The flame retardant provided by the invention can improve the flame retardance and the anti-dripping performance of the polyester fiber.)

1. The flame retardant is characterized by being of a core-shell structure, wherein a component containing silicon dioxide and aluminum hydroxide is used as the core structure, and a surfactant, pentaerythritol phosphate melamine salt and a first coupling agent are used as raw materials for forming a shell, so that a phosphorus-nitrogen shell structure is obtained after reaction.

2. Flame retardant according to claim 1, characterized in that the mass ratio of silica to aluminium hydroxide is 3-6:0.5-1, preferably 5: 0.5.

3. Flame retardant according to claim 1 or 2, wherein the surfactant is present in an amount of 0.1-1 wt% based on the total mass of the silica and aluminium hydroxide, preferably in an amount of 0.5 wt% based on the total mass of the silica and aluminium hydroxide,

preferably, the surfactant is one or a combination of more than two of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, tween-60 and span-60.

4. The flame retardant according to any one of claims 1 to 3, wherein the first coupling agent is contained in an amount of 0.5 to 1.5 wt% based on the total mass of the silica and the aluminum hydroxide,

preferably, the first coupling agent is selected from one or a combination of more than two of epoxy trimethoxy silane, bis- [ gamma- (triethoxy silicon) propyl ] tetrasulfide, N-beta- (aminoethyl) -gamma aminopropyl trimethoxy silane, bis (dioctyloxypyrophosphate) ethylene titanate chelate and gamma-aminopropyl triethoxy silane;

preferably, the first coupling agent is epoxytrimethoxysilane.

5. The flame retardant according to any one of claims 1 to 4, wherein the core-shell structure is obtained by adding a surfactant, a first coupling agent and pentaerythritol phosphate melamine salt to a silica and aluminum hydroxide nanosphere sol, heating and reacting to form a suspension, and spray-drying.

6. The method for preparing the flame retardant of any one of claims 1 to 5, comprising the step of adding a surfactant, a first coupling agent and pentaerythritol phosphate melamine salt to a silica and aluminum hydroxide nanosphere sol, and heating to react to form a suspension, and then spray-drying the suspension to obtain the core-shell structure.

7. The method according to claim 6, wherein the mass of the melamine salt of pentaerythritol phosphate is 50 to 80 wt% of the total mass of the silica and aluminum hydroxide.

8. The preparation method according to claim 6 or 7, wherein the reaction temperature of adding the surfactant and the first coupling agent into the silica nanosphere sol is 40-60 ℃,

preferably, the reaction temperature is 45-55 ℃;

preferably, the reaction time is 0.5 to 2 h.

9. The process according to any one of claims 5 to 7, wherein the reaction time after addition of the melamine salt of pentaerythritol phosphate is 4 to 6 hours, preferably 5 hours.

10. Use of the polyester according to any of claims 1 to 5 or of the flame retardant prepared by the process according to any of claims 6 to 9 in the field of flame retardancy.

11. A flame-retardant anti-dripping polyester fiber, which is obtained by mixing the flame retardant according to any one of claims 1 to 5 or the flame retardant prepared by the preparation method according to any one of claims 6 to 9 with a second coupling agent and polyester particles to form a filament.

12. The polyester fiber according to claim 11, wherein the content of the second coupling agent is 0.4 to 1.2 wt% based on the mass of the flame retardant,

preferably, the second coupling agent is selected from one or a combination of more than two of epoxy trimethoxy silane, bis- [ gamma- (triethoxy silicon) propyl ] tetrasulfide, N-beta- (aminoethyl) -gamma aminopropyl trimethoxy silane, bis (dioctyloxypyrophosphate) ethylene titanate chelate and gamma-aminopropyl triethoxy silane;

preferably, the second coupling agent is gamma-aminopropyltriethoxysilane.

13. The polyester fiber according to claim 11 or 12, wherein the mass ratio of the flame retardant to the polyester is 7 to 13: 100.

14. the polyester fiber according to any one of claims 11 to 13, wherein the polyester fiber has a limiting oxygen index of 28 to 30%.

15. The polyester fiber according to any one of claims 11 to 14, wherein the breaking strength of the polyester fiber is 2.3 to 3.7 cN/dtex.

16. The method for producing the polyester fiber according to any one of claims 11 to 15, which comprises a step of mixing the flame retardant according to any one of claims 1 to 5 or the flame retardant produced by the production method according to any one of claims 6 to 9 with a second coupling agent and polyester particles to form a filament, thereby obtaining the flame-retardant anti-dripping polyester fiber.

Technical Field

The invention belongs to the technical field of flame retardance. In particular to a flame retardant and a preparation method and application thereof.

Background

With the development of economy and the improvement of living standard, the development of modern fabrics is changing day by day, and the application range and the consumption of polyester fibers are continuously increased. As people pay more and more attention to life safety and have higher and higher flame retardant requirements on polyester fibers, the flame retardant polyester fiber is necessary to avoid personal injury and economic loss to the maximum extent and improve the flame retardant property and the anti-dripping property of the polyester fiber.

The anti-dripping polyester fiber flame retardant needs to meet the following requirements: (1) good flame retardant effect; (2) has the function of anti-dripping; (3) the usage amount is small, and the physical and mechanical properties and the appearance of the polyester fiber are basically not influenced; (4) the flame retardant property is durable, and the washing resistance is high; (5) the fabric woven by the polyester fiber can be directly contacted with the human body after being finished; (6) the products after combustion are low in toxicity and small in harm to human bodies, and the maximum escape time of people is obtained; (7) simple and convenient process and low cost. However, all of the above requirements are not currently met by commercial flame retardants.

Disclosure of Invention

Flame retardants for polyester fibers mainly include halogen-based, phosphorus-based, nitrogen-based and silicon-based flame retardants. The halogen flame retardant has obvious flame retardant effect, but the halogen flame retardant damages the environment and also has continuous harm to human bodies, and after combustion, the toxic smoke is released seriously to endanger human life, so the application of the halogen flame retardant is severely limited.

The flame retardant performance of the single flame retardant containing only phosphorus, nitrogen and silicon is not ideal, the phosphorus nitrogen flame retardant has high cost and limits the market utilization rate, and the conventional flame retardant on the market cannot play a role in resisting molten drops on polyester fibers and cannot meet the application requirement.

The halogen-free flame retardant mainly taking phosphorus compounds and metal hydroxides as main materials overcomes the problems that the traditional flame retardant is not environment-friendly, and generates extremely toxic smoke after combustion, but also has the problems of poor compatibility with polyester fibers, easy migration and loss and gradual loss of flame retardant effect in practical application, and the polyester halogen-free flame retardant in the market only plays the role of flame retardant effect and cannot play the role of molten drop resistance,

silicon, phosphorus, nitrogen's fire retardant forms after a series of chemical reactions and uses silicon dioxide as the core, use phosphorus and nitrogen as the novel fire retardant of nucleocapsid formula of shell, in adding the polyester course of working, can react with the terminal hydroxyl in the polyester fiber, graft on the polyester molecular chain, flame retardant effect is superior, and have the anti-molten drop effect that this kind of fire-retardant polyester fiber does not possess on the market, when the fire retardant of silicon, phosphorus, nitrogen uses together, play fire-retardant synergism, at high temperature, the nitrogen system fire retardant absorbs a large amount of heats and releases incombustible gas after decomposing, play and dilute combustible gas and isolated oxygen and take away a large amount of thermal effects, the surface temperature of polyester fabric has been reduced, inhibit burning. The phosphorus flame retardant can reduce the heat release rate of the material and improve the flame retardant effect in the flame retardant process due to the solidification phase flame retardant mechanism and partial gas phase flame retardant mechanism, and can also be decomposed into pyrophosphoric acid or polyphosphoric acid to promote the carbonization of polyester fibers, thereby effectively playing the effects of oxygen isolation, heat insulation and flame retardant. The silicon flame retardant can increase the thickness and stability of the carbon layers, has certain smoke suppression and heat insulation effects and can also play a role in reducing the cost.

Aiming at the problems of poor anti-dripping performance and poor flame retardant effect of the flame retardant in the prior art, the invention provides the flame retardant.

In a first aspect, the invention provides a flame retardant, which is of a core-shell structure, wherein a component containing silicon dioxide and aluminum hydroxide is used as the core structure, and a surfactant, pentaerythritol phosphate melamine salt and a first coupling agent are used as raw materials for forming a shell, and the reaction is carried out to obtain a phosphorus-nitrogen shell structure.

Preferably, the mass ratio of the silicon dioxide to the aluminum hydroxide is 3-6:0.5-1, and preferably, the mass ratio is 5: 0.5.

Preferably, the content of the surfactant is 0.1 to 1 wt% of the total mass of the silica and the aluminum hydroxide, preferably, the content of the surfactant is 0.5 wt% of the total mass of the silica and the aluminum hydroxide,

preferably, the surfactant is one or a combination of more than two of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, tween-60 and span-60.

Preferably, the content of the first coupling agent is 0.5 to 1.5 wt% of the total mass of the silica and the aluminum hydroxide,

preferably, the first coupling agent is selected from one or a combination of more than two of epoxy trimethoxy silane (KH-560), bis- [ gamma- (triethoxy silicon) propyl ] tetrasulfide (silicon-69), N-beta- (aminoethyl) -gamma aminopropyl trimethoxy silane (KH-570), bis (dioctyloxypyrophosphate) ethylene titanate chelate (DN-8311) and gamma-aminopropyltriethoxysilane (KH-550);

preferably, the first coupling agent is epoxytrimethoxysilane (KH-560).

Preferably, the core-shell structure is obtained by adding a surfactant, a first coupling agent and pentaerythritol phosphate melamine salt into silica and aluminum hydroxide nano microsphere sol, heating to react to form a suspension, and performing spray drying.

In a second aspect, the invention provides a preparation method of the flame retardant, which comprises the following steps that the core-shell structure is obtained by adding a surfactant, a first coupling agent and pentaerythritol phosphate melamine salt into silica and aluminum hydroxide nano microsphere sol, heating and reacting to form a suspension, and performing spray drying.

Preferably, the mass of the pentaerythritol phosphate melamine salt is 50 to 80 wt% of the total mass of the silica and the aluminum hydroxide.

Preferably, the reaction temperature of adding the surfactant and the first coupling agent into the silica nano microsphere sol is 40-60 ℃,

preferably, the reaction temperature is 45-55 ℃;

preferably, the reaction time is 0.5 to 2 h.

Preferably, the reaction time after addition of the melamine salt of pentaerythritol phosphate is 4 to 6 hours, preferably 5 hours.

In a third aspect, the invention provides an application of the polyester or the flame retardant prepared by the preparation method in the flame retardant field.

In a fourth aspect, the invention provides a flame-retardant anti-dripping polyester fiber, which is obtained by mixing the flame retardant or the flame retardant prepared by the preparation method, a second coupling agent and polyester particles to form a filament shape.

Preferably, the filamentous fibers are obtained by extrusion molding and spinning.

Preferably, the second coupling agent is present in an amount of 0.4 to 1.2 wt% based on the mass of the flame retardant,

preferably, the second coupling agent is selected from one or a combination of more than two of epoxy trimethoxy silane (KH-560), bis- [ gamma- (triethoxy silicon) propyl ] tetrasulfide (silicon-69), N-beta- (aminoethyl) -gamma aminopropyl trimethoxy silane (KH-570), bis (dioctyloxypyrophosphate) ethylene titanate chelate (DN-8311) and gamma-aminopropyltriethoxysilane (KH-550);

preferably, the second coupling agent is gamma-aminopropyltriethoxysilane (KH-550).

Preferably, the mass ratio of the flame retardant to the polyester is 7-13: 100.

Preferably, the polyester fiber has a limiting oxygen index of 28 to 30%.

Preferably, the breaking strength of the polyester fiber is 2.3-3.7 cN/dtex.

Preferably, the preparation method comprises the following step of mixing the flame retardant or the flame retardant prepared by the preparation method, a second coupling agent and polyester particles to form threads, so as to obtain the flame-retardant anti-dripping polyester fiber.

The beneficial effects obtained by the invention are as follows:

the flame retardant provided by the invention can improve the flame retardance and the anti-dripping performance of the polyester fiber. The flame-retardant anti-dripping polyester fiber prepared by the flame retardant provided by the invention is non-toxic, washing-resistant and smoke-suppressing, and the limiting oxygen index can reach more than 30%.

Detailed Description

The invention provides a flame-retardant anti-dripping polyester fiber.

The surfactant in the invention enables pentaerythritol phosphate melamine salt to be better attached to the silicon dioxide nano microspheres, and the prepared product has more uniform particle size.

The first coupling agent combines nitrogen, phosphorus and silicon flame retardants together by chemical bonds to form a novel flame retardant with a core-shell structure, wherein the core is silicon dioxide and aluminum hydroxide, and the shell is nitrogen and phosphorus flame retardants.

According to the invention, the second coupling agent grafts the prepared core-shell type flame retardant into the molecular chain of the polyester to form a stable chemical bond, so that the polyester and the flame retardant are forcibly compatible due to the formation of the chemical bond and cannot migrate and separate out.

The melamine salt of pentaerythritol phosphate used in the examples of the present invention can be prepared by the following method. Pentaerythritol and phosphoric acid were reacted at a ratio of 1: 3 at a temperature of 120 ℃ for 1.5 hours to form pentaerythritol phosphate. Slowly adding melamine into the formed pentaerythritol phosphate, wherein the mass ratio of the pentaerythritol phosphate to the melamine is 1: 1.5, the temperature is 80 ℃, and reacting for 2 hours to form pentaerythritol phosphate melamine salt.

The present invention is further illustrated by the following examples, which are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention as claimed. Any person skilled in the art should be able to substitute or change the technical solution of the present invention and its inventive concept within the technical scope of the present invention.

The reagents and instrument sources used in the examples of the invention are shown in table 1 below.

TABLE 1

Example 1

Taking 150g of nano silicon dioxide and 15g of aluminum hydroxide, mixing uniformly to obtain a core structure, then adding O.165g of surfactant Tween-60, namely the dosage of the surfactant is 0.1 wt% of the total mass of the silicon dioxide and the aluminum hydroxide, and 0.825g of first coupling agent KH-550, namely the dosage of the first coupling agent is 0.5 wt% of the total mass of the silicon dioxide and the aluminum hydroxide, reacting at 50 ℃ for 1 hour, slowly adding 120g of pentaerythritol phosphate melamine salt, heating to 75 ℃, reacting for 5 hours, and carrying out spray drying on the prepared milky white suspension to form white powder, thus obtaining the silicon dioxide nano microsphere with the core structure, and obtaining the core-shell flame retardant by taking a phosphorus-nitrogen system as a shell.

And adding 0.088g of second coupling agent KH-550 into 22g of the obtained flame retardant, namely adding 0.4 wt% of second coupling agent KH-550 of the mass of the flame retardant, uniformly mixing with 200g of polyester particles with the master batch particle size of 24 mu m, adding into an extruder, extruding, and passing through a spinneret plate to prepare the flame-retardant anti-dripping polyester fiber.

Examples 2 to 4

Examples 2 to 4 differ from the preparation method of example 1 in the surfactant. Wherein the content of the first and second substances,

in the embodiment 2, the surfactant is sodium dodecyl benzene sulfonate, and the particle size of the polyester master batch is 20 um;

in example 3, the surfactant is sodium dodecyl sulfate, and the particle size of the polyester master batch is 22 um;

in example 4, span-60 is used as a surfactant to prepare the flame-retardant anti-dripping polyester fiber, and the particle size of the polyester master batch is 19 um.

Examples 5 to 8

Examples 5 to 8 are different from the preparation method of example 1 in the amount of the surfactant used.

Wherein, in the embodiment 5, the dosage of the surfactant Tween-60 is 0.3 wt% of the total mass of the silicon dioxide and the aluminum hydroxide, and the particle size of the polyester master batch is 18 um;

in example 6, the dosage of the surfactant tween-60 is 0.5 wt% of the total mass of the silicon dioxide and the aluminum hydroxide, and the particle size of the polyester master batch is 16 um;

in example 7, the dosage of the surfactant tween-60 is 0.7 wt% of the total mass of the silicon dioxide and the aluminum hydroxide, and the particle size of the polyester master batch is 15 um;

in example 8, the amount of Tween-60 is 1 wt% of the total weight of silica and aluminum hydroxide to prepare the flame-retardant anti-dripping polyester fiber, and the particle size of the polyester master batch is 14 um.

Examples 9 to 12

Examples 9-12 differ from the preparation of example 1 in the first coupling agent. Wherein the content of the first and second substances,

the first coupling agent in example 9 is epoxy trimethoxy silane KH-560;

the first coupling agent in example 10 was bis- [ gamma- (triethoxysilyl) propyl ] tetrasulfide silicon-69;

the first coupling agent in example 11 is N-beta- (aminoethyl) -gamma aminopropyltrimethoxysilane KH-570;

in example 12, the first coupling agent is bis (dioctyloxypyrophosphate) ethylene titanate chelate DN-8311 to prepare the flame-retardant anti-dripping polyester fiber.

Examples 13 to 15

Examples 13 to 15 are different from the preparation method of example 1 in the amount of the first coupling agent used. Wherein the content of the first and second substances,

the amount of the first coupling agent KH-560 used in example 13 was 0.8% by weight based on the total mass of silica and aluminum hydroxide;

the amount of the first coupling agent KH-560 used in example 14 was 1% by weight based on the total mass of silica and aluminum hydroxide;

in example 15, the first coupling agent KH-560 was used in an amount of 1.5 wt% based on the total mass of silica and aluminum hydroxide to prepare a flame-retardant anti-dripping polyester fiber.

Examples 16 to 19

Examples 16 to 19 differ from the preparation method of example 1 only in that the second coupling agent is different. Wherein the content of the first and second substances,

the second coupling agent in example 16 is epoxy trimethoxy silane KH-560;

the second coupling agent in example 17 was bis- [ gamma- (triethoxysilyl) propyl ] tetrasulfide silicon-69;

the second coupling agent in example 18 is N-beta- (aminoethyl) -gamma aminopropyltrimethoxysilane KH-570;

the second coupling agent in example 19 was gamma-aminopropyltriethoxysilane KH-550.

Examples 20 to 22

Examples 20-22 differ from the preparation of example 1 only in the amount of the second coupling agent used. Wherein the content of the first and second substances,

the second coupling agent KH-550 in example 20 was used in an amount of 0.6 wt% based on the mass of the flame retardant;

the second coupling agent KH-550 in example 21 was used in an amount of 0.8 wt% based on the mass of the flame retardant;

in example 22, the second coupling agent KH-550 is used in an amount of 1.2 wt% based on the mass of the flame retardant to prepare a flame-retardant anti-dripping polyester fiber.

Comparative example 1

And adding the polyester particles into an extruder to be extruded to obtain the polyester fiber.

Example 23

And detecting the physical indexes of the prepared flame-retardant anti-dripping polyester fiber.

The grafting ratios of the polyesters of examples 1 to 8 were measured gravimetrically and the results are shown in Table 2 below.

TABLE 2

	Graft ratio%	Master batch size um
			Example 1	96	18
Example 2	89	20
			Example 3	92	22
Example 4	94	19
			Example 5	96.5	18
Example 6	98.4	16
			Example 7	98.6	15
Example 8	98.8	14

The data in table 2 above show that, as can be seen from examples 1-4, when the particle size of the polyester particle master batch is 24um, the grafting ratio still reaches 87%, so that the grafting ratio of the flame-retardant anti-dripping polyester fiber prepared from the flame retardant prepared from tween-60 is higher than that prepared from other surfactants.

According to the examples 5-8, it can be seen that the larger the amount of the surfactant tween-60 is, the smaller the master batch is, the better the grafting effect is, but the more the surfactant is added, the more the flame retardant performance of the flame retardant is affected, so the addition mass of the surfactant is 0.1-1% of the mass of the core structure of the silica and aluminum hydroxide nano microspheres, especially the addition mass of the surfactant is 0.5% of the mass of the core structure of the silica and aluminum hydroxide nano microspheres, and the optimal effect is achieved.

Physical indexes of the flame-retardant anti-dripping polyester fibers prepared in the examples 1 to 23 and the polyester fiber prepared in the comparative example 1 are detected by referring to the method of GB/T14463-2008. The flame retardant performance is measured by a limit oxygen index, the LOI is measured on an oxygen index tester according to GB/T5454-1997 textile combustion performance test oxygen index method, and finally the calculated LOI value is taken as a final result. The combustion test is carried out according to GB/T5455-2014 (determination of smoldering and afterflame time of the damage length of the textile in the vertical direction of the combustion performance), and the number of ticks refers to the number of test melting ticks in the combustion process.

The results of comparing the physical indexes and the flame retardant properties of the flame retardant fibers subjected to flame retardant treatment by using different coupling agents are shown in table 3.

TABLE 3

According to examples 9-12, it can be seen that the flame retardant anti-dripping polyester fiber prepared by using KH-560 as the first coupling agent has better physical properties.

According to examples 13-15, it can be seen that the addition amount of the first coupling agent KH-560 is 1%, which can produce better physical properties for the flame-retardant anti-dripping polyester fibers, and the addition amount is continuously increased, although the physical properties of the fibers are not improved, but slightly decreased, and the effect is optimized, wherein the addition amount is 0.5-1.5% of the core structure mass of the silica and aluminum hydroxide nano microspheres, and particularly, the addition amount is 1% of the core structure mass of the silica and aluminum hydroxide nano microspheres.

According to the examples 16-19, it can be seen that the KH-550 is used as the second coupling agent to improve the physical index and the flame-retardant anti-dripping performance of the flame-retardant anti-dripping polyester fiber to the maximum extent, the dripping frequency is 0, no melt dripping occurs, the anti-dripping can be effectively realized, and no toxic gas or smoke is released.

As can be seen from examples 20 to 22, when the amount of the second coupling agent KH-550 added is 0.8%, it is possible to impart better physical properties to the first coupling agent, and the amount of the second coupling agent KH-550 added is increased although the physical properties of the fiber are slightly improved. The comprehensive cost is considered, the adding mass of the nano-microsphere core structure is 0.4-1.2% of the core structure mass of the silicon dioxide and the aluminum hydroxide nano-microsphere, and the effect is optimal when the adding mass of the nano-microsphere core structure is 0.8% of the core structure mass of the silicon dioxide and the aluminum hydroxide nano-microsphere.

The carbon slag generated by burning the polyester fiber prepared in the comparative example 1 is loose, large-area cracks and cells appear among the carbon slag, and the original structural form of the fiber is damaged in the burning process. Phosphorus and nitrogen in the flame retardant can promote the formation of a carbon layer, and SiO in the flame retardant and anti-dripping polyester fiber provided by the invention₂The glass body formed by heating the nuclear structure covers the surface of the fiber to form a compact protective layer to prevent the combustible gas cracked by the fiber from diffusing outwards, so that the carbon slagThe surface has almost no bubbles, and the protective film also successfully prevents oxygen from entering, so that the substrate is not easy to burn, and the oxidation of the carbon layer is prevented. The silicon dioxide microspheres absorb heat to release bound water, so that the temperature of the fiber matrix is reduced, the thermal stability of the fiber matrix is improved, and the carbon slag keeps the structural form of the fiber before combustion, thereby achieving the effects of flame retardance and molten drop resistance.

In the whole combustion process, the polyester fiber prepared in the comparative example 1 is immediately ignited after meeting open fire, and is rapidly and completely combusted in a short time; the flame-retardant anti-dripping polyester fiber provided by the invention is slightly burnt after encountering open fire, but has a dripping phenomenon; the fiber fabric using the flame-retardant anti-dripping flame retardant as the flame-retardant material is difficult to combust in case of fire, and because the silicon element is a carbon-forming smoke suppressant, the fiber treated by the flame-retardant anti-dripping flame retardant has the characteristics of no smoke and no molten drops, thereby playing the role of effectively retarding flame and resisting molten drops.

Therefore, compared with the common flame retardant, the flame-retardant anti-dripping flame retardant provided by the invention has the effects of cooling, smoke suppression, gas dilution, anti-dripping and the like, and realizes effective flame retardance of the flame-retardant anti-dripping flame retardant in the flame-retardant polyester fabric.

The flame retardant provided by the invention has higher compatibility with the polyester fiber substrate. The flame retardant provided by the invention has greatly improved flame-retardant anti-dripping performance on polyester fiber, and aiming at the defect that the compatibility of the flame-retardant anti-dripping flame retardant and a base material is poor, so that the mechanical property and the processing property of the base material are poor, the invention utilizes the principle of modifying and grafting a coupling agent, and discovers that the modified silica microspheres with the first coupling agent, especially KH-560, can be combined with the nano silica microspheres and can also react with the phosphorus-nitrogen flame retardant to form stable chemical bonds.

Under the action of a second coupling agent, especially KH-550, the flame retardant provided by the invention is grafted to a molecular chain of polyester to form a stable chemical bond, and finally the prepared flame-retardant anti-dripping fiber has high physical and chemical indexes such as breaking strength, breaking elongation, overlength rate and the like and high limit oxygen index. The second coupling agent can form a stable chemical bond with the surface of the flame retardant and can also react with hydroxyl at the end of the polyester fiber, so that the flame retardant and the polyester fiber are forcibly compatible to form an integral structure due to chemical grafting, and the excellent flame-retardant and anti-dripping performance can be generated when the addition amount of the second coupling agent is 1% of the total weight of the polyester fiber. And after the core-shell type flame retardant is added, the fracture strength of the polyester fiber is hardly influenced, the melt viscosity of the polyester fiber is reduced, and the processability of the polyester fiber is improved.

Meanwhile, the second coupling agent is connected with the shell layer of the phosphorus-nitrogen system and the hydroxyl end groups of the polyester fibers, so that the flame retardant and the polyester fibers are forced to be mutually soluble due to chemical grafting, and the washing fastness of the flame-retardant anti-dripping polyester fabric is greatly improved.

The foregoing is considered as illustrative and not restrictive of the preferred embodiments of the invention, and that various modifications, equivalents, and improvements made within the spirit and scope of the invention are intended to be included therein.