CN106009547A - Modified inflaming retarding polyethylene glycol terephthalate system and preparation method thereof - Google Patents

Abstract

The invention discloses a modified flame-retardant polyethylene terephthalate (PET) system and a preparation method thereof. The modified flame-retardant PET system includes 100 parts by weight of PET resin, 1-10 parts by weight of Phosphorus-containing flame retardant, 1-6 parts by weight of flame retardant synergist, 1-10 parts by weight of anti-dripping additive, 0.01-0.08 parts by weight of heat stabilizer, and 0.01-0.08 parts by weight of antioxidant. The modified flame-retardant PET system in the invention has the characteristics of high flame retardancy, anti-melt droplet and smoke-suppressing effects, and the preparation method is simple and easy to operate, pollution-free and easy to implement.

Description

A kind of modified flame-retardant polyethylene terephthalate system and preparation method thereof

technical field

The invention relates to a flame-retardant PET system, in particular to a polytetrafluoroethylene-zinc borate composite modified flame-retardant PET system and a preparation method thereof.

Background technique

Polyethylene terephthalate (PET), as a synthetic fiber with the fastest development, the highest output and the widest application range, has excellent properties such as high strength, stable size and chemical corrosion resistance, and is widely used in clothing, indoor Exterior decoration and various special materials. However, the limiting oxygen index (LOI) of PET is only about 22%. It is a flammable polymer material, which cannot meet the requirements for flame retardancy in some fields, and has obvious melt dripping during the combustion process. , It is often the cause of ignition, spread and scalds in fires, and it is easy to cause secondary injuries. How to improve the flame retardancy of PET and reduce its hazard in fire has become a widely concerned research direction.

At present, the widely used flame retardants are halogen flame retardants, phosphorus flame retardants or phosphorus-halogen, phosphorus-nitrogen composite flame retardants. Although the flame retardant effect of halogen-based flame retardants is good and the addition amount is small, its combustion products have certain negative effects on the environment, such as releasing toxic and corrosive hydrogen halide gases, etc.; and halogen-free flame retardants For example, phosphorus-based flame retardants have the advantages of safety, non-toxicity, and low price, so their applications are gradually increasing. However, the existing phosphorus-containing flame-retardant PET system has the defects of obvious melt dripping and smoke release while having high flame retardancy, which restricts the application of phosphorus-containing flame retardants.

Based on the above reasons, it is urgent to develop a PET system with high flame retardancy, anti-melt drop and obvious smoke suppression effect.

Contents of the invention

In order to solve the above problems, the present inventors have carried out intensive research and found that in the phosphorus-containing flame-retardant PET system, the compound use of polytetrafluoroethylene (PTFE) and zinc borate can greatly reduce the Droplet amount, smoke suppression effect is remarkable, thereby completed the present invention.

The object of the present invention is to provide the following aspects:

In the first aspect, a modified flame-retardant PET system is provided, and the modified flame-retardant PET system includes the following components by weight:

In a second aspect, a method for preparing a modified flame-retardant PET system is provided, the method comprising the following steps:

Step 1), weighing each component according to the weight ratio, and pre-mixing;

In step 2), each component is sequentially added to the compounding equipment for melt blending.

In step 2), the compounding equipment is a single-screw extruder or a twin-screw extruder, preferably a twin-screw extruder. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, and 270°C in the third zone. ℃, the fourth zone is 270°C, the fifth zone is 260°C, the sixth zone is 240°C, and the screw speed is 15-20r/min.

According to a modified flame retardant PET system provided by the present invention and its preparation method, it has the following beneficial effects:

(1) The present invention uses a halogen-free and environmentally friendly flame retardant, which is highly efficient in flame retardant and meets the requirements of green and environmentally friendly flame retardant. The amount of flame retardant added is very small and has no effect on the mechanical properties of the material;

(2) The combined use of anti-droplet additives and flame retardant synergists greatly reduces droplet and smoke production, thereby reducing fire hazards;

(3) Through the compound use of heat stabilizer and antioxidant, the degradation of PET material is effectively inhibited;

(4) The preparation method provided by the invention is simple to operate and easy to control.

Description of drawings

Figure 1 shows the DSC curves of Examples 1-3 and Comparative Examples 1-2.

detailed description

The following describes the present invention in detail, and the features and advantages of the present invention will become more clear and definite along with these descriptions.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments. While various aspects of the embodiments are shown in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

According to a first aspect of the present invention, a modified flame retardant PET system is provided, comprising the following components in weight ratio:

In the present invention, the modified flame-retardant PET system also includes a flame-retardant synergist, and its components and their weight ratios are:

In the present invention, the phosphorus-containing flame retardant is selected from phosphoric acid esters or phosphorus heterocyclic compounds, preferably 2-carboxyethylphenylphosphinic acid (CEPPA), dicarboxylic acid ethyl methyl phosphate, tris(1-oxygen Generation-1-phospha-2,6,7-trioxabicyclo[2,2,2]octane-4-methylene)phosphate, 9,10-dihydro-9-oxa-10- One or more of phosphaphenanthrene-10-oxides, preferably 2-carboxyethylphenylphosphorous acid.

In the flame retardant process, phosphorus-containing flame retardants have a strong flame retardant effect. On the one hand (gas-phase flame retardant) phosphorus-containing flame retardants can decompose small molecular weight components, which interact with hydrogen radicals and hydroxyl radicals in the gas-phase flame zone, slowing down the combustion chain reaction process; The steam can reduce the temperature of the polymer surface and dilute the concentration of combustibles in the gas phase flame zone, so as to achieve the flame retardant effect; At 300°C, phosphoric acid is further dehydrated to generate metaphosphoric acid, and metaphosphoric acid is further polymerized to generate polymetaphosphoric acid with strong dehydration effect, which promotes dehydration and carbonization of high polymers, reduces the mass loss rate of materials and the generation of combustibles, and phosphorus is large Some remain in the charcoal layer.

Known phosphorus-containing flame retardants used in PET are prone to molten droplets, accompanied by thick smoke, which has obvious fire and safety hazards. Therefore, it is necessary to add additives to reduce the amount of molten droplets and the generation of smoke.

In the present invention, the anti-droplet additive is selected from one or more of layered silicate, benzomelamine, carbon nanotube, graphite and polytetrafluoroethylene, preferably polytetrafluoroethylene (PTFE). The limiting oxygen index of PTFE is about 90%, which is a non-combustible material, and the melt viscosity is very high. Above the melting point (327°C), the melt viscosity reaches 1010Pa.s, even if it is heated to the decomposition temperature, it is difficult to flow. When used in flame retardant materials, PTFE can achieve the purpose of anti-droplet by increasing the viscosity or increasing the amount of charcoal burned.

In the present invention, the flame retardant synergist is selected from one or more of zinc borate, metaborate, iron oxide, aluminum hydroxide, magnesium hydroxide, and melamine, preferably zinc borate (ZB).

ZB is cheap, non-toxic, and non-irritating. It still contains water of hydration below 260°C. It can be decomposed at high temperatures to form B ₂ O ₃ solids and adhere to the surface of the material. It can effectively inhibit the generation of flammable gases and prevent oxidation and thermal decomposition. Further, it does not have much impact on the strength and thermal aging properties of many polymers, and has obvious smoke suppression and anti-droplet functions.

When ZB is used as a flame retardant synergist and phosphorus-containing flame retardant, the flame retardant performance is better, but the smoke suppression effect and anti-droplet performance are worse than when ZB is used alone. After adding PTFE, when the ratio of ZB and PTFE is appropriate, it can achieve obvious smoke suppression and anti-droplet effects on phosphorus-containing flame-retardant PET.

In the present invention, the heat stabilizer is selected from phosphoric acid, phosphorous acid and esters thereof, preferably phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, ammonium phosphate, triphenyl phosphite, bisphenol A phosphite, phosphoric acid One or more of triphenyl ester and trimethyl phosphate, more preferably triphenyl phosphite;

The antioxidant is selected from one or more of antioxidant 1010 and antioxidant 1425, preferably antioxidant 1010.

There is a synergistic effect between the antioxidant 1010 and triphenyl phosphite. There is an active hydrogen atom in the molecule of the antioxidant 1010, which can be separated from the macromolecular chain free radicals to generate hydrogen peroxide and stable phenolic oxygen free radicals. radicals, which trap free radicals, thereby terminating the chain reaction, while the stabilizer, triphenyl phosphite, breaks down the hydrogen peroxide produced.

In the present invention, the modified flame-retardant PET system also includes an intumescent flame retardant (IFR), and the intumescent flame retardant includes three (2-hydroxyethyl) isocyanuric acid terephthalate and polyphosphoric acid Ammonium (APP), where,

The consumption ratio of described three (2-hydroxyethyl) isocyanuric acid terephthalate and ammonium polyphosphate is the quality of three (2-hydroxyethyl) isocyanuric acid terephthalate: poly The quality of ammonium phosphate = 1:6-6:1.

Tris(2-hydroxyethyl)isocyanurate terephthalate is synthesized from tris(2-hydroxyethyl)isocyanurate (THEIC) and terephthalic acid. THEIC can be decomposed by heat to produce nitrogen-containing gas , has three hydroxyethyl groups, which can be used as the carbon source and gas source of the intumescent flame retardant system at the same time; combined with terephthalic acid to partially esterify its hydroxyl groups, it enhances the thermal stability of THEIC and reduces its hydrophilicity . Intumescent flame retardants can generate a layer of expanded porous carbon layer on the surface of the material during the combustion process, which can insulate oxygen, heat, smoke, and can resist molten droplets, so it has good flame retardancy.

According to a second aspect of the present invention, the preparation method of the modified flame-retardant PET system comprises the following steps:

Step 1), weighing each component according to the weight ratio, and pre-mixing;

In step 2), each component is sequentially added to the compounding equipment for melt blending.

In step 2), the compounding equipment is a single-screw extruder or a twin-screw extruder, preferably a twin-screw extruder. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, and 270°C in the third zone. ℃, the fourth zone is 270°C, the fifth zone is 260°C, the sixth zone is 240°C, and the screw speed is 15-20r/min.

Optionally, the obtained product is dried, and the drying is any possible implementation method in the prior art, including any one of normal pressure drying and low pressure drying, preferably vacuum drying, the drying temperature is 110-150 ° C, and the drying time is 10-15h.

Example

Example 1

1) Weigh 910g PET, 40g CEPPA, 40gZB, 10gPTFE, 0.32g antioxidant 1010, 0.32g triphenyl phosphite, and mix well;

2) Add each component into the twin-screw extruder in turn. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, 270°C in the third zone, 270°C in the fourth zone, 260°C in the fifth zone, and 240°C in the sixth zone. °C, the screw speed is 20r/min; the obtained product is vacuum dried at 130 °C for 10 h. The mass content of PTFE (relative to the PET blend) in the obtained blend is 1 wt%, the mass content of ZB (relative to the PET blend) is 4 wt%, and the blend is named F-Z4F1.

Example 2

1) Weigh 910gPET, 40gCEPPA, 30gZB, 20gPTFE, 0.32g antioxidant 1010, 0.32g triphenyl phosphite, and mix well; 2) Add each component to the twin-screw extruder in turn, and the process parameters of the extruder 230°C in the first zone, 260°C in the second zone, 270°C in the third zone, 270°C in the fourth zone, 260°C in the fifth zone, 240°C in the sixth zone, the screw speed is 20r/min; the obtained product is vacuum dried at 140°C for 9 hours. The mass content of PTFE (relative to the PET blend) in the obtained blend is 2 wt%, the mass content of ZB (relative to the PET blend) is 3 wt%, and the blend is named F-Z3F2.

Example 3

1) Weigh 910g PET, 40g CEPPA, 20g ZB, 30g PTFE, 0.32g antioxidant 1010, 0.32g triphenyl phosphite, and mix well;

2) Add each component into the twin-screw extruder in turn. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, 270°C in the third zone, 270°C in the fourth zone, 260°C in the fifth zone, and 240°C in the sixth zone. °C, the screw speed is 20r/min; the obtained product is vacuum dried at 120 °C for 12 hours. The mass content of PTFE (relative to the PET blend) in the obtained blend is 3 wt%, the mass content of ZB (relative to the PET blend) is 2 wt%, and the blend is named F-Z2F3.

Example 4

1) Weigh 860gPET, 40gCEPPA, 20gZB, 30gPTFE, 50gIFR, 0.32g antioxidant 1010, 0.32g triphenyl phosphite, and mix well, among them, tri(2-hydroxyethyl)isocyanurate p-phenylene in IFR The quality of diformate: the quality of ammonium polyphosphate = 1:6;

2) Add each component into the twin-screw extruder in turn. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, 270°C in the third zone, 270°C in the fourth zone, 260°C in the fifth zone, and 240°C in the sixth zone. °C, the screw speed is 20r/min; the obtained product is vacuum dried at 120 °C for 12 hours. Obtaining the mass content of PTFE (relative to PET blend) in the blend is 3wt%, the mass content of ZB (relative to PET blend) is 2wt%, the mass content of IFR (relative to PET blend) is 5wt%, the blend is named F-Z2F3I5.

comparative example

Comparative example 1

1) Weigh 910g PET, 40g CEPPA, 50g ZB, 0.32g antioxidant 1010, 0.32g triphenyl phosphite, and mix well;

2) Add each component into the twin-screw extruder in turn. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, 270°C in the third zone, 270°C in the fourth zone, 260°C in the fifth zone, and 240°C in the sixth zone. °C, the screw speed is 20r/min; the obtained product is vacuum dried at 130 °C for 10 h. The mass content of PTFE (relative to the PET polymer) in the obtained blend is 0 wt%, the mass content of ZB (relative to the PET polymer) is 5 wt%, and the blend is named F-Z5F0.

Comparative example 2

1) Weigh 960g PET, 40g CEPPA, 0.32g antioxidant 1010, 0.32g triphenyl phosphite, and mix well;

2) Add each component into the twin-screw extruder in turn. The process parameters of the extruder are: 230°C in the first zone, 260°C in the second zone, 270°C in the third zone, 270°C in the fourth zone, 260°C in the fifth zone, and 240°C in the sixth zone. °C, the screw speed is 20r/min; the obtained product is vacuum dried at 130 °C for 10 h. No PTFE and ZB were added to the blend, and the blend was named F-Z0F0.

Experimental example

The thermal properties of flame-retardant PET were characterized by Seiko DSC-6200 differential scanning calorimeter (DSC) produced by Seiko Instruments Inc.;

Limiting Oxygen Index (LOI): The LOI of the sample was tested with a Dynisco-type limiting oxygen index analyzer produced by Dynisco Inc. of the United States, and the smoke formation during the combustion process of the sample was observed. The spline size was 80 mm x 6.5 mm x 3 mm and was prepared on a Haake MiniJet micro sample injection machine.

Melting droplet situation: Use the CZF-3 horizontal and vertical combustion instrument produced by Nanjing Jiangning District Analytical Instrument Factory to test the molten droplet situation of the sample, clamp the sample horizontally, and calculate the number of molten droplets within 1 minute under the condition of continuous flame (flame length is 2cm); and measure the quality of dripping droplet. The spline size was 80 mm x 6.5 mm x 3 mm and was prepared on a Haake MiniJet micro sample injection machine.

Cone calorimeter test (CONE): The test was carried out using a standard cone calorimeter produced by Fire Testing Technology Ltd, UK. Sample size: 100mm×100mm×3mm. According to the standard established by ISO5660, the edge and bottom of the sample are wrapped with aluminum foil and placed in a horizontal sample slot. The sample is heated under the condition of 35kw/ ^m2 thermal radiation power, and the ignition time and heat release obtained by analyzing the analysis software of CONE parameters such as speed.

Experimental Example 1 Thermal Performance Analysis

Embodiment 1-3 and comparative example 1-2 are carried out DSC test, and the result is as shown in Figure 1 and Table 1, in Figure 1:

Curve 1 represents the DSC curve of the product obtained in Example 1;

Curve 2 represents the DSC curve of the product obtained in embodiment 2;

Curve 3 represents the DSC curve of the product obtained in embodiment 3;

Curve 4 represents the DSC curve of the product obtained in Comparative Example 1;

Curve 5 represents the DSC curve of the product obtained in Comparative Example 2.

Table 1 Thermal performance data

It can be seen from Figure 1 and Table 1 that the crystallization temperature (Tc) of the three groups of modified flame-retardant PET systems (F-Z4F1, F-Z3F2 and F-Z2F3) containing ZB and PTFE is higher than that of flame-retardant PET (F-Z0F0) Compared with the Tc (128.0°C) of the 5% ZB flame-retardant PET system (F-Z5F0), the Tc (131.9°C) of the system is lower, indicating that the compounding of ZB and PTFE has a greater effect on the crystallization of the PET system than adding alone The role played by ZB.

Experimental Example 2 Limiting Oxygen Index

The products prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to limiting oxygen index determination, and the results are shown in Table 2. During the experiment, on the basis of obtaining the quantitative data of the limiting oxygen index, the smoke situation was described qualitatively at the same time, and its severity was described by the increase in the number of ☆, the more the number, the more serious the smoke situation.

Table 2 Limiting Oxygen Index Data

It can be seen from Table 2 that compared with F-Z0F0, after adding 5% ZB alone, the LOI value of the flame-retardant PET system (F-Z5F0) is slightly increased, and there is still obvious smoke generation. After PTFE and ZB, the LOI value of the modified flame-retardant PET system increased, and the smoke phenomenon was significantly improved, especially when 1% PTFE and 4% ZB were added, the LOI value reached 31%. The smoke production is reduced from 5☆ to 3☆, which shows that PTFE has a better synergistic effect on ZB in terms of smoke suppression. After adding PTFE, ZB and IFR together, the flame retardant effect of the sample is further improved, the oxygen index is significantly increased (35%), and the smoke release is also significantly suppressed (2☆), indicating that the intumescent flame retardant system IFR Together with the former two, it exerts a synergistic flame retardant effect, which greatly enhances the flame retardant performance of the sample.

Experimental example 3 droplet situation

The products prepared in Examples 1-4 and Comparative Examples 1-2 were measured on the vertical combustion tester for the quantity and quality of molten droplets, and the results are shown in Table 3.

Table 3 The data of the droplet situation

It can be seen from Table 3 that the number of droplets in the modified flame-retardant PET system with ZB and PTFE added together is higher than that of the flame-retardant PET system (F-Z0F0) and the 5% ZB flame-retardant PET system (F-Z5F0). Less, but the average droplet mass increased slightly, which is due to the anti-droplet effect of PTFE. The modified flame-retardant PET system (F-Z2F3) after adding 2% ZB and 3% PTFE further improved the anti-droplet effect, and the number of molten droplets and the total mass of molten droplets were respectively reduced by 70% and 64% compared with F-Z0F0. 31% and 22% lower than F-Z5F0 respectively. After co-adding PTFE, ZB and IFR, the number of molten droplets within 1 minute is less than 10 drops (7 drops on average), and the total mass of molten droplets is also significantly reduced, which is about 40% lower than that of F-Z2F3. Excellent anti-dripping effect. The principle of PTFE anti-droplet is mainly to use the fiber-forming principle of the amorphous state of the polymer chain to form a network structure during the extrusion process. This network structure can enhance the melt strength of the polymer. Through physical adhesion, it can change the melt. The rheological behavior of the bulk phase increases the viscosity of the melt and reduces its fluidity to achieve the effect of anti-dripping.

Experimental Example 4 Cone Calorimeter Test

The cone calorimeter of FTT Company was used to measure the time to ignition (TTI), heat release rate (HRR), mass loss rate (MLR), and smoke release rate (RSR) under the condition of radiant power of ^35kw /m2. ); where pk-HRR and tpk-HRR refer to the peak value of HRR and the time required to reach the peak value respectively, and the rest are analogized. The results are shown in Table 4.

Table 4 Cone calorimeter test data

It can be seen from Table 4 that the ignition time (TTI) of the modified flame-retardant PET system after adding PTFE is higher than that of the flame-retardant PET system (F-Z5F0) containing 5% ZB, and the ignition time of the F-Z5F0 system is only 56s. However, the ignition time of the ZB-PTFE composite modified flame-retardant PET system increases to 85s, 114s and 125s with the increase of ZB content (or the decrease of PTFE content), indicating that the compounding effect of PTFE and ZB is better than that of adding ZB alone. Effect. In addition, the total combustion heat release of the ZB-PTFE composite flame-retardant PET system is lower than that of the flame-retardant PET system (F-Z5F0 and F-Z0F0), which shows that PTFE and ZB have a better synergistic flame-retardant effect.

The total smoke emission of the F-Z0F0 flame-retardant PET system is 1913.3m ² /m ² . After adding ZB-PTFE, the total smoke emission of the modified flame-retardant PET system is reduced, and the reduction range increases with The increase of ZB content increased, and decreased from 1605.0m ² /m ² (F-Z2F3) to 1198.2m ² /m ² (F-Z4F1), indicating that the auxiliary addition of PTFE made the smoke suppression effect of ZB play a role.

After co-adding PTFE, ZB and IFR (F-Z2F3I5), the peak heat release rate (pk-HRR) of the sample is significantly reduced, and most importantly, the total amount of smoke release is reduced to 789.9m ² /m ² , indicating that the combustion of the sample The intensity is obviously weakened, which is manifested by the decrease of pk-HRR value and the increase of tpk-HRR value; and it well reflects the smoke suppression effect, which is also one of the most obvious effects of intumescent flame retardant synergists.

The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent replacements, modifications or improvements can be made to the technical solutions and implementations of the present invention, all of which fall within the scope of the present invention. The protection scope of the present invention shall be determined by the appended claims.

Claims (10)

1. a modified flame-retardant polyethylene terephthalate system, its feature exists In, including the component of following weight proportion:

Modified flame-retardant polyethylene terephthalate the most according to claim 1 System, it is characterised in that described modified flame-retardant polyethylene terephthalate system Also include that fire retarding synergist, the most each component and weight proportion thereof are:

Modified flame-retardant poly terephthalic acid second two the most according to claim 1 and 2 Alcohol ester system, it is characterised in that described phosphonium flame retardant is selected from phosphate ester or phosphorus heterocycle Compound, preferably 2-carboxyethyl phenyl hypophosphorous acid, dicarboxylic acids ethyl-methyl phosphate ester, Three (1-oxo-1-phospha-2,6,7-trioxa-l-phosphabicyclo [2,2,2] octane-4-methylene) phosphorus One or more in acid esters, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, More preferably 2-carboxyethyl phenyl hypophosphorous acid.

4. according to the modified flame-retardant poly terephthalic acid one of claims 1 to 3 Suo Shu Glycol ester system, it is characterised in that described anti-dropping additive is selected from laminar silicic acid One in salt, benzoguanamine, CNT, graphite, politef or Multiple, preferably polytetrafluoroethylene.

5. according to the modified flame-retardant poly terephthalic acid one of Claims 1-4 Suo Shu Glycol ester system, it is characterised in that described fire retarding synergist is selected from Firebrake ZB, partially One in borate, ferrum oxide, aluminium hydroxide, magnesium hydroxide, tripolycyanamide or Multiple, preferred boric acid zinc.

6. according to the modified flame-retardant poly terephthalic acid one of claim 1 to 5 Suo Shu Glycol ester system, it is characterised in that described heat stabilizer is selected from phosphoric acid and phosphorous acid And esters, preferably phosphoric acid, phosphorous acid, ortho phosphorous acid, pyrophosphoric acid, ammonium phosphate, In triphenyl phosphite, phosphorous acid bisphenol-A ester, triphenyl phosphate, trimethyl phosphate One or more, more preferably triphenyl phosphite；And/or

Described antioxidant is selected from antioxidant 1010 and/or antioxidant 1425, preferably antioxidant 1010。

7. according to the modified flame-retardant poly terephthalic acid one of claim 1 to 6 Suo Shu Glycol ester system, it is characterised in that described modified flame-retardant poly terephthalic acid second two Alcohol ester system also includes expansion type flame retardant.

Modified flame-retardant polyethylene terephthalate the most according to claim 7 System, it is characterised in that described expansion type flame retardant includes that three (2-ethoxys) are different Cyanuric acid terephthalate and APP, wherein,

The consumption of described three (2-ethoxy) isocyanuric acid terephthalate and poly-phosphorus The quality that amount ratio is three (2-ethoxy) isocyanuric acid terephthalate of acid ammonium: Quality=the 1:6-6:1 of APP.

9. according to the modified flame-retardant poly terephthalic acid one of claim 1 to 8 Suo Shu The preparation method of glycol ester system, comprises the following steps:

Step 1), weigh each component according to weight proportion, mix in advance；

Step 2), each component is sequentially added in Compounders and carries out melt blending.

Modified flame-retardant polyethylene terephthalate the most according to claim 9 The preparation method of ester system, it is characterised in that

Step 2) in, described Compounders is single screw extrusion machine or double screw extruder, Preferably double screw extruder, extruder technological parameter is: 230 DEG C of a district, two 260 DEG C of districts, Three 270 DEG C of districts, four 270 DEG C of districts, five 260 DEG C of districts, six 240 DEG C of districts, screw speed is 15-20r/min,

Optionally, being dried product, baking temperature is 110-150 DEG C, when being dried Between be 10-15h.