A flame-retardant polyester material with a fluorescent finish and its preparation method

Abstract

The present invention relates to the field of polyester flame retardant technology, and discloses a flame retardant polyester material with a fluorescent finish and a preparation method thereof. The material comprises a flame retardant substrate and a fluorescent finishing film coated on the flame retardant substrate. The raw materials of the flame retardant substrate include, by weight, 70-80 parts of PET, 16-24 parts of ammonium polyphosphate, and 4-6 parts of polyol. The raw materials of the fluorescent finishing film include 97-99 parts of PET and 1-3 parts of aromatic fluorescent molecules. The aromatic fluorescent molecules include any one or more of hexaphenylthiole, triphenylamine, and tetraphenylethylene. The material is melted and biaxially stretched to prepare a finishing film, which is then injection-molded and composited with a substrate. In the present invention, the use of aromatic fluorescent molecules to prepare the fluorescent finishing film layer enables the material surface to have unique photoluminescent properties, while also playing a synergistic role in making the carbon layer structure more compact and improving the flame retardant properties of the material.

Description

Technical Field

[0001] The present invention relates to the technical field of polyester flame retardancy, and particularly relates to a flame-retardant polyester material with a fluorescent finish and a preparation method thereof. Background Art

[0002] Polyethylene terephthalate (PET) is a linear polymer with a symmetric aromatic ring structure. This type of polymer material has high tensile strength, hardness and rigidity, good light transmittance and barrier properties, is resistant to most organic solvents, has stable processing performance, and can be prepared into various fibers and film products. However, PET belongs to a slow-burning and smoke-generating resin, and its limiting oxygen index is only 21-22%, which does not meet the flame retardancy requirements of some electronic and electrical application fields.

[0003] To endow PET with flame retardancy, a relatively convenient method is to melt-blend and compound a flame retardant with PET to prepare a flame-retardant PET material. For PET, relatively effective flame retardants include brominated flame retardants, such as decabromodiphenyl ether, pentabromodiphenyl ether, polybromodiphenyl ether, brominated polystyrene, brominated epoxy resin, and tetrabromobisphenol A carbonate oligomer, tris(dibromophenyl) phosphate, etc. However, such brominated flame retardants belong to non-environmental halogen-containing flame retardants and are restricted in use in some regions. Therefore, developing and using halogen-free flame retardants in PET has better application prospects.

[0004] Among the halogen-free flame retardants, there is a phosphorus-containing flame retardant ammonium polyphosphate. This flame retardant decomposes upon heating to generate phosphoric acid and ammonia. The phosphoric acid dehydrates the molten polymer to form carbon, and the ammonia causes the carbon layer to expand, isolating oxygen, heat, and flame in the environment through the condensed-phase flame retardancy mechanism to protect the underlying polymer material from further attack. At present, ammonium polyphosphate has a good flame retardant effect on polyolefin polymers (such as polyethylene, polypropylene, etc.) under the synergistic action of a charring agent, but the flame retardant effect on polyester materials (such as PET, etc.) is not obvious. The main reason is that the carbon layer structure generated after the dehydration of polyester by ammonium polyphosphate is not dense enough, resulting in a decline in the barrier performance. Therefore, in the ammonium polyphosphate flame-retardant polyester system, how to improve the density or barrier performance of the material combustion carbon layer through structural design and formulation adjustment is a core key technology.

[0005] For example, CN109181248A discloses a preparation method of an ammonium polyphosphate-coated carbon microsphere flame retardant. It first performs silanization modification on the carbon microspheres, and then prepares an APP-coated silanized modified CMSs by mixing and refluxing with ammonium polyphosphate. This modified microsphere can be used for PET flame retardancy, and the oxygen index of the prepared flame-retardant PET can reach 27.9-30.6, but the microsphere modification method is complex and the flame retardant effect is not ideal enough.

[0006] Fluorescent polymer materials with photoluminescence properties have developed rapidly in the fields of anti-counterfeiting, identification, decoration, etc. These materials are mainly prepared by two methods. One is to design and synthesize polymers containing aromatic ring structures in the main chain or side chain; the other is to compound materials with fluorescent properties such as rare earths and aromatic polycyclic compounds with general polymer materials without photoluminescence properties. The former has a high preparation cost, while the latter is convenient for mass production. When these fluorescent polymer materials are irradiated by an external light source, the electrons in the material transition from the ground state to the excited state, and then release energy in a radiative manner when returning from the excited state to the ground state, which is the mechanism of photoluminescence.

[0007] In view of the demand for the fluorescent properties of materials in the existing market, it is worth studying how to endow polyester materials with both fluorescence and flame retardancy properties. Summary of the Invention

[0008] Aiming at the insufficient flame retardancy performance of the halogen-free flame retardant of polyester materials in the prior art, the present invention provides a polyester material with unique photoluminescence properties and high-efficiency flame retardancy performance. A small amount of aromatic fluorescent molecules can, on the one hand, achieve a fluorescent finishing effect, and on the other hand, combine with ammonium polyphosphate to improve the density and stability of the carbon layer, thereby enhancing the flame retardancy performance of the polyester matrix.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A flame-retardant polyester material with a fluorescent finish, comprising a flame-retardant substrate and a fluorescent finish film coated on the flame-retardant substrate; calculated by mass fraction, the raw materials of the flame-retardant substrate include: 70-80 parts of PET; 16-24 parts of ammonium polyphosphate; 4-6 parts of polyol; the raw materials of the fluorescent finish film include: 97-99 parts of PET and 1-3 parts of aromatic fluorescent molecules;

[0011] The aromatic fluorescent molecules include any one or more of hexaphenylsilole, triphenylamine, and tetraphenylethylene. These fluorescent molecules belong to typical aggregation-induced emission materials, and the absorption peak spectral band range is 300-360 nm; under ultraviolet light irradiation (325 nm), the emission spectral band range is 375-500 nm. When added to the polymer, blue fluorescence can be released under ultraviolet light irradiation. Therefore, when a polyester film containing these three aromatic compounds is coated on the surface of the flame-retardant substrate, the obtained overall flame-retardant polyester material has photoluminescence properties, and the aromatic ring structure therein makes the carbon layer formed by the combustion of polyester more dense and stable. At the same time, these compounds have good thermal stability and are not prone to thermal decomposition at the PET processing temperature.

[0012] In the present invention, an aromatic fluorescent molecule is used to fabricate a fluorescent decorative film layer, enabling the material surface to have unique photoluminescence characteristics. On the other hand, due to its aromatic structure, the fluorescent molecule can cooperate with the intumescent flame retardant in the flame-retardant substrate during combustion, promoting the carbon layer structure to be denser and further preventing the penetration of oxygen and heat in the environment through the carbon layer. In addition, the aromatic compound is coated on the surface of the flame-retardant substrate by a finishing process. On the one hand, it can first contact the heat source and quickly participate in the dehydration and carbonization process of the polymer. On the other hand, it can reduce the use cost of such synergists.

[0013] If the addition amount of the aromatic compound in the polyester film is too large, its synergistic effect with ammonium polyphosphate on the dehydration and carbonization of the polymer will decrease, and the material cost will increase; if the addition amount is too small, the fluorescence signal of the product will be weak and its flame-retardant synergistic effect will also decrease.

[0014] The flame-retardant substrate and the fluorescent decorative film are combined by injection molding.

[0015] Specifically, the combination of the flame-retardant substrate and the fluorescent decorative film includes: attaching the fluorescent decorative film to the inner surface of the injection mold, closing the mold, injecting the flame-retardant substrate into the mold, and after pressure holding, cooling, demolding, and ejecting, the flame-retardant polyester material with fluorescent decoration is obtained.

[0016] The thickness of the fluorescent decorative film is 50 - 150 μm. If the thickness is too small, the synergistic flame-retardant effect will decrease; if the thickness is too large, it will cause the decorative film to not fit tightly with the mold, and at the same time, due to process limitations, the glossiness of the product surface far from the injection port and near the injection port will vary greatly, that is, the surface glossiness distribution is uneven.

[0017] The particle size of the ammonium polyphosphate is 200 - 500 mesh, and the particle size of the polyol is 300 - 1000 mesh. Ammonium polyphosphate and polyol within a certain particle size range can, on the one hand, achieve their uniform dispersion in the PET matrix; under certain flame temperature conditions of the flame-retardant substrate in the present invention, ammonium polyphosphate can promote the dehydration and carbonization of the molten polymer under the action of the carbonization synergist polyol, and the incombustible gas ammonia generated by the thermal decomposition of ammonium polyphosphate causes the carbon layer to foam rapidly. Cooperating with the aromatic fluorescent molecule that can make the carbon layer denser, the overall flame-retardant performance of the material is effectively improved.

[0018] The degree of polymerization of the ammonium polyphosphate is above 1000. If the degree of polymerization is too small, it is prone to thermal decomposition during the PET processing; the polyol is any one or more of pentaerythritol, sorbitol, and trimethylolpropane.

[0019] The limiting oxygen index value of the flame-retardant polyester material is 34-41, the vertical burning rating is V0, and the tensile strength is above 47 MPa. Due to the flame-retardant synergistic effect of the fluorescent finishing material, the flame-retardant performance of the flame-retardant polyester material of the present invention is effectively improved. On the other hand, compared with the traditional materials with a large amount of flame retardants added, since the amount of flame retardant in the present invention is low and the amount of fluorescent molecules is only 1-3 parts, it not only has little impact on the mechanical properties of the substrate, but also has a low actual production cost.

[0020] The present invention also provides a method for preparing the flame-retardant polyester material with the fluorescent finish, comprising the steps of:

[0021] Step 1: Melt-blend the aromatic fluorescent molecule with PET to form a fluorescent finishing masterbatch with the mass ratio of the aromatic fluorescent molecule being 10-30%; melt-blend the fluorescent finishing masterbatch with PET, and obtain the fluorescent finishing film through die casting, longitudinal stretching, and transverse stretching;

[0022] Step 2: Premix ammonium polyphosphate, polyol, and PET and then melt-blend them, and extrude and pelletize to obtain the flame-retardant substrate;

[0023] Step 3: Attach the fluorescent finishing film prepared in Step 1 to the inner surfaces of the female mold and the male mold. After closing the mold, inject the flame-retardant substrate prepared in Step 2 into the mold, and obtain the flame-retardant polyester material through pressure holding, cooling, demolding, and ejection.

[0024] Since the aromatic fluorescent molecule belongs to an aggregation luminescent material and the usage amount is low, its dispersion uniformity has an obvious influence on its luminescent effect. Therefore, it is preferably made into a masterbatch with PET first and then further mixed with the matrix to improve the dispersion effect and can improve the flame-retardant effect to a certain extent.

[0025] The melt-blending temperature in Step 1 or 2 is 250-275 °C; the premixing in Step 2 is carried out at 45-70 °C for 10-20 min;

[0026] The pressure holding pressure in Step 3 is 40-200 MPa, and the pressure holding time is 15-60 seconds; the temperature of the male mold is 35-50 °C; the temperature of the female mold is 25-40 °C. The process conditions are related to the size, structure, etc. of the workpiece. Generally, the larger the workpiece, the longer the pressure holding time and the greater the pressure.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention uses an aromatic fluorescent molecule to prepare a fluorescent finishing film and covers it on the surface of the flame-retardant substrate. It can not only be used as a synergist for the intumescent flame retardant to make the carbon layer denser and more stable, but also endow the material surface with unique photoluminescent properties, effectively improving the flame-retardant performance of the material with a very small addition amount. Description of the Drawings

[0029] Figure 1 Schematic diagram of the preparation process of the flame-retardant polyester material for the fluorescent finish in Example 1. Specific implementation manners

[0030] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Those skilled in the art who make modifications or equivalent substitutions based on understanding the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall all be covered within the protection scope of the present invention.

[0031] The raw materials used in the following specific implementation manners are all purchased from the market.

[0032] Example 1

[0033] Step 1: Melting and blending hexaphenylsilsesquioxane and PET at 265 - 280 °C to form a fluorescent finish masterbatch with an aromatic fluorescent molecule mass ratio of 20%; melting and blending 1 kg of the masterbatch and 9 kg of PET at 265 - 280 °C, followed by die casting, longitudinal drawing (preheating section at 50 - 76 °C, stretching section at 82 - 28 °C, setting section at 30 - 35 °C), and transverse drawing (preheating section at 85 - 105 °C, stretching section at 112 - 125 °C, setting section at 208 - 226 °C, cooling section at 98 - 116 °C) to obtain the fluorescent finish film with a thickness of 100 μm.

[0034] Step 2: Premixing 20 kg of ammonium polyphosphate, 5 kg of pentaerythritol, and 75 kg of PET in a high-speed mixer for 20 min at a premixing temperature of 65 °C, and then melting and blending and extruding pellets in a twin-screw extruder within the range of 255 - 270 °C to obtain a flame-retardant substrate.

[0035] Step 3: As Figure 1 shown, attaching the fluorescent finish film prepared in Step (1) to the inner surfaces of the female mold and the male mold, closing the mold, and injecting the flame-retardant substrate prepared in Step (2) into the mold at 255 - 275 °C, followed by pressure holding, cooling, demolding, and ejection to obtain the flame-retardant polyester material, with a pressure holding pressure of 100 MPa and a pressure holding time of 30 seconds; the temperature of the male mold is 40 °C; the temperature of the female mold is 30 °C.

[0036] Example 2

[0037] Step 1: Tetraphenylethylene and PET are melt-blended at 265 - 275 °C to form a fluorescent finishing masterbatch with an aromatic fluorescent molecule mass ratio of 20%. 1 kg of the masterbatch and 9 kg of PET are melt-blended at 265 - 275 °C, followed by die casting, longitudinal drawing (preheating section at 50 - 76 °C, stretching section at 82 - 28 °C, sizing section at 30 - 35 °C), and transverse drawing (preheating section at 85 - 105 °C, stretching section at 112 - 125 °C, sizing section at 208 - 226 °C, cooling section at 98 - 116 °C) to obtain the fluorescent finishing film with a thickness of 100 μm.

[0038] Step 2: 20 kg of ammonium polyphosphate, 5 kg of pentaerythritol, and 75 kg of PET are premixed in a high-speed mixer for 20 min at a premixing temperature of 65 °C, and then melt-blended and extruded into pellets in a twin-screw extruder within the range of 255 - 270 °C to obtain a flame-retardant substrate.

[0039] Step 3: As Figure 1 shown, the fluorescent finishing film prepared in Step 1 is attached to the inner surfaces of the female mold and the male mold. After closing the mold, the flame-retardant substrate prepared in Step 2 is injection-molded into the mold at 255 - 275 °C, and the flame-retardant polyester material is obtained through pressure holding, cooling, demolding, and ejection. The pressure holding pressure is 100 MPa, and the pressure holding time is 30 s; the temperature of the male mold is 40 °C; the temperature of the female mold is 30 °C.

[0040] Example 3

[0041] Step 1: Triphenylamine and PET are melt-blended at 250 - 275 °C to form a fluorescent finishing masterbatch with an aromatic fluorescent molecule mass ratio of 20%. 1 kg of the masterbatch and 9 kg of PET are melt-blended at 250 - 275 °C, followed by die casting, longitudinal drawing (preheating section at 50 - 76 °C, stretching section at 82 - 28 °C, sizing section at 30 - 35 °C), and transverse drawing (preheating section at 85 - 105 °C, stretching section at 112 - 125 °C, sizing section at 208 - 226 °C, cooling section at 98 - 116 °C) to obtain the fluorescent finishing film with a thickness of 100 μm.

[0042] Step 2: 20 kg of ammonium polyphosphate, 5 kg of pentaerythritol, and 75 kg of PET are premixed in a high-speed mixer for 20 min at a premixing temperature of 65 °C, and then melt-blended and extruded into pellets in a twin-screw extruder within the range of 255 - 270 °C to obtain a flame-retardant substrate.

[0043] Step 3: As Figure 1As shown, attach the fluorescent decorative film prepared in Step 1 to the inner surfaces of the female mold and the male mold. After closing the mold, inject the flame-retardant base material prepared in Step 2 into the mold at 255 - 275°C. Through pressure holding, cooling, demolding, and ejection, the flame-retardant polyester material is obtained. The pressure holding pressure is 100 MPa, and the pressure holding time is 30 seconds; the temperature of the male mold is 40°C; the temperature of the female mold is 30°C.

[0044] Example 4

[0045] Step 1: Melt and blend hexaphenylsilole with PET at 250 - 275°C to form a fluorescent decorative masterbatch with an aromatic fluorescent molecular mass ratio of 20%. Melt and blend 1 kg of the masterbatch with 9 kg of PET at 250 - 275°C, then through die casting, longitudinal stretching (preheating section at 50 - 76°C, stretching section temperature at 82 - 28°C, sizing section temperature at 30 - 35°C), and transverse stretching (preheating section at 85 - 105°C, stretching section temperature at 112 - 125°C, sizing section at 208 - 226°C, cooling section at 98 - 116°C) to obtain the fluorescent decorative film with a thickness of 100 μm.

[0046] Step 2: Premix 24 kg of ammonium polyphosphate, 6 kg of pentaerythritol, and 70 kg of PET in a high-speed mixer for 20 min at a premixing temperature of 65°C, and then melt and blend and extrude into pellets in a twin-screw extruder within the range of 255 - 270°C to obtain the flame-retardant base material.

[0047] Step 3: As Figure 1 As shown, attach the fluorescent decorative film prepared in Step 1 to the inner surfaces of the female mold and the male mold. After closing the mold, inject the flame-retardant base material prepared in Step 2 into the mold at 255 - 275°C. Through pressure holding, cooling, demolding, and ejection, the flame-retardant polyester material is obtained. The pressure holding pressure is 100 MPa, and the pressure holding time is 30 seconds; the temperature of the male mold is 40°C; the temperature of the female mold is 30°C.

[0048] Example 5

[0049] Step 1: Melt and blend hexaphenylsilole with PET at 250 - 275°C to form a fluorescent decorative masterbatch with an aromatic fluorescent molecular mass ratio of 20%. Melt and blend 1 kg of the masterbatch with 9 kg of PET at 250 - 275°C, then through die casting, longitudinal stretching (preheating section at 50 - 76°C, stretching section temperature at 82 - 28°C, sizing section temperature at 30 - 35°C), and transverse stretching (preheating section at 85 - 105°C, stretching section temperature at 112 - 125°C, sizing section at 208 - 226°C, cooling section at 98 - 116°C) to obtain the fluorescent decorative film with a thickness of 100 μm.

[0050] Step 2: Premix 16 kg of ammonium polyphosphate, 4 kg of pentaerythritol, and 80 kg of PET in a high-speed mixer for 20 min at a premixing temperature of 65°C, and then melt-blend and extrude granulate them in a twin-screw extruder within the range of 255 - 270°C to obtain a flame-retardant base material.

[0051] Step 3: As Figure 1 shown, attach the fluorescent decorative film prepared in Step 1 to the inner surfaces of the female mold and the male mold. After closing the mold, inject the flame-retardant base material prepared in Step 2 into the mold at 255 - 275°C, and obtain the flame-retardant polyester material through pressure holding, cooling, demolding, and ejection. The pressure holding pressure is 100 MPa, and the pressure holding time is 30 seconds; the temperature of the male mold is 40°C; the temperature of the female mold is 30°C.

[0052] Example 6

[0053] Step 1: Melt-blend hexaphenylsilaole and PET at 250 - 275°C to form a fluorescent decorative masterbatch with an aromatic fluorescent molecule mass ratio of 20%. Melt-blend 1 kg of the masterbatch and 9 kg of PET at 250 - 275°C, and through die casting, longitudinal stretching (preheating section at 50 - 76°C, stretching section temperature at 82 - 28°C, sizing section temperature at 30 - 35°C), and transverse stretching (preheating section at 85 - 105°C, stretching section temperature at 112 - 125°C, sizing section at 208 - 226°C, cooling section at 98 - 116°C), obtain the fluorescent decorative film with a thickness of 100 μm;

[0054] Step 2: Premix 20 kg of ammonium polyphosphate, 5 kg of sorbitol, and 75 kg of PET in a high-speed mixer for 20 min at a premixing temperature of 65°C, and then melt-blend and extrude granulate them in a twin-screw extruder within the range of 255 - 270°C to obtain a flame-retardant base material.

[0055] Step 3: As Figure 1 shown, attach the fluorescent decorative film prepared in Step 1 to the inner surfaces of the female mold and the male mold. After closing the mold, inject the flame-retardant base material prepared in Step 2 into the mold at 255 - 275°C, and obtain the flame-retardant polyester material through pressure holding, cooling, demolding, and ejection. The pressure holding pressure is 100 MPa, and the pressure holding time is 30 seconds; the temperature of the male mold is 40°C; the temperature of the female mold is 30°C.

[0056] Comparative Example 1

[0057] Premix 20 kg of ammonium polyphosphate, 5 kg of pentaerythritol, and 75 kg of PET in a high-speed mixer for 20 min at a premixing temperature of 65°C, and then melt-blend and extrude granulate them in a twin-screw extruder within the range of 255 - 270°C to obtain a flame-retardant material.

[0058] Comparative Example 2

[0059] According to Example 1, step 1 is to melt and knead PET and hexaphenylsilaole in the range of 250 - 275 °C to prepare a masterbatch (the concentration of aromatic compounds is 20%), and then melt-blend 2 kg of the masterbatch with 8 kg of PET, die-cast into sheets, longitudinally draw, and transversely draw to obtain a fluorescent decorative film. The preparation process conditions are the same as those in Example 1, and the film thickness is 100 μm.

[0060] Steps 2 and 3 are the same as those in Example 1 to obtain a flame-retardant material.

[0061] Comparative Example 3

[0062] According to Example 1, step 1 is to melt and knead PET and hexaphenylsilaole in the range of 250 - 275 °C to prepare a masterbatch (the concentration of aromatic compounds is 20%), and then melt-blend 0.2 kg of the masterbatch with 9.8 kg of PET, die-cast into sheets, longitudinally draw, and transversely draw to obtain a fluorescent decorative film. The preparation process conditions are the same as those in Example 1, and the film thickness is 100 μm.

[0063] Steps 2 and 3 are the same as those in Example 1 to obtain a flame-retardant material.

[0064] Comparative Example 4

[0065] Prepare a fluorescent decorative film with a film thickness of 25 μm according to step 1 of Example 1.

[0066] Steps 2 and 3 are the same as those in Example 1 to obtain a flame-retardant material.

[0067] Comparative Example 5

[0068] Prepare a fluorescent decorative film with a film thickness of 250 μm according to step 1 of Example 1.

[0069] Steps 2 and 3 are the same as those in Example 1 to obtain a flame-retardant material.

[0070] Test the mechanical properties, oxygen index, vertical burning, and surface glossiness of the flame-retardant materials prepared in the examples and comparative examples. The test standards are "Determination of Tensile Properties of Plastics" GB / T 1040 - 2006, "Test Method for Flammability of Plastics - Horizontal and Vertical Methods" GB / T 2408, "Oxygen Index Method for Test of Flammability of Plastics" GB / T 2406, ASTM D3928 - 2000 "Standard Test Method for Evaluating Gloss or Gloss Uniformity". The results are shown in Table 1.

[0071] Table 1 Properties of Flame-Retardant Materials Prepared in Examples and Comparative Examples

[0072]

[0073] As can be seen from the data in the table, compared with Comparative Example 1 without a decorative layer, the materials of Examples 1-6 all have excellent flame retardant effects, with the highest oxygen index reaching 40.2. However, for Comparative Example 1 with ammonium polyphosphate and polyol as flame retardants, its oxygen index only reaches 31.8. It can be seen that the decorative layer with trace aromatic fluorescent molecules plays a very effective synergistic flame retardant effect. From Comparative Example 2 or 3, it can be seen that too high a content of fluorescent molecules will lead to uneven dispersion in the surface layer of the material, ultimately resulting in a decrease in gloss uniformity, while too little addition fails to achieve an effective synergistic effect and the flame retardant performance is poor.

[0074] From Comparative Example 4, it can be seen that when the thickness of the decorative film decreases, the content of aromatic compounds participating in the synergistic flame retardancy decreases, and the overall flame retardant performance of the material decreases; while from Comparative Example 5, it can be seen that when the thickness of the decorative film is too large, the heat transfer effect of the injection melt on the side of the decorative film close to the mold is insufficient, resulting in different thicknesses of the decorative layers of the products far from and close to the injection port, showing a large difference in surface gloss, and the overall flame retardant performance of the material also decreases slightly.

Claims

1. A flame-retardant polyester material with a fluorescent finish, characterized in that, It includes a flame-retardant substrate and a fluorescent decorative film coated on the flame-retardant substrate; the flame-retardant substrate and the fluorescent decorative film are combined by injection molding; the thickness of the fluorescent decorative film is 50 - 150 μm; By mass fraction, the raw materials of the flame-retardant substrate include: 70 - 80 parts of PET; 16 - 24 parts of ammonium polyphosphate; 4 - 6 parts of polyol; the raw materials of the fluorescent decorative film include: 97 - 99 parts of PET and 1 - 3 parts of aromatic fluorescent molecules; The aromatic fluorescent molecules include any one or more of hexaphenylsilaole, triphenylamine, and tetraphenylethylene.

2. The flame-retardant polyester material of the fluorescent finish according to claim 1, characterized in that, The combination of the flame-retardant substrate and the fluorescent decorative film specifically includes: attaching the fluorescent decorative film to the inner surface of the injection mold, injecting the flame-retardant substrate into the mold after closing the mold, and through pressure holding, cooling, demolding, and ejecting, obtaining the flame-retardant polyester material with a fluorescent finish.

3. The flame-retardant polyester material with a fluorescent finish according to claim 1, characterized in that, The degree of polymerization of the ammonium polyphosphate is above 1000; and / or, the polyol includes any one or more of pentaerythritol, sorbitol, and trimethylolpropane.

4. The flame-retardant polyester material with a fluorescent finish according to claim 1, characterized in that, The particle size of the ammonium polyphosphate is 200 - 500 mesh, and the particle size of the polyol is 300 - 1000 mesh.

5. The flame-retardant polyester material with a fluorescent finish according to claim 1, characterized in that, The limiting oxygen index value of the flame-retardant polyester material is 34 - 41, the vertical burning grade is V0, and the tensile strength is above 47 MPa.

6. The preparation method of the flame-retardant polyester material for the fluorescent finish according to any one of claims 1-5, characterized in that, It includes steps: Step 1, melt-blending the aromatic fluorescent molecules and PET to form a fluorescent decorative masterbatch with the mass ratio of the aromatic fluorescent molecules being 10 - 30%; melt-blending the fluorescent decorative masterbatch and PET, and through die casting, longitudinal stretching, and transverse stretching, obtaining the fluorescent decorative film; Step 2, premixing ammonium polyphosphate, polyol, and PET and then melt-blending them, and extruding and pelletizing to obtain the flame-retardant substrate; Step 3, attaching the fluorescent decorative film prepared in Step 1 to the inner surfaces of the female mold and the male mold, injecting the flame-retardant substrate prepared in Step 2 into the mold after closing the mold, and through pressure holding, cooling, demolding, and ejecting, obtaining the flame-retardant polyester material.

7. The preparation method of the flame-retardant polyester material with a fluorescent finish according to claim 6, characterized in that, The melt-blending temperature in Step 1 or 2 is 250 - 275 °C; the premixing in Step 2 is carried out at 45 - 70 °C for 10 - 20 min.

8. The preparation method of the flame-retardant polyester material with a fluorescent finish according to claim 6, characterized in that, The pressure holding pressure in Step 3 is 40 - 200 MPa, the pressure holding time is 15 - 60 seconds; the temperature of the male mold is 35 - 50 °C; the temperature of the female mold is 25 - 40 °C.

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