Flame-retardant scratch-resistant ultraviolet-proof colorful film and preparation method thereof

Abstract

The invention relates to the technical field of functional films, and discloses a flame-retardant scratch-resistant ultraviolet-resistant colorful film and a preparation method thereof.The colorful film comprises a colorful layer, a flame-retardant layer and an ultraviolet-resistant scratch-resistant protective layer, the colorful layer, the flame-retardant layer and the ultraviolet-resistant scratch-resistant protective layer are of a DC-... ABA...-CD structure, the D layer is the ultraviolet-resistant scratch-resistant protective layer, and the D layer is the ultraviolet-resistant scratch-resistant protective layer. The C layer is a flame-retardant layer, and the middle layer is a colorful layer; the colorful layer is made of materials with different refractive indexes, the materials are arranged alternately according to the arrangement mode of ABA and the like, the layer A is made of polyethylene glycol terephthalate, and the layer B is made of polymethyl methacrylate; according to the preparation method, raw materials of the layer A and the layer B are prepared, and then the colorful layer is prepared in an alternate arrangement mode; then extruding the anti-ultraviolet and anti-scratch protective layer, coating one side, connected with the colorful layer, of the extruded anti-ultraviolet and anti-scratch protective layer with a flame-retardant material to form a flame-retardant layer, and finally performing hot pressing on the anti-ultraviolet and anti-scratch protective layer and the colorful layer to form the required colorful film.

Description

Technical Field

[0001] The present invention relates to the technical field of functional films, and more specifically, to a flame-retardant, scratch-resistant and UV-resistant colorful film and a preparation method thereof. Background Art

[0002] At present, the so-called colorful films on the market are generally polyolefins or polyesters, such as PET, PBT, PP, LDPE and PMMA, etc., with different refractive index resins, which are stacked up to 200 layers at intervals. The thickness of each layer of film is equivalent to the wavelength of the light to be reflected. The light is partially reflected when entering, producing a light interference effect to achieve the purpose of dazzling. Since the 1960s, DOW and CLOEREN in the United States have first developed multi-layer optical films. At the same time, the material ratio used in each layer is also very important, as mentioned in US Patents 5089318 and CN1292746A. PET film has comprehensive performance, high transparency and tensile strength, and can be matched with PMMA with different refractive indices. However, the colorful colors obtained by processing the film using dyeing technology are monotonous and cannot maintain the colorful effect for a long time. The toxic and harmful substances in the dye further limit the scope of use. For the colorful film prepared by using multi-layer superposition and the principle of light interference, a colorful dazzling effect can be achieved, which has certain advantages in packaging, decoration and other fields. However, due to the overlapping of multiple layers, many materials are not compatible and will crack. In addition, a single colorful film is often deformed by external forces, has poor heat resistance, and cannot cope with a variety of environments. Therefore, by adding a protective layer and a flame retardant layer to protect the colorful layer, the use time and scope of the colorful film can be increased. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present invention provides a flame retardant, scratch resistant and UV resistant colorful film and a preparation method thereof, which have the advantage of more precise operation.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a flame-retardant, scratch-resistant and UV-resistant colorful film, comprising: a colorful layer, a flame-retardant layer and an anti-UV scratch-resistant protective layer, wherein the colorful layer, the flame-retardant layer and the anti-UV scratch-resistant protective layer are arranged in a DC-...ABA...-CD structure, wherein the D layer is the anti-UV scratch-resistant protective layer, the C layer is the flame-retardant layer, and the middle layer is the colorful layer; the colorful layer is made of materials with different refractive indices arranged alternately in an...ABA... manner, wherein the A layer is polyethylene terephthalate and the B layer is polymethyl methacrylate;

[0005] As a preferred technical solution of the present invention, the thickness of the colorful layer (1) is 0.09-0.2 mm, the number of layers is not less than 90, the A and B layers are of equal thickness, and a compatibilizer is added to both A and B layers, and a surface lubricant is added to the B layer, and the difference between the refractive index of the surface lubricant and the refractive index of polymethyl methacrylate does not exceed 3%;

[0006] As a preferred technical solution of the present invention, the thickness of the flame retardant layer (2) is 0.007-0.010 mm;

[0007] As a preferred technical solution of the present invention, the thickness of the anti-ultraviolet and anti-scratch protective layer is 0.008 mm to 0.012 mm, and an anti-ultraviolet agent and an antioxidant are added to the anti-ultraviolet and anti-scratch protective layer.

[0008] As a preferred technical solution of the present invention, the compatibilizer is maleic anhydride or a maleic anhydride copolymer containing a non-polar aromatic ring and a polar anhydride group, the amount of the compatibilizer in layer A accounts for 0.25-2.5% of the mass fraction of polyethylene terephthalate, and the amount of the compatibilizer in layer B accounts for 0.25-2.5% of the mass fraction of polymethyl methacrylate; the surface lubricant is one or two of epoxy soybean oil, pentaerythritol stearate, and erucamide, and the amount of the surface lubricant accounts for 0.3-1% of the mass fraction of polymethyl methacrylate.

[0009] As a preferred technical solution of the present invention, the antioxidants are BASF antioxidant 1330 and BASF antioxidant 1330; the anti-ultraviolet agent is one or more of benzotriazoles, benzophenones, and triazines, and the added anti-ultraviolet agent and antioxidant respectively account for 0.3 to 1% of the mass fraction of the anti-ultraviolet and anti-scratch protective layer.

[0010] As a preferred technical solution of the present invention, the flame retardant layer is made of a phosphorus-containing hyperbranched polymer, 3-isocyanatepropyltrimethoxysilane, a catalyst, and carbamate.

[0011] As a preferred technical solution of the present invention, the anti-UV and anti-scratch protective layer is made of amorphous copolyester, and the amorphous copolyester is one of polyethylene terephthalate-1,4-cyclohexanedimethanol or polyethylene terephthalate-1,4-cyclohexanedimethanol.

[0012] As a preferred technical solution of the present invention, the present invention also provides a method for preparing a flame retardant, scratch resistant and UV resistant colorful film, comprising the following steps:

[0013] Step 1: After polyethylene terephthalate, maleic anhydride or maleic anhydride copolymer are mixed and stirred, the mixture is added to extruder 1 for extruding layer A; after polymethyl methacrylate, maleic anhydride or maleic anhydride copolymer and surface lubricant are mixed and stirred, the mixture is added to extruder 2 for extruding layer B; after polyethylene terephthalate-1,4-cyclohexanedimethanol ester or polyethylene terephthalate-1,4-cyclohexanedimethanol ester is mixed and stirred with an antioxidant and an anti-ultraviolet agent, the mixture is added to extruder 3 for extruding an anti-ultraviolet and anti-scratch protective layer;

[0014] Step 2: Use a solvent to prepare a 5-10 wt% solution of the phosphorus-containing hyperbranched polymer, then add 3-isocyanatepropyltrimethoxysilane and a catalyst thereto, react for 14 hours, add water and carbamate and stir evenly to obtain a raw material for a flame retardant layer;

[0015] Step 3: Extruder 1 and Extruder 2 are passed into the distributor, the single layer thickness is set, and three layers are arranged in an ABA manner, and then the layers are further layered into a layer multiplier to reach the specified number of layers to obtain a colorful layer;

[0016] Step 4: After the anti-ultraviolet and anti-scratch protective layer is extruded through the extruder 3, the flame retardant layer raw material prepared in step 2 is sprayed on the side in contact with the colorful layer using a nozzle, and after high-temperature drying, it is coated on the upper and lower surfaces of the colorful layer and hot-pressed with the colorful layer;

[0017] Step 5: According to the sequence of DC—…ABA…—CD combination, extrude from a multi-layer die head, stretch and cool to obtain a flame-retardant, scratch-resistant and UV-resistant colorful film.

[0018] As a preferred technical solution of the present invention, a method for preparing a flame retardant, scratch-resistant and UV-resistant colorful film, in the step 2, the amount of 3-isocyanatepropyltrimethoxysilane is 5% to 10% of the amount of the phosphorus-containing hyperbranched polymer, and the amount of the catalyst is 5% to 20% of the amount of 3-isocyanatepropyltrimethoxysilane; the mass ratio between dibutyltin dilaurate and stannous octoate in the catalyst is 1:1.4 to 1.6.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: the colorful layer provided by the present invention is composed of alternating materials of different refractive layers. When light is irradiated onto the colorful film, the reflected light of different layers undergoes a phase shift. Due to the tiny refractive difference, a rainbow-like effect is produced on the surface of the colorful film. During the preparation process, a lubricant with a refractive index similar to that of the colorful layer material is added to reduce the winding condition during the preparation of the colorful layer, so that the colorful layer achieves a good colorful effect. In order to cope with the different use environments of the colorful film, the outermost layer of the colorful film uses a protective layer of wear-resistant amorphous polyester and is coated with a flame retardant. After a fire, the phosphorus in the flame retardant will generate residues and combine with carbonized products to form a composite inorganic layer, which can prevent the escape of volatiles during the fire and block the contact between combustibles and oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] In the picture: 1. Colorful layer; 2. Flame retardant layer; 3. Anti-UV and anti-scratch protective layer. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1

[0024] The specific steps of this embodiment are as follows:

[0025] Adding polyethylene terephthalate and maleic anhydride accounting for 0.5% by mass of polyethylene terephthalate into extruder 1;

[0026] Add polymethyl methacrylate, 0.5% by mass of epoxidized soybean oil and 2% by mass of maleic anhydride into extruder 2;

[0027] Adding polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 1330 and BASF antioxidant 168 accounting for 0.3% of the mass fraction of polyethylene terephthalate-1,4-cyclohexanedimethanol, and benzotriazole anti-ultraviolet agent into extruder three;

[0028] Acetone was used to prepare a 6 wt% solution of the phosphorus-containing hyperbranched polymer, and then 3-isocyanatepropyltrimethoxysilane accounting for 6% of the amount of the phosphorus-containing hyperbranched polymer and a catalyst accounting for 6% of the amount of 3-isocyanatepropyltrimethoxysilane (the mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) were added thereto. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0029] Extruder 1 and Extruder 2 are connected to the distributor, and the total layer thickness is set to 0.18mm, the number of layers is 90, and the colorful layer 1 is arranged into three layers in an ABA manner, and then enters the layer multiplier for further stratification to reach the specified number of layers. The flame retardant prepared in the above steps is sprayed on the side in contact with the colorful layer 1 using a nozzle, and after high-temperature drying, it is coated on the upper and lower surfaces of the colorful layer 1, and the thickness is set to 0.008mm, and hot pressed with the colorful layer 1. The anti-ultraviolet and scratch-resistant protective layer 3 is extruded, and the thickness is set to 0.010mm. It is extruded from the multi-layer die head in a sequence of DC-...ABA...-CD combination, and after stretching and cooling, a flame-retardant, scratch-resistant and ultraviolet colorful film is obtained.

[0030] Embodiment 2

[0031] The specific steps of this embodiment are as follows:

[0032] Adding polyethylene terephthalate and a maleic anhydride copolymer accounting for 1% by mass of the polyethylene terephthalate into an extruder 1;

[0033] Adding polymethyl methacrylate, 0.5% of pentaerythritol stearate and 2% of maleic anhydride to extruder 2;

[0034] Add polyethylene terephthalate-1,4-cyclohexanedimethanol, 1330 accounting for 0.3% of the mass fraction of polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 168, and benzophenone anti-ultraviolet agent into extruder three;

[0035] A 5 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone, and then 3-isocyanatepropyltrimethoxysilane accounting for 5% of the amount of the phosphorus-containing hyperbranched polymer and a catalyst accounting for 5% of the amount of 3-isocyanatepropyltrimethoxysilane (the mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) were added thereto. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0036] Extruders 1 and 2 are fed into a distributor, and the total layer thickness is set to 0.18 mm, the number of layers is 90, and the colorful layer 1 is arranged into three layers in an ABA manner, and then enters a layer multiplier for further stratification to reach the specified number of layers of 90. The flame retardant prepared in the above steps is sprayed on the side in contact with the colorful layer 1 using a nozzle, and after high-temperature drying, it is coated on the upper and lower sides of the colorful layer 1, and the thickness is set to 0.007 mm, and hot pressed with the colorful layer 1. The anti-ultraviolet and anti-scratch protective layer 3 is extruded, and the thickness is set to 0.012 mm. It is extruded from a multi-layer die head in a sequence of DC-...ABA...-CD, and stretched and cooled to obtain a flame-retardant, scratch-resistant, and anti-ultraviolet colorful film.

[0037] Embodiment 3

[0038] The specific steps of this embodiment are as follows:

[0039] Adding polyethylene terephthalate and maleic anhydride accounting for 0.5% by mass of polyethylene terephthalate into extruder 1;

[0040] Adding polymethyl methacrylate, 0.5% erucamide and 2% maleic anhydride to extruder 2;

[0041] Adding polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 1330 and BASF antioxidant 168 accounting for 0.3% of the mass fraction of polyethylene terephthalate-1,4-cyclohexanedimethanol, and triazine anti-ultraviolet agent into extruder three;

[0042] A 5 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone, and then 3-isocyanatepropyltrimethoxysilane accounting for 5% of the amount of the phosphorus-containing hyperbranched polymer and a catalyst accounting for 5% of the amount of 3-isocyanatepropyltrimethoxysilane (the mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) were added thereto. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0043] Extruder 1 and Extruder 2 are connected to the distributor, and the total layer thickness is set to 0.2mm, the number of layers is 90, and the colorful layer 1 is arranged into three layers in an ABA manner, and then enters the layer multiplier for further stratification to reach the specified number of layers of 90. The flame retardant prepared in the above steps is sprayed on the side in contact with the colorful layer 1 using a nozzle, and after high-temperature drying, it is coated on the upper and lower surfaces of the colorful layer 1, and the thickness is set to 0.005mm, and hot pressed with the colorful layer 1. The anti-ultraviolet and scratch-resistant protective layer 3 is extruded, and the thickness is set to 0.010mm. It is extruded from the multi-layer die head in a sequence of DC-...ABA...-CD combination, and after stretching and cooling, a flame-retardant, scratch-resistant and ultraviolet colorful film is obtained.

[0044] Comparative ratio,

[0045] This comparative example comprises the following steps:

[0046] Adding polyethylene terephthalate and maleic anhydride accounting for 0.5% by mass of polyethylene terephthalate into extruder 1;

[0047] Add polymethyl methacrylate, 0.5% by mass of epoxidized soybean oil and 2% by mass of maleic anhydride into extruder 2;

[0048] Adding polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 1330 and BASF antioxidant 168 accounting for 0.3% of the mass fraction of polyethylene terephthalate-1,4-cyclohexanedimethanol, and triazine anti-ultraviolet agent into extruder three;

[0049] A 5 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone, and then 3-isocyanatepropyltrimethoxysilane accounting for 5% of the amount of the phosphorus-containing hyperbranched polymer and a catalyst accounting for 5% of the amount of 3-isocyanatepropyltrimethoxysilane (the mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) were added thereto. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0050] Extruder 1 and Extruder 2 are fed into a distributor, and the total layer thickness is set to 0.15 mm, the number of layers is 90, and the colorful layer is arranged into three layers in an ABA manner, and then enters a layer multiplier for further stratification to reach the specified number of layers. The flame retardant prepared in the above steps is sprayed on the side in contact with the colorful layer using a nozzle, and after high-temperature drying, it is coated on the upper and lower sides of the colorful layer, and the thickness is set to 0.005 mm, and hot pressed with the colorful layer. The anti-ultraviolet and scratch-resistant protective layer 3 is extruded, and the thickness is set to 0.005 mm. It is extruded from a multi-layer die head in a sequence of DC—…ABA…—CD, and stretched and cooled to obtain a flame-retardant, scratch-resistant, and anti-ultraviolet colorful film.

[0051] In the above embodiments and comparative examples, the color spectrum CT-23 light transmittance meter was used to test the ultraviolet light transmittance of the colorful film. From the experimental data in Table 1, it can be seen that the ultraviolet light transmittance of the colorful film of Example 1, Example 2, and Example 3 is about 2.5%, which proves that the colorful film of the present invention has excellent ultraviolet shielding function. The amount of the anti-ultraviolet and anti-scratch protective layer in the comparative example is not enough to provide a good anti-ultraviolet function.

[0052] GB / T6739-2006 "Determination of paint film hardness by pencil method for paint and varnish" is used as a scratch resistance test, that is, the manual method uses a drawing pencil to test the hardness: 6H, 5H...HB, B,...5B, 6B, among which 6H is the hardest and 6B is the softest. The experimental data in Table 1 show that the pencil hardness of the colorful film of Example 1, Example 2, and Example 3 is improved, proving that the colorful film of the present invention has excellent scratch resistance.

[0053] Through the vertical combustion (UL-94) test of GB / T2408-2008, it can be seen from the experimental data in Table 1 that the flame retardant properties of the colorful films of Example 1, Example 2, and Example 3 are significantly better than those of Comparative Example 1. The flame retardant grades of Example 1, Example 2, and Example 3 reach V-1, while the flame retardant layer of the comparative example is insufficient, and the flame retardant grade is only the lowest HB grade of UL94.

[0054] Table 1 UV transmittance and pencil hardness of colorful films

[0055]

[0056] Through the above embodiments, the shrinkage and incompatibility problems in the preparation process of the colorful film can be improved, and the colorful effect can be better achieved by stacking multiple layers. The multiple properties of flame retardancy, scratch resistance and UV resistance make the colorful film have a wider application range.

[0057] The flame retardant layer 2 and the amorphous polyester protective layer can fit well with the colorful layer 1 without affecting the colorful effect of the colorful film, and improve the mechanical properties of the colorful film. A lubricant is added to ensure that the film does not curl during production. The colorful layer is prepared using the principle of light interference and can achieve a colorful colorful effect. The protective layer makes the colorful film more widely used and extends its service life.

[0058] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flame retardant, scratch resistant and UV resistant colorful film, characterized in that: The invention comprises: a colorful layer (1), a flame retardant layer (2) and an anti-ultraviolet and anti-scratch protective layer (3), wherein the colorful layer (1), the flame retardant layer (2) and the anti-ultraviolet and anti-scratch protective layer (3) follow a DC-...ABA...-CD structure, wherein the D layer is the anti-ultraviolet and anti-scratch protective layer (3), the C layer is the flame retardant layer (2), and the middle layer is the colorful layer (1); the colorful layer (1) is made of materials with different refractive indices arranged alternately in an ...ABA... manner, wherein the A layer is polyethylene terephthalate and the B layer is polymethyl methacrylate; The colorful layer (1) has a thickness of 0.09 to 0.2 mm, a number of layers of not less than 90, the A and B layers have the same thickness, and a compatibilizer is added to both the A and B layers, and a surface lubricant is added to the B layer, and the difference between the refractive index of the surface lubricant and the refractive index of polymethyl methacrylate does not exceed 3%; The thickness of the flame retardant layer (2) is 0.007 to 0.010 mm; The thickness of the anti-ultraviolet and anti-scratch protective layer (3) is 0.008 mm to 0.012 mm, and an anti-ultraviolet agent and an antioxidant are added to the anti-ultraviolet and anti-scratch protective layer (3).

2. The flame retardant, scratch resistant and UV resistant colorful film according to claim 1, characterized in that: The compatibilizer is maleic anhydride or a maleic anhydride copolymer containing a non-polar aromatic ring and a polar anhydride group, the amount of the compatibilizer in layer A accounts for 0.25-2.5% of the mass fraction of polyethylene terephthalate, and the amount of the compatibilizer in layer B accounts for 0.25-2.5% of the mass fraction of polymethyl methacrylate; the surface lubricant is one or two of epoxy soybean oil, pentaerythritol stearate, and erucamide, and the amount of the surface lubricant accounts for 0.3-1% of the mass fraction of polymethyl methacrylate.

3. The flame retardant, scratch resistant and UV resistant colorful film according to claim 1, characterized in that: The antioxidants are BASF antioxidant 1330 and BASF antioxidant 168; the anti-ultraviolet agent is one or more of benzotriazole, benzophenone and triazine, and the added anti-ultraviolet agent and antioxidant account for 0.3-1% of the mass fraction of the anti-ultraviolet and anti-scratch protective layer (3).

4. The flame retardant, scratch resistant and UV resistant colorful film according to claim 1, characterized in that: The flame retardant layer (2) is made of a phosphorus-containing hyperbranched polymer, 3-isocyanate propyltrimethoxysilane, a catalyst, and carbamate.

5. The flame retardant, scratch resistant and UV resistant colorful film according to claim 1, characterized in that: The anti-ultraviolet and anti-scratch protective layer (3) is made of amorphous copolyester, and the amorphous copolyester is one of polyethylene terephthalate-1,4-cyclohexanedimethanol or polyethylene terephthalate-1,4-cyclohexanedimethanol.

6. A method for preparing a flame retardant, scratch resistant and UV resistant colorful film according to any one of claims 1 to 5, characterized in that: The steps include: Step 1: After polyethylene terephthalate, maleic anhydride or maleic anhydride copolymer are mixed and stirred, the mixture is added to extruder 1 for extruding layer A; after polymethyl methacrylate, maleic anhydride or maleic anhydride copolymer and surface lubricant are mixed and stirred, the mixture is added to extruder 2 for extruding layer B; after polyethylene terephthalate-1,4-cyclohexanedimethanol ester or polyethylene terephthalate-1,4-cyclohexanedimethanol ester is mixed and stirred with an antioxidant and an anti-ultraviolet agent, the mixture is added to extruder 3 for extruding an anti-ultraviolet and anti-scratch protective layer (3); Step 2: using a solvent to prepare a 5-10 wt% solution of a phosphorus-containing hyperbranched polymer, then adding 3-isocyanatepropyltrimethoxysilane and a catalyst thereto, reacting for 14 hours, adding water and carbamate and stirring evenly to obtain a raw material for a flame retardant layer (2); Step 3: Extruder 1 and Extruder 2 are introduced into a distributor, the thickness of a single layer is set, and the layers are arranged into three layers in an ABA manner, and then the layers are further layered into a layer multiplier until a specified number of layers is reached to obtain a colorful layer (1); Step 4: After the anti-ultraviolet and anti-scratch protective layer (3) is extruded through the extruder 3, the raw material of the flame retardant layer (2) prepared in step 2 is sprayed on the side of the protective layer in contact with the colorful layer (1) using a nozzle, and after high-temperature drying, the raw material is coated on the upper and lower surfaces of the colorful layer (1), and hot-pressed with the colorful layer (1); Step 5: According to the sequence of DC—…ABA…—CD combination, extrude from a multi-layer die head, stretch and cool to obtain a flame-retardant, scratch-resistant and UV-resistant colorful film.

7. The method for preparing a flame retardant, scratch resistant and UV resistant colorful film according to claim 6, characterized in that: In the step 2, the amount of 3-isocyanatepropyltrimethoxysilane used is 5% to 10% of the amount of the phosphorus-containing hyperbranched polymer used, and the amount of the catalyst used is 5% to 20% of the amount of 3-isocyanatepropyltrimethoxysilane used; the mass ratio of dibutyltin dilaurate to stannous octoate in the catalyst is 1:1.4 to 1.6.

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