Flame-retardant, scratch-resistant, and UV-resistant colorful film and preparation method thereof

Abstract

The present invention relates to the technical field of functional films, and discloses a flame-retardant, scratch-resistant, and UV-resistant colorful film and a preparation method thereof, wherein the colorful film comprises: a colorful layer, a flame-retardant layer, and an anti-UV and scratch-resistant protective layer, wherein the colorful layer, the flame-retardant layer, and the anti-UV and scratch-resistant protective layer follow a DC-…ABA…-CD structure, wherein the D layer is the anti-UV and scratch-resistant protective layer, the C layer is the flame-retardant layer, and the middle layer is a colorful layer; the colorful layer uses materials with different refractive indices alternately arranged in an…ABA… manner, wherein the A layer is polyethylene terephthalate and the B layer is polymethyl methacrylate; the preparation method prepares the colorful layer by preparing the raw materials of the A layer and the B layer and then arranging them alternately; then, the anti-UV and scratch-resistant protective layer is extruded, and after extrusion, the flame-retardant material is coated on the side thereof connected to the colorful layer to form a flame-retardant layer, and finally, the flame-retardant layer and the colorful layer are hot-pressed to form the desired colorful film.

Description

Technical Field

[0001] The present invention relates to the technical field of functional films, and more particularly 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 an optical interference effect to achieve the purpose of dazzling color. Since the 1960s, American companies DOW and CLOEREN have first developed multi-layer optical films. At the same time, the material ratio used in each layer is also crucial, as mentioned in US Patents 5089318 and CN1292746A. PET film has more comprehensive performance, high transparency and tensile strength, and can be paired with PMMA with different refractive indices. However, when the film is processed using dyeing technology, the colorful colors obtained 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 colorful films prepared by using multi-layer superposition and the principle of optical interference, a colorful 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 may crack. Furthermore, single-layered colorful films are often deformed by external forces and have poor heat resistance, making them incapable of surviving a wide range of environments. Therefore, adding a protective layer and a flame-retardant layer to protect the colorful layer increases the lifespan and range of applications of colorful films. 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 objectives, the present invention provides the following technical solution: a flame-retardant, scratch-resistant, and UV-resistant colorful film, comprising: a colorful layer, a flame-retardant layer, and an anti-UV and scratch-resistant protective layer; the colorful layer, flame-retardant layer, and anti-UV and scratch-resistant protective layer follow a DC-...ABA...-CD structure, wherein layer D is the anti-UV and scratch-resistant protective layer, layer C is the flame-retardant layer, and the colorful layer is in the middle; the colorful layers are made of materials with different refractive indices alternating in an...ABA... arrangement, wherein layer A is polyethylene terephthalate and layer B 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 thickness of the A and B layers is equal, 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 each account for 0.3-1% 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-ultraviolet and anti-scratch protective layer is made of amorphous copolyester, and the amorphous copolyester is 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 is 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 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: Prepare a 5-10 wt% solution of the phosphorus-containing hyperbranched polymer using a solvent, then add 3-isocyanatepropyltrimethoxysilane and a catalyst thereto, react for 14 hours, then add water and carbamate and stir evenly to obtain a raw material for the flame retardant layer;

[0015] Step 3: Extruder 1 and Extruder 2 are fed into a distributor, the thickness of a single layer is set, and three layers are arranged in an ABA manner. The layers are then fed into a layer multiplier for further stratification until the specified number of layers is reached to obtain a colorful layer.

[0016] Step 4: After the anti-UV 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 of the protective layer that contacts the colorful layer using a nozzle. 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 the 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 the 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 on 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 close 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 clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0023] The specific steps of the embodiment are as follows:

[0024] Polyethylene terephthalate and maleic anhydride accounting for 0.5% by mass of the polyethylene terephthalate are added into the extruder 1;

[0025] Add polymethyl methacrylate, 0.5% by mass of epoxidized soybean oil and 2% by mass of maleic anhydride into extruder 2;

[0026] Adding polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 1330 and BASF antioxidant 168 accounting for 0.3% of polyethylene terephthalate-1,4-cyclohexanedimethanol, and benzotriazole anti-ultraviolet agent into extruder three;

[0027] A 6 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone. 3-isocyanatepropyltrimethoxysilane (6% of the phosphorus-containing hyperbranched polymer) and a catalyst (4:6 mass ratio of dibutyltin dilaurate:stannous octoate) were added to the solution. After 14 h of reaction, water and carbamate were added and stirred evenly.

[0028] Extruders 1 and 2 are fed into a dispenser, with a total layer thickness of 0.18mm and 90 layers set. Colorful layer 1 is arranged into three layers in an ABA pattern, then enters a layer multiplier for further stratification to achieve the specified number of layers. The flame retardant prepared in the above steps is sprayed onto the surface in contact with colorful layer 1 using a spray nozzle. After high-temperature drying, it is coated onto the upper and lower surfaces of colorful layer 1 to a thickness of 0.008mm and heat-pressed with colorful layer 1. UV and scratch resistant protective layer 3 is extruded with a thickness of 0.010mm in a DC-…ABA……CD pattern. It is extruded from a multilayer die, stretched, and cooled to produce a flame-retardant, scratch-resistant, and UV-resistant colorful film.

[0029] Example 2 The specific steps of this example are as follows:

[0030] Adding polyethylene terephthalate and a maleic anhydride copolymer accounting for 1% by mass of polyethylene terephthalate into extruder 1;

[0031] Add polymethyl methacrylate, 0.5% pentaerythritol stearate and 2% maleic anhydride to extruder 2;

[0032] Add polyethylene terephthalate-1,4-cyclohexanedimethanol, 1330 (accounting for 0.3% by mass of polyethylene terephthalate-1,4-cyclohexanedimethanol), BASF antioxidant 168, and benzophenone-based anti-UV agent into extruder three;

[0033] A 5 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone. 3-isocyanatepropyltrimethoxysilane (5% of the phosphorus-containing hyperbranched polymer) and a catalyst (mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) (5% of the 3-isocyanatepropyltrimethoxysilane) were added to the solution. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0034] Extruders 1 and 2 are fed into a dispenser, with a total layer thickness of 0.18mm and 90 layers set. Colorful layer 1 is arranged into three layers in an ABA pattern, then enters a layer multiplier for further stratification, reaching the specified 90 layers. The flame retardant prepared in the above steps is sprayed onto the surface in contact with colorful layer 1 using a spray nozzle. After high-temperature drying, it is coated onto the upper and lower surfaces of colorful layer 1, set to a thickness of 0.007mm, and then heat-pressed with colorful layer 1. The UV and scratch resistant protective layer 3 is extruded, set to a thickness of 0.012mm, in a DC-…ABA……CD pattern. It is extruded from a multilayer die, stretched, and cooled to produce a flame-retardant, scratch-resistant, and UV-resistant colorful film.

[0035] Example 3 The specific steps of this example are as follows:

[0036] Polyethylene terephthalate and maleic anhydride accounting for 0.5% by mass of the polyethylene terephthalate are added into the extruder 1;

[0037] Add polymethyl methacrylate, 0.5% erucamide by mass of polymethyl methacrylate, and 2% maleic anhydride into extruder 2;

[0038] Adding polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 1330 and BASF antioxidant 168 accounting for 0.3% of polyethylene terephthalate-1,4-cyclohexanedimethanol, and triazine anti-UV agent into extruder three;

[0039] A 5 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone. 3-isocyanatepropyltrimethoxysilane (5% of the phosphorus-containing hyperbranched polymer) and a catalyst (mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) (5% of the 3-isocyanatepropyltrimethoxysilane) were added to the solution. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0040] Extruders 1 and 2 are fed into a dispenser, with a total layer thickness of 0.2mm and 90 layers set. Colorful layer 1 is arranged into three layers in an ABA pattern, then enters a layer multiplier for further stratification, reaching the specified number of 90 layers. The flame retardant prepared in the above steps is sprayed onto the surface in contact with colorful layer 1 using a spray nozzle. After high-temperature drying, it is coated on the upper and lower surfaces of colorful layer 1 to a thickness of 0.005mm and heat-pressed with colorful layer 1. UV and scratch resistant protective layer 3 is extruded with a thickness of 0.010mm in a DC-…ABA……CD pattern. It is extruded from a multilayer die, stretched, and cooled to produce a flame-retardant, scratch-resistant, and UV-resistant colorful film.

[0041] Comparative Example. This comparative example comprises the following steps:

[0042] Polyethylene terephthalate and maleic anhydride accounting for 0.5% by mass of the polyethylene terephthalate are added into the extruder 1;

[0043] Add polymethyl methacrylate, 0.5% by mass of epoxidized soybean oil and 2% by mass of maleic anhydride into extruder 2;

[0044] Adding polyethylene terephthalate-1,4-cyclohexanedimethanol, BASF antioxidant 1330 and BASF antioxidant 168 accounting for 0.3% of polyethylene terephthalate-1,4-cyclohexanedimethanol, and triazine anti-UV agent into extruder three;

[0045] A 5 wt% solution of the phosphorus-containing hyperbranched polymer was prepared using acetone. 3-isocyanatepropyltrimethoxysilane (5% of the phosphorus-containing hyperbranched polymer) and a catalyst (mass ratio of dibutyltin dilaurate:stannous octoate = 4:6) (5% of the 3-isocyanatepropyltrimethoxysilane) were added to the solution. After reacting for 14 hours, water and carbamate were added and stirred evenly.

[0046] Extruders 1 and 2 are fed into a dispenser, with a total layer thickness of 0.15mm and 90 layers set. The color layer is arranged into three layers in an ABA pattern, then enters a layer multiplier for further stratification to achieve the specified number of layers. The flame retardant prepared in the above steps is sprayed onto the surface in contact with the color layer using a spray nozzle. After high-temperature drying, it is coated onto the upper and lower surfaces of the color layer to a thickness of 0.005mm and heat-pressed with the color layer. UV and scratch resistant protective layer 3 is extruded, with a thickness of 0.005mm, in a DC-…ABA……CD pattern. It is extruded from a multilayer die, stretched, and cooled to produce a flame-retardant, scratch-resistant, and UV-resistant color film.

[0047] In the above examples and comparative examples, the UV transmittance of the colorful films was tested using a Color Spectrum CT-23 light transmittance meter. As shown in Table 1, the UV transmittance of the colorful films of Examples 1, 2, and 3 is approximately 2.5%, demonstrating that the colorful films of the present invention have excellent UV shielding properties. However, the amount of UV and scratch-resistant protective layer used in the comparative example is insufficient to provide adequate UV protection.

[0048] GB / T6739-2006, "Paints and Varnishes, Pencil Method for Determination of Film Hardness," was used as a scratch resistance test. This involves manually testing the hardness using a drawing pencil: 6H, 5H, HB, B, 5B, and 6B, with 6H being the hardest and 6B being the softest. The experimental data in Table 1 demonstrates that the pencil hardness of the colorful films of Examples 1, 2, and 3 has been improved, demonstrating the excellent scratch resistance of the colorful films of the present invention.

[0049] The vertical combustion (UL-94) test according to GB / T2408-2008 was conducted. The experimental data in Table 1 show that the flame retardant properties of the colorful films of Examples 1, 2, and 3 are significantly better than those of Comparative Example 1. The flame retardant ratings of Examples 1, 2, and 3 reach V-1, while the flame retardant layer used in the comparative example is insufficient, resulting in a flame retardant rating of only HB, the lowest level of UL94.

[0050] Table 1 UV transmittance and pencil hardness of colorful films

[0051] Example 1 Example 2 Example 3 Comparative Example UV transmittance (%) 2.6 2.5 2.5 18 Pencil hardness value 5H 5H 4H 3H Flame retardant grade V-1 V-1 V-1 HB

[0052] The above embodiment can improve the shrinkage and incompatibility issues during the preparation of the colorful film, and by stacking multiple layers, a better colorful effect can be achieved. The multiple properties of flame retardancy, scratch resistance, and UV protection make the colorful film more widely applicable.

[0053] The flame-retardant layer 2 and the amorphous polyester protective layer adhere well to the colorful layer 1 without affecting the colorful effect of the colorful film and improving its mechanical properties. A lubricant is added to prevent curling during film production. The colorful layer is manufactured using the principle of optical interference, achieving a multi-colored, dazzling effect. The protective layer expands the use of the colorful film and extends its service life.

[0054] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0055] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the 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); 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 in an alternating arrangement of...ABA..., 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, 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 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 the A layer accounts for 0.25 to 2.5% of the mass fraction of polyethylene terephthalate, and the amount of the compatibilizer in the B layer accounts for 0.25 to 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 to 1% of the mass fraction of polymethyl methacrylate; 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 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 respectively account for 0.3-1% of the mass fraction of the anti-ultraviolet and anti-scratch protective layer (3).

3. 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.

4. 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 polyethylene terephthalate-1,4-cyclohexanedimethanol.

5. The method for preparing a flame-retardant, scratch-resistant, and UV-resistant colorful film according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: step 1, mixing polyethylene terephthalate, maleic anhydride or maleic anhydride copolymer, and adding the mixture to extruder 1 for extruding layer A; mixing polymethyl methacrylate, maleic anhydride or maleic anhydride copolymer and a surface lubricant, and adding the mixture to extruder 2 for extruding layer B; mixing polyethylene terephthalate-1,4-cyclohexanedimethanol, an antioxidant and an anti-ultraviolet agent, and adding the mixture 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 fed 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 to reach the specified number of layers, thereby obtaining a colorful layer (1); Step 4: After the anti-ultraviolet and anti-scratch protective layer (3) is extruded through the extruder 3, the flame retardant layer (2) raw material 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, it 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.

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

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