A super weather-resistant transparent composite film and preparation method thereof

Abstract

The invention discloses a super-weather-resistant transparent composite film and a preparation method thereof, wherein the super-weather-resistant transparent composite film comprises an outer film layer and an inner film layer, wherein the outer film layer is adhered to the inner film layer; wherein the inner film layer is prepared from a special resin B, wherein the special resin B is obtained by emulsion polymerization, and the steps include: a first-order copolymerization reaction; a second-order copolymerization reaction; a third-order copolymerization reaction, and then ethylene bis stearic acid amide and an anti-aging agent are added to obtain the film. The special resin B of the invention adopts methyl methacrylate monomer, 3-phenyl-2-acrylic acid-2-propylene ester monomer and 4-cinnamon phenyl methacrylate monomer to copolymerize, graft rigid long side chains, and effectively improve the processing temperature of the copolymer; by copolymerizing butyl methacrylate and a small amount of methacrylamide, the compatibility of the copolymer with hot melt adhesives such as polyurethane, silicone and EVA is improved, and the shortcomings of poor stability and durability of the bonding of the encapsulation film of the existing flexible thin-film solar cells are effectively solved, and the market prospect is broad.

Description

Technical Field

[0001] The invention relates to the field of protective films, and in particular to a super-weather-resistant transparent composite film and a preparation method thereof. Background Art

[0002] Flexible thin film solar cells refer to solar cells made on flexible substrates. Compared with traditional crystalline silicon cells, flexible thin film solar cells have the advantages of being not easy to break, lighter in weight, high in production efficiency, and low in cost. With the continuous development of the thin film photovoltaic industry, flexible thin film solar cells are increasingly used in combination with other substrates, effectively expanding their application range.

[0003] The packaging materials in flexible thin-film solar cells need to have the following functions: softness and impact resistance to encapsulate and protect solar cell elements; heat resistance; high transmittance to allow sunlight to effectively reach solar cell elements, durability, dimensional stability, flame retardancy, insulation, water vapor barrier, etc.

[0004] The most commonly used packaging films at present are PVDF-PET-PVDF three-layer film and ETFE film. Among them, it was found that the PVDF-PET-PVDF three-layer film peeled off at the surrounding packaging and electrode bonding after about 10 years of long-term use, that is, the bonding performance was poor. ETFE film has inherent poor bonding performance with fluorocarbon polymers such as PVDF. The packaging film has the problem of poor bonding and packaging effect, especially the bonding durability is difficult to guarantee, and there will be problems such as opening at the bonding point. Summary of the invention

[0005] The present invention solves the above-mentioned problems existing in the packaging film in the prior art by providing a super-weather-resistant transparent composite film and a preparation method thereof.

[0006] In order to solve the above technical problems, the present invention provides a super weather-resistant transparent composite film, comprising an outer film layer and an inner film layer, wherein the outer film layer is adhered to the inner film layer; wherein the inner film layer is prepared from a special resin B, and the preparation method of the special resin B comprises the following steps:

[0007] (1) First-order copolymerization reaction: under inert gas protection and stirring conditions, 180-250 parts of deionized water, 1.3-1.6 parts of potassium persulfate, 0.3-0.5 parts of sodium dodecyl sulfate, 0.1-0.5 parts of sodium dodecylbenzene sulfonate, and 0.2-0.5 parts of styrenated phenol are added by weight to a reaction container, and 15-25 parts of a mixture of methyl methacrylate and 3-phenyl-2-propenyl-2-acrylate are slowly added to carry out a first-order copolymerization reaction; the molar ratio of the methyl methacrylate to the 3-phenyl-2-propenyl-2-acrylate is 70-40:30-60;

[0008] (2) Second order copolymerization reaction: after the reaction in step (1) is completed, 1.2-1.4 parts of potassium persulfate, 0.2-0.5 parts of sodium dodecyl sulfate, 0.1-0.2 parts of sodium dodecylbenzene sulfonate are continuously added to the reaction kettle by weight, and 15-25 parts of a mixture of methyl methacrylate, 4-cinnamon phenyl methacrylate and butyl methacrylate are slowly added to carry out a second order copolymerization reaction; the molar ratio of methyl methacrylate, 4-cinnamon phenyl methacrylate and butyl methacrylate is 70-30:20-40:10-30;

[0009] (3) a third-order copolymerization reaction: after the reaction in step (2) is completed, 1-5 parts of methacrylamide and 0.1-1 parts of ethylene bisstearamide are continuously added to the reactor by weight, and 0.2-0.4 parts of potassium persulfate are additionally added to carry out a third-order copolymerization reaction;

[0010] (4) After the reaction in step (3) is completed, 0.5-1 part of an anti-aging agent is added, and the mixture is stirred and mixed for 2-3 hours and then naturally cooled. Then, demulsification, centrifugal separation, suction filtration, and drying are performed to obtain a powder of the special resin B.

[0011] In a preferred embodiment of the present invention, in the steps (1) and (2), the process conditions of the reaction are a reaction temperature of 60-75° C., a reaction time of 4.5-6 h, and the potassium persulfate is added in part first and then added in multiple times during the reaction; in the step (3), the process conditions of the reaction are 80-90° C., and the reaction time is 1-3 h.

[0012] In a preferred embodiment of the present invention, the outer film layer is prepared from a special resin A, which includes the following raw materials in parts by weight: 2-10 parts of sodium dimercaprol sulfonate, 1-8 parts of sodium bisulfite, 0.5-3 parts of potassium perfluorooctane sulfonate, 0.1-0.6 parts of 2-methyl-4,6-di(octylthiomethyl)phenol, 0.5-8 parts of dodecylphenol polyoxyethylene ether, 0.3-3 parts of hydroxypropyl methylcellulose, 1-4 parts of sodium dodecylbenzene sulfonate, 0.5-4 parts of polyperfluoroisopropyl ether, 0.1-1.1 parts of initiator, 0.1-3 parts of isooctyl acrylate, 0.1-4 parts of hexafluorobutyl methacrylate, 25-40 parts of primary polymerization monomers, 0.1-0.6 parts of ultraviolet light absorber and 150-200 parts of deionized water.

[0013] In a preferred embodiment of the present invention, the primary monomers include tetrafluoroethylene, ethylene and vinylidene fluoride, and the weight ratio of tetrafluoroethylene, ethylene and vinylidene fluoride is 48-40:44-40:8-20.

[0014] In a preferred embodiment of the present invention, the preparation method of the special resin A comprises the following steps:

[0015] (11) Material mixing: Add the formulated amount of sodium maleate bis (2-(fluorinated alkoxy) propanol sulfonate, sodium bisulfite, potassium perfluorooctane sulfonate, 2-methyl-4,6-di(octylthiomethyl)phenol, dodecylphenol polyoxyethylene ether, hydroxypropyl methylcellulose, sodium dodecylbenzene sulfonate and an appropriate amount of deionized water into a reaction kettle, and stir and mix under an inert gas environment until the mixture is uniform;

[0016] (22) Seed copolymerization reaction: adding the formulated amount of polyperfluoroisopropyl ether, part of the initiator and the monomer to the above reaction kettle under continuous stirring to carry out seed copolymerization reaction to obtain a copolymer seed emulsion;

[0017] (33) Grafting reaction: raising the temperature of the reaction kettle to above 60° C., adding the remaining initiator, isooctyl acrylate and hexafluorobutyl methacrylate according to the formula amount under stirring, and carrying out a grafting reaction;

[0018] (44) adding a formulated amount of ultraviolet absorber, raising the temperature to above 75° C. while stirring, maintaining the temperature until the residual monomers are fully reacted, cooling and releasing the pressure to obtain a white emulsion, adjusting the pH value to 7-8 with aqueous ammonia, breaking the emulsion, centrifuging, filtering, and drying to obtain the special resin A powder.

[0019] In a preferred embodiment of the present invention, in the step (22), the process conditions of the seed copolymerization reaction are: the pressure in the reactor is 0.5-1.3 MPa, the reaction temperature is 40-60° C., and the reaction time is 6-8 hours.

[0020] In order to solve the above technical problems, the present invention provides a method for preparing a super weather-resistant transparent composite film, comprising the following steps:

[0021] 1. Extrusion by extruder: adding the special resin A and the special resin B to the feed ports of the first extruder and the second extruder respectively, and melt-extrude the special resin A and the special resin B by the first extruder and the second extruder;

[0022] 2. Cast film formation: The special resin A melt and the special resin B melt are respectively fed into a co-extrusion die and extruded into films through a cast film head to obtain a double-layer film consisting of an outer film layer made of special resin A as a raw material and an inner film layer made of special resin B as a raw material, and the super weather-resistant transparent composite film is prepared by calendering and cooling.

[0023] In a preferred embodiment of the present invention, the extrusion temperature of the first extruder is 190-240°C; the extrusion temperature of the second extruder is 180-230°C.

[0024] In order to solve the above technical problems, the present invention provides a super weather-resistant transparent self-adhesive composite film, comprising a super weather-resistant transparent composite film prepared by the above method, a self-adhesive layer and a release paper, wherein the self-adhesive layer and the release paper are sequentially adhered to the surface of the inner film layer of the composite film away from the side of the outer film layer.

[0025] To solve the above technical problems, the present invention provides a super weather resistant transparent composite film resin glass, comprising a super weather resistant transparent composite film prepared by the above method and a polycarbonate layer, wherein the polycarbonate layer is located on the surface of the inner film layer of the composite film away from the outer film layer.

[0026] The beneficial effects of the present invention are as follows: the present invention provides a super weather-resistant transparent composite film and a preparation method thereof, wherein the inner film layer is prepared by using a special resin B as a raw material, wherein the special resin B is prepared by copolymerizing methyl methacrylate monomer with 3-phenyl-2-acrylate-2-propenyl ester monomer and 4-cinnamon phenyl methacrylate monomer, and grafting rigid long side chains, thereby effectively increasing the processing temperature of the copolymer while maintaining a high light transmittance of more than 90%; by copolymerizing butyl methacrylate and a small amount of methacrylamide, the compatibility of the copolymer with hot melt adhesives such as polyurethane, silicone and EVA is increased, and the film is easy to bond, thereby effectively solving the shortcomings of poor stability and durability of the bonding of the existing encapsulation film of flexible thin-film solar cells, and the market prospect is broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a super weather-resistant transparent composite film of the present invention;

[0028] Figure 2This is an application example of a super-weather-resistant transparent composite film of the present invention, that is, a structural schematic diagram of a super-weather-resistant transparent composite film resin glass;

[0029] Figure 3 yes Figure 2 A schematic cross-sectional structure diagram of a co-extrusion flow channel used in the preparation of a super-weather-resistant transparent composite film resin glass;

[0030] The markings of the components in the accompanying drawings are as follows:

[0031] 1. Outer film layer, 2. Inner film layer, 3. Polycarbonate layer, 4. Coextrusion die, 41. First flow channel, 42. Second flow channel, 43. Third flow channel. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0033] See also Figure 1-3 , the embodiment of the present invention includes:

[0034] Example 1

[0035] A special resin A is prepared by a step-by-step seed emulsion copolymerization process, and the specific steps are as follows:

[0036] (1) Material mixing: 200 parts by weight of deionized water, 8 parts of sodium maleate bis(2-(fluorinated alkoxy)propanol sulfonate), 3 parts of sodium bisulfite, 1 part of potassium perfluorooctane sulfonate, 0.3 parts of 2-methyl-4,6-di(octylthiomethyl)phenol, 3 parts of dodecylphenol polyoxyethylene ether, 1 part of hydroxypropyl methylcellulose, and 2 parts of sodium dodecylbenzene sulfonate were added to a reaction kettle, and the mixture was continuously stirred at a rate of 1000 r / min in an inert gas environment such as nitrogen to uniformly mix the materials;

[0037] (2) Seed copolymerization reaction: under continuous stirring, 1.5 parts of polyperfluoroisopropyl ether and 0.4 parts of initiator ammonium sulfate were added to the above reactor, the reactor was heated to 45°C, and then 30 parts of monomers were added, wherein the monomers included tetrafluoroethylene, ethylene and vinylidene fluoride in a weight ratio of 48-40:44-40:8-20, the pressure in the reactor was controlled to 1.0 MPa, and the reaction was carried out at a constant temperature and pressure for 5 hours, and then the reactor was heated to 55°C and the reaction was continued for 2 hours to obtain a copolymer seed emulsion;

[0038] (3) Grafting reaction: After the reaction in step (2) is completed, the reactor is heated to 60° C. under continuous stirring and pressure maintenance, and 0.1 part of initiator ammonium persulfate, 1 part of isooctyl acrylate and 1 part of hexafluorobutyl methacrylate are added thereto for reaction for 3 hours;

[0039] (4) After the reaction in step (3) is completed, 0.3 parts of ultraviolet absorber is added to the reaction kettle, and the temperature is raised to 75° C. while stirring, and the temperature is kept for 2 hours until the residual monomers are fully reacted, and then the temperature is cooled and the pressure is released to obtain a white emulsion, and the pH value is adjusted to 7-8 with ammonia water. After demulsification, centrifugal separation, suction filtration, and drying, the special resin A powder is obtained.

[0040] The ultraviolet absorber is at least one of benzophenone, benzotriazole, substituted acrylonitrile and triazine.

[0041] The special resin A is initiated by the initiator ammonium persulfate, and the introduction of vinylidene fluoride monomer disrupts the regularity of the conventional block copolymer long chain of tetrafluoroethylene monomer and ethylene monomer, effectively reducing the crystallinity and glass transition temperature of the polymer, which is beneficial to improving the transparency of the film material and reducing the extrusion processing temperature of the special resin A, so that its processing temperature is close to that of the special resin B. In addition, a small amount of grafting of isooctyl acrylate and hexafluorobutyl methacrylate can further reduce the regularity of the long chain of ethylene and tetrafluoroethylene copolymer, and the grafting of isooctyl acrylate introduces a flexible side chain to play the role of internal plasticization, further reducing the processing temperature; the introduction of acrylate groups improves the similar compatibility with the special resin B, which is beneficial to improving the bonding performance of the composite calendering of the extrusion processing film of the special resin A and the special resin B, thereby ensuring the bonding strength of the composite film.

[0042] Special resin A1, special resin A2 and special resin A3 were prepared by changing the ratio of the main monomers in the special resin A raw material. The specific ratios are shown in Table 1 below.

[0043] Table 1

[0044]

[0045] Example 2

[0046] A method for preparing a special resin B is prepared by emulsion polymerization, and the specific steps are as follows:

[0047] (11) First-order copolymerization reaction: Under nitrogen protection and stirring at a speed of 600 r / min, 200 parts of deionized water, 0.5 parts of potassium persulfate, 0.4 parts of sodium dodecyl sulfate, 0.3 parts of sodium dodecylbenzene sulfonate, and 0.3 parts of styrenated phenol were added to a reaction vessel, and then 20 parts of a mixture of methyl methacrylate and 3-phenyl-2-acrylate-2-propenyl ester in a weight ratio of 70-40:30-60 were gradually added, and the reaction was carried out at a constant temperature of 70° C. for 5 hours, and 0.2 parts of potassium persulfate were added every 1 hour during the reaction;

[0048] (22) Second order copolymerization reaction: After the reaction in step (1) is completed, 0.3 parts of potassium persulfate, 0.3 parts of sodium dodecyl sulfate, 0.1 parts of sodium dodecylbenzene sulfonate and 20 parts of a mixture of methyl methacrylate, 4-cinnamic phenyl methacrylate and butyl methacrylate in a weight ratio of 70-30:20-40:10-30 are added to the reactor, and the mixture is reacted at 70° C. for 5 hours, and 0.2 parts of potassium persulfate are added every 1 hour during the reaction;

[0049] (33) Tertiary copolymerization reaction: After the reaction in step (2) is completed, the reactor is heated to 85° C., and 3 parts of methacrylamide and 0.3 parts of potassium persulfate are added thereto, and the reaction is stirred at a constant temperature for 2 h;

[0050] (44) After the reaction in step (3) is completed, 0.5 parts of ethylene bis stearic acid amide and 0.8 parts of an antioxidant are added to the above-mentioned reaction kettle, stirred and mixed for 2.5 hours, cooled naturally, and then demulsified, centrifuged, filtered, and dried to obtain a powder of the special resin B. The antioxidant is at least one of phenolic antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 300, and distearyl thiodipropionate.

[0051] The special resin B is synthesized by emulsion copolymerization using methyl methacrylate, 4-cinnamon phenyl methacrylate and 3-phenyl-2-acrylate-2-propenyl ester as main monomers, and butyl methacrylate is appropriately used for block copolymerization to improve the elasticity of the copolymer, and a small amount of methacrylamide monomer is used to participate in the tailing polymerization of the macromolecular chain, and the glass transition temperature is high. Among them, the copolymerization chain segments of 3-phenyl-2-acrylate-2-propenyl ester and 4-cinnamon phenyl methacrylate effectively improve the heat resistance and processing temperature of the special resin B, and its glass transition temperature can be increased by 15-50°C compared with commercially available PMMA, and the participation of methacrylamide in polymerization further improves the rigidity and heat resistance of the resin, so that the processing temperatures of the special resin B and the special resin A are similar, and are similar to the processing temperature of PC resin, at 180°C-245°C, which is conducive to the co-extrusion molding of the three materials of A resin, B resin and PC.

[0052] Special resin B1, special resin B2 and special resin B3 were prepared by changing the ratio of the main monomers in the special resin B raw material. The specific ratios are shown in Table 2 below.

[0053] Table 2

[0054]

[0055] Example 3

[0056] A super weather-resistant transparent composite film, comprising an outer film layer 1 and an inner film layer 2, wherein the outer film layer 1 is adhered to the inner film layer 2, and the thickness of the composite film is 0.2 mm, wherein the thickness of the outer film layer is 0.1 mm, and the thickness of the inner film layer is 0.1 mm. The outer film layer is made of the above-mentioned special resin A, has excellent weather resistance, has strong weather resistance stability to sunlight and acid rain, and has high ultraviolet blocking performance, and has better light aging protection for the inner film layer 2. The inner film layer is made of the above-mentioned special resin B, has excellent heat resistance, rigidity and bonding stability, so as to provide better protection effect.

[0057] The method for preparing the super weather-resistant transparent composite film comprises the following steps:

[0058] 1. Extrusion by extruder: Add the special resin A and the special resin B into the feed ports of the first extruder and the second extruder respectively, and melt and extrude them through the first extruder and the second extruder; the extrusion temperature of the first extruder is 300° C.; the extrusion temperature of the second extruder is 200° C.

[0059] 2. Cast film forming: The special resin A melt and the special resin B melt extruded by the first extruder and the second extruder are introduced into the co-extrusion die and the cast film head respectively, to prepare a double-layer film composite of the special resin A film and the special resin B film, and then calendered and cooled to form the super weather-resistant transparent composite film.

[0060] The above-prepared special resins A1, A2, A3 and special resins B1, B2, B3 were selected and combined to prepare super weather-resistant transparent composite films, and relevant performance tests were carried out.

[0061] Performance Test:

[0062] Light transmittance test: The light transmittance of the prepared composite film was tested using a WGT-S light transmittance / haze meter (Shanghai Precision Scientific Instrument Co., Ltd.).

[0063] Adhesive performance test: Henkel MS9220 silane hot melt adhesive and copper sheet were used for sample preparation and testing, referring to the standard GB-T 2790-1995, the adhesive coating thickness was 0.1 mm, and the tensile rate was set to 100 mm / min.

[0064] Test of tensile strength and elongation at break: Cut the membrane into standard dumbbell-shaped tensile test specimens, GB / T2568-1995 test material tensile properties test tensile properties, test equipment RGT230 microcomputer-controlled electronic universal material testing machine (Chengde Testing Machine Co., Ltd.).

[0065] Notched impact strength test: The film material is made into a standard impact specimen of 63.5mm×12.7mm×4mm, and a V-shaped notch is cut on the specimen with a notching machine. The notched cantilever beam impact strength value of the specimen is measured in an AJU-22 impact tester according to ASTMD-256 standard.

[0066] The combination and test results are shown in Table 3. Comparative Example 1 is a PVDF-PET-PVDF three-layer film of equal thickness (the thickness of each layer is 0.02mm-0.16mm-0.02mm), provided by Zhuzhou Hongda Polymer Materials Co., Ltd.; Comparative Example 2 is an ETFE film of equal thickness (0.2mm), provided by Shenzhen Tiansheng Membrane Structure Co., Ltd.

[0067] Table 3

[0068]

[0069] It can be seen from the above test results that the super weather-resistant transparent composite film prepared by the present invention has a light transmittance of more than 90%, good impact resistance and tensile properties, excellent wear resistance, and excellent electrical insulation performance; the bonding strength between the Henkel MS9220 silane hot melt adhesive and the copper sheet reaches 90N / 2.5cm, and the bonding performance is good, which can effectively solve the problem of opening at the bonding point, and after 8000 hours of xenon lamp aging, the bonding strength with the copper sheet is still above 72N / 2.5cm, indicating that it has good bonding stability and durability, and good weather resistance.

[0070] The above-mentioned super weather-resistant transparent composite film can be used in many fields such as surface encapsulation of solar flexible batteries, surface film of automobile glass, outdoor building decoration protective film, and weather-resistant protection of resin glass surface.

[0071] In addition, it can also be used for expansion.

[0072] Expanded Application 1

[0073] A super weather-resistant transparent self-adhesive composite film comprises the super weather-resistant transparent composite film prepared by the above method, a self-adhesive layer and a release paper, specifically, from top to bottom, it comprises an outer film layer, an inner film layer, a self-adhesive layer and a release film, wherein the self-adhesive layer 3 can be a polyurethane adhesive or a silicone adhesive.

[0074] The preparation method of the self-adhesive composite film is as follows: a layer of polyurethane adhesive or silicone adhesive is coated on one side of the inner film layer (i.e., the special resin B film) of the super weather-resistant transparent composite film prepared in the above embodiment relative to the outer film layer, and then a layer of isolation film is attached thereon, so that a double-layer composite film with self-adhesive function can be prepared.

[0075] Expanded Application 2

[0076] A super-weather-resistant transparent composite film resin glass comprises the super-weather-resistant transparent composite film prepared by the above method and a polycarbonate layer, specifically, comprising an outer film layer 1, an inner film layer 2 and a polycarbonate layer 3 in order from top to bottom.

[0077] The preparation method of the super-weather-resistant transparent composite film resin glass is as follows: the special resin A prepared in Example 1, the special resin B prepared in Example 2 and commercially available polycarbonate particles are added to the first extruder, the second extruder and the third extruder respectively for melt extrusion to obtain the special resin A melt, the special resin B melt and the polycarbonate melt, and then the special resin A melt, the special resin B melt and the polycarbonate melt are simultaneously introduced into the first flow channel 41, the second flow channel 42 and the third flow channel 43 in the co-extrusion die 4, wherein, along the direction of melt flow (the direction of flow is defined as the rear), the first flow channel 41, the second flow channel 42 and the third flow channel 43 are arranged in sequence from bottom to top in the co-extrusion die 4, and the outlet of the second flow channel 42 is located behind the outlet of the first flow channel 41, and the outlet of the third flow channel 43 is located behind the outlet of the second flow channel 42. The co-extrusion die 4 is a horizontal flat die, and after extrusion, the super-weather-resistant transparent composite film resin glass is obtained.

[0078] The first extruder has a temperature of 220°C, the second extruder barrel has a temperature of 200°C, the third extruder barrel through which the polycarbonate enters has a temperature of 225°C, and the co-extrusion die has a temperature of 250°C.

[0079] The present invention provides a super weather-resistant transparent composite film, which is prepared by using a special resin A and a special resin B prepared by copolymerization of multiple monomers as raw materials, respectively added into two extruders, and then co-extruded through a co-extrusion die head and then multi-roll calendered and composited. The specific effects of the present invention are as follows:

[0080] 1) Special resin A is copolymerized by introducing the third vinylidene fluoride monomer, the fourth monomer isooctyl acrylate and the fifth monomer hexafluorobutyl methacrylate, which effectively reduces the processing temperature of conventional ethylene-tetrafluoroethylene copolymer to nearly 200°C, maintains its high light transmittance, super weather resistance and super scratch resistance and super performance, and can maintain a light transmittance of more than 88% under long-term outdoor lighting;

[0081] 2) The special resin A is copolymerized with the fourth monomer isooctyl acrylate and the fifth monomer hexafluorobutyl methacrylate to introduce an acrylate group, which effectively improves the similar compatibility with the special resin B, and is conducive to improving the bonding performance of the special resin A and the special resin B in the composite calendering of the extruded processing film;

[0082] 3) The special resin B is copolymerized with methyl methacrylate monomer, 3-phenyl-2-acrylate-2-propenyl ester as the second monomer, and 4-cinnamon phenyl methacrylate as the third monomer. The processing temperature of the copolymer is effectively increased by grafting rigid long side chains to nearly 200°C so as to be formed with the special resin A or PC resin through a co-extrusion mold, while maintaining a high light transmittance of the PMMA resin of more than 90%; the fourth monomer butyl methacrylate and a small amount of methacrylamide as the fifth monomer are copolymerized to improve the compatibility of the copolymer with hot melt adhesives such as polyurethane, silicone resin and EVA, making it easy to bond, effectively making up for the disadvantage of ETFE film and PVDF film that are not easy to bond.

[0083] 4) Special resin A is mainly composed of copolymers of ethylene and tetrafluoroethylene, so it has super weather resistance and super weather stability to sunlight and acid rain; adding a medium ultraviolet absorber during the polymerization process of special resin A makes the dispersion more uniform and effectively blocks more than 90% of the ultraviolet light in sunlight, so that the lower layer of special resin B film composited with it and the surface of the coated object under the special resin B film are better protected against light aging (special resin B is a special resin with a higher processing temperature than PMMA resin), which significantly improves the light aging resistance effect compared with the conventional PMMA resin mixed with ultraviolet absorbers.

[0084] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A super weather-resistant transparent composite film, characterized in that: The invention comprises an outer film layer and an inner film layer, wherein the outer film layer is adhered to the inner film layer; wherein the inner film layer is prepared from a special resin B, and the preparation method of the special resin B comprises the following steps: (1) First-order copolymerization reaction: under inert gas protection and stirring conditions, 180-250 parts of deionized water, 1.3-1.6 parts of potassium persulfate, 0.3-0.5 parts of sodium dodecyl sulfate, 0.1-0.5 parts of sodium dodecylbenzene sulfonate, and 0.2-0.5 parts of styrenated phenol are added by weight to a reaction container, and 15-25 parts of a mixture of methyl methacrylate and 3-phenyl-2-propenyl-2-acrylate are slowly added to carry out a first-order copolymerization reaction; the molar ratio of the methyl methacrylate to the 3-phenyl-2-propenyl-2-acrylate is 70-40:30-60; (2) Second order copolymerization reaction: after the reaction in step (1) is completed, 1.2-1.4 parts of potassium persulfate, 0.2-0.5 parts of sodium dodecyl sulfate, 0.1-0.2 parts of sodium dodecylbenzene sulfonate are continuously added to the reaction kettle by weight, and 15-25 parts of a mixture of methyl methacrylate, 4-cinnamon phenyl methacrylate and butyl methacrylate are slowly added to carry out a second order copolymerization reaction; the molar ratio of methyl methacrylate, 4-cinnamon phenyl methacrylate and butyl methacrylate is 70-30:20-40:10-30; (3) a third-order copolymerization reaction: after the reaction in step (2) is completed, 1-5 parts of methacrylamide and 0.1-1 parts of ethylene bisstearamide are continuously added to the reactor by weight, and 0.2-0.4 parts of potassium persulfate are additionally added to carry out a third-order copolymerization reaction; (4) After the reaction in step (3) is completed, 0.5-1 part of an anti-aging agent is added, and the mixture is stirred and mixed for 2-3 hours and then naturally cooled. Then, demulsification, centrifugal separation, suction filtration, and drying are performed to obtain a powder of the special resin B.

2. The super weather-resistant transparent composite film according to claim 1, characterized in that: In the steps (1) and (2), the process conditions of the reaction are a reaction temperature of 60-75° C., a reaction time of 4.5-6 h, and the potassium persulfate is added in part first and then added in multiple times during the reaction process; in the step (3), the process conditions of the reaction are 80-90° C., and the reaction time is 1-3 h.

3. The super weather-resistant transparent composite film according to claim 1, characterized in that: The outer film layer is prepared from a special resin A, which includes the following raw materials in parts by weight: 2-10 parts of sodium maleic acid bis (2-(fluorinated alkoxy) propanol ester sulfonate, 1-8 parts of sodium bisulfite, 0.5-3 parts of potassium perfluorooctane sulfonate, 0.1-0.6 parts of 2-methyl-4,6-bis (octylthiomethyl) phenol, 0.5-8 parts of dodecylphenol polyoxyethylene ether, 0.3-3 parts of hydroxypropyl methylcellulose, 1-4 parts of sodium dodecylbenzene sulfonate, 0.5-4 parts of polyperfluoroisopropyl ether, 0.1-1.1 parts of initiator, 0.1-3 parts of isooctyl acrylate, 0.1-4 parts of hexafluorobutyl methacrylate, 25-40 parts of primary polymerization monomers, 0.1-0.6 parts of ultraviolet light absorber and 150-200 parts of deionized water.

4. The super weather-resistant transparent composite film according to claim 3, characterized in that: The primary monomers include tetrafluoroethylene, ethylene and vinylidene fluoride, and the weight ratio of tetrafluoroethylene, ethylene and vinylidene fluoride is 48-40:44-40:8-20.

5. The super weather-resistant transparent composite film according to claim 4, characterized in that: The preparation method of the special resin A comprises the following steps: (11) Material mixing: Add the formulated amount of sodium maleate bis (2-(fluorinated alkoxy) propanol sulfonate, sodium bisulfite, potassium perfluorooctane sulfonate, 2-methyl-4,6-di(octylthiomethyl)phenol, dodecylphenol polyoxyethylene ether, hydroxypropyl methylcellulose, sodium dodecylbenzene sulfonate and an appropriate amount of deionized water into a reaction kettle, and stir and mix under an inert gas environment until the mixture is uniform; (22) Seed copolymerization reaction: adding the formulated amount of polyperfluoroisopropyl ether, part of the initiator and the monomer to the above reaction kettle under continuous stirring to carry out seed copolymerization reaction to obtain a copolymer seed emulsion; (33) Grafting reaction: raising the temperature of the reaction kettle to above 60° C., adding the remaining initiator, isooctyl acrylate and hexafluorobutyl methacrylate according to the formula amount under stirring, and carrying out a grafting reaction; (44) adding a formulated amount of ultraviolet absorber, raising the temperature to above 75° C. while stirring, maintaining the temperature until the residual monomers are fully reacted, cooling and releasing the pressure to obtain a white emulsion, adjusting the pH value to 7-8 with aqueous ammonia, breaking the emulsion, centrifuging, filtering, and drying to obtain the special resin A powder.

6. The super weather-resistant transparent composite film according to claim 5, characterized in that: In the step (22), the process conditions of the seed copolymerization reaction are: the pressure in the reactor is 0.5-1.3 MPa, the reaction temperature is 40-60° C., and the reaction time is 6-8 hours.

7. A method for preparing the super weather-resistant transparent composite film according to claim 6, characterized in that: The steps include:

1. Extrusion by extruder: adding the special resin A and the special resin B to the feed ports of the first extruder and the second extruder respectively, and melt-extrude the special resin A and the special resin B by the first extruder and the second extruder; 2. Cast film formation: The special resin A melt and the special resin B melt are respectively fed into a co-extrusion die and extruded into films through a cast film head to obtain a double-layer film consisting of an outer film layer made of special resin A as a raw material and an inner film layer made of special resin B as a raw material, and the super weather-resistant transparent composite film is prepared by calendering and cooling.

8. The method for preparing a super weather-resistant transparent composite film according to claim 7, characterized in that: The extrusion temperature of the first extruder is 190-240°C; the extrusion temperature of the second extruder is 180-230°C.

9. A super weather-resistant transparent self-adhesive composite film, characterized in that: It comprises a super weather-resistant transparent composite film prepared by the method described in claim 8, a self-adhesive layer and a release paper, wherein the self-adhesive layer and the release paper are sequentially adhered to the surface of the inner film layer away from the side of the outer film layer.

10. A super weather-resistant transparent composite film resin glass, characterized in that: The invention comprises a super weather-resistant transparent composite film prepared by the method of claim 8 and a polycarbonate layer, wherein the polycarbonate layer is located on the surface of the inner film layer away from the outer film layer.

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