Droplet-proof ETFE film for greenhouses and method for producing the same

Abstract

The application belongs to the technical field of ETFE film preparation, and particularly relates to a greenhouse anti-dew ETFE film and a preparation method thereof. The ETFE film comprises an outer layer, an intermediate layer and an inner layer. The outer layer is composed of ETFE resin, tetrafluoroethylene, a terpolymer of hexafluoropropylene and vinylidene fluoride, perfluoroalkyl ethyl methacrylate, an antioxidant, a hindered amine light stabilizer and an ultraviolet absorber. The intermediate layer is composed of ETFE resin, tetrafluoroethylene, a terpolymer of hexafluoropropylene and vinylidene fluoride and an anti-dew master batch. The inner layer is composed of ETFE resin, an anti-dew master batch, an ultraviolet absorber and a hindered amine light stabilizer. The three layers synergistically ensure that the prepared ETFE film has excellent mechanical strength, weather resistance, anti-dew performance and high light transmittance, and can meet the long-term outdoor use requirements of the greenhouse film, and can also take into account the light conditions required for crop growth and the stability of the greenhouse environment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ETFE film preparation, and particularly relates to a drip-proof ETFE film for greenhouses and a preparation method thereof. BACKGROUND

[0002] ETFE (ethylene-tetrafluoroethylene copolymer) film as a kind of high-performance fluoropolymer material, due to its excellent comprehensive performance, is applied in high-end construction and agricultural fields. At present, the commercial ETFE film usually shows the following characteristics: ① excellent optical performance; ② outstanding weather resistance; ③ good mechanical strength, tear resistance and chemical stability. In addition, the ETFE film has a very wide working temperature range (-200-150℃) and a melting point of about 275℃, which enables it to adapt to various harsh weather conditions.

[0003] Although the ETFE film has many advantages, when it is directly applied to agricultural greenhouses, a series of problems are still exposed, mainly in the following aspects: ① condensation water problem: due to the plant transpiration and the internal and external temperature difference effect, the air humidity in the greenhouse is usually high. When the water vapor in the greenhouse meets cold on the inner surface of the film, it is easy to reach the dew point and condense into water droplets. The traditional ETFE film surface lacks sufficient hydrophilic or hydrophobic regulation function, and the condensation water is easy to form a large number of discrete water droplets instead of uniform water film. These water droplets not only refract and scatter light, reducing the light transmittance and affecting the photosynthesis of crops, but also accumulate to a certain extent and drop, causing mechanical damage to delicate crops and creating a microenvironment conducive to the breeding of bacteria. ② Single function: the existing ETFE film technology focuses on improving a single performance. For example, the ETFE fluorine film plate disclosed in CN119388811A focuses on reducing the external surface water and improving the self-cleaning performance through the wear-resistant hydrophobic layer; the cross-linked ETFE composite film disclosed in CN120552452B focuses on building a gradient ultraviolet shielding function to achieve high light transmittance and full-waveband ultraviolet shielding. However, these technologies do not systematically solve the problem of inner surface drip-proof in greenhouse applications. ③ Balance between long-acting drip-proof and light transmittance: some studies try to give ETFE film drip-proof function through surface coating, but often have problems such as poor durability of coating, easy aging and falling off, affecting the light transmittance of base film or increasing the haze of film, etc. For example, ordinary hydrophilic coating may fail after long-term use due to ultraviolet rays or hot and humid environment, and may increase the haze of the film, affecting the direct light of light.

[0004] In summary, it has become a technical problem to be solved in this field to develop a special ETFE greenhouse film with efficient drip-proof, high light transmittance and controllable cost. SUMMARY

[0005] The greenhouse anti-dripping ETFE film has good mechanical properties, anti-dripping properties and high light transmittance.

[0006] The greenhouse anti-dripping ETFE film comprises an outer layer, an intermediate layer and an inner layer, wherein the outer layer is composed of 100 parts of ETFE resin, 4-5 parts of a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, 2.0-2.2 parts of perfluoroalkylethyl methacrylate, 0.26-0.28 parts of an antioxidant, 0.28-0.30 parts of a hindered amine light stabilizer and 0.28-0.30 parts of an ultraviolet absorber; the intermediate layer is composed of 100 parts of ETFE resin, 6-8 parts of a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride and 19-20 parts of an anti-dripping master batch; and the inner layer is composed of 100 parts of ETFE resin, 10-11 parts of an anti-dripping master batch, 0.8-1.0 parts of an ultraviolet absorber and 0.28-0.30 parts of a hindered amine light stabilizer.

[0007] The thickness of the greenhouse anti-dripping ETFE film is 200 microns, and the thickness ratio of the outer layer, the intermediate layer and the inner layer is 1:2:1.

[0008] The perfluoroalkylethyl methacrylate in the outer layer has a CAS number of 65530-66-7.

[0009] The hindered amine light stabilizer in the outer layer and the inner layer is light stabilizer XT-8, which is produced by Beijing Tian Gong Additives Co., Ltd.

[0010] The ultraviolet absorber in the outer layer and the inner layer is ultraviolet absorber Tinuvin 1577 produced by BASF.

[0011] The antioxidant in the outer layer is a mixture of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0012] The anti-dripping master batch in the intermediate layer and the inner layer is the same, and the preparation method of the anti-dripping master batch comprises the following steps: adding ETFE resin, anti-dripping filler, antioxidant 1010, antioxidant 168 and hindered amine light stabilizer into a mixer and mixing for 5 minutes, then adding the mixture into a twin-screw extruder for melt extrusion, and then filtering, underwater pelletizing, drying and sieving to obtain the anti-dripping master batch.

[0013] In the preparation method of the anti-dripping master batch, the rotating speed during mixing is 1000 r / min, the mixing temperature is room temperature, and the melt extrusion temperature is 285-287 DEG C.

[0014] The underwater pelletizing temperature in the preparation method of the anti-dripping mother granule is 70-73℃, and the particle size of the obtained granule is 2mm.

[0015] The drying temperature in the preparation method of the anti-dripping mother granule is 80-85℃, and the drying time is 30min, and the obtained granule is passed through an 8-mesh sieve.

[0016] The anti-dripping mother granule is composed of the following raw materials in mass fraction: 100 parts of ETFE resin, 10-12 parts of anti-dripping filler, 0.18-0.2 parts of antioxidant 1010, 0.18-0.2 parts of antioxidant 168, and 0.25-0.27 parts of hindered amine light stabilizer, wherein the hindered amine light stabilizer is light stabilizer XT-8, and the manufacturer is Beijing Tian Gong Additives Co., Ltd.

[0017] The preparation method of the anti-dripping filler comprises the following steps: ① preparation of pretreated nano-sepiolite: the nano-sepiolite is subjected to dehydration treatment to obtain dried nano-sepiolite, and the dried nano-sepiolite powder is added to hydrochloric acid with a mass concentration of 2.5% for magnetic stirring reaction, and after the reaction is completed, the reaction mixture is subjected to vacuum filtration, deionized water washing, and vacuum drying treatment to obtain pretreated nano-sepiolite; ② preparation of pretreated magnesium borate whisker: the magnesium borate whisker is vacuum dried at 80℃ for 2h; ③ preparation of pretreated nano-zinc gallate: the nano-zinc gallate is vacuum dried at 80℃ for 4h; ④ a mixture of anhydrous ethanol and deionized water is uniformly mixed in a volume ratio of 95:5, then KH-560 silane coupling agent is added and uniformly mixed to obtain a mass concentration of 2% of the KH-560 silane coupling agent, and finally glacial acetic acid is added to adjust the pH value of the system to 4.5, and the system is hydrolyzed at room temperature for 10min to obtain a pre-hydrolysis solution; ⑤ the pretreated nano-sepiolite, pretreated magnesium borate whisker, and pretreated nano-zinc gallate are added to the pre-hydrolysis solution and subjected to magnetic stirring at room temperature for 30min, then nitrogen protection is performed for 30min, and then the system is heated to 64℃ for reflux reaction for 2h; ⑥ after the reflux reaction is completed, the system is naturally cooled to 40℃, the nitrogen protection is turned off, and the reaction mixture is subjected to vacuum filtration, the filter cake is washed with anhydrous ethanol for 3 times, and then vacuum drying and sieving are performed to obtain the anti-dripping filler.

[0018] In step ①, the dehydration treatment temperature of the pretreated nano-sepiolite is 80℃, the dehydration treatment pressure is-0.09MPa, and the dehydration treatment time is 4h.

[0019] In step ①, the mass ratio of hydrochloric acid to dried nano-sepiolite is 5:1, the magnetic stirring reaction time is 1.5h, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, and the vacuum drying pressure is-0.09MPa.

[0020] The mass ratio of the pretreated nanometer sepiolite, the pretreated magnesium borate whisker and the pretreated nanometer zinc gallate in step 5 is 6:3:2.

[0021] The mass ratio of the pretreated nanometer sepiolite, the pretreated magnesium borate whisker and the pretreated nanometer zinc gallate in step 5 is 6:3:2.

[0022] The vacuum drying temperature in step 6 is 80 DEG C, the vacuum drying time is 2h, the vacuum drying pressure is -0.09MPa, and the mesh is 200.

[0023] The preparation method of the greenhouse anti-dripping ETFE film comprises the following steps:

[0024] (1) the outer layer material, the intermediate layer material and the inner layer material are respectively added to the high-speed mixer for mixing, and the mixed materials are discharged to obtain the outer layer mixed material, the intermediate layer mixed material and the inner layer mixed material;

[0025] (2) the outer layer mixed material, the intermediate layer mixed material and the inner layer mixed material are respectively added to the three-layer co-extrusion film blowing machine for film blowing forming, then cooling, shaping, traction and winding are carried out to prepare the greenhouse anti-dripping ETFE film.

[0026] In step (1), the parameters of the outer layer, the intermediate layer and the inner layer during mixing are the same, the mixing temperature is room temperature, the mixing speed is 1000r / min, and the mixing time is 5min.

[0027] The feeding section temperature of the three-layer co-extrusion film blowing machine in step (2) is 253-255 DEG C, the compression section temperature is 270-275 DEG C, the melting section temperature is 285-288 DEG C, the homogenization section temperature is 280-283 DEG C, and the die head temperature is 275-278 DEG C.

[0028] The three-layer melt in step (2) is extruded through the three-layer co-extrusion die head, the blow ratio is controlled to be 1.8, and the traction ratio is controlled to be 3.0.

[0029] The air ring temperature during cooling and shaping in step (2) is controlled to be 23 DEG C, and the traction speed is 22m / min.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] (1) The greenhouse anti-dripping ETFE film comprises an outer layer, an intermediate layer and an inner layer, the outer layer plays a role of wear resistance and self-cleaning, the intermediate layer plays a role of mechanical enhancement and anti-dripping performance, and the inner layer enhances surface hydrophilicity and ultraviolet shielding property without affecting light transmittance. Therefore, the three layers synergistically work to ensure that the prepared ETFE film has excellent mechanical strength, weather resistance, anti-dripping performance and high light transmittance, and can meet the needs of long-term outdoor use of the greenhouse film, and balance the light conditions required for crop growth and the stability of the greenhouse environment.

[0032] (2) The greenhouse anti-dripping ETFE film, the outer layer comprises ETFE resin as a main base resin, and a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride is added to improve the wear resistance of the outer layer. The synergistic effect of perfluoroalkyl ethyl methacrylate and the terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride increases the contact angle, so that the outer layer has self-cleaning performance. The addition of antioxidants, hindered amine light stabilizers and ultraviolet absorbers endows the outer layer with excellent weather resistance and prolongs the service life of the ETFE film.

[0033] (3) The greenhouse anti-dripping ETFE film, the intermediate layer mainly comprises ETFE resin, and a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride is added to improve the mechanical strength and melt processing fluidity of the intermediate layer. A high proportion of anti-dripping master batch is also added, wherein the magnesium borate whisker in the anti-dripping filler can further improve the internal durability and mechanical properties of the ETFE film, and the sepiolite endows the intermediate layer with moderate hydrophilicity, thereby constructing a continuous hydrophilic transmission channel inside the film and laying a core structural foundation for the anti-dripping performance of the greenhouse ETFE film. Furthermore, the prepared ETFE film forms a continuous hydrophilic channel inside, so that the water vapor in the greenhouse penetrates into the hydrophilic area of the film, and a uniform water film is formed on the inner surface of the film, avoiding condensation into water droplets.

[0034] (4) The greenhouse anti-dripping ETFE film, the inner layer comprises ETFE resin as a base resin, and anti-dripping master batch, ultraviolet absorber and hindered amine light stabilizer are compounded and used. The sepiolite in the anti-dripping master batch endows the ETFE film with durable hydrophilic properties, so that the condensed water on the inner surface of the film can spread uniformly to form a thin water film instead of discrete water beads, thereby preventing the formation of dripping water droplets. The synergistic effect of the ultraviolet absorber and the hindered amine light stabilizer can improve the anti-ultraviolet performance of the inner layer without affecting the light transmittance. While realizing the anti-dripping function, the inherent high light transmittance of the ETFE film is maintained, the photosynthetic active light flux required for crops is ensured, and the damage of ultraviolet light to crops is avoided.

[0035] (5) The greenhouse anti-dripping ETFE film, the anti-dripping master batch in the greenhouse anti-dripping ETFE film, the ETFE resin is the main resin, and the anti-dripping filler, the antioxidant 1010, the antioxidant 168 and the hindered amine light stabilizer are added. The pretreated nano sepiolite, the pretreated magnesium borate whisker and the pretreated nano zinc gallate are compounded in the anti-dripping filler. The surface hydroxyl content of the pretreated nano sepiolite is greatly improved after etching with dilute hydrochloric acid and vacuum drying pretreatment, the hydrophilicity is significantly enhanced, a continuous hydrophilic channel can be constructed in the ETFE matrix, and it is the core functional component of the anti-dripping performance of the film material. Meanwhile, the nano layered structure can assist in improving the mechanical properties and dimensional stability of the master batch. The pretreated magnesium borate whisker is better in dispersibility after vacuum drying to remove the surface free water, and the needle-shaped structure with a high aspect ratio can form an interwoven mechanical reinforcing network in the ETFE matrix, significantly improving the tensile strength and elongation at break of the anti-dripping master batch and the film material, and providing stable mechanical skeleton support for the film material. The pretreated nano zinc gallate is inhibited after vacuum drying pretreatment, has good ultraviolet shielding capacity, can cooperate with the ultraviolet absorbers of the outer layer and the inner layer of the film material, further broaden the ultraviolet shielding wave band, and improve the overall ultraviolet aging resistance of the film material. Meanwhile, the nano-sized particle size has little effect on the light transmittance of the film material, and the ultraviolet protection and crop photosynthesis demand can be considered.

[0036] (6) The preparation method of the greenhouse anti-dripping ETFE film has short process chain, process parameters are easy to control, and industrialized production can be easily realized. DETAILED DESCRIPTION

[0037] Example 1

[0038] The greenhouse anti-dripping ETFE film in the embodiment 1 is composed of an outer layer, a middle layer and an inner layer. The outer layer is composed of the following raw materials in parts by weight: 100 parts of ETFE resin, 4.5 parts of a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, 2.1 parts of perfluoroalkylethyl methacrylate, 0.27 parts of an antioxidant, 0.29 parts of a hindered amine light stabilizer and 0.29 parts of an ultraviolet absorber. The middle layer is composed of the following raw materials in parts by weight: 100 parts of ETFE resin, 7 parts of a terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride and 19.5 parts of an anti-dripping master batch. The inner layer is composed of the following raw materials in parts by weight: 100 parts of ETFE resin, 10.5 parts of an anti-dripping master batch, 0.9 parts of an ultraviolet absorber and 0.29 parts of a hindered amine light stabilizer.

[0039] The thickness of the greenhouse anti-dripping ETFE film is 200 microns, and the thickness ratio of the outer layer, the middle layer and the inner layer is 1:2:1.

[0040] The CAS number of perfluoroalkylethyl methacrylate in the outer layer is 65530-66-7.

[0041] The hindered amine light stabilizer in both the outer and inner layers is light stabilizer XT-8, manufactured by Beijing Tiangang Additives Co., Ltd.

[0042] The ultraviolet absorber in both the outer and inner layers is Tinuvin 1577, an ultraviolet absorber manufactured by BASF.

[0043] The antioxidant in the outer layer is a mixture of antioxidant 1010 and antioxidant 168, with a mass ratio of antioxidant 1010 to antioxidant 168 of 1:1.

[0044] The intermediate layer and the inner layer contain the same anti-drip masterbatch. The preparation method of the anti-drip masterbatch consists of the following steps: ETFE resin, anti-drip filler, antioxidant 1010, antioxidant 168 and hindered amine light stabilizer are added to a mixer and mixed for 5 minutes. Then the mixture is added to a twin-screw extruder for melt extrusion. After filtration, underwater pelletizing, drying and sieving, the anti-drip masterbatch is obtained.

[0045] In the preparation method of the anti-drip masterbatch, the mixing speed is 1000 r / min, the mixing temperature is room temperature, and the melt extrusion temperature is 286℃.

[0046] In the preparation method of anti-drip masterbatch, the underwater pelleting temperature is 71℃, resulting in particles with a diameter of 2mm.

[0047] In the preparation method of anti-drip masterbatch, the drying temperature is 83℃, the drying time is 30min, and it is passed through an 8-mesh sieve.

[0048] The anti-drip masterbatch is composed of the following raw materials in parts by weight: 100 parts ETFE resin, 11 parts anti-drip filler, 0.19 parts antioxidant 1010, 0.19 parts antioxidant 168, and 0.26 parts hindered amine light stabilizer. The hindered amine light stabilizer is light stabilizer XT-8, manufactured by Beijing Tiangang Additives Co., Ltd.

[0049] The preparation method of the anti-dripping filler comprises the following steps: ① preparation of pretreated nano-sepiolite: the nano-sepiolite is subjected to dehydration treatment to obtain dried nano-sepiolite, the dried nano-sepiolite powder is added into hydrochloric acid with a mass concentration of 2.5% for magnetic stirring reaction, after the reaction is completed, the pretreated nano-sepiolite is prepared by filtration, deionized water washing and vacuum drying treatment; ② preparation of pretreated magnesium borate whisker: the magnesium borate whisker is vacuum dried at 80℃ for 2h; ③ preparation of pretreated nano-zinc gallate: the nano-zinc gallate is vacuum dried at 80℃ for 4h; ④ the dehydrated ethanol and deionized water are uniformly mixed according to a volume ratio of 95:5, then the KH-560 silane coupling agent is added and uniformly mixed, so that the mass concentration of the KH-560 silane coupling agent is 2%, finally, glacial acetic acid is added to adjust the pH value of the system to 4.5, and the pre-hydrolysis liquid is prepared by hydrolysis at room temperature for 10min; ⑤ the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate are added into the pre-hydrolysis liquid for magnetic stirring at room temperature for 30min, then the temperature is increased to 64℃ for reflux reaction for 2h under nitrogen protection; ⑥ after the reflux reaction is completed, the temperature is naturally cooled to 40℃, the nitrogen is turned off, the reaction mixture is vacuum filtered, the filter cake is collected, the filter cake is washed with dehydrated ethanol for 3 times, then vacuum drying and sieving are performed to obtain the anti-dripping filler.

[0050] In the preparation method of the pretreated nano-sepiolite in step ①, the dehydration treatment temperature is 80℃, the dehydration treatment pressure is -0.09MPa, and the dehydration treatment time is 4h.

[0051] In the preparation method of the pretreated nano-sepiolite in step ①, the mass ratio of the hydrochloric acid to the dried nano-sepiolite is 5:1, the magnetic stirring reaction time is 1.5h, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, and the vacuum drying pressure is -0.09MPa.

[0052] In step ⑤, the mass ratio of the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate is 6:3:2.

[0053] In step ⑤, the mass ratio of the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate to the pre-hydrolysis liquid is 1:5.

[0054] In step ⑥, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, the vacuum drying pressure is -0.09MPa, and the sieve size is 200 meshes.

[0055] The preparation method of the anti-dripping ETFE film for a greenhouse comprises the following steps:

[0056] (1) The outer layer raw material, the middle layer raw material and the inner layer raw material are respectively added to a high-speed mixer for mixing, and after being uniformly mixed, the outer layer mixture, the middle layer mixture and the inner layer mixture are obtained.

[0057] (2) The outer layer mixture, the middle layer mixture and the inner layer mixture are respectively added to a three-layer co-extrusion film blowing machine for film blowing forming, and then cooling, traction and winding are performed to prepare the anti-drip ETFE film for greenhouse.

[0058] In step (1), the parameters for mixing the outer layer, the middle layer and the inner layer are the same, the temperature during mixing is room temperature, the rotating speed during mixing is 1000 r / min, and the mixing time is 5 min.

[0059] In step (2), the temperature of the feeding section of the three-layer co-extrusion film blowing machine is 254℃, the temperature of the compression section is 273℃, the temperature of the melting section is 286℃, the temperature of the homogenizing section is 281℃, and the temperature of the die head is 276℃.

[0060] In step (2), the three-layer melt is extruded through a three-layer co-extrusion die head, the blowing ratio is controlled to be 1.8, and the traction ratio is controlled to be 3.0.

[0061] In step (2), the air ring temperature during cooling is controlled to be 23℃, and the traction speed is 22 m / min.

[0062] Example 2

[0063] The anti-drip ETFE film for greenhouse described in this example 2 is composed of an outer layer, a middle layer and an inner layer, the outer layer is composed of the following raw materials in parts by weight: ETFE resin 100 parts, terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride 4 parts, perfluoroalkyl ethyl methacrylate 2.2 parts, antioxidant 0.26 parts, hindered amine light stabilizer 0.30 parts, and ultraviolet absorber 0.28 parts; the middle layer is composed of the following raw materials in parts by weight: ETFE resin 100 parts, terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride 6 parts, anti-drip master batch 19 parts; and the inner layer is composed of the following raw materials in parts by weight: ETFE resin 100 parts, anti-drip master batch 11 parts, ultraviolet absorber 0.8 parts, and hindered amine light stabilizer 0.30 parts.

[0064] The thickness of the anti-drip ETFE film for greenhouse is 200 microns, and the thickness ratio of the outer layer, the middle layer and the inner layer is 1:2:1.

[0065] The CAS number of perfluoroalkyl ethyl methacrylate in the outer layer is 65530-66-7.

[0066] The hindered amine light stabilizer in the outer layer and the inner layer is light stabilizer XT-8, and the manufacturer is Beijing Tian Gong Additives Co., Ltd.

[0067] The ultraviolet absorber in the outer layer and the inner layer is Tinuvin 1577 produced by BASF.

[0068] The antioxidant in the outer layer is a mixture of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0069] The anti-dripping master batch in the middle layer and the inner layer is prepared by the following steps: adding ETFE resin, anti-dripping filler, antioxidant 1010, antioxidant 168 and hindered amine light stabilizer into a mixer and mixing for 5 min, then adding the mixture into a twin-screw extruder for melt extrusion, filtering, underwater pelletizing, drying and sieving to obtain the anti-dripping master batch.

[0070] In the preparation method of the anti-dripping master batch, the rotating speed during mixing is 1000 r / min, the mixing temperature is room temperature, and the melt extrusion temperature is 287℃.

[0071] In the preparation method of the anti-dripping master batch, the underwater pelletizing temperature is 73℃, and particles with a particle size of 2 mm are obtained.

[0072] In the preparation method of the anti-dripping master batch, the drying temperature is 85℃, the drying time is 30 min, and the particles are sieved through an 8-mesh sieve.

[0073] The anti-dripping master batch is prepared from the following raw materials in parts by mass: ETFE resin 100 parts, anti-dripping filler 10 parts, antioxidant 1010 0.18 parts, antioxidant 168 0.18 parts, and hindered amine light stabilizer 0.27 parts, wherein the hindered amine light stabilizer is light stabilizer XT-8 produced by Beijing Tiangong Additives Co., Ltd.

[0074] The preparation method of the anti-dripping filler comprises the following steps: ① preparation of pretreated nano-sepiolite: the nano-sepiolite is subjected to dehydration treatment to obtain dried nano-sepiolite, the dried nano-sepiolite powder is added into hydrochloric acid with a mass concentration of 2.5% for magnetic stirring reaction, after the reaction is completed, the pretreated nano-sepiolite is prepared by filtration, deionized water washing and vacuum drying treatment; ② preparation of pretreated magnesium borate whisker: the magnesium borate whisker is vacuum dried at 80℃ for 2h; ③ preparation of pretreated nano-zinc gallate: the nano-zinc gallate is vacuum dried at 80℃ for 4h; ④ the dehydrated ethanol and deionized water are uniformly mixed according to a volume ratio of 95:5, then the KH-560 silane coupling agent is added and uniformly mixed, so that the mass concentration of the KH-560 silane coupling agent is 2%, finally the glacial acetic acid is added to adjust the pH value of the system to 4.5, and the pre-hydrolysis liquid is prepared by hydrolysis at room temperature for 10min; ⑤ the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate are added into the pre-hydrolysis liquid for magnetic stirring at room temperature for 30min, then the reaction mixture is heated to 64℃ for reflux reaction for 2h under nitrogen protection; ⑥ after the reflux reaction is completed, the reaction mixture is naturally cooled to 40℃, the nitrogen is turned off, the reaction mixture is vacuum filtered, the filter cake is collected, the filter cake is washed with dehydrated ethanol for 3 times, then vacuum drying and sieving are performed to obtain the anti-dripping filler.

[0075] In the preparation method of the pretreated nano-sepiolite in step ①, the dehydration treatment temperature is 80℃, the dehydration treatment pressure is -0.09MPa, and the dehydration treatment time is 4h.

[0076] In the preparation method of the pretreated nano-sepiolite in step ①, the mass ratio of the hydrochloric acid to the dried nano-sepiolite is 5:1, the magnetic stirring reaction time is 1.5h, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, and the vacuum drying pressure is -0.09MPa.

[0077] In step ⑤, the mass ratio of the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate is 6:3:2.

[0078] In step ⑤, the mass ratio of the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate to the pre-hydrolysis liquid is 1:5.

[0079] In step ⑥, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, the vacuum drying pressure is -0.09MPa, and the sieve size is 200 meshes.

[0080] The preparation method of the anti-dripping ETFE film for the greenhouse comprises the following steps:

[0081] (1) The outer layer raw material, the middle layer raw material and the inner layer raw material are respectively added to a high-speed mixer for mixing, and after being uniformly mixed, the outer layer mixture, the middle layer mixture and the inner layer mixture are obtained.

[0082] (2) The outer layer mixture, the middle layer mixture and the inner layer mixture are respectively added to a three-layer co-extrusion film blowing machine for film blowing forming, and then cooled, shaped, drawn and rolled to prepare the anti-drip ETFE film for greenhouse.

[0083] In step (1), the parameters for mixing the outer layer, the middle layer and the inner layer are the same, the temperature during mixing is room temperature, the rotating speed during mixing is 1000 r / min, and the mixing time is 5 min.

[0084] In step (2), the temperature of the feeding section of the three-layer co-extrusion film blowing machine is 255℃, the temperature of the compression section is 275℃, the temperature of the melting section is 288℃, the temperature of the homogenizing section is 283℃, and the temperature of the die head is 278℃.

[0085] In step (2), the three-layer melt is extruded through a three-layer co-extrusion die head, the blowing ratio is controlled to be 1.8, and the drawing ratio is controlled to be 3.0.

[0086] In step (2), the air ring temperature during cooling and shaping is controlled to be 23℃, and the drawing speed is 22 m / min.

[0087] Example 3

[0088] The anti-drip ETFE film for greenhouse described in this example 3 is composed of an outer layer, a middle layer and an inner layer, wherein the outer layer is composed of the following raw materials in parts by weight: ETFE resin 100 parts, terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride 5 parts, perfluoroalkylethyl methacrylate 2.0 parts, antioxidant 0.28 parts, hindered amine light stabilizer 0.28 parts, and ultraviolet absorber 0.30 parts; the middle layer is composed of the following raw materials in parts by weight: ETFE resin 100 parts, terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride 8 parts, anti-drip master batch 20 parts; and the inner layer is composed of the following raw materials in parts by weight: ETFE resin 100 parts, anti-drip master batch 10 parts, ultraviolet absorber 1.0 part, and hindered amine light stabilizer 0.28 parts.

[0089] The thickness of the anti-drip ETFE film for greenhouse is 200 microns, and the thickness ratio of the outer layer, the middle layer and the inner layer is 1:2:1.

[0090] The CAS number of perfluoroalkylethyl methacrylate in the outer layer is 65530-66-7.

[0091] The hindered amine light stabilizer in the outer layer and the inner layer is light stabilizer XT-8, and the manufacturer is Beijing Tiangong Additives Co., Ltd.

[0092] The ultraviolet absorber in the outer layer and the inner layer is Tinuvin 1577 produced by BASF.

[0093] The antioxidant in the outer layer is a mixture of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:1.

[0094] The anti-dripping master batch in the middle layer and the inner layer is prepared by the following steps: adding ETFE resin, anti-dripping filler, antioxidant 1010, antioxidant 168 and hindered amine light stabilizer into a mixer and mixing for 5 min, then adding the mixture into a twin-screw extruder for melt extrusion, filtering, underwater pelletizing, drying and sieving to obtain the anti-dripping master batch.

[0095] In the preparation method of the anti-dripping master batch, the rotating speed during mixing is 1000 r / min, the mixing temperature is room temperature, and the melt extrusion temperature is 285℃.

[0096] In the preparation method of the anti-dripping master batch, the underwater pelletizing temperature is 70℃, and particles with a particle size of 2 mm are obtained.

[0097] In the preparation method of the anti-dripping master batch, the drying temperature is 80℃, the drying time is 30 min, and the particles are sieved through an 8-mesh sieve.

[0098] The anti-dripping master batch is composed of the following raw materials in mass parts: ETFE resin 100 parts, anti-dripping filler 12 parts, antioxidant 1010 0.2 parts, antioxidant 168 0.2 parts and hindered amine light stabilizer 0.25 parts, wherein the hindered amine light stabilizer is light stabilizer XT-8 produced by Beijing Tiangong Additives Co., Ltd.

[0099] The preparation method of the anti-dripping filler comprises the following steps: ① preparation of pretreated nano-sepiolite: the nano-sepiolite is subjected to dehydration treatment to obtain dried nano-sepiolite, the dried nano-sepiolite powder is added into hydrochloric acid with a mass concentration of 2.5% for magnetic stirring reaction, after the reaction is completed, the pretreated nano-sepiolite is prepared by filtration, deionized water washing and vacuum drying treatment; ② preparation of pretreated magnesium borate whisker: the magnesium borate whisker is vacuum dried at 80℃ for 2h; ③ preparation of pretreated nano-zinc gallate: the nano-zinc gallate is vacuum dried at 80℃ for 4h; ④ the dehydrated ethanol and deionized water are uniformly mixed according to a volume ratio of 95:5, then the KH-560 silane coupling agent is added and uniformly mixed, so that the mass concentration of the KH-560 silane coupling agent is 2%, finally, glacial acetic acid is added to adjust the pH value of the system to 4.5, and the pre-hydrolysis liquid is prepared by hydrolysis at room temperature for 10min; ⑤ the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate are added into the pre-hydrolysis liquid for magnetic stirring at room temperature for 30min, then the temperature is increased to 64℃ for reflux reaction for 2h under nitrogen protection; ⑥ after the reflux reaction is completed, the temperature is naturally cooled to 40℃, the nitrogen is turned off, the reaction mixture is vacuum filtered, the filter cake is collected, the filter cake is washed with dehydrated ethanol for 3 times, then vacuum drying and sieving are performed to obtain the anti-dripping filler.

[0100] In the preparation method of the pretreated nano-sepiolite in step ①, the dehydration treatment temperature is 80℃, the dehydration treatment pressure is -0.09MPa, and the dehydration treatment time is 4h.

[0101] In the preparation method of the pretreated nano-sepiolite in step ①, the mass ratio of the hydrochloric acid to the dried nano-sepiolite is 5:1, the magnetic stirring reaction time is 1.5h, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, and the vacuum drying pressure is -0.09MPa.

[0102] In step ⑤, the mass ratio of the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate is 6:3:2.

[0103] In step ⑤, the mass ratio of the pretreated nano-sepiolite, the pretreated magnesium borate whisker and the pretreated nano-zinc gallate to the pre-hydrolysis liquid is 1:5.

[0104] In step ⑥, the vacuum drying temperature is 80℃, the vacuum drying time is 2h, the vacuum drying pressure is -0.09MPa, and the sieve size is 200 meshes.

[0105] The preparation method of the anti-dripping ETFE film for the greenhouse comprises the following steps:

[0106] (1) The outer layer raw material, the middle layer raw material and the inner layer raw material are respectively added to a high-speed mixer for mixing, and after being uniformly mixed, the outer layer mixture, the middle layer mixture and the inner layer mixture are obtained;

[0107] (2) The outer layer mixture, the middle layer mixture and the inner layer mixture are respectively added to a three-layer co-extrusion film blowing machine for film blowing forming, and then cooled, shaped, drawn and wound to prepare the greenhouse anti-drip ETFE film.

[0108] In step (1), the parameters for mixing the outer layer, the middle layer and the inner layer are the same, the mixing temperature is room temperature, the mixing speed is 1000 r / min, and the mixing time is 5 min.

[0109] In step (2), the feeding section temperature of the three-layer co-extrusion film blowing machine is 253℃, the compression section temperature is 270℃, the melting section temperature is 285℃, the homogenization section temperature is 280℃, and the die head temperature is 275℃.

[0110] In step (2), the three-layer melt is extruded through a three-layer co-extrusion die head, the blowing ratio is controlled to be 1.8, and the drawing ratio is controlled to be 3.0.

[0111] In step (2), the air ring temperature during cooling and shaping is controlled to be 23℃, and the drawing speed is 22 m / min.

[0112] Comparative Example 1

[0113] The preparation method of the greenhouse anti-drip ETFE film of the present comparative example 1 is the same as that of Example 1, and the raw material composition of the outer layer and the inner layer is also the same as that of Example 1, the only difference is that no anti-drip master batch is added in the middle layer.

[0114] Comparative Example 2

[0115] The preparation method of the greenhouse anti-drip ETFE film of the present comparative example 2 is the same as that of Example 1, and the raw material composition of the outer layer and the middle layer is also the same as that of Example 1, the only difference is that no anti-drip master batch is added in the inner layer.

[0116] The greenhouse anti-drip ETFE films prepared in Examples 1-3 and Comparative Examples 1-2 are tested for performance, and the results are shown in Table 1 below, wherein the tensile strength and elongation at break are tested according to GB / T 1040.3, the outer and inner sides of the ETFE film are tested for contact angle according to GB / T 30693, the light transmittance is tested according to GB / T 2410, the aging resistance is tested according to GB / T 16422.2, and the anti-drip performance is tested according to NY / T 1452-2007 standard, and the results are shown in Table 1 below:

[0117] Table 1 Performance test results of greenhouse anti-drip ETFE film

[0118]

[0119] From the data of tensile strength and elongation at break in Table 1, it can be seen that the mechanical strength of the ETFE films prepared in Examples 1-3 is greater than that of Comparative Examples 1-2; from the outside contact angle, it can be seen that the outer layer of the ETFE films prepared in Examples 1-3 and Comparative Examples 1-2 has strong hydrophobicity, which can play a self-cleaning role; the inside contact angle of the ETFE films prepared in Examples 1-3 is much smaller than that of Comparative Examples 1-2, indicating that the inside thereof has good hydrophilicity; the light transmittance of the ETFE films prepared in Examples 1-3 and Comparative Examples 1-2 is the same; the tensile strength retention rate and elongation at break retention rate of the ETFE films prepared in Examples 1-3 are much better than those of Comparative Examples 1-2, indicating that the ETFE films prepared in Examples 1-3 have better aging resistance than Comparative Examples 1-2; the dew drop retention rate of the ETFE films prepared in Examples 1-3 is much smaller than that of Comparative Examples 1-2, further proving that the ETFE films prepared in Examples 1-3 have good anti-dew drop performance.

[0120] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to make equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the present application, is still within the scope of the present application.

Claims

1. A drip-proof ETFE film for a greenhouse, characterized by: It is composed of an outer layer, an intermediate layer and an inner layer, the outer layer is composed of 100 parts of ETFE resin, 4-5 parts of terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, 2.0-2.2 parts of perfluoroalkyl ethyl methacrylate, 0.26-0.28 parts of antioxidant, 0.28-0.30 parts of hindered amine light stabilizer and 0.28-0.30 parts of ultraviolet absorber; the intermediate layer is composed of 100 parts of ETFE resin, 6-8 parts of terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride and 19-20 parts of anti-dripping master batch; the inner layer is composed of 100 parts of ETFE resin, 10-11 parts of anti-dripping master batch, 0.8-1.0 parts of ultraviolet absorber and 0.28-0.30 parts of hindered amine light stabilizer; The anti-dripping master batch is composed of 100 parts of ETFE resin, 10-12 parts of anti-dripping filler, 0.18-0.2 parts of antioxidant 1010, 0.18-0.2 parts of antioxidant 168 and 0.25-0.27 parts of hindered amine light stabilizer, and the hindered amine light stabilizer is light stabilizer XT-8; The preparation method of the anti-dripping filler comprises the following steps: ① preparation of pretreated nano-sepiolite: the nano-sepiolite is subjected to dehydration treatment to obtain dried nano-sepiolite, the dried nano-sepiolite powder is added into hydrochloric acid with a mass concentration of 2.5% for magnetic stirring reaction, after the reaction is completed, the reaction mixture is subjected to suction filtration, deionized water washing and vacuum drying to obtain pretreated nano-sepiolite; ② preparation of pretreated magnesium borate whisker: the magnesium borate whisker is vacuum dried at 80℃ for 2h; ③ preparation of pretreated nano-zinc gallate: the nano-zinc gallate is vacuum dried at 80℃ for 4h; ④ anhydrous ethanol and deionized water are uniformly mixed in a volume ratio of 95:5, then KH-560 silane coupling agent is added and uniformly mixed to obtain a mass concentration of 2% of the KH-560 silane coupling agent, finally glacial acetic acid is added to adjust the pH value of the system to 4.5, and the system is hydrolyzed at room temperature for 10min to obtain a pre-hydrolysis solution; ⑤ the pretreated nano-sepiolite, pretreated magnesium borate whisker and pretreated nano-zinc gallate are added into the pre-hydrolysis solution for magnetic stirring at room temperature for 30min, then nitrogen protection is carried out for 30min, and then the system is heated to 64℃ for reflux reaction for 2h; ⑥ after the reflux reaction is completed, the system is naturally cooled to 40℃, the nitrogen is turned off, and the reaction mixture is subjected to vacuum suction filtration, the filter cake is washed with anhydrous ethanol for 3 times, and then vacuum drying and sieving are carried out to obtain the anti-dripping filler.

2. The anti-dripping ETFE film for a greenhouse according to claim 1, characterized by: The thickness of the anti-dripping ETFE film for greenhouse is 200 microns, and the thickness ratio of the outer layer, the intermediate layer and the inner layer is 1:2:1; The hindered amine light stabilizer in the outer layer and the inner layer is light stabilizer XT-8; The ultraviolet absorber in the outer layer and the inner layer is ultraviolet absorber Tinuvin 1577; The antioxidant in the outer layer is a mixture of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 1:

1.

3. The anti-dripping ETFE film for a greenhouse according to claim 1, characterized by: The preparation method of the anti-dripping master batch, which consists of the following steps: adding ETFE resin, anti-dripping filler, antioxidant 1010, antioxidant 168 and hindered amine light stabilizer into a mixer and mixing for 5 min, then adding the mixture into a twin-screw extruder for melt extrusion, filtering, underwater pelletizing, drying and sieving to obtain the anti-dripping master batch.

4. The anti-dripping ETFE film for a greenhouse according to claim 3, characterized by: The rotation speed during mixing in the preparation method of the anti-dripping master batch is 1000 r / min, the mixing temperature is room temperature, and the melt extrusion temperature is 285-287℃; The underwater pelletizing temperature in the preparation method of the anti-dripping master batch is 70-73℃, and particles with a particle size of 2 mm are obtained; The drying temperature in the preparation method of the anti-dripping master batch is 80-85℃, the drying time is 30 min, and the particles are sieved through an 8-mesh sieve.

5. The anti-dripping ETFE film for a greenhouse according to claim 1, characterized by: In the preparation method of the pretreated nanometer sepiolite in step ①, the dehydration treatment temperature is 80℃, the dehydration treatment pressure is -0.09 MPa, and the dehydration treatment time is 4 h; In the preparation method of the pretreated nanometer sepiolite in step ①, the mass ratio of hydrochloric acid to dried nanometer sepiolite is 5:1, the magnetic stirring reaction time is 1.5 h, the vacuum drying temperature is 80℃, the vacuum drying time is 2 h, and the vacuum drying pressure is -0.09 MPa.

6. The anti-dripping ETFE film for a greenhouse according to claim 1, characterized by: In step ⑤, the mass ratio of the pretreated nanometer sepiolite, the pretreated magnesium borate whisker and the pretreated nanometer zinc gallate is 6:3:2; In step ⑤, the mass ratio of the pretreated nanometer sepiolite, the pretreated magnesium borate whisker and the pretreated nanometer zinc gallate to the pre-hydrolysis solution is 1:

5.

7. The anti-dripping ETFE film for a greenhouse according to claim 1, characterized by: In step ⑥, the vacuum drying temperature is 80℃, the vacuum drying time is 2 h, the vacuum drying pressure is -0.09 MPa, and the particles are sieved through a 200-mesh sieve.

8. A method of preparing the anti-dripping ETFE film for a greenhouse according to claim 1, characterized by: The preparation method consists of the following steps: (1) adding the outer layer raw material, the middle layer raw material and the inner layer raw material into a high-speed mixer respectively for mixing, and then discharging to obtain the outer layer mixture, the middle layer mixture and the inner layer mixture; (2) adding the outer layer mixture, the middle layer mixture and the inner layer mixture into a three-layer co-extrusion film blowing machine for film blowing, and then cooling, pulling and winding to obtain the anti-dripping ETFE film for greenhouses.

9. The method of claim 8, wherein the method is characterized by: In step (1), the parameters for mixing the outer layer, the middle layer and the inner layer are the same, the mixing temperature is room temperature, the mixing rotation speed is 1000 r / min, and the mixing time is 5 min; In step (2), the temperature of the feeding section of the three-layer co-extrusion film blowing machine is 253-255℃, the temperature of the compression section is 270-275℃, the temperature of the melting section is 285-288℃, the temperature of the homogenizing section is 280-283℃, and the temperature of the die head is 275-278℃; In step (2), the three-layer melt is extruded through the three-layer co-extrusion die head, the blowing ratio is controlled at 1.8, and the pulling ratio is controlled at 3.0; In step (2), the air ring temperature during cooling is controlled at 23℃, and the pulling speed is 22 m / min.

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