Infrared barrier master batch as well as preparation method and application thereof

Abstract

The invention provides an infrared barrier master batch and a preparation method and application thereof, and the preparation method comprises the following steps: (1) mixing and dispersing an infrared barrier material, a first dispersant and a solvent to obtain an infrared barrier slurry; (2) mixing and dispersing the infrared blocking slurry obtained in the step (1) and a second dispersing agent to obtain an infrared blocking auxiliary agent; and (3) mixing the infrared blocking auxiliary agent obtained in the step (2) with master batch resin, and extruding to obtain the infrared blocking master batch, the second dispersing agent comprises a polymer dispersing agent; the second dispersing agent is mixed and dispersed with the infrared barrier slurry in a liquid phase form or a molten state form. According to the preparation method of the infrared barrier master batch, the problem that in the prior art, a nano infrared barrier material is agglomerated in a polyolefin matrix and is difficult to uniformly disperse is solved, and the infrared barrier efficiency of a film can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer composite materials, and particularly relates to an infrared blocking masterbatch and a preparation method and application thereof. Background Art

[0002] Facility agriculture is a modern agricultural production method that uses technical means and artificial facilities to create and optimize the environmental conditions required for the growth and development of plants and animals, so that traditional agriculture can get rid of the constraints of nature to varying degrees. It can greatly improve land output, resource utilization and labor productivity, and has an important role in enhancing the comprehensive agricultural production capacity. However, facility agriculture has high requirements for environmental regulation and control capabilities and a high degree of scale, which brings about a high demand for energy consumption. The energy consumption of facility agriculture is mainly used for winter heating, summer cooling, artificial light sources, irrigation and other links. Among them, the energy consumption of temperature regulation such as winter heating and summer cooling accounts for a large proportion of the energy consumption of facility agriculture. During the hot seasons of spring and summer, strong light and high temperature outside seriously affect the growth of crops in the facilities, and it is difficult to improve the yield and quality of crops. When the temperature is as high as 35°C, the photosynthesis of many crops is weakened, the nutrient flow is blocked, resulting in poor growth, loss of disease resistance, and easy occurrence of physiological diseases and pests.

[0003] Traditional facility agriculture mainly uses natural ventilation on both sides or sunshade nets to cool down, but the cooling effect is poor. The high temperature in the facility leads to a decrease in crop yield and quality. The thermal energy of sunlight is composed of 53% infrared, 44% visible light and 3% ultraviolet energy. Infrared accounts for a higher proportion. Therefore, by blocking infrared radiation in sunlight, the problem of high temperature in facility agriculture in spring and summer can be solved.

[0004] Polyolefin film is the most widely used and largest type of plastic film products at this stage. It has the characteristics of abundant raw materials, low price, low density, easy processing and excellent comprehensive performance. At present, the polyolefin resins used in domestic agricultural plastic films are mainly polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, etc. At present, the function of blocking infrared radiation is mainly given to plastic products by adding functional materials that reflect or absorb infrared light in sunlight. Common infrared blocking materials include antimony tin oxide (ATO), indium tin oxide (ITO), cesium tungsten bronze (CWO), lanthanum hexaboride (LaB6), etc. The particle size of infrared blocking materials is significantly related to performance. Materials such as ATO, AZO, ITO, and LaB6 have significantly increased light absorption at the nanometer size and produced plasma resonance frequency shifts of the absorption peak. When the surface plasma resonance frequency of the material falls near the infrared light region, it can show the absorption performance of infrared light and play the effect of blocking infrared light. However, in the blending process of nanomaterials and resins, due to the large surface energy of the nano infrared blocking material, the high viscosity of the resin melt, and the limited mixing capacity of the equipment, dispersion is difficult. The nano infrared blocking material forms submicron or micron-sized agglomerates in the organic resin, and the light absorption efficiency of the infrared blocking material is weakened, while the scattering efficiency is enhanced, affecting the infrared blocking effect and visible light transmittance of the film.

[0005] Therefore, developing a method for preparing an infrared blocking masterbatch that has good dispersibility in a matrix resin, is not easy to agglomerate, and can improve the infrared blocking performance of a film is an urgent problem to be solved in the art. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an infrared blocking masterbatch and a preparation method and application thereof, so as to solve the problem in the prior art that nano infrared blocking materials are difficult to achieve nano-scale dispersion in polyolefin resins.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing an infrared blocking masterbatch, the preparation method comprising the following steps:

[0009] (1) mixing and dispersing an infrared blocking material, a first dispersant and a solvent to obtain an infrared blocking slurry;

[0010] (2) The infrared blocking slurry obtained in step (1) is mixed and dispersed with a second dispersant, and an infrared blocking auxiliary agent is obtained after removing the solvent; the second dispersant includes a polymer dispersant; the second dispersant is mixed and dispersed with the infrared blocking slurry in a liquid phase or in a molten state.

[0011] (3) The infrared blocking auxiliary agent obtained in step (2) is mixed with the masterbatch resin, and extruded to obtain the infrared blocking masterbatch.

[0012] In the present invention, in the preparation method, the infrared blocking material is prepared into a nano-scale infrared blocking slurry, and then mixed and dispersed with a second dispersant, the second dispersant includes a polymer dispersant, and the second dispersant can be a polymer emulsion, a polymer dispersion, a polymer solution or a polymer with a low relative molecular mass and a low melt viscosity. The second dispersant is mixed and dispersed with the infrared blocking slurry in the form of an emulsion, a dispersion, a solution or a molten state by stirring, sand milling, high-speed shearing or ultrasound, so that the infrared blocking material can be dispersed in it at the nanometer level, and the polymer can be coated or anchored on the surface of the infrared blocking nanoparticles, avoiding the infrared blocking material and the polymer resin from forming submicron and micron agglomerates during the melt extrusion process, improving the dispersibility of the infrared blocking material in the polymer resin, and being able to obtain a film with a high infrared blocking rate and visible light transmittance; and the process is simple, the versatility is strong, and no harsh reaction conditions are required.

[0013] In the present invention, the mixing and dispersing in liquid phase, i.e., the second dispersant can be a polymer emulsion, or a polymer dispersion, or a polymer solution; the mixing and dispersing in molten state, i.e., the second dispersant is heated and melted to obtain a melt, and then the melt is mixed and dispersed with the infrared blocking slurry.

[0014] Preferably, the average particle size of the infrared blocking material in step (1) is 10nm to 200nm, for example, it can be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, etc.; more preferably, it is 10nm to 50nm.

[0015] Preferably, the infrared blocking material in step (1) includes infrared blocking material A and / or infrared blocking material B; the infrared blocking material A includes at least one of antimony tin oxide, indium tin oxide, aluminum zinc oxide, titanium dioxide or tungsten bronze; and the infrared blocking material B includes rare earth hexaboride.

[0016] Preferably, the rare earth hexaboride includes at least one of neodymium hexaboride, gadolinium hexaboride, praseodymium hexaboride, lanthanum hexaboride, cerium hexaboride or samarium hexaboride.

[0017] Preferably, the mass percentage of the infrared blocking material A in the infrared blocking slurry of step (1) is 1% to 50%, for example, it can be 1%, 5%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50% and the like; more preferably, it is 15% to 30%.

[0018] Preferably, the mass percentage of the infrared blocking material B in the infrared blocking slurry of step (1) is 0.1% to 30%, for example, it can be 0.1%, 0.5%, 1%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc.; more preferably, it is 1% to 10%.

[0019] Preferably, in step (1), the first dispersant comprises a silane coupling agent and / or a surfactant.

[0020] In the present invention, the silane coupling agent includes at least one of vinyl triethoxysilane, 3-aminopropyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane, γ-glycidoxypropyl methyl diethoxysilane, γ-glycidoxypropyl trimethoxysilane, 3-(2,3-epoxypropyloxy)propyl trimethoxysilane, γ-aminopropyl triethoxysilane, acrylate propyl trimethoxysilane and phenylaminopropyl trimethoxysilane.

[0021] Preferably, the surfactant includes at least one of polyvinyl pyrrolidone, sodium polyacrylate, polyvinyl alcohol, polyethylene glycol, stearic acid, sodium lignosulfonate, hexadecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate or tetrapropylammonium bromide.

[0022] Preferably, the mass of the first dispersant in step (1) is 0.5% to 50% of the infrared blocking material, for example, it can be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50% and the like.

[0023] Preferably, the solvent in step (1) comprises water and / or an alcohol solvent.

[0024] In the present invention, the alcohol solvent includes but is not limited to ethanol, methanol, 1-butanol, tert-butanol and the like.

[0025] Preferably, the dispersing method in step (1) includes grinding dispersion.

[0026] In the present invention, the grinding and dispersion includes sand milling and / or ball milling. The grinding balls used in the grinding and dispersion include zirconia beads. The diameter of the zirconia beads is 0.1mm to 0.3mm, the volume of the zirconia beads accounts for 50% to 70% of the volume of the barrel, and the grinding time is 2h to 15h.

[0027] Preferably, the average particle size of the infrared blocking slurry in step (1) is 20nm to 150nm, for example, it can be 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, etc.

[0028] In the present invention, the average particle size of the infrared blocking slurry can be tested by a nano laser particle size analyzer.

[0029] Preferably, the second dispersant in step (2) comprises at least one of ethylene-vinyl acetate copolymer, polyethylene, waterborne polyurethane, acrylic resin, oxidized polyethylene, chlorinated polyethylene, polyethylene grafted with maleic anhydride, etherified polyethylene, and sulfonated polyethylene.

[0030] In the present invention, the second dispersant preferably contains polar groups, has good affinity with inorganic nanoparticles, and contains polymer chains with good compatibility with polyolefins.

[0031] In the present invention, the second dispersant can be a polymer emulsion, dispersion or solution, or a low relative molecular mass polymer; when it is a polymer emulsion, dispersion or solution, the second dispersant is directly mixed and dispersed with the infrared blocking slurry; when it is a low relative molecular mass polymer, the second dispersant is melted at a certain temperature (25°C to 120°C), and then the infrared blocking slurry and the molten second dispersant are mixed and dispersed at the same temperature.

[0032] Preferably, when the second dispersant is a low molecular weight polymer, its molecular weight is between 1000 g / mol and 20000 g / mol.

[0033] Preferably, the mass of the second dispersant in step (2) is 10% to 350% of the mass of the infrared blocking material, for example, it can be 10%, 20%, 30%, 40%, 60%, 80%, 100%, 120%, 140%, 160%, 180%, 200%, 220%, 240%, 260%, 280%, 300%, 320%, 340%, 350%, etc.; more preferably, it is 50% to 250%.

[0034] Preferably, the mixing temperature in step (2) is 25°C to 120°C, for example, it can be 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, etc.

[0035] Preferably, the mixing and dispersing in step (2) is carried out under stirring, sand milling, high-speed shearing or ultrasound, and the mixing and dispersing time is 1 min to 80 min, for example, it can be 1 min, 5 min, 10 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, etc.

[0036] Preferably, the masterbatch resin in step (3) includes one or a combination of at least two of polyethylene, polypropylene, polyolefin elastomer, polyvinyl chloride, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyethylene grafted with maleic anhydride, oxidized polyethylene, and chlorinated polyethylene.

[0037] Preferably, based on the total mass of the infrared blocking agent and the masterbatch resin as 100%, the mass of the infrared blocking agent is 1% to 80%, for example, it can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% and the like.

[0038] Preferably, the mixing temperature in step (3) is 25°C to 100°C, for example, it can be 25°C, 30°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, etc.; the mixing time is 1s to 90min, for example, it can be 1s, 2s, 5s, 10s, 20s, 40s, 60s, 1min, 5min, 10min, 20min, 40min, 60min, 80min, 85min, 90min, etc.

[0039] In the present invention, the mixing equipment includes but is not limited to a magnetic stirrer, a mechanical stirrer, a high-speed mixer, a sand mill, an ultrasonic disperser, and the like.

[0040] Preferably, the extrusion temperature in step (3) is 80°C to 300°C, for example, it can be 80°C, 90°C, 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, etc.; the extrusion speed is 30rpm to 300rpm, for example, it can be 30rpm, 40rpm, 50rpm, 60rpm, 70rpm, 80rpm, 90rpm, 100rpm, 120rpm, 140rpm, 160rpm, 180rpm, 200rpm, 220rpm, 240rpm, 260rpm, 280rpm, 300rpm, etc.

[0041] In the present invention, the extrusion equipment includes but is not limited to one or more of a twin-screw extruder, a single-screw extruder, an extrusion granulator, an internal mixer, an open mixer, and a kneader.

[0042] Preferably, step (3) further includes cooling and pelletizing steps after the extrusion.

[0043] In a second aspect, the present invention provides an infrared blocking masterbatch, which is prepared by the preparation method described in the first aspect.

[0044] In a third aspect, the present invention provides a method for preparing an infrared blocking film, the preparation method comprising the following steps:

[0045] (S1) preparing an infrared blocking masterbatch by the preparation method described in the first aspect;

[0046] (S2) mixing the infrared blocking masterbatch obtained in step (S1) with a film resin, and extruding the mixture to obtain the infrared blocking film.

[0047] Preferably, based on the total mass of the film resin and the infrared blocking masterbatch as 100%, the mass of the infrared blocking masterbatch is 1% to 20%, for example, 1%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, etc.

[0048] In the present invention, if the content of the infrared blocking masterbatch is too much, the transmittance of the film to visible light will decrease; if the content is too little, the infrared blocking effect of the film will be poor and the heat insulation effect will decrease.

[0049] Preferably, the film resin includes one or a combination of at least two of polyethylene, polypropylene, polyethylene elastomer, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, ultra-high molecular weight polyethylene, polyethylene terephthalate, thermoplastic polyurethane, nylon, and polyvinyl chloride.

[0050] Preferably, the mixed materials in step (S2) also include other additives.

[0051] Preferably, the mass of the other additives is 0.1% to 1% of the mass of the infrared blocking film, for example, it may be 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1% and the like.

[0052] Preferably, the other auxiliary agents include any one of a compatibilizer, an antioxidant, a UV absorber, a nucleating agent, a plasticizer, a toughening agent, a heat stabilizer, a dispersant, a lubricant, a colorant, a light stabilizer or an antistatic agent, or a combination of at least two thereof.

[0053] Preferably, the extrusion temperature in step (S2) is 80°C to 300°C, for example, 80°C, 90°C, 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, etc.

[0054] In the present invention, the molding method for obtaining the infrared blocking film includes any one of extrusion molding, blow molding, calendering molding, cast molding or stretching molding.

[0055] In a fourth aspect, the present invention provides an infrared blocking film, which is prepared by the preparation method described in the third aspect.

[0056] In a fifth aspect, the present invention provides an agricultural film or a film for a photobioreactor, wherein the agricultural film or the film for a photobioreactor comprises an infrared blocking masterbatch prepared by the preparation method described in the first aspect or an infrared blocking film prepared by the preparation method described in the third aspect.

[0057] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The preparation method of the infrared blocking masterbatch provided by the present invention solves the problems in the prior art that the nano infrared blocking material is very easy to agglomerate in the resin and the nano infrared blocking material is difficult to disperse uniformly therein by mixing and dispersing the infrared blocking slurry with the second dispersant in the liquid phase or the molten state, and can effectively improve the infrared blocking rate of the film and ensure that the film has a high transmittance to visible light. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Nanoparticle size distribution diagram of infrared blocking slurry in Example 1.

[0061] Figure 2Scanning electron microscope image of the cross section of the infrared blocking masterbatch of Example 1.

[0062] Figure 3 Scanning electron microscope image of the cross section of the infrared blocking masterbatch of Comparative Example 1.

[0063] Figure 4 UV-visible-near-infrared spectra of infrared blocking film of Application Example 1.

[0064] Figure 5 The present invention provides a schematic flow chart of the preparation method. DETAILED DESCRIPTION

[0065] The technical scheme of the present invention is further described below by specific implementation methods. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. The experimental methods in the following examples without specifying specific conditions are selected according to conventional methods and conditions, or according to the product specifications.

[0066] In the present invention, the preparation process flow chart of the infrared blocking masterbatch is as follows Figure 5 As shown, the process includes mixing a nano infrared blocking material, a first dispersant and water, and subjecting the mixture to ball milling or sand milling to obtain an infrared blocking slurry; then mixing and dispersing the infrared blocking slurry with a second dispersant, removing the solvent, and obtaining an infrared blocking auxiliary agent; then mixing the infrared blocking auxiliary agent with a masterbatch resin, and extruding the mixture to obtain the infrared blocking masterbatch.

[0067] Example 1

[0068] This embodiment provides a method for preparing an infrared blocking masterbatch, which specifically includes the following steps:

[0069] (1) Antimony tin oxide powder (average particle size of 20 nm), sodium polyacrylate (Aladdin) and deionized water were mixed, the pH of the solution was adjusted to 8, and the mixture was ground in a sand mill at 3000 rpm using 0.1 mm zirconium oxide beads for 8 h to obtain antimony tin oxide slurry (average particle size of 58 nm); the mass percentage of antimony tin oxide in the antimony tin oxide slurry was 30%; the mass of the sodium polyacrylate was 6% of the mass of the antimony tin oxide powder;

[0070] (2) mixing the antimony tin oxide slurry obtained in step (1) with an ethylene-vinyl acetate copolymer emulsion (Nanjing Tianshi), mixing and dispersing for 30 minutes under magnetic stirring conditions, and freeze-drying to obtain an infrared blocking additive; the mass of the ethylene-vinyl acetate copolymer emulsion is 333% of the mass of the antimony tin oxide powder;

[0071] (3) The infrared blocking auxiliary agent obtained in step (2) and ethylene-vinyl acetate copolymer (EVA resin) are put into a twin-screw extruder, the processing temperature is set to 180° C., the screw speed is set to 120 rpm, and after melt extrusion, the mixture is cooled and pelletized to obtain the infrared blocking masterbatch; the mass percentage of the infrared blocking auxiliary agent in the infrared blocking masterbatch is 50%.

[0072] The particle size of the tin antimony oxide slurry obtained in Example 1 was characterized by a nano-laser particle size analyzer (Zetasizer Pro, Malvern Panalytical, UK). Figure 1 As shown by Figure 1 It can be seen that the particle size of tin oxide antimony in the tin oxide antimony slurry is basically distributed within 100 nm, and the average particle size is 58 nm.

[0073] The morphology of the infrared blocking masterbatch obtained in Example 1 was characterized by a scanning electron microscope (JSM-IT 800, Japan Electronics). Figure 2 As shown by Figure 2 It can be seen that antimony tin oxide is uniformly dispersed in the polymer without any large agglomerates.

[0074] Example 2

[0075] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the sodium polyacrylate in step (1) is 1.5% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0076] Example 3

[0077] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the sodium polyacrylate in step (1) is 4.5% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0078] Example 4

[0079] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the sodium polyacrylate in step (1) is 16% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0080] Example 5

[0081] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the sodium polyacrylate in step (1) is 25% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0082] Example 6

[0083] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the sodium polyacrylate in step (1) is 35% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0084] Example 7

[0085] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the sodium polyacrylate in step (1) is 0.2% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0086] Example 8

[0087] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that in step (1), the sodium polyacrylate is replaced with polyvinyl alcohol of equal mass, and the other step parameters are the same as those in Embodiment 1.

[0088] Example 9

[0089] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that in step (1), the sodium polyacrylate is replaced with 3-aminopropyltrimethoxysilane of equal mass, and the other step parameters are the same as those in Embodiment 1.

[0090] Example 10

[0091] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the ethylene-vinyl acetate copolymer emulsion in step (2) is 280% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0092] Embodiment 11

[0093] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the ethylene-vinyl acetate copolymer emulsion in step (2) is 150% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0094] Example 12

[0095] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the ethylene-vinyl acetate copolymer emulsion in step (2) is 40% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0096] Example 13

[0097] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that the mass of the ethylene-vinyl acetate copolymer emulsion in step (2) is 400% of the mass of the antimony tin oxide powder, and the other step parameters are the same as those in Embodiment 1.

[0098] Embodiment 14

[0099] This embodiment provides a method for preparing an infrared blocking masterbatch, which differs from Embodiment 1 only in that in step (2), the ethylene-vinyl acetate copolymer emulsion is replaced by an aqueous polyurethane emulsion (McLean) of equal mass, and the other step parameters are the same as those in Embodiment 1.

[0100] Embodiment 15

[0101] This embodiment provides a method for preparing an infrared blocking masterbatch, which specifically includes the following steps:

[0102] (1) Antimony tin oxide (average particle size of 20 nm) and sodium polyacrylate were mixed with 69.4 parts of deionized water, the pH of the solution was adjusted to 8, and the mixture was ground at a speed of 3000 rpm for 8 hours using 0.1 mm zirconium oxide beads in a sand mill and agitator to obtain an infrared blocking slurry (average particle size of 58 nm); the mass percentage of antimony tin oxide in the infrared blocking slurry was 30%; the mass of the sodium polyacrylate was 6% of the total mass of the infrared blocking material;

[0103] (2) heating ethylene-vinyl acetate copolymer wax (BASF) to 95° C. until completely melted, heating the infrared blocking slurry obtained in step (1) to the same temperature and then slowly adding it to the melted ethylene-vinyl acetate copolymer wax, while uniformly mixing using a high-speed shear homogenizer, heating until the water is completely evaporated, and cooling to obtain an infrared blocking additive; the ethylene-vinyl acetate copolymer wax accounts for 125% of the infrared blocking material;

[0104] (3) The infrared blocking auxiliary agent obtained in step (2) and ethylene-vinyl acetate copolymer (VA15%) are put into a twin-screw extruder, the processing temperature is set to 180°C, the screw speed is set to 180 rpm, and after melt extrusion, the mixture is cooled and pelletized to obtain the infrared blocking masterbatch; the mass percentage of the infrared blocking auxiliary agent in the infrared blocking masterbatch is 55%.

[0105] Example 16

[0106] This embodiment provides a method for preparing an infrared blocking masterbatch, which specifically includes the following steps:

[0107] (1) Lanthanum hexaboride (average particle size of 50 nm), sodium polyacrylate and deionized water were mixed, the pH of the solution was adjusted to 8, and the mixture was ground in a sand mill with 0.1 mm zirconium oxide beads at a speed of 3000 rpm for 5 h to obtain a lanthanum hexaboride slurry (average particle size of 80 nm); the mass percentage of lanthanum hexaboride in the lanthanum hexaboride slurry was 8%; the mass percentage of the sodium polyacrylate was 6% of the mass of the lanthanum hexaboride;

[0108] (2) mixing the lanthanum hexaboride slurry obtained in step (1) with an ethylene-vinyl acetate copolymer emulsion, mixing and dispersing for 40 minutes under magnetic stirring conditions, and freeze-drying to obtain an infrared blocking additive; the mass of the ethylene-vinyl acetate copolymer emulsion is 333% of the mass of the lanthanum hexaboride;

[0109] (3) The infrared blocking additive obtained in step (2) and polyethylene are put into a twin-screw extruder, the processing temperature is set to 180° C., the screw speed is set to 150 rpm, and after melt extrusion, the mixture is cooled and pelletized to obtain the infrared blocking masterbatch; the mass percentage of the infrared blocking additive in the infrared blocking masterbatch is 20%.

[0110] Embodiment 17

[0111] This embodiment provides a method for preparing an infrared blocking masterbatch, which specifically includes the following steps:

[0112] (1) Antimony tin oxide (average particle size of 20 nm) and lanthanum hexaboride (average particle size of 80 nm), sodium polyacrylate and 69.4 parts of deionized water were mixed, the pH of the solution was adjusted to 8, and the mixture was ground at a speed of 3000 rpm for 8 hours using 0.1 mm zirconium oxide beads in a sand mill and agitator to obtain an infrared blocking slurry (average particle size of 85 nm); the mass percentage of lanthanum hexaboride in the infrared blocking slurry was 3%, and the mass percentage of tungsten bronze was 15%; the mass of the sodium polyacrylate was 6% of the total mass of the infrared blocking material;

[0113] (2) mixing the infrared blocking slurry obtained in step (1) with an ethylene-vinyl acetate copolymer emulsion, mixing and dispersing for 60 minutes under magnetic stirring conditions, and freeze-drying to obtain an infrared blocking auxiliary agent; the mass of the ethylene-vinyl acetate copolymer emulsion is 333% of the mass of the infrared blocking material;

[0114] (3) The infrared blocking auxiliary agent obtained in step (2) and polypropylene are put into a twin-screw extruder, the processing temperature is set to 200° C., the screw speed is set to 180 rpm, and after melt extrusion, the mixture is cooled and pelletized to obtain the infrared blocking masterbatch; the mass percentage of the infrared blocking auxiliary agent in the infrared blocking masterbatch is 20%.

[0115] Comparative Example 1

[0116] System without the addition of a second dispersant

[0117] This comparative example provides a method for preparing an infrared blocking masterbatch, which differs from Example 1 only in that step (2) is not performed in the preparation method, and step (3) is directly performed after the infrared blocking slurry obtained in step (1) is dried, and the other step parameters are the same as those in Example 1.

[0118] The morphology of the infrared blocking masterbatch obtained in Comparative Example 1 was characterized by a scanning electron microscope (JSM-IT 800, Japan Electronics). Figure 3 As shown by Figure 3 It can be seen that the masterbatch infrared barrier material obtained by directly using the ground infrared barrier material without mixing with the second dispersant and melt blending with the polymer forms micron-sized agglomerates.

[0119] Application Examples 1 to 17, Comparative Application Example 1

[0120] Application Examples 1 to 17 and Comparative Application Example 1 respectively provide an infrared blocking film and a preparation method thereof, the preparation method of the infrared blocking film comprising: preparing infrared blocking masterbatch by the methods provided in Examples 1 to 17 and Comparative Example 1 respectively; then mixing the infrared blocking masterbatch with EVA resin, adding the mixture to a twin-screw extruder, wherein the temperature of the heating zone of the extruder is 140°C, the temperature of the head heating extrusion zone is 160°C, the speed of the barrel screw is controlled to be 45r / min, cooling by air cooling after extrusion, and cutting with a cutter to obtain a thermal insulation masterbatch of antimony tin oxide, wherein the mass percentage of antimony tin oxide in the thermal insulation masterbatch of antimony tin oxide is 20%. The infrared blocking film is obtained, wherein the mass percentage of infrared blocking masterbatch in the infrared blocking film is 10%.

[0121] The absorption of light in different bands of the infrared blocking film in Example 1 was characterized using a UV-visible near-infrared spectrophotometer (Shimadzu UV3600). The results are as follows: Figure 4 As shown by Figure 4 It can be seen that the transmittance of the film decreases significantly after a wavelength of 1100 nm.

[0122] Performance Testing

[0123] (1) Particle size distribution of slurry: tested using a nano-laser particle size analyzer.

[0124] (2) Dispersion of nano-infrared barrier materials in masterbatch: tested by scanning electron microscopy; the masterbatch was immersed in liquid nitrogen, rapidly frozen and then broken, and the cross section was sprayed with gold and then observed under a scanning electron microscope.

[0125] (3) The transmittance of infrared blocking film to light of different wavelengths: tested by UV-visible-near infrared spectrophotometer.

[0126] (4) The LS182 solar film tester from Shenzhen Linshang Technology Co., Ltd. was used to measure the visible light transmittance, (1400nm) infrared rejection rate, and (940nm) infrared rejection rate of the transparent thermal insulation film. The specific test results are shown in Table 1.

[0127] Table 1

[0128]

[0129]

[0130] As can be seen from Table 1, according to Examples 1-17, it can be seen that since the infrared blocking material is mixed with the second dispersant to obtain the infrared blocking auxiliary agent before preparing the masterbatch, the infrared blocking material is dispersed at the nanometer level therein, and in the process of preparing the masterbatch, the infrared blocking material is evenly dispersed in the masterbatch and is not easy to produce larger agglomerates, thereby giving the infrared blocking film a higher infrared blocking rate and visible light transmittance; from Comparative Example 1, it can be seen that directly using the infrared blocking material after grinding and dispersion, since the surface energy of the nanoparticles is large during the mixing process, the nanoparticles agglomerate during the mixing process, and the viscosity of the molten resin is large, the nano infrared blocking material is difficult to disperse evenly, and the infrared blocking rate and visible light transmittance of the resulting film are both low.

[0131] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an infrared blocking masterbatch, characterized in that: The preparation method comprises the following steps: (1) mixing and dispersing an infrared blocking material, a first dispersant and a solvent to obtain an infrared blocking slurry; (2) mixing and dispersing the infrared blocking slurry obtained in step (1) with a second dispersant, and removing the solvent to obtain an infrared blocking auxiliary agent; (3) mixing the infrared blocking auxiliary agent obtained in step (2) with the masterbatch resin, extruding, and molding to obtain the infrared blocking masterbatch; The second dispersant includes a polymer dispersant; the second dispersant is mixed and dispersed with the infrared blocking slurry in a liquid phase or in a molten state.

2. The preparation method according to claim 1, characterized in that: The average particle size of the infrared blocking material in step (1) is 10 nm to 200 nm, more preferably 10 nm to 50 nm; Preferably, the infrared blocking material in step (1) includes infrared blocking material A and / or infrared blocking material B; the infrared blocking material A includes at least one of antimony tin oxide, indium tin oxide, aluminum zinc oxide, titanium dioxide or tungsten bronze; the infrared blocking material B includes rare earth hexaboride; Preferably, the rare earth hexaboride comprises at least one of neodymium hexaboride, gadolinium hexaboride, praseodymium hexaboride, lanthanum hexaboride, cerium hexaboride or samarium hexaboride; Preferably, the mass percentage of the infrared blocking material A in the infrared blocking slurry of step (1) is 1% to 50%, more preferably 15% to 30%; Preferably, the mass percentage of the infrared blocking material B in the infrared blocking slurry in step (1) is 0.1% to 30%, more preferably 1% to 10%.

3. The preparation method according to claim 1 or 2, characterized in that: Step (1) the first dispersant comprises a silane coupling agent and / or a surfactant; Preferably, the silane coupling agent includes at least one of vinyl triethoxysilane, 3-aminopropyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane, γ-glycidoxypropyl methyl diethoxysilane, γ-glycidoxypropyl trimethoxysilane, 3-(2,3-epoxypropyloxy)propyl trimethoxysilane, γ-aminopropyl triethoxysilane, acrylate propyl trimethoxysilane and phenylaminopropyl trimethoxysilane; Preferably, the surfactant comprises at least one of polyvinyl pyrrolidone, sodium polyacrylate, polyvinyl alcohol, polyethylene glycol stearic acid, sodium lignosulfonate, hexadecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate or tetrapropylammonium bromide; Preferably, the mass of the first dispersant in step (1) is 0.5% to 50% of the infrared blocking material; Preferably, the solvent in step (1) comprises water and / or an alcohol solvent; Preferably, the dispersing method in step (1) comprises grinding and dispersing; Preferably, the average particle size of the infrared blocking slurry in step (1) is 20 nm to 150 nm.

4. The preparation method according to any one of claims 1 to 3, characterized in that: Step (2) the second dispersant comprises at least one of ethylene-vinyl acetate copolymer, polyethylene, waterborne polyurethane, acrylic resin, oxidized polyethylene, chlorinated polyethylene, polyethylene grafted with maleic anhydride, etherified polyethylene, and sulfonated polyethylene; Preferably, the mass of the second dispersant in step (2) is 10% to 350% of the mass of the infrared blocking material, more preferably 50% to 250%; Preferably, the mixing and dispersing in step (2) is carried out under stirring, sand milling, high-speed shearing or ultrasonic conditions, and the mixing and dispersing time is 1 min to 80 min.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The masterbatch resin in step (3) comprises one or a combination of at least two of polyethylene, polypropylene, polyolefin elastomer, polyvinyl chloride, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyethylene grafted with maleic anhydride, oxidized polyethylene, and chlorinated polyethylene; Preferably, based on the total mass of the infrared blocking agent and the masterbatch resin being 100%, the mass of the infrared blocking agent is 1% to 80%; Preferably, the mixing temperature in step (3) is 25°C to 100°C, and the mixing time is 1s to 90min; Preferably, the extrusion temperature in step (3) is 80°C to 300°C; Preferably, step (3) further includes cooling and pelletizing steps after the extrusion.

6. An infrared blocking masterbatch, characterized in that: The infrared blocking masterbatch is prepared by the preparation method according to any one of claims 1 to 5.

7. A method for preparing an infrared blocking film, characterized in that: The preparation method comprises the following steps: (S1) preparing an infrared blocking masterbatch by the preparation method described in any one of claims 1 to 5; (S2) mixing the infrared blocking masterbatch obtained in step (S1) with a film resin, and extruding the mixture to obtain the infrared blocking film.

8. The preparation method according to claim 7, characterized in that: The mass of the infrared blocking masterbatch is 1% to 20% based on the total mass of the film resin and the infrared blocking masterbatch as 100%; Preferably, the film resin comprises one or a combination of at least two of polyethylene, polypropylene, polyethylene elastomer, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polyethylene terephthalate, thermoplastic polyurethane, nylon, and polyvinyl chloride; Preferably, the mixed material in step (S2) further includes other additives; Preferably, the mass of the other additives is 0.1% to 1% of the mass of the infrared blocking film; Preferably, the other auxiliary agents include any one or a combination of at least two of a compatibilizer, an antioxidant, a UV absorber, a nucleating agent, a plasticizer, a toughening agent, a heat stabilizer, a dispersant, a lubricant, a colorant, a light stabilizer or an antistatic agent; Preferably, the extrusion temperature in step (S2) is 80°C to 300°C.

9. An infrared blocking film, characterized in that: The infrared blocking film is prepared by the preparation method described in claim 7 or 8.

10. An agricultural film or a film for a photobioreactor, characterized in that: The agricultural film or the film for photobioreactor comprises the infrared blocking masterbatch prepared by the preparation method according to any one of claims 1 to 5 or the infrared blocking film prepared by the preparation method according to claim 7 or 8.

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