Packaging adhesive film for heat insulation of assembly and preparation method of packaging adhesive film

Abstract

The invention discloses a packaging adhesive film for heat insulation of a component and a preparation method thereof, and belongs to the technical field of packaging adhesive films. A heat insulation filler is added into the packaging adhesive film, and the heat insulation filler is compounded by a high-particle-size filler and a low-particle-size filler; a high-particle-size filler and a low-particle-size filler are compounded to form heat insulation powder, a'macroscopic-microscopic 'gradient heat insulation network is formed, the high-particle-size filler blocks a heat conduction path, the low-particle-size filler inhibits gas convective heat transfer, the thermal resistance of a filler-matrix interface is reduced through surface modification, and different from traditional single filler addition, the heat insulation effect is good. The heat conductivity is reduced through the multi-scale synergistic effect, and the heat insulation effect is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of packaging films, and in particular relates to a packaging film for component thermal insulation and a preparation method thereof. Background Art

[0002] As the global energy structure transition accelerates, the application of photovoltaic power generation in areas such as construction, agriculture, and transportation continues to expand. Among them, the thermal insulation performance of photovoltaic modules has become a significant factor affecting system efficiency, building energy consumption, and user comfort. High operating temperatures of photovoltaic modules will increase the temperature of the module's hot spots, increasing the risk of hot spots and reducing the reliability of the modules. In winter, the surface temperature of photovoltaic modules during operation often reaches over 60°C; in summer, the surface temperature of photovoltaic modules during operation often reaches over 80°C. The higher the operating temperature of photovoltaic modules, not only does the risk of hot spots increase, but the power generation also decreases. This is especially true for photovoltaic roofs and photovoltaic curtain walls, where their thermal insulation performance directly affects building energy consumption, module power generation efficiency, and indoor comfort. Summary of the Invention

[0003] The present invention provides an encapsulating film for heat insulation of components and a preparation method thereof. Heat insulation fillers are added to the film to reduce the thermal conductivity of the film, thereby reducing the temperature of the component by 10-30°C compared with conventional components when in use.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions: A packaging film for component thermal insulation, comprising the following components in percentage by mass: 70%-85% main thermoplastic particles, 1%-6% cross-linking monomer, 0.6%-1.5% thermal initiator, 0.5%-1.5% coupling agent, 0.2%-1.0% anti-aging additive, 5%-20% thermal insulation powder filler.

[0005] The main thermoplastic particles are EVA particles or POE particles; The cross-linking monomer is one or more of triallyl isocyanurate, divinylbenzene, and propoxylated glycerol triacrylate; The thermal initiator is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester or dicumyl peroxide; The coupling agent is a silane coupling agent, a phthalate coupling agent or a phosphate coupling agent; The anti-aging agent is one or more of phenolic antioxidants, UV-531, UV-P, and carbodiimide stabilizers; The thermal insulation powder is a compound of a high-particle size filler of 10 microns to 50 microns and a low-particle size filler of less than 10 microns; the high-particle size filler is one or two of hollow glass microspheres and hollow ceramic powders, and the low-particle size filler is one or more of expanded graphite, silica aerogel, aluminum hydroxide, carbon nanotubes, paraffin phase change microcapsules, and fluorine-doped tin oxide (FTO) nanoparticles.

[0006] The method for preparing the above-mentioned encapsulation film for component thermal insulation comprises the following steps: All fillers were vacuum dried at 80 °C for 4 h before use to remove surface adsorbed moisture; The inorganic filler was first treated with a coupling agent: the filler was dispersed in an ethanol / water (90 / 10) solution, 1.5 wt% of a silane coupling agent was added, refluxed at 80 °C for 2 h, and filtered to dryness; Use a high-speed mixer (800-1000rpm) to premix the base resin and liquid additives for 10 minutes. After adding the solid filler, reduce the speed to 400-600rpm and continue mixing for 15-20 minutes to avoid damage to the filler structure. The mixing temperature is controlled at 50°C to ensure mixing uniformity and prevent premature cross-linking. After uniform mixing, lamination is performed to obtain a product packaging film with a thickness of 500-600 microns.

[0007] Beneficial effects: The present invention provides a packaging film for component thermal insulation and a preparation method thereof, which has the following advantages over the prior art: 1. The present invention compounds high-particle size fillers with low-particle size fillers to form an insulating powder, forming a "macro-micro" gradient insulation network. The high-particle size filler blocks the heat conduction path, and the low-particle size filler inhibits gas convection heat transfer. Surface modification (such as silane coupling agent grafting) is used to reduce the filler-matrix interface thermal resistance. Unlike traditional single filler additions, the present invention reduces thermal conductivity through multi-scale synergistic effects. The use of the encapsulation film of the present invention reduces the temperature of the components in building facade photovoltaic and photovoltaic roof applications. It improves indoor living comfort and also has fireproof properties. The thermal insulation film can effectively block heat transfer to the indoor environment, reducing the building's air conditioning load and improving the working efficiency and service life of photovoltaics. 2. Use expanded graphite or aluminum hydroxide filler. Expanded graphite expands when heated to form a "worm-like" barrier layer, and aluminum hydroxide decomposes to absorb heat and release water vapor. Both can achieve flame retardancy and reduce the heat transfer rate, breaking through the bottleneck of traditional adhesive films that are difficult to balance flame retardancy and thermal insulation performance, while meeting the fire safety requirements of building photovoltaics (BIPV). BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Schematic diagram of the use of the packaging film in an embodiment of the present invention. DETAILED DESCRIPTION

[0009] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments: Example 1

[0010] A packaging film for component thermal insulation is prepared from the following raw materials in percentage by mass: EVA particles 80%, divinylbenzene 5%, dicumyl peroxide 1%, phthalate coupling agent 1%, phenolic antioxidant 0.5%, and the rest are thermal insulation powder fillers; The thermal insulation powder filler includes 10% hollow ceramic microspheres (average particle size 15 μm), 2% aluminum hydroxide (particle size 1-2 μm), and 0.5% carbon nanotubes (multi-walled, diameter 10-20 nm).

[0011] The method for preparing the above-mentioned encapsulation film for component thermal insulation comprises the following steps: All the above fillers were vacuum dried at 80 °C for 4 h before use to remove surface adsorbed moisture; The inorganic filler was first treated with a coupling agent: the filler was dispersed in an ethanol / water (90 / 10) solution, 1.5 wt% of a silane coupling agent was added, refluxed at 80 °C for 2 h, and filtered to dryness; Use a high-speed mixer (800-1000 rpm) to premix the base resin and liquid additive for 10 minutes. After adding the solid filler, reduce the speed to 400-600 rpm and continue mixing for 15-20 minutes to avoid damage to the filler structure. The mixing temperature is controlled at 50°C to ensure mixing uniformity and prevent premature cross-linking. After mixing evenly, lamination is performed to obtain the product packaging film. Example 2

[0012] A packaging film for component thermal insulation is prepared from the following raw materials in percentage by mass: POE particles 80%, triallyl isocyanurate 5%, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane 1%, KH570 silane coupling agent 1%, carbodiimide stabilizer 1%, and the rest are thermal insulation powder fillers; The thermal insulation powder filler includes 9% hollow glass microspheres (average particle size 20 μm), 2% silica aerogel (hydrophobic type, particle size 1-3 μm), and 1% expanded graphite (particle size 15 μm, expansion multiple 150).

[0013] The method for preparing the above-mentioned encapsulation film for component thermal insulation comprises the following steps: All the above fillers were vacuum dried at 80 °C for 4 h before use to remove surface adsorbed moisture; The inorganic filler was first treated with a coupling agent: the filler was dispersed in an ethanol / water (90 / 10) solution, 1.5 wt% of a silane coupling agent was added, refluxed at 80 °C for 2 h, and filtered to dryness; Use a high-speed mixer (800-1000 rpm) to premix the base resin and liquid additive for 10 minutes. After adding the solid filler, reduce the speed to 400-600 rpm and continue mixing for 15-20 minutes to avoid damage to the filler structure. The mixing temperature is controlled at 50°C to ensure mixing uniformity and prevent premature cross-linking. After mixing evenly, lamination is performed to obtain the product packaging film. Example 3

[0014] A packaging film for component thermal insulation is prepared from the following raw materials in percentage by mass: POE particles 80%, propoxylated glyceryl triacrylate 5%, tert-butyl peroxycarbonate-2-ethylhexyl ester 1.5%, KH570 silane coupling agent 1%, UV-531 0.5%, and the rest are thermal insulation powder fillers; The thermal insulation powder filler includes 9% hollow glass microspheres (average particle size 10 μm), 1% aluminum hydroxide (1-2 μm), 1.5% commercially available paraffin@PMMA phase change microcapsules (phase change temperature 28°C, particle size 2-5 μm), and 0.5% fluorine-doped tin oxide (FTO) nanoparticles.

[0015] The method for preparing the above-mentioned encapsulation film for component thermal insulation comprises the following steps: All the above fillers were vacuum dried at 80 °C for 4 h before use to remove surface adsorbed moisture; The inorganic filler was first treated with a coupling agent: the filler was dispersed in an ethanol / water (90 / 10) solution, 1.5 wt% of a silane coupling agent was added, refluxed at 80 °C for 2 h, and filtered to dryness; Use a high-speed mixer (800-1000 rpm) to premix the base resin and liquid additive for 10 minutes. After adding the solid filler, reduce the speed to 400-600 rpm and continue mixing for 15-20 minutes to avoid damage to the filler structure. The mixing temperature is controlled at 50°C to ensure mixing uniformity and prevent premature cross-linking. After mixing evenly, lamination is performed to obtain the product packaging film.

[0016] The encapsulation film prepared in the above embodiment and conventional EPE film were used in the assembly, and the thermal insulation effect is shown in Table 1. Table 1 shows the thermal insulation effect of each packaging film Test conditions Conventional film components Example 1 Thermal insulation film assembly Example 2 Thermal insulation film assembly Example 3: Thermal insulation film assembly Noon module surface temperature (℃) 73.5 61.8 63.5 62.4 Module backside temperature (℃) 56.2 42.3 41.3 40.8 Indoor temperature (℃) 39.2 29.5 30.5 29.4 As can be seen from Table 1, the encapsulation films prepared in the above-mentioned embodiments have better thermal insulation than conventional encapsulation films. The above-mentioned embodiments use expanded graphite or aluminum hydroxide fillers. Expanded graphite expands upon heat to form a "worm-like" barrier layer, while aluminum hydroxide decomposes to absorb heat and release water vapor, both of which achieve flame retardancy and reduce heat transfer rates. The film of Example 3 is embedded with paraffin wax and PMMA phase change microcapsules (phase change temperature 28±2°C). Their core material absorbs heat during component operation and undergoes a phase change, smoothing temperature fluctuations. Combined with infrared-reflective fillers (antimony-doped tin oxide ATO), a triple-control mechanism of "heat absorption, heat storage, and reflection" is achieved. The synergistic effect of the phase change material and infrared reflection reduces temperature fluctuations of the component under illumination, achieving excellent thermal insulation and minimizing the impact on component operating efficiency.

[0017] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A packaging film for component thermal insulation, characterized in that: Includes the following components by mass percentage: 70%-85% main thermoplastic particles, 1%-6% cross-linking monomer, 0.6%-1.5% thermal initiator, 0.5%-1.5% coupling agent, 0.2%-1.0% anti-aging additive, 5%-20% thermal insulation filler; the thermal insulation filler is a compound of high-particle size filler and low-particle size filler.

2. The packaging film for component thermal insulation according to claim 1, characterized in that: The main thermoplastic particles are EVA particles or POE particles.

3. The packaging film for component thermal insulation according to claim 1, characterized in that: The cross-linking monomer is one or more of triallyl isocyanurate, divinylbenzene, and propoxylated glycerol triacrylate.

4. The packaging film for component thermal insulation according to claim 1, characterized in that: The thermal initiator is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester or dicumyl peroxide.

5. The packaging film for component thermal insulation according to claim 1, characterized in that: The coupling agent is a silane coupling agent, a phthalate coupling agent or a phosphate coupling agent.

6. The packaging film for component thermal insulation according to claim 1, characterized in that: The anti-aging additive is one or more of phenolic antioxidants, UV-531, UV-P, and carbodiimide stabilizers.

7. The packaging film for component thermal insulation according to claim 1, characterized in that: The high-particle size filler is one or both of hollow glass microspheres and hollow ceramic powders.

8. The packaging film for component thermal insulation according to claim 1, characterized in that: The low-particle size filler is one or more of expanded graphite, silica aerogel, aluminum hydroxide, carbon nanotubes, paraffin phase change microcapsules, and fluorine-doped tin oxide nanoparticles.

9. The method for preparing the encapsulating film for component thermal insulation according to any one of claims 1 to 8, characterized in that: The following steps are involved: All fillers were vacuum dried before use to remove surface adsorbed moisture; Disperse the inorganic filler in an ethanol / water (90 / 10) solution, add a silane coupling agent, reflux, and filter and dry; The base resin and liquid additives are premixed using a high-speed mixer. After adding the solid filler, the speed is reduced and the mixing is continued. The mixing temperature is controlled at 50°C. After mixing evenly, the mixture is coated to obtain the product packaging film.

10. The method for preparing a packaging film for component thermal insulation according to claim 9, characterized in that: The packaging film has a thickness of 500-600 microns.

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