Color-changing PET (Polyethylene Terephthalate) master batch and photovoltaic module containing same

Abstract

The invention provides a color-changing PET (Polyethylene Terephthalate) master batch and a photovoltaic module containing the same. The color-changing PET master batch comprises PET and a color-changing material, the color-changing material comprises a color-changing composition and / or a color-changing microcapsule; the color-changing composition comprises the following components in percentage by mass: 0.5-10% of a first color-hiding agent, 0.3-50% of a first color developing agent and 40-99% of a first solvent, and the color-changing microcapsule comprises the following components in percentage by mass: 0.2-6% of a second leuco agent, 1.5-10% of a second color developing agent, 40-98% of a second solvent and 5-60% of a wall material. The color-changing PET master batch can play a role in intelligent temperature adjustment, the temperature of the assembly is reduced when the temperature is too high, material aging is delayed, the power generation efficiency is improved, and the service life is prolonged; and the color-changing PET master batch can present different appearances along with the change of temperature, so that the photovoltaic module has an electric function, decoration and light weight.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic materials technology, specifically relating to a color-changing PET masterbatch and a photovoltaic module containing the same. Background Technology

[0002] Against the backdrop of the global energy transition, photovoltaic (PV) power generation has become one of the core energy forms due to its clean and renewable characteristics. Traditional PV modules mostly use glass as the encapsulation material. While glass has good light transmittance and weather resistance, it also has disadvantages such as being heavy and fragile, making it prone to breakage during transportation, installation, and use, increasing costs and maintenance difficulties. Furthermore, the photoelectric conversion efficiency, mechanical properties, and aging resistance of existing PV modules need further improvement; and they lack warning functions, posing safety hazards.

[0003] Therefore, developing an encapsulation material that can improve the photoelectric conversion efficiency, mechanical properties, and aging resistance of photovoltaic modules, and also serve as a warning, and can replace glass, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a color-changing PET masterbatch and a photovoltaic module containing the same; the color-changing PET masterbatch has thermochromic properties and can improve the photoelectric conversion efficiency, mechanical properties and aging resistance of the photovoltaic module.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a color-changing PET masterbatch, the color-changing PET masterbatch comprising PET and a color-changing material; the color-changing material comprising a color-changing composition and / or color-changing microcapsules; the color-changing composition comprising, by weight percentage, 0.5-10% of a first leucocyanate, 0.3-50% of a first color developer and 40-99% of a first solvent; and the color-changing microcapsules comprising, by weight percentage, 0.2-6% of a second leucocyanate, 1.5-10% of a second color developer, 40-98% of a second solvent and 5-60% of a wall material.

[0007] In this invention, the leuco dye is the core substance providing color change; the color developer reacts with the leuco dye to form color, while the solvent controls the color-changing temperature and provides a phase change environment; by using a specific mixture of leuco dye, color developer, and solvent, it is ensured that the leuco dye and color developer fully react to form a colored substance, and can completely separate when the temperature rises, achieving reversible color change; the color-changing PET masterbatch can play a role in intelligent temperature regulation. When the temperature is too high, the color change will effectively reduce the incident light irradiance, reflect or scatter more sunlight, lower the temperature of the module, delay material aging, and increase power generation efficiency and service life; and the color-changing PET masterbatch can present different appearances with temperature changes, which can meet the aesthetic requirements of building-integrated photovoltaics (BIPV) and other scenarios, allowing photovoltaic modules to have both power generation function and decoration, adapt to different architectural styles, and also meet the requirements of lightweighting.

[0008] In this invention, 0.5-10% of the first leuco agent can be, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc.

[0009] In this invention, the first colorimetric agent is 0.3-50%, for example, it can be 0.5%, 1%, 2%, 4%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, etc.

[0010] In this invention, the first solvent is 40-99%, for example, it can be 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 87%, 89%, 91%, 93%, 95%, 97%, etc.

[0011] In this invention, 0.2% to 6% of the second leuco agent can be, for example, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, etc.

[0012] In this invention, 1.5-10% of the second colorimetric agent can be, for example, 2%, 4%, 6%, 8%, 10%, etc.

[0013] In this invention, the second solvent is 40-98%, for example, it can be 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 87%, 89%, 91%, 93%, 95%, 97%, etc.

[0014] In this invention, 5-60% of the wall material can be, for example, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, etc.

[0015] In this invention, an excessively high concentration of the luminescent agent will result in incomplete color change.

[0016] Preferably, the first leucoant and the second leucoant each independently include at least one of crystal violet lactone, rhodamine B, and fluorane dyes.

[0017] Preferably, the fluorane dyes include red pigment-16 and / or 2′-chloro-6′-diethylaminofluorane.

[0018] Preferably, the first color developer and the second color developer each independently comprise at least one of bisphenol A, alkyl gallate, and octanoic acid.

[0019] In this invention, the alkyl gallate includes lauryl gallate.

[0020] Preferably, the solvent includes long-chain alcohol solvents and / or long-chain ester solvents, wherein the number of carbon atoms in the long-chain alcohol solvent and the long-chain ester solvent is independently ≥10, for example, 12, 14, 16, 18, etc.

[0021] Preferably, the first solvent and the second solvent include at least one of tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol, and dodecyl hexadecyl ester.

[0022] In this invention, the wall material comprises melamine resin.

[0023] Preferably, the color-changing composition comprises system A and / or system B.

[0024] Preferably, system A comprises crystal violet lactone, bisphenol A, and tetradecyl alcohol.

[0025] Preferably, the mass ratio of crystal violet lactone, bisphenol A, and tetradecyl alcohol is 1:(3~5):(100~130); wherein, the specific values ​​of (3~5) can be, for example, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, etc.; and the specific values ​​of 100~130 can be, for example, 105, 110, 115, 120, 125, 128, etc.

[0026] In this invention, when selected from system A, the color-changing PET masterbatch can change from black to transparent at 30°C; the crystal violet lactone, as a colorless lactone structure, combines with the color developer at low temperature to form a black complex; bisphenol A donates protons to cause crystal violet lactone (CVL) to open its ring and develop color; tetradecyl alcohol acts as a synergist, solvent, and melting point regulator, with a melting point of 38°C close to the target color-changing temperature of 30°C, triggering a molecular conformational change through a melt-solidification process. When the temperature exceeds 30°C, tetradecyl alcohol melts and destroys the complex structure, and the material becomes transparent; after cooling, it recrystallizes and returns to black. An excessively high proportion of bisphenol A will cause the color-changing temperature to shift upwards.

[0027] Preferably, system A further includes carbon black microcapsules; the core material of the carbon black microcapsules includes carbon black, and the wall material of the carbon black microcapsules includes urea-formaldehyde resin.

[0028] Preferably, the mass percentage of carbon black microcapsules in system A is 1-5%, for example, it can be 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, etc.

[0029] In this invention, adding carbon black microcapsules to system A makes it easier to achieve a low-temperature black effect; the microcapsule wall material (such as urea-formaldehyde resin) remains intact below 30°C, and the carbon black disperses to form a black appearance; when the temperature exceeds 30°C, the wall material softens and cracks, the carbon black is dissolved by tetradecyl alcohol, and the material becomes transparent.

[0030] Preferably, system A further includes alkyl gallate, with the mass ratio of bisphenol A to alkyl gallate being 1:(0.5~5), wherein the specific values ​​of (0.5~5) can be, for example, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8.

[0031] In this invention, by partially replacing bisphenol A with alkyl gallate, the color change point of system A can be adjusted, changing the color change point from 30°C to 28~32°C.

[0032] Preferably, system A further includes an antioxidant.

[0033] In this invention, the antioxidant includes antioxidant 1010.

[0034] Preferably, the antioxidant in system A is 0.05-0.5% by mass, for example, it can be 0.06%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, etc.

[0035] Preferably, system B comprises fluorescein dyes, octanoic acid, and octadecanol.

[0036] Preferably, the mass ratio of the fluorane dye, octanoic acid, and octadecanol is 1:(0.5~5):(10~50); wherein, the specific values ​​of (0.5~5) can be, for example, 0.6, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, etc.; and the specific values ​​of (10~50) can be, for example, 15, 20, 25, 30, 35, 40, 45, etc.

[0037] In this invention, when system B is selected, the color-changing PET masterbatch turns red at temperatures above 75°C; fluorane dyes (such as Red Pigment-16) react with the color developer at high temperatures to form a red quinone structure; the color developer is octanoic acid, which is a weak acid and requires higher temperatures (>75°C) to effectively protonate the fluorane molecules; octadecanol has a melting point of 59°C, and its high-temperature melting promotes the color reaction and has good compatibility with the PET substrate.

[0038] Preferably, system B further includes tetradecyl alcohol; based on the total mass of tetradecyl alcohol and octadecyl alcohol as 100%, the mass percentage of tetradecyl alcohol is 80-90%, for example, it can be 82%, 84%, 86%, 88%, etc.

[0039] In this invention, tetradecyl alcohol and octadecyl alcohol are combined to broaden the red display range above 75°C, and the higher melting point of octadecyl alcohol slows down the color change process.

[0040] Preferably, the second solvent in the color-changing microcapsule comprises dodecyl hexadecanoate, tetradecyl alcohol, and octadecyl alcohol.

[0041] Preferably, based on the total mass of the color-changing microcapsules as 100%, the second solvent comprises 20-40% (e.g., 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, etc.) dodecanol palmitate, 20-40% tetradecanol (e.g., 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, etc.) and 0.5-4% stearyl alcohol (e.g., 0.6%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, etc.).

[0042] In this invention, the second leucotropic agent, the second color-developing agent, and the second solvent in the color-changing microcapsule are core materials; the color-changing microcapsules can be prepared using conventional methods in the art; exemplaryly, they can be prepared using the following methods:

[0043] The second leucoant, the second color developer, and the second solvent were mixed and completely dissolved to obtain the core material. The core material was mixed with emulsifier (Span-80, 10% of the core material mass) and water at 60°C for 25 min to obtain an emulsion. 10 g of melamine and 16.5 g of formaldehyde solution were mixed with 100 mL of deionized water, and the pH was adjusted to 8.5 with 5% sodium carbonate solution. The mixture was reacted at 80°C for 40 min to form a prepolymer solution. The emulsion was added to the prepolymer solution, and the pH of the mixture was adjusted to 5.0 with 5% citric acid solution. The mixture was stirred at 70°C for 6 h, filtered, washed, and dried to obtain the color-changing microcapsules.

[0044] Preferably, the mass of the color-changing material is 0.4-15% of the mass of PET, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 8%, 10%, 12%, 14%, etc.

[0045] Preferably, the melting point of the PET is 180~200℃.

[0046] In this invention, low-melting-point PET (such as copolymer PET) should be selected to avoid excessively high processing temperatures (usually 230~250℃) that could damage the thermochromic components.

[0047] In this invention, the color-changing PET masterbatch also includes 0.1-5% of additives, such as 0.2%, 0.4%, 0.6%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, etc.

[0048] Preferably, the additives include at least one of dispersants, antioxidants, lubricants, nucleating agents, coupling agents, and ultraviolet absorbers.

[0049] In this invention, the content of each of the dispersant, antioxidant, lubricant, nucleating agent, coupling agent, and ultraviolet absorber is independently 0.1-1%.

[0050] In this invention, the coupling agent includes a silane coupling agent, such as aminopropyltriethoxysilane.

[0051] In this invention, other components may be added to the color-changing PET masterbatch as needed, such as at least one of oil-free alkyd resin, mica titanium pearl pigment, microcrystalline wax powder, and fumed silica.

[0052] Preferably, by weight percentage, the color-changing PET comprises at least one of the following: 10-20% oil-free alkyd resin (e.g., 12%, 14%, 16%, 18%), 5-15% mica titanium pearlescent pigment (e.g., 6%, 8%, 10%, 12%, 14%), 5-10% microcrystalline wax powder (e.g., 6%, 7%, 8%, 9%), and 1-5% fumed silica (e.g., 2%, 3%, 4%).

[0053] In a second aspect, the present invention provides a resin composition comprising, by weight percentage, 85-95% matrix resin (e.g., 86%, 88%, 90%, 92%, 94%, etc.) and 5-15% (e.g., 6%, 8%, 10%, 12%, 14%, etc.) color-changing PET masterbatch as described in the first aspect.

[0054] Thirdly, the present invention provides a PET profile, the PET profile comprising the color-changing PET masterbatch described in the first aspect or the resin composition described in the second aspect.

[0055] In this invention, the color-changing PET profile can be a color-changing PET film or a color-changing PET sheet, and the appropriate shape can be selected according to actual needs.

[0056] In this invention, the color-changing PET film and / or color-changing PET sheet can be a single-layer structure or a multi-layer structure.

[0057] In this invention, the color-changing PET profile is selected from a multi-layer structure, which may include a PET substrate, a color-changing functional layer and a protective layer arranged sequentially; the color-changing functional layer is prepared from the color-changing PET masterbatch described in the first aspect or the resin composition described in the second aspect.

[0058] In this invention, the color-changing PET profile is selected from a multi-layer structure, and the thickness of the PET substrate is 50~300 micrometers, for example, it can be 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, etc.; the thickness of the color-changing functional layer is 5~30 micrometers, for example, it can be 6 micrometers, 8 micrometers, 10 micrometers, 12 micrometers, 15 micrometers, 18 micrometers, 20 micrometers, 22 micrometers, 25 micrometers, 28 micrometers, etc.

[0059] In this invention, the color-changing PET can be configured with a suitable structure according to actual needs. When a single-layer structure is selected, the preparation method includes: mixing PET with a color-changing material, melting it, and then molding it using processes such as extrusion (direct extrusion or multi-layer co-extrusion), injection molding, blow molding, and calendering, so that the color-changing material is uniformly dispersed in the PET matrix, and the color changes with temperature (e.g., low-temperature color development and high-temperature fading). When a multi-layer composite structure is selected, the preparation method can be to coat the surface of the PET substrate with a color-changing material to obtain a color-changing functional layer; then, a protective layer is attached to the surface of the color-changing functional layer to obtain the color-changing PET.

[0060] Fourthly, the present invention provides a photovoltaic module, the photovoltaic module comprising the color-changing PET masterbatch described in the first aspect, the resin composition described in the second aspect, or the color-changing PET profile described in the third aspect.

[0061] Preferably, the photovoltaic module includes a color-changing PET layer, a first encapsulating film layer, a solar cell, a second encapsulating film layer, and a PET layer arranged sequentially.

[0062] In this invention, the first encapsulating film layer and the second encapsulating film layer each independently include an EVA encapsulating film.

[0063] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0064] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0065] The color-changing PET masterbatch provided by this invention uses a specific blend of leucocyanate, developer, and solvent to ensure that the leucocyanate and developer react fully to form a colored substance, while completely separating upon temperature increase, achieving reversible color change. The color-changing PET masterbatch can also provide intelligent temperature regulation; when the temperature is too high, the color change effectively reduces incident light irradiance, reflects or scatters more sunlight, lowers the module temperature, delays material aging, and increases power generation efficiency and lifespan. Furthermore, the color-changing PET presents different appearances with temperature changes, meeting the aesthetic requirements of building-integrated photovoltaics (BIPV) and other scenarios, allowing photovoltaic modules to combine power generation and decoration, adapting to different architectural styles, while also meeting lightweight requirements, reducing weight by approximately 2 / 3 compared to traditional modules. In addition, by selecting different color-changing materials, the product can display a warning color when the temperature exceeds 80℃ during use, serving as an alert. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the structure of a photovoltaic module provided for application example 2 of the present invention.

[0067] Among them, 500 is the color-changing PET layer, 600 is the first EVA encapsulation film layer, 700 is the battery cell, 800 is the second EVA encapsulation film layer, and 900 is the PET layer. Detailed Implementation

[0068] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0069] All materials used in this invention can be obtained commercially available materials or prepared using conventional methods. Unless otherwise specified, the materials used in this invention are as follows.

[0070] PET chips: Juyuanhong

[0071] Regular PET: Shouyu.

[0072] Dispersant: Polyamide wax, Haimings.

[0073] Nucleating agent: Licomont NaV101.

[0074] Antioxidant: Antioxidant 1010.

[0075] Example 1

[0076] This embodiment provides a color-changing PET masterbatch, comprising PET chips and a color-changing material; by mass percentage, the color-changing material comprises 0.8% crystal violet lactone, 3.2% bisphenol A and 96% tetradecyl alcohol (i.e., a mass ratio of 1:4:120); the mass of the color-changing material is 2% of the mass of the PET chips; the color-changing PET masterbatch also comprises 0.4% dispersant, 0.3% antioxidant, 0.2% polyethylene glycol 4000 and 0.2% erucamide.

[0077] This embodiment provides a method for preparing color-changing PET masterbatch, specifically including the following steps:

[0078] (1) Weigh crystal violet lactone, bisphenol A and tetradecyl alcohol according to the ratio, place them in a sealed container, and stir them in a constant temperature water bath at 70°C until they are completely dissolved to form a uniform and transparent color-changing mother liquor.

[0079] (2) The PET chips dried to a moisture content of ≤0.02% are mixed with the above color-changing mother liquor and placed in a high-speed mixer. The mixture is stirred at 110°C for 15 minutes to achieve pre-dispersion and obtain pre-dispersion material.

[0080] (3) The pre-dispersed material is fed into a twin-screw extruder, and the temperature of each zone of the screw is set to 250-270℃ (zone 1 250℃, zone 2 260℃, zone 3 270℃), the die head temperature is 265℃, and the screw speed is 200r / min. After melt blending, the material is extruded through the die head, cooled and pelletized to obtain the color-changing PET masterbatch.

[0081] Example 2

[0082] This embodiment provides a color-changing PET masterbatch, comprising PET chips and color-changing material; by mass percentage, the color-changing material comprises 5.1% red pigment-16, 4.9% octanoic acid and 90% octadecanol (i.e., a mass ratio of 1:0.93:17.5); the mass of the color-changing material is 4% of the mass of PET.

[0083] This embodiment provides a method for preparing color-changing PET masterbatch, specifically including the following steps:

[0084] (1) Weigh out red pigment-16, octanoic acid and octadecanol in a mass ratio of 1:0.93:17.5, mix and stir in a constant temperature stirring tank at 80℃ for 30 minutes until red pigment-16 is completely dissolved to form a homogeneous color-changing mother liquor;

[0085] (2) The color-changing masterbatch is mixed with dried PET chips (moisture content ≤0.02%), melted, extruded and granulated by a twin-screw extruder (process parameters of twin-screw extruder: zone 1 250℃, zone 2 260℃, zone 3 270℃, die head temperature 265℃, speed 200r / min) to obtain the PET color-changing masterbatch.

[0086] Example 3

[0087] This embodiment provides a color-changing PET masterbatch, comprising PET chips and microencapsulated color-changing material; the microencapsulated color-changing material comprises a color-changing material core and a wall material; by mass percentage, the microencapsulated color-changing material comprises 0.5% 2′-chloro-6′-diethylaminofluorane, 4% bisphenol A, 65% a mixed solvent of dodecyl hexadecyl acetate and tetradecyl alcohol (mass ratio of the two is 1:1), 2% octadecyl alcohol, and 28.5% melamine resin wall material; the color-changing PET masterbatch further comprises 0.2% silane coupling agent (KH-550), 0.4% dispersant, 0.5% ultraviolet absorber (UV-P), and 0.4% nucleating agent; the mass of the microencapsulated color-changing material is 14.4% of the mass of the PET chips.

[0088] This embodiment provides a method for preparing the color-changing PET masterbatch, specifically including the following steps:

[0089] (1) Dry the microencapsulated color-changing material (particle size 2~7μm) in a hot air drying oven at 60℃ for 1h to remove the surface adsorbed moisture and set aside.

[0090] (2) Dry the PET chips at 140℃ and -0.09MPa for 4h to obtain dried PET chips (moisture content ≤0.02%); stir the silane coupling agent, dispersant, ultraviolet absorber and nucleating agent at low speed (600rpm) for 8min in a high-speed mixer to obtain well dispersed additives.

[0091] (3) Add the dried PET chips to the end of the high-speed mixer, then slowly add the well dispersed additives, and stir at high speed (2000 rpm) for 15 minutes to make the additives uniformly coat the PET particles; then reduce the speed of the mixer to 700 rpm, slowly add the dried microencapsulated color-changing material, and continue stirring for 12 minutes to ensure that the microencapsulated color-changing material is uniformly dispersed and there are no obvious lumps, and obtain the mixture.

[0092] (4) The mixture is added to a twin-screw extruder and the barrel temperature is controlled in sections: Zone 1 245℃, Zone 2 265℃, Zone 3 275℃, Zone 4 280℃, and the die head temperature 275℃. The screw speed is 2000 rpm and the vacuum degree is -0.08 MPa. The volatiles are discharged through the dual vacuum exhaust ports. The melt is filtered through a filter screen (120-150 mesh) and then extruded to obtain the color-changing PET masterbatch.

[0093] Example 4

[0094] This embodiment provides a color-changing PET masterbatch, which differs from Example 3 in that, by mass percentage, the microencapsulated color-changing material includes 1% 2′-chloro-6′-diethylaminofluorane, 6% bisphenol A, 80% a mixed solvent of dodecyl hexadecyl acetate and tetradecanol (mass ratio of the two is 1:1), 4% octadecyl alcohol, and 9% wall material. Other components, dosages, and preparation methods are the same as in Example 3.

[0095] Example 5

[0096] This embodiment provides a color-changing PET masterbatch, which differs from Example 3 in that, by mass percentage, the microencapsulated color-changing material includes 0.3% 2′-chloro-6′-diethylaminofluorane, 2% bisphenol A, 40% a mixed solvent of dodecyl hexadecyl acetate and tetradecanol (mass ratio of the two is 1:1), 0.5% octadecyl alcohol, and 57.2% wall material. Other components, dosages, and preparation methods are the same as in Example 3.

[0097] Example 6

[0098] This embodiment provides a color-changing PET masterbatch, which differs from Example 1 in that the mass ratio of crystal violet lactone, bisphenol A, and tetradecyl alcohol is 1:6:90 (mass percentages of 1%, 6.2%, and 92.8%, respectively). Other components, dosages, and preparation methods are the same as in Example 1.

[0099] Example 7

[0100] This embodiment provides a color-changing PET masterbatch, which differs from Example 1 in that the mass ratio of crystal violet lactone, bisphenol A, and tetradecyl alcohol is 1:2:140 (mass percentages of 0.7%, 1.4%, and 98%, respectively). The other components, dosages, and preparation methods are the same as in Example 1.

[0101] Example 8

[0102] This embodiment provides a color-changing PET masterbatch, which differs from Example 2 in that the mass ratio of red pigment-16, octanoic acid and octadecanol is 1:0.2:60 (mass percentage content is 1.634%, 0.326% and 98.04% respectively), while the other components, dosages and preparation methods are the same as in Example 1.

[0103] Example 9

[0104] This embodiment provides a color-changing PET masterbatch, which differs from Example 2 in that the mass ratio of red pigment-16, octanoic acid and octadecanol is 1:5:5 (mass percentages of 9%, 45.5% and 45.5% respectively), while the other components, dosages and preparation methods are the same as in Example 1.

[0105] Example 10

[0106] This embodiment provides a color-changing PET masterbatch, which differs from Example 2 in that the octanoic acid is replaced with an equal mass of alkyl 3,4,5-trihydroxybenzoic acid ester, while the other components, dosages, and preparation methods are the same as in Example 1.

[0107] Application Example 1-1

[0108] This application example provides a PET profile, which is prepared from the color-changing PET masterbatch provided in Example 1. The specific preparation method includes the following steps:

[0109] The color-changing PET masterbatch is added to a twin-screw extruder, melt-extruded, and then conveyed to a three-roll calender. After calendering, cooling and shaping, and edge trimming and winding, the PET profile is obtained.

[0110] The process parameters for the twin-screw extruder are: Zone 1 250℃, Zone 2 260℃, Zone 3 270℃, Die head 265℃, and screw speed 200r / min.

[0111] The process parameters for the three-roll calender are as follows: Roll temperature: 85℃ for the first roll, 90℃ for the second roll, and 90℃ for the third roll; adjust the roll spacing to control the sheet thickness (1mm); and match the calendering speed with the extrusion speed (6m / min).

[0112] The cooling and shaping process involves cooling the product to room temperature using a 25°C cooling roller, followed by traction by a traction machine at a speed of 6 m / min.

[0113] Application Example 1-2

[0114] This application example provides a PET profile, which, by weight percentage, is prepared from 10% of the color-changing PET masterbatch provided in Example 2 and 90% ordinary PET. The specific preparation method includes the following steps:

[0115] The color-changing PET masterbatch and ordinary PET are dried at 130℃ for 5 hours (moisture content ≤0.02%). Using a double-layer co-extrusion unit, ordinary PET is added to the main feed port and color-changing masterbatch is added to the side feed port. After melt extrusion, the material is cooled and shaped to obtain the PET profile.

[0116] The process parameters for the double-layer co-extrusion unit are as follows: Zone 1: 250℃, Zone 2: 260℃, Zone 3: 270℃, Die head: 265℃, Die head temperature: 270℃, and Screw speed: 200r / min.

[0117] Cooling and shaping process parameters: After the co-extruded material is extruded through the die head, it immediately enters the cooling roller group (temperature 70℃) for shaping, and the cooling rate is controlled at 10℃ / s.

[0118] Application Examples 1-3

[0119] This application example provides a PET profile, which is prepared from the color-changing PET masterbatch provided in Example 3. The specific preparation method includes the following steps:

[0120] The color-changing PET masterbatch is added to a twin-screw extruder, melt-extruded, and then conveyed to a three-roll calender. After calendering, cooling and shaping, and edge trimming and winding, the PET profile is obtained.

[0121] The process parameters for the twin-screw extruder are: Zone 1 250℃, Zone 2 260℃, Zone 3 270℃, Die head 265℃, and screw speed 200r / min.

[0122] The process parameters for the three-roll calender are as follows: Roll temperature: 85℃ for the first roll, 90℃ for the second roll, and 90℃ for the third roll; adjust the roll spacing to control the sheet thickness (1mm); and match the calendering speed with the extrusion speed (6m / min).

[0123] The cooling and shaping process involves cooling the product to room temperature using a 25°C cooling roller, followed by traction by a traction machine at a speed of 6 m / min.

[0124] Application Examples 1-4 to 10

[0125] Application Examples 1-4 to 10 each provide a PET profile. The only difference between them and Application Example 1 is that the color-changing PET masterbatch is provided in Examples 4-10, and the other preparation methods are the same as in Application Example 1.

[0126] In this invention, unless otherwise specified, the thickness of the PET profiles provided in Application Examples 1-1 to 1-10 is 1 mm.

[0127] Application Example 2

[0128] A photovoltaic module, the structural schematic diagram of which is shown below. Figure 1 As shown, it includes a color-changing PET layer 500, a first EVA encapsulation film layer 600, a battery cell 700, a second EVA encapsulation film layer 800, and a PET layer 900 arranged sequentially; the materials of the color-changing PET layer are the PET profiles provided in Application Examples 1-1 to 1-10.

[0129] Performance testing

[0130] The PET profiles provided in test cases 1-1 to 1-10 were subjected to the following performance tests.

[0131] Reversibility testing methods

[0132] Cyclic color change test: The color-changing PET sample is repeatedly switched between environments >40℃ (color development, such as black, red) and <color change critical temperature (color decolorization, transparency) (such as alternating between a 45℃ oven and a 25℃ room temperature) for 50 cycles. After each cycle, the color development depth and the color decolorization state (transparency after color decolorization) are observed to see if they are consistent with the initial state.

[0133] The color development is divided into two levels: deep color development and light color development. Deep color development indicates high color change sensitivity and good color change effect, while light color development indicates slightly poorer color change sensitivity and slightly poorer color change effect.

[0134] The decolorization is divided into three levels, which are classified as excellent, medium, and poor based on the transparency after decolorization. Among them, if a piece of paper with black text is placed at the bottom of the color-changing PET sample and the text can be clearly seen, it is considered excellent; if it can be seen but is slightly blurry, it is considered medium; and if it cannot be seen, it is considered poor.

[0135] The balance indicates a color rendering level of deep and an achromatic level of medium, which can balance color rendering and achromaticity to achieve the effect of deep color rendering + transparent achromaticity.

[0136] Stability testing methods

[0137] Thermal shock test: A thermal shock chamber was used, employing air thermal shock at a wind speed of 1.5 m / s. The high-temperature range was set to 45-50℃ (holding temperature for 30 min), and the low-temperature range to 20-25℃ (holding temperature for 30 min). 50 shock cycles were performed. After the test, it was checked whether the sample could still develop / decolorize normally, without any color change lag or failure. The thermal shock retention rate was calculated. Specifically, the color change time was used for characterization. The initial color change time was recorded as T0 (the color change time corresponding to 0 shock cycles), and the color change time after 50 thermal shock cycles was recorded as T1.

[0138] Thermal shock retention rate (%) = T0 / T1 × 100%.

[0139] Lightfastness test: A xenon lamp aging test chamber (simulating natural light) was used, with the irradiation intensity controlled at 0.83W / m²@340nm and continuous irradiation for 150h. Referring to GB / T 39822-2021, the color difference before and after aging was tested. The color difference before aging was recorded as E0, and the color difference after aging was recorded as E1. The yellowing index △E=E1-E0.

[0140] Specifically, the color change time is used to characterize the color change stability before and after aging; the color change time before aging is recorded as t0, and the color change time after 150 hours of irradiation is recorded as t1.

[0141] Color retention rate after aging (%) = t0 / t1 × 100%.

[0142] The closer the retention rate is to 100%, the less the material's performance degrades under environmental influences, and the stronger its stability.

[0143] The specific test results are shown in Table 1.

[0144] Table 1

[0145]

[0146] As shown in Table 1, among the schemes with deep color rendering (Examples 1-3, 5-6, and 9), only Example 1-3 achieves a balanced effect of "medium color removal" (core advantage: deep color rendering + transparent color removal), while the rest (Examples 5-6 and 9) are all "poor color removal" (only excellent color rendering, poor color removal performance).

[0147] Among the light-colored schemes (Examples 4, 7-8, 10), only Examples 4 and 7-8 achieve "excellent color removal" (core advantage: color removal transparency), while Example 10 exhibits a dual difference performance of "light color display + color removal difference".

[0148] As shown in Table 1, the profiles containing the color-changing PET masterbatch provided by this invention have good color-changing stability, with a thermal shock performance retention rate of ≥75%, a color-changing retention rate of ≥70% after light aging, and a color difference ΔE ≤2.2 before and after light aging. In fact, they can even achieve a thermal shock performance retention rate of ≥85%, a color-changing retention rate of ≥80% after light aging, and a color difference ΔE ≤1.5 before and after light aging.

[0149] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A color-changing PET masterbatch, characterized in that, The color-changing PET masterbatch includes PET and color-changing material; The color-changing material includes a color-changing composition and / or color-changing microcapsules; The color-changing composition comprises, by weight percentage, 0.5-10% of a first leucoant, 0.3-50% of a first color developer, and 40-99% of a first solvent; The color-changing microcapsules, by mass percentage, comprise 0.2-6% of a second leucocyanate, 1.5-10% of a second color developer, 40-98% of a second solvent, and 5-60% of a wall material.

2. The color-changing PET masterbatch according to claim 1, characterized in that, The first leuco agent and the second leuco agent each independently include at least one of crystal violet lactone, rhodamine B, and fluorane dyes; Preferably, the fluorane dyes include red pigment-16 and / or 2′-chloro-6′-diethylaminofluorane.

3. The color-changing PET masterbatch according to claim 1 or 2, characterized in that, The first color developer and the second color developer each independently include at least one of bisphenol A, alkyl gallate, and octanoic acid; Preferably, the solvent includes long-chain alcohol solvents and / or long-chain ester solvents, wherein the number of carbon atoms in the long-chain alcohol solvent and the long-chain ester solvent is independently ≥10. Preferably, the first solvent and the second solvent each independently comprise at least one of tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol, and dodecyl hexadecanoate.

4. The color-changing PET masterbatch according to claim 1, characterized in that, The color-changing composition comprises system A and / or system B; Preferably, system A comprises crystal violet lactone, bisphenol A, and tetradecyl alcohol; Preferably, the mass ratio of crystal violet lactone, bisphenol A, and tetradecyl alcohol is 1:(3~5):(100~130). Preferably, system A further includes carbon black microcapsules; the core material of the carbon black microcapsules includes carbon black, and the wall material of the carbon black microcapsules includes urea-formaldehyde resin. Preferably, the carbon black microcapsules in system A have a mass percentage content of 1-5%; Preferably, system A further includes alkyl gallate, with the mass ratio of bisphenol A to alkyl gallate being 1:(0.5~5). Preferably, system A further includes an antioxidant; Preferably, the antioxidant in system A is 0.05-0.5% by mass.

5. The color-changing PET masterbatch according to claim 4, characterized in that, System B comprises fluorane dyes, octanoic acid, and octadecanol; Preferably, the mass ratio of the fluorane dye, octanoic acid, and octadecanol is 1:(0.5~5):(10~50). Preferably, system B further includes tetradecyl alcohol; based on the total mass of tetradecyl alcohol and octadecyl alcohol being 100%, the mass percentage of tetradecyl alcohol is 80-90%. Preferably, the second solvent in the color-changing microcapsule comprises dodecyl hexadecanoate, tetradecyl alcohol, and octadecyl alcohol; Preferably, based on the total mass of the color-changing microcapsules as 100%, the second solvent comprises 20-40% dodecanol palmitate, 20-40% tetradecanol, and 0.5-4% octadecyl alcohol.

6. The color-changing PET masterbatch according to any one of claims 1 to 5, characterized in that, The mass of the color-changing material is 0.4-15% of the mass of PET; Preferably, the melting point of the PET is 180~200℃; Preferably, the color-changing PET masterbatch further includes 0.1-5% additives; Preferably, the additives include at least one of dispersants, antioxidants, lubricants, nucleating agents, coupling agents, and ultraviolet absorbers.

7. A resin composition, characterized in that, The resin composition comprises, by weight percentage, 85-95% matrix resin and 5-15% color-changing PET masterbatch as described in any one of claims 1-6; Preferably, the matrix resin includes PET.

8. A PET profile, characterized in that, The PET profile includes the color-changing PET masterbatch as described in any one of claims 1 to 6 or the resin composition as described in claim 7.

9. A photovoltaic module, characterized in that, The photovoltaic module includes the color-changing PET masterbatch according to any one of claims 1 to 6, the resin composition according to claim 7, or the PET profile according to claim 8.

10. The photovoltaic module according to claim 9, characterized in that, The photovoltaic module comprises a color-changing PET layer, a first encapsulating film layer, a solar cell, a second encapsulating film layer, and a PET layer arranged sequentially.

Images