Waterproof and thermal insulation integrated compression garbage truck closed cabin coating and preparation method thereof

Abstract

This invention relates to the field of special functional coating materials technology, and provides a waterproof and heat-insulating integrated sealed compartment coating for compressed garbage trucks and its preparation method. The coating comprises a POSS-modified epoxy-acrylic hybrid emulsion, reactive elastic aerogel microspheres, and a thermally switching phase change-thermal conductive hybrid filler. The reactive microspheres are modified with supercritical CO2, possessing both superhydrophobic groups and polymerizable double bonds on their surface, enabling them to form chemical bonds with the resin matrix, greatly improving vibration resistance and durability. The thermally switching filler consists of a three-dimensional thermally conductive framework encapsulating the phase change material, providing temperature-triggered adaptive thermal management. POSS modification enhances the emulsion stability and the coating's resistance to internal stress. An ultrasonic-assisted stepped curing process guides the coating to form a stable and uniform functional gradient structure. This invention achieves excellent waterproof, heat-insulating, corrosion-resistant, vibration-resistant, and adaptive thermal management performance with a single layer, making it particularly suitable for long-term protection under harsh working conditions such as compressed garbage trucks.

Description

Technical Field

[0001] This invention belongs to the field of special functional coating materials technology, and in particular relates to a waterproof and heat-insulating integrated sealed compartment coating for a compressed garbage truck and its preparation method. Background Technology

[0002] The enclosed compartment of a compressed garbage truck is subjected to extreme and harsh environments, including high temperature, high humidity, corrosive media (leachate), mechanical vibration, and thermal shock. Existing technical solutions have the following main drawbacks:

[0003] Multi-layer structure problems: The commonly used multi-layer coating system of "anti-corrosion primer + heat insulation intermediate layer + waterproof topcoat" has problems such as poor interlayer adhesion, easy delamination and peeling, complicated construction process (requiring multiple coatings and curing), long cycle and high cost. After one year of actual use, garbage truck bodies using this type of multi-layer coating often have problems such as water ingress failure of the heat insulation layer and peeling of the topcoat, and the maintenance cycle is short.

[0004] Limitations of thermal insulation materials:

[0005] Traditional thermal insulation fillers have limited thermal insulation efficiency and a fragile interface with the resin matrix, making them prone to detachment and failure under long-term vibration.

[0006] Static insulation drawback: Existing coatings provide static insulation and cannot respond to drastic changes in ambient temperature. Under intense summer sun, heat will continue to accumulate and enter the cabin, causing excessively high temperatures inside.

[0007] Weak interfacial bonding: Functional fillers (such as thermal insulation fillers and phase change material microcapsules) are usually only physically adsorbed with the resin matrix. Under long-term vibration and thermal cycling, the interface is prone to failure, leading to the degradation of coating performance. Summary of the Invention

[0008] This invention provides a waterproof and heat-insulating integrated coating for the sealed compartment of a compressed garbage truck, aiming to solve the above-mentioned problems.

[0009] This invention is achieved as follows: a waterproof and heat-insulating integrated sealed compartment coating for a compressed garbage truck, comprising the following raw materials in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 10-25 parts of reactive elastic aerogel microspheres, 3-8 parts of thermally switching phase change-thermal conductive hybrid filler, 2-6 parts of organic montmorillonite, 0.5-1.5 parts of wetting and dispersing agent, 0.2-0.8 parts of defoamer, 1-3 parts of film-forming aid, and 10-20 parts of deionized water.

[0010] Preferably, the raw materials include the following in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 15-20 parts of reactive elastic aerogel microspheres, 4-7 parts of thermally switching phase change-thermal conductive hybrid filler, 3-5 parts of organomodified montmorillonite, 0.8-1.2 parts of wetting and dispersing agent, 0.3-0.7 parts of defoamer, 1.5-2.5 parts of film-forming aid, and 12-18 parts of deionized water.

[0011] Preferably, the raw materials include the following in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 18 parts of reactive elastic aerogel microspheres, 5 parts of thermally switching phase change-thermal conductive hybrid filler, 4 parts of organomodified montmorillonite, 1 part of wetting and dispersing agent, 0.5 parts of defoamer, 2 parts of film-forming aid, and 15 parts of deionized water.

[0012] Preferably, the wetting and dispersing agent includes polycarboxylate type and polyether modified polysiloxane type; the defoamer includes mineral oil and polyether modified organosilicon; and the film-forming aid includes dodecyl alcohol ester and propylene glycol methyl ether acetate.

[0013] Preferably, the POSS-modified epoxy-acrylic hybrid emulsion is prepared by mixing component A and component B at a dry basis mass ratio of 7:3.

[0014] Component A: POSS-modified epoxy ester emulsion; prepared by reacting epoxy ester emulsion containing siloxane side chains with octamethyl polyhedral oligomeric silsesquioxane (OctaMethyl-POSS) at 60-70℃, with the amount of POSS added being 3-5 wt% of the dry basis weight of the epoxy ester emulsion; after curing, this component produces a coating film with strong adhesion and corrosion resistance, and the nanocage structure of POSS can provide stress release channels.

[0015] Component B: Fluorinated acrylate dispersion; it is copolymerized from dodecafluoroheptyl methacrylate and butyl acrylate in a mass ratio of (3:7)-(5:5), with allyl polyoxyethylene ether ammonium sulfate as the reactive emulsifier, and its dosage is 3-5% of the total mass of the monomers; after curing, the paint film of this component is hydrophobic and provides low surface energy.

[0016] After mixing, a stable "water-in-oil-in-water" multi-emulsion system is formed. After being stored at 50°C for 30 days (equivalent to about 6 months at room temperature), no stratification or flocculation was observed, and the viscosity change rate was <15%. It is predicted that its storage period at room temperature can reach more than 12 months.

[0017] Preferably, the preparation method of the reactive elastic aerogel microspheres includes the following steps:

[0018] (1) Hydrolysis: Tetraethyl orthosilicate (TEOS), ethanol, water and 0.1M hydrochloric acid were mixed in a molar ratio of 1:3:1:0.05 and stirred at 40°C for 2 hours to obtain silica sol;

[0019] (2) Emulsification: Dissolve the hydroxyl-terminated polybutadiene-type polyurethane prepolymer (molecular weight 3000, amount accounting for 30-50% of the total mass of TEOS and prepolymer) in toluene, mix it with the above silica sol and 2% of the total mass of oil phase emulsifier (Span 80), and emulsify at high speed of 8000-12000 rpm for 10 minutes to form emulsion droplets with a particle size of 20-80 μm;

[0020] (3) Simultaneous gelation and crosslinking: The emulsion was transferred to the reactor, heated to 60°C, and 0.5% of dioxanediamine (crosslinking agent) was added. The mixture was stirred for 6 hours to allow the silica sol gelation and polyurethane crosslinking to proceed simultaneously, resulting in wet gel microspheres.

[0021] (4) Supercritical compound modification: The wet gel microspheres were placed in a supercritical CO2 drying kettle. CO2 fluid containing a mixed modifier of perfluorooctyltriethoxysilane (PFOTES) and γ-methacryloyloxypropyltrimethoxysilane (KH-570) in a mass ratio of 3:1 (total concentration 1wt%, based on the mass of supercritical CO2 fluid) was introduced at a pressure of 10 MPa and a temperature of 45℃ and treated for 2 hours. PFOTES provides a superhydrophobic surface and KH-570 provides polymerizable double bonds. Then the pressure was slowly released to obtain elastic silica / polyurethane interpenetrating network aerogel microspheres with both superhydrophobic and reactive double bonds on the surface.

[0022] Product characteristics: Microspheres with a particle size of 20-80 μm and a bulk density of 0.10-0.15 g / cm³. 3 It has a water contact angle ≥152°, can withstand 30% compression deformation and fully rebound, and the surface C=C double bond density is 0.8-1.2 mmol / g as determined by iodometric titration.

[0023] Preferably, the preparation method of the thermally switching phase change-thermal conductive hybrid filler includes the following steps:

[0024] (1) Constructing a three-dimensional thermally conductive framework: Expanded graphite sheets (100 mesh) were placed in a tube furnace and treated at 850°C in an atmosphere of ammonia and borane ammonia complex (ammonia borane) vapor (molar ratio of 4-6:1) for 1 hour. Boron nitride nanosheets (BNNS) were vertically grown on the surface and between the layers to form a three-dimensional interconnected thermally conductive framework.

[0025] (2) Phase change material loading and encapsulation: The above skeleton and molten eicosane (phase change temperature about 37°C) are impregnated in a vacuum impregnation tank at 60°C for 2 hours. The amount of eicosane is 30-40% of the mass of the three-dimensional thermally conductive skeleton. Then, methyl methacrylate (MMA) monomer (20-30% of the mass of eicosane) and 1% of the mass of MMA initiator (AIBN) are added. The mixture is stirred and polymerized at 75°C for 4 hours under nitrogen protection, so that MMA is polymerized in situ on the surface and pores of the skeleton to form a polymer coating layer to prevent leakage of the phase change material and obtain a composite filler.

[0026] (3) Surface reactive modification: The obtained composite filler was lightly oxidized in an air atmosphere at 80°C for 2 hours to generate carboxyl groups on its surface. Then it was reacted with an ethanol solution of 2wt% γ-glycidyl etheroxypropyltrimethoxysilane (KH-560) at 60°C for 3 hours. After washing and drying, a hybrid filler with epoxy groups on its surface was obtained.

[0027] Product characteristics: The filler is in the form of irregular flakes with a size of 50-200μm. At temperatures below 37℃, its effective thermal conductivity is ≥5W / (m·K). In the phase transition range of 37-45℃, its apparent thermal conductivity decreases to 0.5-1.0W / (m·K) and it absorbs a large amount of latent heat (≥180J / g).

[0028] Preferably, the three-dimensional skeleton with BNNS grown on the surface obtained in step (1) can be first oxidized in air at 80°C for 2 hours, and then grafted with amino-terminated poly(N-isopropylacrylamide) (PNIPAM, molecular weight 5000, low critical solution temperature LCST of 30-34°C) at 60°C for 4 hours through an amidation reaction; the amount of PNIPAM is 25-30% of the three-dimensional skeleton (based on the mass of BNNS), the amidation reaction is carried out in a buffer system with pH=5.5-6.5, using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC·HCl) and N-hydroxysuccinimide (NHS) as activators, the molar ratio of EDC·HCl to carboxyl groups on the skeleton surface is 1.2:1, the molar ratio of NHS to EDC·HCl is 1:1, and the PNIPAM grafting rate is controlled at 15-20wt%. PNIPAM's temperature-sensitive properties (LCST≈32℃) can endow the skeleton with dynamic thermal conduction behavior: at low temperatures, the chain segments expand without affecting thermal conduction; at high temperatures, the chain segments contract and agglomerate, further disrupting the thermal conduction path, causing the apparent thermal conductivity to drop to 0.3-0.5W / (m·K) at high temperatures, and shortening the response time.

[0029] The present invention also provides a method for preparing the above-mentioned waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating, comprising the following steps:

[0030] (1) Pre-dispersion: Mix the wetting and dispersing agent, half of the deionized water and the organic montmorillonite, and disperse at high speed for 20 minutes until a uniform slurry is formed;

[0031] (2) Preparation of main slurry: Under low speed stirring, add the above slurry, reactive elastic aerogel microspheres, thermal switch phase change-thermal conductive hybrid filler, film forming aid and remaining deionized water to the POSS modified epoxy-acrylic hybrid emulsion in sequence, and stir and mix for 30 minutes.

[0032] (3) Defoaming: Add defoamer, stir at low speed for 10 minutes, and let stand for 30 minutes to defoam, to obtain coating slurry;

[0033] (4) Construction and stepped curing:

[0034] a. The slurry is sprayed in a single pass onto the surface of the closed chamber steel plate, which has been sandblasted to Sa2.5 grade, with a surface roughness Ra of 40-80μm, and has been ultrasonically cleaned with acetone and dried. The wet film thickness is controlled at 300-400μm.

[0035] b. First stage (ultrasonic-assisted infrared preheating and shaping): Immediately send it into the medium-wave infrared drying zone equipped with an ultrasonic transducer (frequency 20kHz, power 50W), and apply ultrasonic-assisted dispersion simultaneously for 4 minutes at 80-90℃; the ultrasonic cavitation effect promotes uniform dispersion of the filler, and infrared heating promotes rapid evaporation of moisture and solvent, initially forming a functional gradient and "locking" the filler distribution.

[0036] c. Second stage (gradient temperature curing): Transfer to hot air circulation drying tunnel, heat from 90℃ to 125℃ at a rate of 1.5℃ / min, and hold at 125℃ for 25 minutes; This stage completes the deep cross-linking of the resin. The C=C double bonds on the surface of the reactive elastic aerogel microspheres undergo copolymerization with the acrylate segments in the resin to form a chemical bonding interface; The epoxy groups on the surface of the thermally switched hybrid filler also react with the resin to enhance the bonding force.

[0037] Compared with the prior art, the embodiments of this application have the following main advantages:

[0038] The reactive elastic aerogel microspheres in the waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating provided by this invention are chemically bonded to the resin matrix, improving the adhesion retention rate after vibration and solving the problem of interface peeling under vibration environment.

[0039] POSS-modified hybrid emulsions have a long shelf life, and the ultrasonic-assisted curing process ensures uniform dispersion of functional fillers and good coating performance consistency.

[0040] The thermal switch hybrid filler integrates rapid heat conduction, phase change heat storage, and high-temperature insulation, dynamically responding to changes in ambient temperature and significantly improving thermal protection efficiency in extreme environments.

[0041] Through the synergy of material design and process, a stable gradient is constructed within a single coating layer, from the "superhydrophobic / thermal response layer" to the "main thermal insulation layer" and then to the "strong adhesion layer". The coating has high adhesion, high hydrophobicity, high thermal insulation, excellent corrosion resistance and resistance to thermal shock, long service life and excellent overall performance. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating the preparation method of the waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating provided by the present invention.

[0043] Figure 2 This is a flowchart of the preparation method of reactive elastic aerogel microspheres provided by the present invention.

[0044] Figure 3 This is a flowchart of the preparation method of the thermally switching phase change-thermal conductive hybrid filler provided by the present invention. Detailed Implementation

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0046] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0047] Example 1

[0048] This invention provides a waterproof and heat-insulating integrated sealed compartment coating for a compressed garbage truck, comprising the following raw materials in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 18 parts of reactive elastic aerogel microspheres, 5 parts of thermally switching phase change-thermal conductive hybrid filler, 4 parts of organomodified montmorillonite, 1 part of wetting and dispersing agent, 0.5 parts of defoamer, 2 parts of film-forming aid, and 15 parts of deionized water. Figures 1-3As shown, the preparation method of the waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating includes the following steps:

[0049] (1) Pre-dispersion: Mix the wetting and dispersing agent, half of the deionized water and the organic montmorillonite, and disperse at high speed for 20 minutes until a uniform slurry is formed;

[0050] (2) Preparation of main slurry: Under low speed stirring, add the above slurry, reactive elastic aerogel microspheres, thermal switch phase change-thermal conductive hybrid filler, film forming aid and remaining deionized water to the POSS modified epoxy-acrylic hybrid emulsion in sequence, and stir and mix for 30 minutes.

[0051] (3) Defoaming: Add defoamer, stir at low speed for 10 minutes, and let stand for 30 minutes to defoam, to obtain coating slurry;

[0052] (4) Construction and stepped curing:

[0053] a. The slurry is sprayed in a single pass onto the surface of the sealed chamber steel plate, which has been sandblasted to Sa2.5 grade, with a surface roughness Ra of 40-80μm, and has been ultrasonically cleaned with acetone and dried. The wet film thickness is about 350μm.

[0054] b. First stage (ultrasonic-assisted infrared preheating and shaping): Immediately place it into the mid-wave infrared drying zone equipped with an ultrasonic transducer (frequency 20kHz, power 50W), and simultaneously apply ultrasonic-assisted dispersion for 4 minutes at 80-90℃.

[0055] c. Second stage (gradient temperature curing): Transfer to hot air circulation drying tunnel, heat from 90℃ to 125℃ at a rate of 1.5℃ / min, and hold at 125℃ for 25 minutes; allow to cool naturally, and control the thickness of the resulting dry film coating to 150-180μm.

[0056] The wetting and dispersing agents include polycarboxylate type and polyether-modified polysiloxane type; the defoamers include mineral oil and polyether-modified organosilicon; and the film-forming aids include dodecayl alcohol ester and propylene glycol methyl ether acetate.

[0057] In this embodiment, the preparation method of the POSS-modified epoxy-acrylic hybrid emulsion is as follows:

[0058] Component A (POSS-modified epoxy ester emulsion): An epoxy ester emulsion containing siloxane side chains (50% solid content) was mixed with octamethyl polyhedral oligomeric silsesquioxane (OctaMethyl-POSS), with the amount of POSS added being 4 wt% of the epoxy ester solids. The mixture was stirred and reacted at 65°C for 3 hours to obtain the POSS-modified epoxy ester emulsion.

[0059] Component B (fluorinated acrylate dispersion): Dodecafluoroheptyl methacrylate and butyl acrylate are mixed at a mass ratio of 4:6, and 4% of allyl polyoxyethylene ether ammonium sulfate (reactive emulsifier) ​​and an appropriate amount of deionized water are added. Emulsion polymerization is carried out at 80°C to obtain a fluorinated acrylate dispersion with a solid content of 50%.

[0060] Hybrid emulsion: Mix the above components A and B at a dry basis mass ratio of 7:3 and stir at a moderate shear rate for 30 minutes to form a stable "water-in-oil-in-water" multiple emulsion, denoted as emulsion M.

[0061] In this embodiment, the preparation method of the reactive elastic aerogel microspheres includes the following steps:

[0062] (1) Hydrolysis: Tetraethyl orthosilicate (TEOS), ethanol, water and 0.1M hydrochloric acid were mixed in a molar ratio of 1:3:1:0.05 and stirred at 40°C for 2 hours to obtain silica sol;

[0063] (2) Emulsification: 40% of the total mass of TEOS and prepolymer, of hydroxyl-terminated polybutadiene-type polyurethane prepolymer (molecular weight 3000), was dissolved in toluene and mixed with 2% of the total mass of the silica sol and oil phase, of Span 80. The mixture was then subjected to high-speed shear emulsification at 10000 rpm for 10 minutes to form emulsion droplets with a particle size of 20-80 μm.

[0064] (3) Simultaneous gelation and crosslinking: The emulsion was transferred to a reaction vessel, heated to 60°C, and 0.5% of dioxanediamine (crosslinking agent) by mass of the prepolymer was added. The mixture was stirred and reacted for 6 hours to obtain wet gel microspheres.

[0065] (4) Supercritical compound modification: The wet gel microspheres were placed in a supercritical CO2 drying kettle. CO2 fluid containing a mixed modifier of perfluorooctyltriethoxysilane (PFOTES) and γ-methacryloyloxypropyltrimethoxysilane (KH-570) in a mass ratio of 3:1 (total concentration 1wt%, based on the mass of CO2 fluid) was introduced at 10 MPa and 45℃ and treated for 2 hours. After slow depressurization, reactive elastic aerogel microspheres were obtained, which were denoted as filler A. Its water contact angle was ≥152° and it could withstand 30% compression deformation and rebound.

[0066] In this embodiment, the preparation method of the thermally switching phase change-thermal conductive hybrid filler is as follows:

[0067] (1) Constructing a three-dimensional thermally conductive framework: Expanded graphite sheets (100 mesh) were placed in a tube furnace and treated at 850°C in an atmosphere of ammonia and ammonia borane vapor (molar ratio 5:1) for 1 hour to vertically grow boron nitride nanosheets on their surface to form a three-dimensional framework.

[0068] (2) Phase change material loading and encapsulation: The skeleton and molten eicosane (35% of the skeleton mass) were vacuum impregnated at 60°C for 2 hours; methyl methacrylate monomer (25% of the eicosane mass) and AIBN initiator (1% of MMA mass) were added, and polymerization was carried out at 75°C under N2 protection for 4 hours.

[0069] (3) Surface reactive modification: The obtained filler was oxidized in air at 80°C for 2 hours, and then reacted with 2wt% KH-560 ethanol solution at 60°C for 3 hours. After washing and drying, filler B1 was obtained.

[0070] Product characteristics: The filler is in the form of irregular flakes with a size of 50-200μm. At temperatures below 37℃, its effective thermal conductivity is ≥5W / (m·K). In the phase transition range of 37-45℃, its apparent thermal conductivity decreases to 0.5-1.0W / (m·K) and it absorbs a large amount of latent heat (≥180J / g).

[0071] Example 2

[0072] The difference between this embodiment and Embodiment 1 is that this embodiment provides a waterproof and heat-insulating integrated compression garbage truck sealing compartment coating, comprising the following raw materials in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 10 parts of reactive elastic aerogel microspheres, 3 parts of thermally switching phase change-thermal conductive hybrid filler, 2 parts of organic montmorillonite, 0.5 parts of wetting and dispersing agent, 0.2 parts of defoamer, 1 part of film-forming aid, and 10 parts of deionized water.

[0073] Example 3

[0074] The difference between this embodiment and Embodiment 1 is that this embodiment provides a waterproof and heat-insulating integrated compression garbage truck sealing compartment coating, comprising the following raw materials in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 15 parts of reactive elastic aerogel microspheres, 4 parts of thermally switching phase change-thermal conductive hybrid filler, 3 parts of organic montmorillonite, 0.8 parts of wetting and dispersing agent, 0.3 parts of defoamer, 1.5 parts of film-forming aid, and 12 parts of deionized water.

[0075] Example 4

[0076] The difference between this embodiment and Embodiment 1 is that this embodiment provides a waterproof and heat-insulating integrated compression garbage truck sealing compartment coating, comprising the following raw materials in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 20 parts of reactive elastic aerogel microspheres, 7 parts of thermally switching phase change-thermal conductive hybrid filler, 5 parts of organic montmorillonite, 1.2 parts of wetting and dispersing agent, 0.7 parts of defoamer, 2.5 parts of film-forming aid, and 18 parts of deionized water.

[0077] Example 5

[0078] The difference between this embodiment and Embodiment 1 is that this embodiment provides a waterproof and heat-insulating integrated compression garbage truck sealing compartment coating, comprising the following raw materials in parts by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion (solid content 48%-52%), 25 parts of reactive elastic aerogel microspheres, 8 parts of thermally switching phase change-thermal conductive hybrid filler, 6 parts of organic montmorillonite, 1.5 parts of wetting and dispersing agent, 0.8 parts of defoamer, 3 parts of film-forming aid, and 20 parts of deionized water.

[0079] Example 6

[0080] The difference between this embodiment and Example 1 is that, on the three-dimensional framework obtained in step 1 of Example 1, air oxidation is performed first, and then amino-terminated PNIPAM (molecular weight 5000, LCST≈32℃) is subjected to an amidation reaction via EDC / NHS catalysis (PNIPAM dosage is 28% of the mass of BNNS, pH=6.0), with a grafting rate of about 18wt%; subsequent steps are the same as the basic type, resulting in filler B2; at high temperature (37-45℃), the apparent thermal conductivity decreases to 0.3-0.5W / (m·K), the temperature response time is <2 seconds, and the latent heat is ≥185J / g.

[0081] Comparative Example 1: The "filler A" in Example 3 was replaced with an equal amount of ordinary elastic aerogel microspheres that were only hydrophobically modified with PFOTES (excluding KH-570), while the rest of the formulation and process remained unchanged.

[0082] Comparative Example 2: The "filler B1" in Example 3 was replaced with an equal amount of commercially available paraffin phase change microcapsules, while the rest of the formulation and process remained unchanged.

[0083] Comparative Example 3: Ultrasonic assistance was omitted in the preparation process, and only infrared preheating at 85°C for 4 minutes was performed. The rest was the same as in Example 3.

[0084] Comparative Example 4: The curing process was changed to traditional constant temperature curing: after spraying, it was directly baked at 125℃ for 30 minutes, and the rest was the same as in Example 3.

[0085] Comparative Example 5 (simulating existing technology): A three-layer coating system was adopted; the first layer was sprayed with epoxy zinc-rich primer (dry film 50μm) and cured at room temperature for 24h; the second layer was sprayed with commercially available acrylic heat insulation coating (dry film 150μm) and cured at 80℃ for 30min; the third layer was sprayed with fluorocarbon topcoat (dry film 50μm) and cured at room temperature for 72h, with a total dry film thickness of approximately 250μm.

[0086] Performance tests were conducted on all coated samples from Examples 1-6 and Comparative Examples 1-5.

[0087] The test methods are as follows: For Comparative Example 5 (multilayer system), the adhesion test is for interlayer adhesion, and the test method refers to GB / T 9286. After crossing the grid, focus on observing the interface peeling of the primer-intermediate layer and intermediate layer-topcoat. The level in the table represents the worst interlayer adhesion evaluation. Other examples / comparative examples are for substrate-coating adhesion testing; flexibility (GB / T 1731 shaft bending); impact resistance (GB / T 1732, positive impact); thermal conductivity (GB / T 10295 heat flow meter method, 25℃); steady-state temperature difference (the sample is placed on an 80℃ hot table, and the stable temperature at the center of the back is measured using a thermocouple, and ΔT is calculated); dynamic temperature rise (a 500W iodine-tungsten lamp is vertically irradiated at a distance of 30cm from the sample for 30 minutes, and the highest temperature rise at the center of the back is recorded using an infrared thermal imager); water contact angle (static drop method); salt water resistance (immersion in 3% NaCl solution, GB / T 9274); Vibration durability (frequency 30Hz, amplitude 1mm, vertical vibration for 72h, adhesion was retested and retention rate was calculated); Thermal cycling (-40℃ for 2h, 80℃ for 2h constitutes one cycle), results are shown in Table 1 below:

[0088]

[0089]

[0090] This invention utilizes reactive elastic aerogel microspheres, thermally switched phase change-thermal conductive hybrid fillers, "POSS modified hybrid emulsion" and ultrasonic-assisted step curing process to prepare a high-performance single-layer integrated functional coating.

[0091] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A waterproof and thermal insulation integrated compressed garbage truck closed cabin coating, characterized in that, The raw materials include the following by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion with a solid content of 48%-52%, 10-25 parts of reactive elastic aerogel microspheres, 3-8 parts of thermally switching phase change-thermal conductive hybrid filler, 2-6 parts of organomodified montmorillonite, 0.5-1.5 parts of wetting and dispersing agent, 0.2-0.8 parts of defoamer, 1-3 parts of film-forming aid, and 10-20 parts of deionized water; The reactive elastic aerogel microspheres are silica / polyurethane interpenetrating network microspheres with surfaces modified by a compounding of perfluorooctyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane in a mass ratio of 2-4:1, and the surface C=C double bond density of the microspheres is 0.8-1.2 mmol / g. The thermally switched phase change-thermal conductive hybrid filler comprises a three-dimensional thermally conductive framework consisting of expanded graphite and boron nitride nanosheets grown perpendicularly on its surface. The pores of the framework encapsulate the phase change material eicosane, and the surface has a polymer coating layer and epoxy group modification. The POSS-modified epoxy-acrylic hybrid emulsion is prepared by mixing a polyhedral oligomeric silsesquioxane (POSS) modified epoxy ester emulsion and a fluorinated acrylate dispersion at a dry basis mass ratio of 7:

3. The polyhedral oligomeric silsesquioxane is octamethyl polyhedral oligomeric silsesquioxane, and its addition amount is 3-5 wt% of the dry basis mass of the epoxy ester emulsion. The preparation method of the waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating includes the following steps: (1) Mix and disperse the wetting and dispersing agent, a portion of deionized water and organic montmorillonite to obtain a pre-slurry; (2) Add pre-slurry, reactive elastic aerogel microspheres, thermal switch hybrid filler, film-forming aid and remaining deionized water to POSS modified epoxy-acrylic hybrid emulsion in sequence, and stir to mix; (3) Add defoamer to defoam and obtain coating slurry after defoaming; (4) The slurry is sprayed onto the substrate and cured by ultrasonic-assisted infrared preheating and gradient temperature rise.

2. The waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating as described in claim 1, characterized in that, The raw materials include the following by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion, 15-20 parts of reactive elastic aerogel microspheres, 4-7 parts of thermally switching phase change-thermal conductive hybrid filler, 3-5 parts of organomodified montmorillonite, 0.8-1.2 parts of wetting and dispersing agent, 0.3-0.7 parts of defoamer, 1.5-2.5 parts of film-forming aid, and 12-18 parts of deionized water.

3. The waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating as described in claim 1, characterized in that, The raw materials include the following by weight: 100 parts of POSS modified epoxy-acrylic hybrid emulsion, 18 parts of reactive elastic aerogel microspheres, 5 parts of thermally switching phase change-thermal conductive hybrid filler, 4 parts of organic montmorillonite, 1 part of wetting and dispersing agent, 0.5 parts of defoamer, 2 parts of film-forming aid, and 15 parts of deionized water.

4. The waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating as described in claim 1, characterized in that, The reactive elastic aerogel microspheres are prepared by a method comprising the following steps: (1) A mixture of tetraethyl orthosilicate, ethanol, water and 0.1M hydrochloric acid was hydrolyzed to obtain silica sol; (2) Emulsify the polyurethane prepolymer solution with the silica sol to form emulsion droplets; (3) The silica sol in the emulsion droplets is gelled and crosslinked with polyurethane to obtain wet gel microspheres; (4) The wet gel microspheres were treated with a mixed modifier containing perfluorooctyltriethoxysilane and γ-methacryloxypropyltrimethoxysilane under supercritical CO2 conditions and then dried.

5. The waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating as described in claim 1, characterized in that, The thermally switching phase change-thermal conductive hybrid filler is prepared by a method comprising the following steps: (1) Constructing a three-dimensional thermally conductive framework: Expanded graphite sheets were placed in a tube furnace and treated at 850°C in an atmosphere of ammonia and borane ammonia complex vapor for 1 hour. Boron nitride nanosheets were vertically grown on the surface and between the layers to form a three-dimensional interconnected thermally conductive framework. (2) Phase change material loading and encapsulation: The above skeleton and molten eicosane were impregnated in a vacuum impregnation tank at 60°C for 2 hours; then methyl methacrylate monomer and initiator were added, and the mixture was stirred and polymerized at 75°C for 4 hours under nitrogen protection to obtain composite filler; (3) Surface reactive modification: The obtained composite filler was lightly oxidized in an air atmosphere at 80°C for 2 hours to generate carboxyl groups on its surface. Then it was reacted with an ethanol solution of 2wt% γ-glycidyl etheroxypropyltrimethoxysilane at 60°C for 3 hours. After washing and drying, a hybrid filler with epoxy groups on its surface was obtained.

6. The method for preparing the waterproof and heat-insulating integrated compressed garbage truck sealed compartment coating as described in claim 1, characterized in that, The ultrasonic-assisted infrared preheating in step (4) is as follows: at 80-90℃, ultrasonic treatment with a frequency of 20kHz and a power of 50W is applied simultaneously for 4 minutes; the gradient heating and curing is as follows: the temperature is increased from 90℃ to 125℃ at a rate of 1-2℃ / min, and then kept at 125℃ for 20-30 minutes.

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