Polyurethane laminate, preparation method and application

Abstract

The invention provides a polyurethane laminate as well as a preparation method and application thereof. The polyurethane laminate comprises a first leveling layer, a foaming layer, a second leveling layer, a buffer layer and a wear-resistant layer which are sequentially laminated, wherein the first leveling layer and the second leveling layer are made of polyurethane self-leveling materials, the foaming layer is mainly composed of foaming polyurethane particles with the particle size ranging from 0.5 mm to 3 mm, polyurethane sponge, reactive hot melt adhesive and microcapsule polyurethane prepolymers, the buffering layer is made of polyurethane elastomers, and the wear-resisting layer is made of polyurethane water-based varnish. The microcapsule polyurethane prepolymer takes end-capped polyether polyol as a core material and hydroxymethyl urea as a shell material. The preparation method comprises the following steps: forming the foaming particles through dehydration and mixing, mixing the components of the foaming layer, coating the leveling layer, spraying the foaming layer, and laminating and curing. The polyurethane laminated body disclosed by the invention has excellent physical and waterproof performance, is longer in service life, energy-saving and environment-friendly, is convenient to recycle, and can realize seamless connection through cast-in-place.

Description

Technical Field

[0001] This invention relates to the field of plastic production and manufacturing technology, specifically to a laminate containing polyurethane plastic, a method for preparing the polyurethane laminate, and applications of the laminate. Background Technology

[0002] To improve the safety and performance of sports fields, traditional cinder tracks are gradually being replaced by synthetic materials. Early tracks often used a simple mixture of rubber granules and asphalt, but these were prone to aging and lacked elasticity. Polyurethane, polymerized from isocyanates and polyols, forms a three-dimensional network structure, giving the track high elasticity, wear resistance, and environmental friendliness. Compared to traditional materials, polyurethane running tracks can be poured on-site, achieving seamless connections, reducing the risk of leaks at joints, and offering flexible construction. Furthermore, it exhibits excellent temperature adaptability in outdoor environments ranging from -30℃ to 50℃, effectively preventing cracking caused by thermal expansion and contraction. In addition, the impact absorption capacity of polyurethane running tracks is significantly higher than that of ethylene propylene diene monomer (EPDM) rubber, further reducing the risk of sports injuries for users.

[0003] Traditional polyurethane running tracks rely on hydrophobic groups to initially resist moisture, but they face significant waterproofing technical problems in practical applications, mainly due to material porosity and construction defects. First, polyurethane is prone to forming micropores during curing, leading to water molecule penetration and causing corrosion and reduced elasticity of the substrate (such as concrete). Second, leakage occurs at the joints; if not completely sealed during construction, rainwater can easily penetrate and cause delamination.

[0004] In conclusion, it is necessary to develop a new type of polyurethane to overcome the aforementioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a polyurethane material that has good waterproof performance when used as a plastic running track.

[0006] To achieve the above objectives, the present invention provides the following technical solution. In a first aspect, a polyurethane laminate comprises a first leveling layer, a foaming layer, a second leveling layer, a buffer layer, and a wear-resistant layer stacked sequentially; the first and second leveling layers comprise polyurethane self-leveling materials; the foaming layer comprises foamed polyurethane particles; the buffer layer comprises a polyurethane elastomer; and the wear-resistant layer comprises polyurethane. The polyurethane self-leveling material refers to a liquid polyurethane system with low viscosity and high fluidity, which, after curing, forms a seamless and dense film, eliminating the risk of water seepage caused by unevenness in the substrate. In this invention, foamed polyurethane particles refer to porous particles formed through chemical / physical foaming. The polyurethane elastomer is a polymer formed by crosslinking long-chain polyols and isocyanates, used to provide resilience and load dispersion. The wear-resistant layer is a coating containing polyurethane components, which, after curing, forms a continuous smooth surface, possessing both wear resistance and waterproof properties.

[0007] As a preferred technical solution, the components of the foamed layer, by weight, include 60-80 parts of foamed polyurethane particles with a particle size of 0.5-3 mm; 30-50 parts of polyurethane sponge; 5-15 parts of reactive hot melt adhesive; and 5-10 parts of microencapsulated polyurethane prepolymer. Excessive foamed polyurethane particles will lead to a decrease in interlayer bonding strength, while insufficient particles will reduce buffering capacity. In this invention, the polyurethane sponge serves as a continuous phase, on which the foamed polyurethane particles and microencapsulated polyurethane prepolymer are dispersed. The microcapsule rupture temperature is matched with the application temperature, and the released prepolymer forms an interpenetrating network between the foamed particles, thereby filling some of the voids that were not properly handled during the dispersion or spraying process.

[0008] As a preferred technical solution, the microencapsulated polyurethane prepolymer includes a shell containing a core material, wherein the core material is a capped polyether polyol, and the shell material is hydroxymethyl urea. The capped polyether polyol avoids side reactions occurring in the early stages of construction, preventing premature reactions and losses in the microencapsulated polyurethane prepolymer. Furthermore, the hydroxymethyl urea shell material exhibits pH-responsive characteristics; its swelling degree is favorable for the processing and production of the microencapsulated polyurethane prepolymer when the pH reaches 3-5. It is noteworthy that the capped polyether polyol described in this invention can be an intermediate product in the preparation process of foamed polyurethane particles. Specifically, it is an alcohol ether polymer that does not contain reactive hot melt adhesive, and can be commercially available or self-made. The capping substances include, but are not limited to, isocyanates, epoxy groups, alcohols, and carboxylic acids.

[0009] As a preferred technical solution, the preparation method of the microencapsulated polyurethane prepolymer is as follows: the polyurethane prepolymer is mixed with deionized water, an emulsifier is added, and the mixture is stirred to form a stable emulsion. Urea and formaldehyde are added to the emulsion, and then the pH is adjusted to acidic. The temperature is raised to allow urea and formaldehyde to deposit on the surface of the core material and condense into a shell material.

[0010] As a preferred technical solution, the molar ratio of urea to formaldehyde is 1:2-3, and the temperature is raised to 50-70℃ after adjusting the pH to 3-5. In the above technical features, the urea molecule contains two amino groups, requiring excess formaldehyde to achieve hydroxymethylation. It is worth noting that a molar ratio >3 may result in residual free formaldehyde. Regarding residual formaldehyde, in the preparation method shown in this invention, the residual amount when laid on the plastic running track typically does not exceed 5 ppm. For formaldehyde residue with a higher molar ratio, it can be removed by adding ammonia or similar methods. The temperature window of 50-70℃ is used to ensure the cross-linking degree of the shell material (≥70%). Excessive cross-linking of the shell material will increase the difficulty of release during laying, while insufficient cross-linking will prevent the sealing effect.

[0011] Secondly, the present invention also provides a method for preparing a polyurethane laminate having at least one of the above-mentioned technical features, comprising the following steps: S1, heat and dehydrate the polyether polyol and plasticizer; after cooling, add isocyanate and processing aid in sequence to form polyurethane prepolymer, crush and sieve to make foamed polyurethane granules. S2, mix the foamed polyurethane particles with the polyurethane sponge and the microcapsule polyurethane prepolymer, and then add the reactive hot melt adhesive. S3, apply the first leveling layer to the substrate to be laid; S4, the foam layer with hot melt adhesive is sprayed and bonded to the first leveling layer at the melting temperature; S5, a second leveling layer, a buffer layer, and a wear-resistant layer are sequentially applied to the surface of the foamed layer and then cured.

[0012] As a preferred technical solution, in step S1, by weight, the polyether polyol is 45-60 parts; the plasticizer is 15-20 parts; the isocyanate is 20-30 parts; and the processing aid is 0.5-2 parts.

[0013] As a preferred technical solution, in step S1, the dehydration temperature is 70-85℃, the dehydration time is 2-5 hours, and the mixing temperature is 40-60℃. In the above technical features, polyether polyols are hygroscopic, and moisture can cause isocyanate to react and generate carbon dioxide, resulting in bubbles in the polyurethane prepolymer. Therefore, it is necessary to dehydrate both. In some technical solutions, vacuum dehydration can be used to shorten the dehydration time. Another purpose of high-temperature dehydration in this invention is to fully activate the two prepolymers, thereby improving reaction efficiency. When mixing the two, it is necessary to control the temperature to prevent problems such as uneven dispersion due to isocyanate crystallization below 40℃ and increased side reactions above 60℃.

[0014] As a preferred technical solution, in step S2, the mixing temperature is between 50-65℃, and the mixing humidity is less than or equal to 40%RH. This temperature control is to soften the hot melt adhesive, uniformly coat the foamed polyurethane particles, and prevent premature rupture of the microcapsules. Reactive hot melt adhesives include, but are not limited to, polyamides and other spray-applied hot melt adhesives; the hot melt temperature should not exceed 120℃ to avoid thermal oxidation of the polyurethane material.

[0015] During installation, the shell material undergoes a glass transition at 60-70℃, releasing the internal core material under pressure. The released prepolymer's -NCO end groups react with the -OH groups of the hot melt adhesive, filling the pores to form an interpenetrating network. The microcapsule addition amount is 5-10 parts, suitable for a foam layer porosity of 10-15%.

[0016] Thirdly, the present invention also provides the application of a polyurethane laminate having any one or more of the above-mentioned technical features in a plastic running track.

[0017] The advantages and beneficial effects of this invention are as follows: the polyurethane laminate first uses polyurethane self-leveling material to cure and form a seamless and dense film layer, eliminating the risk of water seepage caused by unevenness of the base layer; the foaming layer and the leveling layer are integrated and bonded by melt spraying technology to achieve seamless connection between layers, which has excellent physical and waterproof properties, long service life, energy saving and environmental protection, and is easy to recycle.

[0018] Under the same rainfall, the structure shown in this invention exhibits minimal water seepage, resulting in a significantly longer service life compared to existing technologies when used in plastic running tracks. The foam layer comprises foamed polyurethane particles, polyurethane sponge, reactive hot melt adhesive, and microcapsulated polyurethane prepolymer. During use, heating the foam layer causes the microcapsulated polyurethane prepolymer to rupture, releasing a core material that undergoes a cross-linking reaction with the remaining substances, generating a dense polyurethane filler that seals poorly filled voids. This blocks the path of moisture penetration into the base layer, reducing corrosion and elasticity loss, giving the polyurethane laminate excellent resilience and providing good cushioning for the user. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the polyurethane laminate shown in this invention. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0021] Example 1: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 50 parts of polyether polyol and 15 parts of plasticizer (dioctyl phthalate) at 70°C for 2 hours. After cooling to 40°C, add 20 parts of isocyanate and 0.5 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 0.5 mm.

[0022] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:2 and adjust the pH to 5. Heat the emulsion to 50°C in a heating kettle for 2 hours to carry out a polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 60 parts of foamed polyurethane granules, 50 parts of polyurethane sponge, and 5 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 50°C and add 5 parts of reactive hot melt adhesive.

[0023] S3: Apply the first leveling layer to the substrate (cement floor) to be laid.

[0024] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (110°C).

[0025] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (polyurethane water-based varnish) to the surface of the foamed layer and wait for it to cure.

[0026] Example 2: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 60 parts of polyether polyol and 20 parts of plasticizer (dimethyl terephthalate) at 85°C for 5 hours. After cooling to 60°C, add 30 parts of isocyanate and 2 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 3mm.

[0027] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:3 and adjust the pH to 3. Heat the emulsion to 70°C in a heating kettle for 3 hours to carry out a polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 80 parts of foamed polyurethane granules, 30 parts of polyurethane sponge, and 10 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 65°C and then add 15 parts of reactive hot melt adhesive.

[0028] S3: Apply the first leveling layer to the substrate (asphalt floor) to be laid.

[0029] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (120°C).

[0030] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (polyurethane water-based varnish) to the surface of the foamed layer and wait for it to cure.

[0031] Example 3: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 55 parts of polyether polyol and 18 parts of plasticizer (dioctyl phthalate) at 80°C for 3 hours. After cooling to 50°C, add 25 parts of isocyanate and 1 part of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 1-2 mm.

[0032] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:2.5 and adjust the pH to 4. Heat the emulsion to 60°C in a heating kettle for 2.5 hours for polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 70 parts of foamed polyurethane particles, 40 parts of polyurethane sponge, and 7 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 55°C and then add 10 parts of reactive hot melt adhesive.

[0033] S3: Apply the first leveling layer to the substrate (cement floor) to be laid.

[0034] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (110°C).

[0035] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (solvent-based polyurethane coating) to the surface of the foamed layer and wait for it to cure.

[0036] Example 4: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 45 parts of polyether polyol and 20 parts of plasticizer (dipropyl terephthalate) at 75°C for 2 hours. After cooling to 45°C, add 28 parts of isocyanate and 1.5 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 2.5 mm.

[0037] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:2 and adjust the pH to 4.5. Heat the emulsion to 55°C in a heating kettle for 1.5 hours for polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 65 parts of foamed polyurethane particles, 45 parts of polyurethane sponge, and 6 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 60°C and add 12 parts of reactive hot melt adhesive.

[0038] S3: Apply the first leveling layer to the substrate (concrete floor) to be laid.

[0039] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (100°C).

[0040] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (solvent-based polyurethane coating) to the surface of the foamed layer and wait for it to cure.

[0041] Example 5: A method for preparing a polyurethane laminate, comprising the following steps: S1: 48 parts of polyether polyol and 16 parts of plasticizer (dibutyl phthalate) are dehydrated at 78°C for 4 hours. After cooling to 55°C, 20 parts of isocyanate and 2 parts of processing aid (silicone oil) are added in sequence to form a polyurethane prepolymer. The prepolymer is then crushed and sieved to produce foamed polyurethane particles with a particle size of 1.5 mm.

[0042] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:2.2 and adjust the pH to 3.5. Heat the emulsion to 65°C in a heating kettle for 2 hours to carry out a polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 75 parts of foamed polyurethane particles, 35 parts of polyurethane sponge, and 8 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤30%RH, adjust the temperature of the mixer to 58°C and then add 9 parts of reactive hot melt adhesive.

[0043] S3: Apply the first leveling layer to the substrate (cement floor) to be laid.

[0044] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (105°C).

[0045] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (polyurethane water-based varnish) to the surface of the foamed layer and wait for it to cure.

[0046] Example 6: A method for preparing a polyurethane laminate, comprising the following steps: S1: 52 parts of polyether polyol and 17 parts of plasticizer (dibutyl terephthalate) are dehydrated at 82°C for 3.5 hours. After cooling to 48°C, 26 parts of isocyanate and 1.2 parts of processing aid (silicone oil) are added in sequence to form a polyurethane prepolymer. The prepolymer is then crushed and sieved to produce foamed polyurethane particles with a particle size of 1.0 mm.

[0047] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:2.5 and adjust the pH to 5. Heat the emulsion to 50°C in a heating kettle for 2.2 hours for polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 68 parts of foamed polyurethane particles, 42 parts of polyurethane sponge, and 9 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 52°C and add 11 parts of reactive hot melt adhesive.

[0048] S3: Apply the first leveling layer to the substrate (asphalt floor) to be laid.

[0049] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (95°C).

[0050] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (solvent-based polyurethane coating) to the surface of the foamed layer and wait for it to cure.

[0051] Example 7: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 58 parts of polyether polyol and 19 parts of plasticizer (dibutyl terephthalate) at 85°C for 2 hours. After cooling to 52°C, add 27 parts of isocyanate and 0.8 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 3mm.

[0052] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:2.8 and adjust the pH to 3.2. Heat the emulsion to 70°C in a heating kettle for 1 hour to carry out a polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 72 parts of foamed polyurethane particles, 38 parts of polyurethane sponge, and 5.5 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 62°C and then add 13 parts of reactive hot melt adhesive.

[0053] S3: Apply the first leveling layer to the substrate (cement floor) to be laid.

[0054] S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (115°C).

[0055] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (solvent-based polyurethane coating) to the surface of the foamed layer and wait for it to cure.

[0056] Example 8: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 60 parts of polyether polyol and 20 parts of plasticizer (diethyl phthalate) at 85°C for 5 hours. After cooling to 60°C, add 30 parts of isocyanate and 2 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to produce foamed polyurethane particles with a particle size of 0.5-3mm.

[0057] S2: Take a portion of the isocyanate-terminated polyurethane prepolymer obtained in S1 and add it to deionized water. Then, add an emulsifier to the deionized water to form an emulsion. During stirring, add urea and formaldehyde at a molar ratio of 1:3 and adjust the pH to 3. Heat the emulsion to 70°C in a heating kettle for 4 hours to carry out a polycondensation reaction to obtain microcapsule polyurethane prepolymer. Mix 80 parts of foamed polyurethane particles, 40 parts of polyurethane sponge, and 10 parts of microcapsule polyurethane prepolymer in a mixer. Then, under the condition of ambient humidity ≤40%RH, adjust the temperature of the mixer to 65°C and then add 15 parts of reactive hot melt adhesive.

[0058] S3: Apply the first leveling layer to the substrate (concrete floor) to be laid; S4: The foam layer with hot melt adhesive is sprayed and bonded to the upper surface of the first leveling layer at the melting temperature (120°C); S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (polyurethane water-based varnish) to the surface of the foamed layer and wait for it to cure.

[0059] Comparative Example 1: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 50 parts of polyether polyol and 15 parts of plasticizer (dioctyl phthalate) at 70°C for 2 hours. After cooling to 40°C, add 20 parts of isocyanate and 0.5 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 0.5 mm.

[0060] S2: The microencapsulation step is omitted. 60 parts of foamed polyurethane granules and 50 parts of polyurethane sponge are directly mixed in a mixer. 5 parts of reactive hot melt adhesive are added at an ambient humidity ≤40%RH and a temperature of 50℃.

[0061] S3: Apply the first leveling layer to the substrate (cement floor) to be laid.

[0062] S4: Spray the mixture onto the upper surface of the first leveling layer at the melting temperature (110°C).

[0063] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (water-based varnish) to the surface of the foamed layer and then cure them.

[0064] Comparative Example 2: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 50 parts of polyether polyol and 15 parts of plasticizer (dioctyl phthalate) at 70°C for 2 hours. After cooling to 40°C, add 20 parts of isocyanate and 0.5 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 0.5 mm.

[0065] S2: Omit microcapsule preparation, mix 60 parts of foamed polyurethane granules and 50 parts of polyurethane sponge in a mixer, and add 5 parts of reactive hot melt adhesive at an ambient humidity ≤40%RH and a temperature of 50℃.

[0066] S3: Apply the first leveling layer to the substrate (concrete floor) to be laid.

[0067] S4: Spray the mixture onto the upper surface of the first leveling layer at the melting temperature (110°C).

[0068] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (water-based varnish) to the surface of the foamed layer and then cure them.

[0069] Comparative Example 3: A method for preparing a polyurethane laminate, comprising the following steps: S1: Dehydrate 50 parts of polyether polyol and 15 parts of plasticizer (dioctyl phthalate) at 70°C for 2 hours. After cooling to 40°C, add 20 parts of isocyanate and 0.5 parts of processing aid (silicone oil) in sequence to form a polyurethane prepolymer. Crush and sieve to make foamed polyurethane particles with a particle size of 0.5 mm.

[0070] S2: Microcapsule preparation: 100 parts of polyethylene are mixed in a mixer, and 5 parts of reactive hot melt adhesive are added at an ambient humidity ≤40%RH and a temperature of 50℃.

[0071] S3: Apply the first leveling layer to the substrate (asphalt floor) to be laid.

[0072] S4: Spray the mixture onto the upper surface of the first leveling layer at the melting temperature (110°C).

[0073] S5: Sequentially apply a second leveling layer, a buffer layer (EPDM rubber), and a wear-resistant layer (water-based varnish) to the surface of the foamed layer and then cure them.

[0074] Performance tests were conducted on the above embodiments and comparative examples. Waterproofing performance was tested according to ASTM E96, simulating a rainfall environment to measure the rate and amount of water passing through the laminate. A 100mm × 100mm sample was placed in the testing apparatus, and a constant water pressure was applied to the upper layer to simulate a rainfall of 30mm / h. The amount of water seeping into the base layer was collected after 24 hours, and the permeability was calculated. A permeability <5 g / m²·h was rated as "excellent," and 5-20 g / m²·h was rated as "good." 2 • h was rated "good", >20 g / m 2 • h is rated "Poor". For abrasion resistance testing, refer to ISO 5470-1. Fix the sample on the testing machine, apply a 500g load using a CS-10 grinding wheel, run for 1000 revolutions, and measure the mass loss rate (mg / 1000 revolutions). A loss rate <50mg is rated "Good", 50-100mg is rated "Average", and >100mg is rated "Poor". The test results are shown in the table below. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A polyurethane laminate, characterized in that, It includes a first leveling layer, a foaming layer, a second leveling layer, a buffer layer, and a wear-resistant layer stacked in sequence; the first and second leveling layers include polyurethane self-leveling material; the foaming layer includes foamed polyurethane particles; the buffer layer includes polyurethane elastomer; and the wear-resistant layer includes polyurethane.

2. The polyurethane laminate according to claim 1, characterized in that, The components of the foamed layer, by weight, include 60-80 parts of foamed polyurethane particles with a particle size of 0.5-3 mm; 30-50 parts of polyurethane sponge; 5-15 parts of reactive hot melt adhesive; and 5-10 parts of microencapsulated polyurethane prepolymer.

3. The polyurethane laminate according to claim 2, characterized in that, The microencapsulated polyurethane prepolymer includes a shell containing a core material, wherein the core material is a capped polyether polyol and the shell material is hydroxymethyl urea.

4. The polyurethane laminate according to claim 3, characterized in that, The preparation method of the microencapsulated polyurethane prepolymer is as follows: the polyurethane prepolymer is mixed with deionized water, an emulsifier is added, and the mixture is stirred to form a stable emulsion. Urea and formaldehyde are added to the emulsion, and then the pH is adjusted to acidic. The temperature is raised to allow urea and formaldehyde to deposit on the surface of the core material and condense into a shell material.

5. The polyurethane laminate according to claim 4, characterized in that, The molar ratio of urea to formaldehyde is 1:2-3, and after adjusting the pH to 3-5, the temperature is raised to 50-70℃.

6. A method for preparing a polyurethane laminate as described in any one of claims 2-4, characterized in that, The steps include the following: S1, heat and dehydrate the polyether polyol and plasticizer; after cooling, add isocyanate and processing aid in sequence to form polyurethane prepolymer, crush and sieve to make foamed polyurethane granules. S2, mix the foamed polyurethane particles with the polyurethane sponge and the microcapsule polyurethane prepolymer, and then add the reactive hot melt adhesive. S3, apply the first leveling layer to the substrate to be laid; S4, the foam layer with hot melt adhesive is sprayed and bonded to the first leveling layer at the melting temperature; S5, a second leveling layer, a buffer layer, and a wear-resistant layer are sequentially applied to the surface of the foamed layer and then cured.

7. The method for preparing the polyurethane laminate according to claim 6, characterized in that, In S1, by weight, the polyether polyol is 45-60 parts; the plasticizer is 15-20 parts; the isocyanate is 20-30 parts; and the processing aid is 0.5-2 parts.

8. The method for preparing the polyurethane laminate according to claim 6, characterized in that, In step S1, the dehydration temperature is 70-85℃, the dehydration time is 2-5 hours, and the mixing temperature is 40-60℃.

9. The method for preparing the polyurethane laminate according to claim 6, characterized in that, In step S2, the mixing temperature is 50-65℃ and the mixing humidity is less than or equal to 40%RH.

10. The application of a polyurethane laminate according to any one of claims 1-5 in a plastic running track.

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