A polyurethane foam composite insulation board and its preparation method

Abstract

This invention relates to a polyurethane foam composite insulation board and its preparation method. The preparation method includes the following steps: S1, applying a layer of polyurethane foam material onto a base template or cement paper; S2, laying a layer of inorganic insulation particles on the top of the polyurethane foam material, and then applying another layer of polyurethane foam material; the inorganic insulation particles and polyurethane foam material are laid alternately in layers until a predetermined height is reached; the inorganic insulation particles are expanded perlite particles or vitrified microsphere particles; S3, placing a pressure plate on the last layer of polyurethane foam material or inorganic insulation particles, selectively placing cement paper between the pressure plate and the polyurethane foam material or inorganic insulation particles, keeping the pressure plate fixed to allow the polyurethane foam material to fully expand, filling the gaps between the inorganic insulation particles after foaming; S4, after the polyurethane foam hardens, a polyurethane foam composite insulation board is obtained.

Description

Technical Field

[0001] This invention relates to the field of insulation board technology, and in particular to a polyurethane foam composite insulation board and its preparation method. Background Technology

[0002] Expanded perlite polyurethane foam composite insulation board or vitrified microsphere polyurethane foam composite insulation board are both insulation boards made by combining inorganic insulation materials with polyurethane foam materials. Inorganic insulation materials such as expanded perlite and vitrified microspheres are Class A non-combustible materials with excellent fire resistance and good insulation performance. The thermal conductivity of polyurethane foam material is 0.02W / (m·K), which has good insulation and bonding performance, but its fire resistance is generally average.

[0003] Currently, most composite materials of inorganic insulation particles and polyurethane foam are produced by mixing and stirring, then pressing them into molds. Because inorganic insulation particles are small and dispersed, if too little polyurethane foam is mixed in, some inorganic insulation particles will not bond properly, resulting in poor tensile strength of the insulation board. Therefore, when producing this type of insulation board by mixing and stirring, only a large amount of polyurethane foam can be added to ensure sufficient bonding between the inorganic insulation particles in the insulation board. As a result, the fire resistance of this type of insulation board can only reach Class B at best, which limits its application in buildings.

[0004] For example, patent application No. 200710070530.3, entitled "Expanded Perlite-Polyurethane Composite Insulation Board and Its Production Process", discloses an insulation board made of expanded perlite as aggregate and polyurethane as adhesive. The insulation board has a thermal conductivity of 0.052 W / (m·K), a tensile strength of 0.2 MPa, and a fire resistance rating of B1.

[0005] Patent No. 201110377576.6, entitled "Rigid Polyurethane Foam-Expanded Vitrified Microsphere Composite Thermal Insulation and Flame Retardant Board and Its Preparation Method", describes the process of mixing expanded vitrified microspheres with polyurethane foam and then casting the mixture to form a thermal insulation and flame retardant board. Four types of thermal insulation and flame retardant boards were prepared according to different ratios of expanded vitrified microspheres to polyurethane foam. The thermal conductivity of these thermal insulation and flame retardant boards ranges from 0.027 to 0.042 W / (m·K), indicating good thermal insulation performance. However, their fire resistance is all B1 level, which cannot reach A level.

[0006] As can be seen from the above, although the insulation board prepared by mixing inorganic insulation particles with polyurethane foam material has good insulation performance and tensile strength, its fire resistance is generally poor and it is difficult to meet the Class A fire resistance requirements of building insulation materials. At present, there is an urgent need for a new preparation technology for expanded perlite polyurethane foam composite insulation board or vitrified microsphere polyurethane foam composite insulation board to solve the above technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing polyurethane foam composite insulation board. The polyurethane foam composite insulation board prepared by this method has a tensile strength of up to 0.15 MPa, and its fire resistance can reach A2 level through a layering process, with excellent thermal insulation performance.

[0008] The technical solution adopted by this invention to solve its technical problem is:

[0009] A method for preparing a polyurethane foam composite insulation board, the method comprising the following steps:

[0010] S1. Pour a layer of polyurethane foam onto the bottom template or cement paper;

[0011] S2. Lay a layer of inorganic thermal insulation particles on the top of the polyurethane foam, and then pour another layer of polyurethane foam. Repeat this process to lay the inorganic thermal insulation particles and polyurethane foam in alternating layers until the predetermined height is reached.

[0012] The inorganic thermal insulation particles are expanded perlite particles or vitrified microspheres.

[0013] S3. Place a pressure plate on the last layer of polyurethane foam or inorganic insulation particles, and optionally place cement paper between the pressure plate and the polyurethane foam or inorganic insulation particles.

[0014] Keep the pressure plate fixed so that the polyurethane foam can fully expand. After the polyurethane foam expands, it fills the gaps between the inorganic insulation particles.

[0015] S4. After the polyurethane foam has hardened, a polyurethane foam composite insulation board is obtained.

[0016] Preferably, the coated polyurethane foam has a diamond-shaped mesh pattern. Leaving appropriate space around the edges of this shape results in better foaming; a uniform layer can actually hinder foaming. The diamond-shaped mesh pattern is typically achieved using a fully automated honeycomb panel coating machine. Figure 1 As shown.

[0017] Preferably, the thickness of each layer of polyurethane foam is 0.7 to 1.5 times the thickness of each layer of inorganic insulation particles. The optimal thickness of each layer of inorganic insulation particles is 10 mm, and the thickness of the polyurethane foam is 10-11 mm.

[0018] Preferably, the polyurethane foam material is a delayed-foaming polyurethane foam material, which includes polymeric polyol, polyphenylmethane polyisocyanate, hydrogen peroxide solution, and appropriate additives. The hydrogen peroxide solution accounts for 1-5% of the total weight of the polyurethane foam material raw materials; the mass concentration of the hydrogen peroxide solution is 10%-20%; the additives include one or more of chain extenders, flame retardants, foam stabilizers, and catalysts; the mass percentage of hydrogen peroxide solution in each layer of delayed-foaming polyurethane foam material used from bottom to top decreases by 0.3%-0.4%. By gradually reducing the amount of catalyst, the foaming speed of polyurethane foam material layers applied at different times is kept consistent. The ratio of ordinary polyurethane foam material to delayed-foaming catalyst in the delayed-foaming polyurethane foam material is adjusted according to the laying time of the insulation particles.

[0019] The additives added to the polyurethane foam material of this invention include one or more of chain extenders, flame retardants, foam stabilizers, and catalysts. The chain extender may be selected from one or more of diethylene glycol, trimethylolpropane, glycerol, and 1,4-butanediol. The flame retardant may be selected from one or more of dimethyl methyl phosphate (DMMP), tris(2-chloroethyl) phosphate (TCPP), tris(1-chloro-ethylpropyl) phosphate (TCEP), and triethyl phosphate (TEP). The selection and dosage of the additives are conventional in the art and will not be elaborated here.

[0020] A further preferred embodiment is that the delayed-foaming polyurethane foam material has the following formulation: 60-86 parts by weight of polymeric polyol (POP), 90-100 parts by weight of polyphenylmethane polyisocyanate, 2-10 parts by weight of flame retardant, 1-5 parts by weight of chain extender, 0.5-2 parts by weight of foam stabilizer, 0.1-2 parts by weight of catalyst, and 1-5% by weight of hydrogen peroxide solution of the total weight of polyurethane foam material raw materials.

[0021] More preferably, the polyurethane foam material is coated with six layers, and the hydrogen peroxide solution accounts for 3% of the mass of the first layer of polyurethane foam material.

[0022] The hydrogen peroxide solution accounts for 2.7% of the mass of the second layer of polyurethane foam.

[0023] The hydrogen peroxide solution accounts for 2.4% of the mass of the third layer of polyurethane foam.

[0024] The hydrogen peroxide solution accounts for 2.1% of the mass of the fourth layer of polyurethane foam.

[0025] The hydrogen peroxide solution accounts for 1.8% of the mass of the fifth layer of polyurethane foam.

[0026] The hydrogen peroxide solution accounts for 1.5% of the mass of the sixth layer polyurethane foam.

[0027] The hydrogen peroxide solution has a mass concentration of 14% to 16%, and the concentration of hydrogen peroxide solution used in each layer of polyurethane foam is the same.

[0028] Since laying inorganic insulation particles requires a certain amount of time, delayed-foaming polyurethane foam is used to ensure that the polyurethane foam applied in the first few applications fills the gaps between the inorganic insulation particles better. Specifically, the delay time of the delayed-foaming polyurethane foam used in each application gradually decreases according to the order of application. The delay time is determined by the time required to lay the insulation particles. By using polyurethane foam with different delay times, after the pressure plate on top of the insulation board is placed, the polyurethane foam at different time points can simultaneously foam and fill the gaps between nearby insulation particles within the same time frame, resulting in better mechanical properties and more stable fire resistance of the insulation board.

[0029] Preferably, the inorganic thermal insulation particles are mixed with aerogel powder, and the amount of aerogel powder is 3-5% of the weight of the inorganic thermal insulation particles. Aerogel powder has a very low thermal conductivity and a fire resistance rating of Class A. Although it is insoluble in water and belongs to hydrophobic materials, the present invention uses polyurethane foam to expand and bond the thermal insulation particles. The thermal insulation particles are not bonded by cement mortar, which can effectively incorporate aerogel powder into the composite thermal insulation board.

[0030] Preferably, the particle size of the inorganic thermal insulation particles ranges from 1 to 6 mm.

[0031] Preferably, the bottom template is provided with side plates on all four sides.

[0032] Preferably, before step S1, the method further includes: S0, mixing and stirring cement mortar containing microsilica powder with inorganic thermal insulation particles, and then naturally air-drying or drying the mixture to form a coating layer on the outer surface of the inorganic thermal insulation particles. Subsequent steps use this material to prepare insulation boards. The microsilica powder and cement powder inorganic materials coating the outer surface of the inorganic thermal insulation particles can effectively improve the particle strength and fire resistance.

[0033] Preferably, the preparation method includes the following steps:

[0034] S0. Mix and stir the cement mortar containing microsilica powder with inorganic thermal insulation particles, and then let it air dry or bake it to form a coating layer on the outer surface of the inorganic thermal insulation particles.

[0035] S1. Apply a layer of polyurethane foam to the bottom template or cement paper; the upper surface of the bottom template is coated with a release agent, and the applied layer of polyurethane foam is in the form of a diamond grid to ensure that the polyurethane foam foams fully. When the polyurethane foam composite insulation board is produced on a continuous production line, multiple bottom templates or multiple sheets of cement paper are continuously placed on the conveyor platform of the production line. The polyurethane foam is applied using a polyurethane coating machine set on one side of the conveyor platform. Lightweight side plates are added around the bottom template to make the insulation board better formed during manufacturing.

[0036] S2. Lay a layer of inorganic thermal insulation particles on the top of the polyurethane foam, and then pour another layer of polyurethane foam. Repeat this process to lay the inorganic thermal insulation particles and polyurethane foam in alternating layers until the predetermined height is reached.

[0037] The inorganic thermal insulation particles are expanded perlite particles or vitrified microspheres with a particle size of 1-6 mm; the inorganic thermal insulation particles are mixed with aerogel powder, and the amount of aerogel powder is 3-5% of the weight of the inorganic thermal insulation particles.

[0038] The thickness of each layer of polyurethane foam is 0.7 to 1.5 times the thickness of each layer of inorganic insulation particles; the coated polyurethane foam presents a diamond-shaped mesh pattern.

[0039] S3. Place a pressure plate on the last layer of polyurethane foam or inorganic insulation particles, and optionally place cement paper between the pressure plate and the polyurethane foam or inorganic insulation particles.

[0040] Keep the pressure plate fixed so that the polyurethane foam can fully expand. After the polyurethane foam expands, it fills the gaps between the inorganic insulation particles.

[0041] The lower surface of the pressure plate is coated with a release agent. When the polyurethane foam composite insulation board is produced on a continuous production line, after the last layer of polyurethane foam or inorganic insulation particles is applied, the resulting insulation board is placed on one side of the production line, and then the pressure plate is placed on the upper side of the insulation board and kept fixed at a predetermined height.

[0042] S4. After the polyurethane foam has hardened, remove the pressure plate and bottom template or cement paper to obtain the polyurethane foam composite insulation board.

[0043] A polyurethane foam composite insulation board prepared by the method described in this invention.

[0044] The beneficial effects of this invention are:

[0045] (1) The present invention uses a method of alternating layers of large-diameter inorganic thermal insulation particles and polyurethane foam material to prepare expanded perlite polyurethane foam composite thermal insulation board or vitrified microsphere polyurethane foam composite thermal insulation board. When the polyurethane foam material foams under the action of a pressure plate at a predetermined height, it quickly fills the gaps between the large-diameter inorganic thermal insulation particles, so that the inorganic thermal insulation particles can bond with each other while the proportion of polyurethane foam material is reduced. While the tensile strength of the thermal insulation composite thermal insulation board remains unchanged, the fire resistance of the composite thermal insulation board is greatly improved.

[0046] (2) The method of the present invention causes the polyurethane foam to expand and penetrate the gap between the inorganic thermal insulation particles, thereby making the inorganic thermal insulation particles bond together. This avoids the defect of the existing inorganic thermal insulation particle mixing method causing a small number of inorganic thermal insulation particles to break, and improves the thermal insulation performance of the inorganic thermal insulation particles.

[0047] (3) In the early stage, inorganic thermal insulation particles and polyurethane foam are alternately laid on the bottom template in layers. In the later stage, the foaming height is limited by the pressure plate. The material laying method on the bottom template in the early stage can be combined with the conveying platform of the continuous production line. It is different from the existing method of polyurethane foaming composite inorganic thermal insulation particles in a closed mold. The material laying method combined with the continuous production line has higher production efficiency and larger output.

[0048] (4) This invention incorporates ultra-low thermal conductivity and Class A fireproof aerogel powder into inorganic insulation particles and uses polyurethane expansion and penetration method to bond inorganic insulation particles and aerogel powder, which solves the disadvantage that aerogel powder is not easy to mix with insulation particles because it is insoluble in water, and further improves the fire resistance and insulation performance of composite insulation board. Attached Figure Description

[0049] Figure 1 It uses a fully automatic honeycomb panel coating machine to apply a diamond-shaped grid of polyurethane foam.

[0050] Figure 2 This is a schematic diagram of the structure of the polyurethane foam composite insulation board of the present invention after the multilayer polyurethane foam material is formed.

[0051] Figure 3 This is a schematic diagram of the preparation of a layer of inorganic thermal insulation particles laid on the top of polyurethane foam. Detailed Implementation

[0052] The technical solution of the present invention will be further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0053] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0054] Unless otherwise specified, the reagents used in the following examples can be purchased from a regular biochemical reagent store.

[0055] Test methods for thermal conductivity, tensile strength and fire resistance:

[0056] 1. Thermal conductivity test: GB / T10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials - protective hot plate method";

[0057] 2. Tensile strength test: JG / T287-2013 "Materials for Thermal Insulation and Decorative Exterior Wall Insulation Systems":

[0058] 3. Fire resistance performance test: in accordance with GB 8624-2012 "Classification of fire performance of building materials and products".

[0059] Raw material source:

[0060] Polyphenylmethane polyisocyanate: crude MDI, BASF M20S;

[0061] The delayed-blowing polyurethane foam material comprises a polymeric polyol, polyphenylmethane isocyanate, hydrogen peroxide solution, and appropriate additives. The hydrogen peroxide solution accounts for 1-5% of the total weight of the polyurethane foam material raw materials; the mass concentration of the hydrogen peroxide solution is 10%-20%; the additives include one or more of chain extenders, flame retardants, foam stabilizers, and catalysts, selected according to actual production. To ensure consistent foaming speed of polyurethane foam layers sprayed at different times, the mass percentage of hydrogen peroxide solution in each layer of delayed-blowing polyurethane foam material used decreases by 0.3%-0.4% from bottom to top.

[0062] A preferred embodiment is that the delayed-foaming polyurethane foam material is formulated as follows: 60-86 parts by weight of polymeric polyol (POP), 90-100 parts by weight of polyphenylmethane polyisocyanate, 2-10 parts by weight of flame retardant, 1-5 parts by weight of chain extender, 0.5-2 parts by weight of foam stabilizer, 0.1-2 parts by weight of catalyst, and 1-5% by weight of hydrogen peroxide solution of the total weight of polyurethane foam material raw materials.

[0063] A preferred embodiment is that the polyurethane foam material is coated with six layers, and the first layer of polyurethane foam material, which is the bottom layer, contains 3% hydrogen peroxide solution by mass.

[0064] The hydrogen peroxide solution accounts for 2.7% of the mass of the second layer of polyurethane foam.

[0065] The hydrogen peroxide solution accounts for 2.4% of the mass of the third layer of polyurethane foam.

[0066] The hydrogen peroxide solution accounts for 2.1% of the mass of the fourth layer of polyurethane foam.

[0067] The hydrogen peroxide solution accounts for 1.8% of the mass of the fifth layer of polyurethane foam.

[0068] The hydrogen peroxide solution accounts for 1.5% of the mass of the sixth layer polyurethane foam.

[0069] The hydrogen peroxide solution has a mass concentration of 14% to 16%, and the concentration of hydrogen peroxide solution used in each layer of polyurethane foam is the same.

[0070] To better compare the product performance, the following examples use the following delayed-foaming polyurethane foam formulation: 80 kg of polymeric polyol (POP), 95 kg of polyphenylmethane polyisocyanate, 5 kg of flame retardant, 2 kg of chain extender, 1 kg of foam stabilizer, 1 kg of catalyst, and 1-5% hydrogen peroxide solution (as described in the examples) accounting for the total weight of the polyurethane foam raw materials. The mass concentration of the hydrogen peroxide solution is approximately 15%.

[0071] Example 1:

[0072] A method for preparing a polyurethane foam composite insulation board, the specific steps of which are as follows:

[0073] 1) Pour the first layer of delayed-foaming polyurethane foam onto the bottom template. The thickness of the delayed-foaming polyurethane foam layer is about 11mm. The mass of hydrogen peroxide solution in each layer of delayed-foaming polyurethane foam is 3% of the total mass of the raw materials of the delayed-foaming polyurethane foam.

[0074] 2) Lay a first layer of expanded perlite particles on the top side of the first layer of delayed foamed polyurethane foam. The thickness of the first layer of expanded perlite particles is about 10mm and the particle size range is 1mm to 6mm.

[0075] 3) Pour a second layer of delayed-expansion polyurethane foam, about 11 mm thick, onto the top of the first layer of expanded perlite particles.

[0076] 4) Lay a second layer of expanded perlite granules on the top of the second layer of delayed-expansion polyurethane foam. The thickness of the second layer of expanded perlite granules is about 10mm.

[0077] 5) Apply a third layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the second layer of expanded perlite particles.

[0078] 6) Lay a third layer of expanded perlite granules on the top side of the third layer of delayed foamed polyurethane foam. The thickness of the third layer of expanded perlite granules is about 10mm.

[0079] 7) Apply a fourth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the third layer of expanded perlite particles.

[0080] 8) Lay a fourth layer of expanded perlite granules on the top side of the fourth layer of delayed foamed polyurethane foam. The thickness of the fourth layer of expanded perlite granules is about 10mm.

[0081] 9) Apply a fifth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the fourth layer of expanded perlite particles.

[0082] 10) Lay a fifth layer of expanded perlite granules on the top side of the fifth layer of delayed foamed polyurethane foam. The thickness of the fifth layer of expanded perlite granules is about 10mm.

[0083] 11) Apply a sixth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the fifth layer of expanded perlite particles.

[0084] 12) Place cement paper and pressure plate on the sixth layer of delayed foamed polyurethane foam in sequence, and keep the pressure plate fixed.

[0085] 13) Keep the pressure plate fixed for about 6 minutes, then remove the cement paper, pressure plate and bottom template to obtain a 50mm thick polyurethane foam composite insulation board.

[0086] The thermal conductivity, tensile strength and fire resistance of the 50mm thick polyurethane foam composite insulation board were tested. The thermal conductivity was 0.05W / (m·K), the tensile strength was 0.15MPa, and the fire resistance was A2 level.

[0087] Example 2:

[0088] A method for preparing a polyurethane foam composite insulation board, the specific steps of which are as follows:

[0089] 0) Cement mortar containing silica fume is mixed and stirred with expanded perlite particles with a particle size range of 1mm to 6mm. After natural drying or baking, reinforced expanded perlite particles are obtained. The amount of silica fume is 15% of the weight of cement mortar, and the weight ratio of cement mortar to expanded perlite particles is 3:7.

[0090] 1) Pour the first layer of delayed-blown polyurethane foam onto the bottom template. The thickness of the delayed-blown polyurethane foam layer is about 11mm. The mass of hydrogen peroxide solution in each layer of delayed-blown polyurethane foam is 3% of the total mass of the raw materials of the delayed-blown polyurethane foam.

[0091] 2) Lay a first layer of reinforced expanded perlite particles on the top side of the first layer of delayed foamed polyurethane foam. The thickness of the first layer of expanded perlite particles is about 10mm and the particle size range is 1mm to 6mm.

[0092] 3) Pour a second layer of delayed-expansion polyurethane foam, about 11 mm thick, onto the top of the first layer of expanded perlite particles.

[0093] 4) Lay a second layer of reinforced expanded perlite granules on the top side of the second layer of delayed foamed polyurethane foam. The thickness of the second layer of expanded perlite granules is about 10mm.

[0094] 5) Apply a third layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the second layer of expanded perlite particles.

[0095] 6) Lay a third layer of reinforced expanded perlite particles on the top side of the third layer of delayed foamed polyurethane foam. The thickness of the third layer of expanded perlite particles is about 10mm.

[0096] 7) Apply a fourth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the third layer of expanded perlite particles.

[0097] 8) Lay a fourth layer of reinforced expanded perlite particles on the top side of the fourth layer of delayed foamed polyurethane foam. The thickness of the fourth layer of reinforced expanded perlite particles is about 10mm.

[0098] 9) Apply a fifth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the fourth layer of reinforced expanded perlite particles.

[0099] 10) Lay a fifth layer of reinforced expanded perlite particles on the top side of the fifth layer of delayed foamed polyurethane foam. The thickness of the fifth layer of reinforced expanded perlite particles is about 10mm.

[0100] 11) Apply a sixth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the fifth layer of expanded perlite particles.

[0101] 12) Place cement paper and pressure plate on the sixth layer of delayed foamed polyurethane foam in sequence, and keep the pressure plate fixed.

[0102] 13) Keep the pressure plate fixed for about 6 minutes, then remove the cement paper, pressure plate and bottom template to obtain a 50mm thick polyurethane foam composite insulation board.

[0103] The thermal conductivity, tensile strength and fire resistance of the 50mm thick polyurethane foam composite insulation board were tested. The thermal conductivity was 0.051W / (m·K), the tensile strength was 0.19MPa, and the fire resistance was A2 level.

[0104] Comparing Example 1 and Example 2, although the thermal conductivity of the insulation board using reinforced expanded perlite particles increased by 0.01 W / (m·K), the tensile strength of the insulation board was significantly improved, and the fire resistance was also rated as A2. Therefore, it can be seen that the overall performance of the insulation board is improved after mixing cement mortar with microsilica powder and expanded perlite particles.

[0105] Example 3 (Best Example):

[0106] A method for preparing a polyurethane foam composite insulation board, the specific steps of which are as follows:

[0107] 1) Pour the first layer of delayed-expansion polyurethane foam onto the bottom template. The thickness of the first layer of delayed-expansion polyurethane foam is about 11mm. The mass percentage of hydrogen peroxide solution in the first layer of delayed-expansion polyurethane foam is 3% (accounting for the total weight of polyurethane foam raw materials, the same below).

[0108] 2) Lay a first layer of expanded perlite particles on the top side of the first layer of delayed foamed polyurethane foam. The thickness of the first layer of expanded perlite particles is about 10mm and the particle size range is 1mm to 6mm.

[0109] 3) Apply a second layer of delayed-expansion polyurethane foam material, approximately 11 mm thick, to the top of the first layer of expanded perlite particles. The hydrogen peroxide solution accounts for 2.7% of the mass of the second layer of delayed-expansion polyurethane foam material.

[0110] 4) Lay a second layer of expanded perlite granules on the top of the second layer of delayed-expansion polyurethane foam. The thickness of the second layer of expanded perlite granules is about 10mm.

[0111] 5) Apply a third layer of delayed-expansion polyurethane foam material, approximately 11 mm thick, to the top of the second layer of expanded perlite particles. The third layer of delayed-expansion polyurethane foam material contains 2.4% hydrogen peroxide solution by mass.

[0112] 6) Lay a third layer of expanded perlite granules on the top side of the third layer of delayed foamed polyurethane foam. The thickness of the third layer of expanded perlite granules is about 10mm.

[0113] 7) Apply a fourth layer of delayed-expansion polyurethane foam material, approximately 11 mm thick, to the top of the third layer of expanded perlite particles. The mass percentage of hydrogen peroxide solution in the fourth layer of delayed-expansion polyurethane foam material is 2.1%.

[0114] 8) Lay a fourth layer of expanded perlite granules on the top side of the fourth layer of delayed foamed polyurethane foam. The thickness of the fourth layer of expanded perlite granules is about 10mm.

[0115] 9) Apply a fifth layer of delayed-expansion polyurethane foam material, approximately 11 mm thick, to the top of the fourth layer of expanded perlite particles. The fifth layer of delayed-expansion polyurethane foam material contains 1.8% hydrogen peroxide solution by mass.

[0116] 10) Lay a fifth layer of expanded perlite granules on the top side of the fifth layer of delayed foamed polyurethane foam. The thickness of the fifth layer of expanded perlite granules is about 10mm.

[0117] 11) Apply a sixth layer of delayed-expansion polyurethane foam material, approximately 11 mm thick, to the top of the fifth layer of expanded perlite particles. The sixth layer of delayed-expansion polyurethane foam material contains 1.5% hydrogen peroxide solution by mass.

[0118] 12) Place cement paper and pressure plate on the sixth layer of delayed foamed polyurethane foam in sequence, and keep the pressure plate fixed.

[0119] 13) Keep the pressure plate fixed for about 6 minutes, then remove the cement paper, pressure plate and bottom template to obtain a 50mm thick polyurethane foam composite insulation board.

[0120] The thermal conductivity, tensile strength and fire resistance of the 50mm thick polyurethane foam composite insulation board were tested. The thermal conductivity was 0.051W / (m·K), the tensile strength was 0.18MPa, and the fire resistance was A2 level.

[0121] Comparing the insulation boards prepared in Example 3 with those prepared in Example 1, the thermal conductivity of the insulation board prepared with polyurethane foam material with different delayed foaming times is basically the same as that of the insulation board prepared with ordinary delayed foaming polyurethane foam material, but the tensile strength can be increased by more than 20%, and the amount of delayed catalyst used in the delayed foaming polyurethane foam material can be reduced, thus reducing costs.

[0122] Insulation boards are prepared by using polyurethane foam materials with different delayed foaming times and layered alternating foaming molding methods. This allows the insulation particles in different parts of the insulation board to be filled with polyurethane foam material in the same time when the top plate is placed. The force on different parts of the insulation board due to the foaming of polyurethane foam material is more uniform, and the strength of the prepared insulation board is significantly improved.

[0123] Example 4 (Comparative Example):

[0124] A method for preparing a polyurethane foam composite insulation board, the specific steps of which are as follows:

[0125] 1) Pour the first layer of delayed-foaming polyurethane foam onto the bottom template. The thickness of the delayed-foaming polyurethane foam layer is about 16mm. The mass of hydrogen peroxide solution in each layer of delayed-foaming polyurethane foam is 3% of the total weight of the raw materials of the delayed-foaming polyurethane foam.

[0126] 2) Lay a first layer of expanded perlite particles on the top side of the first layer of delayed foamed polyurethane foam. The thickness of the first layer of expanded perlite particles is about 10mm and the particle size range is 1mm to 6mm.

[0127] 3) Pour a second layer of delayed-expansion polyurethane foam, about 16mm thick, onto the top of the first layer of expanded perlite particles.

[0128] 4) Lay a second layer of expanded perlite granules on the top of the second layer of delayed-expansion polyurethane foam. The thickness of the second layer of expanded perlite granules is about 10mm.

[0129] 5) Apply a third layer of delayed-expansion polyurethane foam, approximately 16mm thick, to the top of the second layer of expanded perlite particles.

[0130] 6) Lay a third layer of expanded perlite granules on the top side of the third layer of delayed foamed polyurethane foam. The thickness of the third layer of expanded perlite granules is about 10mm.

[0131] 7) Apply a fourth layer of delayed-expansion polyurethane foam, approximately 16mm thick, to the top of the third layer of expanded perlite particles.

[0132] 8) Lay a fourth layer of expanded perlite granules on the top side of the fourth layer of delayed foamed polyurethane foam. The thickness of the fourth layer of expanded perlite granules is about 10mm.

[0133] 9) Apply a fifth layer of delayed-expansion polyurethane foam, approximately 16mm thick, to the top of the fourth layer of expanded perlite particles.

[0134] 10) Lay a fifth layer of expanded perlite granules on the top side of the fifth layer of delayed foamed polyurethane foam. The thickness of the fifth layer of expanded perlite granules is about 10mm.

[0135] 11) Apply a sixth layer of delayed-expansion polyurethane foam, approximately 16mm thick, to the top of the fifth layer of expanded perlite particles.

[0136] 12) Place cement paper and pressure plate on the sixth layer of delayed foamed polyurethane foam in sequence, and keep the pressure plate fixed.

[0137] 13) Keep the pressure plate fixed for about 6 minutes, then remove the cement paper, pressure plate and bottom template to obtain a 50mm thick polyurethane foam composite insulation board.

[0138] The thermal conductivity, tensile strength, and fire resistance of a 50mm thick polyurethane foam composite insulation board were tested. The thermal conductivity was 0.44 W / (m·K), the tensile strength was 0.18 MPa, and the fire resistance was rated as B2.

[0139] Comparing the performance of the insulation boards prepared in Example 4 and Example 1, although the thermal conductivity of the insulation board in this example is reduced, the overall fire resistance of the insulation board cannot reach Class A due to the excessive amount of delayed foaming polyurethane foaming material.

[0140] Example 5:

[0141] A method for preparing a polyurethane foam composite insulation board, the specific steps of which are as follows:

[0142] 1) Pour the first layer of delayed-foaming polyurethane foam onto the bottom template. The thickness of the delayed-foaming polyurethane foam layer is about 7mm. The mass of hydrogen peroxide solution in each layer of delayed-foaming polyurethane foam is 3% of the total weight of the raw materials of the delayed-foaming polyurethane foam.

[0143] 2) Lay a first layer of expanded perlite particles on the top side of the first layer of delayed foamed polyurethane foam. The thickness of the first layer of expanded perlite particles is about 10mm and the particle size range is 1mm to 6mm.

[0144] 3) Pour a second layer of delayed-expansion polyurethane foam, about 7mm thick, onto the top of the first layer of expanded perlite particles.

[0145] 4) Lay a second layer of expanded perlite granules on the top of the second layer of delayed-expansion polyurethane foam. The thickness of the second layer of expanded perlite granules is about 10mm.

[0146] 5) Apply a third layer of delayed-expansion polyurethane foam, approximately 7mm thick, to the top of the second layer of expanded perlite particles.

[0147] 6) Lay a third layer of expanded perlite granules on the top side of the third layer of delayed foamed polyurethane foam. The thickness of the third layer of expanded perlite granules is about 10mm.

[0148] 7) Apply a fourth layer of delayed-expansion polyurethane foam, approximately 7mm thick, to the top of the third layer of expanded perlite particles.

[0149] 8) Lay a fourth layer of expanded perlite granules on the top side of the fourth layer of delayed foamed polyurethane foam. The thickness of the fourth layer of expanded perlite granules is about 10mm.

[0150] 9) Apply a fifth layer of delayed-expansion polyurethane foam, approximately 7mm thick, to the top of the fourth layer of expanded perlite particles.

[0151] 10) Lay a fifth layer of expanded perlite granules on the top side of the fifth layer of delayed foamed polyurethane foam. The thickness of the fifth layer of expanded perlite granules is about 10mm.

[0152] 11) Apply a sixth layer of delayed-expansion polyurethane foam, approximately 7mm thick, to the top of the fifth layer of expanded perlite particles.

[0153] 12) Place cement paper and pressure plate on the sixth layer of delayed foamed polyurethane foam in sequence, and keep the pressure plate fixed.

[0154] 13) Keep the pressure plate fixed for about 6 minutes, then remove the cement paper, pressure plate and bottom template to obtain a 50mm thick polyurethane foam composite insulation board.

[0155] The thermal conductivity, tensile strength, and fire resistance of a 50mm thick polyurethane foam composite insulation board were tested. The thermal conductivity was 0.54 W / (m·K), the tensile strength was 0.09 MPa, and the fire resistance was A2 grade. Although the fire resistance of this insulation board reached A grade, the thermal conductivity of the overall insulation board was relatively high and the tensile strength was low due to the insufficient amount of delayed foaming polyurethane foam material.

[0156] Example 6 (aerogel powder was specially added to the formulation):

[0157] A method for preparing a polyurethane foam composite insulation board, the specific steps of which are as follows:

[0158] 1) Pour the first layer of delayed-foaming polyurethane foam onto the bottom template. The thickness of the delayed-foaming polyurethane foam layer is about 11mm. The mass of hydrogen peroxide solution in each layer of delayed-foaming polyurethane foam is 3% of the total weight of the raw materials of the delayed-foaming polyurethane foam.

[0159] 2) Lay a first layer of expanded perlite particles mixed with aerogel powder on the top side of the first layer of delayed foamed polyurethane foam. The thickness of the first layer of expanded perlite particles is about 10mm. The weight of aerogel powder in the expanded perlite particles mixed with aerogel powder is 3% of the weight of the expanded perlite particles.

[0160] 3) Pour a second layer of delayed-expansion polyurethane foam material, about 11 mm thick, onto the top of the first layer of expanded perlite particles mixed with aerogel powder.

[0161] 4) Lay a second layer of expanded perlite particles mixed with aerogel powder on the top of the second layer of delayed foamed polyurethane foam. The thickness of the second layer of expanded perlite particles is about 10mm.

[0162] 5) Pour a third layer of delayed-expansion polyurethane foam, about 11 mm thick, onto the top of the second layer of expanded perlite particles mixed with aerogel powder.

[0163] 6) Lay a third layer of expanded perlite particles mixed with aerogel powder on the top side of the third layer of delayed foamed polyurethane foam. The thickness of the third layer of expanded perlite particles is about 10mm.

[0164] 7) Pour a fourth layer of delayed-expansion polyurethane foam, about 11 mm thick, onto the top of the third layer of expanded perlite particles mixed with aerogel powder.

[0165] 8) Lay a fourth layer of expanded perlite particles mixed with aerogel powder on the top side of the fourth layer of delayed foamed polyurethane foam. The thickness of the fourth layer of expanded perlite particles is about 10mm.

[0166] 9) Apply a fifth layer of delayed-expansion polyurethane foam, approximately 11 mm thick, to the top of the fourth layer of expanded perlite particles.

[0167] 10) Place cement paper and pressure plate on the fifth layer of delayed-expansion polyurethane foam in sequence, and keep the pressure plate fixed.

[0168] 11) Keep the pressure plate fixed for about 6 minutes, then remove the cement paper, pressure plate and bottom template to obtain a 40mm thick polyurethane foam composite insulation board.

[0169] The thermal conductivity, tensile strength and fire resistance of the 40mm thick polyurethane foam composite insulation board were tested. The thermal conductivity was 0.46W / (m·K), the tensile strength was 0.14MPa, and the fire resistance was A2 level.

[0170] Comparing the insulation boards prepared in Example 6 with those prepared in Example 1, the thermal conductivity of the insulation board decreased significantly, by more than 8%, while the tensile strength decreased only slightly, and the fire resistance remained at A2 level. This indicates that incorporating aerogel powder into expanded perlite particles can significantly improve the thermal conductivity of the insulation board.

[0171] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0172] The foregoing has provided a detailed description of a polyurethane foam composite insulation board and its preparation method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a polyurethane foam composite insulation board, characterized in that: The preparation method includes the following steps: S1. Pour a layer of polyurethane foam onto the bottom template or cement paper; S2. Lay a layer of inorganic thermal insulation particles on the top of the polyurethane foam, and then pour another layer of polyurethane foam. Repeat this process to lay the inorganic thermal insulation particles and polyurethane foam in alternating layers until the predetermined height is reached. The inorganic thermal insulation particles are expanded perlite particles or vitrified microspheres. S3. Place a pressure plate on the last layer of polyurethane foam or inorganic insulation particles, and optionally place cement paper between the pressure plate and the polyurethane foam or inorganic insulation particles. Keep the pressure plate fixed so that the polyurethane foam material can fully foam. After the polyurethane foam material foams, it fills the gaps between the inorganic insulation particles. S4. After the polyurethane foam has hardened, a polyurethane foam composite insulation board is obtained. The polyurethane foam material is a delayed-foaming polyurethane foam material, which includes polymeric polyol, polyphenylmethane polyisocyanate, hydrogen peroxide solution, and appropriate additives. The hydrogen peroxide solution accounts for 1-5% of the total weight of the polyurethane foam material raw materials; the mass concentration of the hydrogen peroxide solution is 10%-20%; the additives include one or more of chain extenders, flame retardants, foam stabilizers, and catalysts. The mass percentage of hydrogen peroxide solution in the delayed-foaming polyurethane foam material used in each layer from bottom to top decreases by 0.3% to 0.4% sequentially. By gradually reducing the amount of hydrogen peroxide solution, the foaming speed of the polyurethane foam material layers sprayed at different times is kept consistent.

2. The preparation method according to claim 1, characterized in that: The applied polyurethane foam material presents a diamond-shaped grid pattern.

3. The preparation method according to claim 1, characterized in that: The thickness of each layer of polyurethane foam is 0.7 to 1.5 times the thickness of each layer of inorganic insulation particles.

4. The preparation method according to claim 1, characterized in that: The polyurethane foam material consists of six layers, with the first layer containing 3% hydrogen peroxide solution by mass. The hydrogen peroxide solution accounts for 2.7% of the mass of the second layer of polyurethane foam. The hydrogen peroxide solution accounts for 2.4% of the mass of the third layer of polyurethane foam. The hydrogen peroxide solution accounts for 2.1% of the mass of the fourth layer of polyurethane foam. The hydrogen peroxide solution accounts for 1.8% of the mass of the fifth layer of polyurethane foam. The hydrogen peroxide solution accounts for 1.5% of the mass of the sixth layer polyurethane foam. The hydrogen peroxide solution has a mass concentration of 14% to 16%, and the concentration of hydrogen peroxide solution used in each layer of polyurethane foam is the same.

5. The preparation method according to claim 1, characterized in that: The inorganic thermal insulation particles are mixed with aerogel powder, and the amount of aerogel powder is 3 to 5% of the weight of the inorganic thermal insulation particles.

6. The preparation method according to claim 1, characterized in that: The particle size range of the inorganic thermal insulation particles is 1–6 mm.

7. The preparation method according to claim 1, characterized in that: The procedure preceding step S1 also includes: S0. Cement mortar mixed with microsilica powder is mixed and stirred with inorganic thermal insulation particles. After natural drying or baking, a coating layer is formed on the outer surface of the inorganic thermal insulation particles. The material is then used to prepare thermal insulation boards in subsequent steps.

8. The preparation method according to claim 1, characterized in that... The preparation method includes the following steps: S0. Mix and stir the cement mortar containing microsilica powder with inorganic thermal insulation particles, and then let it air dry or bake it to form a coating layer on the outer surface of the inorganic thermal insulation particles. S1. Apply a layer of polyurethane foam to the bottom template or cement paper; the upper surface of the bottom template is coated with a release agent, and the applied layer of polyurethane foam is in the form of a diamond grid to ensure that the polyurethane foam foams fully. When the polyurethane foam composite insulation board is produced on a continuous production line, multiple bottom templates or multiple sheets of cement paper are continuously placed on the conveyor platform of the production line. The polyurethane foam is applied using a polyurethane coating machine set on one side of the conveyor platform. Lightweight side plates are added around the bottom template to make the insulation board better formed during manufacturing. S2. Lay a layer of inorganic thermal insulation particles on the top of the polyurethane foam, and then pour another layer of polyurethane foam. Repeat this process to lay the inorganic thermal insulation particles and polyurethane foam in alternating layers until the predetermined height is reached. The inorganic thermal insulation particles are expanded perlite particles or vitrified microspheres with a particle size of 1-6 mm; the inorganic thermal insulation particles are mixed with aerogel powder, and the amount of aerogel powder is 3-5% of the weight of the inorganic thermal insulation particles; The thickness of each layer of polyurethane foam is 0.7 to 1.5 times the thickness of each layer of inorganic insulation particles; the coated polyurethane foam presents a diamond-shaped mesh pattern. S3. Place a pressure plate on the last layer of polyurethane foam or inorganic insulation particles, and optionally place cement paper between the pressure plate and the polyurethane foam or inorganic insulation particles. Keep the pressure plate fixed so that the polyurethane foam material can fully foam. After the polyurethane foam material foams, it fills the gaps between the inorganic insulation particles. The underside of the pressure plate is coated with a release agent. S4. After the polyurethane foam has hardened, remove the pressure plate and bottom template or cement paper to obtain the polyurethane foam composite insulation board.

9. A polyurethane foam composite insulation board prepared by the method described in claim 1.

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