A flame-retardant soundproof polyurethane foam and a preparation method and application thereof

Abstract

The application discloses a kind of flame-retardant soundproof polyurethane foam and its preparation method and application, the flame-retardant soundproof polyurethane foam preparation raw material includes component A and component B;The component A is obtained by the reaction of each component including the following parts by mass: 30-50 parts of polyether polyol-1, 10-20 parts of formaldehyde, 0-10 parts of polyformaldehyde, 20-30 parts of melamine, 1-10 parts of furfurylamine, 2-8 parts of bismaleimide;The component B is obtained by the reaction of each component including the following parts by mass: 25-45 parts of polyether polyol-2, 5-20 parts of isocyanate 1, 40-70 parts of isocyanate 2.The foam material prepared by the application has the advantages of high foam open porosity, fine cell, high foam strength, excellent flame-retardant performance, etc., and can be quickly formed by one-step method, has fast curing speed, can be spray-formed, and is suitable for different construction conditions, complex shape sound insulation requirements.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane foaming technology, and relates to a flame-retardant and sound-insulating polyurethane foam, its preparation method, and its application. Background Technology

[0002] With modernization, transportation networks are becoming increasingly sophisticated. High-speed rail, light rail, and highways are becoming denser in modern metropolises. Noise pollution control has become a pressing social issue. Porous resin materials are commonly used sound-absorbing and noise-reducing materials. When sound waves enter the foam through the pores on the material's surface, the viscoelastic properties of the polymer cause the vibrational energy of the sound waves to be converted into heat energy and dissipated. Simultaneously, the vibration of the air within the open-cell foam, the friction between the air and the pore walls, and the viscous forces between air molecules all contribute to the conversion of vibrational energy into heat energy, which is also dissipated. Therefore, porous polymer resin materials are a very popular choice.

[0003] Polyurethane foam is typically a product obtained by rapidly reacting and curing a mixture of polyisocyanate and polyol components. The curing reaction of polyurethane foam has significant advantages: controllable reaction conditions, adjustable structural differences, and no production of other harmful substances during the reaction. However, its flame retardant properties are poor, requiring the addition of external flame retardants, which can significantly affect its overall performance. Furthermore, if spray coating is used during curing, a faster chain extension rate is required, making it impossible to guarantee a high open-cell ratio.

[0004] In existing technologies, polyurethane foam is modified using powder. Solid powder is added to liquid composites, and phase separation during the foaming process promotes cell opening in the foam. The addition of powder also improves the mechanical properties of the foam. However, the addition of solid powder can severely wear down the foaming machine nozzle, leading to higher equipment costs. On the other hand, if the foam is squeezed during the foaming process before it is fully formed to create cells, the resulting foam opening rate is difficult to control, and the operation is challenging.

[0005] Melamine resin, a polymer obtained by reacting melamine with formaldehyde, possesses advantages such as high temperature resistance, high activity, high open-cell ratio, high hardness, and good dimensional stability. However, its synthesis process involves two steps: prepolymerization and curing, making one-step molding difficult. Research on melamine resin has revealed challenges due to its structure containing numerous NH bonds, resulting in a high density of hydrogen bonds between molecular chains and a large cohesive energy, making the resin brittle and prone to crumbling upon fracture. Current technologies utilize polyols for toughening modification. However, the melamine resin matrix requires a long curing time, hindering the convenient application of polyurethane spray foam. Directly adding melamine resin prepolymer to polyurethane raw materials for curing leads to rapid reaction due to the amine groups, resulting in an excessively fast increase in cross-linking network density, causing high cell wall strength and difficulty in opening pores. Furthermore, direct addition of melamine resin prepolymer to polyurethane raw materials facilitates the reaction of hydroxyl groups with polyisocyanates for curing. Due to steric hindrance, the melamine resin prepolymer is dispersed within the polyurethane, hindering further aggregation and cross-linking of the melamine resin.

[0006] CN200580007879.1 discloses an adhesive, highly reactive rigid polyurethane foam that can adhere to a substrate containing open cavities. This is achieved by reacting a prepolymer with a polyol component in the presence of certain urethane blowing agents, characterized by the use of alkanolamine urethane blowing agents. However, this method still results in a relatively slow curing time (non-sticky time), approximately 15-20 seconds, and does not improve properties such as open-cell ratio or sound insulation.

[0007] CN200780029509.7 discloses a multi-segment expandable polymer composition for cavity filling, which expands in a controllable direction. The polymer composition comprises at least two distinct segments, which may be bonded or unbonded. Upon heating, at least one segment expands before the other segment expands. The segment that expands first forms a physical barrier layer against the expansion of the segment that expands later, thereby limiting the expansion of the later-expanding segment in at least one direction. Unlike the spray-forming process mentioned in this patent, this method is prone to affecting the filling effect due to uneven heating. Furthermore, while this patent discloses a material suitable for sound insulation of automotive cavities, its sound insulation performance is not mentioned in the embodiments.

[0008] Therefore, in this field, there is a desire to develop a flame-retardant and sound-insulating polyurethane foam with high open-cell ratio, high strength, fast curing speed, and sprayable molding capability. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a flame-retardant and sound-insulating polyurethane foam, its preparation method, and its applications. This invention utilizes the characteristic that amine groups can react instantly with isocyanate groups to cure the foam. Simultaneously, isocyanate reacts with water to generate carbon dioxide for foaming, preparing a foam structure containing a triazine ring structure with inherent flame-retardant properties. Furthermore, heat-sensitive non-covalent bonds are introduced into the molecular structure, which break when the heat of reaction accumulates to a certain level, significantly reducing the strength of the cell walls and further increasing the open-cell ratio. The prepared foam material has advantages such as high open-cell ratio, fine pores, high foam strength, and excellent flame-retardant properties. It can be rapidly molded in one step, has a fast curing speed, and can be spray-applied, making it suitable for sound insulation needs with complex shapes under various construction conditions.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] This invention provides a flame-retardant and sound-insulating polyurethane foam, the raw materials for which are prepared include component A and component B;

[0012] Component A is obtained by reacting the following components in parts by mass:

[0013] 30-50 parts of polyether polyol-1, for example 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, preferably 40-50 parts;

[0014] 10-20 parts formaldehyde, such as 10, 12, 14, 16, 18, or 20 parts, preferably 15-17 parts;

[0015] 0-10 parts of paraformaldehyde, such as 0 parts, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, preferably 3-7 parts;

[0016] 20-30 parts of melamine, such as 20 parts, 22 parts, 24 parts, 26 parts, 28 parts, or 30 parts, preferably 23-27 parts;

[0017] 1-10 parts of furfurylamide, for example, 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, preferably 3-7 parts;

[0018] 2-8 parts of bismaleimide, for example, 2 parts, 4 parts, 6 parts, 8 parts, preferably 5-7 parts;

[0019] Component B is obtained by reacting the following components in parts by mass:

[0020] 25-45 parts of polyether polyol-2, for example, 25 parts, 30 parts, 35 parts, 40 parts, or 45 parts, preferably 35-40 parts;

[0021] 5-20 parts of isocyanate 1, for example 5 parts, 10 parts, 15 parts, 20 parts, preferably 10-15 parts;

[0022] 40-70 parts of isocyanate 2, for example 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, preferably 50-60 parts.

[0023] In this invention, the mass ratio of component A to component B is 1:1-2, preferably 1:1.2-1.7.

[0024] The flame-retardant and sound-insulating polyurethane foam of the present invention optionally includes component C in its raw materials, wherein component C includes the following components:

[0025] 1-3 parts of foam stabilizer, such as 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts, preferably 1.5-2.5 parts;

[0026] 0-2 parts of pore-opening agent, such as 0 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, preferably 0.5-1 parts;

[0027] Use 1-3 parts water, such as 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts, preferably 1-2 parts.

[0028] Preferably, the mass ratio of component A to component C is 13-33:1, more preferably 13-19:1.

[0029] In component A of this invention, the polyether polyol-1 has ethylene glycol as the initiator, propylene oxide and / or ethylene oxide as the polymerization unit, and a hydroxyl value of 50-150 mgKOH / g, preferably Wanhua Chemical A210 and / or A220.

[0030] In component B of this invention, the polyether polyol-2 is selected from polyether polyol-21 and / or polyether polyol-22:

[0031] The polyether polyol-21 has glycerol as the initiator, propylene oxide and ethylene oxide as the polymerization units, and a hydroxyl value of 20-150 mgKOH / g, preferably one or more of Wanhua Chemical F3135, F3156 and F3128.

[0032] The polyether polyol-22 has toluene diamine as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 300-600 mgKOH / g, preferably Wanhua Chemical A42-a;

[0033] Preferably, the polyether polyol-2 is a combination of polyether polyol-21 and polyether polyol-22, comprising, by mass parts:

[0034] 20-40 parts of polyether polyol-21, such as 20 parts, 25 parts, 30 parts, 35 parts, or 40 parts, preferably 20-30 parts;

[0035] 5-20 parts of polyether polyol-22, for example, 5 parts, 10 parts, 15 parts, 20 parts, preferably 10-20 parts.

[0036] In component B of this invention, isocyanate 1 is diphenylmethane diisocyanate and / or toluene diisocyanate, preferably one or more of Wanhua Chemical's MDI-100, MDI-50, and TDI-80.

[0037] In component B of this invention, isocyanate 2 is a polyphenylmethane polyisocyanate with a viscosity of 100-800 cp, preferably one or more of Wanhua Chemical PM200, PM400, and PM700.

[0038] In component C of this invention, the foam stabilizer is a silicon-carbon bond non-hydrolyzable polysiloxane-polyether copolymer, preferably one or more of Momentive L6164, Oscar UX1256, Dow Corning DC1959, and Dow Corning DC5000.

[0039] In component C of this invention, the pore-opening agent is a polyoxypropylene-ethylene oxide copolyether, preferably Evonik O500 and / or O501.

[0040] This invention also provides a method for preparing the flame-retardant and sound-insulating polyurethane foam, which is prepared by mixing component A and component C, and then reacting them with component B, the steps of which include:

[0041] 1) After mixing furfural, formaldehyde, paraformaldehyde and melamine, add polyether polyol-1 and react at 50-80℃, for example 55, 60, 65, 70, 75℃, preferably 60-70℃ for 20-30 min, for example 22, 24, 26, 28 min, preferably 25-30 min. Then add bismaleimide and mix evenly. React at 50-60℃, for example 53, 55, 57℃, preferably 55-60℃ for 18-24 h, for example 19, 20, 21, 22, 23 h, preferably 18-22 h, to obtain component A;

[0042] 2) After mixing polyether polyol-2 and isocyanate 1 evenly, heat to 50-80℃, for example 55, 60, 65, 70, 75℃, preferably 50-70℃, and react under nitrogen protection for 3-10h, for example 4, 5, 6, 7, 8, 9h, preferably 5-7h, then cool to 18-25℃, for example 20, 22, 24℃, preferably 20-22℃, and then mix evenly with isocyanate 2 to obtain component B;

[0043] 3) Mix the foam stabilizer, cell opener, and water evenly to obtain component C;

[0044] 4) After mixing components A and C evenly, mix them with component B, pour the mixture into a mold for curing or spraying. The ambient temperature during the molding process is 10-30℃, for example, 15, 20, or 25℃, preferably 20-25℃, to obtain flame-retardant and sound-insulating polyurethane foam.

[0045] This invention also provides an application of the flame-retardant and sound-insulating polyurethane foam in the fields of automotive NVH, vacuum panel core materials, and building sound insulation.

[0046] This invention relates to flame-retardant and sound-insulating polyurethane foam, which has advantages such as high foam open-cell ratio, fine pores, high foam strength, and good flame retardancy. It can also be rapidly molded in one step, has a fast curing speed, and can be sprayed and molded. It is suitable for sound insulation needs with complex shapes under different construction conditions, and is especially suitable for use in automotive NVH, vacuum insulation panel core materials, building sound insulation and other fields.

[0047] This invention can prepare flame-retardant and sound-insulating polyurethane foam using mold curing or spray coating processes, wherein...

[0048] The characteristic parameters of the flame-retardant and sound-insulating polyurethane foam obtained by the mold curing process are: curing time 7-10s, foam density 27-53kg / m³. 3 Compressive strength 250-562 kPa, porosity 98.1-99.9%, oxygen index 27.9-29.1%, average sound absorption coefficient 0.71-0.88;

[0049] The characteristic parameters of flame-retardant and sound-insulating polyurethane foam obtained by spray coating process are: curing time 3.6-5s, foam density 26.4-52.2kg / m³. 3 The compressive strength is 261-559 kPa, the porosity is 99.1-99.9%, the oxygen index is 27.5-30.1%, and the average sound absorption coefficient is 0.79-0.92.

[0050] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0051] This invention modifies rigid polyurethane foam with melamine-formaldehyde resin to form an internally cross-linked triazine ring structure. On the one hand, this provides more inherently flame-retardant sites for the foam structure resin matrix. On the other hand, the strong polarity of the triazine ring structure promotes foam opening in the early stage of the foaming reaction.

[0052] In the prepolymer preparation process, this invention introduces a polyol-modified furfurylamine structure into the melamine resin prepolymer to increase the distance between adjacent triazine rings, resulting in a more extended chain structure. Subsequently, bismaleimide is used to extend the prepolymer chain, introducing thermosensitive reactive groups to make the melamine resin structure more compact. As the reaction proceeds, the heat of reaction accumulates, the thermosensitive groups break down, and the cell wall strength decreases. Simultaneously, the melamine resin prepolymer chain structure becomes more free, allowing for further cross-linking and curing under the influence of the heat of reaction, generating an internal cross-linked network structure within the melamine resin. This structure, while increasing the cross-linking density, results in higher cohesive energy, greater polarity, and is more conducive to foam opening.

[0053] This invention utilizes furfurylamine and bismaleimide to construct a heat-sensitive reactive group within the polyurethane foam structure. This reactive group can weaken the cell wall structure by breaking down chains at high temperatures, thereby further increasing the open-cell ratio. Conversely, at low temperatures, the reactive group reconnects, ensuring the strength of the foam body. Simultaneously, the substantial heat generated during polyurethane foaming further catalyzes the internal cross-linking reaction, enabling one-step molding and simplifying the manufacturing process. Detailed Implementation

[0054] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0055] Information on the main raw material sources used in the embodiments of this invention; unless otherwise specified, all other raw materials are common commercially available materials:

[0056] Furfuralamine: Nantong Runfeng Petrochemical Co., Ltd.;

[0057] Formaldehyde, paraformaldehyde: Shanghai Aladdin Chemical Reagent Co., Ltd.;

[0058] Melamine: Sinopharm Chemical Reagent Co., Ltd.;

[0059] Bismaleimide: Sinopharm Chemical Reagent Co., Ltd.;

[0060] Polymer polyols (F3135, F3156, F3128, A42-a): Wanhua Chemical Group Co., Ltd.

[0061] Isocyanates (PM200, PM400, PM700, MDI-50, MDI-100, TDI-80): Wanhua Chemical Group Co., Ltd.

[0062] Opening agents: Evonik O501, O502

[0063] Foam stabilizers: Momentive L6164, Auscar UX1256, Dow Corning DC1959, Dow Corning DC5000.

[0064] The main performance testing methods used in the embodiments of this invention are as follows:

[0065] Curing time: Start timing with a stopwatch, starting when the two components are evenly mixed and ending when the curing is complete and the surface is dry.

[0066] Density: Tested according to GB / T 6343-2009, take the middle position after removing 30mm from each boundary, the same below.

[0067] Compressive strength: Tested according to GB / T 8813-2008.

[0068] Open area ratio: Tested according to GB / T 10799-2008.

[0069] Oxygen index: Tested according to GB 8624.

[0070] Sound absorption coefficient: The sound absorption coefficient was tested using the standing wave tube method. The sound absorption coefficient data were measured at 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz and 4000Hz respectively, and the average value was calculated as the average sound absorption coefficient.

[0071] Example 1

[0072] Preparation of flame-retardant and sound-insulating polyurethane foam:

[0073] 1) Mix 10g furfurylamine, 20g formaldehyde and 30g melamine, add 30g polyether polyol-1 (Wanhua Chemical A210), react at 50℃ for 30min, add 7g bismaleimide and mix evenly, react at 55℃ for 24h to obtain component A.

[0074] 2) Mix 30g of polyether polyol-2 (25g F3128, 5g A42-a) and 10g of isocyanate 1 (MDI-100) evenly, heat to 80℃, react for 3h under nitrogen protection, cool to 18℃, and mix evenly with 60g of isocyanate 2 (PM200) to obtain component B.

[0075] 3) Mix 1g of foam stabilizer (Dow Corning DC5000), 1g of cell opener (Evonik O500), and 1g of water evenly to obtain component C.

[0076] 4) Mix components A and C evenly at a mass ratio of 33:1. Then, mix component B quickly at a mass ratio of (A+C) / B=1. Use two methods: pouring into a mold for curing and molding, or spraying with a Normac two-component spray gun. The ambient temperature during the molding process is 10℃. Two types of flame-retardant and sound-insulating polyurethane foams are obtained.

[0077] Example 2

[0078] 1) Mix 1g furfural, 16g formaldehyde, 5g paraformaldehyde and 21g melamine, then add 50g polyether polyol-1 (Wanhua Chemical A220), react at 60℃ for 30min, then add 2g bismaleimide and mix well, then react at 57℃ for 22h. Component A is obtained.

[0079] 2) Mix 35g of polyether polyol-2 (20g of Wanhua Chemical F3156 and 15g of Wanhua Chemical A42-a) and 15g of isocyanate 1 (Wanhua Chemical MDI-50) evenly, heat to 60℃, react for 6h under nitrogen protection, cool to room temperature 20℃, and mix evenly with 50g of isocyanate 2 (Wanhua Chemical PM200) to obtain component B.

[0080] 3) Mix 2.5g of foam stabilizer (Dow Corning DC1959), 0.5g of cell opener (Evonik O501) and 2g of water evenly to obtain component C.

[0081] 4) Mix components A and C evenly at a mass ratio of 19:1. Then, mix component B quickly at a mass ratio of (A+C) / B = 1.5. Use two methods: pouring into a mold for curing and molding, or spraying with a Normac two-component spray gun. The ambient temperature during the molding process is 15℃. Two types of flame-retardant and sound-insulating polyurethane foams are obtained.

[0082] Example 3

[0083] 1) Mix 3g of furfural, 17g of formaldehyde, 10g of paraformaldehyde and 27g of melamine, then add 30g of polyether polyol-1 (Wanhua Chemical A210), react at 70℃ for 25min, then add 8g of bismaleimide and mix thoroughly, react at 58℃ for 20h. Component A is obtained.

[0084] 2) Mix 40g of polyether polyol-2 (30g of Wanhua Chemical F3128 and 10g of Wanhua Chemical A42-a) and 20g of isocyanate 1 (Wanhua Chemical TDI80) evenly, heat to 60℃, react for 8h under nitrogen protection, cool to room temperature 22℃, and mix evenly with 40g of isocyanate 2 (Wanhua Chemical PM400) to obtain component B.

[0085] 3) Mix 1.5g of foam stabilizer (Momentive L6164), 0.5g of cell opener (Evonik O501) and 3g of water evenly to obtain component C.

[0086] 4) Mix components A and C evenly at a mass ratio of 19:1. Then, mix component B quickly at a mass ratio of (A+C) / B = 1.2. The mixture is then cured by pouring it into a mold or sprayed using a Normac two-component spray gun. The ambient temperature during the molding process is 20°C. Two types of flame-retardant and sound-insulating polyurethane foams are obtained.

[0087] Example 4

[0088] 1) Mix 7g furfural, 10g formaldehyde, 7g paraformaldehyde and 20g melamine, then add 45g polyether polyol-1 (Wanhua Chemical A220), react at 80℃ for 20min, then add 6g bismaleimide and mix well, react at 60℃ for 18h. Component A is obtained.

[0089] 2) Mix 45g of polyether polyol-2 (40g of Wanhua Chemical F3135 and 5g of Wanhua Chemical A42-a) and 15g of isocyanate 1 (Wanhua Chemical MDI-100) evenly, heat to 50℃, react for 10h under nitrogen protection, cool to room temperature 24℃, and mix evenly with 40g of isocyanate 2 (Wanhua Chemical PM400) to obtain component B.

[0090] 3) Mix 2.5g of foam stabilizer (Auskin UX1256), 1.5g of cell opener (Evonik O500) and 1g of water evenly to obtain component C.

[0091] 4) Mix components A and C evenly at a mass ratio of 19:1. Then mix component B quickly at a mass ratio of (A+C) / B = 1.7. Use two methods: pouring into a mold for curing and molding, or spraying with a Normac two-component spray gun. The ambient temperature during the molding process is 25℃, resulting in two types of flame-retardant and sound-insulating polyurethane foams.

[0092] Example 5

[0093] 1) Mix 6g furfural, 15g formaldehyde, 3g paraformaldehyde and 24g melamine, then add 40g polyether polyol-1 (Wanhua Chemical A210), react at 70℃ for 25min, then add 8g bismaleimide and mix thoroughly, react at 56℃ for 20h. Component A is obtained.

[0094] 2) Mix 40g of polyether polyol-2 (20g of Wanhua Chemical F3156 and 20g of Wanhua Chemical A42-a) and 20g of isocyanate 1 (Wanhua Chemical TDI-80) evenly, heat to 70℃, react for 7h under nitrogen protection, cool to room temperature 25℃, and mix evenly with 40g of isocyanate 2 (Wanhua Chemical PM400) to obtain component B.

[0095] 3) Mix 3g of foam stabilizer (Dow Corning DC1959) and 1g of water evenly to obtain component C.

[0096] 4) Mix components A and C evenly at a mass ratio of 24:1. Then, mix component B quickly at a mass ratio of (A+C) / B=2. Use two methods: pouring into a mold for curing and molding, or spraying with a Normac two-component spray gun. The ambient temperature during the molding process is 30℃. Two types of flame-retardant and sound-insulating polyurethane foams are obtained.

[0097] Example 6

[0098] 1) Mix 2g of furfural, 11g of formaldehyde, 9g of paraformaldehyde and 20g of melamine, then add 46g of polyether polyol-1 (Wanhua Chemical A220), react at 65℃ for 30min, then add 5g of bismaleimide and mix well, react at 60℃ for 18h. Component A is obtained.

[0099] 2) Mix 25g of polyether polyol-2 (20g of Wanhua Chemical F3135 and 5g of Wanhua Chemical A42-a) and 5g of isocyanate 1 (Wanhua Chemical MDI-50) evenly, heat to 65℃, react for 5h under nitrogen protection, cool to room temperature 21℃, and mix evenly with 70g of isocyanate 2 (Wanhua Chemical PM200) to obtain component B.

[0100] 3) Mix 2g of foam stabilizer (Dow Corning DC5000), 2g of cell opener (Evonik O500) and 3g of water evenly to obtain component C.

[0101] 4) Mix components A and C evenly at a mass ratio of 13:1. Then mix component B quickly at a mass ratio of (A+C) / B = 1.1. Use two methods: pouring into a mold for curing and molding, or spraying with a Normac two-component spray gun. The ambient temperature during the molding process is 23℃. Two types of flame-retardant and sound-insulating polyurethane foams are obtained.

[0102] Comparative Example 1

[0103] The method of Example 1 was followed, except that no formaldehyde was added to component A, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0104] Comparative Example 2

[0105] The method of Example 1 was followed, except that melamine was not added to component A, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0106] Comparative Example 3

[0107] The method of Example 1 was followed, except that polyether polyol-1 was not added to component A, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0108] Comparative Example 4

[0109] The method of Example 1 was followed, except that furfurylamine was not added to component A, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0110] Comparative Example 5

[0111] The method of Example 1 was followed, except that furfurylamine in component A was replaced with aniline, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0112] Comparative Example 6

[0113] The method of Example 1 was followed, except that bismaleimide was not added to component A, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0114] Comparative Example 7

[0115] The method of Example 1 was followed, except that bismaleimide in component A was replaced with maleimide, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring into a mold for curing and by spraying with a Normac two-component spray gun.

[0116] Comparative Example 8

[0117] The method of Example 1 was followed, except that polyether polyol-2 was not added to component B, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0118] Comparative Example 9

[0119] The method of Example 1 was followed, except that isocyanate 2 was not added to component B, while other operations and conditions remained unchanged. Two types of polyurethane foam were obtained by pouring the foam into a mold for curing and by spraying it with a Normac two-component spray gun.

[0120] The polyurethane foams prepared in the examples and comparative examples were tested for properties such as open cell ratio, foam density, compressive strength, flame retardancy (oxygen index), and sound insulation. The performance results of the polyurethane foam prepared by the mold curing process are shown in Table 1, and the performance results of the polyurethane foam prepared by the spray coating process are shown in Table 2.

[0121] Table 1. Performance data of polyurethane foam (mold-cured) in the examples and comparative examples.

[0122] Curing time / s <![CDATA[Foam density / kg / m 3 > Open area ratio / % Compressive strength / kPa Oxygen Index / % Average sound absorption coefficient Example 1 7.2 40.0 99.8 340 28.7 0.81 Example 2 8.1 36.0 99.6 310 28.5 0.78 Example 3 7.9 30.5 99.9 292 29.0 0.86 Example 4 9.3 46.8 98.9 411 28.1 0.73 Example 5 10.0 53.2 98.1 562 29.1 0.71 Example 6 7.8 27.3 99.9 258 27.9 0.88 Comparative Example 1 7.8 40.1 78.2 298 23.8 0.34 Comparative Example 2 13.2 41.2 76.1 287 23.7 0.36 Comparative Example 3 6.7 43.8 94.2 312 27.3 0.41 Comparative Example 4 12.3 42.5 78.6 209 27.9 0.27 Comparative Example 5 7.1 40.1 82.3 299 26.8 0.23 Comparative Example 6 7.2 40.8 75.1 290 25.8 0.29 Comparative Example 7 7.3 40.3 73.2 297 26.6 0.31 Comparative Example 8 7.6 46.1 87.3 335 27.1 0.34 Comparative Example 9 4.0 32.4 89.6 210 25.7 0.43

[0123] Table 2 Performance data of polyurethane foam (spray-coated) in the examples and comparative examples.

[0124] Curing time / s <![CDATA[Foam density / kg / m 3 > Open area ratio / % Compressive strength / kPa Oxygen Index / % Average sound absorption coefficient Example 1 3.6 39.8 99.9 332 28.5 0.83 Example 2 4.1 35.5 99.7 301 28.6 0.81 Example 3 3.9 29.8 99.8 295 28.0 0.9 Example 4 4.5 45.0 99.1 410 29.2 0.8 Example 5 5.0 52.2 99.2 559 30.1 0.79 Example 6 3.9 26.4 99.9 261 27.8 0.92 Comparative Example 1 3.9 39.7 76.2 289 23.8 0.35 Comparative Example 2 7.8 40.6 75.9 265 23.8 0.41 Comparative Example 3 3.9 42.5 92.8 315 27.1 0.39 Comparative Example 4 7.3 41.8 77.1 211 27.8 0.25 Comparative Example 5 3.5 39.6 82.4 301 26.6 0.21 Comparative Example 6 3.6 40.1 73.1 283 25.1 0.33 Comparative Example 7 3.5 39.6 72.9 289 26.7 0.32 Comparative Example 8 3.1 45.3 88.1 330 26.9 0.35 Comparative Example 9 2.9 29.8 88.2 198 25.9 0.46

[0125] It is evident that polyurethane foams prepared through mold curing and spraying processes have advantages such as high foam open-cell ratio, high foam strength, good sound insulation performance, and oxygen index that meets the B2 standard.

[0126] Comparative Examples 1, 2, and 1 show that formaldehyde and melamine can react to form a melamine resin structure. The absence of formaldehyde or melamine significantly affects the open-cell ratio, thus impacting the sound absorption coefficient. Comparative Examples 3 and 1 show that the addition of polyether polyol 1 enhances the compatibility between the melamine resin structure and the polyurethane matrix. The absence of polyether polyol 1 affects compatibility, thus affecting the sound absorption coefficient. Comparative Examples 4, 5, 6, 7, and 1 show that furfurylamine resin and bismaleimide can form reversible chemical bonds. The absence or replacement of furfurylamine and bismaleimide greatly affects the foam's sound absorption performance. Comparative Examples 8 and 1 show that the absence of polymer polyol 2 significantly reduces the open-cell ratio of the finished product, thus affecting its sound absorption performance. Comparative Examples 9 and 1 show that isocyanate 2 significantly affects foam strength and oxygen index.

[0127] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A flame-retardant and sound-insulating polyurethane foam, characterized in that, The raw materials for preparation include component A and component B; Component A is obtained by reacting the following components in parts by mass: 30-50 parts of polyether polyol-1; 10-20 parts formaldehyde; 0-10 parts paraformaldehyde; 20-30 parts melamine; 1-10 parts furfurylamide; 2-8 parts bismaleimide; In component A, the polyether polyol-1 has ethylene glycol as the initiator, propylene oxide and / or ethylene oxide as the polymerization unit, and a hydroxyl value of 50-150 mgKOH / g. Component B is obtained by reacting the following components in parts by mass: 25-45 parts of polyether polyol-2; 5-20 parts isocyanate 1; 40-70 parts isocyanate 2; In component B, the polyether polyol-2 is selected from polyether polyol-21 and polyether polyol-22: the polyether polyol-21 has glycerol as the initiator, propylene oxide and ethylene oxide as the polymerization units, and a hydroxyl value of 20-150 mgKOH / g; the polyether polyol-22 has toluene diamine as the initiator, propylene oxide as the polymerization unit, and a hydroxyl value of 300-600 mgKOH / g. The isocyanate 2 is a polyphenylmethane polyisocyanate.

2. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, Component A is obtained by reacting the following components in parts by mass: Polyether polyol-1, 40-50 parts; Formaldehyde, 15-17 parts; Paraformaldehyde, 3-7 parts; Melamine, 23-27 parts; Furfural, 3-7 parts; Bismaleimide, 5-7 parts; Component B is obtained by reacting the following components in parts by mass: Polyether polyol-2, 35-40 parts; Isocyanate 1, 10-15 parts; Isocyanate 2,50-60 parts.

3. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, The mass ratio of component A to component B is 1:1-2.

4. The flame-retardant and sound-insulating polyurethane foam according to claim 3, characterized in that, The mass ratio of component A to component B is 1:1.2-1.

7.

5. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, The raw materials may also optionally include component C, which comprises the following components: 1-3 parts foam stabilizer; 0-2 parts of pore-opening agent; 1-3 parts water.

6. The flame-retardant and sound-insulating polyurethane foam according to claim 5, characterized in that, Component C includes the following components: Foam stabilizer, 1.5-2.5 parts; 0.5-1 part of pore-opening agent; Water, 1-2 parts.

7. The flame-retardant and sound-insulating polyurethane foam according to claim 5, characterized in that, The mass ratio of component A to component C is 13-33:

1.

8. The flame-retardant and sound-insulating polyurethane foam according to claim 7, characterized in that, The mass ratio of component A to component C is 13-19:

1.

9. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, The polyether polyol-1 is selected from Wanhua Chemical A210 and / or A220.

10. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, The polyether polyol-21 is selected from one or more of Wanhua Chemical's F3135, F3156, and F3128; The polyether polyol-22 is Wanhua Chemical A42-a.

11. The flame-retardant and sound-insulating polyurethane foam according to claim 10, characterized in that, The polyether polyol-2 is a combination of polyether polyol-21 and polyether polyol-22, and by mass parts, comprises: 20-40 parts of polyether polyol-21; 5-20 parts of polyether polyol-22.

12. The flame-retardant and sound-insulating polyurethane foam according to claim 11, characterized in that, The polyether polyol-2, by mass parts, comprises: Polyether polyol-21, 20-30 parts; Polyether polyol-22, 10-20 parts.

13. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, In component B, isocyanate 1 is diphenylmethane diisocyanate and / or toluene diisocyanate.

14. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, In component B, the isocyanate 1 is selected from one or more of Wanhua Chemical's MDI-100, MDI-50, and TDI-80.

15. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, In component B, the viscosity of isocyanate 2 is 100-800 cp.

16. The flame-retardant and sound-insulating polyurethane foam according to claim 1, characterized in that, In component B, the isocyanate 2 is selected from one or more of Wanhua Chemical's PM200, PM400, and PM700.

17. The flame-retardant and sound-insulating polyurethane foam according to claim 5, characterized in that, In component C, the foam stabilizer is a silicon-carbon bond non-hydrolyzable polysiloxane-polyether copolymer; The pore-opening agent is a polyoxypropylene-ethylene oxide copolyether.

18. The flame-retardant and sound-insulating polyurethane foam according to claim 17, characterized in that, The foam stabilizer is selected from one or more of Momentive L6164, Oscar UX1256, Dow Corning DC1959, and Dow Corning DC5000.

19. The flame-retardant and sound-insulating polyurethane foam according to claim 17, characterized in that, The pore-opening agent is selected from Evonik O500 and / or O501.

20. A method for preparing flame-retardant and sound-insulating polyurethane foam according to any one of claims 1-19, characterized in that the steps include... include: 1) Mix furfural, formaldehyde, paraformaldehyde and melamine, add polyether polyol-1, react at 50-80℃ for 20-30 min, then add bismaleimide and mix evenly, react at 50-60℃ for 18-24 h to obtain component A; 2) After mixing polyether polyol-2 and isocyanate 1 evenly, heat to 50-80℃ and react under nitrogen protection for 3-10 hours. Then cool to 18-25℃ and mix evenly with isocyanate 2 to obtain component B. 3) Mix the foam stabilizer, cell opener, and water evenly to obtain component C; 4) After mixing components A and C evenly, mix them with component B, pour the mixture into a mold and cure or spray it into shape. The ambient temperature during the molding process is 10-30℃ to obtain flame-retardant and sound-insulating polyurethane foam.

21. The application of the flame-retardant and sound-insulating polyurethane foam according to any one of claims 1-19 or the flame-retardant and sound-insulating polyurethane foam prepared by the method of claim 20 in the fields of automobiles, vacuum panel core materials, and building sound insulation.