Flame-retardant polyurethane foam material containing fire-extinguishing microcapsules and preparation method of flame-retardant polyurethane foam material

Abstract

The invention relates to a flame-retardant polyurethane foam material containing fire-extinguishing microcapsules and a preparation method of the flame-retardant polyurethane foam material, and belongs to the technical field of fire-extinguishing materials. The method comprises the following steps: uniformly mixing perfluorohexanone, an oil-phase substance, polyol and a phase solvent to obtain an oil-phase mixture; adding the oil-phase mixture into an aqueous solution of an emulsifier, and uniformly mixing to obtain an emulsion; adding an aliphatic amine compound into the emulsion to initiate a polymerization reaction, and obtaining a mixed solution containing an initial fire extinguishing microcapsule after the reaction is completed; carrying out surface modification on the initial fire-extinguishing microcapsules to obtain the fire-extinguishing microcapsules coated with calcium carbonate particles on the surfaces; uniformly mixing the fire-extinguishing microcapsules, a polyol component and isocyanate, and performing condensation reaction to obtain the flame-retardant polyurethane foam material containing the fire-extinguishing microcapsules. According to the invention, the polyurethane foam composite material with flame-retardant and fire-extinguishing functions is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of fire extinguishing materials, and in particular to a flame retardant polyurethane foam material containing fire extinguishing microcapsules and a preparation method thereof. Background Art

[0002] The battery cell spacer is located between the battery cell and the external shell, and mainly plays the role of heat insulation, shockproof, wear-proof and support. At the same time, it can absorb the expansion stress generated by the charging and discharging of the battery cell and buffer the impact vibration suffered by the battery. It is usually made of high-rebound polymer materials, such as EVA and polyurethane foam. However, in the case of thermal runaway of a battery cell in the battery, the thermal runaway battery cell can easily have a negative impact on other adjacent battery cells and even cause a fire. The existing battery cell spacers do not have both flame retardant and fire extinguishing functions during thermal runaway. Therefore, it is urgent to research and develop a flame retardant polyurethane foam material containing fire extinguishing microcapsules and a preparation method thereof. Summary of the invention

[0003] In order to solve the problem that the current battery core spacers do not have both flame retardant and fire extinguishing functions, the present invention provides a flame retardant polyurethane foam material containing fire extinguishing microcapsules and a preparation method thereof.

[0004] In a first aspect, the present invention provides a method for preparing a flame retardant polyurethane foam material containing fire extinguishing microcapsules, comprising:

[0005] (1) mixing perfluorohexanone, an oil phase substance, a polyol and a phase solvent to obtain an oil phase mixture;

[0006] (2) adding the oil phase mixture to the aqueous solution of the emulsifier and mixing to obtain an emulsion;

[0007] (3) adding a fatty amine compound to the emulsion to initiate a polymerization reaction, and after the reaction is completed, a mixed solution including initial fire extinguishing microcapsules is obtained;

[0008] (4) surface-modifying the initial fire-extinguishing microcapsules to obtain fire-extinguishing microcapsules coated with calcium carbonate particles;

[0009] (5) The fire extinguishing microcapsules, polyol component and isocyanate are mixed and then subjected to condensation reaction to obtain the flame retardant polyurethane foam material containing the fire extinguishing microcapsules.

[0010] Preferably, in step (1), the oil phase substance is isophorone diisocyanate; and the phase solvent is cyclohexane.

[0011] Preferably, in step (1), the polyol is at least one of polypropylene glycol 2000, glycerol or pentaerythritol.

[0012] Preferably, in step (1), the ratio of the amount of perfluorohexanone, the oil phase substance, the polyol and the phase solvent is (3.8-4.2) mL: (0.60-0.68) g: (0.60-0.68) g: 2 mL.

[0013] Preferably, in step (2), the emulsifier is sodium lauryl sulfate.

[0014] Preferably, in step (2), the mass ratio of the emulsifier to water in the aqueous solution of the emulsifier is (0.3-0.34):30.

[0015] Preferably, in step (2), the ratio of the amount of the emulsifier to the amount of perfluorohexanone is (0.30-0.34) g: (3.8-4.2) mL.

[0016] Preferably, in step (2), the oil phase mixture is added dropwise to the aqueous solution of the emulsifier and mixed uniformly, the mixing speed is 1000-2000 rpm, and the emulsification time is 8-15 min.

[0017] Preferably, in step (3), the fatty amine compound is tetraethylenepentamine.

[0018] Preferably, in step (3), the mass ratio of the fatty amine compound to the oil phase substance is (8.1-8.5):(3.1-3.5).

[0019] Preferably, in step (3), the polymerization reaction temperature is 20-30° C., the reaction time is 0.5-1 h, and the reaction speed is 300-400 rpm.

[0020] Preferably, in step (4), after adding calcium chloride to the mixed solution and mixing well, sodium carbonate is added to modify the surface of the initial fire extinguishing microcapsules.

[0021] Preferably, in step (4), the ratio of calcium chloride, sodium carbonate and perfluorohexanone is (3.2-3.5) g: (3.2-3.5) g: (3.8-4.2) mL.

[0022] Preferably, in step (4), after the surface modification of the initial fire extinguishing microcapsules, a cleaning treatment and a drying treatment are also included.

[0023] More preferably, in step (4), the cleaning treatment uses deionized water and anhydrous ethanol;

[0024] More preferably, in step (4), the drying treatment is freeze-drying; more preferably, the freeze-drying temperature is -60 to -40°C, the vacuum degree is 0.1 to 10 Pa, and the drying time is 8 to 12 hours.

[0025] Preferably, in step (5), the mass ratio of the fire extinguishing microcapsules, the polyol component and the isocyanate is (1-4.8):8:8.

[0026] Preferably, in step (5), the polyol component comprises polyester polyol, a catalyst, a surfactant and a foaming agent.

[0027] Preferably, in step (5), ammonium polyphosphate is also included, and the mass ratio of ammonium polyphosphate, polyol component and isocyanate is (0.8-1.2):5:5.

[0028] Preferably, in step (5), the polyol component comprises the following raw materials in percentage by mass: 60% to 80% of polyester polyol, 2% to 5% of catalyst, 2% to 5% of surfactant and 5% to 10% of foaming agent.

[0029] More preferably, in step (5), the catalyst is triethylenediamine and dibutyltin dilaurate; the surfactant is polysiloxane-polyether copolymer; and the foaming agent is water.

[0030] In a second aspect, the present invention provides a flame retardant polyurethane foam material containing fire extinguishing microcapsules, which is prepared by any preparation method of the first aspect.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] (1) In the present invention, by preparing perfluorohexanone fire extinguishing microcapsules with a three-layer shell structure, the volatilization of perfluorohexanone is reduced, and the storage and application problems of perfluorohexanone are solved, and the dependence and space limitation of fire detection and automatic fire extinguishing devices on sensors are eliminated. The flame-retardant polyurethane foam material containing fire extinguishing microcapsules prepared by the present invention can effectively release perfluorohexanone in the fire extinguishing microcapsules in the case of fire or overheating, quickly suppress the spread of flames, and enhance the safety of batteries and other flammable materials.

[0033] (2) The fire-extinguishing microcapsules prepared by the present invention are not only safe, environmentally friendly, non-toxic and harmless, but also have excellent flame retardant properties and significant fire extinguishing capabilities; they can quickly take effect when a fire occurs and effectively inhibit the spread of flames without causing harm to the environment or human health.

[0034] (3) In the present invention, the surface of the fire-extinguishing microcapsule is coated with calcium carbonate particles, which can also absorb heat and cool down the fire during the fire extinguishing process. When calcium carbonate comes into contact with the fire source, it will quickly decompose and release carbon dioxide gas, which will absorb a large amount of heat, causing the temperature around the fire source to drop rapidly; at the same time, the released carbon dioxide gas can dilute the oxygen concentration in the air and reduce the speed of the combustion reaction, thereby achieving rapid fire extinguishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a flow chart of a method for preparing a flame retardant polyurethane foam material containing fire extinguishing microcapsules provided by one embodiment of the present invention;

[0036] Figure 2 This is a SEM image of a fire extinguishing microcapsule provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] like Figure 1 As shown, the present invention provides a method for preparing a flame retardant polyurethane foam material containing fire extinguishing microcapsules, comprising:

[0039] (1) mixing perfluorohexanone, an oil phase substance, a polyol and a phase solvent to obtain an oil phase mixture;

[0040] (2) adding the oil phase mixture to the aqueous solution of the emulsifier and mixing to obtain an emulsion;

[0041] (3) adding a fatty amine compound to the emulsion to initiate a polymerization reaction, and after the reaction is completed, a mixed solution including initial fire extinguishing microcapsules is obtained;

[0042] (4) surface modifying the initial fire-extinguishing microcapsules to obtain fire-extinguishing microcapsules coated with calcium carbonate particles;

[0043] (5) The fire extinguishing microcapsules, the polyol component and the isocyanate are mixed and then subjected to a condensation reaction to obtain a flame retardant polyurethane foam material containing the fire extinguishing microcapsules.

[0044] In the present invention, perfluorohexanone fire extinguishing agent is used as a core layer and coated in a liquid state, polyurea and polyurethane are used as an inner shell layer, and calcium carbonate is used as an outer shell layer, so as to obtain perfluorohexanone fire extinguishing microcapsules with a three-layer core-shell structure, which not only reduces the volatilization of perfluorohexanone, but also solves the storage and application problems of perfluorohexanone, eliminates the dependence of fire detection and automatic fire extinguishing devices on sensors and space limitations, and realizes the thermal transition temperature of the fire extinguishing microcapsules through the inner shell layer and the outer shell layer, realizes the effective release of perfluorohexanone within a certain temperature range, realizes the flame retardant and fire extinguishing functions of the flame retardant polyurethane foam material containing the fire extinguishing microcapsules, and enhances the safety of batteries and other flammable materials.

[0045] The perfluorohexanone selected by the present invention is non-conductive, residue-free, has zero ozone depletion and has a low global warming potential. However, due to the low solubility and high volatility of perfluorohexanone, microencapsulation can solve the above problems, while solving the storage and application problems of perfluorohexanone, eliminating the dependence on sensors and space limitations.

[0046] According to some preferred embodiments, in step (1), the oil phase substance is isophorone diisocyanate; and the phase solvent is cyclohexane.

[0047] According to some preferred embodiments, in step (1), the polyol is at least one of polypropylene glycol 2000, glycerol or pentaerythritol.

[0048] It should be noted that at least one is any one or a mixture of any several in any proportion.

[0049] According to some preferred embodiments, in step (1), the ratio of the amount of perfluorohexanone, the oil phase substance, the polyol and the phase solvent is (3.8-4.2) mL: (0.60-0.68) g: (0.60-0.68) g: 2 mL (for example, it can be 3.8 mL: 0.60 g: 0.60 g: 2 mL, 4.0 mL: 0.60 g: 0.60 g: 2 mL, 4.2 mL: 0.60 g: 0.60 g: 2 mL, 3.8 mL: 0.62 g: 0.60 g: 2 mL, 4.0 mL: 0.62 g: 0.60 g: 2 mL, 4.2 mL: 0.62 g: 0.60 g: 2 mL, 3.8 mL: 0.65 g: 0.60 g: 2 mL, 4.0 mL: 0.65 g: 0.60 g: 2 mL, 4.2 mL: 0.65 g:0.60g:2mL, 3.8mL:0.68g:0.60g:2mL, 4.0mL:0.68g:0.60g:2mL, 4.2mL:0.68g:0 .60g:2mL, 3.8mL:0.60g:0.62g:2mL, 4.0mL:0.60g:0.62g:2mL, 4.2mL:0.60g:0.62 g:2mL, 3.8mL:0.60g:0.65g:2mL, 4.0mL:0.60g:0.65g:2mL, 4.2mL:0.60g:0.65g:2 mL, 3.8mL:0.60g:0.68g:2mL, 4.0mL:0.60g:0.68g:2mL or 4.2mL:0.60g:0.68g:2mL).

[0050] In the present invention, since perfluorohexanone and oil phase substances are not miscible, direct mixing will result in stratification, so a phase solvent needs to be added to evenly disperse perfluorohexanone and oil phase substances, and then perfluorohexanone is encapsulated during the polymerization reaction to obtain initial fire extinguishing microcapsules.

[0051] According to some preferred embodiments, in step (3), the fatty amine compound is tetraethylenepentamine.

[0052] According to some preferred embodiments, in step (3), the mass ratio of the fatty amine compound to the oil phase substance is (8.1-8.5):(3.1-3.5) (for example, it can be 8.1:3.1, 8.1:3.2, 8.1:3.3, 8.1:3.4, 8.1:3.5, 8.2:3.1, 8.2:3.3, 8.2:3.5, 8.3:3.1, 8.3:3.3, 8.3:3.5, 8.4:3.2, 8.4:3.3, 8.4:3.5 or 8.5:3.5).

[0053] In the present invention, the control of the initial size of the fire-extinguishing microcapsules is achieved by limiting the mass ratio of perfluoroacetone, oil phase material, polyol, fatty amine compound and phase solvent. Under the premise that the amount of other components remains unchanged, if the amount of perfluoroacetone is too much, the shell layer of the initial fire-extinguishing microcapsules is relatively thin, and its mechanical strength is poor, which will cause the fire-extinguishing microcapsules to break easily during storage; but if the amount of perfluoroacetone is too little, the fire-extinguishing ability of the fire-extinguishing microcapsules will be reduced, and the shell layer of the initial fire-extinguishing microcapsules will be relatively thick, and it is not easy to break and release perfluoroacetone. Oil phase material, polyol, and fatty amine compound are used to form the inner shell layer of the fire-extinguishing microcapsules, that is, polyurea and polyurethane shell layers. Therefore, under the premise that the amount of other components remains unchanged, by controlling the ratio of the amount of these three, not only can an inner shell layer with better mechanical properties be obtained, but also the size of the initial fire-extinguishing microcapsules can be controlled so that the inner shell layer can wrap more perfluoroacetone. Specifically, under the premise that the amounts of other components remain unchanged, if the amount of oil phase substances, polyols and fatty amine compounds is too much, the shell layer of the initial fire extinguishing microcapsules will be relatively thick, and it will not be easy to break and release perfluorohexanone, which will lead to poor fire extinguishing ability of the fire extinguishing microcapsules; if the amount is too little, the shell layer of the initial fire extinguishing microcapsules will be relatively thin, and the mechanical properties will be poor, which will cause the fire extinguishing microcapsules to break easily during storage. Therefore, by coordinating and controlling the amount of each substance, the prepared fire extinguishing microcapsules still have excellent mechanical properties and a high content of perfluorohexanone after coating the calcium carbonate particles.

[0054] According to some preferred embodiments, in step (2), the emulsifier is sodium dodecyl sulfate.

[0055] According to some preferred embodiments, in step (2), the mass ratio of the emulsifier to water in the aqueous solution of the emulsifier is (0.3-0.34):30 (for example, it can be 0.3:30, 0.31:30, 0.32:30, 0.33:30 or 0.34:30).

[0056] According to some preferred embodiments, in step (2), the ratio of the amount of emulsifier to perfluorohexanone is (0.30-0.34) g:(3.8-4.2) mL (for example, it can be 0.3:3.8, 0.32:3.8, 0.34:3.8, 0.3:4, 0.32:4, 0.34:4, 0.3:4.2, 0.32:4.2 or 0.34:4.2).

[0057] According to some preferred embodiments, in step (2), the mixing speed is 1000-2000 rpm (for example, it can be 1000 rpm, 1200 rpm, 1500 rpm, 1800 rpm or 2000 rpm), and the emulsification time is 8-15 min (for example, it can be 8 min, 10 min, 12 min, 14 min or 15 min).

[0058] Specifically, in step (2), the emulsifier is first dissolved in deionized water to obtain an aqueous solution of the emulsifier, and then the oil phase mixture is added dropwise to the aqueous solution of the emulsifier at a rotation speed of 1000 to 2000 rpm to obtain an oil-in-water (O / W) emulsion.

[0059] In the present invention, by controlling the amount of the added emulsifier, the stability of the emulsion is promoted while ensuring that the emulsion is in an oil-in-water state, so as to ensure the smooth progress of the subsequent polymerization reaction.

[0060] According to some preferred embodiments, in step (3), the polymerization reaction temperature is 20-30°C (for example, it can be 20°C, 22°C, 25°C, 26°C, 28°C or 30°C), the reaction time is 0.5-1h (for example, it can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h), and the reaction speed is 300-400rpm (for example, it can be 300rpm, 320rpm, 350rpm, 360rpm, 380rpm or 400rpm).

[0061] According to some preferred embodiments, in step (4), after adding calcium chloride to the mixed solution and mixing well, sodium carbonate is added to modify the surface of the initial fire extinguishing microcapsules.

[0062] According to some preferred embodiments, in step (4), the ratio of calcium chloride, sodium carbonate and perfluorohexanone is (3.2-3.5) g:(3.2-3.5) g:(3.8-4.2) mL (for example, it can be 3.2:3.2:3.8, 3.3:3.2:3.8, 3.5:3.2:3.8, 3.2:3.3:3.8, 3.3:3.5:3.8, 3.2:3.2:4, 3.3:3.2:4, 3.5:3.2:4, 3.2:3.2:4.2, 3.3:3.2:4.2 or 3.5:3.2:4.2.

[0063] In the present invention, calcium carbonate particles are coated on the surface of the initial fire extinguishing microcapsules to further absorb heat and reduce the temperature and fire intensity. When calcium carbonate comes into contact with the fire source, it will quickly decompose and release carbon dioxide gas, which will absorb a large amount of heat, causing the temperature around the fire source to drop rapidly; at the same time, the released carbon dioxide gas can dilute the oxygen concentration in the air and reduce the speed of the combustion reaction, thereby achieving rapid fire extinguishing. In addition, the calcium carbonate particle layer can further improve the strength and heat resistance of the polyurethane foam material. The present invention controls the thickness of the outer shell calcium carbonate particle layer by controlling the dosage of calcium chloride, sodium carbonate and perfluorohexanone, thereby preventing the calcium carbonate particle layer from being too thick, which results in an overly dense structure of the fire extinguishing microcapsule and reduces the release efficiency; and preventing the calcium carbonate particle layer from being too thin, which results in insufficient mechanical strength of the fire extinguishing microcapsule and affects its stability and durability. Therefore, the mass ratio of calcium chloride, sodium carbonate and perfluorohexanone is limited to (3.2-3.5) g: (3.2-3.5) g: (3.8-4.2) mL, and the size of the finally prepared fire extinguishing microcapsule is 5-15 μm.

[0064] According to some preferred embodiments, in step (4), after the initial fire-extinguishing microcapsules are surface-modified, a cleaning treatment and a drying treatment are also included.

[0065] According to some more preferred embodiments, in step (4), the cleaning treatment uses deionized water and anhydrous ethanol.

[0066] According to some more preferred embodiments, in step (4), the drying treatment adopts freeze-drying; more preferably, the freeze-drying temperature is -60 to -40°C (for example, it can be -60°C, -55°C, -50°C, -45°C or -40°C), the vacuum degree is 0.1 to 10Pa (for example, it can be 0.1Pa, 0.5Pa, 1Pa, 2Pa, 3Pa, 4Pa, 5Pa, 6Pa, 7Pa, 8Pa, 9Pa or 10Pa), and the drying time is 8 to 12h (for example, it can be 8h, 9h, 10h, 11h or 12h).

[0067] In the present invention, since perfluorohexanone is highly volatile, freeze drying is used to avoid the rupture of the fire extinguishing microcapsules due to the volatilization of perfluorohexanone during heating and drying, and the residual phase solvent, deionized water, anhydrous ethanol, etc. are removed by freeze drying.

[0068] According to some preferred embodiments, in step (5), the mass ratio of the fire extinguishing microcapsules, the polyol component and the isocyanate is (1-4.8):8:8 (for example, it can be 1:8:8, 1.5:8:8, 2:8:8, 2.5:8:8, 3:8:8, 3.5:8:8, 4:8:8, 4.5:8:8 or 4.8:8:8).

[0069] In the present invention, the content of the fire-extinguishing microcapsules in the polyurethane foam material is controlled by limiting the mass ratio of the fire-extinguishing microcapsules, the polyol component and the isocyanate, so that the flame-retardant polyurethane foam material containing the fire-extinguishing microcapsules has excellent flame retardant and fire extinguishing functions. At the same time, the problem of excessively high content of the fire-extinguishing microcapsules leading to decreased mechanical properties of the foam material and excessively fragile structure is avoided; and the flame-retardant polyurethane foam material does not have a fire extinguishing function when the content of the fire-extinguishing microcapsules is too low is avoided.

[0070] According to some preferred embodiments, in step (5), the polyol component includes polyester polyol, a catalyst, a surfactant and a blowing agent.

[0071] According to some preferred embodiments, in step (5), ammonium polyphosphate is also included, and the mass ratio of ammonium polyphosphate, polyol component and isocyanate is (0.8-1.2):5:5 (for example, it can be 0.8:5:5, 0.9:5:5, 1:5:5, 1.1:5:5 or 1.2:5:5).

[0072] In the present invention, the flame retardant property of the polyurethane foam material is further improved by adding ammonium polyphosphate, so that the ammonium polyphosphate and the fire extinguishing microcapsules act synergistically to improve the flame retardant and fire extinguishing properties of the polyurethane foam material.

[0073] According to some preferred embodiments, in step (5), the polyol component includes the following raw materials in mass percentage: 60% to 80% of polyester polyol (for example, 60%, 65%, 70%, 75% or 80%), 2% to 5% of catalyst (for example, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%), 2% to 5% of surfactant (for example, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%) and 5% to 10% of foaming agent (for example, 5%, 6%, 8% or 10%).

[0074] According to some more preferred embodiments, in step (5), the catalyst is triethylenediamine and dibutyltin dilaurate; the surfactant is polysiloxane-polyether copolymer; and the foaming agent is water.

[0075] In a second aspect, the present invention provides a flame retardant polyurethane foam material containing fire extinguishing microcapsules, which is prepared by any preparation method of the first aspect.

[0076] Unless otherwise specified, the raw materials used in the present invention can be products that can be directly purchased on the market or synthesized by existing methods;

[0077] In the present invention, “and / or” appearing between multiple technical features means that these technical features are connected in an “and / or” relationship, indicating that it can be any one of these technical features, or a combination of any two or more of these technical features.

[0078] The present invention will be further described below by way of examples, but the protection scope of the present invention is not limited to these embodiments.

[0079] Example 1

[0080] (1) 4 mL of perfluorohexanone, 0.64 g of isophorone diisocyanate, 0.64 g of polypropylene glycol 2000 and 2 mL of cyclohexane were uniformly mixed at room temperature to obtain an oil phase mixture;

[0081] (2) 0.32 g of sodium dodecyl sulfate emulsifier was dissolved in 30 mL of deionized water, and then the oil phase mixture of step (1) was slowly added to the aqueous solution of the emulsifier at a rotation speed of 2000 rpm, and the emulsification was continued at this speed for 10 minutes to fully emulsify the perfluorohexanone therein to obtain a uniform oil-in-water emulsion;

[0082] (3) At a speed of 300 to 400 rpm, 2 g of tetraethylenepentamine is added to the emulsion of step (2) to initiate a polymerization reaction, and the reaction is carried out at room temperature (20 to 30° C.) for 1 hour. After the reaction is completed, 3.4 g of calcium chloride is added, and a sodium carbonate solution (wherein the content of sodium carbonate is 3.4 g) is added dropwise to generate calcium carbonate particles, which are deposited on the surface of the microcapsules. The solution in the reaction container is then filtered to obtain white solid small particles, which are then repeatedly rinsed with deionized water and anhydrous ethanol for 5 times, and finally vacuum freeze-dried at -60° C. and -0.08 MPa for 12 hours to obtain fire-extinguishing microcapsules;

[0083] (4) 1.4 g of the fire extinguishing microcapsules of step (3), 7 g of a polyol component (including 80 wt % of polyester polyol, 2.5 wt % of triethylenediamine, 2.5 wt % of dibutyltin dilaurate, 5 wt % of a polysiloxane-polyether copolymer and 10 wt % of water) and 7 g of isocyanate were stirred at 1500 rpm for 30 s to fully mix them, and the stirred mixture was quickly poured into a mold and the foaming was completed to obtain a flame retardant polyurethane foam material containing the fire extinguishing microcapsules.

[0084] Example 2

[0085] Embodiment 2 is substantially the same as Embodiment 1, except that:

[0086] In step (4), 2.8 g of the fire extinguishing microcapsules prepared in step (3), 7 g of a polyol component and 7 g of isocyanate were added to prepare a flame retardant polyurethane foam material containing fire extinguishing microcapsules.

[0087] Example 3

[0088] Embodiment 3 is substantially the same as Embodiment 1, except that:

[0089] In step (4), 4.2 g of the fire extinguishing microcapsules prepared in step (3), 7 g of a polyol component and 7 g of isocyanate were added to prepare a flame retardant polyurethane foam material containing fire extinguishing microcapsules.

[0090] Example 4

[0091] Embodiment 4 is substantially the same as Embodiment 1, except that:

[0092] In step (4), 1.4 g of the fire extinguishing microcapsules of step (3), 1.4 g of ammonium polyphosphate (APP), 7 g of a polyol component and 7 g of isocyanate were added to prepare a flame retardant polyurethane foam material containing fire extinguishing microcapsules.

[0093] Example 5

[0094] Example 5 is substantially the same as Example 1, except that:

[0095] In step (4), 2.8 g of the fire extinguishing microcapsules of step (3), 1.4 g of ammonium polyphosphate (APP), 7 g of a polyol component and 7 g of isocyanate were added to prepare a flame retardant polyurethane foam material containing fire extinguishing microcapsules.

[0096] Example 6

[0097] Embodiment 6 is substantially the same as Embodiment 1, except that:

[0098] In step (4), 4.2 g of the fire extinguishing microcapsules of step (3), 1.4 g of ammonium polyphosphate (APP), 7 g of a polyol component and 7 g of isocyanate were added to prepare a flame retardant polyurethane foam material containing fire extinguishing microcapsules.

[0099] Example 7

[0100] Example 7 is substantially the same as Example 1, except that:

[0101] In step (1), 3.8 mL of perfluorohexanone, 0.60 g of isophorone diisocyanate, 0.68 g of propylene glycol and 2 mL of cyclohexane are uniformly mixed at room temperature to obtain an oil phase mixture.

[0102] Example 8

[0103] Example 8 is substantially the same as Example 1, except that:

[0104] In step (1), 4.2 mL of perfluorohexanone, 0.68 g of isophorone diisocyanate, 0.60 g of propylene glycol and 2 mL of cyclohexane are uniformly mixed at room temperature to obtain an oil phase mixture.

[0105] Comparative Example 1

[0106] Stir 7g of polyol component (including 80wt% of polyester polyol, 2.5wt% of triethylenediamine, 2.5wt% of dibutyltin dilaurate, 5wt% of polysiloxane-polyether copolymer and 10wt% of water) and 7g of isocyanate at 1500rpm for 30s to fully mix them, and quickly pour the stirred mixture into a mold and wait for foaming to be completed to obtain a polyurethane foam material RPUF.

[0107] Comparative Example 2

[0108] Comparative Example 2 is substantially the same as Example 4, except that:

[0109] No fire extinguishing microcapsules were added in step (4).

[0110] Comparative Example 3

[0111] Comparative Example 3 is substantially the same as Example 3, except that: no polyol is added;

[0112] In step (1), 4 mL of perfluorohexanone, 0.64 g of isophorone diisocyanate and 2 mL of cyclohexane are uniformly mixed at room temperature to obtain an oil phase mixture.

[0113] Comparative Example 4

[0114] Comparative Example 4 is substantially the same as Example 3, except that: the fire extinguishing microcapsules are not coated with calcium carbonate;

[0115] In step (3), 2 g of tetraethylenepentamine is added to the emulsion of step (2) at a rotation speed of 300 to 400 rpm to initiate a polymerization reaction, and the reaction is carried out at room temperature (20 to 30° C.) for 1 hour. After the reaction is completed, it is repeatedly rinsed with deionized water and anhydrous ethanol for 5 times, and finally vacuum freeze-dried at -60° C. and -0.08 MPa for 12 hours to obtain fire-extinguishing microcapsules.

[0116] Comparative Example 5

[0117] Comparative Example 5 is substantially the same as Example 3, except that:

[0118] In step (1), 4 mL of perfluorohexanone, 0.5 g of isophorone diisocyanate, 0.5 g of polypropylene glycol 2000 and 2 mL of cyclohexane are uniformly mixed at room temperature to obtain an oil phase mixture.

[0119] Comparative Example 6

[0120] Comparative Example 6 is substantially the same as Example 3, except that:

[0121] In step (1), 4 mL of perfluorohexanone, 0.7 g of isophorone diisocyanate, 0.7 g of polypropylene glycol 2000 and 2 mL of cyclohexane are uniformly mixed at room temperature to obtain an oil phase mixture.

[0122] The present invention compares the performance of the flame-retardant polyurethane foam materials containing fire-extinguishing microcapsules prepared in each embodiment and the polyurethane foam materials prepared in each comparative example. The evaluation results are shown in Table 1 and Table 2. Figure 2 The fire extinguishing microcapsules prepared in Example 1 are shown to have regular morphology, smooth surface and a particle size of 6 μm.

[0123] Table 1

[0124]

[0125]

[0126] It should be noted that the limiting oxygen index is LOI. MPCM is used to represent fire extinguishing microcapsules, and RPUF-MPCM-APP (100 / 10 / 10) means that the mass ratio of the polyurethane component, the fire extinguishing microcapsule component, and the ammonium polyphosphate in the prepared flame retardant polyurethane foam material containing fire extinguishing microcapsules is 100 / 10 / 10.

[0127] It can be seen from the experimental data in Table 1 that due to the addition of fire extinguishing microcapsules, the LOI values ​​of Examples 1 to 3 are significantly increased relative to the RPUF of Comparative Example 1, and the LOI values ​​are 25%, 26.4% and 27.25%, respectively, and the UL-94 grade test results show V-2 and V-1. Examples 4 to 6 are the addition of ammonium polyphosphate APP to RPUF-MPCM, and the LOI values ​​of the flame-retardant polyurethane foam materials containing fire extinguishing microcapsules are 27.7%, 28.2% and 29.1%, respectively. The UL-94 grade shows a significant improvement from V-1 to V-0 (the highest level), indicating that more excellent flame retardancy can be obtained when a certain mass fraction of APP is added. At the same time, Examples 7 and 8 also have excellent flame retardant properties due to the addition of fire extinguishing microcapsules. Comparative Example 1 is the original polyurethane foam material RPUF, which shows an LOI of 19%, fails the UL-94 test, and shows a dripping effect, which also shows that RPUF is a flammable material. Comparative Example 2 adds ammonium polyphosphate APP to the sample RPUF, but its fire extinguishing performance is not as good as that of Example 4. Obviously, the fire extinguishing performance is significantly improved after adding the fire extinguishing microcapsules. The fire extinguishing microcapsules prepared in Comparative Examples 3 and 4 do not have a three-layer core-shell structure, and their flame retardant performance is relatively poor; the fire extinguishing microcapsules prepared in Comparative Examples 5 and 6 have the problem of easy rupture and too thick shell layer, which also affects the flame retardant performance.

[0128] Table 2

[0129]

[0130] Table 2 shows the results of the fire extinguishing test, and the experimental method of the fire extinguishing test is: burning an alcohol lamp in a large beaker to simulate a closed environment. Place polyurethane foam materials of the same size on the top of the beaker, and use an infrared thermal imager (DT-980) to measure the temperature range on the top of the beaker. Among them, the mass content of RPUF in the polyurethane foam material of RPUF+APP and the polyurethane foam material of RPUF+MPCM is the same. The specific test results are shown in Table 2. In the case of no polyurethane foam material on the top of the beaker, in the case of RPUF on the top of the beaker (Comparative Example 1), and in the case of RPUF+APP on the top of the beaker (Comparative Example 2), the alcohol lamp burned for about 27 seconds, and in the case of RPUF+MPCM on the top of the beaker (Example 1), the alcohol lamp burned for about 22 seconds. The results show that the APP-based RPUF polyurethane foam material has excellent flame retardancy, but it cannot extinguish the flame. In contrast, the MPCM-based RPUF composite material has fire extinguishing performance and can extinguish the flame of the alcohol lamp 5 seconds in advance. According to the thermal image, the maximum temperature at the top of the beaker gradually decreased. Compared with the maximum temperature (141.7°C) of the control group (i.e., the case where no polyurethane foam material was placed on the top of the beaker), the maximum temperature at the top of the beaker of the MPCM-based RPUF composite material experimental group decreased by 61%. Therefore, it can be seen from the results of Table 1 and Table 2 that the flame-retardant polyurethane foam material containing fire-extinguishing microcapsules prepared by the present invention has dual functions, namely, flame retardancy and fire extinguishing performance.

[0131] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a flame retardant polyurethane foam material containing fire extinguishing microcapsules, It is characterized in that include: (1) mixing perfluorohexanone, an oil phase substance, a polyol and a phase solvent to obtain an oil phase mixture; (2) adding the oil phase mixture to the aqueous solution of the emulsifier and mixing to obtain an emulsion; (3) adding a fatty amine compound to the emulsion to initiate a polymerization reaction, and after the reaction is completed, a mixed solution including initial fire extinguishing microcapsules is obtained; (4) surface-modifying the initial fire-extinguishing microcapsules to obtain fire-extinguishing microcapsules coated with calcium carbonate particles; (5) The fire extinguishing microcapsules, polyol component and isocyanate are mixed and then subjected to condensation reaction to obtain the flame retardant polyurethane foam material containing the fire extinguishing microcapsules.

2. The preparation method according to claim 1, It is characterized in that In step (1): The oil phase substance is isophorone diisocyanate; the phase solvent is cyclohexane; Preferably, the polyol is at least one of polypropylene glycol 2000, glycerol or pentaerythritol; and / or, The usage ratio of perfluorohexanone, the oil phase substance, the polyol and the phase solvent is (3.8-4.2) mL: (0.60-0.68) g: (0.60-0.68) g: 2 mL.

3. The preparation method according to claim 1, It is characterized in that In step (2): The emulsifier is sodium lauryl sulfate; Preferably, the mass ratio of the emulsifier to water in the aqueous solution of the emulsifier is (0.3-0.34):30; and / or, The ratio of the amount of the emulsifier to the amount of perfluorohexanone is (0.30-0.34) g: (3.8-4.2) mL.

4. The preparation method according to claim 1, It is characterized in that In step (2): The oil phase mixture is added dropwise into the aqueous solution of the emulsifier and mixed evenly. The mixing speed is 1000-2000 rpm and the emulsification time is 8-15 minutes.

5. The preparation method according to claim 1, It is characterized in that In step (3): The fatty amine compound is tetraethylenepentamine; and / or, The mass ratio of the fatty amine compound to the oil phase substance is (8.1-8.5):(3.1-3.5).

6. The preparation method according to claim 1, It is characterized in that In step (3): The polymerization reaction temperature is 20-30° C., the reaction time is 0.5-1 h, and the reaction speed is 300-400 rpm.

7. The preparation method according to claim 1, It is characterized in that In step (4): After adding calcium chloride to the mixed solution and mixing evenly, sodium carbonate is added to modify the surface of the initial fire extinguishing microcapsules; Preferably, the ratio of calcium chloride, sodium carbonate and perfluorohexanone is (3.2-3.5) g: (3.2-3.5) g: (3.8-4.2) mL; and / or, After the surface modification of the initial fire extinguishing microcapsules, a cleaning process and a drying process are also included; Preferably, the cleaning process uses deionized water and anhydrous ethanol; Preferably, the drying process is freeze-drying; more preferably, the freeze-drying temperature is -60 to -40°C, the vacuum degree is 0.1 to 10 Pa, and the drying time is 8 to 12 hours.

8. The preparation method according to claim 1, It is characterized in that In step (5): The mass ratio of the fire extinguishing microcapsules, the polyol component and the isocyanate is (1-4.8):8:8; and / or, The polyol component comprises polyester polyol, catalyst, surfactant and foaming agent; Preferably, ammonium polyphosphate is also included, and the mass ratio of ammonium polyphosphate, polyol component and isocyanate is (0.8-1.2):5:

5.

9. The preparation method according to claim 8, It is characterized in that In step (5): The polyol component comprises the following raw materials in percentage by mass: 60% to 80% of polyester polyol, 2% to 5% of catalyst, 2% to 5% of surfactant and 5% to 10% of foaming agent; Preferably, the catalyst is triethylenediamine and dibutyltin dilaurate; the surfactant is polysiloxane-polyether copolymer; and the foaming agent is water.

10. A flame retardant polyurethane foam material containing fire extinguishing microcapsules, It is characterized in that The method is prepared by any one of claims 1 to 9.

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