Preparation method of flatulence slow-rebound foam composition

Abstract

The invention provides a preparation method of a flatulence slow-rebound foam composition. The preparation method comprises the following steps: with isocyanate as a unique monomer, preparing linear polyurea microspheres in a reaction medium by using a precipitation polymerization method; adding a multifunctional amine cross-linking agent and polyether amine, and supplementing similar isocyanate, so that the surface of the polyurea microsphere is subjected to a cross-linking reaction to obtain a polyurea core-shell microsphere with a linear core and a cross-linked shell; and dissolving out the inner core of the polyurea core-shell microsphere to obtain the porous hollow polyurea microsphere. The microspheres prepared by the method are good in flatulence effect, and the flatulence slow-rebound foam composition is excellent in air permeability and mechanical property.

Description

Invention Field

[0001] This invention belongs to the field of polyurethane foam, and specifically relates to a method for preparing an inflatable slow-rebound foam composition. Background Technology

[0002] In recent years, inflatable slow rebound foam (SRB) has gradually replaced ordinary SRB due to its strong support, low cost, and good comfort, and is used in mattresses, headrests, U-shaped pillows, toys, and other fields. SRB is a typical porous material with a cell size of approximately 100–600 μm. It contains more than 50% closed-cell structures and less than 50% open-cell structures. Its slow rebound effect is based on the ratio of open to closed-cell structures and the phase separation principle of the polyurethane's soft and hard segments. However, SRB has two drawbacks due to its unique structure: poor breathability and low mechanical strength. Currently, there are no reports of solutions to these two problems. These two drawbacks of SRB are closely related to its open and closed-cell structure. Achieving both a feeling of inflatability and breathability simultaneously is an industry challenge; furthermore, its structure also determines its poor mechanical properties.

[0003] Hollow polymer microspheres have wide applications in coatings, microreactors, and biomedicine due to their unique structure. Their preparation methods mainly include seed emulsion polymerization, template methods, and block polymer self-assembly. Among these, the template method is widely used because it can effectively control the morphology and cavity size of the hollow microspheres. Traditional template methods generally require the preparation of a template first using a special method, followed by the polymerization of monomers on the template particle surface or the ordered assembly of polymers on the template surface to form microspheres with a core-shell structure. The hollow microspheres are then obtained after removing the template particles. The core templates used in this method can be broadly classified into two categories: hard templates and soft templates. Commonly used hard templates include polymer microspheres (such as polystyrene PSt), inorganic oxide particles (such as SiO2, TiO2), and metal nanoparticles. A drawback of this method is that removing the hard template can easily cause shell damage or collapse. Soft templates include micelles, bubbles, and emulsion droplets. This method does not require template removal and can directly obtain hollow microspheres, but it is difficult to control the morphology and particle size of the resulting hollow microspheres, limiting its applications.

[0004] Currently, reported polyurea microspheres are produced using precipitation polymerization or interfacial polymerization methods, resulting in solid or porous solid microspheres with potential applications in enzyme immobilization, dye and heavy metal ion adsorption. Polyurea microspheres have not yet been used in inflated slow-rebound foams. The preparation and application of porous hollow polyurea microspheres are also rarely reported, likely due to the difficulty in their preparation and the lack of specific application scenarios.

[0005] In summary, the field of slow-rebound polyurethane foam still faces problems of poor air permeability and poor mechanical properties that urgently need to be addressed. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing porous hollow polyurea microspheres, which produces a slow-rebound foam composition with good inflatability, air permeability, and mechanical properties.

[0007] To achieve the above-mentioned objectives, this application adopts the following technical solution:

[0008] A method for preparing porous hollow polyurea microspheres, the method comprising the following steps:

[0009] S1: Linear polyurea microspheres E were prepared by precipitation polymerization in a reaction medium using isocyanate as the sole monomer;

[0010] S2: Add a polyfunctional amine crosslinking agent and a polyether amine, and add an isocyanate of the same type as S1 to cause a crosslinking reaction on the surface of polyurea microspheres E, and obtain polyurea core-shell microspheres F with a linear core and a crosslinked shell.

[0011] S3: Dissolve the core of the polyurea core-shell microsphere F to obtain porous hollow polyurea microspheres G.

[0012] Currently, the disclosed polyurea microspheres have not been applied in the field of polyurethane foam. Furthermore, most polyurea microspheres are solid spheres or small-diameter hollow spheres, which cannot control the gas flow into and out of the cells to achieve the desired slow rebound effect, making them unsuitable for use in slow rebound foam. The inventors have utilized porous hollow polyurea microspheres to control the gas flow rate in slow rebound foam. The residual polyetheramine on the surface of the microspheres can react with isocyanate to form a new polyurea structure. The introduction of this polyurea structure endows the microspheres with strong tear strength, tensile strength, and elongation at break, thus solving the common problems of poor air permeability and poor mechanical properties in slow rebound foam.

[0013] In one embodiment of the present invention, the diisocyanate in S1 is selected from one or more of aromatic isocyanates, aliphatic isocyanates, alicyclic isocyanates, and aryliphatic isocyanates; preferably, the functionality of the isocyanate is 2, and more preferably one or more of toluene diisocyanate, diphenylmethane diisocyanate (MDI), hexahydrotoluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), 1-isocyano-3,3,5-trimethyl-5-isocyano-methylcyclohexane (IPDI), and bis(isocyano-methyl)cyclohexane (HXDI).

[0014] In one embodiment of the present invention, the reaction medium in S1 is an organic solvent and water, wherein the organic solvent is preferably a polar solvent, more preferably one or more of acetonitrile, acetone, cyclohexanone, dimethyl sulfoxide, N,N-dimethylformamide, pyridine, dioxane, tetrahydrofuran, methyl formate, methyl ethyl ketone, and dimethyl carbonate; preferably, the mass ratio of the organic polar solvent to water in the reaction medium is 100:10 to 40:50, wherein preferably it is 90:10 to 50:50.

[0015] In one embodiment of the present invention, the isocyanate in S1 accounts for 3% to 30% of the total weight of the solution containing isocyanate and reaction medium.

[0016] In one embodiment of the present invention, the reaction temperature in S1 is 10-100°C, preferably 30-90°C, and the reaction time is 0.5-10h, preferably 1-9h.

[0017] In one embodiment of the present invention, E in S1 is linear polyurea microspheres with a particle size of 50-400 μm.

[0018] In one embodiment of the present invention, the polyfunctional amine S2 comprises one or more of 3,3′,5,5′-tetraalkyl-4,4′-diaminodiphenylmethane, 3,3′,5,5′-tetraalkyl-2,2′-diaminodiphenylmethane, 3,3′,5,5′-tetraalkyl-2,4′-diaminodiphenylmethane, 3,3′,5,5′-tetramethyl-4,4′-diaminodiphenylmethane, and 3,3′-dialkyl-4,4′-diaminodiphenylmethane, wherein the alkyl groups at the 3, 3′, 5, and 5′ positions may be the same or different, and each is independently selected from straight-chain or branched alkyl groups having 1 to 12 carbon atoms; preferably, the alkyl group is one or more of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl.

[0019] In one embodiment of the present invention, the polyetheramine in S2 comprises a polyetheramine with a molecular weight of 230-5000, preferably one or more of polyetheramines with a molecular weight of 230, 400, or 2000.

[0020] In one embodiment of the present invention, the isocyanate in S2 comprises one or more of aromatic isocyanates, aliphatic isocyanates, alicyclic isocyanates, and aryliphatic isocyanates, preferably isocyanates with a functionality of 2, more preferably toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexahydrotoluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), 1-isocyano-3,3,5-trimethyl-5-isocyano-methylcyclohexane (IPDI), and bis(isocyano-methyl)cyclohexane (HXDI).

[0021] In one embodiment of the present invention, the molar ratio of polyfunctional amine, polyether amine and isocyanate in S2 is 1:(1-2):(1-2).

[0022] In one embodiment of the present invention, the reaction temperature in S2 is 10-100°C, preferably 30-90°C, and the reaction time is 0.5-5h, preferably 1-4h.

[0023] In one embodiment of the present invention, F in S2 is a porous polyurea microsphere with a core-shell structure and a particle size of 100-600 μm.

[0024] In one embodiment of the present invention, S3 uses a polar solvent to dissolve the core; preferably, the polar solvent includes one or more of formic acid, oxalic acid, hydrochloric acid, phosphoric acid, pyridine, dimethylformamide, and acetic acid, and more preferably one or more of formic acid, dimethylformamide, and acetic acid.

[0025] In one embodiment of the present invention, the solvent in S3 is 15 to 40 times the mass of the microspheres.

[0026] In one embodiment of the present invention, the reaction temperature in S3 is 70-120°C, preferably 80-110°C, and the reaction time is 7-12h, preferably 8-11h.

[0027] In one embodiment of the present invention, G in S3 is a porous hollow polyurea microsphere with a particle size of 100-550 μm, a pore size of 10-30 μm, and an amine value of 18-30 mg KOH / g.

[0028] Another objective of this invention is to provide hollow polyurea microspheres.

[0029] A hollow polyurea microsphere is prepared by the above-described preparation method. The microsphere is porous and hollow, and the shell structure is a polyurea structure with residual amino groups of polyetheramine in the shell. Preferably, the porous hollow polyurea microsphere has a particle size of 100-550 μm, a pore size of 10-30 μm, and an amine value of 18-30 mg KOH / g.

[0030] Another objective of this invention is to provide an inflatable slow-rebound foam composition.

[0031] An inflatable slow-rebound foam composition, wherein the composition comprises microspheres prepared by the above-described preparation method, or microspheres prepared by the above-described method, and the composition comprises the following components:

[0032] Component A:

[0033]

[0034]

[0035] In one embodiment of the present invention, the polyether polyol has a functionality of 2-4, a molecular weight of 500-7000, and a hydroxyl value of 20-260 mgKOH / g; including common gas-expanding slow-rebound polyether grades F3140A, F3150A, F3160A, S3007, RW2307 and common ordinary polyether polyols F3135, F3140, F3150, F3160, C2020, C2040, F3156D, F3147, FB340, FB350, FB390, F4719, F3170A, wherein one or more of F3140A, F3150A, S3007, C2020, F3135, F3156D, F3140, and F3150 are preferred.

[0036] In one embodiment of the present invention, the foaming agent is one or more selected from H2O, HCFC-141B, dichloromethane (MC), cyclopentane, isopentane, n-pentane, HCFC-245FA, LBA, and methyl formate, preferably one or more selected from H2O, HCFC-141B, dichloromethane (MC), HCFC-245FA, and LBA. The above-mentioned foaming agents are commonly used additives in the art.

[0037] In one embodiment of the present invention, the isocyanate used in component B is selected from one or more of aromatic isocyanates, aliphatic isocyanates, alicyclic isocyanates, and aryliphatic isocyanates, preferably 2,4- and / or 2,6-toluene diisocyanate, various isomers of diphenylmethane diisocyanate (MDI), hexahydrotoluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), polymethylene polyphenyl isocyanate (PMDI), and 3,3′-dimethoxy-4,4 One or more of ′-biphenyl diisocyanate, toluene-2,4,6-triisocyanate, toluene diisocyanate-trimethylolpropane, and prepolymers of the above isocyanates, more preferably one or more of various isomers of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane diisocyanate (MDI), hexahydrotoluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), polymethylene polyphenyl isocyanate (PMDI), and their prepolymers. Common grades include PM 8001, PM8019, PM8122, PM8223B, etc.

[0038] Another object of the present invention is to provide an application of hollow polyurea microspheres.

[0039] An application of hollow polyurea microspheres, wherein the microspheres are prepared by the above-described preparation method or are the microspheres described above, and the microspheres are used to prepare inflatable slow rebound foam.

[0040] Another object of the present invention is to provide an application of an inflatable slow-rebound foam composition.

[0041] Application of an inflatable slow rebound foam composition, wherein the composition is the foam composition described above, and the foam composition is used to prepare inflatable slow rebound foam.

[0042] Another object of the present invention is to provide an inflatable slow-rebound foam.

[0043] A slow-rebound inflatable foam, wherein the raw material composition of the foam is prepared by the above-described preparation method to obtain microspheres, or by using the above-described microspheres, or by using the above-described composition.

[0044] Compared with the prior art, the positive effects of the present invention are as follows:

[0045] 1. The inflatable slow rebound foam produced by this invention has good mechanical strength compared with ordinary inflatable slow rebound foam because it incorporates polyurea microspheres and the polyurea microspheres are connected to the foam body through the polyurea structure. This overcomes the disadvantage of poor mechanical properties of ordinary inflatable slow rebound foam.

[0046] 2. The porous hollow polyurea microspheres used in this invention can control the gas flow rate, thereby controlling the inflation effect. When pressed, the airflow formed by the upward rush of gas can be clearly felt. After the pressure disappears, the gas slowly flows back to the hollow microspheres. This also makes the foam have good air permeability, improving the shortcomings of poor air permeability of ordinary foams that inflate slowly and rebound poorly.

[0047] 3. This invention uses polyamines and polyetheramines as crosslinking agents to form a shell on the surface of polyurea microspheres. The polyetheramine, under the swelling effect of the solvent, has a pore-forming effect on the polyurea microspheres. Simultaneously, the amine groups remaining on the polyetheramine surface of the polyurea microspheres can react with isocyanates during the foaming reaction to form new polyurea structures. This ensures the strength and elasticity of the polyurea microspheres themselves, preventing deformation or collapse, and also reduces the use of other pore-forming agents. Detailed Implementation

[0048] Each material was placed separately in its own container according to the specified proportions, and the entire raw material was kept at a temperature of (22±0.5)℃ for subsequent processing. The materials used are shown in the table below.

[0049]

[0050]

[0051]

[0052] The experimental instruments used are shown in the table below:

[0053] Instrument Name model factory high-speed centrifuge HC-3514 USTC Innovation Co., Ltd. Water bath constant temperature oscillator SN2-88 Medical Instrument Factory of Jintan City, Jiangsu Province Electric constant temperature drying oven DHG-9070A Shanghai Yiheng Technology Co., Ltd. Scanning electron microscope Quanta200 Dutch company FEI Fourier transform infrared spectrometer Spectrum GX Perkin Elmer, USA UV-Vis spectrophotometer Lambda 35 Perkin Elmer, USA Surface area and pore size analyzer Nora 200E Quantachrome, Inc. (USA) Porosity meter AutoPore IV 9500 Micromeritics, Inc. (USA) Automatic potentiometric titrator 905Titrando METROHM

[0054] Example 1

[0055] 2100g of acetonitrile / water (mass ratio 50 / 50) was selected as the reaction medium. 900g of p-diphenylmethane diisocyanate was added, and the mixture was ultrasonically mixed and poured into a 5000ml stainless steel high-pressure reactor. Under nitrogen protection, the reaction was carried out at a constant temperature of 35℃ and a fixed rotation speed of 30rpm for 1h to prepare linear polyurea microspheres E1 with a particle size of 50-350μm.

[0056] At a constant speed of 100 rpm and a constant temperature of 35℃, 215 g of p-diphenylmethane diisocyanate, 244.63 g of polyamine 3,5-diethyl-3',5'-dimethyl-4,4'-diaminodiphenylmethane, and 197.8 g of polyetheramine D230 were added to the system under stirring conditions. The mixture was stirred for 1 h to induce a cross-linking reaction on the surface of the linear polyurea microspheres, thus obtaining polyurea polyol core-shell microspheres F1 with a linear core and a porous cross-linked outer shell, with a particle size of 100–600 μm.

[0057] The above-mentioned polyurea microspheres were added to 29.81 kg of acetone and dispersed by ultrasonication at 60 kHz. Then, 46.5 kg of formic acid was added to fix the mass fraction of microspheres in the system at 2%. The dispersion was then poured into an enamel-lined reactor equipped with a mechanical stirrer and stirred at 30 rpm at 80°C for 8 hours to prevent microsphere aggregation, which dissolved the core. The product was then centrifuged and washed three times repeatedly with 25 kg of a 70 / 30 acetone / water mixture, and then dried to constant weight. Porous hollow polyurea microspheres G1 were obtained. Scanning electron microscopy showed that the size of the porous hollow polyurea microspheres was 100–600 μm, with a pore size of 5–20 μm. The amine value was 28 mg KOH / g.

[0058] The hollow microspheres prepared by the above method are added to component A of the gas-expanding slow-rebound polyether composite and reacted with component B isocyanate in a certain proportion.

[0059] The following materials were selected as raw materials: 100g polyol, 1.8g silicone oil SF 8180, 0.2g silicone oil SF8581, 0.3g triethylenediamine solution catalyst, 2.4g water (main blowing agent), and 5g dichloromethane (auxiliary blowing agent). The 100g polyol was composed of the following four components in the following proportions: 60g 5000 molecular weight polyether polyol F3150A, 20g 700 molecular weight polyether polyol S3007, 15g porous hollow polyurea microspheres, and 5g 2000 molecular weight polyether polyol C2020. After thorough mixing, this was set aside as component A.

[0060] WANNATE 8019 was selected as component B. Components A and B were heated to (22±0.5)℃. Then, 60g of component B was rapidly added to component A, and mechanical stirring at 3000rpm for 8 seconds was performed using a stopwatch. The mixture was then poured into a cardboard box. After foaming, the mixture was allowed to mature at room temperature for 72 hours. The matured foam was used as a sample for testing various properties.

[0061] Example 2

[0062] 2500g of acetone / water (70 / 30 by mass) was selected as the reaction medium. 500g of p-isophorone diisocyanate (IPDI) was added and ultrasonically mixed. The mixture was then poured into a 5000ml stainless steel high-pressure reactor. Under nitrogen protection, the reactor was kept at a constant temperature of 85℃ and a fixed rotation speed of 50rpm for 9 hours to prepare linear polyurea microspheres E2 with a particle size of 100-400μm.

[0063] At a constant speed of 100 rpm and a constant temperature of 85 ℃, 100 g of p-isophorone diisocyanate (IPDI), 82.94 g of polyamine 3,3',5,5'-tetraisopropyl-2,4'-diaminodiphenylmethane, and 120 g of polyetheramine D400 were added to the system under stirring conditions. The mixture was stirred for 4 h to induce a cross-linking reaction on the surface of the linear polyurea microspheres, thus obtaining polyurea polyol core-shell microspheres F2 with a linear core and a porous cross-linked outer shell, with a particle size of 200–600 μm.

[0064] The above-mentioned polyurea microspheres were added to 7.65 kg of acetone and dispersed by ultrasonication at 60 kHz. Then, 31.69 kg of dimethylformamide was added to fix the mass fraction of microspheres in the system at 2%. The dispersion was then poured into an enamel-lined reactor equipped with a mechanical stirrer and stirred at 110 °C for 11 h at a stirring rate of 30 rpm to prevent microsphere aggregation, which dissolved the core. The product was then centrifuged and washed three times repeatedly with 20 kg of a 70 / 30 acetone / water mixture, and then dried to constant weight. Porous hollow polyurea microspheres G2 were obtained. Scanning electron microscopy showed that the size of the porous hollow polyurea microspheres was 50–500 μm, with a pore size of 1–15 μm. The amine value was 22 mg KOH / g.

[0065] The following materials were selected as raw materials: 100g polyol, 1.5g silicone oil B8211, 0.15g triethylenediamine solution catalyst, 0.1g organotin catalyst T12, 2.6g water (main blowing agent), and 4g dichloromethane (auxiliary blowing agent). The 100g polyol was composed of the following four components in the following proportions: 50g 5000 molecular weight polyether polyol F3160A, 15g 700 molecular weight polyether polyol S3007, 20g hollow polyurea microspheres D, and 15g 2000 molecular weight polyether polyol C2020. After thorough mixing, this was set aside as component A.

[0066] WANNATE 8223B was selected as component B. Components A and B were heated to (22±0.5)℃. Then, 55g of component B was rapidly added to component A, and mechanical stirring at 3000rpm for 8 seconds was performed using a stopwatch. The mixture was then poured into a cardboard box. After foaming, the mixture was allowed to mature at room temperature for 72 hours. The matured foam was used as a sample for testing various properties.

[0067] Example 3

[0068] Using 2100g of pyridine / water at a mass ratio of 90 / 10 as the reaction medium, 100g of p-tolyl diisocyanate was added. After ultrasonic mixing, the mixture was poured into a 5000ml stainless steel high-pressure reactor. Under nitrogen protection, the reactor was kept at a constant temperature of 55℃ and a fixed rotation speed of 30rpm for 5 hours to prepare linear polyurea microspheres E3 with a particle size of 50-300μm.

[0069] With a fixed rotation speed of 100 rpm and a constant temperature of 55 ℃, 31 g of p-diphenylmethane diisocyanate, 22.89 g of polyamine 3,3',5,5'-tetramethyl-2,2'-diaminodiphenylmethane, and 360 g of polyetheramine D2000 were added to the system under stirring conditions. The mixture was stirred for 2 h to induce a cross-linking reaction on the surface of the linear polyurea microspheres, thus obtaining polyurea polyol core-shell microspheres F3 with a linear core and a porous cross-linked outer shell, with a particle size of 100–400 μm.

[0070] The above-mentioned polyurea microspheres were added to 15.1 kg of acetone and dispersed by ultrasonication at 60 kHz. Then, 10.08 kg of acetic acid was added to fix the mass fraction of microspheres in the system at 2%. The dispersion was then poured into an enamel-lined reactor equipped with a mechanical stirrer and stirred at 30 rpm at 95°C for 9.5 h to prevent microsphere aggregation, which dissolved the core. The product was then centrifuged and washed three times repeatedly with 5 kg of a 70 / 30 acetone / water mixture, and then dried to constant weight. Porous hollow polyurea microspheres G3 were obtained. Scanning electron microscopy showed that the size of the porous hollow polyurea microspheres was 100–550 μm, and the pore size was 10–30 μm. The amine value was 20 mg KOH / g.

[0071] The hollow microspheres prepared by the above method are added to component A of the gas-expanding slow-rebound polyether composite and reacted with component B isocyanate in a certain proportion.

[0072] The following materials were selected as raw materials: 100g polyol, 0.8g silicone oil B8409, 0.45g triethylenediamine solution catalyst, 2.0g water (main blowing agent), and 10g dichloromethane (auxiliary blowing agent). The 100g polyol was composed of the following four components in the following proportions: 80g 4000 molecular weight polyether polyol F3140A, 10g 700 molecular weight polyether polyol S3007, 10g hollow polyurea microspheres, and 5g 3000 molecular weight polyether polyol F3156D. After thorough mixing, this was set aside as component A.

[0073] WANNATE 8122 was selected as component B. Components A and B were heated to (22±0.5)℃. Then, 70g of component B was rapidly added to component A, and mechanical stirring at 3000rpm for 8 seconds was performed using a stopwatch. The mixture was then poured into a cardboard box. After foaming, the mixture was allowed to mature at room temperature for 72 hours. The matured foam was used as a sample for testing various properties.

[0074] Comparative Example 1

[0075] Compared with Example 1, the only difference is that POP2045 is used instead of hollow polyurea microspheres.

[0076] The following ingredients are used: 100g polyol, 1.8g silicone oil SF 8180, 0.2g silicone oil SF 8581, 0.3g triethylenediamine solution catalyst A33, 2.4g water (main blowing agent), and 5g dichloromethane (auxiliary blowing agent). The 100g polyol is composed of the following four components in the following proportions: 60g 5000 molecular weight polyether polyol F3150A, 20g 700 molecular weight polyether polyol S3007, 15g polymer polyol POP2045, and 5g 2000 molecular weight polyether polyol C2020. After thorough mixing, this is set aside as component A.

[0077] WANNATE 8019 was selected as component B. Components A and B were heated to (22±0.5)℃. Then, 60g of component B was rapidly added to component A, and mechanical stirring at 3000rpm for 8 seconds was performed using a stopwatch. The mixture was then poured into a cardboard box. After foaming, the mixture was allowed to mature at room temperature for 72 hours. The matured foam was used as a sample for testing various properties.

[0078] Comparative Example 2

[0079] Compared with Example 2, the only difference is that POP3630 is used instead of hollow polyurea microspheres.

[0080] The following materials were selected as raw materials: 100g polyol, 1.5g silicone oil B8211, 0.15g triethylenediamine solution catalyst A33, 2.6g water (main blowing agent), and 4g dichloromethane (auxiliary blowing agent). The 100g polyol was composed of the following four components in the following proportions: 50g 6000 molecular weight polyether polyol F3160A, 15g 700 molecular weight polyether polyol S3007, 20g polymer polyol POP3630, and 15g 2000 molecular weight polyether polyol C2020. After thorough mixing, this was set aside as component A.

[0081] WANNATE 8223B was selected as component B. Components A and B were heated to (22±0.5)℃. Then, 55g of component B was rapidly added to component A, and mechanical stirring at 3000rpm for 8 seconds was performed using a stopwatch. The mixture was then poured into a cardboard box. After foaming, the mixture was allowed to mature at room temperature for 72 hours. The matured foam was used as a sample for testing various properties.

[0082] Comparative Example 3

[0083] Compared with Example 3, the only difference is that POP2140 is used instead of hollow polyurea microspheres.

[0084] The following materials are selected as raw materials: 100g polyol, 0.8g silicone oil B8409, 0.45g triethylenediamine solution catalyst A33, 2.2g water (main blowing agent), and 10g dichloromethane (auxiliary blowing agent). The 100g polyol is composed of the following four components in the following proportions: 80g 4000 molecular weight polyether polyol F3140A, 5g 700 molecular weight polyether polyol S3007, 10g polymer polyol POP2140, and 5g 3000 molecular weight polyether polyol F3156D. After thorough mixing, this is set aside as component A.

[0085] WANNATE 8122 was selected as component B. Components A and B were heated to (22±0.5)℃. Then, 70g of component B was rapidly added to component A, and mechanical stirring at 3000rpm for 8 seconds was performed using a stopwatch. The mixture was then poured into a cardboard box. After foaming, the mixture was allowed to mature at room temperature for 72 hours. The matured foam was used as a sample for testing various properties.

[0086]

[0087]

[0088] As can be seen from the table above, the foams prepared in Examples 1, 2, and 3, compared with the foams prepared in Comparative Examples 1, 2, and 3, not only have the inflatable characteristics of slow rebound, but also have significantly improved air permeability, tensile strength, elongation at break, and tear strength.

Claims

1. A method for preparing porous hollow polyurea microspheres, characterized by, The preparation method comprises the following steps: S1: preparing linear polyurea microspheres E by using a precipitation polymerization method in a reaction medium with isocyanate as the only monomer; S2: adding a multifunctional amine crosslinking agent and a polyether amine, supplementing the same isocyanate as S1, and allowing the surface of the polyurea microspheres E to undergo a crosslinking reaction to obtain polyurea core-shell microspheres F with a linear core and a crosslinked shell; S3: dissolving the core of the polyurea core-shell microspheres F to obtain porous hollow polyurea microspheres G.

2. The production method according to claim 1, characterized by, The diisocyanate in S1 is selected from one or more of aromatic isocyanate, aliphatic isocyanate, alicyclic isocyanate, and araliphatic isocyanate; Preferably, the functionality of the isocyanate is 2, preferably one or more of toluene diisocyanate, methylene dianiline (MDI), hexahydro-toluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), and bis(isocyanatomethyl)cyclohexane (HXDI); And / or, the reaction medium in S1 is an organic solvent and water, wherein the organic solvent is preferably a polar solvent, more preferably one or more of acetonitrile, acetone, cyclohexanone, dimethyl sulfoxide, N,N-dimethylformamide, pyridine, dioxane, tetrahydrofuran, methyl formate, methyl ethyl ketone, and dimethyl carbonate; Preferably, the mass ratio of the organic polar solvent to water in the reaction medium is 100:10 to 40:50, and more preferably 90:10 to 50:50; And / or, the proportion of isocyanate in S1 is 3% to 30% of the total weight of the solution containing isocyanate and the reaction medium; And / or, the reaction temperature in S1 is 10-100°C, preferably 30-90°C, and the reaction time is 0.5-10h, preferably 1-9h; And / or, E in S1 is a linear polyurea microsphere with a particle size of 50-400μm.

3. The production method according to claim 1 or 2, characterized by, The multifunctional amine in S2 comprises one or more of 3,3',5,5'-tetraalkyl-4,4'-diaminodiphenyl methane, 3,3',5,5'-tetraalkyl-2,2'-diaminodiphenyl methane, 3,3',5,5'-tetraalkyl-2,4'-diaminodiphenyl methane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenyl methane, and 3,3'-dialkyl-4,4'-diaminodiphenyl methane, wherein the alkyl groups at positions 3, 3', 5, and 5' can be the same or different and are each independently selected from linear or branched alkyl groups having 1 to 12 carbon atoms; Preferably, the alkyl groups are one or more of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl; And / or, the polyether amine in S2 comprises a polyether amine with a molecular weight of 230-5000, preferably one or more of polyether amines with a molecular weight of 230, 400, and 2000. and / or, the isocyanate in S2 comprises one or more of aromatic isocyanate, aliphatic isocyanate, alicyclic isocyanate, araliphatic isocyanate, preferably the isocyanate has a functionality of 2, more preferably one or more of toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), hexahydro-toluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), bis(isocyanatomethyl)cyclohexane (HXDI); and / or, the molar ratio of the polyfunctional amine, the polyether amine, the isocyanate in S2 is 1:(1-2):(1-2); and / or, the reaction temperature in S2 is 10-100°C, preferably 30-90°C, and the reaction time is 0.5-5h, preferably 1-4h; and / or, the F in S2 is a porous polyurea microsphere with a core-shell structure, and the particle size is 100-600μm.

4. The production method according to any one of claims 1 to 3, characterized by, S3 uses a polar solvent to dissolve the inner core; Preferably, the polar solvent comprises one or more of formic acid, oxalic acid, hydrochloric acid, phosphoric acid, pyridine, dimethylformamide, acetic acid, preferably one or more of formic acid, dimethylformamide, acetic acid; and / or, the solvent in S3 is 15-40 times the mass of the microsphere; and / or, the reaction temperature in S3 is 70-120°C, preferably 80-110°C, and the reaction time is 7-12h, preferably 8-11h; and / or, the G in S3 is a porous hollow polyurea microsphere, the particle size is 100-550μm, the pore size is 10-30μm, and the amine value is 18-30mgKOH / g.

5. A hollow polyurea microsphere, which is prepared by the preparation method of any one of claims 1-4, characterized in that, The microsphere is porous and hollow, and the shell structure is a polyurea structure with residual amino groups of the polyether amine, preferably a porous and hollow polyurea microsphere with a particle size of 100-550μm, a pore size of 10-30μm, and an amine value of 18-30mgKOH / g.

6. An intumescent slow-rebound foam composition, said composition being prepared using the microspheres prepared according to any one of claims 1 to 4, or the microspheres according to claim 5, characterized in that, The composition comprises the following components: Component A:

7. The foam composition according to claim 6, characterized in that, The polyether polyol has a functionality of 2-4, a molecular weight of 500-7000, and a hydroxyl value of 20-260mgKOH / g; and / or, the blowing agent is one or more of H2O, HCFC-141B, dichloromethane, cyclopentane, isopentane, n-pentane, HCFC-245FA, LBA, methyl formate, preferably one or more of H2O, HCFC-141B, dichloromethane, HCFC-245FA, LBA; and / or the isocyanate employed by the B component is selected from one or more of aromatic isocyanates, aliphatic isocyanates, cycloaliphatic isocyanates, araliphatic isocyanates, preferably one or more of 2,4- and / or 2,6-toluene diisocyanate, various isomers of diphenylmethane diisocyanate (MDI), hexahydro-toluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), polymethylene polyphenyl isocyanate (PMDI), 3,3'-dimethoxy-4,4'-diphenyl diisocyanate, toluene-2,4,6-triisocyanate, toluene diisocyanate-trishydroxymethylpropane, and prepolymers of the aforementioned isocyanates, more preferably one or more of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, various isomers of diphenylmethane diisocyanate (MDI), hexahydro-toluene diisocyanate, methoxyphenyl-2,4-diisocyanate, hydrogenated MDI (HMDI), polymethylene polyphenyl isocyanate (PMDI), and prepolymers thereof.

8. Use of hollow polyurea microspheres, which are microspheres produced by the production process according to any one of claims 1 to 4 or which are microspheres according to claim 5, for producing a gas-inflatable slow-rebound foam.

9. Use of a gas-inflatable slow-rebound foam composition, which is a foam composition according to claim 6 or 7, for producing a gas-inflatable slow-rebound foam.

10. A gas-inflatable slow-rebound foam, which is produced from a raw material composition using microspheres produced by the production process according to any one of claims 1 to 4 or using microspheres according to claim 5 or using a composition according to claim 6 or 7.

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