A flame-retardant polyurethane foaming filler and its preparation process

Abstract

This application relates to the field of polymer materials, and specifically discloses a flame-retardant polyurethane foaming filler and its preparation process. A flame-retardant polyurethane foaming filler includes the following raw materials in parts by weight: 300 - 400 parts of white material composition, 220 - 250 parts of black material, 60 - 70 parts of dimethyl ether, 75 - 80 parts of propane-butane. The white material composition includes the following raw materials in parts by weight: 95 - 105 parts of polyether diol, 130 - 150 parts of polyether triol, 30 - 45 parts of foam stabilizer, 12 - 18 parts of catalyst, 460 - 500 parts of plasticizer, 210 - 250 parts of flame retardant. The flame retardant includes a phosphorus-based flame retardant and a phosphorus-nitrogen-based flame retardant with a mass ratio of 1:0.5 - 0.6. The polyurethane foaming filler of this application can be foamed on site to fill voids of any shape, and has the advantages of uniform and fine cell structure, good flame retardant effect, stable foam size after curing, and high bonding strength.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and more specifically, it relates to a flame-retardant polyurethane foam filler and its preparation process. Background Art

[0002] Polyurethane foam sealant is a one-component, moisture-curing, multi-purpose polyurethane foam filling elastic sealing material, also known as polyurethane foam adhesive (commonly known as polyurethane foam agent), which is an essential auxiliary product in the doors and windows curtain wall industry. Polyurethane foam sealant is a mixture of an isocyanate group-terminated prepolymer and catalysts, flame retardants, foam stabilizers, and plasticizers, used in combination with a physical blowing agent and a gas propellant. After the prepolymer is ejected, it reacts chemically with water vapor in the air or the moisture on the surface of the substrate, and then crosslinks and cures. During construction, the aerosol colloid is sprayed onto the construction site through a supporting glue gun or a manual spray pipe to complete the processes of forming, foaming, bonding, and sealing in a short time. The construction operation is simple, and the on-site foaming is convenient for filling any shape of voids, and the bonding surface is tightly connected to the substrate. Especially for the connection and sealing between doors and windows and walls, its bonding strength exceeds the tear strength of the polyurethane foam itself. The cured foam has multiple effects such as caulking, bonding, sealing, heat insulation, waterproofing, and noise absorption. As a building thermal insulation material for doors and windows curtain walls, polyurethane foam sealant breaks the common problem of traditional building materials that the waterproof layer is not heat-insulating when it is waterproof, and the heat-insulating layer loses its heat-insulating function once the waterproof layer leaks.

[0003] However, polyurethane rigid foam itself is a kind of highly flammable polymer material, and its combustion speed is very fast, and a large amount of toxic and harmful smoke will be generated. How to develop a flame-retardant and self-extinguishing product that can self-extinguish away from an open flame, effectively prevent the spread of fire, and protect the lives and property of residents has put forward new difficulties. Summary of the Invention

[0004] In order to make the polyurethane foam filler have a good flame-retardant effect, the present application provides a flame-retardant polyurethane foam filler and its preparation process.

[0005] In the first aspect, the present application provides a flame-retardant polyurethane foam filler, adopting the following technical solution:

[0006] A flame-retardant polyurethane foam filler, comprising the following raw materials in parts by weight: 300 - 400 parts of white material composition, 220 - 250 parts of black material, 60 - 70 parts of dimethyl ether, 75 - 80 parts of propane-butane. The white material composition comprises the following raw materials in parts by weight: 95 - 105 parts of polyether diol, 130 - 150 parts of polyether triol, 30 - 45 parts of foam stabilizer, 12 - 18 parts of catalyst, 460 - 500 parts of plasticizer, 210 - 250 parts of flame retardant. The flame retardant comprises a phosphorus-based flame retardant and a phosphorus-nitrogen-based flame retardant with a mass ratio of 1:0.5 - 0.6.

[0007] By adopting the above technical solution, polyether diol and polyether triol, as the main components of the white material composition, react with the black material isocyanate, etc. to form a polyurethane foam with excellent properties. Polyether polyols (including diol and triol) contain rich hydroxyl groups, and these hydroxyl groups can react rapidly with the isocyanate groups in the isocyanate to form a stable polyurethane structure. By adjusting the dosages of polyether diol and polyether triol, good fluidity can be obtained, which helps to obtain a uniform and delicate foam structure and can effectively control the physical properties such as the density, hardness, and elasticity of the polyurethane filler; phosphorus-based flame retardants and phosphorus-nitrogen-based flame retardants can form intermediates containing N-P bonds during the reaction process. This structure can improve the carbonyl reaction activity and phosphorylation rate, increase the char yield. At the same time, nitrogen compounds can delay the volatilization loss of phosphorus-containing compounds in the condensed phase and strengthen the oxidation of phosphorus compounds, releasing non-combustible gases such as ammonia and nitrogen, thereby improving the flame retardancy efficiency. Phosphorus-based flame retardants mainly prevent combustion by forming a charred layer, while phosphorus-nitrogen-based flame retardants can release non-combustible gases during thermal decomposition and promote the formation of an expanded char layer. The combination of the two can form a more stable and efficient flame retardant system, and both flame retardants belong to environmentally friendly flame retardants, having the characteristics of low toxicity and low smoke, and will not produce toxic and harmful by-products during combustion, reducing the harm to the human body and the environment.

[0008] Optionally, the phosphorus-based flame retardant includes chlorinated alkane phosphate, flame retardant TCPP, and triphenyl phosphate with a mass ratio of 1:0.7:0.3 - 0.5.

[0009] By adopting the above technical solution, the chlorine element and phosphorus element in chlorinated alkane phosphate and TCPP can, during the combustion process, promote the formation of the char layer and increase its stability, while the phosphorus element can generate compounds such as phosphoric acid at high temperatures, further promoting the formation of the char layer and effectively isolating oxygen and heat. At the same time, the addition of triphenyl phosphate can further improve the stability and compactness of the char layer, thereby enhancing the overall flame retardant effect. TCPP has good processability and stability and can be fully compatible with polymer materials. When used in combination with chlorinated alkane phosphate and triphenyl phosphate, it can maintain the physical properties of the material and the stability of the processing technology, and improve the flame retardant performance, processing performance, and thermal stability of the polyurethane foaming filler.

[0010] Optionally, modified basalt fiber is further added to the flame retardant, and the mass ratio of modified basalt fiber to the phosphorus-based flame retardant is 1:0.1 - 0.3. The preparation method of the modified basalt fiber is as follows:

[0011] Polyvinyl alcohol and polyacrylamide were added to deionized water, stirred and dissolved. Basalt fibers were added, and ultrasonic treatment was carried out for 20 - 30 min. Then boric acid was added. After stirring evenly, the pH was adjusted to 9 - 9.5 with sodium hydroxide solution. It was left standing and then dried to obtain modified basalt fibers. The mass ratio of basalt fibers, polyvinyl alcohol and polyacrylamide was 3 - 4:2.5 - 3:1.5 - 2.

[0012] By adopting the above technical solution, the tensile strength of basalt fibers is higher than that of glass fibers, with excellent elastic modulus, and stable chemical properties, showing a very wide working temperature range and excellent high-temperature resistance. At the same time, it has excellent fire prevention, high-temperature resistance, no melting and dripping, no heat shrinkage and other advantages. Polyvinyl alcohol is a water-soluble polymer material. There are extremely strong hydroxyl (-OH) O atoms in the molecular chain, with strong adhesiveness, good mechanical properties and biocompatibility. Polyacrylamide is an organic linear polymer. There are a large number of carbonyl and amide groups on the molecular chain, which can form associative hydrogen bonds with surrounding molecules. Its chemical properties are active, with a typical three-dimensional network structure, good adhesiveness and thickening property. Polyvinyl alcohol can form a cross-linked network structure under the action of boric acid, and the gel has good elasticity and high mechanical strength. There are a large number of hydroxyl, carbonyl and amide groups in the molecular chains of polyacrylamide and polyvinyl alcohol, which can interact with water molecules through intermolecular hydrogen bonds. At the same time, hydrogen bonds can be formed between the two to achieve a secondary cross-linking effect, forming a double-network gel structure on the surface of basalt fibers.

[0013] The modified basalt fibers, as a heterogeneous nucleating agent, increase the bubble nucleation sites, which has a positive effect on the formation of foam, and can also increase the strength of the foaming components, avoiding collapse due to insufficient strength during the foaming stage and increasing the dimensional stability of the foam. Moreover, the water molecules in the double-network gel structure on the modified basalt fibers can produce an endothermic cooling effect. During the heating process, the movement of water molecules intensifies and they evaporate rapidly, thereby absorbing heat and reducing the environmental temperature. In addition, the double-network structure can release a part of the free water molecules in the early stage. After the temperature rises, the double-network structure is damaged and the hydrogen bonds are broken, causing the continuous release of water molecules and increasing the cooling effect. In addition, the good thermal stability of basalt fibers hinders the movement of water molecules in the gel system, increasing the residence time and making the endothermic evaporation process of water continue, improving the fire-retardant and fire-extinguishing effect.

[0014] After being dispersed, the modified basalt fibers are filled into the foaming material, where they play a covering and filling role during the oxidation heating stage, reducing the oxygen adsorption area and oxygen uptake of the polyurethane foaming material, thereby playing a flame retardant role. When the temperature continues to rise, the double-network gel structure decomposes thermally, releasing basalt fibers. Basalt fibers have good thermal stability and are not easily decomposed by heat. After the double-network gel structure is damaged, they continue to fill the pores of the polyurethane foam, playing a role in filling and plugging leaks. When the combustion continues to heat up, the basalt fiber structure decomposes, releasing metal ions such as Al and Si, which act on the polyurethane sealant, making the re-ignition reaction blocked and playing a dual inhibitory role in preventing re-ignition.

[0015] Optionally, the basalt fibers are pretreated as follows:

[0016] Mix ultra-high molecular weight polyethylene, 2,5-bis(tert-butylperoxy-2,5-dimethyl-3-hexyne), and hydroxylated multi-walled carbon nanotubes, and melt them to obtain a melt. Add basalt fibers in an amount of 0.5 - 1 times the mass of the melt, mix well, extrude, and pelletize. The mass ratio of ultra-high molecular weight polyethylene, 2,5-bis(tert-butylperoxy-2,5-dimethyl-3-hexyne), and hydroxylated multi-walled carbon nanotubes is 1:0.01 - 0.15:0.04 - 0.08.

[0017] By adopting the above technical solution, ultra-high molecular weight polyethylene has excellent flame retardancy. When subjected to the action of a fire source, it can quickly form a charred layer, isolating the contact between oxygen and the interior of the material, thereby effectively suppressing the spread of the flame. The charred layer has good heat insulation effect and can reduce heat transfer. Hydroxylation modification introduces hydroxyl groups onto the multi-walled carbon nanotubes, improving their dispersibility and compatibility in ultra-high molecular weight polyethylene, making their distribution more uniform, thereby exerting a better strengthening and flame retardant effect. Hydroxylated multi-walled carbon nanotubes have high thermal stability and high temperature resistance, can maintain a stable structure in a high-temperature environment, are not easily thermally decomposed or melted, can effectively prevent the spread of the fire, and have good thermal conductivity, which can quickly conduct heat from the fire source to the surrounding environment, reducing the fire source temperature. Utilizing the adhesion of ultra-high molecular weight polyethylene, hydroxylated multi-walled carbon nanotubes can be assisted on the basalt fibers, forming a stable char layer covering the surface of the material during combustion, thereby preventing the penetration of oxygen and combustible gases and inhibiting the progress of the combustion reaction.

[0018] Optionally, 20 - 40 parts of modified epoxy resin are further added to the white material composition. The preparation method of the modified epoxy resin is as follows: In terms of parts by weight, mix 20 - 40 parts of epoxy resin, 0.1 - 0.2 parts of silicon coupling agent, and 0.05 - 0.1 parts of dibutyltin dilaurate, stir at 55 - 60 °C under nitrogen protection, add 50 - 100 parts of zinc oxide and 30 - 70 parts of POSS, and mix evenly to obtain the modified epoxy resin.

[0019] By adopting the above technical solution, an amino group is introduced onto the epoxy resin through a silane coupling agent. The amino group also serves as an effective hydrogen bond site in the system, increasing the degree of hydrogen bonding between the epoxy resin and the polyurethane. Moreover, the rigid aromatic ring in the epoxy resin has higher regularity, thus improving the regularity of the molecular chain to a certain extent, increasing the degree of microphase separation of the material, and thereby improving the dimensional stability of the polyurethane material. In addition, it contains ether bonds and hydroxyl groups, which are beneficial to improving wettability and adhesion, and has a strong bonding ability to zinc oxide. Under the action of the silane coupling agent, zinc oxide is evenly dispersed with the epoxy resin, and there is a strong interfacial interaction. When the modified epoxy resin is added to the polyurethane raw material, the epoxy resin can regulate zinc oxide, enabling it to be evenly and densely distributed on the inner wall of the cell cavity of the foamed material. As a heterogeneous nucleating agent, it can increase the cell density, thin the cell wall, reduce the shrinkage rate, and increase the dimensional stability. Moreover, the addition of zinc oxide can improve the flame resistance of the polyurethane foam. The heat released during the combustion process can be quickly transferred and consumed, reducing the combustion heat and increasing the limiting oxygen index. POSS is polymethylsilsesquioxane, which can enhance the stability of the carbon layer, making the carbon layer formed by the combustion of the epoxy resin not easily damaged due to heat convection, and also preventing the contact of heat and oxygen, improving the flame retardant effect of the modified epoxy resin itself, and reducing the weakening of the flame retardancy caused by the addition of the epoxy resin. POSS is polycarboxylcaged phenylsilsesquioxane. The surface polar groups of polycarboxylcaged phenylsilsesquioxane chemically react with the amino and hydroxyl groups in the epoxy resin and have intermolecular forces with zinc oxide, thereby improving the bonding strength between the components in the modified epoxy resin, and further enhancing the interfacial force of the polyurethane foaming filler to various caulking materials.

[0020] Optionally, low molecular weight polyphenylene ether is also added in the preparation method of the modified epoxy resin. The mass ratio of the low molecular weight polyphenylene ether to the epoxy resin is 1:0.15 - 0.2.

[0021] By adopting the above technical solution, polyphenylene ether has excellent mechanical properties, good dimensional stability, high strength, high hardness, strong rigidity, strong creep resistance, and good heat resistance. Moreover, the low molecular weight polyphenylene ether has good compatibility with the epoxy resin and is evenly dispersed in the modified epoxy resin. During the foaming of the polyurethane, as a heterogeneous nucleating agent, it increases the nucleation sites and reduces the thickness of the cell wall, providing favorable conditions for the preparation of an open-cell structure. The polyphenylene ether exists in the form of a dispersed phase on the cell wall, and is conducive to inducing stress concentration during the foaming process, resulting in the rupture of the cell wall, improving the foaming ratio, and facilitating the formation of an open-cell structure, thereby increasing the porosity of the polyurethane foaming filler and improving the cell uniformity.

[0022] Optionally, the plasticizer is one or more of environmentally friendly chlorinated paraffin, epoxy soybean oil glyceride, aromatic oil, and alkylsulfonyl benzene ester.

[0023] By adopting the above technical solutions, the plasticizer can reduce the viscosity during the mixing process of the polyurethane foaming material, making it easier to mix and process, increasing its flexibility and elongation at break. This makes the product softer, easier to bend, improves its use comfort and durability, can extend the service life, simplifies the production process, improves production efficiency, reduces energy consumption, increases the plasticity of the rubber compound, improves the processing performance and the low-temperature performance of the vulcanized rubber, enabling the product to still maintain good use performance in a low-temperature environment.

[0024] Optionally, the foam stabilizer is one or more of modified silicone oil, polyacrylamide, polyvinyl alcohol, cellulose, and sodium dodecyl sulfate.

[0025] By adopting the above technical solutions, the foam stabilizer can increase the viscosity of the foam, reduce the fluidity of the foam, enhance the foam stability, prevent the foam from rupturing prematurely, and endow the foam with good elasticity and self-healing ability.

[0026] Optionally, the catalyst is bis(morpholinodiethyl) ether;

[0027] The black material is polyisocyanate, selected from at least one of TDI, MDI, and PAPI.

[0028] By adopting the above technical solutions, bis(morpholinodiethyl) ether can accelerate the curing reaction of polyurethane, increase the reaction rate, shorten the curing time, improve production efficiency, and can also extend the storage period of the polyurethane foaming filler.

[0029] MDI is diphenylmethane diisocyanate, which has high reactivity and functionality. TDI is toluene diisocyanate. PAPI has high functionality and viscosity. The polyurethane foaming filler produced therefrom has good foam fineness, smooth gun discharge during construction, and is not prone to gun blockage.

[0030] In a second aspect, the present application provides a preparation process for a flame-retardant polyurethane foaming filler, adopting the following technical solutions:

[0031] A preparation process for a flame-retardant polyurethane foaming filler includes the following steps:

[0032] Mix polyether diol, polyether triol, foam stabilizer, catalyst, flame retardant, modified epoxy resin, plasticizer, and toughening agent evenly to form a white material composition. The stirring speed is 140 - 170 rpm, and the stirring temperature is 30 - 40 °C;

[0033] After alternately filling the white material mixture and the black material into the aerosol can in portions, immediately seal it with a sealer, sequentially add dimethyl ether and propane-butane, shake well, react for 20 - 24 h, and cool to room temperature.

[0034] By adopting the above technical solution, first, polyether diol, polyether triol, etc. are mixed to form a white material composition, and then it is mixed with isocyanate and foaming agent, which can more precisely control the molecular structure and properties of the white material composition, ensuring its reaction activity and foam properties when mixed with the black material. This step-by-step synthesis method helps to reduce the uncertainty during the reaction process, improve product quality, and is more flexible and adaptable to the market's demand for the use of polyurethane foaming fillers. Moreover, when the white material composition is mixed with the black material, the two have high reaction activity, which can trigger the foaming reaction faster, improve production efficiency, reduce the occurrence of side reactions, improve the purity of the product, and better control the microstructure of the polyurethane foam filler, such as cell size, distribution, and density, which helps to improve the mechanical properties of the product, etc.; compared with the one-step method, manual foaming, etc., the process is easier to adjust, the stability and consistency of the product are better, the production efficiency is high, and it is suitable for large-scale production.

[0035] In summary, the present application has the following beneficial effects:

[0036] 1. Since the present application uses polyether diol and polyether triol, etc. as the white material composition, which is mixed with the black material, n-butane, and dimethyl ether for foaming, and a specific proportion of phosphorus-based flame retardant and phosphorus-nitrogen-based flame retardant are used in the white material composition, a firm carbonized layer can be formed during combustion, and incombustible gases are released, reducing the oxygen content, improving the flame retardant efficiency and flame retardant effect, and being more environmentally friendly without releasing harmful gases.

[0037] 2. In the present application, a certain amount of modified basalt fiber is preferably added to the flame retardant. By synthesizing a double network structure on the basalt fiber, the flame retardant effect of the polyurethane foaming filler is improved. On the one hand, the release of water molecules in the double network structure reduces the combustion temperature. On the other hand, after the double network structure is damaged, the basalt fiber itself has strong heat resistance and fire prevention effects, and can continuously play a flame retardant role. Moreover, by pretreating the basalt fiber with ultra-high molecular weight polyethylene, initiator, and hydroxylated multi-walled carbon nanotubes, the anti-flame retardant effect of the basalt fiber can be improved.

[0038] 3. In the present application, modified epoxy resin is preferably added to the white material composition. Through raw materials such as epoxy resin, silane coupling agent, zinc oxide, and POSS, the epoxy resin can improve and regulate the uniform and dense distribution of zinc oxide on the inner wall of the cell cavity, making the carbon layer formed by the combustion of the polyurethane foaming filler after combustion relatively dense. Zinc oxide can consolidate the strength of the carbon layer and enhance the oxygen index, further improving the flame retardant effect. Specific Embodiments

[0039] The following examples further illustrate the present application in detail.

[0040] Preparation Examples 1-7 of Modified Basalt Fiber

[0041] Preparation Example 1: 40 g of polyvinyl alcohol and 30 g of polyacrylamide were added to 1000 g of deionized water, stirred and dissolved. 20 g of basalt fibers were added, sonicated at a frequency of 30 kHz for 30 min, 1 g of boric acid was added. After stirring evenly, the pH was adjusted to 9 with a 2 wt% sodium hydroxide solution, allowed to stand, and dried at 50 °C for 4 h to obtain modified basalt fibers. The mass ratio of basalt fibers, polyvinyl alcohol and polyacrylamide was 4:3:2. The polyvinyl alcohol had a grade of 2488, the molecular weight of polyacrylamide was 16 million, and the length of the basalt fibers was 6 mm.

[0042] Preparation Example 2: 30 g of polyvinyl alcohol and 25 g of polyacrylamide were added to 1000 g of deionized water, stirred and dissolved. 15 g of basalt fibers were added, sonicated at a frequency of 30 kHz for 30 min, 1 g of boric acid was added. After stirring evenly, the pH was adjusted to 9.5 with a 2 wt% sodium hydroxide solution, allowed to stand, and dried at 50 °C for 4 h to obtain modified basalt fibers. The mass ratio of basalt fibers, polyvinyl alcohol and polyacrylamide was 3:2.5:1.5. The polyvinyl alcohol had a grade of 2488, the molecular weight of polyacrylamide was 16 million, and the length of the basalt fibers was 6 mm.

[0043] Preparation Example 3: 40 g of polyvinyl alcohol was added to 1000 g of deionized water, stirred and dissolved. 20 g of basalt fibers were added, sonicated at a frequency of 30 kHz for 30 min, 1 g of boric acid was added. After stirring evenly, the pH was adjusted to 9 with a 2 wt% sodium hydroxide solution, allowed to stand, and dried at 50 °C for 4 h to obtain modified basalt fibers. The mass ratio of basalt fibers and polyvinyl alcohol was 4:3. The polyvinyl alcohol had a grade of 2488, and the length of the basalt fibers was 6 mm.

[0044] Preparation Example 4: The difference from Preparation Example 1 was that boric acid was not added.

[0045] Preparation Example 5: The difference from Preparation Example 1 was that the basalt fibers were pretreated as follows:

[0046] 100 g of ultra-high molecular weight polyethylene, 2,5-bis(tert-butylperoxy-2,5-dimethyl-3-hexyne) and hydroxylated multi-walled carbon nanotubes were mixed, heated to 150 °C for hot melting to obtain a melt, 1 time the total weight of the melt of basalt fibers was added, mixed evenly, extruded and granulated. The mass ratio of ultra-high molecular weight polyethylene, 2,5-bis(tert-butylperoxy-2,5-dimethyl-3-hexyne) and hydroxylated multi-walled carbon nanotubes was 1:0.15:0.08. The ultra-high molecular weight polyethylene was selected from Mitsui L5000, and the hydroxylated multi-walled carbon nanotubes were selected from Sichuan Kenye Technology, model KYSCNT-C002.

[0047] Preparation Example 6: The difference from Preparation Example 1 is that the basalt fibers are pretreated as follows:

[0048] 100 g of ultra-high molecular weight polyethylene melt, 2,5-bis(tert-butylperoxy-2,5-dimethyl-3-hexyne), and hydroxylated multi-walled carbon nanotubes were mixed, heated to 150 °C for hot melting to obtain a melt, and basalt fibers weighing 1 times the total weight of the melt were added, mixed evenly, extruded, and granulated. The mass ratio of ultra-high molecular weight polyethylene, 2,5-bis(tert-butylperoxy-2,5-dimethyl-3-hexyne), and hydroxylated multi-walled carbon nanotubes was 1:0.01:0.04. The ultra-high molecular weight polyethylene was selected from Mitsui L5000, and the hydroxylated multi-walled carbon nanotubes were selected from Sichuan Kenye Technology, with the model KYSCNT-C002.

[0049] Preparation Example 7: The difference from Preparation Example 6 is that hydroxylated multi-walled carbon nanotubes were not added.

[0050] Preparation Examples 8 - 15 of Modified Epoxy Resin

[0051] Preparation Example 8: 40 g of epoxy resin, 0.2 g of silicon coupling agent KH550, and 0.1 g of dibutyltin dilaurate were mixed, stirred at 55 °C under nitrogen protection, 100 g of zinc oxide, 70 g of POSS, and 8 g of low molecular weight polyphenylene ether were added, and mixed evenly to obtain a modified epoxy resin. The epoxy resin was bisphenol A type epoxy resin E51, the POSS was polycarboxyl cage-type phenylsilsesquioxane, selected from Hangzhou Tuomu Technology, with the model B-140, and the low molecular weight polyphenylene ether was selected from Sabic, with the model SA90.

[0052] Preparation Example 9: 20 g of epoxy resin, 0.1 g of silicon coupling agent KH550, and 0.05 g of dibutyltin dilaurate were mixed, stirred at 60 °C under nitrogen protection, 50 g of zinc oxide, 30 g of POSS, and 3 g of low molecular weight polyphenylene ether were added, and mixed evenly to obtain a modified epoxy resin. The epoxy resin was bisphenol A type epoxy resin E51, the POSS was polycarboxyl cage-type phenylsilsesquioxane, selected from Hangzhou Tuomu Technology, with the model B-140, and the low molecular weight polyphenylene ether was selected from Sabic, with the model SA90.

[0053] Preparation Example 10: The difference from Preparation Example 8 is that zinc oxide, POSS, and low molecular weight polyphenylene ether were not added.

[0054] Preparation Example 11: The difference from Preparation Example 8 is that low molecular weight polyphenylene ether was not added.

[0055] Preparation Example 12: The difference from Preparation Example 8 is that an equal amount of POSS was used to replace low molecular weight polyphenylene ether.

[0056] Preparation Example 13: The difference from Preparation Example 8 is that an equal amount of zinc oxide was used to replace POSS.

[0057] Preparation Example 14: The difference from Preparation Example 8 is that an equal amount of low molecular weight polyphenylene ether is used to replace zinc oxide.

[0058] Preparation Example 15: The difference from Preparation Example 8 is that an equal amount of POSS is used to replace zinc oxide.

[0059] Examples

[0060] Example 1: A flame-retardant polyurethane foaming filler, comprising 350 g of white material composition, 230 g of black material, 65 g of dimethyl ether and 78 g of propane-butane. The black material is isocyanate, specifically TDI (toluene diisocyanate) selected from Jinan Jinsheng New Materials, with the model of TDI-80. The white material composition is made by mixing raw materials with the following weights: 100 g of polyether diol, 140 g of polyether triol, 35 g of foam stabilizer, 15 g of catalyst, 480 g of plasticizer, 230 g of flame retardant. The polyether diol is selected from Guangzhou Yinghong Chemical Industry, with the model of N210. The polyether triol is selected from Jiangsu Xinsu New Materials, with the product number of 303b. The foam stabilizer is modified silicone oil, selected from Jiashan Jiangnan Textile Materials, with the model of JF-203. The catalyst is bis(morpholino)diethyl ether. The plasticizer is environmentally friendly chlorinated paraffin, selected from Xuzhou Peize New Materials, with the product number of 50#. The flame retardant includes 145 g of phosphorus-based flame retardant and 85 g of phosphorus-nitrogen-based flame retardant. The phosphorus-based flame retardant includes chlorinated paraffin phosphate, flame retardant TCPP and triphenyl phosphate with a mass ratio of 1:0.7:0.5. The phosphorus-nitrogen-based flame retardant is TF-611, from Lattice Momentum (Shanghai) New Materials. The flame retardant TCPP is selected from Zhangjiagang Yarui Chemical Industry, with the product number of 103. The chlorinated paraffin phosphate is tris(1,3-dichloroisopropyl) phosphate (TDCPP).

[0061] The preparation process of the above flame-retardant polyurethane foaming filler includes the following steps:

[0062] Mix the polyether diol, polyether triol, foam stabilizer, catalyst, flame retardant, modified epoxy resin, plasticizer and toughening agent evenly to form a white material composition. The stirring speed is 170 rpm and the stirring temperature is 30 °C;

[0063] After alternately filling 350 g of the white material composition and 230 g of the black material into the aerosol can, immediately seal it with a sealer. After sealing, add 65 g of dimethyl ether and 79 g of propane-butane in sequence and shake well, react for 24 h, and cool to room temperature.

[0064] Example 2: A flame-retardant polyurethane foam filler, comprising 300 g of white material composition, 220 g of black material, 60 g of dimethyl ether and 75 g of propane-butane. The black material is isocyanate, specifically diphenylmethane diisocyanate MDI, selected from Hebei Shengmao Chemical Industry, with the model PM200. The white material composition is made by mixing raw materials with the following weights: 95 g of polyether diol, 130 g of polyether triol, 30 g of foam stabilizer, 12 g of catalyst, 460 g of plasticizer, 210 g of flame retardant. The polyether diol is selected from Guangzhou Yinghong Chemical Industry, with the model N210. The polyether triol is selected from Jiangsu Xinsu New Materials, with the product number 303b. The foam stabilizer is modified silicone oil, selected from Jiashan Jiangnan Textile Materials, with the model JF-203. The catalyst is bis(morpholino)diethyl ether. The plasticizer is environmentally friendly chlorinated paraffin, selected from Xuzhou Peize New Materials, with the product number 50#. The flame retardant includes 140 g of phosphorus-based flame retardant and 70 g of phosphorus-nitrogen-based flame retardant. The phosphorus-based flame retardant includes chlorinated paraffin phosphate, flame retardant TCPP and triphenyl phosphate with a mass ratio of 1:0.7:0.3. The flame retardant TCPP is selected from Zhangjiagang Yarui Chemical Industry, with the product number 103. The chlorinated paraffin phosphate is tris(1,3-dichloroisopropyl) phosphate (TDCPP). The phosphorus-nitrogen-based flame retardant is selected from Lattice Momentum (Shanghai) New Materials, with the model TF-611.

[0065] The preparation process of the above flame-retardant polyurethane foam filler includes the following steps:

[0066] Mix the polyether diol, polyether triol, foam stabilizer, catalyst, flame retardant, modified epoxy resin, plasticizer and toughening agent evenly to form a white material composition. The stirring speed is 140 rpm and the stirring temperature is 40 °C;

[0067] After alternately filling 300 g of white material composition and 220 g of black material into the aerosol can, immediately seal it with a sealer. After sealing, add 60 g of dimethyl ether and 75 g of propane-butane in sequence and shake well, react for 20 h, and cool to room temperature.

[0068] Example 3: A flame-retardant polyurethane foam filler, comprising 400 g of white material composition, 250 g of black material, 70 g of dimethyl ether, and 80 g of propane-butane. The black material is isocyanate, specifically PAPI (polyphenyl polymethylene polyisocyanate), with a molecular weight of 250.252 and a CSA number of 9016-87-9, selected from Zhejiang Hualang Wuchan. The white material composition is made by mixing raw materials with the following weights: 105 g of polyether diol, 150 g of polyether triol, 45 g of foam stabilizer, 18 g of catalyst, 500 g of plasticizer, and 250 g of flame retardant. The polyether diol is selected from Guangzhou Yinghong Chemical Industry, with a model of N210. The polyether triol is selected from Jiangsu Xinsu New Materials, with a product number of 303b. The foam stabilizer is modified silicone oil, selected from Jiashan Jiangnan Textile Materials, with a model of JF-203. The catalyst is bis(morpholino)diethyl ether. The plasticizer is environmentally friendly chlorinated paraffin, selected from Xuzhou Peize New Materials, with a product number of 50#. The flame retardant includes 156 g of phosphorus-based flame retardant and 94 g of phosphorus-nitrogen-based flame retardant. The phosphorus-based flame retardant includes chlorinated paraffin phosphate, flame retardant TCPP, and triphenyl phosphate with a mass ratio of 1:0.7:0.4. The flame retardant TCPP is selected from Zhangjiagang Yarui Chemical Industry, with a product number of 103. The chlorinated paraffin phosphate is tris(1,3-dichloroisopropyl) phosphate (TDCPP). The phosphorus-nitrogen-based flame retardant is selected from Lattice Momentum (Shanghai) New Materials, with a model of TF-611.

[0069] The preparation process of the above flame-retardant polyurethane foam filler includes the following steps:

[0070] Mix the polyether diol, polyether triol, foam stabilizer, catalyst, flame retardant, modified epoxy resin, plasticizer, and toughening agent evenly to form a white material composition. The stirring speed is 140 rpm, and the stirring temperature is 40 °C;

[0071] After alternately filling 400 g of the white material composition and 250 g of the black material into the aerosol can, immediately seal it with a sealing machine. After sealing, add 70 g of dimethyl ether and 80 g of propane-butane in sequence and shake well, react for 20 h, and cool to room temperature.

[0072] Example 4: A flame-retardant polyurethane foam filler, which is different from Example 1 in that the flame retardant further contains modified basalt fiber. The flame retardant includes a phosphorus-based flame retardant, a phosphorus-nitrogen-based flame retardant, and modified basalt fiber with a mass ratio of 1:0.58:0.3. The modified basalt fiber is made from Preparation Example 1. The phosphorus-based flame retardant includes chlorinated paraffin phosphate, flame retardant TCPP, and triphenyl phosphate with a mass ratio of 1:0.7:0.4. The flame retardant TCPP is selected from Zhangjiagang Yarui Chemical Industry, with a product number of 103. The chlorinated paraffin phosphate is tris(1,3-dichloroisopropyl) phosphate (TDCPP). The phosphorus-nitrogen-based flame retardant is selected from Lattice Momentum (Shanghai) New Materials, with a model of TF-611.

[0073] Example 5: A flame-retardant polyurethane foam filler, which is different from Example 1 in that modified basalt fibers are further added to the flame retardant. The flame retardant includes a phosphorus-based flame retardant, a phosphorus-nitrogen-based flame retardant, and modified basalt fibers in a mass ratio of 1:0.58:0.1. The modified basalt fibers are made from Preparation Example 2. The phosphorus-based flame retardant includes chlorinated alkane phosphate, flame retardant TCPP, and triphenyl phosphate in a mass ratio of 1:0.7:0.4. Flame retardant TCPP is selected from Zhangjiagang Yarui Chemical Industry, and the product number is 103. The chlorinated alkane phosphate is tris(1,3-dichloroisopropyl) phosphate (TDCPP). The phosphorus-nitrogen-based flame retardant is selected from Lattice Momentum (Shanghai) New Materials Co., Ltd., and the model is TF-611.

[0074] Example 6: A flame-retardant polyurethane foam filler, which is different from Example 4 in that the modified basalt fibers are made from Preparation Example 3.

[0075] Example 7: A flame-retardant polyurethane foam filler, which is different from Example 4 in that the modified basalt fibers are made from Preparation Example 4.

[0076] Example 8: A flame-retardant polyurethane foam filler, which is different from Example 4 in that the modified basalt fibers are made from Preparation Example 5.

[0077] Example 9: A flame-retardant polyurethane foam filler, which is different from Example 4 in that the modified basalt fibers are made from Preparation Example 6.

[0078] Example 10: A flame-retardant polyurethane foam filler, which is different from Example 4 in that the modified basalt fibers are made from Preparation Example 7.

[0079] Example 11: A flame-retardant polyurethane foam filler, which is different from Example 4 in that equal amounts of basalt fibers are used to replace the modified basalt fibers.

[0080] Example 12: A flame-retardant polyurethane foam filler, which is different from Example 4 in that 40 g of modified epoxy resin is further added to the white material composition. The modified epoxy resin is made from Preparation Example 8.

[0081] Example 13: A flame-retardant polyurethane foam filler, which is different from Example 4 in that 20 g of modified epoxy resin is further added to the white material composition. The modified epoxy resin is made from Preparation Example 9.

[0082] Example 14: A flame-retardant polyurethane foam filler, which is different from Example 12 in that the modified epoxy resin is made from Preparation Example 10.

[0083] Example 15: A flame-retardant polyurethane foam filler, which is different from Example 12 in that the modified epoxy resin is made from Preparation Example 11.

[0084] Example 16: A flame-retardant polyurethane foam filler, which is different from Example 12 in that the modified epoxy resin is made from Preparation Example 12.

[0085] Example 17: A flame-retardant polyurethane foam filler, which is different from Example 12 in that the modified epoxy resin is made from Preparation Example 13.

[0086] Example 18: A flame-retardant polyurethane foam filler, which is different from Example 12 in that the modified epoxy resin is made from Preparation Example 14.

[0087] Example 19: A flame-retardant polyurethane foam filler, which is different from Example 12 in that the modified epoxy resin is made from Preparation Example 15.

[0088] Example 20: A flame-retardant polyurethane foam filler, which is different from Example 8 in that 40 g of modified epoxy resin is further added to the white material composition, and the modified epoxy resin is made from Preparation Example 8.

[0089] Comparative Example

[0090] Comparative Example 1: A flame-retardant polyurethane foam filler, which is different from Example 1 in that the flame retardants are all phosphorus-nitrogen-based flame retardants.

[0091] Comparative Example 2: A flame-retardant polyurethane foam filler, which is different from Example 1 in that the flame retardants are all phosphorus-based flame retardants.

[0092] Comparative Example 3: A flame-retardant polyurethane foam filler, which is different from Example 1 in that the phosphorus-based flame retardant is all triphenyl phosphate.

[0093] Performance Detection Test

[0094] Prepare polyurethane foam fillers according to the methods in the examples and comparative examples, and perform performance detection with reference to the following methods. Record the detection results in Table 1.

[0095] 1. Density: Detect according to GB / T6343-2009 "Determination of Apparent Density of Foamed Plastics and Rubber".

[0096] 2. Dimensional Stability (23 ± 2 °C, 48 h): Test according to GB / T8811-2008 "Test Method for Dimensional Stability of Rigid Cellular Plastics".

[0097] 3. Bonding Strength: According to ASTM D3931-2008 "Standard Test Method for Determining the Bonding Strength of Filled-Crack Adhesives in Shear Tests Using Pressure Loading"

[0098] 4. Limiting oxygen index: Tested in accordance with GB / T 2406.2-2009 Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient - temperature test

[0099] Table 1 Performance testing of polyurethane foam filler

[0100]

[0101]

[0102] Combined with the data in Table 1, it can be seen that the flame - retardant grade of the polyurethane foam fillers prepared in Examples 1 - 3 reaches B2 level, and they have high bonding strength to aluminum plates, PVC plastic plates and cement mortar plates, which is convenient for filling gaps of different materials to obtain a long - lasting filling effect, and they have high dimensional stability and are not prone to shrinkage.

[0103] In Examples 4 and 5, the modified basalt fibers prepared in Preparation Example 1 and Preparation Example 2 are used in the flame - retardant respectively. From the data in Table 1, it can be seen that the polyurethane foam sealants prepared in Examples 4 and 5 have better dimensional stability, less shrinkage, stronger bonding ability to various material plates and better flame - retardancy.

[0104] In Example 6, the modified basalt fiber prepared in Preparation Example 3 is used, and compared with Example 4, polyacrylamide is not added. In Example 7, the modified basalt fiber prepared in Preparation Example 4 is used, and boric acid is not added. As shown in Table 1, the oxygen index of the polyurethane foam fillers prepared in Examples 6 and 7 decreases, the flame - retardant effect deteriorates, and the bonding strength and dimensional stability decrease slightly.

[0105] In Examples 8 and 9, the modified basalt fibers prepared in Preparation Example 5 and Preparation Example 6 are used. Compared with Example 4, the polyurethane foam fillers prepared in Examples 8 and 9 have increased dimensional stability and improved flame - retardancy.

[0106] In Example 10, the modified basalt fiber prepared in Preparation Example 7 is used. Compared with Example 9, hydroxylated multi - walled carbon nanotubes are not added. It can be seen that the dimensional stability of the polyurethane foam filler decreases slightly and the oxygen index decreases.

[0107] In Example 11, only basalt fiber is used in the flame - retardant without modification treatment. Compared with Example 4, it can be seen that all performances decrease, but the bonding strength decreases slightly compared with Example 1, indicating that adding unmodified basalt fiber can improve flame - retardancy, but has an adverse effect on other properties of the polyurethane foam filler.

[0108] Compared with Example 4, in Example 12 and Example 13, modified epoxy resins prepared from Preparation Example 8 and Preparation Example 9 were respectively added. The data in Table 1 show that the oxygen index of the polyurethane foam filler prepared in Example 12 and Example 13 increased, the flame retardant effect was further improved, and the bonding strength with materials such as aluminum plates was greater, it was not easy to break away, the service life was longer, and in addition, the size shrinkage was smaller and the dimensional stability was better.

[0109] In Example 14, the modified epoxy resin prepared from Preparation Example 10 was used. Compared with Example 12, zinc oxide, POSS and low molecular weight polyphenylene ether were not added. As shown in Table 1, the flame retardant effect of the polyurethane foam filler decreased, the bonding strength with materials such as PVC weakened, and the dimensional stability decreased.

[0110] In Example 15, the modified epoxy resin prepared from Preparation Example 11 was used. Compared with Example 12, low molecular weight polyphenylene ether was not added. The density of the polyurethane foam filler decreased, and the foaming ratio decreased slightly, and the other properties changed little.

[0111] Compared with Example 12, in Example 16, the modified epoxy resin prepared from Preparation Example 12 was used, in which POSS was used to replace low molecular weight polyphenylene ether. As can be seen in Table 1, the flame retardant effect of the polyurethane foam filler increased, the adhesion increased, but the density decreased.

[0112] Compared with Example 12, in Example 17, zinc oxide was used to replace POSS in the modified epoxy resin. The oxygen index of the polyurethane foam filler increased, the flame retardant effect improved, and the dimensional stability increased, but the bonding effect decreased.

[0113] In Example 18, the modified epoxy resin prepared from Preparation Example 14 was used. Compared with Example 12, low molecular weight polyphenylene ether was used to replace zinc oxide. The flame retardancy of the polyurethane foam filler prepared in Example 18 decreased, and the foaming performance increased.

[0114] In Example 19, the modified epoxy resin prepared from Preparation Example 15 was used. Compared with Example 12, POSS was used to replace zinc oxide. As can be seen from the data in Table 1, the flame retardant effect of the polyurethane foam filler prepared in Example 19 decreased, and the bonding effect weakened.

[0115] Compared with Example 1, in Comparative Example 1, only the phosphorus-nitrogen system was used, and in Comparative Example 2, only the phosphorus-based flame retardant was used. As shown in Table 1, the oxygen index of the polyurethane foam filler prepared in Comparative Example 1 and Comparative Example 2 decreased, the flame retardant effect decreased, and the foaming effect became worse and the density decreased; compared with Example 1, in Comparative Example 3, only triphenyl phosphate was used in the phosphorus-based flame retardant. It can be seen that the oxygen index of the polyurethane foam filler decreased, and all properties were inferior to those of Example 1.

[0116] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A flame retardant polyurethane foam filler, characterized in that: The invention comprises the following raw materials in parts by weight: 300-400 parts of a white material composition, 220-250 parts of a black material, 60-70 parts of dimethyl ether, and 75-80 parts of propane-butane. The white material composition comprises the following raw materials in parts by weight: 95-105 parts of a polyether diol, 130-150 parts of a polyether triol, 30-45 parts of a foam leveling agent, 12-18 parts of a catalyst, 460-500 parts of a plasticizer, and 210-250 parts of a flame retardant. The flame retardant comprises a phosphorus-based flame retardant and a phosphorus-nitrogen-based flame retardant in a mass ratio of 1:0.5-0.

6. Modified basalt fiber is also added to the flame retardant, and the mass ratio of the modified basalt fiber to the phosphorus flame retardant is 1:0.1-0.

3. The preparation method of the modified basalt fiber is as follows: Add polyvinyl alcohol and polyacrylamide to deionized water, stir to dissolve, add basalt fiber, ultrasonicate for 20-30 minutes, add boric acid, stir evenly, adjust pH to 9-9.5 with sodium hydroxide solution, let stand, dry to obtain modified basalt fiber, the mass ratio of basalt fiber, polyvinyl alcohol and polyacrylamide is 3-4:2.5-3:1.5-2; The white material composition is further added with 20-40 parts of modified epoxy resin, and the preparation method of the modified epoxy resin is as follows: by weight, 20-40 parts of epoxy resin, 0.1-0.2 parts of silicon coupling agent and 0.05-0.1 parts of dibutyltin dilaurate are mixed, stirred at 55-60° C. under nitrogen protection, 50-100 parts of zinc oxide and 30-70 parts of polycarboxyl cage-type phenyl silsesquioxane are added, and mixed evenly to obtain the modified epoxy resin.

2. The flame retardant polyurethane foam filler according to claim 1, characterized in that: The phosphorus-based flame retardant comprises TDCPP, flame retardant TCPP and triphenyl phosphate in a mass ratio of 1:0.7:0.3-0.

5.

3. The flame retardant polyurethane foam filler according to claim 1, characterized in that: The basalt fiber is pretreated as follows: Ultra-high molecular weight polyethylene, 2,5-bis(tert-butyl peroxide)-2,5-dimethyl-3-hexyne and hydroxylated multi-walled carbon nanotubes are mixed and hot-melted to obtain a melt, 0.5-1 times the mass of basalt fiber as much as the mass of the melt is added, mixed, extruded and granulated, and the mass ratio of ultra-high molecular weight polyethylene, 2,5-bis(tert-butyl peroxide)-2,5-dimethyl-3-hexyne and hydroxylated multi-walled carbon nanotubes is 1:0.01-0.15:0.04-0.

08.

4. The flame retardant polyurethane foam filler according to claim 1, characterized in that: Low molecular weight polyphenylene ether is also added into the preparation method of the modified epoxy resin, and the mass ratio of the low molecular weight polyphenylene ether to the epoxy resin is 1:0.15-0.

2.

5. The flame retardant polyurethane foam filler according to claim 1, characterized in that: The plasticizer is one or more of environmentally friendly chlorinated paraffin, epoxy soybean glyceride, aromatic oil and alkyl sulfonyl phenyl ester.

6. The flame retardant polyurethane foam filler according to claim 1, characterized in that: The foam leveling agent is one or more of modified silicone oil, polyacrylamide, polyvinyl alcohol, cellulose and sodium lauryl sulfate.

7. The flame retardant polyurethane foam filler according to claim 1, characterized in that: The catalyst is bismorpholine diethyl ether; The black material is polyisocyanate, which is selected from at least one of TDI, MDI and PAPI.

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