A kind of microcapsule flame retardant material for mining and its manufacturing process

Abstract

The present invention discloses a mining microcapsule flame retardant material and a manufacturing process thereof. The mining microcapsule flame retardant material uses a polyurethane foam mixture as a core, a synergistic flame retardant layer is coated on the outer surface of the polyurethane foam mixture, and a modified filling flame retardant layer is coated on the outer side of the synergistic flame retardant layer to form a dense three-layer core-shell structure, wherein the synergistic flame retardant layer is a modified short chopped glass fiber, and the modified filling flame retardant layer is a modified graphene oxide. The present invention relates to the technical field of mining flame retardant materials. The mining microcapsule flame retardant material and the manufacturing process thereof, through the addition of organic silsesquioxane, a small amount of silicon dioxide generated during pyrolysis can improve the dispersibility of the flame retardant in the matrix, which is helpful for foam nucleation, thereby reducing the size of the pores, and at the same time, the diameter of the pores of the polyurethane foam mixture and the dispersibility of the flame retardant are improved to a certain extent, thereby improving the flame retardant effect of the flame retardant material and improving its self-extinguishing ability.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardant materials for mining, in particular to a microcapsule flame retardant material for mining and a manufacturing process thereof. Background Art

[0002] In recent years, my country's economy has continued to grow, and high-molecular polymer materials have developed rapidly. Since high-molecular materials have the advantages of light weight, excellent corrosion resistance, excellent antistatic performance and sealing performance, and easy processing and low cost, "plastics instead of steel" has been gradually promoted in underground coal mines, and various high-molecular materials with specific functions are applied to coal mining work, which can not only meet the basic requirements of production, but also reflect obvious economic benefits; however, high-molecular polymers are mostly flammable materials, which can easily cause fire accidents in mines; for this reason, the present invention provides a mining microcapsule flame retardant material and a production process thereof to solve the above problems. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a microcapsule flame retardant material for mining and a manufacturing process thereof, which solves the problems mentioned in the above background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical scheme: a mining microcapsule flame retardant material, which uses a polyurethane foam mixture as a core, a synergistic flame retardant layer is coated on the outer surface of the polyurethane foam mixture, and a modified filling flame retardant layer is coated on the outer side of the synergistic flame retardant layer to form a dense three-layer core-shell structure, wherein the synergistic flame retardant layer is modified chopped glass fiber, and the modified filling flame retardant layer is modified graphene oxide, and the weight proportions of the three are: 70 to 80 parts of the polyurethane foam mixture, 3 to 12 parts of the synergistic flame retardant layer, and 10 to 20 parts of the modified filling flame retardant layer.

[0005] Preferably, the polyurethane foam mixture is formed by mixing soft polyurethane foam, hard polyurethane foam and organic silsesquioxane, and the mass ratio thereof is 6:(0.8-1):(0.2-4).

[0006] Preferably, the preparation method of the modified graphene oxide is:

[0007] S1. Add deionized water to graphene oxide and stir evenly;

[0008] S2, pour in NaOH solution, adjust the pH of the mixed solution in S1 to 10-11, and perform ultrasonic dispersion;

[0009] S3, adding ZnS0 4 , and continue stirring, and react at 55-60°C for 30-40 minutes;

[0010] S4, centrifuging, washing and drying to obtain modified graphene oxide.

[0011] Preferably, in S3, NaOH solution is continuously added dropwise during the reaction process.

[0012] Preferably, the modification method of the modified short chopped glass fiber is: placing the short chopped glass fiber in a 90% ethanol solution, stirring, then washing with deionized water and filtering, and finally placing in a drying oven to dry, so as to obtain the modified short chopped glass fiber;

[0013] Wherein, the stirring temperature is 50-55° C., and the stirring time is 7-9 hours; the drying temperature is 110-120° C., and the drying time is 6-8 hours.

[0014] A process for producing a microcapsule flame retardant material for mining comprises the following steps:

[0015] Step 1: weigh the raw materials according to the above ratio and set aside;

[0016] Step 2, dispersing the modified chopped glass fibers into deionized water and subjecting them to ultrasonic treatment;

[0017] Step 3: immerse the polyurethane foam mixture into the solution of step 2, let it stand for 4 to 6 hours, coat the outer surface of the polyurethane foam with a synergistic flame retardant layer, and then take it out and dry it;

[0018] Step 4, dispersing the modified graphene oxide in deionized water and subjecting it to ultrasonic treatment;

[0019] Step 5, immersing the mixture of step 3 into the mixed solution of step 4, and coating the outer layer with a modified filling flame retardant layer;

[0020] Step 6: Dry and mix the mixture in step 5 to obtain the microcapsule flame retardant material for mining.

[0021] Preferably, the ultrasonic time in step 2 and step 4 is 5 to 8 minutes.

[0022] Beneficial Effects

[0023] The present invention provides a microcapsule flame retardant material for mining and a manufacturing process thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The mining microcapsule flame retardant material and its manufacturing process, the surface microstructure of the modified short-cut glass fiber is relatively rough, which can significantly increase the bonding performance between the synergistic flame retardant layer and the polyurethane foam mixture and the modified filling flame retardant layer, and improve the mechanical properties of the flame retardant material.

[0025] (2) The mining microcapsule flame retardant material and its production process, through the addition of organic silsesquioxane, produces a small amount of silicon dioxide during pyrolysis, which can improve the dispersion of the flame retardant in the matrix, help foam nucleation, thereby reducing the size of the pores, and at the same time improve the diameter of the pores of the polyurethane foam mixture and the dispersion of the flame retardant to a certain extent, thereby improving the flame retardant effect of the flame retardant material and enhancing its self-extinguishing ability.

[0026] (3) The mining microcapsule flame retardant material and its production process can effectively improve the charring ability of the flame retardant material during combustion by adding modified graphene oxide, and the generated expanded carbon layer will not fall off during combustion, thereby protecting the substrate from further combustion, significantly improving the flame retardant properties of the flame retardant material. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A process flow chart of modified graphene oxide provided for a microcapsule flame retardant material for mining and its manufacturing process of the present invention;

[0028] Figure 2 The SEM image of the modified chopped glass fiber provided by the present invention for a kind of microcapsule flame retardant material for mining and its manufacturing process;

[0029] Figure 3 The flame retardant material LOI test provided for a kind of microcapsule flame retardant material for mining and its manufacturing process of the present invention;

[0030] Figure 4 A scanning electron microscope image of the residual carbon after combustion of a flame retardant material provided by the present invention for a microcapsule flame retardant material for mining and its manufacturing process;

[0031] Figure 5 A test of the total amount of heat released by combustion of a flame retardant material provided by the present invention for a microcapsule flame retardant material for mining and its manufacturing process;

[0032] Figure 6 The SEM image of the cross section of the flame retardant material provided for the mining microcapsule flame retardant material and its production process of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention.

[0034] Preparation of soft polyurethane foam: at room temperature, pour polyether polyol 950 and isocyanate 950 into a mold at a mass ratio of 5:2, stir evenly, and obtain soft polyurethane foam after foaming.

[0035] Preparation of rigid polyurethane foam: At room temperature, pour polyether polyol 903 and isocyanate 903 into a mold in a mass ratio of 1:1 and stir evenly. After the foaming is completed, rigid polyurethane foam is obtained.

[0036] Example 1

[0037] A process for producing a microcapsule flame retardant material for mining comprises the following steps:

[0038] Step 1, weigh the raw materials according to the ratio: 70g of polyurethane foam mixture, 12g of modified chopped glass fiber, and 20g of modified graphene oxide, and set them aside; wherein the mass ratio of soft polyurethane foam, hard polyurethane foam and organic silsesquioxane is 6:0.8:4;

[0039] The preparation method of modified graphene oxide is as follows: add 100 mL of deionized water to 20 g of graphene oxide and stir evenly; then pour in NaOH solution, adjust the pH of the mixed solution to 10, and perform ultrasonic dispersion at the same time; then add 0.2 mol / L of ZnS0 4 , continue stirring, and continuously add 30mL of 4mol / L NaOH solution, and react at 55°C for 30min; finally centrifuge, wash, and dry to obtain modified graphene oxide;

[0040] The modification method of the modified short chopped glass fiber is as follows: 10 g of the short chopped glass fiber is placed in 100 ml of 90% ethanol solution, stirred at 50° C. for 7 hours, then washed with deionized water and filtered, and finally placed in a drying oven at 110° C. for 6 hours to obtain the modified short chopped glass fiber;

[0041] Step 2: Disperse the modified chopped glass fibers into deionized water and perform ultrasonic treatment for 5 minutes;

[0042] Step 3: immerse the polyurethane foam mixture into the solution of step 2, let it stand for 4 hours, coat the outer surface of the polyurethane foam with a synergistic flame retardant layer, and then take it out and dry it;

[0043] Step 4, dispersing the modified graphene oxide in deionized water and ultrasonically treating for 5 minutes;

[0044] Step 5, immersing the mixture of step 3 into the mixed solution of step 4, and coating the outer layer with a modified filling flame retardant layer;

[0045] Step 6: Dry and mix the mixture in step 5 to obtain the microcapsule flame retardant material for mining.

[0046] Example 2

[0047] A process for producing a microcapsule flame retardant material for mining comprises the following steps:

[0048] Step 1, weigh the raw materials according to the ratio: 75g of polyurethane foam mixture, 7g of modified chopped glass fiber, and 15g of modified graphene oxide, and set them aside; wherein the mass ratio of soft polyurethane foam, hard polyurethane foam and organic silsesquioxane is 6:0.9:2.1;

[0049] The preparation method of modified graphene oxide is as follows: add 100 mL of deionized water to 25 g of graphene oxide and stir evenly; then pour in NaOH solution, adjust the pH of the mixed solution to 10, and perform ultrasonic dispersion at the same time; then add 0.2 mol / L of ZnS0 4 , continue stirring, and continuously add 35mL of 4mol / L NaOH solution, and react at 58°C for 35min; finally centrifuge, wash, and dry to obtain modified graphene oxide;

[0050] The modification method of the modified short chopped glass fiber is as follows: 12 g of the short chopped glass fiber is placed in 100 ml of 90% ethanol solution, stirred at 52° C. for 8 hours, then washed with deionized water and filtered, and finally placed in a drying oven at 115° C. for 7 hours to obtain the modified short chopped glass fiber;

[0051] Step 2: Disperse the modified chopped glass fibers into deionized water and perform ultrasonic treatment for 7 minutes;

[0052] Step 3: immerse the polyurethane foam mixture into the solution of step 2, let it stand for 5 hours, coat the outer surface of the polyurethane foam with a synergistic flame retardant layer, and then take it out and dry it;

[0053] Step 4, dispersing the modified graphene oxide in deionized water and ultrasonically treating for 6 minutes;

[0054] Step 5, immersing the mixture of step 3 into the mixed solution of step 4, and coating the outer layer with a modified filling flame retardant layer;

[0055] Step 6: Dry and mix the mixture in step 5 to obtain the microcapsule flame retardant material for mining.

[0056] Example 3

[0057] A process for producing a microcapsule flame retardant material for mining comprises the following steps:

[0058] Step 1, weigh the raw materials according to the ratio: 80g of polyurethane foam mixture, 3g of modified chopped glass fiber, and 10g of modified graphene oxide, and set them aside; wherein the mass ratio of soft polyurethane foam, hard polyurethane foam and organic silsesquioxane is 6:1:0.2;

[0059] The preparation method of modified graphene oxide is as follows: add 100 mL of deionized water to 30 g of graphene oxide and stir evenly; then pour in NaOH solution, adjust the pH of the mixed solution to 11, and perform ultrasonic dispersion at the same time; then add 0.2 mol / L of ZnS0 4 , continue stirring, and continuously add 40mL of 4mol / L NaOH solution, react at 60°C for 40min; finally centrifuge, wash, and dry to obtain modified graphene oxide;

[0060] The modification method of the modified short chopped glass fiber is as follows: 15 g of the short chopped glass fiber is placed in 100 ml of 90% ethanol solution, stirred at 55° C. for 9 hours, then washed with deionized water and filtered, and finally placed in a drying oven at 120° C. for 8 hours to obtain the modified short chopped glass fiber;

[0061] Step 2, dispersing the modified chopped glass fibers into deionized water and ultrasonically treating for 8 minutes;

[0062] Step 3: immerse the polyurethane foam mixture into the solution of step 2, let it stand for 6 hours, coat the outer surface of the polyurethane foam with a synergistic flame retardant layer, and then take it out and dry it;

[0063] Step 4, dispersing the modified graphene oxide in deionized water and ultrasonically treating for 8 minutes;

[0064] Step 5, immersing the mixture of step 3 into the mixed solution of step 4, and coating the outer layer with a modified filling flame retardant layer;

[0065] Step 6: Dry and mix the mixture in step 5 to obtain the microcapsule flame retardant material for mining.

[0066] Comparative Example 1

[0067] A process for producing a microcapsule flame retardant material for mining comprises the following steps:

[0068] Step 1, weigh the raw materials according to the ratio: 80g of polyurethane foam mixture, 3g of glass fiber, and 10g of graphene oxide, and set aside; wherein the mass ratio of soft polyurethane foam to hard polyurethane foam is 6:1;

[0069] Step 2: Disperse the glass fiber in deionized water and perform ultrasonic treatment for 8 minutes;

[0070] Step 3: immerse the polyurethane foam mixture into the solution of step 2, let it stand for 6 hours, cover the outer surface of the polyurethane foam with a glass fiber layer, and then take it out and dry it;

[0071] Step 4: Disperse graphene oxide in deionized water and perform ultrasonic treatment for 8 minutes;

[0072] Step 5, immersing the mixture of step 3 into the mixed solution of step 4, and coating the outer layer with a graphene oxide layer;

[0073] Step 6: Dry and mix the mixture in step 5 to obtain the microcapsule flame retardant material for mining.

[0074] Performance Test:

[0075] Total heat release test: Tested according to ISO5660, the heat radiation is 50kW / m 2 , the sample size is 100mmx 100mm x 30mm.

[0076] Limiting oxygen index (LOI): The sample was tested according to GB / T2406-93, and the sample size was 100mm x15mm x 3.5mm; the results are shown in Table 1.

[0077] Burning grade test: The sample was tested according to ASTM D 3801 standard, and the sample size was 100mm x 10mm x 3mm; the results are shown in Table 1.

[0078] Compression performance test: According to the "Determination of Compression Performance of Rigid Polyurethane Foam Plastics" (DB / T8813-2008), the sample is placed between the two flat plates of the electronic universal testing machine, and the sample is compressed at a rate of 2mm / min, with a relative deformation of not less than 10%. The sample size is 50mm x 50mm x 50mm. The results are shown in Table 1.

[0079] Table 1

[0080]

[0081] It can be seen from Table 1 that the flame retardant material prepared in this embodiment has significantly improved mechanical properties and combustion grade compared with the flame retardant material prepared in Comparative Example 1, and has better flame retardant performance.

[0082] like Figure 2 As shown, the surface of the chopped glass fiber is relatively smooth, while the surface of the modified chopped glass fiber is adhered with polyurethane, showing strong compatibility and adhesion with polyurethane.

[0083] like Figure 3As shown, after combustion, the charring ability of the flame retardant material is significantly improved, and the generated expanded char layer will not fall off during the test, thereby protecting the substrate from further combustion, thereby improving the flame retardant properties of the flame retardant material.

[0084] like Figure 4 As shown in the figure, it can be seen that after the flame retardant material prepared in comparative example 1 is burned, the surface of the residual carbon layer is porous and the inside presents a relatively loose structure. After the flame retardant materials prepared in embodiments 1-3 are burned, a uniform and dense cross-linked carbon layer will be formed on the surface of the substrate. This is because the addition of flame retardants will improve the carbonization performance of the polyurethane foam mixture, and the protective carbon layer formed on the surface of the substrate plays a role in isolating heat transfer, and effectively prevents small combustible molecules and air from entering the interior of the substrate, interrupting the combustion process, and playing a role in condensation and flame retardancy.

[0085] like Figure 5 As shown in the figure, it can be seen that during the combustion of the flame retardant material, the total amount of heat released by the flame retardant material prepared in Examples 1-3 is significantly reduced compared with the flame retardant material prepared in Comparative Example 1, so its fire retardant effect is better.

[0086] like Figure 6 As shown in the figure, it can be seen that the cells in Comparative Example 1 are mostly through-holes, the cell size is increased, and the flame retardant agglomerates; while the cell diameter and the dispersion of the filler in Example 3 are improved to a certain extent. This is because the small amount of silica produced by the pyrolysis of organic sesquisiloxane can improve the dispersion of the filler in the flame retardant and help the foam nucleation, thereby reducing the cell size and improving the flame retardant efficiency of the foam.

[0087] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0088] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0089] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A microcapsule flame retardant material for mining, characterized in that: The mining microcapsule flame retardant material takes a polyurethane foam mixture as a core, a synergistic flame retardant layer is coated on the outer surface of the polyurethane foam mixture, and a modified filling flame retardant layer is coated on the outer side of the synergistic flame retardant layer to form a dense three-layer core-shell structure, wherein the synergistic flame retardant layer is modified short chopped glass fiber, and the modified filling flame retardant layer is modified graphene oxide, and the weight proportions of the three are: 70 to 80 parts of the polyurethane foam mixture, 3 to 12 parts of the synergistic flame retardant layer, and 10 to 20 parts of the modified filling flame retardant layer; The polyurethane foam mixture is formed by mixing soft polyurethane foam, hard polyurethane foam and organic silsesquioxane, and the mass ratio thereof is 6: (0.8-1): (0.2-4); The preparation method of the modified graphene oxide is: S1. Add deionized water to graphene oxide and stir evenly; S2, pour in NaOH solution, adjust the pH of the mixed solution in S1 to 10-11, and perform ultrasonic dispersion; S3, add ZnSO4, continue stirring, and react at 55-60°C for 30-40 minutes; S4, centrifuging, washing, and drying to obtain modified graphene oxide; The modification method of the modified short chopped glass fiber is as follows: placing the short chopped glass fiber in a 90% ethanol solution, stirring, then washing with deionized water and filtering, and finally placing in a drying oven to dry, thereby obtaining the modified short chopped glass fiber; The modified chopped glass fibers are stirred at a temperature of 50 to 55° C. for 7 to 9 hours; the drying oven has a temperature of 110 to 120° C. for 6 to 8 hours.

2. The microcapsule flame retardant material for mining according to claim 1, characterized in that: In S3, NaOH solution is continuously added dropwise during the reaction.

3. A process for producing a microcapsule flame retardant material for mining according to claim 1, characterized in that: The following steps are involved: Step 1: Weigh each raw material according to the ratio and set aside; Step 2, dispersing the modified chopped glass fibers into deionized water and subjecting them to ultrasonic treatment; Step 3: immerse the polyurethane foam mixture into the solution of step 2, let it stand for 4 to 6 hours, coat the outer surface of the polyurethane foam with a synergistic flame retardant layer, and then take it out and dry it; Step 4, dispersing the modified graphene oxide in deionized water and subjecting it to ultrasonic treatment; Step 5, immersing the mixture of step 3 into the mixed solution of step 4, and coating the outer layer with a modified filling flame retardant layer; Step 6: Dry and mix the mixture in step 5 to obtain the microcapsule flame retardant material for mining.

4. The process for producing a microcapsule flame retardant material for mining according to claim 3 is characterized in that: The ultrasonic time in step 2 and step 4 is 5 to 8 minutes.

Images