A low-temperature safe polyurethane modified grouting material for coal rock reinforcement and preparation method thereof

Abstract

The present invention belongs to the field of polyurethane materials, and specifically relates to a low-temperature safe polyurethane modified grouting material for coal rock reinforcement and a preparation method thereof. It comprises component A and component B, wherein component A comprises the following raw materials by weight: 15-25 parts of filler; 70-95 parts of liquid sodium silicate; 1-5 parts of glycerol; 0.5-5 parts of catalyst; wherein the materials used for preparing the filler are: n-docosane, silicon-based macroporous material, polycarbonate polyol, water, anti-settling agent, and concentrated sulfuric acid. Component B comprises the following raw materials by weight: 100 parts of isocyanate prepolymer. The present invention solves the safety hazards of high reaction temperature during the curing process of the existing polyurethane modified grouting material, and large-scale use may cause core burning, spontaneous combustion, and the like.

Description

Technical Field

[0001] The invention belongs to the field of polyurethane materials, and in particular relates to a low-temperature safe polyurethane modified grouting material for coal rock reinforcement and a preparation method thereof. Background Art

[0002] During the excavation process of coal mine tunnels, broken or loose coal and rock masses often lead to coal mine accidents such as roof collapse and rock spalling, which not only seriously endanger the lives of miners, but also seriously affect the production efficiency of coal mining enterprises. Therefore, in the production process of coal mines, grouting reinforcement is generally performed on the broken coal and rock masses.

[0003] There are many types of grouting materials. Among them, polyurethane grouting materials have become the best choice for mine reinforcement due to their moderate viscosity, adjustable setting time, fast reaction speed, good mechanical properties, convenient construction methods and many other advantages. They have been widely used in the field of coal mine reinforcement.

[0004] The maximum reaction temperature of the commonly used ordinary polyurethane grouting materials is very high. When a large amount of grouting is used, a heat accumulation effect will occur. Large-scale use may cause heartburn, spontaneous combustion and other phenomena, posing a safety hazard.

[0005] Therefore, it is urgent to design a low-temperature safe polyurethane modified grouting material for coal rock reinforcement that can solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the above-mentioned prior art and provide a polyurethane modified grouting material suitable for use in the field of coal rock reinforcement, which solves the safety hazards of high reaction temperature during the curing process of the existing polyurethane modified grouting material and the possibility of core burning and spontaneous combustion when used in large quantities.

[0007] One of the purposes of the present invention is to provide a low-temperature safe polyurethane modified grouting material for coal rock reinforcement, comprising component A and component B, the special features of which are:

[0008] The A component comprises the following raw materials in parts by weight:

[0009] 15-25 parts of filler;

[0010] Liquid sodium silicate 70-95 parts;

[0011] 1-5 parts of glycerol;

[0012] Catalyst 0.5-5 parts;

[0013] The materials used to prepare the filler are: n-docosane, silicon-based macroporous material, polycarbonate polyol, water, anti-settling agent, and concentrated sulfuric acid, and the weight ratio of the above materials is: (35-38): (10-12): (15-17): (45-48): (0.5-1.5): (0.5-1.5).

[0014] The B component comprises the following raw materials in parts by weight:

[0015] Isocyanate prepolymer 100 parts.

[0016] The liquid sodium silicate in the A component is an aqueous solution of sodium silicate, with a Baume degree of 40.4-41.6 and a modulus of 3.2-3.3; the catalyst is tris(dimethylaminopropyl)hexahydrotriazine;

[0017] The liquid sodium silicate adopts SSL3241 produced by Qingdao Haiwan Chemical Co., Ltd.; the glycerol adopts industrial-grade glycerol produced by Jinan Guoshi Weiye Chemical Co., Ltd.; the catalyst adopts tris(dimethylaminopropyl)hexahydrotriazine produced by Evonik Specialty Chemicals (Shanghai) Co., Ltd.;

[0018] The B component is: an isocyanate prepolymer prepared by polymerization of polytetramethylene ether glycol and diphenylmethane diisocyanate under the condition of dibutyl phthalate as solvent, and the NCO content thereof is 21%-25%;

[0019] The diphenylmethane diisocyanate is obtained from Wanhua Chemical Group Co., Ltd. MDI-100; the polytetramethylene ether glycol adopts 3000 molecular weight polytetramethylene ether glycol produced by BASF; the dibutyl phthalate adopts dibutyl phthalate produced by Yu Rui (Shanghai) Chemical Co., Ltd.

[0020] The second object of the present invention is to provide a method for preparing a low-temperature safe polyurethane modified grouting material for coal rock reinforcement, which is special in that it comprises the following steps:

[0021] 1) Preparation of filler

[0022] Add n-docosane into the reaction kettle and gradually raise the temperature to 150°C. After the n-docosane is fully melted, gradually add the silicon-based macroporous material according to proportion and stir thoroughly for 1 hour.

[0023] Add 100°C high-temperature liquefied polycarbonate polyol, mix thoroughly, then drop concentrated sulfuric acid as a catalyst, gradually raise the temperature to 150°C, and react for 1 hour under stirring;

[0024] Cool down to 60℃, add 40℃ water, stir and disperse, then let stand, separate into layers, filter, and take the solid-liquid mixed turbid liquid at the bottom layer;

[0025] Use sodium hydroxide solution to neutralize the turbid liquid, then add anti-settling agent, fully disperse to obtain filler, and package for later use;

[0026] 2) Preparation of component A

[0027] First, glycerol and catalyst are fully mixed to form mixture A, which is packaged for later use. Liquid sodium silicate is added to a clean reactor, and then mixture A is gradually added under stirring conditions, and the mixture is fully stirred and mixed. Then fillers are gradually added, and the mixture is fully mixed to form component A, which is packaged for later use;

[0028] 3) Mixed reaction of components A and B

[0029] Add component A and component B into a cup at a mass ratio of (38-40):30, stir with an electric stirrer (3000 rpm) for about 10 seconds, and react to form a polymer grouting material after mixing evenly.

[0030] The weight ratio of n-docosane, silicon-based macroporous material, polycarbonate polyol, water, anti-settling agent and concentrated sulfuric acid is: (35-38): (10-12): (15-17): (45-48): (0.5-1.5): (0.5-1.5).

[0031] The pore size of the silicon-based macroporous material is 60nm-1μm;

[0032] The silicon-based macroporous material is GJ-WSY from Shanghai Jiuzhou Chemical Co., Ltd.; the polycarbonate polyol is UH-300 from Ube Industries, Ltd., with a melting point of 52±3°C; the n-docosane is n-docosane from Tianmen Hengchang Chemical Co., Ltd. (melting point is 43-46°C); the water is purified water; and the anti-settling agent is BYK-410 from Germany's BYK.

[0033] The invention introduces a special filler into the formula system. The special filler is a special solid-liquid mixed filler with heat absorption function formed by the mixed reaction of silicon-based macroporous material, polycarbonate polyol, n-docosane and catalyst. The silicon-based macroporous material has dense pores, and the pore size is between 60nm and 1μm, which can allow high molecular compound molecules to enter. At a high temperature of 150°C, n-docosane melts and fully reacts with the silicon-based macroporous material, and n-docosane fully fills the internal pores of the silicon-based macroporous material; then the heated and melted polycarbonate polyol is added to the reactor. Since the silicon-based macroporous material has a silicon dioxide content of more than 40%, its surface contains rich silanol groups. At a high temperature of 150°C and the action of the catalyst, the hydroxyl groups in the polycarbonate polyol and the silanol groups undergo condensation and dehydration reactions to generate ether bonds, and the silicon-based macroporous material and the polycarbonate polyol form a stable chemical bond connection (see 1 for the chemical reaction equation), and the polycarbonate polyol polymer chain segments will tightly wrap the particles. After the temperature is lowered to 60°C, water (40°C) is added for stirring and dispersion. Due to the attraction and restraint of the pores in the silicon-based macroporous material on the n-docosane molecules and the wrapping of the polycarbonate polyol molecular chain segments on the outer wall, n-docosane will not overflow from the pores. According to the different effects of the modified silicon-based macroporous material, high molecular weight polycarbonate polyol, n-docosane and water, after dispersion and standing, an upper layer of polycarbonate polyol and n-docosane solidification layer and a lower layer of solid-liquid mixed turbid liquid are formed. Finally, the lower layer of solid-liquid mixed turbid liquid is separated and neutralized, and an anti-settling agent is added to obtain a special solid-liquid mixed filler.

[0034] The introduction of special fillers into the formula has three beneficial effects. First, in the process of forming the polyurethane modified grouting material (after the A component and the B component are mixed in a volume ratio of 1:1 (mass ratio of 39:30), an exothermic reaction will occur to form a composite polymer material. As the temperature rises, the polycarbonate polyol and n-docosane in the special filler will change from solid phase to liquid phase. This process can absorb a large amount of heat, greatly reducing the maximum reaction temperature of the material, thereby ensuring the low heat release of the material during the application process and eliminating the problem of spontaneous combustion caused by heat storage inside the material. Second, when the polycarbonate polyol changes from solid to liquid, the small amount of hydroxyl groups it carries can react with the isocyanate groups in the system to form a carbamate segment with large cohesive energy, which eliminates the problem of the mechanical properties of the material being reduced due to solid fillers, and improves the mechanical properties of the material to a certain extent; third, due to the encapsulation of the silicon-based macroporous material particles by the polycarbonate polyol segment, it has good compatibility with the silicate aqueous solution system, can be stably dispersed in the system, and has excellent storage stability.

[0035] In addition, component A uses silicate aqueous solution to replace the polyether polyol in traditional polyurethane materials, eliminating the gel reaction, the main exothermic reaction, from the reaction mechanism, and reducing the maximum reaction temperature of the material. In component B, high-toughness polyether polyol is used to modify the isocyanate, release the reaction heat in advance, and reduce the NCO content of the isocyanate. More importantly, the isocyanate modified with high-toughness polyether polyol can give the material excellent toughness, eliminating the problem of brittleness of silicate-modified polyurethane materials.

[0036] The preparation method of this material is simple and easy, has low requirements for production equipment and personnel, has a short production cycle, does not produce three wastes in the whole process, and does not affect the environment and workers' health. This invention gives the polyurethane modified grouting material for coal rock reinforcement a lower reaction temperature, which is a milestone in the safety assurance of the coal mine reinforcement industry.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a state diagram of the solid-liquid mixed special filler in Example 1 of the present invention;

[0039] Figure 2 This is a diagram showing the toughness test of the polyurethane modified grouting material of Sample 3 in Example 4. DETAILED DESCRIPTION

[0040] 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.

[0041] Example 1

[0042] Preparation of special fillers:

[0043] 360g of n-docosane was added to the reaction kettle, and the temperature was gradually raised to 150°C. After the n-docosane was fully melted, 110g of silicon-based macroporous material (GJ-WSY of Shanghai Jiuzhou Chemical Co., Ltd.) was gradually added in 5 times within 30min, and fully stirred for 1 hour; then, 160g of high-temperature liquefied (100°C) polycarbonate polyol (HT-300 of Ube Industries, Ltd. (melting point 52±3°C)) was added, and after fully mixing, 1.2g of catalyst concentrated sulfuric acid (mass fraction 98%) was added dropwise, and the temperature was gradually raised to 150°C, and fully reacted for 1 hour under stirring conditions. The temperature was lowered to 60°C, 470g of water (40°C) was added, and the mixture was stirred and dispersed, and then allowed to stand for stratification, filtered, and the bottom solid-liquid mixed turbid liquid was taken. Use a certain amount of sodium hydroxide solution (40% by mass) to neutralize the turbid liquid to pH 7-8, then add anti-settling agent (BYK-410 from Germany), fully disperse to obtain special filler, and package for later use. See attached for the finished product of special filler Figure 1 .

[0044] Example 2

[0045] Preparation of isocyanate prepolymer of this embodiment:

[0046] 270 g of BASF's 3000 molecular weight polytetramethylene ether glycol and 500 g of dibutyl phthalate (Yu Rui (Shanghai) Chemical Co., Ltd.) were added to the reactor, and vacuum-dried for 2 hours at 110 ° C., then cooled to 80 ° C., and 2000 g of diphenylmethane diisocyanate (Wanhua Chemical Group Co., Ltd.) was added. MDI-100), react for 2 hours to generate isocyanate prepolymer, which is packaged under nitrogen atmosphere for later use. The NCO content of the isocyanate prepolymer is 21-25%. The room temperature viscosity is 600-800 mpas.

[0047] Example 3

[0048] The low-temperature safe polyurethane modified grouting material for coal rock reinforcement of this embodiment has raw materials divided into component A and component B, and the mixing mass ratio of component A to component B is 39:30. The specific formula includes:

[0049] B component, 100 parts of the isocyanate prepolymer of Example 2.

[0050] Component A, in parts by weight, specific data see Table 2:

[0051] The component A, in parts by weight, comprises:

[0052] Table 2A Component formula data list

[0053]

[0054]

[0055] Table 3 Comparison of performance parameters of examples

[0056]

[0057] From the above table, it can be concluded that, compared with sample 1 and sample 2, sample 1 is added with 15 parts of special filler, and sample 2 is added with 15 parts of calcium carbonate (1250 mesh), which is the most widely used general filler. From the data comparison in Table 3, it can be seen that the maximum reaction temperature of sample 1 is 86°C, which is 16°C lower than that of sample 2, which can explain that the special filler has a significant effect of reducing the maximum reaction temperature. In addition, the compressive strength of sample 1 is 63MPa, and the compressive strength of sample 2 is 43MPa. Sample 1 is much better than sample 2 in mechanical properties. It can be concluded that the special filler forms a stable ether bond due to the reaction of polycarbonate polyol and silicon-based macroporous material with silanol. Later, in the process of polymer formation, the hydroxyl group it carries reacts chemically with the isocyanate group of the system to form a high cohesive energy urethane group, which can give the material excellent mechanical properties. Finally, sample 1 has better toughness (maximum compressive strength deformation is 52%) and excellent storage stability than sample 2.

[0058] Example 4

[0059] A low-temperature safe polyurethane modified grouting material for coal rock reinforcement, the raw materials are divided into component A and component B, the mixing mass ratio of component A to component B is 39:30, and the specific formula is as follows:

[0060] Table 4 Recipe List

[0061]

[0062] Note: 8313, produced by Wanhua Chemical Group Co., Ltd., is a widely used type of isocyanate prepolymer. It is an isocyanate prepolymer polymerized using polyether polyol DL2000 and MDI. The prepolymer has an NCO content of 22-25% and a room temperature viscosity of 550-800mpas.

[0063] Table 5 Comparison of performance parameters of examples

[0064]

[0065] From the above table, it can be concluded that the isocyanate prepolymer of Example 2 used in Sample 3 has a maximum reaction temperature of 86°C, a compressive strength of 63 MPa, and a maximum compressive strength deformation of 52%. 8313, the highest reaction temperature is 88℃, the compressive strength is 50MPa, and the maximum compressive strength deformation is 40%. It can be seen that the highest reaction temperature of sample 3 is slightly lower than that of sample 4, but the compressive strength of sample 3 is better, especially the toughness is excellent, and the maximum compressive strength deformation can reach 52%, which has changed the problem of the brittleness of silicate polyurethane modified materials. The sample can be folded 180° without breaking (see the attached Figure 2 ).

[0066] 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 low-temperature safe polyurethane modified grouting material for coal rock reinforcement, comprising component A and component B, characterized in that: The A component comprises the following raw materials in parts by weight: 15-25 parts of filler; Liquid sodium silicate 70-95 parts; 1-5 parts of glycerol; Catalyst 0.5-5 parts; The materials used to prepare the filler are: n-docosane, silicon-based macroporous material, polycarbonate polyol, water, anti-settling agent, concentrated sulfuric acid, and the weight ratio of the above materials is: (35-38): (10-12)：(15-17)：(45-48):(0.5-1.5):(0.5-1.5)； The B component comprises the following raw materials in parts by weight: Isocyanate prepolymer 100 parts; The pore size of the silicon-based macroporous material is 60nm-1μm; The silicon-based macroporous material is GJ-WSY from Shanghai Jiuzhou Chemical Co., Ltd.; the polycarbonate polyol is UH-300 from Ube Industries, Ltd., with a melting point of 52±3°C; the n-docosane is n-docosane from Tianmen Hengchang Chemical Co., Ltd., with a melting point of 43-46°C; the water is purified water; the anti-settling agent is BYK-410 from Germany BYK; The preparation method of the low-temperature safe polyurethane modified grouting material for coal rock reinforcement comprises the following steps: 1) Preparation of filler Add n-docosane into the reaction kettle and gradually raise the temperature to 150°C. After the n-docosane is fully melted, gradually add the silicon-based macroporous material according to proportion and stir thoroughly for 1 hour. Add 100°C high-temperature liquefied polycarbonate polyol, mix thoroughly, then drop concentrated sulfuric acid as a catalyst, gradually raise the temperature to 150°C, and react for 1 hour under stirring; Cool down to 60℃, add 40℃ water, stir and disperse, then let stand, separate into layers, filter, and take the solid-liquid mixed turbid liquid at the bottom layer; Use sodium hydroxide solution to neutralize the turbid liquid, then add anti-settling agent, fully disperse to obtain filler, and package for later use; 2) Preparation of component A First, glycerol and catalyst are fully mixed to form mixture A, which is packaged for later use; liquid sodium silicate is added to a clean reactor, and then mixture A is gradually added under stirring conditions, and fully stirred and mixed; then fillers are gradually added, and fully mixed to form component A, which is packaged for later use; 3) Mixed reaction of components A and B Add component A and component B into a cup at a mass ratio of (38-40):30, and stir with an electric stirrer at 3000 rpm for about 10 seconds. After mixing evenly, react to generate a polymer grouting material.

2. A low-temperature safe polyurethane modified grouting material for coal rock reinforcement according to claim 1, characterized in that The liquid sodium silicate in the A component is an aqueous solution of sodium silicate, with a Baume degree of 40.4-41.6 and a modulus of 3.2-3.3; the catalyst is tris(dimethylaminopropyl)hexahydrotriazine.

3. A low-temperature safe polyurethane modified grouting material for coal rock reinforcement according to claim 1, characterized in that The liquid sodium silicate is SSL3241 produced by Qingdao Haiwan Chemical Co., Ltd.; the glycerol is industrial-grade glycerol produced by Jinan Guoshi Weiye Chemical Co., Ltd.; and the catalyst is tris(dimethylaminopropyl)hexahydrotriazine produced by Evonik Specialty Chemicals (Shanghai) Co., Ltd.

4. A low-temperature safe polyurethane modified grouting material for coal rock reinforcement according to claim 1, characterized in that The B component is an isocyanate prepolymer prepared by polymerizing polytetramethylene ether glycol and diphenylmethane diisocyanate under the condition of dibutyl phthalate as solvent, and the NCO content of the prepolymer is 21%-25%.

5. A low temperature safe polyurethane modified grouting material for coal rock reinforcement according to claim 4, characterized in that The diphenylmethane diisocyanate is obtained from Wanhua Chemical Group Co., Ltd. MDI-100; the polytetramethylene ether glycol adopts 3000 molecular weight polytetramethylene ether glycol produced by BASF; the dibutyl phthalate adopts dibutyl phthalate produced by Yu Rui (Shanghai) Chemical Co., Ltd.

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