Preparation method of environment-friendly cold-resistant high-temperature-resistant polyurethane conveying belt material

Abstract

The invention belongs to the technical field of polyurethane conveying belts, and particularly relates to a preparation method of an environment-friendly cold-resistant high-temperature-resistant polyurethane conveying belt material, which comprises the following steps: carrying out liquid-phase treatment on silica to realize silica modification so as to obtain silica modified silica, mixing a polyurethane prepolymer, polyethylene glycol, silica modified silica, hydroxyl silicone oil, a curing agent and a curing accelerator according to a ratio, and carrying out extrusion molding to obtain the environment-friendly cold-resistant high-temperature-resistant polyurethane conveying belt material. And uniformly stirring to obtain prefabricated polyurethane, and defoaming the prefabricated polyurethane to obtain the polyurethane. The problem that existing polyurethane resin is poor in temperature resistance is solved, the temperature resistance and cohesiveness of polyurethane are improved through doping and blending of the silica, meanwhile, silica on the surface of the silica is modified to form silicon hydroxyl, the silicon hydroxyl and a polyurethane prepolymer form a stable chemical connection effect, and therefore the cold resistance and the high temperature resistance of the polyurethane conveying belt are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane conveyor belts, and in particular relates to a method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material. Background Art

[0002] Polyurethane conveyor belts, also known as environmentally friendly polyurethane conveyor belts, use high-strength synthetic polyurethane fabric as the load-bearing skeleton and polyurethane resin as the coating layer. The polyurethane conveyor belt has extremely high wear resistance and can operate stably for a long time at high speeds, heavy loads and harsh environments. In addition, it has good corrosion resistance and can resist the erosion of common chemicals such as acids, alkalis, and oils, thereby extending its service life. However, the polyurethane resin on the polyurethane conveyor belt itself has poor high temperature resistance and can only be used normally within 80°C and cannot withstand higher temperatures. Therefore, the market urgently needs a polyurethane resin that is both cold-resistant and high-temperature resistant. Summary of the invention

[0003] In view of the problems in the prior art, the present invention provides a method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material, which solves the problem of poor temperature resistance of existing polyurethane resins. The temperature resistance and adhesion of polyurethane are improved by doping and blending with silica. At the same time, the silicon oxide on the surface of silica is modified to form silicon hydroxyl groups, which form a stable chemical connection with the polyurethane prepolymer, thereby ensuring the cold resistance and high temperature resistance of the polyurethane conveyor belt.

[0004] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0005] A method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material comprises the following steps:

[0006] Step 1, putting silica into ether for ultrasonic dispersion for 20-30 minutes, then adding trichloromethylsilane to reduce pressure and concentrate, filtering and drying to obtain coated silica, wherein the silica uses silica powder, the mass ratio of silica to ether is 1:10-15, the ultrasonic temperature of ultrasonic dispersion is 15-20°C, the ultrasonic frequency is 70-90kHz, the mass ratio of trichloromethylsilane to ether is 1:4-7, the pressure of the reduced pressure concentration is 80-90% of the atmospheric pressure, the temperature is 30-35°C, and the volume ratio of the solution before and after compression is 10 :1-3, the drying temperature is 40-45°C; this step uses ether to disperse the silica powder, and uses ultrasonic high-frequency vibration to homogenize the silica; trichloromethylsilane has good ether solubility and can be quickly dispersed in ether. The good adsorption of silica itself can adsorb trichloromethylsilane in the solution to the surface of silica, and form a silica surface film after filtration. Therefore, the ether is removed during the drying process, thereby forming a trichloromethylsilane film on the surface of the silica, and the trichloromethylsilane itself has good liquid fluidity and can form a homogeneous package;

[0007] Step 2, placing the coated silica at rest for 2-4 hours and sintering for 1-2 hours to obtain silicon-oxygen modified silica, wherein the atmosphere of the rest is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10-12:1, and the rest temperature is 20-30°C; the sintering temperature is 160-190°C; in this step, the coated silica is placed in an atmosphere containing water vapor, and the silica at this time exhibits excellent hygroscopicity, absorbing water vapor in the air and cooperating with trichloromethylsilane on the surface of the silica, so that the trichloromethylsilane is in-situ hydrolyzed to form trihydroxymethylsilane, and in the subsequent sintering process, the trihydroxymethylsilane is in-situ polycondensed to form a silicon-oxygen structure, and the silicon-oxygen structure is wrapped on the surface of the silica;

[0008] Step 3, mixing a polyurethane prepolymer, polyethylene glycol, siloxane-modified silica, hydroxy silicone oil, a curing agent, and a curing accelerator in proportion, and stirring evenly to obtain a prefabricated polyurethane, and then degassing the prefabricated polyurethane to obtain a polyurethane; the mass ratio of the prefabricated polyurethane is: 100 parts of polyurethane prepolymer, 3-8 parts of polyethylene glycol, 10-20 parts of siloxane-modified silica, 3-8 parts of hydroxy silicone oil, 2-3 parts of curing agent, and 1-2 parts of curing accelerator, the curing agent is a trimer polyurethane curing agent, and the curing accelerator is an organic amine curing accelerator WL-710; the stirring speed for the uniform stirring is 100-300r / min, the vacuum degree of the degassing treatment is -0.08 to -0.1MPa, and the temperature is 20-30°C.

[0009] It can be seen from the above description that the present invention has the following advantages:

[0010] 1. The present invention solves the problem of poor temperature resistance of existing polyurethane resins by utilizing silica doping and blending to improve the temperature resistance and adhesion of polyurethane. At the same time, the silicon oxide on the surface of silica is modified to form silanol groups, which form a stable chemical connection with the polyurethane prepolymer, thereby ensuring the cold resistance and high temperature resistance of the polyurethane conveyor belt.

[0011] 2. The present invention adopts a silicon-oxygen modification method to form a silicon-oxygen thin film structure on the surface of silica. The thin film structure not only plays a hydrophobic isolation role, solving the hygroscopicity of silica itself, but also the silicon-oxygen thin film is rich in silanol groups, achieving uniform activity on the surface of silica and forming a uniform and stable chemical connection with the polyurethane prepolymer.

[0012] 3. The present invention utilizes the active groups of polyethylene glycol to form a cross-linked structure on the polyurethane prepolymer, thereby enhancing the reaction between the silicon-oxygen modified silica and the polyurethane prepolymer and achieving the thermal stability of the polyurethane.

[0013] 4. The present invention utilizes hydroxy silicone oil to improve the water resistance of polyurethane and minimize the hydrophilicity brought by polyethylene glycol. At the same time, hydroxy silicone oil can improve the wear resistance and thermal stability to meet the requirements of different environments of polyurethane conveyor belts. DETAILED DESCRIPTION

[0014] The present invention is described in detail with reference to the embodiments, but no limitation is imposed on the claims of the present invention.

[0015] Example 1

[0016] A method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material comprises the following steps:

[0017] Step 1, putting silica into ether for ultrasonic dispersion for 20 minutes, then adding trichloromethylsilane to concentrate under reduced pressure, filtering and drying to obtain coated silica, wherein the silica uses silica powder, the mass ratio of silica to ether is 1:10, the ultrasonic temperature of ultrasonic dispersion is 15°C, the ultrasonic frequency is 70kHz, the mass ratio of trichloromethylsilane to ether is 1:4, the pressure of the reduced pressure concentration is 80% of the atmospheric pressure, the temperature is 30°C, the volume ratio of the solution before and after compression is 10:1, and the drying temperature is 40°C;

[0018] Step 2, leaving the coated silica to stand for 2 hours and sintering for 1 hour to obtain silicon-oxygen modified silica, wherein the standing atmosphere is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10:1, and the standing temperature is 20° C.; the sintering temperature is 160° C.;

[0019] Step 3, the polyurethane prepolymer, polyethylene glycol, siloxane-modified silica, hydroxy silicone oil, curing agent, curing accelerator are mixed in proportion, and stirred evenly to obtain prefabricated polyurethane, and then the prefabricated polyurethane is degassed to obtain polyurethane; the mass ratio of the prefabricated polyurethane is: 100 parts of polyurethane prepolymer, 3 parts of polyethylene glycol, 10 parts of siloxane-modified silica, 3 parts of hydroxy silicone oil, 2 parts of curing agent, and 1 part of curing accelerator, the polyurethane prepolymer is purchased from Hubei Xinghengye Technology Co., Ltd., the polyethylene glycol is purchased from PEG800 of Shandong Baihua Chemical Co., Ltd., and the hydroxy silicone oil is purchased from Shandong Ruderui New Materials Co., Ltd.; the curing agent adopts a trimer polyurethane curing agent, HT100 is selected, and the curing accelerator adopts an organic amine curing accelerator WL-710, which is purchased from Hangzhou Lin'an Weilan Auxiliary Agent Co., Ltd.; the stirring speed for the uniform stirring is 100r / min, the vacuum degree of the degassing treatment is -0.08MPa, and the temperature is 20°C.

[0020] Example 2

[0021] A method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material comprises the following steps:

[0022] Step 1, putting silica into ether for ultrasonic dispersion for 30 minutes, then adding trichloromethylsilane to concentrate under reduced pressure, filtering and drying to obtain coated silica, wherein the silica uses silica powder, the mass ratio of silica to ether is 1:15, the ultrasonic temperature of ultrasonic dispersion is 20°C, the ultrasonic frequency is 90kHz, the mass ratio of trichloromethylsilane to ether is 1:7, the pressure of the reduced pressure concentration is 90% of the atmospheric pressure, the temperature is 35°C, the volume ratio of the solution before and after compression is 10:3, and the drying temperature is 45°C;

[0023] Step 2, leaving the coated silica to stand for 4 hours and sintering for 2 hours to obtain silicon-oxygen modified silica, wherein the standing atmosphere is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 12:1, and the standing temperature is 30° C.; the sintering temperature is 190° C.;

[0024] Step 3, the polyurethane prepolymer, polyethylene glycol, siloxane-modified silica, hydroxy silicone oil, curing agent, curing accelerator are mixed in proportion, and stirred evenly to obtain prefabricated polyurethane, and then the prefabricated polyurethane is degassed to obtain polyurethane; the mass ratio of the prefabricated polyurethane is: 100 parts of polyurethane prepolymer, 8 parts of polyethylene glycol, 20 parts of siloxane-modified silica, 8 parts of hydroxy silicone oil, 3 parts of curing agent, and 2 parts of curing accelerator, the polyurethane prepolymer is purchased from Hubei Xinghengye Technology Co., Ltd., the polyethylene glycol is purchased from PEG800 of Shandong Baihua Chemical Co., Ltd., and the hydroxy silicone oil is purchased from Shandong Ruderui New Materials Co., Ltd.; the curing agent adopts a trimer polyurethane curing agent, HT100 is selected, and the curing accelerator adopts an organic amine curing accelerator WL-710, which is purchased from Hangzhou Lin'an Weilan Auxiliary Agent Co., Ltd.; the stirring speed for the uniform stirring is 300r / min, the vacuum degree of the degassing treatment is -0.1MPa, and the temperature is 30°C.

[0025] Example 3

[0026] A method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material comprises the following steps:

[0027] Step 1, putting silica into ether for ultrasonic dispersion for 25 minutes, then adding trichloromethylsilane to concentrate under reduced pressure, filtering and drying to obtain coated silica, wherein the silica uses silica powder, the mass ratio of silica to ether is 1:13, the ultrasonic temperature of ultrasonic dispersion is 18°C, the ultrasonic frequency is 80kHz, the mass ratio of trichloromethylsilane to ether is 1:6, the pressure of the reduced pressure concentration is 85% of the atmospheric pressure, the temperature is 33°C, the volume ratio of the solution before and after compression is 5:1, and the drying temperature is 43°C;

[0028] Step 2, allowing the coated silica to stand for 3 hours and sintering for 2 hours to obtain silicon-oxygen modified silica, wherein the atmosphere of the standing is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 11:1, and the standing temperature is 25° C.; the sintering temperature is 170° C.;

[0029] Step 3, the polyurethane prepolymer, polyethylene glycol, siloxane-modified silica, hydroxy silicone oil, curing agent, curing accelerator are mixed in proportion, and stirred evenly to obtain prefabricated polyurethane, and then the prefabricated polyurethane is degassed to obtain polyurethane; the mass ratio of the prefabricated polyurethane is: 100 parts of polyurethane prepolymer, 5 parts of polyethylene glycol, 15 parts of siloxane-modified silica, 7 parts of hydroxy silicone oil, 3 parts of curing agent, and 2 parts of curing accelerator, the polyurethane prepolymer is purchased from Hubei Xinghengye Technology Co., Ltd., the polyethylene glycol is purchased from PEG800 of Shandong Baihua Chemical Co., Ltd., and the hydroxy silicone oil is purchased from Shandong Ruderui New Materials Co., Ltd.; the curing agent adopts a trimer polyurethane curing agent, HT100 is selected, and the curing accelerator adopts an organic amine curing accelerator WL-710, which is purchased from Hangzhou Lin'an Weilan Auxiliary Agent Co., Ltd.; the stirring speed for the uniform stirring is 200r / min, the vacuum degree of the degassing treatment is -0.09MPa, and the temperature is 25°C.

[0030] Comparative Example 1

[0031] A method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material comprises the following steps:

[0032] The polyurethane prepolymer, polyethylene glycol, silica powder, hydroxy silicone oil, curing agent and curing accelerator are mixed in proportion and stirred evenly to obtain a prefabricated polyurethane, and then the prefabricated polyurethane is degassed to obtain a polyurethane; the mass ratio of the prefabricated polyurethane is: 100 parts of polyurethane prepolymer, 5 parts of polyethylene glycol, 15 parts of silica powder, 7 parts of hydroxy silicone oil, 3 parts of curing agent and 2 parts of curing accelerator; the polyurethane prepolymer is purchased from Hubei Xinghengye Technology Co., Ltd., the polyethylene glycol is purchased from PEG800 of Shandong Baihua Chemical Co., Ltd., and the hydroxy silicone oil is purchased from Shandong Ruderui New Materials Co., Ltd.; the curing agent adopts a trimer polyurethane curing agent, HT100, and the curing accelerator adopts an organic amine curing accelerator WL-710, which is purchased from Hangzhou Lin'an Weilan Additive Co., Ltd.; the stirring speed for the uniform stirring is 200r / min, the vacuum degree of the degassing treatment is -0.09MPa, and the temperature is 25°C.

[0033] Performance Testing

[0034] The products of Examples 1-3 and the product of Comparative Example 1 were used as test samples to perform performance tests, and the results are as follows:

[0035] Table 1 Performance test results of polyurethane materials

[0036]

[0037]

[0038] The damage rate is the amount of wear after the material has been used as a conveyor belt surface layer (0.4 mm thick) for one year.

[0039] From the comparison of the above-mentioned Examples 1-3 and Comparative Example 1, it can be seen that the silicon-oxygen modified silica provided by the present technical solution can effectively improve the connection stability of silica in the polyurethane material, and improve the heat resistance and cold resistance through the stable connection of surface groups. At the same time, the modification of silica powder realizes the connection stability of silica powder, improves the curing effect of silica powder, effectively reduces the wear damage rate, and improves the hardness and mechanical strength.

[0040] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for preparing an environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material, characterized in that: The steps include: Step 1, placing silica in ether and ultrasonically dispersing for 20-30 minutes, then adding trichloromethylsilane and concentrating under reduced pressure, filtering and drying to obtain coated silica; Step 2, allowing the coated silica to stand for 2-4 hours and sintering for 1-2 hours to obtain silicon-oxygen modified silica; Step 3, the polyurethane prepolymer, polyethylene glycol, silicone-modified silica, hydroxy silicone oil, curing agent, and curing accelerator are mixed in proportion, and stirred evenly to obtain prefabricated polyurethane, and then the prefabricated polyurethane is degassed to obtain polyurethane.

2. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The mass ratio of silica to ether in step 1 is 1:10-15, the ultrasonic temperature of ultrasonic dispersion is 15-20° C., the ultrasonic frequency is 70-90 kHz, and the silica is silica powder.

3. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The mass ratio of trichloromethylsilane to diethyl ether in step 1 is 1:4-7, the pressure of the reduced pressure concentration is 80-90% of the atmospheric pressure, the temperature is 30-35° C., and the volume ratio of the solution before and after compression is 10:1-3.

4. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The drying temperature in step 1 is 40-45°C.

5. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The static atmosphere in step 2 is a mixed atmosphere of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 10-12:1, and the static temperature is 20-30°C.

6. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The sintering temperature in step 2 is 160-190°C.

7. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The mass ratio of the prefabricated polyurethane in step 3 is: 100 parts of polyurethane prepolymer, 3-8 parts of polyethylene glycol, 10-20 parts of silicone-modified silica, 3-8 parts of hydroxy silicone oil, 2-3 parts of curing agent, and 1-2 parts of curing accelerator.

8. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 7, characterized in that: The curing agent is a trimer polyurethane curing agent, and the curing accelerator is an organic amine curing accelerator WL-710.

9. The method for preparing the environmentally friendly cold-resistant and high-temperature-resistant polyurethane conveyor belt material according to claim 1, characterized in that: The stirring speed for uniform stirring in step 3 is 100-300 r / min, the vacuum degree of the degassing treatment is -0.08 to -0.1 MPa, and the temperature is 20-30°C.

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