Polyurethane material for extra-heavy caster and preparation method and product thereof

Abstract

The invention discloses a polyurethane material for an extra-heavy caster, and a preparation method and a product thereof, and relates to the field of polyurethane materials for casters. The polyurethane material is prepared from the following components in parts by weight: 100 parts of MDI-terminated polyurethane prepolymer, 15-20 parts of polytetrahydrofuran ether glycol, 15-20 parts of polycarbonate diol, 2-4 parts of micromolecular dihydric alcohol, 1-2 parts of trimethylolpropane, 0.1-0.2 part of 4, 4 '-methylene bis (3-chloro-2, 2, 4-trimethyl-1, 3-pentanediol), 0.1-0.2 part of an antioxidant, 0.1-0.2 part of a coupling agent and 0.1-0.2 part of a catalyst. The polyurethane material is prepared from the following components in parts by weight: 1 part of MDI (diphenylmethane diisocyanate), 4.5-5.5 parts of multi-walled carbon nanotubes, 0.1-0.2 part of nano diamond powder and 0.01-0.02 part of a catalyst, the MDI-terminated polyurethane prepolymer is prepared by reacting MDI and polypropylene glycol according to a molar ratio of (1.1-1.3): 1, the hardness range of the polyurethane material is 89A-95A, and the polyurethane material is good in loading wear resistance and low-temperature resistance and is particularly suitable for an extra-heavy trundle.

Description

Technical Field

[0001] The present application relates to the field of polyurethane materials for casters, and in particular to a polyurethane material for ultra-heavy-duty casters, its preparation method and products. Background Art

[0002] In modern industry and daily life, polyurethane materials are widely used in various fields due to their excellent properties, such as good abrasion resistance, elasticity, and chemical corrosion resistance. Among them, the tread material of caster wheels is one of its important application scenarios.

[0003] However, when traditional polyurethane materials are applied to ultra-heavy-duty casters (casters with a single load of more than 1500 kg), many problems are exposed. First, the load abrasion resistance of traditional polyurethane materials is insufficient. Ultra-heavy-duty casters need to carry huge weights for a long time and move frequently. Ordinary polyurethane materials wear quickly under such working conditions and need to be replaced frequently, increasing the use cost and maintenance difficulty. Second, in a low-temperature environment, traditional polyurethane materials are prone to cracking problems when the ultra-heavy-duty casters are operating continuously under load, which greatly limits their application in cold regions or low-temperature working scenarios. To solve the above problems, it is particularly important to develop a polyurethane material with a suitable hardness range, good load abrasion resistance, and excellent low-temperature cracking resistance. Summary of the Invention

[0004] In order to improve the problems of insufficient load abrasion resistance and low-temperature cracking resistance of existing polyurethane materials, the present application provides a polyurethane material for ultra-heavy-duty casters, its preparation method and products. The ultra-heavy-duty casters mentioned in the present application mainly refer to casters with a single load of more than 1500 kg.

[0005] In the first aspect, a polyurethane material provided by the present application adopts the following technical solution: A polyurethane material is prepared from 100 parts by weight of MDI-capped polyurethane prepolymer, 15 - 20 parts by weight of polytetrahydrofuran glycol, 15 - 20 parts by weight of polycarbonate diol, 2 - 4 parts by weight of small molecule diol, 1 - 2 parts by weight of trimethylolpropane, 0.1 - 0.2 parts by weight of 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 4.5 - 5.5 parts by weight of multi-walled carbon nanotubes, 0.1 - 0.2 parts by weight of nanodiamond powder, and 0.01 - 0.02 parts by weight of catalyst. Among them, the MDI-capped polyurethane prepolymer is prepared by reacting MDI with polypropylene glycol at a molar ratio of (1.1 - 1.3):1.

[0006] Through the synergistic cooperation of MDI-capped polyurethane prepolymer, polytetrahydrofuran glycol, polycarbonate diol, small molecule diol, trimethylolpropane, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), multi-walled carbon nanotubes and nanodiamond powder with specific ratios, a polyurethane material with a hardness range of 89A - 95A, good load-bearing wear resistance and good low-temperature cracking resistance can be obtained, and the load-bearing noise is low, which is especially suitable for ultra-heavy-duty casters.

[0007] In some specific embodiments, the multi-walled carbon nanotubes are modified multi-walled carbon nanotubes with an amino silane coupling agent, and the nanodiamond powder is modified nanodiamond powder with an amino silane coupling agent.

[0008] In this application, the multi-walled carbon nanotubes are preferably multi-walled carbon nanotubes modified with an amino silane coupling agent, and the nanodiamond powder is preferably nanodiamond powder modified with an amino silane coupling agent, which is beneficial to further improving the load-bearing wear resistance of the polyurethane material and can be applied to ultra-heavy-duty casters with a load not exceeding 3500 kg.

[0009] In some specific embodiments, the multi-walled carbon nanotubes are multi-walled carbon nanotubes modified with carboxymethyl chitosan, and the nanodiamond powder is diamond powder modified with carboxymethyl chitosan.

[0010] In this application, the multi-walled carbon nanotubes are further preferably multi-walled carbon nanotubes modified with carboxymethyl chitosan, and the nanodiamond powder is further preferably diamond powder modified with carboxymethyl chitosan. By the reaction of the hydroxyl groups on the carboxymethyl chitosan with the MDI-capped polyurethane prepolymer, the interfacial bonding strength between the carboxymethyl chitosan-modified multi-walled carbon nanotubes, the carboxymethyl chitosan-modified diamond powder and the organic polyurethane material can be effectively enhanced, which is beneficial to further improving the load-bearing wear resistance and low-temperature cracking resistance of the polyurethane material and can be applied to ultra-heavy-duty casters with a load not exceeding 5000 kg.

[0011] In some specific embodiments, the molecular weight of the polytetrahydrofuran glycol is 1500 - 2000.

[0012] In some specific embodiments, the molecular weight of the polycarbonate diol is 1500 - 2000.

[0013] In some specific embodiments, the molecular weight of the polypropylene glycol is 1000 - 2000.

[0014] In some specific embodiments, the small molecule diol is at least one of ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and diethylene glycol.

[0015] In some preferred embodiments, the small molecule diol is a composition of diethylene glycol and 1,4-butanediol with a weight ratio of (8-10):1.

[0016] In this application, the small molecule diol is preferably a composition of diethylene glycol and 1,4-butanediol with a weight ratio of (8-10):1. The polyurethane material is beneficial to balance the load-bearing wear resistance and load-bearing low-temperature crack resistance.

[0017] Second, a preparation method of a polyurethane material provided by this application adopts the following technical solution: A preparation method of a polyurethane material includes the following steps: S1. Dehydrate MDI and polypropylene glycol, then raise the temperature to 75-85°C and react for 3-4 hours to prepare an MDI-capped polyurethane prepolymer; S2. After dehydrating polytetrahydrofuran ether glycol, polycarbonate diol, multi-walled carbon nanotubes, and nano-diamond powder, add them to the MDI-capped polyurethane prepolymer, stir evenly, then add a catalyst, raise the temperature to 75-85°C and react for 4-5 hours. Then add small molecule diol, trimethylolpropane, and 4,4'-methylenebis(3-chloro-2,6-diethylaniline), continue to react at 75-85°C, and finally carry out vacuum degassing to obtain the polyurethane material.

[0018] In this application, adopting the above preparation method is beneficial to the uniform dispersion and full reaction of each raw material, and is beneficial to obtaining a polyurethane material with a hardness range of 89A-95A, good load-bearing wear resistance, low load-bearing noise, and good low-temperature crack resistance.

[0019] Third, a super heavy-duty caster provided by this application includes a tread material made of the polyurethane material described in any one of the above.

[0020] In summary, this application includes at least the following beneficial technical effects: (1) Through the synergistic cooperation of the MDI-capped polyurethane prepolymer, polytetrahydrofuran ether glycol, polycarbonate diol, small molecule diol, trimethylolpropane, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), multi-walled carbon nanotubes, and nano-diamond powder with specific ratios, this application can obtain a polyurethane material with a hardness range of 89A-95A, good load-bearing wear resistance, and good low-temperature crack resistance, and the load-bearing noise is low, which is especially suitable for super heavy-duty casters.

[0021] (2) In this application, the multi-walled carbon nanotubes are further preferably carboxymethyl chitosan-modified multi-walled carbon nanotubes, and the nanodiamond powder is further preferably carboxymethyl chitosan-modified diamond powder. By reacting the hydroxyl groups on carboxymethyl chitosan with the MDI-terminated polyurethane prepolymer, the interfacial bonding strength between the carboxymethyl chitosan-modified multi-walled carbon nanotubes, the carboxymethyl chitosan-modified diamond powder and the organic polyurethane material can be effectively enhanced, which is beneficial to further improving the load-bearing wear resistance and low-temperature cracking resistance of the polyurethane material, and can be applied to super-heavy casters with a load not exceeding 5000 kg. Description of the Drawings

[0022] Figure 1 is a flowchart of a preparation method of a polyurethane material of this application. Detailed Embodiments

[0023] The following further describes this application in combination with specific experiments. Examples

[0024]

Example 1

[0025] In this example, the preparation method of the polyurethane material includes the following steps: S1. Dehydrate MDI and polypropylene glycol, and then raise the temperature to 75 °C and react for 4 h to prepare the MDI-terminated polyurethane prepolymer; S2. After dehydrating the polytetrahydrofuran ether diol, polycarbonate diol, multi-walled carbon nanotubes and nanodiamond powder, add them to the MDI-terminated polyurethane prepolymer, stir evenly, then add dibutyltin dilaurate, raise the temperature to 75 °C and react for 5 h, then add propylene glycol, trimethylolpropane and 4,4'-methylenebis(3-chloro-2,6-diethylaniline), continue to react at 75 °C for 2 h, and finally perform vacuum degassing to obtain the polyurethane material.

[0026]

Example 2

[0027] In this example, the preparation method of the polyurethane material includes the following steps: S1. Dehydrate MDI and polypropylene glycol, then raise the temperature to 85°C and react for 3 h to prepare the MDI-capped polyurethane prepolymer; S2. After dehydrating the polytetrahydrofuran ether diol, polycarbonate diol, multi-walled carbon nanotubes, and nanodiamond powder, add them to the MDI-capped polyurethane prepolymer, stir evenly, then add dibutyltin dilaurate, raise the temperature to 85°C and react for 4 h. Then add diethylene glycol, 1,4-butanediol, trimethylolpropane, and 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and continue to react at 85°C for 1 h. Finally, perform vacuum degassing to obtain the polyurethane material.

[0028]

Example 3

Example 2

[0029] Among them, the preparation method of the amino silane coupling agent KH550-modified multi-walled carbon nanotubes used in this example is as follows: Add 6 kg of multi-walled carbon nanotubes (Zhongke Leiming, length 10 - 30 nm, diameter 20 - 30 nm, bulk density 0.22 g / cm 3 ) to 500 kg of a mixed solution obtained by mixing the silane coupling agent KH550 and a 1+1 ethanol solution in a weight ratio of 1:10. Then raise the temperature to 55°C, stir and react for 1.5 h. Then separate the solid, wash and dry the solid to obtain the amino silane coupling agent KH550-modified multi-walled carbon nanotubes.

[0030] The preparation method of the amino-silane coupling agent KH550 modified nano-diamond powder used in this example is as follows: Add 0.5 kg of nano-diamond powder (basalt, particle size 10 nm) into 100 kg of a mixed solution obtained by mixing the silane coupling agent KH550 and a 1+1 ethanol solution in a weight ratio of 1:10. Then, heat the mixture to 55 °C and stir for reaction for 1.5 h. Next, separate the solid, wash and dry the solid to obtain the amino-silane coupling agent KH550 modified nano-diamond powder.

[0031]

Example 4

Example 2

[0032] Among them, the preparation method of the carboxymethyl chitosan modified multi-walled carbon nanotubes used in this example is as follows: Add 6 kg of multi-walled carbon nanotubes (Zhongke Leiming, length 10 - 30 nm, tube diameter 20 - 30 nm, bulk density 0.22 g / cm 3 ) into 1000 kg of an aqueous solution of carboxymethyl chitosan with a mass concentration of 1%. Then, heat the mixture to 100 °C and react for 1.5 h under the catalysis of 0.01 kg of p-toluenesulfonic acid. Next, separate the solid, wash and dry the solid to obtain the carboxymethyl chitosan modified multi-walled carbon nanotubes.

[0033] The preparation method of the carboxymethyl chitosan modified nano-diamond powder used in this example is as follows: Add 0.5 kg of nano-diamond powder (basalt, particle size 10 nm) into 1000 kg of an aqueous solution of carboxymethyl chitosan with a mass concentration of 1%. Then, heat the mixture to 100 °C and react for 1.5 h under the catalysis of 0.01 kg of p-toluenesulfonic acid. Next, separate the solid, wash and dry the solid to obtain the carboxymethyl chitosan modified nano-diamond powder.

[0034]

Example 5

Example 4

[0035]

Example 6

Example 4

[0036] Comparative Example

Comparative Example 1

[0037] [Comparative Example 2] A polyurethane material, different from [Example 2] in that: In this comparative example, trimethylolpropane was replaced with an equal mass of 4,4'-methylenebis(3-chloro-2,6-diethylaniline).

[0038] [Comparative Example 3] A polyurethane material, different from [Example 2] in that: the ratio between the raw materials is different. In this comparative example, the polyurethane material was prepared from 100 kg of MDI-capped polyurethane prepolymer, 5 kg of polytetrahydrofuran glycol with a molecular weight of 1800, 30 kg of polycarbonate diol with a molecular weight of 2000, 8 kg of 1,4-butanediol, 1 kg of trimethylolpropane, 0.5 kg of 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 2.5 kg of multi-walled carbon nanotubes (Zhongke Leiming, length 10 - 30 nm, diameter 20 - 30 nm, bulk density 0.22 g / cm 3 ), 1 kg of nanodiamond powder (Xuanwu, particle size 10 nm) and 0.02 kg of dibutyltin dilaurate, wherein the MDI-capped polyurethane prepolymer was prepared by reacting MDI with polypropylene glycol with a molecular weight of 1500 at a molar ratio of 1.3:1.

[0039] Performance detection test Test 1: Take the polyurethane materials prepared in the above examples and comparative examples as test samples, and test the hardness of the polyurethane materials.

[0040] Test 2: Use the polyurethane materials prepared in the examples and comparative examples as the tread materials of super heavy-duty casters to make different super heavy-duty caster samples, and the only difference between the super heavy-duty caster samples is the tread material. Then use the super heavy-duty caster samples to test the load wear resistance and load low-temperature crack resistance.

[0041] Among them, the test method for load-bearing wear resistance is as follows: In an environment of 25 - 30 °C, apply weights of 2000 kg, 3500 kg, and 5000 kg to a single super heavy-duty caster sample respectively, and then conduct a walking test on the load-bearing super heavy-duty casters (back and forth 50000 times along the same 500 m straight channel). Before and after the wear resistance test, measure the thickness of the tread material of the super heavy-duty caster sample. When measuring the thickness of the tread material, randomly select 5 points at equal distances for testing, and then calculate the average value. Finally, calculate the thickness difference of the tread material of the super heavy-duty caster sample before and after the wear resistance test. Among them, a thickness difference less than 0.2 mm indicates no obvious wear, a thickness difference between 0.2 - 0.4 mm indicates slight wear, and a thickness difference greater than 0.4 mm indicates obvious wear.

[0042] The test method for load-bearing low-temperature anti-cracking is as follows: In an environment of -10 to -5 °C, apply weights of 2000 kg, 3500 kg, and 5000 kg to a single super heavy-duty caster sample respectively, and then conduct a walking test on the load-bearing super heavy-duty casters (back and forth 50000 times along the same 500 m straight channel), and observe whether the tread of the load-bearing super heavy-duty casters cracks.

[0043] Table 1 specimen hardness Example 1 89A-95A Example 2 89A-95A Example 3 89A-95A Example 4 89A-95A Example 5 89A-95A Example 6 89A-95A Comparative Example 1 84A-88A Comparative Example 2 89A-95A Comparative Example 3 89A-95A Table 2 Table 3 Combining the above Comparative Examples 1 - 3, Example 2, and the content recorded in Tables 1 - 3, it can be seen that when the polyurethane material is applied to super heavy-duty casters with a load of 2000 kg, the ratio between the components of the polyurethane material is not within the scope of this application, which is not conducive to obtaining a polyurethane material with good load-bearing wear resistance, good low-temperature anti-cracking property, and suitable for super heavy-duty casters.

[0044] Combining the content recorded in Examples 2 - 3 and Tables 1 - 3, it can be seen that when multi-walled carbon nanotubes are replaced with multi-walled carbon nanotubes modified with an equal mass of amino silane coupling agent KH550, and nano-diamond powder is replaced with nano-diamond powder modified with an equal mass of amino silane coupling agent KH550, it is beneficial to further improve the load-bearing wear resistance of the polyurethane material, and the polyurethane material can be applied to super heavy-duty casters with a load not exceeding 3500 kg.

[0045] Combined with the content recorded in Example 4, Example 2, and Tables 1-3, it can be seen that when multi-walled carbon nanotubes are replaced with multi-walled carbon nanotubes modified with an equal mass of amino silane coupling agent KH550, and nano-diamond powder is replaced with nano-diamond powder modified with an equal mass of amino silane coupling agent KH550, it is beneficial to further improve the load-bearing wear resistance and load-bearing low-temperature crack resistance of the polyurethane material, and the polyurethane material can be applied to super-heavy casters with a load not exceeding 5000 kg.

[0046] Combined with the content recorded in Examples 4-6 and Tables 1-3, it can be seen that when the small molecule diol is a composition of diethylene glycol and 1,4-butanediol with a weight ratio of (8-10):1, the polyurethane material is beneficial to balance the load-bearing wear resistance and load-bearing low-temperature crack resistance.

[0047] This specific embodiment is only an interpretation of the present application, and it is not a limitation of the present application. After reading this specification, those skilled in the art can make modifications without creative contributions to this specific embodiment 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 polyurethane material, characterized in that: The invention is prepared from 100 parts by weight of MDI-terminated polyurethane prepolymer, 15-20 parts by weight of polytetramethylene glycol, 15-20 parts by weight of polycarbonate diol, 2-4 parts by weight of small molecule diol, 1-2 parts by weight of trimethylolpropane, 0.1-0.2 parts by weight of 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 4.5-5.5 parts by weight of multi-walled carbon nanotubes, 0.1-0.2 parts by weight of nano-diamond powder and 0.01-0.02 parts by weight of catalyst. The MDI-terminated polyurethane prepolymer is prepared by reacting MDI and polypropylene glycol in a molar ratio of (1.1-1.3):

1.

2. A polyurethane material according to claim 1, characterized in that: The multi-walled carbon nanotubes are modified by aminosilane coupling agents, and the nano-diamond powders are modified by aminosilane coupling agents.

3. A polyurethane material according to claim 1, characterized in that: The multi-walled carbon nanotubes are multi-walled carbon nanotubes modified by carboxymethyl chitosan, and the nano diamond powder is diamond powder modified by carboxymethyl chitosan.

4. A polyurethane material according to any one of claims 1 to 3, characterized in that: The molecular weight of the polytetramethylene ether glycol is 1500-2000.

5. A polyurethane material according to any one of claims 1 to 3, characterized in that: The molecular weight of the polycarbonate diol is 1500-2000.

6. A polyurethane material according to any one of claims 1 to 3, characterized in that: The molecular weight of the polypropylene glycol is 1000-2000.

7. A polyurethane material according to any one of claims 1 to 3, characterized in that: The small molecule diol is at least one of ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol and diethylene glycol.

8. A polyurethane material according to claim 7, characterized in that: The small molecule diol is a composition of diethylene glycol and 1,4-butanediol in a weight ratio of (8-10):

1.

9. A method for preparing a polyurethane material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, dehydrating the MDI and polypropylene glycol and heating to 75-85° C. for reaction for 3-4 hours to prepare an MDI-terminated polyurethane prepolymer; S2. After dehydrating the polytetrahydrofuran ether diol, polycarbonate diol, multi-walled carbon nanotubes and nano-diamond powder, add them to the MDI-terminated polyurethane prepolymer and stir evenly. Then add a catalyst and heat to 75-85°C for reaction for 4-5h. Then add small molecule diol, trimethylolpropane and 4,4'-methylenebis(3-chloro-2,6-diethylaniline), continue to keep the reaction at 75-85°C, and finally vacuum degassing to obtain a polyurethane material.

10. An extra heavy-duty caster, characterized in that: A tread material comprising a polyurethane material as claimed in any one of claims 1 to 8.

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