Low-rolling-resistance polyurethane rubber and preparation method thereof

Abstract

The invention discloses peroxide vulcanized low-rolling-resistance polyurethane rubber and a preparation method thereof. The low-rolling-resistance polyurethane rubber is prepared from the following raw materials: mixed polyurethane rubber, a reinforcing filler, an antioxidant and peroxide. Wherein the mixed polyurethane rubber is prepared by the following steps: reacting oligomer polyol with 4, 4 '-diphenylmethane diisocyanate at 60-80 DEG C for 1-2 hours, adding a chain extender, pentaerythritol triallyl ether and a catalyst, and stirring and curing the mixture. The polyurethane rubber disclosed by the invention has the characteristic of low rolling resistance, is suitable for rubber mixing equipment, and is higher in modulus and good in controllability.

Description

Technical Field

[0001] The invention relates to the field of tire materials, and more particularly to a peroxide-cured low rolling resistance polyurethane rubber and a preparation method thereof. Background Art

[0002] As the wheels rotate, the tires and the road surface undergo periodic deformation due to load bearing. During the deformation process, the heat generated by the tires is the rolling resistance. This energy will be dissipated in the form of heat energy, which comes from the engine or motor of the car. Therefore, reducing the rolling resistance of the tire is of great significance for reducing energy consumption and improving the mileage of the car.

[0003] The internal heat of tires is essentially derived from friction at the microscopic level, including friction between molecular chains, friction between molecular chains and fillers, and friction between fillers. Researchers have reduced the internal friction of traditional rubber nanocomposites by reducing polymer ends, using filler surface modifiers, and designing new rubber structures, thereby reducing rolling resistance. However, since the surface energy of the filler itself is large, such as white carbon black (nano-silica), it is still easy to self-aggregate, which is not conducive to reducing rolling resistance.

[0004] Polyurethane elastomers are composed of oligomer polyols to form soft segments, and diisocyanates and small molecule cross-linking agents and chain extenders to form hard segments. Polyurethane elastomers are different from rubber systems in two obvious ways: first, natural rubber and styrene-butadiene rubber, which are commonly used rubber systems for tire treads, are non-polar systems, while polyurethane elastomers are polar systems, which allows polyurethane elastomers to achieve a more uniform dispersion of polar filler silica without the use of surface modifiers; second, polyurethane elastomers themselves have a microphase separation structure due to the polarity difference between the soft and hard segments, which reduces the internal friction between the molecular chains and further reduces the rolling resistance. At the same time, the mixing type polyurethane elastomer can adapt to the processing and mixing processes and equipment of traditional rubbers, making it possible to use mixing type polyurethane to prepare low rolling resistance tire materials.

[0005] Therefore, the present invention combines the high wear resistance of polyurethane elastomer to design and prepare a low internal friction, low heat generation and low rolling resistance polyurethane rubber material, which is of great significance for improving the mileage of automobiles and saving energy. Summary of the invention

[0006] In order to solve the technical problems existing in the above prior art, the present invention provides a peroxide-cured low rolling resistance polyurethane rubber and a preparation method thereof.

[0007] One of the objects of the present invention is to provide a low rolling resistance polyurethane rubber.

[0008] The polyurethane rubber is prepared from raw materials including the following components:

[0009] 100.0 parts by weight of millable polyurethane rubber;

[0010] 20 to 40 parts by weight of reinforcing filler; preferably 20 to 30 parts by weight;

[0011] 1.0 to 2.0 parts by weight of antioxidant; preferably 1.0 to 1.5 parts by weight;

[0012] Peroxide 0.2-1.5 parts by weight; preferably 0.4-1.0 parts by weight.

[0013] In a preferred embodiment of the present invention,

[0014] The reinforcing filler is selected from at least one of white carbon black and carbon black, preferably at least one of fumed white carbon black A200, white carbon black VN3, carbon black N220, carbon black N330, and carbon black N234, and more preferably A200.

[0015] In a preferred embodiment of the present invention,

[0016] The antioxidant is a hindered phenol antioxidant, preferably at least one of antioxidant 1010 and antioxidant 1076.

[0017] In a preferred embodiment of the present invention,

[0018] The peroxide is one of 1,3-bis(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide and 2,5-dimethyl-2,5(di-tert-butylperoxy)hexane.

[0019] The polyurethane rubber of the present invention uses peroxide as a vulcanizing agent. Compared with the traditional sulfur vulcanization system, the molecular chain network has stronger rigidity and less friction between molecular chains. Therefore, the polyurethane rubber of the present invention has less internal heat and lower rolling resistance, and has the advantages of energy saving, fuel saving, and low heat generation. At the same time, the vulcanization network of the polyurethane rubber can be adjusted by adjusting the unsaturation, amount of vulcanizing agent, degree of vulcanization, etc. of the polyurethane rubber, and has a significant advantage of strong designability. The polyurethane rubber also has the characteristics of rubber extrudability and moldability, has low requirements for equipment, and has low application cost.

[0020] In a preferred embodiment of the present invention,

[0021] The number average molecular weight of the mixed polyurethane rubber is 4.0×10 4 ~1.0×10 5 , preferably 4.0×10 4 ~8.0×10 4 , for example, it can be 4.0×104 5.0×10 4 , 6.0×10 4 , 7.0×10 4 , 8.0×10 4 9.0×10 4 , 1.0×10 5 etc., or any value between the above values ​​or a numerical range between any two of the above values.

[0022] In a preferred embodiment of the present invention,

[0023] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0024] 100 parts by weight of oligomer polyol;

[0025] 20 to 30 parts by weight of 4,4'-diphenylmethane diisocyanate; preferably 20 to 26 parts by weight;

[0026] Chain extender 5 to 12 parts by weight; preferably 5 to 10 parts by weight;

[0027] Pentaerythritol triallyl ether 0.1 to 0.3 parts by weight; preferably 0.1 to 0.2 parts by weight;

[0028] Catalyst 0.4-0.8 parts by weight; preferably 0.4-0.6 parts by weight;

[0029] The water content of the oligomer polyol is less than 0.03 wt%.

[0030] In a preferred embodiment of the present invention,

[0031] The 4,4'-diphenylmethane diisocyanate has the advantages of low rolling resistance and low cost. Compared with toluene diisocyanate, the main chain structure of 4,4'-diphenylmethane diisocyanate has no side groups, so its rolling resistance is lower.

[0032] The oligomer polyol is selected from at least one of polyethylene adipate diol, polypropylene adipate diol, and polybutylene adipate diol, for example, it can be one or more of polyethylene adipate diol 2000, polypropylene adipate diol 2000, polybutylene adipate diol 2000, and the like.

[0033] The use of the oligomer polyol is beneficial to reduce the friction of the molecular chain, reduce the heat generated during the operation of the material, and reduce the hysteresis and energy consumption of the material. In addition, it can ensure that the material has a higher 0°C loss factor as much as possible, that is, a higher anti-slip performance, so that the material has low heat generation characteristics while having wear resistance and anti-slip performance, and comprehensively breaks through the traditional "magic triangle" performance.

[0034] In a preferred embodiment of the present invention,

[0035] The chain extender is at least one of glycerol monoallyl ether, trimethylolpropane monoallyl ether, 2,3-dihydroxy-1-butene and 1,4-butenediol.

[0036] Based on 100 parts by weight of the oligomer polyol, the amount of the chain extender can be 5, 6, 7, 8, 9, 10, 11, 12 parts by weight, or any value between the above values ​​or a numerical range between any two of the above values.

[0037] Based on 100 parts by weight of the oligomer polyol, the amount of pentaerythritol triallyl ether can be 0.1, 0.15, 0.2, 0.25, 0.3 parts by weight, or any value between the above values ​​or a numerical range between any two of the above values.

[0038] In a preferred embodiment of the present invention,

[0039] The catalyst is at least one of dibutyltin dilaurate, stannous octoate and dibutyltin diacetate.

[0040] In a preferred embodiment of the present invention,

[0041] The mixing type polyurethane rubber is prepared by the following steps:

[0042] After the oligomer polyol and 4,4'-diphenylmethane diisocyanate react at 60°C to 80°C for 1 to 2 hours, a chain extender, pentaerythritol triallyl ether and a catalyst are added, and the mixture is stirred and cured to obtain the millable polyurethane rubber.

[0043] The present invention adopts a two-stage process, first preparing polyurethane rubber, and then reinforcing and vulcanizing it to prepare a peroxide-vulcanized low rolling resistance polyurethane rubber. The prepared polyurethane rubber has a lower 60°C loss factor. Compared with traditional thermoplastic and cast polyurethane elastomers, the polyurethane rubber has the characteristics of being able to be mixed and processed. At the same time, due to the characteristics of polyurethane, compared with traditional rubber systems, the hysteresis and heat generation are lower, and the characteristics of low rolling resistance can reduce automobile energy consumption and improve automobile endurance.

[0044] The second object of the present invention is to provide a method for preparing the low rolling resistance polyurethane rubber, comprising mixing components including a mixing type polyurethane rubber, a reinforcing filler, an antioxidant and a peroxide to obtain a rubber mix, and then vulcanizing the rubber mix.

[0045] In a preferred embodiment of the present invention,

[0046] The polyurethane rubber compound is prepared by using an internal mixer. After the mixed polyurethane rubber is added into the internal mixer, reinforcing fillers, antioxidants and peroxides are added in sequence and fully mixed to prepare the compound.

[0047] The mixed rubber needs to be left for at least 24 hours before vulcanization, and the vulcanization temperature is 150-180°C, preferably 150-160°C.

[0048] The vulcanization time is measured by a vulcanizer, and the mixed polyurethane rubber is vulcanized by molding in a mold that is fully preheated at a suitable vulcanization temperature to obtain polyurethane rubber.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. Compared with traditional rubber tires, the mixed polyurethane in the present invention has a higher 0°C loss factor and better anti-skid performance.

[0051] 2. Compared with traditional tires, the mixed polyurethane in the present invention has a higher modulus under low strain and better handling of the tire.

[0052] 3. The mixed polyurethane in the present invention is a polar system, which can better achieve the dispersion of polar fillers in the system, avoid the problem of uneven dispersion of white carbon black, reduce the friction between fillers, greatly reduce the wear caused by the friction of fillers, and thus reduce rolling resistance.

[0053] 4. Compared with cast polyurethane and thermoplastic polyurethane, the kneadable polyurethane rubber of the present invention has the characteristics of being kneadable, calendered and extruded, is compatible with the formula system and processing technology of traditional rubber, and has the characteristics of low application cost.

[0054] 5. Compared with the use of white carbon black in the traditional rubber system, the mixing system of the mixing type polyurethane and white carbon black in the present invention needs to be matched with a silane coupling agent as a surface modifier, thereby avoiding the generation of volatile organic compounds (VOC) small molecule ethanol and eliminating the hidden dangers of safety and environmental protection.

[0055] 5. The rolling resistance of the kneadable polyurethane rubber in the present invention can be adjusted by the copolymer composition of the molecular chain: by controlling and improving the rigidity of the molecular chain, the friction between the molecular chains is reduced, the 0°C loss factor is reduced, and the rolling resistance is reduced. DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0057] The raw materials used in the examples and comparative examples are all conventional commercially available raw materials.

[0058] Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber according to GB / T 528-2009.

[0059] Gel permeation chromatography (GPC) analysis was carried out in a US Waters 1515GPC equipped with a differential refractive index detector and a chromatographic column at a maximum flow rate of 22.5 mL, using tetrahydrofuran as solvent and polystyrene as a standard.

[0060] Dynamic mechanical analysis (DMA) test conditions: frequency 1 Hz, strain 0.1%, temperature change rate 3 ° C min -1 , the test temperature range is -100~80℃ in tensile mode.

[0061] Example 1

[0062] The polyurethane rubber described in Example 1 is prepared from raw materials including the following components:

[0063]

[0064] The polyurethane rubber compound is prepared by using an internal mixer. After the mixed polyurethane rubber is added to the internal mixer, A200, antioxidant 1076 and diisopropylbenzene peroxide are added in sequence and fully mixed to prepare the compound. The compound needs to be parked for 24 hours, and then the compound is molded and vulcanized at 160°C to obtain the polyurethane rubber.

[0065] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0066]

[0067]

[0068] The water content of polypropylene adipate diol 2000 is less than 0.03wt%;

[0069] After polypropylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate react at 80° C. for 1 hour, propylene glycol monoallyl ether, pentaerythritol triallyl ether and dibutyltin dilaurate are added, and the mixture is stirred and cured to obtain the millable polyurethane rubber.

[0070] Example 2

[0071] The polyurethane rubber described in Example 2 is prepared from raw materials including the following components:

[0072]

[0073] The polyurethane rubber compound is prepared by using an internal mixer. After the mixed polyurethane rubber is added to the internal mixer, A200, antioxidant 1076 and diisopropylbenzene peroxide are added in sequence and fully mixed to prepare the compound. The compound needs to be parked for 24 hours, and then the compound is molded and vulcanized at 160°C to obtain the polyurethane rubber.

[0074] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0075]

[0076] The water content of the polypropylene adipate diol 2000 is less than 0.03wt%;

[0077] After polypropylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate react at 80° C. for 1 hour, trimethylolpropane monoallyl ether, pentaerythritol triallyl ether and dibutyltin dilaurate are added, and the mixture is stirred and cured to obtain the millable polyurethane rubber.

[0078] Example 3

[0079] The polyurethane rubber described in Example 1 is prepared from raw materials including the following components:

[0080] 100.0 parts by weight of millable polyurethane rubber;

[0081] A200 30.0 parts by weight;

[0082] Antioxidant 10102.0 parts by weight;

[0083] 1.5 parts by weight of 1,3-bis(tert-butylperoxyisopropyl)benzene;

[0084] The polyurethane rubber compound was prepared by using an internal mixer. After the mixed polyurethane rubber was added to the internal mixer, A200, antioxidant 1010 and 1,3-bis(tert-butylperoxyisopropyl)benzene were added in sequence and fully mixed to prepare the compound. The compound was left for 24 hours, and then the compound was vulcanized at 170°C to obtain the polyurethane rubber.

[0085] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0086] Polybutylene adipate diol 2000 100 parts by weight;

[0087] 29.4 parts by weight of 4,4'-diphenylmethane diisocyanate;

[0088] 11.6 parts by weight of trimethylolpropane monoallyl ether;

[0089] Pentaerythritol triallyl ether 0.3 parts by weight;

[0090] 0.8 parts by weight of dibutyltin dilaurate;

[0091] The water content of the polybutylene adipate diol 2000 is less than 0.03wt%;

[0092] After polybutylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate were reacted at 80°C for 1 hour, trimethylolpropane monoallyl ether, pentaerythritol triallyl ether and dibutyltin dilaurate were added, and the mixture was stirred and cured to obtain the millable polyurethane rubber.

[0093] Comparative Example 1

[0094] Comparative Example 1 uses a TPU sample of BASF of Germany, with a brand name of C85AHPM. The pellets are placed in a preheated 190°C mold, hot-pressed at 190°C for 25 minutes, taken out and cold-pressed for 5 minutes, and peeled from the mold to obtain a sample of Comparative Example 1.

[0095] Comparative Example 2

[0096] Comparative Example 2 uses a commercial green tire rubber compound (HT166).

[0097] Comparative Example 3

[0098] The difference between Comparative Example 3 and Example 1 is that pentaerythritol triallyl ether is not added to the mixed polyurethane rubber of Comparative Example 3.

[0099] The polyurethane rubber described in Comparative Example 3 is prepared from raw materials including the following components:

[0100] 100.0 parts by weight of millable polyurethane rubber;

[0101] A200 20.0 parts by weight;

[0102] Antioxidant 1076 1.0 parts by weight;

[0103] 1.0 parts by weight of dicumyl peroxide;

[0104] The polyurethane rubber compound is prepared by using an internal mixer. After the mixed polyurethane rubber is added to the internal mixer, A200, antioxidant 1076 and diisopropylbenzene peroxide are added in sequence and fully mixed to prepare the compound. The compound needs to be parked for 24 hours, and then the compound is molded and vulcanized at 160°C to obtain the polyurethane rubber.

[0105] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0106]

[0107] The water content of polypropylene adipate diol 2000 is less than 0.03wt%;

[0108] After polypropylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate react at 80° C. for 1 hour, propylene glycol monoallyl ether and dibutyltin dilaurate are added, and the mixture is stirred and cured to obtain the millable polyurethane rubber.

[0109] Comparative Example 4

[0110] The difference between Comparative Example 4 and Example 3 is that pentaerythritol triallyl ether is not added to the mixed polyurethane rubber of Comparative Example 4.

[0111] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0112]

[0113] The water content of the polybutylene adipate diol 2000 is less than 0.03wt%;

[0114] After polybutylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate were reacted at 80° C. for 1 hour, trimethylolpropane monoallyl ether and dibutyltin dilaurate were added, and the mixture was stirred and cured to obtain the millable polyurethane rubber.

[0115] Due to the large molecular weight and high hard segment content of the mixed polyurethane rubber, the internal mixer experienced excessive torque and automatic shutdown protection during the mixing process, and the mixing process was not completed.

[0116] Comparative Example 5

[0117] The difference between Comparative Example 5 and Example 3 is that more pentaerythritol triallyl ether is added to the mixed polyurethane rubber of Comparative Example 5.

[0118] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0119] Polybutylene adipate diol 2000 100 parts by weight;

[0120] 29.4 parts by weight of 4,4'-diphenylmethane diisocyanate;

[0121] 11.6 parts by weight of trimethylolpropane monoallyl ether;

[0122] Pentaerythritol triallyl ether 0.5 parts by weight;

[0123] 0.8 parts by weight of dibutyltin dilaurate;

[0124] The water content of the polybutylene adipate diol 2000 is less than 0.03wt%;

[0125] After polybutylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate were reacted at 80° C. for 1 hour, trimethylolpropane monoallyl ether and dibutyltin dilaurate were added, and the mixture was stirred and cured to obtain the millable polyurethane rubber.

[0126] The kneading polyurethane rubber has more chain ends and lower molecular weight due to the large amount of pentaerythritol triallyl ether added. During the kneading process, the torque is low, the raw rubber is difficult to eat, and it is difficult to evenly disperse the powders such as fillers and additives.

[0127] Comparative Example 6

[0128] The only difference between Comparative Example 6 and Example 3 is that the mixed polyurethane rubber in Comparative Example 6 is vulcanized with sulfur instead of peroxide.

[0129] The polyurethane rubber described in Comparative Example 6 is prepared from raw materials including the following components:

[0130]

[0131] The polyurethane rubber compound is prepared by using an internal mixer. After the mixed polyurethane rubber is added to the internal mixer, A200, antioxidant 1076, accelerator M, accelerator DM, active agent NH-2 and sulfur are added in sequence and fully mixed to prepare the compound. The compound needs to be parked for 24 hours, and then the compound is vulcanized at 160°C to obtain the polyurethane rubber.

[0132] The mixing type polyurethane rubber is prepared from raw materials including the following components:

[0133]

[0134]

[0135] The water content of the polybutylene adipate diol 2000 is less than 0.03wt%;

[0136] After polybutylene adipate diol 2000 and 4,4'-diphenylmethane diisocyanate were reacted at 80° C. for 1 hour, trimethylolpropane monoallyl ether and dibutyltin dilaurate were added, and the mixture was stirred and cured to obtain the millable polyurethane rubber.

[0137] The tensile strength and elongation at break of Examples 1 to 3 were tested, and the results are shown in Table 1.

[0138] Table 1 Elongation at break of Examples 1 to 3

[0139] Tensile strength(MPa) Elongation at break (%) Example 1 38.3±1.4 783±31 Example 2 30.5±1.1 512±24 Example 3 22.9±0.9 351±15

[0140] The tensile strength and elongation at break of Examples 1 to 3 are all relatively high, meeting the mechanical property requirements for use as tire treads.

[0141] The number average molecular weight and molecular weight distribution of the millable polyurethane rubbers in Examples 1 to 3 and Comparative Examples 3 to 6 were tested. The results are shown in Table 2.

[0142] Table 2 Number average molecular weight and molecular weight distribution of compound polyurethane rubber

[0143] Number average molecular weight Molecular weight distribution Example 1 <![CDATA[4.3×10 4 ]]> 2.35 Example 2 <![CDATA[6.5×10 4 ]]> 2.26 Example 3 <![CDATA[8.4×10 4 ]]> 2.67 Comparative Example 3 <![CDATA[1.1×10 5 ]]> 2.38 Comparative Example 4 <![CDATA[1.7×10 5 ]]> 2.50 Comparative Example 5 <![CDATA[2.9×10 4 ]]> 2.37 Comparative Example 6 <![CDATA[8.4×10 4 ]]> 2.67

[0144] Comparing Example 1 with Comparative Example 3, the molecular weight of Example 1 is smaller than that of Comparative Example 3. Comparing Example 3 with Comparative Example 4, the molecular weight of Example 3 is smaller. This shows that pentaerythritol triallyl ether plays a good role in reducing the molecular weight as a molecular weight regulator, which is beneficial to the improvement of processing performance.

[0145] In Comparative Example 4, no pentaerythritol triallyl ether was added. After the obtained mixed polyurethane was added to the internal mixer, excessive torque occurred and the internal mixer automatically stopped for protection. This was because the hard segment content was relatively high and the molecular weight was relatively large under this formula. The mixed polyurethane was difficult to process under this condition, so the polyurethane rubber under this formula was not obtained.

[0146] In Comparative Example 5, since the amount of the end-capping agent pentaerythritol triallyl ether used is relatively large, the obtained mixed polyurethane has a low viscosity in the internal mixer, and it is difficult to fully disperse the filler and powder in the processing process, so the polyurethane rubber under this formula is not obtained.

[0147] The polyurethane rubbers obtained in Examples 1 to 3, Comparative Examples 1 to 3 and Comparative Example 6 were subjected to dynamic mechanical property tests under the test conditions of 1 Hz, 0.1% deformation and 3° C. / min heating rate. The results are shown in Table 3.

[0148] Table 3 Dynamic mechanical properties of polyurethane rubber

[0149] Loss peak(℃) 60℃ loss factor Example 1 -6.8 0.093 Example 2 -12.6 0.066 Example 3 -16.3 0.043 Comparative Example 1 -9.4 0.129 Comparative Example 2 -18.6 0.101 Comparative Example 3 -8.1 0.107 Comparative Example 6 -6.1 0.106

[0150] As shown in Table 3, the glass transition temperatures of Examples 1 to 3 are all lower than room temperature, and their elasticity at room temperature is good. The 60°C loss factor of Examples 1 to 3 is significantly lower than that of Comparative Examples 1 to 3, which proves that Examples 1 to 3 have smaller internal friction and less heat generation, that is, smaller rolling resistance. When used as a tread material, they will have the advantages of more fuel saving and energy saving. Although Example 3 has a lower 60°C loss factor and lower rolling resistance, its elongation at break is relatively low due to the large amount of peroxide used. Compared with Example 1, Comparative Example 3 does not add pentaerythritol triallyl ether, and the prepared mixed polyurethane has more free ends, so the 60°C loss factor will be higher than that of Example 1, that is, the rolling resistance is higher. Compared with Example 3, Comparative Example 6 has a single sulfur bond and sulfur bridge in the sulfur-cured system, and the cross-linking strength of peroxide is higher, so the friction between the molecular chains of the sulfur system will be relatively more intense, and its 60°C loss factor is larger and the rolling resistance is larger.

[0151] The chain extender compounded pentaerythritol triallyl ether system used in the present invention has the function of accurately adjusting the molecular weight of polyurethane rubber. When the molecular weight of polyurethane rubber is too small, the tensile orientation of the material is weak and the mechanical properties of the material are low; when the molecular weight is too large, the processing performance of the material is poor, and there is a risk of damaging the equipment due to excessive torque during processing. Adding an appropriate amount of pentaerythritol triallyl ether as a capping agent is conducive to controlling the molecular weight of polyurethane rubber within a suitable molecular weight range and balancing the mechanical properties and processing properties of polyurethane rubber. Without adding a capping agent, the molecular chain ends of the polyurethane rubber are the hydroxyl groups of the oligomer polyols or the isocyanate groups in the isocyanate. These two groups cannot participate in the vulcanization process of the peroxide, so the internal friction of the polyurethane rubber without adding a capping agent is relatively high. The molecular chain ends of the polyurethane rubber capped with pentaerythritol triallyl ether can participate in the vulcanization process, which can reduce the number of molecular chain ends in the vulcanization network, reduce the friction between the free ends of the molecular chains and the molecular chains, improve the synergy of the molecular chain network movement, and reduce the movement hysteresis of the molecular chain network, thereby reducing the heat generation of the tire and playing a role in reducing rolling resistance.

[0152] Compared with traditional rubber tire materials, the polyurethane rubber in the present invention has a lower 60°C loss factor and smaller rolling resistance; compared with thermoplastic polyurethane and cast polyurethane, it is compatible with the formula system and processing equipment of traditional rubber and has lower application cost. In general, the present invention has broad potential application prospects.

Claims

1. A low rolling resistance polyurethane rubber prepared from raw materials comprising the following components: 100.0 parts by weight of millable polyurethane rubber; 20 to 40 parts by weight of reinforcing filler; preferably 20 to 30 parts by weight; 1.0 to 2.0 parts by weight of antioxidant; preferably 1.0 to 1.5 parts by weight; Peroxide 0.2-1.5 parts by weight; preferably 0.4-1.0 parts by weight.

2. The low rolling resistance polyurethane rubber according to claim 1, Features: The reinforcing filler is selected from at least one of white carbon black and carbon black, preferably at least one of fumed white carbon black A200, white carbon black VN3, carbon black N220, carbon black N330, and carbon black N234.

3. The low rolling resistance polyurethane rubber according to claim 1, Features: The antioxidant is a hindered phenol antioxidant, preferably at least one of antioxidant 1010 and antioxidant 1076; The peroxide is selected from one of 1,3-bis(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide, and 2,5-dimethyl-2,5(di-tert-butylperoxy)hexane.

4. The low rolling resistance polyurethane rubber according to claim 1, Features: The number average molecular weight of the mixed polyurethane rubber is 4.0×10 4 ~1.0×10 5 , preferably 4.0×10 4 ~8.0×10 4 .

5. The low rolling resistance polyurethane rubber according to claim 1, Features The mixing type polyurethane rubber is prepared from raw materials including the following components: 100.0 parts by weight of oligomer polyol; 20 to 30 parts by weight of 4,4'-diphenylmethane diisocyanate; preferably 20 to 26 parts by weight; Chain extender 5 to 12 parts by weight; preferably 5 to 10 parts by weight; Pentaerythritol triallyl ether 0.1 to 0.3 parts by weight; preferably 0.1 to 0.2 parts by weight; Catalyst 0.4-0.8 parts by weight; preferably 0.4-0.6 parts by weight.

6. The low rolling resistance polyurethane rubber according to claim 5, Features The mixing type polyurethane rubber is prepared by the following steps: After the oligomer polyol and 4,4'-diphenylmethane diisocyanate are reacted at 60-80°C for 1-2 hours, a chain extender, pentaerythritol triallyl ether and a catalyst are added for curing.

7. The low rolling resistance polyurethane rubber according to claim 5, Features: The oligomer polyol is selected from at least one of polyethylene adipate diol, polypropylene adipate diol, and polybutylene adipate diol; The water content of the oligomer polyol is less than 0.03 wt%.

8. The low rolling resistance polyurethane rubber according to claim 5, Features: The chain extender is selected from at least one of glycerol monoallyl ether, trimethylolpropane monoallyl ether, 2,3-dihydroxy-1-butene, and 1,4-butenediol.

9. The low rolling resistance polyurethane rubber according to claim 5, Features: The catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate and dibutyltin diacetate.

10. A method for preparing the low rolling resistance polyurethane rubber according to any one of claims 1 to 9, comprising mixing components including a mixing type polyurethane rubber, a reinforcing filler, an antioxidant and a peroxide to obtain a rubber mix, and then vulcanizing the rubber mix.

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