Heat-resistant polyurethane composition for tire filling as well as preparation method and application of heat-resistant polyurethane composition

Abstract

The invention provides a heat-resistant polyurethane composition for tire filling as well as a preparation method and application of the heat-resistant polyurethane composition for tire filling, and the heat-resistant polyurethane composition for tire filling comprises a component A and a component B in parts by weight, the component A is prepared from the following raw materials in parts by weight: 30-40 parts of polycaprolactone polyol, 1-6 parts of a crosslinking reinforcing agent, 2-6 parts of micromolecular polyamine and 30-55 parts of a high-boiling-point plasticizer; the component B is prepared from the following raw materials in parts by weight: 30 to 40 parts of polycaprolactone polyol, 30 to 60 parts of a high-boiling-point plasticizer and 10 to 20 parts of isocyanate. The polyurethane composition provided by the invention has the advantages of good fluidity, simple operation, low rolling internal heat generation and good heat resistance, and can be used for engineering vehicles running at high speed.

Description

Technical Field

[0001] The present invention belongs to the field of chemical synthesis, and relates to a heat-resistant polyurethane composition for tire filling, a preparation method thereof and an application thereof. Background Art

[0002] The load-bearing tires of engineering vehicles include pneumatic tires and filled tires. Due to risks such as air leakage or puncture, pneumatic tires are replaced by filled tires on large engineering vehicles. Filled tires usually use soft polyurethane elastomers filled in rubber tires. Filled tires have the advantages of easy adjustment of soft hardness, fast deformation recovery, less hysteresis heat generation, fewer product defects, and long service life.

[0003] At present, most of the load-bearing filled tires of engineering vehicles can only be used for engineering vehicles running at low speeds (10 km / h). When the driving speed of the engineering vehicle is too high, the heat generated inside the tire causes the temperature inside the tire to be too high, resulting in thermal decomposition of the soft polyurethane elastomer filled in the tire, and the load-bearing performance of the filled tire drops rapidly, seriously affecting the service life of the tire. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a heat-resistant polyurethane composition for tire filling, a preparation method thereof and an application thereof.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides a heat-resistant polyurethane composition for tire filling, which includes component A and component B. In terms of parts by weight, the preparation raw materials of component A include the following components:

[0007]

[0008]

[0009] In terms of parts by weight, the preparation raw materials of component B include the following components:

[0010] Polycaprolactone polyol 30 - 40 parts

[0011] High-boiling-point plasticizer 30 - 60 parts

[0012] Isocyanate 10 - 20 parts.

[0013] In the present invention, polycaprolactone polyol is used in both component A and component B, which has excellent resilience performance and mechanical properties. At the same time, the polycaprolactone polyol contains an ester group, which can endow the polyurethane with more excellent heat resistance. The polycaprolactone polyol has a low glass transition temperature, which can endow the polyurethane with more excellent low-temperature mechanical properties.

[0014] In the preparation raw materials of component A in the heat-resistant polyurethane composition for tire filling of the present invention, the dosage of polycaprolactone polyol can be 30 parts, 33 parts, 35 parts, 38 parts or 40 parts, the dosage of the crosslinking reinforcing agent can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts or 6 parts, the dosage of the small molecule polyamine can be 2 parts, 3 parts, 4 parts, 5 parts or 6 parts, and the dosage of the high-boiling plasticizer can be 30 parts, 33 parts, 35 parts, 38 parts, 40 parts, 43 parts, 45 parts, 48 parts, 50 parts, 53 parts or 55 parts; in the preparation raw materials of component B in the heat-resistant polyurethane composition for tire filling of the present invention, the dosage of polycaprolactone polyol can be 30 parts, 33 parts, 35 parts, 38 parts or 40 parts, and the dosage of the high-boiling plasticizer can be 30 parts, 33 parts, 35 parts, 38 parts, 40 parts, 43 parts, 45 parts, 48 parts, 50 parts, 53 parts, 55 parts, 58 parts or 60 parts; the dosage of the isocyanate can be 10 parts, 12 parts, 15 parts, 18 parts or 20 parts.

[0015] Preferably, the molecular weight of the polycaprolactone polyol is 2000 - 3000, such as 2000, 2200, 2300, 2400, 2500, 2700, 2900 or 3000, etc.

[0016] Preferably, the functionality of the polycaprolactone polyol is 3.

[0017] Preferably, the examples of the polycaprolactone polyol include one or at least two combinations of Julong Chemical PCL - 3207, capa 3201 of Perstorp Company or capa3301.

[0018] Preferably, the crosslinking reinforcing agent is enzymatically hydrolyzed lignin. Enzymatically hydrolyzed lignin contains a large number of hydroxyl groups and benzene rings, and can be used as a macromolecular crosslinking agent for the crosslinking and reinforcement of polyurethane chains, improving the crosslinking density of polyurethane elastomers. The present invention researches and discovers that at a high temperature of 130 °C, the mechanical properties of the polyurethane elastomer prepared using enzymatically hydrolyzed lignin as a crosslinking agent decrease very little, and the service life of the polyurethane-filled tire prepared is long.

[0019] Preferably, the small molecule polyamine is a diamine chain extender. Preferably, the small molecule polyamine is a complex of 4,4'-diaminodiphenylmethane and sodium chloride dispersed in an ester plasticizer; preferably Suzhou Xiangyuan Xlink311. Xlink311 is a heat-sensitive delayed reactive diamine chain extender. It is composed of a complex of symmetric 4,4'-diaminodiphenylmethane and sodium chloride and is dispersed in an ester plasticizer. It hardly reacts with the prepolymer at room temperature, but when heated to about 120 °C, this salt complex begins to dissociate, and the liberated diamine quickly reacts with the prepolymer to form a tough PU elastomer. Due to the high symmetry of 4,4'-diaminodiphenylmethane, the heat resistance of the hard segment obtained by its reaction with aromatic isocyanate is higher than that of other diamine chain extenders, and the elastomer prepared therefrom has good dynamic mechanical properties (less internal heat generation during the actual application of the prepared tire). Since Xlink311 only reacts with the prepolymer at high temperature, the reaction operation time of the heat-resistant polyurethane composition for tire filling is very long (>60 min), which is beneficial to the production of large filling tires. The ester plasticizer contained in Xlink311 has good compatibility with the polyol A component.

[0020] Preferably, the high-boiling plasticizer refers to a low-volatility plasticizer with a boiling point higher than 250 °C. The plasticizer has a low saturated vapor pressure at 120 °C. Preferably, the high-boiling plasticizer can be one or a combination of at least two of aromatic hydrocarbon-based, fatty acid ester-based, phthalate-based, terephthalate-based, phosphate-based, and halogenated phosphate-based plasticizers. Preferably, the high-boiling plasticizer has a viscosity less than 300 mPa·s at 25 °C, such as 300 mPa·s, 280 mPa·s, 250 mPa·s, 230 mPa·s, 200 mPa·s, 180 mPa·s, 150 mPa·s, 130 mPa·s, 100 mPa·s, 80 mPa·s, 60 mPa·s, 50 mPa·s, etc., and more preferably less than 100 mPa·s.

[0021] Preferably, the aromatic hydrocarbon-based plasticizer is an aromatic oil with a boiling point >250 °C.

[0022] Preferably, the fatty acid ester-based plasticizer is 2,2,4-trimethyl-1,3-pentanediol diisobutyrate.

[0023] Preferably, the phthalate-based plasticizer is any one or a combination of at least two of dioctyl phthalate, diethyl phthalate, or dibutyl phthalate.

[0024] Preferably, the phosphate-based plasticizer is isopropyltriphenyl phosphate and / or resorcinol bis(diphenyl phosphate).

[0025] Preferably, the halogenated phosphate plasticizer is tris(2-chloropropyl) phosphate.

[0026] Preferably, the isocyanate is selected from one or a combination of at least two of a mixture of 2,6-toluene diisocyanate and 2,4-toluene diisocyanate, diphenylmethane diisocyanate (MDI), or liquefied MDI.

[0027] Preferably, the mixture of 2,6-toluene diisocyanate and 2,4-toluene diisocyanate can be commercially available TDI-80, TDI-65, or TDI-100. The preferred liquefied MDI is MDI-100L from Wanhua.

[0028] Preferably, the raw materials for preparing the component A further include 0.3 - 1 part of an antifoaming agent, such as 0.3 part, 0.5 part, 0.8 part, or 1 part.

[0029] Preferably, the antifoaming agent is a solvent-free organosilicon oil antifoaming agent, and preferably SAKG47 from Momentive.

[0030] Preferably, the raw materials for preparing the component A further include 0.5 - 2.0 parts of a thermal-oxidative stabilizer, such as 0.3 part, 0.5 part, 0.8 part, 1 part, 1.3 parts, 1.5 parts, 1.8 parts, or 2.0 parts.

[0031] Preferably, the thermal-oxidative stabilizer is selected from one or a combination of at least two of antioxidant 245, antioxidant 1010, and antioxidant 1076. The thermal-oxidative stabilizer can effectively prevent the thermal degradation of the polyurethane composition at high temperatures.

[0032] Preferably, the raw materials for preparing the component A further include 0.02 - 0.5 part of a catalyst, such as 0.02 part, 0.05 part, 0.08 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, or 0.5 part.

[0033] Preferably, the catalyst is a delayed-action metal catalyst, and the preferred delayed-action metal catalyst is UL-29 from Momentive.

[0034] In order for the heat-resistant polyurethane composition for tire filling to well fill the voids of the tire, its viscosity needs to be controlled within a lower range.

[0035] In a preferred embodiment of the present invention, the viscosity of the component A at 50 °C is 500 - 1000 mPa·s, such as 500 mPa·s, 600 mPa·s, 700 mPa·s, 800 mPa·s, 900 mPa·s, or 1000 mPa·s.

[0036] In a preferred embodiment of the present invention, the viscosity of the component B at 50 °C is 500 - 1000 mPa·s, such as 500 mPa·s, 600 mPa·s, 700 mPa·s, 800 mPa·s, 900 mPa·s or 1000 mPa·s.

[0037] On the other hand, the present invention provides a method for preparing the heat-resistant polyurethane composition for tire filling as described above, and the preparation method includes the following steps:

[0038] (1) Mix the crosslinking reinforcing agent with the polycaprolactone polyol, heat and melt, then remove moisture under vacuum, cool down, add small molecule polyamine, high-boiling plasticizer and optionally defoaming agent, optionally heat and oxidation stabilizer and optionally catalyst, and stir and mix to obtain the component A;

[0039] (2) React the polycaprolactone polyol with the isocyanate, and then add the high-boiling plasticizer to obtain the component B.

[0040] Preferably, the heating and melting in step (1) is heating to 100 - 110 °C, such as 100 °C, 103 °C, 105 °C, 108 °C or 110 °C.

[0041] Preferably, the moisture removal under vacuum in step (1) is carried out at a temperature of 110 °C.

[0042] Preferably, the moisture removal under vacuum reduces the moisture to less than 0.05%, such as 0.05%, 0.04%, 0.03%, 0.02%, 0.01%, etc.

[0043] Preferably, the cooling in step (1) is cooling to 50 - 60 °C, such as 50 °C, 53 °C, 55 °C, 58 °C or 60 °C.

[0044] Preferably, the stirring and mixing in step (1) is carried out at a temperature of 50 - 60 °C (such as 50 °C, 53 °C, 55 °C, 58 °C or 60 °C) for 1 - 3 h (such as 1 h, 1.5 h, 2 h, 2.5 h or 3 h).

[0045] The viscosity of the component A obtained in step (1) at 50 °C is 500 - 1000 mPa·s, such as 500 mPa·s, 600 mPa·s, 700 mPa·s, 800 mPa·s, 900 mPa·s or 1000 mPa·s.

[0046] Preferably, the temperature of the reaction in step (2) is 75 - 85 °C, such as 75 °C, 78 °C, 80 °C, 83 °C or 85 °C, and the reaction time is 2 - 3 hours, such as 2 hours, 2.3 hours, 2.5 hours, 2.8 hours or 3 hours.

[0047] The viscosity of the B component obtained in step (2) at 50 °C is 500 - 1000 mPa·s, such as 500 mPa·s, 600 mPa·s, 700 mPa·s, 800 mPa·s, 900 mPa·s or 1000 mPa·s.

[0048] The heat-resistant polyurethane composition for tire filling described in the present invention has good fluidity, simple operation, low rolling internal heat generation. Compared with the traditional polyurethane composition for tire filling, it has a lower load sinking amount, lower rolling internal heat generation, and better heat resistance, and can be used for engineering vehicles traveling at high speeds.

[0049] On the other hand, the present invention provides an elastomer, which is obtained by curing the heat-resistant polyurethane composition for tire filling as described above.

[0050] Preferably, the hardness of the elastomer is 35 - 45 A, such as 35 A, 37 A, 38 A, 39 A, 40 A, 42 A, 44 A or 45 A.

[0051] On the other hand, the present invention provides a tire, and the preparation raw materials of the tire include the heat-resistant polyurethane composition for tire filling as described above.

[0052] In the present invention, the preparation method of the tire is as follows:

[0053] Mix the A component and the B component, inject them into the cavity of the tire according to the weight ratio of 1:1. After the polyurethane composition completely fills the cavity of the tire, seal the tire, perform heat treatment, cool down and cure to obtain the tire.

[0054] Preferably, the heat treatment is heating in an oven at 110 - 120 °C (such as 110 °C, 113 °C, 115 °C, 118 °C or 120 °C) for 2 - 3 h (such as 2 h, 2.3 h, 2.5 h, 2.8 h or 3 h).

[0055] Preferably, the cooling and curing is curing at 20 - 30 °C (such as 20 °C, 22 °C, 25 °C, 28 °C or 30 °C) for 7 - 10 days (such as 7 days, 7.5 days, 8 days, 8.5 days, 9 days, 9.5 days or 10 days).

[0056] Generally, when a tire rotates at high speed, the temperature of the tire rises. When the temperature is higher than the thermal degradation temperature of the polyurethane composition, the polyurethane composition will undergo thermal decomposition, resulting in a decrease in the hardness of the tire and a reduction in the load-bearing performance. At the same time, the thermal decomposition will cause a decrease in the weight of the polyurethane composition and an increase in the volatile matter, leading to an increase in the internal pressure of the tire and causing damage to the tire. The heat-resistant polyurethane composition for tire filling of the present invention has good heat resistance and low heat generation during operation. When the tire filled with this composition rotates at high speed (≥25 km / h), its internal temperature is always lower than its thermal degradation temperature, thus ensuring the safety and service life of the tire.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The heat-resistant polyurethane composition for tire filling prepared by the present invention uses polycaprolactone polyol as a raw material. The prepared elastomer has good heat resistance and a high thermal degradation temperature, which allows the tire to be used for a long time at a relatively high operating speed. Moreover, the prepared elastomer has good dynamic mechanical properties, and there is less heat generation during the actual application of the prepared tire.

[0059] The heat-resistant polyurethane composition for tire filling prepared by the present invention has a small viscosity after mixing, good fluidity, and a long pot life, and can fill the cavities of large tires.

[0060] The heat-resistant polyurethane composition of the present invention uses enzymatically hydrolyzed lignin as a cross-linking reinforcing agent. The tire filler has a high performance retention rate at a high temperature of 130 °C, improving the service life of the tire.

[0061] The heat-resistant polyurethane composition of the present invention uses a complex of 4,4'-diaminodiphenylmethane with good symmetry and sodium chloride (XLink311) as an amine chain extender. The prepared elastomer has good dynamic mechanical properties and high heat resistance.

[0062] The heat-resistant polyurethane composition of the present invention uses a high-boiling plasticizer, which can prevent the plasticizer from volatilizing during the use of the tire and improve the service life of the tire. The heat-resistant polyurethane composition for tire filling can be used to produce various large load-bearing filling tires with an operating speed ≥25 km / h and filling tires for vehicle equipment with extremely high requirements for puncture resistance, etc. Specific Embodiments

[0063] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0064] Example 1

[0065] This example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0066] Preparation of Component A: Add 2.1 kg of enzymatically hydrolyzed lignin (Shandong Longli Biotechnology Co., Ltd., LIG-II type) to 35.2 kg of polycaprolactone PCL3207, heat to 110 °C to melt, then keep at 110 °C and evacuate to remove moisture. When the moisture content drops to 0.05%, cool to 60 °C and add 4.1 kg of Xlink311 and 45.7 kg of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate to the reaction kettle and stir. Then add 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 1010, and 0.04 kg of catalyst UL-29, and stir at 55 °C for 2 h. After stirring evenly, cool to room temperature, seal and store. The viscosity at 50 °C is 560 mPa·s;

[0067] Preparation of Component B: React 33.80 kg of polycaprolactone PCL3207 with 15.4 kg of MDI and 1.0 kg of MDI-100L in a reaction kettle at 85 °C for 2 h, then add 50.5 kg of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate in a measured amount to obtain a prepolymer containing isocyanate groups. The viscosity at 50 °C is 550 mPa·s;

[0068] Inject Component A and Component B into the material tanks of a low-pressure casting machine respectively, and inject them into the cavity of the tire according to a weight ratio of 1:1. After the polyurethane composition completely fills the cavity of the tire, seal the tire. Place the tire in an oven at 120 °C and heat for 2 h. After taking it out, cure at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0069] Example 2

[0070] This example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0071] Preparation of Component A: Add 4.0 kg of enzymatically hydrolyzed lignin to 39.2 kg of polycaprolactone capa3301, heat to 110 °C to melt, then keep at 110 °C and evacuate to remove moisture. When the moisture content drops to 0.05%, cool to 50 °C and add 6.0 kg of Xlink311 and 53.7 kg of resorcinol bis(diphenyl phosphate) to the reaction kettle and stir. Then add 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 1076, and 0.1 kg of catalyst UL-29, and stir at 50 °C for 2 h. After stirring evenly, cool to room temperature, seal and store. The viscosity at 50 °C is 780 mPa·s;

[0072] Preparation of Component B: React 39.20 kg of polycaprolactone capa3301, 12.4 kg of TDI-80, and 2.0 kg of MDI in a reaction kettle at 80 °C for 3 hours. Then add 54.5 kg of dioctyl phthalate in a measured amount to obtain a prepolymer containing isocyanate groups with a viscosity of 810 mPa·s at 50 °C;

[0073] Inject Component A and Component B into the material tanks of a low-pressure casting machine respectively. According to a weight ratio of 1:1, inject them into the cavity of the tire equipped. After the polyurethane composition completely fills the cavity of the tire, seal the tire. Place the tire in an oven at 120 °C and heat for 2 h. After taking it out, cure at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0074] Example 3

[0075] This example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0076] Preparation of Component A: Add 5.8 kg of enzymatically hydrolyzed lignin to 31.3 kg of polycaprolactone PCL3207, heat to 110 °C to melt, and then keep at 110 °C to evacuate and remove moisture. When the moisture content is reduced to 0.05%, cool to 60 °C and add 2.6 kg of Xlink311 and 33.3 kg of triphenyl phosphate isopropyl to the reaction kettle and stir. Then add 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 245, and 0.16 kg of catalyst UL-29 in a measured amount and stir at 60 °C for 2 h. After stirring evenly, cool to room temperature and store in a sealed manner with a viscosity of 620 mPa·s at 50 °C;

[0077] Preparation of Component B: React 31.80 kg of polycaprolactone PCL3207, 17.4 kg of MDI, and 1.5 kg of TDI-100 in a reaction kettle at 75 °C for 2 hours. Then add 43.6 kg of aromatic oil with a boiling point > 270 °C (Changzhou Heshili Chemical Co., Ltd., aromatic solvent s-3000) in a measured amount to obtain a prepolymer containing isocyanate groups with a viscosity of 660 mPa·s at 50 °C;

[0078] Inject Component A and Component B into the material tanks of a low-pressure casting machine respectively. According to a weight ratio of 1:1, inject them into the cavity of the tire equipped. After the polyurethane composition completely fills the cavity of the tire, seal the tire. Place the tire in an oven at 120 °C and heat for 2 h. After taking it out, cure at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0079] Comparative Example 1

[0080] This comparative example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0081] Preparation of Component A: Heat 35.2 kg of polycaprolactone PCL3207 to 110 °C to melt it, then keep it at 110 °C and evacuate to remove moisture. When the moisture content is reduced to 0.05%, cool it to 60 °C and add 4.1 kg of Xlink311 and 45.7 kg of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate to the reaction kettle and stir. Then add a measured amount of 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 1010, and 0.04 kg of catalyst UL-29, and stir at 55 °C for 2 h. After stirring evenly, cool it to room temperature, seal it for storage, and the viscosity at 50 °C is 480 mPa·s;

[0082] Preparation of Component B: React 33.80 kg of polycaprolactone PCL3207 with 15.4 kg of MDI and 1.0 kg of MDI-100L in the reaction kettle at 85 °C for 2 h, then add a measured amount of 50.5 kg of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate to obtain a prepolymer containing isocyanate groups, and the viscosity at 50 °C is 510 mPa·s;

[0083] Inject Component A and Component B into the material tanks of a low-pressure casting machine respectively, and inject them into the cavity of the tire according to a weight ratio of 1:1. After the polyurethane composition completely fills the cavity of the tire, seal the tire. Place the tire in an oven at 120 °C and heat for 2 h, and cure at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0084] Comparative Example 2

[0085] This comparative example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0086] Preparation of Component A: Add 4.0 kg of enzymatically hydrolyzed lignin to 39.2 kg of polycaprolactone capa3301, heat to 110 °C to melt it, then keep it at 110 °C and evacuate to remove moisture. When the moisture content is reduced to 0.05%, cool it to 50 °C and add 6.0 kg of Xlink311 and 53.7 kg of aromatic oil with a boiling point of about 200 °C (high-boiling aromatic solvent oil S-1500 from Wujiang Hongwei Environmental Protection Additive Co., Ltd.) to the reaction kettle and stir. Then add a measured amount of 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 1076, and 0.1 kg of catalyst UL-29, and stir at 50 - 60 °C for 2 h. After stirring evenly, cool it to room temperature, seal it for storage, and the viscosity at 50 °C is 680 mPa·s;

[0087] Preparation of Component B: 39.20 kg of polycaprolactone capa3301, 12.4 kg of TDI-80, and 2.0 kg of MDI were reacted in a reaction kettle at 80 °C for 3 hours. Then, 54.5 kg of aromatic oil with a boiling point of about 200 °C (high-boiling aromatic solvent oil S-1500 from Wujiang Hongwei Environmental Protection Additive Co., Ltd.) was added in a measured amount to obtain a prepolymer containing isocyanate groups, with a viscosity of 710 mPa·s at 50 °C;

[0088] Component A and Component B were respectively injected into the material tanks of a low-pressure casting machine and injected into the cavity of the tire according to a weight ratio of 1:1. After the polyurethane composition completely filled the cavity of the tire, the tire was sealed. The tire was placed in an oven at 120 °C and heated for 2 h, and after being taken out, it was cured at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0089] Comparative Example 3

[0090] This comparative example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0091] Preparation of Component A: 5.8 kg of enzymatically hydrolyzed lignin was added to 31.3 kg of polyether polyol 330N, heated to 110 °C to melt, and then vacuumed to remove moisture while maintaining 110 °C. When the moisture decreased to 0.05%, the temperature was lowered to 60 °C, and 2.6 kg of Xlink311 and 33.3 kg of triphenyl phosphate isopropyl were added to the reaction kettle and stirred. Then, 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 245, and 0.16 kg of catalyst UL-29 were added in a measured amount and stirred at 60 °C for 2 h. After stirring evenly, the temperature was lowered to room temperature and sealed for storage, with a viscosity of 351 mPa·s at 50 °C;

[0092] Preparation of Component B: 31.80 kg of polyether polyol 330N, 17.4 kg of MDI, and 1.5 kg of TDI-100 were reacted in a reaction kettle at 75 °C for 2 hours. Then, 43.6 kg of aromatic oil with a boiling point > 270 °C was added in a measured amount to obtain a prepolymer containing isocyanate groups, with a viscosity of 372 mPa·s at 50 °C;

[0093] Component A and Component B were respectively injected into the material tanks of a low-pressure casting machine and injected into the cavity of the tire according to a weight ratio of 1:1. After the polyurethane composition completely filled the cavity of the tire, the tire was sealed. The tire was placed in an oven at 120 °C and heated for 2 h, and after being taken out, it was cured at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0094] Comparative Example 4

[0095] This comparative example provides a heat-resistant polyurethane composition for tire filling and a tire prepared therefrom:

[0096] Preparation of Component A: Add 2.1 kg of enzymatically hydrolyzed lignin to 35.2 kg of polycaprolactone PCL3207, heat to 110 °C to melt, then maintain at 110 °C and evacuate to remove moisture. When the moisture content is reduced to 0.05%, cool to 60 °C and add 4.1 kg of DETDA and 45.7 kg of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate to the reaction kettle and stir. Then add a measured amount of 0.5 kg of defoamer SAG47, 1.0 kg of antioxidant 1010, and 0.04 kg of catalyst UL-29 and stir at 55 °C for 2 h. After stirring evenly, cool to room temperature, seal and store. The viscosity at 50 °C is 515 mPa·s;

[0097] Preparation of Component B: React 33.80 kg of polycaprolactone PCL3207 with 15.4 kg of MDI and 1.0 kg of MDI-100L in the reaction kettle for 2 h, then add a measured amount of 50.5 kg of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate to obtain a prepolymer containing isocyanate groups. The viscosity at 50 °C is 560 mPa·s;

[0098] Inject Component A and Component B into the material tanks of a low-pressure casting machine respectively, and inject them into the cavity of the tire according to a weight ratio of 1:1. After the polyurethane composition completely fills the cavity of the tire, seal the tire. Place the tire in an oven at 120 °C and heat for 2 h. After taking it out, cure at 25 °C for 7 days to achieve the final curing effect. The performance test indexes are shown in Table 1.

[0099] Table 1 Performance Test Indexes

[0100]

[0101] Hardness: Test the hardness with a Shore A durometer according to GB / T 531-2008.

[0102] Rebound rate: Test the falling ball rebound rate according to GB / T 6670-2008.

[0103] Compression set: Test the compression set of the polyurethane elastomer test piece sample at 70 °C for 22 h according to GB / T 7759.1-2015.

[0104] Tensile strength: Test the tensile strength of the polyurethane elastomer test piece sample according to GB / T 528-2009.

[0105] Tire fatigue test: The polyurethane-filled tire is paired with an engineering truck tire, and the test is carried out on a radial load fatigue testing machine for the load wheel (the size model of the engineering truck tire is 355 / 55D625). The load is 1000 kg, and it rolls at a speed of 25 km / h for 10,000 km. During the tire fatigue test, a temperature sensor is equipped inside the tire to measure the internal temperature change. After the tire fatigue test, the tire is cooled to room temperature, and the weight of the tire is measured and compared with the weight before the fatigue test. The tire is cut to take samples for testing the tensile strength and compared with the tensile strength before the fatigue test.

[0106] The applicant declares that the present invention uses the above embodiments to illustrate the heat-resistant polyurethane composition for tire filling, its preparation method and application of the present invention. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A heat-resistant polyurethane composition for tire filling, characterized in that: The composition comprises component A and component B. The raw materials for preparing component A comprise the following components in parts by weight: In parts by weight, the raw materials for preparing the B component include the following components: 30-40 parts of polycaprolactone polyol 30-60 parts of high boiling point plasticizer Isocyanate 10-20 parts.

2. The heat-resistant polyurethane composition for tire filling according to claim 1, characterized in that: The molecular weight of the polycaprolactone polyol is 2000-3000; Preferably, the functionality of the polycaprolactone polyol is 3; Preferably, the polycaprolactone polyol includes one or a combination of at least two of PCL-3207 from Polyren Chemical, capa3201 or capa3301 from Perstorp.

3. The heat-resistant polyurethane composition for tire filling according to claim 1 or 2, characterized in that: The cross-linking reinforcing agent is enzymatic lignin; Preferably, the small molecule polyamine is a diamine chain extender; Preferably, the small molecule polyamine is a complex of 4,4'-diaminodiphenylmethane and sodium chloride dispersed in an ester plasticizer; Preferably, the small molecule polyamine is Suzhou Xiangyuan Xlink311.

4. The heat-resistant polyurethane composition for tire filling according to any one of claims 1 to 3, characterized in that: The high boiling point plasticizer is a low volatility plasticizer with a boiling point higher than 250°C; Preferably, the high boiling point plasticizer can be one or a combination of at least two of aromatic hydrocarbons, fatty acid esters, phthalates, terephthalates, phosphates, and halogenated phosphate plasticizers; Preferably, the viscosity of the high boiling point plasticizer at 25°C is less than 300 mPa·s; more preferably less than 100 mPa·s; Preferably, the aromatic hydrocarbon plasticizer is an aromatic hydrocarbon oil with a boiling point of >250°C; Preferably, the fatty acid ester plasticizer is 2,2,4-trimethyl-1,3-pentanediol diisobutyrate. Preferably, the phthalate plasticizer is any one of dioctyl phthalate, diethyl phthalate or dibutyl phthalate, or a combination of at least two thereof; Preferably, the phosphate plasticizer is isopropylated triphenyl phosphate and / or resorcinol bis(diphenyl phosphate); Preferably, the halogenated phosphate plasticizer is tris(2-chloropropyl) phosphate.

5. The heat-resistant polyurethane composition for tire filling according to any one of claims 1 to 4, characterized in that: The isocyanate is selected from one or a combination of at least two of a mixture of 2,6-toluene diisocyanate and 2,4-toluene diisocyanate, diphenylmethane diisocyanate or liquefied diphenylmethane diisocyanate.

6. The heat-resistant polyurethane composition for tire filling according to any one of claims 1 to 5, characterized in that: The raw materials for preparing the A component also include 0.3-1 part of a defoaming agent; Preferably, the defoamer is a solvent-free silicone oil defoamer, preferably Maitu SAKG47; Preferably, the raw materials for preparing component A also include 0.5-2.0 parts of a thermal oxygen stabilizer; Preferably, the thermal oxygen stabilizer is selected from one or a combination of at least two of antioxidant 245, antioxidant 1010, and antioxidant 1076; Preferably, the raw materials for preparing the A component also include 0.02-0.5 parts of a catalyst; Preferably, the catalyst is selected from a delayed metal catalyst, and the delayed metal catalyst is preferably Momentive UL-29; Preferably, the viscosity of component A at 50°C is 500-1000 mPa·s; The viscosity of the B component at 50° C. is 500-1000 mPa·s.

7. A method for preparing the heat-resistant polyurethane composition for tire filling according to any one of claims 1 to 6, the method comprising the following steps: (1) mixing a cross-linking reinforcing agent and a polycaprolactone polyol, heating and melting them, then removing moisture in a vacuum, cooling, adding a small molecule polyamine, a high boiling point plasticizer, and an optional defoaming agent, an optional thermal oxidation stabilizer, and an optional catalyst, stirring and mixing, to obtain the A component; (2) reacting polycaprolactone polyol with isocyanate, and then adding a high boiling point plasticizer to obtain component B; Preferably, the heating and melting in step (1) is heating to 100-110° C. Preferably, the vacuum dehydration in step (1) is carried out at a temperature of 110°C; Preferably, the vacuum dehumidification reduces the moisture content to below 0.05%; Preferably, the cooling in step (1) is to cool to 50-60°C; Preferably, the stirring and mixing in step (1) is carried out at a temperature of 50-60° C. for 1-3 hours; Preferably, the reaction temperature in step (2) is 75-85°C, and the reaction time is 2-3 hours.

8. An elastomer, characterized in that: The elastomer is obtained by curing the heat-resistant polyurethane composition for tire filling according to any one of claims 1 to 6; Preferably, the hardness of the elastomer is 35-45A.

9. A tire, characterized in that: The raw material for preparing the tire comprises the heat-resistant polyurethane composition for tire filling according to any one of claims 1 to 7.

10. The method for preparing a tire according to claim 9, characterized in that: The preparation method comprises the following steps: Mixing component A and component B at a weight ratio of 1:1, injecting the mixture into a cavity containing a tire, and after the polyurethane composition completely fills the cavity of the tire, sealing the tire, heating it, cooling it, and curing it to obtain the tire; Preferably, the heating treatment is heating in an oven at 110-120° C. for 2-3 hours; Preferably, the curing by temperature reduction is curing at 20-30° C. for 7-10 days.

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