A one-component polyurethane adhesive, its preparation method and application

Abstract

The present invention discloses a one-component polyurethane adhesive and its preparation method and application, belonging to the technical field of adhesives. The one-component polyurethane adhesive of the present invention comprises the following components in parts by weight: 20-40 parts of polyurethane prepolymer, 10-25 parts of plasticizer, 20-40 parts of filler, 1-3 parts of silane coupling agent, 0.5-2 parts of water remover, and 0.1-0.5 part of catalyst; the polyurethane prepolymer is prepared by reacting isocyanate, polyether polyol, polyester polyol, polyetheramine and catalyst. The one-component polyurethane adhesive of the present invention has the advantages of high temperature resistance, high bonding strength, good water resistance, high oxidation resistance, good fatigue resistance and good aging resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and particularly relates to a one-component polyurethane adhesive and a preparation method and application thereof. Background Art

[0002] With the rise of the automotive industry, the requirements for automobile tires are getting higher and higher. The traditional inflation method of tires may bring potential safety hazards of tire blowouts, which has led to the emergence of non-pneumatic tires. Non-pneumatic tires have the advantages of safety, no risk of blowouts, comfortable ride, and strong durability, and are one of the future development trends of automobile tires.

[0003] Non-pneumatic tires generally consist of an aluminum alloy rim, a rubber spoke, and a rubber tread, and are bonded together through an adhesive to form an integral structure. During use, when the tread contacts the ground, high temperatures (about 90°C) will be generated. At the same time, it is necessary to be in contact with water vapor and oxygen for a long time, and the tire undergoes repeated deformations during the process of bearing and rolling. Therefore, the adhesive is required to have good bonding strength (≥4 MPa) at high temperatures, and also have good water resistance, antioxidant properties, and dynamic fatigue aging properties, and the bonding strength after aging is ≥4 MPa.

[0004] Chinese Patent CN200710031519 provides an adhesive and a preparation method thereof that can be used for bonding fluororubber, with a bonding strength ≥3.5 MPa, a fast crosslinking and curing speed, good flexibility after curing, no cracking, and can be used at a high temperature of 250°C.

[0005] Chinese Patent CN201310203286 provides an adhesive and a preparation method thereof for rapid mutual adhesion of vulcanized silicone rubber. This adhesive has the advantages of fast curing speed, short curing cycle, and high bonding strength, and the T-peel strength can reach more than 10 KN / m.

[0006] Chinese Patent CN202010448619 provides an adhesive film for rubber materials and a use method thereof. This adhesive bonds to nitrile rubber, does not flow during the bonding process, has good thixotropy, extends the operation cycle of the coating process, reduces the difficulty coefficient of the coating process, and at the same time reduces the coating workload.

[0007] None of the above inventions can meet the requirements of non-pneumatic tire bonding for temperature resistance, bonding strength, and aging resistance. Summary of the Invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a one-component polyurethane adhesive with high temperature resistance, high bonding strength, good water resistance, high antioxidant properties, good fatigue resistance, and good aging resistance, as well as a preparation method and application thereof.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] In a first aspect, the present invention provides a one-component polyurethane adhesive, comprising the following components in parts by weight: 20-40 parts of a polyurethane prepolymer, 10-25 parts of a plasticizer, 20-40 parts of a filler, 1-3 parts of a silane coupling agent, 0.5-2 parts of a water scavenger, and 0.1-0.5 parts of a catalyst;

[0011] The polyurethane prepolymer is prepared by reacting an isocyanate, a polyether polyol, a polyester polyol, a polyetheramine, and a catalyst.

[0012] In the present invention, a polyether polyol molecular chain segment is introduced into the polyurethane adhesive, improving the fatigue resistance and high-temperature resistance of the polyurethane adhesive; at the same time, polyetheramine is introduced, enabling the reaction of isocyanate groups with amino groups to form polyurea groups, thereby enhancing the high-temperature bonding strength, high-temperature fatigue resistance, and aging resistance of the product. During the moisture curing process of the present invention, isocyanate reacts with water, crosslinking and curing to form urea groups with high polarity and high bond energy, further increasing the bonding strength and high-temperature resistance of the polyurethane adhesive.

[0013] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, the NCO content of the polyurethane prepolymer is 4-8%.

[0014] In the present invention, the NCO content of the polyurethane prepolymer affects the performance of the polyurethane adhesive. If the NCO content is too low, the product has poor high-temperature resistance and low bonding strength. If the NCO content is too high, the fatigue resistance of the product decreases sharply. The inventor selects the NCO content of the polyurethane prepolymer to be 4-8% to obtain a polyurethane adhesive with good high-temperature resistance, high bonding strength, and high high-temperature fatigue resistance.

[0015] Preferably, the preparation method of the polyurethane prepolymer is as follows: dehydrate the polyether polyol, polyester polyol, and polyetheramine at 120°C to 130°C and -0.095 Mpa for 2-4 hours, cool to 60°C, add the isocyanate, and react at 75°C to 80°C until the theoretical NCO is reached to obtain the polyurethane prepolymer.

[0016] By controlling parameters such as temperature and time during the preparation of the polyurethane prepolymer within the above preferred range, the obtained polyurethane prepolymer has relatively certain properties and can play an ideal role in the entire polyurethane adhesive.

[0017] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, the mass ratio of the isocyanate, polyether polyol, polyester polyol, polyetheramine, and catalyst is isocyanate: polyether polyol: polyester polyol: polyetheramine: catalyst = 4-5: 2-4: 4-6: 1-3: 0.004-0.005.

[0018] The mass ratio of the above raw materials affects the NCO content of the polyurethane prepolymer. By controlling the mass ratio of the raw materials, a polyurethane prepolymer with an NCO content of 4-6% can be obtained.

[0019] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, the polyether polyol is polypropylene glycol and / or polytetrahydrofuran glycol; the average molecular weight of the polyether polyol is 500-3000; the functionality of the polyether polyol is 2-3.

[0020] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, the polyester polyol is polybutylene adipate; the average molecular weight of the polyester polyol is 500-3000; the functionality of the polyester polyol is 2-3.

[0021] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, the catalyst is at least one of dibutyltin dilaurate, stannous octoate, and bis(morpholino)diethyl ether; the isocyanate is toluene diisocyanate or diphenylmethane diisocyanate.

[0022] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, the average molecular weight of the polyetheramine is 2000-3000.

[0023] As a preferred embodiment of the one-component polyurethane adhesive of the present invention, at least one of the following (a)-(d):

[0024] (a) The plasticizer is at least one of dioctyl phthalate, dibutyl phthalate, and diisononyl phthalate;

[0025] (b) The filler is at least one of carbon black, silica powder, fumed silica, and calcium carbonate; the filler of the present invention is a solid and insoluble in the polyol component. The particle size of the filler is 100 nm-100 μm. The preferred particle size is 1 μm-10 μm. The filler mainly improves the viscosity of the adhesive, making it more conducive to construction, and at the same time can also improve the mechanical properties of the polyurethane adhesive.

[0026] (c) The silane coupling agent is at least one of 3-aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, and methacryloxypropyltrimethoxysilane;

[0027] The silane coupling agent added in the present invention can form a new interface layer at the bonding layer and the rubber bonding interface, and can increase the effect of interface bonding.

[0028] (d) The water scavenger is at least one of oxazolidine, vinyltrimethoxysilane, and phenyl isocyanate;

[0029] The water scavenger added in the present invention can reduce the moisture content of the polyurethane adhesive and improve the stability of the polyurethane adhesive.

[0030] (f) The catalyst is at least one of dibutyltin dilaurate, stannous octoate, and bis(morpholino)diethyl ether.

[0031] The catalyst added in the present invention catalyzes the reaction between the NCO group and moisture, promotes crosslinking and curing, and improves the bonding strength between the polyurethane adhesive and the rubber.

[0032] In the second aspect, the present invention also provides a method for preparing the above-mentioned one-component polyurethane adhesive, which includes the following steps: uniformly stirring the polyurethane prepolymer, plasticizer, filler, silane coupling agent, water scavenger, and catalyst to obtain the one-component polyurethane adhesive.

[0033] During the preparation of the one-component polyurethane adhesive, the plasticizer and filler need to be pretreated separately.

[0034] The method for pretreating the plasticizer is: dehydrating the plasticizer at 120°C - 130°C under a condition of -0.095 Mpa for 2 hours.

[0035] The method for pretreating the filler is: baking the filler at 150 - 250°C for 20 - 30 h, and then cooling to obtain the filler.

[0036] The purpose of baking and pretreating the filler is to remove the moisture in the filler, prevent the water in the filler from reacting with the polyurethane prepolymer, and affect the performance of the adhesive or cause gelation. During the pretreatment process of the filler, the baking temperature is the main factor affecting the performance of the filler. When the temperature is lower than 150°C, the bound water in the filler cannot be removed. If the baking temperature of the filler is too high, the physical and chemical properties of the filler will change, resulting in a decline in the performance of the product.

[0037] In the third aspect, the present invention also provides the application of the above-mentioned one-component polyurethane adhesive in the bonding of non-inflatable tires.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) The present invention introduces a polyether polyol molecular chain segment into the polyurethane adhesive, improving the fatigue resistance and high-temperature resistance of the polyurethane adhesive; at the same time, polyetheramine is introduced, enabling the isocyanate group to react with the amino group to form a polyurea group, thereby improving the high-temperature bonding strength, high-temperature fatigue resistance, and aging resistance of the product. During the moisture curing process of the present invention, the isocyanate reacts with water, crosslinks and cures, forming a urea group with high polarity and high bond energy, further increasing the bonding strength and high-temperature resistance of the polyurethane adhesive.

[0040] (2) The curing process of the polyurethane adhesive of the present invention is moisture curing, without the need for vulcanization at high temperature, thus simplifying the use of equipment and processes. At the same time, it avoids the accelerated aging effect on the tread and spoke rubber of non-inflatable tires during high-temperature vulcanization, making up for some deficiencies of the current hot vulcanization bonding process for rubber bonding. Detailed implementation manners

[0041] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0042] In the embodiments, the experimental methods used are all conventional methods without special instructions, and the materials, reagents, etc. used can all be obtained from commercial channels without special instructions.

[0043] The raw materials used in the examples and comparative examples are described as follows, but are not limited to these materials:

[0044] Polyether polyol 1: Polytetrahydrofuran diol, PTMG-1000, with an average molecular weight of 1000 and a functionality of 2, manufactured by BASF;

[0045] Polyether polyol 2: Polytetrahydrofuran diol, PTMG-3000, with an average molecular weight of 3000 and a functionality of 2, manufactured by BASF;

[0046] Polyether polyol 3: Polytetrahydrofuran diol, PTMG-500, with an average molecular weight of 500 and a functionality of 2, manufactured by BASF;

[0047] Polyether polyol 4: Polypropylene glycol, with an average molecular weight of 1000 and a functionality of 2, manufactured by JiaHua Chemical;

[0048] Polyester polyol 1: Polybutylene adipate, PBA-2000, with an average molecular weight of 2000 and a functionality of 2, manufactured by Asahi Kasei Chemicals;

[0049] Polyetheramine 1: Polyetheramine D-2000, with an average molecular weight of 2000; manufactured by Huntsman;

[0050] Polyetheramine 2: Polyetheramine T-3000, with an average molecular weight of 3000; manufactured by Huntsman;

[0051] Polyetheramine 3: Polyetheramine T-5000, with an average molecular weight of 5000. Manufactured by Huntsman.

[0052] Example 1

[0053] This example provides a polyurethane prepolymer, comprising the following raw materials in parts by weight: 300 parts of polyether polyol 1, 500 parts of polyester polyol, 200 parts of polyetheramine 1, 420 parts of diphenylmethane diisocyanate, and 0.5 part of dibutyltin dilaurate;

[0054] This embodiment also provides a method for preparing a polyurethane prepolymer, comprising the following steps:

[0055] Add polyether polyol 1, polyester polyol, and polyetheramine 1 into a reaction kettle, heat the temperature of the reaction kettle to 120 °C, evacuate to -0.095 MPa, dehydrate for 2 h, test the moisture content every half hour. When the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 80 °C, add diphenylmethane diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour. When the NCO content decline tends to be stable, end the reaction to obtain the polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 6%.

[0056] Example 2

[0057] This embodiment provides a polyurethane prepolymer, comprising the following raw materials in parts by weight: 300 parts of polyether polyol 2, 500 parts of polyester polyol, 200 parts of polyetheramine 2, 420 parts of diphenylmethane diisocyanate, 0.5 part of dibutyltin dilaurate;

[0058] This embodiment also provides a method for preparing a polyurethane prepolymer, comprising the following steps:

[0059] Add polyether polyol 2, polyester polyol, and polyetheramine 2 into a reaction kettle, heat the temperature of the reaction kettle to 130 °C, evacuate to -0.095 MPa, test the moisture content every half hour. When the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 75 °C, add diphenylmethane diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour. When the NCO content decline tends to be stable, end the reaction to obtain the polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 6%.

[0060] Example 3

[0061] This embodiment provides a polyurethane prepolymer, comprising the following raw materials in parts by weight: 300 parts of polyether polyol 3, 500 parts of polyester polyol, 200 parts of polyetheramine 3, 390 parts of toluene diisocyanate, 0.5 part of dibutyltin dilaurate;

[0062] This embodiment also provides a method for preparing a polyurethane prepolymer, comprising the following steps:

[0063] Add polyether polyol 3, polyester polyol, and polyetheramine 3 into the reaction kettle. Heat the temperature of the reaction kettle to 125°C, evacuate to -0.095 MPa, and dehydrate for 2 h. Test the moisture content every half hour. When the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 78°C, add toluene diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour. When the NCO content decline tends to be stable, end the reaction to obtain a polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 8%.

[0064] Example 4

[0065] This example provides a polyurethane prepolymer, including the following raw materials in parts by weight: 300 parts of polyether polyol 4, 500 parts of polyester polyol, 200 parts of polyetheramine 1, 320 parts of diphenylmethane diisocyanate, 0.5 part of dibutyltin dilaurate;

[0066] This example also provides a preparation method of a polyurethane prepolymer, including the following steps:

[0067] Add polyether polyol 1, polyester polyol, and polyetheramine 1 into the reaction kettle. Heat the temperature of the reaction kettle to 120°C, evacuate to -0.095 MPa, and dehydrate for 2 h. Test the moisture content every half hour. When the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 80°C, add diphenylmethane diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour. When the NCO content decline tends to be stable, end the reaction to obtain a polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 4%.

[0068] Comparative Example 1

[0069] This comparative example provides a polyurethane prepolymer, including the following raw materials in parts by weight: 300 parts of polyether polyol 1, 500 parts of polyester polyol, 420 parts of diphenylmethane diisocyanate, 0.5 part of dibutyltin dilaurate;

[0070] This comparative example also provides a preparation method of a polyurethane prepolymer, including the following steps:

[0071] Add polyether polyol 1 and polyester polyol into the reaction kettle. Heat the temperature of the reaction kettle to 120°C, evacuate to -0.095 MPa, and dehydrate for 2 h. Test the moisture content every half hour. When the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 80°C, add diphenylmethane diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour. When the NCO content decline tends to be stable, end the reaction to obtain a polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 6%.

[0072] Comparative Example 2

[0073] This example provides a polyurethane prepolymer, comprising the following raw materials in parts by weight: 300 parts of polyether polyol 3, 500 parts of polyester polyol, 200 parts of polyetheramine 3, 425 parts of toluene diisocyanate, 0.5 part of dibutyltin dilaurate;

[0074] This example also provides a method for preparing a polyurethane prepolymer, comprising the following steps:

[0075] Add polyether polyol 3, polyester polyol, and polyetheramine 3 into a reaction kettle, heat the temperature of the reaction kettle to 125°C, evacuate to -0.095 MPa, dehydrate for 2 h, test the moisture content every half hour, when the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 78°C, add toluene diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour, and end the reaction when the NCO content decline tends to be stable, to obtain a polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 9%.

[0076] Comparative Example 3

[0077] This example provides a polyurethane prepolymer, comprising the following raw materials in parts by weight: 300 parts of polyether polyol 3, 500 parts of polyester polyol, 200 parts of polyetheramine 3, 236 parts of toluene diisocyanate, 0.5 part of dibutyltin dilaurate;

[0078] This example also provides a method for preparing a polyurethane prepolymer, comprising the following steps:

[0079] Add polyether polyol 3, polyester polyol, and polyetheramine 3 into a reaction kettle, heat the temperature of the reaction kettle to 125°C, evacuate to -0.095 MPa, dehydrate for 2 h, test the moisture content every half hour, when the moisture content ≤ 500 ppm; after reducing the temperature of the reaction kettle to 78°C, add toluene diisocyanate and dibutyltin dilaurate, keep warm and stir, test the NCO percentage content every half hour, and end the reaction when the NCO content decline tends to be stable, to obtain a polyurethane prepolymer, and the NCO content of the polyurethane prepolymer = 3%.

[0080] Example 5

[0081] This example provides a one-component polyurethane adhesive, comprising the following components in parts by weight: 32 parts of the polyurethane prepolymer obtained in Example 1, 25 parts of diisononyl phthalate, 16 parts of carbon black, 23 parts of nano calcium carbonate, 2.7 parts of glycidoxypropyltrimethoxysilane, 0.8 part of phenyl isocyanate, 0.1 part of dibutyltin dilaurate, 0.4 part of bis(morpholinoethyl) ether.

[0082] This embodiment also provides a preparation method of a one-component polyurethane adhesive, comprising the following steps:

[0083] S1: Dehydrate diisononyl phthalate at 130°C and -0.095 Mpa for 2 hours;

[0084] S2: Bake carbon black and nano calcium carbonate at 150°C for 24 hours respectively, and then cool to room temperature to obtain carbon black and nano calcium carbonate;

[0085] S3: Place the diisononyl phthalate, phenyl isocyanate obtained in step S1 and the polyurethane prepolymer obtained in Example 1 into a reaction kettle, stir under vacuum for 15 minutes, then add the carbon black and nano calcium carbonate obtained in step S2, stir under vacuum for 1 hour, and then add glycidyl ether oxypropyl trimethoxysilane, dibutyltin dilaurate and bis(morpholinoethyl) ether, stir under vacuum for 20 minutes, and then a one-component polyurethane adhesive is obtained.

[0086] Example 6

[0087] This embodiment provides a one-component polyurethane adhesive, comprising the following components in parts by weight: 40 parts of the polyurethane prepolymer obtained in Example 1, 15 parts of dioctyl phthalate, 12 parts of carbon black, 5 parts of fumed silica, 24.2 parts of silica powder, 2 parts of glycidyl ether oxypropyl trimethoxysilane, 1 part of methacryloxypropyl trimethoxysilane, 0.5 part of vinyl trimethoxysilane, 0.04 part of dibutyltin dilaurate, 0.26 part of bis(morpholinoethyl) ether.

[0088] This embodiment also provides a preparation method of a one-component polyurethane adhesive, comprising the following steps:

[0089] S1: Dehydrate dioctyl phthalate at 120°C and -0.095 Mpa for 2 hours;

[0090] S2: Bake carbon black, fumed silica and silica powder at 150°C for 24 hours respectively to obtain carbon black, fumed silica and silica powder;

[0091] S3: Place the dioctyl phthalate, vinyl trimethoxysilane obtained in step S1 and the polyurethane prepolymer obtained in Example 1 into a reaction kettle, stir under vacuum for 15 minutes, then add the carbon black, fumed silica and silica powder obtained in step S2, stir under vacuum for 1 hour, and then add glycidyl ether oxypropyl trimethoxysilane, methacryloxypropyl trimethoxysilane, dibutyltin dilaurate and bis(morpholinoethyl) ether, stir under vacuum for 20 minutes, and then a one-component polyurethane adhesive is obtained.

[0092] Example 7

[0093] This example provides a one-component polyurethane adhesive, comprising the following components in parts by weight: 35 parts of the polyurethane prepolymer obtained in Example 1, 10 parts of dioctyl phthalate, 12 parts of dibutyl phthalate, 18 parts of carbon black, 2 parts of fumed silica, 19.5 parts of silica powder, 1 part of glycidoxypropyltrimethoxysilane, 1 part of aminopropyltriethoxysilane, 1.2 parts of phenyl isocyanate, 0.1 part of dibutyltin dilaurate, and 0.2 part of bis(morpholinoethyl)ether.

[0094] This example also provides a method for preparing a one-component polyurethane adhesive, comprising the following steps:

[0095] S1: Dehydrate dioctyl phthalate and dibutyl phthalate at 125 °C and -0.095 Mpa for 2 hours.

[0096] S2: Bake carbon black, fumed silica, and silica powder at 150 °C for 24 h respectively, and cool to room temperature to obtain carbon black, fumed silica, and silica powder.

[0097] S3: Place the dioctyl phthalate, dibutyl phthalate, phenyl isocyanate obtained in step S1, and the polyurethane prepolymer obtained in Example 1 into a reaction kettle, stir under vacuum for 15 min, then add the carbon black, fumed silica, and silica powder obtained in step S2, stir under vacuum for 1 h, and then add glycidoxypropyltrimethoxysilane, aminopropyltriethoxysilane, dibutyltin dilaurate, and bis(morpholinoethyl)ether, stir under vacuum for 20 min, and thus obtain the one-component polyurethane adhesive.

[0098] Example 8

[0099] This example provides a one-component polyurethane adhesive and its preparation method. The difference between this example and Example 5 is only that 32 parts of the polyurethane prepolymer obtained in Example 2 are used to replace 32 parts of the polyurethane prepolymer obtained in Example 1.

[0100] Example 9

[0101] This example provides a one-component polyurethane adhesive and its preparation method. The difference between this example and Example 5 is only that 32 parts of the polyurethane prepolymer obtained in Example 3 are used to replace 32 parts of the polyurethane prepolymer obtained in Example 1.

[0102] Example 10

[0103] This example provides a one-component polyurethane adhesive and its preparation method. The difference between this example and Example 5 is only that 32 parts of the polyurethane prepolymer obtained in Example 4 are used to replace 32 parts of the polyurethane prepolymer obtained in Example 1.

[0104] Comparative Example 4

[0105] This comparative example provides a one-component polyurethane adhesive and its preparation method. The difference between this comparative example and Example 5 is only that 32 parts of the polyurethane prepolymer obtained in Comparative Example 1 are used to replace 32 parts of the polyurethane prepolymer obtained in Example 1.

[0106] Comparative Example 5

[0107] This comparative example provides a one-component polyurethane adhesive and its preparation method. The difference between this comparative example and Example 5 is only that 32 parts of the polyurethane prepolymer obtained in Comparative Example 2 are used to replace 32 parts of the polyurethane prepolymer obtained in Example 1.

[0108] Comparative Example 6

[0109] This comparative example provides a one-component polyurethane adhesive and its preparation method. The difference between this comparative example and Example 5 is only that 32 parts of the polyurethane prepolymer obtained in Comparative Example 3 are used to replace 32 parts of the polyurethane prepolymer obtained in Example 1.

[0110] Performance Test

[0111] The one-component polyurethane adhesives obtained in Examples 5 - 10 and Comparative Examples 4 - 6 were subjected to performance tests. The test methods are as follows:

[0112] (1) Hardness (unit: Shore A): GB / T 531 - 1999 Rubber Pocket Hardness Tester Indentation Hardness Test Method;

[0113] (2) Tensile strength (unit: MPa): GB / T 528 - 2009 Determination of Tensile Stress - Strain Properties of Vulcanized Rubber or Thermoplastic Rubber;

[0114] (3) Elongation at break (unit: %): GB / T 528 - 2009 Determination of Tensile Stress - Strain Properties of Vulcanized Rubber or Thermoplastic Rubber;

[0115] (4) Shear strength (unit: MPa): GB / T 7124 - 2008 Determination of Tensile Shear Strength of Adhesives;

[0116] (5) Dynamic fatigue failure state: Visual inspection, divided into interfacial failure and cohesive failure;

[0117] (6) Shear strength after 3 million times of dynamic fatigue (unit: MPa): Apply a tensile shear stress of 0.8 - 1.0 MPa, frequency of 20 Hz, repeat 3 million times, and then test according to the shear strength test method.

[0118] (7) Aging resistance (unit: MPa): After aging the product at 85°C / 85% RH for 1000 h, compare the performance changes of the product before and after aging. The test results are shown in Table 1.

[0119] Table 1

[0120]

[0121]

[0122] As can be seen from Table 1, the polyurethane adhesive of the present invention has excellent adhesion performance, high temperature resistance, high temperature fatigue resistance and aging resistance.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A one-component polyurethane adhesive, characterized in that, It comprises the following components in parts by weight: 20 - 40 parts of polyurethane prepolymer, 10 - 25 parts of plasticizer, 20 - 40 parts of filler, 1 - 3 parts of silane coupling agent, 0.5 - 2 parts of water scavenger, 0.1 - 0.5 part of catalyst; The polyurethane prepolymer is prepared by reacting 300 parts by weight of polytetrahydrofuran glycol, 500 parts by weight of polybutylene adipate, 200 parts by weight of polyetheramine, 390 parts by weight of toluene diisocyanate, and 0.5 part by weight of dibutyltin dilaurate; the NCO content of the polyurethane prepolymer is 8%; The average molecular weight of the polytetrahydrofuran glycol is 500, and the functionality is 2; The average molecular weight of the polybutylene adipate is 2000, and the functionality is 2; The average molecular weight of the polyetheramine is 5000.

2. The one-component polyurethane adhesive according to claim 1, characterized in that, The catalyst is at least one of dibutyltin dilaurate, stannous octoate, and bis(morpholinoethyl) ether.

3. The one-component polyurethane adhesive according to claim 1, characterized in that, At least one of the following (a) - (d): (a) The plasticizer is at least one of dioctyl phthalate, dibutyl phthalate, and diisononyl phthalate; (b) The filler is at least one of carbon black, silica powder, fumed silica, and calcium carbonate; (c) The silane coupling agent is at least one of 3 - aminopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, and methacryloxypropyltrimethoxysilane; (d) The water scavenger is at least one of oxazolidine, vinyltrimethoxysilane, and phenyl isocyanate.

4. A method for preparing a one-component polyurethane adhesive according to any one of claims 1-3, characterized in that, It includes the following steps: uniformly stirring the polyurethane prepolymer, plasticizer, filler, silane coupling agent, water scavenger, and catalyst to obtain a one - component polyurethane adhesive.

5. The application of the one-component polyurethane adhesive according to any one of claims 1-3 in the bonding of non-inflatable tires.

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