Polyurethane foam rubber for mute tire and preparation method of polyurethane foam rubber

Abstract

The invention discloses a polyurethane foam adhesive for mute tires and a preparation method thereof, and relates to the technical field of foam adhesives, the polyurethane foam adhesive is prepared from the following raw materials by weight: 30-40 parts of diisocyanate polyethylene glycol, 10-15 parts of N-[(4-methyl-1H-benzotriazole-1-yl) methyl] diethanol amine, 10-20 parts of 10-(2, 2, 6-triazole-1-yl)-2, 2, 6-triazole-1-yl)-2, 2, 6-triazole-1-yl)-2, 2, 6-triazole-1-yl)-2 The foaming agent is prepared from the following components in parts by weight: 20 to 25 parts of 2, 5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10 to 20 parts of 2, 7-dihydroxy-9-fluorenone, 3 to 5 parts of 2-hydroxyethyl disulfide, 0.3 to 1.2 parts of a catalyst, 3 to 5 parts of a microsphere expansion type foaming agent, 3 to 5 parts of other foaming agents, 4 to 7 parts of filler, 0.5 to 2 parts of a coupling agent, 1 to 3 parts of a chain extender and 1 to 3 parts of a stabilizer. The foam rubber is remarkable in sound absorption effect, excellent in weather resistance, fatigue resistance and bonding performance and long in service life.

Description

Technical Field

[0001] The present invention relates to the technical field of foam adhesives, and in particular to a polyurethane foam adhesive for silent tires and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry, consumers are placing higher demands on driving comfort and quietness. As the only part of a car that contacts the road, tires generate a significant source of noise. Traditionally, soundproofing materials are added to reduce tire noise during tire manufacturing. However, these materials often suffer from poor sound insulation and poor adhesion to the tire substrate. This is precisely the situation that led to the emergence of polyurethane foam for silent tires, which has garnered widespread attention within the industry.

[0003] During the preparation process, existing polyurethane foam adhesives suffer from an irrational formulation and process, resulting in an uneven cell structure, which affects their sound insulation and mechanical properties. Furthermore, existing preparation methods make it difficult to precisely control the density and hardness of the foam adhesive, making it unable to meet the quieting requirements of different tire types. Furthermore, during use, tires are subject to a variety of complex mechanical loads and environmental factors, such as temperature fluctuations and humid environments. Existing polyurethane foam adhesives lack weather resistance and fatigue resistance, and are prone to cracking and deformation, which reduces the tire's service life and quieting effect.

[0004] To address these issues, Chinese invention patent CN107099017B discloses a method for preparing high-density polyurethane foam, comprising the following steps: Step 1: Add polyester polyol, starch, and water to a reactor and mix thoroughly; Step 2: Add isocyanate to the reactor in Step 1 and heat to 80-90°C under nitrogen for 2-4 hours; Step 3: Cool the reactor in Step 2 to 50-60°C, add a catalyst and a chain extender, and maintain the temperature for 3-5 hours; Step 4: Add a stabilizer to the reactor in Step 3, stir thoroughly, and then heat to 120°C and maintain the temperature for 20-30 minutes to cure the high-density polyurethane foam. The high-density polyurethane foam produced by this invention exhibits good density uniformity and excellent shock-absorbing and cushioning properties. However, its sound absorption and weather resistance still need to be further improved.

[0005] It can be seen that the development of a polyurethane foam adhesive for silent tires with significant sound absorption effect, excellent weather resistance, fatigue resistance and bonding performance, and long service life and its preparation method meets market demand, has broad market value and application prospects, and is of great significance to promoting the development of the field of foam adhesive for silent tires. Summary of the Invention

[0006] The main purpose of the present invention is to provide a polyurethane foam adhesive for silent tires with significant sound absorption effect, excellent weather resistance, fatigue resistance and bonding performance, and long service life, and a preparation method thereof.

[0007] To achieve the above objectives, the present invention provides a polyurethane foam adhesive for silent tires, which is made from the following raw materials in parts by weight: 30-40 parts of diisocyanate polyethylene glycol, 10-15 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 20-25 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-20 parts of 2,7-dihydroxy-9-fluorenone, 3-5 parts of 2-hydroxyethyl disulfide, 0.3-1.2 parts of a catalyst, 3-5 parts of a microsphere expansion foaming agent, 3-5 parts of other foaming agents, 4-7 parts of a filler, 0.5-2 parts of a coupling agent, 1-3 parts of a chain extender, and 1-3 parts of a stabilizer.

[0008] Preferably, the diisocyanate polyethylene glycol has a number average molecular weight of 400 and is provided by Guangdong Wengjiang Chemical Reagent Co., Ltd.

[0009] Preferably, the catalyst is one or more of dibutyltin dilaurate, triethylamine, and triethylenediamine.

[0010] Preferably, the microsphere expandable foaming agent is a mixture of Akzo Nobel Expancel® 051 DU 40 and Expancel 820 SLU 40 in a mass ratio of 1:(1-2).

[0011] Preferably, the other foaming agent is at least one of HFC-245fa and n-pentane.

[0012] Preferably, the filler is a mixture of boron nitride nanosheets and carboxylated graphene in a mass ratio of 1:(0.8-1.2).

[0013] Preferably, the boron nitride nanosheets have a diameter of 1-2 μm and a thickness of 4-10 nm.

[0014] Preferably, the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm.

[0015] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0016] Preferably, the chain extender is one or more of ethylene glycol, propylene glycol, and 1,4-butanediol.

[0017] Preferably, the stability is Maitu L-580.

[0018] Another object of the present invention is to provide a method for preparing the polyurethane foam adhesive for silent tires, comprising the following steps: Step S1, preparation of a prepolymer: dehydrate polyethylene glycol diisocyanate under vacuum at 110-130° C. for 2-3 hours, then cool to 40-60° C., add N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst, and react at 60-80° C. for 2-4 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 20-40° C. for 5-10 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 50-80° C. for 1-3 hours; Step S3, post-processing: taking the foamed foam glue out of the mold, heat-treating it at 100-120° C. for 2-4 hours, and then cooling it to room temperature at room temperature.

[0019] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The preparation method of the polyurethane foam adhesive for silent tires disclosed in the present invention has a simple preparation process, convenient operation and control, low dependence on equipment, high preparation efficiency and finished product qualification rate, is suitable for continuous large-scale production, and has high promotion and application value.

[0020] (2) The polyurethane foam adhesive for silent tires disclosed in the present invention is made of the following raw materials in parts by weight: 30-40 parts of diisocyanate polyethylene glycol, 10-15 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 20-25 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-20 parts of 2,7-dihydroxy-9-fluorenone, 3-5 parts of 2-hydroxyethyl disulfide, 0.3-1.2 parts of catalyst, 3-5 parts of microsphere expansion type foaming agent, 3-5 parts of other foaming agents, 4-7 parts of filler, 0.5-2 parts of coupling agent, 1-3 parts of chain extender, and 1-3 parts of stabilizer. Through the mutual coordination and joint action of the raw materials, the polyurethane foam adhesive for silent tires has a significant sound absorption effect, excellent weather resistance, fatigue resistance and bonding properties, and a long service life. Benzotriazole, phosphaphenanthrene, fluorenone and disulfide structures are introduced into the film at the same time. These structures, under the multiple effects of electronic effect, steric effect and conjugation effect, make the sound absorption effect of the polyurethane foam adhesive product more significant, and the weather resistance, fatigue resistance and mechanical properties are better, and the service life is longer.

[0021] (3) The polyurethane foam adhesive for silent tires disclosed in the present invention, through the compounding of microsphere expandable foaming agents and other foaming agents, in conjunction with other raw material components, results in a uniform and dense pore structure in the prepared foam adhesive, significantly improving its sound absorption coefficient. Carboxylated graphene forms reversible hydrogen bonds with the polar groups (-COOH / -OH) of the tire's airtight layer, which reorganizes rather than breaks under thermal stress, thereby enhancing peel strength. Furthermore, in conjunction with other raw material components, it further improves weather resistance, sound absorption, and fatigue resistance.

[0022] (4) The polyurethane foam adhesive for silent tires disclosed in the present invention has axially arranged boron nitride nanosheets to quickly dissipate heat from the tire; radially low thermal conductivity blocks external heat radiation; and the "cell-shell" composite structure formed by the use of microsphere expansion foaming agents produces a dual sound absorption effect, thereby effectively improving the sound absorption effect and also enhancing fatigue resistance. The use of different types of foaming agents further improves the sound absorption effect through a multi-level pore synergistic noise reduction mechanism. 2-Hydroxyethyl disulfide introduces disulfide bonds, and the microcracks generated by tire deformation promote the breakage and recombination of disulfide bonds (-SS-), avoiding the adhesive failure of traditional foams caused by repeated deformation. DETAILED DESCRIPTION

[0023] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations. Example 1

[0024] A polyurethane foam adhesive for silent tires is made from the following raw materials in parts by weight: 30 parts of diisocyanate polyethylene glycol, 10 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 20 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10 parts of 2,7-dihydroxy-9-fluorenone, 3 parts of 2-hydroxyethyl disulfide, 0.3 parts of a catalyst, 3 parts of a microsphere expansion-type foaming agent, 3 parts of other foaming agents, 4 parts of a filler, 0.5 parts of a coupling agent, 1 part of a chain extender, and 1 part of a stabilizer.

[0025] The number average molecular weight of the diisocyanate polyethylene glycol is 400, and it is provided by Guangdong Wengjiang Chemical Reagent Co., Ltd.; the catalyst is dibutyltin dilaurate; the microsphere expandable foaming agent is a mixture of Akzo Nobel Expancel® 051 DU 40 and Expancel 820 SLU 40 in a mass ratio of 1:1; the other foaming agent is HFC-245fa; the filler is a mixture of boron nitride nanosheets and carboxylated graphene in a mass ratio of 1:0.8; the boron nitride nanosheets have a sheet diameter of 1-2 μm and a thickness of 4-10 nm; the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm; the coupling agent is silane coupling agent KH550; the chain extender is ethylene glycol; and the stabilizer is Maitu L-580.

[0026] A method for preparing the polyurethane foam adhesive for silent tires comprises the following steps: Step S1, preparation of a prepolymer: dehydrate polyethylene glycol diisocyanate under vacuum at 110° C. for 2 hours, then cool to 40° C., add N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst, and react at 60° C. for 2 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 20° C. for 5 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 50° C. for 1 hour; Step S3, post-processing: the foamed foam adhesive is taken out from the mold, heat-treated at 100° C. for 2 hours, and then cooled to room temperature at room temperature. Example 2

[0027] A polyurethane foam adhesive for silent tires is made from the following raw materials in parts by weight: 32 parts of diisocyanate polyethylene glycol, 12 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 21 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 12 parts of 2,7-dihydroxy-9-fluorenone, 3.5 parts of 2-hydroxyethyl disulfide, 0.5 part of a catalyst, 3.5 parts of a microsphere expansion foaming agent, 3.5 parts of other foaming agents, 5 parts of a filler, 0.9 part of a coupling agent, 1.5 parts of a chain extender, and 1.5 parts of a stabilizer.

[0028] The number average molecular weight of the diisocyanate polyethylene glycol is 400, and it is provided by Guangdong Wengjiang Chemical Reagent Co., Ltd.; the catalyst is triethylamine; the microsphere expandable foaming agent is a mixture of Akzo Nobel Expancel® 051 DU 40 and Expancel 820 SLU 40 in a mass ratio of 1:1.3; the other foaming agent is n-pentane; the filler is a mixture of boron nitride nanosheets and carboxylated graphene in a mass ratio of 1:0.9; the boron nitride nanosheets have a sheet diameter of 1-2 μm and a thickness of 4-10 nm; the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm; the coupling agent is silane coupling agent KH560; the chain extender is propylene glycol; and the stabilizer is Maitu L-580.

[0029] A method for preparing the polyurethane foam adhesive for silent tires comprises the following steps: Step S1, preparation of a prepolymer: dehydrate polyethylene glycol diisocyanate under vacuum at 115° C. for 2.3 hours, then cool to 45° C., add N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst, and react at 65° C. for 2.5 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 25° C. for 6 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 60° C. for 1.5 hours; Step S3, post-processing: the foamed foam adhesive is taken out from the mold, heat-treated at 105° C. for 2.5 hours, and then cooled to room temperature at room temperature. Example 3

[0030] A polyurethane foam adhesive for silent tires is made from the following raw materials in parts by weight: 35 parts of diisocyanate polyethylene glycol, 13 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 23 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 15 parts of 2,7-dihydroxy-9-fluorenone, 4 parts of 2-hydroxyethyl disulfide, 0.8 parts of a catalyst, 4 parts of a microsphere expansion foaming agent, 4 parts of other foaming agents, 5.5 parts of a filler, 1.3 parts of a coupling agent, 2 parts of a chain extender, and 2 parts of a stabilizer.

[0031] The number average molecular weight of the diisocyanate polyethylene glycol is 400, and it is provided by Guangdong Wengjiang Chemical Reagent Co., Ltd.; the catalyst is triethylenediamine; the microsphere expandable foaming agent is a mixture of Akzo Nobel Expancel® 051 DU40 and Expancel 820 SLU 40 in a mass ratio of 1:1.5; the other foaming agent is HFC-245fa; the filler is a mixture of boron nitride nanosheets and carboxylated graphene in a mass ratio of 1:1; the boron nitride nanosheets have a sheet diameter of 1-2 μm and a thickness of 4-10 nm; the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm; the coupling agent is silane coupling agent KH570; the chain extender is 1,4-butanediol; and the stabilizer is Maitu L-580.

[0032] A method for preparing the polyurethane foam adhesive for silent tires comprises the following steps: Step S1, preparation of a prepolymer: diisocyanate polyethylene glycol is vacuum dehydrated at 120° C. for 2.5 hours, then cooled to 50° C., N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst are added, and the mixture is reacted at 70° C. for 3 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 30° C. for 8 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 65° C. for 2 hours; Step S3, post-processing: the foamed foam adhesive is taken out from the mold, heat-treated at 110° C. for 3 hours, and then cooled to room temperature at room temperature. Example 4

[0033] A polyurethane foam adhesive for silent tires is made from the following raw materials in parts by weight: 38 parts of diisocyanate polyethylene glycol, 14 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 24 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 18 parts of 2,7-dihydroxy-9-fluorenone, 4.5 parts of 2-hydroxyethyl disulfide, 1.1 parts of a catalyst, 4.5 parts of a microsphere expansion foaming agent, 4.5 parts of other foaming agents, 6.5 parts of a filler, 1.8 parts of a coupling agent, 2.5 parts of a chain extender, and 2.5 parts of a stabilizer.

[0034] The number average molecular weight of the diisocyanate polyethylene glycol is 400 and is provided by Guangdong Wengjiang Chemical Reagent Co., Ltd.; the catalyst is a mixture of dibutyltin dilaurate, triethylamine, and triethylenediamine in a mass ratio of 1:2:1; the microsphere expandable foaming agent is Akzo Nobel Expancel® 051 DU 40 and Expancel 820 SLU 40 are mixed in a mass ratio of 1:1.8; the other foaming agent is HFC-245fa and n-pentane are mixed in a mass ratio of 1:1; the filler is boron nitride nanosheets and carboxylated graphene are mixed in a mass ratio of 1:1.1; the boron nitride nanosheets have a sheet diameter of 1-2 μm and a thickness of 4-10 nm; the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm; the coupling agent is a silane coupling agent KH550, a silane coupling agent KH560, and a silane coupling agent KH570 mixed in a mass ratio of 1:2:1; the chain extender is a mixture of ethylene glycol, propylene glycol, and 1,4-butanediol in a mass ratio of 1:2:3; and the stabilizer is Maitu L-580.

[0035] A method for preparing the polyurethane foam adhesive for silent tires comprises the following steps: Step S1, preparation of a prepolymer: diisocyanate polyethylene glycol is vacuum dehydrated at 125° C. for 2.8 hours, then cooled to 55° C., N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst are added, and the mixture is reacted at 75° C. for 3.5 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 35° C. for 9 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 75° C. for 2.5 hours; Step S3, post-processing: the foamed foam adhesive is taken out from the mold, heat-treated at 115° C. for 3.5 hours, and then cooled to room temperature at room temperature. Example 5

[0036] A polyurethane foam adhesive for silent tires is made from the following raw materials in parts by weight: 40 parts of diisocyanate polyethylene glycol, 15 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 25 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 20 parts of 2,7-dihydroxy-9-fluorenone, 5 parts of 2-hydroxyethyl disulfide, 1.2 parts of a catalyst, 5 parts of a microsphere expansion foaming agent, 5 parts of other foaming agents, 7 parts of a filler, 2 parts of a coupling agent, 3 parts of a chain extender, and 3 parts of a stabilizer.

[0037] The number average molecular weight of the diisocyanate polyethylene glycol is 400, and it is provided by Guangdong Wengjiang Chemical Reagent Co., Ltd.; the catalyst is dibutyltin dilaurate; the microsphere expandable foaming agent is a mixture of Akzo Nobel Expancel® 051 DU 40 and Expancel 820 SLU 40 in a mass ratio of 1:2; the other foaming agent is HFC-245fa; the filler is a mixture of boron nitride nanosheets and carboxylated graphene in a mass ratio of 1:1.2; the boron nitride nanosheets have a sheet diameter of 1-2 μm and a thickness of 4-10 nm; the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm; the coupling agent is silane coupling agent KH550; the chain extender is ethylene glycol; and the stabilizer is Maitu L-580.

[0038] A method for preparing the polyurethane foam adhesive for silent tires comprises the following steps: Step S1, preparation of a prepolymer: diisocyanate polyethylene glycol is vacuum dehydrated at 130° C. for 3 hours, then cooled to 60° C., N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst are added, and the mixture is reacted at 80° C. for 4 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 40° C. for 10 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 80° C. for 3 hours; Step S3, post-processing: the foamed foam adhesive is taken out from the mold, heat-treated at 120° C. for 4 hours, and then cooled to room temperature at room temperature.

[0039] Comparative Example 1 A polyurethane foam adhesive for silent tires and a preparation method thereof are basically the same as those in Example 1, except that an equal amount of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide is used instead of 2-hydroxyethyl disulfide, and other foaming agents are used instead of the microsphere expansion foaming agent.

[0040] Comparative Example 2 A polyurethane foam adhesive for silent tires and a preparation method thereof are basically the same as those in Example 1, except that an equal amount of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine is used instead of 2,7-dihydroxy-9-fluorenone, and no carboxylated graphene is added.

[0041] In order to further illustrate the beneficial technical effects of the polyurethane foam adhesive for silent tires involved in each embodiment of the present invention, relevant performance tests were conducted on the polyurethane foam adhesive for silent tires involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows: (1) Sound insulation performance test: Refer to GB / T 18696.1-2004 "Measurement of sound absorption coefficient and impedance in acoustic impedance tubes Part 1: Standing wave ratio method" for testing, and use an impedance tube to test the sound absorption coefficient of the foam glue at different frequencies.

[0042] (2) Fatigue resistance test: Refer to GB / T 1687-1993 "Fatigue resistance of vulcanized rubber in flexure test" to conduct flexure test, the test number is 100,000 times, and then observe whether there is any cracking on the surface of the foam rubber.

[0043] (3) Peel strength: Test according to GB / T 2792-2014 "Test method for 180° peel strength of pressure-sensitive adhesive tapes"; stick the tape on a stainless steel plate with a peel angle of 180° and measure the peel strength.

[0044] (4) Weather resistance: Refer to GB / T 16422.2-2014 "Plastics Laboratory Light Source Exposure Test Methods Part 2: Xenon Arc Lamp" to conduct xenon arc lamp aging test, the test time is 1000 hours, and then detect the change in the peel strength of the foam glue, measured by the peel strength retention rate. The larger the value, the better the weather resistance.

[0045] Table 1 Performance test results of polyurethane foam adhesive for silent tires project 500Hz sound absorption coefficient Peel strength Fatigue resistance Weather resistance unit — N / cm — % Example 1 0.82 19.5 No cracking 98.92 Example 2 0.85 19.9 No cracking 99.05 Example 3 0.87 20.1 No cracking 99.30 Example 4 0.88 20.6 No cracking 99.52 Example 5 0.90 20.9 No cracking 99.82 Comparative Example 1 0.69 18.7 Obvious cracking 98.80 Comparative Example 2 0.77 17.9 Obvious cracking 98.11 As can be seen from Table 1, the polyurethane foam adhesive for silent tires disclosed in the embodiment of the present invention has better sound absorption effect, better bonding performance, and better fatigue resistance and weather resistance than the comparative example product; the combined addition of 2-hydroxyethyl disulfide, microsphere expandable foaming agent, 2,7-dihydroxy-9-fluorenone and carboxylated graphene is beneficial to improving the above properties.

[0046] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A polyurethane foam adhesive for silent tires, characterized in that: The invention is prepared from the following raw materials in parts by weight: 30-40 parts of diisocyanate polyethylene glycol, 10-15 parts of N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 20-25 parts of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-20 parts of 2,7-dihydroxy-9-fluorenone, 3-5 parts of 2-hydroxyethyl disulfide, 0.3-1.2 parts of a catalyst, 3-5 parts of a microsphere expansion type foaming agent, 3-5 parts of other foaming agents, 4-7 parts of a filler, 0.5-2 parts of a coupling agent, 1-3 parts of a chain extender, and 1-3 parts of a stabilizer.

2. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The number average molecular weight of the diisocyanate polyethylene glycol is 400; the catalyst is one or more of dibutyltin dilaurate, triethylamine, and triethylenediamine.

3. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The microsphere expansion foaming agent is a mixture of Akzo Nobel Expancel® 051 DU 40 and Expancel 820 SLU 40 in a mass ratio of 1:(1-2).

4. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The other foaming agent is at least one of HFC-245fa and n-pentane.

5. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The filler is a mixture of boron nitride nanosheets and carboxylated graphene in a mass ratio of 1:(0.8-1.2).

6. The polyurethane foam adhesive for silent tire according to claim 5, characterized in that: The boron nitride nanosheets have a sheet diameter of 1-2 μm and a thickness of 4-10 nm; the carboxylated graphene has a size of 0.5-3 μm and a thickness of 0.55-3.74 nm.

7. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

8. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The chain extender is one or more of ethylene glycol, propylene glycol, and 1,4-butanediol.

9. The polyurethane foam adhesive for silent tire according to claim 1, characterized in that: The stability is Momentive L-580.

10. A method for preparing the polyurethane foam adhesive for silent tires according to any one of claims 1 to 9, characterized in that: The steps include: Step S1, preparation of a prepolymer: dehydrate polyethylene glycol diisocyanate under vacuum at 110-130° C. for 2-3 hours, then cool to 40-60° C., add N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 2,7-dihydroxy-9-fluorenone and a catalyst, and react at 60-80° C. for 2-4 hours to obtain a prepolymer; Step S2, mixing and foaming: adding the prepolymer, microsphere expandable foaming agent, other foaming agents, fillers, coupling agents, chain extenders, 2-hydroxyethyl disulfide and stabilizers into a reactor, stirring and mixing at 20-40° C. for 5-10 minutes, and then injecting the mixture into a mold for foaming reaction at a reaction temperature of 50-80° C. for 1-3 hours; Step S3, post-processing: taking the foamed foam glue out of the mold, heat-treating it at 100-120° C. for 2-4 hours, and then cooling it to room temperature at room temperature.