Tire sealing composition based on cooperative locking and hydrodynamic layering and preparation method thereof

Abstract

The invention relates to the technical field of vehicle tire maintenance, in particular to a tire sealing composition based on cooperative locking and hydrodynamic layering and a preparation method of the tire sealing composition based on cooperative locking and hydrodynamic layering. The anti-freezing emulsion comprises the following raw materials: 5-20% of a pretreated emulsion matrix, 65.5-88.5% of a composite anti-freezing carrier liquid, 0.5-1% of a fiber skeleton, 5-10% of a hydrophobic synergistic filling system, 0.5-1.5% of a thickening agent and 0.5-2% of a functional auxiliary agent. The hydrophobic synergistic filling system is a composition of LDPE (Low-Density Polyethylene) micro powder, PTFE (Polytetrafluoroethylene) micro powder and PET (Polyethylene Terephthalate) paillette; the functional auxiliary agent is a composition of an ion activator aqueous solution, a corrosion inhibitor and a preservative. The tire sealing composition based on cooperative locking and hydrodynamic layering prepared by the invention has excellent sealing performance, and has the characteristics of quicker response, firmer structure, more intuitive state and more convenient use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle tire maintenance, in particular to a tire sealing composition based on cooperative locking and fluid dynamics layering and a preparation method thereof. BACKGROUND

[0002] With the vigorous development of global cycling and the rapid changes in related manufacturing technology, high-performance bicycles, especially mountain bikes and road bikes, have reached an unprecedented level of requirements for tire systems. Vacuum tire systems, which can effectively reduce rolling resistance, provide a wider range of tire pressure adjustment to enhance grip, and have superior puncture resistance, have become a standard configuration for medium and high-end sports bicycles, from professional competition to the general public. Tire sealant, commonly known as "self-repairing liquid", is the soul of the vacuum system. It forms a flowing protective layer inside the tire and is responsible for sealing instantly and automatically when the tire is punctured by a sharp object, ensuring the continuity and safety of cycling.

[0003] However, after years of development, the current bicycle self-repairing liquid products on the market, although diverse in types, still have limitations in core technology, making it difficult to perfectly balance the contradiction between sealing performance, durability, stability, and ease of use. The existing technology mainly faces the following difficult-to-overcome technical bottlenecks: First, the inherent defects of "hydrated plasticized" clots and the problem of long-term pressure decay. To solve the dispersion problem of solid particles in aqueous carrier liquid, existing technologies generally use inorganic powders (such as, but not limited to, diatomaceous earth, mica powder, talc powder, etc.) or hydrophilic treated organic particles as the main filler. The fundamental defect of this design is that these hydrophilic particles, when participating in the formation of sealing clots, will absorb and encapsulate a large amount of water through their hydrophilic groups on the surface, forming a "hydrated plasticized" clot with loose structure, soft texture, and high water content. The internal structure of the clot will weaken the interaction between polymer chains due to the presence of water molecules, resulting in a serious lack of mechanical strength and difficulty in resisting continuous impact under high pressure. More seriously, during the long-term use of the tire, due to the micro-permeability of the tire rubber, the water in the clot will gradually dissipate or be expelled under continuous dynamic pressure, causing irreversible volume shrinkage and hardening of the clot. As a result, a small gap is created between the clot and the puncture, causing slow secondary air leakage, which is the problem of "sealing effect dropping sharply after the expiration of the self-repairing liquid" commonly reported by users; Second, the coagulation mechanism is passive, and the sealing response speed has an upper limit. The core sealing material of most traditional self-sealing liquids is natural or synthetic latex. Its coagulation mechanism mainly depends on two passive processes: one is that when the liquid rushes out of the puncture, due to the sudden drop in pressure and volume expansion, the water rapidly evaporates, causing the latex particle concentration to rise sharply and solidify; the second is that the latex particles are subjected to strong mechanical shear force when passing through the narrow wound, which causes demulsification. These two mechanisms can cope with small and medium-sized, regular punctures, but in the case of large-sized (e.g. more than 5mm) punctures or high-pressure environments, the ejection speed of the liquid is much greater than the coagulation speed of the latex, often resulting in a large amount of sealing liquid being lost before an effective seal is formed, not only polluting the frame and the environment, but also often leading to complete failure of the seal; Third, the filling particles have single function and disorder, and cannot pass through the precise valve core. The selection and application of filling particles in the prior art lack systematic fluid mechanics and packing theory guidance, and are mostly simple mixtures of irregularly shaped and sized powders, debris or fibers. These particles exhibit chaotic Brownian motion in high-speed flowing liquid and cannot form an ordered and efficient dense packing at the puncture according to size and shape differences. This not only limits the size and shape of the puncture that can be sealed, but also brings serious application inconvenience. In order to achieve more precise inflation and deflation control, the valve core structure of many modern high-performance bicycles is increasingly precise, with narrow internal channels. The particles in the traditional formula, which are larger in size or tend to agglomerate at low flow rates, often block the air valve when the sealant is replenished or the tire is inflated, causing great inconvenience to the user; Fourth, the long-term storage stability of the formula system and the production process control are complex. In order to stably suspend a variety of components with different densities and different surface properties in a low-viscosity liquid, the traditional formula has to use a large amount of and complex surfactants and thickeners. This not only increases the cost, but also makes the formula system extremely sensitive to temperature changes, mechanical shear and storage time, prone to problems such as delamination, sedimentation, viscosity change and premature solidification, and requires extremely strict control of the production process.

[0004] Therefore, there is an urgent need in the art for a completely new technical solution that can fundamentally overturn the design concept of traditional self-sealing liquids, get rid of the dependence on "hydrophilic filling" and "passive drying", and provide a tire sealing composition that is more responsive, structurally stronger, more intuitive in state, and more convenient to use. SUMMARY

[0005] In view of the problems existing in the prior art, the purpose of the present application is to obtain a tire sealing composition based on cooperative locking and fluid dynamics layering that is more responsive, structurally stronger, more intuitive in state, and more convenient to use.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: The application provides a tire sealing composition based on cooperative locking and fluid dynamics layering, containing the following raw materials in percentage of 100% by mass: pretreated skim latex matrix 5-20%, composite antifreezing carrier liquid 50-85%, fiber framework 0.5-1%, hydrophobic cooperative filling system 5-10%, thickening agent 0.5-1.5%, and functional auxiliary agent 0.5-2%; the hydrophobic cooperative filling system is a combination of LDPE micro powder, PTFE micro powder and PET flake; and the functional auxiliary agent is a combination of ionic activator aqueous solution, corrosion inhibitor and preservative.

[0007] Preferably, the average particle size of the LDPE micro powder is 70-90 mu m, the average particle size of the PTFE micro powder is 5-10 mu m, and the PET flake is a regular hexagonal flake coated with a color coating on the upper layer, and the diagonal size of the flake is 150-250 mu m and the thickness is 10-20 mu m.

[0008] The application has excellent sealing performance, and has the characteristics of faster response, more solid structure, more intuitive state and more convenient use.

[0009] The application adopts a combination of LDPE micro powder, PTFE micro powder and PET flake as the hydrophobic cooperative filling system, completely abandoning the traditional hydrophilic inorganic filler, and instead using non-polar, water-incompatible polymer particles matched in three physical properties. The sealing mechanism of the application is as follows: when puncture occurs, the sealing composition flows to the puncture under high pressure, and under the combined action of stable laminar flow and high shear field of the hole, the hydrophobic particle system first undergoes near-hole size and shape dominated screening and bridging. Particles with smaller particle size or compact morphology (such as PTFE micro powder) are more likely to enter the initial gap to form a base resistance; then, large-size, flaky PET particles are oriented along the shear surface of the hole and inlaid, stacked on the micro-pore framework formed previously, and a dense mechanical locking structure is constructed, and the particle density difference and inertial effect provide secondary regulation for the process, improving the compactness and pressure-bearing capacity of the accumulation.

[0010] In some embodiments, the pretreated skim latex matrix is pretreated high-ammonia natural latex.

[0011] In some embodiments, the method for preparing the pretreated high-ammonia natural latex comprises the following steps: adding high-ammonia natural latex into a reaction kettle, controlling the rotation speed at 80-100 rpm, slowly increasing the temperature of the latex to 38-42°C within 25-30 min and keeping it constant, keeping the exhaust port at the top of the reaction kettle open, continuously stirring for 4.5-5.5 h, stopping heating immediately when the pH is stable in the interval of 8.2±0.2, rapidly cooling to below 25°C, and standing for 10-15 h for curing.

[0012] Preferably, the method for preparing the pretreated high-ammonia natural latex comprises the following steps: adding high-ammonia natural latex into a reaction kettle, controlling the rotation speed at 80-100 rpm, slowly increasing the temperature of the latex to 38-42°C within 25-30 min and keeping it constant by circulating hot water at 40-50°C through the jacket of the kettle, keeping the exhaust port at the top of the reaction kettle open, continuously stirring for 4.5-5.5 h, recording the pH every 15 min when stirring for 4 h, stopping heating immediately when the pH is stable in the interval of 8.2±0.2 for three consecutive readings, rapidly cooling to below 25°C by circulating cooling water at 10-15°C through the jacket, and then transferring to a sealed storage tank under nitrogen protection, standing for 10-15 h for curing.

[0013] Preferably, the dry rubber content of the high-ammonia natural latex is 58.5-61.5 wt%, and the ammonia content is 0.6-0.8 wt%.

[0014] In the present application, the pretreated high-ammonia natural latex is used as the latex matrix. This step is designed to remove excess ammonia stabilizer from the latex in a controllable manner, so that it changes from a chemically inert stable state to a highly sensitive "activated" or "metastable" state to external stimuli (such as changes in ionic environment, mechanical shear). The purpose of this is to improve the response speed of the latex matrix when puncture occurs, providing a reaction basis for subsequent rapid coagulation.

[0015] In some embodiments, the composite antifreeze carrier liquid is a mixture of glycerol, propylene glycol and deionized water, and the mass ratio of the three is (2.5-3.5):1:(3.5-4.5).

[0016] For the composite antifreeze carrier liquid, the present application innovatively uses a composite system mainly composed of glycerol and assisted by propylene glycol. In the design of this system, the applicant has overturned the traditional cognition of pursuing low-viscosity carrier liquid in the industry. Through research, it is found that the high-viscosity fluid environment constructed by glycerol can significantly reduce the actual Reynolds number of the fluid when flowing at high speed, thereby greatly enhancing the ability of the system to maintain laminar flow. This stable laminar flow state is the fluid mechanics basis for ensuring that a variety of hydrophobic particles can move and accumulate in an orderly manner according to the pre-set physical law, thereby forming the most efficient and dense mechanical embolism.

[0017] In some embodiments, the method for preparing the fiber framework comprises the following steps: A1, dipping the chopped carbon fibers into a sodium hypochlorite solution for 6-8 h, washing, filtering, and drying to obtain oxidized chopped carbon fibers; A2, adding benzoyl peroxide to toluene, stirring for 20-30 min, adding the oxidized chopped carbon fibers obtained in step A1 to the toluene solution, ultrasonically dispersing at 60-70 °C for 30-60 min, adding acrylic acid, fluorine-containing acrylate, and hydroquinone, heating to 80-85 °C and reacting for 3-6 h at a stirring speed of 400-500 rpm, cooling to room temperature, washing, suction filtering, and drying to obtain the fiber framework.

[0018] Preferably, the average length of the chopped carbon fibers is 0.8 mm, and more than 95 wt% of the chopped carbon fibers have a length of 0.5-1.5 mm; the diameter of the chopped carbon fibers is 7-8 μm.

[0019] Preferably, the concentration of the sodium hypochlorite solution is 0.01-0.03 mol / L.

[0020] Preferably, the mass ratio of the chopped carbon fibers to the sodium hypochlorite solution is 1: (50-100).

[0021] Preferably, the fluorine-containing acrylate is one or more of trifluoroethyl methacrylate, hexafluorobutyl methacrylate, trifluoroethyl acrylate, and hexafluorobutyl acrylate.

[0022] Further preferably, the fluorine-containing acrylate is trifluoroethyl acrylate.

[0023] The present application preferably uses chopped carbon fibers as the fiber framework, which not only provides structural support and toughness to the coagulum, but also may have a positive auxiliary effect on the sealing process due to its physicochemical properties. When the tire sealing composition passes through the puncture at high speed, the severe friction between the liquid and the tire rubber may generate local static charges, and the carbon fibers, as conductors, may help to homogenize these charges, thereby creating a more stable microenvironment for the ordered packing of the filler particles.

[0024] The present application can make the tire sealing composition have a long-lasting sealing performance by first using sodium hypochlorite to oxidize the chopped carbon fiber and grafting the copolymer segment of acrylic acid and fluorine-containing acrylic ester on the surface thereof, which can be because: (1) the fluorine branched chain on the fiber skeleton is free between the hydrophobic and synergistic filling system, which plays a filling and repairing role, and the strong hydrophobic and oleophobic properties can resist the reverse penetration of water, oil stains and the like on the road surface through the sealing layer, ensuring the durability of the sealing effect; (2) the introduction of the fluorine segment weakens the adsorption of the oxidized chopped carbon fiber to water molecules, weakening the "hydration plasticization" effect; (3) the residual carboxyl group on the fiber skeleton can produce a strong hydrogen bond with the amino group in the pretreated emulsion matrix, so that the pretreated emulsion matrix can be quickly guided to the damaged area through the fiber skeleton for repair.

[0025] In some embodiments, the mass ratio of the oxidized chopped carbon fiber and the acrylic acid in step A2 is 1: (0.2-0.6).

[0026] In some embodiments, the mass ratio of the oxidized chopped carbon fiber and the fluorine-containing acrylic ester in step A2 is 1: (0.05-0.1).

[0027] In some embodiments, the mass ratio of the LDPE micro powder, the PTFE micro powder and the PET flake is 1: (0.15-0.35): (0.5-2.5).

[0028] In some embodiments, the thickening agent is sodium carboxymethyl cellulose.

[0029] In some embodiments, the degree of substitution of the sodium carboxymethyl cellulose is 0.9-1.2.

[0030] The present application finds that the degree of substitution of the sodium carboxymethyl cellulose is 0.9-1.2, which can make the tire sealing composition have good stability, which can be because the distribution of the anionic sites (carboxymethyl) on the molecular chain of the sodium carboxymethyl cellulose in this substitution degree range is most suitable for instantaneous and controllable interaction with the divalent cations (Ca 2+ ) subsequently added, thereby triggering a viscosity mutation of the system.

[0031] In some embodiments, the concentration of the aqueous solution of the ion activator is 8-11 wt%.

[0032] In some embodiments, the mass ratio of the aqueous solution of the ion activator, the corrosion inhibitor and the preservative is (6-8): (1-3): 1.

[0033] In some embodiments, the aqueous solution of the ion activator is an aqueous solution of a divalent metal salt electrolyte.

[0034] Further preferably, the aqueous solution of ionic activator is an aqueous solution of calcium chloride of analytical reagent grade without water.

[0035] Preferably, the corrosion inhibitor is benzotriazole.

[0036] Preferably, the preservative is isothiazolinone preservative.

[0037] The role of the divalent metal salt electrolyte is to trigger the "to be activated" latex into a metastable flocculation pre-stage formed by ion-induced charge shielding under the action of high shear force, and a slight and uniform viscosity increase occurs, providing a reaction basis for subsequent rapid coagulation and mechanical locking at the orifice. Although chloride ions pose a potential corrosion risk to some metals, this risk can be effectively controlled at the catalytic dosage of the present application and through subsequent compounding with corrosion inhibitors.

[0038] Another aspect of the present application provides a preparation method of a tire sealing composition based on synergistic locking and fluid dynamics layering, comprising the following steps: S1, adding a composite antifreeze carrier liquid into a reaction container, absorbing a thickening agent into the reaction container in 20-30 min, adjusting the rotation speed to 800-1000 rpm, and stirring for 1-3 h to obtain a high-viscosity base liquid; S2, adding a fiber skeleton, PET flakes, LDPE micro powder, and PTFE micro powder into the high-viscosity base liquid obtained in step S1 in sequence with an interval of 12-17 min, and stirring at 5000-7000 rpm for 30-60 min to obtain a suspension; S3, adjusting the rotation speed to 400-600 rpm / min, and injecting an aqueous solution of ionic activator into the suspension obtained in step S2 at a constant speed for 30-60 s, immediately reducing the rotation speed to 80-120 rpm after the injection is completed, adding pretreated high-ammonia natural latex in 5-10 min, continuing to stir for 20-40 min after the addition is completed, adding a corrosion inhibitor and a preservative in sequence, and stirring for 20-40 min, and then performing coarse filtration, defoaming, and packaging to obtain the product.

[0039] Preferably, the preparation method of the tire sealing composition based on synergistic locking and fluid dynamics layering comprises the following steps: S1, adding a composite antifreeze carrier liquid into a reaction container, absorbing a thickening agent into the reaction container in 20-30 min by a Venturi powder suction device, adjusting the rotation speed to 800-1000 rpm, and starting a high-shear homogenizer pump at the bottom of the container to perform internal and external circulation at a rotation speed of 7000-8000 rpm, and stirring for 1-3 h to obtain a high-viscosity base liquid; S2, the fiber skeleton, PET flakes, LDPE micro powder, PTFE micro powder interval 12-17 min sequentially added to the high viscosity base fluid obtained in step S1, 5000-7000 rpm stirring 30-60 min, to obtain the suspension; S3, the speed is adjusted to 400-600 rpm / min, by peristaltic pump, in 30-60s ion-activating agent aqueous solution constant speed injection to the suspension obtained in step S2 near the high shear zone vortex center, after injection immediately the speed is reduced to 80-120 rpm, in 5-10 min adding pretreated high ammonia natural latex, after the addition, continue to stir 20-40 min, sequentially adding corrosion inhibitor, preservative, stirring 20-40 min, through coarse filter, defoaming, sub-packaging, detection pH value between 8.0-8.8, detection 25℃ apparent viscosity between 1000-1500 mPa·s, namely.

[0040] Compared with the prior art, the present application has the following beneficial effects: (1) the present application by the pretreated latex matrix, composite antifreeze carrier liquid, fiber skeleton, hydrophobic synergistic filling system, thickening agent, functional additives can be compounded to obtain the tire sealing composition has excellent sealing performance, and has the characteristics of more rapid response, more solid structure, more intuitive state, more convenient to use.

[0041] (2) the present application by the “to be activated” latex and “ion-activating agent” fast trigger mechanism, and the orderly accumulation of particles under the guidance of laminar flow effect, sealing speed compared with traditional products is obviously improved, the sealing response speed of the sealing composition is significantly improved; by hydrophobic particles in the accumulation process effectively remove water, form a low water content of the dense mechanical structure, its compressive strength and durability surpass the traditional “hydration plasticization” coagulation; by adding PET flakes with a specific color coating, when it is rich in the puncture, the obvious color change can be observed from the outside of the tire, so as to intuitively judge whether the sealing is successful.

[0042] (3) the present application by using sodium hypochlorite to oxidize the chopped carbon fiber, then by grafting acrylic acid and fluorine-containing acrylic ester copolymer segment on its surface, the tire sealing composition can have durable sealing performance. DETAILED DESCRIPTION

[0043] The present application will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the present application, only used to illustrate the present application, and not to limit the present application. Without departing from the spirit or scope of the present application, other combinations and various modifications within the concept of the present application can be made.

[0044] In the following examples and comparative examples, the compounds and related reagents used, except for the fiber skeleton, were commercially available, wherein the average particle size of the LDPE micro powder was 80 μm, which was purchased from Dongguan Xiuzheng Plastic Co., Ltd.; the average particle size of the PTFE micro powder was 6 μm, which was purchased from Shanghai Mofachan Polymer Material Co., Ltd.; the PET sequins were regular hexagonal sequins with a silver coating on the upper layer, and the diagonal line size of the sequins was 200 μm, and the thickness was 15 μm; the high ammonia natural latex was a standard rubber SMR from Malaysia, the solid content was 61.2 wt%, and the ammonia content was 0.75 wt%; the average length of the chopped carbon fiber was 0.8 mm, and more than 95 wt% of the chopped carbon fiber had a length of 0.5-1.5 mm; the diameter of the chopped carbon fiber was 7-8 μm; the degree of substitution of the sodium carboxymethyl cellulose was 1.1; and the average particle size of the rubber powder was 80 mesh, which was a polyisoprene rubber.

[0045] Preparation Example 1 The preparation method of the fiber skeleton-1 included the following steps: A1, 10 g of the chopped carbon fiber was immersed in 750 g of a 0.02 mol / L sodium hypochlorite solution for 7 h, washed to neutral with deionized water, filtered, and dried to obtain the oxidized chopped carbon fiber; A2, 0.1 g of benzoyl peroxide was added to 80 g of toluene, stirred for 25 min, 10 g of the oxidized chopped carbon fiber obtained in step A1 was ultrasonically dispersed at 65 °C for 45 min, the ultrasonic power was 300 W, 4 g of acrylic acid, 0.7 g of trifluoroethyl acrylate, and 0.01 g of hydroquinone were added, the temperature was raised to 85 °C, and the reaction was carried out for 4 h, the stirring speed was 450 rpm, the temperature was cooled to room temperature, washed with acetone, suction filtered, and dried to obtain the fiber skeleton-1.

[0046] Preparation Example 2 The preparation method of the fiber skeleton-2 was the same as that in the preparation example 1, except that the addition amount of the acrylic acid was 8 g.

[0047] Preparation Example 3 The preparation method of the fiber skeleton-3 was the same as that in the preparation example 1, except that the addition amount of the trifluoroethyl acrylate was 1.2 g.

[0048] Preparation Example 4 The preparation method of the fiber skeleton-4 included the following steps: 10 g of the chopped carbon fiber was immersed in 750 g of a 0.02 mol / L sodium hypochlorite solution for 7 h, washed to neutral with deionized water, filtered, and dried to obtain the fiber skeleton-4.

[0049] Preparation Example 5 The preparation method of the pretreated high-ammonia natural latex comprises the following steps: adding high-ammonia natural latex into a reaction kettle, controlling the rotating speed at 90 rpm, passing circulating hot water at 45 DEG C into the kettle through a jacket to slowly raise the latex to 40 DEG C within 25 min and keep constant, keeping the exhaust port at the top of the reaction kettle open, continuously stirring for 5 h, recording the pH every 15 min when stirring for 4 h, stopping heating immediately when the three consecutive readings are stable in the interval of 8.2+ / -0.2, passing cooling water at 10 DEG C through the jacket to rapidly lower the temperature to below 25 DEG C, then transferring to a sealed storage tank under nitrogen protection, and standing for 12 h to obtain the pretreated high-ammonia natural latex.

[0050] Example 1 A tire sealing composition based on synergistic locking and fluid dynamics stratification comprises, by mass percentage 100%, the following raw materials: pretreated high-ammonia natural latex 12%, composite antifreeze carrier liquid 78.3%, fiber framework-1 0.7%, hydrophobic synergistic filling system 7%, sodium carboxymethyl cellulose 1%, and functional additives 1%; the hydrophobic synergistic filling system is a composition of LDPE micro powder, PTFE micro powder, and PET flakes, with a mass ratio of 1:0.25:1.5; the functional additives are a composition of 10 wt% anhydrous analytical grade calcium chloride aqueous solution, benzotriazole, and casone, with a mass ratio of 7:2:1; and the composite antifreeze carrier liquid is a mixture of glycerol, propylene glycol, and deionized water, with a mass ratio of 3:1:4.

[0051] The preparation method of the tire sealing composition based on synergistic locking and fluid dynamics stratification comprises the following steps: S1, adding the composite antifreeze carrier liquid into a reaction container, absorbing the thickening agent into the reaction container through a Venturi powder suction device within 25 min, adjusting the rotating speed to 900 rpm, starting the high-shear homogenizer pump at the bottom of the reaction container, adjusting the rotating speed to 7500 rpm for internal and external circulation, and stirring for 2 h to obtain a high-viscosity base liquid; S2, adding fiber framework-1, PET flakes, LDPE micro powder, and PTFE micro powder into the high-viscosity base liquid obtained in step S1 at intervals of 15 min, and stirring at 6000 rpm for 45 min to obtain a suspension; S3, adjust the rotation speed to 500 rpm / min, inject 10 wt% of anhydrous analytically pure grade calcium chloride aqueous solution into the suspension obtained in step S2 near the vortex center of the high shear zone at a constant speed through a peristaltic pump, immediately reduce the rotation speed to 100 rpm after the injection is completed, add the pretreated high ammonia natural latex in 7 min, continue stirring for 30 min after the addition is completed, add benzotriazole, casone in turn, stir for 30 min, coarsely filter through a 500 μm filter screen, defoam, sub-pack, detect the pH value at 8.5, and detect the apparent viscosity at 25°C to be 1300 mPa·s by a rotary viscometer method.

[0052] Example 2 A tire sealing composition based on synergistic locking and fluid dynamics layering, comprising the following raw materials in 100% by mass: pretreated high ammonia natural latex 5%, composite antifreeze carrier liquid 88.5%, fiber skeleton-1 0.5%, hydrophobic synergistic filling system 5%, sodium carboxymethyl cellulose 0.5%, and functional additives 0.5%; the hydrophobic synergistic filling system is a composition of LDPE micro powder, PTFE micro powder, and PET flakes, and the mass ratio of the three is 1:0.15:0.5; the functional additives are a composition of 10 wt% of anhydrous analytically pure grade calcium chloride aqueous solution, benzotriazole, and casone, and the mass ratio of the three is 6:1:1; the composite antifreeze carrier liquid is a mixture of glycerol, propylene glycol, and deionized water, and the mass ratio of the three is 2.5:1:3.5.

[0053] The present embodiment is based on the preparation method of a tire sealing composition based on synergistic locking and fluid dynamics layering, comprising the following steps: S1, add the composite antifreeze carrier liquid into the reaction container, and absorb the thickening agent into the reaction container through the Venturi powder absorption device in 20 min, adjust the rotation speed to 800 rpm, start the high shear homogenizer pump at the bottom of the reaction container, adjust the rotation speed to 800 rpm for internal and external circulation, and stir for 3 h to obtain a high viscosity base liquid; S2, add fiber skeleton-1, PET flakes, LDPE micro powder, and PTFE micro powder into the high viscosity base liquid obtained in step S1 in turn with an interval of 12 min, and stir at 5000 rpm for 60 min to obtain a suspension; S3, adjust the rotation speed to 400 rpm / min, inject 10 wt% of anhydrous analytically pure grade calcium chloride aqueous solution into the suspension obtained in step S2 near the vortex center of the high shear zone at a constant speed through a peristaltic pump, immediately reduce the rotation speed to 80 rpm after the injection is completed, add the pretreated high ammonia natural latex in 5 min, continue stirring for 40 min after the addition is completed, add benzotriazole, casone in turn, stir for 40 min, coarsely filter through a 500 μm filter screen, defoam, sub-pack, detect the pH value at 8.0, and detect the apparent viscosity at 25°C using a rotational viscometer method to be 1000 mPa·s, and the preparation is completed.

[0054] Example 3 A tire sealing composition based on synergistic locking and fluid dynamics layering, comprising the following raw materials in 100% by mass: pretreated high ammonia natural latex 20%, composite antifreeze carrier liquid 65.5%, fiber skeleton-1 1%, hydrophobic synergistic filling system 10%, sodium carboxymethyl cellulose 1.5%, and functional additives 2%; the hydrophobic synergistic filling system is a composition of LDPE micro powder, PTFE micro powder, and PET flakes in a mass ratio of 1:0.35:2.5; the functional additives are a composition of 10 wt% of anhydrous analytically pure grade calcium chloride aqueous solution, benzotriazole, and casone in a mass ratio of 8:3:1; the composite antifreeze carrier liquid is a mixture of glycerol, propylene glycol, and deionized water in a mass ratio of 3.5:1:4.5.

[0055] The present embodiment is based on a preparation method of a tire sealing composition based on synergistic locking and fluid dynamics layering, comprising the following steps: S1, add the composite antifreeze carrier liquid to the reaction vessel, and absorb the thickening agent into the reaction vessel through the Venturi powder absorption device in 30 min, adjust the rotation speed to 1000 rpm, start the high shear homogenizer pump at the bottom of the kettle, adjust the rotation speed to 8000 rpm for internal and external circulation, and stir for 1 h to obtain a high viscosity base liquid; S2, add fiber skeleton-1, PET flakes, LDPE micro powder, and PTFE micro powder into the high viscosity base liquid obtained in step S1 in turn at intervals of 17 min, and stir at 7000 rpm for 30 min to obtain a suspension; S3, the rotation speed is adjusted to 600 rpm / min, and 10 wt% of anhydrous calcium chloride of analytical purity is injected into the suspension obtained in step S2 near the vortex center of the high shear zone at a constant speed by a peristaltic pump within 60 s, and immediately after the injection is completed, the rotation speed is reduced to 120 rpm, the pretreated high ammonia natural latex is added within 10 min, after the addition is completed, stirring is continued for 20 min, benzotriazole and casone are added in sequence, stirring is continued for 20 min, coarse filtration is performed through a 500 μm filter screen, defoaming, sub-packaging, detection of pH value at 8.8, and detection of apparent viscosity at 25℃ by a rotary viscometer method at 1500 mPa·s are performed, and thus the product is obtained.

[0056] Example 4 A tire sealing composition based on synergistic locking and fluid dynamics layering and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the fiber framework-1 is replaced by the fiber framework-2 in equal amount.

[0057] Example 5 A tire sealing composition based on synergistic locking and fluid dynamics layering and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the fiber framework-1 is replaced by the fiber framework-3 in equal amount.

[0058] Example 6 A tire sealing composition based on synergistic locking and fluid dynamics layering and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the fiber framework-1 is replaced by the fiber framework-4 in equal amount.

[0059] Example 7 A tire sealing composition based on synergistic locking and fluid dynamics layering and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the fiber framework-1 is replaced by short carbon fibers in equal amount.

[0060] Example 8 A tire sealing composition and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the mass ratio of glycerol, propylene glycol and deionized water is 1:3:4.

[0061] Comparative Example 1 A tire sealing composition and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the hydrophobic synergistic filling system is a combination of LDPE micro powder and PET flakes, the mass ratio of the two is 1:1.5; and no PTFE micro powder is added in step S2.

[0062] Comparative Example 2 A tire sealing composition and a preparation method thereof, the specific implementation manner is the same as that of example 1, and the difference lies in that the hydrophobic synergistic filling system is replaced by rubber powder in equal amount.

[0063] Comparative Example 3 A tire sealant composition and its preparation method, the same as Example 1, except that the pretreated high ammonia natural latex is replaced by high ammonia natural latex in equal amount.

[0064] Performance test The tire sealant compositions obtained from each of the above examples and comparative examples were tested: (1) Seal speed test: A standard 29-inch mountain bike wheel set (DT Swiss XM481, inner width 30 mm) and a brand new Maxxis Ikon 29x2.2-inch tire were used to build a tubeless system. 100 mL of the tire sealant composition to be tested was injected. A standard air compressor was used to inflate the tire to 40 psi. The wheel set was installed on an electric rotary test bench with adjustable speed. During the test, a brand new standard steel nail with a diameter of 6 mm and a tip angle of 30° was vertically pierced into the center of the crown at a speed of 50 mm / s using a pneumatic device. The nail was pulled out at a speed of 100 mm / s after staying in the tire for 1 second. From the moment the nail was completely pulled out, a high-speed camera and an acoustic sensor were used to record the sealing time until the tire no longer ejected liquid or emitted a deflated sound. Each sample was tested in parallel n=5, and the mean value ± standard deviation (SD) was reported.

[0065] (2) Blowout pressure test: After completing the seal speed test, the tire was left to stand for 10 minutes, and then a precise pressure controller was used to slowly inflate the tire at a rate of 1 psi / s. The critical pressure value when the seal leaked again was recorded. Each sample was tested in parallel n=5, and the mean value ± SD was reported.

[0066] (3) Low temperature flowability test: A Brookfield LVDV2 viscometer was used, equipped with Spindle LV-3 rotor. 100 mL of the sample was sealed in a glass bottle and placed in a constant temperature box at -10°C for 12 hours. After taking it out, its apparent viscosity was tested immediately at a speed of 60 rpm. Each sample was tested in parallel n=5, and the mean value ± SD was reported.

[0067] (4) Accelerated stability series test: High temperature stability: 200 mL of the sample was placed in a sealed transparent glass bottle and stored in a 40°C oven for 3 months, and the state was observed and recorded every week.

[0068] Freeze-thaw stability: The sample was frozen at -20°C for 12 hours, then thawed at 25°C for 12 hours, which was one cycle, and a total of 10 cycles were performed, and the final state was observed.

[0069] Vibration stability: seal the sample in a container, fix on a three-axis vibration table, continuously vibrate at a frequency of 50 Hz and an acceleration of 2g for 72 hours, simulate long-term transportation and riding bumps, and observe the final state.

[0070] The test results are shown in Table 1: Table 1 As can be seen from the data in Table 1, the tire sealing compositions based on synergistic locking and fluid dynamics layering of embodiments 1-3 have sub-second sealing speed and ultra-high pressure resistance value, and the low-temperature viscosity of embodiments 1-3 is significantly better than that of Comparative Examples 1 and 2, which strongly proves the theory of the present application, that is, the particle-base liquid synergistically reduces the effective friction, and macroscopically presents a strong shear thinning effect, successfully overcoming the problem of high base viscosity of the glycerol system, and in all accelerated aging tests, embodiments 1-3 all show excellent stability, as can be seen from the comparison of Example 4 and Example 1, changing the ratio of the oxidized short carbon fiber and the acrylic acid will make the hydrophilic group in the system more, and the "hydration plasticization" phenomenon occurs, resulting in a slight decrease in the sealing performance and pressure resistance of the tire sealing composition; as can be seen from the comparison of Example 5 and Example 1, changing the ratio of the short carbon fiber and the fluorine-containing acrylate will make the dispersion of the fiber skeleton in the system decrease, resulting in a slight decrease in the sealing performance and pressure resistance of the tire sealing composition; as can be seen from the comparison of Example 6 and Example 1, not grafting the acrylic acid and the fluorine-containing acrylate segment on the short carbon fiber, there will be a small gap between the fiber skeleton and the hydrophobic synergistic filling system as much as possible, and the "hydration plasticization" phenomenon easily occurs, resulting in a decrease in the sealing performance and pressure resistance of the tire sealing composition; as can be seen from the comparison of Example 7 and Example 1, directly using the short carbon fiber, the sealing performance and pressure resistance of the tire sealing composition decrease; as can be seen from the comparison of Example 8 and Example 1, changing the mass ratio of glycerol, propylene glycol and deionized water will increase the actual Reynolds number of the fluid when flowing at high speed, resulting in a decrease in the sealing performance and pressure resistance of the tire sealing composition; as can be seen from the comparison of Comparative Example 1 and Example 1, without adding PTFE powder, the synergistic locking effect is weakened, resulting in poor sealing performance and pressure resistance of the tire sealing composition; as can be seen from the comparison of Comparative Example 2 and Example 1, the tire sealing composition with conventional rubber powder has poor performance; as can be seen from the comparison of Comparative Example 3 and Example 1, the tire sealing composition using unpretreated high ammonia natural latex has poor long-term stability and compatibility in the ion and complex particle system, and has poor sealing performance and pressure resistance.

[0071] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the present application and implement it, and cannot limit the protection scope of the present application, and any equivalent changes or modifications made according to the spirit and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A tire sealing composition based on synergistic lock and fluid dynamics stratification, characterized in that, According to 100% by mass, the following raw materials are included: pretreated 5-20% of the skim milk base, 50-85% of the composite antifreezing carrier liquid, 0.5-1% of the fiber framework, 5-10% of the hydrophobic synergistic filling system, 0.5-1.5% of the thickening agent, and 0.5-2% of the functional auxiliary agent; the hydrophobic synergistic filling system is a combination of LDPE micro powder, PTFE micro powder, and PET flakes; and the functional auxiliary agent is a combination of ionic activator aqueous solution, corrosion inhibitor, and preservative.

2. The synergistic lock and fluid dynamics layered tire sealing composition of claim 1, wherein, The pretreated skim milk base is pretreated high-ammonia natural latex.

3. The synergistic interlock and fluid dynamics layered based tire sealant composition according to claim 1, wherein, The preparation method of the pretreated high-ammonia natural latex includes the following steps: adding high-ammonia natural latex into a reaction kettle, controlling the rotation speed to be 80-100 rpm, slowly raising the latex to 38-42 ℃ within 25-30 min and keeping it constant, keeping the exhaust port at the top of the reaction kettle open, continuously stirring for 4.5-5.5 h, stopping heating when the pH is stable in the interval of 8.2±0.2, quickly cooling to below 25 ℃, and standing for 10-15 h for curing.

4. The synergistic lock and fluid dynamics layered tire sealing composition of claim 1, wherein, The composite antifreezing carrier liquid is a mixture of glycerol, propylene glycol, and deionized water, and the mass ratio of the three is (2.5-3.5):1:(3.5-4.5).

5. The method of making a tire sealing composition based on the synergy of lock and fluid dynamics stratification according to claim 1, characterized in that, The preparation method of the fiber framework includes the following steps: A1, dipping the chopped carbon fiber into a sodium hypochlorite solution for 6-8 h, washing, filtering, and drying to obtain the oxidized chopped carbon fiber; A2, adding benzoyl peroxide into toluene, stirring for 20-30 min, adding the oxidized chopped carbon fiber obtained in step A1 into toluene, ultrasonic dispersing for 30-60 min at 60-70 ℃, adding acrylic acid, fluorine-containing acrylate, and hydroquinone, heating to 80-85 ℃ for reaction for 3-6 h, and stirring at a speed of 400-500 rpm, cooling to room temperature, washing, suction filtering, and drying to obtain the fiber framework.

6. The synergistic lock and fluid dynamics layered tire sealing composition of claim 5, wherein, The mass ratio of the oxidized chopped carbon fiber and the acrylic acid in step A2 is 1:(0.2-0.6).

7. The method of preparing a tire sealing composition based on the synergy of interlocking and fluid dynamics layering of claim 5, wherein, The mass ratio of the oxidized chopped carbon fiber and the fluorine-containing acrylate in step A2 is 1:(0.05-0.1).

8. The synergistic interlock and fluid dynamics layered based tire sealant composition according to Claim 1, wherein, The mass ratio of the combination of LDPE micro powder, PTFE micro powder, and PET flakes is 1:(0.15-0.35):(0.5-2.5).

9. The synergistic interlock and fluid-dynamics layered based tire sealant composition according to claim 1, wherein, The ionic activator is a divalent metal salt electrolyte.

10. A method of preparing the tire sealing composition based on the synergy of the mechanical interlocking and the fluid dynamics delamination according to any one of claims 1-9, characterized in that, The method includes the following steps: S1, adding the composite antifreezing carrier liquid into a reaction container, absorbing the thickening agent into the reaction container within 20-30 min, adjusting the rotation speed to be 800-1000 rpm, and stirring for 1-3 h to obtain a high-viscosity base liquid; S2, adding the fiber framework, PET flakes, LDPE micro powder, and PTFE micro powder into the high-viscosity base liquid obtained in step S1 in sequence with an interval of 12-17 min, and stirring at 5000-7000 rpm for 30-60 min to obtain a suspension. S3, the rotation speed is adjusted to 400-600 rpm / min, the ion activator aqueous solution is injected into the suspension obtained in step S2 at a constant speed for 30-60 s, immediately after the injection is completed, the rotation speed is reduced to 80-120 rpm, the pretreated high-ammonia natural latex is added in 5-10 min, after the addition is completed, the stirring is continued for 20-40 min, the corrosion inhibitor and the preservative are added in sequence, the stirring is continued for 20-40 min, and then the obtained product is coarsely filtered, defoamed, and packed, thereby obtaining the product.

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