Marking paint capable of preventing layering at normal temperature and preparation method of marking paint

Abstract

The invention provides a marking coating capable of preventing normal-temperature layering and a preparation method of the marking coating, and belongs to the technical field of coatings. Comprising the following raw materials in parts by weight: 1-2 parts of a temperature-sensitive reversible cross-linking agent, 15-30 parts of epoxy resin, 10-20 parts of an acrylic monomer, 1-2 parts of an emulsifier, 2-4 parts of temperature-sensitive microcapsules, 0.5-1 part of nano titanium dioxide, 1-2 parts of inorganic asbestos fibers, 0.5-1.5 parts of polymer fibers, 0.01-0.02 part of an initiator, 3-4 parts of a water-soluble epoxy curing agent, 2-3 parts of hollow glass beads, 2-4 parts of an auxiliary agent and 40-80 parts of water. The marking paint has the temperature-sensitive characteristic, is a weak gel network at normal temperature, inhibits filler sedimentation, hydrogen bond fracture during construction heating, paint fluidity recovery and cooling recovery crosslinking, and has high strength and hardness, so that the tensile strength, bending strength, hardness and other mechanical properties of a paint film are remarkably improved, and the wear resistance and impact resistance are also enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly relates to a marking coating for preventing stratification at normal temperature and a preparation method thereof. Background Art

[0002] Traffic markings can visually provide the required information, which is beneficial to guiding and controlling channelized traffic, ensuring the safe and efficient operation of the entire traffic system, and at the same time ensuring the safety of drivers, passengers and pedestrians. At present, traffic marking coatings can be mainly divided into hot-melt type, solvent type, two-component and waterborne traffic marking coatings. With the continuous enhancement of people's environmental protection awareness, the development of the traffic marking industry has entered a new era, and at the same time, higher requirements are put forward for traffic marking coatings. On the basis of ensuring quality and performance, it is necessary to reduce the emission of volatile organic compounds (VOCs) and pay attention to green environmental protection.

[0003] When using hot-melt traffic marking coatings, it is necessary to continuously heat them to 180 - 220 °C, resulting in huge energy consumption; when solvent-based traffic marking coatings are constructed, a large amount of organic solvents will volatilize, which not only seriously endangers the physical and mental health of construction workers, but also causes serious pollution to the surrounding environment. Therefore, traditional hot-melt and solvent-based traffic marking coatings obviously do not meet the development requirements. Waterborne traffic marking coatings have significant advantages over traditional solvent-based and hot-melt coatings due to their excellent practical performance, environmental protection performance and high construction efficiency.

[0004] According to different matrix emulsions, waterborne traffic marking coatings can be divided into waterborne acrylic, waterborne polyurethane, waterborne epoxy and waterborne alkyd traffic marking coatings, etc. Waterborne acrylic-based coatings have been widely used in the coating industry due to their good film-forming properties, stability (including light, heat and chemical stability), weather resistance, corrosion resistance and stain resistance, etc., and acrylic emulsions are easy to modify. Environmentally friendly traffic marking coatings represented by waterborne acrylic traffic marking coatings have good durability performance throughout the life cycle, and are expected to replace solvent-based and hot-melt traffic marking coatings and become the mainstream development direction in the marking field in the future.

[0005] In the formulation of marking coatings, a large amount of fillers are usually added to meet their various properties. However, when inorganic fillers are added to an organic resin system, problems such as easy precipitation and stratification often occur, resulting in poor storage stability, affecting construction operations, and greatly limiting the application of marking coatings. Summary of the Invention

[0006] The object of the present invention is to provide a marking paint that prevents stratification at normal temperature and its preparation method. It has a thermosensitive property, is a weak gel network at normal temperature to inhibit the sedimentation of fillers. When heated during construction, the hydrogen bonds break, and the paint restores fluidity. After the construction is completed, crosslinking resumes, having relatively high strength and hardness, significantly improving the mechanical properties such as the tensile strength, bending strength, and hardness of the paint film, and also enhancing the wear resistance and impact resistance of the paint, with broad application prospects.

[0007] The technical solution of the present invention is realized as follows:

[0008] The present invention provides a marking paint that prevents stratification at normal temperature, comprising the following raw materials in parts by weight: 1 - 2 parts of a thermosensitive reversible crosslinking agent, 15 - 30 parts of epoxy resin, 10 - 20 parts of acrylic monomer, 1 - 2 parts of emulsifier, 2 - 4 parts of thermosensitive microcapsules, 0.5 - 1 part of nano-titanium dioxide, 1 - 2 parts of inorganic asbestos fiber, 0.5 - 1.5 parts of polymer fiber, 0.01 - 0.02 parts of initiator, 3 - 4 parts of water-soluble epoxy curing agent, 2 - 3 parts of hollow glass microspheres, 2 - 4 parts of additives, and 40 - 80 parts of water.

[0009] As a further improvement of the present invention, the preparation method of the thermosensitive reversible crosslinking agent is as follows: Add polyvinyl alcohol to ethanol, add boric acid and 1 - hydroxyethyl - 3 - methylimidazolium chloride, stir and react, and remove the solvent under reduced pressure to obtain the thermosensitive reversible crosslinking agent.

[0010] As a further improvement of the present invention, the mass ratio of polyvinyl alcohol, boric acid, and 1 - hydroxyethyl - 3 - methylimidazolium chloride is 6 - 10:3 - 5:0.5 - 1.5, and the stirring reaction time is 2 - 4 h.

[0011] As a further improvement of the present invention, the preparation method of the thermosensitive microcapsules is as follows:

[0012] S1. Preparation of branched polyester: Add trimellitic anhydride, trimethylolpropane, and a catalyst to N,N - dimethylformamide, heat and stir to react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain the branched polyester;

[0013] S2. Preparation of intercalated montmorillonite powder: Add montmorillonite powder to water, add the branched polyester, stir and react for intercalation, filter, wash, and dry to obtain the intercalated montmorillonite powder;

[0014] S3. Preparation of modified fumed silica: Add fumed silica to a Tris - HCl solution, add tannic acid, heat and stir to react, filter, wash, and dry to obtain the modified fumed silica;

[0015] S4. Preparation of thixotropic agent: Add modified fumed silica and intercalated montmorillonite powder into water, stir and react, filter, wash, and dry to obtain the thixotropic agent;

[0016] S5. Preparation of thermosensitive microcapsules: Dissolve glycerol monostearate in ethanol, add konjac gum, heat and stir to mix evenly to obtain the ethanol phase; Add the thixotropic agent and emulsifier into water, stir and mix evenly to obtain the water phase, drop the water phase into the ethanol phase, stir and mix, place in an ice-water bath, filter, wash, and dry to obtain the thermosensitive microcapsules.

[0017] As a further improvement of the present invention, in step S1, the molar ratio of trimellitic anhydride, trimethylolpropane, and catalyst is 2-4:1:0.1-0.15, the catalyst is p-toluenesulfonic acid, and the temperature of the heating and stirring reaction is 120-140 °C; in step S2, the mass ratio of montmorillonite powder and branched polyester is 10:1.5-2.5, the temperature of the stirring and reaction intercalation is 35-45 °C, and the time is 0.5-1.5 h.

[0018] As a further improvement of the present invention, in step S3, the pH value of the Tris-HCl solution is 8.5-9.5, the mass ratio of fumed silica and tannic acid is 8-10:2-3, the temperature of the heating and stirring reaction is 40-50 °C, and the time is 3-5 h; in step S4, the ratio of modified fumed silica to intercalated montmorillonite powder is 3-5:6-8; in step S5, the mass ratio of glycerol monostearate, konjac gum, thixotropic agent, and emulsifier is 6-8:2-4:3-5:0.5-1, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, and Tween-85, and the heating temperature is 40-50 °C.

[0019] As a further improvement of the present invention, the acrylic monomers include methyl methacrylate, butyl acrylate, acrylamide, styrene, and 1-allyl-3-methylimidazolium tetrafluoroborate, and the mass ratio is 3-5:4-6:2-4:1-2:2-4.

[0020] Introducing a rigid styrene monomer with a benzene ring structure into the monomer can significantly improve the hardness and mechanical strength of the coating. At the same time, introducing 1-allyl-3-methylimidazolium tetrafluoroborate improves the thermal stability of the coating, reduces the occurrence of thermal degradation, and at the same time improves the flame retardancy and antibacterial properties, enhancing the chemical corrosion resistance. The 1-allyl-3-methylimidazolium tetrafluoroborate monomer contains active double bonds and an imidazole ring structure, which can undergo cross-linking reactions with other monomers or the molecular chains of polypropylene resin under appropriate conditions. The double bonds in its molecule can carry out copolymerization or grafting reactions with unsaturated groups in the polypropylene resin, and the active hydrogen on the imidazole ring can also carry out cross-linking and curing reactions with some compounds containing active groups, thereby forming a three-dimensional cross-linked network structure and improving the cross-linking density and properties of the material.

[0021] As a further improvement of the present invention, the high molecular fiber is selected from at least one of polyester fiber, polyethylene fiber, polypropylene fiber, and nylon fiber; the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, and Tween-85; the initiator is selected from at least one of sodium persulfate, potassium persulfate, and ammonium persulfate; the hollow glass microspheres include hollow glass microspheres with an average particle size of 40-50 μm and hollow glass microspheres with an average particle size of 100-150 μm, and the mass ratio is 3-5:7-10.

[0022] Selecting hollow glass microspheres with different particle sizes to form a density gradient buffer layer with the resin base material, blocking the sedimentation path of inorganic substances and prolonging the storage period.

[0023] The present invention further protects a preparation method of the above-mentioned marking paint for preventing stratification at normal temperature, which includes the following steps:

[0024] (1) Mix water and the emulsifier evenly to obtain a pre-emulsion.

[0025] (2) Add epoxy resin and acrylic monomer to the pre-emulsion, stir and mix evenly to obtain an emulsion.

[0026] (3) Add thermosensitive microcapsules, nano-titanium dioxide, hollow glass microspheres, inorganic asbestos fibers, and high molecular fibers to the emulsion, stir and mix evenly, add the initiator and water-soluble epoxy curing agent, heat and stir for reaction, add the thermosensitive reversible cross-linking agent and additives, stir and mix evenly to obtain the marking paint for preventing stratification at normal temperature.

[0027] The present invention has the following beneficial effects:

[0028] The present invention prepares a temperature-sensitive reversible cross-linking agent. The cross-linking formed by polyvinyl alcohol and boric acid mainly forms borate bonds, which are a type of dynamic reversible covalent bond. Under heating conditions, the borate bonds will break due to obtaining sufficient energy, causing the cross-linked structure to disintegrate, thereby enabling the polyvinyl alcohol to regain fluidity. The present invention also adds 1-hydroxyethyl-3-methylimidazolium chloride with a hydroxyl structure, which can increase the flexibility and fluidity of the polyvinyl alcohol molecular chain, making the borate bonds easier to break when heated and promoting the reversibility of cross-linking. By adding this temperature-sensitive reversible cross-linking agent, the coating forms a weak gel network at room temperature (<25 °C) to inhibit the sedimentation of fillers; when heated during construction (>60 °C), the hydrogen bonds break, the coating regains fluidity, and after coating and cooling, it cross-links again, thereby obtaining a coating that meets the requirements.

[0029] The present invention further prepares a temperature-sensitive microcapsule, with a thixotropic agent as the core material and a temperature-sensitive polymer as the shell layer. Glycerol monostearate as the wall material of the microcapsule can protect the core material, but microcapsules with glycerol monostearate as the wall material have problems such as low encapsulation efficiency and easy leakage of the core material when encountering water. The main component of konjac gum is konjac glucomannan, which has strong gelling and film-forming properties, and is beneficial to improving the encapsulation efficiency and stability of the microcapsule. The prepared capsules are intact at room temperature and the thixotropic agent is not released; when heated during construction, the shell layer softens, and the thixotropic agent is slowly released into the system. During high-speed stirring, under shear force (such as stirring, brushing, etc.), it quickly transforms into a low-viscosity fluid to ensure the smoothness of construction, and returns to a high-viscosity state after removing the external force, taking into account both storage stability and workability.

[0030] During the preparation process of the thixotropic agent of the present invention, branched polyester intercalated montmorillonite is first prepared. When the intercalated montmorillonite is fully dispersed in the organic resin system, the interlayers of the intercalated montmorillonite are easily bridged with each other through hydrogen bonds to form a thixotropic gel body with a card layer structure, thereby improving the viscosity, thixotropy, film-forming property, etc. of the material. At the same time, the branched polyester can not only expand the layer spacing of the montmorillonite to improve the thixotropic performance, but also its structure can support and wrap the filler particles with the network structure, making it difficult for them to aggregate and settle with each other. A large number of active functional groups such as carboxyl groups can react with the active groups in the polyacrylic resin to form a chemically bonded cross-linked network structure, promoting the curing reaction process of the coating, improving the cross-linking density and performance of the coating. The branched polyester also has good compatibility with the polyacrylic resin, improving the dispersibility of the material.

[0031] In addition, the montmorillonite intercalated with branched polyester itself has relatively high strength and hardness. Through the cross-linking reaction with the polyacrylic resin, the mechanical properties of the branched polyester are transferred to the coating system, significantly improving the mechanical properties such as the tensile strength, flexural strength, and hardness of the paint film, thereby enhancing the wear resistance and impact resistance of the coating.

[0032] Fumed silica usually contains a small amount of silanol groups on its surface. When the particles approach each other, hydrogen bonds are easily formed between the hydroxyl groups on the silanols, causing the particles to be interconnected through weak bond interactions and further forming a three-dimensional network structure. This three-dimensional network structure hinders the movement of other substances in the system, resulting in an increase in the viscosity of the system and thus exhibiting thixotropy. After surface polymerization modification with tannic acid, on the one hand, it can react well with intercalated montmorillonite powder to prepare a composite thixotropic agent. On the other hand, the tannic acid structure can also play a function similar to that of branched polyester, thus improving the crosslinkability, mechanical properties of the coating and preventing precipitation, etc.

[0033] The marking paint prepared by the present invention to prevent stratification at normal temperature has a thermosensitive property. It is a weak gel network at normal temperature, inhibiting the settlement of fillers. When heated during construction, the hydrogen bonds break, and the paint restores fluidity. After the construction is completed, it restores crosslinking, has relatively high strength and hardness, significantly improves the mechanical properties such as the tensile strength, bending strength and hardness of the paint film, and also enhances the wear resistance and impact resistance of the paint, having broad application prospects. Specific embodiments

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0035] Preparation Example 1 Preparation of thermosensitive reversible crosslinking agent

[0036] The method is as follows: Add 6 g of polyvinyl alcohol to ethanol, add 3 g of boric acid and 0.5 g of 1-hydroxyethyl-3-methylimidazolium chloride, stir and react for 2 h, and remove the solvent under reduced pressure to obtain a thermosensitive reversible crosslinking agent.

[0037] Preparation Example 2 Preparation of thermosensitive reversible crosslinking agent

[0038] The method is as follows: Add 10 g of polyvinyl alcohol to ethanol, add 5 g of boric acid and 1.5 g of 1-hydroxyethyl-3-methylimidazolium chloride, stir and react for 4 h, and remove the solvent under reduced pressure to obtain a thermosensitive reversible crosslinking agent.

[0039] Preparation Example 3 Preparation of thermosensitive reversible crosslinking agent

[0040] The method is as follows: Add 8 g of polyvinyl alcohol to ethanol, add 4 g of boric acid and 1 g of 1-hydroxyethyl-3-methylimidazolium chloride, stir and react for 3 h, and remove the solvent under reduced pressure to obtain a thermosensitive reversible crosslinking agent.

[0041] Comparative Preparation Example 1

[0042] Compared with Preparation Example 3, the difference lies in that 1-hydroxyethyl-3-methylimidazolium chloride is not added.

[0043] The method is as follows: Add 9 g of polyvinyl alcohol to ethanol, add 4 g of boric acid, stir and react for 3 h, remove the solvent under reduced pressure to obtain a thermosensitive reversible crosslinking agent.

[0044] Preparation of Thermosensitive Microcapsules in Preparation Example 4

[0045] The method is as follows:

[0046] S1. Preparation of branched polyester: Add 0.2 mol of trimellitic anhydride, 0.1 mol of trimethylolpropane, and 0.01 mol of p-toluenesulfonic acid to 200 mL of N,N-dimethylformamide, heat to 120 °C, stir and react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain a branched polyester;

[0047] S2. Preparation of intercalated montmorillonite powder: Add 10 g of montmorillonite powder to 200 mL of water, add 1.5 g of branched polyester, stir and react for intercalation at 35 °C for 0.5 h, filter, wash, and dry to obtain intercalated montmorillonite powder;

[0048] S3. Preparation of modified fumed silica: Add 8 g of fumed silica to 150 mL of Tris-HCl solution with a pH value of 8.5, add 2 g of tannic acid, heat to 40 °C, stir and react for 3 h, filter, wash, and dry to obtain modified fumed silica;

[0049] S4. Preparation of thixotropic agent: Add 3 g of modified fumed silica and 6 g of intercalated montmorillonite powder to 150 mL of water, stir and react for 30 min, filter, wash, and dry to obtain a thixotropic agent;

[0050] S5. Preparation of thermosensitive microcapsules: Dissolve 6 g of glyceryl monostearate in 200 mL of ethanol, add 2 g of konjac gum, heat to 40 °C, stir and mix evenly to obtain an ethanol phase; Add 3 g of thixotropic agent and 0.5 g of Tween-85 to 100 mL of water, stir and mix evenly to obtain an aqueous phase, drop the aqueous phase into the ethanol phase, stir and mix for 30 min, place in an ice-water bath, filter, wash, and dry to obtain thermosensitive microcapsules.

[0051] Preparation of Thermosensitive Microcapsules in Preparation Example 5

[0052] The method is as follows:

[0053] S1. Preparation of branched polyester: Add 0.4 mol of trimellitic anhydride, 0.1 mol of trimethylolpropane, and 0.015 mol of p-toluenesulfonic acid to 200 mL of N,N-dimethylformamide, heat to 140 °C, stir and react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain a branched polyester;

[0054] S2. Preparation of intercalated montmorillonite powder: Add 10 g of montmorillonite powder to 200 mL of water, add 2.5 g of branched polyester, stir and react at 45 °C for 1.5 h for intercalation, filter, wash, and dry to obtain intercalated montmorillonite powder;

[0055] S3. Preparation of modified fumed silica: Add 10 g of fumed silica to 150 mL of Tris-HCl solution with a pH value of 9.5, add 3 g of tannic acid, heat to 50 °C, stir and react for 5 h, filter, wash, and dry to obtain modified fumed silica;

[0056] S4. Preparation of thixotropic agent: Add 5 g of modified fumed silica and 8 g of intercalated montmorillonite powder to 150 mL of water, stir and react for 30 min, filter, wash, and dry to obtain thixotropic agent;

[0057] S5. Preparation of thermosensitive microcapsules: Dissolve 8 g of glyceryl monostearate in 200 mL of ethanol, add 4 g of konjac gum, heat to 50 °C, stir and mix evenly to obtain the ethanol phase; Add 5 g of thixotropic agent and 1 g of Tween-60 to 100 mL of water, stir and mix evenly to obtain the aqueous phase. Drop the aqueous phase into the ethanol phase, stir and mix for 30 min, place in an ice-water bath, filter, wash, and dry to obtain thermosensitive microcapsules.

[0058] Preparation Example 6 Preparation of thermosensitive microcapsules

[0059] The method is as follows:

[0060] S1. Preparation of branched polyester: Add 0.3 mol of trimellitic anhydride, 0.1 mol of trimethylolpropane, and 0.012 mol of p-toluenesulfonic acid to 200 mL of N,N-dimethylformamide, heat to 130 °C, stir and react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain branched polyester;

[0061] S2. Preparation of intercalated montmorillonite powder: Add 10 g of montmorillonite powder to 200 mL of water, add 2 g of branched polyester, stir and react at 40 °C for 1 h for intercalation, filter, wash, and dry to obtain intercalated montmorillonite powder;

[0062] S3. Preparation of modified fumed silica: Add 9 g of fumed silica to 150 mL of Tris-HCl solution with a pH value of 9, add 2.5 g of tannic acid, heat to 45 °C, stir and react for 4 h, filter, wash, and dry to obtain modified fumed silica;

[0063] S4. Preparation of thixotropic agent: Add 4 g of modified fumed silica and 7 g of intercalated montmorillonite powder to 150 mL of water, stir and react for 30 min, filter, wash, and dry to obtain thixotropic agent;

[0064] S5. Preparation of thermosensitive microcapsules: Dissolve 7 g of glyceryl monostearate in 200 mL of ethanol, add 3 g of konjac gum, heat to 45 °C, stir and mix evenly to obtain an ethanol phase; Add 4 g of thixotropic agent and 0.7 g of Tween-80 to 100 mL of water, stir and mix evenly to obtain an aqueous phase, drop the aqueous phase into the ethanol phase, stir and mix for 30 min, place it in an ice-water bath, filter, wash, and dry to obtain thermosensitive microcapsules.

[0065] Comparative Preparation Example 2

[0066] Compared with Preparation Example 6, the difference lies in that steps S1 and S2 are not carried out.

[0067] Specifically as follows:

[0068] S1. Preparation of modified fumed silica: Add 9 g of fumed silica to 150 mL of Tris-HCl solution with a pH value of 9, add 2.5 g of tannic acid, heat to 45 °C, stir and react for 4 h, filter, wash, and dry to obtain modified fumed silica;

[0069] S2. Preparation of thixotropic agent: Add 4 g of modified fumed silica and 7 g of montmorillonite powder to 150 mL of water, stir and react for 30 min, filter, wash, and dry to obtain a thixotropic agent;

[0070] S3. Preparation of thermosensitive microcapsules: Dissolve 7 g of glyceryl monostearate in 200 mL of ethanol, add 3 g of konjac gum, heat to 45 °C, stir and mix evenly to obtain an ethanol phase; Add 4 g of thixotropic agent and 0.7 g of Tween-80 to 100 mL of water, stir and mix evenly to obtain an aqueous phase, drop the aqueous phase into the ethanol phase, stir and mix for 30 min, place it in an ice-water bath, filter, wash, and dry to obtain thermosensitive microcapsules.

[0071] Comparative Preparation Example 3

[0072] Compared with Preparation Example 6, the difference lies in that step S3 is not carried out.

[0073] Specifically as follows:

[0074] S1. Preparation of branched polyester: Add 0.3 mol of trimellitic anhydride, 0.1 mol of trimethylolpropane, and 0.012 mol of p-toluenesulfonic acid to 200 mL of N,N-dimethylformamide, heat to 130 °C, stir and react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain branched polyester;

[0075] S2. Preparation of intercalated montmorillonite powder: Add 10 g of montmorillonite powder to 200 mL of water, add 2 g of branched polyester, stir and react at 40 °C for intercalation for 1 h, filter, wash, and dry to obtain intercalated montmorillonite powder;

[0076] S3. Preparation of thixotropic agent: Add 4 g of fumed silica and 7 g of intercalated montmorillonite powder into 150 mL of water, stir and react for 30 min, filter, wash, and dry to obtain the thixotropic agent;

[0077] S4. Preparation of thermosensitive microcapsules: Dissolve 7 g of glycerol monostearate in 200 mL of ethanol, add 3 g of konjac gum, heat to 45 °C, stir and mix evenly to obtain the ethanol phase; Add 4 g of thixotropic agent and 0.7 g of Tween-80 into 100 mL of water, stir and mix evenly to obtain the water phase. Drop the water phase into the ethanol phase, stir and mix for 30 min, place it in an ice-water bath, filter, wash, and dry to obtain the thermosensitive microcapsules.

[0078] Comparative Preparation Example 4

[0079] Compared with Preparation Example 6, the difference is that modified fumed silica is not added in step S4.

[0080] Specifically as follows:

[0081] S1. Preparation of branched polyester: Add 0.3 mol of trimellitic anhydride, 0.1 mol of trimethylolpropane, and 0.012 mol of p-toluenesulfonic acid into 200 mL of N,N-dimethylformamide, heat to 130 °C, stir and react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain the branched polyester;

[0082] S2. Preparation of intercalated montmorillonite powder: Add 10 g of montmorillonite powder into 200 mL of water, add 2 g of branched polyester, stir and react for intercalation at 40 °C for 1 h, filter, wash, and dry to obtain the intercalated montmorillonite powder, which is the thixotropic agent;

[0083] S3. Preparation of thermosensitive microcapsules: Dissolve 7 g of glycerol monostearate in 200 mL of ethanol, add 3 g of konjac gum, heat to 45 °C, stir and mix evenly to obtain the ethanol phase; Add 4 g of thixotropic agent and 0.7 g of Tween-80 into 100 mL of water, stir and mix evenly to obtain the water phase. Drop the water phase into the ethanol phase, stir and mix for 30 min, place it in an ice-water bath, filter, wash, and dry to obtain the thermosensitive microcapsules.

[0084] Comparative Preparation Example 5

[0085] Compared with Preparation Example 6, the difference is that intercalated montmorillonite powder is not added in step S4.

[0086] Specifically as follows:

[0087] S1. Preparation of modified fumed silica: Add 9 g of fumed silica into 150 mL of Tris-HCl solution with a pH value of 9, add 2.5 g of tannic acid, heat to 45 °C, stir and react for 4 h, filter, wash, and dry to obtain modified fumed silica, which is the thixotropic agent.

[0088] S2. Preparation of thermosensitive microcapsules: Dissolve 7 g of glyceryl monostearate in 200 mL of ethanol, add 3 g of konjac gum, heat to 45 °C, stir and mix evenly to obtain the ethanol phase; add 4 g of thixotropic agent and 0.7 g of Tween-80 into 100 mL of water, stir and mix evenly to obtain the water phase, drop the water phase into the ethanol phase, stir and mix for 30 min, place in an ice-water bath, filter, wash, and dry to obtain thermosensitive microcapsules.

[0089] Comparative Preparation Example 6

[0090] Compared with Preparation Example 6, the difference is that step S5 is not carried out.

[0091] Specifically as follows:

[0092] S1. Preparation of branched polyester: Add 0.3 mol of trimellitic anhydride, 0.1 mol of trimethylolpropane, and 0.012 mol of p-toluenesulfonic acid into 200 mL of N,N-dimethylformamide, heat to 130 °C, stir and react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain branched polyester.

[0093] S2. Preparation of intercalated montmorillonite powder: Add 10 g of montmorillonite powder into 200 mL of water, add 2 g of branched polyester, stir and react for intercalation at 40 °C for 1 h, filter, wash, and dry to obtain intercalated montmorillonite powder.

[0094] S3. Preparation of modified fumed silica: Add 9 g of fumed silica into 150 mL of Tris-HCl solution with a pH value of 9, add 2.5 g of tannic acid, heat to 45 °C, stir and react for 4 h, filter, wash, and dry to obtain modified fumed silica.

[0095] S4. Preparation of thixotropic agent: Add 4 g of modified fumed silica and 7 g of intercalated montmorillonite powder into 150 mL of water, stir and react for 30 min, filter, wash, and dry to obtain the thixotropic agent.

[0096] Example 1

[0097] This example provides a marking paint for preventing stratification at room temperature.

[0098] Raw material composition (parts by weight): 1 part of the thermosensitive reversible crosslinking agent prepared in Preparation Example 1, 15 parts of epoxy resin (NPEL 128, South Asia Resins), 10 parts of acrylic monomer, 1 part of emulsifier, 2 parts of the thermosensitive microcapsules prepared in Preparation Example 4, 0.5 part of nano-titanium dioxide, 1 part of inorganic asbestos fiber, 0.5 part of polyester fiber, 0.01 part of ammonium persulfate, 3 parts of water-soluble epoxy curing agent (BANCO901, Banghe Chemical (China) Co., Ltd.), 2 parts of hollow glass microspheres, 2 parts of additives, and 40 parts of water. The additives include dipropylene glycol butyl ether, dispersant (BYK-190, BYK Chemie), defoamer (TEGO Airex 902W, Evonik Degussa), and 2-amino-2-methyl-1-propanol, with a mass ratio of 1:0.2:0.1:0.5. The acrylic monomer includes methyl methacrylate, butyl acrylate, acrylamide, styrene, and 1-allyl-3-methylimidazolium tetrafluoroborate, with a mass ratio of 3:4:2:1:2.

[0099] The preparation method comprises the following steps:

[0100] (1) Mix water and the emulsifier, and stir and mix at 800 r / min for 20 min to obtain a pre-emulsion.

[0101] (2) Add the epoxy resin and the acrylic monomer to the pre-emulsion, and stir and mix at 800 r / min for 30 min to obtain an emulsion.

[0102] (3) Add the thermosensitive microcapsules, nano-titanium dioxide, hollow glass microspheres, inorganic asbestos fiber, and polyester fiber to the emulsion, stir and mix at 800 r / min for 20 min, add ammonium persulfate and the water-soluble epoxy curing agent, heat to 60 °C, continue stirring and reacting for 2 h, add the thermosensitive reversible crosslinking agent and the additives, and continue heat-preserving and stirring and reacting for 1 h to obtain a marking paint that prevents stratification at normal temperature.

[0103] Example 2

[0104] This example provides a marking paint that prevents stratification at normal temperature.

[0105] Raw material composition (parts by weight): 2 parts of the thermosensitive reversible crosslinking agent prepared in Preparation Example 2, 30 parts of epoxy resin (NPEL 128, South Asia Resins), 20 parts of acrylic monomer, 2 parts of emulsifier, 4 parts of the thermosensitive microcapsules prepared in Preparation Example 5, 1 part of nano-titanium dioxide, 2 parts of inorganic asbestos fiber, 1.5 parts of polypropylene fiber, 0.02 part of potassium persulfate, 4 parts of water-soluble epoxy curing agent (BANCO901, Banghe Chemical (China) Co., Ltd.), 3 parts of hollow glass microspheres, 4 parts of additives, and 80 parts of water. The additives include dipropylene glycol butyl ether, dispersant (BYK-190, BYK Chemie), defoamer (TEGO Airex 902W, Evonik Degussa), and 2-amino-2-methyl-1-propanol, with a mass ratio of 1:0.2:0.1:0.5. The acrylic monomer includes methyl methacrylate, butyl acrylate, acrylamide, styrene, and 1-allyl-3-methylimidazolium tetrafluoroborate, with a mass ratio of 5:6:4:2:4.

[0106] The preparation method includes the following steps:

[0107] (1) Mix water and emulsifier, and stir and mix at 800 r / min for 20 min to obtain a pre-emulsion.

[0108] (2) Add epoxy resin and acrylic monomer to the pre-emulsion, and stir and mix at 800 r / min for 30 min to obtain an emulsion.

[0109] (3) Add thermosensitive microcapsules, nano-titanium dioxide, hollow glass microspheres, inorganic asbestos fiber, and polypropylene fiber to the emulsion, stir and mix at 800 r / min for 20 min, add potassium persulfate and water-soluble epoxy curing agent, heat to 80 °C, continue stirring and reacting for 3 h, add thermosensitive reversible crosslinking agent and additives, and continue heat-preserving and stirring and reacting for 3 h to obtain a marking paint that prevents stratification at normal temperature.

[0110] Example 3

[0111] This example provides a marking paint that prevents stratification at normal temperature.

[0112] Raw material composition (parts by weight): 1.5 parts of the thermosensitive reversible crosslinking agent prepared in Preparation Example 3, 22 parts of epoxy resin (NPEL 128, South Asia Resins), 15 parts of acrylic monomers, 1.5 parts of emulsifier, 3 parts of the thermosensitive microcapsules prepared in Preparation Example 6, 0.7 part of nano-titanium dioxide, 1.5 parts of inorganic asbestos fiber, 1 part of polyester fiber, 0.015 part of sodium persulfate, 3.5 parts of water-soluble epoxy curing agent (BANCO901, Banghe Chemical (China) Co., Ltd.), 2.5 parts of hollow glass microspheres, 3 parts of additives, and 60 parts of water. The additives include dipropylene glycol butyl ether, dispersant (BYK-190, BYK Chemie), defoamer (TEGO Airex 902W, Evonik Degussa), and 2-amino-2-methyl-1-propanol, with a mass ratio of 1:0.2:0.1:0.5. The acrylic monomers include methyl methacrylate, butyl acrylate, acrylamide, styrene, and 1-allyl-3-methylimidazolium tetrafluoroborate, with a mass ratio of 4:5:3:1.5:3.

[0113] The preparation method comprises the following steps:

[0114] (1) Mix water and the emulsifier, and stir and mix at 800 r / min for 20 min to obtain a pre-emulsion.

[0115] (2) Add the epoxy resin and acrylic monomers to the pre-emulsion, and stir and mix at 800 r / min for 30 min to obtain an emulsion.

[0116] (3) Add the thermosensitive microcapsules, nano-titanium dioxide, hollow glass microspheres, inorganic asbestos fiber, and polyester fiber to the emulsion, stir and mix at 800 r / min for 20 min, add sodium persulfate and the water-soluble epoxy curing agent, heat to 70 °C, continue to stir and react for 2.5 h, add the thermosensitive reversible crosslinking agent and additives, and continue to keep warm and stir and react for 2 h to obtain a marking paint that prevents stratification at room temperature.

[0117] Comparative Example 1

[0118] Compared with Example 3, the difference lies in that the thermosensitive reversible crosslinking agent is prepared from Comparative Preparation Example 1.

[0119] Comparative Example 2

[0120] Compared with Example 3, the difference lies in that the thermosensitive reversible crosslinking agent is not added.

[0121] Comparative Example 3

[0122] Compared with Example 3, the difference lies in that the thermosensitive microcapsules are prepared from Comparative Preparation Example 2.

[0123] Comparative Example 4

[0124] Compared with Example 3, the difference lies in that the thermosensitive microcapsules are prepared from Comparative Preparation Example 3.

[0125] Comparative Example 5

[0126] Compared with Example 3, the difference lies in that the thermosensitive microcapsules are prepared from Comparative Preparation Example 4.

[0127] Comparative Example 6

[0128] Compared with Example 3, the difference lies in that the thermosensitive microcapsules are prepared from Comparative Preparation Example 5.

[0129] Comparative Example 7

[0130] Compared with Example 3, the difference lies in that the thixotropic agent prepared from Comparative Preparation Example 6 is used to replace the thermosensitive microcapsules.

[0131] Comparative Example 8

[0132] Compared with Example 3, the difference lies in that no thermosensitive microcapsules are added.

[0133] Comparative Example 9

[0134] Compared with Example 3, the difference lies in that 1-allyl-3-methylimidazolium tetrafluoroborate is not added to the acrylic monomer. The acrylic monomer includes methyl methacrylate, butyl acrylate, acrylamide and styrene, and the mass ratio is 4:5:3:1.5.

[0135] Comparative Example 10

[0136] Compared with Example 3, the difference lies in that styrene is not added to the acrylic monomer. The acrylic monomer includes methyl methacrylate, butyl acrylate, acrylamide and 1-allyl-3-methylimidazolium tetrafluoroborate, and the mass ratio is 4:5:3:3.

[0137] Test Example 1

[0138] The performance of the anti-temperature-layer separation marking coatings prepared in Examples 1-3 and Comparative Examples 1-10 was tested, and the results are shown in Table 1.

[0139] The adhesion was detected according to the method of GB / T 9286-2021;

[0140] The pencil hardness was detected according to the method of GB / T 6739-2022;

[0141] The water resistance was detected according to the method of GB / T 1733-1993;

[0142] The abrasion resistance was detected according to the method of GB / T 1768-2006;

[0143] The detection method of compressive strength is as follows: Cast 3 coating compressive test blocks of 20mm×20mm×20mm, place them at room temperature for 24 hours, and then conduct a compressive test. The accuracy of the electronic universal material testing machine is not less than 0.5 level, the preload is 10N, and the loading speed is 30mm / min to test the compressive strength of the coating.

[0144] Table 1

[0145]

[0146]

[0147] As can be seen from the above table, the marking coatings for preventing stratification at normal temperature prepared in Examples 1-3 of the present invention have good comprehensive performance.

[0148] Test Example 2

[0149] Place the marking coatings for preventing stratification at normal temperature prepared in Examples 1-3 and Comparative Examples 1-10 at room temperature for 6 months and 12 months, and observe their precipitation changes. The results are shown in Table 2.

[0150] Table 2

[0151]

[0152]

[0153] As can be seen from the above table, the marking coatings for preventing stratification at normal temperature prepared in Examples 1-3 of the present invention will not produce precipitation after being placed at normal temperature for more than 12 months, and have good storage performance.

[0154] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A marking paint for preventing stratification at normal temperature, characterized in that, It includes the following raw materials in parts by weight: 1-2 parts of thermosensitive reversible crosslinking agent, 15-30 parts of epoxy resin, 10-20 parts of acrylic monomer, 1-2 parts of emulsifier, 2-4 parts of thermosensitive microcapsule, 0.5-1 part of nano-titanium dioxide, 1-2 parts of inorganic asbestos fiber, 0.5-1.5 parts of polymer fiber, 0.01-0.02 part of initiator, 3-4 parts of water-soluble epoxy curing agent, 2-3 parts of hollow glass microspheres, 2-4 parts of auxiliary agent, and 40-80 parts of water.

2. The road marking paint for preventing stratification at normal temperature according to claim 1, wherein The preparation method of the thermosensitive reversible crosslinking agent is as follows: Add polyvinyl alcohol to ethanol, add boric acid and 1-hydroxyethyl-3-methylimidazolium chloride, stir and react, and remove the solvent under reduced pressure to obtain the thermosensitive reversible crosslinking agent.

3. The marking paint for preventing normal-temperature stratification according to claim 2, characterized in that, The mass ratio of the polyvinyl alcohol, boric acid and 1-hydroxyethyl-3-methylimidazolium chloride is 6-10: 3-5: 0.5-1.5, and the stirring reaction time is 2-4 h.

4. The marking paint for preventing normal-temperature stratification according to claim 1, characterized in that, The preparation method of the thermosensitive microcapsule is as follows: S1. Preparation of branched polyester: Add trimellitic anhydride, trimethylolpropane, and catalyst to N,N-dimethylformamide, heat and stir to react until the acid value remains unchanged, remove the solvent under reduced pressure, wash, and dry to obtain branched polyester; S2. Preparation of intercalated montmorillonite powder: Add montmorillonite powder to water, add branched polyester, stir and react for intercalation, filter, wash, and dry to obtain intercalated montmorillonite powder; S3. Preparation of modified fumed silica: Add fumed silica to Tris-HCl solution, add tannic acid, heat and stir to react, filter, wash, and dry to obtain modified fumed silica; S4. Preparation of thixotropic agent: Add modified fumed silica and intercalated montmorillonite powder to water, stir and react, filter, wash, and dry to obtain thixotropic agent; S5. Preparation of thermosensitive microcapsule: Dissolve glycerol monostearate in ethanol, add konjac gum, heat and stir to mix evenly to obtain an ethanol phase; Add the thixotropic agent and emulsifier to water, stir and mix evenly to obtain an aqueous phase, drop the aqueous phase into the ethanol phase, stir and mix, place in an ice-water bath, filter, wash, and dry to obtain thermosensitive microcapsules.

5. The marking paint for preventing normal-temperature stratification according to claim 4, characterized in that, In step S1, the molar ratio of the trimellitic anhydride, trimethylolpropane, and catalyst is 2-4: 1: 0.1-0.15, the catalyst is p-toluenesulfonic acid, and the temperature of the heating and stirring reaction is 120-140 °C; In step S2, the mass ratio of the montmorillonite powder and the branched polyester is 10: 1.5-2.5, the temperature of the stirring reaction for intercalation is 35-45 °C, and the time is 0.5-1.5 h.

6. The marking paint for preventing normal-temperature delamination according to claim 4, characterized in that In step S3, the pH value of the Tris-HCl solution is 8.5 - 9.5, the mass ratio of the fumed silica to tannic acid is 8 - 10:2 - 3, the temperature of the heating and stirring reaction is 40 - 50 °C, and the time is 3 - 5 h; in step S4, the mass ratio of the modified fumed silica to the intercalated montmorillonite powder is 3 - 5:6 - 8; in step S5, the mass ratio of glyceryl monostearate, konjac gum, thixotropic agent and emulsifier is 6 - 8:2 - 4:3 - 5:0.5 - 1, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, Tween-85, and the heating temperature is 40 - 50 °C.

7. The marking paint for preventing normal-temperature stratification according to claim 1, characterized in that, The acrylic monomers include methyl methacrylate, butyl acrylate, acrylamide, styrene and 1-allyl-3-methylimidazolium tetrafluoroborate, and the mass ratio is 3 - 5:4 - 6:2 - 4:1 - 2:2 - 4.

8. The marking paint for preventing stratification at normal temperature according to claim 1, characterized in that, The polymer fibers are selected from at least one of polyester fiber, polyethylene fiber, polypropylene fiber, nylon fiber; the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, Tween-85; the initiator is selected from at least one of sodium persulfate, potassium persulfate, ammonium persulfate; the hollow glass microspheres include hollow glass microspheres with an average particle size of 40 - 50 μm and hollow glass microspheres with an average particle size of 100 - 150 μm, and the mass ratio is 3 - 5:7 - 10.

9. A method for preparing a marking paint for preventing stratification at normal temperature according to any one of claims 1-8, characterized in that, It includes the following steps: (1) Mix water and emulsifier evenly to prepare a pre-emulsion. (2) Add epoxy resin and acrylic monomers to the pre-emulsion, stir and mix evenly to prepare an emulsion. (3) Add thermosensitive microcapsules, nano-titanium dioxide, hollow glass microspheres, inorganic asbestos fibers, and polymer fibers to the emulsion, stir and mix evenly, add an initiator and a water-soluble epoxy curing agent, heat and stir for reaction, add a thermosensitive reversible crosslinking agent and an auxiliary agent, stir and mix evenly to prepare a marking paint that prevents stratification at room temperature.

10. The preparation method according to claim 9, characterized in that, The heating temperature is 50 - 80 °C.

Images