A leveling agent for hot-melt road marking paint and its preparation method

Abstract

The present invention belongs to the field of coating technology, and specifically relates to a leveling agent for hot-melt road marking paint and a preparation method thereof. The chemical structural formula of the leveling agent is: #imgabs0# wherein P is a polyisobutylene polymer chain. The preparation method comprises: (1) adding highly active polyisobutylene to a reactor, then adding a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator, introducing an inert gas at a predetermined pressure to completely replace the air therein with the inert gas, stirring, and heating to a predetermined temperature; (2) turning on an ultraviolet lamp, irradiating at a predetermined wavelength for a predetermined time; (3) stopping stirring, separating the liquid while hot, and washing the oil phase twice with hot water to obtain a leveling agent for hot-melt road marking paint. The present invention can prepare a leveling agent with extremely low organic small molecule residue, light color, good leveling properties, and low odor in a relatively short time and at a relatively low temperature.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and particularly relates to a leveling agent for hot-melt road marking coatings and a preparation method thereof. Background Art

[0002] Road marking paint is a specialized coating used in the transportation sector, marking roads to guide the flow of vehicles and pedestrians. The markings are primarily white and yellow. Road marking paints are categorized into four main types: hot melt, solvent-based, water-based, and two-component. Among these, hot melt reflective marking paint is the most widely used. Hot melt marking paint is made from a thermoplastic resin (C5 petroleum resin, modified C5 petroleum resin, modified rosin resin, etc.) as the primary film-forming component, along with pigments, fillers, reflective materials, and other additives, which are thoroughly mixed in a mixer to form a powdery granular form. During application, hot melt marking paint is heated to 180-220°C to achieve a melt-flowing state. It is then applied to the road surface using a hot melt road marking machine. Under natural conditions, the paint cures within 3 minutes, with adjustments depending on temperature, road surface properties, and raw material specifications. Leveling agents are often used as modifiers for C5 petroleum resins and can also be directly added to coating formulas to effectively reduce the surface tension of the coating liquid, improve its leveling and uniformity, and promote the coating to form a flat, smooth and uniform coating during the drying process, thereby reducing the possibility of spots and marks when brushing, thereby improving the leveling of the prepared hot-melt reflective marking coating.

[0003] Patent application publication number CN104673045A discloses a method for improving the performance of petroleum resin products by adding polyisobutylene maleic anhydride as a modifier to the petroleum resin. The resulting hot-melt road marking paint, prepared with this modified petroleum resin, exhibits superior weather resistance, stain resistance, leveling, and adhesion compared to unmodified road marking paint. Patent application publication number CN113527979A employs a similar method to produce a crack-resistant, durable hot-melt road marking paint. Patent application publication number CN106280663A provides an anti-yellowing plasticizer for hot-melt road marking paints that incorporates maleic anhydride-modified polyisobutylene, a surfactant, an anti-corrosion agent, and a biocide. By improving the components of existing plasticizers, the compatibility between the various components of hot-melt coatings is improved, the fluidity of hot-melt coatings is increased, the amount of petroleum resin used is reduced, and the color of the marking paint is guaranteed to remain unchanged during storage, transportation and construction. The anti-discoloration performance of the formed markings when exposed to extreme environments for a long time is improved, while reducing production costs and environmental pollution.

[0004] In current industrial applications, polyisobutylene succinic anhydride is often used to modify petroleum resins and plasticizers in road marking paints to improve their leveling properties. However, these paints exhibit a strong odor during hot-melt processing and poor weather resistance. This is closely related to the production methods of the petroleum resins and the modifier, polyisobutylene succinic anhydride. Currently, polyisobutylene succinic anhydride, used as a leveling agent, is produced primarily through three processes: chlorination, thermal adduction, and free radical initiation.

[0005] The chlorination method involves mixing polyisobutylene and maleic anhydride at a constant temperature (170°C to 190°C) and introducing chlorine gas to react to produce polyisobutylene succinic anhydride. (See patent applications No. 3172892 and No. 3231587.) This process is relatively mature and is currently the most widely used method for large-scale production of olefin anhydride. However, the production of polyisobutylene succinic anhydride using this method generates a large amount of hydrogen chloride that requires disposal. Both the synthesis and separation equipment must be made of special materials, increasing production costs. Furthermore, the product contains chlorine, which is not environmentally friendly.

[0006] Patent applications such as EP0629638, US4472588, and US4599433 disclose a method for preparing polyisobutylene maleic anhydride using a "thermal addition method." Polyisobutylene and excess maleic anhydride are mixed at a relatively high temperature (220°C to 240°C) and then reacted directly, requiring a reaction time of more than 6 hours, to produce polyisobutylene succinic anhydride. The reaction process is prone to side reactions such as unsaturated acid polymerization, copolymerization of polyolefins and unsaturated acids, olefin oligomerization, and pyrolysis of olefin copolymerization and unsaturated acids. Finally, charring forms an insoluble tar-like byproduct, resulting in a low conversion rate and darker color. Furthermore, the long residence time at high temperatures results in high energy consumption. Separating the excess maleic anhydride is also complex, as maleic anhydride is prone to sublimation and desublimation, which can clog pipelines and pose a safety hazard.

[0007] In recent years, many additive companies have proposed free radical synthesis processes for preparing polyisobutylene maleic anhydride, as described in patent applications such as US Pat. No. 5319030, EP Pat. No. 0744413A2, CN Pat. No. 200810011482, and JP Pat. No. 2004256668A. These processes utilize a free radical initiator as a catalyst to promote the reaction between polyisobutylene and maleic anhydride. The reaction temperature is 160-210°C, resulting in a short cycle and minimal coking. However, the introduction of free radicals can easily lead to the formation of maleic anhydride polymers, resulting in a yellowish product color with a Gardner color of 1.5-4.0.

[0008] In summary, the current process for preparing polyisobutylene maleic anhydride has the following main problems: high reaction temperature (>160°C) and long reaction time lead to high energy consumption; the presence of double bonds and long reaction time at high temperature easily lead to dark product color; and excessive but unprocessed maleic anhydride residue causes the product to have a strong odor, which is unfriendly to construction workers. Summary of the Invention

[0009] The present invention aims to provide a leveling agent for hot-melt road marking paint and a preparation method thereof, which can prepare a leveling agent with extremely low organic small molecule residue, light color, good leveling property and low odor in a relatively short time and at a relatively low temperature.

[0010] A leveling agent for hot-melt road marking paint, the chemical structure of the leveling agent is: Wherein, P is a polyisobutylene polymer chain.

[0011] Preferably, the chemical structure of R1 includes one or more of the following structures:

[0012]

[0013] Another object of the present invention is to provide a method for preparing the leveling agent for hot-melt road marking paint, which is characterized by comprising the following steps:

[0014] (1) adding highly active polyisobutylene into a reactor, and then adding a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator, introducing an inert gas of a predetermined pressure to completely replace the air therein with the inert gas, stirring, and heating to a predetermined temperature;

[0015] (2) turning on the UV lamp and irradiating at a predetermined wavelength for a predetermined time;

[0016] (3) Stop stirring, separate the liquid while hot, and wash the oil phase twice with hot water to obtain a leveling agent for hot-melt road marking paint.

[0017] Adopting the above technical scheme, the present application includes highly active polyisobutylene, which is then acid-modified and irradiated with ultraviolet light to provide energy, which is conducive to initiating the reaction and is one of the necessary reaction conditions.

[0018] Preferably, in the highly active polyisobutylene, the α-terminal double bond content accounts for more than 70% of the total terminal double bonds of the polyisobutylene, and the number average molecular weight is 800-2300 Da;

[0019] The polar solvent includes one or more of water, tetrahydrofuran, methanol, and ethanol, and the mass ratio of the polar solvent to the highly active polyisobutylene is 0.1:1 to 5.0:1.

[0020] Preferably, in the highly active polyisobutylene, the α-terminal double bond content accounts for more than 80% of the total terminal double bonds of the polyisobutylene, and the number average molecular weight is 900-1300 Da; the mass ratio of the polar solvent to the highly active polyisobutylene is 0.2:1 to 2.0:1.

[0021] Preferably, the mercapto acid reagent includes one or more of mercaptopropionic acid, 4-mercaptobutyric acid, mercaptosuccinic acid, 5-mercaptovaleric acid, 6-mercaptohexanoic acid, 4-mercaptobenzoic acid, 4-mercaptophenylacetic acid, 6-mercaptonicotinic acid, 8-mercaptooctanoic acid, 11-mercaptoundecanoic acid, 12-mercaptododecanoic acid, 16-mercaptohexadecanoic acid, 18-mercaptooctadecanoic acid, 2,3-dimercaptosuccinic acid, and 2-(5-mercapto-1,3,4-thiadiazole-2-sulfanyl)succinic acid.

[0022] Preferably, the molar ratio of the thiol reagent to the highly reactive polyisobutylene is 0.7:1 to 1.1:1, and the amount of the thiol reagent is not less than the amount of the polyisobutylene containing α-terminal double bonds in the highly reactive polyisobutylene.

[0023] Preferably, the dispersant comprises one or more of gelatin, polyvinyl alcohol, calcium oxalate, calcium sulfate, barium sulfate, calcium phosphate, talc, kaolin, diatomaceous earth, and bentonite, and the amount of the dispersant is 0.01-1.0 wt% of the highly active polyisobutylene;

[0024] The emulsifier includes one or more of sodium lauryl sulfate, sodium lauryl sulfonate, potassium palmitate, sodium stearate, potassium stearate, and sodium octadecyl sulfate, and the amount of the emulsifier is 0.01-1.0 wt% of the highly active polyisobutylene;

[0025] In step (2), the wavelength range of the ultraviolet lamp is 200-410 nm, and the predetermined time is 5-120 min.

[0026] Preferably, the photoinitiator includes one or more of 2,4-dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenylpropanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, and 2-dimethylamino-2-benzyl-1-[4-(4-morpholino)phenyl]-1-butanone; the inert gas includes one or more of nitrogen, argon, and helium;

[0027] In step (1), the predetermined pressure is 0.1-0.6 MPa, and the predetermined temperature is 15-90° C.;

[0028] In step (2), the wavelength range of the ultraviolet lamp is 250-390 nm, and the predetermined time is 10-60 min.

[0029] By adopting the above technical scheme, the present invention utilizes the advantages of mild reaction conditions, rapid reaction, high yield, and few side reactions of the thiol-olefin click chemistry reaction; uses a polar solvent as a solvent, and the thiol acid has good solubility; the reaction time is short and the temperature is relatively low: 15-90°C, saving energy consumption; the emulsifier and dispersant do not need to be removed; water washing can significantly reduce the residual thiol reagent, and the product has a low odor; the reaction temperature is relatively low, avoiding the dark color caused by high temperature and oxidation. The color number of the leveling agent of the present invention is 0.1-0.4, while the color number of commercially available leveling agents is generally 1.5-3.0.

[0030] Preferably, in the highly active polyisobutylene, the number average molecular weight is 900-1100 Da;

[0031] In step (1), the predetermined temperature is 60-80°C;

[0032] In step (2), the predetermined time is 15-30 minutes.

[0033] The beneficial effects of the present invention are:

[0034] First, the present invention has a short preparation time, low temperature, little residue and low odor. Specifically, the present invention utilizes the advantages of mild reaction conditions, rapid reaction, high yield and few side reactions of the thiol-olefin click chemistry reaction; a polar solvent is used as a solvent, and the thiol acid has good solubility; the reaction time is short and the temperature is low: 15-90°C, which saves energy; the emulsifier and dispersant do not need to be removed; water washing can significantly reduce the residue of the thiol reagent, and the product has a low odor.

[0035] Second, the color of the leveling agent prepared by the present invention is light, specifically: the reaction temperature is low, which avoids the dark color caused by high temperature and oxidation. The color number of the leveling agent of the present invention is 0.1-0.4, while the color number of commercially available leveling agents is generally 1.5-3.0.

[0036] Third, the components of the present invention include highly active polyisobutylene, and the present invention acid-modifies the highly active polyisobutylene. The leveling agent of the present invention has a certain improvement in leveling performance compared to polyisobutylene succinic anhydride, with the leveling performance being improved by 10-15%, and up to 15%.

[0037] Fourth, the post-processing of the present invention is simple, energy-saving and environmentally friendly, with basically no emissions of major pollutants, and the carbon emission intensity is significantly reduced, which is more conducive to the realization of carbon neutrality.

[0038] In summary, the present invention can prepare a leveling agent with extremely low organic small molecule residue, light color, good leveling property and low odor in a relatively short time and at a relatively low temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0040] In the attached figure:

[0041] Figure 1 is the infrared spectrum of Example 2 of the present invention;

[0042] Marked in the figure: 1. infrared spectrum of Example 2; 2. infrared spectrum of Comparative Example 1. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0044] Example 1

[0045] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0046] Table 1

[0047]

[0048] S1. Referring to Table 1, the preparation steps of the leveling agent are as follows:

[0049] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 80° C. in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1.05:1.

[0050] (2) Irradiate the reaction with a UV LED lamp with a power of 50 W and a wavelength of 265 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W) for 20 min;

[0051] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 50 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A1 for hot-melt road marking paint. The properties of the leveling agent were measured, and the results are shown in Table 8.

[0052] The chemical structure of A1 is: P is a polyisobutylene polymer chain.

[0053] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A1 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180°C electric furnace until melted and constant temperature, and the total time on the electric furnace does not exceed 15 minutes to obtain a hot-melt road marking paint B1. The leveling property of the paint is measured, and the results are shown in Table 8.

[0054] Example 2

[0055] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0056] Table 2

[0057]

[0058] S1. Referring to Table 2, the preparation steps of the leveling agent are as follows:

[0059] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 85°C in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1:1;

[0060] (2) Irradiate the reaction with a UV LED lamp with a power of 50 W and a wavelength of 265 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W) for 20 min;

[0061] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 60 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A2 for hot-melt road marking paint. The performance of the leveling agent was measured, and the results are shown in Table 8.

[0062] The chemical structure of A2 is: and / or P is a polyisobutylene polymer chain.

[0063] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A2 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180°C electric furnace until melted and constant temperature, and the total time on the electric furnace does not exceed 15 minutes to obtain a hot-melt road marking paint B2. The leveling property of the paint is measured, and the results are shown in Table 8.

[0064] Example 3

[0065] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0066] Table 3

[0067]

[0068] S1. Referring to Table 3, the preparation steps of the leveling agent are as follows:

[0069] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 85°C in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1:1;

[0070] (2) Irradiate the reaction with a UV LED lamp with a power of 50 W and a wavelength of 265 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W) for 20 min;

[0071] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 60 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A3 for hot-melt road marking paint. The performance of the leveling agent was measured, and the results are shown in Table 8.

[0072] The chemical structure of A3 is: and / or P is a polyisobutylene polymer chain.

[0073] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A3 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180°C electric furnace until melted and constant temperature, and the total time on the electric furnace does not exceed 15 minutes to obtain a hot-melt road marking paint B3. The leveling property of the paint is measured, and the results are shown in Table 8.

[0074] Example 4

[0075] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0076] Table 4

[0077]

[0078] S1. The preparation steps of the leveling agent are as follows:

[0079] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 80° C. in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1.05:1.

[0080] (2) Irradiate the reaction for 60 min using a 50 W UV LED lamp with a wavelength of 265 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W);

[0081] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 60 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A4 for hot-melt road marking paint. The performance of the leveling agent was measured, and the results are shown in Table 8.

[0082] The chemical structure of A4 is: and / or P is a polyisobutylene polymer chain.

[0083] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A4 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180°C electric furnace until melted and constant temperature, and the total time on the electric furnace does not exceed 15 minutes to obtain a hot-melt road marking paint B4. The leveling property of the paint is measured, and the results are shown in Table 8.

[0084] Example 5

[0085] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0086] Table 5

[0087]

[0088] S1. Referring to Table 5, the preparation steps of the leveling agent are as follows:

[0089] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 60° C. in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1.05:1.

[0090] (2) Irradiate the reaction for 60 min using a UV LED lamp with a power of 50 W and a wavelength of 365 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W);

[0091] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 60 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A5 for hot-melt road marking paint. The performance of the leveling agent was measured, and the results are shown in Table 8.

[0092] The chemical structure of A5 is: P is a polyisobutylene polymer chain.

[0093] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A5 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180°C electric furnace until melted and constant temperature, with a total time on the electric furnace of no more than 15 min to obtain a hot-melt road marking paint B5. The leveling property of the paint was measured, and the results are shown in Table 8.

[0094] Example 6

[0095] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0096] Table 6

[0097]

[0098] S1. Referring to Table 6, the preparation steps of the leveling agent are as follows:

[0099] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 80°C in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1:1;

[0100] (2) Irradiate the reaction for 60 min using a UV LED lamp with a power of 50 W and a wavelength of 365 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W);

[0101] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 60 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A6 for hot-melt road marking paint. The performance of the leveling agent was measured, and the results are shown in Table 8.

[0102] The chemical structure of A6 is: and / or P is a polyisobutylene polymer chain.

[0103] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A6 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180°C electric furnace until melted and constant temperature, and the total time on the electric furnace does not exceed 15 minutes to obtain a hot-melt road marking paint B6. The leveling property of the paint is measured, and the results are shown in Table 8.

[0104] Example 7

[0105] A leveling agent for hot-melt road marking paint and a preparation method thereof,

[0106] Table 7

[0107]

[0108] S1. Referring to Table 7, the preparation steps of the leveling agent are as follows:

[0109] (1) Highly active polyisobutylene was added to a 250 ml three-necked flask with a condenser, and then a polar solvent, a mercapto acid reagent, a dispersant, an emulsifier, and a photoinitiator were added. 0.3 MPa nitrogen was passed through the three-necked flask for 20 minutes to completely replace the air therein with nitrogen. The stopper was tightly plugged, stirring was started, and the stirring bar speed was 500 rpm. The pressure of the reaction system was maintained at 0.11 MPa. Cooling water was passed through the condenser, and the temperature was raised to 80°C in an oil bath. In addition, the molar ratio of the mercapto acid reagent to the highly active polyisobutylene was 1:1;

[0110] (2) Irradiate the reaction for 60 min using a UV LED lamp with a power of 50 W and a wavelength of 365 nm (Shenzhen Taoyuan Broadcasting and Television Co., Ltd., model: TY-M-265 / 365nm-50W);

[0111] (3) After the reaction was completed, stirring was stopped, the liquid was separated while hot, and washed twice with 60 g of 80°C hot water to remove a small amount of unreacted mercapto acid reagent, emulsifier, and dispersant. The oil phase was the leveling agent A7 for hot-melt road marking paint. The performance of the leveling agent was measured, and the results are shown in Table 8.

[0112] The chemical structure of A7 is: and / or P is a polyisobutylene polymer chain.

[0113] S2. Preparation of road marking paint (refer to JPS5728434A) The steps include: weighing 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 44.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A7 on an electronic balance using a paper cup, totaling 300 g, pouring the mixture into a 500 ml stainless steel spoon, and uniformly heating and stirring on a 180 ° C electric furnace until melted and constant temperature, and the total time on the electric furnace does not exceed 15 min to obtain a hot-melt road marking paint B7. The leveling property of the paint is measured, and the results are shown in Table 8.

[0114] Comparative Example 1

[0115] The high-activity polyisobutylene HRPIB-1000 used as the raw material in Example 1 is used as comparative example 1 and is recorded as leveling agent A01. The performance of leveling agent A01 is measured, and the results are shown in Table 8.

[0116] Except for using HRPIB-1000 (A01) instead of leveling agent A1, the same steps as in Example 1 were used to prepare hot-melt road marking paint B01. The leveling results are shown in Table 8.

[0117] Comparative Example 2

[0118] Commercial polyisobutylene succinic anhydride (Sinopec Yangzi Petrochemical Company, PIBSA1000 brand) was used as leveling agent A02. The performance of leveling agent A02 was measured, and the results are shown in Table 8.

[0119] The same steps as in Example 1 were followed to prepare hot-melt road marking paint B02, except that commercial polyisobutylene succinic anhydride (A02) was used instead of leveling agent A1. The leveling results are shown in Table 8.

[0120] Comparative Example 3

[0121] 114.0 g of lime powder, 60.0 g of glass beads, 60.0 g of quartz sand, 40.2 g of petroleum resin, 9.0 g of titanium dioxide, 4.5 g of PE wax, 4.5 g of EVA, 3.0 g of DOP, and 0.8 g of leveling agent A3, totaling 296.0 g, were poured into a 500 ml stainless steel spoon and heated and stirred on an electric furnace at 180° C. until melted and kept at a constant temperature. The total time on the electric furnace did not exceed 15 min to prepare a hot-melt road marking paint B03. The leveling properties of the paint were measured, and the results are shown in Table 8.

[0122] Comparative Example 4

[0123] Prepare blank control:

[0124] A total of 299.2 g of lime powder (114.0 g), glass beads (60.0 g), quartz sand (60.0 g), petroleum resin (44.2 g), titanium dioxide (9.0 g), PE wax (4.5 g), EVA (4.5 g), and DOP (3.0 g) were poured into a 500 ml stainless steel spoon and heated and stirred on a 180° C. electric furnace for 15 min until melted and kept at a constant temperature. The total time on the electric furnace did not exceed 15 min to prepare a hot-melt road marking paint B04. The leveling properties of the paint were measured, and the results are shown in Table 8.

[0125] Testing: Samples were taken for testing of Examples 1-7 and Comparative Examples 1-4. Except for T4, samples of T1-T3 were all A1-A7 and A01-A02, as follows:

[0126] T1: Determination of Gardner color: Determined according to ASTM D6166-12 method

[0127] Weigh 5.0 g of the sample into a conical flask, add 5.0 g of toluene, and then place it in an ultrasonic cleaner at room temperature to mix evenly. Measure the Gardner color number of the solution. This chromaticity value is the Gardner color of the sample.

[0128] T2: Determination of acid value:

[0129] Acid value: The number of milligrams of potassium hydroxide consumed in the saponification reaction per 1g of sample under the test conditions. The test is carried out in accordance with GB / T2895-2008. The test steps are as follows:

[0130] (1) Use a graduated cylinder to measure 25 ml of toluene and 25 ml of ethanol into a 100 ml conical flask, add 3-5 drops of 1% phenolphthalein indicator, and neutralize with potassium hydroxide standard titrant until it turns pink. Record the potassium hydroxide standard titrant reading V1 in the burette;

[0131] (2) Weigh m grams of sample, accurate to 0.001 g, and place it in a conical flask containing the solution treated in step (1). The solution becomes a clear, transparent, and colorless solution. Gently shake until the sample is completely dissolved.

[0132] (3) Add at least 3 to 5 drops of phenolphthalein solution to the dissolved sample and titrate with potassium hydroxide standard titrant using the burette in step (1) while shaking the conical flask until a pink color just appears and the pink color remains for more than 10 seconds while shaking the solution. Record the reading V2 of the potassium hydroxide standard titrant in the burette.

[0133] In summary, the volume of potassium hydroxide standard titrant consumed in titrating the sample is V2-V1.

[0134] The acid value of the sample is expressed as A (mgKOH / g) and calculated as follows:

[0135] A=56.1C(V2-V1) / m

[0136] Where C is the concentration of potassium hydroxide standard titrant;

[0137] V1——the consumption of potassium hydroxide standard titrant during the blank titration test, ml;

[0138] V2——The consumption of potassium hydroxide standard titrant when titrating the sample, ml;

[0139] m——mass of the sample, g.

[0140] T3: Determination of odor, as follows:

[0141] Preheat a clean 50ml iodine flask in an oven at 180°C for 5 minutes. Weigh 1.0000g (accurate to 0.0001g) of sample into the preheated iodine flask and secure it with the included stopper. Place the sample flask and an empty iodine flask in a pre-set oven at 180°C for one hour. Cool to 50°C and evaluate the odor by smell. Work in groups of five. Discard the highest and lowest values ​​and average the remaining three results.

[0142] Standard: Compared with the empty bottle, the smell is basically the same and there is no other smell, which is judged as 1; compared with the empty bottle, there is a slight smell, which is judged as 2; compared with the empty bottle, there is an odor and a slightly pungent odor, which is judged as 3; compared with the empty bottle, there is an odor and a slightly pungent odor, which is judged as 4; there is a strong odor and a strong irritation, which is judged as 5.

[0143] T4: Determination of leveling properties, refer to the method in JPS5728434A, as follows:

[0144] To avoid the influence of the residual amount of paint on the crucible wall on the leveling results, the hot-melt road marking paint (B1-B7, B01-B04) was kept at a constant temperature of 180°C after melting, and the total time on the electric furnace did not exceed 15 minutes. Then 200g of it was quickly poured out and dropped from a height of 20cm onto a flat aluminum plate. On the aluminum plate, the sample appeared approximately circular. After cooling, its long and short diameters were measured and the average value was calculated. The fluidity was judged based on the average value. The larger the average value, the better the fluidity.

[0145] T5: Determination of α-terminal double bond content: The α-terminal double bond content and the total double bond content were determined by 1H NMR testing according to the method described in the literature “Synthesis and Characterization of Reactive Polyisobutylene”.

[0146] The test results are shown in Table 8 below.

[0147] Table 8

[0148]

[0149] Analysis of test results:

[0150] (1) Color: As can be seen from Table 8, the color of leveling agents A1-A7 in Examples 1-7 is very light, very similar to the color of the raw material, highly reactive polyisobutylene HRPIB-1000. In addition, the color of the commercial polyisobutylene succinic anhydride in Comparative Example 2 is significantly darker than that of leveling agents A1-A7 in Examples 1-7, with a numerical difference of up to 2, and exhibits a very distinct orange-yellow color. Prolonged exposure to air will cause oxidation to deepen the color, even turning reddish-brown. However, the color of leveling agents A1-A7 remains essentially unchanged after long-term storage in air (1-3 months), indicating that the leveling agents of the present application contain no residual unsaturated double bonds and are not susceptible to oxidation and deterioration.

[0151] (2) Odor: The raw material, highly reactive polyisobutylene HRPIB-1000, is odorless, while commercial polyisobutylene succinic anhydride contains 0.1-0.4% residual maleic anhydride, resulting in a strong odor and a significant irritation. The mercapto acid reagent used in this application is water-soluble and has a high solubility and a high reaction conversion rate. The ratio of the mass of the unreacted mercapto acid reagent to the mass of the total reaction system is between 0.4-0.8%. However, after two subsequent hot water washes, the residual mercapto acid reagent content is negligible. Therefore, the odor of leveling agents A1-A7 is significantly lower than that of A02, with a numerical difference of up to 2.3, and is non-irritating.

[0152] (3) When the mercapto acid reagent is a mercapto acid reagent with a carboxyl group, such as 4-mercaptobutyric acid and 4-mercaptobenzoic acid in Examples 1 and 5, the acid values ​​of leveling agents A1 and A5 are relatively low. Although the leveling properties of the hot-melt road marking paints B1, B5 and B02 are slightly worse, at the same level, the acid value and leveling properties are highly correlated, but not in a linear relationship.

[0153] (4) Leveling: In industrial production, according to the leveling test method, the leveling of road marking paint is qualified at 14.5-15.5cm. It can be seen from Comparative Example 4 (blank control) and Comparative Example 1 that the leveling of road marking paints prepared without adding a leveling agent or adding unmodified polyisobutylene is very poor, while in Comparative Example 2 with the addition of the leveling agent PIBSA1000, the road marking paint B02 can meet the production needs. In Examples 2, 3, 4 and 7, B2, B3, B4 and B7 have excellent leveling, which is significantly improved compared to the road marking paint B02 with the same amount of polyisobutylene succinic anhydride added, and the leveling is improved by 10-15%. In Comparative Example 3, the amount of petroleum resin is reduced to 40.2g, and the other conditions remain unchanged. The leveling of the hot-melt road marking paint B03 can still meet the requirements. In other words, in actual production, the leveling properties of road marking paint can be adjusted by adding a smaller amount of leveling agent or petroleum resin, so that the leveling property is between 14.5-15.5 cm. In the formulation of road marking paint, petroleum resin and leveling agent are much more expensive than lime powder, quartz sand, glass beads, etc., which helps reduce the production cost of road marking paint.

[0154] (5) Figure 1 As can be seen from the spectrum, leveling agent A2, the highly reactive polyisobutylene HRPIB-1000 (Comparative Example 1), exhibits distinct carbonyl absorption peaks at 1724 cm⁻¹ and 1696 cm⁻¹, demonstrating successful reaction between mercaptosuccinic acid and highly reactive polyisobutylene. No distinct peaks are observed at 3200-3600 cm⁻¹, indicating the absence of thiol or carboxyl groups. However, a distinct absorption peak at 1269 cm⁻¹, characteristic of COC, confirms the presence of anhydride. This suggests that after the reaction, mercaptosuccinic acid dehydrates during post-processing to form an anhydride structure.

[0155] In summary, the present invention can prepare a leveling agent with extremely low organic small molecule residue, light color, good leveling property and low odor in a relatively short time and at a relatively low temperature.

[0156] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A leveling agent for hot melt road marking paint, characterized in that: The chemical structure of the leveling agent is: , wherein P is a polyisobutylene polymer chain; The chemical structure of R1 includes one or more of the following structures: 。 2. A method for preparing the leveling agent for hot-melt road marking paint according to claim 1, characterized in that The following steps are involved: (1) Add highly active polyisobutylene into a reactor, then add a polar solvent, mercaptosuccinic acid, a dispersant, an emulsifier, and a photoinitiator, introduce an inert gas of a predetermined pressure to completely replace the air therein with the inert gas, stir, and heat to a predetermined temperature; (2) Turn on the UV lamp and irradiate at a predetermined wavelength for a predetermined time; (3) Stop stirring, separate the liquid while hot, and wash the oil phase twice with hot water to obtain a leveling agent for hot-melt road marking paint.

3. The preparation method according to claim 2, wherein In the highly active polyisobutylene, the α-terminal double bond content accounts for more than 70% of the total terminal double bonds of the polyisobutylene, and the number average molecular weight is 800-2300 Da; The polar solvent is water, and the mass ratio of the polar solvent to the highly active polyisobutylene is 0.1:1 to 5.0:

1.

4. The preparation method according to claim 3, wherein In the highly active polyisobutylene, the α-terminal double bond content accounts for more than 80% of the total terminal double bonds of the polyisobutylene, and the number average molecular weight is 900-1300 Da; the mass ratio of the polar solvent to the highly active polyisobutylene is 0.2:1-2.0:

1.

5. The preparation method according to claim 3, characterized in that The molar ratio of the mercaptosuccinic acid to the highly active polyisobutylene is 0.7:1 to 1.1:1, and the amount of the mercaptosuccinic acid is not less than the amount of the polyisobutylene containing an α-terminal double bond in the highly active polyisobutylene.

6. The preparation method according to claim 2, characterized in that The dispersant includes one or more of gelatin, polyvinyl alcohol, calcium oxalate, calcium sulfate, barium sulfate, calcium phosphate, talc, kaolin, diatomaceous earth, and bentonite, and the amount of the dispersant is 0.01-1.0wt% of the high-activity polyisobutylene; The emulsifier includes one or more of sodium lauryl sulfate, sodium lauryl sulfonate, potassium palmitate, sodium stearate, potassium stearate, and sodium octadecyl sulfate, and the amount of the emulsifier is 0.01-1.0wt% of the highly active polyisobutylene; In step (2), the wavelength range of the ultraviolet lamp is 200-410 nm, and the predetermined time is 5-120 min.

7. The preparation method according to claim 6, wherein The photoinitiator includes one or more of 2,4-dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenylpropanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphonate, and 2-dimethylamino-2-benzyl-1-[4-(4-morpholino)phenyl]-1-butanone; the inert gas includes one or more of nitrogen, argon, and helium; In step (1), the predetermined pressure is 0.1-0.6 MPa, and the predetermined temperature is 15-90°C; In step (2), the wavelength range of the ultraviolet lamp is 250-390 nm, and the predetermined time is 10-60 min.

8. The preparation method according to claim 7, wherein In the highly active polyisobutylene, the number average molecular weight is 900-1100 Da; In step (1), the predetermined temperature is 60-80°C; In step (2), the predetermined time is 15-30 minutes.

9. Use of the leveling agent for hot-melt road marking paint according to claim 1 as a leveling agent for hot-melt road marking paint.

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