Preparation method and preparation device system of transparent fluorescent green phase yellow colorant

Abstract

This invention belongs to the field of colorant materials technology, and relates to a method and apparatus system for preparing a transparent fluorescent green-yellow colorant. The preparation method involves a combination of one initiator component, a chromogenic group-containing substance without independent polymerization initiation ability, and another initiator component, a substance that can cause the chromogenic group-containing substance to dehalogenate and form a chromogenic group-containing cationic initiator. These components are combined with a solvent at a specific temperature, in a protective gas atmosphere, and under conditions of isolation from air and active hydrogen contaminants, to initiate the polymerization of polymerizable monomers, thereby obtaining a polymer-type transparent fluorescent green-yellow colorant. After removing the initiator residue by adsorption with an alkali agent, solid-liquid separation is performed, and the solvent is thoroughly removed from the filtrate. The resulting transparent fluorescent green-yellow colorant exhibits excellent compatibility, high heat resistance and oxidation stability, and maintains a stable fluorescent green-yellow hue.

Description

Technical Field

[0001] This invention belongs to the field of colorant materials technology, and relates to a method and apparatus system for preparing a transparent fluorescent green-yellow colorant. Background Technology

[0002] Transparent fluorescent green colorants are popular in the coatings and plastics industries due to their clear and elegant hue. However, these colorants are typically low-molecular-weight organic pigments or dyes, and generally face the following technical problems in resin systems: poor compatibility with the matrix, leading to bleeding, staining, and adhesion; potential negative impact on the mechanical strength of the product; and limited migration resistance and weather resistance, especially resistance to light aging and heat oxidation, making it difficult to meet the requirements of harsh application environments. Therefore, the application of such colorants in high-weather-resistance scenarios, such as automotive coatings and plastic parts exposed to prolonged sunlight, has certain limitations.

[0003] While bismuth vanadate pigments possess a fluorescent green-yellow hue, their opacity limits their application in the aforementioned multilayer effect systems. Furthermore, existing transparent fluorescent green-yellow colorants suffer from insufficient heat and oxidation stability, easily exhibiting dullness and discoloration under high outdoor temperatures, thus failing to meet the stringent requirements for long-term weather resistance in high-end applications such as transportation vehicles.

[0004] Polymer-based colorants have become a research hotspot due to their large molecular weight, environmental friendliness (free of heavy metals), and the excellent heat oxidation resistance exhibited by some varieties. For example, US6103006 discloses a method for introducing fluorescent groups containing carboxylic acids or anhydrides into the main chain of polyesters or polyamides through polycondensation, and the prepared colorants can maintain good heat oxidation resistance. However, existing commercially available or research-based polymer-based colorants still have many shortcomings: commercially available polyether-based products, such as Milliken's "Reactint," are difficult to meet high heat oxidation resistance requirements; although CN110964195A involves the preparation of polymer-based colorants by reacting polyols with reactive dyes, it should be noted that only polyethylene glycol can effectively participate in the reaction in real-world scenarios, and the resulting product has extremely poor thermal oxidation stability at high temperatures, limiting its practicality; while the acrylic polymer-based colorants disclosed in CN103159904A may have good performance, they lack information on transparency. Specific descriptions of fluorescent green-yellow hues; US5019350 uses polyacrylates with easily oxidized groups such as phenolic hydroxyl groups in the side chain as the color-developing structure, but it is difficult to apply because phenolic hydroxyl groups are prone to yellowing under thermal oxidation conditions; US5714090 physically fixes pigments through coating, but fails to achieve molecular-level dispersion and coloring; US8067506B2 describes fluorescent polymers based on siloxane chemistry, but its surface energy is low and its compatibility with general resins is poor, limiting its application; the polyetherified colorant involved in US20230287170A1 also lacks practical application value in plastics and coatings.

[0005] In summary, existing transparent fluorescent green-yellow colorants face a core contradiction: flexible polymer backbones, such as polyethers, often exhibit poor heat and oxidation resistance; while backbones with good heat resistance, such as polysiloxanes, have poor compatibility with conventional resins. Therefore, there is an urgent need to develop a novel polymer colorant that combines excellent compatibility, high heat and oxidation stability, and the ability to maintain a stable fluorescent green-yellow hue, to meet the stringent requirements for high weather resistance and transparent coloring effects in outdoor coatings or plastic parts for transportation vehicles. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method and apparatus system for preparing a transparent fluorescent green-yellow colorant. The prepared transparent fluorescent green-yellow colorant has excellent compatibility, high heat resistance and oxidation stability, and can maintain the stability of the fluorescent green-yellow hue.

[0007] To achieve this objective, the present invention employs the following technical solution: In a first aspect, the present invention provides a method for preparing a transparent fluorescent green-yellow colorant, the preparation method comprising the following steps: (1) The solvent, polymerizable monomer and first initiator component are premixed, and the resulting premixed solution is mixed with the second initiator component to initiate a polymerization reaction to obtain a reaction solution; the first initiator component is a chromogenic substance that cannot initiate polymerization on its own, and the second initiator component is a substance that can cause the chromogenic substance to dehalogenate and form a chromogenic cationic initiator; the second initiator component and the first initiator component together form an initiator system; (2) The alkaline agent is mixed with the reaction solution obtained in step (1) and reacted. The reaction product is separated into solid and liquid to obtain the filtrate. The filtrate is then subjected to vacuum decompression treatment to obtain the transparent fluorescent green phase yellow colorant. The preparation process is carried out in a protective gas atmosphere.

[0008] The present invention provides a method for preparing a transparent fluorescent green-yellow colorant. This method involves combining one initiator component (a substance containing chromophores without independent polymerization initiation ability) and another initiator component (a substance that can cause the chromophores to dehalogenate, forming a cationic initiator containing chromophores). These components, along with a solvent, are used to initiate the polymerization of polymerizable monomers under specific temperature and protective gas atmosphere conditions, isolated from air and active hydrogen contaminants. This yields a polymer-type transparent fluorescent green-yellow colorant. After removing initiator residues by alkali adsorption, solid-liquid separation is performed. The solvent is then removed from the filtrate to obtain the transparent fluorescent green-yellow colorant. This invention utilizes an initial cationic initiator containing chromophores to initiate monomer polymerization, allowing the chromophores to bond into the ends of the polymer backbone and interact with the backbone to form a colored polymer colorant. The resulting colorant exhibits excellent thermal oxidative stability and is better suited for coatings or plastics used in transportation applications.

[0009] Preferably, the protective gas includes nitrogen or argon.

[0010] Preferably, the solvent in step (1) includes at least one of toluene, xylene, mesitylene, cyclohexane or methylcyclohexane.

[0011] Preferably, the polymerizable monomer in step (1) includes at least one of α-methylstyrene, vinylcyclohexane, or α-methylvinylcyclohexane.

[0012] It should be noted that the copolymerization method of the polymerizable monomers is: to copolymerize the polymerizable monomers by mixing them; or to copolymerize the polymerizable monomers by adding them in sequence.

[0013] Preferably, in step (1), the first initiator component comprises triphenyl halomethane.

[0014] Preferably, the triphenyl halomethane includes at least one of triphenylfluoromethane, triphenylchloromethane, or triphenylbromomethane.

[0015] The first initiator component is a potential chromogenic group containing an active halogen group that can generate carbocations.

[0016] Preferably, the mass ratio of the solvent to the polymerizable monomer in step (1) is not less than 1:1, for example, it can be 1:1, 2:1, 3:1, 5:1 or 10:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 3:1.

[0017] Preferably, the mass ratio of the polymerizable monomer to the initiator system in step (1) is (10-150):1, for example, it can be 10:1, 14:1, 15:1, 20:1, 30:1, 50:1, 80:1, 100:1, 120:1 or 150:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably (14-20):1.

[0018] Preferably, before the premixing in step (1), the solvent, polymerizable monomer and first initiator component are dried for 11-13 hours, for example, 11 hours, 11.5 hours, 12 hours, 12.5 hours or 13 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] It should be noted that the first initiator component was dried at 50°C and a vacuum oven pressure of 3 mbar for 11-13 hours.

[0020] Preferably, in the drying step, the mass ratio of the liquid to the desiccant is not higher than 200:1, for example, it can be 200:1, 180:1, 150:1, 100:1 or 50:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] Preferably, in the premixing step (1), the polymerizable monomer and the first initiator component are mixed uniformly first, and the resulting mixture is then mixed uniformly with the solvent.

[0022] Preferably, the polymerization reaction in step (1) is as follows: first, add the premixed liquid and control its temperature to -30°C to 5°C, control the forced reflux temperature of the protective gas to be no higher than 5°C, and then add the second initiator component to carry out the polymerization reaction for a time of >1h.

[0023] The temperature of the premixed liquid is controlled to be between -30°C and 5°C, for example, it can be -30°C, -20°C, -15°C, 0°C or 5°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably between -15°C and 5°C.

[0024] The temperature of the premixed liquid should be controlled within a reasonable range, i.e., the polymerization reaction temperature from -30℃ to 5℃. Too high a temperature is not conducive to the bonding of triphenylmethane into the polymer and the improvement of the degree of polymerization, while too low a temperature is not conducive to the dissolution of the initiator system and its physical liquid characteristics.

[0025] The forced reflux temperature of the controlled protective gas shall not exceed 5°C, for example, it may be 5°C, 3°C, 0°C, -5°C or -10°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Controlling the maximum value of the forced reflux temperature helps prevent some reactants from being carried away by the protective gas flow, thus improving the retention of reactants and the sufficiency of the reaction.

[0027] The polymerization reaction time is greater than 1 hour, for example, it can be 2 hours, 5 hours, 6 hours, 8 hours or 10 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, in step (1), the mass ratio of the first initiator component to the second initiator component is (4-8):1, for example, it can be 4:1, 5:1, 6.58:1, 7:1 or 8:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, in step (1), the second initiator component includes at least one of boron trihalide and its coordination complex.

[0030] Preferably, the boron trihalide coordination complex comprises a boron trihalide diethyl ether coordination compound.

[0031] Preferably, the boron trihalide comprises boron trifluoride.

[0032] The boron trihalide can be dissolved in an ether solution before being added to form a boron trihalide ether solution containing not less than 48 wt% boron trihalide.

[0033] Preferably, the alkali agent in step (2) includes hydroxides and / or oxides containing alkaline earth metals.

[0034] Preferably, the alkali agent in step (2) includes calcium hydroxide and / or calcium oxide.

[0035] The addition of the alkali can adsorb Lewis acidic boron trihalides and their coordination complexes to form easily filterable solids, thereby removing initiator residues.

[0036] Preferably, in molar terms, the amount of alkali added in step (2) is not less than the sum of 6 times the molar amount of the second initiator component and 2 times the molar amount of the first initiator component. For example, it can be the sum of 6 times the molar amount of the second initiator component and 2 times the molar amount of the first initiator component, 7 times the molar amount of the second initiator component and 3 times the molar amount of the first initiator component, or 8 times the molar amount of the second initiator component and 4 times the molar amount of the first initiator component. However, it is not limited to the listed values. Other unlisted values ​​within the range are also applicable, but the total amount should be as low as possible below 10 times. Excessive alkali will also adsorb a certain amount of polymer colorant, resulting in the loss of the target product.

[0037] Preferably, the reaction time in step (2) is ≥30 min, for example, it can be 30 min, 35 min, 40 min, 50 min or 60 min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the endpoint of the vacuum decompression treatment in step (2) is to achieve an oil bath temperature of 195-205℃, a system pressure of <5mbar, and no volatile matter evaporation for more than 30 minutes.

[0039] The oil bath temperature reaches 195-205℃, for example, it can be 195℃, 198℃, 200℃, 202℃ or 205℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] The system pressure is <5 mbar, for example, it can be 4.5 mbar, 4 mbar, 3 mbar, 2 mbar or 1 mbar, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] The duration of no volatile matter evaporation for more than 30 minutes can be, for example, 30 minutes, 35 minutes, 40 minutes, 50 minutes or 60 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0042] Secondly, the present invention provides a preparation apparatus system for a transparent fluorescent green hue yellow colorant. The preparation apparatus system operates by the preparation method of the transparent fluorescent green hue yellow colorant described in the first aspect. The preparation apparatus system includes a solvent preparation unit, a mixing preparation unit, a premixer, and a reactor connected in sequence. The reactor is connected to an initiator preparation unit. It also includes a protective gas storage unit and a vacuum pump. The protective gas storage unit is connected in sequence to a protective gas pipe and a first liquid seal device. The vacuum pump is connected to a vacuum pipe. The solvent preparation unit, the mixing preparation unit, the premixer, the reactor, and the initiator preparation unit are each independently connected to the protective gas pipe and the vacuum pipe.

[0043] The apparatus system for preparing transparent fluorescent green-phase yellow colorant provided by the present invention employs devices such as a side-wall circulating self-purifying dehumidifier, which avoids the complex requirements of multiple processes that are generally required for such reaction apparatuses, which must strictly isolate air and moisture and effectively remove impurities such as polymerization inhibitors in the reaction raw materials. Therefore, it simplifies the process path and potentially benefits the consistency of the product.

[0044] It should be noted that the reaction liquid obtained by the polymerization reaction in the reactor can be directly added to the reactor for reaction, or it can be transferred to another separate reactor for reaction; the solid-liquid separation step of the reaction product is carried out in another solid-liquid separation device, and the vacuum decompression treatment step of the filtrate is carried out in another vacuum decompression device.

[0045] Preferably, the solvent dispenser is sequentially connected to a first metering pump and a first three-way valve. One port of the first three-way valve is connected to the solvent dispenser through a first dehumidifier, and the other port of the first three-way valve is connected to the mixing dispenser.

[0046] Preferably, the mixing device is sequentially connected to a second metering pump and a second three-way valve. One port of the second three-way valve is connected to the mixing device through a second dehumidifier, and the other port of the second three-way valve is connected to the premixer.

[0047] Preferably, the premixer is connected to the reactor via a third metering pump.

[0048] Preferably, the reactor is connected to the initiator dispenser via a fourth metering pump.

[0049] Preferably, the reactor is connected to a second liquid seal device via a forced reflux cooling pipe consisting of a single-cycle cooler and a reflux condenser.

[0050] During the polymerization reaction in the reactor, the temperature of the forced reflux cooling pipe is controlled at ≤5℃. For example, it can be 5℃, 3℃, 0℃, -5℃ or -10℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0051] Preferably, the first liquid sealing device and the second liquid sealing device are each independently provided with polymer silicone oil inside.

[0052] Preferably, the reactor is connected to a thermostatic circulator.

[0053] Preferably, a thermometer is provided on the reactor.

[0054] Preferably, the reactor is equipped with a stirring paddle, which is connected to a motor.

[0055] Preferably, a third dehumidifier is provided between the protective gas storage device and the protective gas pipe.

[0056] Preferably, a hollow needle is provided between the protective gas tube and the first liquid seal device.

[0057] The protective gas reservoir includes at least one of a nitrogen reservoir, an argon reservoir, or a helium reservoir.

[0058] The protective gas tube includes at least one of a nitrogen tube, an argon tube, or a helium tube.

[0059] The hollow needle is designed to provide a high-purity protective gas environment for the original packaging of raw materials that require protection, such as bottles with soft stoppers.

[0060] Preferably, the internal desiccant of the first dehumidifier, the second dehumidifier, and the third dehumidifier each independently includes 3A molecular sieve.

[0061] Preferably, a cold trap is provided between the vacuum pump and the vacuum tube.

[0062] Preferably, when the solvent dispenser, mixing dispenser, premixer, reactor, and initiator dispenser are each independently connected to the protective gas pipe and vacuum pipe, a drying filter is also independently installed on each connecting pipe.

[0063] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0064] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for preparing a transparent fluorescent green-yellow colorant. This method involves combining one initiator component (a substance containing chromogenic groups without independent polymerization ability) and another initiator component (a substance that can cause the chromogenic group-containing substance to dehalogenate and form a chromogenic cationic initiator). These components are then combined with a solvent at a specific temperature in a protective gas atmosphere, isolated from air and active hydrogen contaminants, to initiate the polymerization of polymerizable monomers, yielding a polymer-type transparent fluorescent green-yellow colorant. After removing initiator residues by alkali adsorption, solid-liquid separation is performed. The solvent is then removed from the filtrate to obtain the transparent fluorescent green-yellow colorant. This colorant exhibits excellent compatibility, high heat resistance and oxidation stability, a number-average Mn of 1474, a distribution PDI of 2.11, and a conversion rate of up to 98%. It also maintains a stable fluorescent green-yellow hue, making it suitable for the stringent requirements of high weather resistance and transparent coloring effects for outdoor coatings or plastic parts used in transportation vehicles. Attached Figure Description

[0065] Figure 1This is a schematic diagram of the preparation device system for the transparent fluorescent green-yellow colorant provided in Embodiment 1 of the present invention.

[0066] Figure 2 This is an optical image of the transparent fluorescent green-yellow colorant provided in Embodiment 2 of the present invention.

[0067] Figure 3 This is the GPC diagram of the transparent fluorescent green-yellow colorant provided in Example 2 of the present invention.

[0068] Figure 4 This is the FTIR image of the transparent fluorescent green-yellow colorant provided in Example 2 of the present invention.

[0069] The components are as follows: 1. Solvent dispenser; 2. Mixing dispenser; 3. Premixer; 4. Reactor; 5. Initiator dispenser; 6. Nitrogen storage tank; 7. Vacuum pump; 8. Third dehumidifier; 9. Nitrogen pipe; 10. Hollow needle; 11. First liquid seal device; 12. Cold trap; 13. Vacuum pipe; 14. Dryer filter; 15. First metering pump; 16. First dehumidifier; 17. Second metering pump; 18. Second dehumidifier; 19. Third metering pump; 20. Fourth metering pump; 21. Single-cycle cooler; 22. Reflux condenser; 23. Second liquid seal device; 24. Thermostatic circulator; 25. Thermometer. Detailed Implementation

[0070] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0071] Example 1 This embodiment provides a device system for preparing a transparent fluorescent green-phase yellow colorant, the structural schematic diagram of which is shown below. Figure 1 As shown, the preparation apparatus system includes a solvent dispenser 1, a mixing dispenser 2, a premixer 3, and a reactor 4 connected in sequence. The reactor 4 is connected to an initiator dispenser 5. It also includes a nitrogen storage tank 6 and a vacuum pump 7. The nitrogen storage tank 6 is connected in sequence to a third dehumidifier 8, a nitrogen pipe 9, a hollow needle 10, and a first liquid seal device 11. The vacuum pump 7 is connected in sequence to a cold trap 12 and a vacuum pipe 13. The solvent dispenser 1, the mixing dispenser 2, the premixer 3, the reactor 4, and the initiator dispenser 5 are each independently connected to the nitrogen pipe 9 and the vacuum pipe 13, and each connecting pipe is independently equipped with a drying filter 14.

[0072] The solvent dispenser 1 is sequentially connected to a first metering pump 15 and a first three-way valve. One port of the first three-way valve is connected to the solvent dispenser 1 via a first dehumidifier 16, and the other port of the first three-way valve is connected to the mixing dispenser 2. The mixing dispenser 2 is sequentially connected to a second metering pump 17 and a second three-way valve. One port of the second three-way valve is connected to the mixing dispenser 2 via a second dehumidifier 18, and the other port of the second three-way valve is connected to the premixer 3. The premixer 3 is connected to the reactor 4 via a third metering pump 19. The desiccant inside the first dehumidifier 16, the second dehumidifier 18, and the third dehumidifier 8 is 3A molecular sieve.

[0073] The reactor 4 is connected to the initiator dispenser 5 via a fourth metering pump 20; the reactor 4 is connected to a second liquid seal device 23 via a forced reflux cooling pipe consisting of a single-circulation cooler 21 and a reflux condenser 22; the first liquid seal device 11 and the second liquid seal device 23 are each independently filled with polymer silicone oil; the reactor 4 is connected to a thermostatic circulator 24; a thermometer 25 is installed on the reactor 4; a stirring paddle is installed inside the reactor 4; and the stirring paddle is connected to a motor.

[0074] Example 2 This embodiment provides a method for preparing a transparent fluorescent green hue yellow colorant. The preparation apparatus system provided in Example 1 is used to prepare the transparent fluorescent green hue yellow colorant. The preparation method includes the following steps: (1) Toluene, α-methylstyrene, and triphenylchloromethane were dried for 12 h each, wherein the triphenylchloromethane was dried at 50 °C and a vacuum oven pressure of 3 mbar for 12 h, and the mass ratio of the dried liquid to the desiccant 3A molecular sieve was 200:1; then α-methylstyrene and triphenylchloromethane were mixed uniformly, and the resulting mixture was then mixed uniformly with toluene, the mass ratio of toluene to α-methylstyrene was 3:1, and the resulting premixed solution was mixed with boron trifluoride at a concentration of 48 wt%. The polymerization reaction was carried out by mixing boron trifluoride diethyl ether solution with α-methylstyrene. The mass ratio of boron trifluoride and triphenylchloromethane in the boron trifluoride diethyl ether solution was 15:1, and the mass ratio of triphenylchloromethane to boron trifluoride in the boron trifluoride diethyl ether solution was 6.58:1. The specific steps were as follows: first, a premixed solution was added and its temperature was controlled at -11.15±0.2℃, and the forced reflux temperature was controlled at -10℃. Then, the boron trifluoride diethyl ether solution was added to carry out the polymerization reaction for 3 hours to obtain the reaction solution.

[0075] (2) Calcium hydroxide is mixed with the reaction solution obtained in step (1) and reacted for 30 min. The amount of calcium hydroxide added is the sum of 6 times the molar amount of boron trifluoride and 2 times the molar amount of triphenylchloromethane. The reaction product is filtered to obtain a filter cake and a filtrate. The filter cake is washed three times with toluene and the residual liquid is filtered out and added to the filter cake. The filtrate is subjected to vacuum decompression treatment until the oil bath temperature reaches 200°C, the system pressure is 3 mbar and no volatile matter evaporates for 30 min. The unevaporated matter is collected to obtain the transparent fluorescent green phase yellow colorant. The preparation process is carried out in a nitrogen atmosphere.

[0076] The optical image of the obtained transparent fluorescent green-yellow colorant is as follows: Figure 2 As shown in the figure, the transparent fluorescent green hue yellow colorant is a solid transparent fluorescent green hue yellow; the GPC diagram of the transparent fluorescent green hue yellow colorant is shown below. Figure 3 As shown in the figure, its number-average molecular weight Mn = 1474, weight-average molecular weight Mw = 3111, z-average molecular weight Mz = 6918, and molecular weight distribution PDI = 2.11; the FTIR spectrum of the transparent fluorescent green-phase yellow colorant is shown in the figure. Figure 4 As shown in the figure, the colorant largely maintains the main framework of poly(α-methylstyrene) (i.e., AMS resin), for example, at 2961 cm⁻¹. -1 2926cm -1 The peaks represent the asymmetric and symmetric CH stretching vibrations of methyl and methylene groups, at 1599 cm⁻¹. -1 1494cm -1 The characteristic absorption peak for the stretching vibration of the benzene ring is 1443 cm⁻¹. -1 1383cm -1 The absorption peaks are for the asymmetric and symmetric bending vibrations of methyl groups, at 756 cm⁻¹. -1 695cm -1 The absorption peaks are due to the out-of-plane bending vibration of the CH group of the monosubstituted benzene ring. The chromogenic groups also contain benzene ring structures. Other groups are not listed one by one. They are generally covered by the characteristic peaks of AMS.

[0077] Example 3 This embodiment provides a method for preparing a transparent fluorescent green hue yellow colorant. The preparation apparatus system provided in Example 1 is used to prepare the transparent fluorescent green hue yellow colorant. The preparation method includes the following steps: (1) Xylene, vinylcyclohexane, and triphenylfluoromethane were dried for 11 h, respectively. Triphenylfluoromethane was dried at 50 °C and 3 mbar in a vacuum oven for 11 h. The mass ratio of the dried liquid to the 3A molecular sieve desiccant was 150:1. Then, vinylcyclohexane and triphenylfluoromethane were mixed uniformly, and the resulting mixture was then mixed uniformly with xylene. The mass ratio of xylene to vinylcyclohexane was 149.31:100. The resulting premixed solution was then mixed with boron trifluoride. A 48 wt% boron trifluoride diethyl ether solution was mixed for polymerization. The mass ratio of vinylcyclohexane to the total amount of boron trifluoride and triphenylfluoromethane in the boron trifluoride diethyl ether solution was 10:1, and the mass ratio of triphenylfluoromethane to boron trifluoride in the boron trifluoride diethyl ether solution was 4:1. The specific steps were as follows: first, a premixed solution was added and its temperature was controlled at 5°C, and the forced reflux temperature was controlled at -20°C. Then, the boron trifluoride diethyl ether solution was added to carry out the polymerization reaction for 2 hours to obtain the reaction solution.

[0078] (2) Calcium hydroxide is mixed with the reaction solution obtained in step (1) and reacted for 40 min. The amount of calcium hydroxide added is the sum of 6 times the molar amount of boron trifluoride and 2 times the molar amount of triphenylfluoromethane. The reaction product is filtered to obtain a filter cake and a filtrate. The filter cake is washed three times with toluene and the residual liquid is filtered out and added to the filter cake. The filtrate is subjected to vacuum decompression treatment until the oil bath temperature reaches 195°C, the system pressure is 4 mbar and no volatile matter evaporates for 30 min. The unevaporated matter is collected to obtain the transparent fluorescent green phase yellow colorant. The preparation process is carried out in a nitrogen atmosphere.

[0079] Example 4 This embodiment provides a method for preparing a transparent fluorescent green hue yellow colorant. The preparation apparatus system provided in Example 1 is used to prepare the transparent fluorescent green hue yellow colorant. The preparation method includes the following steps: (1) Cyclohexane, vinylcyclohexane, and triphenylchloromethane were dried for 13 h, respectively. Triphenylchloromethane was dried at 50 °C and 3 mbar in a vacuum oven for 13 h. The mass ratio of the dried liquid to the 3A molecular sieve desiccant was 100:1. Then, vinylcyclohexane and triphenylchloromethane were mixed uniformly, and the resulting mixture was then mixed uniformly with cyclohexane. The mass ratio of cyclohexane to vinylcyclohexane was 134.17:100. The resulting premixed liquid was then mixed with boron trifluoride. A 48 wt% boron trifluoride diethyl ether solution was mixed for polymerization. The mass ratio of vinylcyclohexane to the total amount of boron trifluoride and triphenylchloromethane in the boron trifluoride diethyl ether solution was 150:1, and the mass ratio of triphenylchloromethane to boron trifluoride in the boron trifluoride diethyl ether solution was 8:1. The specific steps were as follows: first, a premixed solution was added and its temperature was controlled at 5°C, and the forced reflux temperature was controlled at -30°C. Then, the boron trifluoride diethyl ether solution was added to carry out the polymerization reaction for 4 hours to obtain the reaction solution.

[0080] (2) Calcium hydroxide is mixed with the reaction solution obtained in step (1) and reacted for 30 min. The amount of calcium hydroxide added is the sum of 6 times the molar amount of boron trifluoride and 2 times the molar amount of triphenylchloromethane. The reaction product is filtered to obtain a filter cake and a filtrate. The filter cake is washed three times with toluene and the residual liquid is filtered out and added to the filter cake. The filtrate is subjected to vacuum decompression treatment until the oil bath temperature reaches 205°C and the system pressure is 3 mbar for 30 min without any volatile matter evaporating. The unevaporated matter is collected to obtain the transparent fluorescent green phase yellow colorant. The preparation process is carried out in a nitrogen atmosphere.

[0081] Example 5 This embodiment provides a method for preparing a transparent fluorescent green-phase yellow colorant. The difference between this embodiment and Example 2 is that, except that the temperature of the polymerization reaction in step (1) is adjusted to 12°C, the rest is the same as in Example 2.

[0082] Example 6 This embodiment provides a method for preparing a transparent fluorescent green-phase yellow colorant. The difference from Example 2 is that, except that the temperature of the polymerization reaction in step (1) is adjusted to -40°C, the rest is the same as in Example 2.

[0083] Example 7 This embodiment provides a method for preparing a transparent fluorescent green-phase yellow colorant. The difference between this embodiment and Embodiment 2 is that, except for adjusting the forced reflux temperature in step (1) to 10°C, the rest is the same as in Embodiment 2.

[0084] Comparative Example 1 This comparative example provides a method for preparing a transparent fluorescent green-phase yellow colorant. The difference from Example 2 is that the triphenylchloromethane in step (1) is not added during the polymerization reaction but after the polymerization reaction is terminated. All other steps are the same as in Example 2.

[0085] Comparative Example 2 This comparative example provides a method for preparing a transparent fluorescent green-phase yellow colorant. The difference from Comparative Example 1 is that the triphenylchloromethane is replaced with 30g of Solvent Yellow 160:1 (Anhui Qingke Ruijie New Materials Co., Ltd., brand name PresolFY 10GN, CAS No. 35773-43-4), and all other aspects are the same as Comparative Example 1.

[0086] Transparent fluorescent green-yellow colorant was prepared using the methods provided in Examples 2-7 and Comparative Examples 1 and 2. The colorant was then placed in a box-shaped aluminum foil container and placed in a 210°C forced-air oven for 8 hours under natural air conditions. After cooling to room temperature, the appearance before and after placing it in the forced-air oven was visually assessed to intuitively demonstrate its thermal oxidative stability. The results are shown in Table 1. The mass change of the polymer implanted with triphenyl halomethyl groups was ignored (the addition of a relatively large amount of solvent yellow 160:1 in Comparative Example 2 was not negligible due to its large quantity). The conversion rate was directly used as the percentage of the obtained polymer solid (which may contain colorant groups) to the initial amount of polymerizable monomer added to test the polymerization of the transparent fluorescent green-yellow colorant. The molecular weight and distribution of the obtained product were determined by gel permeation chromatography (GPC). The number-average Mn, distribution PDI, and conversion rate results are shown in Table 1. The thermal oxidative stability results were evaluated as "Excellent," "Fair," and "Poor," and the results are shown in Table 1.

[0087] Table 1 As can be seen from Table 1, the transparent fluorescent green-yellow colorant prepared by the method provided by the present invention has a triphenyl halomethane main molecular structure that has been polymerized and incorporated into the main skeleton of the polymer resin, and has good thermal oxidation stability.

[0088] A comparison of Examples 2 with Examples 3 and 4 shows that although the transparent fluorescent green-phase yellow colorants formed by monomers α-methylstyrene and vinylcyclohexane have good heat resistance to oxidation, the former has a relatively higher coloring intensity. Meanwhile, Examples 3 and 4 show that the physical properties of the solvent, such as melting point, have a certain impact on the polymerization process. Cyclohexane (industrial mixed type) has a higher melting point, lower conversion rate, and wider molecular weight distribution than xylene.

[0089] As can be seen from the comparison between Examples 2 and Examples 5 and 6, if the polymerization temperature is too low, it is not conducive to the dissolution of the initiator system and the physical liquid state or even non-polymerization characteristics, while if it is too high, the reaction chain transfer is too fast and the molecular weight is too low, making it difficult to form a stable heat-resistant polymer structure. As can be seen from the comparison between Examples 2 and Examples 7, if the forced reflux temperature is too high, some reactants will be carried away by the protective gas flow, which reduces the monomer conversion rate, the retention of reactants and the sufficiency of the reaction, and also reduces the molecular weight.

[0090] As can be seen from the comparison between Example 2 and Comparative Example 1, the first initiator component is not added during the polymerization reaction, but after the polymerization reaction is terminated. This will cause the triphenylmethane bond to fail to bond into the polymer backbone, making it easy to remove. However, the trace amount of residual free impurities will weaken the overall heat resistance and oxidation resistance of the polymer. As can be seen from the comparison between Example 2 and Comparative Example 2, the use of externally added dyes may have problems such as poor compatibility and migration, resulting in decreased thermal oxidation stability.

[0091] In summary, the method for preparing the transparent fluorescent green-yellow colorant provided by this invention involves combining one of the initiator components, a substance containing chromogenic groups without independent polymerization initiation ability, and another of the initiator components, a substance that can cause the chromogenic group-containing substance to undergo dehalogenation to form a chromogenic group-containing cationic initiator. These components, along with a solvent, are used to initiate the polymerization of polymerizable monomers under specific temperature, protective gas atmosphere, and conditions that isolate air and active hydrogen contaminants. This yields a polymer-type transparent fluorescent green-yellow colorant. After removing the initiator residue with an alkali adsorption agent, solid-liquid separation is performed. The solvent is then removed from the filtrate to obtain the transparent fluorescent green-yellow colorant. This colorant exhibits excellent compatibility, high heat resistance and oxidation stability, a number-average Mn of 1474, a distribution PDI of 2.11, and a conversion rate of up to 98%. It also maintains a stable fluorescent green-yellow hue, making it suitable for the stringent requirements of high weather resistance and transparent coloring effects for outdoor coatings or plastic parts used in transportation vehicles.

[0092] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a transparent fluorescent green-phase yellow colorant, characterized in that, The preparation method includes the following steps: (1) The solvent, polymerizable monomer and first initiator component are premixed, and the resulting premixed solution is mixed with the second initiator component to initiate a polymerization reaction to obtain a reaction solution; the first initiator component is a chromogenic substance that cannot initiate polymerization on its own, and the second initiator component is a substance that can cause the chromogenic substance to dehalogenate and form a chromogenic cationic initiator; the second initiator component and the first initiator component together form an initiator system; (2) The alkaline agent is mixed with the reaction solution obtained in step (1) and reacted. The reaction product is separated into solid and liquid to obtain the filtrate. The filtrate is then subjected to vacuum decompression treatment to obtain the transparent fluorescent green phase yellow colorant. The preparation process is carried out in a protective gas atmosphere.

2. The preparation method according to claim 1, characterized in that, The solvent in step (1) includes at least one of toluene, xylene, mesitylene, cyclohexane, or methylcyclohexane; Preferably, the polymerizable monomer in step (1) includes at least one of α-methylstyrene, vinylcyclohexane, or α-methylvinylcyclohexane; Preferably, in step (1), the first initiator component comprises triphenyl halomethane; Preferably, the triphenyl halomethane includes at least one of triphenylfluoromethane, triphenylchloromethane, or triphenylbromomethane; Preferably, the mass ratio of the solvent to the polymerizable monomer in step (1) is not less than 1:1, and more preferably 3:1; Preferably, the mass ratio of the polymerizable monomer to the initiator system in step (1) is (10-150):1, more preferably (14-20):

1.

3. The preparation method according to claim 1 or 2, characterized in that, Before the premixing in step (1), the solvent, polymerizable monomer and first initiator component are dried for 11-13 hours respectively. Preferably, in the drying step, the mass ratio of the liquid to the desiccant is not higher than 200:1; Preferably, in the premixing step (1), the polymerizable monomer and the first initiator component are mixed uniformly first, and the resulting mixture is then mixed uniformly with the solvent.

4. The preparation method according to any one of claims 1-3, characterized in that, The polymerization reaction in step (1) is as follows: first, add the premixed liquid and control its temperature to -30℃ to 5℃, control the forced reflux temperature of the protective gas to be no higher than 5℃, and then add the second initiator component to carry out the polymerization reaction for a time of >1h; Preferably, in step (1), the mass ratio of the first initiator component to the second initiator component is (4-8):1; Preferably, in step (1), the second initiator component includes at least one of boron trihalide and its coordination complex; Preferably, the boron trihalide comprises boron trifluoride.

5. The preparation method according to any one of claims 1-4, characterized in that, The alkali agent in step (2) includes hydroxides and / or oxides containing alkaline earth metals; Preferably, in molar terms, the amount of alkali added in step (2) is not less than the sum of 6 times the molar amount of the second initiator component and 2 times the molar amount of the first initiator component; Preferably, the reaction time in step (2) is ≥30 min.

6. The preparation method according to any one of claims 1-5, characterized in that, The endpoint of the vacuum decompression treatment in step (2) is to make the oil bath temperature reach 195-205℃, the system pressure <5mbar, and no volatile matter evaporate for more than 30 minutes.

7. A preparation apparatus system for a transparent fluorescent green-phase yellow colorant, characterized in that, The preparation apparatus system operates according to the preparation method of the transparent fluorescent green-yellow colorant according to any one of claims 1-6. The preparation apparatus system includes a solvent preparation unit, a mixing preparation unit, a premixer, and a reactor connected in sequence. The reactor is connected to an initiator preparation unit. It also includes a protective gas storage unit and a vacuum pump. The protective gas storage unit is connected in sequence to a protective gas pipe and a first liquid seal device. The vacuum pump is connected to a vacuum pipe. The solvent preparation unit, the mixing preparation unit, the premixer, the reactor, and the initiator preparation unit are each independently connected to the protective gas pipe and the vacuum pipe.

8. The preparation apparatus system according to claim 7, characterized in that, The solvent dispenser is connected in sequence to a first metering pump and a first three-way valve. One port of the first three-way valve is connected to the solvent dispenser through a first dehumidifier, and the other port of the first three-way valve is connected to the mixing dispenser. Preferably, the mixing device is sequentially connected to a second metering pump and a second three-way valve, one port of the second three-way valve is connected to the mixing device through a second dehumidifier, and the other port of the second three-way valve is connected to the premixer; Preferably, the premixer is connected to the reactor via a third metering pump.

9. The preparation apparatus system according to claim 7 or 8, characterized in that, The reactor is connected to the initiator dispensing device via a fourth metering pump; Preferably, the reactor is connected to a second liquid seal device via a forced reflux cooling pipe consisting of a single-cycle cooler and a reflux condenser; Preferably, the reactor is connected to a thermostatic circulator.

10. The preparation apparatus system according to any one of claims 7-9, characterized in that, A third dehumidifier is installed between the protective gas storage container and the protective gas pipe; Preferably, when the solvent dispenser, mixing dispenser, premixer, reactor, and initiator dispenser are each independently connected to the protective gas pipe and vacuum pipe, a drying filter is also independently installed on each connecting pipe.

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