Preparation method and application of sulfonylurea structure thermosensitive color developing agent

Abstract

The invention discloses a preparation method and application of a sulfonylurea structure thermosensitive color developing agent, and relates to the technical field of color developing agents. The core of the thermosensitive color developing agent is a # imgabs0 # compound in a formula 1 containing a sulfonylurea structure. The preparation method comprises the following three steps: synthesizing an intermediate 1 through esterification of raw materials, obtaining an intermediate 2 through boric acidification, and synthesizing a target compound through Suzuki reaction. Through the synergistic effect of sulfonyl and ureido, hydrogen bond network regulation and electron transfer efficiency optimization are realized, and the technical bottlenecks of high-temperature activation requirements and insufficient color development stability of a traditional thermosensitive color developing agent are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of developers, and particularly to a preparation method and application of a sulfonylurea-structured thermosensitive developer. Background Art

[0002] In the modern color development technology field, the demand for highly efficient, stable, and excellent-performance developers is increasing day by day. Traditional developers, such as monoazo dyes, direct dyes, etc., have many limitations in practical applications. On the one hand, they perform poorly in terms of color development persistence and are prone to fading or color change due to the influence of light, temperature change, or chemical environment, resulting in the instability of information display. This problem is particularly prominent in some scenarios with high requirements for color stability, such as high-precision printing, professional image recording and storage, etc. On the other hand, the thermosensitivity of traditional developers is often difficult to accurately control and cannot meet the precise requirements for temperature response sensitivity in specific fields.

[0003] In addition, from the perspective of the preparation process, the synthesis process of some traditional developers is relatively complex, involving multiple steps of chemical reactions and requiring strict control of reaction conditions. This not only increases the production cost but also reduces the production efficiency and is difficult to meet the needs of large-scale industrial production. At the same time, some developers may produce environmentally harmful waste during the production process, bringing a burden to the environment, which has become an urgent problem to be solved under the current increasingly strict environmental protection requirements.

[0004] Therefore, developing a new type of sulfonylurea-structured thermosensitive developer has important practical significance. This developer aims to overcome the deficiencies of traditional developers and provide a solution with long-lasting color development effect, controllable thermosensitivity, and environmentally friendly preparation process to meet the market demand for high-performance developers. Summary of the Invention

[0005] The object of the present invention is to provide a preparation method and application of a sulfonylurea-structured thermosensitive developer with improved color development effect and excellent thermosensitivity in view of the deficiencies of existing developers in terms of color development persistence, thermosensitivity regulation, and preparation process.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a compound containing a sulfonylurea structure, and the compound containing a sulfonylurea structure has the structure shown in Formula 1: Formula 1; The R1 is selected from: an alkyl group with 1 - 10 carbon atoms, an alkoxy group with 1 - 10 carbon atoms, an aryl group with 6 - 15 carbon atoms, a heteroaryl group with 5 - 10 carbon atoms; Or R1 is selected from: an aryl group having 6 to 15 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; Or R1 is selected from: a heteroaryl group having 5 to 10 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

[0007] Furthermore, the alkyl group having 1 to 10 carbon atoms is selected from , , , , ; Furthermore, the alkoxy group having 1 to 10 carbon atoms is selected from: , .

[0008] Furthermore, the aryl group having 6 to 15 carbon atoms is selected from: , , .

[0009] Furthermore, the heteroaryl group having 5 to 10 carbon atoms is selected from: , .

[0010] Furthermore, the aryl group having 6 to 15 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms is selected from: , , .

[0011] Furthermore, the heteroaryl group having 5 to 10 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms is selected from: , , .

[0012] Furthermore, the compound containing a sulfonylurea structure is selected from the compounds represented by the following structures: ; ; ; ; .

[0013] A method for preparing a compound containing a sulfonylurea structure, comprising the following steps: ; In the first step, raw material 1 and raw material 2 are synthesized through an esterification reaction to obtain intermediate 1; In the second step, intermediate 1 is borylated to obtain intermediate 2; In the third step, intermediate 2 and raw material 3 are synthesized through a Suzuki reaction to obtain a compound containing a sulfonylurea structure.

[0014] Furthermore, raw material 2 is selected from the compounds shown by the following structures: , , , , , , , , , , , , , , .

[0015] Application of a compound containing a sulfonylurea structure in a developer.

[0016] Furthermore, the developer is a thermosensitive color development system, and the compound containing a sulfonylurea structure is used as an electron donor to form a color development composition with a phenolic compound and an acidic substance, wherein the mass fraction of the compound containing a sulfonylurea structure in the composition is 0.5 - 15 parts, and the color development reaction activation temperature is 60 - 120 °C.

[0017] Furthermore, the phenolic compound is selected from at least one of bisphenol A, hydroquinone, resorcinol, and 4 - hydroxybenzoate.

[0018] Furthermore, the acidic substance is selected from at least one of stearic acid, salicylic acid, p - toluenesulfonic acid, and dodecylbenzenesulfonic acid.

[0019] Furthermore, the hot - melt filler is selected from at least one of paraffin wax, microcrystalline wax, and polyethylene wax.

[0020] Furthermore, the preparation method of the thermosensitive color development system is: mixing the compound containing a sulfonylurea structure, the phenolic compound, the acidic substance, and the hot - melt filler according to mass parts, heating the mixture to 50 - 100 °C to melt and stirring evenly, then cooling to room temperature, and grinding to obtain the thermosensitive color development system. Compounds containing a sulfonylurea structure act as electron donors. In their structure, the sulfonyl group (a strong electron-withdrawing group) and the urea group (which can form hydrogen bonds) work together, endowing the molecule with unique electron distribution characteristics. When heated to the activation temperature, the hot-melt filler (such as paraffin) melts, releasing acidic substances and providing a protonation environment. At this time: the nitrogen atom of the sulfonylurea compound is protonated to form a highly reactive intermediate. Phenolic compounds (such as bisphenol A), as electron acceptors, form a hydrogen bond network with sulfonylurea through phenolic hydroxyl groups. Electrons transfer from the electron-rich region of sulfonylurea to the phenolic acceptor, forming a conjugated chromophore (such as a quinoid structure) and producing a color development effect. The hydrogen bond ability of the urea group and the polarity of the sulfonyl group make the compound temperature-responsive. At low temperatures, the hydrogen bond network is stable, inhibiting electron transfer. After reaching the activation temperature, the hot-melt filler melts, breaking the hydrogen bonds and releasing the degree of freedom of molecular motion, triggering the color development reaction.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Improved color development sensitivity: Compounds containing a sulfonylurea structure significantly reduce the activation temperature of the color development reaction by enhancing the electron transfer efficiency, solving the bottleneck of high-temperature activation in traditional technologies.

[0022] 2. Optimized color development stability and contrast: The design of the hydrogen bond network and conjugated structure of sulfonylurea improves the stability of the thermosensitive color development system and enhances the color development contrast through the molecular pre-organization effect.

[0023] 3. Extended application compatibility: Compared with traditional electron donors, the compounds containing a sulfonylurea structure in the present invention show better solubility and component compatibility in the thermosensitive color development system, and are suitable for more complex or temperature-sensitive scenarios. Description of the Drawings

[0024] Figure 1 It is the synthetic route of the photoinitiator described in the present invention. Detailed Embodiments

[0025] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention. Example 1

[0026] Synthesis of Compound 1: ; First step, under a nitrogen atmosphere, 20 g of raw material 1, 5.48 g of raw material 2, 7.46 g of sulfuric acid, and 200 g of toluene were successively added into the reaction system. The reaction system was heated to 80 °C and stirred and heated for 6 hours. An aqueous solution of 0.1 mol / L NaHCO3 was added to adjust the system to neutrality, 200 g of water was added, shaken, allowed to stand, separated, the organic phase was collected, dried over anhydrous MgSO4, and after evaporation, column chromatography was carried out using a mixture of petroleum ether and ethyl acetate as the eluent, and finally 19.30 g of intermediate 1 was obtained. MS[MS+1]: 304.

[0027] Second step, under a nitrogen atmosphere, 19.30 g of intermediate 1, 500 ml of ultra-dry tetrahydrofuran were successively added into the reaction system, cooled to -70 °C, 4.25 g of n-butyllithium was added dropwise. After the addition was complete, it was stirred for 1 h, 17.84 g of triisopropyl borate was added dropwise. After the addition was complete, it was allowed to warm to room temperature naturally and reacted overnight. The solvent was evaporated to obtain 13.05 g of intermediate 2. MS[MS+1]: 271.

[0028] Third step, under a nitrogen atmosphere, 13.05 g of intermediate 2, 20.80 g of raw material 3, 1.68 g of tetrakis(triphenylphosphine)palladium, 13.36 g of anhydrous potassium carbonate, and a mixed solution of 200 g of toluene, ethanol, and water (volume ratio 2:1:1) were successively added into the reaction system. The reaction system was heated to 75 °C and stirred and heated under reflux for 10 h. The heating was turned off, cooled to room temperature, and allowed to stand for separation. The aqueous phase was extracted twice with ethyl acetate, the organic phases were combined, washed three times with water, evaporated, and column chromatography was carried out using a mixture of petroleum ether and dichloromethane as the eluent, and finally 20.62 g of compound 1 was obtained. MS[MS+1]: 537.

[0029] For compound 1 1 1H NMR (deuterated chloroform): δ 8.11 (t, 1H), 8.08–8.00 (m, 1H), 7.86 (ddd, 1H), 7.71–7.57 (m, 3H), 7.51–7.41 (m, 2H), 7.38–7.27 (m, 2H), 6.80 (s, 1H), 6.41 (s, 1H), 2.13 (s, 3H), 1.68 (s, 2H), 1.33 (s, 6H), 0.98 (s, 9H).

[0030] Examples 2 - 6 For the compounds synthesized in Examples 2 - 6, referring to the preparation method of Example 1, raw material 2 was replaced, and the rest was the same as in Example 1. The specific structures of raw material 2, compound structures, and MS[MS+1] data are shown in the following table.

[0031]

[0032]

[0033] Performance Testing Preparation of thermosensitive color developing system 1: The compound containing sulfonylurea structure (the compound prepared in Example 1, 7 parts), phenolic compound (hydroquinone, 30 parts), acidic substance (salicylic acid, 30 parts) and hot-melt filler (paraffin, 7 parts) are mixed according to mass parts, the mixture is heated to 100°C to melt and stirred evenly, then cooled to room temperature and ground to obtain a thermosensitive color developing composition.

[0034] Thermosensitive color developing system 2 to thermosensitive color developing system 6 are prepared by referring to the thermosensitive color developing system 1, and the compounds with sulfonylurea structure therein are replaced with the compounds prepared in Example 2 to Example 6 in sequence, and the rest remain the same as Example 1.

[0035] Thermochromic system 7 was prepared by referring to the thermochromic system 1, except that the compound containing sulfonylurea structure was replaced by comparative compound 1, and the rest was the same as Example 1.

[0036] Comparative Compound 1: .

[0037] Thermochromic system 8 was prepared by referring to the thermochromic system 1, except that the compound containing sulfonylurea structure was replaced by comparative compound 2, and the rest was the same as Example 1.

[0038] Comparative Compound 2: .

[0039] Color reaction activation temperature and color contrast test: Thermochromic systems 1-8 were mixed with colorless substrate (thermosensitive paper) at a mass ratio of 1:5, deionized water was added to make slurry, and evenly coated on the surface of PET film (coating amount: 5g / m 2 ), dried at 50°C and cut into 10 mm × 50 mm test pieces for use. A controllable temperature thermal gradient plate (accuracy ±1°C) was used, and the temperature gradient was set to 50-150°C, with a temperature difference of 5°C in adjacent areas. Each temperature zone is 10 mm long, corresponding to different positions of the test piece. The test piece was flatly attached to the surface of the thermal gradient plate, pressurized at 0.5 MPa for 2 seconds, and then quickly peeled off. Immediately use a colorimeter (CIE-Lab mode) to measure the color contrast ΔE of each temperature zone 1 (relative to the unheated area). Definition ΔE 1 ≥15 is effective color development, and the lowest activation temperature of each sample (the first time ΔE 1 ≥15). Perform accelerated aging (85℃ / 85% RH environment, 24h) on the color-developed test piece and re-measure ΔE1 The value of the calculated color difference retention rate is shown in the following table.

[0040]

[0041] The thermosensitive color - developing system of the examples shows significantly better activation characteristics and color - developing stability than those of the comparative examples. The activation temperature gradient of the examples is evenly distributed and is overall in the low - temperature range. Both the color - developing contrast and the color - difference retention rate show a stable trend at a high level, indicating that the sulfonylurea group and substituents in the molecular structure effectively reduce the reaction energy barrier and enhance the color - developing persistence. In contrast, due to the lack of the synergistic effect of key functional groups in the comparative examples, the activation temperature is significantly higher, and the color - developing performance and stability decrease sharply, reflecting the irreplaceability of the sulfonylurea structure.

[0042] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A compound containing a sulfonylurea structure, characterized in that, The compound containing a sulfonylurea structure has the structure shown in Formula 1: Formula 1; R1 is selected from: an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, a heteroaryl group having 5 to 10 carbon atoms; or R1 is selected from: an aryl group having 6 to 15 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms; or R1 is selected from: a heteroaryl group having 5 to 10 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.

2. The compound with a sulfonylurea structure according to claim 1, characterized in that, The alkyl group having 1 to 10 carbon atoms is selected from: , , , , ; The alkoxy group having 1 to 10 carbon atoms is selected from: , ; * is the linking site.

3. A compound having a sulfonylurea structure according to claim 1, characterized in that, The aryl group having 6 to 15 carbon atoms is selected from: , , ; The heteroaryl group having 5 to 10 carbon atoms is selected from: , .

4. A compound having a sulfonylurea structure according to claim 1, characterized in that, The aryl group having 6 to 15 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is selected from: , , .

5. A compound having a sulfonylurea structure as described in claim 1, characterized in that, The heteroaryl group having 5 to 10 carbon atoms substituted by an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is selected from: , , .

6. A compound having a sulfonylurea structure according to claim 1, characterized in that, The compound containing a sulfonylurea structure is selected from the compounds shown in the following structures: ； ； ； ； 。 7. A method for preparing a compound having a sulfonylurea structure as described in claim 1, characterized in that, Comprising the following steps: ； In the first step, Intermediate 1 is synthesized by the esterification reaction of Raw Material 1 and Raw Material 2; In the second step, Intermediate 2 is obtained by borylation of Intermediate 1; In the third step, the compound is synthesized by the Suzuki reaction of Intermediate 2 and Raw Material 3.

8. The preparation method of a compound containing a sulfonylurea structure according to claim 7, characterized in that, The raw material 2 is selected from the compounds shown in the following structures: , , , , , , , , , , , , , , .

9. Use of a compound containing a sulfonylurea structure as described in Claim 1 in a developer.

10. Use of a compound having a sulfonylurea structure according to claim 9 in a developer, characterized in that, The developer is a thermosensitive color development system, and the compound containing a sulfonylurea structure is used as an electron donor to form a color development composition with a phenolic compound and an acidic substance, wherein the mass fraction of the compound containing a sulfonylurea structure in the composition is 0.5 to 15 parts, and the color development reaction activation temperature is 60 to 120 °C.

Images