Preparation Method and Application of a Sulfonylurea Structure Thermosensitive Chromogenic Agent

Abstract

The present invention discloses a preparation method and application of a sulfonylurea-structured thermosensitive color developer, relating to the technical field of color developers. The core of the thermosensitive color developer is a compound of formula 1 containing a sulfonylurea structure. The preparation method is achieved through three steps: esterification of raw materials to synthesize intermediate 1, borylation to obtain intermediate 2, and then synthesis of the target compound through the Suzuki reaction. Through the synergistic effect of the sulfonyl group and the urea group, the regulation of the hydrogen bond network and the optimization of the electron transfer efficiency are realized, solving the technical bottlenecks of the high-temperature activation requirement and insufficient color development stability of traditional thermosensitive color developers.

Description

Technical Field

[0001] The present invention relates to the technical field of developers, and particularly relates 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. Especially in some scenarios with high requirements for color stability, such as high-precision printing, professional image recording and storage, etc., this problem is particularly prominent. 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 requires 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 situation of increasingly strict environmental protection requirements.

[0004] Therefore, it is of great practical significance to develop a new type of sulfonylurea-structured thermosensitive developer. This developer aims to overcome the deficiencies of traditional developers, and provides 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 control 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:

[0007] ;

[0008] 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;

[0009] 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;

[0010] 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.

[0011] Further, the alkyl group having 1 to 10 carbon atoms is selected from: , , , , ;

[0012] The * is a linking site.

[0013] Further, the alkoxy group having 1 to 10 carbon atoms is selected from: , .

[0014] Further, the aryl group having 6 to 15 carbon atoms is selected from: , , .

[0015] Further, the heteroaryl group having 5 to 10 carbon atoms is selected from: , .

[0016] Further, 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: , , .

[0017] Further, 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: , , .

[0018] Further, the compound containing a sulfonylurea structure is selected from the compounds shown in the following structures:

[0019] ; ;

[0020] ; ; .

[0021] A preparation method of a compound containing a sulfonylurea structure, comprising the following steps:

[0022] ;

[0023] In the first step, intermediate 1 is synthesized by the esterification reaction of raw material 1 and raw material 2;

[0024] In the second step, intermediate 2 is obtained by borylation of intermediate 1;

[0025] In the third step, the compound shown in formula 1 is synthesized by the Suzuki reaction of intermediate 2 and raw material 3.

[0026] Furthermore, the raw material 2 is selected from the compounds shown in the following structures: , , , , , , , , , , , , , , .

[0027] Application of a compound containing a sulfonylurea structure in a color developer.

[0028] Furthermore, the color developer is a thermosensitive color development system, and the compound containing a sulfonylurea structure forms a color development composition as an electron donor 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 activation temperature of the color development reaction is 60 - 120 °C.

[0029] Furthermore, the phenolic compound is selected from at least one of bisphenol A, hydroquinone, resorcinol, and 4-hydroxybenzoate.

[0030] Furthermore, the acidic substance is selected from at least one of stearic acid, salicylic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid.

[0031] Furthermore, the hot-melt filler is selected from at least one of paraffin wax, microcrystalline wax, and polyethylene wax.

[0032] 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 the mass fraction, 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.

[0033] 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 protonated 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) act as electron acceptors and 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 change 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 change reaction.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. Improved color development sensitivity: Compounds containing a sulfonylurea structure significantly reduce the activation temperature of the color change reaction by enhancing the electron transfer efficiency, solving the bottleneck of high-temperature activation in traditional technologies.

[0036] 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.

[0037] 3. Extended application compatibility: Compared with traditional electron donors, the compounds containing a sulfonylurea structure in the present invention exhibit better solubility and component compatibility in the thermosensitive color development system, and are suitable for more complex or temperature-sensitive scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is the synthetic route of the photoinitiator described in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. 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

[0040] Synthesis of Compound 1:

[0041] ;

[0042] 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.

[0043] Second step, under a nitrogen atmosphere, 19.30 g of intermediate 1 and 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 rise to room temperature naturally and reacted overnight. The solvent was evaporated to obtain 13.05 g of intermediate 2. MS[MS+1]: 271.

[0044] 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.

[0045] For compound 1 1 1H NMR (deuterochloroform): 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).

[0046] Examples 2 - 6

[0047] 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.

[0048]

[0049]

[0050] Performance test

[0051] Preparation of thermosensitive color-developing system 1: Mix 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) according to the mass parts. Heat the mixture to 100 °C until it melts and stir evenly, then cool it to room temperature and grind to obtain the thermosensitive color-developing composition.

[0052] For thermosensitive color-developing systems 2 - 6, referring to the preparation of thermosensitive color-developing system 1, replace the compound containing sulfonylurea structure therein with the compounds prepared in Examples 2 - 6 in sequence, and the rest are the same as in Example 1.

[0053] For thermosensitive color-developing system 7, referring to the preparation of thermosensitive color-developing system 1, replace the compound containing sulfonylurea structure therein with Comparative Compound 1, and the rest are the same as in Example 1.

[0054] Comparative Compound 1: .

[0055] For thermosensitive color-developing system 8, referring to the preparation of thermosensitive color-developing system 1, replace the compound containing sulfonylurea structure therein with Comparative Compound 2, and the rest are the same as in Example 1.

[0056] Comparative Compound 2: .

[0057] Test of color-reaction activation temperature and color-contrast:

[0058] Mix thermosensitive color-developing systems 1 - 8 with a colorless substrate (thermal paper) at a mass ratio of 1:5 respectively, add deionized water to make a slurry, and evenly coat it on the surface of the PET film (coating amount: 5 g / m 2 ). After drying at 50 °C, cut it into 10 mm × 50 mm test pieces for standby. Use a controllable temperature gradient plate (accuracy ±1 °C), set the temperature gradient to 50 - 150 °C, and the temperature difference between adjacent regions is 5 °C. The length of each temperature region is 10 mm, corresponding to different positions of the test piece. Place the test piece flat on the surface of the thermal gradient plate, apply a pressure of 0.5 MPa and hold for 2 seconds, then quickly peel it off. Immediately use a color difference meter (CIE-Lab mode) to measure the color-contrast ΔE 1 (relative to the unheated region). Define ΔE 1 ≥15 as effective color development, and record the lowest activation temperature of each sample (the first time when ΔE 1≥15). Accelerate aging (85℃ / 85% RH environment, 24h) of the color-developed test piece and re-measure ΔE 1 The color difference retention rate was calculated based on the values, and the data are shown in the table below.

[0059]

[0060] The thermosensitive color development system of the embodiment shows significantly better activation characteristics and color development stability than the comparative example. The activation temperature gradient of the embodiment is evenly distributed and is generally in the low temperature range. The color development contrast and color difference retention rate both show a high stable trend, indicating that the optimization of the sulfonylurea group and substituent in the molecular structure effectively reduces the reaction energy barrier and enhances the color development durability. However, due to the lack of synergistic effects of key functional groups, the activation temperature of the comparative example is significantly higher, and the color development performance and stability drop sharply, reflecting the irreplaceable nature of the sulfonylurea structure.

[0061] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that 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: ； The R1 is selected from: alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, aryl groups having 6 to 15 carbon atoms, and heteroaryl groups having 5 to 10 carbon atoms; or the R1 is selected from: aryl groups having 6 to 15 carbon atoms substituted by alkyl groups having 1 to 10 carbon atoms and alkoxy groups having 1 to 10 carbon atoms; or the R1 is selected from: heteroaryl groups having 5 to 10 carbon atoms substituted by alkyl groups having 1 to 10 carbon atoms and alkoxy groups having 1 to 10 carbon atoms.

2. A compound containing 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: , ; The * is the linking site.

3. A compound containing 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 containing a sulfonylurea structure as described in claim 1, characterized in that, The aryl groups having 6 to 15 carbon atoms substituted by alkyl groups having 1 to 10 carbon atoms and alkoxy groups having 1 to 10 carbon atoms are selected from: 、 、 。 5. A compound containing a sulfonylurea structure according to 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, wherein, The compounds containing a sulfonylurea structure are selected from the compounds shown in the following structures: ； ； ； ； 。 7. A method for preparing a compound with 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 shown in Formula 1 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 by 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 chromogenic agent, 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 parts of the compound containing a sulfonylurea structure in the composition are 0.5 to 15 parts, and the color development reaction activation temperature is 60 to 120 °C.

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