A method for preparing a highly sensitive reversible thermochromic fluoran dye and a compound thereof

Abstract

The present invention discloses a method for preparing a highly sensitive, reversible thermochromic fluoran dye and a compound thereof, belonging to the fields of fine chemicals and materials science. The present invention designs a series of novel fluoran dyes and develops two-component reversible thermochromic dyes and microcapsules prepared based on these novel fluoran dyes. The resulting two-component reversible thermochromic dyes and microcapsules can achieve thermochromism without the addition of bisphenol A. Compared to traditional three-component color-changing systems, this avoids the effects of bisphenol A's oxidative properties on the color-changing system. While optimizing the cost structure, this achieves improved reversible thermochromic performance, promoting the application of thermochromic systems in high-precision, high-value-added fields.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemicals and material science, and particularly relates to a preparation method of a high-sensitivity reversible thermochromic fluoran dye and a compound. Background Art

[0002] Fluorane thermochromic materials, as the third generation of thermochromic materials, use xanthene and lactone rings as the parent rings. They have the characteristics of high sensitivity, high color density, and good stability. By introducing different substituents on the fluorane parent, dyes of various colors can be obtained, making the colors of fluorane dyes extremely rich. Due to the above advantages, fluorane dyes are widely used in textiles and clothing, ink printing, temperature-indicating coatings, building materials and coatings, energy-saving materials, anti-counterfeiting labels, etc., and are one of the most promising thermochromic materials.

[0003] Traditional materials of this type are usually composed of a three-component system consisting of an electron donor, an electron acceptor, and a solvent. Fluoran dyes, as electron donors, are usually colorless or light-colored, which determines the color of the material before and after color change; the color developer, as an electron acceptor, determines the depth of the color; and the solvent determines the temperature of color change. By regulating the three components, the desired color and color change temperature can be obtained. Color change is based on intermolecular electron transfer. When the color developer combines with the color developer, the lactone ring inside the color developer opens, the conjugated system increases, and the central carbon atom is replaced by SP. 3 Hybrid state converted to SP 2 In the hybrid state, the thermochromic system develops color; above the phase transition temperature, the chromogen and developer separate, the lactone ring inside the chromogen closes, the conjugated system shortens, and the system appears colorless. Existing research results on three-component systems have shown that competition between the solvent and the dye and developer molecules affects the electron transfer reaction, which in turn affects the color development properties of the system, limiting the application and development of this type of dye in areas such as high sensitivity and fast response. Therefore, for three-component systems of fluorane thermochromic materials, it is necessary to explore how to reduce the number of components in the system to reduce the internal competition and improve the overall color change performance.

[0004] Chinese patent CN113429420A proposes a method for preparing highly sensitive thermosensitive reversible color-changing microcapsules. The disclosed fluorane dye structure is relatively small, and the final product that achieves the thermosensitive reversible color-changing effect is still a microcapsule, which is not convenient to use. Summary of the Invention

[0005] Technical issues

[0006] Traditional three-component temperature-sensitive color-changing fluorane dyes require the action of a color developer to show color, have low color change sensitivity, and suffer from color lag.

[0007] Technical Solution

[0008] To solve the above problems, this project designed and synthesized a series of new fluoran dyes, utilized the structural characteristics of the new fluoran dye molecules to achieve temperature-sensitive color changes, and prepared a two-component color-changing system consisting of fluoran dyes and phase change materials.

[0009] The present invention provides a novel fluoran dye, the structure of which is shown in the following formula I:

[0010]

[0011] In formula I, R1 is selected from N(CH2CH3)2, N(CH3)2, OCH3, OCH2CH3, Any of the following;

[0012] R2 is selected from H, CH3, N(CH2CH3)2, N(CH3)2, OCH3, OCH2CH3, Any of the halogens;

[0013] R3 is selected from H, Any of the following;

[0014] R4 is selected from Any of the following;

[0015] R5 is selected from any one of H, methyl, ethyl, isopropyl, halogen, cyano, and nitro.

[0016] Furthermore, the halogen is any one of fluorine, chlorine, bromine and iodine.

[0017] Further, the R4 is specifically selected from Any of .

[0018] Furthermore, in Formula I, when R1 and R2 are selected from N(CH2CH3)2 or OCH2CH3, and R3 is selected from H, the color of the novel fluoran dye changes to purple.

[0019] Furthermore, in Formula I, when R1 and R2 are selected from OCH3 or N(CH3)2, and R3 is selected from H, the color of the novel fluoran dye changes to yellow.

[0020] Furthermore, in Formula I, when R1 is selected as N(CH2CH3)2, R2 is selected as H, and R3 is selected as When , the color of the new fluoran dye changes to green.

[0021] Furthermore, in Formula I, when R1 is selected as N(CH2CH3)2, R2 is selected as CH3, and R3 is selected as When , the new fluoran dye changes color to black.

[0022] Furthermore, in Formula I, when R1 and R2 are When , the color of the new fluoran dye changes to blue.

[0023] Furthermore, in Formula I, when R1 is N(CH2CH3)2, R2 is halogen, and R3 is H, the color of the novel fluoran dye changes to red.

[0024] Furthermore, the halogen selected by R2 is chlorine.

[0025] The fluoran dye provided by the present invention is used in the fields of textiles and clothing, ink printing, temperature-indicating coatings, building material coatings, energy-saving materials, and anti-counterfeiting labels.

[0026] The present invention also provides a two-component color-changing system, which consists of the novel fluoran dye and a phase change material.

[0027] Furthermore, the phase change material includes one or more of diphenyl carbonate, methyl stearate, n-tridecyl carbonate, distearic acid glyceryl, monostearic acid glyceryl, tristearic acid glyceryl, 4-benzyloxyphenylethyl caprylate, tetradecyl myristate, and methyl p-methoxybenzoate.

[0028] Furthermore, in the two-component color-changing system, the mass ratio of the new fluoran dye to the phase change material is 1:10-500.

[0029] Furthermore, in the two-component color-changing system, the mass ratio of the new fluoran dye to the phase change material is 1:20-400.

[0030] Furthermore, in the two-component color-changing system, the mass ratio of the new fluoran dye to the phase change material is 1:40-200.

[0031] The present invention also provides a method for preparing a two-component color-changing system, wherein the preparation method comprises heating and uniformly mixing the novel fluoran dye and the phase change material to obtain a two-component temperature-sensitive reversible color-changing system;

[0032] Alternatively, the preparation method may also be to uniformly mix the novel fluoran dye and the molten phase change material to obtain a two-component temperature-sensitive reversible color-changing system.

[0033] Furthermore, the heating temperature is equal to or greater than the melting point of the selected phase change material.

[0034] Furthermore, the molten phase change material refers to a phase change material that is heated to a temperature above its melting point to melt and form a liquid phase change material.

[0035] Furthermore, in the preparation method, the phase change material includes one or more of diphenyl carbonate, methyl stearate, n-tridecyl carbonate, distearic acid glyceryl, monostearic acid glyceryl, tristearic acid glyceryl, 4-benzyloxyphenylethyl caprylate, tetradecyl myristate, and methyl p-methoxybenzoate.

[0036] Furthermore, in the preparation method, the mass ratio of the novel fluoran dye to the phase change material is 1:10-500.

[0037] Furthermore, in the preparation method, the mass ratio of the novel fluoran dye to the phase change material is 1:20-400.

[0038] Furthermore, in the preparation method, the mass ratio of the novel fluoran dye to the phase change material is 1:40-200.

[0039] Furthermore, in the preparation method, uniform mixing can be achieved by mechanical stirring or manual stirring.

[0040] Furthermore, in the preparation method, the uniform mixing time is 10 to 600 minutes.

[0041] The two-component color-changing system provided by the present invention is applied in the fields of textiles and clothing, ink printing, temperature-indicating coatings, building material coatings, energy-saving materials, and anti-counterfeiting labels.

[0042] The present invention also provides a thermosensitive reversible color-changing microcapsule, which is composed of a two-component color-changing system, a wall material and an emulsifier.

[0043] Furthermore, the wall material includes one or more of polymethyl methacrylate, polystyrene, polyethyl methacrylate, and polybutyl methacrylate.

[0044] Furthermore, the emulsifier includes one or more of gelatin, OP-10, Span 20, Span 40, Span 80, Tween 20, Tween 40, Tween 80, gum arabic, and sodium dodecylbenzenesulfonate.

[0045] Furthermore, the dual-component color-changing system in the thermosensitive reversible color-changing microcapsules accounts for 40 to 50 wt% of the total mass.

[0046] Furthermore, the wall material in the thermosensitive reversible color-changing microcapsules accounts for 20 to 30 wt% of the total mass.

[0047] Furthermore, the emulsifier in the thermosensitive reversible color-changing microcapsules accounts for 25 to 40 wt% of the total mass.

[0048] The present invention also provides a method for preparing thermosensitive reversible color-changing microcapsules, which comprises the following steps: dissolving a two-component color-changing system and a wall material in an organic solvent, then adding an emulsifier aqueous solution, mixing thoroughly to form an O / W emulsion, then heating and stirring, filtering to retain solids, and washing and drying the solids to obtain thermosensitive reversible color-changing microcapsules.

[0049] Furthermore, the organic solvent includes dichloromethane.

[0050] Furthermore, the mass ratio of the two-component color-changing system and the wall material is 4-5:2-3.

[0051] Furthermore, the mass ratio of the two-component color-changing system and the organic solvent is 4-5:15-30.

[0052] Furthermore, the mass ratio of the two-component color-changing system and the emulsifier aqueous solution is 4-5:100-200.

[0053] Furthermore, the mass fraction of the emulsifier in the emulsifier aqueous solution is 1 to 5 wt%.

[0054] Furthermore, the heating temperature is 30-50°C.

[0055] Furthermore, the heating time is 8 to 12 hours.

[0056] The thermosensitive reversible color-changing microcapsules provided by the present invention are used in the fields of textiles and clothing, ink printing, temperature-indicating coatings, building material coatings, energy-saving materials, and anti-counterfeiting labels.

[0057] Beneficial effects of the present invention:

[0058] 1. The present invention designs a series of new fluoran dyes and develops two-component reversible thermochromic dyes and microcapsules prepared based on these new fluoran dyes. The obtained two-component reversible thermochromic dyes and microcapsules can achieve thermochromism without adding bisphenol A. Compared with the traditional three-component color-changing system, the influence of the easy oxidation property of bisphenol A on the color-changing system is avoided. While optimizing the cost structure, the reversible thermochromic performance is upgraded, which promotes the application of thermochromic systems in high-precision and high-value-added fields.

[0059] 2. The novel fluoran dye of the present invention can produce a thermochromic effect after simply adding a phase change material and mixing. The color change effect is sensitive, and the temperature color change range is ≤3°C, making it more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Purple No. 1 1 HNMR spectrum.

[0061] Figure 2 Purple No. 2 1 HNMR spectrum.

[0062] Figure 3 Purple No. 4 1 HNMR spectrum. DETAILED DESCRIPTION

[0063] The outstanding advantages and significant features of the present invention are further described below by implementing examples, but the present invention is by no means limited to the implementing examples.

[0064] Source of raw materials

[0065] The monomers used in the examples are 3-bromophthalic anhydride, 2-hydroxyphenylboric acid, 3-hydroxyphenylboric acid, and 2-hydroxy-5-nitrophenylboric acid, with CAS numbers of 82-73-5, 89466-08-0, 87199-18-6, and 677746-32-6, respectively, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; 3-diethylaminophenol and 2-hydroxy-5-fluorophenylboric acid, with CAS numbers of 91-68-9 and 259209-20-6, respectively, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; 2-hydroxy-5-methylphenylboric acid, with CAS number of 259209-21-7, purchased from Sinopharm Chemical Reagent Co., Ltd.; and 2-hydroxy-5-cyanophenylboric acid, with CAS number of 1256355-57-3, purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0066] The molecular structures of the fluoran dyes involved in the embodiments and comparative examples of the present invention are as follows:

[0067] Table 1 Structure of new purple fluoran dyes

[0068]

[0069]

[0070] Table 2 Structures of new yellow fluoran dyes

[0071]

[0072] Table 3 Structures of new blue fluoran dyes

[0073]

[0074]

[0075] Table 4 Structures of new green fluoran dyes

[0076]

[0077] Table 5 Structures of new red fluoran dyes

[0078]

[0079] Table 6 Structure of new black fluoran dyes

[0080]

[0081]

[0082] Table 7 Structure of new red fluoran dyes

[0083]

[0084] Example 1

[0085] This example is the preparation of Purple No. 1 to No. 6.

[0086] Preparation of intermediate P-Br: 3-(Diethylamino)phenol (40 mmol), 3-bromophthalic anhydride (20 mmol), and niobium pentoxide (10 mmol) were added to a three-necked flask, then heated in an oil bath at 140°C for 2 h to allow the mixture to melt and react. After completion of the reaction, the mixture was cooled to room temperature and the reaction solution was subjected to column chromatography using dichloromethane / methanol (volume ratio of 15:1) as the eluent. The substance with an Rf value of 0.47 was extracted and dried to obtain a purple-red powder, which was the intermediate P-Br.

[0087] Preparation of the new purple fluoran dye No. 1 (PFlu1): P-Br (0.4 mmol), 2-hydroxyphenylboronic acid (0.6 mmol), and potassium carbonate (0.8 mmol) were dissolved in 30 mL of toluene, 10 mL of ethanol, and 10 mL of water, respectively. The three solutions were then poured into a three-necked flask and mixed. The mixture was preheated in a 75°C oil bath. Nitrogen was passed through for 5 minutes and then tetrakistriphenylphosphine palladium (0.26 mol) was added to start the reaction. The entire reaction was carried out in a nitrogen atmosphere, refluxed for 24 hours, and then cooled to room temperature. The solvent was removed by rotary evaporation, and the reaction solution after rotary evaporation was subjected to column chromatography using dichloromethane / methanol (volume ratio of 10:1) as the eluent. The substance with an Rf value of 0.34 was taken and dried to obtain a purple-red powder, i.e., the new purple fluoran dye No. 1.

[0088] The molecular formula of the intermediate P-Br is shown below, and its molecular weight is 520.14.

[0089]

[0090] Preparation of the new purple fluoran dye No. 2 (PFlu2): Referring to the synthesis method of the new purple fluoran dye No. 1 (PFlu1), only 2-hydroxyphenylboronic acid was replaced with an equimolar amount of 3-hydroxyphenylboronic acid to obtain the new purple fluoran dye No. 2.

[0091] Preparation of the new purple fluoran dye No. 3 (PFlu3): Referring to the synthesis method of the new purple fluoran dye No. 1 (PFlu1), only 2-hydroxyphenylboronic acid was replaced with an equimolar amount of 2-hydroxy-5-methylphenylboronic acid to obtain the new purple fluoran dye No. 3.

[0092] Preparation of the new purple fluoran dye No. 4 (PFlu4): Referring to the synthesis method of the new purple fluoran dye No. 1 (PFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-fluorophenylboronic acid to obtain the new purple fluoran dye No. 4.

[0093] Preparation of the new purple fluoran dye No. 5 (PFlu5): Referring to the synthesis method of the new purple fluoran dye No. 1 (PFlu1), only 2-hydroxyphenylboronic acid was replaced with an equimolar amount of 2-hydroxy-5-cyanophenylboronic acid to obtain the new purple fluoran dye No. 5.

[0094] Preparation of the new purple fluoran dye No. 6 (PFlu6): Referring to the synthesis method of the new purple fluoran dye No. 1 (PFlu1), 2-hydroxyphenylboronic acid was adjusted to an equimolar amount of 2-hydroxy-5-nitrophenylboronic acid to obtain the new purple fluoran dye No. 6.

[0095] Example 2

[0096] This example is the preparation of Yellow No. 1 to No. 6.

[0097] Preparation of Yellow No. 1 Fluoran Dye (YFlu1): The synthesis method was followed by reference to Example 1. First, the reactant 3-(diethylamino)phenol in the preparation of the intermediate P-Br was adjusted to an equimolar amount of 3-methoxyphenol to obtain the intermediate Y-Br, whose Rf value was 0.41. Then, according to the preparation process of the purple No. 1 Fluoran Dye, the intermediate P-Br was replaced with an equimolar amount of the intermediate Y-Br to obtain the yellow No. 1 Fluoran Dye, whose Rf value was 0.35.

[0098] The molecular formula of the intermediate Y-Br is shown below, and its molecular weight is 438.01.

[0099]

[0100] Preparation of Yellow No. 2 Novel Fluoran Dye (YFlu2): Referring to the synthesis method of Yellow No. 1 Novel Fluoran Dye (YFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 3-hydroxyphenylboronic acid to obtain Yellow No. 2 Novel Fluoran Dye.

[0101] Preparation of Yellow No. 3 fluoran dye (YFlu3): Referring to the synthesis method of Yellow No. 1 fluoran dye (YFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-methylphenylboronic acid to obtain Yellow No. 3 fluoran dye.

[0102] Preparation of Yellow No. 4 Novel Fluoran Dye (YFlu4): Referring to the synthesis method of Yellow No. 1 Novel Fluoran Dye (YFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-fluorophenylboronic acid to obtain Yellow No. 4 Novel Fluoran Dye.

[0103] Preparation of Yellow No. 5 Novel Fluoran Dye (YFlu5): Referring to the synthesis method of Yellow No. 1 Novel Fluoran Dye (YFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-cyanophenylboronic acid to obtain Yellow No. 5 Novel Fluoran Dye.

[0104] Preparation of Yellow No. 6 Novel Fluoran Dye (YFlu6): Referring to the synthesis method of Yellow No. 1 Novel Fluoran Dye (YFlu1), 2-hydroxyphenylboronic acid was adjusted to an equimolar amount of 2-hydroxy-5-nitrophenylboronic acid to obtain Yellow No. 6 Novel Fluoran Dye.

[0105] Example 3

[0106] This example is the preparation of blue No. 1 to No. 6.

[0107] Preparation of Blue No. 1 Fluoran Dye (BFlu1): The synthesis method in Example 1 was followed. First, the reactant 3-(diethylamino)phenol in the preparation of the intermediate P-Br was adjusted to an equimolar amount of p-methyl-m-hydroxydiphenylamine to obtain the intermediate B-Br. Then, according to the preparation process of the purple No. 1 Fluoran Dye, the intermediate P-Br was replaced with an equimolar amount of the intermediate B-Br to obtain the blue No. 1 Fluoran Dye.

[0108] The molecular formula of the intermediate B-Br is shown below, and its molecular weight is 768.20.

[0109]

[0110] Preparation of Blue No. 2 Fluoran Dye (BFlu2): Referring to the synthesis method of Blue No. 1 Fluoran Dye (BFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 3-hydroxyphenylboronic acid to obtain Blue No. 2 Fluoran Dye.

[0111] Preparation of Blue No. 3 Fluoran Dye (BFlu3): Referring to the synthesis method of Blue No. 1 Fluoran Dye (BFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-methylphenylboronic acid to obtain Blue No. 3 Fluoran Dye.

[0112] Preparation of Blue No. 4 Fluoran Dye (BFlu4): Referring to the synthesis method of Blue No. 1 Fluoran Dye (BFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-fluorophenylboronic acid to obtain Blue No. 4 Fluoran Dye.

[0113] Preparation of Blue No. 5 Fluoran Dye (BFlu5): Referring to the synthesis method of Blue No. 1 Fluoran Dye (BFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-cyanophenylboronic acid to obtain Blue No. 5 Fluoran Dye.

[0114] Preparation of Blue No. 6 Fluoran Dye (BFlu6): Referring to the synthesis method of Blue No. 1 Fluoran Dye (BFlu1), 2-hydroxyphenylboronic acid was adjusted to an equimolar amount of 2-hydroxy-5-nitrophenylboronic acid to obtain Blue No. 6 Fluoran Dye.

[0115] Example 4

[0116] This example is the preparation of Green No. 1 to No. 6.

[0117] Preparation of intermediate G-Br1: 3-(diethylamino)phenol (40 mmol), 3-bromophthalic anhydride (20 mmol), and niobium pentoxide (10 mmol) were added to a three-necked flask, and then placed in a 140°C oil bath for heating and melting reaction for 2 h. After the reaction was completed, it was cooled to room temperature and then the reaction solution was subjected to column chromatography using dichloromethane / methanol (volume ratio of 10:1) as the eluent. The substance with an Rf value of 0.39 was taken and dried to obtain a purple-red powder, namely intermediate G-Br1 (intermediate P-Br);

[0118] Preparation of intermediate G-Br2: 0.5 mmol of intermediate G-Br1 and 15 mL of concentrated sulfuric acid were placed in a three-necked flask and stirred in an ice bath until dissolved. 5 mmol of 4-methoxy-N-phenylaniline was then added to the three-necked flask and reacted at 25°C for 24 hours. After the reaction was completed, the reaction solution was slowly dripped into 500 mL of ice water to produce a dark green precipitate. The pH of the ice-water mixture was then adjusted to neutral with triethylamine, and then filtered. The filter cake was dried to obtain a crude product, which was then subjected to column chromatography using dichloromethane / methanol (volume ratio of 10:1) as an eluent. The substance with an Rf value of 0.36 was taken and dried to obtain a green powder, namely, intermediate G-Br2;

[0119] Preparation of green No. 1 new fluoran dye (GFlu1): Take 0.4mmol G-Br2, 0.6mmol 2-hydroxyphenylboronic acid, and 0.8mmol potassium carbonate and dissolve them in 30mL toluene, 10mL ethanol, and 10mL water respectively. Then pour the three solutions into a three-necked flask and mix them. Put them into a 75℃ oil bath for preheating. First, pass nitrogen for 5min and then add 0.26mol tetrakistriphenylphosphine palladium to react. The reaction is carried out in a nitrogen atmosphere throughout the process and refluxed for 24h. After the reaction is completed, the solvent is removed by rotary evaporation. The reaction solution after rotary evaporation is subjected to column chromatography with dichloromethane / methanol (volume ratio of 10:1) as eluent. The substance with an Rf value of 0.33 is taken and dried to obtain a green powder, i.e., green No. 1 new fluoran dye.

[0120] The molecular formula of G-Br2 is shown below, and its molecular weight is 546.15.

[0121]

[0122] Preparation of Green No. 2 Novel Fluoran Dye (GFlu2): Referring to the synthesis method of Green No. 1 Novel Fluoran Dye (GFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 3-hydroxyphenylboronic acid to obtain Green No. 2 Novel Fluoran Dye.

[0123] Preparation of Green No. 3 Novel Fluoran Dye (GFlu3): Referring to the synthesis method of Green No. 1 Novel Fluoran Dye (GFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-methylphenylboronic acid to obtain Green No. 3 Novel Fluoran Dye.

[0124] Preparation of Green No. 4 Novel Fluoran Dye (GFlu4): Referring to the synthesis method of Green No. 1 Novel Fluoran Dye (GFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-fluorophenylboronic acid to obtain Green No. 4 Novel Fluoran Dye.

[0125] Preparation of Green No. 5 Novel Fluoran Dye (GFlu5): Referring to the synthesis method of Green No. 1 Novel Fluoran Dye (GFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-cyanophenylboronic acid to obtain Green No. 5 Novel Fluoran Dye.

[0126] Preparation of Green No. 6 Novel Fluoran Dye (GFlu6): Referring to the synthesis method of Green No. 1 Novel Fluoran Dye (GFlu1), 2-hydroxyphenylboronic acid was adjusted to an equimolar amount of 2-hydroxy-5-nitrophenylboronic acid to obtain Green No. 6 Novel Fluoran Dye.

[0127] Example 5

[0128] This example is the preparation of Red No. 1 to No. 6.

[0129] Preparation of Red No. 1 Fluoran Dye (RFlu1): Refer to the synthesis method in Comparative Example 4. Adjust the 4-methoxy-N-phenylaniline in the preparation of intermediate G-Br2 to an equimolar amount of 3-chlorophenol to obtain intermediate R-Br2; then, according to the preparation process of Green No. 1 Fluoran Dye, replace G-Br2 with an equimolar amount of R-Br2 to obtain Red No. 1 Fluoran Dye.

[0130] The molecular formula of R-Br2 is shown below, and its molecular weight is 483.02.

[0131]

[0132] Preparation of Red No. 2 Novel Fluoran Dye (RFlu2): Referring to the synthesis method of Red No. 1 Novel Fluoran Dye (RFlu1), only 2-hydroxyphenylboronic acid was replaced with an equimolar amount of 3-hydroxyphenylboronic acid to obtain Red No. 2 Novel Fluoran Dye.

[0133] Preparation of Red No. 3 Novel Fluoran Dye (RFlu3): Referring to the synthesis method of Red No. 1 Novel Fluoran Dye (RFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-methylphenylboronic acid to obtain Red No. 3 Novel Fluoran Dye.

[0134] Preparation of Red No. 4 Novel Fluoran Dye (RFlu4): Referring to the synthesis method of Red No. 1 Novel Fluoran Dye (RFlu1), only 2-hydroxyphenylboronic acid was replaced with an equal molar amount of 2-hydroxy-5-fluorophenylboronic acid to obtain Red No. 4 Novel Fluoran Dye.

[0135] Preparation of Red No. 5 Novel Fluoran Dye (RFlu5): Referring to the synthesis method of Red No. 1 Novel Fluoran Dye (RFlu1), only 2-hydroxyphenylboronic acid was replaced with an equimolar amount of 2-hydroxy-5-cyanophenylboronic acid to obtain Red No. 5 Novel Fluoran Dye.

[0136] Preparation of Red No. 6 Novel Fluoran Dye (RFlu6): Referring to the synthesis method of Red No. 1 Novel Fluoran Dye (RFlu1), 2-hydroxyphenylboronic acid was adjusted to an equimolar amount of 2-hydroxy-5-nitrophenylboronic acid to obtain Red No. 6 Novel Fluoran Dye.

[0137] Example 6

[0138] This example is the preparation of black No. 1 to No. 6.

[0139] Preparation of black novel fluoran dye No. 1 (DFlu1): refer to the synthesis method in Comparative Example 4. The 4-methoxy-N-phenylaniline in the preparation of intermediate G-Br2 was adjusted to an equimolar amount of 4-methoxy-2-methyldiphenylamine to obtain intermediate D-Br2; then, according to the preparation process of green novel fluoran dye No. 1, G-Br2 was replaced with an equimolar amount of D-Br2 to obtain black novel fluoran dye No. 1.

[0140] The molecular formula of D-Br2 is shown below, and its molecular weight is 555.47.

[0141]

[0142] Preparation of black novel fluoran dye No. 2 (DFlu2): Referring to the synthesis method of black novel fluoran dye No. 1 (DFlu1), only 2-hydroxyphenylboronic acid is replaced by an equimolar amount of 3-hydroxyphenylboronic acid to obtain black novel fluoran dye No. 2.

[0143] Preparation of black fluoran dye No. 3 (DFlu3): Referring to the synthesis method of black fluoran dye No. 1 (DFlu1), only 2-hydroxyphenylboronic acid is replaced by an equimolar amount of 2-hydroxy-5-methylphenylboronic acid to obtain black fluoran dye No. 3.

[0144] Preparation of black fluoran dye No. 4 (DFlu4): Referring to the synthesis method of black fluoran dye No. 1 (DFlu1), only 2-hydroxyphenylboronic acid is replaced by an equimolar amount of 2-hydroxy-5-fluorophenylboronic acid to obtain black fluoran dye No. 4.

[0145] Preparation of black fluoran dye No. 5 (DFlu5): Referring to the synthesis method of black fluoran dye No. 1 (DFlu1), only 2-hydroxyphenylboronic acid is replaced with an equal molar amount of 2-hydroxy-5-cyanophenylboronic acid to obtain black fluoran dye No. 5.

[0146] Preparation of black fluoran dye No. 6 (DFlu6): Referring to the synthesis method of black fluoran dye No. 1 (DFlu1), 2-hydroxyphenylboronic acid was adjusted to an equimolar amount of 2-hydroxy-5-nitrophenylboronic acid to obtain black fluoran dye No. 6.

[0147] Example 7

[0148] Preparation of Purple No. 1 two-component reversible thermochromic dye complex (PFlu1@DPC): Purple No. 1 new fluoran dye and diphenyl carbonate (DPC) were mixed in a mass ratio of 1:40, and magnetically stirred at 85°C for 30 minutes to obtain a uniformly mixed PFlu1@DPC.

[0149] PFlu1@DPC is purple-red at room temperature (20-25°C), becomes colorless when heated to 82°C, and turns purple-red when cooled to 64°C.

[0150] Example 8

[0151] Preparation of Yellow No. 1 two-component reversible thermochromic dye complex (YFlu1@DPC): Take the new Yellow No. 1 fluoran dye and diphenyl carbonate (DPC) in a mass ratio of 1:40, mix them, and magnetically stir them at 85°C for 30 minutes to obtain a uniformly mixed YFlu1@DPC.

[0152] YFlu1@DPC is yellow at room temperature (20-25°C), turns colorless when heated to 82°C, and turns yellow when cooled to 64°C.

[0153] Example 9

[0154] Preparation of Blue No. 1 two-component reversible thermochromic dye complex (BFlu1@DPC): Take the new Blue No. 1 fluoran dye and diphenyl carbonate (DPC) in a mass ratio of 1:40, and magnetically stir at 85°C for 30 minutes to obtain a uniformly mixed YFlu1@DPC.

[0155] YFlu1@DPC appears blue at room temperature (20-25°C), turns colorless when heated to 82°C, and turns blue when cooled to 64°C.

[0156] Example 10

[0157] Preparation of Purple No. 5 two-component reversible thermochromic dye complex (PFlu5@DPC): Take the new Purple No. 5 fluoran dye and diphenyl carbonate (DPC) in a mass ratio of 1:40, mix them, and magnetically stir them at 85°C for 30 minutes to obtain a uniformly mixed PFlu5@DPC.

[0158] PFlu5@DPC is purple-red at room temperature (20-25°C), becomes colorless when heated to 82°C, and turns purple-red when cooled to 64°C.

[0159] Example 11

[0160] Preparation of Purple No. 6 two-component reversible thermochromic dye complex (PFlu6@DPC): Take the new Purple No. 6 fluoran dye and diphenyl carbonate (DPC) in a mass ratio of 1:40, mix them, and magnetically stir them at 85°C for 30 minutes to obtain a uniformly mixed PFlu6@DPC.

[0161] PFlu6@DPC is purple-red at room temperature (20-25°C), becomes colorless when heated to 82°C, and turns purple-red when cooled to 64°C.

[0162] Table 8 Color change performance of Examples 7 to 11

[0163]

[0164]

[0165] It can be seen from Table 8 that when diphenyl carbonate (DPC) is selected as the phase change material, the color-changing system can achieve the effect of thermochromic change without adding bisphenol A, and the temperature color change range during the heating and cooling process is ≤3°C.

[0166] Example 12

[0167] Green No. 2 two-component reversible thermochromic dye complex (GFlu2@C9H 10 Preparation of O3): Take the new green fluoran dye No. 2 and methyl paramethoxybenzoate (C9H 10 O3) were mixed at a mass ratio of 1:40 and magnetically stirred at 60 ° C for 30 min to obtain a uniformly mixed GFlu2@C9H 10 O3.

[0168] GFlu2@C9H 10 O3 is green at room temperature (20-25°C), becomes colorless when heated to 50°C, and turns green when cooled to 42°C.

[0169] Example 13

[0170] Example 13 uses the same green No. 2 novel fluoran dye as Example 12.

[0171] Preparation of Green No. 2 two-component reversible thermochromic dye complex (GFlu2@MM): Take the new Green No. 2 fluoran dye and tetradecanoic acid tetradecyl ester (MM) in a mass ratio of 1:40, mix them, and stir them magnetically at 60°C for 30 minutes to obtain a uniformly mixed GFlu2@MM.

[0172] GFlu2@MM is green at room temperature (20-25°C), turns colorless when heated to 50°C, and turns green when cooled to 37.5°C.

[0173] Example 14

[0174] Example 14 uses the same green No. 2 novel fluoran dye as Example 12.

[0175] Green No. 2 two-component reversible thermochromic dye complex (GFlu2@C 14 Preparation of violet No. 2 new fluoran dye and tetradecanol (C 14 OH) were mixed at a mass ratio of 1:40 and magnetically stirred at 50 °C for 30 min to obtain a uniformly mixed GFlu2@C 14 OH.

[0176] GFlu2@C 14 OH appears green at room temperature (20-25°C) and remains green when heated to 43°C. The results show that long-chain alkyl alcohol phase change materials do not have the property of making dyes thermochromic.

[0177] Table 9 Color change performance of Examples 12 to 14

[0178]

[0179] Example 15

[0180] Blue No. 3 two-component reversible thermochromic dye complex (BFlu3@C9H 10 Preparation of O3): Take the new blue fluoran dye No. 3 and methyl p-methoxybenzoate (C9H 10 O3) were mixed at a mass ratio of 1:40 and magnetically stirred at 60 ° C for 30 min to obtain a uniformly mixed YFlu1@C9H 10 O3.

[0181] YFlu1@C9H 10 O3 appears blue at room temperature (20-25°C), becomes colorless when heated to 50°C, and turns blue when cooled to 42°C.

[0182] Example 16

[0183] Red No. 3 two-component reversible thermochromic dye complex (RFlu3@C9H 10 Preparation of O3): Take the new red 3 fluoran dye and methyl p-methoxybenzoate (C9H 10 O3) were mixed at a mass ratio of 1:40 and magnetically stirred at 60 ° C for 30 min to obtain a uniformly mixed C9H 10 O3.

[0184] RFlu3@C9H 10 O3 appears red at room temperature (20-25°C), becomes colorless when heated to 50°C, and turns red when cooled to 42°C.

[0185] Example 17

[0186] Example 17 uses the same blue No. 3 new fluoran dye as Example 15.

[0187] Preparation of Blue No. 3 two-component reversible thermochromic dye complex (BFlu3@DPMPE): Take the new Blue No. 3 fluoran dye and 2-(4-benzyloxyphenyl)ethyl decanoate (DPMPE) in a mass ratio of 1:40 and magnetically stir at 75°C for 30 minutes to obtain a uniformly mixed BFlu3@DPMPE.

[0188] BFlu3@DPMPE appears blue at room temperature (20-25°C), becomes colorless when heated to 67°C, and turns blue when cooled to 41°C.

[0189] Example 18

[0190] Preparation of blue No. 3 two-component reversible temperature-sensitive color-changing microcapsules: 1.5g BFlu3@C9H 10 O3 and 0.75g polymethyl methacrylate (PMMA) were dissolved in 5mL dichloromethane, and then an emulsifier aqueous solution (1.0g gelatin mixed in 49mL water) was added and stirred at 5000r / min for 30min at room temperature to form an O / W emulsion. The O / W emulsion was poured into a beaker and stirred at 35°C at a speed of 400r / min for 8h. After DCM was completely evaporated, deionized water was added and allowed to stand. The supernatant was poured out, the floating matter was removed, and the solid was retained by filtration. The solid was washed with deionized water and ethanol to obtain blue No. 3 two-component reversible temperature-sensitive color-changing microcapsules (BFlu3@C9H 10 O3-Ms).

[0191] The BFlu3@C9H 10 O3-Ms appears blue at room temperature (20-25°C) and becomes colorless when heated to 47°C. After the temperature is removed, the blue color can be maintained for 1 minute.

[0192] Example 19

[0193] Preparation of Red No. 3 two-component reversible temperature-sensitive color-changing microcapsules: Take 1.5g RFlu3@C9H 10O3 and 0.75g polymethyl methacrylate (PMMA) were dissolved in 5mL dichloromethane, and then an emulsifier aqueous solution (2%, 1.0g gelatin mixed in 49mL water) was added and stirred at 5000r / min for 30min at room temperature to form an O / W emulsion. The O / W emulsion was poured into a beaker and stirred at 35°C at a speed of 400r / min for 8h. After DCM was completely evaporated, deionized water was added and allowed to stand. The supernatant was poured out, the floating matter was removed, and the solid was retained by filtration. The solid was washed with deionized water and ethanol to obtain red No. 3 two-component reversible temperature-sensitive color-changing microcapsules (RFlu3@C9H 10 O3-Ms).

[0194] The RFlu3@C9H 10 O3-Ms appears red at room temperature (20-25°C) and becomes colorless when heated to 47°C. After the temperature is removed, it can maintain the red color for 1 minute.

[0195] Example 20

[0196] Preparation of Blue No. 3 two-component reversible thermochromic microcapsules: 1.5g BFlu3@DPMPE and 0.75g polymethyl methacrylate (PMMA) were dissolved in 5mL of dichloromethane, and then an emulsifier aqueous solution (2%, 1.0g gelatin mixed in 49mL of water) was added and stirred at 5000r / min for 30min at room temperature to form an O / W emulsion. The O / W emulsion was poured into a beaker and stirred at 400r / min at 35°C for 8h. After DCM was completely evaporated, deionized water was added and allowed to stand. The supernatant was poured out, the floating matter was removed, and the solid was retained. The solid was washed with deionized water and ethanol to obtain Blue No. 3 two-component reversible thermochromic microcapsules (BFlu3@DPMPE-Ms).

[0197] The BFlu3@DPMPE-Ms appears blue at room temperature (20-25°C) and becomes colorless when heated to 62°C; and after the temperature is removed, it can maintain the blue color for 2 minutes.

[0198] Table 10 Color change performance of Examples 15 to 20

[0199]

[0200]

[0201] It can be seen from Table 10 that compared with the color-changing compound, after being coated with microencapsulation technology, the color-changing temperature range of the color-changing microcapsules during the heating and cooling processes becomes wider, and the color-changing response sensitivity decreases, but it has a bistable effect of maintaining color.

[0202] Example 21

[0203] Black No. 4 two-component reversible temperature-sensitive color-changing dye compound (DFlu4@C9H 10 Preparation of O3): Take the black No. 4 new fluoran dye and methyl p-methoxybenzoate (C9H 10 O3) were mixed at a mass ratio of 1:40 and magnetically stirred at 60 ° C for 30 min to obtain a uniformly mixed C9H 10 O3.

[0204] DFlu4@C9H 10 O3 appears black at room temperature (20-25°C), becomes colorless when heated to 50°C, and turns black when cooled to 42°C.

[0205] Example 22

[0206] Obtaining Black No. 0 Traditional Fluoran Dye: Black No. 0 Traditional Fluoran Dye was purchased from Haishan Technology Co., Ltd.

[0207] Two-component temperature-sensitive reversible color-changing dye complex based on traditional fluoran dye (DFlu0@C9H 10 Preparation of O3: Take black No. 0 traditional fluoran dye and methyl paramethoxybenzoate (C9H 10 O3) were mixed at a mass ratio of 1:40 and magnetically stirred at 60 ° C for 30 min to obtain a uniformly mixed DFlu0@C9H 10 O3.

[0208] DFlu0@C9H 10 O3 is colorless at room temperature (20-25°C) and remains colorless when heated to 50°C. The results show that traditional fluoran dyes do not have thermochromic properties in the absence of a color developer.

[0209] Example 23

[0210] Red No. 0 traditional fluoran dye was obtained by purchasing Red No. 0 traditional fluoran dye from Haishan Technology Co., Ltd.

[0211] Two-component temperature-sensitive reversible color-changing dye complex based on traditional fluoran dye (RFlu0@C9H 10 Preparation of O3: Take red 0 traditional fluoran dye and methyl paramethoxybenzoate (C9H 10 O3) were mixed at a mass ratio of 1:40 and magnetically stirred at 60 ° C for 30 min to obtain a uniformly mixed RFlu0@C9H 10 O3.

[0212] RFlu0@C9H 10O3 is colorless at room temperature (20-25°C) and remains colorless when heated to 50°C. The results show that traditional fluoran dyes do not have thermochromic properties in the absence of a color developer.

[0213] Table 11 Color change performance of Examples 21 to 23

[0214]

[0215] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A novel fluoran dye, characterized in that the structure of the novel fluoran dye is as shown in the following formula I: Formula I In formula I, R1 is selected from N(CH2CH3)2, N(CH3)2, OCH3, OCH2CH3, Any of the following; R2 is selected from H, CH3, N(CH2CH3)2, N(CH3)2, OCH3, OCH2CH3, , any one of halogen; R3 is selected from H, 、 Any of the following; R4 is selected from 、 Any of the following; R5 is selected from any one of H, methyl, ethyl, isopropyl, halogen, cyano, and nitro.

2. according to the fluoran dye described in claim 1, its characteristic value is, described R4 is specifically selected from 、 、 、 、 、 Any of .

3. The novel fluoran dye according to claim 1, wherein, in formula I, when R1 and R2 are selected from N(CH2CH3)2 or OCH2CH3, and R3 is selected from H, the color of the novel fluoran dye changes to purple.

4. The novel fluoran dye according to claim 1, wherein, in formula I, when R1 and R2 are selected from one of OCH3 or N(CH3)2, and R3 is selected from H, the color of the novel fluoran dye changes to yellow.

5. The novel fluoran dye according to claim 1, wherein the characteristic value is that, in formula I, when R1 is selected as N(CH2CH3)2, R2 is selected as H, and R3 is selected as When , the color of the new fluoran dye changes to green.

6. The novel fluoran dye according to claim 1, wherein the characteristic value is that, in formula I, when R1 is selected from N(CH2CH3)2, R2 is selected from CH3, and R3 is selected from When , the new fluoran dye changes color to black.

7. The novel fluoran dye according to claim 1, wherein the characteristic value is that, in formula I, when R1 and R2 are When , the color of the novel fluoran dye changes to blue.

8. The novel fluoran dye according to claim 1, wherein, in formula I, when R1 is N(CH2CH3)2, R2 is halogen, wherein the halogen is chlorine, and R3 is H, the color of the novel fluoran dye changes to red.

9. Application of the novel fluoran dye according to any one of claims 1 to 8 in the fields of textiles and garments, ink printing, temperature-indicating coatings, building materials and coatings, energy-saving materials, and anti-counterfeiting labels.

10. A two-component color-changing system, characterized in that: The two-component color-changing system consists of the new fluoran dye according to any one of claims 1 to 8 and a phase change material; the mass ratio of the new fluoran dye to the phase change material is 1:10-500.

11. The two-component color-changing system according to claim 10, characterized in that: The phase change material includes one or more of diphenyl carbonate, methyl stearate, n-tridecyl carbonate, glyceryl distearate, glyceryl monostearate, glyceryl tristearate, 4-benzyloxyphenylethyl caproate, myristyl tetradecanoate, and methyl p-methoxybenzoate.

12. The two-component color-changing system according to claim 10, characterized in that: In the two-component color-changing system, the mass ratio of the new fluoran dye to the phase change material is 1:20-400.

13. The two-component color-changing system according to claim 10, characterized in that: In the two-component color-changing system, the mass ratio of the new fluoran dye to the phase change material is 1:40-200.

14. A method for preparing the two-component color-changing system according to any one of claims 10 to 13, characterized in that: The preparation method comprises: Method 1: The novel fluoran dye according to any one of claims 1 to 8 and the phase change material are heated and uniformly mixed to obtain a two-component temperature-sensitive reversible color-changing system; Method 2: The novel fluoran dye according to any one of claims 1 to 8 and the molten phase change material are uniformly mixed to obtain a two-component temperature-sensitive reversible color-changing system.

15. The preparation method according to claim 14, characterized in that: The heating temperature in method 1 is equal to or greater than the melting point of the selected phase change material.

16. The preparation method according to claim 14, characterized in that: The uniform mixing time in Method 1 and Method 2 is 10 to 600 minutes.

17. Application of the two-component color-changing system according to any one of claims 10 to 13 in the fields of textiles and clothing, ink printing, temperature-indicating coatings, building materials and coatings, energy-saving materials, and anti-counterfeiting labels.

18. A thermosensitive reversible color-changing microcapsule, characterized in that: The thermosensitive reversible color-changing microcapsule is composed of the two-component color-changing system according to any one of claims 10 to 13, a wall material and an emulsifier.

19. The thermosensitive reversible color-changing microcapsule according to claim 18, characterized in that: The wall material includes one or more of polymethyl methacrylate, polystyrene, polyethyl methacrylate, and polybutyl methacrylate.

20. The thermosensitive reversible color-changing microcapsule according to claim 18, characterized in that: The emulsifier includes one or more of gelatin, OP-10, Span 20, Span 40, Span 80, Tween 20, Tween 40, Tween 80, gum arabic, and sodium dodecylbenzenesulfonate.

21. The thermosensitive reversible color-changing microcapsule according to claim 18, characterized in that: The dual-component color-changing system in the thermosensitive reversible color-changing microcapsule accounts for 40-50 wt % of the total mass.

22. The thermosensitive reversible color-changing microcapsule according to claim 18, characterized in that: The wall material in the thermosensitive reversible color-changing microcapsule accounts for 20-30 wt % of the total mass.

23. The thermosensitive reversible color-changing microcapsule according to claim 18, characterized in that: The emulsifier in the thermosensitive reversible color-changing microcapsules accounts for 25-40 wt % of the total mass.

24. Use of the thermosensitive reversible color-changing microcapsule according to any one of claims 18 to 23 in the fields of textiles and clothing, ink printing, temperature-indicating coatings, building materials and coatings, energy-saving materials, and anti-counterfeiting labels.

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