Coumarin-based imine hydrazide derivatives, and preparation method and application thereof

Abstract

The application discloses a coumarin-based imine hydrazide derivative, and has the following structure: the coumarin-based imine hydrazide derivative is prepared through Schiff base condensation reaction of 4-methyl-7-hydroxyl coumarin derivative and 4-pyridine formyl hydrazine, the reaction is easy to prepare, and post-treatment is simple; when the compound is used as a coating film forming aid, the compound has good effect.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically, it relates to a coumarin-based imine hydrazide derivative, its preparation method, and its application. Background Technology

[0002] Film-forming aids are additives that assist in the gradual formation of a paint film during the coating process, lowering the glass transition temperature of solids in the coating. The most basic requirement for a good film-forming additive is solubility. It must be able to dissolve well in the solids of the emulsion, allowing the film-forming aid molecules to adhere to the surface of the solids. This process gives the solid molecules a certain degree of fluidity, enabling them to extend and perform other activities.

[0003] Film-forming aids have good solubility in latex paints, promote film formation during the process, and evaporate smoothly after film formation. During the final evaporation process, they do not cause any change in the properties of the paint film. Film-forming aids are high-boiling-point substances added to coatings or inks to help form films. They enable polymers with high glass transition temperatures to form films at lower temperatures, thus achieving better film-forming effects. Currently, film-forming aids used in water-based coatings or inks, such as alcohol ester 12, each have their own advantages and disadvantages and require further improvement.

[0004] Therefore, there is a need for a novel film-forming aid that outperforms existing film-forming aids. Coumarin, after structural modification, has excellent film-forming properties, and is low in toxicity, easy to prepare and modify, and stable. Summary of the Invention

[0005] The purpose of this invention is to provide a coumarin-based imine hydrazide derivative.

[0006] Another object of the present invention is to provide a method for preparing the coumarin-based imine hydrazide derivative.

[0007] Another object of the present invention is to provide the application of the coumarin-imine hydrazine derivative in the preparation of coating film-forming aids.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a coumarin-based imine hydrazide derivative with the following structure:

[0010]

[0011] A second aspect of the present invention provides a method for preparing the coumarin-based imine hydrazide derivative, comprising the following steps:

[0012] Step 1: Synthesis of the compound represented by formula (II):

[0013]

[0014] The compound of formula (III) and hexamethylenetetramine in a molar ratio of 1:1.5 to 3 (preferably 1:2.1) are dissolved in acetic acid and refluxed at 80 to 100°C (preferably 90°C) for 1 to 12 hours (preferably 6 hours). A catalyst is added and the reaction is continued for 30 to 90 minutes (preferably 1 hour). The molar ratio of the catalyst to the compound of formula (III) is 0.01 to 1:1 to obtain the compound of formula (II).

[0015] The second step is the synthesis of the compound shown in formula (Ⅰ):

[0016]

[0017] The compounds shown in formula (II) and formula (IV) in a molar ratio of 1:1 to 3 (preferably 1:2) are dissolved in tetrahydrofuran, and a catalytic amount of acetic acid is added dropwise. The mixture is refluxed at a temperature of 55 to 80°C (preferably 65°C) for 1 to 12 hours (preferably 4 hours) to obtain the compound shown in formula (I).

[0018] The catalyst in the first step is a 20% hydrochloric acid solution.

[0019] A third aspect of the present invention provides the application of the coumarin-imine hydrazide derivative in the preparation of a coating film-forming aid.

[0020] By adopting the above technical solution, the present invention has the following advantages and beneficial effects:

[0021] This invention prepares coumarin-imine hydrazide derivatives via a Schiff base condensation reaction of 4-methyl-7-hydroxycoumarin derivatives and 4-pyridinecarboxylhydrazide. The reaction is easy to prepare and the post-processing is simple. The compounds of this invention exhibit excellent performance as film-forming aids in coatings.

[0022] The additives synthesized in this invention exhibit good performance in terms of film-forming state, film-forming time, container state, storage stability, water resistance, alkali resistance, scrub resistance, low viscosity, pulverization (grade), and color uniformity. Detailed Implementation

[0023] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0024] Example 1

[0025] The method for synthesizing the coumarin derivative molecule represented by formula (Ⅰ) in this invention is as follows:

[0026] Step 1: Synthesis of the compound represented by formula (II):

[0027]

[0028] 7-hydroxy-4-methylcoumarin (5 g, 28 mmol) and hexamine (8.7 g, 60 mmol) of formula (III) were dissolved in acetic acid (45 mL) and refluxed at 90 °C for 6 hours. Then, 1 mL of 20% hydrochloric acid solution was added to continue the reaction for 1 hour. The molar ratio of hydrochloric acid to the compound of formula (III) was 0.1:1. After the reaction was complete, the mixture was cooled to room temperature. Ice water was added, and the mixture was extracted three times with 150 mL of ethyl acetate. The organic phase was dried over anhydrous sodium sulfate, filtered, and the solvent was removed. The crude product was further purified by silica gel column chromatography using ethyl acetate / petroleum ether (v:v, 1:5) as the eluent to give the compound of formula (II) (0.84 g, yield: 14%). NMR spectral data: 1 H NMR (600MHz, DMSO) δ (ppm) 11.89 (s, 1H), 10.42 (s, 1H), 7.92 (d, 1H), 6.95 (d, 1H), 6.29 (d, 1H), 2.40 (d, 3H). 13 C NMR (151MHz, DMSO) δ (ppm) δ 191.31, 163.65, 158.85, 155.10, 153.65, 133.33, 113.51, 111.84, 111.09, 108.99, 18.29.

[0029] The second step is the synthesis of the compound shown in formula (Ⅰ):

[0030]

[0031] The compound shown in formula (II) (102.1 mg, 0.5 mmol) and 4-pyridinecarboxylhydrazine shown in formula (IV) (137.1 mg, 1 mmol) were dissolved in 15 mL of tetrahydrofuran, and two drops of acetic acid were added dropwise. The mixture was refluxed at 65 °C for 4 hours. A yellow precipitate formed during the reaction. After the reaction was completed, the mixture was cooled to room temperature, filtered, and dried to give the compound shown in formula (I) (0.143 g, yield: 88%). NMR spectral data: 1H NMR (400MHz, DMSO) δ (ppm) 12.62 (s, 1H), 12.56 (s, 1H), 9.07 (s, 1H), 8.81 (d, 2H), 7.85 (d, 2H), 7.67 (d, 1H), 6.92 (d, 1H), 6.21 (s, 1H), 2.36 (s, 3H). 13 CNMR (151MHz, DMSO) δ (ppm): 161.02, 159.13, 153.83, 152.54, 150.50, 144.74, 139.08, 128.44, 121.39, 113.35, 111.83, 110.75, 105.31, 18.35. Mass spectrometry data: MS [ESI]: m / z, calculated for [M+H] + 324.0984; found: 324.0983.

[0032] Example 2

[0033] Solution preparation

[0034] The compound shown in formula (Ⅰ) (0.0324 g, 0.1 mmol) was dissolved in propylene glycol methyl ether acetic acid (PGMEA) (5 g, 38 mmol) to form a solution for later use.

[0035] Film formation and film performance testing

[0036] The compound shown in formula (I) and the existing commercial film-forming aid - alcohol ester 12 (as a control) were applied to oil-based coatings (industrial grade, formula provided by Nippon Paint (China) Co., Ltd.) to obtain coating a (the coating prepared by compound (I)) and control coating (the coating prepared by alcohol ester 12).

[0037] The formulations of coating a and the control coating are shown in Table 1.

[0038] Table 1

[0039]

[0040]

[0041] Color-changing dyes without base color * Titanium dioxide was purchased from Shanghai Gantian Optical Materials Co., Ltd.

[0042] The film-forming time, film-forming state, water resistance, and alkali resistance of coating a and the control coating were tested. The film-forming state was tested according to the polymer cement waterproof coating GB / T 23445-2009 standard, the film-forming time was tested according to the solvent-based polyurethane coating (two-component) HG / T 2454-2006 standard, the water resistance was tested according to the HG / T3668-2009 standard, or the acrylic varnish HG / T2593-1994 standard, the alkali resistance was tested according to the building interior latex paint GB / T9756-2001 standard, and the scrub resistance was tested according to the interior wall putty JG / T3049-1998 standard, or the scrub resistance was tested according to the polyurethane waterproof coating GB / T19250-2003 standard.

[0043] The test results are shown in Table 2:

[0044] Table 2

[0045]

[0046]

[0047] As shown in Table 2, the film-forming properties (such as film-forming grade and film-forming time) of water-based coatings or inks using the coumarin-imine hydrazine derivative of the present invention as a film-forming aid are superior to those of water-based coatings or inks using the existing film-forming aid alcohol ester 12.

[0048] The film-forming state of the compound shown in Formula (I) is superior to that of alcohol ester 12, and the film-forming time of the compound shown in Formula (I) is shorter than that of alcohol ester 12. The container state of the compound shown in Formula (I) is equivalent to that of alcohol ester 12. The storage stability of the compound shown in Formula (I) is equivalent to that of alcohol ester 12. The water resistance of the compound shown in Formula (I) is equivalent to that of alcohol ester 12. The alkali resistance of the compound shown in Formula (I) is equivalent to that of alcohol ester 12. The scrub resistance (in cycles) of the compound shown in Formula (I) is superior to that of alcohol ester 12. The viscosity (grade) of the compound shown in Formula (I) is lower than that of alcohol ester 12. The powdering (grade) of the compound shown in Formula (I) is superior to that of alcohol ester 12. The color uniformity (grade) of the compound shown in Formula (I) is superior to that of alcohol ester 12.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. The application of a coumarin-based imine hydrazide derivative in the preparation of coating film-forming aids, characterized in that, The structure of the coumarin-imine hydrazide derivative is shown below: 。

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