CN106978013B - Ink capable of generating different fluorescence at different temperatures, and preparation method and application thereof - Google Patents

Abstract

The application discloses ink capable of generating different fluorescence at different temperatures, a preparation method and application thereof, wherein the ink comprises basic components consisting of water, tetrahydrofuran, acetonitrile and acetone; an organic compound selected from one or more of a silacyclopentadiene derivative, a cyclic polyene compound, a substituted ethylene compound, a nitrile substituted stilbene compound, a pyran compound and a biphenyl compound, wherein the mass ratio of the organic compound to the basic component is 0.04-0.07; the water-soluble quantum dot comprises an In/S/Zn/Cu alloy, and the mass ratio of the water-soluble quantum dot to a base component is 0.02-0.04. The ink obtained by the invention has no exciting light in a fluid state, but can generate green light with the wavelength of 480-490 nm under the irradiation of light of ultraviolet light at normal temperature (15-25 ℃) after a solvent is removed to form a solid phase; meanwhile, when the temperature of the solid-phase ink is raised to 60-80 ℃, red light with the wavelength of 620-650 nm can be generated under the irradiation of ultraviolet light.

Description

Ink capable of generating different fluorescence at different temperatures, and preparation method and application thereof

Technical Field

The application relates to ink capable of generating different fluorescence at different temperatures, a preparation method and application thereof, and the ink can be applied to anti-counterfeiting marks.

Background

With the proliferation of information, the secure and accurate identification of information has become a topic of widespread social attention today. The existing safety identification technology generally has various technical defects of complex manufacturing process, high price, poor precision, easy cracking, instability, easy interference by external factors and the like, and can not meet the requirement of the safety development of the information in the current society. In the case of two-dimensional bar codes, etc., the printed matter can be visually observed and can be easily reproduced using an easily available desktop copier or printer.

The anti-counterfeit ink is used to form a security mark to achieve the objectives of easy verification and anti-counterfeit, and is becoming one of the more and more favored ways in the industry. The anti-counterfeiting ink is special printing ink which is prepared by adding anti-counterfeiting material with special performance into an ink vehicle and processing the anti-counterfeiting material by a special process, and has the advantages of good stability, convenience in printing, low cost, convenience in identification, high reliability, good concealment and the like. The traditional anti-counterfeiting ink is usually prepared by dispersing a fluorescent material with a specific excitation wavelength in a solvent and then adding other materials such as resin and the like. However, with the progress and popularization of the technology, counterfeiters can conveniently prepare the anti-counterfeiting ink and can forge high-quality counterfeits by using digital cameras, scanners, printers and the like. This also makes the industry more demanding for security inks.

Disclosure of Invention

The invention aims to provide ink capable of generating different fluorescence at different temperatures, a preparation method and application thereof, so as to overcome the defects in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme:

the embodiment of the application discloses ink capable of generating different fluorescence at different temperatures, which comprises:

the base component consists of water, tetrahydrofuran, acetonitrile and acetone, wherein the weight ratio of water: tetrahydrofuran: acetonitrile: the mass ratio of acetone is (1-2): (0.4-1): (0.2-1): 0.7-1.2);

an organic compound selected from one or more of a silacyclopentadiene derivative, a cyclic polyene compound, a substituted ethylene compound, a nitrile substituted stilbene compound, a pyran compound and a biphenyl compound, wherein the mass ratio of the organic compound to the basic component is 0.04-0.07;

the water-soluble quantum dot comprises an In/S/Zn/Cu alloy, and the mass ratio of the water-soluble quantum dot to a base component is 0.02-0.04.

Preferably, in the above-described ink producing different fluorescence at different temperatures, the ratio of water: tetrahydrofuran: acetonitrile: the mass ratio of acetone is 1:0.4:0.8: 1; the mass ratio of the organic compound to the basic component is 0.05; the mass ratio of the water-soluble quantum dots to the basic component is 0.04.

Correspondingly, the application also discloses a preparation method of the ink capable of generating different fluorescence at different temperatures, which comprises the following steps:

(1) and preparing a basic component: dissolving tetrahydrofuran in water under a stirring condition, heating to 40-60 ℃, preserving heat for 10-15 min, adding acetonitrile, continuously heating to 70-80 ℃, stirring and mixing for 10-15 min, and finally dripping acetone under a stirring state;

(2) uniformly dispersing an organic compound in the basic component, and continuously stirring for 0.5-1 hour at the temperature of 80-100 ℃ to obtain a first mixture;

(3) and preparing the water-soluble quantum dots:

dissolving zinc diethyldithiocarbamate and tri-n-octylphosphine in octadecene to obtain a 12-15 mmol/L original solution;

mixing CuI and InI₃Dissolving in oleylamine, and adding to the original solution to obtain a mixed solution, wherein CuI and InI₃The molar ratio of (1-2): 1;

adding dodecyl mercaptan into the mixed solution, heating to 180-220 ℃, wherein the volume ratio of the dodecyl mercaptan to the oleylamine is 1 (2-2.4), and obtaining a second mixed solution;

dispersing sulfur powder with the purity of 99.99% in an octadecene solution with the concentration of 85-90% to obtain a precursor solution, wherein the sulfur content in the precursor solution is 2-3 mol/L;

adding the precursor solution into the second mixed solution, stirring and reacting for 20-30 min at 80-100 ℃, then cooling to room temperature, and carrying out centrifugal precipitation to obtain quantum dots;

dissolving 92-95% of sulfydryl undecanoic acid in a methanol solution, wherein the content of sulfydryl undecanoic acid is 0.3-0.4 g/mL, adjusting the pH value to 8-9, then adding quantum dots and a toluene solution, heating to 80-100 ℃, stirring for 1-2 hours, and performing centrifugal precipitation to obtain water-soluble quantum dots;

(4) and adding the water-soluble quantum dots into the first mixture, and continuously stirring for 0.5-1 hour at the temperature of 80-100 ℃ to obtain the ink.

The application also discloses a fluorescent anti-counterfeiting coating, and the ink capable of generating different fluorescence at different temperatures is adopted.

Preferably, in the above method for preparing a fluorescent anti-counterfeiting coating, the ink is formed on the substrate by a printing or coating method, and then the volatile substances are removed by air drying or baking, so as to obtain a solid anti-counterfeiting fluorescent layer.

Preferably, in the above method for preparing a fluorescent anti-counterfeiting coating, the printing includes letterpress printing, intaglio printing, lithography, screen printing and inkjet printing.

Compared with the prior art, the invention has the advantages that:

(1) when the ink is in a fluid state, no exciting light is generated, but after the solvent is removed to form a solid phase, the ink can generate green light with the wavelength of 480-490 nm under the irradiation of light of ultraviolet light at normal temperature (15-25 ℃);

(2) meanwhile, when the temperature of the solid-phase ink is raised to 60-80 ℃, red light with the wavelength of 620-650 nm can be generated under the irradiation of ultraviolet light;

(3) the fluorescent coating made of the ink has the luminous efficiency of over 68 percent, and the fluorescent effect can still keep good effect underwater.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 shows a photograph of a fluorescent coating after excitation in an embodiment of the present invention.

Detailed Description

As described above, in view of the disadvantages of the prior art, the present inventors have conducted long-term research and extensive practice in an attempt to solve these problems. In the research process, the inventor of the present invention has surprisingly found that:

when the solvent in the ink containing the uniformly dispersed organic compound is removed, the formed solid phase substance can generate fluorescence, and the solid phase substance can be excited to emit green light with the wavelength of 480-490 nm by adjusting the using amounts of water, acetonitrile, acetone and tetrahydrofuran and the drying temperature of the ink.

In addition, when the temperature of the solid-phase ink is raised to 60-80 ℃, red light with the wavelength of 620-650 nm can be generated under the irradiation of ultraviolet light.

The invention is further illustrated by the following examples: the invention will be better understood from the following examples. However, those skilled in the art will readily appreciate that the specific material ratios, process conditions and results thereof described in the examples are illustrative only and should not be taken as limiting the invention as detailed in the claims.

The preparation method of the ink comprises the following steps:

(1) and preparing a basic component: dissolving tetrahydrofuran in water under the stirring condition, heating to 60 ℃, preserving heat for 15min, adding acetonitrile, continuously heating to 70 ℃, stirring and mixing for 12 min, and finally dripping acetone under the stirring state, wherein the weight ratio of tetrahydrofuran: acetonitrile: the mass ratio of acetone is 1:0.4:0.8: 1;

(2) uniformly dispersing an organic compound in a basic component, and continuously stirring for 1 hour at the temperature of 80 ℃ to obtain a first mixture, wherein the organic compound comprises a cyclic polyene compound, a pyran-type compound and a biphenyl-type compound, the mass ratio of the organic compound to the basic component is 1:1:2.2, and the mass ratio of the whole organic compound to the basic component is 0.05;

(3) and preparing the water-soluble quantum dots:

dissolving zinc diethyldithiocarbamate and tri-n-octylphosphine in octadecene to obtain 15mmol/L of original solution;

mixing CuI and InI₃Dissolving in oleylamine, and adding to the original solution to obtain a mixed solution, wherein CuI and InI₃In a molar ratio of 1: 1;

adding dodecyl mercaptan into the mixed solution, heating to 200 ℃, wherein the volume ratio of the dodecyl mercaptan to the oleylamine is 1:2.2, and obtaining a second mixed solution;

dispersing sulfur powder with the purity of 99.99% in octadecene solution with the concentration of 90% to obtain precursor solution, wherein the content of sulfur in the precursor solution is 2 mol/L;

adding the precursor solution into the second mixed solution, stirring and reacting for 30min at 80 ℃, then cooling to room temperature, and carrying out centrifugal precipitation to obtain quantum dots;

dissolving mercaptoundecanoic acid with the mass concentration of 95% in a methanol solution, wherein the content of mercaptoundecanoic acid is 0.4g/mL, adjusting the pH value to 9, then adding quantum dots and a toluene solution, heating to 90 ℃, stirring for 1 hour, and performing centrifugal precipitation to obtain water-soluble quantum dots;

(4) and adding the water-soluble quantum dots into the first mixture, and continuously stirring for 1 hour at the temperature of 80 ℃ to obtain the ink, wherein the mass ratio of the water-soluble quantum dots to the base component is 0.04.

The prepared ink was applied to white paper by ink-jet printing and dried at a temperature of 50 ℃ for 1 hour to form a solid-phase coating.

The ultraviolet lamp is used as a light source, the ink and the solid-phase coating are respectively irradiated at normal temperature, fluorescence of the ink and the solid-phase coating is respectively detected, and it can be seen that the ink in a non-solid phase has no exciting light, and green light with the wavelength of 480-490 nm is generated under the excitation of ultraviolet light of the solid-phase coating.

Raising the ambient temperature to 60-80 ℃, and generating red light with the wavelength of 620-650 nm under the light irradiation of ultraviolet light.

In summary, the present invention also includes at least the following advantages: the luminescent ink has the advantages of simple preparation process, cheap and easily-obtained raw materials, low cost and good controllability, and for example, the luminescent property of the obtained luminescent ink after curing can be effectively regulated and controlled by regulating the content range of organic compounds or basic components in the ink, the drying temperature of the ink and the like, thereby being beneficial to large-scale production and application.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Claims (2)

1. A method for preparing ink capable of generating different fluorescence at different temperatures is characterized by comprising the following steps:

(1) and preparing a basic component: dissolving tetrahydrofuran in water under a stirring condition, heating to 40-60 ℃, preserving heat for 10-15 min, adding acetonitrile, continuously heating to 70-80 ℃, stirring and mixing for 10-15 min, and finally dripping acetone under a stirring state, wherein the water: tetrahydrofuran: acetonitrile: the mass ratio of acetone = (1-2): (0.4-1): (0.2-1): 0.7-1.2);

(2) uniformly dispersing an organic compound in a basic component, and continuously stirring for 0.5-1 hour at the temperature of 80-100 ℃ to obtain a first mixture, wherein the organic compound is one or more of a silicon heterocyclic cyclopentadiene derivative, a cyclic polyene compound, a substituted ethylene compound, a nitrile substituted stilbene compound, a pyran compound and a biphenyl compound, and the mass ratio of the organic compound to the basic component is 0.04-0.07;

(3) and preparing the water-soluble quantum dots:

dissolving zinc diethyldithiocarbamate and tri-n-octylphosphine in octadecene to obtain a 12-15 mmol/L original solution;

mixing CuI and InI₃Dissolving in oleylamine, and adding to the original solution to obtain a mixed solution, wherein CuI and InI₃The molar ratio of (1-2): 1;

adding dodecyl mercaptan into the mixed solution, heating to 180-220 ℃, wherein the volume ratio of the dodecyl mercaptan to the oleylamine is 1 (2-2.4), and obtaining a second mixed solution;

dispersing sulfur powder with the purity of 99.99% in an octadecene solution with the concentration of 85-90% to obtain a precursor solution, wherein the sulfur content in the precursor solution is 2-3 mol/L;

adding the precursor solution into the second mixed solution, stirring and reacting for 20-30 min at 80-100 ℃, then cooling to room temperature, and carrying out centrifugal precipitation to obtain quantum dots;

dissolving 92-95% of sulfydryl undecanoic acid In a methanol solution, wherein the content of sulfydryl undecanoic acid is 0.3-0.4 g/mL, adjusting the pH value to 8-9, then adding quantum dots and a toluene solution, heating to 80-100 ℃, stirring for 1-2 hours, and performing centrifugal precipitation to obtain water-soluble quantum dots, wherein the water-soluble quantum dots contain In/S/Zn/Cu alloy, and the mass ratio of the water-soluble quantum dots to the basic component is 0.02-0.04;

(4) and adding the water-soluble quantum dots into the first mixture, and continuously stirring for 0.5-1 hour at the temperature of 80-100 ℃ to obtain the ink.

2. The method of claim 1, wherein the ratio of water: tetrahydrofuran: acetonitrile: the mass ratio of acetone =1:0.4: 0.8: 1; the mass ratio of the organic compound to the basic component is 0.05; the mass ratio of the water-soluble quantum dots to the basic component is 0.04.

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