CN1237130C - Friction luminous antiforge printing ink and mfg. method thereof - Google Patents

Abstract

The invention discloses a triboluminescent anti-counterfeiting ink and a manufacturing method thereof. Process the triboluminescent material into a powder with a particle size of no more than 5 μm, remove the ultraviolet fluorescence characteristics of the material, and then chemically or physically coat the triboluminescent material powder, and coat the particle surface with a layer of moisture-resistant and acid-resistant Protective film made of strong material, and then put triboluminescent material into printing ink in a certain proportion to make anti-counterfeiting ink. The invention also discloses an improved CVD method for forming a silicon dioxide film on the surface of the triboluminescent material powder, which is chemical treatment. The triboluminescent anti-counterfeit ink produced by the above method does not emit fluorescence under the irradiation of ultraviolet lamps, has stable chemical and physical properties and long service life, and can be used for printing anti-counterfeit marks of banknotes and securities.

Description

Triboluminescent anti-counterfeiting ink and manufacturing method thereof

technical field

The invention relates to a triboluminescent anti-counterfeiting ink for printing and a manufacturing method thereof.

Background technique

British Patent GB2232119A discloses a method of putting triboluminescent material into printing ink in a certain proportion to make anti-counterfeiting ink for printing valuable securities. However, the triboluminescent material has orange fluorescence under the ultraviolet lamp, and there are usually many kinds of anti-counterfeiting marks on the banknotes and securities. A coating containing an ultraviolet absorber is printed on the triboluminescent material, which increases the printing process and difficulty. And because the triboluminescent material used in this technology has poor moisture resistance and acid resistance, the triboluminescent function of the material is easily weakened or disappeared under normal use conditions, which affects the use.

Contents of the invention

Aiming at the problems existing in the prior art, the object of the present invention is to provide a triboluminescent anti-counterfeiting ink which does not emit ultraviolet fluorescence under the irradiation of an ultraviolet lamp, and is strong in moisture resistance and acid resistance. The present invention further provides a method for manufacturing the triboluminescent anti-counterfeiting ink.

In order to achieve the above object, the present invention provides a triboluminescent anti-counterfeiting ink, which is composed of a triboluminescent material and an ink. The triboluminescent material is ZnS:Mn with a particle size not greater than 5 μm, and the triboluminescent material accounts for The ratio is 15%-60% by weight, and the surface of the triboluminescent material particles is coated with a protective film made of a material with strong moisture resistance and acid resistance.

Further, the protective film on the surface of the triboluminescent material is silicon dioxide.

A method for making a triboluminescent anti-counterfeiting ink whose protective film is silicon dioxide comprises the following steps:

(1) Process the triboluminescent material into a powder with a particle size not greater than 5 μm by jet milling or ball milling;

(2) Put the triboluminescent material powder into a high-temperature vacuum furnace capable of high-speed vibration, and evacuate the vacuum furnace to 0.1-0.28Pa, then fill the vacuum furnace with nitrogen, and the nitrogen input flow rate is 80-100ml/min ;

(3) The vacuum furnace is heated to 800-1000° C., and it starts to vibrate, and the vibration acceleration is 6-15m/s ² ;

(4) Input SiCl ₄ high-purity gas and water vapor into the vacuum furnace simultaneously through two pipelines, the input flow rate of SiCl ₄ high-purity gas is 50-70ml/min, and the input flow rate of water vapor is 70-90ml/min ;

(5) The reaction lasts for 30-120 minutes, and the gas reacts on the surface of the triboluminescent material to form a silicon dioxide film. The chemical reaction equation is: ;

(6) After the reaction reaches the predetermined time, stop heating and vibration, stop inputting reaction gas, and keep nitrogen input;

(7) When the vacuum furnace is cooled to room temperature, stop inputting nitrogen, put the atmosphere into the vacuum furnace, and take out the treated triboluminescent material;

(8) Finally, put 15%-60% triboluminescent material into the printing ink by weight, mix well to make triboluminescent anti-counterfeiting ink.

Since the triboluminescent material is processed to be below 5 μm, its fluorescence intensity is only 10% of the original under the irradiation of the ultraviolet lamp, which is extremely weak and negligible, and will not interfere with the ultraviolet recognition, so there is no need to print the ultraviolet absorber coating At the same time, the surface is covered with a silicon dioxide film with stable physical and chemical properties, which improves the moisture resistance and acid resistance of the triboluminescent material, thus greatly improving its service life.

Detailed ways:

Example 1

Firstly, the triboluminescent material is processed into a powder with a particle size of less than 5 μm by airflow pulverization or ball milling to remove the ultraviolet fluorescence characteristics of the material; then the triboluminescent material powder is loaded into a high-temperature vacuum furnace capable of high-speed vibration, and Vacuumize the vacuum furnace to 0.1Pa, then fill it with nitrogen, and the nitrogen input flow rate is 80ml/min; raise the temperature of the vacuum furnace to 800°C, and start to vibrate, with a vibration acceleration of 6m/s ² ; then pass through two pipelines at the same time Input SiCl ₄ high-purity gas and water vapor into the vacuum furnace, the input flow rate of SiCl ₄ high-purity gas is 50ml/min, and the input flow rate of water vapor is 70ml/min; the reaction lasts for 30 minutes, and the waste gas is discharged after purification and reaches the predetermined After a certain time, stop heating, vibrating and inputting reaction gas, and keep nitrogen input; after natural cooling to room temperature, stop inputting nitrogen, put into the atmosphere, take out the treated triboluminescent material; finally put 15% triboluminescent material into Add it to the printing ink and mix it well to make triboluminescent anti-counterfeiting ink.

Example 2

Put the triboluminescent material powder with a particle size of 5 μm or less into a high-temperature vacuum furnace; vacuumize to 0.2Pa, nitrogen flow rate is 120ml/min; heat up to 900°C; start vibration, and the vibration acceleration is 10m/s ² ; Then input SiCl ₄ high-purity gas and water vapor, the flow rates of SiCl ₄ high-purity gas and water vapor are 60ml/min and 80ml/min respectively, and the reaction lasts for 75 minutes. Adding 35% triboluminescence material into printing ink by weight makes triboluminescence anti-counterfeiting ink.

Example 3

Put the triboluminescent material powder with a particle size of 5 μm or less into a high-temperature vacuum furnace, evacuate to 0.28Pa, nitrogen flow rate is 150ml/min, heat up to 1000°C, vibration acceleration is 16m/s ² , and then input SiCl ₄ high-purity gas and water vapor, SiCl ₄ high-purity gas and water vapor flow rates are 70ml/min and 90ml/min, and the reaction lasts for 120 minutes. Putting 60% triboluminescence material into printing ink by weight to prepare triboluminescence anti-counterfeiting ink.

In the above-mentioned embodiments, the higher the vacuum degree in the furnace is, the higher the nitrogen concentration is, the more stable the environment of the chemical reaction is, the higher the vibration acceleration is, the more fully the surface of the triboluminescent material particles is in contact with the reaction gas, and the secondary gases generated by the reaction of the gas on the powder surface The better the quality of the silicon oxide film, the better the thickness of the film, and determine the duration of the reaction to obtain a uniform and firm film layer.

Example 4

Stir the suspension of aluminum isopropoxide at 80°C for 30 minutes, then add a small amount of nitric acid (nitric acid is a catalyst for gel formation), boil for 24 hours to form a slightly cloudy solution, and then add ZnS:Mn with a particle size of no more than 5 μm powder, after evaporating for 30 minutes under stirring, the suspension forms a gel, and the gel is dried at 110°C for 24 hours to form a ZnS:Mn powder coated with an aluminum oxide film on the surface, 40% by weight The triboluminescent material is put into printing ink to make triboluminescent anti-counterfeiting ink.

Example 5

Add ZnS:Mn powder with a particle size not greater than 5 μm into a solution of 2.5% polymer (polymethacrylic acid, polyvinylpyrimidine and its derivatives, polyethyleneimine, polyethylene oxide, etc.), and stir the mixture 60 minutes, to ensure that the ZnS:Mn powder was wetted, then filtered, and the filter cake was dried at 140°C for a period of time to obtain the ZnS:Mn powder with a polymer film on the surface, and 35% triboluminescent material was added by weight Put it into printing ink to make triboluminescent anti-counterfeiting ink.

Claims (3)

1. The triboluminescence anti-counterfeiting ink is characterized in that the triboluminescence material is ZnS: Mn with the particle size of not more than 5 mu m, the triboluminescence material accounts for 15-60 wt% in the ink, and the surface of the triboluminescence material particle is coated with a protective film made of a material with high moisture resistance and acid resistance.

2. The triboluminescent security ink according to claim 1, wherein the protective film on the surface of the triboluminescent material is silica.

3. A method of making the triboluminescent security ink of claim 2, comprising the steps of:

(1) processing the triboluminescence material into powder with the diameter not more than 5 μm by using a jet milling method or a ball milling method;

(2) filling the friction luminescent material powder into a high-temperature vacuum furnace capable of vibrating at a high speed, vacuumizing the vacuum furnace to 0.1-0.28Pa, and then filling nitrogen into the vacuum furnace, wherein the input flow of the nitrogen is 80-100 ml/min;

(3) heating the vacuum furnace to 800-1000 ℃ and starting vibration with the vibration acceleration of 6-15m/s²；

(4) Then simultaneously inputting SiCl into the vacuum furnace through two pipelines₄High purity gas and water vapor, SiCl₄The input flow rate of the high-purity gas is 50-70ml/min, and the input flow rate of the water vapor is 70-90 ml/min;

(5) the reaction lasts for 30-120 minutes, the gas reacts on the surface of the friction luminescent material to generate a silicon dioxide film, and the chemical reaction equation is as follows: ；

(6) after the reaction is carried out for a preset time, stopping heating and vibrating, stopping inputting reaction gas, and keeping inputting nitrogen;

(7) stopping inputting nitrogen when the vacuum furnace is cooled to room temperature, putting the atmosphere into the vacuum furnace, and taking out the treated friction luminescent material;

(8) and finally, putting 15-60% of friction luminescent material by weight into the printing ink, and fully mixing to prepare the friction luminescent anti-counterfeiting ink.