EP-3914668-B1 - NEAR INFRARED LUMINESCENT MATERIAL EXCITED BY NEAR INFRARED RAY

Inventors

• KIM, SHI SURK
• KIM, SI BO
• LEE, SANG GEUN

Dates

Publication Date

20260513

Application Date

20200122

Claims (6)

1. A luminescent material which is a compound expressible by the following chemical formula: Yb a Y x V y Si z O 4 : M where, 0 < a ≤ 1, 0 < X ≤ 1, 0 < Y ≤ 1, 0 < Z ≤ 1, M is Nd 3+ or Er 3+ , and 0 weight% < M ≤ 0.01 weight%.
2. The luminescent material of claim 1, wherein the compound of luminescent material expressible by the formula is excited by IR (Infrared) to emit an IR ray.
3. A forgery/alteration preventive security ink containing the luminescent material of claim 1, wherein the ink includes 0.1 ~ 25 weight% of the luminescent material based on a total weight of the ink.
4. A printed matter containing the luminescent material of claim 1, wherein the printed matter includes 0.1 ~ 25 weight% of the luminescent material based on a total weight of the printed matter, and the luminescent material is printable as a printing object on printing material of paper or polymeric film.
5. A printing material of paper or polymeric film containing the luminescent material of claim 1, wherein the printing material of paper or polymeric film includes 0.1 ~ 25 weight% of the luminescent material based on a total weight of the printing material of paper or polymeric film.
6. The said paper of claim 5, wherein the paper is selected from a group consisting of bank note paper, gift card paper and general paper, and the polymeric film is selected from a group consisting of polycarbonate, polyester, polyethylene, polypropylene, ABS (acrylonitrile butadiene styrene) and SAN (styrene-acrylonitrile).

Description

Technical Field The teachings in accordance with exemplary and non-limiting embodiments of this invention relate generally to near infrared luminescent material excited by near infrared ray and method of manufacturing the same, and more particularly, to a near infrared luminescent material excited by a light of near infrared ray region and luminescent of infrared light, and a method of manufacturing the same. Background Art The fluorescent material printed on bank notes or checks for anti-forgery of domestic and foreign bank notes for being luminescent of fluorescent light by ultraviolet light can be a bit easily obtained by anybody who has interest therein, consistent with overall progress of industrial technologies, and may be utilized by a UV lamp whereby the fluorescence printed on bank notes can be easily ascertained, and the trend is that magnetic ink is also commonly used on conventional printed materials, and therefore, it can be said that there is room for the fluorescent material to be used for forgery. Thus, in order to prevent forgery of special printed materials such as bank notes, negotiable securities and other security documents, it can be expected that forgery prevention and authenticity may be established when non-visible luminescent material which emits infrared rays invisible in light emission to naked eyes is printed on special printed materials including bank notes and negotiable securities in a small area within 10mm2. The Korean Laid-Open Patent Application No. 1998-027003 (July 15, 1998) of prior art relates to "Non-visible luminescent material and method thereof", disclosing a non-visible luminescent material having a molecular formula of Y2SiV2O10:Nd+3, Er+3 and manufacturing method thereof, in which yttrium compound, silicone compound and vanadium compound oxide are used as matrix, and Nd2O3 and Er2O3 are added thereto as an activation agent, and equally mixed, plasticized for 3-5 hours under 600-700°C in oxidative atmosphere as a first step reaction, pulverized to a diameter of 5-15µm, and as a second step reaction, the pulverized material is plasticized to a diameter of 2-4µm for 3-5 hours under 1000-1200°C, and as a third step reaction, the second step reactant is plasticized for 1-3 hours under 500-700°C for 1-3 hours and crushed to the size of about 1µm. The said prior art of Korean application failed to disclose the configuration of infrared luminescent material excited by infrared ray, although a configuration of emitting infrared light when irradiated by UV light and visible light is disclosed. Furthermore, the Korean Laid-Open patent application No. 2010-0110068 of prior art relates to "luminescent material and manufacturing method thereof", and discloses the light characteristic of emitting a light excited by visible light, and the Korean registered patent application No.1238197 relates to "non-visible luminescent material and manufacturing method thereof" and discloses luminescent material excited by a light of UV ray region to emit a light of infrared ray region. In addition, the Korean registered patent application No. 0959362 relates to "luminescent material and manufacturing method thereof", and discloses that, because there has been difficulty in mass production of luminescent materials excited by visible light to emit infrared ray such as Gd2O2S:Er(1550 nm), NaYW2O6:Er (1550 nm), CaF2:Er,Yb(980 nm, 1550 nm) due to low yield, and difficulty in cohesion and powderization, calsium in CaMoO4 luminescent material is partially replaced by magnesium or zinc, in order to solve these problems, and one or two species of lanthanide metals selected from a group consisting of Nd3+, Yb3+ and Er3+ are used as activation agents to manufacture luminescent material excellent in luminescent characteristics emitting an infrared light excited by visible light. However, the prior patents also failed to disclose a luminescent material excited by infrared ray. Thus, needs to develop a low-cost, detection sensitivity-excellent infrared or near infrared luminescent material concurrently useable as silicon and InGaAs detector are requested, configured to be excited by a light of infrared or near infrared ray region to thereby emit a light of infrared or near infrared ray for use as a commercialized infrared LED light source. US 9 409 434 B2 discloses a silicate luminescent material according to the general formula Y2-5z(Nd1Yb4)zSiO5, for use in a security feature. Disclosure of invention Technical Problem Therefore, it is an object of the present invention to provide a near infrared luminescent material excited by near infrared ray for emission of a light of near infrared ray. It is another object of the present invention to provide a near infrared luminescent material excited by near infrared ray and adequate for prevention of forgery and alteration, and a method of manufacturing the same. Solution to Problem In one general aspect of the present invention, there is provided a luminescent