RU2323955C1 - Water-resistant fluorescent pigment and fluorescent ink based thereon - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: water-resistant fluorescent pigment is an oxide matrix based on aluminium oxide and, at least, one of the following elements: Mg, Са, Sr, Ва, Zn, Mn, Si, В, Р, Ga, activated with, at least, single rare earth element, treated with a mixture of salts from the following group: Na₃PO₄, Na₂HPO₄, (NH₄)₂HPO₄, Ca₃(PO₄)₂, with acids from the following group: HCl, H₂SO₄, HNO₃, pH not exceeding 4 at the end of treatment. Oxide matrix may be of formula MO-SiO₂Al₂O₃:R, where М stands for, at least, a single metal from the following group: Ca, Sr, Ba, Mg, Zn; R stands for, at least, a single element from the following group: Dy, Nd, Eu, Tm, Tb, Y, Yb; MAl₂O₄:R, where М stands for, at least, a single metal from the following: Ca, Sr, Mg, Ba, while R stands for, at least, a single element from the following: Dy, Nd, Eu, Tm, Tb, Y, Yb; MAlO₄:R, where М stands for, at least, a single metal from the following: Sr, Ca, Ba; R stands for, at least, a single element from the following group: Dy, Nd, Eu, Tm, Tb, Y, Yb. Ink contains the said fluorescent pigment and thickening agent.

EFFECT: water-resistant at room or elevated temperature, fluorescent properties being retained.

5 cl, 5 tbl, 57 ex

Description

The present invention relates to the field of luminescent pigments and inks for printing with their use.

In particular, the invention relates to the creation of water-resistant and weather-resistant luminescent pigments (phosphors) belonging to the class of aluminates that can be used for the manufacture of emergency and autonomous lighting systems, evacuation signs, workwear elements, road lighting, advertising, etc.

Currently, there is an increasing interest in the use of phosphors. They can be used in photoluminescent materials such as surface coatings, plastics, ceramic tiles, coatings for glass and enamel.

Phosphors are used in warning signs when designating safe passageways in rocks, metro stations, tunnels, public buildings, in fencing of dangerous places in ports, airports, and industrial territories.

There is an increasing need for protection against counterfeiting of banknotes, credit cards, passports and other documents and securities.

Phosphors are used when creating signs indicating the exit, and other forms of marking, in road signs, vests and jackets for workers.

For all these purposes, luminescent pigments are used, in particular the so-called glow in the dark pigments - glowing in the dark.

It is known that the market for signs visible in a fire, power outage, and evacuation, for example, in New York, doubles annually.

Due to the fact that both in our and foreign literature there is an inadequate use of terminology in relation to luminescent pigments, which makes it difficult to evaluate technical solutions, including those proposed for patenting, the following terminology is given from the work:

“Chemistry and Physics of Special-Purpose Pigments, Dyes, Printing Inks, and Coating Inks” A.Nurhan Becidyan [United Mineral & Chemical Corp, Paint Coating Industry, 06/15/2003]

Luminescence: fluorescence and phosphorescence.

Luminescent dye (pigment) - a substance that emits light (visible, UV or IR) with appropriate excitation, without heating.

Excitation is an active reason forcing a luminescent dye to emit light.

Fluorescence - the emission of light by a luminescent pigment in the presence of excitation (for example, fluorescence in daylight).

Phosphorescence is the emission of light by a luminescent pigment after excitation has ceased (for example, glow in the dark).

In fact, luminescent pigments glowing in the dark, in accordance with the above terminology, should more correctly be called phosphorescent pigments (phosphors). Both names are used in the literature. In the description we used the term luminescent pigments (as well as in the patent prototype).

There are many types of energy that certain luminescent pigments can absorb and convert to luminescence (radioactivity, x-ray radiation, cathode radiation, mechanical stress, electricity, UV, visible or infrared radiation).

Inorganic luminescent pigments called phosphors differ from fluorescent pigments in that they are mostly colorless or pale pastel colored, but when excited by UV radiation, they begin to fluoresce quite brightly.

Classical inorganic fluorescent pigments were created on the basis of zinc sulfide and zinc sulfide - cadmium.

ZnS: Cu is the most widely used phosphor of this class. The material is relatively inexpensive and has moderate resistance to hydrolysis at ordinary temperatures and in the absence of light.

However, this material has significant drawbacks and limitations. In particular, it has a low brightness of the initial afterglow and a short afterglow period.

In addition, its disadvantage is its low resistance to light and, in particular, to UV radiation, and therefore it is not suitable in cases requiring a long exposure outdoors.

To improve the pigments, attempts have been made to introduce radioactive substances into their composition, but their use is extremely limited due to the harmful effects on the human body, since the radioactive effect cannot be neglected.

Therefore, pigments were developed that have a long glow period in the dark, based on metal oxides with the addition of rare earth elements.

The second generation of light-accumulating phosphors is based on the use of aluminates of the second main subgroup of the Periodic system of elements (Ca, Sr, Ba) O: Al ₂ O ₃ .

There are a number of patents that describe luminophores based on aluminates with various compositions and crystal-chemical structures.

RF patent No. 2192444 proposes a phosphor based on calcium and strontium aluminates activated by manganese, europium, dysprosium and / or neodymium, as well as an additional activator of Mg and Y of the general chemical formula:

Me _1-xy Mn _x Eu _y (Al _1-qz YqLn _z ) ₂ O ₄ ,

where Ln is Nd and / or Dy

Me is a combination of Sr - Mg and Ca - Mg,

0.001 <x≤0.002

0.01 <y≤0.05

0.005 <z≤0.05

0.005 <q≤0.05, with the ratio y / (x + z) = 1: 2-2: 1

In the patent of the Russian Federation No. 2194736 a photoluminophore with ultra-long afterglow is described, containing aluminum oxide, silicon oxide, oxide of the elements of the main subgroup of the second group of the Periodic system of elements and a rare-earth element, while it additionally contains oxide of the element of the fourth group with a molecular ratio of MeO: Al ₂ O ₃ : MeO ₂ : SiO ₂ = 3: 1: 2: 1.

The description of the patent states that the phosphor can be used, in particular, for special clothing, clothing for schoolchildren and divers.

In the patent of the Russian Federation No. 2217467 a stable photoluminophore with a long afterglow of the general formula is described:

(SrO) _1-x-2y-z (EuO) _x (Ln ₂ O ₃ ) _y (Me ₂ O) _z (Al ₂ O ₃ ) _1-q (B ₂ O ₃ ) _q

where Ln is Dy or Nd

Me - Na, K, Li

x = 0.005-0.1

y = 0.005-0.1

z = 0.002-0.1

q = 0.005-0.1

The description of the patent states that the new phosphor can find application, in particular, for special clothing and that it has increased moisture resistance compared to known phosphors, largely due to the introduction of Na.

RF patent No. 2236434 describes a photon-accumulating phosphor based on strontium-magnesium aluminate activated by at least europium (Eu), dysprosium (Dy), neodymium (Nd), and manganese oxide is additionally introduced into the cationic sublattice, and cerium oxide in the form of Ce ₂ O ₃ forming the general stoichiometric formula:

Mg _1-xyz Sr _x Eu _y ²⁺ Mnz ²⁺ (ΣTR) _p Al _q O ₄ ,

where ΣTP = Dy, Nd, Ce,

x = 0.80-0.96

y = 0.001-0.03

z = 0.005-0.010

p = 0.01-0.05

1.99 <q <2.05 atomic fractions

The description indicates that the phosphor is weather and water resistant and that various varnishes and polymer compositions are made from it for use in printing and silkscreen printing.

In US Pat. No. 5,424,006, an aluminate phosphor is introduced to increase the afterglow duration in addition to the activator - europium, the second rare-earth element selected from the group: dysprosium, cerium, neodymium, erbium, lanthanum, praseodymium, samarium, gadolinium, holmium, thulium, ytterbium lutetium, tin and bismuth.

The phosphor has the composition:

MAl ₂ O ₄ , where M is at least one metal selected from the group consisting of Ca, Sr, or Ba.

The disadvantages of such phosphors are low resistance to the aquatic environment and to high ambient temperatures.

In addition, the technology for producing these phosphors requires very high temperatures during their synthesis, which increases the cost of the final product and reduces the reproducibility of their lighting characteristics.

A disadvantage of aluminate phosphors is their instability to moisture, which is noted both in the literature and in patent descriptions.

The analysis of patent descriptions allows us to distinguish two main directions in solving the problem of increasing the stability of phosphors to moisture.

The first is to change the composition and / or structure of the phosphor. For example, according to US patent No. 5665793 elimination of hydrolytic instability contributes to the additional introduction of Al ₂ About ₃ . Changing the formula composition compared with US patent No. 5424006 allowed to increase hydrolytic stability, but at the same time decreased light efficiency.

In US patent No. 6117362 in the composition of the phosphor additionally introduced elements of the second (Zn, Mg) and third (B) groups.

Compared with the previous one, the luminous efficiency increases, but the properties deteriorate upon contact with water.

In accordance with RF patent No. 2217467, hydrolytic activity can be reduced by introducing monovalent alkali metal atoms into the lattice. It is assumed that the increase in hydrolytic stability occurs due to the filling of the voids of the crystal lattice, as well as due to a change in the type of crystal lattice. This approach is limited to a small class of structures and is not universal. In addition, the method requires the strict observance of technology.

Another proposed way to solve the instability to hydrolysis of certain phosphors is to use them in a composition that physically protects or encapsulates moisture-sensitive phosphor particles. Manufacturers of phosphors based on alkaline earth metal aluminates aluminates recommend protecting these materials from moisture by encapsulation or even with a transparent coating (for example, the manufacturer of luminescent pigments LumiNova is Nemoto & Co. Ltd., Japan, and their distributor is UMC, USA).

US patent No. 6005024 relates to non-aqueous epoxy systems containing phosphors. These systems are of limited use since their immediate use is required after mixing the two components, i.e. epoxy hardener and epoxy polymer.

US Pat. No. 6,359,048 describes a non-aqueous alkyd-based system containing a phosphor. This system has the disadvantage that it requires a base — an alkyd resin and a diluent that releases organic fumes that are flammable and usually have a strong odor. In addition, cleaning paint equipment also requires the use of a solvent with the same hazardous properties.

RF patent No. 2236434 relates to a multistage process for producing a phosphor, which includes ultrasonic treatment of phosphor particles in water-silicone ash at 25 kHz at the last stage to cover them with a thin silicate film that protects the particles from water. The method includes the step of manually sorting the phosphor particles to remove non-luminous by-products and phosphors with different radiation wavelengths. The method is not practical for industrial use.

In a certain sense, this direction may include methods for producing modified water-resistant phosphors having films or membranes on the surface, presumably from insoluble salts formed by the reaction of oxides that make up phosphors with acid or acid-forming compounds.

Japanese patent No. 2929162 proposes a method for improving the properties of a phosphor, which consists in the fact that on the surface of phosphors consisting of metal oxides (calcium, aluminum, strontium, barium, cerium) with the addition of activators from rare earth elements, a water-insoluble or hardly soluble film in water is obtained, formed as a result of exposure to an aqueous medium of an acid or any compound having the properties of an acid to a metal oxide forming a phosphor.

The method consists in placing the phosphor in an aqueous solution that contains acid or at least one compound having an acidic effect. The processing of the phosphor can also be carried out by spraying on its surface an aqueous solution that contains acid or at least one compound having an acidic effect. A third embodiment of the method is that the phosphor is placed in a gaseous medium containing, in a high concentration, water vapor of acid or water vapor of at least one compound having an acidic effect.

Japanese application No. 07292282 A proposes a modified phosphor containing a metal oxide with the addition of a rare earth element treated with an acid, preferably phosphoric, or an acid-forming substance.

The luminescent pigment is modified by immersion in a 0.5-4% acid solution for 10-60 minutes at 50 ° C.

Regarding these decisions, the description of US patent No. 6264855 says that the phosphors obtained by the above methods lose their resistance to water during prolonged contact with it at a temperature of 60 ° C, although their use does not cause special problems at ordinary temperature. Thus, there is a need to solve the problem of water resistance in more severe temperature conditions.

Japanese Patent Application No. 11140438 A describes a substance obtained by coating the surface of phosphor particles with organic derivatives of phosphoric acid, for example, an acidic ester of phosphoric acid or a chelating derivative of phosphoric acid.

Japanese application No. 10273654 A proposes a waterproof fluorescent substance obtained by treating a phosphor (oxide of one or more metals from the group consisting of Ca, Sr and Ba, and aluminum oxide, as well as rare earth oxide, preferably lanthanide) with diammonium hydrogen phosphate or ammonium dihydrogen phosphate in aqueous solution subsequent heat treatment.

Japanese application No. 11140439 A proposes a luminous fluorescent substance which, according to the inventors, has excellent resistance to light, weather and water for a long time. A fluorescent substance is a crystalline matrix of an alkaline earth metal aluminate doped with a rare earth element, coated on the surface with an insoluble salt of an alkaline earth metal (e.g., sulfate, carbonate, phosphate, oxalate or silicate).

The method of receipt is not specified.

The closest solution to the claimed technical solution is the product obtained by the method patented in US patent No. 6264855.

To increase the resistance to moisture at elevated temperatures, it is proposed to process the phosphor in two stages: in the first stage, with acid at pH no higher than 3, and in the second with alkali at pH 4-9.

According to the first claim of the patent in question, in the first stage, any acids or acid-forming compounds can be used, and in the second stage, any alkali or compounds forming them.

In the dependent claims, the acids are limited to a group: phosphoric acid, phosphorous acid, polyphosphoric acid, sodium dihydrogen phosphate, sulfuric acid.

Alkaline agents are limited to the group: hydroxides of sodium, potassium, calcium, strontium, lithium, trisodium phosphate, strontium oxide.

According to the claims, the above agents can be used separately and in combinations (combinations of alkalis and acids).

The description contains a long list of recommended acids, in which there are the following acids: nitric, boric, hydrochloric, carbonic, a number of organic acids.

As acid forming compounds, disodium phosphate, salts and anhydrides of the above acids are provided.

In the examples of US Pat. No. 6,264,855, only phosphoric acid is shown for acid treatment, trisodium phosphate and sodium hydroxide for alkaline treatment.

No experimental evidence of the use of any acid or any mixed agents is given in the patent specification.

At the same time, it is known from the prior art that when acting on phosphors that do not contain silicon, i.e. it is on those that are used in US Pat. No. 6,264,855, phosphoric or dilute hydrochloric acids, that they corrode (see US Pat. No. 5,961,884).

Our thorough experimental studies of the effects of various acids on luminescent pigments have shown that a number of acids recommended in US Pat. No. 6,264,855 do not protect against hydrolysis. Such acids include: H ₃ BO ₃ , HCl, HNO ₃ . Moreover, HCl and HNO ₃ , both diluted and concentrated, easily react with all the luminescent pigments we used to form the corresponding salts soluble in the reaction medium. So, if hydrochloric or nitric acid is added dropwise to an aqueous dispersion of a luminescent pigment, a reaction occurs with an increase in the temperature of the reaction medium. Moreover, a few minutes after adding each portion of the acid, the pH of the medium increases. This indicates that the acid is consumed by reacting with the phosphor. The reaction can be brought to the complete disappearance of the phosphor.

We found that a number of possible “acid-forming” compounds do not protect the phosphor from hydrolysis. These include: Na ₂ HPO ₄ , Na ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ . Those. treatment of the phosphor with aqueous solutions of these salts does not lead to the formation of waterproof phosphors.

The above data, which we have confirmed experimentally, indicate that the closest analogue (US patent No. 6264855) includes inoperable objects and does not disclose teachings on how a specialist, without resorting to creative research, can choose agents or their combinations for processing the phosphor to obtain the effect of resistance to the action of water, and even more so at high temperatures.

The present invention is the creation of a waterproof luminescent pigment that retains its properties at high temperatures, using available means and simple techniques.

The problem is solved by creating a new luminescent pigment, which is an oxide matrix based on aluminum oxide and at least one of the oxides of elements selected from the group: Mg, Ca, Sr, Ba, Zn, Mn, Si, B, P, Ga, activated at least one rare earth element treated with a mixture of salts selected from the group: Na ₃ PO ₄ , Na ₂ HPO ₄ , (NH ₄ ) ₂ HPO ₄ , Ca ₃ (PO ₄ ) ₂ , with acids selected from the group: HCl, H ₂ SO ₄ , HNO ₃ .

Oxide matrices can be represented by the following structures:

- MO · SiO ₂ · Al ₂ O ₃ : R, where M is at least one metal selected from the group consisting of Ca, Sr, Ba, Mg, Zn; R is at least one element selected from the group consisting of Dy, Nd, Eu, Tm, Tb, Y, Yb;

- MAl ₂ O ₄ : R where M is at least one metal selected from the group consisting of Ca, Sr, Mg, Ba, and R is at least one element selected from the group Dy, Nd, Eu, Tm, Tb , Y, Yb;

- MAlO ₄ : R, where M is at least one metal selected from the group Sr, Ca, Ba; R is at least one element selected from the group Dy, Nd, Eu, Tm, Tb, Y, Yb.

The invention is not limited to these specific formulas and can be extended to any complex alumina-based oxides that are used as luminescent pigments.

Another object is printing ink based on a new luminescent pigment, for the preparation of which you can use components for thickening (binder, thickener, fixative, softener), offered by a wide range of companies for conventional pigment printing.

In the process of research, it was unexpectedly discovered that the task of obtaining a waterproof pigment can be solved by treating the luminescent pigment with a mixture of salts selected from the group: Na ₃ PO ₄ , Na ₂ HPO ₄ , (NH ₄ ) ₂ HPO ₄ , Ca ₃ (PO ₄ ) ₂ , with acids selected from the group: HCl, H ₂ SO ₄ , HNO ₃ .

This decision is all the more unexpected since each agent individually, with the exception of H ₂ SO ₄ , does not protect the luminescent pigment from hydrolysis, despite recommendations not confirmed by experiment existing at a certain level.

Water-protected luminescent pigment is obtained in one stage, which greatly simplifies the process compared with the implementation of the protection proposed in US patent No. 6264855.

The description examples show the results of the proposed solutions. These solutions make it possible to obtain luminescent pigments that are waterproof at high temperatures. It should be noted:

1. Each of the acids HCl or HNO ₃ interacts with luminescent pigments, destroying them. But in a mixture with H ₃ PO ₄ perform protective functions from hydrolysis of the luminescent pigment.

2. H ₃ PO ₄ and H ₂ SO ₄ - each of these acids individually in a certain concentration protects the luminescent pigment from hydrolysis. Their mixture in the same concentrations loses its protective function.

3. The processing of luminescent pigments in the conditions of the proposed solution does not reduce compared with the original lighting characteristics of the obtained waterproof luminescent pigments.

Giving water resistance to luminescent pigments is especially important because the instability of phosphors based on alkaline earth metal aluminates makes it difficult to use them when water is part of the composition or when the final product is in contact with moisture.

Another objective of the present invention is to provide a printing ink based on waterproof luminescent pigment and thickeners.

For printing on fabrics or fabric products using pigments for textile printing. These pigments are produced as water-based dispersions. In dispersion, in addition to organic or inorganic pigments, dispersants and other surface-active substances (surfactants) are added, which provide the necessary complex of applied properties of pigment pastes. When using conventional luminescent pigments, for example, a yellow-green glow, it is impossible to prepare an outlet pigment form based on water, which is stable during storage for several hours. In an aqueous medium, a luminescent pigment is hydrolyzed and then coagulated. Overcoming this problem by encapsulating phosphors significantly increases the cost of production. On the other hand, any encapsulation of phosphors with the formation of surface polymer shells reduces their lighting characteristics.

We offer luminescent pigments can be used for the preparation of final pigment forms on a water basis, stable during long-term storage. On the other hand, they can be used for the preparation of printing inks based on conventional thickeners used in textile pigment printing. These printing inks can be used for printing both immediately after their preparation, and after 6-7 months. Their storage stability is determined by the water resistance of the inventive luminescent pigments. It should be noted their resistance to high temperatures in the aquatic environment. When luminescent pigments are heated in water at 90-95 ° C for 6-8 hours or at 130 ° C for 3 hours, they remain resistant to hydrolysis and retain luminescent properties. This property is of great importance in printing processes using both the screen printing method (silk screen printing) and in production using flat and round patterns. The printing process involves stages of drying and fixing. At the drying stage, moisture evaporates from the printed fabric. In this case, the temperature reaches 90-95 ° C. When fixing, the temperature on the fabric is even higher (at the end of heating it can reach 160-165 °), and the residual moisture is removed at temperatures above 95 ° C. Protected by the described method, the luminescent pigment withstands such harsh processing without hydrolysis and preserving its lighting characteristics.

The proposed luminescent pigments are readily dispersible in aqueous media, even in the absence of a surfactant. This property is of great importance in the preparation of printed compositions for spray. When applying printing ink to the fabric using the spray method, the dispersion of the particles and their tendency to agglomerate are very important. If the particles agglomerate, clots form that clog the spray device, and patches of uneven suspension are formed on the tissue. In the case of using the proposed luminescent pigments, there are no such drawbacks and there is no need to add special substances to increase the aggregative stability of the suspension.

As the initial luminescent pigments, luminescent pigments of a long afterglow (yellow-green) were used:

Table 1 No. Name of company and country of manufacture Name of luminescent pigment one. Nemoto and Co., Ltd. - Japan Sample submitted by UM (United Mineral and Chemical Corporation). Lumi Nova G - 300 M 2. Honeywell - USA Lumilux Green SN-F2 3. Dalian Luminglight Science and Tehnology Co., Ltd. - China SP-2, SP-4, SP-6 four. NPK Luminofor-Platan LLC - Russia LDP-2M 5. CJSC NPF Luminofor - Russia FV-530D

table 2
Some chemical and physical properties of luminescent pigments. The properties Name of luminescent pigments Lumi Nova G-300M Lumilux Green SN-F2 SP-2, SP-4, SP-6 LDP-2M FV-530D Chemical Composition SrAl ₂ O ₄ : Eu, Dy - MO · SiO ₂ · Al ₂ O ₃ : Eu M is one or more elements selected from the group: Ca, Mg, Sr, Ba, Zn SrCaAl ₂ O ₄ : Eu, Dy, Y SrAlO ₄ : Eu, Dy Powder color greenish white greenish yellow light yellow greenish white greenish yellow Density relative
water, g / cm ³ 3.65 3,50 SP-2 - 2.7-3.5
SP-4 - 2.7-3.5
SP-6 - 3.6 4.0 - The average particle diameter, microns 19.8 SP-2 - 10-25
SP-4 - 20-40
SP-6 - 25-35 10-30 10-25 Emission color yellow green yellow green yellow green yellow green yellow green Radiation wavelength (max), nm 520 520 520 520 520 ± 10 pH of the aqueous extract 10 at 25 ° C
(10% in water) 10 at 20 ° C - 6.7-7.3 - Solubility in water 0.3 g / l at 20 ° C partially soluble not soluble not soluble - Chemical properties Moisture sensitive Decomposed in acids, water and alkalis - - ^*) In accordance with the passport data of manufacturers

General procedure for treating luminescent pigments with a mixture of salts selected from the group: Na ₃ PO ₄ , Na ₂ HPO ₄ , (NH ₄ ) ₂ HPO ₄ , Ca ₃ (PO ₄ ) ₂ , with acids selected from the group: HCl, H ₂ SO ₄ , HNO ₃ .

Orthophosphoric acid salt and one of the acids selected from the group: HCl, HNO ₃ or H ₂ SO ₄ are added to the corresponding amount of water with stirring at room temperature. The mixture was stirred for 10 minutes and a luminescent pigment was added in portions over the course of 5 minutes.

The mixture was stirred for 1 hour. The precipitate is filtered off, washed thoroughly first with ordinary, then with distilled water and dried to constant weight at 130-140 ° C.

When processing a luminescent pigment with a mixture of salts and acids, if necessary, the temperature of the reaction medium is increased by heating using an external heat source (water bath or electric heating). During the processing of the luminescent pigment, the pH of the aqueous suspension is measured.

For the treatment of luminescent pigments, acids are used: 35% HCl, 55% HNO ₃ , 96% H ₂ SO ₄ .

Water resistance test.

5 g of the luminescent pigment obtained as described in the examples and 45 ml of water are placed in a 100 ml container and stirred at room temperature for 8 hours, controlling the pH of the suspension. The conclusion about water resistance is made on the basis of whether the pH of the test suspension becomes alkaline or not. Some processed luminescent pigments were tested in an aqueous medium at room temperature for several weeks.

The alkaline pH is explained by the fact that the alkaline earth metal oxide of the luminescent pigment reacts with water to form a water-soluble hydroxide. With prolonged contact with water, a luminescent pigment that is not resistant to hydrolysis, the concentration of hydroxides in water increases and they precipitate. This amorphous white precipitate can be decanted, separated from the heavier undecomposed phosphor. In parallel, crystallization occurs with the formation of light yellow compounds that do not have luminescent properties.

All luminescent pigments shown in Tables 1, 2, are not resistant to water at room temperature (hydrolyzed).

The luminescent pigment obtained as described in the examples, resistant to water at room temperature, is subjected to additional testing for water resistance at 90 ° C, and then at 130 ° C. Testing is carried out on laboratory equipment of the drum type of the Swiss company "Mathis", designed for dyeing tissue samples. The device is equipped with 12 metal cups with screw caps. 45 ml of distilled water and 5 g of the tested luminescent pigment are placed in each 100 ml beaker. Cups are closed with lids and placed in special openings of the device. Set the temperature to 90 ° C and heat with stirring for 6 hours. Then cool, unscrew the lids and determine the pH of the solution. The luminescent pigments that are resistant to water at 90 ° C are subjected to additional heating at 130 ° C for 3 hours by a similar procedure. Then determine the pH.

EXAMPLES

Table 3 shows the luminescent pigments used in the description examples:

Table 3 Name of luminescent pigment No examples Lumi Nova G - 300 M 1-11, 23-31, 33-37 Lumilux Green SN-F2 22, 32, 50 SP-2 12-21, 51 SP-4 38 SP-6 39 LDP - 2 M 40-46 FV - 530 D 47-49

EXAMPLE 1

16 g of water are placed in a glass cup equipped with a magnetic stirrer and 15.5 g of Na ₃ PO ₄ · 12H ₂ O are added with stirring, followed by 8.5 g of 35% HCl. To 40 g of the resulting solution, 10.0 g of a luminescent pigment was added portionwise over 5 minutes. As a result of spontaneous heating, the temperature of the reaction mixture increased to 28 ° C. Stirred for 1 hour. At the end of the reaction, the temperature of the phosphor suspension is 25-26 ° C. The suspension is filtered off, the precipitate is washed with water and dried at 130-140 ° C. 9.82 g of a light yellow luminescent pigment are obtained.

After mixing water, salt and acid, the resulting solution had a pH of 5. At the end of the reaction, the pH was 5.5.

The resulting luminescent pigment is hydrolyzed in water at room temperature. When added to water, it begins to decompose immediately. The pH of the solution within 10-40 minutes reaches 10, and after 2 hours, the pH is 11-12.

EXAMPLES 2-8

Examples 2-8 are summarized in Table 4. 10.0 g of the luminescent pigment is treated under the conditions of Example 140 g of a solution obtained by mixing a constant amount of Na ₃ PO ₄ · 12H ₂ O with various amounts of water and 35% hydrochloric acid. The pH of the reaction solution is controlled before and after pigment treatment. The resistance of the treated luminescent pigment to the action of water at room temperature is determined.

Table 4

No. of Example Amount, g pH Resistance of luminescent pigment to water Na ₃ PO ₄ · 12H ₂ O H ₂ O 35% HCl stock solution at the end of the reaction 2. 15,5 15.4 9.1 four 4,5 not stable 3. 15,5 14.9 9.6 3 four steady four. 15,5 13.9 10.6 2 3 steady 5. 15,5 12.8 11.7 1,5 1,5 steady 6. 15,5 11.7 12.8 one one steady 7. 15,5 10.7 13.8 <1 <1 steady 8. 15,5 7.7 16.8 A gel-like, difficult-to-filter reaction mass was formed

Luminescent pigments processed under the conditions of Examples 3-7 are resistant to water at room temperature for 14 days and are resistant to water at 90 ° C and 130 ° C.

The yield of pigments dried to constant weight obtained in experiments 2–7 was 9.7–9.8 g.

EXAMPLE 9

To 40 g of a solution with pH 1 obtained by mixing 15.5 g of H ₂ O, 15,5r Na ₂ HPO ₄ · 12H ₂ · O and 9.0 g of 35% HCl, 10.0 g of a luminescent pigment was added. Processing and isolation of the product is carried out under the conditions of Example 1. At the end of mixing, the solution has a pH of 2. Receive 9.83 g of a waterproof luminescent pigment.

EXAMPLE 10

To 40 g of a solution with pH 1 obtained by mixing 25.3 g of H ₂ O, 6.2 g of (NH ₄ ) ₂ HPO ₄ and 8.5 g of 35% HCl, 10.0 g of a luminescent pigment was added. Processing and isolation of the product is carried out under the conditions of Example 1. At the end of mixing, the solution has a pH of 2. Obtain 9.72 g of a waterproof luminescent pigment.

EXAMPLE 11

To 40 g of a solution with pH 1 obtained by mixing 20.8 g of H ₂ O, 6.3 g of Ca ₃ (PO ₄ ) ₂ and 12.9 g of 35% HCl, 10.0 g of a luminescent pigment was added. Processing and isolation of the product is carried out under the conditions of Example 1. At the end of mixing, the reaction solution has a pH of 2. The precipitate is poorly filtered. Obtain 9.61 g of a waterproof luminescent pigment.

EXAMPLES 12-21

In the conditions of Examples 2-11, the luminescent pigment SP-2 is treated. 9.0-9.3 g of water-resistant luminescent pigments are obtained.

EXAMPLE 22

In the conditions of Example 4, the luminescent pigment Lumilux Green SN-F2 is treated. 9.80 g of a waterproof luminescent pigment are obtained.

EXAMPLE 23

To 40 g of a 10% HCl solution, 10.0 g of the LumiNova G-300M luminescent pigment was added portionwise and stirred for one hour at 30 ° C. The precipitate is filtered off, washed thoroughly with water and dried. 1.2 g of a phosphor unstable to water are obtained. The processed phosphor is easily hydrolyzed. When added to water, the solution immediately becomes alkaline.

EXAMPLE 24

To 40 g of a HNO ₃ solution, 10.0 g of the LumiNova G-300M luminescent pigment was added portionwise. The mixture is stirred for 1 hour. The weight of the isolated product is 1.54 g. The product is easily hydrolyzed. When added to water, the solution immediately becomes alkaline.

EXAMPLE 25

The processing of the luminescent pigment is carried out in the conditions of Example 1, reducing the load of the phosphor by 2 times (using 40 g of solution and 5.0 g of phosphor). The output of the luminescent substance is 4.83 g. The product is easily hydrolyzed in water at room temperature.

EXAMPLE 26

To 35.5 g of H ₂ O add 4.7 g of 85% H ₃ PO ₄ , 10.0 g of a luminescent pigment and stirred at 28-30 ° C for 1 hour. The product is isolated under the conditions of Example 1. Receive 9.82 g of a luminescent pigment resistant to water at room temperature. The initial solution has a pH of 1, at the end of mixing pH 3.

EXAMPLE 27

15.5 g of Na ₃ PO ₄ · 12H ₂ O are dissolved at 50 ° C in 24.5 g of H ₂ O. The solution is cooled to 25 ° C, 10.0 g of luminescent pigment is added in portions and stirred at 28-30 ° C 30 min The suspension, having a pH of 13-14, is filtered off, washed 5 times with 30 ml of distilled water and dried. Get 8.94 g of a luminescent substance, easily hydrolyzed in water at room temperature.

EXAMPLE 28

To 40 g of an aqueous solution containing 9.6 g of Na ₂ HPO ₄ · 12H ₂ O, add 10.0 g of a luminescent pigment and mix at 25 ° C for 30 minutes. The product is isolated in the same manner as in Example 27. 9.75 g of a luminescent substance is obtained, which reacts with water at room temperature to form an alkaline solution.

EXAMPLE 29

Luminescent pigment treatment is conducted under conditions of Example 28, except that instead of Na ₂ HPO _4, 3.8 g of charge (NH _{4) 2} HPO _4. 9.81 g of a luminescent substance are obtained, which, interacting with water at room temperature, forms a solution with an alkaline pH.

EXAMPLE 30

3.8 g of H ₃ BO _{3 are} dissolved at 50 ° C in 80 g of H ₂ O. To 40 g of a solution cooled to 30 ° C, 2.0 g of a luminescent pigment is added and stirred for 1 hour at this temperature. The solution at the beginning and end of mixing had a pH of 7. When adding a phosphor, a slight heating of the reaction mass was observed. The suspension is filtered off, washed with water and dried. 1.90 g of a luminescent substance hydrolyzed in water at room temperature are obtained.

EXAMPLE 31

40 g of solution are prepared by mixing 15.5 g of Na ₃ PO ₄ · 12H ₂ O, 10.5 g of H ₂ O and 14.0 g of 55% HNO ₃ . 10.0 g of a luminescent pigment is added to 40 g of the solution and stirred for 1 hour at 25 ° C. The initial solution has a pH of 1. At the end of mixing, pH = 2. The suspension is filtered. The precipitate is washed with water and dried. 9.85 g of a light yellow luminescent pigment are obtained. The pigment is waterproof at room temperature, as well as at 90 ° C and 130 ° C.

EXAMPLE 32

To 40 g of a solution of Na ₃ PO ₄ · 12H ₂ O in water obtained under the conditions of Example 27, 10.0 g of a luminescent pigment was added with stirring, then 12.8 g of 35% HCl was added over 10 minutes. The suspension is stirred at 28-30 ° C for 1 hour. After adding the entire amount of HCl, the suspension has a pH of 1, at the end of stirring, pH 2. The suspension is filtered off, washed with water and dried. 9.25 g of a light yellow luminescent pigment are obtained. The pigment is water resistant at room temperature, as well as at 90 ° C and 130 ° C.

EXAMPLE 33

To 35.8 g of H ₂ O was added dropwise 4.2 g of 96% H ₂ SO ₄ . To the resulting aqueous solution of sulfuric acid cooled to room temperature, 10.0 g of a luminescent pigment was added and the temperature was raised to 40-45 ° C. The suspension is stirred at this temperature for 1 hour. The initial solution has a pH of 1. At the end of stirring, pH 4. The precipitate is filtered off, washed with water and dried to constant weight. 9.54 g of a light yellow luminescent substance are obtained. The product is resistant to water at room temperature for 20-24 hours. Then the pH of the solution increases and after 30-35 hours the pH of the solution reaches 11-12.

EXAMPLE 34

In 40 g of the solution obtained by adding 15.5 g of Na ₃ PO ₄ · 12H ₂ O and 6.3 g of 96% H ₂ SO ₄ to 18.2 g of H ₂ O, 10.0 g of luminescent pigment is added and mixed at 28- 30 ° C for 1 hour. The initial solution has a pH of 1. At the end of stirring, pH is 3. The suspension is filtered. The precipitate is washed with water and dried at 130-140 ° C to constant weight. Obtain 11.1 g of a waterproof luminescent pigment. The pH of the suspension of the pigment in water was controlled at room temperature; The pH of the solution was at 7 for 3 days. Upon further testing for water resistance under these conditions, the pH did not increase. The obtained luminescent pigment is waterproof at 90 ° C and at 130 ° C.

EXAMPLE 35

Two solutions are mixed: 20 g obtained under the conditions of Example 26 with 20 g obtained under the conditions of Example 33. To 40 g of the total solution containing H ₃ PO ₄ and H ₂ SO ₄ , add 10.0 g of a luminescent pigment and mix at 28-30 ° C for 1 hour.

The product was isolated under the conditions of Example 1. 9.80 g of a luminescent product unstable to water at room temperature were obtained.

EXAMPLE 36

The experiment is carried out by analogy with Example 35 except that 5.0 g of a luminescent pigment is used for processing. 4.85 g of a luminescent substance unstable to water at room temperature are obtained.

EXAMPLE 37

4.7 g of 85% H ₃ PO ₄ and 2.0 g of 35% HCl are added to 33.3 g of H ₂ O. To the resulting solution was added 10.0 g of a luminescent pigment. All other operations are carried out under the conditions of Example 1. Receive 9.81 g of a luminescent substance resistant to water at room temperature.

EXAMPLE 38

In the conditions of Example 4, 10.0 g of the luminescent pigment SP-4 are treated. Obtain 9.32 g of a waterproof luminescent pigment.

EXAMPLE 39

In the conditions of Example 5, 10.0 g of the luminescent pigment SP-6 are treated. 8.91 g of a waterproof luminescent pigment are obtained.

EXAMPLES 40-46

Under the conditions of Examples 4, 9, 10, 26, 31, 33, 34, the LDP-2 M luminescent pigment is treated with 2 M (10.0 g each). Get 9.1-9.3 g of waterproof luminescent pigments at room temperature, as well as at 90 ° C and 130 ° C.

EXAMPLES 47-49.

In the conditions of Examples 4, 31, 34, the luminescent pigment FV-530 D (10.0 g each) is processed. Get 9.2-9.4 g of waterproof luminescent pigments at room temperature, as well as at 90 ° C and 130 ° C.

EXAMPLE 50

Under the conditions of Example 33, 10.0 g of the Lumilux Green SN-F2 luminescent pigment is treated. Obtain 9.42 g of a product resistant to water at room temperature for 16 hours. Then the pH of the solution increases and after 24-26 hours reaches a pH of 12.

EXAMPLE 51

Under the conditions of Example 34, 10.0 g of SP-2 luminescent pigment is treated. Obtain 11.0 g of a waterproof luminescent pigment at 90 ° C and at 130 ° C.

EXAMPLE 52

The treatment of the luminescent pigment Lumi Nova G-300M is carried out as in Example 34, but instead of 15.5 g of Na ₃ PO ₄ · 12H ₂ O, 12.6 g of Ca ₃ (PO ₄ ) ₂ are taken, leaving the same amounts of 96% H ₂ SO ₄ and H ₂ O. The initial solution had a pH of 1, at the end of the reaction, pH 3. The resulting luminescent pigment is waterproof at 90 ° C and at 130 ° C.

EXAMPLE 53

The treatment of the luminescent pigment Lumi Nova G-300M is carried out as in Example 31, but instead of 15.5 g of Na ₃ PO ₄ · 12H ₂ O, 12.6 g of Ca ₃ (PO ₄ ) ₂ are taken, leaving the same amounts of H ₂ O and 55% HNO ₃ . The initial solution had a pH of 1, at the end of the reaction, pH 2. The resulting luminescent pigment is waterproof at 90 ° C and at 130 ° C.

EXAMPLE 54

The treatment of the luminescent pigment Lumi Nova G-300M is carried out as in Example 34, only instead of 15.5 g of Na ₃ PO ₄ · 12H ₂ O, 14.6 g of Na ₂ HPO ₄ · 12H ₂ O are taken, leaving the same amounts of 96% H ₂ SO ₄ and H ₂ O. The initial solution had a pH of 1, at the end of the reaction, pH 3. The resulting luminescent pigment is waterproof at 90 ° C and at 130 ° C.

EXAMPLE 55

The treatment of the luminescent pigment Lumi Nova G-300M is carried out as in Example 31, only instead of 15.5 g of Na ₃ PO ₄ · 12H ₂ O, 14.6 g of Na ₂ HPO ₄ · 12H ₂ O are taken, leaving the same amounts of H ₂ O and 55% HNO ₃ . The initial solution had a pH of 1, at the end of the reaction, pH 3. The resulting luminescent pigment is waterproof at 90 ° C and at 130 ° C.

EXAMPLE 56

The treatment is carried out, as in Example 54, only instead of 14.6 g of Na ₂ HPO ₄ · 12H ₂ About take 5.38 g (NH ₄ ) ₂ HPO ₄ . The initial solution had a pH of 1, at the end of the reaction, pH 3. The resulting luminescent pigment is waterproof at 90 ° C and at 130 ° C.

EXAMPLE 57

The treatment is carried out, as in Example 55, only instead of 14.6 g of Na ₂ HPO ₄ · 12H ₂ About take 5.38 g (NH ₄ ) ₂ HPO ₄ . The initial solution had a pH of 1, at the end of the reaction, pH 2. The resulting luminescent pigment is waterproof at 90 ° C and at 130 ° C.

For a more visual analysis of the experiment, examples 1-57 are summarized in the table:

From the table it follows:

A) In examples 1-2, the treatment of the initial phosphor is carried out with the reagent included in the claims, however, at a pH at the end of the reaction more than 4 (5.5 and 4.5, respectively), the result is not achieved.

B) In examples 35 and 36, the reagent is H ₂ SO ₄ + H ₃ PO ₄ , which is not included in the scope of the claims and which demonstrates the fact that not all acids or mixtures thereof, presented in generic terms in the claims of analogues, including in the closest analogue, they provide a technical effect.

B) In Examples 23 and 24, hydrolysis-unstable products were obtained, i.e. technical effect is not achieved.

In Example 26, a product is obtained that is stable only at room temperature, i.e. not achieved the effect of resistance to hydrolysis at elevated temperatures.

In Example 33, a product is obtained that is stable only at room temperature and only for a day, i.e. the effect of long-term resistance to hydrolysis at elevated temperature has not been achieved.

D) From the table it also follows that an essential feature of the proposed technical solution is the pH value, which should be no more than 4 at the end of the reaction.

Thus, in examples 3-11, 13-22, 26, 31, 32, 34, 37-49, 51-57, the preparation of hydrolysis resistant phosphors is described.

Inks

For the preparation of printing inks used waterproof luminescent pigments obtained as described in the examples, and components for the preparation of thickeners from the company "USA Specialty Chemicals Inc":

Binder - Alcoprint PB-HC

Thickener - Alcoprint PT-XN

Lock - Alcoprint PFL

Softener - Alcoprint PSC

GENERAL METHODS

1. Preparation of a thickener for printing with a luminescent pigment.

200 g of a binder is added to 370 ml of distilled water, the stirrer is turned on and 10-20 g of a thickener are added dropwise with stirring for 10 minutes until a homogeneous mass is formed, then 10-30 g of a softener, 10-30 g of fixative are added and mixed for 10 minutes. The viscosity of the resulting thickener is determined. Viscosity should be in the range of 60 to 80 dPa · s. Viscosity is controlled by adding a thickener or aqueous ammonia to the composition. Typically, the pH of the thickener is maintained at 9.

2. Preparation of luminescent ink for printing.

To 800-850 g of a thickener for printing with vigorous stirring, 150-200 g of luminescent pigment powder is added in portions until a homogeneous mass of light yellow is formed.

3. Preparation of a thickener for spray with a luminescent pigment.

200 g of a binder are added to 750 ml of distilled water. Then, with stirring, 10-13 g of a thickener are added dropwise over 10 minutes and the mixture is stirred for another 10 minutes until a homogeneous mass is formed. Then, with stirring, 30 g of softener and 10 g of fixative are added. The viscosity of the thickener is determined. Viscosity should be 30-40 dPa · s. To control the viscosity, either a thickener (for thickening) or a 20% aqueous NaCl solution (for dilution) is used. The consistency of the thickener should be such that it can be easily sprayed without clogging the nozzle of the spray device.

4. Preparation of luminescent paint for spray.

Spray paint is prepared similarly to preparing ink for printing using a spray thickener.

5. Screen printing, manual.

For printing, templates with a mesh No. 34 (with a mesh size of 34 mesh) of Saati single-strand polyester were used.

A textile product (jeans, a T-shirt, a T-shirt, etc.) is placed on a printed table and pressed with a template.

Printing ink is evenly applied to the template (in the place where there is no picture). Then with a squeegee with a certain pressure along the template, printing ink is pressed in the place of the drawing. To ensure hiding power, it is necessary to make two to three passes with a squeegee. Then the template is lifted and the printed product is subjected to intermediate drying at a temperature of 100-110 ° C for 20-30 seconds. Then the printed product is subjected to heat setting. The product is placed on the perforated tape of the dryer. When the tape moves, the product moves to the heating zone, where the fixing process takes place. Fixation is carried out at a temperature on the surface of the fabric 158-160 ° C for 80-90 seconds. Depending on the product and the area of the printed pattern, the fixing process is repeated 2-3 times.

6. Application of luminescent paint on the product by spray.

The product (e.g. jeans) is put on a mannequin. Prepare the compressor, connect all the components of the spray device (gun). The operating pressure in the system is ≈2 atm. Luminescent paint for spray is poured into a special container of the gun and regulate the air supply. Then the product is sprayed. At the end of the application of paint, the product is dried at room temperature, put on the mannequin again and re-applied the suspension of the thickener for the spray (without luminescent pigment). The product is removed from the mannequin and again dried at room temperature. Then it is subjected to a heat-setting process at 158-160 ° C for 80-90 seconds. The process of heat setting is repeated 2-3 times.

The preparation of printing ink for printing or spraying on fabrics can be carried out without emitting a waterproof luminescent pigment after processing the original luminescent pigment in accordance with the proposed method. In fact, we are talking about the fact that it is not necessary to isolate the product in the form of a dry powder after processing, since the technology for the preparation of printing ink involves the addition of water to the thickener. So, after several decantations and rinses, the aqueous paste of the processed luminescent pigment can be used to prepare printing ink.

It should be noted that if decantation is not performed with the addition of new portions of water to remove reaction salts, a printing ink containing a luminescent pigment and thickening components begins to coagulate.

7. Preparation of printing ink without emitting luminescent pigment.

To a suspension of 15.5 g of Na ₃ PO ₄ -12 H ₂ O in 13.9 g of H ₂ O is added dropwise with stirring 10.6 g of 35% HCl, stirred for 10 minutes, 10.0 g of a luminescent pigment is added and stirred 1 hour at 20 ° C. Before the introduction of the phosphor, the solution has a pH of 2, at the end of stirring, pH 4. The suspension of the luminescent pigment is sedimented for 3-5 minutes, the solution is drained, the precipitate is washed 3 times with 20 ml of H ₂ O, each time decanting the solution. After the last wash, the solution has a pH of 7. Decantation after washing takes place with virtually no loss of product, since the latter has a high density. An aqueous paste of a luminescent pigment is obtained. To the paste was added 16.0 g of H ₂ O, then 8.0 g of Alcoprint PB-HC, 0.8 g of Alcoprint PT-XN, 0.8 g of Alcoprint PFL and 0.8 g of Alcoprint PSC were added successively with stirring. Stirred for 30 minutes. Get a printing ink in the form of a homogeneous mass of light yellow.

For the preparation of luminescent inks for printing and spray, you can use components for thickening (binder, thickener, fixative, softener), offered by a wide range of companies for ordinary pigment printing.

Claims (5)

1. Waterproof luminescent pigment, which is an oxide matrix based on aluminum oxide and at least one of the oxides of elements selected from the group Mg, Ca, Sr, Ba, Zn, Mn, Si, B, P, Ga, activated, at least one rare earth element treated with a mixture of salts selected from the group Na ₃ PO ₄ , Na ₂ HPO ₄ , (NH ₄ ) ₂ HPO ₄ , Ca ₃ (PO ₄ ) ₂ , with acids selected from the group HCl, H ₂ SO ₄ , HNO ₃ , at pH not more than 4 at the end of processing. 2. The waterproof luminescent pigment according to claim 1, in which the oxide matrix has the formula MO · SiO ₂ · Al ₂ O ₃ : R, where M is at least one metal selected from the group consisting of Ca, Sr, Ba, Mg Zn; R is at least one element selected from the group consisting of Dy, Nd, Eu, Tm, Tb, Y, Yb. 3. The waterproof luminescent pigment according to claim 1, in which the oxide matrix has the formula MAl ₂ O ₃ : R, where M is at least one metal selected from the group consisting of Ca, Sr, Mg, Ba, and R is at least at least one element selected from the group Dy, Nd, Eu, Tm, Tb, Y, Yb. 4. The waterproof luminescent pigment according to claim 1, in which the oxide matrix has the formula MAl ₂ O ₃ : R, where M is at least one metal selected from the group Sr, Ca, Ba; R is at least one element selected from the group Dy, Nd, Eu, Tm, Tb, Y, Yb. 5. Printing ink based on a thickener and a luminescent pigment, characterized in that the product according to claim 1 is used as a luminescent pigment.