CN101117578A - Hydrophobic rare earth long-lasting luminescent material, luminescent plastic and preparation method thereof - Google Patents

Abstract

The invention relates to a hydrophobic rare earth long afterglow luminescent material and a polymer composite rare earth long afterglow luminescent material. The polymer composite rare earth long afterglow luminescent material is a hydrophobic rare earth long afterglow luminescent material modified by a coupling agent. It is obtained by in-situ emulsion polymerization of quasi-monomer or styrene-based monomer. The inorganic particles of this material are combined with polyacrylate based on covalent bonds, added to the polymer matrix resin, mixed uniformly, extruded, and granulated to obtain luminous plastic masterbatches, which can be used to prepare luminous doors and windows, luminous profiles, luminous signs, etc. .

Description

Hydrophobic rare earth long-lasting luminescent material, luminescent plastic and preparation method thereof

technical field

The invention relates to a hydrophobic rare earth long afterglow luminescent material, a polymer composite rare earth long afterglow luminescent material and a preparation method thereof, belonging to the field of luminescent materials.

Background technique

Rare earth luminescent materials can be made into luminescent coatings, luminescent ceramics, etc., used in various indication signs, and have important uses in the fields of transportation, fire safety, architectural decoration, military products, emergency lighting, and civilian products. The rare earth luminescent materials commonly used in the past are mainly sulfide series, which contain radioactive elements, which will cause harm to human health and the environment, and greatly restrict the use of materials. Rare earth-doped strontium aluminate-based luminescent material with aluminate as the substrate, divalent europium ions as the activator, and trivalent dysprosium ions as the co-activator, has high luminous brightness, high efficiency, long afterglow time, and does not contain radioactive elements. It is a new type of inorganic luminescent material and energy-saving "green" light source. In order to prepare water-resistant long-lasting luminescent materials, the surface of the luminescent material can be coated with a silicon-aluminum binary film. Since the silicon-aluminum binary film has many anchor points on the surface of rare earth-doped strontium aluminate, it is necessary to increase the cladding layer and rare earth-doped aluminate. The adhesion of strontium. In addition, the silicon-aluminum binary film is organically combined. Through the synergy between its network structure, it can overcome the volume shrinkage of a single SiO ₂ coating film during drying, which will cause fragments or peel off to destroy the coating. The shortcomings of the integrity of the coating better ensure the compact integrity of the coating. The silicon-aluminum binary coating film is chemically combined with rare earth-doped strontium aluminate in an amorphous state; the dense silicon-aluminum binary coating film protective layer formed on the surface of rare earth-doped strontium aluminate is resistant to rare earth doping The luminescence performance of strontium aluminate has little effect, but it can greatly improve the water resistance of rare earth doped strontium aluminate, and there are also waterproof long-lasting luminescent materials directly prepared by doping, such as Chinese patent application No. 200610172187.9.

However, rare earth-doped aluminate is an inorganic powder material, which has poor molding processability and heavy dust pollution, which greatly restricts its development. Polymer materials have rich sources of raw materials, low density, excellent mechanical, electrical and optical properties, corrosion resistance, easy molding and processing, and are widely used in many different occasions. At present, rare earth polymer long afterglow materials are limited to the physical doping of inorganic rare earth luminescent materials and polymer materials. For example, long afterglow luminescent polypropylene fiber is made by blending thermoplastic material polypropylene and luminescent pigment rare earth aluminate [Si Chunlei. Research on long afterglow luminescent polypropylene fiber [J]. Liaoning Chemical Industry, 2003, 32(1): 22- 23]; using methyl methacrylate and ethyl acrylate as monomers, and a small amount of luminescent powder as key components, the luminescent spheres were synthesized by suspension polymerization [Yan Shuyi, Zhong Chuanrong, Jin Yongdong, et al. Synthesis of Luminescent Polymethacrylate Copolymer Spherules [J]. Chemical Research and Application, 2002, 14(6): 682-684]. This kind of physical doping is difficult for rare earth polymer long afterglow materials, rare earth luminescent materials are difficult to uniformly disperse in the polymer matrix, and the force between inorganic particles and organic molecules is weak, which will affect the quality of the final prepared polymer material products. Luminescence properties and mechanical properties.

The inventors of the present invention propose to use in-situ emulsion polymerization to coat a layer of high polymer PMMA on the surface of rare earth doped strontium aluminate. Preparation and luminescent properties of aluminum-coated strontium aluminate composite luminescent materials, Polymer Materials Science and Engineering, 2007, 23(3), 156-159], the polymer long afterglow material obtained by this method has a relatively simple polymer structure , it is difficult to ensure the compatibility of powder luminescent materials with various matrix resins, and the scope of use is limited to a certain extent.

Contents of the invention

The technical problem to be solved by the present invention is: in order to improve the compatibility between the powder luminescent material and the matrix resin, so that the luminescent material is uniformly dispersed in the polymer matrix, a polymer composite rare earth long-lasting luminescent material is provided, the inorganic particles and organic The molecules are combined by chemical bonds, which not only maintains the original luminous performance, but also facilitates the preparation of polymer material products.

The technical scheme of the present invention is as follows, wherein the parts are all parts by weight unless otherwise specified.

The present invention firstly provides a hydrophobic rare earth long-lasting luminescent material, which is a hydrophobic rare earth long-lasting luminescent material modified by a coupling agent and with unsaturated double bonds on the surface. It is obtained by reacting a coupling agent and a rare earth long-lasting luminescent material in an alcohol solution at 40-80°C. The raw material ratio is: 10-30 parts of a rare-earth long-lasting luminescent material, 0.1-3 parts of a coupling agent .

The polymer composite rare earth long-lasting luminescent material provided by the present invention is obtained by in-situ emulsion polymerization of a hydrophobic rare-earth long-lasting luminescent material and an acrylic monomer or a styrene monomer. Price bonds.

The long afterglow luminescent plastic masterbatch of the present invention is obtained by uniformly mixing a polymer composite rare earth long afterglow luminescent material with a polymer matrix, extruding and granulating. Wherein, the polymer matrix may be low-density polyethylene (LDPE), polyvinyl chloride (PVC), ABS, SBS, PC, etc., and is used for preparing luminous doors and windows, luminous profiles, luminous signs, and the like.

The present invention has the following advantages:

1. In the polymer composite rare earth long afterglow luminescent material, the polymer and the luminescent powder are combined in the form of covalent bonds. When the polymer composite rare earth long afterglow luminescent material is mixed with the polymer matrix, the silicon aluminum coated rare earth is doped Strontium aluminate can be uniformly dispersed in the polymer matrix.

2. The molecular structure of the acrylate polymer in the polymer composite rare earth long afterglow luminescent material can be designed. According to different polymer matrix structures, composite luminescent material particles with different structures can be designed to improve the polyacrylate composite rare earth long afterglow luminescence The interfacial compatibility between the material and the polymer matrix expands its application range.

3. The polyacrylate/silicon-alumina-coated rare earth-doped strontium aluminate composite luminescent material is prepared by the emulsion polymerization method, which is environmentally friendly, has relatively mature industrial technology, and is easy to realize industrialization.

In short, the present invention modifies the rare earth long-lasting luminescent material with a coupling agent, and then in-situ emulsion polymerizes it with acrylate monomers to obtain a polymer composite rare earth long-lasting luminescent material, wherein the molecular structure of the polymer can be highly designed. Ester and inorganic particles are combined based on covalent bonds, and added to the matrix resin of the polymer material to endow the polymer material with long afterglow performance. Moreover, the emulsion polymerization method is adopted, the industrial technology is relatively mature, and it is easy to realize industrialization.

Description of drawings

Figure 1 is the FTIR spectra of rare earth-doped strontium aluminate coated with silicon aluminum (a) and polyacrylate/silicon aluminum coated rare earth doped strontium aluminate (b) after extraction with chloroform.

Fig. 2 is the thermogravimetric diagram of rare earth-doped strontium aluminate coated with silicon aluminum (a) and polyacrylate/silicon aluminum coated rare earth doped strontium aluminate after extraction with chloroform (b).

Fig. 3 is the excitation emission spectrum and emission spectrum of rare earth-doped strontium aluminate coated with silicon aluminum (a) and polyacrylate/silicon aluminum coated rare earth doped strontium aluminate (b).

Fig. 4 is a spectrogram of light attenuation curves of rare earth doped strontium aluminate coated with silicon aluminum (a) and polyacrylate/silicon aluminum coated rare earth doped strontium aluminate (b).

Fig. 5 is a graph showing the relationship between the pH value of the aqueous phase of the rare earth doped strontium aluminate (a) and the polyacrylate/silicon aluminum coated rare earth doped strontium aluminate (b) and soaking time.

The present invention will be described in detail below in conjunction with specific examples through specific embodiments. It is necessary to point out that the examples are only to further illustrate the present invention, and can not be interpreted as limiting the protection scope of the present invention. Those skilled in the art can according to the above-mentioned The content of the invention makes some non-essential improvements and adjustments.

Detailed ways

The present invention firstly provides a hydrophobic rare-earth long-lasting luminescent material—a rare-earth long-lasting luminescent material modified by a coupling agent to obtain luminescence with unsaturated double bonds (CH ₂ =CR ₁ -) and lipophilic and hydrophobic surfaces. Material.

It is obtained by reacting a coupling agent and a rare earth long-lasting luminescent material in an alcohol solution at 40-80°C. The raw material ratio is: 10-30 parts of a rare-earth long-lasting luminescent material, 0.1-3 parts of a coupling agent .

Its specific preparation method is:

a. Raw material preparation: 10-30 parts of rare earth long-lasting luminescent material, 0.1-3 parts of coupling agent, and alcohol solvent; wherein, the rare-earth long-lasting luminescent material can be doped with at least one rare earth element such as europium, neodymium, and dysprosium Inorganic long-lasting luminescent materials such as strontium aluminate. The coupling agent is CH ₂ =C(R ₁ )-R ₂ -Si-(OR ₃ ) ₃ , wherein, R ₁ =H, -CH ₃ or -CH ₂ CH ₃ , R ₂ =O or -COO(CH ₂ ) ₃ -, R ₃ = -CH ₃ or -CH ₂ CH ₃ .

The alcoholic solvent may be a C ₁ -C ₃ small molecule alcohol, such as at least one of methanol, ethanol, and propanol.

b. Add the raw materials prepared in step a into the reactor with a stirrer, thermometer and reflux condenser, and stir at 40-80°C for 0.5-6 hours; the function of the reflux condenser is mainly to ensure that the solvent can be dissolved in time during the reaction Condensation, avoid solvent evaporation.

c. Dry to remove the solvent, and grind to obtain.

The interaction mode between the coupling agent molecules and the rare earth-doped strontium aluminate coated with the silicon-aluminum binary film has a great influence on whether the organic monomer can be grafted and polymerized on the surface of the rare-earth-doped strontium aluminate covered with the silicon-aluminum binary film. It is very important to coat rare earth doped strontium aluminate with polymer/silicon aluminum binary film based on chemical bonding. Use silane coupling agent (MAPS) such as methacryloxypropyltrimethoxysilane (CH ₂ =C(CH ₃ )CO ₂ (CH ₂ ) ₃ Si(OCH ₃ ) ₃ ) to surface the inorganic powder. After modification, the alkoxy groups on MAPS can undergo hydrolysis reaction. After the hydrolysis reaction, the alkoxy group will be replaced by the hydroxyl group, and the MAPS replaced by the hydroxyl group has a high reactivity. It can not only undergo the condensation reaction of the intermolecular hydroxyl group, but also bond with various functional groups such as the hydroxyl group on the surface of the inorganic powder to form Strong chemical bonds are adsorbed on the surface of inorganic powder; at the same time, the coupling agent molecules have unsaturated double bonds, which can undergo polymerization reactions with organic monomers.

The polyacrylate composite rare earth long-lasting luminescent material provided by the present invention is obtained by in-situ emulsion polymerization of the hydrophobic rare-earth long-lasting luminescent material of the present invention and acrylate monomers or styrene monomers, through the bridging effect of coupling agents , to firmly combine two materials with very different properties, so that a chemical bond with strong interaction is established between the inorganic powder and the organic polymer.

a. Raw material preparation: raw materials according to weight ratio: 5-20 parts of hydrophobic rare earth long-lasting luminescent material of the present invention, 1-5 parts of emulsifier, 0.01-2 parts of initiator, acrylate monomer or styrene monomer 1-10 parts, the dispersion medium is water;

b. The emulsifier and initiator are respectively dissolved in water to obtain an aqueous solution, and the emulsifier aqueous solution and the hydrophobic rare earth long-lasting luminescent material are mixed uniformly at 50-80°C, and the initiator aqueous solution is added under the protection of nitrogen, and the acrylate monomer is continuously dropped;

c. React for 2 to 5 hours after adding the monomers, lower the temperature, filter with suction, wash and dry.

In actual operation, the emulsifier can be prepared as an aqueous solution with a concentration of 0.5-5 wt%, and the initiator can be prepared as an aqueous solution with a concentration of 0.5-4 wt%.

Due to the high transparency of polyacrylate, good chemical stability, light stability, processability and weather resistance, it is grafted on the surface of silicon-aluminum binary film coated with rare earth doped strontium aluminate, endowing polyacrylate with long afterglow luminescence function, The use value of the rare earth-doped strontium aluminate luminescent material is greatly improved.

The acrylate monomer may be at least one of methyl methacrylate, methyl acrylate, 2-ethylhexyl acrylate, butyl acrylate, butyl methacrylate or ethyl acrylate monomer.

Those skilled in the art can design composite luminescent material particles with different molecular structures according to different polymer matrix structures, and other monomers, such as styrene monomers, can be used.

The emulsifier can be at least one of conventional emulsifiers such as sodium maleic anhydride sulfonate, lauryl ammonium chloride, sodium lauryl sulfate, and sodium dodecylbenzenesulfonate. It is formulated into an aqueous solution of a certain concentration for use.

The initiator can be at least one of potassium persulfate, ammonium persulfate, cumene hydroperoxide and potassium persulfate-sodium bisulfite. It is formulated into an aqueous solution of a certain concentration for use.

b. Mix the intermediate of the rare earth polymer long-lasting luminescent material with the emulsifier solution evenly, and add the initiator solution and acrylate monomer at 50-80°C under the protection of nitrogen;

c. React for 1 to 5 hours after monomer addition, cool down and discharge, filter, wash and dry.

It is well known in the art that strontium aluminate is easily hydrolyzed in a humid environment, resulting in a decrease in the luminous performance of the material until the brightness disappears and loses its use value. In order to prepare the polyacrylate composite rare earth long-lasting luminescent material in a water environment without weakening its long-lasting luminescent performance, a rare-earth long-lasting luminescent material with waterproof performance can be used. For example, the rare earth long-lasting luminescent material coated with silicon-aluminum binary film or the waterproof long-lasting luminescent material in the invention patent application No. 200610172187.9. Covalently bonded polyacrylate/silicon-aluminum-coated rare-earth-doped strontium aluminate composite luminescent materials were prepared by coupling modified long-lasting luminescent materials and in situ emulsion polymerization with acrylate monomers. The prepared composite luminescent material is added to the polymer matrix resin to endow the polymer material with luminescent properties.

The molecular structure of the polyacrylate composite rare earth long-lasting luminescent material of the present invention is designable, and the composite luminescent material particles with different molecular structures are designed according to different polymer matrix structures, so that the composite rare earth long-lasting luminescent material is added to the polymer material In this process, the interfacial compatibility between the long-lasting luminescent material and the polymer matrix resin is improved. Wherein, the above-mentioned polymer matrix resin may be low-density polyethylene (LDPE), polyvinyl chloride (PVC), ABS, SBS, PC and the like.

The polyacrylate composite rare earth long-lasting luminescent material of the present invention is added to a polymer matrix resin and mixed evenly, extruded and granulated to obtain a long-lasting luminous plastic masterbatch, which can be used to prepare luminous doors and windows, luminous profiles, luminous signs and the like.

Example 1 Preparation of the hydrophobic rare earth long-lasting luminescent material of the present invention

Raw materials: 50g of rare earth-doped strontium aluminate coated with silicon-aluminum binary film (provided by Sichuan University);

Coupling agent (γ-methacryloxypropyltrimethoxysilane) 4g;

Ethanol 200ml.

Add the above raw materials into the reactor, stir at 70° C. for 5 hours; dry and remove the solvent to obtain about 50 g of yellow-green powdery hydrophobic rare earth long-lasting luminescent material.

Coupling rare earth-doped strontium aluminate with MAPS coupling modified silicon-aluminum binary film can chemically adsorb silane coupling agent molecules on the surface of silicon-aluminum binary film-coated rare earth-doped strontium aluminate to make silicon-aluminum binary The film-coated rare earth-doped strontium aluminate band has unsaturated double bonds, which become a bridge between inorganic powder and organic monomer, so that materials with very different properties are firmly combined, and the grafting rate of the coupling agent was 0.34%.

According to the pH value test, the pH value of the aqueous solution of coupling-modified rare earth-doped strontium aluminate foam increases continuously with time. Rare-earth-doped strontium aluminate bubble solution has been kept between 6 and 7; the morphology of silicon-aluminum binary film-coated rare-earth-doped strontium aluminate before and after modification is almost the same, and it can be clearly seen that the coating is coated with silicon-aluminum Layer, can well solve the problem of water resistance.

Example 2 Preparation of the hydrophobic rare earth long-lasting luminescent material of the present invention

Raw material: 4g of the sample (Sample 3) of Patent Application No. 200610172187.9;

Coupling agent (γ-methacryloxypropyltrimethoxysilane) 0.32g;

Ethanol 16ml.

Add the above raw materials into a reactor equipped with a stirrer, a thermometer and a reflux condenser, and stir at 75°C for 5 hours; dry and remove the solvent to obtain about 4g of yellow-green powdery hydrophobic rare earth long-lasting luminescent material.

Example 3 Preparation of hydrophobic rare earth long-lasting luminescent material of the present invention

Using the same method as in Example 1, use 4%, 6%, 8% and 10% of the MAPS coupling agent to modify the silicon-aluminum binary film to coat the rare earth-doped strontium aluminate, and extract it with absolute ethanol after drying. Extracted for 48 hours, and then dried at 120°C to prepare coupling-modified samples with different coupling agent dosages.

Hydrophobic test: all the coupling modified samples and the silicon-aluminum binary membrane coated rare earth doped strontium aluminate without coupling modification were dispersed in deionized water, and the hydrophobic characteristics of the samples were observed and evaluated. The results showed that there was no The rare-earth-doped strontium aluminate coated with silicon-aluminum binary membrane modified by coupling has strong hydrophilicity, and all sink to the bottom of the container soon; while all samples modified by coupling, without stirring, Each sample has a part that can float on the water surface, showing strong hydrophobicity.

FTIR analysis: FTIR analysis was carried out on the sample with a Fourier transform infrared spectrometer (Nicolet 560FTIR spectrometer), and the sample was prepared by KBr pellet method.

In the FTIR spectrum of the hydrophobic rare earth long-lasting luminescent material of the present invention, the stretching vibration absorption peak of the carbonyl group (>C=O) can be clearly observed near 1745.03cm-1, while the unmodified silicon-aluminum binary film In the FTIR spectrum of coated rare earth-doped strontium aluminate, no stretching vibration absorption peak of carbonyl group (>C=O) can be observed near 1700cm-1, indicating that after modification by the coupling agent, the coupling agent molecule chemically adsorbs The rare earth-doped strontium aluminate surface is coated with a silicon-aluminum binary film. Comparing the FTIR spectrogram of the hydrophobic rare earth long-lasting luminescent material of the present invention with the FTIR spectrogram of the coupling agent shows that the stretching vibration absorption peak of the carbonyl (>C=O) in the rare earth-doped strontium aluminate coated with a silicon-aluminum binary film is in the direction of The displacement in the direction of high wave number is up to 25cm ^-1 , which further proves that there is a chemical interaction between the coupling agent molecules and the silicon-aluminum binary film-coated rare earth-doped strontium aluminate surface, rather than general physical adsorption.

SEM test: The surface morphology of the sample after coupling modification is almost the same as that before modification, indicating that the silicon-aluminum layer on the surface of the rare earth-doped strontium aluminate has not been damaged after the coupling modification reaction.

Luminescence performance test: After extraction with absolute ethanol, the excitation spectrum and emission spectrum test results of the coupling modified sample show that the excitation wavelength of rare earth doped strontium aluminate before and after coupling modification is in the range of 200-480nm (ultraviolet visible light area), daylight and white fluorescent lamps are good excitation light sources, and the sources of light sources are wide. The strong excitation wavelengths before and after modification are around 320 and 360nm, and the strongest excitation wavelength is around 320nm; the emitted light wavelengths appear in visible light region (400-680nm), the wavelength of the strongest emitted light is 520nm. The main peak wavelengths of the excitation spectrum and emission spectrum did not change, and the peak area did not change much, indicating that the rare earth long afterglow material modified by coupling with the silane coupling agent did not destroy its crystal structure. The brightness attenuation curves of the two almost overlap together, indicating that the coupling modification treatment has little effect on the luminescent properties of rare earth-doped strontium aluminate.

Example 4 Preparation of polyacrylate composite rare earth long-lasting luminescent material of the present invention

1. Raw material preparation:

8g of the hydrophobic rare earth long-lasting luminescent material prepared in Example 1;

Preparation of emulsifier solution: 30ml of deionized water and 1.2 grams of sodium lauryl sulfate are configured with a concentration of 3.8wt%;

Preparation of initiator solution: the concentration of potassium persulfate is 1.5wt%;

Acrylate monomer: methyl methacrylate monomer.

2. Preparation process:

Add 30ml of deionized water and 1.2g of sodium lauryl sulfate into a reactor equipped with a stirrer, a thermometer and a reflux condenser, stir evenly at 40°C, add the hydrophobic rare earth long-lasting luminescent material prepared in Example 1, 75 Stir evenly at ℃, under the protection of nitrogen, add 6 grams of potassium persulfate solution with a concentration of 1.5 wt%, and continuously drop 8 grams of methyl methacrylate monomer; react for 1.5 hours after the addition of the monomer, cool down and discharge, and filter with suction , Wash and dry.

Example 5 Control Sample, Preparation of Polyacrylate Composite Rare Earth Long-lasting Luminescent Material Without Coupling Agent Modification

Using the same preparation method as in Example 4, the silicon-alumina-coated rare-earth-doped strontium aluminate composite luminescent material not modified by the coupling agent was subjected to in-situ emulsion polymerization with methyl methacrylate monomer to obtain a control sample. The extraction experiment and FTIR test were carried out simultaneously with the rare earth-doped strontium aluminate composite luminescent material prepared in Example 4.

Structure of Polyacrylate Composite Rare Earth Long-lasting Luminescent Material

FTIR of polyacrylate/silicon aluminum coated rare earth doped strontium aluminate composite luminescent material and polyacrylate/silicon aluminum coated rare earth doped strontium aluminate composite luminescent material after chloroform extraction for 10 days to remove homopolymer The analysis results are shown in Figure 1. The results show that the polyacrylate and inorganic particles in the polyacrylate/silicon-alumina-coated rare-earth-doped strontium aluminate composite luminescent material are not simply physically mixed, but are combined with each other through chemical bonds.

The control sample without coupling modification began to be coated with a lot of polyacrylate; after 5 days of extraction with chloroform, a weak carbonyl characteristic absorption peak appeared at 1700.00cm-1, indicating that the polyacrylate coated on the sample The amount of acrylate decreased; the sample extracted with chloroform for 10 days did not have a carbonyl characteristic absorption peak at 700.00cm-1, indicating that the sample was not coated with polyacrylate. It can be seen that the polyacrylate coated on the control sample without coupling modification is purely physical coating, and the physically coated polyacrylate can be removed by extraction with chloroform for a certain period of time.

The thermal gravimetric analysis results of the polyacrylate/silicon-alumina-coated rare-earth-doped strontium aluminate composite luminescent material after extraction with chloroform are shown in Figure 2. The results show that there is a strong chemical bond between the polyacrylate in the composite particles and the rare earth-doped strontium aluminate coated with silicon and aluminum.

Luminescent Properties of Polyacrylate Composite Rare Earth Long-lasting Luminescent Materials

As shown in Figure 3, the excitation wavelengths of the composite luminescent material and silicon-alumina-coated rare earth-doped strontium aluminate are in the range of 200-480nm, and the maximum excitation wavelength is about 320nm; the composite luminescent material and rare earth-doped strontium aluminate The wavelengths of emitted light all appear in the visible light region (400-680nm), and the maximum emission wavelength is 520nm. Compared with rare earth-doped strontium aluminate, although the peak height and peak area in the excitation spectrum and emission spectrum of the composite luminescent material are slightly reduced, the frequency of the main peak remains unchanged, indicating that the composite luminescent material The main phase structure has not changed, that is, the luminescent center and the matrix crystal field have not changed, and the polymer/rare earth doped strontium aluminate composite luminescent material based on covalent bonding can maintain the original luminescence characteristics of rare earth doped strontium aluminate.

Figure 4 shows that the initial luminance and end luminance (10 hours) of rare earth-doped strontium aluminate are 25.18cd/m2 and 0.00468cd/ ^m2 respectively; The initial brightness and final brightness (10 hours) are 27.84cd/m2 and 0.00296cd/ ^m2 respectively. The brightness decay curve (a) of the composite luminescent material and the brightness decay curve (b) of the rare earth doped strontium aluminate are almost coincident at Together, it further demonstrates that the covalently bonded polymer/silicon-alumina-coated rare earth-doped strontium aluminate composite luminescent material can maintain the original luminescent properties of the rare earth-doped strontium aluminate.

Water Resistance of Polyacrylate Composite Rare Earth Long-lasting Luminescent Materials

As shown in Figure 5, curve a is rare earth doped strontium aluminate. It can be seen that the pH value of the rare earth doped strontium aluminate raw material has reached 10.05 after soaking for 10 minutes; after soaking for 6 hours, the pH value rose to 12.01, indicating that the raw material rare earth The water resistance of doped strontium aluminate is very poor, and polymer/silicon aluminum coated rare earth doped strontium aluminate composite luminescent material (curve b), after soaking for 6 hours, the pH is between 6 and 7, indicating that composite luminescence The material has very good water resistance.

Example 6 Preparation of P(MMA-BA) composite rare earth long-lasting luminescent material of the present invention

1. Raw material preparation:

5 grams of the hydrophobic rare earth long-lasting luminescent material prepared in Example 1;

Preparation of emulsifier solution: 33ml of deionized water and 1 gram of sodium lauryl sulfate, the configuration concentration is 2.9wt%;

The preparation of initiator solution: 100ml deionized water, 0.8 potassium persulfate and 0.2 gram of sodium bisulfite, the configuration concentration is 1.0wt% potassium persulfate-sodium bisulfite solution;

Acrylic monomer: a mixed monomer of methyl methacrylate and butyl acrylate (the mixing ratio is 3:1 by weight).

2. Preparation process:

Add the emulsifier solution to 5 grams of rare earth-doped strontium aluminate coated with the coupling-modified silicon-aluminum binary film prepared in Example 1, stir evenly at a temperature of 53° C., protect with nitrogen, and then add persulfuric acid with a concentration of 1.0 wt % 3 grams of potassium-sodium bisulfite solution, 4 grams of mixed monomers of methyl methacrylate and butyl acrylate were added dropwise continuously, and the reaction was continued for 3.0 hours after the monomers were added dropwise, the temperature was cooled and the material was discharged, and after suction filtration, washing, After drying, the polyacrylate/silicon-alumina-coated rare earth-doped strontium aluminate composite luminescent material, that is, the P(MMA-BA) composite rare earth long-lasting luminescent material is obtained.

The composite luminescent material after chloroform extraction shows by FTIR analysis results that the composite luminescent material has strong saturated CH stretching vibration absorption peaks at 2924.67cm ^-1 and 2856.28cm ^-1 , and saturated CH at 1440.24cm ^-1 The bending vibration absorption peak, 1734.06cm ^-1 has a strong carbonyl characteristic absorption peak, which shows that P(MMA BA) is grafted to the rare earth-doped strontium aluminate coated with the coupling modified silicon-aluminum binary film by chemical bond. The water resistance test shows that the pH value of the soaking aqueous solution of the coupling-modified rare earth doped strontium aluminate increases continuously with time. The luminescent material soaking aqueous solution has been maintained between 6 and 7, indicating its good water resistance. The SEM test shows that the morphology after modification is almost the same, and it can be clearly seen that the silicon-aluminum layer is coated.

Excitation spectrum, emission spectrum and luminous brightness tests show that polymer/silicon-aluminum binary film-coated rare earth-doped strontium aluminate composite luminescent material hardly changes the luminescent properties of rare earth-doped strontium aluminate.

Example 7 Preparation of P(MMA-BA-MAA) composite rare earth long-lasting luminescent material of the present invention

1. Raw material preparation:

10 g of the hydrophobic rare earth long-lasting luminescent material prepared in Example 1;

Preparation of emulsifier solution: 33ml deionized water and 1.5 grams of sodium lauryl sulfate, the configuration concentration is 4.3wt%;

The preparation of initiator solution: 1.5wt% ammonium persulfate solution;

Acrylic monomers: methyl methacrylate, methacrylic acid and butyl acrylate (the mixing ratio is 3:0.2:1 by weight).

2. Preparation process:

Add the emulsifier solution to 10 grams of the hydrophobic rare earth long-lasting luminescent material prepared in Example 1, stir evenly at a temperature of 68° C., then add 3 grams of ammonium persulfate solution with a concentration of 1.5 wt %, under nitrogen protection, and continuously add acrylate A total of 8 grams of similar monomers, after the addition of the monomers, continued to react for 2.0 hours, cooled and discharged, filtered, washed, and dried to obtain a polyacrylate/silicon-alumina-coated rare earth-doped strontium aluminate composite luminescent material, namely P (MMA-BA-MAA) composite rare earth long afterglow luminescent material.

Example 8 Preparation of polystyrene composite rare earth long-lasting luminescent material of the present invention

Sodium maleic anhydride sulfonate was used as emulsifier to carry out styrene emulsion polymerization to prepare polystyrene (PSt) composite rare earth long-lasting luminescent material.

XPS analysis: the Sr3d doublet electron binding energies of rare earth doped strontium aluminate are 133.46 and 135.018ev, respectively, and the Sr3d doublet electron binding energies of composite luminescent material samples are 134.04 and 135.640ev, respectively, and the electron binding energies are higher than those of rare earth doped aluminum The Sr3d of strontium oxide increased by 0.58 and 0.632ev, which is due to the chemical interaction between PSt and the surface of rare earth-doped strontium aluminate coated with silicon-aluminum binary film, PSt, silicon-aluminum layer and rare earth-doped strontium aluminate The effect leads to a change in the electronic binding energy of Sr3d. This also proves that PSt and silicon-aluminum binary film coating rare earth-doped strontium aluminate is the effect of chemical bonding, rather than the general physical effect

The results of FTIR analysis of the composite luminescent material after chloroform extraction show that there are benzene rings in the composite luminescent material, indicating that PSt is grafted to the coupling-modified silicon-aluminum binary film-coated rare-earth-doped strontium aluminate by chemical bonds. The water resistance test shows that the pH value of the soaking aqueous solution of the coupling-modified rare earth doped strontium aluminate increases with time. Between 6 and 7, it shows good water resistance. The SEM test shows that the morphology after modification is almost the same, and it can be clearly seen that the silicon-aluminum layer is coated.

Excitation spectrum, emission spectrum and luminous brightness tests show that polystyrene/silicon-aluminum binary film-coated rare earth-doped strontium aluminate composite luminescent material hardly changes the luminescent properties of rare earth-doped strontium aluminate.

In short, the present invention reacts the rare earth long-lasting luminescent material with a coupling agent, connects lipophilic and hydrophobic materials on the surface, and performs in-situ emulsion polymerization with acrylate monomers to obtain a polymer composite rare earth long-lasting luminescent material. The inorganic particles of the material Combined with polyacrylate based on covalent bonds, it is beneficial to melt into polymer materials to obtain luminous plastics, which can be used to prepare luminous doors and windows, luminous profiles, luminous signs, etc.

Claims (10)

1. Hydrophobic rare earth long-lasting luminescent material, characterized in that it is a rare earth long-lasting luminescent material modified by a coupling agent, with unsaturated double bonds on the surface. 2. The hydrophobic rare-earth long-lasting luminescent material according to claim 1, characterized in that it is composed of 0.1-3 parts of coupling agent and 10-30 parts of rare-earth long-lasting luminescent material in alcohol solution at 40-70°C The coupling agent is CH ₂ =C(R ₁ )-R ₂ -Si-(OR ₃ ) ₃ , wherein, R ₁ =H, -CH ₃ or -CH ₂ CH ₃ , R ₂ = O or -COO(CH ₂ ) ₃ -, R ₃ = -CH ₃ or -CH ₂ CH ₃ . 3. The hydrophobic rare earth long-lasting luminescent material according to claim 1, characterized in that: the rare earth long-lasting luminescent material is strontium aluminate doped with one or more rare earth elements. 4. The hydrophobic rare earth long-lasting luminescent material according to claim 3, characterized in that: the rare earth long-lasting luminescent material is a rare earth long-lasting luminescent material with waterproof performance. 5. The preparation method of the hydrophobic rare earth long-lasting luminescent material according to any one of claims 1-4, comprising the following steps: a. Weigh the raw materials in the following weight ratio: 10-30 parts of rare earth long-lasting luminescent material, 0.1-3 parts of coupling agent; b. Add the raw materials described in step a into the reactor, add alcohol solvent, and stir at 40-80°C for 0.5-6 hours; c. Dry to remove the solvent, and grind to obtain. 6. Polymer composite rare earth long afterglow luminescent material, characterized in that: it is made of hydrophobic rare earth long afterglow luminescent material according to any one of claims 1-4 and acrylate monomer or styrene monomer Emulsion polymerization obtained. 7. The preparation method of the polymer composite rare earth long afterglow luminescent material according to claim 6, comprising the following steps: a. Weigh the raw materials in the following weight ratio: 5-20 parts of the hydrophobic rare earth long-lasting luminescent material according to claim 1, 1-5 parts of emulsifier, 0.01-2 parts of initiator, acrylate monomer or 1-10 parts of styrene monomer, the dispersion medium is water; b. The emulsifier and initiator are respectively dissolved in water to obtain an aqueous solution, and the emulsifier aqueous solution and the hydrophobic rare earth long-lasting luminescent material are mixed evenly at 50-80°C, and the initiator aqueous solution is added under the protection of nitrogen, and the acrylate monomer or Styrene monomer; c. React for 1 to 5 hours after monomer addition, cool down, filter with suction, wash and dry. 8. The preparation method of polymer composite rare earth long afterglow luminescent material according to claim 7, characterized in that: said acrylate monomer is methyl methacrylate, methyl acrylate, 2-ethylhexyl acrylate At least one of ester, butyl acrylate, butyl methacrylate, ethyl acrylate monomer or styrene monomer; the initiator is potassium persulfate, ammonium persulfate, cumene hydroperoxide, peroxide At least one of potassium sulfate-sodium bisulfite. 9. The application of the polymer composite rare earth long afterglow luminescent material according to claim 6 in plastics. 10. Long-lasting luminescent plastic masterbatch, characterized in that it is obtained by uniformly mixing the polymer-composited rare earth long-lasting luminescent material according to claim 6 with a polymer matrix, extruding and granulating.

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