Preparation method of bonding type rare earth modified waterborne polyurethane acrylate coating

Abstract

The preparation method comprises the following steps: taking europium oxide, 2, 2-dimethylolpropionic acid and dibenzoylmethane as raw materials, reacting the prepared hydroxyl-containing rare earth complex with isophorone diisocyanate, polyethylene glycol, 2, 2-dimethylolpropionic acid and hydroxyethyl acrylate to obtain a prepolymer emulsion, and adding the prepolymer emulsion into a reaction kettle to obtain the bonding type rare earth modified waterborne polyurethane acrylate coating. And then initiating by an initiator and curing by ultraviolet light to obtain the bonding type rare earth modified waterborne polyurethane acrylate coating. The rare earth modified waterborne polyurethane acrylate coating contains the bonding type rare earth complex, so that the rare earth modified waterborne polyurethane acrylate coating has good compatibility with waterborne polyurethane acrylate, the prepolymer emulsion only needs to be initiated by an initiator and cured by ultraviolet light, the obtained coating has good film-forming property and stability, the preparation method is simple, the use is convenient, and the preparation cost is low. The method is suitable for the fields of luminescent paint, luminescent ink, medical materials and the like of a water-soluble photocuring system.

Description

Technical Field

[0001] The invention relates to a method for preparing a bonding rare earth modified waterborne polyurethane acrylate coating, specifically to the technical field of ultraviolet light curing coatings. Background Art

[0002] Rare earth polymer luminescent material refers to a functional polymer material obtained by physically or chemically introducing luminescent rare earth ions into polymers. This material combines the good properties of polymer materials such as good stability and excellent processing and molding performance with the function of excited fluorescence due to rare earth ions, and is a new material with broad prospects. Rare earth polymer composite materials are divided into two types: doped type and bonded type. There are the following problems with doped rare earth polymer composite materials: when preparing rare earth polymer materials by doping method, with the addition of rare earth complexes, the dispersion of dopants deteriorates, agglomeration occurs, and the compatibility with polymer materials deteriorates, which makes the transparency of the composite material decrease and the fluorescence performance greatly reduced. Therefore, it is not easy to prepare rare earth polymer luminescent materials with high rare earth content and good transparency, resulting in limited application; rare earth doping will also reduce the solvent resistance and water resistance of the composite material; rare earth polymer composite materials take a long time to dry and have a slow curing speed. Therefore, the mixing compatibility, film processing and stability between rare earth and polymer materials in rare earth doped polymer materials are still the problems that need to be solved at present.

[0003] In order to reduce the fluorescence quenching of the complex caused by the increase of dopant concentration and the aggregation, a bonded rare earth polymer composite material can be used to prepare a rare earth polymer composite material with good dispersion, compatibility, transparency and excellent fluorescence performance. Compared with the traditional bonded rare earth polymer, the structure and performance of the bonded rare earth polymer composite material prepared by the reaction of hydrogen atoms on the active group with isocyanate on isophorone-diisocyanate can be adjusted, and due to the existence of the network structure, the rare earth ions will be effectively fixed in the grid, avoiding the displacement, dissociation and aggregation of small molecule ligands, so the rare earth content in the composite material is high, so that the rare earth properties in the composite material can be fully exerted.

[0004] The present invention combines two green technologies, ultraviolet light curing technology and water-based environmentally friendly materials, introduces rare earth compounds into environmentally friendly technology, and proposes a preparation method of a bonded rare earth modified water-based polyurethane acrylate coating. The method can solve the problems of uneven mixing of rare earth elements in polymer materials, poor stability, and difficult processing, and endows light-curing materials with unique rare earth properties. The light-curing materials can be used in the fields of luminous coatings, inks, etc., and have important practical significance for the development of radiation curing technology. Summary of the invention

[0005] In view of the problems existing in the above-mentioned doped rare earth polymer composite materials, the object of the present invention is to provide a method for preparing a bonded rare earth modified waterborne polyurethane acrylate coating.

[0006] The invention discloses a method for preparing a bonded rare earth modified waterborne polyurethane acrylate coating. The method comprises the following steps: using europium oxide, 2,2-dihydroxymethylpropionic acid (DMPA) and dibenzoylmethane (DBM) as raw materials to prepare a hydroxyl-containing rare earth complex (Eu(DMPA)3•DBM), which is then reacted with isophorone diisocyanate (IPDI), polyethylene glycol (PEG400), 2,2-dihydroxymethylpropionic acid (DMPA) and hydroxyethyl acrylate (HEA) to obtain a prepolymer emulsion, which is then cured by ultraviolet light to obtain a bonded rare earth modified waterborne polyurethane acrylate coating. The specific process is as follows: Step 1: Preparation of rare earth complexes Add europium oxide (Eu2O3) to hydrochloric acid, heat and stir until europium oxide is completely dissolved, and continue to heat until the reaction solution is completely evaporated to obtain white powdery europium chloride (EuCl3). After cooling, add anhydrous ethanol to dissolve it to obtain an anhydrous ethanol solution of europium chloride for use; After stirring and heating the mixture of 2,2-dihydroxymethylpropionic acid (DMPA) and ethanol to 70°C, sodium hydroxide solution was added to adjust the pH to 7, and then anhydrous ethanol solution of europium chloride was added dropwise; after the addition was completed, dibenzoylmethane (DBM) was added dropwise, and the reaction was stirred for 4 hours before the reaction was terminated. After 24 hours of static precipitation, the product was filtered and vacuum dried to obtain a hydroxyl-containing rare earth complex (Eu(DMPA)3•DBM); Step 2: Preparation of prepolymer emulsion Under stirring conditions at 50°C, polyethylene glycol (PEG400) and catalyst dibutyltin dilaurate (DBTL) were added dropwise to isophorone diisocyanate (IPDI), stirred for reaction for 2 hours, and then the temperature was raised to 60°C, and then N-vinyl pyrrolidone (NVP) solution of rare earth complex was added dropwise, and the stirring reaction was continued for 2 hours, and then inhibitors p-hydroxyanisole (MEHQ) and hydroxyethyl acrylate (HEA) were added dropwise, and after 4 hours of reaction, the mixture was cooled to room temperature, and triethylamine was added and stirred rapidly to react fully, and then water was added dropwise to fully emulsify the reaction product to obtain a prepolymer emulsion; Step 3: Preparation of bonded rare earth modified waterborne polyurethane acrylate coating A photoinitiator with a mass percentage of 5% is added to the prepolymer emulsion, stirred and dissolved, and then evenly applied to form a film, which is then cured by ultraviolet light to obtain a bonded rare earth modified waterborne polyurethane acrylate coating.

[0007] The molar ratio of europium oxide, 2,2-dimethylolpropionic acid and dibenzoylmethane is 1:3:1; the molar ratio of isophorone diisocyanate, polyethylene glycol, 2,2-dimethylolpropionic acid and hydroxyethyl acrylate is 1:1:1:1.

[0008] The photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173).

[0009] Beneficial effects of the present invention: The rare earth modified waterborne polyurethane acrylate coating of the present invention has good compatibility with waterborne polyurethane acrylate due to the presence of a bonded rare earth complex, and the prepolymer emulsion only needs to be initiated by an initiator and cured by ultraviolet light, and the obtained coating has good film-forming property and stability, the preparation method is simple, and the use is convenient, and the coating is suitable for the fields of luminescent coatings, luminescent inks, medical materials, etc. of water-soluble photocuring systems. DETAILED DESCRIPTION

[0010] Example 1 Step 1: Preparation of rare earth complexes (1) Weigh 1 mmol (0.352 g) of Eu2O3 into a beaker, add 10 ml of hydrochloric acid, and heat with a constant temperature heating magnetic stirrer until Eu2O3 is completely dissolved. Continue heating until the solution is completely evaporated to obtain white powdery solid EuCl3. After cooling, add 5 ml of anhydrous ethanol to dissolve it to obtain anhydrous ethanol solution of EuCl3 for later use.

[0011] (2) Place a three-necked flask equipped with a thermometer and a condenser on a constant temperature heating magnetic stirrer.

[0012] (3) Weigh 6 mmol (0.804 g) of DMPA and 5 ml of ethanol (for dissolution) into a three-necked flask, add a stirring bar, adjust the temperature to 70 °C and stir.

[0013] (4) After complete dissolution, add 6 ml of sodium hydroxide solution and adjust the pH to 7.

[0014] (5) Use a rubber-tipped dropper to add anhydrous ethanol solution of EuCl3. After the addition is complete, measure the pH value and adjust the pH value to 7. Weigh 4 mmol (0.896 g) of DBM and dissolve it in ethanol. After the system reacts for 1 hour, add the dissolved DBM and adjust the pH value of the system to 7.

[0015] (6) After continuing the reaction for 4 hours, the constant temperature heating magnetic stirrer was turned off and the mixture was left to stand overnight to allow the precipitate to completely settle out. The mixture was then filtered and rinsed with deionized water and anhydrous ethanol. Finally, the product was vacuum dried to a constant weight to obtain a rare earth complex.

[0016] Step 2: Preparation of prepolymer emulsion (1) Assemble a stirrer, a thermometer, a constant pressure funnel, a condenser, and a four-necked flask, add 22.2 g of IPDI (isophorone diisocyanate) into the four-necked flask, and add 40 g of PEG400 (polyethylene glycol) and a catalyst DBTL (dibutyltin dilaurate) into the constant pressure funnel while stirring at 50°C, dripping them in at a rate of about one drop every three seconds.

[0017] (2) Measure the concentration of isocyanate (-NCO) in the reaction system every hour until the amount of -NCO in the system is consumed by the reaction to the specified value. Then, add 13.4 g of DMPA (2,2-dihydroxymethylpropionic acid) and a rare earth complex dissolved in 10 ml of NVP (N-vinyl pyrrolidone) under stirring, and raise the temperature to 60°C.

[0018] (3) After 2 hours of reaction, add 0.1% of inhibitor MEHQ (p-hydroxyanisole) and 11.6g of hydroxyethyl acrylate (HEA) under stirring, and continue to measure the concentration of -NCO in the reaction system every hour. When the concentration of -NCO in the system is consumed by 98%, cool the device to room temperature, add 10.1g of triethylamine and stir rapidly. After sufficient reaction, keep stirring and add 10ml of water. After sufficient emulsification, the prepolymer emulsion can be obtained.

[0019] Step 3: Preparation of bonded rare earth modified waterborne polyurethane acrylate coating Weigh 1 g of prepolymer emulsion, add 0.05 g of photoinitiator 1173, and after the photoinitiator is completely dissolved, evenly apply it on the patch with a glass rod, then prevent irradiation in a UV curing device and cure for 60 seconds to obtain a bonded rare earth modified waterborne polyurethane acrylate coating.

[0020] Example 2 Step 1: Preparation of rare earth complexes The specific method is the same as that of Example 1.

[0021] Step 2: Preparation of prepolymer emulsion (1) Assemble a stirrer, a thermometer, a constant pressure funnel, a condenser, and a four-necked flask, add 17.4 g of TDI (toluene diisocyanate) into the four-necked flask, and add 40 g of PEG400 (polyethylene glycol) and a catalyst DBTL (dibutyltin dilaurate) into the constant pressure funnel while stirring at 50°C, dripping them in at a rate of about one drop every three seconds.

[0022] (2) After reacting for 2 hours, 13.4 of DMPA (2,2-dihydroxymethylpropionic acid) and a rare earth complex dissolved in 10 ml of NVP (N-vinylpyrrolidone) were added under stirring, and the temperature was raised to 60°C.

[0023] (3) After 2 hours of reaction, add 0.1% of inhibitor MEHQ (p-hydroxyanisole) and hydroxyethyl acrylate (HEA) under stirring, and continue to measure the concentration of -NCO in the reaction system every hour. When the concentration of -NCO in the system is consumed by 98%, cool the device to room temperature, add 10.1g of triethylamine and stir rapidly. After sufficient reaction, keep stirring and add 10ml of water. After sufficient emulsification, the prepolymer emulsion can be obtained.

[0024] Step 3: Preparation of bonded rare earth modified waterborne polyurethane acrylate coating Weigh 1 g of prepolymer emulsion, add 0.05 g of photoinitiator 1173, stir, and after the photoinitiator is completely dissolved, evenly apply it on a glass sheet with a glass rod, then place it in a UV curing device for irradiation, and cure it for 60 seconds to obtain a bonded rare earth modified waterborne polyurethane acrylate coating.

Claims

1. A method for preparing a bonded rare earth modified waterborne polyurethane acrylate coating, characterized in that: The preparation method is to use europium oxide, 2,2-dimethylolpropionic acid, and dibenzoylmethane as raw materials to prepare a hydroxyl-containing rare earth complex, which is then reacted with isophorone diisocyanate, polyethylene glycol, 2,2-dimethylolpropionic acid, and hydroxyethyl acrylate to obtain a prepolymer emulsion, which is then cured by ultraviolet light to obtain a bonded rare earth modified waterborne polyurethane acrylate coating. The specific process is as follows: Step 1: Preparation of rare earth complexes Add europium oxide to hydrochloric acid, heat and stir until europium oxide is completely dissolved, continue heating until the reaction solution is completely evaporated to obtain white powdery europium chloride, then add anhydrous ethanol to dissolve it, and obtain an anhydrous ethanol solution of europium chloride for use; After stirring and heating the mixture of 2,2-dimethylolpropionic acid and ethanol to 70°C, sodium hydroxide solution is added to adjust the pH to 7, and then anhydrous ethanol solution of europium chloride is added dropwise; after the addition is completed, dibenzoylmethane is added dropwise, and the reaction is stirred for another 4 hours before the reaction is terminated. After 24 hours of static precipitation, the product is filtered and vacuum dried to obtain a hydroxyl-containing rare earth complex; Step 2: Preparation of prepolymer emulsion Under stirring conditions at 50° C., polyethylene glycol and a catalyst dibutyltin dilaurate are added dropwise to isophorone diisocyanate, stirred for reaction for 2 hours, and then the temperature is raised to 60° C., then a rare earth complex N-vinyl pyrrolidone solution is added dropwise, and the stirring reaction is continued for 2 hours, and then a polymerization inhibitor p-hydroxyanisole and hydroxyethyl acrylate are added dropwise, and after 4 hours of reaction, the mixture is cooled to room temperature, and then triethylamine is added and stirred rapidly. After the reaction is fully completed, water is added dropwise to fully emulsify the reaction product to obtain a prepolymer emulsion; Step 3: Preparation of bonded rare earth modified waterborne polyurethane acrylate coating A photoinitiator with a mass percentage of 5% is added to the prepolymer emulsion, stirred and dissolved, and then evenly applied to form a film, which is then cured by ultraviolet light to obtain a bonded rare earth modified waterborne polyurethane acrylate coating.

2. The method for preparing a bonded rare earth modified waterborne polyurethane acrylate coating according to claim 1, characterized in that: The molar ratio of europium oxide, 2,2-dimethylolpropionic acid and dibenzoylmethane is 1:3:1; the molar ratio of isophorone diisocyanate, polyethylene glycol, 2,2-dimethylolpropionic acid and hydroxyethyl acrylate is 1:1:1:

1.

3. The method for preparing a bonded rare earth modified waterborne polyurethane acrylate coating according to claim 1, characterized in that: The photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone.