Scratch-resistant ultraviolet-resistant polycarbonate resin composite coating material and preparation method thereof

Abstract

The present disclosure relates to the technical field of high polymer materials, and particularly relates to a scratch-resistant and ultraviolet-resistant polycarbonate resin composite coating material and a preparation method thereof. The composite coating material comprises a hardening layer and an ultraviolet-resistant layer. The hardening layer is prepared by blending polycarbonate and poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) and taking polycarbonate as a base. The ultraviolet-resistant layer is a polyurethane material containing a first ultraviolet-resistant agent. The first ultraviolet-resistant agent is second metal oxide nanoparticles doped with a first metal element. The first metal element and the second metal element are both selected from rare earth elements.

Description

Technical Field

[0001] This disclosure relates to the field of polymer materials technology, and in particular to a scratch-resistant and UV-resistant polycarbonate resin composite coating material and its preparation method. Background Technology

[0002] Polycarbonate (PC) is a high-molecular-weight polymer containing carbonate groups in its molecular chain. Based on the structure of the ester groups, it can be classified into various types, including aliphatic, aromatic, and aliphatic-aromatic. Polycarbonate is a thermoplastic engineering plastic with excellent comprehensive properties, possessing advantages such as high impact strength, good light transmittance, good dimensional stability, easy coloring, and good aging resistance. It also has excellent electrical insulation properties, making it suitable for various molding methods such as injection molding, extrusion, and blow molding. Therefore, it is widely used in electronics, electrical appliances, construction, machinery, packaging, and transportation. However, polycarbonate has poor UV resistance. Polycarbonate used outdoors is often exposed to ultraviolet radiation, shortening its service life and reducing its performance. Adding a UV-resistant layer to polycarbonate can enhance its UV resistance, but this may also lead to a decrease in the material's flame retardant properties. Therefore, there is an urgent need to develop a polycarbonate composite material that combines UV resistance and flame retardancy. Summary of the Invention

[0003] This disclosure provides a scratch-resistant and UV-resistant polycarbonate resin composite coating material and its preparation method to address the shortcomings of related technologies.

[0004] According to a first aspect of the present disclosure, a scratch-resistant and UV-resistant polycarbonate resin composite coating material is provided, the composite coating material comprising: Hardened layer and UV-resistant layer; The hardened layer is prepared by blending polycarbonate with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) based on polycarbonate. The UV-resistant layer is a polyurethane material containing a first UV-resistant agent; the first UV-resistant agent is a second metal oxide nanoparticle doped with a first metal element, wherein the first metal element and the second metal element are selected from rare earth elements.

[0005] In one aspect of this disclosure, the hardened layer further comprises a first flame retardant compound; the first flame retardant compound is selected from octaphenyl-polyhedral oligomeric silsesquioxane.

[0006] In one aspect of this disclosure, the first UV stabilizer is selected from lanthanum-doped cerium dioxide nanoparticles.

[0007] In one aspect of this disclosure, the lanthanum-doped cerium dioxide nanoparticles are prepared by the following steps: Step A-1: ​​Dissolve cerium carbonate and lanthanum carbonate separately using nitric acid solution to obtain an acid solution containing cerium ions and an acid solution containing lanthanum ions; wherein the molar ratio of lanthanum carbonate to cerium carbonate is selected from (0.01-0.1):1; Step A-2: Dissolve ammonium carbonate in nitric acid solution to obtain a coprecipitant solution; under stirring, simultaneously add the coprecipitant solution and the acid solution containing lanthanum ions to the acid solution containing cerium ions, and then age for 10-24 hours to obtain an aged mixture. Step A-3: Heat the aged mixture at 150℃-200℃ for 1.5-3 hours, then filter, wash and dry to obtain precursor particles; Step A-4: The precursor particles are calcined at 500℃-700℃ for 3-6 hours to obtain the lanthanum-doped cerium dioxide nanoparticles.

[0008] In one aspect of this disclosure, the polyurethane material further comprises a second UV stabilizer, wherein the second UV stabilizer is hydrotalcite nanoparticles; preferably, the hydrotalcite nanoparticles are zinc-titanium hydrotalcite nanoparticles.

[0009] In one aspect of this disclosure, the hydrotalcite nanoparticles are zinc-titanium hydrotalcite nanoparticles; wherein, the zinc-titanium hydrotalcite nanoparticles are prepared through the following steps. Step B-1: Add titanium tetrachloride and zinc nitrate to water, and while stirring, add urea aqueous solution; then place the resulting mixture in an autoclave and age it at 180℃-200℃ for 24-36h to obtain the product of step B-1; wherein, the molar ratio of titanium tetrachloride and zinc nitrate is selected from (1-4):1; Step B-2: After centrifugation, the solid product obtained in step B-1 is separated. The solid product is then washed and dried to obtain the zinc-titanium hydrotalcite nanoparticles.

[0010] In one aspect of this disclosure, the polyurethane material further comprises a third UV stabilizer, which is prepared by the following steps: Step C-1: Compound C-1 is obtained by reacting 2,4-dihydroxybenzophenone with epichlorohydrin; the structural formula of compound C-1 is shown below:

[0011] Step C-2: React compound C-1 with polyethyleneimine to obtain the third UV stabilizer.

[0012] In one aspect of this disclosure, the polyurethane material further comprises a second flame retardant compound; the second flame retardant compound is prepared by the following steps: Step D-1: Add DOPO to the reaction vessel and raise the temperature to 120℃-140℃ until the DOPO is completely melted; Step D-2: Keeping the temperature constant, add tris(epoxypropyl)isocyanurate to the completely melted DOPO. After the tris(epoxypropyl)isocyanurate is completely melted, add the resulting mixture to an organic solvent, then raise the temperature to 160℃-170℃ and react for 2-5 hours. Then, after extraction and purification, compound D-1 is obtained. The structural formula of compound D-1 is shown below:

[0013] Step D-3: React compound D-1 with polyethyleneimine to obtain the second flame retardant compound.

[0014] According to a second aspect of the present disclosure, a method for preparing the aforementioned polycarbonate resin composite coating material is provided, the method comprising the following steps: Step 1: Provide dry polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane; melt-blend the polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane; then hot-press and quench-form to obtain the hardened layer; Step 2: Prepare the third UV stabilizer and the second flame retardant compound; Step 3: Add one of the dried polyether polyol or polyester polyol to the container, heat to 60℃-80℃ and mechanically stir and reflux. Then dissolve the diisocyanate and catalyst in an organic solvent and add them dropwise to the container. Continue the reaction for 1-2 hours. Then add the prepared third UV stabilizer and second flame retardant compound and continue the reaction for 1-2 hours to obtain the polyurethane prepolymer. Step 4: Prepare the first and second UV stabilizers; Step 5: Dissolve the chain extender and catalyst in an organic solvent to obtain a chain extender solution. Add a portion of the chain extender solution to the polyurethane prepolymer and continue the reaction at 60℃-80℃ for 1-2 hours. Then add the prepared second UV stabilizer and continue the reaction for 30-60 minutes. Then add the prepared first UV stabilizer and the remaining chain extender solution and continue the reaction for 2-4 hours. Pour the mixture into a mold and dry it to obtain the UV stabilizer layer. Step 6: The prepared UV-resistant layer and hardened layer are bonded together to obtain a polycarbonate resin composite coating material.

[0015] In one aspect of the embodiments of this disclosure, in step 3, the polyether polyol is selected from polytetrahydrofuran ether diol, polypropylene glycol, or polyethylene glycol; the polyester polyol is selected from polycaprolactone diol, polyethylene adipate diol, polybutylene adipate diol, polypropylene adipate diol, polyhexyl adipate diol, or polybutylene phthalate diol.

[0016] In one aspect of this disclosure, in step 3, the catalyst is selected from dibutyltin dilaurate, stannous octoate, triethylamine, triethylenediamine, triethanolamine, or aromatic amine compounds.

[0017] In one aspect of this disclosure, in step 3, the diisocyanate is selected from toluene diisocyanate, dimethylbiphenyl diisocyanate, diphenylmethane diisocyanate, isophenyl dimethyl isocyanate, tetramethylphenyl dimethylene diisocyanate, isophorone diisocyanate trimer, hexamethylene diisocyanate trimer, 1,4-cyclohexane dimethyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, or hexamethylene diisocyanate.

[0018] In one aspect of the embodiments of this disclosure, in step 3, the chain extender is selected from 1,4-butanediol, diethylene glycol, trimethylolpropane, ethylene glycol, glycerol, 1,4-cyclohexanediol, or resorcinol hydroxy ether.

[0019] In one aspect of the embodiments of this disclosure, in step 1, the conditions for melt blending are: temperature selected from 170℃-190℃, rotor speed selected from 50-80 r / min, and mixing time selected from 5-10 min.

[0020] In one aspect of the embodiments of this disclosure, in step 1, the hot pressing conditions are: preheating at 170°C-190°C for 3-5 minutes, followed by hot pressing for 3-5 minutes, with the pressure selected from 10 MPa.

[0021] In one aspect of the present disclosure, in step 1, the quenching temperature is selected from 0-5°C.

[0022] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: As can be seen from the above embodiments, this disclosure provides an environmentally friendly polycarbonate composite material that combines scratch resistance, UV resistance, and flame retardancy.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Detailed Implementation

[0024] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0026] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0027] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0028] In this description, unless otherwise stated, "above" and "below" include the stated number.

[0029] Unless otherwise stated, the terms used in this disclosure have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the values ​​of the parameters mentioned in this disclosure can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this disclosure).

[0030] The term "about" is used to describe and indicate small variations. When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0031] The list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

[0032] In this disclosure, specifically, lanthanum-doped cerium dioxide nanoparticles are prepared via the following steps: Step A-1: ​​Dissolve 9.2g of cerium carbonate in 180mL of 3mol / L nitric acid solution, and dissolve 0.46g of lanthanum carbonate in 20mL of 3mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. Step A-2: Dissolve 2.88g of ammonium carbonate in 25mL of 3mol / L nitric acid solution to obtain a coprecipitant solution; under stirring, simultaneously add the coprecipitant solution and the acid solution containing lanthanum ions to the acid solution containing cerium ions, and then age for 18h to obtain an aged mixture. Step A-3: The aged mixture is heated at 180°C for 2.5 hours, and then filtered, washed and dried to obtain precursor particles; Step A-4: The precursor particles were calcined at 600℃ for 5 hours to obtain lanthanum-doped cerium dioxide nanoparticles.

[0033] In one aspect of this disclosure, zinc-titanium hydrotalcite nanoparticles are specifically prepared through the following steps. Step B-1: Add 4.4 mL of titanium tetrachloride (7.6 g) and 5.42 g of zinc nitrate to 100 mL of water, and while stirring, add 45 mL of 20% urea aqueous solution; then place the resulting mixture in an autoclave and age it at 185 °C for 32 h to obtain the product of step B-1; Step B-2: After centrifuging the product obtained in step B-1 at 3000 r / min for 5 min, the solid product is separated. The obtained solid product is washed and dried to obtain zinc-titanium hydrotalcite nanoparticles.

[0034] In one aspect of this disclosure, specifically, the third UV stabilizer is prepared by the following steps: Step C-1: Dissolve 21.4 g of 2,4-dihydroxybenzophenone in 200 mL of 1.5 mol / L NaOH solution, then add 9.25 g of epichlorohydrin dropwise. React at 120 °C and 300 W microwave power for 30 min. After the reaction, add ethyl acetate to the mixture, separate the layers, wash the organic phase three times with hot water, and then dry with anhydrous sodium sulfate to obtain compound C-1. The structural formula of compound C-1 is shown below:

[0035] Step C-2: Compound C-1 was dissolved in 60 mL of DMF under nitrogen protection, and then 18 mL of polyethyleneimine was added. The mixture was reacted at 70 °C for 6 h to obtain the third UV stabilizer. The third UV stabilizer has the following structure:

[0036] In one aspect of this disclosure, specifically, the second flame retardant compound is prepared by the following steps: Step D-1: Add 21.6g of DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) to a 500mL four-necked round-bottom glass flask equipped with a reflux condenser and a thermometer, and raise the temperature to 130°C until the DOPO is completely melted. Step D-2: While maintaining a constant temperature, add 29.7 g of tris(epoxypropyl)isocyanurate to the completely melted DOPO at a rate of 1.2 g / min. After the tris(epoxypropyl)isocyanurate is completely melted, add the mixture to DMAc, then raise the temperature to 165 °C and react for 3 h. After extraction, washing, and purification, compound D-1 is obtained. The structural formula of compound D-1 is shown below:

[0037] Step D-3: Dissolve compound D-1 in 100 mL of DMF under nitrogen protection, then add 25 mL of polyethyleneimine and react at 70 °C for 8 h to obtain the second flame retardant compound; the second flame retardant compound has the following structure (the following formula only shows that one epoxy group undergoes an ammoniation reaction with polyethyleneimine, but in fact both epoxy groups undergo an ammoniation reaction with polyethyleneimine):

[0038] Specifically, for the polyurethane obtained in this disclosure, the polyester polyol used is polycaprolactone diol 2000; the catalyst used is dibutyltin dilaurate; the diisocyanate used is selected from isophorone diisocyanate; and the obtained polyurethane prepolymer includes the following structure:

[0039] The Ar portion and the two amino groups connected to Ar are the aforementioned second flame retardant compound and / or third UV stabilizer; in this disclosure, the second flame retardant compound and / or third UV stabilizer enter the polyurethane chain segment, which has better flame retardant / UV stabilizer capabilities and higher weather resistance.

[0040] In this disclosure, the chain extender used is selected from, but not limited to, 1,4-butanediol.

[0041] In this disclosure, when the polyurethane material contains only a first UV stabilizer, a method for preparing the aforementioned polycarbonate resin composite coating material is provided, the method comprising the following steps: Dry polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are provided; the polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended; and then the mixture is hot-pressed and quenched to obtain the hardened layer. One of the dried polyether polyol or polyester polyol is added to a container, heated to 60℃-80℃ and mechanically stirred and refluxed. Then, the diisocyanate and catalyst are dissolved in an organic solvent and added dropwise to the container. The reaction is continued for 2-4 hours to obtain a polyurethane prepolymer. Step 4: Prepare the first UV stabilizer; Step 5: Dissolve the chain extender and catalyst in an organic solvent to obtain a chain extender solution. Add a portion of the chain extender solution to the polyurethane prepolymer and continue the reaction at 60℃-80℃ for 1.5-3h. Then add the prepared first UV absorber and the remaining chain extender solution and continue the reaction for 2-4h. Then pour it into a mold and dry it to obtain the UV absorber layer. Step 6: The prepared UV-resistant layer and hardened layer are bonded together to obtain a polycarbonate resin composite coating material.

[0042] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention were obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process was carried out at room temperature.

[0043] Examples and comparative examples: Example 1: Example 1 includes the following steps: 1. Preparation of lanthanum-doped cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution, and 0.46 g of lanthanum carbonate was dissolved in 20 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. Under stirring, the coprecipitant solution and the acid solution containing lanthanum ions were simultaneously added dropwise to the acid solution containing cerium ions, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain lanthanum-doped cerium dioxide nanoparticles as the first UV stabilizer.

[0044] 2. Preparation of composite coating materials: 150 parts by weight of dried polycarbonate (all polycarbonates used in the examples are propylene carbonate), 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane were provided. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane were melt-blended. The mixture was then subjected to hot pressing and quenching. The hot pressing conditions were: preheating at 185°C for 3 min, followed by hot pressing for 5 min at a pressure of 10 MPa. The quenching temperature was 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 3 hours to obtain polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 2 hours. Then, 8 parts by weight of the first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 hours. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The obtained UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 1.

[0045] Example 2: Example 2 includes the following steps: 1. Preparation of cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. The coprecipitant solution was added dropwise to the acid solution containing cerium ions under stirring, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain cerium dioxide nanoparticles as the first UV stabilizer.

[0046] 2. Preparation of composite coating materials: The method provides 150 parts by weight of dried polycarbonate, 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended. The mixture is then hot-pressed and quenched. The hot-pressing conditions are: preheating at 185°C for 3 minutes, followed by hot pressing for 5 minutes at a pressure of 10 MPa. The quenching temperature is 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 3 hours to obtain polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 2 hours. Then, 8 parts by weight of the first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 hours. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The obtained UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 2.

[0047] Example 3: The steps of Example 3 are the same as those of Example 1, except that the same molar amount of copper carbonate is used in Example 3 instead of the lanthanum carbonate used in Example 1.

[0048] Example 4: The steps of Example 4 are the same as those of Example 1, except that the same molar amount of ferric chloride is used in Example 4 instead of the lanthanum carbonate used in Example 1.

[0049] Example 5: The steps of Example 5 are the same as those of Example 1, except that the same molar amount of neodymium carbonate is used in Example 5 instead of lanthanum carbonate used in Example 1.

[0050] UV resistance test: The UV absorbance of samples from Examples 1-5 after being placed outdoors for 1 day and 45 days was tested. The UV transmittance under transmitted light conditions was tested using a spectrophotometer (Konica Corporation of Japan, model CM-5). The test results are shown in Table 1 below.

[0051] Table 1:

[0052] As can be seen, compared with cerium dioxide nanoparticles doped with other metal elements, cerium dioxide nanoparticles doped with lanthanum can better improve the UV resistance of composite materials.

[0053] Example 6: Example 6 includes the following steps: 1. Preparation of lanthanum-doped cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution, and 0.46 g of lanthanum carbonate was dissolved in 20 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. Under stirring, the coprecipitant solution and the acid solution containing lanthanum ions were simultaneously added dropwise to the acid solution containing cerium ions, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain lanthanum-doped cerium dioxide nanoparticles as the first UV stabilizer.

[0054] 2. Preparation of the second UV stabilizer: 4.4 mL of titanium tetrachloride (7.6 g) and 5.42 g of zinc nitrate were added to 100 mL of water. While stirring, 45 mL of 20% urea aqueous solution was added. The resulting mixture was then placed in an autoclave and aged at 185 °C for 32 h. The resulting product was centrifuged at 3000 r / min for 5 min to separate the solid product. The solid product was washed and dried to obtain zinc-titanium hydrotalcite nanoparticles as a second UV stabilizer.

[0055] 3. Preparation of composite coating materials: The method provides 150 parts by weight of dried polycarbonate, 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended. The mixture is then hot-pressed and quenched. The hot-pressing conditions are: preheating at 185°C for 3 minutes, followed by hot pressing for 5 minutes at a pressure of 10 MPa. The quenching temperature is 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 3 hours to obtain polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 1.5 h. Then, 5 parts by weight of the prepared second UV inhibitor were added, and the reaction was continued for 30 min. Then, 8 parts by weight of the prepared first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 h. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The prepared UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 6.

[0056] Example 7: The steps of Example 7 are the same as those of Example 6, except that in Example 7, aluminum nitrate is used instead of titanium tetrachloride used in Example 1, and magnesium nitrate is used instead of zinc nitrate used in Example 1; the hydrotalcite material obtained in Example 7 is magnesium aluminum hydrotalcite.

[0057] Example 8: The steps of Example 8 are the same as those of Example 6, except that in Example 8, aluminum nitrate is used instead of titanium tetrachloride used in Example 1 in the same molar amount, and nickel nitrate is used instead of zinc nitrate used in Example 1 in the same molar amount; the hydrotalcite material obtained in Example 7 is nickel-aluminum hydrotalcite.

[0058] Example 9: The steps of Example 9 are the same as those of Example 6, except that in Example 8, the same molar amount of aluminum nitrate is used instead of titanium tetrachloride used in Example 1, and the same molar amount of cobalt nitrate is used instead of zinc nitrate used in Example 1; the hydrotalcite material obtained in Example 7 is cobalt aluminum hydrotalcite.

[0059] Example 10: The steps of Example 10 are the same as those of Example 6, except that in Example 8, the same molar amount of ferric nitrate is used instead of titanium tetrachloride used in Example 1, and the same molar amount of nickel nitrate is used instead of zinc nitrate used in Example 1; the hydrotalcite material obtained in Example 7 is nickel-iron hydrotalcite.

[0060] UV protection test: The UV absorbance of samples from Examples 1-5 after being placed outdoors for 1 day and 45 days was tested. The UV transmittance under transmitted light conditions was measured using a spectrophotometer (Konica Minolta, Japan, model CM-5). The test results are shown in Table 2 below.

[0061] Table 2:

[0062] As can be seen, the zinc-titanium hydrotalcite nanoparticles provided in this disclosure can effectively improve the UV resistance of composite materials.

[0063] Example 11: Example 11 includes the following steps: 1. Preparation of lanthanum-doped cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution, and 0.46 g of lanthanum carbonate was dissolved in 20 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. Under stirring, the coprecipitant solution and the acid solution containing lanthanum ions were simultaneously added dropwise to the acid solution containing cerium ions, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain lanthanum-doped cerium dioxide nanoparticles as the first UV stabilizer.

[0064] 2. Preparation of the second UV stabilizer: 4.4 mL of titanium tetrachloride (7.6 g) and 5.42 g of zinc nitrate were added to 100 mL of water. While stirring, 45 mL of 20% urea aqueous solution was added. The resulting mixture was then placed in an autoclave and aged at 185 °C for 32 h. The resulting product was centrifuged at 3000 r / min for 5 min to separate the solid product. The solid product was washed and dried to obtain zinc-titanium hydrotalcite nanoparticles as a second UV stabilizer.

[0065] 3. Preparation of the third UV stabilizer: 21.4 g of 2,4-dihydroxybenzophenone was dissolved in 200 mL of 1.5 mol / L NaOH solution, and then 9.25 g of epichlorohydrin was added dropwise. The reaction was carried out at 120 °C with a microwave power of 300 W for 30 min. After the reaction was completed, ethyl acetate was added to the mixture, and the liquid was separated. The organic phase was washed three times with hot water and then dried with anhydrous sodium sulfate to obtain compound C-1. The structural formula of compound C-1 is shown below:

[0066] Compound C-1 was dissolved in 60 mL of DMF under nitrogen protection, and then 18 mL of polyethyleneimine was added. The mixture was reacted at 70 °C for 6 h to obtain the third UV stabilizer. The third UV stabilizer has the following structure:

[0067] 3. Preparation of composite coating materials: The method provides 150 parts by weight of dried polycarbonate, 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended. The mixture is then hot-pressed and quenched. The hot-pressing conditions are: preheating at 185°C for 3 minutes, followed by hot pressing for 5 minutes at a pressure of 10 MPa. The quenching temperature is 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C, and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of the catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 1.5 h. Then, 8 parts by weight of the prepared third UV stabilizer were added, and the reaction was continued for 1.5 h to obtain the polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 1.5 h. Then, 5 parts by weight of the prepared second UV inhibitor were added, and the reaction was continued for 30 min. Then, 8 parts by weight of the prepared first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 h. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The prepared UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 11.

[0068] Example 12: Example 12 includes the following steps: 1. Preparation of lanthanum-doped cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution, and 0.46 g of lanthanum carbonate was dissolved in 20 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. Under stirring, the coprecipitant solution and the acid solution containing lanthanum ions were simultaneously added dropwise to the acid solution containing cerium ions, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain lanthanum-doped cerium dioxide nanoparticles as the first UV stabilizer.

[0069] 2. Preparation of the second UV stabilizer: 4.4 mL of titanium tetrachloride (7.6 g) and 5.42 g of zinc nitrate were added to 100 mL of water. While stirring, 45 mL of 20% urea aqueous solution was added. The resulting mixture was then placed in an autoclave and aged at 185 °C for 32 h. The resulting product was centrifuged at 3000 r / min for 5 min to separate the solid product. The solid product was washed and dried to obtain zinc-titanium hydrotalcite nanoparticles as a second UV stabilizer.

[0070] 3. Preparation of the third UV stabilizer: 21.4 g of 2,4-dihydroxybenzophenone was dissolved in 200 mL of 1.5 mol / L NaOH solution, and then 9.25 g of epichlorohydrin was added dropwise. The mixture was reacted at 120 °C with a microwave power of 300 W for 30 min. After the reaction, ethyl acetate was added to the mixture, and the liquid was separated. The organic phase was washed three times with hot water and then dried with anhydrous sodium sulfate to obtain compound C-1 as the third UV stabilizer. The structural formula of compound C-1 is shown below:

[0071] 4. Preparation of composite coating materials: The method provides 150 parts by weight of dried polycarbonate, 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended. The mixture is then hot-pressed and quenched. The hot-pressing conditions are: preheating at 185°C for 3 minutes, followed by hot pressing for 5 minutes at a pressure of 10 MPa. The quenching temperature is 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C, and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of the catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 1.5 h. Then, 8 parts by weight of the prepared third UV stabilizer were added, and the reaction was continued for 1.5 h to obtain the polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 1.5 h. Then, 5 parts by weight of the prepared second UV inhibitor were added, and the reaction was continued for 30 min. Then, 8 parts by weight of the prepared first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 h. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The prepared UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 11.

[0072] The main difference between Example 12 and Example 11 is that Example 12 directly uses the unammonized compound C-1 as the third UV stabilizer.

[0073] Example 13: The steps of Example 13 are the same as those of Example 11, except that the same mass of 3,3'-diaminobenzophenone is used in Example 13 instead of the third UV stabilizer used in Example 11.

[0074] Example 14: The steps of Example 14 are the same as those of Example 11, except that the same mass of 2,4-dihydroxybenzophenone (UV absorber UV-0) is used in Example 14 instead of the third UV absorber used in Example 11.

[0075] Example 15: The steps of Example 15 are the same as those of Example 11, except that the same mass of N-(p-ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine (UV absorber UV-1) is used instead of the third UV absorber used in Example 11.

[0076] UV resistance test: The UV absorbance of samples from Examples 1-5 after being placed outdoors for 1 day and 45 days was tested. The UV transmittance under transmitted light conditions was tested using a spectrophotometer (Konica Corporation of Japan, model CM-5). The test results are shown in Table 3 below.

[0077] Table 3:

[0078] As can be seen, the third UV stabilizer prepared in this disclosure can significantly improve the UV resistance of the composite material. Furthermore, since it is introduced into the polyurethane chain segment, the third UV stabilizer not only has strong UV resistance, but also shows a more obvious advantage in UV resistance compared to other commonly used UV stabilizers after 45 days of storage.

[0079] Example 16: Example 16 includes the following steps: 1. Preparation of lanthanum-doped cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution, and 0.46 g of lanthanum carbonate was dissolved in 20 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. Under stirring, the coprecipitant solution and the acid solution containing lanthanum ions were simultaneously added dropwise to the acid solution containing cerium ions, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain lanthanum-doped cerium dioxide nanoparticles as the first UV stabilizer.

[0080] 2. Preparation of the second UV stabilizer: 4.4 mL of titanium tetrachloride (7.6 g) and 5.42 g of zinc nitrate were added to 100 mL of water. While stirring, 45 mL of 20% urea aqueous solution was added. The resulting mixture was then placed in an autoclave and aged at 185 °C for 32 h. The resulting product was centrifuged at 3000 r / min for 5 min to separate the solid product. The solid product was washed and dried to obtain zinc-titanium hydrotalcite nanoparticles as a second UV stabilizer.

[0081] 3. Preparation of the third UV stabilizer: 21.4 g of 2,4-dihydroxybenzophenone was dissolved in 200 mL of 1.5 mol / L NaOH solution, and then 9.25 g of epichlorohydrin was added dropwise. The reaction was carried out at 120 °C with a microwave power of 300 W for 30 min. After the reaction was completed, ethyl acetate was added to the mixture, and the liquid was separated. The organic phase was washed three times with hot water and then dried with anhydrous sodium sulfate to obtain compound C-1. The structural formula of compound C-1 is shown below:

[0082] Compound C-1 was dissolved in 60 mL of DMF under nitrogen protection, and then 18 mL of polyethyleneimine was added. The mixture was reacted at 70 °C for 6 h to obtain the third UV stabilizer. The third UV stabilizer has the following structure:

[0083] 3. Preparation of the second flame retardant: 21.6 g of DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) was added to a 500 mL four-necked round-bottom glass flask equipped with a reflux condenser and a thermometer. The temperature was raised to 130 °C until the DOPO was completely melted. While maintaining the temperature, 29.7 g of tris(epoxypropyl)isocyanurate was added to the completely melted DOPO at a rate of 1.2 g / min. After the tris(epoxypropyl)isocyanurate was completely melted, the mixture was added to DMAc, and the temperature was raised to 165 °C. The reaction was allowed to proceed for 3 h. The mixture was then extracted, washed, and purified to obtain compound D-1. The structural formula of compound D-1 is shown below.

[0084] Compound D-1 was dissolved in 100 mL of DMF under nitrogen protection, and then 25 mL of polyethyleneimine was added. The mixture was reacted at 70 °C for 8 h to obtain the second flame retardant compound. The second flame retardant compound has the following structure (the following formula only shows that one epoxy group undergoes an ammoniation reaction with polyethyleneimine; in fact, both epoxy groups undergo an ammoniation reaction with polyethyleneimine):

[0085] 4. Preparation of composite coating materials: The method provides 150 parts by weight of dried polycarbonate, 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended. The mixture is then hot-pressed and quenched. The hot-pressing conditions are: preheating at 185°C for 3 minutes, followed by hot pressing for 5 minutes at a pressure of 10 MPa. The quenching temperature is 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C, and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of the catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 1.5 h. Then, 8 parts by weight of the prepared third UV stabilizer and 5 parts by weight of the second flame retardant compound were added, and the reaction was continued for 1.5 h to obtain the polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 1.5 h. Then, 5 parts by weight of the prepared second UV inhibitor were added, and the reaction was continued for 30 min. Then, 8 parts by weight of the prepared first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 h. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The prepared UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 16.

[0086] The UV resistance test results of Example 16 are basically the same as those of Example 11, proving that the addition of the second flame retardant does not lead to a change in UV resistance.

[0087] Example 17: The steps of Example 17 are the same as those of Example 16, except that Example 17 directly uses the same mass of unammonized compound D-1 as the second flame retardant.

[0088] Example 18: The steps of Example 18 are the same as those of Example 16, except that Example 18 uses the same mass of DOPO flame retardant instead of the second flame retardant in Example 16.

[0089] Example 19: The steps of Example 19 are the same as those of Example 16, except that Example 19 uses the same mass of tri(2-chloropropyl) phosphate flame retardant instead of the second flame retardant in Example 16.

[0090] Example 20: Example 20 includes the following steps: 1. Preparation of lanthanum-doped cerium dioxide nanoparticles: 9.2 g of cerium carbonate was dissolved in 180 mL of 3 mol / L nitric acid solution, and 0.46 g of lanthanum carbonate was dissolved in 20 mL of 3 mol / L nitric acid solution to obtain acid solutions containing cerium ions and lanthanum ions. 2.88 g of ammonium carbonate was dissolved in 25 mL of 3 mol / L nitric acid solution to obtain a coprecipitant solution. Under stirring, the coprecipitant solution and the acid solution containing lanthanum ions were simultaneously added dropwise to the acid solution containing cerium ions, and then aged for 18 h to obtain an aged mixture. The aged mixture was heated at 180 °C for 2.5 h, and then filtered, washed, and dried to obtain precursor particles. The precursor particles were calcined at 600 °C for 5 h to obtain lanthanum-doped cerium dioxide nanoparticles as the first UV stabilizer.

[0091] 2. Preparation of the second UV stabilizer: 4.4 mL of titanium tetrachloride (7.6 g) and 5.42 g of zinc nitrate were added to 100 mL of water. While stirring, 45 mL of 20% urea aqueous solution was added. The resulting mixture was then placed in an autoclave and aged at 185 °C for 32 h. The resulting product was centrifuged at 3000 r / min for 5 min to separate the solid product. The solid product was washed and dried to obtain zinc-titanium hydrotalcite nanoparticles as a second UV stabilizer.

[0092] 3. Preparation of the third UV stabilizer: 21.4 g of 2,4-dihydroxybenzophenone was dissolved in 200 mL of 1.5 mol / L NaOH solution, and then 9.25 g of epichlorohydrin was added dropwise. The mixture was reacted at 120 °C with a microwave power of 300 W for 30 min. After the reaction was completed, ethyl acetate was added to the mixture, and the liquid was separated. The organic phase was washed three times with hot water and then dried with anhydrous sodium sulfate to obtain compound C-1. Compound C-1 was dissolved in 60 mL of DMF under nitrogen protection, and then 18 mL of polyethyleneimine was added. The mixture was reacted at 70 °C for 6 h to obtain the third UV inhibitor. 3. Preparation of the second flame retardant: 21.6 g of DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) was added to a 500 mL four-necked round-bottom glass flask equipped with a reflux condenser and thermometer. The temperature was raised to 130 °C until the DOPO was completely melted. While maintaining the temperature, 29.7 g of tris(epoxypropyl)isocyanurate was added to the completely melted DOPO at a rate of 1.2 g / min. After the tris(epoxypropyl)isocyanurate was completely melted, the mixture was added to DMAc, and the temperature was raised to 165 °C for 3 h. After the reaction temperature was lowered to 100 °C, γ-aminoethylaminopropyltrimethoxysilane (KH792) was slowly poured into the above solution, and the mixture was stirred for 12 h under a nitrogen atmosphere at 50 °C. The solvent was then removed by vacuum distillation. The resulting product was washed and dried as the second flame retardant in Example 20.

[0093] 4. Preparation of composite coating materials: The method provides 150 parts by weight of dried polycarbonate, 40 parts by weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and 10 parts by weight of octaphenyl-polyhedral oligomeric silsesquioxane. The polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane are melt-blended. The mixture is then hot-pressed and quenched. The hot-pressing conditions are: preheating at 185°C for 3 minutes, followed by hot pressing for 5 minutes at a pressure of 10 MPa. The quenching temperature is 0°C, resulting in a hardened layer (0.3 mm). 100 parts by weight of dried polycaprolactone diol 2000 were added to a container, heated to 70°C, and mechanically stirred and refluxed. Then, 45 parts by weight of isophorone diisocyanate and 0.5 parts by weight of the catalyst dibutyltin dilaurate were dissolved in DMF and added dropwise to the container. The reaction was continued for 1.5 h. Then, 8 parts by weight of the prepared third UV stabilizer and 5 parts by weight of the second flame retardant compound were added, and the reaction was continued for 1.5 h to obtain the polyurethane prepolymer. 40 parts by weight of 1,4-butanediol chain extender and 0.5 parts by weight of dibutyltin dilaurate catalyst were dissolved in an organic solvent to obtain a chain extender solution. Half the volume of the chain extender solution was added to the polyurethane prepolymer, and the reaction was continued at 70°C for 1.5 h. Then, 5 parts by weight of the prepared second UV inhibitor were added, and the reaction was continued for 30 min. Then, 8 parts by weight of the prepared first UV inhibitor and the remaining chain extender solution were added, and the reaction was continued for 3 h. The mixture was then poured into a mold and dried to obtain a UV-resistant layer (0.5 mm). The prepared UV-resistant layer and the hardened layer were laminated to obtain the polycarbonate resin composite coating material of Example 20.

[0094] The flame retardant effect test results are shown in Table 4 below: Table 4:

[0095] As can be seen, the second flame retardant prepared in this disclosure can significantly improve the flame retardancy of the composite material. Furthermore, since it is introduced into the polyurethane chain segment, the second flame retardant not only has a good flame retardant effect, but also shows a more obvious advantage in flame retardancy compared to other flame retardants after 45 days of storage.

[0096] Scratch resistance and self-healing ability test: The self-healing capabilities of Examples 1, 6, 11, and 16 were tested separately. The coated surface of Q235 steel was placed face down on 600-grit sandpaper measuring 25cm × 20cm. A 20g weight was applied to the sample, and it was pulled 25cm at a speed of 5cm / s. Then, it was pulled back in the opposite direction at the same speed. This was recorded as one wear cycle (50cm). Five wear cycles were performed on the samples from Examples 1, 6, 11, and 16 respectively, and their water contact angle and oil contact angle were then tested; the results are shown in Table 5.

[0097] Table 5:

[0098] As can be seen, due to the branched alkylamine groups of the second flame retardant and the third UV stabilizer, they can form hydrogen bonds with the hydroxyl groups in the polyurethane material and the hydroxyl groups contained in its own structure, thereby giving it scratch resistance and self-healing ability, while Examples 1 and 6 do not have this effect.

[0099] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A scratch-resistant and UV-resistant polycarbonate resin composite coating material, characterized in that, The composite coating material includes: Hardened layer and UV-resistant layer; The hardened layer is prepared by blending polycarbonate with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) based on polycarbonate. The UV-resistant layer is a polyurethane material containing a first UV-resistant agent; the first UV-resistant agent is a second metal oxide nanoparticle doped with a first metal element, wherein the first metal element and the second metal element are selected from rare earth elements; The polyurethane material further comprises a third UV stabilizer, which is prepared by the following steps: Step C-1: Compound C-1 is obtained by reacting 2,4-dihydroxybenzophenone with epichlorohydrin; the structural formula of compound C-1 is shown below: ； Step C-2: React compound C-1 with polyethyleneimine to obtain the third UV stabilizer; The polyurethane material further comprises a second flame retardant compound; the second flame retardant compound is prepared by the following steps: Step D-1: Add DOPO to the reaction vessel and raise the temperature to 120℃-140℃ until the DOPO is completely melted; Step D-2: Keeping the temperature constant, add tris(epoxypropyl)isocyanurate to the completely molten DOPO. After the tris(epoxypropyl)isocyanurate is completely melted, add the resulting mixture to an organic solvent, then raise the temperature to 160℃-170℃ and react for 2-5 hours. Then, after extraction and purification, compound D-1 is obtained. The structural formula of compound D-1 is shown below: ； Step D-3: React compound D-1 with polyethyleneimine to obtain the second flame retardant compound.

2. The scratch-resistant and UV-resistant polycarbonate resin composite coating material according to claim 1, characterized in that, The hardened layer further comprises a first flame retardant compound; the first flame retardant compound is selected from octaphenyl-polyhedral oligomeric silsesquioxane.

3. The scratch-resistant and UV-resistant polycarbonate resin composite coating material according to claim 2, characterized in that, The first UV stabilizer is selected from lanthanum-doped cerium dioxide nanoparticles; wherein the lanthanum-doped cerium dioxide nanoparticles are prepared by the following steps: Step A-1: ​​Dissolve cerium carbonate and lanthanum carbonate separately using nitric acid solution to obtain an acid solution containing cerium ions and an acid solution containing lanthanum ions; wherein the molar ratio of lanthanum carbonate to cerium carbonate is selected from (0.01-0.1):1; Step A-2: Dissolve ammonium carbonate in nitric acid solution to obtain a coprecipitant solution; under stirring, simultaneously add the coprecipitant solution and the acid solution containing lanthanum ions to the acid solution containing cerium ions, and then age for 10-24 hours to obtain an aged mixture. Step A-3: Heat the aged mixture at 150℃-200℃ for 1.5-3 hours, then filter, wash and dry to obtain precursor particles; Step A-4: The precursor particles are calcined at 500℃-700℃ for 3-6 hours to obtain the lanthanum-doped cerium dioxide nanoparticles.

4. The scratch-resistant and UV-resistant polycarbonate resin composite coating material according to claim 3, characterized in that, The polyurethane material also contains a second UV stabilizer, which is hydrotalcite nanoparticles.

5. The scratch-resistant and UV-resistant polycarbonate resin composite coating material according to claim 4, characterized in that, The hydrotalcite nanoparticles are zinc-titanium hydrotalcite nanoparticles; wherein, the zinc-titanium hydrotalcite nanoparticles are prepared through the following steps: Step B-1: Add titanium tetrachloride and zinc nitrate to water, and while stirring, add urea aqueous solution; then place the resulting mixture in an autoclave and age it at 180℃-200℃ for 24-36h to obtain the product of step B-1; wherein, the molar ratio of titanium tetrachloride and zinc nitrate is selected from (1-4):1; Step B-2: After centrifugation, the solid product obtained in step B-1 is separated. The solid product is then washed and dried to obtain the zinc-titanium hydrotalcite nanoparticles.

6. A method for preparing the polycarbonate resin composite coating material according to claim 5, characterized in that, The method includes the following steps: Step 1: Provide dry polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane; melt-blend the polycarbonate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and octaphenyl-polyhedral oligomeric silsesquioxane; then hot-press and quench-form to obtain the hardened layer; Step 2: Prepare the third UV stabilizer and the second flame retardant compound; Step 3: Add the dried polyether polyol or polyester polyol to the container, heat to 60℃-80℃ and mechanically stir and reflux. Then dissolve the diisocyanate and catalyst in an organic solvent and add them dropwise to the container. Continue the reaction for 1-2 hours. Then add the prepared third UV stabilizer and second flame retardant compound and continue the reaction for 1-2 hours to obtain the polyurethane prepolymer. Step 4: Prepare the first and second UV stabilizers; Step 5: Dissolve the chain extender and catalyst in an organic solvent to obtain a chain extender solution. Add a portion of the chain extender solution to the polyurethane prepolymer and continue the reaction at 60℃-80℃ for 1-2 hours. Then add the prepared second UV stabilizer and continue the reaction for 30-60 minutes. Then add the prepared first UV stabilizer and the remaining chain extender solution and continue the reaction for 2-4 hours. Pour the mixture into a mold and dry it to obtain the UV stabilizer layer. Step 6: The prepared UV-resistant layer and hardened layer are bonded together to obtain a polycarbonate resin composite coating material.

7. The method according to claim 6, characterized in that, The method satisfies at least one of the following conditions: (1) In step 3, the polyether polyol is selected from polytetrahydrofuran ether diol, polypropylene glycol or polyethylene glycol; the polyester polyol is selected from polycaprolactone diol, polyethylene adipate diol, polybutylene adipate diol, polypropylene adipate diol or polyhexane adipate diol. (2) In step 3, the catalyst is selected from dibutyltin dilaurate, stannous octoate, triethylamine, triethylenediamine, triethanolamine or aromatic amine compounds; (3) In step 3, the diisocyanate is selected from toluene diisocyanate, dimethyl biphenyl diisocyanate, diphenylmethane diisocyanate, isophenyl dimethyl isocyanate, tetramethyl phenyl dimethylene diisocyanate, isophorone diisocyanate trimer, hexamethylene diisocyanate trimer, 1,4-cyclohexane dimethyl diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate; (4) In step 5, the chain extender is selected from 1,4-butanediol, diethylene glycol, trimethylolpropane, ethylene glycol, glycerol, 1,4-cyclohexanediol or resorcinol hydroxy ether. (5) In step 1, the conditions for melt blending are: temperature selected from 170℃-190℃, rotor speed selected from 50-80r / min, and mixing time selected from 5-10min; (6) In step 1, the hot pressing conditions are: preheating at 170℃-190℃ for 3-5 minutes, then hot pressing for 3-5 minutes, with a pressure of 10MPa; (7) In step 1, the quenching temperature is selected from 0-5℃.

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