Highly transparent wear-resistant fireproof pc composition applied to aerospace and preparation method and application thereof

Abstract

The application relates to a high-transparency wear-resistant fireproof PC composition applied to aerospace and a preparation method and application thereof, and comprises the following components: phosphate-modified epoxy polyurethane acrylate, aliphatic polyurethane acrylate oligomer, multifunctional monomer, heat-resistant monomer, acrylate monomer, sol silica, photoinitiator, antioxidant, UV absorber and light stabilizer. The phosphate-modified epoxy polyurethane acrylate is used to improve the oxygen index of the coating itself, make the coating achieve the flame-retardant effect similar to that of the base material, improve the overall oxygen index of the material, and reduce the smoke density; meanwhile, the phosphate-modified epoxy polyurethane acrylate can be used as an adhesion promoter to make the coating achieve better adhesion without using a solvent.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and specifically relates to a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications, its preparation method, and its application. Background Technology

[0002] Polycarbonate resin has a wide range of applications in the aerospace industry, including flame-retardant interior materials and civil aviation glass windows. However, due to the large free volume of the PC molecular chains, the surface is easily scratched during use, and harsh operating environments increase the life-cycle cost. In addition to the material needing to be scratch-resistant, civil aircraft also have stringent flame-retardant requirements. However, with traditional coatings, the acrylic esters on the surface are relatively flammable, which reduces the overall flame retardancy of the product.

[0003] CN103073700B uses photocurable acrylic acid and adds isocyanate siloxane monomers to the acrylate to prepare a high-hardness fluorine-containing low surface energy coating. Its function is limited and its weather resistance is not suitable for outdoor products.

[0004] CN11237524A achieves scratch resistance by adding a perfluorinated trichlorosilane, but since it is not attached to the main chain, it is difficult to achieve sustained hardening and scratch resistance.

[0005] CN105885674B uses solvent evaporation to allow a coating containing silica sol to adhere to the substrate surface, and then uses photocuring to increase the molecular weight of the coating, but it does not improve the flame retardant properties of the coating. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a highly transparent, wear-resistant and fire-retardant PC composition for aerospace applications, its preparation method and application, which effectively overcomes the defects of existing PCs used in aerospace applications.

[0007] This invention provides a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications, comprising the following components by weight:

[0008] 20-35 parts of phosphate-modified epoxy polyurethane acrylate;

[0009] 10-40 parts of aliphatic polyurethane acrylate oligomer;

[0010] 20-60 parts of multifunctional monomers;

[0011] 2-5 parts of heat-resistant monomer;

[0012] 10-15 parts of acrylate monomer;

[0013] 1-3 parts of sol-gel silica;

[0014] 1-1.5 parts of photoinitiator;

[0015] Antioxidant 0.5-1 part;

[0016] 2-3 parts UV absorber;

[0017] Light stabilizer 0.5-1 part;

[0018] The phosphate-modified epoxy polyurethane acrylate is prepared from glycidyl ester, phosphate ester, diisocyanate, hydroxy acrylate, polymerization inhibitor, and catalyst; the preparation method includes the following steps: Glycidyl ester was added to a three-necked flask, and the temperature was raised to 60-80°C. Phosphate ester was slowly added dropwise over 1 hour, and the temperature was raised to 80-90°C and reacted for 10-12 hours to obtain phosphorus-containing diol. Then, diisocyanate was added, and the mixture was heated to 40-50°C. A polymerization inhibitor and catalyst were added, and then hydroxy acrylate was added to the three-necked flask. The reaction was continued until the -NCO value remained unchanged to obtain phosphate-modified epoxy polyurethane acrylate.

[0019] Preferably, the mass ratio of the glycidyl ester, phosphate ester, diisocyanate, hydroxy acrylate, polymerization inhibitor, and catalyst is 200~300:200~300:200~300:100~150:0.1~1:0.1~1.

[0020] Preferably, the glycidyl ester comprises one or more of 3,4-epoxycyclohexylcarboxylate-3',4'-epoxycyclohexylmethyl ester, bis((3,4-epoxycyclohexyl)methyl)adipic acid ester, and 1,4-cyclohexanediethanol bis(3,4-epoxycyclohexylcarboxylate).

[0021] Preferably, the phosphate ester includes one or more of dipropyl phosphate, diisopropyl phosphate, and dibutyl phosphate.

[0022] Preferably, the diisocyanate includes one or more of isoflurone diisocyanate, hexamethylene diisocyanate, and cyclohexanedimethylene diisocyanate.

[0023] Preferably, the hydroxyacrylate includes one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl acrylate.

[0024] Preferably, the polymerization inhibitor includes one or more of p-hydroxyanisole, hydroquinone, and p-tert-butylcatechol.

[0025] Preferably, the catalyst comprises one or more of dibutyltin dilaurate and stannous octoate.

[0026] Preferably, the multifunctional monomer comprises one or more of tripropylene glycol diacrylate, trimethylolpropane triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

[0027] Preferably, the heat-resistant monomer comprises one or more of 2-acrylate-[2-[1,1-dimethyl-2-[(2-acryloyloxy]ethyl]-5-ethyl-1,3-dioxane-5-yl]methyl acrylate and (octahydro-4,7-methylene-1H-inden-1,5-ylidene)bis(methylene)diacrylate.

[0028] Preferably, the acrylate monomer includes one or more of isobornyl methacrylate, tricyclodecanediethanol diacrylate, and tricyclodecanediethanol dimethacrylate.

[0029] Preferably, the photoinitiator includes one or more of benzoin and its derivatives, benzoyl and its derivatives, acetophenone derivatives, and α-hydroxyketone derivatives.

[0030] Preferably, the antioxidant includes one or more of hindered phenolic antioxidants 1076, 1098, and 1010.

[0031] Preferably, the UV absorber includes one or more of the triazine UV absorbers UV1164, UV1577, and UV400.

[0032] Preferably, the light stabilizer includes one or more of benzotriazole light stabilizers UV1130 and UV928.

[0033] This invention also provides a method for preparing a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications, comprising the following steps:

[0034] The components are mixed in the specified proportions to obtain a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications.

[0035] This invention also provides an application of a highly transparent, wear-resistant, and fire-retardant PC composition used in aerospace applications in civil aviation glass windows.

[0036] Beneficial effects

[0037] (1) The present invention uses phosphate-modified epoxy polyurethane acrylate to improve the oxygen index of the coating itself, so that the coating achieves a flame retardant effect similar to that of the substrate, improves the overall oxygen index of the material, and reduces the smoke density; at the same time, phosphate-modified epoxy polyurethane acrylate can be used as an adhesion promoter to achieve better adhesion of the coating without the use of solvents.

[0038] (2) The composition of the present invention uses sol-gel silica, which acts as a core filler at high temperature to achieve organic-inorganic flame retardancy, reduce the flame propagation speed, and does not affect the overall transparency of the material.

[0039] (3) In the presence of phosphate-modified epoxy polyurethane acrylate, the present invention uses aliphatic polyurethane acrylate oligomers to achieve one-step photocuring and reduce process steps.

[0040] (4) In addition to multifunctional monomers, the present invention uses heat-resistant monomers to make the heat resistance of the coating and the substrate more compatible, improve the thermal aging performance of the material, and is suitable for outdoor product requirements.

[0041] (5) Under the action of the composition of the present invention, products conforming to aviation AF853DT can be prepared using ordinary transparent flame-retardant 1.5mmV-0 / 3.2mm5VB PC. Detailed Implementation

[0042] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0043] Table 1. Formulations of phosphate-modified epoxy polyurethane acrylates (parts by weight)

[0044]

[0045] The preparation method of phosphate-modified epoxy polyurethane acrylate includes the following steps:

[0046] According to the proportions in Table 1, 3,4'-epoxycyclohexylcarboxylic acid-3,4'-epoxycyclohexylmethyl ester was added to a three-necked flask, the temperature was raised to 70°C, and dibutyl phosphate was slowly added dropwise over 1 hour. The temperature was then raised to 90°C and reacted for 10 hours to obtain a phosphorus-containing diol. Subsequently, isoflurane diisocyanate was added, the mixture was heated to 40-50°C, hydroquinone and dibutyltin dilaurate were added, and then 2-hydroxyethyl acrylate was added to the three-necked flask. The reaction was continued until the -NCO value remained unchanged to obtain phosphate-modified epoxy polyurethane acrylate.

[0047] Table 2 Formulation of High Transparency, Wear-Resistant, and Fire-Retardant PC Compositions (Parts by Weight, Examples)

[0048]

[0049] Table 3 Formulation of high-transparency, wear-resistant, and fire-retardant PC compositions (parts by weight, comparative examples)

[0050]

[0051] Table 4 Performance Tests of High Transparency, Wear-Resistant, and Fire-Retardant PC Compositions (Examples)

[0052]

[0053] Table 5 Performance Tests of High Transparency, Wear-Resistant, and Fire-Retardant PC Compositions (Comparative Example)

[0054]

[0055] The testing method is as follows:

[0056] 1. Mix the high-transparency, wear-resistant, and fire-retardant PC composition according to the formula ratio, stir with a twin-shaft mixer, and then degas at 50°C for 2 hours to obtain the coating.

[0057] 2. The PC substrate uses CN113583421B sheet material, which is cast into an 8mm sheet.

[0058] 3. Apply the coating once to the PC substrate surface using a 30μm extrusion coater. After standing for 3 minutes to defoam, place it in a UV chamber at a constant temperature of 30℃. The UV LED curing lamp has a wavelength of 365nm and a power of 1~5W / cm². 2 LED irradiation time is 30s~40s;

[0059] 4. Cut the board material and test it according to the test requirements.

[0060] Test Result Analysis:

[0061] 1. As can be seen from Example 1 and Comparative Example 1, phosphate-modified epoxy polyurethane acrylate can significantly improve the overall oxygen index, reduce the burning time, and reduce the smoke density. This is mainly because the phosphorus content is higher and the oxygen index is higher, making it easier to extinguish under restricted propagation conditions.

[0062] 2. Examples 2, 1, and 2 demonstrate that aliphatic polyurethane oligomers can significantly improve the UV resistance and aging resistance of materials in damp heat. At the same time, if the phosphate-modified epoxy polyurethane acrylate is not present, the adhesion of the coating after aging will decrease. The phosphate-modified epoxy polyurethane acrylate acts as both a flame retardant and an adhesion promoter.

[0063] 3. Examples 2, 3, 3, and 4 demonstrate that high-functionality acrylates can improve the hardness of materials, mainly because the degree of crosslinking is determined by the multifunctional resin.

[0064] 4. Examples 3, 4, and 5 demonstrate that increasing the degree of cross-linking of resins increases hardness, especially for the multifunctional resin dipentaerythritol hexaacrylate.

[0065] 5. Examples 5, 6, and Comparative Example 4 demonstrate that heat-resistant monomers can significantly improve the heat resistance of materials, especially their resistance to aging and damp heat.

[0066] 6. Examples 6, 7, and Comparative Example 5 demonstrate that organosilicon sol can significantly reduce the smoke density of materials and reduce flame propagation. This is mainly because the increased number of carbonization centers in the material makes it more difficult for the flame to propagate. The silicon-containing carbonization layer can also reduce the smoke density of the material.

[0067] 7. Examples 7 and 8 illustrate that increasing the monomer content increases the weather resistance of the material. However, the monomer diluent has a significant impact on flame retardancy because the degree of crosslinking of the monomer is limited and the molecular weight is small, resulting in a higher smoke density.

[0068] 8. Examples 1 and 9 illustrate that using a formulation with a higher phosphorus content increases coating adhesion and reduces combustion diffusion, but reduces overall photothermal stability. This is because the increase in phosphorus accelerates carbonization, and the corresponding smoke density increases with the increase in phosphorus content via copolymerization.

Claims

1. A highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications, characterized in that, By weight, it includes the following components: 20-35 parts of phosphate-modified epoxy polyurethane acrylate; 10-40 parts of aliphatic polyurethane acrylate oligomer; 20-60 parts of multifunctional monomers; 2-5 parts of heat-resistant monomer; 10-15 parts of acrylate monomer; 1-3 parts of sol-gel silica; 1-1.5 parts of photoinitiator; Antioxidant 0.5-1 part; 2-3 parts UV absorber; Light stabilizer 0.5-1 part; The phosphate-modified epoxy polyurethane acrylate is prepared from glycidyl ester, phosphate ester, diisocyanate, hydroxy acrylate, polymerization inhibitor, and catalyst; the preparation method includes the following steps: Glycidyl ester was added to a three-necked flask, and the temperature was raised to 60-80°C. Phosphate ester was slowly added dropwise over 1 hour, and the temperature was raised to 80-90°C and reacted for 10-12 hours to obtain phosphorus-containing diol. Then, diisocyanate was added, and the mixture was heated to 40-50°C. A polymerization inhibitor and catalyst were added, and then hydroxy acrylate was added to the three-necked flask. The reaction was continued until the -NCO value remained unchanged to obtain phosphate-modified epoxy polyurethane acrylate.

2. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1, characterized in that, The mass ratio of glycidyl ester, phosphate ester, diisocyanate, hydroxy acrylate, polymerization inhibitor, and catalyst is 200~300:200~300:200~300:100~150:0.1~1:0.1~1.

3. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1 or 2, characterized in that, The glycidyl ester includes one or more of 3,4-epoxycyclohexylcarboxylate-3',4'-epoxycyclohexylmethyl ester, bis((3,4-epoxycyclohexyl)methyl)adipate, and 1,4-cyclohexanediethanol bis(3,4-epoxycyclohexanecarboxylate); the phosphate ester includes one or more of dipropyl phosphate, diisopropyl phosphate, and dibutyl phosphate; the diisocyanate includes one or more of isoflurane diisocyanate, hexamethylene diisocyanate, and cyclohexanedimethylene diisocyanate; the hydroxyacrylate includes one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl acrylate; the polymerization inhibitor includes one or more of p-hydroxyanisole, hydroquinone, and p-tert-butylcatechol; and the catalyst includes one or more of dibutyltin dilaurate and stannous octoate.

4. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1, characterized in that, The multifunctional monomers include one or more of tripropylene glycol diacrylate, trimethylolpropane triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

5. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1, characterized in that, The heat-resistant monomer includes one or more of 2-acrylate-[2-[1,1-dimethyl-2-[(2-acryloyloxy]ethyl]-5-ethyl-1,3-dioxane-5-yl]methyl acrylate and (octahydro-4,7-methylene-1H-indene-1,5-ylidene)bis(methylene)diacrylate.

6. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1, characterized in that, The acrylate monomers include one or more of isobornyl methacrylate, tricyclodecanediethanol diacrylate, and tricyclodecanediethanol dimethacrylate.

7. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1, characterized in that, The photoinitiator includes one or more of benzoin and its derivatives, benzoyl and its derivatives, acetophenone derivatives, and α-hydroxyketone derivatives.

8. The high-transparency, wear-resistant, and fire-retardant PC composition for aerospace applications according to claim 1, characterized in that, The antioxidant includes one or more of hindered phenolic antioxidants 1076, 1098, and 1010; the UV absorber includes one or more of triazine UV absorbers UV1164, UV1577, and UV400; and the light stabilizer includes one or more of benzotriazole light stabilizers UV1130 and UV928.

9. A method for preparing a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications as described in any one of claims 1 to 8, characterized in that, Includes the following steps: The components are mixed in the specified proportions to obtain a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications.

10. The application of a highly transparent, wear-resistant, and fire-retardant PC composition for aerospace applications as described in any one of claims 1 to 8 in civil aviation glass windows.

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