Method for preventing ultraviolet aging of aircraft composite packaging box

Abstract

The invention discloses a method for preventing ultraviolet aging of an aircraft composite material packaging box, and belongs to the field of composite material packaging boxes. The resin solution consistent with the resin used by the composite material packaging box is prepared; synthesizing an ultraviolet light absorber from benzoic acid, benzaldehyde and phenylmethylsulfuric acid; adding an ultraviolet light absorber, a curing agent and an accelerant into the resin solution to obtain an improved resin solution; the strong core felt is soaked in the improved resin solution and taken out, the strong core felt is laid according to the shape of the mold, and then the improved resin solution is integrally coated with the strong core felt through a brush; and the composite material packaging box is continuously laid and manufactured according to the composite material packaging box laying technology, and the composite material packaging box capable of preventing ultraviolet aging is obtained. The composite material packaging box can be effectively protected from being damaged by ultraviolet rays, the anti-aging performance of a product can be remarkably improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] The invention belongs to the field of composite material packaging boxes, and in particular relates to a method for preventing ultraviolet aging of an aircraft composite material packaging box. Background Art

[0002] Current aircraft composite packaging boxes are generally made of vinyl ester resin, unsaturated polyester resin or epoxy resin, and have poor UV protection. The main reason is that the composite materials will age under long-term exposure to ultraviolet rays, which will cause the surface resin to degrade and the surface to become yellow and powdery, thereby causing a decrease in strength and toughness. Over time, composite products may gradually become brittle and easy to break. In addition, ultraviolet rays can also cause cracks, cracks and discoloration on the surface of composite products, thus affecting their appearance and service life. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preventing ultraviolet aging of a composite packaging box for a traveler, which can effectively protect the composite packaging box from damage by ultraviolet rays, significantly improve the anti-aging performance of the product, and extend its service life.

[0004] The technical solution adopted by the present invention to achieve its purpose is as follows:

[0005] A method for preventing ultraviolet aging of a composite packaging box for a travel device comprises the following steps:

[0006] Cut the strong core felt to the same size as the first layer of the composite packaging box mold;

[0007] Prepare a resin solution that is consistent with the resin used in composite packaging boxes;

[0008] The ultraviolet absorber is synthesized by benzoic acid, benzaldehyde and benzylsulfuric acid, and then purified;

[0009] adding an ultraviolet absorber, a curing agent and an accelerator to the resin solution to obtain an improved resin solution;

[0010] The strong core felt is soaked in the improved resin solution for a period of time and then taken out, and the strong core felt is laid from back to front according to the shape of the mold;

[0011] After standing for a period of time, the improved resin solution is applied to the entire surface with a brush;

[0012] The composite material packaging box is continuously layered according to the layering process to obtain a composite material packaging box capable of preventing ultraviolet aging.

[0013] Furthermore, the mass concentration of the resin solution is 65%-75%.

[0014] Furthermore, after the resin solution is prepared, it is allowed to stand for 18-25 minutes to eliminate air bubbles.

[0015] Further, the core felt is soaked in the improved resin solution for 15-18 minutes.

[0016] Furthermore, after standing for 8-10 minutes, the entire surface is coated with the resin solution again with a brush.

[0017] Further, the step of synthesizing the ultraviolet absorber by benzoic acid, benzaldehyde and benzylsulfuric acid comprises:

[0018] Benzoic acid and benzaldehyde are reacted by acylation to produce phenolic compounds;

[0019] The phenolic compound is subjected to a reduction reaction to generate a phenolic compound;

[0020] The phenolic compound is reacted with phenylsulfonic acid to produce a UV absorber.

[0021] Furthermore, the steps of purifying the ultraviolet absorber include: crystallization, filtration and drying.

[0022] Furthermore, the weight ratio of the resin solution, the ultraviolet absorber, the curing agent and the accelerator is 100:(2.5-5):(1-4):(0.3-1).

[0023] Further, the weight ratio of the resin solution, the ultraviolet absorber, the curing agent and the accelerator is adjusted according to the ambient temperature of the working area for making the composite material packaging box, including:

[0024] At 15-20℃, resin solution: UV absorber: curing agent: accelerator = 100:5:4:1;

[0025] At 21-25°C, resin solution: UV absorber: curing agent: accelerator = 100:3:2.5:0.5;

[0026] At 26-35°C, resin solution: UV absorber: curing agent: accelerator = 100:2.5:1:0.3.

[0027] The working principle of the ultraviolet absorber of the present invention:

[0028] 1. Ultraviolet absorption mechanism: The present invention uses a benzophenone ultraviolet absorber (UV-24 (BP-8)), which absorbs ultraviolet rays through the special structure of the conjugated π electron system and the movement of hydrogen atoms in the molecule, and mainly absorbs ultraviolet rays with a wavelength range of 200-400 nanometers, including UVA (320-400nm), UVB (275-320nm) and UVC (200-275nm). After absorbing ultraviolet rays, the intrinsic hydrogen bonds (formed by ketone groups and hydroxyl groups) of the absorbent molecules break, and the molecules are isomerized, accompanied by thermal vibrations. In this process, the absorbed ultraviolet energy is converted into heat energy or harmless longer wavelength light release, thereby avoiding direct damage to the material by ultraviolet rays.

[0029] 2. Energy conversion and molecular stability: During the energy conversion process, the molecular structure of the absorbent remains stable and does not significantly degrade, ensuring the long-term photostability of the absorbent. Energy conversion is accompanied by the opening of the chelate ring and the generation of an enol structure through tautomerism, which further consumes ultraviolet energy, thereby achieving the effect of continuous protection of the material.

[0030] 3. Compatibility with resin: The specific structure of benzophenone absorbent molecules (such as two ortho-hydroxyl groups) enhances its compatibility with the resin used in composite materials. This good compatibility ensures that the absorbent can be evenly distributed in the composite material, improves the material's UV resistance and protects its matrix from UV damage.

[0031] 4. Protection mechanism: UV absorbers form a protective barrier on the surface of the composite material, preventing UV rays from further penetrating into the material, thereby reducing direct damage to the composite matrix by UV rays. The process of converting UV energy slows down the photodegradation and chemical aging of the material, improving the overall anti-aging performance.

[0032] The technical effects achieved by the present invention are:

[0033] 1. Improve anti-aging performance: significantly reduce the aging rate of composite materials under ultraviolet irradiation, so that the material can maintain long-term stable performance under ultraviolet exposure. Reduce the problems of strength loss and appearance damage caused by aging, and delay the degradation of material performance.

[0034] 2. Extend service life: Improve the weather resistance of composite materials (such as fiberglass products) so that they can be used for a long time in harsh outdoor environments. By reducing the frequency of material replacement and maintenance costs, the overall cost of use is reduced and the economy is improved.

[0035] 3. Wide applicability: It can be used in composite packaging boxes, anti-corrosion coatings, outdoor structural materials and other scenarios to provide stable anti-ultraviolet protection. It is suitable for plastic products, sunscreen cosmetics and other fields to protect the skin and other objects from ultraviolet damage, showing diversified application potential.

[0036] 4. Optimize production process: During the production process, the scientific ratio design of raw materials such as absorbent and resin improves the process controllability and ensures the stability and consistency of material quality. Combined with process improvement, it not only improves product performance, but also optimizes production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a physical picture of the aging of the packaging box sample that has not been treated by the method of the present invention.

[0038] Figure 2 This is a real picture of the anti-aging of the packaging box sample treated by the method of the present invention. DETAILED DESCRIPTION

[0039] In order to make the various technical features and advantages or technical effects in the above technical solutions of the present invention more obvious and easy to understand, they are described in detail below with reference to the accompanying drawings.

[0040] The embodiment of the present invention specifically discloses a method for preventing ultraviolet aging of a composite packaging box for a traveler, which is achieved by using an ultraviolet absorber and a soaking operation process, including the following steps:

[0041] 1. Soaking operation

[0042] 1. Material preparation: Cut the strong core felt that is consistent with the first layer size of the composite material packaging box product mold.

[0043] 2. Resin preparation: Prepare a resin solution (mass concentration 65%-75%) that is consistent with the resin used in the composite packaging box product, and let it stand for 18-25 minutes to eliminate bubbles.

[0044] 3. Soaking and laying: Soak the strong core felt in the resin solution for 15-18 minutes, take it out and lay it according to the shape of the mold to avoid bubbles.

[0045] 4. Standing and brushing: Standing for 8-10 minutes, after the material is slightly warm, use a brush to apply a layer of resin solution to enhance the surface strength.

[0046] 5. Continue laying: Complete the production of subsequent layers according to the laying process of the composite material packaging box to obtain a semi-finished packaging box.

[0047] The weight of the strong core felt used in this impregnation operation is only 50%-60% of that of the glass fiber product of the same thickness, the amount of resin is reduced, and the matrix performance is improved. In addition, the strong core felt is easy to cut and has strong impregnation, which is equivalent to the thickness of multi-layer glass fiber materials, and significantly improves the anti-ultraviolet and anti-aging properties.

[0048] 2. Use of UV absorbers

[0049] 1. Synthesis of absorbent: Select raw materials such as benzoic acid, benzaldehyde, and benzylsulfuric acid, react benzoic acid with benzaldehyde to generate a phenolic compound through an acylation reaction, then react the phenolic compound with a reduction reaction to generate a phenolic compound, and finally react the phenolic compound with benzylsulfuric acid to generate an ultraviolet absorber.

[0050] 2. Purification of absorbent: UV absorbents are crystallized, filtered, and dried to remove impurities and improve product stability. The crystallization process can be achieved by controlling temperature and solvent concentration.

[0051] 3. Add absorbent: Add UV absorber to the prepared resin solution to make an improved resin solution, and then carry out subsequent soaking and covering operations so that it can absorb UV rays and convert them into heat energy, thereby protecting the material.

[0052] 4. Dosage and ratio: Adjust the dosage of UV absorber, curing agent and accelerator according to the ambient temperature of the working area. See the following weight ratio:

[0053] At 15-20℃, resin solution: UV absorber: curing agent: accelerator = 100:5:4:1;

[0054] At 21-25°C, resin solution: UV absorber: curing agent: accelerator = 100:3:2.5:0.5;

[0055] At 26-35°C, resin solution: UV absorber: curing agent: accelerator = 100:2.5:1:0.3.

[0056] To further improve the anti-ultraviolet aging effect, the synthesis and performance of the absorbent can be optimized by controlling the reaction temperature, time and catalyst type.

[0057] Experimental Test:

[0058] This test includes two groups of samples for comparison. The first group is the packaging box samples that have not been treated by the method of the present invention and no ultraviolet absorber is added. The aging condition is observed under sunlight for a period of time. The second group is the packaging box samples that have been treated by the method of the present invention and ultraviolet absorber is added. The aging condition is observed under sunlight for the same period of time. The two groups of samples are tested for illumination at the same time in the same scene to eliminate environmental interference factors.

[0059] The aging of the first group of samples is shown in Figure 1 As shown in the figure, the white area is the damage caused by ultraviolet aging. The aging of the second group of samples is as follows Figure 2As shown in the figure, the whitish area within the red dotted line is the damage caused by ultraviolet aging. It can be clearly seen from these two figures that the aging condition of the second group of samples has been significantly improved, indicating that the treatment of the method of the present invention can effectively improve the anti-ultraviolet aging performance of the composite material packaging box.

[0060] The specific test results of the anti-ultraviolet aging performance of the second group of samples are shown in Table 1 below.

[0061] Table 1 Anti-ultraviolet aging performance test results

[0062]

[0063] The test in Table 1 is determined in accordance with GB / T 18830-2009. When the sample UPF>40 and T(UVA) AV When it is <5%, it can be called a "UV protection product".

[0064] T(UVA) AV : The average transmittance of ultraviolet A. The lower the value, the stronger the material's ability to block UVA.

[0065] T(UVB) AV : Average transmittance of ultraviolet B. The lower the value, the stronger the material's ability to block UVB.

[0066] UPF (Ultraviolet Protection Factor): Ultraviolet protection factor, which indicates the ability of a material to block ultraviolet radiation. The higher the value, the better the protection effect.

[0067] UPF AV : The average value of UPF, used to more comprehensively evaluate the protective performance of the sample.

[0068] From the test results in Table 1, we can see that the T(UVA) of the sample AV and T(UVB) AV The values ​​are all far below 5%, indicating that the samples have extremely low transmittance to UVA and UVB, and have good UV blocking ability. The UPF values ​​are all greater than 50, exceeding the minimum limit of UPF>40 required by the standard, further proving the excellent protection effect. The test results show that the sample can be used as an anti-UV product and is suitable for use in scenes where UV resistance is required.

[0069] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions of the technical solutions of the present invention made by ordinary technicians in the field should all be included in the protection scope of the present invention. The protection scope of the present invention shall be based on what is defined in the claims.

Claims

1. A method for preventing ultraviolet aging of a composite packaging box for a mobile device, comprising the following steps: Cut the strong core felt to the same size as the first layer of the composite material packaging box mold; Prepare a resin solution that is consistent with the resin used in composite packaging boxes; The ultraviolet absorber is synthesized by benzoic acid, benzaldehyde and benzylsulfuric acid, and then purified; adding an ultraviolet absorber, a curing agent and an accelerator to the resin solution to obtain an improved resin solution; The strong core felt is soaked in the improved resin solution for a period of time and then taken out, and the strong core felt is laid from back to front according to the shape of the mold; After standing for a period of time, the improved resin solution is applied to the entire surface with a brush; The composite material packaging box is continuously layered according to the layering process to obtain a composite material packaging box capable of preventing ultraviolet aging.

2. The method according to claim 1, characterized in that The mass concentration of the resin solution is 65%-75%.

3. The method according to claim 1, characterized in that After the resin solution is prepared, let it stand for 18-25 minutes to eliminate bubbles.

4. The method according to claim 1, characterized in that The core felt is soaked in the modified resin solution for 15-18 minutes.

5. The method according to claim 1, characterized in that After standing for 8-10 minutes, use a brush to apply the resin solution all over again.

6. The method according to claim 1, characterized in that The steps of synthesizing the ultraviolet absorber from benzoic acid, benzaldehyde and benzylsulfuric acid include: Benzoic acid and benzaldehyde are reacted by acylation to produce phenolic compounds; The phenolic compound is subjected to a reduction reaction to generate a phenolic compound; The phenolic compound is reacted with phenylsulfonic acid to produce a UV absorber.

7. The method according to claim 1, characterized in that The steps of purifying the ultraviolet absorber include crystallization, filtration and drying.

8. The method according to claim 1, characterized in that The weight ratio of the resin solution, the ultraviolet absorber, the curing agent and the accelerator is 100:(2.5-5):(1-4):(0.3-1).

9. The method according to claim 8, characterized in that The weight ratio of the resin solution, UV absorber, curing agent and accelerator is adjusted according to the ambient temperature of the work area where the composite packaging box is made, including: At 15-20℃, resin solution: UV absorber: curing agent: accelerator = 100:5:4:1; At 21-25°C, resin solution: UV absorber: curing agent: accelerator = 100:3:2.5:0.5; At 26-35°C, resin solution: UV absorber: curing agent: accelerator = 100:2.5:1:0.3.

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