Automobile lamp shade with self cleaning function

Technical field of car lamp shade with self-cleaning function

[0001] The present invention relates to the technical field of auto parts, in particular to a lampshade with a self-cleaning function.

Background technique

[0002] In recent years, with the rapid development of urbanization, my countrys per capita car ownership has increased year by year, but parking spaces have not matched the increase in cars, resulting in most cars parked outdoors or on the roadside, and because of the car lights It is external, so it is exposed to the outdoors for a long time under the influence of sun, rain, and air pollution. Dust and water vapor will easily enter the inside of the lampshade from the gap to form dirt. Long-term use will easily reduce the intensity of the car lights, cause the lights to dim, and affect driving safety .

[0003] The material of the internal parts of the car lights is basically plastic. Since the lights are turned on, the internal environment temperature of the lights is very high. 15 minutes after the front lights are turned on, the temperature of the LED headlights is about 84.4°C. Xenon lights The temperature of the light-emitting point is about 90°C, and the plastic parts will continuously volatilize small molecular organic matter at high temperature. At the same time, the temperature of the light distribution lens is relatively low, and the organic matter is easily condensed on the inner surface of the light distribution lens. Therefore, after the lamp is used for a period of time, organic matter will be adsorbed on the inner surface of the light distribution lens, which will cause the light distribution lens of the car light to be dim and reduce the light transmittance. In addition, due to long-term exposure to the sun, the penetration of ultraviolet rays will degrade the molecular chains of the plastic parts inside the lamp, which will make the plastic more volatile, such as producing VOC substances. The adsorption of small molecules will result in the loss of the activity of the hydrophilic groups on the surface of the anti-fog coating on the inside of the car light lens. If things go on like this, the problems of car light fogging and decreased transmittance will become more serious. At present, the problem of yellowing of organic matter absorbed by the light distribution lens of car lights is usually carried out by controlling the heating temperature of the car light, increasing the heat resistance temperature of the material, and using specially treated low-volatile materials to reduce the organic matter on the light distribution lens.ofsorption. However, these treatment methods will increase the cost of vehicle lamp materials and the cost of heat dissipation components, and cannot fundamentally solve the problems of organic matter adsorption and fogging. Therefore, there is an urgent need for an automobile lamp shade that can solve the problem of the absorption of organic volatiles on the inner surface of the light distribution lens, fogging, and ultraviolet degradation of plastic parts during the use of the existing automobile lamp.

Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a lampshade with a self-cleaning function to solve the problem that the inner surface of the lampshade absorbs organic volatiles after long-term use of the existing lampshade. , Fogging and internal contamination problems.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] A lampshade for a car lamp with a self-cleaning function, the inner surface of the light distribution lens is covered with a transparent self-cleaning coating, the self-cleaning coating includes a micro-erosion layer and a self-cleaning layer, the micro-erosion layer It has an uneven microstructure outer surface, the roughness Ra of the micro-erosion layer is 10-20um, and the self-cleaning layer is mainly composed of methyltriethoxysilane, aluminum isopropoxide and carbodiimide. Made of aluminosiloxane resin.

[0007] Further, the thickness of the self-cleaning coating does not exceed 0.3 cm.

[0008] The self-cleaning coating on the inner surface of the light distribution lens is a transparent coating, which will not block the light emitted by the vehicle lamp and cause the loss of vision, so driving safety is ensured. The self-cleaning layer prepared by the hydrolysis and polycondensation of methyltriethoxysilane and aluminum isopropoxide has the characteristics of high transparency, good heat resistance, and anti-volatile organic matter adhesion, which can keep the inner surface of the lens of the lampshade clean , Prevent the car lights from fogging, and solve the problem of internal contamination.

[0009] Further, the material of the light distribution lens is polycarbonate.

[0010] Further, the micro-erosion layer includes the following parts by weight of raw materials: 50-20 0 parts of N,N dimethylformamide, 2-10 parts of propylene glycol methyl ether, 30-70 parts of titanium dioxide, the self-cleaning layer It includes the following raw materials in parts by weight: 150-180 parts of methyltriethoxysilane, 90-108 parts of aluminum isopropoxide, and 2.7-5.4 parts of carbodiimide.

[0011] Further, the preparation steps of the self-cleaning coating on the inner surface of the light distribution lens are as follows:

[0012] (1) Pre-treatment: preheat the clean lens in an oven to 30-35°C, and wait for use;

[0013] Preparation of micro-erosion layer: add N,N dimethylformamide into the ethanol solution, stir well and prepare a N,N dimethylformamide-ethanol mixed solution, then add propylene glycol methyl ether and titanium dioxide, and stir After 10-15 minutes, the binding agent is obtained. The binding agent is evenly applied to the inner surface of the pre-treated light distribution lens, and then placed in a 40-45 Ό thermostat for 10-15 minutes. After taking it out, spray 0.5 0.5 on the inside surface of the light distribution lens. -1wt% hydrochloric acid solution, after standing for 2-3min, apply the bonding agent evenly on the inner surface of the lens, then place it in a 55-60Ό thermostat for 8-10min, take it out at room temperature and ventilate and dry it to get micro-erosion Floor;

[0014] (3) Preparation of aluminum-containing siloxane resin: After mixing methyltriethoxysilane and deionized water, the water bath is heated to 4042°C, and then aluminum isopropoxide, carbodiimide, and nitric acid are added and stirred evenly. After stirring and reacting at 70-90°C for 12h in a closed container, take it out, add ammonia and heat to 60-70°C, stir and react under nitrogen protection for 6.5-7h, and obtain aluminum-containing siloxane resin after cooling;

[0015] Preparation of the self-cleaning layer: spraying the aluminum-containing siloxane resin on the surface of the micro-eroded layer of the light distribution lens, and after curing, the self-cleaning layer on the inner surface of the light distribution lens is obtained.

[0016] Cleaning the light distribution lens cleanly can prevent the surface of the light distribution lens from being oily or impurity, resulting in not tightly bonding with the micro-erosion layer and causing the self-cleaning layer to fall off. The smaller the particle size of titanium dioxide, the more uniform dispersion in the N,N dimethylformamide-ethanol mixed solution, but in order to further increase the dispersibility and surface activity of titanium dioxide, it is necessary to first activate the titanium dioxide surface in a low-temperature plasma equipment. Then, the activated titanium dioxide is mixed with propylene glycol methyl ether to weaken the surface tension between the titanium dioxide and the N,N dimethylformamide-ethanol mixed solution to make the dispersion more uniform. Because the material of the light distribution lens is polycarbonate, the mixed solution of N, N dimethylformamide and ethanol can slightly corrode the inner surface of the light distribution lens, causing micro swelling of the inner surface of the light distribution lens at a certain temperature. After spraying low-concentration hydrochloric acid solution, spraying N, N dimethylformamide-ethanol mixed solution and keeping the temperature at constant temperature to promote the micro-swelling surface to deform slightly at a certain temperature. After cooling, the titanium dioxide is adhered or wrapped in the lens The surface undergoes photocatalysis. After the preparation of the micro-erosion layer is completed, the organic residues can be cleaned with clean water.

[0017] Methyltriethoxysilane is hydrolyzed under the action of a nitric acid catalyst to obtain silanol. The protonation of the silanol on the silanol will reduce the electron density on the silicon atom, and the silicon atom is vulnerable to nucleophilic attack. Reduce the reaction rate and add carbodiimide to inhibit the hydrolysis rate of methyltriethoxysilane and prevent its excessive hydrolysis from causing instability of the silanol, which in turn causes the condensation reaction to fail. Aluminum isopropoxide decomposes into aluminum hydroxide and isopropanol in water, providing aluminum ions. Methyltriethoxysilane contains Si-OS i bonds, but it cannot exist stably for a long time under acidic conditions, so it breaks into Si -OH bond and aluminum ion undergo condensation reaction to form Si-O-Al, forming a cross-linked siloxane resin. Under the action of ammonia, the siloxane resin with a low degree of cross-linking will continue to be cross-linked to form a high degree of cross-linking. Transparent aluminum-containing siloxane resin. The obtained siloxane resin is coated on the surface of the micro-deformed micro-erosion layer until the light distribution lens forms a smooth inner surface, and a transparent, smooth and self-cleaning coating is obtained after curing. Methyltriethoxysilane and aluminum ion are hydrolyzed and then polycondensed to form aluminum-containing siloxane resin with higher hardness, enhanced heat resistance, decreased adhesion, and less contamination.

[0018] Further, the concentration of N,N dimethylformamide in the N,N dimethylformamide-ethanol mixed solution is 911 wt%. Too high concentration can easily cause over-corrosion of the inner surface of the light distribution lens and damage the structure of the lampshade.

[0019] Further, the titanium dioxide in the step (2) is pretreated, and the pretreatment is to first reduce the particle size to

CN 110566898 A

20-25nm titanium dioxide is cleaned with ethanol solution, dried and put into oxygen as working gas, processed in a low-temperature plasma equipment with a power of 100W and a pressure of IPa for 1-2min...

[0020] Further, in the step (3), the mass ratio of methyltriethoxysilane to aluminum isopropoxide is 1:0.6, and the mass ratio of methyltriethoxysilane to deionized water is 1: (2 -2.5) ο

[0021] Further, in the step (3), the mass ratio of aluminum isopropoxide to carbodiimide is 1: (0.03-0.05).

[0022] The beneficial effects of a lampshade with self-cleaning function provided by the present invention are as follows:

[0023] 1. The interior of the lampshade is coated with a self-cleaning coating that is not easy to absorb volatile organic compounds and contaminate dirt, which reduces the number of cleanings and prolongs the life of the lampshade.

[0024] 2. The self-cleaning coating has a certain hardness, which can prevent the scattered debris inside the lampshade from scratching the coating and weaken its self-cleaning function.

[0025] 3. The micro-erosion layer contains nano-titanium dioxide, which can perform photocatalysis and can also play a role in purifying volatile organic compounds.

[0026] 4. After the micro-erosion layer is micro-etched, the titanium dioxide is not only wrapped in, but also the roughness of the micro-erosion layer is increased, so that the self-cleaning layer is better attached to the micro-erosion layer and is not easy to fall off.

[0027] 5. The self-cleaning layer is mainly aluminum-containing siloxane resin. The aluminum-containing siloxane resin has high hardness, enhanced heat resistance, and its adhesion is reduced, and it is not easy to be stained and is suitable for higher temperature lampshades. use.

Description of the drawings

[0028] FIG. 1 is a schematic diagram of the structure of the present invention;

[0029] Among them, the light distributing lens 1, the housing 2, and the reflecting mirror 3.

Detailed ways

[0030] The present invention will be described in detail below in conjunction with specific embodiments:

[0031] A lampshade with a self-cleaning function for car lights, comprising a light distribution lens 1, a reflector 3 and a housing 2, wherein the inner surface of the light distribution lens is covered with a transparent self-cleaning coating, and the self-cleaning coating includes micro-erosion The weight ratio of the micro-erosion layer and the self-cleaning layer of the self-cleaning coating of the lens is shown in Table 1:

[0032] Table 1

<td></td><td colspan="3">Micro-eroded layer</td><td colspan="3">Self-cleaning layer</td>

<td>Example</td><td>N, N dimethylformamide</td><td>Propylene Glycol M</td><td>Titanium dioxide</td><td>Methyl triethoxy silane</td><td>Aluminum isopropoxide</td><td>Carbodiimide</td>

<td>Example 1</td><td>200</td><td>10</td><td>70</td><td>180</td><td>108</td><td>3. 24</td>

<td>Example 2</td><td>100</td><td>5</td><td>40</td><td>160</td><td>96</td><td>2. 88</td>

<td>Example 3</td><td>50</td><td>2</td><td>30</td><td>150</td><td>90</td><td>4.5</td>

[0034] Embodiment 1:

[0035] In this example, the raw materials were weighed according to the ratio of Example 1 in Table 1. The preparation steps are as follows:

[0036] Titanium dioxide pretreatment: first clean the titanium dioxide with a particle size of about 20nm with ethanol solution, then remove the ethanol with clean water, dry it and put it into a low-temperature plasma equipment with oxygen as the working gas, pressure of IPa, and power of 100W Place

Treat for 1 min, then take it out for later use;

[0037] (1) Pretreatment: the surface of the light distribution lens is cleaned with 35wt% ethanol solution, and then cleaned with water, placed in an oven, and the light distribution lens is preheated to 30° C. for use;

[0038] (2) Preparation of the micro-eroded layer: add N,N dimethylformamide into the ethanol solution, stir it evenly and prepare a N,N dimethylformamide-ethanol mixed solution, in which N,N dimethylformamide The concentration of formamide is 11wt%, then propylene glycol methyl ether is added, and the pre-treated titanium dioxide is added after mixing uniformly. After stirring at 1200 rpm for 15 minutes, the binding agent is obtained. The binding agent is evenly applied to the pre-heated formulation. The inner surface of the light mirror is coated with a thickness of about 0.1cm, and then placed in a constant temperature box at 40C for 15 minutes. After taking it out, spray 0.5wt% hydrochloric acid solution on the inner surface of the light mirror. After standing for 2 minutes, the bonding agent is uniformly distributed again Smear on the inner surface of the light distribution lens with a coating thickness of about 0.05cm, then place it in a 55C constant temperature box for 10 minutes, take it out and dry it at room temperature, and obtain a micro-eroded layer, measured Ra = 20um;

[0039] (3) Preparation of aluminum-containing siloxane resin: mix methyltriethoxysilane and 450 parts by weight of deionized water and heat the water bath to 40°C, then add aluminum isopropoxide and carbodiimide and stir evenly, Then slowly add 75wt% nitric acid dropwise, stir well and place in a closed container, stir and react at 70C for 1h, then take it out, add 25ml pH=12 ammonia water and heat to 60C, stir and react under nitrogen protection for 7h, after cooling to obtain aluminum-containing silicon Oxane resin

[0040] (4) Preparation of self-cleaning layer: heating the aluminum-containing siloxane resin to a molten state and spraying it on the surface of the micro-erosion layer of the light distribution lens, the coating thickness is about 0.15 cm, and the light distribution lens is obtained after static curing Self-cleaning layer on the inner surface.

[0041] Embodiment 2:

[0042] In this example, the raw materials were weighed according to the ratio of Example 2 in Table 1. The preparation steps are as follows:

[0043] Titanium dioxide pretreatment: first clean the titanium dioxide with a particle size of about 25nm with ethanol solution, then remove the ethanol with clean water, dry it and put it into a low-temperature plasma equipment with oxygen as a working gas, a pressure of 1Pa, and a power of 100W Treat for 2min, then take it out for later use;

[0044] (1) Pretreatment: the surface of the light distribution lens is cleaned with 35wt% ethanol solution, then cleaned with clean water, placed in an oven, and the light distribution lens is preheated to 33°C for use;

[0045] Preparation of micro-erosion layer: add N,N dimethylformamide into the ethanol solution, stir well and prepare a N,N dimethylformamide-ethanol mixed solution, in which N,N dimethylformamide The concentration of is 10wt%, then propylene glycol methyl ether is added, and the pretreated titanium dioxide is added after mixing uniformly, and the binding agent is obtained after stirring at 1200 rpm for 12 minutes, and the binding agent is evenly smeared into the pre-heated lens The coating thickness is about 0.1cm on the surface, and then placed in a constant temperature box at 42C for 12 minutes. After taking it out, spray 0.6wt% hydrochloric acid solution on the inner surface of the light distribution lens. After standing for 2 minutes, apply the bonding agent evenly on the distribution lens. The inner surface of the light mirror is coated with a thickness of about 0.05cm, and then placed in a 58C constant temperature box for 9 minutes, taken out of the room temperature and ventilated and dried to obtain a micro-eroded layer, measured Ra = 15um;

[0046] (3) Preparation of aluminum-containing siloxane resin: mix methyltriethoxysilane and 320 parts by weight of deionized water and heat the water bath to 41C, then add aluminum isopropoxide and carbodiimide and stir evenly, Then slowly add 75wt% nitric acid dropwise, stir evenly, place in a closed container, stir and react at 80 C for 1.5 hours, then take it out, add 22ml of pH=12 ammonia water and heat to 65C, stir and react under nitrogen for 6.5 hours, and cool to obtain Aluminum-containing siloxane resin;

[0047] (4) Preparation of the self-cleaning layer: heating the aluminum-containing siloxane resin to a molten state and spraying on the surface of the micro-erosion layer of the light distribution lens, the coating thickness is about 0.15 cm, and the light distribution lens is obtained after static curing Self-cleaning layer on the inner surface.

[0048] Embodiment 3:

[0049] In this example, the raw materials were weighed according to the ratio of Example 3 in Table 1. The preparation steps are as follows:

[0050] Titanium dioxide pretreatment: first wash the titanium dioxide with a particle size of about 20nm with an ethanol solution, and then use clean water

Remove ethanol, dry it and put it into a low-temperature plasma equipment with oxygen as working gas, pressure of IPa and power of 100W for 1min, and then take it out for use;

[0051] (1) Pretreatment: the surface of the light distribution lens is cleaned with 35wt% ethanol solution, and then cleaned with clean water, placed in an oven, and the light distribution lens is preheated to 35°C for use;

[0052] Preparation of the micro-eroded layer: add Ν,Ν dimethylformamide to the ethanol solution, stir it evenly and prepare a Ν,Ν dimethylformamide-ethanol mixed solution, wherein Ν,Ν dimethylformamide The concentration is 9wt%, and then propylene glycol formaldehyde is added, and the pretreated titanium dioxide is added after mixing uniformly. The binding agent is obtained after stirring at a rate of 1200 rpm for 10 minutes, and the binding agent is evenly smeared into the pre-heated lens On the surface, the coating thickness is about 0.1cm, and then placed in a thermostat at 45°C for 10 minutes. After taking it out, spray 1wt% hydrochloric acid solution on the inner surface of the light distribution lens. After standing for 3 minutes, apply the bonding agent evenly on The inner surface of the light distribution lens is coated with a thickness of about 0.05cm, and then placed in a constant temperature box at 60 °C for 8 minutes, taken out of the room temperature and ventilated and dried to obtain a micro-eroded layer, measured Ra = 12um;

[0053] (3) Preparation of aluminum-containing siloxane resin: mix methyltriethoxysilane and 300 parts by weight of deionized water and heat the water bath to 42° C., then add aluminum isopropoxide and carbodiimide and stir. Evenly, slowly add 75wt% nitric acid dropwise, stir well and place in a closed container, stir and react at 90°C for 2h, then take it out, add 20ml pH=12 ammonia water and heat to 70°C, stir and react under nitrogen for 6.5h , Obtain aluminum-containing siloxane resin after cooling;

[0054] (4) Preparation of the self-cleaning layer: heating the aluminum-containing siloxane resin to a molten state and spraying on the surface of the micro-erosion layer of the light distribution lens, the coating thickness is about 0.15 cm, and the light distribution lens is obtained after static curing Self-cleaning layer on the inner surface.

[0055] Car lamp lampshades and ordinary polycarbonate lampshades prepared in Examples 1-3 were tested for dust prevention and adsorption of volatile organic compounds:

[0056] Take each of the lampshades and ordinary polycarbonate lampshades prepared in Examples 1-3, and conduct dust-proof experiments. The experimental methods are as follows: test the original light transmittance of the lampshades and record them , Then put the dry lampshade in a 70 °C experiment box, let air with a dust content of 50% in the box, take it out after 15min, wipe the outer surface of the lampshade clean and test the light transmittance again, get The light transmittance is also recorded; then the lampshade is cleaned with clean water, the lampshade with the wet surface is put into the test box at 70°C again and the experiment is carried out under the same conditions, and the outer surface of the lampshade is wiped clean and tested again. Light rate, get light transmittance two and record;

[0057] The lamp shades of the above-mentioned car lights were cleaned and dried, and they were respectively subjected to the experiment of adsorbing volatile organic compounds. The experimental methods were as follows: the lamp shades of the above-mentioned car lamps were placed in an experiment box at 70° C., and then passed to the experiment box. Put in the burning gas of the butyl sealant, take out the lampshade after 24h, wipe the outer surface of the lampshade clean and test the light transmittance again, and record the light transmittance three times. The data obtained is shown in Table 2;

[0058] The experimental data obtained is shown in Table 2:

[0059] Table 2

<td></td><td>Original transmittance (%)</td><td>Light transmittance one (%)</td><td>Light transmittance two (%)</td><td>Light transmittance three (ship</td>

<td>Example 1</td><td>85</td><td>84</td><td>83</td><td>82</td>

<td>Example 2</td><td>86</td><td>85</td><td>83</td><td>83</td>

<td>Example 3</td><td>85</td><td>85</td><td>84</td><td>83</td>

<td>Ordinary polycarbonate lampshade</td><td>85</td><td>73</td><td>50</td><td>49</td>

[0061] It can be seen from Table 2 that (1) In a dry and dusty environment, the light transmittance of the lampshade prepared in Examples 1-3 is not greatly reduced, which has a small impact on driving safety. Under the environment, the decrease in light transmittance is still small, which has a small impact on driving safety, but the light transmittance of ordinary polycarbonate lampshades has dropped by 12% and 35% respectively, and it has almost no self-cleaning function, which has a serious impact on driving safety. A certain influence may cause safety hazards, so the lampshade with self-cleaning function prepared by the present invention has a self-cleaning function, which can prevent the inner surface of the lampshade from being contaminated with dirt;

[0062] (2) The volatile organic compound adsorption experiment was carried out by simulating the volatile organic compounds after the combustion of the butyl sealant. The data in Table 2 shows that compared with the original light transmittance, Example 1 decreased by 3%. Example 2 dropped by 3%, and Example 3 dropped by 2%, which has little impact on driving safety, but ordinary polycarbonate lampshades have dropped by 36% and have almost no self-cleaning function, which has an impact on driving safety. It may cause potential safety hazards, so the lampshade with self-cleaning function of the vehicle lamp prepared by the present invention has a self-cleaning function and is not easy to absorb volatile organic compounds.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or modified. Equivalent replacements, without departing from the purpose and scope of the technical solution of the present invention, shall be covered by the scope of the claims of the present invention. The technologies, shapes, and structures that are not described in detail in the present invention are all known technologies.