A polypropylene diffusion material with low color temperature change during aging and preparation method thereof

Abstract

The invention belongs to the technical field of polymer materials, and relates to a polypropylene diffusion material with low color temperature change after aging and a preparation method thereof, specifically: by weight, 100 parts of polypropylene, 0.02-0.06 parts of fluorescent whitening agent and 1-3 parts of migration diffusion and reflection aid are taken, and each component is mixed in a high-speed rotating mixer, and granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging; wherein the fluorescent whitening agent is a mixture of a stilbene fluorescent whitening agent and a benzoxazole fluorescent whitening agent in a mass ratio of 2:1; the migration diffusion and reflection aid is a mixture of a cross-linked methacryloyloxy silicone powder and a silicone diffuser in a mass ratio of 1:1; the particle size of the cross-linked methacryloyloxy silicone powder is 3-4 μm. The polypropylene diffusion material of the present invention has low color temperature change when used under high temperature and high humidity conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a polypropylene diffusion material with low color temperature change due to aging and a preparation method thereof. Background Art

[0002] With the continuous expansion of the development and use of domestic LED lamps, PP or PC diffusion materials have been widely used as lampshades. In related fields, the research, functionalization and patent application of polypropylene diffusion materials have become the focus. For example, there are patents such as CN202011149808.8 and CN202011149805.4, which respectively involve flame-retardant light-diffusing polypropylene compositions and their applications, as well as light-diffusing polypropylene compositions and light-diffusing polypropylene and their applications. These patents use polypropylene, synergistic diffusers and other ingredients to not only improve the light diffusion properties of polypropylene materials, but also improve their thermal deformation properties and flame retardancy. They can even absorb blue light and / or ultraviolet light and convert it into visible light, which is suitable for anti-blue light LED lamps.

[0003] At the same time, there are also patents such as CN202111334783.3 and CN202011577491.8, which focus on the performance of materials under wet and hot aging conditions or the problem of flame retardant precipitation, and respectively provide a light diffusion flame retardant PC with excellent resistance to wet and hot aging and a preparation method thereof, as well as a high temperature and high humidity environment resistant precipitation flame retardant polypropylene composite material and a preparation method thereof.

[0004] However, despite many related patents and research, there is little research on the color temperature change of materials under hot and humid conditions, especially when applied in high temperature and high humidity environments such as Southeast Asia. Due to the dual influence of humidity and temperature, the color temperature of materials often changes, which violates the original design intention and even affects consumers' willingness to use. This has become a very important factor. However, at present, there are very limited research or patent disclosures on reducing the color temperature change of materials under high temperature and high humidity conditions.

[0005] Therefore, as the application of LEDs further expands, it becomes very necessary to develop a diffusion material with low color temperature change when used under high temperature and high humidity conditions. This will be one of the issues that the relevant industry must pay attention to in the future. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art and to provide a polypropylene diffusion material with low color temperature change upon aging and a preparation method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme:

[0008] A polypropylene diffusion material with low color temperature change after aging, comprising, by weight, 100 parts of polypropylene, 0.02-0.06 parts of fluorescent brightener, and 1-3 parts of migration, diffusion and reflection aid;

[0009] The fluorescent whitening agent is a mixture of a stilbene fluorescent whitening agent and a benzoxazole fluorescent whitening agent in a mass ratio of 2:1;

[0010] The migration, diffusion and reflection aid is a mixture of cross-linked methacryloyloxy-containing organosilicon powder and organosilicon diffusing agent in a mass ratio of 1:1;

[0011] The particle size of the cross-linked methacryloyloxy-containing organic silicon powder is 3-4 μm.

[0012] The diffusion material of the present invention has the characteristic of low color temperature change due to aging, which is mainly attributed to the following two points:

[0013] (1) The diffusion material contains a certain amount of diphenylethylene fluorescent brighteners. The diphenylethylene fluorescent brighteners have a conjugated large π bond in their structure. Therefore, diphenylethylene fluorescent brighteners have good two-photon excitation characteristics, can absorb ultraviolet light, and produce blue fluorescence. At the same time, diphenylethylene fluorescent brighteners also have up-conversion fluorescence characteristics, can absorb low-energy light, and produce fluorescence. More than 95% of the light emitted by LEDs is low-energy visible light with a wavelength of 400-800nm. Diphenylethylene fluorescent brighteners can absorb this light and produce blue fluorescence. When the high temperature and high humidity environment causes the lampshade to turn yellow, the blue fluorescence can have a counteracting effect on the yellow light, which ultimately reflects a low change in color temperature (the color temperature of yellow light is about 3500, and the color temperature of blue light is about 6000).

[0014] (2) The diffusion material contains a certain amount of cross-linked methacryloyloxy silicone powder, which has a large polarity (containing acyloxy groups) and has the characteristic of migrating to the surface when added to polypropylene. At the same time, it has a suitable particle size and can specifically reflect and scatter light of a certain wavelength, thereby reducing the yellow light entering the diffusion material. According to the principle of complementary colors, this will cause the diffusion material to tend to display blue. Combined with the effect of fluorescent brighteners, the color temperature change caused by yellowing of the material under high temperature and high humidity conditions is reduced as a whole, thereby ensuring that the light source of the warm white light design does not deviate significantly from the original color temperature.

[0015] The fluorescent whitening agent of the present invention is a mixture of a stilbene fluorescent whitening agent and a benzoxazole fluorescent whitening agent, the purpose of which is to allow the two to play a synergistic role and reduce the amount of the fluorescent whitening agent. The stilbene fluorescent whitening agent has up-conversion fluorescence characteristics, which can absorb light with a longer wavelength and further enhance the color of the material observed by the naked eye from being yellowish.

[0016] The diffusion material needs to ensure that the light can be scattered evenly, reduce directness and improve the uniformity of light distribution in space, so a certain amount of silicone diffuser needs to be added. Silicone diffusers play a vital role in diffusion materials. They usually exist in the form of tiny transparent spheres in the matrix, and through refraction and scattering, they can effectively change the path of light and make the light more evenly distributed in space. This uniform scattering characteristic can not only reduce the uneven brightness of light, but also improve the lighting effect, making the light softer and more comfortable. In view of the fact that there are some overlaps in the functions of silicone diffusers and cross-linked methacryloyloxy silicone powders, the present invention regards the mixture of the two as an auxiliary agent and names it as a migration diffusion and reflection auxiliary agent.

[0017] As the preferred technical solution:

[0018] The polypropylene diffusion material with low color temperature change after aging as described above is a highly crystalline polypropylene, and the crystallization peak area exceeds 115 J / g (obtained using NETZSCH's differential scanning calorimeter DSC300Classic) under a cooling rate of 20 K / min.

[0019] In the polypropylene diffusion material with low color temperature change after aging as described above, the diphenylethylene fluorescent brightener is 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene (CAS No. 13001-40-6).

[0020] In the above-mentioned polypropylene diffusion material with low color temperature change after aging, the benzoxazole fluorescent brightener is 2,2-(4,4-diphenylethylene)bisbenzoxazole (CAS No. 1533-45-5).

[0021] As described above, the polypropylene diffusion material with low color temperature change after aging, the silicone diffuser is a silicone spherical powder.

[0022] The polypropylene diffusion material with low color temperature change after aging as described above further contains 1-3 parts of flame retardant and 0.5-1 parts of antioxidant.

[0023] In the above-mentioned polypropylene diffusion material with low color temperature change after aging, the flame retardant is a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (FLAMESTAB NOR116) in a mass ratio of 2:1; and the antioxidant is a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1. The present invention reduces the hue change caused by the yellowing of the diffusion material itself by selecting a flame retardant and an antioxidant with low yellowing and high efficiency.

[0024] For an aged polypropylene diffusion material with low color temperature change as described in any of the above items, in a needle flame test, the flame of the polypropylene diffusion material continues to burn for 10-25s; under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is less than 500K after being placed in an environment with a temperature of 90°C and a relative humidity of 95% for 1000h.

[0025] The present invention also provides a method for preparing a polypropylene diffusion material with low color temperature change due to aging as described in any of the above items, wherein the components are mixed in a high-speed rotating mixer according to a ratio, and then granulated by a twin-screw extruder to obtain the polypropylene diffusion material with low color temperature change due to aging.

[0026] Beneficial effects:

[0027] The polypropylene diffusion material of the present invention realizes the low color temperature change of the polypropylene material under high temperature and high humidity aging conditions by specially selecting a diffusant, using a fluorescent whitening agent containing two-photon characteristics and compounding a low yellowing flame retardant. Compared with general flame retardant diffusion materials, the diffusant with mobility increases its enrichment degree on the surface, and the diffusant not only has a diffusion effect, but also has corresponding reflection and scattering effects; at the same time, the fluorescent whitening agent containing two-photon characteristics further enhances the blue light whiteness of the material, effectively avoiding the visual hue change caused by yellowing of the material due to aging. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0029] The testing methods for the relevant indicators in the following embodiments and comparative examples are as follows: Color temperature: The color temperature of the sample is tested using the LPCE-2 (LMS-9000) CCD fast light, color and electricity comprehensive testing system according to CIE-15.

[0030] Needle flame test: Test in accordance with standard GB / T 5169.5-2020.

[0031] The cross-linked methacryloyloxy-containing silicone powder in the following examples and comparative examples is from Suzhou Sisuo New Materials Co., Ltd., with a weight average molecular weight of 350,000 g / mol and the structural formula is as follows:

[0032]

[0033] Example 1

[0034] A method for preparing a polypropylene diffusion material with low color temperature change after aging is as follows:

[0035] (1) Raw material preparation:

[0036] Polypropylene: The crystallization peak area is 120 J / g at a cooling rate of 20 K / min;

[0037] Fluorescent brightener: a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,2-(4,4-diphenylethylene)bisbenzoxazole in a mass ratio of 2:1;

[0038] Migration, diffusion and reflection aid: a mixture of cross-linked methacryloxy-containing organosilicon powder and organosilicon spherical powder (polydimethylsiloxane with a degree of polymerization of 4000) in a mass ratio of 1:1, wherein the particle size of the cross-linked methacryloxy-containing organosilicon powder is 3-4 μm;

[0039] Flame retardant: a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (BASF's FLAMESTAB NOR116) in a mass ratio of 2:1;

[0040] Antioxidant: a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1;

[0041] (2) Preparation of polypropylene diffusion material:

[0042] By weight, take 100 parts of polypropylene, 0.02 parts of fluorescent brightener, 1 part of migration, diffusion and reflection aid, 1 part of flame retardant and 0.5 parts of antioxidant;

[0043] All the above components are added into a high-speed rotating mixer and mixed, and then granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging;

[0044] Among them, the processing temperature of the twin-screw extruder is 170-180℃.

[0045] The final aged polypropylene diffusion material with low color temperature change has a flame duration of 10s in the needle flame test. Under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is 380K after being placed in an environment of 90℃ and 95% relative humidity for 1000h.

[0046] Comparative Example 1

[0047] A method for preparing a polypropylene diffusion material is basically the same as Example 1, except that the fluorescent brightener in this comparative example is a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,5-di-bis(benzoxazole-2-)thiophene (CAS No. 12224-41-8) in a mass ratio of 2:1.

[0048] The polypropylene diffusion material finally obtained, under the condition that the design color temperature of the lamp is 5000K, the color temperature of the polypropylene diffusion material changes to 520K after being placed in an environment with a temperature of 90°C and a relative humidity of 95% for 1000 hours.

[0049] Compared with Example 1, the color temperature change value of the polypropylene diffusion material prepared in Comparative Example 1 is larger. This is because the 2,2-(4,4-diphenylethylene)bisbenzoxazole used in Example 1 can absorb LED light to emit blue-white light, which can offset the yellow light generated to a certain extent, while the 2,5-di-bis(benzoxazole-2-)thiophene used in Comparative Example 1 does not have two-photon excitation characteristics, which weakens the blue-white light emitted by the fluorescent whitening agent in Comparative Example 1 and reduces the offset effect on the yellow light, resulting in a larger color temperature change value of the polypropylene diffusion material.

[0050] Comparative Example 2

[0051] A method for preparing a polypropylene diffusion material is basically the same as Example 1, except that the migration diffusion and reflection aid in this comparative example is a mixture of cross-linked methacryloyloxy-containing silicone powder and silicone diffusing agent in a mass ratio of 1:10.

[0052] The polypropylene diffusion material finally obtained has a color temperature change value of 700K under the condition that the design color temperature of the lamp is 5000K and the polypropylene diffusion material is placed in an environment with a temperature of 90°C and a relative humidity of 95% for 1000 hours.

[0053] Compared with Example 1, the color temperature change value of the polypropylene diffusion material prepared in Comparative Example 2 is larger. This is because the cross-linked methacryloyloxy silicone powder contained in Comparative Example 2 is less, and after migrating to the surface, the reflection and scattering of yellow light are insufficient, and the effect of yellowing on color temperature cannot be effectively reduced, resulting in a higher color temperature change value.

[0054] Example 2

[0055] A method for preparing a polypropylene diffusion material with low color temperature change after aging is as follows:

[0056] (1) Raw material preparation:

[0057] Polypropylene: The crystallization peak area is 120 J / g at a cooling rate of 20 K / min;

[0058] Fluorescent brightener: a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,2-(4,4-diphenylethylene)bisbenzoxazole in a mass ratio of 2:1;

[0059] Migration, diffusion and reflection aid: a mixture of cross-linked methacryloxy-containing organosilicon powder and organosilicon spherical powder (polydimethylsiloxane with a degree of polymerization of 4000) in a mass ratio of 1:1, wherein the particle size of the cross-linked methacryloxy-containing organosilicon powder is 3-4 μm;

[0060] Flame retardant: a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (BASF's FLAMESTAB NOR116) in a mass ratio of 2:1;

[0061] Antioxidant: a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1;

[0062] (2) Preparation of polypropylene diffusion material:

[0063] By weight, take 100 parts of polypropylene, 0.02 parts of fluorescent brightener, 1 part of migration, diffusion and reflection aid, 3 parts of flame retardant and 0.5 parts of antioxidant;

[0064] All the above components are added into a high-speed rotating mixer and mixed, and then granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging;

[0065] Among them, the processing temperature of the twin-screw extruder is 170-180℃.

[0066] The final aged polypropylene diffusion material with low color temperature change has a flame duration of 25s in the needle flame test. Under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is 430K after being placed in an environment of 90℃ and 95% relative humidity for 1000h.

[0067] Example 3

[0068] A method for preparing a polypropylene diffusion material with low color temperature change after aging is as follows:

[0069] (1) Raw material preparation:

[0070] Polypropylene: The crystallization peak area is 120 J / g at a cooling rate of 20 K / min;

[0071] Fluorescent brightener: a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,2-(4,4-diphenylethylene)bisbenzoxazole in a mass ratio of 2:1;

[0072] Migration, diffusion and reflection aid: a mixture of cross-linked methacryloxy-containing organosilicon powder and organosilicon spherical powder (polydimethylsiloxane with a degree of polymerization of 4000) in a mass ratio of 1:1, wherein the particle size of the cross-linked methacryloxy-containing organosilicon powder is 3-4 μm;

[0073] Flame retardant: a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (BASF's FLAMESTAB NOR116) in a mass ratio of 2:1;

[0074] Antioxidant: a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1;

[0075] (2) Preparation of polypropylene diffusion material:

[0076] By weight, take 100 parts of polypropylene, 0.04 parts of fluorescent brightener, 3 parts of migration, diffusion and reflection aid, 1 part of flame retardant and 1 part of antioxidant;

[0077] All the above components are added into a high-speed rotating mixer and mixed, and then granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging;

[0078] Among them, the processing temperature of the twin-screw extruder is 170-180℃.

[0079] The final aged polypropylene diffusion material with low color temperature change has a flame duration of 10s in the needle flame test. Under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is 250K after being placed in an environment of 90℃ and 95% relative humidity for 1000h.

[0080] Example 4

[0081] A method for preparing a polypropylene diffusion material with low color temperature change after aging is as follows:

[0082] (1) Raw material preparation:

[0083] Polypropylene: The crystallization peak area is 120 J / g at a cooling rate of 20 K / min;

[0084] Fluorescent brightener: a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,2-(4,4-diphenylethylene)bisbenzoxazole in a mass ratio of 2:1;

[0085] Migration, diffusion and reflection aid: a mixture of cross-linked methacryloxy-containing organosilicon powder and organosilicon spherical powder (polydimethylsiloxane with a degree of polymerization of 4000) in a mass ratio of 1:1, wherein the particle size of the cross-linked methacryloxy-containing organosilicon powder is 3-4 μm;

[0086] Flame retardant: a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (BASF's FLAMESTAB NOR116) in a mass ratio of 2:1;

[0087] Antioxidant: a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1;

[0088] (2) Preparation of polypropylene diffusion material:

[0089] By weight, take 100 parts of polypropylene, 0.04 parts of fluorescent brightener, 2 parts of migration, diffusion and reflection aid, 3 parts of flame retardant and 0.5 parts of antioxidant;

[0090] All the above components are added into a high-speed rotating mixer and mixed, and then granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging;

[0091] Among them, the processing temperature of the twin-screw extruder is 170-180℃.

[0092] The final aged polypropylene diffusion material with low color temperature change has a flame duration of 20s in the needle flame test. Under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is 300K after being placed in an environment of 90℃ and 95% relative humidity for 1000h.

[0093] Example 5

[0094] A method for preparing a polypropylene diffusion material with low color temperature change after aging is as follows:

[0095] (1) Raw material preparation:

[0096] Polypropylene: The crystallization peak area is 120 J / g at a cooling rate of 20 K / min;

[0097] Fluorescent brightener: a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,2-(4,4-diphenylethylene)bisbenzoxazole in a mass ratio of 2:1;

[0098] Migration, diffusion and reflection aid: a mixture of cross-linked methacryloxy-containing organosilicon powder and organosilicon spherical powder (polydimethylsiloxane with a degree of polymerization of 4000) in a mass ratio of 1:1, wherein the particle size of the cross-linked methacryloxy-containing organosilicon powder is 3-4 μm;

[0099] Flame retardant: a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (BASF's FLAMESTAB NOR116) in a mass ratio of 2:1;

[0100] Antioxidant: a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1;

[0101] (2) Preparation of polypropylene diffusion material:

[0102] By weight, take 100 parts of polypropylene, 0.06 parts of fluorescent brightener, 1 part of migration, diffusion and reflection aid, 3 parts of flame retardant and 1 part of antioxidant;

[0103] All the above components are added into a high-speed rotating mixer and mixed, and then granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging;

[0104] Among them, the processing temperature of the twin-screw extruder is 170-180℃.

[0105] The final aged polypropylene diffusion material with low color temperature change has a flame duration of 20s in the needle flame test. Under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is 350K after being placed in an environment of 90℃ and 95% relative humidity for 1000h.

[0106] Example 6

[0107] A method for preparing a polypropylene diffusion material with low color temperature change after aging is as follows:

[0108] (1) Raw material preparation:

[0109] Polypropylene: The crystallization peak area is 120 J / g at a cooling rate of 20 K / min;

[0110] Fluorescent brightener: a mixture of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene and 2,2-(4,4-diphenylethylene)bisbenzoxazole in a mass ratio of 2:1;

[0111] Migration, diffusion and reflection aid: a mixture of cross-linked methacryloxy-containing organosilicon powder and organosilicon spherical powder (polydimethylsiloxane with a degree of polymerization of 4000) in a mass ratio of 1:1, wherein the particle size of the cross-linked methacryloxy-containing organosilicon powder is 3-4 μm;

[0112] Flame retardant: a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer (BASF's FLAMESTAB NOR116) in a mass ratio of 2:1;

[0113] Antioxidant: a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:1;

[0114] (2) Preparation of polypropylene diffusion material:

[0115] By weight, take 100 parts of polypropylene, 0.06 parts of fluorescent brightener, 3 parts of migration, diffusion and reflection aid, 1 part of flame retardant and 1 part of antioxidant;

[0116] All the above components are added into a high-speed rotating mixer and mixed, and then granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging;

[0117] Among them, the processing temperature of the twin-screw extruder is 170-180℃.

[0118] The final aged polypropylene diffusion material with low color temperature change has a flame duration of 10s in the needle flame test. Under the condition that the design color temperature of the lamp is 5000K, the color temperature change value of the polypropylene diffusion material is 150K after being placed in an environment of 90℃ and 95% relative humidity for 1000h.

Claims

1. A polypropylene diffusion material with low color temperature change after aging, characterized in that: By weight, it contains 100 parts of polypropylene, 0.02-0.06 parts of fluorescent brightener and 1-3 parts of migration, diffusion and reflection aid; The fluorescent whitening agent is a mixture of a stilbene fluorescent whitening agent and a benzoxazole fluorescent whitening agent in a mass ratio of 2:1; The migration, diffusion and reflection aid is a mixture of cross-linked methacryloyloxy-containing organosilicon powder and organosilicon diffusing agent in a mass ratio of 1:1; The particle size of the cross-linked methacryloyloxy-containing organic silicon powder is 3-4 μm.

2. The polypropylene diffusion material with low color temperature change after aging according to claim 1, characterized in that: The crystallization peak area of ​​polypropylene at a cooling rate of 20K / min exceeds 115J / g.

3. The polypropylene diffusion material with low color temperature change after aging according to claim 1, characterized in that: The diphenylethylene fluorescent brightener is 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene.

4. The polypropylene diffusion material with low color temperature change after aging according to claim 1, characterized in that: The benzoxazole fluorescent whitening agent is 2,2-(4,4-diphenylethylene)bisbenzoxazole.

5. The polypropylene diffusion material with low color temperature change after aging according to claim 1, characterized in that: The silicone diffuser is a spherical silicone powder.

6. The polypropylene diffusion material with low color temperature change after aging according to claim 1, characterized in that: It also contains 1-3 parts of flame retardant and 0.5-1 parts of antioxidant.

7. The polypropylene diffusion material with low color temperature change after aging according to claim 6, characterized in that: The flame retardant is a mixture of melamine and a monomolecular nitrogen alkoxy hindered amine stabilizer in a mass ratio of 2:1; the antioxidant is a mixture of antioxidant 626, antioxidant 1790 and antioxidant 412s in a mass ratio of 3:1:

1.

8. The polypropylene diffusion material with low color temperature change after aging according to any one of claims 1 to 7, characterized in that: In the needle flame test, the flame of the polypropylene diffusion material continues to burn for 10-25s; under the condition that the design color temperature of the lamp is 5000K, the color temperature change of the polypropylene diffusion material is less than 500K after being placed in an environment with a temperature of 90℃ and a relative humidity of 95% for 1000h.

9. A method for preparing a polypropylene diffusion material with low color temperature change after aging as claimed in any one of claims 1 to 8, characterized in that: After the components are mixed in a high-speed rotating mixer according to a proportion, the mixture is granulated by a twin-screw extruder to obtain a polypropylene diffusion material with low color temperature change after aging.

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