A high beam angle polypropylene flame retardant material

Abstract

The present invention relates to a high beam angle polypropylene flame retardant material, which comprises the following components in parts by weight: 100 parts of polypropylene; 0.5 - 2 parts of a high refractive index diffusing agent; 0.5 - 2 parts of a low refractive index diffusing agent; 2 - 4 parts of a flame retardant; the refractive index of the high refractive index diffusing agent is 0.05 - 0.1 higher than that of polypropylene, and the particle size range is 1 - 10 μm; the refractive index of the low refractive index diffusing agent is more than 0.15 lower than that of polypropylene, and the particle size range is 1 - 4 μm; the beam angle of the high beam angle polypropylene flame retardant material is more than 100°, and the light transmittance is more than 63%. The high beam angle polypropylene flame retardant material of the present invention avoids the strongest reflection by controlling the particle size of the diffusing agent. By adding a high refractive index diffusing agent and a low refractive index diffusing agent relative to polypropylene, the light transmittance can be improved, and at the same time, the beam angle of the corresponding lamp is also improved, avoiding complex procedures such as LED design, light distribution, and lens selection.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials and relates to a high beam angle polypropylene flame retardant material. Background Art

[0002] The LED lighting industry is one of the industries with relatively fast development and continuous growth in market scale at present, and the LED lighting industry is regarded as the future of LED applications.

[0003] The beam angle is one of the most important technical parameters of lamps. The International Commission on Illumination (CIE) stipulates that the angle formed by both sides where the luminous intensity reaches 50% of the normal luminous intensity is called the beam angle. In practical applications, different types of lamps such as downlights, spotlights, bulb lamps or wall lamps often select different beam angles to achieve good presentation effects. Generally speaking, the beam angles of downlights and spotlights are relatively small, generally about 100 degrees, while those of bulb lamps are relatively large, up to 200 degrees.

[0004] It has been found through research that under the same LED chip power, a design with a larger beam angle can better avoid blue light hazards. At present, in the lighting industry, the corresponding beam angle settings are often achieved by changing the LED lamp bead design or changing the lens.

[0005] For example: CN202010756726.3 provides a switchable beam angle LED floodlighting device and method, which records three types of lenses: narrow beam angle, medium beam angle, and wide beam angle; CN202321151990.X provides a lamp with adjustable beam angle, including a first lens and a second lens assembly; however, for manufacturers with large-scale and continuous production, in order to obtain lamps with higher beam angles, the above two design schemes increase multiple sets of lens components, resulting in a significant increase in design costs.

[0006] Changing the beam angle through a diffusion cover within a certain range becomes an alternative and efficient option, and the corresponding design angle is achieved by adjusting the light diffusion.

[0007] For example: CN201811058182.2 provides a flame retardant light-diffusing polypropylene composite material for LEDs and its components, and the compound flame retardant is a compound of ammonium polyphosphate and melamine polyphosphate; Patent CN202011535519.1 provides a high haze and high light transmittance flame retardant polypropylene material, its preparation method and application. Without adding an additional light diffusing agent, a secondary phosphate and a brominated flame retardant are compounded as a flame retardant system, and by adjusting their mass ratio and the particle size of the secondary phosphate, a high haze and high light transmittance flame retardant polypropylene material is prepared to obtain the corresponding beam angle;

[0008] However, there is a problem in the existing technology. As the beam angle increases, the light transmittance of the material decreases. As a result, it is necessary to increase the number of LED beads to increase the light brightness to meet the required lumen value. The reason for this problem is the reflection effect of the added substances in the matrix. The reflection effect is the key factor affecting the light transmittance and greatly affects the overall light transmittance. Especially for flame-retardant materials (such as patent CN******), a large amount of additional additives are required (because these additives are all added substances), which will further affect the reflection effect.

[0009] Therefore, it is of great significance to study a high-beam-angle polypropylene flame-retardant material to solve the problem of the decrease in light transmittance while increasing the beam angle in the existing technology. Summary of the Invention

[0010] The purpose of the present invention is to solve the problems existing in the existing technology and provide a high-beam-angle polypropylene flame-retardant material.

[0011] To achieve the above object, the technical scheme adopted by the present invention is as follows:

[0012] A high-beam-angle polypropylene flame-retardant material, comprising the following components in parts by weight:

[0013]

[0014] The refractive index of the high-refractive-index diffusing agent is 0.05-0.1 higher than that of the polypropylene, and the particle size range is 1-10 μm; within the range of the refractive index difference of 0.05-0.1 from the polypropylene, the surface secondary reflection loss caused by it is less, and it can play a role in reducing total reflection in the polypropylene matrix;

[0015] The refractive index of the low-refractive-index diffusing agent is more than 0.15 lower than that of the polypropylene, and the particle size range is 1-4 μm;

[0016] The beam angle of the high-beam-angle polypropylene flame-retardant material is more than 100°, and the light transmittance is more than 63%.

[0017] As a preferred technical solution:

[0018] For the high-beam-angle polypropylene flame-retardant material as described above, the haze of the polypropylene is less than 5% (thickness 1 mm), and the melt index under the test conditions of 230°C and 2.16 kg is 12-18 g / 10 min; among them, the lower haze can avoid the inhomogeneity inside the polypropylene and reduce the situation where the light transmittance or beam angle is difficult to control due to the reflection and scattering caused by the crystal grain size;

[0019] Low haze of polypropylene is a requirement for raw material purity, to avoid the reduction of light intensity at non-desired angles caused by non-directional scattering or reflection of substances with different refractive indices such as impurities, (the beam angle is the vector angle at 50% of the light intensity). The high haze of the prepared high-beam-angle polypropylene flame retardant material is due to the fact that achieving a high beam angle will inevitably result in high haze of the material.

[0020] For a high-beam-angle polypropylene flame retardant material as described above, the high refractive index diffusing agent with a high refractive index is polystyrene PS with a refractive index of 1.59.

[0021] For a high-beam-angle polypropylene flame retardant material as described above, the low refractive index diffusing agent is fluorinated ethylene propylene copolymer (FEP), whose refractive index is more than 0.15 lower than that of polypropylene, which can achieve a higher light diffusion effect, thus reaching the required beam angle. At the same time, due to its relatively low refractive index (1.33), it can significantly reduce the reflection loss on the surface, thereby improving the light transmittance.

[0022] For a high-beam-angle polypropylene flame retardant material as described above, the flame retardant is a flame retardant containing a quaternary carbon structure with a low molar refractive index contribution in its molecular structure.

[0023] For a high-beam-angle polypropylene flame retardant material as described above, the flame retardant is a mixture of 2,3-dimethyl-2,3-diphenylbutane and tris(tribromoneopentyl) phosphate; the refractive index of 2,3-dimethyl-2,3-diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61.

[0024] For a high-beam-angle polypropylene flame retardant material as described above, the mass ratio of 2,3-dimethyl-2,3-diphenylbutane to tris(tribromoneopentyl) phosphate in the flame retardant is 1:10.

[0025] By using a flame retardant containing a quaternary carbon structure with a low molar refractive index contribution in its molecular structure, the added flame retardant has a relatively low refractive index among available flame retardant categories, ensuring that the final material has high transparency and low reflection loss. At the same time, the selected flame retardant has a relatively low melting point. The melting point of tris(tribromoneopentyl) phosphate is 181°C, and the melting point of 2,3-dimethyl-2,3-diphenylbutane is 90 - 110°C. The processing or injection molding temperature range of polypropylene is 200°C - 250°C. In this way, the particle size of the flame retardant (which can be better dispersed by the screw after melting, resulting in a relatively small particle size, generally for mineral flame retardants or particle size) is much smaller than the visible light range, minimizing its impact on the light transmittance and beam angle.

[0026] Principle of the invention:

[0027] According to the law of total reflection, when light travels from a medium with a higher refractive index (optically thinner medium) to a medium with a lower refractive index (optically denser medium) (the refractive index of polypropylene is about 1.5, and for example, the commonly used silicone diffusing agent is 1.4), total reflection will occur.

[0028] Regarding the propagation of light in a plastic matrix, when light in a matrix with a high refractive index hits a diffusing agent with a lower refractive index, total reflection will be caused. A part of this totally reflected light will also be reflected outside the matrix, resulting in a decrease in transmittance. However, when a high refractive index substance is added, there is no such total reflection phenomenon, or the total reflection is reduced to a certain extent, so that a part of the light can enter the material interior. Therefore, only adding a high refractive index substance can reduce the internal reflection phenomenon in the matrix and increase the transmittance.

[0029] There is interface secondary reflection for any substance. Interface secondary reflection occurs when light enters the plastic from the air and is caused by other substances added. The higher the refractive index of the added substance, the more reflection occurs. This actually leads to a large reflection loss due to the high refractive index when only a high refractive index substance is added. Instead of achieving the purpose of increasing the transmittance, the overall transmittance is reduced due to interface secondary reflection.

[0030] Regarding the problem that a high refractive index substance cannot increase the transmittance due to interface secondary reflection but instead reduces the transmittance, the present invention adds a low refractive index substance while adding a high refractive index substance. The low refractive index substance compensates for the reflection loss problem caused by the addition of the high refractive index substance.

[0031] Regarding the problem of large refractive index and large reflection loss of a high refractive index substance, the present invention limits the range of the high refractive index, so that the surface secondary reflection loss caused by it is less, and it can play a role in reducing total reflection in the polypropylene matrix.

[0032] The refractive index of the low refractive index substance of the present invention is lower than that of the conventional silicone diffusing agent, greatly compensating for the reflection loss caused by the addition of the high refractive index substance.

[0033] In the present invention, whether it is a high refractive index substance or a low refractive index substance, because there is a large difference from the polypropylene matrix, the beam angle of the material can be increased to a corresponding value. The greater the refractive index difference, the better the diffusion effect. At the same time, a relatively high refractive index difference ensures the haze of the final material, avoiding the situation of light leakage of lamp beads due to low haze.

[0034] In addition, the present invention avoids the particle size range with the strongest reflection (the reflection is the strongest when the particle size is close to the wavelength) by controlling the particle size of the diffusing agent, and then selects the range of 1 - 4 um. If the particle size is too large, the scattering will decrease, and a larger amount of diffusing agent needs to be added to meet the requirements, thus affecting the physical properties and cost. If the particle size is too small and falls within the strong reflection range, the transmittance will decrease significantly.

[0035] Beneficial effects:

[0036] A high-beam-angle polypropylene flame retardant material of the present invention avoids the strongest reflection by controlling the particle size of the diffusing agent. By adding a high-refractive-index diffusing agent and a low-refractive-index diffusing agent relative to polypropylene, the light transmittance can be increased while the beam angle of the corresponding lamp is also increased, avoiding complex procedures such as LED design, light distribution, and lens selection. Specific embodiments

[0037] 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 not 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 also fall within the scope defined by the appended claims of this application.

[0038] The test methods related to the embodiments of the present invention are as follows:

[0039] Flame retardancy: Tested according to GB / T 2408-2008, the thickness of the high-beam-angle polypropylene flame retardant material is 1.6 mm;

[0040] Glow wire GWFI: Tested according to GB / T 5169.10 / 12-2013;

[0041] Light transmittance and haze: Tested according to GB / T 2410-2008, the thickness of the high-beam-angle polypropylene flame retardant material is 2.0 mm;

[0042] Beam angle: Tested according to GB / T 19658-2013.

[0043] The information of the raw materials used in the present invention is as follows:

[0044] Polypropylene: Dongming Petrochemical HC 8016, thickness 1 mm, haze 4-4.5%;

[0045] High-refractive-index diffusing agent: Solvay Chemicals (Suzhou) Co., Ltd., model KSR-3, average particle size 3 μm, refractive index 1.59;

[0046] Low-refractive-index diffusing agent: Chemours, grade FEP 9819FL, a microsphere material with an average particle size of 1.8 μm after further treatment by liquid nitrogen cryogenic air flow pulverization technology;

[0047] 2,3-Dimethyl-2,3-diphenylbutane: Shandong Xinghai Chemical Co., Ltd., purity 99%;

[0048] Tris(tribromoneopentyl) phosphate: Shandong Rixing New Materials Co., Ltd., RX-974.

[0049] Example 1

[0050] A high beam angle polypropylene flame retardant material, by weight, comprises 100 parts of polypropylene, 0.5 part of high refractive index diffusing agent, 0.5 part of low refractive index diffusing agent and 2 parts of flame retardant;

[0051] The haze of the polypropylene is 4.5%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 15 g / 10 min;

[0052] The high refractive index diffusing agent is PS microspheres, with a refractive index of 1.59 and an average particle size of 3 μm;

[0053] The low refractive index diffusing agent is a fluorinated ethylene propylene copolymer, whose refractive index is 0.17 lower than that of polypropylene, and the average particle size is 1.8 μm;

[0054] The flame retardant is a mixture of 2,3-dimethyl-2,3-diphenylbutane and tris(tribromoneopentyl) phosphate with a mass ratio of 1:10; the refractive index of 2,3-dimethyl-2,3-diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61.

[0055] The flame retardant grade of the high beam angle polypropylene flame retardant material is V2, the beam angle is 100°, the light transmittance is 75%, the haze is 84%, and the glow wire GWFI is 830 °C.

[0056] Example 2

[0057] A high beam angle polypropylene flame retardant material, by weight, comprises 100 parts of polypropylene, 1 part of high refractive index diffusing agent, 1 part of low refractive index diffusing agent and 2 parts of flame retardant;

[0058] The haze of the polypropylene is 4.5%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 15 g / 10 min;

[0059] The high refractive index diffusing agent is PS microspheres, with a refractive index of 1.59 and an average particle size of 3 μm;

[0060] The low refractive index diffusing agent is a fluorinated ethylene propylene copolymer, whose refractive index is 0.17 lower than that of polypropylene, and the average particle size is 1.8 μm;

[0061] The flame retardant is a mixture of 2,3-dimethyl-2,3-diphenylbutane and tris(tribromoneopentyl) phosphate with a mass ratio of 1:10; the refractive index of 2,3-dimethyl-2,3-diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61.

[0062] The flame retardant grade of the high beam angle polypropylene flame retardant material is V2, the beam angle is 105°, the light transmittance is 71%, the haze is 89%, and the glow wire GWFI is 820 °C.

[0063] Example 3

[0064] A high beam angle polypropylene flame retardant material, by weight, comprises 100 parts of polypropylene, 1 part of high refractive index diffusing agent, 1.5 parts of low refractive index diffusing agent and 3 parts of flame retardant;

[0065] The haze of the polypropylene is 4.5%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 15 g / 10 min;

[0066] The high refractive index diffusing agent is PS microspheres, with a refractive index of 1.59 and an average particle size of 3 μm;

[0067] The low refractive index diffusing agent is a fluorinated ethylene propylene copolymer, whose refractive index is 0.17 lower than that of polypropylene, and the average particle size is 1.8 μm;

[0068] The flame retardant is a mixture of 2,3-dimethyl-2,3-diphenylbutane and tris(tribromoneopentyl) phosphate with a mass ratio of 1:10; the refractive index of 2,3-dimethyl-2,3-diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61.

[0069] The flame retardant grade of the high beam angle polypropylene flame retardant material is V2, the beam angle is 113°, the light transmittance is 69%, the haze is 90%, and the glow wire GWFI is 930 °C.

[0070] Example 4

[0071] A high beam angle polypropylene flame retardant material, by weight, comprises 100 parts of polypropylene, 1.5 parts of high refractive index diffusing agent, 1.5 parts of low refractive index diffusing agent and 3 parts of flame retardant;

[0072] The haze of the polypropylene is 4.5%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 15 g / 10 min;

[0073] The high refractive index diffusing agent is PS microspheres, with a refractive index of 1.59 and an average particle size of 3 μm;

[0074] The low refractive index diffusing agent is a fluorinated ethylene propylene copolymer, whose refractive index is 0.17 lower than that of polypropylene, and the average particle size is 1.8 μm;

[0075] The flame retardant is a mixture of 2,3 - dimethyl - 2,3 - diphenylbutane and tris(tribromoneopentyl) phosphate with a mass ratio of 1:10; the refractive index of 2,3 - dimethyl - 2,3 - diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61.

[0076] The flame - retardant grade of the high - beam - angle polypropylene flame - retardant material is V2, the beam angle is 115°, the light transmittance is 67%, the haze is 94%, and the glow - wire GWFI is 910 °C.

[0077] Example 5

[0078] A high - beam - angle polypropylene flame - retardant material, by weight, comprises 100 parts of polypropylene, 2 parts of high - refractive - index diffusing agent, 2 parts of low - refractive - index diffusing agent, and 4 parts of flame retardant;

[0079] The haze of the polypropylene is 4.5%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 15 g / 10 min;

[0080] The high - refractive - index diffusing agent is PS microspheres with a refractive index of 1.59 and an average particle size of 3 μm;

[0081] The low - refractive - index diffusing agent is a fluorinated ethylene - propylene copolymer, whose refractive index is 0.17 lower than that of polypropylene, and the average particle size is 1.8 μm;

[0082] The flame retardant is a mixture of 2,3 - dimethyl - 2,3 - diphenylbutane and tris(tribromoneopentyl) phosphate with a mass ratio of 1:10; the refractive index of 2,3 - dimethyl - 2,3 - diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61.

[0083] The flame - retardant grade of the high - beam - angle polypropylene flame - retardant material is V2, the beam angle is 120°, the light transmittance is 63%, the haze is 96%, and the glow - wire GWFI is 950 °C.

[0084] Comparative Example 1

[0085] A polypropylene flame - retardant material, by weight, comprises 100 parts of polypropylene (Zhenhai Petrochemical T30S), 2 parts of silicone diffusing agent (Dongguan Xingyuan Chemical KS950), and 4 parts of flame retardant (Guangzhou Yinyuan New Materials);

[0086] The haze of the polypropylene is 20%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 3 g / 10 min;

[0087] The refractive index of the silicone diffusing agent is 1.43, and the average particle size is 1.5 μm;

[0088] The flame retardant is a phosphorus-nitrogen-bromine compound flame retardant FR-500;

[0089] The flame retardant grade of the polypropylene flame retardant material is V2, the beam angle is 100°, the light transmittance is 62%, the haze is 86%, and the glow wire GWFI is 820 °C.

[0090] Comparing Comparative Example 1 and Example 5, it can be found that Example 5 has a higher beam angle and light transmittance. This is because the difference in refractive index between the low refractive index diffusing agent and polypropylene in Example 5 is larger and the diffusivity is better, so it has a higher beam angle. Due to the addition of high refractive index substances and flame retardants with specific structures, the light transmittance is higher and the haze is also more excellent, and at the same time the flame retardant performance does not decay.

[0091] Comparative Example 2

[0092] A polypropylene flame retardant material, by weight, includes 100 parts of polypropylene (Zhenhai Petrochemical T30S), 4 parts of silicone diffusing agent (Dongguan Xingyuan Chemical KS950) and 4 parts of flame retardant (Guangzhou Yinyuan New Materials);

[0093] The haze of the polypropylene is 20%, the refractive index is 1.5, and the melt index under the test conditions of 230 °C and 2.16 kg is 3 g / 10 min;

[0094] The refractive index of the silicone diffusing agent is 1.43 and the average particle size is 1.5 μm;

[0095] The flame retardant is a phosphorus-nitrogen-bromine compound flame retardant FR-500.

[0096] The flame retardant grade of the polypropylene flame retardant material is V2, the beam angle is 115°, the light transmittance is 58%, the haze is 95%, and the glow wire GWFI is 930 °C.

[0097] Comparing Comparative Example 2 and Comparative Example 1, it can be found that as the content of the diffusing agent increases, the beam angle of the material in Comparative Example 2 will also increase, but its light transmittance decreases greatly. This is because the internal reflection of the polypropylene flame retardant material becomes stronger, resulting in a larger decrease in light transmittance, while the decrease in light transmittance amplitude of the present invention is smaller.

Claims

1. A high beam angle polypropylene flame retardant material, characterized in that Comprising the following components in parts by weight: The haze of the polypropylene is less than 5%; The high refractive index diffusing agent is polystyrene microspheres with a refractive index of 1.59; The low refractive index diffusing agent is a fluorinated ethylene propylene copolymer; The refractive index of the high refractive index diffusing agent is 0.05 - 0.1 higher than that of the polypropylene, and the particle size range is 1 - 10 μm; the refractive index of the low refractive index diffusing agent is more than 0.15 lower than that of the polypropylene, and the particle size range is 1 - 4 μm; The flame retardant is a mixture of 2,3 - dimethyl - 2,3 - diphenylbutane and tris(tribromoneopentyl) phosphate; the refractive index of 2,3 - dimethyl - 2,3 - diphenylbutane is 1.55, and the refractive index of tris(tribromoneopentyl) phosphate is 1.61; The high beam angle polypropylene flame retardant material has a beam angle of 100° or more and a light transmittance of 63% or more.

2. The high-beam-angle polypropylene flame-retardant material according to claim 1, wherein The melt index of the polypropylene under the test conditions of 230°C and 2.16 kg is 12 - 18 g / 10 min.

3. The high-beam-angle polypropylene flame-retardant material according to claim 1, wherein The mass ratio of 2,3 - dimethyl - 2,3 - diphenylbutane to tris(tribromoneopentyl) phosphate in the flame retardant is 1:10.

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