A PC / GF composite LED kit and preparation method thereof

Abstract

The present invention relates to the technical field of polymer materials, and in particular to a PC / GF composite LED kit and a preparation method thereof. The kit comprises polycarbonate, glass fiber, modified silicon-based flame retardant, phosphate, light stabilizer, light diffuser, antioxidant, and lubricant; wherein the raw materials for preparing the modified silicon-based flame retardant include octahydrogen cage-shaped silsesquioxane, unsaturated sulfonate, and initiator. The LED kit prepared by melt blending the prepared modified silicon-based flame retardant with polycarbonate and glass fiber through addition reaction of the silicon-hydrogen bond in the octahydrogen cage-shaped silsesquioxane and the carbon-carbon double bond in the unsaturated sulfonate has good flame retardant effect, and the flame retardant performance of the material is further improved through the synergistic effect of the phosphate and the modified silicon-based flame retardant.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a PC / GF composite LED kit and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) is a high molecular polymer containing carbonate groups in its molecular structure. According to the different ester groups, polycarbonate is generally divided into three categories: aliphatic, aromatic, and aliphatic-aromatic. Among them, aromatic polycarbonate is the most widely used. Due to the presence of the rigid group benzene ring, polycarbonate has certain strength and mechanical properties, while improving thermal stability, so that the polymer can maintain the stability of the chain segment under heating. In addition, ether bonds and isopropyl groups can increase the flexibility of the overall chain segment of polycarbonate, making polycarbonate easy to process and apply.

[0003] Glass fiber (GF) is a micron-sized fibrous material that is drawn or centrifugally spun from glass after high-temperature melting. It mainly contains silicon dioxide, calcium oxide, sodium oxide, magnesium oxide, boron oxide, sodium oxide, etc. Glass fiber is usually added to a polymer matrix to give the composite material higher mechanical properties, and the mechanical properties of the composite material depend to a large extent on the amount of glass fiber added, the arrangement of the fibers, etc. The most common injection-molded products of short-fiber composite materials have fibers roughly oriented along the injection pressure direction, making the composite material highly anisotropic.

[0004] PC / GF composite materials are glass fibers added to a polycarbonate matrix to enhance the mechanical properties of the material. However, when used in automotive interiors, electronic appliances and other fields, the flame retardant properties of the composite materials need to be improved. Secondly, since polycarbonate materials release a large amount of heat and toxic smoke when burned, they pose a great threat to the human body and the environment. Summary of the invention

[0005] In order to improve the flame retardant properties of LED kit materials, the present application provides a PC / GF composite LED kit and a preparation method thereof.

[0006] In order to achieve the above purpose, this application adopts the following technical solutions:

[0007] In the first aspect, the present application provides a PC / GF composite LED kit and a preparation method thereof, which adopts the following technical solutions:

[0008] A PC / GF composite LED kit, comprising the following materials:

[0009] Polycarbonate 70-90 parts;

[0010] 12-16 parts of glass fiber;

[0011] 2-4 parts of modified silicon flame retardant;

[0012] Phosphate 0.5-0.7 part;

[0013] Light stabilizer 0.3-0.5 parts;

[0014] 1.2 to 1.4 parts of light diffuser;

[0015] 0.2-0.4 parts of antioxidant;

[0016] Lubricant 0.3-0.7 parts;

[0017] The raw materials for preparing the modified silicon-based flame retardant include octahydrogen cage silsesquioxane, unsaturated sulfonate and an initiator. The silicon-hydrogen bonds in the octahydrogen cage silsesquioxane and the carbon-carbon double bonds in the unsaturated sulfonate undergo addition reaction. The weight ratio of the octahydrogen cage silsesquioxane to the sulfonate is 2:(0.5-0.9).

[0018] By adopting the above device, when the material is burning, the octahydrogen cage silsesquioxane gradually migrates to the surface of the polycarbonate to form a ceramic-like layer to isolate the external oxygen and heat from diffusing into the polycarbonate matrix. Among them, the silicon-hydrogen bond in the octahydrogen cage silsesquioxane reacts with the carbon-carbon double bond in the unsaturated sulfonate to produce a modified silicon-based flame retardant with good flame retardant effect when applied to polycarbonate plastics. And when phosphate ester is used together with the modified silicon-based flame retardant, a synergistic effect can be produced to further improve the flame retardant effect of the polymer. The glass fiber is evenly distributed in the PC matrix, which can effectively transmit and disperse stress, reduce stress concentration, thereby improving the material's bearing capacity and impact resistance, and during processing, the glass fiber can well maintain the shape of the material and reduce the shrinkage of the material.

[0019] Preferably, the unsaturated sulfonate includes one or both of sodium methyl methacrylate sulfonate and potassium p-styrene sulfonate.

[0020] By adopting the above device, sodium methacrylate sulfonate and potassium p-styrene sulfonate will decompose at high temperature to produce sulfonic acid, which can promote the dehydration and carbonization reaction of polycarbonate, thereby promoting the cross-linking of polycarbonate molecules into carbon, forming a protective carbon layer, thereby isolating oxygen and heat and improving the flame retardant effect. In addition, when sodium methacrylate sulfonate and potassium p-styrene sulfonate are burned, they will produce gases such as hydrogen sulfide, which can dilute the oxygen concentration to inhibit the spread of flames and achieve a flame retardant effect.

[0021] Preferably, the phosphate ester includes one or both of triphenyl phosphate and hydroquinone bis(diphenyl phosphate).

[0022] By adopting the above device, triphenyl phosphate and hydroquinone bis(diphenyl phosphate) release incombustible gas during the combustion process, dilute the mass concentration of combustible gas, slow down the combustion, and at the same time, triphenyl phosphate decomposes to form -PO free radicals, capture the active -H and -OH free radicals generated by the combustion of polycarbonate, and inhibit the chain reaction of combustion in the gas phase.

[0023] Preferably, the light stabilizer includes one or both of 2-(2'-hydroxy 5'-tert-octylphenyl)benzotriazole (UV-329) and 2,2,6,6-tetramethylpiperidinamine.

[0024] By using the above device, 2-(2'-hydroxy 5'-tert-octylphenyl) benzotriazole (UV-329) is an ultraviolet absorber, and there is a hydrogen bond chelate ring in its molecule. When absorbing ultraviolet light, the hydrogen bond is destroyed, and the ultraviolet light energy can be converted into harmless heat energy, effectively reducing the damage of ultraviolet radiation to plastic products, slowing down the speed of yellowing, aging and cracking of plastic products, etc., maintaining the physical properties of plastics and extending the service life. 2,2,6,6-tetramethylpiperidinamine is a free radical scavenger, and its molecular structure contains a piperidine ring. When exposed to ultraviolet radiation, it can be converted into a stable nitrogen oxide free radical. After the polycarbonate polymer material is exposed to ultraviolet radiation and becomes an excited state molecule, it begins to produce alkyl free radicals, peroxyalkyl free radicals, etc. The appearance of these free radicals will accelerate the light aging of the polycarbonate material. The nitrogen oxide free radicals in the 2,2,6,6-tetramethylpiperidinamine molecule will capture the free radicals generated by the polycarbonate molecule to generate corresponding esters or peroxide esters and other compounds to terminate the chain reaction and achieve the effect of light stabilization, thereby preventing the occurrence of light aging of the material.

[0025] Preferably, the light diffuser is a silicone light diffuser.

[0026] By adopting the above device, the silicone light diffuser is evenly dispersed in the plastic, and through its tiny particle size and surface treatment, a large number of diffuse scattering points are formed on the plastic surface, so that the light is reflected and refracted multiple times when passing through the plastic, so that the plastic product presents a soft, misty, uniform halo effect, and has little effect on the light transmittance of the material.

[0027] Preferably, the antioxidant includes one or both of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecylβ(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0028] By adopting the above device, the benzene ring in the antioxidant molecule carries a hydroxyl group, and the ortho or para position of the hydroxyl functional group has two tert-butyl substituent groups. Since the hydroxyl group is restricted by spatial barriers, the hydrogen atom can easily fall off from the original molecular structure, thereby achieving the effect of donating protons and combining with peroxy radicals, alkyl radicals or hydroxyl radicals, causing them to lose their original activity, reducing the source of free radicals, and causing the oxidation reaction to terminate, thereby achieving an antioxidant effect and extending the service life of the material.

[0029] Preferably, the lubricant includes one or both of ethylene bisstearamide and erucic acid amide.

[0030] By adopting the above device, ethylene bis stearamide and erucic acid amide play a role in reducing the cohesive force between molecules inside the plastic melt, which can reduce the internal friction of the plastic melt, increase the melting rate and melt deformability of the plastic, and reduce the melt viscosity. At the same time, ethylene bis stearamide and erucic acid amide can also reduce the adhesion of molten polymers to the surface of thermal processing equipment. In addition, the molecular surfaces of ethylene bis stearamide and erucic acid amide contain hydrophilic groups, which can combine with moisture in the air to form a conductive channel, so that the charge can be quickly removed from the plastic surface, thereby reducing static electricity accumulation, playing an antistatic effect, and reducing the adhesion of dust on the surface of plastic products.

[0031] In a second aspect, the present application provides a method for preparing a PC / GF composite LED kit using the following technical solution: A method for preparing a PC / GF composite LED kit, comprising the following steps:

[0032] (1) weighing raw materials according to the composition ratio, stirring and mixing polycarbonate, modified silicon flame retardant, phosphate, light stabilizer, light diffuser, antioxidant, and lubricant, and then adding glass fiber and mixing evenly;

[0033] (2) After being uniformly mixed, the mixture is fed into a screw machine for melt mixing at a speed of 300 to 400 rpm and a temperature of 230 to 270° C.;

[0034] (3) After mixing, the mixture is injection molded and cooled in a water tank at a temperature of 50 to 65° C. to obtain the finished product.

[0035] Preferably, in step (3), the injection molding temperature is 230-250° C., the injection molding pressure is 60-100 MPa, the injection molding speed is 40-60 mm / s, and the cooling rate is 10-30° C. / min.

[0036] By adopting the above-mentioned device, since polycarbonate has a linear structure, the degree of molecular orientation along the flow direction is the largest. Under rapid cooling conditions, if the straightened molecular chains do not have time to relax, orientation stress will be generated in this direction. By reasonably controlling the injection molding temperature, injection molding pressure, injection molding pressure and cooling rate, on the one hand, the shear stress can be reduced and the molecular orientation degree can be reduced. On the other hand, stress relaxation can be accelerated, the deorientation ability can be enhanced, and the fatigue strength and wear resistance of the LED kit can be further improved.

[0037] Preferably, the preparation method of the modified silicon-based flame retardant is:

[0038] Add octahydrogen cage-shaped silsesquioxane to anhydrous ethanol, mix evenly and heat to 40-60° C. to obtain an organic solution, mix unsaturated sulfonate and deionized water evenly to prepare a sulfonate aqueous solution, add a catalyst to the organic solution, and add the sulfonate aqueous solution dropwise to the organic solution to react for 2-3 hours, finally remove the anhydrous ethanol by distillation, and filter, wash and dry the reaction product to obtain a modified silicon-based flame retardant;

[0039] The catalyst is rhodium trichloride.

[0040] By adopting the above-mentioned device, the modified silicon-based flame retardant prepared in the present application is applied to the material of the LED kit, which is beneficial to improving the flame retardant performance of the material without affecting the light transmission performance of the material.

[0041] This application has the following beneficial effects:

[0042] 1. In the present application, when the material is burning, the octahydrogen cage silsesquioxane gradually migrates to the surface of the polycarbonate to form a ceramic-like carbon layer to isolate the external oxygen and heat from diffusing into the polycarbonate matrix. Among them, the silicon-hydrogen bonds in the octahydrogen cage silsesquioxane react with the carbon-carbon double bonds in the unsaturated sulfonate to produce a modified silicon-based flame retardant that has a good flame retardant effect when applied to polycarbonate plastics. And when phosphate esters are used together with modified silicon-based flame retardants, a synergistic effect can be produced to further improve the flame retardant effect of the polymer. The glass fibers are evenly distributed in the PC matrix, which can effectively transmit and disperse stress, reduce stress concentration, and thus improve the material's bearing capacity and impact resistance. In addition, during processing, the glass fibers can well maintain the shape of the material and reduce the shrinkage of the material.

[0043] 2. In the present application, 2-(2'-hydroxy 5'-tert-octylphenyl)benzotriazole (UV-329) is an ultraviolet absorber. There is a hydrogen bond chelate ring in its molecule. When absorbing ultraviolet light, the hydrogen bond is destroyed, and the ultraviolet light energy can be converted into harmless heat energy, effectively reducing the damage of ultraviolet radiation to plastic products, slowing down the speed of yellowing, aging and cracking of plastic products, etc., maintaining the physical properties of plastics and extending the service life. 2,2,6,6-tetramethylpiperidinamine is a free radical scavenger. Its molecular structure contains a piperidine ring. When exposed to ultraviolet radiation, it can be converted into a stable nitroxide free radical. After the polycarbonate polymer material is exposed to ultraviolet radiation and becomes an excited state molecule, it begins to produce alkyl free radicals, peroxyalkyl free radicals, etc. The appearance of these free radicals will accelerate the light aging of the polycarbonate material. The nitrogen oxide free radicals in the 2,2,6,6-tetramethylpiperidinamine molecule will capture the free radicals generated by the polycarbonate molecule to generate corresponding esters or peroxide esters and other compounds to terminate the chain reaction and achieve the effect of light stabilization, thereby preventing the occurrence of light aging of the material. DETAILED DESCRIPTION

[0044] Preparation Example

[0045] Preparation Example 1

[0046] Preparation of modified silicon flame retardant:

[0047] 2 kg of octahydrogen cage-shaped silsesquioxane was added to anhydrous ethanol, mixed evenly and heated to 40°C to obtain an organic solution, 0.5 kg of sodium methyl methacrylate sulfonate was evenly mixed with 1 kg of deionized water to prepare a sulfonate aqueous solution, 0.02 kg of rhodium trichloride was added to the organic solution, and the sulfonate aqueous solution was dropwise added to the organic solution to react for 2 hours, and finally the anhydrous ethanol was removed by distillation, and the reaction product was filtered, washed, and dried to obtain a modified silicon-based flame retardant.

[0048] Preparation Example 2

[0049] Preparation of modified silicon flame retardant:

[0050] 3 kg of octahydrogen cage-shaped silsesquioxane was added to anhydrous ethanol, mixed evenly and heated to 50°C to obtain an organic solution, 0.7 kg of potassium p-styrenesulfonate and 1 kg of deionized water were mixed evenly to prepare a sulfonate aqueous solution, 0.02 kg of rhodium trichloride was added to the organic solution, and the sulfonate aqueous solution was added dropwise to the organic solution to react for 2.5 hours, and finally the anhydrous ethanol was removed by distillation, and the reaction product was filtered, washed, and dried to obtain a modified silicon-based flame retardant.

[0051] Preparation Example 3

[0052] Preparation of modified silicon flame retardant:

[0053] 4 kg of octahydrogen cage-shaped silsesquioxane was added to anhydrous ethanol, mixed evenly and heated to 60°C to obtain an organic solution, 0.9 kg of potassium p-styrenesulfonate and 1 kg of deionized water were mixed evenly to prepare a sulfonate aqueous solution, 0.02 kg of rhodium trichloride was added to the organic solution, and the sulfonate aqueous solution was added dropwise to the organic solution to react for 3 hours, and finally the anhydrous ethanol was removed by distillation, and the reaction product was filtered, washed, and dried to obtain a modified silicon-based flame retardant.

[0054] Example

[0055] Example 1

[0056] A PC / GF composite LED kit, comprising the following materials:

[0057] Polycarbonate: 70kg, polycarbonate is L-1250Y from Teijin of Japan;

[0058] Glass fiber: 12kg;

[0059] Modified silicon-based flame retardant: 2 kg, wherein the modified silicon-based flame retardant is the modified silicon-based flame retardant prepared in Preparation Example 1;

[0060] Triphenyl phosphate: 0.5kg;

[0061] 2-(2'-Hydroxy 5'-tert-octylphenyl)benzotriazole (UV-329): 0.3 kg;

[0062] Organic silicon light diffuser: 1.2kg, organic silicon light diffuser is DOWSIL 30-424;

[0063] Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate: 0.2 kg;

[0064] Erucamide: 0.3kg.

[0065] The preparation method of the PC / GF composite LED kit in the first embodiment includes the following steps:

[0066] (1) weighing raw materials according to the composition ratio, placing polycarbonate, glass fiber, and modified silicon flame retardant in an oven at 110° C. and drying for 10 h;

[0067] (2) mixing the dried polycarbonate, modified silicon flame retardant, triphenyl phosphate, 2-(2'-hydroxy 5'-tert-octylphenyl)benzotriazole (UV-329), silicone light diffuser, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and erucamide, and then adding glass fiber and mixing evenly;

[0068] (3) After being uniformly mixed, the mixture is sent to a screw machine for melt mixing at a speed of 300 rpm and a temperature of 230° C.;

[0069] (4) After kneading, the mixture was injection molded at an injection temperature of 230° C., an injection pressure of 60 MPa, and an injection speed of 40 mm / s, and then cooled in a water tank at a water temperature of 50° C. to obtain an LED kit.

[0070] Example 2

[0071] A PC / GF composite LED kit, comprising the following materials:

[0072] Polycarbonate: 80kg, polycarbonate is L-1250Y from Teijin of Japan;

[0073] Glass fiber: 14kg;

[0074] Modified silicon-based flame retardant: 3 kg, wherein the modified silicon-based flame retardant is the modified silicon-based flame retardant prepared in Preparation Example 1;

[0075] Hydroquinone bis(diphenyl phosphate): 0.6kg;

[0076] 2,2,6,6-Tetramethylpiperidinamine: 0.4kg;

[0077] Organic silicon light diffuser: 1.3 kg, wherein the organic silicon light diffuser is DOWSIL 30-424;

[0078] β (3,5-di-tert-butyl-4-hydroxybenzene) propionate octadecyl alcohol ester: 0.3kg;

[0079] Ethylene bisstearamide: 0.5kg.

[0080] The preparation method of the PC / GF composite LED kit in the second embodiment includes the following steps:

[0081] (1) weighing raw materials according to the composition ratio, placing polycarbonate, glass fiber, and modified silicon flame retardant in an oven at 110° C. and drying for 11 hours;

[0082] (2) mixing the dried polycarbonate, modified silicon flame retardant, hydroquinone bis(diphenyl phosphate), 2,2,6,6-tetramethylpiperidinamine, silicone light diffuser, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol, and ethylene bisstearic acid amide, and then adding glass fiber and mixing evenly;

[0083] (3) After being uniformly mixed, the mixture is sent to a screw machine for melt mixing at a speed of 350 rpm and a temperature of 250° C.;

[0084] (4) After kneading, the mixture was injection molded at an injection temperature of 240° C., an injection pressure of 80 MPa, and an injection speed of 50 mm / s, and then cooled in a water tank at a water temperature of 60° C. to obtain an LED kit.

[0085] Example 3

[0086] A PC / GF composite LED kit, comprising the following materials:

[0087] Polycarbonate: 90kg, polycarbonate is L-1250Y from Teijin of Japan;

[0088] Glass fiber: 16kg;

[0089] Modified silicon-based flame retardant: 4 kg, wherein the modified silicon-based flame retardant is the modified silicon-based flame retardant prepared in Preparation Example 1;

[0090] Triphenyl phosphate: 0.7kg;

[0091] 2,2,6,6-Tetramethylpiperidinamine: 0.5kg;

[0092] Organic silicon light diffuser: 1.4kg, organic silicon light diffuser is DOWSIL 30-424;

[0093] β (3,5-di-tert-butyl-4-hydroxybenzene) propionate octadecyl alcohol ester: 0.4kg;

[0094] Erucamide: 0.7kg.

[0095] The preparation method of the PC / GF composite LED kit in the third embodiment includes the following steps:

[0096] (1) weighing the raw materials according to the composition ratio, placing the polycarbonate, glass fiber, and modified silicon flame retardant in an oven at 110° C. and drying for 12 hours;

[0097] (2) mixing the dried polycarbonate, modified silicon flame retardant, triphenyl phosphate, 2,2,6,6-tetramethylpiperidinamine, silicone light diffuser, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and erucamide, and then adding glass fiber and mixing evenly;

[0098] (3) After being uniformly mixed, the mixture is sent to a screw machine for melt mixing at a speed of 400 rpm and a temperature of 270°C;

[0099] (4) After kneading, the mixture was injection molded at an injection temperature of 250° C., an injection pressure of 100 MPa, and an injection speed of 60 mm / s, and then cooled in a water tank at a water temperature of 65° C. to obtain an LED kit.

[0100] Example 4

[0101] The difference between this embodiment and embodiment 2 is that the modified silicon-based flame retardant adopts an equal amount of the modified silicon-based flame retardant prepared in preparation example 2.

[0102] Example 5

[0103] The difference between this embodiment and embodiment 2 is that the modified silicon-based flame retardant adopts an equal amount of the modified silicon-based flame retardant prepared in preparation example 3.

[0104] Comparative Example

[0105] Comparative Example 1

[0106] A PC / GF composite LED kit raw material, which differs from Example 2 in that an equal amount of hydroquinone bis(diphenyl phosphate) is used instead of a modified silicon-based flame retardant.

[0107] Comparative Example 2

[0108] A PC / GF composite LED kit is different from Example 2 in that an equal amount of polysiloxane is used to replace the modified silicon-based flame retardant.

[0109] Comparative Example 3

[0110] A PC / GF composite LED kit is different from Example 2 in that an equal amount of octahydrogen cage-shaped silsesquioxane is used to replace the modified silicon-based flame retardant.

[0111] Comparative Example 4

[0112] A PC / GF composite LED kit is different from Example 2 in that an equal amount of sodium methyl methacrylate sulfonate is used to replace the modified silicon-based flame retardant.

[0113] Comparative Example 5

[0114] A PC / GF composite LED kit, which is different from Example 2 in that no hydroquinone bis(diphenyl phosphate) is added.

[0115] Comparative Example 6

[0116] A PC / GF composite LED kit is different from Example 2 in that an equal amount of potassium perfluorobutyl sulfonate is used to replace the sodium methyl methacrylate sulfonate in the modified silicon-based flame retardant.

[0117] Performance testing

[0118] 1. Flame retardant performance test

[0119] Vertical combustion test: The test is conducted in accordance with the UL-94 standard. During the test, the sample is fixed vertically on the bracket, the top of the sample is ignited with a flame, and then the flame is removed to observe the burning of the sample. The flame retardant performance of the material is divided into three levels: V-2, V-1 and V-0 according to the sample's burning time, flame propagation speed, and whether there are dripping objects.

[0120] Limiting oxygen index test (LOI): The test method of limiting oxygen index is to place the sample vertically in a combustion tank with gradually decreasing oxygen concentration, and adjust the oxygen concentration to obtain the minimum oxygen concentration for spontaneous combustion of the sample, usually expressed as a percentage. The higher the index, the better the flame retardant performance of the material. The test is carried out by JF-20 limiting oxygen index analyzer and in accordance with GB / T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method". The prepared foam plastic is cut into 80mm×10mm×10mm strips, with at least 6 strips in each group.

[0121] Smoke density: Smoke density is an important indicator used to determine whether plastics are safe when burning. It is mainly expressed by the maximum smoke density value MSD and the smoke density grade SDR. The larger the value, the greater the smoke density generated by the burning material. The test was conducted using the SCY-3 building material smoke density tester produced by Nanjing Shangyuan Analytical Instrument Co., Ltd. in accordance with GB / T8323.2-2008 "Plastic Smoke Generation Part 2 Single Chamber Method for Determining Smoke Density Test Method", and the sample size was 75mm×75mm×25mm.

[0122] Table 1: Flame retardant performance test results

[0123]

[0124]

[0125] 2. Mechanical properties test

[0126] Notched impact strength: Use a pendulum impact tester to test the notched impact toughness of the material. The material notch is type B, with a span of 60mm, and the sample specifications are (80±0.5)×(10±0.2)×(4±0.2)mm. Each group tests 5-6 specimens and calculates the average value.

[0127] Weathering performance: The prepared material was injected into a 2.0 mm thick color plate on an injection molding machine, and then placed in a UV aging box for testing. After 1500 hours, the color plates were taken out to test their L, a, and b color values, and then compared with the original values ​​of L, a, and b to calculate the aging color difference ΔE. The calculation formula for ΔE is:

[0128]

[0129] Table 2: Mechanical properties test results

[0130]

[0131]

[0132] Combining the data in Table 1 and Table 2 with Example 2 and Comparative Example 1 of the present application, it can be seen that when the PC / GF composite LED kit of the present application is prepared, the flame retardant effect is not ideal when phosphate ester is used alone as a flame retardant. Therefore, the lack of modified silicon-based flame retardant does not significantly improve the flame retardant properties of the material. The reason for this is that when phosphate ester is used as a flame retardant, the heat released by the combustion of the material will affect the thermal stability of the phosphate ester. When the modified silicon-based flame retardant is used together with the phosphate ester, a synergistic effect can be produced to improve the flame retardant effect of the material, and also improve the weather resistance and impact strength of the material.

[0133] Combining Example 2 and Comparative Example 2 described in the present application and combining the data in Tables 1 and 2, it can be seen that when making the PC / GF composite LED kit of the present application, the use of unmodified silicon-based flame retardants does not significantly improve the flame retardant properties of the material, and also affects the aging speed of the material, causing the weather resistance of the material to decrease.

[0134] In combination with the data in Example 2 and Comparative Examples 3-4 of the present application and in combination with Tables 1 and 2, it can be seen that when the PC / GF composite LED kit of the present application is made, the silicon-hydrogen bond in the octahydrogen cage-shaped silsesquioxane reacts with the carbon-carbon double bond in the unsaturated sulfonate to form an addition reaction, and the obtained modified silicon-based flame retardant is applied to polycarbonate plastics with good flame retardant effect. Among them, the octahydrogen cage-shaped silsesquioxane and the unsaturated sulfonate are indispensable, and the silicon-hydrogen bond on the molecular chain, according to the condensation phase mechanism, will form -Si-C- bonds upon combustion, thereby producing an oxygen-insulating and heat-insulating silicon-carbon layer, and the unsaturated sulfonate will decompose at high temperature to produce sulfonic acid, which can promote the dehydration and carbonization reaction of polycarbonate, thereby promoting the cross-linking of polycarbonate molecules into carbon, to promote the formation of a carbon layer, thereby isolating oxygen and heat, and improving the flame retardant effect, and the unsaturated sulfonate will produce gases such as hydrogen sulfide when burning, which can dilute the concentration of oxygen to suppress the spread of flames, and further improve the flame retardant effect of the material. In addition, octahydrogen cage silsesquioxane and unsaturated sulfonate will also affect the weather resistance and impact resistance of the material and accelerate the aging of the material.

[0135] Combining the description of Example 2 and Comparative Example 5 of the present application and the data in Tables 1 and 2, it can be seen that when making the PC / GF composite LED kit of the present application, if phosphate is not added, the flame retardant properties of the material will be affected. On the contrary, since phosphate releases difficult-to-burn gas during combustion, the mass concentration of the combustible gas is diluted, the combustion is slowed down, and at the same time, the phosphate decomposes to form -PO free radicals, which can capture the active -H and -OH free radicals generated by the combustion of polycarbonate, thereby inhibiting the chain reaction of combustion and achieving a flame retardant effect.

[0136] Combining the data in Table 1 and Table 2 with Example 2 and Comparative Example 6 of the present application, it can be seen that the silicon-hydrogen bond in the octahydrogen cage-shaped silsesquioxane in the modified silicon-based flame retardant reacts with the carbon-carbon double bond in the unsaturated sulfonate, and the prepared modified silicon-based flame retardant is applied to polycarbonate plastics and has a good flame retardant effect. However, potassium perfluorobutyl sulfonate does not contain a carbon-carbon double bond in its molecular structure and cannot react with the octahydrogen cage-shaped silsesquioxane, so the flame retardant effect is poor. In addition, the use of saturated sulfonates instead of unsaturated sulfonates in the modified silicon-based flame retardant will affect the aging rate of the material and reduce the material's load-bearing capacity and impact resistance.

[0137] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A PC / GF composite LED kit, characterized in that: By weight, it includes the following raw materials: Polycarbonate 70-90 parts; Glass fiber 12~16 parts; 2~4 parts of modified silicon flame retardant; Phosphate 0.5-0.7 parts; Light stabilizer 0.3~0.5 parts; Light diffuser 1.2~1.4 parts; 0.2~0.4 parts of antioxidant; Lubricant 0.3~0.7 parts; The raw materials for preparing the modified silicon-based flame retardant include octahydrogen cage silsesquioxane, unsaturated sulfonate and a catalyst. The silicon-hydrogen bonds in the octahydrogen cage silsesquioxane and the carbon-carbon double bonds in the unsaturated sulfonate undergo addition reaction. The weight ratio of the octahydrogen cage silsesquioxane to the sulfonate is 2:(0.5-0.9).

2. A PC / GF composite LED kit according to claim 1, characterized in that: The unsaturated sulfonate includes one or both of sodium methacrylic sulfonate and potassium p-styrene sulfonate.

3. A PC / GF composite LED kit according to claim 1, characterized in that: The phosphate ester includes one or both of triphenyl phosphate and hydroquinone bis(diphenyl phosphate).

4. The PC / GF composite LED kit according to claim 1, characterized in that: The light stabilizer includes one or two of 2-(2'-hydroxy 5'-tert-octylphenyl)benzotriazole (UV-329) and 2,2,6,6-tetramethylpiperidinamine.

5. The PC / GF composite LED kit according to claim 1, characterized in that: The light diffuser is an organic silicon light diffuser.

6. The PC / GF composite LED kit according to claim 1, characterized in that: The antioxidant includes one or both of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecylβ(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

7. The PC / GF composite LED kit according to claim 1, characterized in that: The lubricant comprises one or both of ethylene bis stearamide and erucic acid amide.

8. The method for preparing the PC / GF composite LED kit according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Weighing raw materials according to the above-mentioned component ratio, stirring and mixing polycarbonate, modified silicon-based flame retardant, phosphate ester, light stabilizer, light diffuser, antioxidant, and lubricant, and then adding glass fiber and mixing evenly; (2) After being evenly mixed, the mixture is sent into a screw machine for melt mixing at a speed of 300-400 rpm and a temperature of 230-270°C; (3) After mixing, injection molding is performed and the finished product is obtained after cooling in a water tank with a water temperature of 50~65℃.

9. The method for preparing the PC / GF composite LED kit according to claim 8, characterized in that: In the step (3), the injection molding temperature is 230-250° C., the injection molding pressure is 60-100 MPa, the injection molding speed is 40-60 mm / s, and the cooling rate is 10-30° C. / min.

10. The method for preparing the PC / GF composite LED kit according to claim 8, characterized in that: The preparation method of the modified silicon-based flame retardant is: Add octahydrogen cage-shaped silsesquioxane to anhydrous ethanol, mix evenly and heat to 40-60° C. to obtain an organic solution, mix unsaturated sulfonate and deionized water evenly to prepare a sulfonate aqueous solution, add a catalyst to the organic solution, and add the sulfonate aqueous solution dropwise to the organic solution to react for 2-3 hours, finally remove the anhydrous ethanol by distillation, and filter, wash and dry the reaction product to obtain a modified silicon-based flame retardant; The catalyst is rhodium trichloride.

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