A plastic for a paint-free lamp with a metallic effect and a preparation method thereof

Abstract

The present invention discloses a paint-free lamp plastic with a metallic effect and a preparation method thereof. The lamp plastic comprises the following raw materials in parts by weight: 80-90 parts of modified polymethacrylate, 3-5 parts of a modifier, 1.5-2.5 parts of aluminum powder, 0.02-0.05 parts of carbon black, 0.1-0.3 parts of an antioxidant, and 0.2-0.3 parts of a dispersant. The lamp plastic molecules contain a chelate ring formed by a hindered amine and an intramolecular hydrogen bond. After the chelate ring is irradiated by ultraviolet light, the light energy is converted into heat energy and released. The hindered phenol can capture free radicals, thereby reducing the aging rate of the lamp plastic. When the modifier and the modified polymethacrylate are melt-extruded, dynamic cross-linking occurs, increasing the cross-linking sites of the plastic molecules. At the same time, the modifier molecules contain organosilicon segments, which can further improve the heat aging resistance of the plastic, and when subjected to external forces, the plastic is not prone to cracking, thereby increasing the service life of the lamp.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic preparation for lamps, and particularly relates to a paint-free lamp plastic with a metallic effect and a preparation method thereof. Background Art

[0002] The paint-free plastic with a metallic effect refers to adding additives such as metal powder and high-gloss powder to plastic by melt blending. After compatibilization modification, it is directly injection molded to make the plastic product have a metallic texture. This material not only has a metallic effect in appearance, but also is uniform inside, and there will be no problem of paint peeling or chipping. At present, most lamp plastics are acrylic materials, that is, polymethyl methacrylate. Polymethyl methacrylate is a transparent, hard and easy-to-process engineering plastic. Its good optical properties and processing convenience make it widely used in various fields such as architectural decoration, transportation products, lamp lighting, medical devices, and electronic products. However, when it is exposed to light and oxidation environments for a long time, its surface is prone to yellowing and its texture becomes brittle, affecting its toughness and strength, and thus affecting the service life of the lamp. Summary of the Invention

[0003] The purpose of the present invention is to provide a paint-free lamp plastic with a metallic effect and a preparation method thereof, which solves the problem that the lamp plastic is prone to yellowing after long-term use at present.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A preparation method of a paint-free lamp plastic with a metallic effect specifically includes the following steps:

[0006] Step A1: Mix methyl methacrylate, 2-hydroxyethyl methacrylate, azobisisobutyronitrile and n-octane evenly, introduce nitrogen protection, and react for 20 - 25 h under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 70 - 75 °C to obtain pretreated polymethacrylate. Dissolve the pretreated polymethacrylate in acetone, stir and add potassium carbonate and furan carbonyl chloride under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 50 - 55 °C, and react for 3 - 5 h to obtain modified polymethacrylate;

[0007] Step A2: Mix the modified polysiloxane, maleic anhydride and DMF, and react for 2 - 3 h under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 25 - 30 °C. Then, raise the temperature to 80 - 85 °C, add p-toluenesulfonic acid, and continue to react for 4 - 6 h to obtain a modifier. Weigh the following raw materials in parts by weight: 80 - 90 parts of modified polymethacrylate, 3 - 5 parts of modifier, 1.5 - 2.5 parts of aluminum powder, 0.02 - 0.05 parts of carbon black, 0.1 - 0.3 parts of antioxidant, and 0.2 - 0.3 parts of dispersant. Melt-extrude and cool the raw materials to obtain a paint-free lamp plastic with a metallic effect.

[0008] Furthermore, the molar ratio of methyl methacrylate, 2-hydroxyethyl methacrylate and azobisisobutyronitrile in Step A1 is 500:20:9, and the molar ratio of hydroxyl groups, potassium carbonate and furan carbonyl chloride on the pretreated polymethacrylate is 1:1.1:1.

[0009] Furthermore, the molar ratio of amino groups on the modified polysiloxane and maleic anhydride in Step A2 is 1:1, and the dosage of p-toluenesulfonic acid is 5‰ of the mass of maleic anhydride.

[0010] Furthermore, the modified polysiloxane is prepared by the following steps:

[0011] Step B1: Mix cyanuric chloride, resorcinol and chlorobenzene evenly, and stir and add aluminum chloride under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 45 - 50 °C to react for 3 - 5 h to obtain Intermediate 1. Mix Intermediate 1, potassium carbonate and DMF evenly, and stir and add acryloyl chloride under the conditions of a rotation speed of 200 - 300 r / min and a temperature of 100 - 110 °C to react for 3 - 5 h to obtain Intermediate 2;

[0012] Step B2: Mix octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane and deionized water, introduce nitrogen protection, and react for 10 - 12 h under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 90 - 95 °C to obtain polysiloxane. Mix polysiloxane, Intermediate 2, chloroplatinic acid and DMF evenly, introduce nitrogen protection, and react for 6 - 8 h under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 80 - 90 °C to obtain hyperbranched polysiloxane;

[0013] Step B3: Dissolve cyanuric chloride in toluene. Under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 0 - 3 °C, stir and add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and react for 2 - 3 h. Then add an aqueous sodium hydroxide solution, raise the temperature to 70 - 75 °C, and continue to react for 10 - 14 h. Add allyl alcohol, raise the temperature to 80 - 90 °C, and continue to react for 3 - 5 h to obtain a capping agent. Mix the hyperbranched polysiloxane, capping agent, chloroplatinic acid, and DMF evenly, introduce nitrogen protection, and react for 3 - 5 h under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 80 - 90 °C to obtain the modified polysiloxane.

[0014] Further, the dosage ratio of cyanuric chloride, resorcinol, and aluminum chloride described in Step B1 is 40 mmol: 120 mmol: 20 g, and the molar ratio of Intermediate 1, potassium carbonate, and acryloyl chloride is 1: 3.2: 3.

[0015] Further, the dosage ratio of octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane, and deionized water described in Step B2 is 2.3 mol: 2 mol: 0.1 mol: 3 mol: 5 L, the molar ratio of polysiloxane and Intermediate 2 is 2n + 1: n, where n is a natural number greater than 0, and the dosage of chloroplatinic acid is 1‰ of the mass of polysiloxane.

[0016] Further, the dosage ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, aqueous sodium hydroxide solution, and allyl alcohol described in Step B3 is 10 mmol: 20 mmol: 3 mL: 10 mmol, the concentration of the sodium hydroxide solution is 10 mol / L, the molar ratio of the Si-H bond on the hyperbranched polysiloxane and the capping agent is 1: 1, and the dosage of chloroplatinic acid is 1‰ of the mass of the hyperbranched polysiloxane.

[0017] The beneficial effects of the present invention: A kind of paint-free lamp plastic with a metallic effect prepared by the present invention comprises the following raw materials: modified polymethacrylate, modifier, aluminum powder, carbon black, antioxidant, and dispersant. The modified polymethacrylate is polymerized from methyl methacrylate and 2-hydroxyethyl methacrylate to obtain a pretreated polymethacrylate with hydroxyl groups in the side chain. Under the action of potassium carbonate, the hydroxyl group on the pretreated methacrylate reacts with the acyl chloride group on the furan carbonyl chloride to obtain modified polymethyl methacrylate.

[0018] The modifier is prepared by reacting a modified polysiloxane and maleic anhydride as raw materials to form a maleimide structure in the side chain. The modified polysiloxane is prepared by a bimolecular nucleophilic substitution reaction using cyanuric chloride and resorcinol as raw materials to obtain intermediate 1. Intermediate 1 is subjected to an etherification reaction with acryloyl chloride to obtain intermediate 2. Octamethylcyclotetrasiloxane is ring-opened and hydrolytically condensed with 3-aminopropylmethyldimethoxysilane, and finally capped with tetramethyldisiloxane to obtain polysiloxane. The polysiloxane and intermediate 2 are reacted so that the Si-H bond on the polysiloxane reacts with the double bond on intermediate 2 to obtain hyperbranched polysiloxane. Cyanuric chloride and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine are reacted, and by controlling the temperature, the two chlorine atom sites on cyanuric chloride react with the secondary amine on N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and then reacted with allyl alcohol so that the remaining chlorine atom sites react with the hydroxyl group on allyl alcohol to obtain a capping agent. The hyperbranched polysiloxane and the capping agent are reacted so that the Si-H bond on the hyperbranched polysiloxane reacts with the double bond on the capping agent to obtain modified polysiloxane.

[0019] The plastic of the lamp contains a chelate ring formed by a hindered amine and an intramolecular hydrogen bond. After the chelate ring is irradiated with ultraviolet light, these hydrogen bonds are broken, resulting in a change in the molecular structure and the formation of a high-energy state. This high-energy state is unstable and will return to a stable state by releasing energy, thus effectively preventing the aging of the plastic molecules by ultraviolet rays. The hindered phenol can convert peroxy radicals into hydroperoxides, and the generated phenoxy radicals will continue to react with peroxy radicals to generate non-radical products, reducing the aging rate of the plastic of the lamp. When the modifier and the modified polymethacrylate are melt-extruded, dynamic cross-linking occurs, increasing the cross-linking sites of the plastic molecules. At the same time, the modifier molecule contains an organosilicon segment, which can further improve the heat aging resistance of the plastic. And when subjected to external force, the plastic is not easy to generate cracks, thereby increasing the service life of the lamp. Specific embodiments

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Example 1. A preparation method of a paint-free lamp plastic with a metallic effect specifically includes the following steps:

[0022] Step A1: Mix methyl methacrylate, 2-hydroxyethyl methacrylate, azobisisobutyronitrile, and n-octane evenly, introduce nitrogen for protection, and react for 20 h under the conditions of a rotation speed of 150 r / min and a temperature of 70 °C to obtain pretreated polymethacrylate. Dissolve the pretreated polymethacrylate in acetone, stir and add potassium carbonate and furan carbonyl chloride under the conditions of a rotation speed of 120 r / min and a temperature of 50 °C, and react for 3 h to obtain modified polymethacrylate;

[0023] Step A2: Mix modified polysiloxane, maleic anhydride, and DMF, and react for 2 h under the conditions of a rotation speed of 150 r / min and a temperature of 25 °C. Then raise the temperature to 80 - 85 °C, add p-toluenesulfonic acid, and continue to react for 4 h to obtain a modifier. Weigh the following raw materials in parts by weight: 80 parts of modified polymethacrylate, 3 parts of modifier, 1.5 parts of aluminum powder, 0.02 part of carbon black, 0.1 part of antioxidant, and 0.2 part of dispersant. Melt and extrude the raw materials and cool them to obtain a paint-free lamp plastic with a metallic effect.

[0024] The molar ratio of methyl methacrylate, 2-hydroxyethyl methacrylate, and azobisisobutyronitrile in Step A1 is 500:20:9, and the molar ratio of the hydroxyl group on the pretreated polymethacrylate, potassium carbonate, and furan carbonyl chloride is 1:1.1:1.

[0025] The molar ratio of the amino group on the modified polysiloxane and maleic anhydride in Step A2 is 1:1. The dosage of p-toluenesulfonic acid is 5‰ of the mass of maleic anhydride. The antioxidant is 1010, and the dispersant is glyceryl tristearate.

[0026] The modified polysiloxane is prepared by the following steps:

[0027] Step B1: Mix cyanuric chloride, resorcinol, and chlorobenzene evenly, stir and add aluminum chloride under the conditions of a rotation speed of 150 r / min and a temperature of 45 °C, and react for 3 h to obtain Intermediate 1. Mix Intermediate 1, potassium carbonate, and DMF evenly, stir and add acryloyl chloride under the conditions of a rotation speed of 200 r / min and a temperature of 100 °C, and react for 3 h to obtain Intermediate 2;

[0028] Step B2: Mix octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane, and deionized water, introduce nitrogen for protection, and react for 10 h under the conditions of a rotation speed of 120 r / min and a temperature of 90 °C to obtain polysiloxane. Mix the polysiloxane, Intermediate 2, chloroplatinic acid, and DMF evenly, introduce nitrogen for protection, and react for 6 h under the conditions of a rotation speed of 150 r / min and a temperature of 80 °C to obtain hyperbranched polysiloxane;

[0029] Step B3: Cyanuric chloride is dissolved in toluene. Under the conditions of a rotation speed of 120 r / min and a temperature of 0 °C, it is stirred and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine is added. After reacting for 2 h, an aqueous sodium hydroxide solution is added, the temperature is raised to 70 °C, and the reaction continues for 10 h. Allyl alcohol is added, the temperature is raised to 80 °C, and the reaction continues for 3 h to obtain a capping agent. The hyperbranched polysiloxane, capping agent, chloroplatinic acid, and DMF are mixed evenly, nitrogen protection is introduced, and under the conditions of a rotation speed of 150 r / min and a temperature of 80 °C, the reaction is carried out for 3 h to obtain a modified polysiloxane.

[0030] The dosage ratio of cyanuric chloride, resorcinol, and aluminum chloride described in Step B1 is 40 mmol: 120 mmol: 20 g, and the molar ratio of Intermediate 1, potassium carbonate, and acryloyl chloride is 1: 3.2: 3.

[0031] The dosage ratio of octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane, and deionized water described in Step B2 is 2.3 mol: 2 mol: 0.1 mol: 3 mol: 5 L, the molar ratio of polysiloxane and Intermediate 2 is 3: 1, and the dosage of chloroplatinic acid is 1‰ of the mass of polysiloxane.

[0032] The amounts of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, aqueous sodium hydroxide solution, and allyl alcohol described in Step B3 are 10 mmol: 20 mmol: 3 mL: 10 mmol, the concentration of the sodium hydroxide solution is 10 mol / L, the molar ratio of the Si-H bond on the hyperbranched polysiloxane and the capping agent is 1: 1, and the dosage of chloroplatinic acid is 1‰ of the mass of the hyperbranched polysiloxane.

[0033] Example 2. A preparation method of a plastic for a paint-free lamp with a metallic effect specifically includes the following steps:

[0034] Step A1: Methyl methacrylate, 2-hydroxyethyl methacrylate, azobisisobutyronitrile, and n-octane are mixed evenly, nitrogen protection is introduced, and under the conditions of a rotation speed of 150 r / min and a temperature of 75 °C, the reaction is carried out for 20 h to obtain a pretreated polymethacrylate. The pretreated polymethacrylate is dissolved in acetone, and under the conditions of a rotation speed of 150 r / min and a temperature of 50 °C, it is stirred and potassium carbonate and furan carbonyl chloride are added, and the reaction is carried out for 4 h to obtain a modified polymethacrylate.

[0035] Step A2: Mix the modified polysiloxane, maleic anhydride and DMF, react at a rotation speed of 150 r / min and a temperature of 30 °C for 2 h, then raise the temperature to 85 °C, add p-toluenesulfonic acid, and continue to react for 5 h to obtain a modifier. Weigh the following raw materials by weight: 85 parts of modified polymethacrylate, 4 parts of modifier, 3 parts of aluminum powder, 0.03 parts of carbon black, 0.2 parts of antioxidant and 0.2 parts of dispersant. Melt-extrude and cool the raw materials to obtain a paint-free lamp plastic with a metallic effect.

[0036] The molar ratio of methyl methacrylate, 2-hydroxyethyl methacrylate and azobisisobutyronitrile in Step A1 is 500:20:9, and the molar ratio of hydroxyl groups, potassium carbonate and furan carbonyl chloride on the pretreated polymethacrylate is 1:1.1:1.

[0037] The molar ratio of amino groups on the modified polysiloxane and maleic anhydride in Step A2 is 1:1, the dosage of p-toluenesulfonic acid is 5‰ of the mass of maleic anhydride, the antioxidant is 1076, and the dispersant is glyceryl tristearate.

[0038] The modified polysiloxane is prepared by the following steps:

[0039] Step B1: Mix cyanuric chloride, resorcinol and chlorobenzene evenly, stir and add aluminum chloride at a rotation speed of 150 r / min and a temperature of 50 °C, and react for 4 h to obtain Intermediate 1. Mix Intermediate 1, potassium carbonate and DMF evenly, stir and add acryloyl chloride at a rotation speed of 200 r / min and a temperature of 105 °C, and react for 4 h to obtain Intermediate 2;

[0040] Step B2: Mix octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane and deionized water, introduce nitrogen protection, and react at a rotation speed of 150 r / min and a temperature of 95 °C for 11 h to obtain polysiloxane. Mix polysiloxane, Intermediate 2, chloroplatinic acid and DMF evenly, introduce nitrogen protection, and react at a rotation speed of 150 r / min and a temperature of 85 °C for 7 h to obtain hyperbranched polysiloxane;

[0041] Step B3: Dissolve cyanuric chloride in toluene, stir and add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine at a rotation speed of 150 r / min and a temperature of 0 °C, react for 3 h, then add an aqueous sodium hydroxide solution, raise the temperature to 70 °C, continue to react for 12 h, add allyl alcohol, raise the temperature to 85 °C, and continue to react for 4 h to obtain a capping agent. Mix hyperbranched polysiloxane, capping agent, chloroplatinic acid and DMF evenly, introduce nitrogen protection, and react at a rotation speed of 150 r / min and a temperature of 85 °C for 4 h to obtain modified polysiloxane.

[0042] The dosage ratio of cyanuric chloride, resorcinol and aluminum chloride described in step B1 is 40 mmol: 120 mmol: 20 g, and the molar ratio of intermediate 1, potassium carbonate and acryloyl chloride is 1: 3.2: 3.

[0043] The dosage ratio of octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane and deionized water described in step B2 is 2.3 mol: 2 mol: 0.1 mol: 3 mol: 5 L, the molar ratio of polysiloxane and intermediate 2 is 5: 2, and the dosage of chloroplatinic acid is 1‰ of the mass of polysiloxane.

[0044] The dosage ratio of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, sodium hydroxide aqueous solution and allyl alcohol described in step B3 is 10 mmol: 20 mmol: 3 mL: 10 mmol, the concentration of the sodium hydroxide solution is 10 mol / L, the molar ratio of Si-H bond on hyperbranched polysiloxane and the end-capping agent is 1: 1, and the dosage of chloroplatinic acid is 1‰ of the mass of hyperbranched polysiloxane.

[0045] Example 3. A preparation method of a paint-free lamp plastic with a metallic effect specifically comprises the following steps:

[0046] Step A1: Mix methyl methacrylate, 2-hydroxyethyl methacrylate, azobisisobutyronitrile and n-octane evenly, introduce nitrogen protection, and carry out a reaction for 25 h under the conditions of a rotation speed of 200 r / min and a temperature of 75 °C to obtain a pretreated polymethacrylate. Dissolve the pretreated polymethacrylate in acetone, stir and add potassium carbonate and furan carbonyl chloride under the conditions of a rotation speed of 150 r / min and a temperature of 55 °C, and carry out a reaction for 5 h to obtain a modified polymethacrylate.

[0047] Step A2: Mix the modified polysiloxane, maleic anhydride and DMF, carry out a reaction for 3 h under the conditions of a rotation speed of 200 r / min and a temperature of 30 °C, then raise the temperature to 85 °C, add p-toluenesulfonic acid, and continue the reaction for 6 h to obtain a modifier. Weigh the following raw materials in parts by weight: 90 parts of modified polymethacrylate, 5 parts of modifier, 2.5 parts of aluminum powder, 0.05 part of carbon black, 0.3 part of antioxidant and 0.3 part of dispersant. Melt-extrude and cool the raw materials to obtain a paint-free lamp plastic with a metallic effect.

[0048] The molar ratio of methyl methacrylate, 2-hydroxyethyl methacrylate and azobisisobutyronitrile described in step A1 is 500: 20: 9, and the molar ratio of the hydroxyl group on the pretreated polymethacrylate, potassium carbonate and furan carbonyl chloride is 1: 1.1: 1.

[0049] The molar ratio of the amino group on the modified polysiloxane described in step A2 to maleic anhydride is 1:1, the dosage of p-toluenesulfonic acid is 5‰ of the mass of maleic anhydride, the antioxidant is 1076, and the dispersant is barium stearate.

[0050] The modified polysiloxane is prepared by the following steps:

[0051] Step B1: Mix cyanuric chloride, resorcinol, and chlorobenzene evenly. Under the conditions of a rotation speed of 200 r / min and a temperature of 50 °C, stir and add aluminum chloride, and react for 5 h to obtain intermediate 1. Mix intermediate 1, potassium carbonate, and DMF evenly. Under the conditions of a rotation speed of 300 r / min and a temperature of 110 °C, stir and add acryloyl chloride, and react for 5 h to obtain intermediate 2;

[0052] Step B2: Mix octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane, and deionized water, introduce nitrogen protection, and react at a rotation speed of 150 r / min and a temperature of 95 °C for 12 h to obtain polysiloxane. Mix polysiloxane, intermediate 2, chloroplatinic acid, and DMF evenly, introduce nitrogen protection, and react at a rotation speed of 200 r / min and a temperature of 90 °C for 8 h to obtain hyperbranched polysiloxane;

[0053] Step B3: Dissolve cyanuric chloride in toluene. Under the conditions of a rotation speed of 150 r / min and a temperature of 3 °C, stir and add N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, react for 3 h, then add an aqueous sodium hydroxide solution, raise the temperature to 75 °C, continue to react for 14 h, add allyl alcohol, raise the temperature to 90 °C, and continue to react for 5 h to obtain a capping agent. Mix hyperbranched polysiloxane, the capping agent, chloroplatinic acid, and DMF evenly, introduce nitrogen protection, and react at a rotation speed of 200 r / min and a temperature of 90 °C for 5 h to obtain modified polysiloxane.

[0054] The dosage ratio of cyanuric chloride, resorcinol, and aluminum chloride described in step B1 is 40 mmol: 120 mmol: 20 g, and the molar ratio of intermediate 1, potassium carbonate, and acryloyl chloride is 1: 3.2: 3.

[0055] The dosage ratio of octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane, and deionized water described in step B2 is 2.3 mol: 2 mol: 0.1 mol: 3 mol: 5 L, the molar ratio of polysiloxane to intermediate 2 is 7: 3, and the dosage of chloroplatinic acid is 1‰ of the mass of polysiloxane.

[0056] In step B3, the amounts of cyanuric chloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, aqueous sodium hydroxide solution, and allyl alcohol are 10 mmol:20 mmol:3 mL:10 mmol. The concentration of the sodium hydroxide solution is 10 mol / L. The molar ratio of the Si-H bonds on the hyperbranched polysiloxane to the capping agent is 1:1. The amount of chloroplatinic acid used is 1‰ of the mass of the hyperbranched polysiloxane.

[0057] Comparative Example 1: Compared with Example 1, methyl methacrylate, azobisisobutyronitrile, and n-octane were mixed evenly, purged with nitrogen, and reacted for 20 h under the conditions of a rotation speed of 150 r / min and a temperature of 70 °C. The resulting product was used to replace the modified polymethyl methacrylate, and the remaining steps were the same.

[0058] Comparative Example 2: Compared with Example 1, hyperbranched polysiloxane was used to replace the modified polysiloxane, and the remaining steps were the same.

[0059] Comparative Example 3: Compared with Example 1, polysiloxane was used to replace the hyperbranched polysiloxane, and the remaining steps were the same.

[0060] The lamp plastics prepared in Examples 1-3 and Comparative Examples 1-3 were made into specimens with dimensions of 168 mm × 13 mm × 3.2 mm according to the standard of GB / T 1040.3-2006. The tensile speed was 50 mm / min, and the tensile strength was measured. According to the standard of GB / T 16422.3-2022, ultraviolet light with an irradiation intensity of 600 W / m 2 was used for irradiation, and the cumulative irradiation dose was 400 kWh / m 2 . The tensile strength after photoaging was measured. According to the standard of GB / T 3512-2014, the temperature was 120 °C, and the thermal-oxidative aging time was 72 h. The tensile strength degradation rate was measured. The test results are shown in Table 1 below.

[0061] Table 1

[0062]

[0063] As can be seen from the above table, this application has good mechanical strength, and good effects of resistance to photoaging and thermal-oxidative aging.

[0064] The above content is only an example and explanation of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a paint-free lamp plastic with a metallic effect, characterized in that: The specific steps include: Step A1: methyl methacrylate, hydroxyethyl methacrylate, azobisisobutyronitrile and n-octane are uniformly mixed, nitrogen is introduced for protection, and a reaction is carried out to obtain pretreated polymethacrylate; the pretreated polymethacrylate is dissolved in acetone, potassium carbonate and furancarbonyl chloride are added, stirred, and a reaction is carried out to obtain modified polymethacrylate; Step A2: After the modified polysiloxane, maleic anhydride and DMF are mixed and reacted, the temperature is raised and p-toluenesulfonic acid is added, and the reaction is continued to obtain a modifier, and the following raw materials are weighed in parts by weight: 80-90 parts of modified polymethacrylate, 3-5 parts of modifier, 1.5-2.5 parts of aluminum powder, 0.02-0.05 parts of carbon black, 0.1-0.3 parts of antioxidant and 0.2-0.3 parts of dispersant, and the raw materials are melted, extruded and cooled to obtain a paint-free lamp plastic with a metallic effect; The modified polysiloxane is prepared by the following steps: Step B1: uniformly mix cyanuric chloride, resorcinol and chlorobenzene, stir and add aluminum chloride at a speed of 150-200 r / min and a temperature of 45-50° C., and react for 3-5 hours to obtain intermediate 1; uniformly mix intermediate 1, potassium carbonate and DMF, stir and add acryloyl chloride at a speed of 200-300 r / min and a temperature of 100-110° C., and react for 3-5 hours to obtain intermediate 2; Step B2: octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane and deionized water are mixed, nitrogen is introduced for protection, and a reaction is carried out to obtain polysiloxane; polysiloxane, intermediate 2, chloroplatinic acid and DMF are mixed uniformly, nitrogen is introduced for protection, and a reaction is carried out to obtain hyperbranched polysiloxane; Step B3: dissolving cyanuric chloride in toluene, stirring and adding N-n-butyl-2,2,6,6-tetramethyl-4-piperidinamine at a speed of 120-150 r / min and a temperature of 0-3° C., reacting, adding an aqueous sodium hydroxide solution, heating to 70-75° C., continuing the reaction, adding allyl alcohol, heating to 80-90° C., continuing the reaction to obtain a capping agent, uniformly mixing the hyperbranched polysiloxane, the capping agent, chloroplatinic acid and DMF, introducing nitrogen protection, reacting at a speed of 150-200 r / min and a temperature of 80-90° C., and obtaining a modified polysiloxane.

2. The method for preparing a paint-free lamp plastic with a metallic effect according to claim 1, characterized in that: The molar ratio of methyl methacrylate, hydroxyethyl methacrylate and azobisisobutyronitrile in step A1 is 500:20:9, and the molar ratio of hydroxyl groups on the pretreated polymethacrylate, potassium carbonate and furanyl chloride is 1:1.1:

1.

3. The method for preparing a paint-free lamp plastic with a metallic effect according to claim 1, characterized in that: The molar ratio of the amino group on the modified polysiloxane described in step A2 to maleic anhydride is 1:

1.

4. The method for preparing a paint-free lamp plastic with a metallic effect according to claim 1, characterized in that: The amount ratio of cyanuric chloride, resorcinol and aluminum chloride in step B1 is 40mmol:120mmol:20g, and the molar ratio of intermediate 1, potassium carbonate and acryloyl chloride is 1:3.2:

3.

5. The method for preparing a paint-free lamp plastic with a metallic effect according to claim 1, characterized in that: The amount ratio of octamethylcyclotetrasiloxane, tetramethylammonium hydroxide, 3-aminopropylmethyldimethoxysilane, tetramethyldisiloxane and deionized water in step B2 is 2.3 mol: 2 mol: 0.1 mol: 3 mol: 5 L, and the molar ratio of polysiloxane to intermediate 2 is 2n+1: n, where n is a natural number greater than 0.

6. The method for preparing a paint-free lamp plastic with a metallic effect according to claim 1, characterized in that: The 10mmol:20mmol:3mL:10mmol of cyanuric chloride, N-n-butyl-2,2,6,6-tetramethyl-4-piperidinamine, sodium hydroxide aqueous solution and allyl alcohol described in step B3, and the molar ratio of Si-H bonds on the hyperbranched polysiloxane and the capping agent is 1:

1.

7. A paint-free lamp plastic with a metallic effect, characterized in that: Prepared according to any one of claims 1 to 6.

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