Preparation method of halogen-free flame-retardant PC plastic material

Abstract

The invention relates to the technical field of polycarbonate, and discloses a preparation method of a halogen-free flame-retardant PC plastic material. According to the invention, polycarbonate and a triazine sulfonate-based silicone oil flame retardant are blended in a torque rheometer to obtain the halogen-free flame-retardant PC plastic material. A sulfonate group in the flame retardant can catalyze polycarbonate to be crosslinked into carbon, polysiloxane is pyrolyzed, an S-C layer is formed on the surface of polycarbonate, and a triazine group is pyrolyzed to generate nitrogen and other non-combustible gases, so that the limit oxygen index, the UL94 grade and the flame retardant property of the polycarbonate plastic material are improved. The triazine sulfonate-based silicone oil flame retardant contains hydroxyl, imino and other groups and has good compatibility with polycarbonate, the main chain is a flexible polysiloxane main chain, a good toughening effect can be achieved, and the bending strength and impact strength of a polycarbonate material are improved.

Description

Technical Field

[0001] The invention relates to the technical field of polycarbonate, in particular to a method for preparing a halogen-free flame-retardant PC plastic material. Background Art

[0002] Polycarbonate is colorless and transparent, has high mechanical strength, good heat resistance, and excellent processing performance. It is a general engineering plastic that is widely used in electronic products, automobile industry, building materials, medical equipment and other fields. Improving the flame retardant properties of polycarbonate is of great significance. Common flame retardants for polycarbonate include halogen-containing flame retardants, sulfonate flame retardants, nitrogen-phosphorus flame retardants, silicon-based flame retardants, etc. The development of green and environmentally friendly halogen-free flame retardants is a research hotspot.

[0003] Polysiloxanes such as silicone oil and hydrogenated silicone oil are a type of organic silicon polymers with excellent chemical stability, high temperature resistance and insulation properties, and are widely used in toughening agents, flame retardants, fabric finishing agents, etc. Patent No. CN116332983B discloses that a modified cyclic siloxane flame retardant is formed by combining sulfonated cyclic siloxane with an alkali metal, thereby improving the flame retardancy of polycarbonate. However, the patent does not significantly improve the mechanical properties of polycarbonate, such as bending strength and impact strength. Summary of the invention

[0004] The technical problem solved by the invention is to provide a PC polycarbonate plastic material with good mechanical properties and excellent flame retardancy.

[0005] The technical solution provided by the present invention is: a method for preparing a halogen-free flame-retardant PC plastic material, comprising the following steps:

[0006] Step A, add toluene, hydrogen-containing silicone oil, 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine, and chloroplatinic acid-isopropanol solution into a reaction container, introduce nitrogen, heat to 100-110° C., condense and reflux for 6-12 hours, rotary evaporate, and dry to obtain glycidyl ether triazine modified silicone oil.

[0007] Step B: Add tetrahydrofuran, glycidyl ether triazine silicone oil and sodium 4-aminobenzenesulfonate in a mass ratio of 100:(120-150) to a reaction vessel, heat to 40-50°C, stir and react for 5-8h, rotary evaporate, add methanol, filter and dry to obtain a triazine sulfonate silicone oil flame retardant. The reaction formula is:

[0008]

[0009] Step C, blending polycarbonate and triazine sulfonate-based silicone oil flame retardant in a mass ratio of 100:(1-8) at 270-280° C. for 15-20 minutes, discharging, and obtaining a halogen-free flame-retardant PC plastic material.

[0010] Preferably, in step A, the molar ratio of the SiH group of the hydrogen-containing silicone oil and 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine is (1-1.2):1. The mass ratio of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine and chloroplatinic acid is 100:(0.02-0.03).

[0011] Preferably, the preparation method of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine comprises the following steps:

[0012] Step (1), adding cyanuric chloride, dichloromethane and 2-methylallyl alcohol to a reaction container, dropping sodium hydroxide aqueous solution and tetrabutylammonium bromide, stirring and reacting at 10-15° C. for 10-20 minutes, adding water, standing and stratifying, separating and obtaining a dichloromethane organic phase, drying and removing water with anhydrous sodium sulfate, rotary evaporation, and drying to obtain 2-methylallyloxy-4,6-dichloro-1,3,5-triazine.

[0013] Step (2), adding 2-methylallyloxy-4,6-dichloro-1,3,5-triazine and glycidyl ether to toluene, adding sodium hydride, first heating to 40-50° C. and stirring for reaction for 1-1.5 hours, then heating to 80-90° C. and stirring for reaction for 2-3 hours, filtering and rotary evaporating the filtrate, washing with water, and recrystallizing the product with ethanol to obtain 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine.

[0014] The reaction formula is:

[0015]

[0016] Preferably, in step (1), the molar ratio of cyanuric chloride, 2-methylallyl alcohol, sodium hydroxide and tetrabutylammonium bromide is 1:1:(12-13):(0.1-0.11).

[0017] Preferably, in step (2), the molar ratio of 2-methylallyloxy-4,6-dichloro-1,3,5-triazine, glycidyl ether and sodium hydride is 1:(2-2.8):(2.6-3).

[0018] The technical effect of the present invention is: using cyanuric chloride, 2-methylallyl alcohol, and glycidyl ether as reactants, 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine is prepared, and then an addition reaction is carried out with hydrogen-containing silicone oil to obtain a novel nitrogen-phosphorus silicon-based triazine sulfonate-based silicone oil flame retardant, and then melt-blended with polycarbonate to obtain a halogen-free flame-retardant PC plastic material. The sulfonate group in the flame retardant can catalyze the cross-linking of polycarbonate into carbon, and at the same time, polysiloxane is pyrolyzed to form a SiC layer on the surface of polycarbonate, which plays a flame retardant role such as heat insulation and oxygen isolation, and anti-melting dripping, and the pyrolysis of the triazine group produces non-flammable gases such as nitrogen, which is conducive to reducing the oxygen concentration during combustion, thereby improving the limiting oxygen index, UL94 grade and flame retardant performance of the polycarbonate plastic material.

[0019] The triazine sulfonate-based silicone oil flame retardant of the present invention contains hydroxyl groups, imino groups and the like, and forms hydrogen bonds and the like interactions with terminal hydroxyl groups of polycarbonate and the like, so that the flame retardant and polycarbonate have good compatibility. The flame retardant contains a flexible polysiloxane main chain, which plays a good toughening role, thereby improving the bending strength and impact strength of the polycarbonate material. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0021] Polycarbonate, model Covestro 2405, Shanghai Hehongcheng Plastic Technology Co., Ltd. Hydrogenated silicone oil, model HS-004, hydrogen content 1.6%, Jiangxi Hongshi New Materials Co., Ltd.

[0022] Example 1

[0023] (1) Add 40 mmol cyanuric chloride, 150 mL dichloromethane and 40 mmol 2-methylallyl alcohol to a reaction vessel, dropwise add 40 mL of an aqueous solution containing 520 mmol sodium hydroxide and 4 mmol tetrabutylammonium bromide, stir and react at 10°C for 20 min, add water, stand and separate to obtain a dichloromethane organic phase, dry with anhydrous sodium sulfate to remove water, rotary evaporate and dry to obtain 2-methylallyloxy-4,6-dichloro-1,3,5-triazine.

[0024] (2) Add 30 mmol 2-methylallyloxy-4,6-dichloro-1,3,5-triazine and 60 mmol glycidyl ether to 70 mL toluene, add 72 mmol sodium hydride, heat to 50°C and stir to react for 1.5 h, then heat to 80°C and stir to react for 3 h. After filtering, the filtrate is rotary evaporated, washed with water, and the product is recrystallized from ethanol to obtain 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine.

[0025] (3) Add toluene solvent, hydrogen-containing silicone oil (hydrogen content 1.6%), 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine, and 0.03 g / mL chloroplatinic acid-isopropanol solution into a reaction container, control the molar ratio of the SiH group of the hydrogen-containing silicone oil and 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine to be 1:1; the mass ratio of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine and chloroplatinic acid to be 100:0.025; introduce nitrogen, heat to 100° C., condense and reflux for reaction for 12 h, rotary evaporate, and dry to obtain glycidyl ether triazine modified silicone oil.

[0026] (4) Add 600 mL of tetrahydrofuran, 30 g of glycidyl ether triazine modified silicone oil, and 40 g of sodium 4-aminobenzenesulfonate into a reaction container, heat to 40° C., stir and react for 8 h, rotary evaporate, add methanol, filter and dry to obtain a triazine sulfonate-based silicone oil flame retardant.

[0027] (5) 1 kg of polycarbonate and 10 g of triazine sulfonate-based silicone oil flame retardant were mixed in a torque rheometer at 275° C. for 20 min, and the mixture was discharged to obtain a halogen-free flame-retardant PC plastic material.

[0028] Example 2

[0029] (1) Add 40 mmol cyanuric chloride, 120 mL dichloromethane and 40 mmol 2-methylallyl alcohol to a reaction vessel, dropwise add 40 mL of an aqueous solution containing 480 mmol sodium hydroxide and 4.4 mmol tetrabutylammonium bromide, stir and react at 15° C. for 10 min, add water, stand and separate to obtain a dichloromethane organic phase, dry with anhydrous sodium sulfate to remove water, rotary evaporate and dry to obtain 2-methylallyloxy-4,6-dichloro-1,3,5-triazine.

[0030] (2) Add 30 mmol 2-methylallyloxy-4,6-dichloro-1,3,5-triazine and 78 mmol glycidyl ether to 80 mL toluene, add 90 mmol sodium hydride, heat to 40°C and stir to react for 1 hour, then heat to 90°C and stir to react for 2 hours. After filtering, the filtrate is rotary evaporated, washed with water, and the product is recrystallized from ethanol to obtain 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine.

[0031] (3) Add toluene solvent, hydrogen-containing silicone oil (hydrogen content 1.6%), 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine, and 0.03 g / mL chloroplatinic acid-isopropanol solution into a reaction container, control the molar ratio of the SiH group of the hydrogen-containing silicone oil and 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine to be 1.2:1; the mass ratio of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine and chloroplatinic acid to be 100:0.03; introduce nitrogen, heat to 110° C., condense and reflux for 6 hours, rotary evaporate, and dry to obtain glycidyl ether triazine modified silicone oil.

[0032] (4) Add 500 mL of tetrahydrofuran, 30 g of triazine-modified silicone oil, and 36 g of sodium 4-aminobenzenesulfonate into a reaction container, heat to 50° C., stir and react for 5 h, rotary evaporate, add methanol, filter and dry to obtain a triazine sulfonate-based silicone oil flame retardant.

[0033] (5) 1 kg of polycarbonate and 25 g of triazine sulfonate-based silicone oil flame retardant were mixed in a torque rheometer at 270° C. for 20 min, and the mixture was discharged to obtain a halogen-free flame-retardant PC plastic material.

[0034] Example 3

[0035] (1) Add toluene solvent, hydrogen-containing silicone oil (hydrogen content 1.6%), 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine (prepared in Example 1), and 0.03 g / mL chloroplatinic acid-isopropanol solution into a reaction container, and control the molar ratio of the SiH group of the hydrogen-containing silicone oil and 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine to be 1.1:1; the mass ratio of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine to chloroplatinic acid to be 100:0.02; introduce nitrogen, heat to 110° C., condense and reflux for 10 h, rotary evaporate, and dry to obtain glycidyl ether triazine modified silicone oil;

[0036] (2) Add 600 mL of tetrahydrofuran, 30 g of triazine-modified silicone oil, and 45 g of sodium 4-aminobenzenesulfonate into a reaction vessel, heat to 45° C., stir and react for 8 h, rotary evaporate, add methanol, filter and dry to obtain a triazine sulfonate-based silicone oil flame retardant.

[0037] (3) 1 kg of polycarbonate and 40 g of triazine sulfonate-based silicone oil flame retardant were mixed in a torque rheometer at 280° C. for 15 min, and the mixture was discharged to obtain a halogen-free flame-retardant PC plastic material.

[0038] Example 4

[0039] (1) 1 kg of polycarbonate and 55 g of triazine sulfonate-based silicone oil flame retardant (prepared in Example 1) were mixed in a torque rheometer at 275° C. for 20 min, and the mixture was discharged to obtain a halogen-free flame-retardant PC plastic material.

[0040] Example 5

[0041] (2) 1 kg of polycarbonate and 70 g of triazine sulfonate-based silicone oil flame retardant (prepared in Example 1) were mixed in a torque rheometer at 275° C. for 20 min, and the mixture was discharged to obtain a halogen-free flame-retardant PC plastic material.

[0042] Example 6

[0043] (2) 1 kg of polycarbonate and 80 g of triazine sulfonate-based silicone oil flame retardant (prepared in Example 1) were mixed in a torque rheometer at 275° C. for 20 min, and the mixture was discharged to obtain a halogen-free flame-retardant PC plastic material.

[0044] Comparative Example 1

[0045] (1) Treat 1 kg of polycarbonate in a torque rheometer at 275°C for 20 min, and then discharge the material to obtain a PC plastic material.

[0046] Comparative Example 2

[0047] (1) 1 kg of polycarbonate and 10 g of hydrogen-containing silicone oil (hydrogen content 1.6%) were mixed in a torque rheometer at 275° C. for 20 min, and the mixture was discharged to obtain a PC plastic material.

[0048] Comparative Example 3

[0049] (1) 1 kg of polycarbonate and 10 g of glycidyl ether triazine modified silicone oil (prepared in Example 1) were mixed in a torque rheometer at 275° C. for 20 min, and the mixture was discharged to obtain a PC plastic material.

[0050] The PC plastic material is injected into a standard specimen by an injection molding machine at a temperature of 280°C and a pressure of 60MPa. The vertical combustion test is tested according to the UL94 method. The oxygen index is tested according to the GB / T2406.1-2008 standard. The bending performance is tested according to the GB / T9341-2008 standard. The impact strength is tested according to the GB / T1843-2008 standard.

[0051] Table 1: Test results

[0052]

[0053]

[0054] It can be seen from Table 1 that, compared with Comparative Example 1, triazine sulfonate-based silicone oil flame retardant is added to the polycarbonate of Examples 1-6. The flame retardant has silicone oil polysiloxane as the main molecular chain, and triazine and sulfonate groups are introduced into the side chain to form a sulfonate-based nitrogen silicon flame retardant. When the polycarbonate burns, the sulfonate group can catalyze the cross-linking of the polycarbonate into carbon, and the polysiloxane undergoes pyrolysis to form a SiC layer on the surface of the polycarbonate, which plays a flame retardant role such as heat insulation, oxygen isolation, and anti-dropping. In addition, the pyrolysis of the triazine group produces non-combustible gases such as nitrogen, which is beneficial to reducing the oxygen concentration during combustion, thereby improving the limiting oxygen index and UL94 grade of the polycarbonate plastic material, and having strong flame retardant properties. In addition, the triazine sulfonate-based silicone oil flame retardant contains hydroxyl groups, imino groups and other groups, which form hydrogen bonds and other interactions with terminal hydroxyl groups such as polycarbonate, thereby improving the compatibility between the flame retardant and polycarbonate. The flame retardant contains a flexible polysiloxane main chain, which can play a good toughening role and is beneficial to improving the bending strength and impact strength of the polycarbonate material.

[0055] In Comparative Example 2, only polysiloxane is added, which does not contain triazine and sulfonate groups, has poor flame retardant effect, and does not contain hydroxyl, imino and other groups. It has poor compatibility with polycarbonate and poor toughening effect. The bending strength and impact strength of polycarbonate are low.

[0056] Comparative Example 3 adds glycidyl ether triazine modified silicone oil, which does not contain sulfonate groups, has poor flame retardant effect, does not contain hydroxyl groups, imino groups, etc., has poor compatibility with polycarbonate, has poor toughening effect, and has low bending strength and impact strength of polycarbonate.

[0057] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a halogen-free flame-retardant PC plastic material, characterized in that: The preparation method comprises the following steps: Step A, adding toluene, hydrogen-containing silicone oil, 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine, and chloroplatinic acid-isopropanol solution into a reaction container, introducing nitrogen, heating to 100-110° C., condensing and refluxing for 6-12 hours, rotary evaporation, and drying to obtain glycidyl ether triazine modified silicone oil; Step B, adding tetrahydrofuran, glycidyl ether triazine-based silicone oil and sodium 4-aminobenzenesulfonate into a reaction container, rotary evaporating after the reaction, adding methanol, filtering and drying to obtain a triazine sulfonate-based silicone oil flame retardant; Step C, blending polycarbonate and triazine sulfonate-based silicone oil flame retardant in a mass ratio of 100:(1-8), discharging the mixture, and obtaining a halogen-free flame-retardant PC plastic material.

2. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 1, characterized in that: In the step A, the molar ratio of the Si-H group of the hydrogen-containing silicone oil and 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine is (1-1.2):1; the mass ratio of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine and chloroplatinic acid is 100:(0.02-0.03).

3. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 1, characterized in that: In the step B, the mass ratio of glycidyl ether triazine silicone oil to sodium 4-aminobenzenesulfonate is 100:(120-150).

4. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 1, characterized in that: The reaction temperature in step B is 40-50° C., and the reaction time is 5-8 hours.

5. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 1, characterized in that: In the step C, the blending temperature is 270-280° C. and the blending time is 15-20 min.

6. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 1, characterized in that: The preparation method of 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine comprises the following steps: Step (1), adding cyanuric chloride, dichloromethane and 2-methylallyl alcohol to a reaction container, dropping sodium hydroxide aqueous solution and tetrabutylammonium bromide, stirring and reacting at 10-15° C. for 10-20 minutes, adding water, standing and stratifying, separating to obtain a dichloromethane organic phase, drying with anhydrous sodium sulfate to remove water, rotary evaporation, and drying to obtain 2-methylallyloxy-4,6-dichloro-1,3,5-triazine; Step (2), adding 2-methylallyloxy-4,6-dichloro-1,3,5-triazine and glycidyl ether to toluene, adding sodium hydride, stirring to react, filtering, rotary evaporating the filtrate, washing with water, and recrystallizing the product with ethanol to obtain 2-methylallyloxy-4,6-di(glycidyl ether)-1,3,5-triazine.

7. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 6, characterized in that: In the step (1), the molar ratio of cyanuric chloride, 2-methylallyl alcohol, sodium hydroxide and tetrabutylammonium bromide is 1:1:(12-13):(0.1-0.11).

8. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 6, characterized in that: In the step (2), the molar ratio of 2-methylallyloxy-4,6-dichloro-1,3,5-triazine, glycidyl ether and sodium hydride is 1:(2-2.8):(2.6-3).

9. The method for preparing the halogen-free flame-retardant PC plastic material according to claim 6, characterized in that: In the step (2), the reaction is first carried out at 40-50° C. for 1-1.5 h, and then at 80-90° C. for 2-3 h.

10. A halogen-free flame-retardant PC plastic material prepared by the preparation method according to any one of claims 1 to 9.

Images