Flame-retardant PC material with high forming efficiency and preparation method thereof

Abstract

The invention discloses a flame-retardant PC material with high forming efficiency and a preparation method thereof. The flame-retardant PC material with high forming efficiency comprises the following components in parts by weight: 87-99 parts of polycarbonate; 0.1 to 5 parts of nano inorganic particles; 0.01 to 1 part of a flame retardant; 0.5 to 5 parts of a flame retardant; 0.1 to 1 part of an antioxidant; 0.1 to 1 part of a lubricant; and 0.5-5 parts of titanium dioxide. The invention also discloses a preparation method of the flame-retardant PC material. The preparation method comprises the following steps: S1, weighing the components in parts by weight; and S2, after blending, extruding and granulating to obtain the composite material. According to the flame-retardant PC material disclosed by the invention, inorganic particles such as superfine nano SiO2 are added into the PC base material, so that the strength of the material under a high-temperature condition is improved, high forming efficiency is achieved, the production cost is further reduced, hard spots and silver wires on the surface of the PC material can be eliminated, and a relatively good flame-retardant effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flame retardant materials, in particular to a flame retardant PC material with high molding efficiency and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) is an amorphous thermoplastic engineering plastic with excellent optical clarity, impact toughness, heat resistance, and inherent V2 flame retardancy. It is currently widely used in electronics, lighting systems, automobiles, and household appliances. However, the flame retardancy of unmodified polycarbonate still cannot meet the requirements of certain specialized high-end industries. Therefore, research on modifying PC to improve its flame retardancy is extremely necessary.

[0003] Nowadays, with the increasing homogeneity of materials and the increasing prominence of price wars, many companies want to gain a greater competitive advantage, and low-cost products are a very important dimension. In many industrial production processes, among the materials used in existing products, the molding efficiency of materials has a great impact on the production cycle and cost. Traditional materials often require a long time for curing, shaping, and other operations during molding, which leads to low production efficiency. It is not only difficult to meet the growing market demand, but also increases the cost of the product. For example, in the production of plastic products, conventional plastic raw materials require a long cooling time after injection molding before demolding for subsequent processing. Therefore, developing a material that can improve the efficiency of injection molding has important commercial value. Summary of the Invention

[0004] In order to solve the above technical problems, the object of the present invention is to provide a flame retardant PC material with high molding efficiency and a preparation method thereof.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a flame retardant PC material with high molding efficiency, comprising the following components in parts by weight:

[0007]

[0008]

[0009] As some specific embodiments of the present invention, the polycarbonate has a melt flow rate of 3-20 g / 10 min at 300° C.*1.2 kg;

[0010] The number average molecular weight of the polycarbonate is 24,000-30,000 g / mol.

[0011] As some specific embodiments of the present invention, the nano-inorganic particles include one or more of nano-SiO2, nano-calcium carbonate, nano-montmorillonite, and nano-talc; and the particle size of the nano-inorganic particles is 20-550 nm.

[0012] As some specific embodiments of the present invention, the flame retardant 1 is a sulfonate flame retardant, including one or more of PPFBS, KSS, STB, and HES.

[0013] As some specific embodiments of the present invention, the flame retardant 2 is a phosphorus-based flame retardant, including one or more of BDP, RDP, RDX, TPP, and HPCTP.

[0014] As some specific embodiments of the present invention, the antioxidant includes one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris[2,4-di-tert-butylphenyl] phosphite, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate].

[0015] As some specific embodiments of the present invention, the lubricant includes one or more of pentaerythritol stearate, silicone powder, and ethylene bisstearamide.

[0016] As some specific embodiments of the present invention, the titanium dioxide includes one or more of KRONOS 2233, CITIC Titanium CR211, and CITIC Titanium CR210.

[0017] In a second aspect, the present invention provides a method for preparing a flame-retardant PC material with high molding efficiency as described in any one of the above, comprising the following steps:

[0018] S1. Weigh each component by weight;

[0019] S2. After blending, extrusion and granulation are performed to obtain the product.

[0020] As some specific embodiments of the present invention, in step S2, the blending is performed using a high-speed mixer.

[0021] As some specific embodiments of the present invention, in step S2, the extrusion is carried out using a twin-screw extruder, and the temperature of the twin-screw extruder from the feeding port to the die is: 180-200°C in zones 1-2, 240-260°C in zones 3-5, and 250-270°C in zones 6-10; the speed of the twin-screw extruder is 400-600 rpm.

[0022] As some specific embodiments of the present invention, in step S2, the raw materials are stirred and mixed uniformly in a high-speed mixer, and then fed into a twin-screw extruder through a metering device. Under the conveying, shearing and mixing of the screw, the materials are melted, compounded, melt-extruded, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0023] Patent CN106349676B provides a halogen-free flame-retardant PC, which exhibits surface silver streaks and low gloss. Patent application CN111205617A provides a polycarbonate composition with a flame-retardant PC / ABS substrate. If the flame-retardant PC substrate is replaced, the appearance will deteriorate (such as degradation leading to silver streaks and gloss), and the heat resistance of the flame-retardant PC / ABS will be severely reduced, failing to meet the ball pressure requirement of 125°C, making it unsuitable for use in electronic and electrical appliance housings.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention adds ultrafine nano-SiO2 and other inorganic particles to the PC substrate, which not only plays a role in rapid crystallization of PC, but also accelerates the heat release rate of PC materials when cooling from high temperature to low temperature, shortening the cooling time, and also improves the strength of the material under high temperature conditions. It is not easy to cause top cracking during ejection during the molding process, thereby achieving high molding efficiency and meeting the requirements of the ball pressure test at 125°C. Because the added nano-level rigid particles still have a high gloss effect, and there are no defects such as silver streaks on the surface. At the same time, the Si in the nanoparticles undergoes a cross-linking reaction with the sulfonate flame retardant to accelerate the carbonization of PC. At the same time, it has excellent flame retardant properties and can meet the needs of various industrial application scenarios, such as electronic product housings, automotive parts, home appliance housings and other parts.

[0026] (2) Compared with conventional PC materials, the high-molding-efficiency material of the present invention has a molding cycle shortened by approximately 5%-15%, greatly improving production efficiency and achieving higher molding efficiency. For example, under the same injection molding process conditions, the molding cycle of conventional PC materials is 30 seconds, while the material of the present invention can be completed in only 20 to 28 seconds.

[0027] (3) Due to the improved molding efficiency, the output per unit time is increased, which reduces the capital investment in equipment and the investment in manpower and material resources, thereby reducing the production cost per unit product. According to calculations, in large-scale batch production, the use of the material of the present invention can reduce production costs by 15%-30%. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0029] 1. Antioxidants:

[0030] Antioxidant 1076: β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecanol;

[0031] Antioxidant 168: tris[2,4-di-tert-butylphenyl]phosphite;

[0032] Antioxidant 245: triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate];

[0033] Antioxidant 1010: Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0034] The antioxidant used in the flame-retardant PC material of the present invention is selected from one or more of the above antioxidants.

[0035] Specifically in the following examples and comparative examples, the antioxidants used were compounded with antioxidants 1076 and 168 in a ratio of 2:1.

[0036] 2. Sulfonate flame retardants:

[0037] PPFBS: potassium perfluorobutanesulfonate;

[0038] KSS: potassium phenylsulfonylbenzenesulfonate;

[0039] STB: 2,4,5-trichlorobenzenesulfonate sodium;

[0040] HES: sodium diphenyl sulfone disulfonate.

[0041] The flame retardant 1 in the flame-retardant PC material of the present invention is selected from any one of the above-mentioned sulfonate flame retardants.

[0042] 3. Phosphorus flame retardants:

[0043] BDP: bisphenol A-bis(diphenyl phosphate);

[0044] RDP: resorcinol bis(diphenyl phosphate);

[0045] RDX: resorcinol bis[di(2,6-dimethylphenyl) phosphate];

[0046] TPP: triphenyl phosphate;

[0047] HPCTP: Hexaphenoxycyclotriphosphazene.

[0048] The flame retardant 2 in the flame-retardant PC material of the present application is selected from any one of the above-mentioned phosphorus-based flame retardants.

[0049] 4. Titanium dioxide:

[0050] KRONOS 2233; Citi Titanium CR211, CR210.

[0051] The titanium dioxide in the flame-retardant PC material of the present application is selected from any one of the above-mentioned titanium dioxides.

[0052] In the following examples and comparative examples, the actual titanium dioxide used is KRONOS 2233.

[0053] 5. Polycarbonate:

[0054] The polycarbonate of the present application is selected from a polycarbonate PC material having a melt flow rate of 3-20 g / 10 min at 300℃*1.2 kg and a number average molecular weight of 24000-30000 g / mol.

[0055] In the following examples and comparative examples, the actual polycarbonate used is Letian PC-1100, which has a melt index (melt flow rate) of 10 g / 10 min and a number average molecular weight of about 26000 g / mol.

[0056] 6. Nano-inorganic particles:

[0057] The nano-inorganic particles in the flame-retardant PC material of the present application are selected from one or more of nano-SiO2, nano-calcium carbonate, nano-montmorillonite, and nano-talc, and the nano-inorganic particles have a particle size of 20-550 nm.

[0058] In the following examples and comparative examples, the actual nano-inorganic particles used are nano-SiO2, specifically Starbeads NanOsil ASD nucleating agent, having a particle size of 20-550 nm.

[0059] The micro-inorganic particles used in the comparative examples are micron-sized YH180B silica microparticles from Winhov, having a particle size of 1-3 μm.

[0060] 7. Lubricant:

[0061] The lubricant in the flame-retardant PC material of the present application is selected from one or more of pentaerythritol stearate, silicone powder, and ethylene bis-stearamide. The lubricant used in each of the examples and comparative examples is pentaerythritol stearate (PETS).

[0062] Example 1

[0063] This embodiment provides a method for preparing a flame-retardant PC material with high molding efficiency, comprising the following steps:

[0064] (1) Weigh the following components by weight: polycarbonate 100 kg; nano-SiO2 0.5 kg; flame retardant 1 (PPFBS) 0.05 kg; flame retardant 2 (BDP) 1 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0065] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melt-extruded at a speed of 600, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0066] Example 2

[0067] A flame-retardant PC material with high molding efficiency and a preparation method thereof, the method comprising the following steps:

[0068] (1) Weigh the following components by weight: polycarbonate 100 kg; nano-SiO2 1 kg; flame retardant 1 (PPFBS) 0.05 kg; flame retardant 2 (BDP) 1 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0069] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melt-extruded at a speed of 600, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0070] Example 3

[0071] A flame-retardant PC material with high molding efficiency and a preparation method thereof, the method comprising the following steps:

[0072] (1) Weigh the following components by weight: polycarbonate 100 kg; nano-SiO2 2 kg; flame retardant 1 (KSS) 0.05 kg; flame retardant 2 (BDP) 1 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0073] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melt-extruded at a speed of 600, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0074] Example 4

[0075] A flame-retardant PC material with high molding efficiency and a preparation method thereof, the method comprising the following steps:

[0076] (1) Weigh the following components by weight: polycarbonate 100 kg; nano inorganic particles 5 kg; flame retardant 1 (PPFBS) 0.05 kg; flame retardant 2 (BDP) 1 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0077] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melt-extruded at a speed of 600, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0078] Comparative Example 1

[0079] A general PC material and a preparation method thereof, the method comprising the following steps:

[0080] (1) Weigh the following components by weight: polycarbonate 100 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide KRONOS 2233 2 kg;

[0081] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melted and extruded at a speed of 600, and cooled and granulated to obtain a universal PC material.

[0082] Comparative Example 2

[0083] A flame retardant PC material and a preparation method thereof, the method comprising the following steps:

[0084] (1) Weigh the following components by weight: polycarbonate 100 kg; flame retardant 1 (PPFBS) 0.05 kg; flame retardant 2 (BDP) 1 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0085] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melted and extruded at a speed of 600, and cooled and granulated to obtain a flame-retardant PC material.

[0086] Comparative Example 3

[0087] A flame-retardant PC material with high molding efficiency and a preparation method thereof, the method comprising the following steps:

[0088] (1) Weigh the following components by weight: polycarbonate 100 kg; nano inorganic particles 1 kg; flame retardant 1 (PPFBS) 0.05 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0089] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melt-extruded at a speed of 600, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0090] Comparative Example 4

[0091] A flame-retardant PC material with high molding efficiency and a preparation method thereof, the method comprising the following steps:

[0092] (1) Weigh the following components by weight: polycarbonate 100 kg; micron inorganic particles 1 kg; flame retardant 1 (PPFBS) 0.05 kg; antioxidant 0.1 kg; lubricant 0.2 kg; titanium dioxide 2 kg;

[0093] (2) The above raw materials are placed in a high-speed mixer and stirred according to the formula. After being mixed evenly, they are sent to a twin-screw extruder through a metering device. The temperature of the twin-screw extruder is controlled to be 190°C in zone 1-2, 250°C in zone 3-5, and 260°C in zone 6-10. Under the conveying, shearing and mixing of the screw, the materials are melted and compounded. The screw is melt-extruded at a speed of 600, cooled and granulated to obtain a flame-retardant PC material with high molding efficiency.

[0094] The components of each example and comparative example are shown in Table 1.

[0095] Table 1 Composition of Examples and Comparative Examples

[0096]

[0097] The flame retardant PC materials prepared in the above embodiments and comparative examples were tested for their properties according to Table 2:

[0098] Table 2 Performance test standards

[0099]

[0100]

[0101] Note 1: The flame-retardant PC materials of Examples 1 to 4 and Comparative Examples 1-4 were injection molded into tensile specimens according to the following parameters. The shortest molding cycle that could ensure smooth demoulding without deformation was recorded as the time by adjusting the cooling time only.

[0102] Injection molding parameters: injection temperature 300℃, mold temperature 80℃, injection speed 60mm / s, injection pressure 80MPa, holding pressure 40MPa, holding time 3s.

[0103] The results of the performance tests on the flame retardant PC materials prepared in the examples and comparative examples are shown in Table 3:

[0104] Table 3 Performance test results of various embodiments and comparative examples

[0105]

[0106]

[0107] According to Comparative Examples 1 and 2, after adding 0.05 kg of flame retardant 1 (sulfonate flame retardant) and 1 kg of flame retardant 2 (phosphoric acid flame retardant), its flame retardant performance did not improve significantly; on this basis, adding 1% of nano inorganic particles (Example 2) shows that its glow wire performance is improved. According to the experimental results of Examples 1-4 and Comparative Example 2, it can be seen that with the increase in the content of nano inorganic particles, its high temperature modulus gradually increases, heat resistance improves, molding cycle is shortened, and molding efficiency is improved. When the nano silica content is 5%, its cycle is shortened by up to 8 s. According to Example 2 and Comparative Examples 3 and 4, after adding 1% of flame retardant 2, its surface is free of silver wire and has a glossy surface, which is comparable to the pure PC solution of Comparative Example 1. At the same time, nano inorganic particles are used to replace micron inorganic particles, and its appearance does not have the problem of pitting. Therefore, nano inorganic particles can eliminate pitting on the surface of PC materials, and the synergistic use of flame retardants further eliminates silver wire on the surface of PC materials.

[0108] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A flame retardant PC material with high molding efficiency, characterized in that: The composition comprises the following components in parts by weight:

2. The flame retardant PC material according to claim 1, characterized in that: The polycarbonate has a melt flow rate of 3-20 g / 10 min at 300° C. and 1.2 kg; The number average molecular weight of the polycarbonate is 24,000-30,000 g / mol.

3. The flame retardant PC material according to claim 1, characterized in that: The nano inorganic particles include one or more of nano SiO2, nano calcium carbonate, nano montmorillonite, and nano talc; and the particle size of the nano inorganic particles is 20-550 nm.

4. The flame retardant PC material according to claim 1, characterized in that: The flame retardant 1 is a sulfonate flame retardant, including one or more of PPFBS, KSS, STB, and HES.

5. The flame retardant PC material according to claim 1, characterized in that: The flame retardant 2 is a phosphorus-based flame retardant, including one or more of BDP, RDP, RDX, TPP, and HPCTP.

6. The flame retardant PC material according to claim 1, characterized in that: The antioxidant includes one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris[2,4-di-tert-butylphenyl] phosphite, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate], and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate].

7. The flame retardant PC material according to claim 1, characterized in that: The lubricant includes one or more of pentaerythritol stearate, silicone powder, and ethylene bisstearamide.

8. The flame retardant PC material according to claim 1, characterized in that: The titanium dioxide includes one or more of KRONOS2233, CITIC Titanium CR211, and CR210.

9. A method for preparing a flame-retardant PC material with high molding efficiency according to any one of claims 1 to 8, characterized in that: The steps include: S1. Weigh each component by weight; S2. After blending, extrusion and granulation are performed to obtain the product.

10. The preparation method according to claim 9, characterized in that In step S2, the blending is performed using a high-speed mixer; And / or, the extrusion is carried out using a twin-screw extruder, and the temperature of the twin-screw extruder from the feed port to the die is: 180-200°C in zones 1-2, 240-260°C in zones 3-5, and 250-270°C in zones 6-10; the speed of the twin-screw extruder is 400-600rpm.

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