High-transparency thin-wall flame-retardant polycarbonate modified material, and preparation method and application thereof

Abstract

This invention relates to a high-transparency thin-walled flame-retardant polycarbonate modified material, its preparation method, and its application. The materials include: homopolymer polycarbonate resin, silicone copolymer polycarbonate resin, polyphosphonate copolymer polycarbonate resin, potassium perfluorobutyl sulfonate flame retardant, brominated polycarbonate, an octamethylcyclotetrasiloxane / methylphenyl silicone composition flame retardant synergist, antioxidant, and lubricant. The preparation method includes the following steps: mixing the raw materials, then placing them in a twin-screw extruder for cooling and granulation to obtain the high-transparency thin-walled flame-retardant polycarbonate modified material. Compared with the prior art, the transparent flame-retardant polycarbonate modified material provided by this invention has high transparency, low haze, and stable flame-retardant properties even at relatively thin thicknesses.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, and particularly relates to the field of polycarbonate modified materials, specifically to a high-transparency thin-walled flame-retardant polycarbonate modified material, its preparation method, and its application. Background Technology

[0002] Polycarbonate (PC) is a highly transparent amorphous thermoplastic, one of the five major engineering plastics. Besides its excellent transparency, polycarbonate possesses high rigidity, modulus, good high-temperature resistance, and dimensional stability due to its rigid benzene rings and flexible carbonate groups, while also exhibiting excellent impact resistance. Given these superior properties, polycarbonate is widely used in numerous industries and products, including electronics, home appliances, office equipment, power tools, and charging stations. Certain specific industries, such as electronics, office equipment, and charging stations, have varying degrees of requirements regarding the flame-retardant properties of modified polycarbonate products.

[0003] Polycarbonate itself has a flame retardancy rating of V2 (3.2mm) and a transmittance of approximately 89% (2mm). However, the addition of conventional flame retardant systems generally affects the transparency of polycarbonate, and some flame retardants can reduce its impact strength to some extent. This limits the application of polycarbonate materials in special applications that require both high transparency and good flame retardancy.

[0004] CN111117187A discloses a high-toughness, high-transparency silicone flame-retardant polycarbonate material and its preparation method. The material comprises the following raw materials in parts by weight: 90-99 parts polycarbonate, 0.05-3 parts silicone flame retardant, 0-0.5 parts anti-dripping agent, 0.1-1 parts dispersant, and 0.1-0.5 parts antioxidant; wherein the polycarbonate is composed of polycarbonate resin powder and polycarbonate resin particles. The polycarbonate material prepared by this method exhibits high toughness, high transparency, and environmentally friendly flame retardancy. The flame retardant has good dispersibility and stable flame retardant effect, meeting the market demand for fully transparent flame-retardant products. However, its highest flame retardant rating can only reach V0 2.0 mm, thus failing to meet the requirements for thinner-walled transparent flame-retardant applications.

[0005] CN119529500 A discloses a high-transparency, high-impact, flame-retardant modified polycarbonate material and its preparation method. The modified material comprises the following raw materials in parts by weight: 0-25 parts homopolymer polycarbonate resin, 60-95 parts silicone copolymer polycarbonate resin, 5-15 parts phosphazene flame retardant, 0.1-1 parts organosilicon synergistic flame retardant, 0.05-0.2 parts antioxidant, and 0.05-0.2 parts lubricant. The polycarbonate modified material prepared by this method has high toughness, high transparency, and environmentally friendly flame retardant properties; however, its flame retardant rating can only reach V0 1.6 mm, thus failing to meet the demand for thinner-walled, transparent, flame-retardant materials. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the prior art by providing a high-transparency thin-walled flame-retardant polycarbonate modified material, its preparation method, and its application.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] This invention provides a high-transparency, thin-walled, flame-retardant polycarbonate modified material, comprising the following components in parts by weight: 0-44 parts of homopolymer polycarbonate resin; 44-88 parts of silicone copolymer polycarbonate resin; 2-3 parts of polyphosphonate copolymerized polycarbonate resin; Sulfonate flame retardant 0.05-0.1 parts; 9-35 parts of halogenated flame retardant; 0.5-0.7 parts of organosilicon synergistic flame retardant; Processing aids: 0.2-1.5 parts.

[0009] Preferably, the homopolymer polycarbonate resin accounts for no more than 40% of the total mass of the homopolymer polycarbonate resin and the silicone copolymer polycarbonate resin. The total number of parts of the homopolymer polycarbonate resin, the silicone copolymer polycarbonate resin, the polyphosphonate copolymer polycarbonate resin, and the halogen flame retardant is preferably 100 parts.

[0010] Preferably, the homopolymer polycarbonate resin has an molecular weight (MI) of 2.5~110g / 10min and a weight-average molecular weight of 18000-38000 under conditions of 300℃ and 1.2kg.

[0011] Preferably, the MI of the silicon copolymer polycarbonate resin (silicon copolymer PC resin) is 2.5~110g / 10min under the conditions of 300℃ and 1.2kg.

[0012] Preferably, the weight-average molecular weight of the silicon copolymer polycarbonate resin is 18,000-38,000.

[0013] Preferably, the silicon content of the silicon copolymer polycarbonate resin is in the range of 5wt%-40wt%.

[0014] In this invention, the silicon copolymer polycarbonate resin (PC-PDMS) is a copolymer formed from polycarbonate (PC) and polydimethylsiloxane (PDMS).

[0015] Preferably, the sulfonate flame retardant is potassium perfluorobutyl sulfonate (KFPBS). The addition amount of KFPBS sulfonate flame retardant is generally no more than 0.1%. Adding more than 0.1% will affect overall performance such as transmittance.

[0016] Preferably, the halogenated flame retardant is brominated polycarbonate. The amount of halogenated flame retardant used depends on its bromine content, and is 5-7 parts by weight of bromine. If CH6305 (bromine content of about 20%) is used, the amount of brominated polycarbonate can be 25-35 parts; if BC58 (bromine content of about 58%) is used, the amount of brominated polycarbonate can be 9-12 parts. The preferred brominated polycarbonate is BC58, with a weight of 9-12 parts.

[0017] Preferably, the organosilicon synergistic flame retardant includes methyl, phenyl, epoxy, hydroxyl, or vinyl groups.

[0018] More preferably, the organosilicon synergistic flame retardant includes organosilicon containing different proportions of methyl or phenyl components, and may contain certain branched structures or a certain amount of reactive groups, such as epoxy groups, hydroxyl groups, or vinyl groups.

[0019] More preferably, the organosilicon synergistic flame retardant includes one or more of octaphenylcyclotetrasiloxane and methylphenyl organosilicon. The organosilicon synergistic flame retardant is preferably a combination of octaphenylcyclotetrasiloxane and methylphenyl organosilicon in a mass ratio of 2:0.8-1.2.

[0020] Preferably, the processing aids include antioxidants and lubricants. The antioxidant is 0.1-1 parts, and the lubricant is 0.1-0.5 parts.

[0021] More preferably, the antioxidant includes any one or a combination of two of antioxidants 1010, 168, 1076, and PEPQ.

[0022] More preferably, the lubricant comprises any one or a combination of two of pentaerythritol stearate (PETS) internal lubricants and silicone external lubricants. The lubricant may include PETS internal lubricants and silicone external lubricants of different molecular weights.

[0023] The present invention also provides a method for preparing the above-mentioned high-transparency thin-walled flame-retardant polycarbonate modified material, comprising the following steps: After thoroughly mixing all raw materials, they are placed in a twin-screw extruder with a temperature range of 250-300 ℃ and a rotation speed of 200-500 rpm for cooling and granulation to obtain a high-transparency thin-walled flame-retardant polycarbonate modified material.

[0024] The present invention also provides an application of the above-mentioned high-transparency thin-walled flame-retardant polycarbonate modified material in transparent parts of electronic appliances.

[0025] Preferably, the material is used to prepare transparent shells for charging piles, transparent shells for mobile phone fast chargers, transparent shells for 3D printers, and other application scenarios that require transparency and flame retardancy with a relatively thin thickness.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) The transparent flame-retardant polycarbonate modified material provided by the present invention has high transparency and low haze, and at the same time has stable flame-retardant properties at a relatively thin thickness; (2) The present invention achieves flame retardant requirements of V0 1.0mm and V0 1.2mm by compounding silicon copolymer polycarbonate resin, sulfonate flame retardant, halogen flame retardant, organosilicon synergistic flame retardant, etc. (3) This invention discloses a high transparency thin-walled transparent flame-retardant polycarbonate modified material, which uses silicon copolymer polycarbonate, sulfonate flame retardant, halogen flame retardant, organosilicon functional additives, etc. The synergistic effect of multiple materials gives the material excellent comprehensive performance, including transparency up to 87% (2.2mm), haze as low as about 3% (2.2mm), and flame retardant performance that can reach the flame retardant levels of UL94 standard V0 1.0mm and V0 1.2mm. The material is very suitable for use in relatively thin transparent electronic and electrical parts, such as transparent shells for charging piles, transparent shells for mobile phone fast chargers, transparent shells for 3D printers, etc. Detailed Implementation

[0027] The present invention will now be described in detail with reference to specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, providing detailed implementation methods and specific operating procedures, which will help those skilled in the art to further understand the present invention. It should be noted that the scope of protection of the present invention is not limited to the following embodiments; any adjustments and improvements made under the concept of the present invention are all within the scope of protection of the present invention.

[0028] This invention provides a high-transparency, thin-walled, flame-retardant polycarbonate modified material, comprising the following components by weight: 0-44 parts homopolymer polycarbonate resin; 44-88 parts silicone copolymer polycarbonate; 2-3 parts polyphosphonate copolymer polycarbonate resin; 0.05-0.1 parts sulfonate flame retardant; 9-11 parts halogen flame retardant; 0.5-0.7 parts organosilicon synergistic flame retardant; and 0.2-1.5 parts processing aids, wherein the processing aids include 0.1-1 parts antioxidant and 0.1-0.5 parts lubricant.

[0029] The following detailed description is provided with reference to specific embodiments: The raw materials used in the embodiments and comparative examples of this invention are all commercially available, but are not limited to the following materials: The homopolymer polycarbonate resin used is M7027BF from Mitsubishi Chemical, Japan; The silicone copolymer polycarbonate resin is PC-PDMS, using S1240T from Shandong Wanhua Chemical. The polyphosphonate-copolycarbonate used is CO-6010EX from FRX Corporation, USA; Sulfonate flame retardant 1 is potassium benzenesulfonylbenzenesulfonate KSS, using KSS-FR from Arichem, USA; Sulfonate flame retardant 2 is potassium perfluorobutyl sulfonate KFPBS, using FR-2025 from 3M Company, USA; Halogen flame retardant 1 is a brominated polycarbonate with a bromine content of approximately 20% by mass, using CH6305 from Cangzhou Dahua. Halogen flame retardant 2 is a brominated polycarbonate with a bromine content of approximately 58% by mass, using BC58 from Lanxess GmbH, Germany; The phosphate flame retardant is bisphenol A bis(diphenyl phosphate) (BPADP), using ADK BDP from Adico. The nitrogen-phosphorus flame retardant is hexaphenoxycyclotriphosphazene, using Shandong Weihai Jinwei HPCTP; Organosilicon synergistic flame retardant 1 is octaphenylcyclotetrasiloxane, using OPCTS from Shin-Etsu Chemical Co., Ltd., Japan; The organosilicon synergistic flame retardant 2 is a methylphenyl organosilicon, using Momentive's SFR320 from the United States; Other additives include: antioxidant (Irgafos 168) and lubricant (pentaerythritol stearate PETS).

[0030] The preparation methods of the embodiments and comparative examples of the present invention are as follows: After the raw materials are fully mixed according to the mass proportions described in Tables 1 and 2, they are placed in a twin-screw extruder with the temperature range set at 250-300℃ and the speed set at 200-500rpm for cooling and granulation to obtain a high-transparency thin-walled flame-retardant polycarbonate modified material.

[0031] Example 1 This embodiment provides a high-transparency thin-walled flame-retardant PC modified material and its preparation method. The specific steps are as follows: First, the components are mixed evenly in a mixing tank and fed into a twin-screw extruder through the main feed port; then, the mixture is blended and granulated through the extruder, followed by melt extrusion and granulation to obtain a high-transparency thin-walled flame-retardant PC modified material. The above material is melt-extruded, cooled, dried, and pelletized to obtain a sample. Specifically, the twin-screw extruder is a co-rotating twin-screw extruder with a screw length-to-diameter ratio of 40:1. The screw barrel is equipped with a vacuum extraction device and a temperature control device, with the temperature range set to 200-250℃ and the rotation speed set to 400 rpm.

[0032] Example 2 This embodiment is similar to Embodiment 1, except that some of the silicon copolymer PC is replaced with ordinary homopolymer PC in this embodiment.

[0033] Example 3 This embodiment is similar to Embodiment 2, except that: in this embodiment, octaphenylcyclotetrasiloxane is replaced by a combination of octaphenylcyclotetrasiloxane and methylphenyl organosilicon.

[0034] Example 4 This embodiment is similar to Embodiment 3, except that the ratio of silicon copolymer PC to ordinary PC in this embodiment is higher than that in Embodiment 3.

[0035] Example 5 This embodiment is similar to Embodiment 3, except that BC58, which has a higher bromine content, is replaced with CH6305, which has a lower bromine content, but the total bromine content remains basically unchanged.

[0036] Example 6 This embodiment is similar to Embodiment 3, except that the amount of potassium perfluorobutyl sulfonate (KFPBS) added in this embodiment is higher.

[0037] Example 7 This embodiment is similar to Embodiment 3, with the main difference being that the polyphosphonate-copolycarbonate is replaced with the phosphate flame retardant BPADP, and the dosage is increased to 5 parts. BPADP has a lower flame retardant efficiency than HPCTP, so a larger dosage is required, and BPADP has a greater negative impact on heat resistance and impact resistance.

[0038] Example 8 This embodiment is similar to Embodiment 3, except that the polyphosphonate-copolycarbonate is replaced with phosphazene flame retardant HPCTP in this embodiment.

[0039] The performance composition of the modified material in the example is shown in Figure 1.

[0040] Table 1 Specific component ratios of the embodiments

[0041] Comparative Example 1 The difference between this comparative example and Example 3 is that in this example, all silicon copolymer PC is replaced with ordinary homopolymer PC.

[0042] Comparative Example 2 Comparative Example 2 is similar to Example 3, except that: no organosilicon synergistic flame retardant was used in this example.

[0043] Comparative Example 3 The difference between this comparative example and Example 3 is that the sulfonate flame retardant KFPBS is replaced with the sulfonate flame retardant KSS in this comparative example.

[0044] Comparative Example 4 The difference between this comparative example and Example 3 is that brominated PC BC58 was not used in this comparative example.

[0045] Comparative Example 5 The difference between this comparative example and Example 3 is that polyphosphonate-copolycarbonate CO-6010EX was not used in this comparative example.

[0046] Comparative Example 6 The difference between this comparative example and Example 3 is that the amount of halogen flame retardant BC58 added in this comparative example is lower.

[0047] Comparative Example 7 The difference between this comparative example and Example 3 is that the amount of polyphosphonate-copolycarbonate CO-6010EX added in this comparative example is lower.

[0048] Comparative Example 8 The difference between this comparative example and Example 3 is that the amount of potassium perfluorobutyl sulfonate (KFPBS) added in this comparative example is lower.

[0049] Comparative Example 9 The difference between this comparative example and Example 3 is that the amount of organosilicon combination added in this comparative example is higher.

[0050] Comparative Example 10 The difference between this comparative example and Example 3 is that polyphosphonate-copolycarbonate was not used, but replaced with an equal amount of halogenated flame retardant 2.

[0051] Comparative Example 11 The difference between this comparative example and Example 3 is that the sulfonate flame retardant is in excess.

[0052] Comparative Example 12 The difference between this comparative example and Example 3 is that sulfonate flame retardant was not used, but replaced with an equal amount of organosilicon synergistic flame retardant 1.

[0053] The performance composition of the comparative modified materials is shown in Table 2.

[0054] Table 2. Specific group allocation ratios in the comparative example

[0055] Performance testing: After drying the PC materials obtained in the examples and comparative examples at 120°C for 4 hours, they were injection molded into test blocks under the same injection molding conditions according to ASTM standards for physical property testing. At the same time, according to UL standards, test strips were injection molded for vertical burning flame retardancy testing. In addition, the material was injection molded into a 100*65*2.2mm sample for transmittance testing. The specific test conditions and standards are shown in Table 3.

[0056] Table 3 Test Standards and Conditions

[0057] The performance test results of the modified materials in the examples are shown in Table 4.

[0058] Table 4 Physical properties of the examples (DR: ignites cotton, DL: dripping does not ignite cotton)

[0059] As shown in Table 4, comparing Examples 1 and 2, it is evident that as the amount of silicon-copolymer polycarbonate added decreases, the dripping risk significantly increases, and the flame retardant instability increases. Comparing Examples 2 and 3, it is evident that with the effective combination of organosilicon synergists, the flame retardant dripping risk significantly decreases, and the flame retardant stability increases. Comparing Examples 3 and 4, it is evident that further increasing the amount of silicon-copolymer polycarbonate added is beneficial for improving flame retardant stability. Comparing Examples 4 and 5, it is evident that when the total bromine content is the same, replacing different halogenated flame retardants has a similar effect on the system. Comparing Examples 3, 7, and 8, it is evident that 5% BPADP or 2% phosphazene produces a similar flame retardant synergistic effect to 2% polyphosphonate-copolymer polycarbonate, but BPADP has a more significant impact on notched impact and heat resistance grade.

[0060] The performance test results of the comparative modified materials are shown in Table 5.

[0061] Table 5 Comparative physical properties (DR: ignites cotton, DL: dripping does not ignite cotton)

[0062] As shown in Table 5, Comparative Example 1, which does not contain silicone copolymer polycarbonate resin, has a high probability of dripping ignition. Comparative Example 2, which does not contain silicone flame retardant synergists, has poor flame retardant performance. Comparative Examples 3, 8, and 12, which use sulfonate flame retardant KSS, have high dripping ignition probabilities when the amount of sulfonate flame retardant KFPBS added is insufficient or when it is replaced with silicone flame retardant synergists. Comparative Examples 4 and 6, which do not contain halogen flame retardants or have insufficient amounts added, also have poor flame retardant effects. Comparative Examples 5, 7, and 10, which do not contain polyphosphonate-copolycarbonate, have high dripping ignition rates when the amount added is insufficient or when it is replaced with halogen flame retardants. In Comparative Example 9, excessive silicone synergists actually worsen the flame retardant effect. In Comparative Example 11, when the amount of sulfonate flame retardant KFPBS added is excessive, the system's transmittance and haze performance deteriorate, and its impact resistance and flame retardant performance both decrease significantly. These phenomena indicate that to achieve more robust high-transparency thin-walled flame-retardant performance, it is necessary to simultaneously add appropriate amounts of key components such as silicone copolymer PC, polyphosphonate-copolycarbonate CO-6010EX, sulfonate flame retardant KFPBS, brominated PC BC58, and organosilicon synergistic flame retardants to the system.

[0063] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A high-transparency, thin-walled, flame-retardant polycarbonate modified material, characterized in that, The components include the following parts by weight: 0-44 parts of homopolymer polycarbonate resin; 44-88 parts of silicone copolymer polycarbonate resin; 2-3 parts of polyphosphonate copolymerized polycarbonate resin; Sulfonate flame retardant 0.05-0.1 parts; 9-35 parts of halogenated flame retardant; 0.5-0.7 parts of organosilicon synergistic flame retardant; Processing aids: 0.2-1.5 parts.

2. The high-transparency thin-walled flame-retardant polycarbonate modified material according to claim 1, characterized in that, The silica-copolymer polycarbonate resin has an molecular weight index (MI) of 2.5~110g / 10min at 300℃ and 1.2kg. And / or, the weight-average molecular weight of the silicon copolymer polycarbonate resin is 18,000-38,000; And / or, the silicon content of the silicon copolymer polycarbonate resin is in the range of 5wt%-40wt%.

3. The high-transparency thin-walled flame-retardant polycarbonate modified material according to claim 1, characterized in that, The sulfonate flame retardant is potassium perfluorobutyl sulfonate.

4. The high-transparency thin-walled flame-retardant polycarbonate modified material according to claim 1, characterized in that, The halogenated flame retardant is brominated polycarbonate.

5. The high-transparency thin-walled flame-retardant polycarbonate modified material according to claim 1, characterized in that, Preferably, the organosilicon synergistic flame retardant includes methyl, phenyl, epoxy, hydroxyl, or vinyl groups.

6. The high-transparency thin-walled flame-retardant polycarbonate modified material according to claim 5, characterized in that, The organosilicon synergistic flame retardant includes one or more of octaphenylcyclotetrasiloxane and methylphenyl organosilicon.

7. The high-transparency thin-walled flame-retardant polycarbonate modified material according to claim 1, characterized in that, The processing aids include antioxidants and lubricants; the antioxidant is 0.1-1 parts and the lubricant is 0.1-0.5 parts.

8. A method for preparing a high-transparency thin-walled flame-retardant polycarbonate modified material as described in claim 1, characterized in that, Includes the following steps: After the raw materials are thoroughly mixed, they are placed in a twin-screw extruder for cooling and granulation to obtain a high-transparency thin-walled flame-retardant polycarbonate modified material.

9. The preparation method according to claim 8, characterized in that, During cooling granulation, the temperature range is set to 250-300℃ and the rotation speed is set to 200-500 rpm.

10. The application of a high-transparency thin-walled flame-retardant polycarbonate modified material as described in claim 1 in transparent components of electronic and electrical appliances.

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