Flame-retardant PC (polycarbonate) material as well as preparation method and application thereof

Abstract

The invention relates to a flame-retardant PC (polycarbonate) material as well as a preparation method and application thereof. The flame-retardant PC material is prepared from the following components in parts by weight: 65 to 85 parts of polycarbonate resin, 29 to 96 parts of polycarbonate siloxane copolymer resin, 1 to 16 parts of MDQ silicon resin and 1 to 15 parts of phosphorus flame retardant. The polycarbonate siloxane copolymer resin, the MDQ silicon resin and the phosphorus flame retardant are added, so that the obtained flame-retardant PC material can reach a V0 flame-retardant grade under a fluorine-free condition, the yield elongation after light aging is good, and the ultrasonic welding strength is good.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material modification, and more specifically, to a flame retardant PC material and a preparation method and application thereof. Background Art

[0002] Polycarbonate (PC) is a common engineering plastic with excellent mechanical properties and heat resistance, and has the advantages of high strength and elastic modulus, high impact strength, high heat resistance, free dyeing, low molding shrinkage, good dimensional stability, good fatigue resistance, etc. Modified PC products are widely used in many fields such as automotive parts, industrial machinery parts, optical disks, packaging, office equipment such as computers, medical and health care, films, leisure and protective equipment, etc.

[0003] One of the disadvantages of PC is that after being exposed to ultraviolet light, its molecular chains break, causing its yield elongation to drop significantly, which limits its application in some electronic and electrical products that are exposed to light for a long time.

[0004] In the fields of electronics, electrical engineering, and machinery, PC products are usually required to have a flame retardant rating of V0. PC will drip during combustion, and the existing technology relies heavily on fluorinated anti-drip agents. If only flame retardants are added without fluorinated anti-drip agents, the flame retardant rating of PC products is difficult to reach V0. However, as people gradually recognize the harmful effects of fluorinated anti-drip agents on the environment, the call for fluorine-free PC products is getting louder and louder.

[0005] In addition, with the improvement of the precision of current electronic products, ultrasonic welding is increasingly recognized by all walks of life. Ultrasonic welding uses high-frequency vibration waves to transmit to the surfaces of two objects to be welded. It is fast, efficient, clean and strong. Ultrasonic welding is also one of the main ways to assemble or process PC products. According to the needs of current market development, the ultrasonic welding strength of PC products needs to be further improved.

[0006] Patent CN 117327382 A discloses a fluorine-free halogen-free flame-retardant PC plastic. Compared with the prior art, although this patent also solves the problem that the halogen-free flame-retardant V0 grade PC material has potential PFAS environmental risks due to the addition of PTFE fluorine-containing anti-drip agents, and the thin-wall flame-retardant V0 does not meet the standard due to the absence of PTFE-free anti-drip agents, this patent does not focus on the yield elongation after light aging and the ultrasonic welding strength.

[0007] Therefore, it is necessary to develop PC materials that can achieve V0 flame retardancy without fluorine, have good yield elongation after light aging, and have good ultrasonic welding strength. Summary of the invention

[0008] The primary purpose of the present invention is to overcome the technical problems existing in the above-mentioned prior art and provide a flame retardant PC material.

[0009] A further object of the present invention is to provide a method for preparing the flame retardant PC material.

[0010] A further object of the present invention is to provide the use of the flame retardant PC material in the preparation of electronic product parts, electrical product parts or mechanical product parts.

[0011] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0012] A flame retardant PC material, comprising the following components in parts by weight:

[0013]

[0014] The inventors of the present invention have found that polycarbonate siloxane copolymer resin has good compatibility with polycarbonate resin, and MDQ silicone resin has good molecular chain flexibility. The combination of polycarbonate siloxane copolymer resin and MDQ silicone resin can form a network to prevent melting and dripping when the flame-retardant PC material burns, and cooperate with the flame extinguishing effect of the phosphorus-based flame retardant and the effect of forming a phosphorus-containing carbonized layer with good thermal stability, so that the flame retardant grade of the flame-retardant PC material reaches V-0 level without adding a fluorine-containing anti-drip agent.

[0015] The inventors of the present invention also found that the addition of MDQ silicone resin and polycarbonate siloxane copolymer resin, after being subjected to ultrasonic vibration, causes vibration friction between molecular chains to generate heat, thereby increasing the entanglement between molecules, thereby improving the ultrasonic welding strength of the flame-retardant PC material.

[0016] In addition, the molecular chains of MDQ silicone resin and polycarbonate siloxane copolymer resin are entangled with polycarbonate resin, and after the flame-retardant PC material is irradiated by UV light, the molecular chains are not easily broken, thereby maintaining a high yield elongation retention rate.

[0017] That is, the flame-retardant PC material obtained by adding polycarbonate siloxane copolymer resin, MDQ silicone resin and phosphorus flame retardant in the present invention can achieve V0 flame retardancy (1.5mm) in the absence of fluorine, has good yield elongation after light aging, and has good ultrasonic welding strength.

[0018] In the present invention, polycarbonate resin is used as the main resin, and its content preferably accounts for 30wt% of the flame-retardant PC material; the polycarbonate is preferably bisphenol A polycarbonate.

[0019] Preferably, the viscosity average molecular weight of the polycarbonate resin is 16,000 to 32,000.

[0020] In the present invention, the viscosity average molecular weight of the polycarbonate resin can be measured with reference to GB / T 21863-2008.

[0021] Preferably, the siloxane content in the polycarbonate siloxane copolymer resin is ≥5wt%.

[0022] More preferably, the siloxane content in the polycarbonate siloxane copolymer resin is 7-22 wt %.

[0023] More preferably, the polycarbonate siloxane copolymer resin has a siloxane content of 19 to 21 wt%.

[0024] By selecting the polycarbonate siloxane copolymer resin with the siloxane content, the flame-retardant PC material has higher ultrasonic welding strength and higher retention rate of yield elongation after aging.

[0025] In the present invention, the siloxane content in the polycarbonate siloxane copolymer resin can be measured by SEM / EDX quantitative analysis.

[0026] Preferably, the polycarbonate siloxane copolymer resin has a melt index of 1 to 15 g / 10 min measured at 300° C. and 1.2 kg.

[0027] In the present invention, the melt index of the polycarbonate siloxane copolymer resin can be measured according to ASTM D1238-2010.

[0028] Preferably, the phosphorus-based flame retardant is at least one of bisphenol A bis(diphenyl phosphate), trimethyl phosphate, triethyl phosphate, triphenyl phosphate, resorcinol bisphosphate or phosphazene.

[0029] Preferably, the MDQ silicone resin is MDQ type phenyl vinyl silicone resin.

[0030] Preferably, the molecular formula of the MDQ silicone resin is:

[0031] (Ph2SiO) a (ViMe2SiO 0.5 ) b (Me3SiO 0.5 ) c (SiO2) d ;

[0032] Among them, Ph is phenyl, Me is methyl, Vi represents vinyl; the value range of a is 0.1~1; the value range of b+c is 0~0.1, and b>0; the value range of d is 0~0.8, and a+b+c+d>0; the value range of a / d is 1.6~2.5; the value range of (b+c) / d is 1.6~2.5.

[0033] Preferably, the MDQ type phenyl vinyl silicone resin has a vinyl content of 6 to 9 wt % and a refractive index of 1.53 to 1.55 / 25°C.

[0034] Preferably, the viscosity of the MDQ silicone resin is 2000-30000 mPa·s.

[0035] More preferably, the viscosity of the MDQ silicone resin is 7000-8000 mPa·s.

[0036] By selecting the MDQ silicone resin with this viscosity, the flame-retardant PC material obtained has higher ultrasonic welding strength and higher retention rate of yield elongation after aging.

[0037] The MDQ silicone resin of the present invention can be purchased from the market or can be prepared by oneself. The prepared MDQ silicone resin can be prepared by firstly subjecting alkyl silicate and phenyl alkoxy silane to a hydrolysis condensation reaction and then capping with a vinyl capping agent and / or a methyl capping agent. The specific process can be as follows:

[0038] S01 100 to 1000 parts by mass of phenyl alkoxysilane, 10 to 300 parts by mass of alkyl silicate and 50 to 500 parts by mass of an organic solvent are mixed and stirred at room temperature to obtain a mixed solution;

[0039] S02. Add 20 to 300 parts by mass of an acidic aqueous solution to the mixed solution, raise the temperature to 60 to 70°C after the addition is complete, react for 4 to 6 hours, then add 20 to 200 parts by mass of a vinyl capping agent and / or a methyl capping agent, maintain the temperature at 60 to 70°C for 6 to 8 hours, and obtain a reaction solution, wherein the mass concentration of the acidic aqueous solution is 5 to 15%;

[0040] S03. The reaction solution was allowed to stand for stratification, the upper acid layer was removed, and a base was added to adjust the pH value to neutral, and washed to obtain a mixture;

[0041] S04. The mixture is heated to 140-160° C. for 2-5 hours under a vacuum degree equal to or greater than 0.1 MPa to obtain the MDQ silicone resin.

[0042] More preferably, the phenylalkoxysilane is at least one of diphenyldimethoxysilane or diphenyldiethoxysilane.

[0043] More preferably, the alkyl silicate is at least one of ethyl orthosilicate or methyl orthosilicate.

[0044] More preferably, the acidic aqueous solution is at least one of a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution or a nitric acid aqueous solution.

[0045] More preferably, the vinyl capping agent is at least one of divinyltetramethyldisiloxane, diphenyldimethyldivinyldisiloxane, dimethylvinylsiloxane or phenylvinylsiloxane; and the methyl capping agent is hexamethyldisiloxane.

[0046] Preferably, the flame retardant PC material further comprises 0.3 to 3 parts of other additives.

[0047] Optionally, the other auxiliary agents include but are not limited to at least one of an antioxidant, a lubricant or an anti-UV agent.

[0048] Optionally, the antioxidant includes but is not limited to at least one of a propionate antioxidant or a phosphite antioxidant; the propionate antioxidant includes but is not limited to octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; the phosphite antioxidant includes but is not limited to at least one of tris(nonylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite or distearylpentaerythritol diphosphite.

[0049] Optionally, the lubricant includes but is not limited to at least one of pentaerythritol tetrastearate (PETS), glyceryl monostearate (GMS) or glyceryl tristearate.

[0050] Optionally, the anti-UV agent includes but is not limited to at least one of benzophenone weathering agents, benzotriazole weathering agents, salicylate weathering agents, triazine weathering agents, substituted acrylonitrile weathering agents or hindered amine weathering agents.

[0051] The method for preparing the flame retardant PC material comprises the following steps: mixing the components, melt extruding, and granulating to obtain the flame retardant PC material.

[0052] Preferably, the temperature of the melt extrusion is 220-250° C.; the screw speed of the extruder for the melt extrusion is 400-500 rpm, and the screw aspect ratio is 40-50:1.

[0053] The use of the flame-retardant PC material in the preparation of parts for electronic products, electrical products or mechanical products also falls within the protection scope of the present invention.

[0054] Preferably, the electronic product is a power adapter.

[0055] Preferably, the electrical product is a compressor cover or an optical communication product.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] The invention adds polycarbonate siloxane copolymer resin, MDQ silicone resin and phosphorus flame retardant to obtain a flame retardant PC material which can reach V0 flame retardant grade in the absence of fluorine, has good yield elongation after light aging and good ultrasonic welding strength. DETAILED DESCRIPTION

[0058] In order to more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail through specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. Various changes can be made within the scope of the rights of the present invention.

[0059] Some of the reagents selected in the embodiments and comparative examples of the present invention are described as follows:

[0060] (1) Polycarbonate resin

[0061] PC1#: Mitsubishi, S-2000F, viscosity average molecular weight is 25000;

[0062] PC2#: Mitsubishi, H-2000F, viscosity average molecular weight is 20000;

[0063] PC3#: Mitsubishi, S-3000F, viscosity average molecular weight is 23000;

[0064] (2) Polycarbonate siloxane copolymer resin:

[0065] SiPC-1#: Wanhua, S2060, siloxane content 20%, melt index 1.5g / 10min;

[0066] SiPC-2#: Samyang, South Korea, ST4-3022PJ, siloxane content 7%, melt index 4g / 10min;

[0067] SiPC-3#: Illuminated, AG2530, 9% siloxane content, melt index 5g / 10min;

[0068] (3) MDQ silicone resin:

[0069] MDQ silicone resin 1#: prepared according to Example 1 of patent CN 104448318 B, and its viscosity was measured to be 7900 mPa·s / 25°C;

[0070] MDQ silicone resin 2#: prepared according to Example 2 of patent CN 104448318 B, and its viscosity was measured to be 20200 mPa·s / 25°C;

[0071] MDQ silicone resin 3#: prepared according to Example 3 of patent CN 104448318 B, and its viscosity was measured to be 5070 mPa·s / 25°C;

[0072] (4) Phosphorus flame retardants

[0073] Phosphorus flame retardant 1#: BDP (bisphenol A bis(diphenyl phosphate)), Zhejiang Wansheng;

[0074] Phosphorus flame retardant 2#: RDP (resorcinol diphosphate), Zhejiang Wansheng;

[0075] (5) Other additives

[0076] Other additives 1#: lubricant, pentaerythritol stearate, commercially available;

[0077] (6) Others

[0078] MQ silicone resin 1#: SFR100, Momentive;

[0079] Silicon flame retardant 1#: FCA-107, Dow Corning, phenyl silicone flake resin with hydroxyl functional group;

[0080] Brominated flame retardant 1#: SR-245, ICL, brominated triazine;

[0081] Unless otherwise specified, the components (such as other auxiliary agent 1#) selected in each parallel example and comparative example are the same commercially available products.

[0082] The flame retardant PC materials provided in the embodiments and comparative examples of the present invention were tested for performance according to the following test methods:

[0083] (1) Flame retardant properties: The flammability test was conducted in accordance with the "Flammability Test for Plastic Materials, UL94-2020". The sample used for the test: The sample size was 125 mm length × 13 mm width × 1.5 mm, and was prepared using a 160T injection molding machine, with an injection molding temperature of 250°C and an injection molding speed of 80 mm / s.

[0084] (2) Ultrasonic welding strength: The size of the sample strip is 60*10mm*2.0mm; the two sample strips are connected end to end and welded using ultrasonic welding equipment. The welding process conditions are: welding time 2S, welding pressure 220N, and ultrasonic amplitude 30KHZ. The two welded connected sample strips are clamped at one end of the universal tensile testing machine fixture, and the pull-off force (maximum experimental tensile force) is used to characterize the ultrasonic welding strength.

[0085] (3) Yield elongation retention rate: Tested according to standard ISO 527-2-2012, with a tensile speed of 10 mm / min, and the initial tensile yield elongation was recorded. After 1000 hours of light aging, the post-aging tensile yield elongation was tested, and the post-aging tensile yield elongation / initial tensile yield elongation = yield elongation retention rate.

[0086] Light aging conditions: ISO 4892-2 cycle 1, time 1000h;

[0087] Filter system: Daylight filter system (filter combination inside / outside: S / S);

[0088] Lighting stage: irradiance: 0.51w / m2·nm@340nm; black mark temperature: (65±3)℃; box temperature: (38±3)℃;

[0089] Relative humidity: (50±10)%

[0090] Cycle phase:

[0091] Stage 1: light, 102 min, no spraying;

[0092] Phase 2: Light exposure, 18 min, spraying water mist on the front side of the specimen.

[0093] The preparation process of the flame retardant PC material of each embodiment of the present invention and each comparative example is as follows:

[0094] Weigh each component according to the formula, mix them, and then add them into a twin-screw extruder, melt extrude, and granulate to obtain a flame-retardant PC material. The setting temperatures of each zone of the twin-screw extruder are 250°C, 240°C, 240°C, 240°C, 240°C, 240°C, 240°C, 230°C, and 220°C, the screw speed is 450 rpm, and the screw aspect ratio is 45:1.

[0095] Examples 1 to 10

[0096] Examples 1 to 10 provide a series of flame retardant PC materials, the formulations of which are shown in Table 1.

[0097] Table 1 Formulas of Examples 1 to 10 (parts by weight)

[0098]

[0099] Comparative Examples 1 to 6

[0100] Comparative Examples 1 to 6 provide a series of flame retardant PC materials, and their formulations are shown in Table 2.

[0101] Table 2 Formulas of Comparative Examples 1 to 6 (parts by weight)

[0102]

[0103]

[0104] The properties of the flame retardant PC materials of the embodiments and comparative examples were tested according to the above-mentioned test methods. The test results are shown in Table 3.

[0105] Table 3 Performance results of flame retardant PC materials of various embodiments and comparative examples

[0106]

[0107]

[0108] From Table 3, we can see that:

[0109] The flame retardant grades of the flame retardant PC materials of Examples 1 to 10 are all V-0 (1.5 mm), the ultrasonic welding strengths are all above 925 N, and the retention rates of the yield elongation after aging are all above 91%, indicating that the flame retardant PC material of the present invention can achieve a V0 flame retardant grade in the absence of fluorine, has a good yield elongation after light aging, and has good ultrasonic welding strength.

[0110] In Comparative Example 1, polycarbonate siloxane copolymer resin is not added, and the flame retardant PC material obtained has poor flame retardancy, low ultrasonic welding strength, and low yield elongation retention after light aging. In Comparative Example 2, MDQ silicone resin is not added, and the flame retardant PC material obtained has poor flame retardancy, low ultrasonic welding strength, and low yield elongation retention after light aging. In Comparative Example 3, silicon-based flame retardant 1# is used to replace MDQ silicone resin, and the flame retardant PC material obtained has poor flame retardancy, low ultrasonic welding strength, and low yield elongation retention after light aging. In Comparative Example 4, phosphorus-based flame retardant is not added, and the flame retardant PC material obtained has poor flame retardancy and low yield elongation retention after light aging. In Comparative Example 5, bromine-based flame retardant is used to replace phosphorus-based flame retardant, and the flame retardant PC material obtained has low yield elongation retention after light aging. In Comparative Example 6, MQ silicone resin is used to replace MDQ silicone resin, and the flame retardant PC material obtained has low ultrasonic welding strength and low yield elongation retention after light aging.

[0111] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A flame retardant PC material, 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 viscosity average molecular weight of the polycarbonate resin is 18000-32000.

3. The flame retardant PC material according to claim 1, characterized in that: The siloxane content in the polycarbonate siloxane copolymer resin is ≥5wt%.

4. The flame retardant PC material according to claim 1, characterized in that: The polycarbonate siloxane copolymer resin has a melt index of 1 to 15 g / 10 min measured at 300° C. and 1.2 kg.

5. The flame retardant PC material according to claim 1, characterized in that: The phosphorus-based flame retardant is at least one of bisphenol A bis(diphenyl phosphate), trimethyl phosphate, triethyl phosphate, triphenyl phosphate, resorcinol bisphosphate or phosphazene.

6. The flame retardant PC material according to claim 1, characterized in that: The MDQ silicone resin is an MDQ type phenyl vinyl silicone resin.

7. The flame retardant PC material according to claim 1, characterized in that: The viscosity of the MDQ silicone resin is between 2000 and 30000 mpa·s.

8. The flame retardant PC material according to claim 1, characterized in that: The flame retardant PC material also includes 0.3 to 3 parts of other additives.

9. The method for preparing the flame retardant PC material according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: mixing the components, melting and extruding, and granulating to obtain the flame retardant PC material.

10. Use of the flame-retardant PC material according to any one of claims 1 to 8 in the preparation of electronic product parts, electrical product parts or mechanical product parts.

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