A polycarbonate composition, its preparation and use

Abstract

The application belongs to the field of polycarbonate materials, and specifically discloses a polycarbonate composition, a preparation method and application thereof. A certain amount of PCT, a metal passivator and a compatilizer containing a GMA functional group are added, so that the polycarbonate composition has good compatibility and stability, sufficient strength and processing stability are ensured, and the polycarbonate composition has good flame retardation, heat resistance and chemical resistance.

Description

Technical Field

[0001] This invention belongs to the field of polycarbonate materials, specifically relating to a polycarbonate composition, its preparation method, and its application. Background Technology

[0002] As is well known, due to the characteristics of the polycarbonate (PC) molecular structure, it possesses outstanding impact toughness, excellent thermal stability, outstanding dimensional stability, and electrical insulation properties, making it widely used in electronics, transportation, medical devices, construction, and lighting, and is an important component of engineering plastics. With the trend of replacing steel with plastics, the application fields of plastics are becoming increasingly broad, thus, people have increasingly stringent requirements for the flame retardancy, heat resistance, chemical resistance, and dimensional accuracy of plastic parts. Although specialty engineering plastics, such as PPS and LCP, have high heat resistance (operating temperature >180℃) and excellent chemical resistance and dimensional accuracy, their high price makes their cost-effectiveness less outstanding. While PC excels in dimensional stability and cost-effectiveness, its inability to be used for extended periods above 140℃ also limits its application in certain electronic and electrical fields.

[0003] LED light sources boast advantages such as high reliability, high luminous power, low power consumption, fast response speed, long lifespan, low price, and rich colors. LEDs are widely used in various fields including streetlights, indoor lighting, backlit displays, automotive headlights, and landscape lighting. Especially for displays without backlighting, such as large outdoor advertising screens and electronic signs, a back frame is essential for support, placing strict requirements on material strength, dimensional accuracy, and temperature resistance. Furthermore, outdoor products also require waterproofing, flame retardancy, and chemical resistance. Currently, ordinary PC materials have shortcomings in heat and chemical resistance. For applications like LED display back frames, further improvements in material heat resistance (heat distortion temperature HDT > 140℃) are needed to ensure no deformation at high temperatures and maintain assembly precision. Since these products require the use of fixing and sealing adhesives, excellent chemical resistance is also crucial. However, in practice, improving chemical and heat resistance often sacrifices flame retardancy, making it difficult to achieve a comprehensive improvement in chemical resistance, heat resistance, and flame retardancy. Balancing chemical resistance, heat resistance, and flame retardancy to expand the application of PC materials in scenarios with ever-evolving performance requirements has become one of the main directions in the development of polycarbonate materials. Summary of the Invention

[0004] In view of the deficiencies of the existing technology involving PC materials in terms of flame retardancy, temperature resistance, and chemical resistance, the present invention will provide a polycarbonate composition with good flame retardancy, heat resistance, and chemical resistance, as well as its preparation method and application.

[0005] To achieve the above objectives, the following technical solutions are specifically included:

[0006] A polycarbonate composition comprising the following components in parts by weight: 100 parts polycarbonate resin, 15-105 parts poly(1,4-cyclohexanedimethyl terephthalate) (PCT), 0.1-30 parts flame retardant, 0-50 parts filler, 0.01-5 parts anti-dripping agent, 0-0.8 parts stabilizer, 0.03-4.5 parts compatibilizer containing GMA functional groups, and 0.01-1.5 parts metal passivator;

[0007] The melt flow rate of the polycarbonate resin is 2.5-30 g / 10 min, and it is tested according to ISO 1133-12011 standard under the following conditions: 300 °C and 1.2 kg.

[0008] Compatibilizers containing GMA functional groups are short for compatibilizers containing glycidyl methacrylate.

[0009] The compatibilizer containing GMA functional groups added in this invention contains epoxy groups of GMA. These groups react with the end groups of PC or PCT in advance, thereby achieving passivation and improving compatibility. The metal passivator also mainly reacts with the end groups of PC or PCT to extinguish the highly active end groups. At the same time, the metal passivator inhibits the catalytic reaction caused by metal impurities remaining in the ester. The compatibilizer containing GMA functional groups and the metal passivator work synergistically to give the polycarbonate composition good compatibility and stability, ensuring sufficient strength and processing stability, and giving the polycarbonate composition good flame retardancy, heat resistance, and chemical resistance.

[0010] In a preferred embodiment of the present invention, the intrinsic viscosity of the polyethylene terephthalate (PET) is 0.5-0.85 dL / g; preferably, the intrinsic viscosity of the PET is 0.55-0.8 dL / g, and even more preferably, the intrinsic viscosity of the PET is 0.62-0.72 dL / g.

[0011] This invention uses the Ubbelohde viscosity test to test the intrinsic viscosity of poly(1,4-cyclohexanediethanol) terephthalate.

[0012] In a preferred embodiment of the present invention, the poly(1,4-cyclohexanediethanol) terephthalate is 20-100 parts by weight. More preferably, the poly(1,4-cyclohexanediethanol) terephthalate is 20-80 parts by weight. Even more preferably, the poly(1,4-cyclohexanediethanol) terephthalate is 30-50 parts by weight. The weight of the poly(1,4-cyclohexanediethanol) terephthalate can also be 15.5, 20.5, 25.5, 30.5, 35.5, 40.5, 45.5, 50.5, 55.5, 60.5, 65.5, 70.5, 75.5, 80.5, 85.5, 90.5, 95.5, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list all the specific values ​​included in the range.

[0013] In a preferred embodiment of the present invention, the polycarbonate resin has a mass percentage content of 40-80% in the polycarbonate composition, more preferably 56-67%, and even more preferably 60-66%.

[0014] In a preferred embodiment of the present invention, the melt flow rate of the polycarbonate resin is 3-15 g / 10 min.

[0015] In a preferred embodiment of the present invention, the total weight of the metal passivator and the compatibilizer containing GMA functional groups accounts for 0.03-5% of the total weight of the polycarbonate resin and poly(1,4-cyclohexanedimethyl terephthalate), more preferably 0.3-4.6%, and may also be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5.5%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0016] In a preferred embodiment of the present invention, the mass ratio of the metal passivating agent to the compatibilizer containing the GMA functional group is 1:(1-3).

[0017] In a preferred embodiment of the present invention, the metal passivating agent includes at least one of 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine and dodecanoic acid bis[2-(2-hydroxybenzoyl)hydrazine].

[0018] In a preferred embodiment of the present invention, the compatibilizer containing the GMA functional group includes at least one of PE-g-GMA, EMA-g-GMA, POE-g-GMA, EVA-g-GMA, and SAN-g-GMA.

[0019] In a preferred embodiment of the present invention, the epoxy equivalent in the compatibilizer containing GMA functional groups is 200-1200, and more preferably 400-850.

[0020] In a preferred embodiment of the present invention, the flame retardant is 1-20 parts by weight, more preferably 5-15 parts by weight.

[0021] In a preferred embodiment of the present invention, the flame retardant includes at least one of aromatic sulfonates, phosphate esters, bromine-containing polycarbonate oligomers, and silicone compounds.

[0022] In a preferred embodiment of the present invention, the anti-dripping agent is 0.1-4 parts by weight, more preferably 0.1-2 parts.

[0023] In a preferred embodiment of the present invention, the anti-dripping agent comprises polytetrafluoroethylene.

[0024] In a preferred embodiment of the present invention, the filler is 8-40 parts by weight, more preferably 10-30 parts by weight.

[0025] In a preferred embodiment of the present invention, the filler includes at least one of glass fiber, wollastonite, potassium titanate whiskers, kaolin, talc, and mica.

[0026] In a preferred embodiment of the present invention, the stabilizer comprises at least one of pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (1010) and tris[2,4-di-tert-butylphenyl]phosphite (168).

[0027] The present invention also provides a method for preparing a polycarbonate composition, comprising the following steps: melting and blending polycarbonate resin, poly(1,4-cyclohexanediethanol terephthalate), flame retardant, optional stabilizer, anti-dripping agent, optional filler, compatibilizer containing GMA functional group, and metal passivator, extruding and granulating to obtain the polycarbonate composition.

[0028] In a preferred embodiment of the present invention, the melt blending temperature is 230–300°C.

[0029] The above-mentioned polycarbonate composition can be used to prepare LED display screen back frames, TV mid-frames, and tablet computer back frames, and can meet the performance requirements of these application areas in terms of flame retardancy, heat resistance, and chemical resistance.

[0030] Compared with the prior art, the present invention has the following beneficial effects: the polycarbonate composition of the present invention has a flame retardant rating of V-1-V-0, an HDT of 138°C or higher, and an interfacial strain of 1.0% or higher, and has good flame retardant, heat resistance and chemical resistance properties. Detailed Implementation

[0031] To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be used to further explain the invention below. Unless otherwise specified, the test methods used in the embodiments and / or comparative examples are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.

[0032] Raw material information used in the examples and comparative examples:

[0033] PC1: LXTY1615T-11, Luxi, melt mass flow rate 15g / 10min;

[0034] PC2: PC 1300-30, LG, melt mass flow rate 30g / 10min;

[0035] PC3: LXTY1603T-11, Luxi, melt mass flow rate 3g / 10min;

[0036] PC4: PC 2030, Wanhua, melt mass flow rate 2.5 g / 10 min;

[0037] PC5: PC 2350, Wanhua, melt flow rate 35g / 10min.

[0038] PCT1: PCT 36296, Eastman, intrinsic viscosity 0.72 dL / g;

[0039] PCT2: PCT 36294, Eastman, intrinsic viscosity 0.62 dL / g;

[0040] PCT4: PCTG TX1500HF, Eastman, intrinsic viscosity 0.55 dL / g;

[0041] PCT5: PCT 1631, SK Korea, intrinsic viscosity 0.8 dL / g.

[0042] The intrinsic viscosity test method involved in the embodiments and comparative examples of this invention is the Ubbelohde viscosity test method.

[0043] Filler fiberglass: Fiberglass E7CS10-03-568H, Jushi.

[0044] Flame retardant: Brominated polycarbonate oligomer FG8500, Teijin, Japan.

[0045] Anti-dripping agent: Polytetrafluoroethylene AD541, commercially available.

[0046] Metal passivating agent: dodecanoic acid bis[2-(2-hydroxybenzoyl)hydrazide], CDA-6, Adico.

[0047] Compatibilizer 1: SAG-002T (SAN-g-GMA), epoxy equivalent 400-850, excellent compatibilization;

[0048] Compatibilizer 2: SAG-001 (SAN-g-GMA), epoxy equivalent of 200-400, excellent compatibilization;

[0049] Compatibilizer 3: SAG-005 (SAN-g-GMA), epoxy equivalent 850-920, excellent compatibilization;

[0050] Compatibilizer 4: SOG02 (POE-g-GMA), epoxy equivalent of 800-1200, excellent compatibilization;

[0051] The above-mentioned method for testing epoxy equivalent is: acid-base titration method: in a suitable solvent, excess hydrochloric acid is used to react with epoxy groups to quantitatively generate chlorohydrin, and the excess hydrochloric acid is quantitatively determined by alkali titration. Commonly used solvents include acetone, anhydrous ether, pyridine, etc.

[0052] Traditional stabilizer: a mixture of 0.2 parts by weight of stabilizer 1010 and stabilizer 168, both of which are commercially available.

[0053] Examples 1-17 and Comparative Examples 1-6

[0054] A method for preparing a polycarbonate composition according to Examples 1-17 and Comparative Examples 1-6 includes the following steps:

[0055] Weigh each component according to the raw material ratios in Tables 1 and 2, then stir and blend them in a high-speed mixer to obtain a premix, and then melt-blend and extrude granulate it through a twin-screw extruder, wherein the temperature of the twin-screw extruder is set to 270°C to obtain the polycarbonate composition.

[0056] Table 1 (parts by weight)

[0057]

[0058]

[0059] Table 2 (parts by weight)

[0060]

[0061] The test methods for various properties of the flame-retardant polycarbonate alloy compositions of the embodiments and comparative examples of the present invention are as follows:

[0062] 1) Flame Retardant Rating: Flame retardancy testing was conducted according to the "Flammability Testing of Plastic Materials, UL94" standard. The flame retardant rating was determined based on the burning rate, extinguishing time, resistance to dripping, and whether the dripping material was actively burning. The sample used for testing was 125mm long and 13mm wide. In this invention, the thickness was 1.5mm during testing. According to the UL94 standard, the flame retardant rating of the material can be classified as (UL94-HB): V0, V1, V2, 5VA, and / or 5VB. Simultaneously, the flame retardant rating of the sample was determined under the same conditions after undergoing damp heat aging treatment at 85℃ and 85% humidity for 500 hours in a constant temperature and humidity chamber.

[0063] 2) Heat resistance test: Place the container in an environment with a room temperature of 25°C and a humidity of 50% for more than 48 hours, and then conduct the HDT test according to the ASTM D648 standard and record the results. The higher the test result value, the better the heat resistance.

[0064] 3) Chemical resistance test: Used to evaluate the resistance of plastic materials to various chemicals, such as acids, alkalis, and oils. Plastic products will come into contact with chemicals to varying degrees during post-processing or use. Through chemical resistance testing, we can understand the chemical resistance characteristics of various materials and avoid risks caused by chemical resistance during use.

[0065] Chemical resistance was tested using the quarter-ellipse method.

[0066] 1. Test fixtures and test strips

[0067] Chemical resistance testing was conducted using a quarter-ellipse fixture with a major axis of 120 mm and a minor axis of 40 mm. ASTM tensile testing was performed using a specimen with a width of 12.7 mm, a length of 127.0 mm, and a thickness of 3.2 mm.

[0068] 2. Spline installation

[0069] Use clamps to firmly attach the 3.2mm thick template to the elliptical surface.

[0070] 3. Testing Procedures

[0071] a. Select the chemical to be evaluated. In this example and comparative example, acetone is used as the test chemical; b. Apply the acetone chemical evenly to the exposed part of the test piece clamped on the fixture; c. It is recommended to test five sets of the same set of test pieces in parallel. After applying the chemical, store the test piece in a static environment (environmental requirements: 23°C, 50% RH) for 5 minutes.

[0072] The critical strain of the sample is calculated using the following formula:

[0073] ε0={0.139×(1-0.0000617×X×2)-3 / 2}T×100, where ε0 is the critical strain (%); X is the distance from the center of the ellipse to the critical point (mm); and T is the thickness of the test piece (mm).

[0074] 4. Results Analysis

[0075] Table 3

[0076] Boundary strain % Stress conditions that cause cracks in materials Less than 0.3 Cracks form under very low stress. 0.3-0.5 Cracks form under low stress 0.5-0.8 Cracks only form under high stress. 0.8-2.0 Cracks only form under high stress. Greater than 2.0 No cracks will form under stress.

[0077] Table 4 Test Results

[0078]

[0079]

[0080] As can be seen from Examples 1-4 and Comparative Example 1, when the PC melt flow rate is too low, the dispersion between components is poor, resulting in poor flame retardancy of the polycarbonate composition; when the PC melt flow rate is too high, due to the low molecular weight of the substrate, the HDT and interfacial strain values ​​of the polycarbonate composition are low, making it easier to drip during combustion, thus causing the polycarbonate composition to fail to achieve V-1 flame retardancy.

[0081] Examples 1 and 5-7 show different PCT contents. Increasing the PCT content within a certain range increases the HDT and interfacial strain values ​​of the polycarbonate composition. It can be seen that by adding PCT, PCT and PC form an alloy material, which can greatly improve the heat resistance of the polycarbonate composition alloy and improve the chemical resistance of the alloy material. Comparative Examples 2-3 show cases that exceed the PCT content range of the present invention. When the PCT addition is too low, the HDT of the polycarbonate composition is low; when it is too high, PCT will significantly reduce the flame retardancy of the polycarbonate composition.

[0082] Examples 1 and 8-10 illustrate cases with different intrinsic viscosities of PCT. Within a certain range, as the intrinsic viscosity of PCT increases, the HDT and interfacial strain values ​​of the polycarbonate composition also increase.

[0083] Examples 1 and 11 show that, with the same total amount of metal passivator and compatibilizer complex, appropriately increasing the amount of metal passivator slightly increases the HDT and interfacial strain values ​​of the polycarbonate composition.

[0084] In Examples 1 and 12-13, when the mass ratio of metal passivator to compatibilizer is the same, increasing the content of the metal passivator and compatibilizer composite within a certain range gradually increases the HDT and interfacial strain values ​​of the polycarbonate composition. However, as the content of the composite increases, the HDT and interfacial strain values ​​remain basically unchanged.

[0085] Compared with Example 1, Comparative Examples 4-6 represent three cases: no metal passivator and no compatibilizer, containing compatibilizer but no metal passivator, and containing metal passivator but no compatibilizer, respectively. Analysis shows that compatibilizers containing GMA functional groups can further stabilize the polycarbonate composition system. The combination of compatibilizers containing GMA functional groups and metal passivators can synergistically give the polycarbonate composition good compatibility and stability, and give the polycarbonate composition good flame retardancy, heat resistance and chemical resistance.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polycarbonate composition, characterized in that, The product comprises the following components in parts by weight: 100 parts polycarbonate resin, 15-105 parts poly(1,4-cyclohexanedimethyl terephthalate), 0.1-30 parts flame retardant, 0-50 parts filler, 0.01-5 parts anti-dripping agent, 0-0.8 parts stabilizer, 0.03-4.5 parts compatibilizer containing GMA functional groups, and 0.01-1.5 parts metal passivator. The melt flow rate of the polycarbonate resin is 2.5-30 g / 10 min, and it is tested according to ISO 1133-12011 standard under the following conditions: 300℃ and 1.2 kg. The metal passivating agent includes at least one of 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine and dodecanoic acid bis[2-(2-hydroxybenzoyl)hydrazine].

2. The polycarbonate composition according to claim 1, characterized in that, The total weight of the metal passivator and the compatibilizer containing GMA functional groups is 0.03-5% of the total weight of the polycarbonate resin and poly(1,4-cyclohexanediethanol terephthalate).

3. The polycarbonate composition according to claim 1, characterized in that, The compatibilizer containing the GMA functional group includes at least one of PE-g-GMA, EMA-g-GMA, POE-g-GMA, EVA-g-GMA, and SAN-g-GMA.

4. The polycarbonate composition according to claim 1, characterized in that, The mass ratio of the metal passivating agent to the compatibilizer containing the GMA functional group is 1:(1-3).

5. The polycarbonate composition according to claim 1, characterized in that, The poly(1,4-cyclohexanediethanol) terephthalate is present in parts by weight of 20-100.

6. The polycarbonate composition according to claim 1, characterized in that, The compatibilizer containing GMA functional groups has an epoxy equivalent of 200-1200.

7. The polycarbonate composition according to claim 1, characterized in that, Includes at least one of the following: The flame retardant includes at least one of aromatic sulfonates, phosphate esters, brominated polycarbonate oligomers, and silicone compounds. The anti-dripping agent includes polytetrafluoroethylene; The filler includes at least one of glass fiber, wollastonite, potassium titanate whiskers, kaolin, talc, and mica; The stabilizer includes at least one of pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and tris[2,4-di-tert-butylphenyl]phosphite; The melt mass flow rate of the polycarbonate resin is 3-15 g / 10 min; The poly(1,4-cyclohexanediethanol) terephthalate is present in parts by weight of 20-100.

8. A method for preparing the polycarbonate composition according to any one of claims 1-7, characterized in that, The process includes the following steps: melting and blending polycarbonate resin, poly(1,4-cyclohexanediethanol) terephthalate, flame retardant, optional stabilizer, anti-dripping agent, optional filler, compatibilizer containing GMA functional group, and metal passivator, followed by extrusion and granulation to obtain the polycarbonate composition.

9. The use of the polycarbonate composition according to any one of claims 1-7 in the preparation of LED display screen back frames, television mid-frames, and tablet computer back frames.

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