A low-temperature resistant PC / PBT polycarbonate composition

Abstract

This invention provides a low-temperature resistant PC / PBT polycarbonate composition, comprising the following components by weight: 40-45 parts polycarbonate, 10-15 parts polysiloxane-polycarbonate random copolymer, 35-40 parts PBT, 4-7 parts flame retardant BC-58, 0.1-1 parts antimony trioxide, 1-3 parts toughening compatibilizer, and 0.1-1 parts antioxidant. The polycarbonate composition of this invention has a simple preparation process, is easy to operate, does not use a low-temperature toughening agent, and exhibits excellent low-temperature mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of polymers, and specifically relates to a low-temperature resistant PC / PBT polycarbonate composition and its preparation method. Background Technology

[0002] Both PC and PBT (polybutylene terephthalate) are general-purpose engineering plastics. Simply mixing and blending them before injection molding yields poor results and often results in delamination. PC's advantages include room temperature rigidity and toughness, but it suffers from stress cracking and high viscosity. PBT's advantages include temperature-independent rigidity and low deformation, but it has a low heat distortion temperature. The resulting blend, PC / PBT, retains the advantages of both materials, exhibiting high surface hardness, high rigidity and toughness, and high resistance to stress cracking; its mechanical properties fall between the two. PC / PBT becomes brittle at -30°C. To maintain good toughness at low temperatures, a large amount of toughening agent must be added. However, this significantly reduces the material's flexural strength and HDT (highest heat distortion temperature). Therefore, improving the low-temperature performance of PC / PBT materials is crucial. Summary of the Invention

[0003] The present invention aims to overcome the shortcomings of the prior art and provide a low-temperature resistant PC / PBT polycarbonate composition.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a low-temperature resistant PC / PBT polycarbonate composition, characterized in that it is composed of the following components in parts by weight:

[0005] 40-45 parts polycarbonate, 10-15 parts polysiloxane-polycarbonate random copolymer, 35-40 parts PBT, 4-7 parts flame retardant BC-58, 0.1-1 part antimony trioxide, 1-3 parts toughening compatibilizer, and 0.1-1 part antioxidant.

[0006] The melt flow rate of the polycarbonate is 8-13 g / 10 min;

[0007] The polysiloxane-polycarbonate random copolymer has a polysiloxane block weight accounting for 22-28% of the total copolymer weight, and a melt flow rate of 0-15 g / 10min.

[0008] The toughening compatibilizer is ethylene-methyl acrylate-glycidyl methacrylate; the antioxidant is a phenolic antioxidant.

[0009] The preparation method of the low-temperature resistant PC / PBT polycarbonate composition is as follows: Polycarbonate is placed in silo one; 50% PBT, polysiloxane-polycarbonate random copolymer, flame retardant BC-58, antimony trioxide, toughening compatibilizer, and antioxidant are added to a high-speed mixer, followed by the remaining 50% PBT. After mixing evenly, the material is placed in silo two. The material from silos one and two, along with the material from silos two, is fed into a twin-screw extruder at a uniform speed using a metering scale. After extrusion molding, cooling, drying, granulation, performance analysis, and packaging are performed.

[0010] The advantages of this invention are: the process is simple, no low-temperature toughening agent is used, it has a composition with good flame retardancy and low-temperature resistance, the raw materials are readily available, the processing performance is good, and it is suitable for industrial production. Detailed Implementation

[0011] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0012] Example 1:

[0013] Polycarbonate: LG Chem PC1300-12, melt flow rate is 12 g / 10 min;

[0014] The polysiloxane block in the polysiloxane polycarbonate random copolymer accounts for 23% of the total weight of the copolymer, and the melt flow rate is 5 g / 10 min.

[0015] Antioxidant: 1076;

[0016] Toughening compatibilizer: Ethylene-methyl acrylate-glycidyl methacrylate.

[0017] According to the weights in Table (I), first add 50% PBT, polysiloxane-polycarbonate random copolymer, flame retardant BC-58, antimony trioxide, toughening compatibilizer and antioxidant to the high-speed mixer, then add the remaining 50% PBT. After mixing evenly, place the material in silo No. 2; place the polycarbonate in silo No. 1, and use a weighing scale to uniformly feed the materials in silos No. 1 and No. 2 into the twin-screw extruder according to the proportion. After extrusion molding, cooling, drying and granulation are performed. The performance analysis is shown in Table (II), and then packaged.

[0018] Examples 2-5: The preparation method is the same as in Example 1. The specific components are shown in Table (I), and the performance analysis is shown in Table (II).

[0019]

[0020]

[0021] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A low-temperature resistant PC / PBT polycarbonate composition, characterized in that: Composed of the following components in parts by weight: 40-45 parts polycarbonate, 10-15 parts polysiloxane-polycarbonate random copolymer, 35-40 parts PBT, 4-7 parts flame retardant BC-58, 0.1-1 part antimony trioxide, 1-3 parts toughening compatibilizer, and 0.1-1 part antioxidant. The polycarbonate has a melt flow rate of 8-13 g / 10 min, and the polysiloxane blocks in the polysiloxane-polycarbonate random copolymer account for 23-28% of the total weight of the copolymer, with a melt flow rate of 5-15 g / 10 min. The low-temperature resistant PC / PBT polycarbonate composition is prepared by the following method: Polycarbonate is placed in hopper No. 1, and PBT, polysiloxane-polycarbonate random copolymer, flame retardant BC-58, antimony trioxide, toughening compatibilizer and antioxidant are mixed evenly and placed in hopper No.

2. The materials in hopper No. 1 and hopper No. 2 are fed into a twin-screw extruder at a uniform speed according to the proportion using a weighing scale. After extrusion molding, cooling, drying and granulation are performed, the properties are analyzed and packaged.

2. The low-temperature resistant PC / PBT polycarbonate composition as described in claim 1, characterized in that: The toughening compatibilizer is ethylene-methyl acrylate-glycidyl methacrylate; the antioxidant is a phenolic antioxidant.

3. The low-temperature resistant PC / PBT polycarbonate composition as described in claim 1, characterized in that: In the preparation method, the material placed in the No. 2 silo is a material that has been uniformly mixed by a high-speed mixer. First, 50% of PBT, polysiloxane-polycarbonate random copolymer, flame retardant BC-58, antimony trioxide, toughening compatibilizer and antioxidant are added in the high-speed mixer, and then the remaining 50% of PBT is added. After mixing evenly, the material is placed in the No. 2 silo.

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