Polyethylene modified polycarbonate composite material

Abstract

The invention relates to a polyethylene modified polycarbonate composite material, which is composed of the following components in parts by weight: 59 to 62 parts of polycarbonate A, 16 to 18 parts of polycarbonate B, 0.4 to 0.7 part of low density polyethylene, 20 to 23 parts of polysiloxane-polycarbonate random copolymer, and 0.1 to 0.4 part of antioxidant. The polycarbonate A is polycarbonate of which the solution flow rate is greater than 15g / (10min), and the polycarbonate B is polycarbonate of which the solution flow rate is less than 10g / (10min). The polyethylene modified polycarbonate composite material obtained by the invention is excellent in processability and simple in processing process, and the product has the advantages of stable quality, impact resistance, low temperature resistance, excellent heat resistance and the like.

Description

Technical Field

[0001] The invention relates to a polycarbonate modified material, in particular to a polyethylene modified polycarbonate composite material. Background Art

[0002] Polycarbonate is a high molecular polymer containing carbonate groups in the molecular chain. It has good heat resistance and mechanical properties. It is one of the five major engineering plastics. Polycarbonate engineering plastics are mainly used in the three major fields of glass assembly industry, automobile industry and electronics and electrical industry. In addition, there are industrial machinery parts, optical disks, packaging, office equipment such as computers, medical and health care, films, leisure and protective equipment, building materials, etc. The linear molecular main chain structure of polycarbonate contains benzene rings and ester bonds, which makes it rigid, tough and has good high temperature resistance. However, it also has the problems of high melt viscosity and poor processing performance. In general, polycarbonate has no obvious melting point. The melt viscosity is high within the normal processing temperature range (230-320℃), and the viscosity is less sensitive to shear rate but more sensitive to temperature. In addition, there are problems such as easy hydrolysis at high temperature. Therefore, polycarbonate is a plastic that is difficult to process.

[0003] Polyethylene is the leader among plastics because of its excellent comprehensive performance, abundant raw material sources and low cost, but it also has disadvantages such as low softening point, low strength, difficulty in dyeing, poor atmospheric aging resistance and insufficient barrier properties to hydrocarbon solvents and fuel oil. Low-density polyethylene, also known as high-pressure polyethylene, is the lightest variety of polyethylene resin. It is milky white, tasteless, odorless, non-toxic, and matte waxy particles. It has good softness, extensibility, electrical insulation, transparency, easy processing and certain air permeability.

[0004] The blending and modification of polyethylene and polycarbonate can effectively improve the processing performance of polycarbonate. The introduction of polyethylene segments reduces the melt viscosity of polycarbonate, making it easier to flow and form during processing. At the same time, the addition of polyethylene also improves the melt stability of polycarbonate and reduces the risk of thermal degradation during processing. This allows the modified polycarbonate to show higher efficiency and quality stability in processing technologies such as injection molding and extrusion. At the same time, the heat resistance of polyethylene-modified polycarbonate has been significantly improved. The introduction of polyethylene segments has enhanced the thermal stability of polycarbonate. In a high temperature environment, the modified polycarbonate can maintain high mechanical properties and stability, meeting the application requirements of engineering plastics under high temperature conditions.

[0005] Although the product performance obtained by polyethylene-modified polycarbonate is relatively excellent, the compatibility between polycarbonate and polyethylene is poor and it is easy to delaminate, resulting in a decrease in the performance of the modified product or even waste. At the same time, the product's low-temperature resistance is poor. Summary of the invention

[0006] The purpose of the present invention is to provide a polyethylene modified polycarbonate composite material in view of the problem that the polycarbonate in the prior art has poor processing performance.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a polyethylene modified polycarbonate composite material, characterized in that it is composed of the following components by weight: 59-62 parts of polycarbonate A, 16-18 parts of polycarbonate B, 0.4-0.7 parts of low-density polyethylene, 20-23 parts of polysiloxane-polycarbonate random copolymer, and 0.1-0.4 parts of antioxidant; The polycarbonate A is a polycarbonate having a melt flow rate greater than 15 g / (10 min), and the polycarbonate B is a polycarbonate having a melt flow rate less than 10 g / (10 min); The polyethylene modified polycarbonate composite material is prepared by the following method: polycarbonate A is placed in a No. 1 silo, polycarbonate B, polysiloxane-polycarbonate random copolymer, polyethylene, and antioxidant are mixed evenly in proportion and placed in a No. 2 silo, and the materials in the No. 1 silo and the No. 2 silo are fed into a twin-screw extruder at a uniform speed according to the proportion through a metering scale, and the materials are melt-extruded, cooled, blow-dried, pelletized, and packaged.

[0008] Furthermore, the density of the low-density polyethylene is 0.91-0.92 g / cm3.

[0009] Furthermore, the weight of the polysiloxane block in the polysiloxane-polycarbonate random copolymer accounts for 18-22% of the total weight of the copolymer, and the melt flow rate is 0-15 g / (10 min).

[0010] Furthermore, the antioxidant is a phenolic antioxidant.

[0011] Furthermore, in the preparation method, polycarbonate B, polysiloxane-polycarbonate random copolymer, polyethylene, and antioxidant are mixed evenly in proportion and placed in the No. 2 silo. The mixing is specifically as follows: 50% of polycarbonate B is first added to a high-speed mixer, and then polyethylene, polysiloxane-polycarbonate random copolymer and antioxidant are added in sequence, and finally the remaining 50% of polycarbonate B is added, mixed evenly, and placed in the No. 2 silo.

[0012] The beneficial effects of the present invention are: overcoming the problem of poor compatibility between polycarbonate and polyethylene, enhancing the low-temperature resistance of the composite by adding a polysiloxane-polycarbonate random copolymer, reducing production costs, simplifying the processing process, and ensuring stable product quality. The invention has the advantages of excellent impact resistance, low-temperature resistance, and heat resistance. DETAILED DESCRIPTION

[0013] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. Example 1

[0014] A polyethylene modified polycarbonate composite material is prepared from the following components: Polycarbonate A: melt flow rate is 17 g / (10min), Jiaxing Teijin L-1225Z (100K); Polycarbonate B: melt flow rate 8 g / (10min), Jiaxing Teijin L1225Y; Low-density polyethylene: density 0.91g / cm3, Yanshan Petrochemical; Polysiloxane-polycarbonate random copolymer: melt flow rate is 5 g / (10min), the weight of polysiloxane block accounts for 20% of the total weight of the copolymer, Gansu Yinguang Polysilver Chemical Co., Ltd.; Antioxidant: 1010; The specific proportions of the above components are shown in Table 1.

[0015] The preparation method is specifically as follows: According to the mass in Table 1, 50% of polycarbonate B was first added into the high-speed mixer, followed by polyethylene, polysiloxane-polycarbonate random copolymer and antioxidant, and finally the remaining 50% of polycarbonate B was added. After uniform mixing, the materials were placed in the No. 2 silo; polycarbonate A was placed in the No. 1 silo, and then the materials in the No. 1 silo and the No. 2 silo were uniformly fed into the twin-screw extruder. After the materials were melt-extruded and molded, they were cooled, blow-dried, pelletized, and packaged to obtain polyethylene-modified polycarbonate composite materials.

[0016] The performance of the composite material was analyzed and the results are shown in Table 2.

[0017] Embodiment 2-5: The distribution ratio of each group is shown in Table 1. The preparation method is the same as Example 1. The performance analysis of the composite material is shown in Table 2.

[0018]

[0019] It can be seen from Table 2 that the quality of the modified material is stable, the cantilever beam notch impact strength at -30°C reaches 740J / m and above, the material has excellent impact resistance and low temperature resistance, the heat deformation temperature reaches 122°C and above, and the heat resistance is good.

[0020] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also 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 scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A polyethylene modified polycarbonate composite material, characterized in that: The invention is composed of the following components by weight: 59-62 parts of polycarbonate A, 16-18 parts of polycarbonate B, 0.4-0.7 parts of low-density polyethylene, 20-23 parts of polysiloxane-polycarbonate random copolymer, and 0.1-0.4 parts of antioxidant; The polycarbonate A is a polycarbonate having a melt flow rate greater than 15 g / (10 min), and the polycarbonate B is a polycarbonate having a melt flow rate less than 10 g / (10 min); The polyethylene modified polycarbonate composite material is prepared by the following method: polycarbonate A is placed in a No. 1 silo, polycarbonate B, polysiloxane-polycarbonate random copolymer, polyethylene, and an antioxidant are mixed evenly in proportion and placed in a No. 2 silo, and the materials in the No. 1 silo and the No. 2 silo are fed into a twin-screw extruder at a uniform speed according to the proportion through a metering scale, and the materials are melt-extruded, cooled, blow-dried, pelletized, and packaged.

2. A polyethylene-modified polycarbonate composite material according to claim 1, characterized in that: The density of the low-density polyethylene is 0.91-0.92 g / cm 3 .

3. The polyethylene-modified polycarbonate composite material according to claim 1, characterized in that: The weight of the polysiloxane block in the polysiloxane-polycarbonate random copolymer accounts for 18-22% of the total weight of the copolymer, and the melt flow rate is 0-15 g / (10 min).

4. The polyethylene-modified polycarbonate composite material according to claim 1, characterized in that: The antioxidant is a phenolic antioxidant.

5. The polyethylene-modified polycarbonate composite material according to claim 1, characterized in that: In the preparation method, polycarbonate B, polysiloxane-polycarbonate random copolymer, polyethylene, and antioxidant are mixed evenly in proportion and placed in the No. 2 silo. The mixing is specifically as follows: 50% of polycarbonate B is first added into a high-speed mixer, and then polyethylene, polysiloxane-polycarbonate random copolymer and antioxidant are added in sequence, and finally the remaining 50% of polycarbonate B is added, mixed evenly, and placed in the No. 2 silo.

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