Flame-retardant polypropylene material prepared from storage battery shell reclaimed material and preparation method of flame-retardant polypropylene material

Abstract

The invention discloses a flame-retardant polypropylene material prepared from a storage battery shell reclaimed material and a preparation method of the flame-retardant polypropylene material. The polypropylene composition is composed of the following components by weight: 80-90% of a storage battery case reclaimed material; 5-10% of a toughening agent; 5-10% of expandable graphite; 0.2 to 0.4 percent of an antioxidant; and 0.15-0.3% of a light stabilizer. The material has the mechanical property similar to that of a halogen-free storage battery shell material produced from brand new materials, and the flame retardant property can reach the V0 grade. According to the invention, wastes are recycled, so that environmental pollution is reduced, resource recycling is realized, and great economic benefits and social benefits are achieved.

Description

Technical Field

[0001] The invention relates to the field of polypropylene composite materials, and in particular to a flame-retardant polypropylene material prepared by utilizing recycled materials of storage battery shells and a preparation method thereof. Background Art

[0002] Polypropylene has always been the focus of the automotive industry and the plastics industry because of its advantages such as low density, high strength, high hardness, wear resistance, bending fatigue resistance, high heat resistance, excellent moisture and chemical resistance, easy processing and molding, and low price. The battery pack is the core energy source of new energy vehicles (electric vehicles) and provides driving power for the entire vehicle. Backup energy batteries have also gradually entered everyone's lives. At present, the shells of automotive battery packs and backup energy batteries use a large amount of halogen-free V0 flame-retardant polypropylene materials.

[0003] Polypropylene material is a thermoplastic material that can be repeatedly processed and used because of its excellent thermal stability. However, halogen-free flame retardants will degrade after being reheated. Therefore, if the battery shell recycled material is directly processed in an extruder, its mechanical properties and flame retardant properties will drop significantly and cannot meet the needs of reuse. Expandable graphite can be widely used as sealing materials, adsorbent materials, thermal insulation materials, flame retardant materials and packaging materials due to its light weight, high flexibility, high specific surface area, high porosity and strong adsorption capacity. In the present invention, expandable graphite is blended and extruded with battery shell recycled material in a certain proportion through an extruder. Due to the synergistic effect of expandable graphite and halogen-free flame retardant, the flame retardant property of the prepared composite material can reach a stable V0 level. In addition, this patent adds a toughening agent to the composite material to offset the influence of expandable graphite on the impact performance of the composite material. Summary of the invention

[0004] The invention discloses a flame-retardant polypropylene material prepared by utilizing recycled materials of battery shells and a preparation method thereof, which can replace the halogen-free V0 grade polypropylene material produced by virgin materials and can be used in products such as battery shells of new energy vehicles and backup energy shells.

[0005] A flame retardant polypropylene material prepared from recycled battery shell material and a preparation method thereof, characterized in that the material is composed of the following components in percentage by weight: Battery shell recycled materials 80%~90%; Toughening agent 5%~10%; Expandable graphite 5%~10%; Antioxidant 0.2%~0.4%; Light stabilizer 0.15%~0.4%; The method comprises the following steps: The battery shell recycled material, toughening agent, expandable graphite, antioxidant, light stabilizer and colorant are mixed to obtain a mixture, and then the mixture is added to a twin-screw extruder from a main feeding port for melt blending, and extruded and granulated by the twin-screw extruder to obtain a material whose mechanical properties and flame retardant properties are similar to those of the battery shell material produced from new materials.

[0006] The battery shell recycled material is sourced from waste halogen-free V0-grade battery shells, which are directly used after being cleaned and crushed.

[0007] The expandable graphite has an expansion ratio of 100-400 times, and is preferably a product produced by Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd., with a specification of DL100 and an expansion ratio of 100-200.

[0008] The toughening agent is selected from polyethylene octene copolymer elastomer.

[0009] The antioxidant comprises a primary antioxidant and a secondary antioxidant, wherein the primary antioxidant is one or a combination of hindered phenol or thioester antioxidants, and the secondary antioxidant is one or a combination of phosphite or ester antioxidants.

[0010] The light stabilizer is a hindered amine light stabilizer.

[0011] A method for preparing a flame-retardant polypropylene material using recycled battery shell material, characterized in that it comprises the following steps: The battery shell recycled material, toughening agent, expandable graphite, antioxidant and light stabilizer are added into a mixer and mixed, and then put into a twin-screw extruder. The twin-screw extrusion granulation temperature is 170-220 degrees Celsius. The high-toughness V0 grade flame-retardant polypropylene composite material for battery shell is obtained by extrusion granulation.

[0012] The flame-retardant polypropylene material prepared from recycled battery shell materials can be used in various battery shell fields.

[0013] Compared with the prior art, the present invention has the following advantages: With the widespread popularity of new energy vehicles, the recycling of waste batteries will become an unavoidable environmental issue. The present invention uses waste battery shells as the main raw material, adds expandable graphite to enhance the flame retardant properties of battery recycled materials, and adds a toughening agent to improve the toughness of battery shell recycled materials. Thus, a material with mechanical properties and flame retardant properties equivalent to those of battery materials produced from new materials is obtained, which has significant social and economic benefits.

[0014] The invention discloses a flame retardant polypropylene material prepared by utilizing recycled materials of storage battery shells and a preparation method thereof, which has simple equipment, is easy to implement and operate, is easy to industrialize and has broad application prospects. DETAILED DESCRIPTION

[0015] The recycled material of battery shell is a homemade product; the toughening agent is model 8200 produced by Dow; the expandable graphite is a product produced by Qingdao Yanhai Company (expansion ratio 100-200) and Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd. (DL50, expansion ratio 200-350 and DL100, expansion ratio 100-200); the light stabilizer is 5590 produced by Yantai Xinxiu Chemical Co., Ltd.; the antioxidant 1010 is a product produced by BASF of Germany; the antioxidant 168 is also a product produced by BASF of Germany, and the extrusion temperature of the twin-screw extruder is 180~200 degrees Celsius.

[0016] Example 1

[0017] 90 parts by weight of battery shell recycled material, 5 parts by weight of expandable graphite, 5 parts by weight of toughening agent 8200, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, and 0.15 parts by weight of light stabilizer 5590 were added to a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added to a twin-screw extruder at the main feeding port. Polypropylene composite material was obtained by extrusion granulation. Expandable graphite is a product produced by Qingdao Yanhai Company, with an expansion ratio of 100-200.

[0018] Example 2

[0019] 90 parts by weight of battery shell recycled material, 5 parts by weight of expandable graphite, 5 parts by weight of toughening agent 8200, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, and 0.15 parts by weight of light stabilizer 5590 were added to a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added to a twin-screw extruder at the main feeding port. Polypropylene composite material was obtained by extrusion granulation. Expandable graphite is a product produced by Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd., with a specification of DL100 and an expansion ratio of 100-200.

[0020] Example 3

[0021] 90 parts by weight of battery shell recycled material, 5 parts by weight of expandable graphite, 5 parts by weight of toughening agent 8200, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, and 0.15 parts by weight of light stabilizer 5590 were added to a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added to a twin-screw extruder at the main feeding port. Polypropylene composite material was obtained by extrusion granulation. Expandable graphite is a product produced by Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd., with a specification of DL50 and an expansion ratio of 200-350.

[0022] Example 4

[0023] 80 parts by weight of battery shell recycled material, 10 parts by weight of halogen-free flame retardant, 10 parts by weight of toughening agent 8200, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.15 parts by weight of light stabilizer 5590, and 0.5 parts by weight of carbon black were added into a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added into a twin-screw extruder at the main feeding port. The polypropylene composite material was obtained by extrusion granulation.

[0024] Comparative Example 1 99 parts by weight of battery shell recycled material, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.1 parts by weight of light stabilizer 5590, and 1 part by weight of carbon black were added into a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added into a twin-screw extruder at the main feeding port, and extruded and granulated to obtain a polypropylene composite material.

[0025] Comparative Example 2 94 parts by weight of battery shell recycled material, 5 parts by weight of expandable graphite, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.1 parts by weight of light stabilizer 5589, and 1 part by weight of carbon black were added to a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added to a twin-screw extruder at the main feeding port. The polypropylene composite material was obtained by extrusion granulation. The expandable graphite is a product produced by Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd., with a specification of DL100 and an expansion ratio of 100-200.

[0026] Comparative Example 3 94 parts by weight of battery shell recycled material, 10 parts by weight of expandable graphite, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.1 parts by weight of light stabilizer 5589, and 1 part by weight of carbon black were added to a high-speed mixer with a rotation speed of about 1000 rpm and mixed for 5 minutes, and then the mixture was added to a twin-screw extruder at the main feeding port. The polypropylene composite material was obtained by extrusion granulation. The expandable graphite is a product produced by Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd., with a specification of DL100 and an expansion ratio of 100-200.

[0027] Table 1 Mechanical and flame retardant properties of the examples and comparative examples Test indicators Test Standards unit Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 New materials for battery shell Tensile Strength ISO527 / 2-93 MPa 16.1 16.8 15.6 15.6 16.8 17.2 17.6 16.8 Flexural modulus ISO178-93 MPa 1480 1520 1430 1420 1520 1560 1590 1500 Notched impact strength ISO 180:2000 kJ / m2 9.4 9.5 9.0 9.3 8.6 6.6 6.2 9.2 Vertical burning 1.6mm UL94 / V0 V0 V0 V0 V1 V0 V0 V0 By analyzing the above examples and comparative data, it is not difficult to find that the flame retardant properties of the composite materials of Examples 1 to 4 produced using the formula and processing method of the present invention can reach V0 level, and the notched impact strength reaches 9 kJ / m2 or more. The performance is equivalent to or better than that of the new material battery shell material, and can meet the needs of battery shell products. Comparative Example 1 directly granulates the battery shell recycled material in the extruder. The flame retardant properties of the obtained material are reduced from V0 level to V1 level due to the degradation of the flame retardant, which cannot meet the flame retardant performance requirements of the battery shell material. Comparative Example 2 and Comparative Example 3 extrude and blend expandable graphite with the battery shell recycled material. Due to the synergistic effect of expandable graphite and halogen-free flame retardant, the flame retardant properties of the obtained composite material can meet the V0 level again. However, due to the filling of expandable graphite, its impact strength has a significant decrease, and the toughness cannot meet the requirements of the battery shell material. Therefore, the formula and processing method of the invention of this patent can be used to prepare a V0-level glass fiber flame-retardant polypropylene material with performance close to or exceeding that of new materials.

Claims

1. A flame-retardant polypropylene material prepared from recycled battery shell material, characterized in that: The following weight percentages of components composition: Battery shell recycled materials 80%~90%; Toughening agent 5%~10%; Expandable graphite 5%~10%; Antioxidant 0.2%~0.4%; Light stabilizer 0.15%~0.3%.

2. The flame retardant polypropylene material prepared from recycled battery shell material according to claim 1, characterized in that The battery shell recycled material is sourced from waste halogen-free V0-grade battery shells, which are directly used after being cleaned and crushed.

3. The flame-retardant polypropylene material prepared from recycled battery shell material according to claim 1, characterized in that: The toughening agent is selected from polyethylene octene copolymer elastomer.

4. The flame retardant polypropylene material prepared from recycled battery shell material according to claim 1, characterized in that The expandable graphite has an expansion ratio of 100-400 times, and is preferably a product produced by Heilongjiang Dongfang Juneng Graphite Technology Co., Ltd., with a specification of DL100 and an expansion ratio of 100-200.

5. The flame retardant polypropylene material prepared from recycled battery shell material according to claim 1, characterized in that The antioxidant comprises a primary antioxidant and a secondary antioxidant, wherein the primary antioxidant is one or a combination of hindered phenol or thioester antioxidants, and the secondary antioxidant is one or a combination of phosphite or ester antioxidants.

6. The flame retardant polypropylene material prepared from recycled battery shell material according to claim 1, characterized in that The light stabilizer is a hindered amine light stabilizer.

7. A method for preparing a flame-retardant polypropylene material using recycled battery shell material according to claims 1 to 7, characterized in that: The following steps are involved: The battery shell recycled material, toughening agent, expandable graphite, antioxidant and light stabilizer are added into a mixer for mixing, and then put into a twin-screw extruder for extrusion and granulation to obtain a flame-retardant polypropylene material.

8. A flame-retardant polypropylene material prepared from recycled battery shell materials according to claims 1 to 7 is used in various battery shell fields.