Recycled ABS (Acrylonitrile Butadiene Styrene) material and preparation method thereof

Abstract

The invention provides a recycled ABS (Acrylonitrile Butadiene Styrene) material and a preparation method thereof, and belongs to the field of waste plastic recycling. According to the recycled ABS material provided by the invention, common waste ABS plastic is taken as a raw material and is subjected to melt blending with the anhydride compound and the polybutadiene-g-styrene acrylonitrile grafted copolymer, the raw material is easy to obtain and relatively low in cost, and the problems of plastic garbage recycling and carbon emission can be solved. The mechanical property of the recycled ABS material provided by the invention is close to that of new ABS plastic, and the profit is high. In addition, the preparation method provided by the invention is simple to operate, low in equipment investment, low in asset investment, high in product added value and suitable for industrial production, and equipment required by extrusion processing and granulation of common polymers is the same as equipment required by extrusion processing and granulation of common polymers.

Description

Technical Field

[0001] The invention belongs to the field of recycling of waste plastics, and in particular relates to a recycled ABS material and a preparation method thereof. Background Art

[0002] China has entered the peak period of household appliances use, and the corresponding number of waste household appliances has increased significantly compared with previous years. It has been reported that more than 30 million household appliances are discarded each year, and each computer uses about 3kg of plastic, a TV uses 4kg of plastic, a refrigerator uses 10kg of plastic, and a mobile phone uses 100g of plastic. It is roughly estimated that up to 10 million tons of waste plastic are generated each year. Such a large amount of waste plastic has brought great harm to our living environment and physical and mental health, so the recycling of waste plastics has attracted widespread attention from the academic community.

[0003] Such a huge number of waste electrical plastics, not to mention high-quality engineering plastics such as ABS and HIPS used in electrical appliances such as refrigerators and televisions, if the waste materials recovered from scrap yards can be utilized to produce resins with performance comparable to that of new materials, the recycling rate of waste electrical plastics can be increased and its high-value recycling and reuse can be achieved. This will be a major step forward in the development of human civilization.

[0004] The prior art discloses a variety of ABS recycled material recycling and modification technologies. For example, Chinese patent document No. 201610541118.4 discloses a method for modifying waste ABS materials. The processing process is also extrusion processing. Two compounds, bisoxazoline and acid anhydride, are added to the modified formula of waste ABS materials. Although the modified ABS material has good mechanical properties, there is still room for improvement. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a recycled ABS material and a preparation method thereof. The mechanical properties of the material obtained by the present invention are very excellent.

[0006] According to one aspect of the present invention, there is provided a recycled ABS material, which is made by melt blending raw materials, wherein the raw materials contain 100 parts by mass of recycled ABS material, 0.1 to 1.5 parts of anhydride compounds, and 5 to 30 parts of polybutadiene-g-styrene acrylonitrile graft copolymer.

[0007] Optionally, the raw materials contain, by mass, 100 parts of recycled ABS material, 0.5 to 1 part of anhydride compound, and 10 to 20 parts of polybutadiene-g-styrene acrylonitrile graft copolymer.

[0008] Optionally, the acid anhydride compound is selected from at least one of maleic anhydride, pyromellitic dianhydride or nadic anhydride.

[0009] Optionally, the styrene acrylonitrile grafting rate of the polybutadiene-g-styrene acrylonitrile graft copolymer is 20 mol% to 80 mol%.

[0010] The present invention prepares recycled ABS material with excellent mechanical properties by melt blending recycled ABS material, anhydride compound and polybutadiene-g-styrene acrylonitrile graft copolymer, so that the ABS recycled material has a wider range of applications. Taking the general recycled ABS material as an example, the tensile strength of ABS before melt blending is less than 35MPa, the flexural strength is less than 56Mpa, and the notched impact strength is less than 5.7kJ / m 2 The tensile strength of the recycled ABS material obtained by melt blending and modification is ≥60MPa, the bending strength is ≥70MPa, and the impact strength is ≥15.0kJ / m 2 .

[0011] In the present invention, the tensile strength is tested according to the standard test method GB / T1040-92; the flexural strength is tested according to the standard test method GB / T 9341-2000; and the notched impact strength is tested according to the standard test method GB1843-80.

[0012] According to another aspect of the present invention, a method for preparing recycled ABS material is provided, the method comprising the following steps:

[0013] a) subjecting a mixture I containing recycled ABS material and anhydride compound to melt blending I and forming and curing I to obtain an intermediate;

[0014] b) melt blending II, molding and curing II of a mixture II containing the intermediate and the polybutadiene-g-styrene acrylonitrile graft copolymer.

[0015] Optionally, the ratio of the recycled ABS material to the anhydride compound and the polybutadiene-g-styrene acrylonitrile graft copolymer is 100:0.1-1.5:5-30 in parts by mass.

[0016] Optionally, the acid anhydride compound is selected from at least one of maleic anhydride, pyromellitic dianhydride or nadic anhydride.

[0017] Optionally, the styrene acrylonitrile grafting rate of the polybutadiene-g-styrene acrylonitrile graft copolymer is 20 mol% to 80 mol%.

[0018] Optionally, the temperature of the melt blending I is 200-220°C.

[0019] Optionally, the intermediate obtained is dried at 70-90° C. for 8-12 hours.

[0020] Optionally, the temperature of the melt blending II is 210-230°C.

[0021] Optionally, in step a), the recycled ABS material is crushed and sieved to obtain flakes, and the maximum size of the flakes does not exceed 10 mm.

[0022] Optionally, the obtained flake material is dried at 70-90° C. for 8-12 hours.

[0023] According to another aspect of the present invention, there is provided a recycled ABS material prepared by the above preparation method.

[0024] Optionally, the recycled ABS material has a tensile strength of ≥60 MPa, and / or a flexural strength of ≥70 MPa, and / or an impact strength of ≥15.0 kJ / m 2 .

[0025] The present invention includes the following beneficial effects:

[0026] The present invention uses generally discarded ABS plastic as raw material, and adopts a melt blending processing method to melt blend the recycled ABS plastic with anhydride compounds and polybutadiene-g-styrene acrylonitrile graft copolymer. The raw materials are easy to obtain and the cost is low, which can help solve the problems of plastic waste recycling and carbon emissions. The mechanical properties of the recycled ABS material obtained by the present invention are close to those of new ABS plastic, with a tensile strength of ≥60MPa, a flexural strength of ≥70MPa, and an impact strength of ≥15.0kJ / m 2 The tensile strength is increased by at least 71.4%, the flexural strength is increased by at least 25.0%, the impact strength is increased by at least 163.2%, and the mechanical properties are greatly improved. The processing method of the present invention is simple to operate, and has the same equipment required for general polymer extrusion processing and granulation, with small asset investment, suitable for large-scale industrial production, and excellent product performance and high added value. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below by way of examples, which are merely illustrative and are not intended to limit the scope of application of the present invention. The raw materials or components used in the present invention can be obtained by commercial routes or conventional methods unless otherwise specified.

[0028] The recycled ABS material provided by the invention is prepared by melt-blending recycled ABS plastic, anhydride compounds and polybutadiene-g-styrene acrylonitrile graft copolymer.

[0029] The recycled ABS material used in the present invention can be directly recycled from ABS plastic products.

[0030] In an embodiment of the present invention, the tensile strength of the recycled ABS material is lower than 35 MPa.

[0031] In an embodiment of the present invention, the flexural strength of the recycled ABS material is lower than 56 MPa.

[0032] In the embodiment of the present invention, the notched impact strength of the recycled ABS material is lower than 5.7 kJ / m 2 .

[0033] In the present invention, the acid anhydride compound is a mixture of one or more of maleic anhydride, pyromellitic dianhydride, and nadic anhydride in any proportion. The polybutadiene-g-styrene acrylonitrile graft copolymer is a mixture of one or more of polybutadiene-g-styrene acrylonitrile graft copolymers with a styrene acrylonitrile grafting rate of 20 mol% to 80 mol% in any proportion. In the raw materials, by mass, the recycled ABS material is 100 parts; the acid anhydride compound is 0.1 to 1.5 parts, preferably 0.5 to 1 part; the polybutadiene-g-styrene acrylonitrile graft copolymer is 5 to 30 parts, preferably 10 to 20 parts.

[0034] The recycled ABS plastic provided by the present invention has a tensile strength of ≥60MPa, a bending strength of ≥70MPa, and an impact strength of ≥15.0kJ / m 2 The tensile strength is increased by at least 71.4%, the flexural strength is increased by at least 25.0%, and the impact strength is increased by at least 163.2%, and the mechanical properties are good.

[0035] The specific process of preparing the recycled ABS material provided by the present invention is:

[0036] a) recovering ABS material and melt-blending it with anhydride compound to obtain an intermediate;

[0037] b) The intermediate is melt-blended with a polybutadiene-g-styrene acrylonitrile graft copolymer to obtain a recycled ABS material.

[0038] In the above technical solution, the recycled ABS material needs to be crushed before step a), and the recycled ABS material is crushed by a crusher and filtered by a screen to obtain fine flakes, and the maximum size of the flakes does not exceed 10 mm.

[0039] Preferably, the flaky recovered ABS material after crushing and filtration is dried in a forced air oven at 70 to 90° C. for 8 to 12 hours.

[0040] In the above technical solution, the temperature of the melt blending in step a) is 200-220°C. The present invention does not particularly limit the equipment used for the melt blending, and a twin-screw extruder is preferably used. In the present invention, the temperature of each section of the twin-screw extruder from the hopper to the die during the melt blending process is preferably 200°C, 205°C, 210°C, 215°C, 220°C, 215°C, 210°C, and 210°C, respectively.

[0041] After the melt blending in step a) is completed, the melt is cooled and granulated in sequence to obtain an intermediate ABS material.

[0042] Preferably, the intermediate ABS material is dried in a forced air oven at 70-90° C. for 8-12 hours.

[0043] In the above technical solution, the temperature of the melt blending in step b) is 210-230°C. The present invention does not particularly limit the equipment used for the melt blending, and a twin-screw extruder is preferably used. In the present invention, the temperatures of the twin-screw extruder from the hopper to the die during the melt blending are preferably 210°C, 215°C, 220°C, 225°C, 230°C, 225°C, 220°C, and 215°C, respectively.

[0044] After the melt blending in step b) is completed, the melt is cooled and granulated in sequence to obtain the final recycled ABS material.

[0045] The processing method provided by the invention can obtain recycled ABS material with excellent mechanical properties, so that waste ABS plastics can be effectively recycled, the impact on the environment can be reduced, and good economic and social benefits can be brought about.

[0046] In the embodiment of the present invention, the twin-screw extruder used is a KET-36A extruder produced by Kolter Company.

[0047] In the embodiment of the present invention, the recycled ABS material comes from Dongguan Xinyixin Plastic Co., Ltd.;

[0048] The polybutadiene-g-styrene acrylonitrile graft copolymers with styrene acrylonitrile grafting ratios of 30 mol % and 60 mol % were prepared by conventional methods;

[0049] Maleic anhydride and nadic anhydride were both from Maclean.

[0050] Example 1

[0051] (1) The flakes with a maximum size of no more than 10 mm obtained after crushing the recycled ABS material are placed in a forced air drying oven and dried at 80° C. for 8 h.

[0052] (2) After 1000 g of the recycled ABS flake material and 5 g of maleic anhydride were mixed evenly, the mixture was added to a twin-screw extruder for melt blending. The temperatures of the twin-screw extruder from the hopper to the die were set to 200° C., 205° C., 210° C., 215° C., 220° C., 215° C., 210° C., and 210° C. After the melt blending was completed, the mixture was cooled and granulated to obtain an intermediate ABS material modified by anhydride compounds.

[0053] (3) The intermediate ABS material was placed in a forced air oven at 80° C. and dried for 8 h.

[0054] (4) The dried intermediate ABS material and 50 g of a polybutadiene-g-styrene acrylonitrile graft copolymer having a styrene acrylonitrile grafting ratio of 60 mol% were mixed uniformly, and then added to a twin-screw extruder for melt blending. The temperatures of the twin-screw extruder from the hopper to the die were set at 210° C., 215° C., 220° C., 225° C., 230° C., 225° C., 220° C., and 215° C., respectively. After the melt blending was completed, the material was cooled and granulated to obtain a recyclable ABS material.

[0055] Example 2

[0056] (1) The flakes with a maximum size of no more than 10 mm obtained after crushing the recycled ABS plastic are placed in a forced air drying oven and dried at 80° C. for 8 h.

[0057] (2) After 1000 g of the recycled ABS flake material and 10 g of maleic anhydride were mixed evenly, the mixture was added to a twin-screw extruder for melt blending, and the temperatures of the sections from the hopper to the die of the twin-screw extruder were set to 200° C., 205° C., 210° C., 215° C., 220° C., 215° C., 210° C., and 210° C., respectively. After the melt blending was completed, the mixture was cooled and granulated to obtain an intermediate ABS material modified by anhydride compounds.

[0058] (3) The intermediate ABS material was placed in a forced air oven at 80° C. and dried for 8 h.

[0059] (4) The dried intermediate ABS material and 100 g of a polybutadiene-g-styrene acrylonitrile graft copolymer having a styrene acrylonitrile grafting ratio of 60 mol% were mixed uniformly, and then added to a twin-screw extruder for melt blending. The temperatures of the twin-screw extruder from the hopper to the die were set at 210° C., 215° C., 220° C., 225° C., 230° C., 225° C., 220° C., and 215° C., respectively. After the melt blending was completed, the material was cooled and granulated to obtain a recyclable ABS material.

[0060] Example 3

[0061] (1) The flakes with a maximum size of no more than 10 mm obtained after crushing the recycled ABS plastic are placed in a forced air drying oven and dried at 80° C. for 8 h.

[0062] (2) After 1000 g of the flake material of the recycled ABS material and 5 g of nadic anhydride were mixed evenly, the mixture was added to a twin-screw extruder for melt blending, and the temperatures of the sections from the hopper to the die of the twin-screw extruder were respectively set to 200° C., 205° C., 210° C., 215° C., 220° C., 215° C., 210° C., and 210° C. After the melt blending was completed, the mixture was cooled and granulated to obtain an intermediate ABS material modified by anhydride compounds.

[0063] (3) The intermediate ABS material was placed in a forced air oven at 80° C. and dried for 8 h.

[0064] (4) The dried intermediate ABS material and 100 g of a polybutadiene-g-styrene acrylonitrile graft copolymer having a styrene acrylonitrile grafting ratio of 30 mol% were mixed uniformly, and then added to a twin-screw extruder for melt blending. The temperatures of the twin-screw extruder from the hopper to the die were set at 210° C., 215° C., 220° C., 225° C., 230° C., 225° C., 220° C., and 215° C., respectively. After the melt blending was completed, the material was cooled and granulated to obtain a recyclable ABS material.

[0065] Example 4

[0066] (1) The flakes with a maximum size of no more than 10 mm obtained after crushing the recycled ABS plastic are placed in a forced air drying oven and dried at 80° C. for 8 h.

[0067] (2) After 1000 g of the flake material of the recycled ABS material and 10 g of nadic anhydride were mixed uniformly, the mixture was added to a twin-screw extruder for melt blending, and the temperatures of the sections from the hopper to the die of the twin-screw extruder were respectively set to 200° C., 205° C., 210° C., 215° C., 220° C., 215° C., 210° C., and 210° C. After the melt blending was completed, the mixture was cooled and granulated to obtain an intermediate ABS material modified by anhydride compounds.

[0068] (3) The intermediate ABS material was placed in a forced air oven at 80° C. and dried for 8 h.

[0069] (4) The dried intermediate ABS material and 100 g of a polybutadiene-g-styrene acrylonitrile graft copolymer having a styrene acrylonitrile grafting ratio of 60 mol% were mixed uniformly, and then added to a twin-screw extruder for melt blending. The temperatures of the twin-screw extruder from the hopper to the die were set at 210° C., 215° C., 220° C., 225° C., 230° C., 225° C., 220° C., and 215° C., respectively. After the melt blending was completed, the material was cooled and granulated to obtain a recyclable ABS material.

[0070] Comparative Example 1

[0071] The preparation of the recycled ABS material is similar to that in Example 2, except that maleic anhydride is not added to the formulation.

[0072] Comparative Example 2

[0073] The preparation of the recycled ABS material is similar to that in Example 4, except that the polybutadiene-g-styrene acrylonitrile graft copolymer is not added to the formula.

[0074] The tensile strength, flexural strength and notched impact strength of the recycled ABS materials obtained in Example 1, Example 2, Example 3 and Example 4 and Comparative Examples 1 and 2 were tested. The tensile strength was tested according to the standard test method GB / T1040-92; the flexural strength was tested according to the standard test method GB / T 9341-2000; and the notched impact strength was tested according to the standard test method GB1843-80.

[0075] The test results are shown in Table 1.

[0076] Table 1 Mechanical properties test results of recycled modified ABS materials

[0077]

[0078] It can be seen from Table 1 that the mechanical properties of the recycled ABS material provided by the present invention are significantly better than those of the recycled ABS material.

[0079] Any numerical value mentioned in the present invention, if there is only an interval of two units between any minimum value and any maximum value, includes all values ​​from the minimum value to the maximum value each time increasing by one unit. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, time, etc. is declared to be 50-90, in this specification it means that 51-89, 52-88... and 69-71 and 70-71 are specifically listed. For non-integer values, 0.1, 0.01, 0.001 or 0.0001 can be appropriately considered as a unit. These are just some specially specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0080] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for recycling ABS material, characterized in that: The invention is prepared by melt blending raw materials, wherein the raw materials contain 100 parts of recycled ABS materials, 0.1 to 1.5 parts of anhydride compounds and 5 to 30 parts of polybutadiene-g-styrene acrylonitrile graft copolymer by weight.

2. The recycled ABS material according to claim 1, characterized in that: The acid anhydride compound is selected from at least one of maleic anhydride, pyromellitic dianhydride or nadic anhydride; And / or, the styrene acrylonitrile grafting rate of the polybutadiene-g-styrene acrylonitrile graft copolymer is 20 mol% to 80 mol%.

3. The recycled ABS material according to claim 1 or 2, characterized in that: The recycled ABS material has a tensile strength of ≥60 MPa, and / or a flexural strength of ≥70 MPa, and / or an impact strength of ≥15.0 kJ / m 2 .

4. A method for preparing ABS material for recycling and reuse, characterized in that: The preparation method comprises the following steps: a) subjecting a mixture I containing recycled ABS material and anhydride compound to melt blending I and forming and curing I to obtain an intermediate; b) melt blending II, molding and curing II of a mixture II containing the intermediate and the polybutadiene-g-styrene acrylonitrile graft copolymer.

5. The preparation method according to claim 4, characterized in that: Calculated by weight, the ratio of the recycled ABS material to the anhydride compound and the polybutadiene-g-styrene acrylonitrile graft copolymer is 100:0.1-1.5:5-30.

6. The preparation method according to claim 4 or 5, characterized in that: The acid anhydride compound is selected from at least one of maleic anhydride, pyromellitic dianhydride or nadic anhydride; And / or, the styrene acrylonitrile grafting rate of the polybutadiene-g-styrene acrylonitrile graft copolymer is 20 mol% to 80 mol%.

7. The preparation method according to any one of claims 4 to 6, characterized in that: The temperature of the melt blending I is 200-220° C.; And / or, the temperature of the melt blending II is 210-230°C.

8. The preparation method according to any one of claims 4 to 7, characterized in that: In the step a), the recycled ABS material is crushed and sieved to obtain flakes, and the maximum size of the flakes does not exceed 10 mm.

9. A recycled ABS material obtained by the preparation method according to any one of claims 4 to 8.

10. The recycled ABS material according to claim 9, characterized in that: The recycled ABS material has a tensile strength of ≥60 MPa, and / or a flexural strength of ≥70 MPa, and / or an impact strength of ≥15.0 kJ / m 2 .

Images