A flame-retardant ABS composite material and its preparation method and application

Abstract

The present invention discloses a flame-retardant ABS composite material comprising the following components, by weight: 67-80 parts ABS resin, 3-6 parts low-molecular-weight SAN resin, 13-16 parts brominated flame retardant, 3-5 parts antimony trioxide, 1-2 parts ester additive, and 1-2 parts PLA resin. The present invention utilizes the ester additive to reduce friction between ABS molecules, improve lubricity between ABS molecules, and enhance internal lubricity. The synergistic effect of the three enhances the weld mark tensile strength of the flame-retardant ABS while maintaining excellent mechanical toughness and overall performance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a flame-retardant ABS composite material and a preparation method and application thereof. Background Art

[0002] ABS resin boasts excellent low-temperature resistance, impact resistance, chemical resistance, heat resistance, dimensional stability, surface gloss, and low mold shrinkage, making it widely used in a wide range of applications, including home appliances, electronic products, office equipment, industrial parts, and the automotive industry. However, ABS resin is a flammable material. Before it can be recommended for use in home appliances, electronic products, and other fields, its flammability must comply with the relevant provisions of the US safety laboratory standard UL-94; therefore, flame-retardant modification of ABS resin is particularly important. However, the addition of brominated and antimony-based flame retardants to impart flame retardancy to ABS resin not only significantly reduces its physical and mechanical properties, particularly its toughness and heat resistance, but also hinders its widespread application in large-scale and thin-walled parts. This is because large, thin-walled parts often have multiple glue inlets, resulting in weld marks, necessitating the improvement of the material's weld mark tensile strength.

[0003] To address the shortcomings of flame-retardant modified ABS resin, such as poor weld mark tensile strength, three approaches are commonly used: 1. Using high melt flow rate ABS resin; 2. Using chlorinated polyethylene to replace ABS high-rubber powder; 3. Adding a high proportion of small molecule amide lubricants and other technical means. Overall, the first approach has low impact resistance and poor overall performance; the second approach uses chlorinated polyethylene, which has poor heat resistance and a narrow processing window, and easily decomposes and produces yellow streaks when exposed to strong shear molds; and the third approach has lubricant precipitation, which affects the material's heat resistance and is not conducive to mass production applications. Therefore, while maintaining the flame retardancy and impact resistance of ABS resin, the use of composite modification technology to significantly improve its weld mark tensile strength has led to the development of flame-retardant ABS composite materials with broad application prospects, especially in the home appliance industry, such as LCD displays, which require large sizes and thin walls. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies or defects of the prior art, the present invention provides a flame-retardant ABS composite material and a preparation method and application thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] A flame retardant ABS composite material, comprising the following components in parts by weight:

[0007]

[0008] The low molecular weight SAN resin has a weight average molecular weight of 33,000 to 43,000 g / mol, and the test standard for weight average molecular weight is GB / T 21863-2008;

[0009] The PLA resin has a melt flow rate of 5 to 15 g / 10 min, preferably 6 to 10 g / 10 min, at 210° C. and 2.16 kg. The melt flow rate is determined according to ASTM D1238.

[0010] The ester auxiliary agent is a phosphate ester.

[0011] In the technical solution of the present invention, a low molecular weight SAN resin is selected, which can not only enhance the rigidity of the ABS resin composition, but also promote the movement of the ABS resin polymer molecular chains under processing temperature conditions, playing a significant external lubricating role. Secondly, the present invention also selects an ester auxiliary agent with a special structure, which can improve the internal lubricity between ABS molecules and improve the dispersion uniformity between the flame retardant and the ABS resin, which can not only improve the weld mark tensile strength of the material system, but also improve the flame retardant properties of the material. In addition, the present invention also adds polylactic acid, which can improve the wettability of the blend and, by utilizing the high mechanical strength of polylactic acid, make up for the defect of insufficient mechanical strength of ABS resin. The ester auxiliary agent of the present invention can improve the lubricity within the molecule, and the polylactic acid and low molecular weight SAN resin can improve the lubricity between molecules. The synergistic use of the three can make the flame retardant ABS resin have very excellent weld mark strength, and the thermal stability will not be greatly reduced.

[0012] As a preferred embodiment, the butadiene content of the ABS resin is 18-35 wt %, and the melt index of the ABS resin is 12-28 g / 10 min at a temperature of 220° C. and a load of 10 kg. The melt index of the ABS resin is tested in accordance with ISO 1133-2005.

[0013] As a preferred embodiment, the ester auxiliary agent is one or more of bisphenol A bis(diphenyl phosphate), polyaryl phosphate, resorcinol bis(diphenyl phosphate) and triphenyl phosphate.

[0014] The ester additive is a preferred solution, wherein the melting point of the ester additive is 45-50°C and the density is 1.90-1.22 g / cm 3 .

[0015] The ester additives can improve the processing and molding properties of the product of the present invention.

[0016] As a preferred embodiment, the weight ratio of low molecular weight SAN resin: ester additive: polylactic acid is (2-4): (1-2): 1, more preferably 3:1:1.

[0017] After a large number of tests, the present invention determined that the specific ratio of low molecular weight SAN resin, ester additives, and polylactic acid compounding can make the ABS composite material of the present invention have the advantages of high weld line tensile strength and good thermal stability.

[0018] As a preferred embodiment, the brominated flame retardant is at least one of tetrabromobisphenol A, blocked brominated epoxy resin, brominated triazine, decabromodiphenylethane, brominated polystyrene, and octabromoether.

[0019] As a preferred solution, the D50 particle size of the antimony trioxide is 0.4-1 μm, and the cubic crystal form is greater than 95%.

[0020] As a preferred embodiment, the present invention further comprises the following components in parts by weight:

[0021] Processing aid 0-2 parts;

[0022] The processing aid is selected from at least one of a lubricant, an anti-drip agent, and an antioxidant. Preferably, the lubricant is an amide lubricant, the anti-drip agent is a polytetrafluoroethylene anti-drip agent, and the antioxidant is a hindered phenol antioxidant.

[0023] In the ABS composite material of the present invention, the content of ABS resin is not less than 60wt%.

[0024] The present invention also provides a method for preparing the flame-retardant ABS composite material, comprising the following steps:

[0025] S1: Weigh each component according to the ratio, and pre-mix the components to obtain a premix;

[0026] S2: putting the premix of step S1 into an extruder, performing melt blending and extrusion granulation to obtain the flame retardant ABS composite material.

[0027] More specifically, the preparation process of the flame-retardant ABS composite material of the present invention comprises the following steps:

[0028] (1) ABS resin, low molecular weight SAN resin, brominated flame retardant, antimony trioxide, ester additive and PLA resin are mixed uniformly in a mixer;

[0029] (2) The mixture obtained in step (1) is melted, mixed and extruded through a twin-screw extruder, granulated and dried to obtain the flame-retardant ABS composite material.

[0030] Preferably, the mixer in step (1) is a high-speed mixer with a rotation speed of 900-1100 r / min and a mixing time of 2 to 5 minutes.

[0031] Preferably, the temperature of the twin-screw extruder barrel in step (2) is controlled between 190 and 210° C., the aspect ratio of the twin-screw extruder is 40:1, and the screw speed is 350 to 450 rpm.

[0032] The flame-retardant ABS composite material of the present invention can also be used in the fields of household appliances and film and television equipment, especially in the household appliance industry such as LCD displays with large size and thin wall requirements.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention uses ABS, low molecular weight SAN, ester additives, and polylactic acid for blending and modification. The low molecular weight SAN resin and polylactic acid improve the intermolecular lubricity of the blend and enhance the external lubricity. In addition, the present invention uses the ester additive to reduce the friction between ABS molecules, improve the intermolecular lubricity of ABS, and enhance the internal lubricity. Under the synergistic effect of the three, the weld mark tensile strength of the flame-retardant ABS is enhanced while maintaining excellent mechanical toughness and comprehensive performance. DETAILED DESCRIPTION

[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0036] <Preparation of Examples and Comparative Examples>

[0037] The raw materials used in the examples and comparative examples of the present invention are all commercially available, but are not limited to these materials:

[0038] ABS resin A: brand ABS AG10NP-AK, purchased from Taiwan Chemical Fiber Co., Ltd.

[0039] ABS resin B: brand ABS AG15A1-H, purchased from Taiwan Chemical Fiber Co., Ltd.

[0040] Low molecular weight SAN resin A: weight average molecular weight 43000, brand EMI-100, purchased from Jiangsu Jiayirong Company;

[0041] Low molecular weight SAN resin B: weight average molecular weight 36000, brand EMI-200, purchased from Jiangsu Jiayirong Company;

[0042] Low molecular weight SAN resin C: weight average molecular weight 32000, brand EMI-230B, purchased from Jiangsu Jiayirong Company;

[0043] Low molecular weight SAN resin D: weight average molecular weight 85000, brand SAN 310TR, purchased from Kumho Corporation, South Korea;

[0044] Brominated flame retardant: bromotriazine, brand HW-245, purchased from Shandong Haiwang Company;

[0045] Antimony trioxide: D50 particle size 0.8 μm, brand S-04N, purchased from Yiyang Shengli Materials Technology Co., Ltd.

[0046] Ester additive A: hydroquinone bis(diphenyl phosphate), brand WSFR-PX-220, purchased from Zhejiang Wansheng Company;

[0047] Ester additive B: bisphenol A bis(diphenyl phosphate), brand WSFR-BDP-N2, purchased from Zhejiang Wansheng Company;

[0048] PLA resin A: brand PLA 4032D, purchased from Nature Works, USA, with a melt flow rate of 7.0 g / 10 min at 210°C and 2.16 kg;

[0049] PLA resin B: PLA LX175, purchased from Corbin, the Netherlands, with a melt flow rate of 4.3 g / 10 min at 210°C and 2.16 kg;

[0050] PLA resin C: brand PLA 2003D, purchased from Nature Works, USA, with a melt flow rate of 20 g / 10 min at 210°C and 2.16 kg;

[0051] The preparation methods of the embodiments of the present invention and the comparative examples are as follows:

[0052] S1: According to the ratio in Table 2, weigh and pre-mix the components to obtain a premix;

[0053] S2: The premix of step S1 is put into a twin-screw extruder for melt blending and extrusion granulation to obtain a flame retardant ABS composite material.

[0054] The screw length-diameter ratio of the twin-screw extruder is 40:1, the barrel temperature of the twin-screw extruder is 200°C, the feeding speed is 40r / min, and the screw speed of the twin-screw extruder is 40r / min.

[0055] Flame retardant ABS composite material particles are added to the injection molding machine to form the required test specimens. The injection molding conditions are barrel temperature 190℃, injection pressure 55MPa, and speed 55cm 3 / s.

[0056] <Test Standard>

[0057] The performance test standards of the embodiments and comparative examples of the present invention are shown in Table 1 below:

[0058] Table 1. Performance test items and test standards

[0059]

[0060]

[0061] The ABS composite materials of the embodiment and the comparative example were injection molded into tensile specimens by a two-end injection method for performance testing. The dimensions (length, width and thickness) of the specimens were 170×10×4 mm. The data are shown in the table below.

[0062] Table 2. Formulas of Examples and Comparative Examples (parts by weight)

[0063]

[0064] Table 3. Performance test results of examples and comparative examples

[0065]

[0066] From the comparison of the examples and comparative examples in the above table, it can be seen that the composite use of low molecular weight SAN resin, polylactic acid and ester additives can greatly improve the weld mark tensile strength of flame retardant ABS, while ensuring that the material has good comprehensive mechanical properties, and the cantilever beam notched impact strength is 13kJ / m 2 The weld line tensile strength exceeds 37 MPa, and the material exhibits high thermal stability, with a TGA mass loss of less than 4.1% at 230°C. The ester additive improves intramolecular lubricity, while the polylactic acid and low-molecular-weight SAN resin improve intermolecular lubricity. The synergistic effect of these three elements imparts exceptional weld line tensile strength to the flame-retardant ABS, enhancing the material's mechanical strength and meeting the performance requirements of large-scale and thin-walled parts.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flame retardant ABS composite material, characterized in that: Calculated by weight, it includes the following components: The weight average molecular weight of the low molecular weight SAN resin is 33000 to 43000 g / mol; The PLA resin has a melt flow rate of 5 to 15 g / 10 min at 210° C. and 2.16 kg test conditions; The ester auxiliary agent is a phosphate ester.

2. The flame retardant ABS composite material according to claim 1, characterized in that: The brominated flame retardant is at least one of tetrabromobisphenol A, blocked brominated epoxy resin, brominated triazine, decabromodiphenylethane, brominated polystyrene, and octabromoether.

3. The flame retardant ABS composite material according to claim 1, characterized in that: The phosphate ester is one or more of hydroquinone bis(diphenyl phosphate), resorcinol bis(diphenyl phosphate) and bisphenol A bis(diphenyl phosphate).

4. The flame retardant ABS composite material according to claim 1, characterized in that: The following components are also included by weight: Processing aid 0-2 parts; The processing aid is selected from at least one of a lubricant, an anti-dripping agent, and an antioxidant.

5. The flame retardant ABS composite material according to claim 1, characterized in that: The ABS resin has a melt index of 12-28 g / 10 min at a temperature of 220° C. and a load of 10 kg.

6. A method for preparing the flame-retardant ABS composite material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Weigh each component according to the ratio, and pre-mix the components to obtain a premix; S2: putting the premix of step S1 into an extruder, performing melt blending and extrusion granulation to obtain the flame retardant ABS composite material.

7. Use of the flame-retardant ABS composite material according to any one of claims 1 to 5 in the preparation of electronic appliances.

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