Halogen-free flame-retardant ABS composite material, preparation method therefor, and use thereof

Abstract

Disclosed in the present invention is a halogen-free flame-retardant ABS composite material, which comprises the following raw material components in parts by weight: 26-50 parts of an ABS resin, 25-35 parts of a PLA resin, 5-12 parts of a compatilizer, 5-12 parts of a toughening agent, 6-15 parts of a phosphorus-containing flame retardant and 2-5 parts of a nitrogen-containing flame retardant. The present invention uses the ABS resin and the PLA resin as resin matrixes for alloy design and development, and uses the compatilizer to achieve compatibility of the alloy system, thereby overcoming a performance defect caused by the difference of polarities of resins; adding the toughening agent can greatly improve the mechanical properties of the alloy material; in addition, the present invention also performs development of halogen-free flame-retardant properties. Therefore, the halogen-free flame-retardant ABS composite material of the present invention has excellent comprehensive properties and halogen-free flame-retardant properties, and the alloy material has good value in industrial application.

Description

A halogen-free flame-retardant ABS composite material and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of engineering plastics, and in particular to a halogen-free flame-retardant ABS composite material. Background Art

[0002] Bio-based polymers have become valuable alternatives to fossil-based polymers, enabling the production of materials with a reduced carbon footprint and independent of petrochemical production. Among these, polylactic acid (PLA) boasts high modulus, high strength, and complete biodegradability, along with numerous advantages similar to those of petroleum-based resins, such as molding and processing methods. This has made it one of the most commercially successful biodegradable plastics in the past 20 years. It is widely used in packaging materials and biomedicine. However, PLA's slow crystallization rate and low crystallinity result in poor heat resistance, and its low toughness limits its applications. ABS resin offers excellent heat resistance and high toughness, and existing research has explored the production of alloys by blending ABS with PLA.

[0003] However, ABS resin is a flammable material. For its recommended use in household appliances, electronic appliances, 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 / PLA resin is particularly important. To address the flammability disadvantage of ABS / PLA resin, the following improvements are commonly made in the existing technology: First, using phenylphosphoryl dichloride as the main flame retardant can achieve a V-2 rating, but the impact resistance is poor. Second, using oligomeric chain extenders to react with PLA and ABS to form a new polymer can increase the heat deflection temperature, but the impact resistance is poor.

[0004] Therefore, it is necessary to develop a PLA / ABS alloy with high impact resistance and better flame retardancy that can be widely used in personal consumer electronics and household appliances. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies or defects of the prior art, the present invention provides a halogen-free flame-retardant ABS composite material.

[0006] The present invention is achieved through the following technical solutions:

[0007] A halogen-free flame-retardant ABS composite material, comprising the following raw material components in parts by weight:

[0008] 26-50 parts of ABS resin

[0009] 25-35 parts of PLA resin

[0010] 6-15 parts of phosphorus flame retardant

[0011] 2-5 parts nitrogen flame retardant

[0012] Compatibilizer 5-12 parts

[0013] 5-12 parts of toughening agent;

[0014] The PLA resin has a melt flow rate of 6.5-10 g / 10 min under the test conditions of 210° C.×2.16 kg; and the compatibilizer is any one of PET, PBT, PC, and PMMA.

[0015] The melt index and monomer ratio of the ABS resin are not particularly limited. Preferably, the melt flow rate is 10-15 g / 10 min under the test conditions of 210° C.×2.16 kg, the proportion of acrylonitrile monomer is 22wt%-25wt%, the proportion of butadiene monomer is 18wt%-22wt%, and the proportion of styrene monomer is 53wt%-60wt%.

[0016] In the technical solution of the present invention, ABS resin is modified using PLA resin. PLA resin primarily consists of optically active ester bonds formed by the reaction of hydroxyl and carboxyl groups. This improves the strength of the ABS hard segment, softens the entire ABS molecular chain, reduces shrinkage, and enhances material fluidity. Selecting PLA with a higher melt flow rate is particularly beneficial for achieving a flame retardancy rating of V-2. Furthermore, the present invention incorporates phosphorus and nitrogen flame retardants into the formulation to achieve a synergistic flame retardant effect, imparting flame retardancy to the ABS material. The terminal carboxyl groups in the PLA molecular chain have excellent compatibility with these flame retardants, thereby enhancing their flame retardant effect on the PLA-modified ABS. Furthermore, phosphorus flame retardants require an acid source to exert their flame retardant effect. PLA, however, contains terminal carboxyl groups, which can also serve as an acid source, synergizing with the phosphorus flame retardant during the flame retardant process to achieve a more effective flame retardant effect. This allows the addition of a reduced amount of inorganic flame retardant to still achieve a V-2 flame retardancy rating, thereby reducing the impact of inorganic flame retardants on the material's toughness. Furthermore, by adding a compatibilizer and a toughening agent to the formulation, the present invention achieves excellent compatibility between the components of the PLA / ABS system, resulting in a PLA / ABS composite material with excellent flame retardancy and toughness. The inventors have also discovered that using any of the polyester macromolecular weights (PET, PBT, PC, and PMMA) as the compatibilizer can address the polarity differences among the alloy components, improve the uniformity of the phase interface dispersion, and enhance overall mechanical properties.

[0017] As a preferred embodiment, the structure of the nitrogen-based flame retardant is shown in the following formula I:

[0018] Wherein, R1, R2, and R3 are identical and independent of each other, and their structures are -NCH, -NO3, -NH2, -N(CH3) or -N2Cl.

[0019] As a preferred embodiment, the mass ratio of the phosphorus-based flame retardant to the nitrogen-based flame retardant is (3-7):1.

[0020] After a large number of tests, the present invention determined that a specific ratio of phosphorus-based flame retardant and nitrogen-based flame retardant is compounded to enable the ABS composite material of the present invention to have optimal flame retardancy, toughness and impact resistance.

[0021] As a preferred solution, the compatibilizer is PMMA or PC, more preferably a macromolecular PMMA containing an acrylate structure, with a melt flow rate of 9-12 g / 10 min (tested at 230° C. and 3.8 kg), and the best mechanical properties.

[0022] As a preferred solution, the toughening agent is one of MBS, SBS, SEBS, and ASA, and the toughening agent is preferably a butadiene-styrene copolymer MBS with a core-shell structure. The use of MBS toughening agent in conjunction with a polyester compatibilizer helps to reduce the flame retardancy of ABS and improve the flame retardant efficiency.

[0023] Using a butadiene-styrene copolymer with a core-shell structure as a toughening agent to toughen polylactic acid can more effectively improve the elongation at break, impact strength and tensile strength of polylactic acid, thereby obtaining polylactic acid with good comprehensive performance.

[0024] In the polystyrene composition of the present invention, the content of ABS and PLA is not less than 45wt%;

[0025] The composition of the present invention may further contain a lubricant and an antioxidant without impairing the effects of the present invention. The lubricant may be selected from EBS B50 of the amide class, and the antioxidant may be selected from SONOX 1010 of the hindered phenol class.

[0026] The preparation process of the halogen-free flame-retardant ABS composite material of the present invention specifically comprises the following steps:

[0027] (1) ABS resin, PLA resin, compatibilizer, toughening agent, phosphorus flame retardant, and nitrogen flame retardant are mixed uniformly in a mixer according to the ratio;

[0028] (2) The mixture obtained in step (1) is melted, mixed and extruded through a twin-screw extruder, granulated and dried to obtain the halogen-free flame-retardant ABS composite material.

[0029] Preferably, the mixer in step (1) is a high-speed mixer with a rotation speed of 1000-1200 r / min and a mixing time of 2-5 minutes.

[0030] Preferably, the temperature of the twin-screw extruder barrel in step (2) is controlled between 170-185° C., the aspect ratio of the twin-screw extruder is (38-41):1, and the screw speed is 300-500 rpm.

[0031] The halogen-free flame-retardant ABS composite material of the present invention is used in the preparation of electronic appliances or office supplies, especially in chargers and UPS in the field of electronic appliances or printers and projectors in the field of office supplies.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The beneficial effects of the present invention are as follows: the present invention provides a halogen-free flame-retardant ABS composite material, which is designed and developed by alloying ABS resin and PLA resin as resin matrices, solving the compatibility of the alloy system by using a compatibilizer, overcoming the performance defects caused by the difference in resin polarity, and adding a toughening agent to greatly improve the mechanical properties of the alloy material, while developing halogen-free flame-retardant properties. The halogen-free flame-retardant ABS composite material of the present invention has excellent comprehensive performance and halogen-free flame-retardant properties, and the alloy material has good industrial application value. DETAILED DESCRIPTION

[0034] 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.

[0035] <Preparation of Examples and Comparative Examples>

[0036] 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:

[0037] ABS resin: brand ABS8391, purchased from Sinopec Shanghai Gaoqiao Company;

[0038] PLA resin A: brand PLA 4032D, purchased from Nature Works, USA, with a melt flow rate of 7.0 g / 10 min;

[0039] PLA resin B: brand PLA 4043D, purchased from Nature Works, USA, with a melt flow rate of 6.7 g / 10 min;

[0040] PLA resin C: brand PLA 4060D, purchased from Nature Works, USA, with a melt flow rate of 5.6 g / 10 min;

[0041] PLA resin D: brand PLA 3052D, purchased from Nature Works, USA, with a melt flow rate of 14 g / 10 min;

[0042] Phosphorus flame retardant: hydroquinone bis(diphenyl phosphate), brand WSFR-PX-220, purchased from Zhejiang Wansheng Company;

[0043] Nitrogen flame retardant: melamine cyanurate, brand MCA, purchased from Sichuan Fine Chemical Research and Design Institute;

[0044] Compatibilizer A: polymethyl methacrylate, brand PMMA 20HR, purchased from Sabic China Company;

[0045] Compatibilizer B: polycarbonate, brand PC1300 10NP, purchased from LG Chemical Company;

[0046] Compatibilizer C: maleic anhydride grafted ABS compatibilizer, brand KT-2, purchased from Shenyang Ketong Plastic Co., Ltd.

[0047] Toughener A: methacrylic acid-butadiene-styrene copolymer, brand EM500, purchased from LG Chemical Company;

[0048] Toughener B: styrene-butadiene copolymer, brand YH-792E, purchased from Sinopec Baling Petrochemical Company;

[0049] Toughening agent C: ASA material, brand A600N, purchased from Guangzhou Runfeng Chemical Company;

[0050] The composite materials of the embodiments and comparative examples of the present invention were prepared by the following process:

[0051] The components are weighed according to the proportions and added to a mixer for uniform mixing to obtain a premix. The premix is ​​then fed into a twin-screw extruder for mixing, extrusion, and processing to produce a halogen-free flame-retardant ABS composite material. The twin-screw extruder operates at a speed of 300-500 rpm, a temperature of 170-185°C, and an aspect ratio of 40:1.

[0052] The examples and comparative examples were subjected to the following test methods or test standards:

[0053] Izod notched impact strength: ISO 180-2000 (A-notch), test conditions: 23°C, 4mm;

[0054] Flame retardant rating: UL 94-2018, test sample thickness 2.0mm;

[0055] Table 1 Formula of composite materials in each embodiment (parts by weight)

[0056] Table 2 Formula of each comparative example composite material (parts by weight)

[0057] Table 3 Performance test results of the embodiment

[0058] Table 4 Performance test results of comparative examples

[0059] From the comparison of the examples and comparative examples in Tables 3 and 4, it can be seen that phosphate flame retardants and nitrogen flame retardants have good flame retardant effects in ABS / PLA composite materials. After being used together, they can achieve a stable V-2 flame retardant grade at a low addition amount. Compatibilizers can effectively solve the compatibility of composite materials, improve mechanical toughness, and solve the shortcomings of poor mechanical properties of flame-retardant composite materials. Tougheners can effectively improve the toughness of composite materials, giving them excellent comprehensive properties. The vertical burning grade of the prepared material can reach V-2 grade, and the cantilever beam notched impact strength can reach 12kJ / m 2 And above, compared with the control ratio, it has obvious advantages and can effectively meet the high standards of customers and the market.

[0060] Compared with Example 3, in Comparative Examples 1-8, only a phosphorus-based flame retardant was added in Comparative Example 1, and no nitrogen-based flame retardant was added; only a nitrogen-based flame retardant was added in Comparative Example 2, and no phosphorus-based flame retardant was added, which reduced the flame retardant properties of the material; the amount of PLA resin added in Comparative Example 3 was small, resulting in the material failing to achieve a good V-2 flame retardant grade; the PLA resin added in Comparative Example 4 had a low melt flow rate and could not assist in flame retardancy; the PLA resin added in Comparative Example 5 had a high melt flow rate, which reduced the mechanical properties of the material; no compatibilizer and toughening agent were added in Comparative Example 6 and Comparative Example 7, respectively, so that the mechanical properties of the material could not be significantly improved; the compatibilizer added in Comparative Example 8 was maleic anhydride-grafted ABS, and the mechanical properties could not be significantly improved.

[0061] 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 halogen-free flame-retardant ABS composite material, characterized in that: The composition comprises the following components by weight: 26-50 parts of ABS resin, 25-35 parts of PLA resin, 6-15 parts of phosphorus flame retardant, 2-5 parts of nitrogen flame retardant, 5-12 parts of compatibilizer, 5-12 parts of toughening agent; The melt flow rate of the PLA resin is 6.5-10 g / 10 min, and the compatibilizer is any one of PET, PBT, PC and PMMA.

2. The halogen-free flame-retardant ABS composite material according to claim 1, characterized in that: The structure of the nitrogen-based flame retardant is shown in the following formula I: Among them, R1, R2, and R3 are the same and independent of each other, and their structures are -NCH, -NO3, -NH2, -N(CH3) or -N2Cl.

3. The halogen-free flame-retardant ABS composite material according to claim 1, characterized in that: The mass ratio of the phosphorus-based flame retardant to the nitrogen-based flame retardant is (3-7):

1.

4. The halogen-free flame-retardant ABS composite material according to claim 1, characterized in that: The toughening agent is any one of MBS, SBS, SEBS and ASA.

5. A method for preparing the halogen-free flame-retardant ABS composite material according to any one of claims 1 to 4, characterized in that: The steps include: (1) uniformly mixing ABS resin, PLA resin, compatibilizer, toughening agent, phosphorus flame retardant, and nitrogen flame retardant in a mixer according to a proportion; (2) The mixture obtained in step (1) is melted, mixed and extruded through a twin-screw extruder, granulated and dried to obtain the halogen-free flame-retardant ABS composite material.

6. The preparation method according to claim 5, characterized in that: The mixer in step (1) is a high-speed mixer with a rotation speed of 1000-1200 r / min and a mixing time of 2-5 minutes; and / or In step (2), the temperature of the twin-screw extruder barrel is controlled between 170-185° C., the aspect ratio of the twin-screw extruder is (38-41):1, and the screw speed is 300-500 rpm.

7. Use of the halogen-free flame-retardant ABS composite material according to any one of claims 1 to 4 in the preparation of electronic appliances or office supplies.

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