Flame-retardant PC / ABS composition with fiber point effect, preparation method therefor, and use thereof

Abstract

Disclosed in the present invention are a flame-retardant PC / ABS composition with a fiber point effect, a preparation method therefor, and a use thereof. The flame-retardant PC / ABS composition with the fiber point effect according to the present invention comprises the following components: a polycarbonate, an ABS resin, a flame retardant, a high-temperature-resistant fiber point, and an anti-dripping agent, wherein the high-temperature-resistant fiber point is a regenerated cellulose fiber having a melting point of greater than or equal to 300ºC. In the flame-retardant PC / ABS composition with the fiber point effect according to the present invention, the high-temperature-resistant fiber point is used instead of a conventional carbon fiber- or glass fiber-reinforced conventional material, so that when the PC / ABS composition is combusted and contracted under heat, the anti-dripping agent can contract and gather at the high-temperature-resistant fiber point serving as a node to greatly slow down the perforation rate, and a carbon layer structure with a star-net-shaped dense distribution can be formed to isolate flame and heat, thus significantly improving flame-retardant properties. Moreover, the impact properties of the PC / ABS composition can also be better maintained, and the surface of the PC / ABS composition has a point-like aesthetic appearance effect similar to that of paint spraying.

Description

A flame-retardant PC / ABS composition with fiber point effect, preparation method and application thereof Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, and more particularly to a flame-retardant PC / ABS composition with a fiber point effect, a preparation method thereof, and applications thereof. Background Art

[0002] PC / ABS is a thermoplastic blend of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS). It combines the mechanical strength and high heat distortion temperature of polycarbonate with the excellent processing and molding properties of ABS. It is widely used in automotive interior parts, communications equipment, and electronic products. However, PC / ABS itself has a low limiting oxygen index (LOI) of 19.8%, making it flammable and unable to pass the vertical burn test (UL-94).

[0003] The problem of poor flame retardancy of PC / ABS materials is generally solved by adding halogen-free phosphorus flame retardants; however, simple flame retardants are still difficult to effectively improve their vertical flame retardancy. Anti-dripping agents need to be added to use the anti-dripping agent to drive melt retraction and work together with the flame retardant to improve the vertical flame retardancy.

[0004] However, in actual application, it was found that although the addition of anti-dripping agents improved the vertical flame retardant performance, the melt retraction accelerated the perforation rate, which significantly increased the risk of burn-through. In order to solve the problem of the material being easily burn-through, a common improvement method is to increase the melt strength by adding mineral powder fillers and adding carbon fiber or glass fiber reinforcement, thereby reducing the risk of burn-through. For example, the prior art discloses a UL94-5VA grade high-performance flame-retardant reinforced PC / ABS blend material and its preparation method, which uses a combination of halogen-free flame retardants and carbon fibers to ensure the integrity of the carbon layer on the outer surface of the part, thereby preventing burn-through; however, the toughness of the material is poor, and the appearance performance needs to be improved. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects and shortcomings of existing flame retardant PC / ABS compositions that are difficult to achieve high toughness, high flame retardancy and good appearance, and to provide a flame retardant PC / ABS composition with a fiber dot effect.

[0006] Another object of the present invention is to provide a method for preparing a flame retardant PC / ABS composition having a fiber point effect.

[0007] Another object of the present invention is to provide a flame retardant PC / ABS composition with fiber point effect for use in the preparation of automotive interior parts, communication equipment or electronic products.

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] The present invention provides a flame retardant PC / ABS composition having a fiber point effect, comprising the following components in parts by weight:

[0010] 60-90 parts of polycarbonate, 5-20 parts of ABS resin, 3-9 parts of flame retardant, 0.01-0.1 parts of high-temperature resistant fiber, and 0.8-1.8 parts of anti-dripping agent; wherein the high-temperature resistant fiber is regenerated cellulose fiber and its melting point is ≥300°C.

[0011] The flame-retardant PC / ABS composition with a fiber dot effect, which replaces conventional carbon fiber or glass fiber reinforcements with high-temperature-resistant fiber dots, not only allows the anti-drip agent to shrink and aggregate at the high-temperature-resistant fiber dots when the PC / ABS composition contracts due to combustion and heat, significantly slowing the perforation rate; it also forms a dense, star-shaped carbon layer structure that isolates flames and heat, significantly improving flame retardancy. Furthermore, research has found that the high-temperature-resistant fiber dots can better maintain the impact resistance (toughness) of the PC / ABS composition and give the surface of the PC / ABS composition a dotted aesthetic effect similar to spray paint.

[0012] Furthermore, since the injection molding temperature of PC / ABS compositions is generally around 280-290°C, the melting point of the heat-resistant fiber point must be ≥300°C to prevent it from changing shape due to melting during the injection molding process. The mass percentage of polycarbonate in the flame-retardant PC / ABS composition with the fiber point effect is ≥58%.

[0013] Optionally, the flame-retardant PC / ABS composition with fiber dot effect further comprises the following components in parts by weight: 2 to 7 parts of toughening agent, 1 to 3 parts of titanium dioxide, 0.1 to 1 part of antioxidant, and 0.2 to 1 part of lubricant.

[0014] Preferably, the flame retardant PC / ABS composition with fiber point effect comprises the following components in parts by weight:

[0015] 70-80 parts of polycarbonate, 9-18 parts of ABS resin, 3-5 parts of toughening agent, 4-7 parts of flame retardant, 1-3 parts of titanium dioxide, 0.02-0.05 parts of high temperature resistant fiber, 1.0-1.5 parts of anti-dripping agent, 0.1-1 parts of antioxidant, and 0.2-1 parts of lubricant.

[0016] Specifically, the polycarbonate can be 72 parts, 74 parts, 76 parts or 78 parts; the ABS resin can be 10 parts, 12 parts, 14 parts or 16 parts; the toughening agent can be 3.5 parts, 4 parts or 4.5 parts; the flame retardant can be 4.5 parts, 5 parts, 5.5 parts, 6 parts or 6.5 parts; the titanium dioxide can be 1.5 parts, 2 parts or 2.5 parts; the high temperature resistant fiber point can be 0.03 parts or 0.04 parts; the anti-dripping agent can be 1.1 parts, 1.2 parts, 1.3 parts or 1.4 parts; the antioxidant can be 0.2 parts, 0.4 parts, 0.6 parts or 0.8 parts; and the lubricant can be 0.4 parts, 0.6 parts or 0.8 parts.

[0017] Optionally, the mass ratio of the high-temperature resistant fiber points to the anti-dripping agent is 1:(14-80); preferably 1:(20-61); specifically 1:23, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, or 1:60. Studies have found that the mass ratio of the high-temperature resistant fiber points to the anti-dripping agent also has a significant impact on the flame retardancy and toughness of the PC / ABS composition. When the mass ratio of the two is within the above range, a higher flame retardancy rating and better toughness can be achieved.

[0018] Optionally, the average length of the regenerated cellulose fiber is 0.1 to 0.5 μm. The length of the regenerated cellulose fiber can be measured by the following method: weigh 1 g of regenerated cellulose fiber and place it in 20 mL of anhydrous ethanol. Ultrasonic dispersion is performed for 20 minutes using an ultrasonic device. 0.1 mL of the dispersed solution is dropped onto a glass slide. After the ethanol evaporates, the fiber is observed using a scanning microscope with a magnification of 200 times. Measurement software is used to test and record the fiber length in the field of view. Five fields of view are randomly selected for measurement and the average length is calculated.

[0019] Optionally, the polycarbonate is bisphenol A polycarbonate with a number average molecular weight of 22,000 to 30,000 g / mol; the ABS resin is an acrylonitrile-butadiene-styrene terpolymer, which can be produced by a bulk or emulsion method. The number average molecular weight of the polycarbonate can be measured by gel permeation chromatography-multi-angle laser light scattering (SEC-MALLS). The number average molecular weight also has a certain impact on the flame retardancy and toughness of the PC / ABS composition. A lower number average molecular weight will reduce the flame retardancy and toughness of the PC / ABS composition.

[0020] Optionally, the toughening agent is at least one of an organic silicon core-shell copolymer, a styrene-butadiene-methyl methacrylate terpolymer or ABS high-rubber powder.

[0021] Currently, the halogen-free flame retardants used in PC / ABS compositions are mainly phosphorus-based, mainly including phosphates or phosphazenes, both of which will reduce the melt strength of the material. Under the same flame retardancy, phosphazenes have a smaller reduction and are more conducive to preventing the support material from perforation. Specifically, the phosphazene flame retardant can be at least one of hexaphenoxytriphosphazene, octaphenoxycyclotetraphosphazene, or decaphenoxypentaphosphazene.

[0022] Specifically, the antioxidant may be at least one of a hindered phenol antioxidant, a phosphite antioxidant or a thioester antioxidant; and the lubricant may be pentaerythritol stearate and / or silicone masterbatch.

[0023] Specifically, the anti-drip agent can be polytetrafluoroethylene (PTFE) or SAN-coated PTFE. Compared to PTFE, SAN-coated PTFE has better dispersibility in PC / ABS compositions and is more conducive to improving the stability of flame retardancy. Optionally, the effective PTFE content in the SAN-coated PTFE is approximately 50 wt%.

[0024] The present invention also protects a method for preparing the flame-retardant PC / ABS composition having a fiber point effect, comprising the following steps:

[0025] The components are mixed and melt-extruded to obtain a flame-retardant PC / ABS composition with a fiber dot effect.

[0026] In the above preparation method, a twin-screw extruder can be used for melt extrusion, and the melt extrusion temperature is 140-250°C.

[0027] The flame-retardant PC / ABS composition having a fiber dot effect is used in the preparation of automotive interior parts, communication equipment, or electronic products. Specifically, the automotive interior parts may be a central control panel, an on-board charging support component, or the like.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The flame-retardant PC / ABS composition with a fiber dot effect, which replaces conventional carbon fiber or glass fiber reinforcements with high-temperature-resistant fiber dots, not only allows the anti-drip agent to shrink and aggregate at the high-temperature-resistant fiber dots when the PC / ABS composition contracts due to combustion and heat, significantly slowing the perforation rate, but also forms a dense, star-shaped carbon layer structure that isolates flames and heat, significantly improving flame retardancy. Furthermore, the impact resistance (toughness) of the PC / ABS composition is better maintained, while giving the surface of the PC / ABS composition a dotted aesthetic effect similar to spray paint. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram showing a visual representation of the appearance of a fiber dot effect.

[0031] FIG. 2 is a schematic diagram showing a visual representation of the appearance without the fiber dot effect. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with specific embodiments, but the examples do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the examples of the present invention are conventionally purchased raw materials and reagents.

[0033] 1. Raw materials and reagents

[0034] PC resin 1, number average molecular weight of about 30,000, brand PC 2030, manufacturer Wanhua Chemical;

[0035] PC resin 2, number average molecular weight of about 22,000, brand PC 2100, manufacturer Wanhua Chemical;

[0036] ABS resin, brand 275, manufacturer Gaoqiao Petrochemical;

[0037] Toughening agent 1: silicone core-shell copolymer, brand S-2501, manufacturer Mitsubishi Rayon;

[0038] Toughening agent 2: MBS, brand M-521, manufacturer Zhongyuan;

[0039] Flame retardant: Hexaphenoxytriphosphazene, brand HPCTP, manufacturer Weihai Jinwei Chemical;

[0040] High temperature resistant fiber point, brand X108A, manufacturer Guangzhou Changjin New Material Technology Co., Ltd.

[0041] Glass fiber, brand ECS13-4.5-534A, manufacturer China Jushi;

[0042] Carbon fiber, brand T700SC-12000-50C, manufacturer Toray;

[0043] Fiber point, brand name Vicnyl 400P, manufacturer Haiwantong Special Engineering Plastics Co., Ltd.;

[0044] Titanium dioxide, brand CR-211, manufacturer Jinzhou Titanium Industry;

[0045] Anti-dripping agent, brand POLY TS 30X, manufacturer Pacific InterChem Co., Ltd;

[0046] Lubricant: Pentaerythritol stearate, brand PETS-AP, manufacturer’s hair base;

[0047] The antioxidant is prepared by mixing SONOX 1076 and SONOX 168 in a mass ratio of 1:1. Both SONOX 1076 and SONOX 168 are commercially available.

[0048] 2. The flame-retardant PC / ABS compositions with fiber point effect in the embodiments and comparative examples of the present invention are prepared by the following preparation method:

[0049] After weighing and uniformly mixing the components according to the formula, the components are added to a twin-screw extruder for melt blending and extrusion granulation to obtain a flame-retardant PC / ABS composition with a fiber point effect; wherein the specific process parameters of the twin-screw extruder are: metering section temperature of 150-190°C, compression section temperature of 230-250°C, conveying section temperature of 230-250°C, and screw speed of 550r / min.

[0050] 3. Performance testing

[0051] (1) Izod notched impact test: The notched impact strength of the sample was tested directly according to ASTM D256-10 (2018) standard.

[0052] (2) 5VA flame retardant test: Test standard strips and standard panels according to the UL94-2018 5V flame retardant requirements.

[0053] (3) Appearance performance: Under D65 light source, the color plate state was observed to evaluate its fiber dot appearance effect. A visual representative schematic diagram of a plate with a fiber dot appearance effect is shown in FIG1 , and a visual representative schematic diagram of a plate without a fiber dot appearance effect is shown in FIG2 .

[0054] Examples 1 to 10 and Comparative Examples 1 to 5

[0055] The weight proportions of the components in the flame-retardant PC / ABS compositions with fiber point effects in Examples 1 to 10 and Comparative Examples 1 to 5 are shown in Table 1, where X is the mass ratio of the high-temperature resistant fiber points to the anti-dripping agent.

[0056] Table 1 Weight percentage of each component in the flame retardant PC / ABS composition with fiber point effect in each embodiment and comparative example

[0057] The performance test results of the flame retardant PC / ABS compositions with fiber point effect in various examples and comparative examples according to the above-mentioned method are shown in Table 2.

[0058] Table 2 Test results of various embodiments and comparative examples

[0059] As can be seen from Examples 1 and 2, the number-average molecular weight of the PC resin primarily affects the toughness of the PC / ABS composition. Under the same conditions, PC resins with larger number-average molecular weights are more conducive to improving toughness. Furthermore, according to Examples 1 and 4-6, the mass ratio of high-temperature-resistant fiber points to anti-drip agent also plays a significant role in the toughness of the PC / ABS composition. The notched impact strength first increases and then decreases with decreasing high-temperature-resistant fiber point content. This is primarily due to the increased compatibility with decreasing high-temperature-resistant fiber point content, which increases the toughness of the composite material. However, as the high-temperature-resistant fiber point content further decreases, the filler's reinforcing effect becomes less effective, causing the toughness of the composite material to begin to decrease.

[0060] As shown in Example 1 and Comparative Examples 1-3, high-temperature-resistant fiber dots are a key factor in determining whether a PC / ABS composition exhibits a fiber-dot appearance, and can, to a certain extent, enhance the flame retardancy and toughness of the PC / ABS composition. Example 1 and Comparative Examples 4-5 further demonstrate that only the combined action of high-temperature-resistant fiber dots and an anti-drip agent can achieve 5VA flame retardancy, good toughness, and a fiber-dot appearance.

[0061] The above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the claims of the present invention.

Claims

1. A flame retardant PC / ABS composition with fiber point effect, characterized in that: Calculated by weight, it includes the following components: Polycarbonate 60-90 parts, ABS resin 5-20 parts, flame retardant 3-9 parts, high temperature resistant fiber 0.01-0.1 parts, anti-dripping agent 0.8-1.8 parts; Wherein, the high temperature resistant fiber is regenerated cellulose fiber and its melting point is ≥300°C.

2. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The following components are also included by weight: 2 to 7 parts of toughening agent, 1 to 3 parts of titanium dioxide, 0.1 to 1 part of antioxidant, and 0.2 to 1 part of lubricant.

3. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The mass ratio of the high temperature resistant fiber points to the anti-dripping agent is 1:(14-80).

4. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The average length of the regenerated cellulose fibers is 0.1 to 0.5 μm.

5. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The polycarbonate is bisphenol A polycarbonate, and its number average molecular weight is 22000-30000 g / mol.

6. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The toughening agent is at least one of an organic silicon core-shell structure copolymer, a styrene-butadiene-methyl methacrylate terpolymer or an ABS high-rubber powder.

7. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The flame retardant is at least one phosphazene flame retardant.

8. The flame retardant PC / ABS composition with fiber point effect according to claim 1, characterized in that: The antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant or a thioester antioxidant; and the lubricant is pentaerythritol stearate and / or silicone masterbatch.

9. A method for preparing the flame-retardant PC / ABS composition with fiber point effect according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are mixed and melt-extruded to obtain a flame-retardant PC / ABS composition with a fiber dot effect.

10. Use of the flame-retardant PC / ABS composition with fiber dot effect according to any one of claims 1 to 8 in the preparation of automotive interior parts, communication equipment or electronic products.

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