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

Abstract

The present invention discloses a flame-retardant PC / ABS composite material, comprising: 75-85 parts of polycarbonate; 1-18 parts of acrylonitrile-butadiene-styrene copolymer; 9-13 parts of flame retardant; 4×10 ‑6 -1000×10 ‑6 parts of LAP activator; 0.1-0.5 parts of dispersant; the LAP activator is selected from any one or more of carbon nanotubes or conductive carbon black; the dispersant is selected from any one or more of pentaerythritol stearate, polyester wax or E wax. The flame-retardant PC / ABS composite material of the present invention can make the surface of the material carbonize more quickly during laser engraving by adding a small amount of LAP activator. There is a significant difference in the conductivity between the carbon layer surface formed and the un-engraved surface. The electroless plating catalyst and metal ions are selective during electroplating, so as to effectively improve the plating effect of the material and solve the problems of missing plating or overflow plating, and is particularly suitable for the LAP process.

Description

Technical Field

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

[0002] LAP (LASER ACTIVATED PROCESS) is a manufacturing process for fabricating three-dimensional circuits on the surface of plastics through direct laser forming and chemical surface nano-treatment. Briefly speaking, it is to laser engrave circuit lines on the surface of injection-molded structural parts, and then chemically electroplate to form three-dimensional metal circuits, so that the structural parts have certain electrical properties. Compared with the currently mature LDS (LASER DIRECT STRUCTURING) process, the advantages of LAP technology are mainly reflected in that its three-dimensional performance is the same as that of LDS, but it does not require the use of specific laser equipment and LDS laser-induced materials, effectively reducing costs. In addition, the LDS process requires that the material must add metal activation substances, and the addition of metal substances will cause the mechanical properties of the material to deteriorate, and have a great impact on the color of the material, and can only be made into black, white, and gray, which is not suitable for structural parts. While the LAP process is applicable to common plastic substrates, including PC, PC / ABS, ABS, etc. Therefore, the LAP technology has broad application prospects in the fields of smart phones, wearable devices, mobile Internet devices, etc.

[0003] The PC / ABS alloy material combines the formability of ABS (acrylonitrile-butadiene-styrene copolymer) and the mechanical strength, toughness, and dimensional stability of PC (polycarbonate), and has wide applications in the fields of electronic communication equipment (such as tablet computers, routers, etc.). Materials used in electronic and electrical products usually require good flame-retardant properties. However, for existing flame-retardant PC / ABS materials, the addition of flame retardants will reduce the glass transition temperature of the material, and the heat generated during the laser engraving process is likely to cause the material to soften and collapse before carbonization. The specific surface area of the surface layer is relatively small, affecting the adsorption of subsequent laser engraving catalysts, resulting in problems such as poor coating adhesion, over-plating, and missing plating, making it difficult to meet the product use requirements and restricting the popularization and application of LAP technology; therefore, there is an urgent need to develop a new flame-retardant PC / ABS material suitable for the LAP process. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a flame-retardant PC / ABS composite material with excellent flame-retardant performance, which is particularly suitable for the LAP process, has a good plating effect, can form a metal coating with good adhesion, and effectively improves the problems of over-plating and missing plating;

[0005] Another object of the present invention is to provide a method for preparing the above flame-retardant PC / ABS composite material.

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

[0007] A flame-retardant PC / ABS composite material, by weight, comprises the following components:

[0008] Polycarbonate 75 - 85 parts;

[0009] Acrylonitrile-butadiene-styrene copolymer 1 - 18 parts;

[0010] Flame retardant 9 - 13 parts;

[0011] LAP activator 4×10 -6 - 1000×10 -6 parts;

[0012] Dispersant 0.1 - 0.5 parts;

[0013] Wherein, the LAP activator is selected from any one or more of carbon nanotubes or conductive carbon black;

[0014] The dispersant is selected from any one or more of pentaerythritol stearate, polyester wax or E wax.

[0015] For the flame-retardant PC / ABS composite material of the present invention, by introducing a trace amount of LAP activator, it helps the material to absorb heat, enabling the material to carbonize more quickly before softening and collapsing. Moreover, on the surface of the carbon layer formed after laser engraving and burning, the LAP activator plays a conduction role inside, making a significant difference in the conductivity between the surface after laser engraving and the un-laser-engraved surface. As a result, metal ions in the electroplating solution are selectively enriched on the surface after laser engraving, forming a metal coating with good adhesion and effectively preventing the occurrence of non-plating or over-plating. If the addition amount of the LAP activator is too much, the conductivity of the material surface increases, instead resulting in a decrease in the conductivity difference between the laser-engraved surface and the un-laser-engraved surface, making the electroplating effect worse.

[0016] Preferably, the LAP activator is selected from conductive carbon black.

[0017] Preferably, the weight parts of the LAP activator are 20×10 -6 - 200×10 -6 parts.

[0018] The carbon nanotubes of the present invention are preferably single-walled carbon nanotubes; more preferably, the average length of the carbon nanotubes is 2 - 50 μm. Specifically, the average length of the carbon nanotubes can be 2μm, 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, all of which can achieve the present invention.

[0019] The conductive carbon black in the present invention is preferably acetylene carbon black; more preferably, the average particle size of the conductive carbon black is 10 - 50 nm. Specifically, the average particle size of the conductive carbon black can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, all of which can achieve the present invention.

[0020] A certain amount of dispersant is added in the present invention to enable the LAP activator to be evenly dispersed, which plays a good conduction role on the surface of the carbon layer formed after laser engraving and burning, achieving a good electroplating effect. Preferably, the dispersant is selected from E wax, which has good compatibility with the LAP activator and is more conducive to the uniform dispersion of the LAP activator.

[0021] Preferably, the melt index of the polycarbonate in the present invention is 3 - 34 g / 10 min under the conditions of 300 °C / 1.2 kg, and more preferably 9 - 22 g / 10 min. The test method for the melt index is ASTM D1238 - 2010.

[0022] Preferably, the butadiene content of the acrylonitrile - butadiene - styrene copolymer is 17 - 50%, and more preferably 20 - 35%. The butadiene content can be quantitatively measured by infrared characteristic peaks, specifically by testing the infrared characteristic peak of butadiene at 1638 cm -1 of the test sample, and the butadiene content of the test sample is obtained by comparing and converting the peak area with a 100% polybutadiene standard sample.

[0023] The weight parts of the acrylonitrile - butadiene - styrene copolymer are preferably 6 - 12 parts

[0024] The flame retardant in the present invention is selected from any one or more of phosphate flame retardants or phosphazene flame retardants; preferably, the flame retardant is selected from phosphazene flame retardants.

[0025] Preferably, the phosphate flame retardants are selected from any one or more of triphenyl phosphate, resorcinol - bis(diphenyl phosphate), bisphenol A - bis(diphenyl phosphate) or resorcinol bis(di(2,6 - dimethylphenyl) phosphate).

[0026] Preferably, the phosphazene flame retardants are selected from any one or more of hexaphenoxycyclotriphosphazene, silacyclotriphosphazene, fluorosilacyclotriphosphazene derivatives or polydiphenoxyphosphazene.

[0027] On the basis of introducing the LAP activator, the present invention adds a specific content of phosphate flame retardant or phosphazene flame retardant as a flame retardant system, so that the material has good flame retardant performance while still maintaining a good electroplating effect.

[0028] The flame retardant system of the present invention can be composed only of phosphate flame retardants and / or phosphazene flame retardants to achieve good flame retardant effects (UL-94 V0 level), or synergistic flame retardants commonly used in the art can be added according to actual needs.

[0029] According to the material property requirements, the flame retardant PC / ABS composite material of the present invention further includes, by weight: 2-6 parts of a toughening agent.

[0030] Preferably, the toughening agent is selected from any one or more of core-shell structure toughening agents with methyl methacrylate or styrene acrylonitrile as the shell and acrylate and silicone composition as the core, or core-shell structure toughening agents with methyl methacrylate as the shell and butadiene styrene as the core. Specifically, the core-shell structure toughening agent with methyl methacrylate as the shell and acrylate and silicone composition as the core includes but is not limited to S-2001, S-2501, S-2030, S-2100, SX-005 of Mitsubishi; the core-shell structure toughening agent with styrene acrylonitrile as the shell and acrylate and silicone composition as the core includes but is not limited to SRK 200A, SX-006 of Mitsubishi; the core-shell structure toughening agent with methyl methacrylate as the shell and butadiene styrene as the core includes but is not limited to 2620 of Rohm and Haas, M-732 of Kaneka, M-711 of Kaneka, E920 of Arkema. The addition of the toughening agent can effectively improve the toughness and low-temperature toughness of the material and still maintain good plating effect.

[0031] The present invention also provides a preparation method of the above-mentioned flame retardant PC / ABS composite material, including the following steps: according to the ratio, put each component into a mixer and mix for 10-20 minutes; after mixing evenly, put it into a twin-screw extruder, melt extrude, pelletize to obtain the flame retardant PC / ABS composite material; wherein, the temperature of the twin-screw extruder is set at 200-260°C.

[0032] The flame retardant PC / ABS composite material of the present invention is particularly suitable for products that need to be treated by LAP technology, and can be specifically used for tablet computers, routers, etc.

[0033] The present invention has the following beneficial effects:

[0034] The flame retardant PC / ABS composite material of the present invention can make the surface of the material carbonize more quickly during laser engraving by adding a small amount of LAP activator. There is a significant difference in the conductivity between the surface of the formed carbon layer and the un-engraved surface. The chemical plating catalyst and metal ions have selectivity during electroplating, so as to effectively improve the plating effect of the material, and effectively solve the problems of poor coating adhesion, missing plating or overflow plating existing in the existing flame retardant PC / ABS composite material, and is particularly suitable for the LAP process. Specific embodiments

[0035] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0036] The raw materials used in the embodiments and comparative examples of the present invention are described as follows, but are not limited to these materials:

[0037] Polycarbonate 1: Samyang TRIREX 3025PJ, melt index at 300°C / 1.2kg is 9 g / 10 min.

[0038] Polycarbonate 2: Samyang TRIREX 3020PJ, melt index at 300°C / 1.2kg: 22 g / 10min.

[0039] Polycarbonate 3: Wanhua PC 2350, with a melt index of 34 g / 10 min at 300°C / 1.2 kg.

[0040] Acrylonitrile-butadiene-styrene copolymer 1: butadiene content is 26%, Chimei ABS 757;

[0041] Acrylonitrile-butadiene-styrene copolymer 2: butadiene content is 17%, Gaoqiao Petrochemical ABS 275;

[0042] Flame retardant 1: phosphazene flame retardant, Weihai Jinwei HPCTP;

[0043] Flame retardant 2: phosphate flame retardant, Zhejiang Wansheng WSFR-BDP-N2;

[0044] LAP activator 1: acetylene carbon black, average particle size 26 nm, Denks Black 2, Denks Co., Ltd.

[0045] LAP activator 2: acetylene carbon black, average particle size 57 nm, Denks Black 1, Inc.

[0046] LAP activator 3: conductive carbon black, average particle size 30 nm, Cabot VXC605;

[0047] LAP activator 4: single-walled carbon nanotubes, with an average length of 10 microns, TUBALL™ from OCSiAl;

[0048] LAP activator 5: multi-walled carbon nanotubes, average length of carbon nanotubes is 10 microns, Dazhan GT-300;

[0049] Dispersant 1: E wax, Clariant Licowax E;

[0050] Dispersant 2: Pentaerythritol stearate, Lonza F538;

[0051] Dispersant 3: Polyester wax, Clariant Liocwax PED 521;

[0052] Toughening agent 1: A core - shell structure toughening agent with a polystyrene acrylonitrile shell and a polyacrylate grafted dimethylsiloxane core, Mitsubishi SRK 200A;

[0053] Toughening agent 2: A core - shell structure toughening agent with a methyl methacrylate shell and a polyacrylate grafted dimethylsiloxane core, Mitsubishi S - 2001;

[0054] Toughening agent 3: A core - shell structure toughening agent with a methyl methacrylate shell and a butadiene styrene core, Rohm and Haas 2620.

[0055] Preparation methods of the examples and comparative examples:

[0056] According to the ratios in Table 1 / Table 2 / Table 3, put each component into a mixer and mix for 10 - 20 minutes; after mixing evenly, put it into a twin - screw extruder, melt - extrude, pelletize, and obtain the PC / ABS alloy material; among them, the twin - screw extruder includes ten temperature control zones, the temperature of temperature control zones 1 - 2 is 200 - 250 °C, the temperature of temperature control zones 3 - 4 is 220 - 260 °C, the temperature of temperature control zones 5 - 6 is 220 - 260 °C, the temperature of temperature control zones 7 - 8 is 220 - 260 °C, and the temperature of temperature control zones 9 - 10 is 220 - 260 °C.

[0057] Relevant performance testing methods:

[0058] (1) Flame retardant performance: UL - 94 - 2018 vertical burning test;

[0059] (2) LAP process laser engraving plating effect test:

[0060] ① Plating good product rate: Heat - melt and injection - mold the polycarbonate composite material under the condition of 220 - 270 °C to make a flat test piece of 100 mm × 100 mm × 2 mm. After laser engraving and plating using the LAP process, use a Leica microscope tester to observe whether there are phenomena of missing plating or over - plating on the surface circuit layer (no metal layer plated on the laser - engraved surface is missing plating; there is a plating layer at the edge of the laser - engraved surface or there is plating on the non - laser - engraved surface is over - plating). If there is missing plating or over - plating, it is regarded as unqualified. Count the circuit conditions of 100 test pieces in each group to obtain the good product rate.

[0061] ② Evaluation of the surface fastness of the coating: The cross-cut test is adopted. After the test piece is laser-engraved and electroplated using the LAP process, use a cross-cut knife to draw 10×10 (100) small square grids with a side length of 1 mm on the surface of the tested coating; use 3M adhesive tape to adhere to the surface of the small grid area to be tested on the test piece, use an eraser to wipe the surface of the adhesive tape forcefully to make it firmly adhere to the small grid to be tested, hold the adhesive tape in the air for a while, and in the direction where the angle with the surface of the test piece is as close as possible to 60°, smoothly peel off the adhesive tape within 0.5 - 1.0 s; conduct 2 identical tests for the same example, observe the situation of the coating peeling off within the grid, and the evaluation criteria are divided into 6 grades, from 5B - 0B:

[0062] Grade 5B: No peeling at the incision and its edges, and at the grid intersections.

[0063] Grade 4B: Partial peeling at the intersections or edges of the incisions, 0 < peeling area of the cross-cut area ≤ 5%.

[0064] Grade 3B: Partial peeling at the intersections or edges of the incisions, 5% < peeling area of the cross-cut area ≤ 15%.

[0065] Grade 2B: Partial peeling at the intersections or edges of the incisions, and / or partial whole grids peeling off, 15% < peeling area of the cross-cut area ≤ 35%.

[0066] Grade 1B: Partial peeling at the intersections or edges of the incisions, and / or partial whole grids peeling off, 35% < peeling area of the cross-cut area ≤ 65%.

[0067] Grade 0B: Partial peeling at the intersections or edges of the incisions, and / or partial whole grids peeling off, peeling area of the cross-cut area > 65%.

[0068] Table 1: Component ratios of each group in Examples 1 - 10 (by weight parts) and test results of various properties

[0069]

[0070] Table 2: Component ratios of each group in Examples 11 - 18 (by weight parts) and test results of various properties

[0071]

[0072] Table 3: Component ratios of each group in Comparative Examples 1 - 5 (by weight parts) and test results of various properties

[0073]

[0074] As can be seen from the above results, for the flame-retardant PC / ABS composite material of the present invention, by adding a small amount of LAP activator, the plating effect of LAP on the material can be effectively improved, the adhesion of the plating layer is good, and the problems of over-plating and non-plating are well solved.

[0075] In Comparative Example 1, an excessive amount of LAP activator was added, the surface conductivity of the material increased, resulting in a reduction in the difference in conductivity between the laser-engraved surface and the non-laser-engraved surface, poor plating effect, and easy occurrence of problems such as non-plating and over-plating.

[0076] In Comparative Example 2, it was difficult to plate on the surface of the material without adding LAP activator.

[0077] In Comparative Example 3, without adding a dispersant, it was difficult to disperse the LAP activator evenly, and the plating effect was poor.

[0078] In Comparative Example 4, the amount of flame retardant was too small, and the flame retardant performance of the material was poor, only reaching the V2 flame retardant grade.

[0079] In Comparative Example 5, an excessive amount of flame retardant was used, which instead led to a poor plating effect.

Claims

1. A flame-retardant PC / ABS composite material, characterized in that, By weight parts, it includes the following components: 75 - 85 parts of polycarbonate; 1 - 18 parts of acrylonitrile - butadiene - styrene copolymer; 9 - 13 parts of flame retardant; LAP Activator 4×10 -6 -1000×10 -6 share; 0.1 - 0.5 part of dispersant; Wherein, the LAP activator is selected from any one or more of carbon nanotubes or conductive carbon black; The dispersant is selected from any one or more of pentaerythritol stearate, polyester wax or E wax.

2. The flame-retardant PC / ABS composite material according to claim 1, wherein The weight parts of the LAP activator are 20×10 -6 - 200×10 -6 parts.

3. The flame-retardant PC / ABS composite material according to claim 1, characterized in that The melt index of the polycarbonate under the condition of 300℃ / 1.2 kg is 3 - 34 g / 10 min.

4. The flame-retardant PC / ABS composite material according to claim 3, wherein, The melt index of the polycarbonate under the condition of 300℃ / 1.2 kg is 9 - 22 g / 10 min.

5. The flame-retardant PC / ABS composite material according to claim 1, wherein The butadiene content of the acrylonitrile - butadiene - styrene is 17 - 50%.

6. The flame-retardant PC / ABS composite material according to claim 5, characterized in that, The butadiene content of the acrylonitrile - butadiene - styrene is 20 - 35%.

7. The flame-retardant PC / ABS composite material according to claim 1, wherein, The flame retardant is selected from any one or more of phosphate flame retardants or phosphazene flame retardants.

8. The flame-retardant PC / ABS composite material according to claim 7, wherein, The flame retardant is selected from phosphazene flame retardants.

9. The flame-retardant PC / ABS composite material according to claim 7, wherein, The phosphate flame retardants are selected from any one or more of triphenyl phosphate, resorcinol - bis(diphenyl phosphate), bisphenol A - bis(diphenyl phosphate) or resorcinol bis(di(2,6 - dimethylphenyl) phosphate); the phosphazene flame retardants are selected from any one or more of hexaphenoxycyclotriphosphazene, silacyclotriphosphazene, fluorosilacyclotriphosphazene derivatives or polydiphenoxyphosphazene.

10. The flame-retardant PC / ABS composite material according to claim 1, wherein The carbon nanotubes are selected from single - wall carbon nanotubes.

11. The flame-retardant PC / ABS composite material according to claim 1, wherein The average length of the carbon nanotubes is 2 - 50 microns.

12. The flame-retardant PC / ABS composite material according to claim 1, wherein, The conductive carbon black is selected from acetylene black.

13. The flame-retardant PC / ABS composite material according to claim 1, wherein The average particle size of the conductive carbon black is 10 - 50 nm.

14. The flame-retardant PC / ABS composite material according to claim 1, wherein, The LAP activator is selected from conductive carbon black; the dispersant is selected from E wax.

15. The flame-retardant PC / ABS composite material according to claim 1, characterized in that, By weight parts, it further includes: 2 - 6 parts of toughening agent.

16. The preparation method of the flame-retardant PC / ABS composite material according to any one of claims 1-15, characterized in that, It includes the following steps: according to the ratio, put each component into a mixer and mix for 10 - 20 minutes; after mixing evenly, put it into a twin - screw extruder, melt - extrude and pelletize to obtain the flame - retardant PC / ABS composite material; wherein, the temperature of the twin - screw extruder is set at 200 - 260℃.

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