A polycarbonate composite material, its preparation method and application

Abstract

The present invention discloses a polycarbonate composite material, comprising: 100 parts of polycarbonate; 0 - 100 parts of silicone copolymer polycarbonate; 0 - 6 parts of toughening agent; 4×10 ‑6 -100×10 ‑6 parts; 0.1 - 0.5 parts 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. By introducing a small amount of LAP activator and dispersant, the present invention makes the conductivity of the material on the laser-engraved surface and the non-laser-engraved surface form a significant difference. The electroless plating catalyst and metal ions have selectivity during electroplating, effectively improving the plating effect of the material and solving the problem of overflow plating, and is particularly suitable for the LAP process; moreover, the material has high toughness and colorability, can be used for structural components, realizes directly engraving an antenna on the structural component, and is beneficial to the thinner development of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a polycarbonate 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. Simply put, it is to laser engrave circuit lines on the surface of an injection-molded structural part, and then chemically electroplate to form a three-dimensional metal circuit, enabling the structural part to have certain electrical properties. Compared with the currently mature LDS (LASER DIRECT STRUCTURING) process, the main advantages of the LAP technology are that its three-dimensional performance is the same as that of LDS, but it does not require specific laser equipment and LDS laser-induced materials, effectively reducing costs. In addition, the LDS process requires that the material must be added with metal activation substances, and the addition of metal substances will cause deterioration of the mechanical properties of the material and have a great impact on the color of the material. It can only be made into black, white, and gray, and is not suitable for structural components. Therefore, a separate antenna bracket component needs to be fabricated, occupying a certain volume. The LAP process is applicable to common plastic substrates, including PC, PC / ABS, ABS, etc., and can realize arbitrary engraving of antennas on structural components (such as mobile phone battery covers). Directly engraving the antenna on the mobile phone battery cover greatly increases the designability of the antenna, eliminating the need for a dedicated antenna bracket and making the mobile phone thinner. Therefore, the LAP technology has broad application prospects in the fields of smart phones, wearable devices, etc.

[0003] Due to its excellent properties such as impact resistance, dimensional stability, and weather resistance, polycarbonate materials have good applications in the fields of electronic appliances such as smart phones and wearable devices. However, the existing polycarbonate materials for the LAP process have poor laser roughening effect, and the difference formed between the surface after laser engraving and the surface without laser engraving during chemical electroplating is not obvious (especially for products with a fine texture on the surface), resulting in problems such as poor coating adhesion, overplating, and underplating, and it is difficult to meet the high-standard manufacturing requirements of the mobile phone antenna industry, restricting the popularization and application of the LAP technology. Therefore, there is an urgent need to develop a new polycarbonate material suitable for the LAP process and having a good electroplating effect. 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 polycarbonate composite material, which is particularly suitable for the LAP process, has a good electroplating effect, can form a metal coating with good adhesion, and effectively improves the problems of overplating and underplating.

[0005] Another object of the present invention is to provide a method for preparing the polycarbonate composite material.

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

[0007] A polycarbonate composite material, comprising the following components by weight:

[0008] Polycarbonate 100 parts;

[0009] Siloxane copolymer polycarbonate 0-100 parts;

[0010] Toughener 0-6 parts;

[0011] LAP Activator 4×10 -6 -100×10 -6 share;

[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] Preferably, the polycarbonate composite material comprises the following components in parts by weight:

[0016] Polycarbonate 100 parts;

[0017] Siloxane copolymer polycarbonate 20-40 parts;

[0018] 1-4 parts of toughening agent;

[0019] LAP Activator 10×10 -6 -30×10 -6 share;

[0020] Dispersant 0.3-0.4 parts.

[0021] The polycarbonate composite material of the present invention forms a carbon layer surface after laser burning by introducing a trace amount of LAP activator. The LAP activator plays a conductive role inside, so that the conductive properties of the surface after laser carving and the surface without laser carving are significantly different, so that the metal ions in the electroplating solution are selectively enriched on the surface after laser carving, forming a metal plating layer with good adhesion, and effectively preventing the occurrence of leaking plating or overflow plating.

[0022] Preferably, the LAP activator is selected from conductive carbon black.

[0023] The carbon nanotubes in the present invention are preferably single-walled carbon nanotubes; more preferably, the average length of the carbon nanotubes is 2-50 microns. 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.

[0024] The conductive carbon black in the present invention is preferably acetylene black; more preferably, the average particle size of the conductive carbon black is 10-50nm. Specifically, the average particle size of the conductive carbon black can be 10nm, 20nm, 30nm, 40nm, 50nm, all of which can achieve the present invention.

[0025] A certain amount of dispersant is added in the present invention to enable the LAP activator to be uniformly dispersed in the material, achieving a good plating effect. Preferably, the dispersant is selected from E wax.

[0026] The number-average molecular weight of the polycarbonate in the present invention is 17,000-30,000; preferably, the number-average molecular weight of the polycarbonate is 20,000-25,000.

[0027] In the present invention, by adding a silicone copolymer polycarbonate, silicon atoms generate silicon dioxide after laser engraving and remain as a solid on the surface, which is beneficial to the stability of the surface after laser engraving, effectively preventing the problem that carbon atoms generate carbon dioxide gasification after laser engraving, destroying the density of the laser-engraved surface, resulting in surface blistering and black smoke generation, which affects chemical plating.

[0028] Preferably, the content of silicone in the silicone copolymer polycarbonate is 5%-20%, more preferably, the content of silicone in the silicone copolymer polycarbonate is 6%-9%;

[0029] The toughening agent in the present invention is selected from any one or more of a core-shell structure toughening agent with methyl methacrylate or styrene acrylonitrile as the shell and acrylate and silicone as the core. Specifically, the core-shell structure toughening agent with methyl methacrylate as the shell and acrylate and silicone as the core includes but is not limited to Mitsubishi's S-2001, S-2501, S-2030, S-2100, SX-005; the core-shell structure toughening agent with styrene acrylonitrile as the shell and acrylate and silicone as the core includes but is not limited to Mitsubishi's SRK 200A, SX-006. The addition of the toughening agent can effectively improve the low-temperature toughness of the material and still maintain a good plating effect.

[0030] The present invention also provides a preparation method of the above polycarbonate 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 and granulate to obtain the polycarbonate composite material; wherein, the temperature of the twin-screw extruder is set at 200-280°C.

[0031] The present invention also provides an application of the above polycarbonate composite material, which is particularly suitable for products that need to be processed by the LAP technology, specifically smartphones, wearable devices, etc.

[0032] The present invention has the following beneficial effects:

[0033] The polycarbonate composite material of the present invention, by adding a trace amount of LAP activator and adding a certain amount of dispersant, makes the surface of the material after laser engraving treatment form a significant difference from the surface without laser engraving. The electroless plating catalyst and metal ions have selectivity during electroplating, thereby effectively improving the plating effect of the material, solving the problems of missing plating or overflow plating, and being particularly suitable for the LAP process; and the material has high toughness and color matching property, and can be used for structural components of electronic products such as smartphones and wearable devices, realizing arbitrary engraving of antennas on the structural components, greatly improving the designability of antennas, and being beneficial to the thinner development of products. Specific embodiments

[0034] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0035] 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:

[0036] Polycarbonate 1: The number average molecular weight is 22,000, 3022PJ from Samyang, Korea;

[0037] Polycarbonate 2: The number average molecular weight is 17,000, FN17000 from Idemitsu, Japan;

[0038] Siloxane copolymer polycarbonate 1: FG1760 from Idemitsu, Japan, with a siloxane content of 6%;

[0039] Siloxane copolymer polycarbonate 2: D0013 from Xintongcai, with a siloxane content of 20%;

[0040] Toughening agent 1: A core-shell structure toughening agent with polystyrene acrylonitrile as the shell and polyacrylate grafted dimethylsiloxane as the core, Mitsubishi SRK 200A;

[0041] Toughening agent 2: A core-shell structure toughening agent with methyl methacrylate as the shell and polyacrylate grafted dimethylsiloxane as the core, Mitsubishi S-2001;

[0042] LAP Activator 1: Acetylene black, average particle size 26 nm, Denks Black 2 of Denki Kagaku Kogyo Kabushiki Kaisha;

[0043] LAP Activator 2: Acetylene black, average particle size 57 nm, Denks Black 1 of Denki Kagaku Kogyo Kabushiki Kaisha;

[0044] LAP Activator 3: Conductive carbon black, average particle size 30 nm, Cabot VXC605;

[0045] LAP Activator 4: Single-walled carbon nanotubes, average carbon tube length 10 μm, OCSiAl TUBALL™;

[0046] LAP Activator 5: Multi-walled carbon nanotubes, average carbon tube length 10 μm, Dazhan GT-300;

[0047] Dispersant 1: E wax, Clariant Licowax E;

[0048] Dispersant 2: Pentaerythritol stearate, Lonza F538;

[0049] Dispersant 3: Polyester wax, Clariant Liocwax PED 521.

[0050] Preparation methods for the examples and comparative examples:

[0051] 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, place it in a twin-screw extruder, melt extrude, granulate, and obtain the polycarbonate composite 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 260 - 280 °C, the temperature of temperature control zones 5 - 6 is 260 - 270 °C, the temperature of temperature control zones 7 - 8 is 240 - 260 °C, and the temperature of temperature control zones 9 - 10 is 250 - 260 °C.

[0052] Related performance test methods:

[0053] (1) Notched impact strength: Tested with reference to the standard ASTM D256 - 2010, the sample test thickness is 3.2 mm.

[0054] (2) LAP process laser engraving plating effect test:

[0055] ① Yield rate of plating: The polycarbonate composite material is heated and melted at 260 - 320 °C and injection molded to make a flat test piece of 100 mm × 100 mm × 2 mm. After laser engraving and plating using the LAP process, a Leica microscope measuring instrument is used to observe whether there is any missing plating or over-plating on the surface circuit (missing plating means the metal layer is not plated on the laser-engraved surface; over-plating means there is a plating layer at the edge of the laser-engraved surface or the non-laser-engraved surface is plated with metal). Any missing plating or over-plating is regarded as unqualified. The circuit conditions of 100 test pieces in each group are counted to obtain the yield rate.

[0056] ② Evaluation of the firmness of the plating layer surface: Adopt the cross-cut test. After the test piece is laser engraved and plated 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 plating layer; use 3M adhesive tape to adhere to the small grid area on the surface of the test piece to be tested, 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 a 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 the same test 2 times for the same example, observe the situation of the plating layer peeling off within the grid, and according to the ASTM evaluation standard, it is divided into 6 grades, from 5B - 0B:

[0057] Grade 5B: There is no peeling at the incision and its edge, and the grid intersection points.

[0058] Grade 4B: There is partial peeling at the intersection or edge of the incision, 0 < peeled area of the cross-cut area ≤ 5%.

[0059] Grade 3B: There is partial peeling at the intersection or edge of the incision, 5% < peeled area of the cross-cut area ≤ 15%.

[0060] Grade 2B: There is partial peeling at the intersection or edge of the incision, and / or some whole grids peel off, 15% < peeled area of the cross-cut area ≤ 35%.

[0061] Grade 1B: There is partial peeling at the intersection or edge of the incision, and / or some whole grids peel off, 35% < peeled area of the cross-cut area ≤ 65%.

[0062] Grade 0B: There is partial peeling at the intersection or edge of the incision, and / or some whole grids peel off, peeled area of the cross-cut area > 65%.

[0063] Table 1: Component ratios (by weight parts) and various performance test results of Examples 1 - 7

[0064] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Polycarbonate 1 100 100 100 100 100 100 100 Siloxane Copolycarbonate 1 20 20 20 80 / 20 20 Toughening Agent 1 2 2 2 2 2 6 / LAP Activator 1 <![CDATA[4×10 -6 > <![CDATA[30×10 -6 > <![CDATA[100×10 -6 > <![CDATA[30×10 -6 > <![CDATA[30×10 -6 > <![CDATA[30×10 -6 > <![CDATA[30×10 -6 > Dispersant 1 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Notched Izod Impact Strength (23°C) J / m 746 748 712 723 745 701 735 Notched Izod Impact Strength (-30°C) J / m 582 592 562 621 297 592 312 Plating Yield Rate of Good Products % 85 95 82 86 88 87 89 Adhesion Grade of Coating Surface 4B 5B 4B 4B 4B 4B 4B

[0065] Table 2: Component ratios (by weight parts) and various performance test results of Examples 8 - 13

[0066] Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Polycarbonate 1 100 100 100 100 100 100 Siloxane Copolycarbonate 1 20 20 20 20 20 20 Toughening Agent 1 2 2 2 2 2 2 LAP Activator 1 <![CDATA[30×10 -6 > <![CDATA[30×10 -6 > LAP Activator 2 <![CDATA[30×10 -6 > LAP Activator 3 <![CDATA[30×10 -6 > LAP Activator 4 <![CDATA[30×10 -6 > LAP Activator 5 <![CDATA[30×10 -6 > Dispersant 1 0.3 0.3 0.3 0.3 Dispersant 2 0.3 Dispersant 3 0.3 Notched Izod Impact Strength (23°C) J / m 729 714 679 645 736 729 Notched Izod Impact Strength (-30°C) J / m 532 567 435 412 369 345 Plating Yield Rate of Good Products / % 91 93 94 89 91 92 Adhesion Grade of Coating Surface 4B 5B 5B 4B 4B 5B

[0067] Table 3: Distribution ratios (by weight parts) of each group in Examples 14 - 17 and Comparative Examples 1 - 3 and results of various performance tests

[0068] Example 14 Example 15 Example 16 Example 17 Comparative Example 1 Comparative Example 2 Comparative Example 3 Polycarbonate 1 100 100 100 100 100 Polycarbonate 2 100 100 Siloxane Copolycarbonate 1 20 40 20 20 20 20 Siloxane Copolycarbonate 2 20 Toughening Agent 1 2 2 4 Toughening Agent 2 2 LAP Activator 1 <![CDATA[30×10 -6 > <![CDATA[30×10 -6 > <![CDATA[80×10 -6 > <![CDATA[10×10 -6 > <![CDATA[1000×10 -6 > / <![CDATA[30×10 -6 > Dispersant 1 0.3 0.3 0.5 0.3 0.3 0.3 / Notched Izod Impact Strength (23°C) J / m 701 713 756 709 702 721 701 Notched Izod Impact Strength (-30°C) J / m 513 534 621 562 236 289 276 Plating Yield Rate of Good Products / % 94 89 88 89 65 35 56 Adhesion Grade of Coating Surface 5B 4B 4B 4B 3B 3B 2B

[0069] It can be seen from the above results that for the polycarbonate material of the present invention, through the introduction of a trace amount of LAP activator and dispersant, the material is particularly suitable for the LAP process, has a very good plating effect, good adhesion of the plating layer, and effectively reduces the problems of overplating and underplating; at the same time, by adding a silicone copolymer polycarbonate and a toughening agent component, while effectively improving the toughness of the material (especially low - temperature toughness), the LAP plating effect can be further improved.

[0070] In Comparative Example 1, the LAP activator was added in excess, 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 underplating and overplating.

[0071] In Comparative Example 2, it was difficult to plate the surface of the material without adding the LAP activator.

[0072] In Comparative Example 3, without adding a dispersant, it was difficult to disperse the LAP activator evenly, and the plating effect was poor.

Claims

1. A polycarbonate composite material, characterized in that, By weight parts, it includes the following components: 100 parts of polycarbonate; 0 - 100 parts of silicone copolymer polycarbonate; 0 - 6 parts of toughening agent; LAP activator 4×10 -6 -100×10 -6 parts; 0.1 - 0.5 part of dispersant; Among them, the LAP activator is selected from any one or several of carbon nanotubes or conductive carbon black; The dispersant is selected from any one or several of pentaerythritol stearate, polyester wax or E wax.

2. The polycarbonate composite material according to claim 1, characterized in that, By weight parts, it includes the following components: 100 parts of polycarbonate; 20 - 40 parts of silicone copolymer polycarbonate; 1 - 4 parts of toughening agent; LAP activator 10×10 -6 -30×10 -6 parts; 0.3 - 0.4 part of dispersant.

3. The polycarbonate composite material according to claim 1, wherein The carbon nanotubes are selected from single-walled carbon nanotubes.

4. The polycarbonate composite material according to claim 1, characterized in that, The average length of the carbon nanotubes is 2 - 50 microns.

5. The polycarbonate composite material according to claim 1, characterized in that, The conductive carbon black is selected from acetylene carbon black.

6. The polycarbonate composite material according to claim 1, characterized in that, The average particle size of the conductive carbon black is 10 - 50 nm.

7. The polycarbonate composite material according to claim 1, characterized in that, The LAP activator is selected from conductive carbon black.

8. The polycarbonate composite material according to claim 1, wherein The dispersant is selected from E wax.

9. The polycarbonate composite material according to claim 1, characterized in that, The number-average molecular weight of the polycarbonate is 17,000 - 30,000.

10. The polycarbonate composite material according to claim 9, wherein The number-average molecular weight of the polycarbonate is 20,000 - 25,000.

11. The polycarbonate composite material according to claim 1, characterized in that, The content of silicone in the silicone copolymer polycarbonate is 5% - 20%.

12. The polycarbonate composite material according to claim 11, characterized in that, The content of silicone in the silicone copolymer polycarbonate is 6% - 9%.

13. The polycarbonate composite material according to claim 1, wherein The toughening agent is selected from any one or several of methyl methacrylate or core-shell structure toughening agents with methyl methacrylate or styrene acrylonitrile as the shell and acrylate and silicone as the core.

14. The preparation method of the polycarbonate composite material according to any one of claims 1-13, 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 a polycarbonate composite material; among them, the temperature of the twin-screw extruder is set at 200 - 280 °C.

15. Use of the polycarbonate composite material according to any one of claims 1 to 13, characterized in that, For products that need to be processed by the LAP process.