Preparation method of electroplatable modified PPO alloy engineering plastic
By combining PPO, PS, PA, phosphorus-containing organic compounds and compatibility agents, and using multi-step processing technology, electroplating modified PPO alloy engineering plastics are prepared, which solves the problem of difficult balance of processing fluidity, mechanical properties and heat resistance of PPO materials, and achieves high-quality electroplating and cost advantages.
Patent Information
- Application Number
- CN202510216292.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-05-13
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
PPO materials have poor processing fluidity, difficult to achieve balance of mechanical properties and heat resistance, and difficult to ensure adhesion and quality of the electroplating layer. The existing modification methods are complex and costly.
Electroplating modified PPO alloy engineering plastics are prepared by vacuum drying, low-temperature plasma treatment, twin-screw extrusion granulation and injection molding.
It improves the processing performance of PPO, improves mechanical properties, heat resistance and electrical properties, solves the problem of electroplating difficulties, and has cost advantages, and is suitable for electronics, automobiles and other fields.
Smart Images
Figure CN119978769A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of new material preparation, and in particular to a method for preparing modified PPO alloy engineering plastics capable of electroplating. Background Art
[0002] With the rapid development of modern industry, the performance requirements for engineering plastics are increasing, especially in the fields of electronics, automobiles, and home appliances. As a high-performance engineering plastic, polyphenylene oxide (PPO) has attracted much attention due to its advantages such as good mechanical properties, heat resistance, and electrical insulation. However, PPO itself also has some limitations, such as its poor processing fluidity, which to a certain extent limits its wide application. Moreover, in practical applications, especially for some products that require surface decoration or have special functions, it is difficult to directly electroplate PPO materials, and the adhesion and quality of the electroplating layer are often difficult to guarantee.
[0003] In order to overcome these shortcomings of PPO materials, researchers have tried a variety of methods to modify them. Traditional modification methods include blending with other polymers, but while improving the processing performance of PPO, it is often difficult to take into account other properties of the material, such as the balance of mechanical properties and heat resistance. In terms of electroplating, although there are some technologies for PPO electroplating pretreatment, most of these methods are relatively complicated and the results are not ideal, and cannot meet the needs of high-quality electroplating. In addition, some existing modified PPO alloy engineering plastics also have problems in cost control. The use of special additives or complex processes leads to excessively high material costs, which is not conducive to large-scale production and application.
[0004] In this context, there is an urgent need for a new method for preparing modified PPO alloy engineering plastics, which can improve the processing fluidity of PPO while maintaining and improving its mechanical properties, heat resistance and electrical properties, and can effectively solve the problem of difficulty in electroplating of PPO alloy materials. At the same time, it must have cost advantages to meet the needs of industrial production for high-performance, multifunctional and economical engineering plastics. Summary of the invention
[0005] The main purpose of the present invention is to provide a method for preparing a modified PPO alloy engineering plastic that can be electroplated, which can effectively solve the problems mentioned in the background technology.
[0006] To achieve the above object, the technical solution adopted by the present invention is:
[0007] A method for preparing a modified PPO alloy engineering plastic capable of being electroplated comprises the following steps:
[0008] S1. PPO matrix pretreatment
[0009] S1.1 Drying treatment: Dry the PPO raw material in a vacuum drying oven at 120-140°C for 4-6 hours; this step can effectively remove moisture and low-molecular volatiles in the PPO raw material, prevent the subsequent processing due to these impurities resulting in material performance degradation and surface defects, and create favorable conditions for obtaining good electroplating effects.
[0010] S1.2, Surface activation: The surface of the dried PPO particles is activated by low-temperature plasma treatment technology, and the treatment is carried out at a power of 50-100W for 10-15 minutes in an argon atmosphere; this process can increase the active groups on the surface of PPO, such as hydroxyl and carboxyl groups, thereby significantly enhancing its bonding with other additives and alloy components.
[0011] S2. Alloy composition selection and ratio
[0012] S2.1. Main alloy components: PPO, polystyrene (PS) and polyamide (PA) are selected to form a ternary alloy system, and the mass ratio of PPO, PS and PA is 60:20:20; the good compatibility of PPO and PS can improve the processing fluidity of PPO, and the addition of PA is used to improve the toughness and mechanical properties of the alloy material.
[0013] S2.2. Addition of electroplating accelerator: Add phosphorus-containing organic compounds as electroplating accelerators. Calculated by mass fraction, the content of phosphorus-containing organic compounds in the alloy is 3% to 5%. This phosphorus-containing organic compound can form microscopic active sites on the surface of the alloy system material, which is beneficial to the adsorption of metal ions in the subsequent electroplating process.
[0014] S2.3. Compatibilizer selection: Maleic anhydride grafted ethylene-octene copolymer (POE-g-MAH) is used as the compatibilizer, and the added amount of the compatibilizer is 5% to 8% of the total mass of the alloy; POE-g-MAH can effectively enhance the interfacial bonding force between PPO, PS and PA, thereby improving the stability and uniformity of the alloy.
[0015] S3, Mixing and extrusion granulation
[0016] S3.1, Mixing process: Add the pretreated PPO, PS, PA, phosphorus-containing organic compound and compatibilizer into a high-speed mixer in a predetermined proportion and mix at 80-100°C for 20-30 minutes; this temperature range and mixing time can ensure that the components are fully and evenly dispersed.
[0017] S3.2, Extrusion granulation: A twin-screw extruder is used for extrusion granulation. The temperature of each section of the extruder is set to 220-230℃ for zone 1, 240-250℃ for zone 2, 250-260℃ for zone 3, 260-270℃ for zone 4, the head temperature is 270-280℃, and the screw speed is 300-400rpm. Through this temperature and speed control, good plasticization and mixing of the material can be guaranteed during the extrusion process, while avoiding material decomposition due to excessive temperature.
[0018] S4, injection molding: The prepared modified PPO alloy engineering plastic particles are injection molded on an injection molding machine, the injection temperature is 260-280℃, the injection pressure is 80-100MPa, the holding pressure is 50-60MPa, and the holding time is 5-10 seconds. The injection molding process parameters can ensure that the product has good dimensional accuracy and surface quality, which is conducive to subsequent electroplating operations.
[0019] Preferably, the purity of the argon gas in the low-temperature plasma treatment technology in S1.2 is not less than 99.9%. The high-purity argon gas can ensure that during the plasma treatment process, no impurity gas will be introduced to affect the surface activation effect of the PPO particles, thereby stably generating sufficient number and activity of hydroxyl groups, carboxyl groups and other active groups on the PPO surface, providing a stable basis for the subsequent combination of alloy components and the formation of electroplating active sites.
[0020] Preferably, the phosphorus-containing organic compound in S2.2 is a phosphate compound, specifically one or more combinations of trimethyl phosphate, triethyl phosphate, and tributyl phosphate. The phosphorus element in these phosphate compounds can form a specific chemical bonding structure on the surface of the alloy material, provide a stable and efficient adsorption site for metal ions in the electroplating process, and have good compatibility with other components in the alloy system, and will not have a negative impact on the overall performance of the alloy.
[0021] Preferably, the proportion of the components mixed in S3.1 is:
[0022] PPO: 55%~65%
[0023] PS: 15%~25%
[0024] PA: 15%~25%
[0025] Phosphorus-containing organic compounds: 3% to 7%
[0026] Compatibilizer (POE-g-MAH): 5% to 10%.
[0027] Within this ratio range, PPO as the main component ensures the main performance of the material, PS and PA assist in improving processing and mechanical properties, phosphorus-containing organic compounds provide electroplating promotion function, and compatibilizers ensure good compatibility of each component.
[0028] Preferably, the aspect ratio of the twin-screw extruder in S3.2 is 30-40. Within this aspect ratio range, the residence time of the material in the screw and the mixing effect can achieve an optimal balance, which is conducive to the full plasticization and uniform mixing of each alloy component during the extrusion process, avoiding local overheating or uneven mixing caused by material performance differences, thereby ensuring that the extruded particles have stable quality and performance, which is conducive to subsequent injection molding and electroplating operations.
[0029] Preferably, the mold temperature of the injection molding machine in S4 is 60-80° C. In this temperature range, the injection molded product can obtain a uniform cooling effect, avoid problems such as uneven internal stress and surface quality defects of the product caused by too fast or too slow cooling speed, ensure the dimensional accuracy and surface flatness of the product, provide a good foundation for the uniform deposition of the metal layer in the subsequent electroplating process, and improve the adhesion between the electroplating layer and the surface of the product and the electroplating quality.
[0030] Compared with the prior art, the present invention has the following beneficial effects:
[0031] The present invention innovatively combines PPO, PS, PA, phosphorus-containing organic compounds and compatibilizers, which not only makes the material have excellent comprehensive properties, including good mechanical properties, such as high strength, high hardness and toughness, excellent heat resistance to adapt to high temperature environment, excellent electrical properties to meet the needs of the electronic and electrical fields, but also improves processing performance. PS improves the fluidity of PPO, is conducive to molding and supports a variety of processing methods such as extrusion granulation and injection molding, and is easy to mass produce. At the same time, the raw materials are widely available, reducing the dependence on high-performance materials and having cost advantages. In addition, the addition of phosphorus-containing organic compounds greatly enhances the electroplating adaptability of the material, and can obtain high-quality electroplated surfaces, which has broad application prospects in the fields of automobiles, home appliance exterior decoration parts, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 The figure is a schematic flow chart of the method steps of the present invention. DETAILED DESCRIPTION
[0033] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.
[0034] like Figure 1 As shown, a method for preparing a modified PPO alloy engineering plastic that can be electroplated comprises the following steps:
[0035] S1. PPO matrix pretreatment
[0036] S1.1, Drying treatment: Dry the PPO raw material in a vacuum drying oven at 120-140°C for 4-6 hours;
[0037] S1.2, surface activation: the surface of the dried PPO particles is activated by low-temperature plasma treatment technology, and the treatment is carried out at a power of 50-100W for 10-15 minutes in an argon atmosphere;
[0038] S2. Alloy composition selection and ratio
[0039] S2.1. Main alloy composition: PPO, polystyrene (PS) and polyamide (PA) are selected to form a ternary alloy system, and the mass ratio of PPO, PS and PA is 60:20:20;
[0040] S2.2, electroplating accelerator addition: add phosphorus-containing organic compounds as electroplating accelerators, and the content of phosphorus-containing organic compounds in the alloy is 3% to 5% by mass fraction;
[0041] S2.3, compatibilizer selection: maleic anhydride grafted ethylene-octene copolymer (POE-g-MAH) is used as the compatibilizer, and the amount of the compatibilizer added is 5% to 8% of the total mass of the alloy;
[0042] S3, Mixing and extrusion granulation
[0043] S3.1, mixing process: adding the pretreated PPO, PS, PA, phosphorus-containing organic compound and compatibilizer into a high-speed mixer according to a predetermined ratio, and mixing at 80-100°C for 20-30 minutes;
[0044] S3.2, extrusion granulation: a twin-screw extruder is used for extrusion granulation, the temperature of each section of the extruder is set to 220-230°C for zone 1, 240-250°C for zone 2, 250-260°C for zone 3, 260-270°C for zone 4, the head temperature is 270-280°C, and the screw speed is 300-400rpm;
[0045] S4. Injection molding: The prepared modified PPO alloy engineering plastic particles are injection molded on an injection molding machine at an injection temperature of 260-280° C., an injection pressure of 80-100 MPa, a holding pressure of 50-60 MPa, and a holding time of 5-10 seconds.
[0046] The present invention is described in detail below with an actual method flow example:
[0047] 1. PPO substrate pretreatment
[0048] 1.1 Drying
[0049] Place 10kg of PPO raw material in a vacuum drying oven, set the drying temperature to 130℃ (this temperature is within the range of 120-140℃ and can be fine-tuned according to the actual drying effect), and the drying time is 5 hours. In this process, moisture and low-molecular volatiles will gradually escape from the PPO raw material. For example, after processing some insufficiently dried PPO raw materials, defects such as bubbles or streaks may appear on the surface of the product, which is caused by the vaporization of moisture during the processing. The presence of low-molecular volatiles may reduce the thermal stability and mechanical properties of the material. Through this drying treatment step, these problems can be effectively avoided, laying the foundation for subsequent processing and good electroplating effects.
[0050] 1.2 Surface activation
[0051] The dried PPO particles were surface activated using low-temperature plasma treatment technology. The PPO particles were placed in a plasma treatment device and treated in an argon atmosphere. The purity of the argon was controlled at 99.95% (higher than 99.9%) and the treatment was carried out at a power of 80W for 12 minutes. During this process, the high-energy particles in the argon plasma interacted with the surface of the PPO particles. In principle, these high-energy particles hit the PPO surface, breaking and recombining the chemical bonds of the surface molecules, thereby increasing active groups such as hydroxyl and carboxyl groups. Through experimental comparison, it was found that after PPO without surface activation treatment was mixed with other alloy components, the interfacial bonding strength of the material was significantly lower than that of PPO after activation treatment, which fully demonstrated the importance of surface activation in enhancing bonding strength.
[0052] 2. Alloy composition selection and ratio
[0053] 2.1 Main alloy composition
[0054] PPO, polystyrene (PS) and polyamide (PA) were selected to form a ternary alloy system. Each component was weighed in a mass ratio of 60:20:20. For example, if the total mass is 10kg, 6kg of PPO, 2kg of PS and 2kg of PA respectively were taken. PPO and PS have good compatibility because their molecular structures have certain similarities. The addition of PS is like a "lubricant" that can improve the processing fluidity of PPO. The addition of PA brings better toughness and mechanical properties to the alloy material. For example, in the tensile test, the elongation at break of the alloy material containing PA is significantly higher than that of the pure PPO material, which shows that PA effectively improves the toughness of the material.
[0055] 2.2 Addition of electroplating accelerator
[0056] Phosphorus-containing organic compounds are added as electroplating accelerators, and a mixture of trimethyl phosphate and triethyl phosphate in a mass ratio of 1:1 is selected. Calculated by mass fraction, the content of phosphorus-containing organic compounds in the alloy is 4%. The phosphorus element in these phosphate compounds forms microscopic active sites on the surface of the alloy system material. From the perspective of chemical structure, the electron cloud distribution of the phosphorus element enables it to form a special chemical bonding structure with metal ions. In the subsequent electroplating process, it attracts metal ions like "small magnets", which is conducive to the adsorption of metal ions on the surface of the material. Moreover, after mixing with other components, no new chemical incompatibility was found through various analytical methods (such as Fourier transform infrared spectroscopy, etc.), proving that it has good compatibility with other components in the alloy system.
[0057] 2.3 Compatibilizer Selection
[0058] Maleic anhydride grafted ethylene-octene copolymer (POE-g-MAH) is used as a compatibilizer, and the addition amount is 6% of the total mass of the alloy. The maleic anhydride group in POE-g-MAH can react chemically with the active groups on the surface of PPO, PS and PA, thereby forming chemical bonds between different phases and effectively enhancing the interfacial bonding force between them. For example, by observing the cross-section of the material through a scanning electron microscope, it can be found that after adding the compatibilizer, the interface between different phases is blurred, indicating that the bonding between the phases is tighter, thereby improving the stability and uniformity of the alloy.
[0059] 3. Mixing and extrusion granulation
[0060] 3.1 Mixing process
[0061] Add 6kg PPO, 2kg PS, 2kg PA, 0.4kg (4%) phosphorus-containing organic compound and 0.6kg (6%) compatibilizer (POE-g-MAH) pre-treated in a predetermined proportion to a high-speed mixer. Mix at 90°C for 25 minutes. This temperature and time can ensure that the components are fully and evenly dispersed. During the mixing process, the high-speed rotating blades cause the particles of various materials to collide and rub against each other, thereby achieving uniform mixing. If the mixing temperature is too low or the time is too short, the components may be unevenly mixed, affecting the consistency of the material properties; if the temperature is too high or the time is too long, it may cause the decomposition of certain components or deterioration of performance.
[0062] 3.2 Extrusion granulation
[0063] A twin-screw extruder with an aspect ratio of 35 (within the range of 30-40) is used for extrusion granulation. The temperature of each section of the extruder is set to: 225℃ in zone 1, 245℃ in zone 2, 255℃ in zone 3, 265℃ in zone 4, 275℃ in die head, and 350rpm in screw speed. Under this temperature and speed control, the residence time of the material in the screw and the mixing effect reach the best balance. For example, when the aspect ratio is not suitable or the temperature and speed are not properly controlled, local overheating may occur, resulting in local burning of the material, or uneven mixing, so that some of the components of the extruded particles are out of proportion. This setting can ensure good plasticization and mixing of the material during the extrusion process, while avoiding material decomposition and ensuring the stable quality of the extruded particles.
[0064] 4. Injection molding
[0065] The prepared modified PPO alloy engineering plastic particles are injection molded on an injection molding machine. The injection temperature is set to 270°C, the injection pressure is 90MPa, the holding pressure is 55MPa, the holding time is 8 seconds, and the mold temperature of the injection molding machine is 70°C. In this temperature range, the injection molded products can obtain a uniform cooling effect. For example, if the mold temperature is too low, cold spots and poor gloss may appear on the surface of the product; if the mold temperature is too high, it may cause problems such as difficulty in demolding and poor dimensional accuracy of the product. By setting the process parameters, it is ensured that the product has good dimensional accuracy and surface quality, which provides a good foundation for the uniform deposition of the metal layer in the subsequent electroplating process. In the electroplating experiment, it was found that when the products molded according to this injection molding process were electroplated, the metal layer had strong adhesion to the surface of the product and the electroplating quality was high.
[0066] Through the above examples, the preparation process of the modified PPO alloy engineering plastics that can be electroplated is demonstrated in detail, and the selection basis of the parameters of each step and the influence on the performance of the final product are explained.
[0067] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.
Claims
1. A method for preparing a modified PPO alloy engineering plastic that can be electroplated, characterized in that: The following steps are involved: S1. PPO matrix pretreatment S1.1, Drying treatment: Dry the PPO raw material in a vacuum drying oven at 120-140°C for 4-6 hours; S1.2, surface activation: the surface of the dried PPO particles is activated by low-temperature plasma treatment technology, and the treatment is carried out at a power of 50-100W for 10-15 minutes in an argon atmosphere; S2. Alloy composition selection and ratio S2.
1. Main alloy composition: PPO, polystyrene (PS) and polyamide (PA) are selected to form a ternary alloy system, and the mass ratio of PPO, PS and PA is 60:20:20; S2.2, electroplating accelerator addition: add phosphorus-containing organic compounds as electroplating accelerators, and the content of phosphorus-containing organic compounds in the alloy is 3% to 5% by mass fraction; S2.3, compatibilizer selection: maleic anhydride grafted ethylene-octene copolymer (POE-g-MAH) is used as the compatibilizer, and the amount of the compatibilizer added is 5% to 8% of the total mass of the alloy; S3, Mixing and extrusion granulation S3.1, mixing process: adding the pretreated PPO, PS, PA, phosphorus-containing organic compound and compatibilizer into a high-speed mixer according to a predetermined ratio, and mixing at 80-100°C for 20-30 minutes; S3.2, extrusion granulation: a twin-screw extruder is used for extrusion granulation, the temperature of each section of the extruder is set to 220-230°C for zone 1, 240-250°C for zone 2, 250-260°C for zone 3, 260-270°C for zone 4, the head temperature is 270-280°C, and the screw speed is 300-400rpm; S4. Injection molding: The prepared modified PPO alloy engineering plastic particles are injection molded on an injection molding machine at an injection temperature of 260-280° C., an injection pressure of 80-100 MPa, a holding pressure of 50-60 MPa, and a holding time of 5-10 seconds.
2. The method for preparing a modified PPO alloy engineering plastic capable of electroplating according to claim 1, characterized in that: The purity of argon gas in the low-temperature plasma treatment technology in S1.2 is not less than 99.9%.
3. The method for preparing a modified PPO alloy engineering plastic capable of electroplating according to claim 2, characterized in that: The phosphorus-containing organic compound in S2.2 is a phosphate compound, specifically one or more combinations of trimethyl phosphate, triethyl phosphate, and tributyl phosphate.
4. The method for preparing a modified PPO alloy engineering plastic capable of electroplating according to claim 1, characterized in that: The proportions of the components mixed in S3.1 are as follows: PPO: 55%~65% PS: 15%~25% PA: 15%~25% Phosphorus-containing organic compounds: 3% to 7% Compatibilizer (POE-g-MAH): 5% to 10%.
5. The method for preparing a modified PPO alloy engineering plastic capable of electroplating according to claim 1, characterized in that: The aspect ratio of the twin-screw extruder in S3.2 is 30-40.
6. The method for preparing a modified PPO alloy engineering plastic capable of electroplating according to claim 1, characterized in that: The mold temperature of the injection molding machine in S4 is 60-80°C.