Hydrolysis-resistant low-linear expansion coefficient PC / ABS composition and preparation method thereof

Abstract

The invention discloses a hydrolysis-resistant PC / ABS (polycarbonate / acrylonitrile butadiene styrene) composition with a low linear expansion coefficient. The composition comprises the following components in percentage by weight: 40-60% of PC resin; 15%-30% of ABS resin; 5%-15% of specially treated talcum powder; 3%-6% of a silicon-containing core-shell structure toughening agent; 3%-6% of a compatilizer; and 0.5-1.5% of a processing aid. The obtained material can be used on parts of automobiles or household appliances with high requirements on dimensional stability, such as automobile spoilers, door plates, air conditioner wind shields and the like.

Description

Technical Field

[0001] This field relates to PC alloy materials, specifically to a hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion and its preparation method. Background Technology

[0002] PC / ABS alloys are widely used in the automotive, electronics, power tool, and home appliance industries due to their combination of heat resistance and excellent formability. Because the material itself is non-crystalline, it also possesses excellent dimensional stability, making it highly favored in many small parts applications in automotive, electronics, and home appliance products. However, in some longer applications such as automotive spoilers and air conditioning deflectors, its dimensional stability still needs improvement. This invention patent is specifically designed for such long-sized components, exhibiting excellent hydrolysis resistance and even better dimensional stability.

[0003] Patent No.: CN 115926419 B, a flame-retardant PC / ABS alloy material with low linear expansion coefficient and its preparation method, which obtains a flame-retardant PC / ABS alloy with low linear expansion coefficient by adding flame retardant synergists, glass fibers and anti-hydrolysis agent carbodiimide, and by setting different processing technology and twin-screw extrusion equipment with different length-to-diameter ratios, and optimizing the combination of the screw blocks of the screw assembly.

[0004] Patent No.: CN 106349675 B, a hydrolysis-resistant and low-temperature resistant PC / ABS composite material and its preparation method, improves the interfacial compatibility of LLDPE and PC / ABS alloy by utilizing the linear structure of LLDPE, the shrinkage properties of PTFE and the compatibilizing effect of SAM, greatly improving the low-temperature impact resistance, ductility and tear resistance of the composite material, while also exhibiting high hydrolysis resistance.

[0005] CN 115926419 B uses glass fiber for reinforcement, but the presence of glass fiber easily leads to fiber floating problems in the product, and requires adjustment of the screw combination to ensure product performance. Furthermore, the patent does not provide data demonstrating its hydrolysis resistance. Patent application number: CN 106349675 B mainly focuses on developing hydrolysis resistance for traditional PC / ABS alloys, but it still cannot solve the fundamental problem for materials with high requirements for dimensional stability. This invention mainly modifies the material using specially treated talc powder, adds a silicon-containing core-shell toughening agent and compatibilizer with hydrolysis resistance, and selects a suitable PC / ABS system to obtain a hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion. Summary of the Invention

[0006] To address the above problems, this invention provides a hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion and a method for preparing the same.

[0007] The specific solution is: a hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion, the components of which, by weight percentage, include: PC resin 40%–60% ABS resin 15%–30% Specially treated talc powder 5%~15% Silicon-containing core-shell toughening agents 3%–6% Compatibilizer 3%–6% Processing aids: 0.5-1.5%.

[0008] The PC resin mentioned above is synthesized by the phosgene method and is purchased from Mitsubishi Chemical, grade PC 7025PJ.

[0009] The ABS resin has a rubber phase particle size of 0.5~5μm and a rubber phase content of 7%~15%, and is graded ABS 8434, purchased from Gaoqiao Petrochemical.

[0010] The specially treated talc powder used was of the brand name Performaflex, purchased from Guiguang Shenba. The treatment involved mixing bisphenol A-bis(diphenyl phosphate), abbreviated as BDP, with talc powder at 80°C for half an hour, with a mass ratio of BDP to talc powder of 1:50. The mixture was then dried at 100°C for 1 hour, followed by further treatment at 120°C for 1 hour.

[0011] The silicon-containing core-shell toughening agent has a silicon content of ≥60%, is grade MR-01, and was purchased from Kanekachi, Japan.

[0012] The compatibilizer is maleic anhydride-grafted ABS with a maleic anhydride content of 1%-3%, brand name HW-102M, purchased from Huawen.

[0013] The processing aids are antioxidants, light stabilizers, and lubricants; the antioxidants are hindered phenols and phosphites, purchased from Ciba; the light stabilizers are benzotriazole UV absorbers, purchased from BASF; and the lubricant is pentaerythritol stearate, purchased from LOZA.

[0014] The present invention also discloses a method for preparing a hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion.

[0015] The steps include: mixing the components by weight percentage, using a twin-screw extruder, and extrusion temperature of 230~250℃.

[0016] The material obtained by this invention can be used in some automotive or home appliance parts that have high requirements for dimensional stability, such as automotive spoilers, door panels, and air conditioning deflectors.

[0017] This invention is innovative compared to existing technologies, specifically in that: talc powder is pretreated to neutralize alkaline substances and prevent PC degradation; at the same time, a silicon-containing core-shell toughening agent and compatibilizer are added to prevent the system from degrading in long-term double 85 experiments; the addition of talc powder can also reduce the linear expansion coefficient of the material, further improving the dimensional stability of the material. Detailed Implementation

[0018] Raw material: PC resin, grade PC 7025PJ, purchased from Mitsubishi Chemical; ABS resin, grade ABS 8434, purchased from Gaoqiao Petrochemical; Talc powder, brand name performaflex, purchased from Guiguang Shenba; Silicon-containing core-shell toughening agent, brand name MR-01, purchased from Kanekachi, Japan; Maleic anhydride-grafted ABS, grade HW-102M, purchased from Huawen; The antioxidants were hindered phenols and phosphites, purchased from Ciba; the light stabilizers were benzotriazole UV absorbers, purchased from BASF; and the lubricant was pentaerythritol stearate, purchased from LOZA.

[0019] Talc pretreatment: Bisphenol A-bis(diphenyl phosphate) (BDP) and talc are mixed evenly at 80°C for half an hour, wherein the mass ratio of BDP to talc is 1:50. Then, the mixture is dried at 100°C for 1 hour and then treated at 120°C for 1 hour.

[0020] Talc powder treated with commercially available KH560 silane coupling agent: 2% by weight of KH560 is added to talc powder that is stirred at high speed for 20 minutes at a stirring speed of 500 rpm.

[0021] The dried PC resin, ABS resin, silicon-containing core-shell toughening agent, treated talc, compatibilizer, antioxidant, light stabilizer, and lubricant are mixed according to the composition formula in Table 1 and then added to the main barrel of a twin-screw extruder (screw diameter 35mm, length-to-diameter ratio L / D = 40). The main barrel temperature is controlled at 230℃-250℃, the twin screw speed is 400 rpm, and the extruded strip is cooled in a water tank and then pelletized to obtain the product of this invention.

[0022] composition Example 1 Example 2 Example 3 Example 4 Compare with Example 1 Compare with Example 2 Compare with Example 3 Compare with Example 4 Compare with Example 5 PC resin 55 55 55 45 55 55 55 55 55 ABS resin 29 24 19 29 19 19 24 24 19 talcum powder 15 BDP-treated talc 5 10 15 15 15 15 15 Talc treated with KH560 silane coupling agent 15 compatibilizer 5 5 5 5 5 5 5 5 Silicon-containing core-shell toughening agents 5 5 5 5 5 5 5 MBS toughening agent 5 Processing aids 1 1 1 1 1 1 1 1 1 The product performance testing methods are as follows: Tensile strength is in accordance with ISO 527 standard, with a tensile rate of 50 mm / min; flexural modulus is in accordance with ISO 178 standard, with a flexural rate of 2 mm / min; and notched impact strength is in accordance with ISO 179 standard.

[0023] The hydrolysis resistance test conditions were 85% humidity, 85℃, and 1000h.

[0024] The coefficient of linear expansion was tested according to ISO 11359, using data from -30℃ to 100℃. The test results are shown in Table 2.

[0025] performance Example 1 Example 2 Example 3 Example 4 Compare with Example 1 Compare with Example 2 Compare with Example 3 Compare with Example 4 Compare with Example 5 Tensile strength (MPa) 52 54 57 55 57 56 56 58 58 Flexural modulus (MPa) 2705 3411 4023 3954 3998 4123 4078 4211 4105 Notched impact strength (kJ / m2) 58 52 45 40 41 44 42 11 47 Coefficient of linear expansion [µm / (m·°C)] 67 60 50 51 51 49 49 48 50 After double 85, 1000h testing: Notched impact strength 50 47 39 35 10 16 20 2 11 After double 85, 1000h testing: Notched impact strength retention rate 86% 90% 87% 88% 24% 36% 48% 18% 24% In Examples 1-3, as the amount of talc increases, the coefficient of linear expansion of the material also decreases, indicating that the material has better dimensional stability.

[0026] Compared with Control Example 1, the talc powder treated in Example 3 showed a higher notched impact strength retention rate of 87% after being tested in the system at 85 for 1000 hours.

[0027] Compared with Control Example 2, Example 3 also showed that the silicon-containing toughening agent provided excellent hydrolysis resistance in the system. After 1000 hours, the MBS toughening agent exhibited higher impact performance, and the notched impact strength retention rate after the MBS toughening agent double 85 test was 36%.

[0028] Compared with Control Example 3, the compatibilizer is also crucial to the hydrolysis resistance of the system in Example 3. The notched impact strength retention rate without compatibilizer is only 48%, which is much lower than 87% in Example 3.

[0029] Compared with Control Example 4, Example 3 did not add toughening agent, and the notched impact strength of the material was very poor. After a double 85, 1000h test, the notched impact strength retention rate was 18%.

[0030] Compared with Control Example 5, the talc powder treated with BDP showed a higher notched impact strength retention rate of 87% after a double 85, 1000h test in the system.

Claims

1. A hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion, comprising, by weight percentage: PC resin 40%–60% ABS resin 15%–30% Specially treated talc powder 5%~15% Silicon-containing core-shell toughening agents 3%–6% Compatibilizer 3%–6% Processing aids: 0.5-1.5%.

2. The hydrolysis-resistant, low linear expansion coefficient PC / ABS composition according to claim 1, characterized in that, The PC resin is synthesized using the phosgene method.

3. The hydrolysis-resistant, low linear expansion coefficient PC / ABS composition according to claim 1, characterized in that, The ABS resin has a rubber phase particle size of 0.5~5μm and a rubber phase content of 7%~15%.

4. The hydrolysis-resistant, low linear expansion coefficient PC / ABS composition according to claim 1, characterized in that, The specially treated talc powder is processed as follows: Bisphenol A-bis(diphenyl phosphate), abbreviated as BDP, is mixed with talc powder at 80°C for half an hour, wherein the mass ratio of BDP to talc powder is 1:

50. Then it is dried at 100°C for 1 hour, and then treated at 120°C for 1 hour.

5. The hydrolysis-resistant, low linear expansion coefficient PC / ABS composition according to claim 1, characterized in that, The silicon-containing core-shell toughening agent has a silicon content of ≥60%.

6. The hydrolysis-resistant, low linear expansion coefficient PC / ABS composition according to claim 1, characterized in that, The compatibilizer is maleic anhydride-grafted ABS, and its maleic anhydride content is 1%-3%.

7. The hydrolysis-resistant, low linear expansion coefficient PC / ABS composition according to claim 1, characterized in that, The processing aids are antioxidants, light stabilizers, and lubricants; the antioxidants are hindered phenols and phosphites, the light stabilizers are benzotriazole UV absorbers, and the lubricants are pentaerythritol stearate.

8. The method for preparing a hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion according to any one of claims 1 to 7 is as follows: the components are mixed according to the weight percentage, the extruder used is a twin-screw extruder, and the extrusion temperature is 230~250℃.

9. A hydrolysis-resistant PC / ABS composition with a low coefficient of linear expansion is used in automotive spoilers, door panels, and air conditioning deflectors.