High-impact low-linear expansion coefficient PC / ABS material and preparation method thereof

Abstract

The invention discloses a PC / ABS material with high impact and low linear expansion coefficient and a preparation method thereof, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: uniformly mixing 53-68 parts of PC resin, 10-32 parts of ABS resin, 3-6 parts of a flexibilizer, 0.5 part of a compatilizer, 0.5 part of an antioxidant, 0.5 part of a lubricant and 0.5 part of carbon black, feeding the obtained mixture through a main feeding port of a double-screw extruder, feeding 10-20 parts of silane modified talcum powder through a side feeding port, extruding, granulating, cooling and drying to obtain the PC / ABS material with high impact and low linear expansion coefficient. The material has high tensile strength and flexural modulus and extremely low linear expansion coefficient, and can meet the requirements of good dimensional stability and good appearance performance at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high-impact, low-linear expansion coefficient PC / ABS material and a preparation method thereof. Background Art

[0002] PC / ABS alloy material is a thermoplastic polymer alloy material blended from polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS). It combines the excellent properties of the two materials and has excellent mechanical properties and heat resistance. It is currently widely used in automobiles, home appliances, and medical treatment. With the increasing application of insert injection molding, real wood injection molding, IMD and other processes in automotive interiors, higher requirements are placed on the appearance, performance and dimensional stability of PC / ABS alloy materials.

[0003] The modern automobile industry requires that the assembly gap between different parts be as small as possible. If there are dimensional problems with the parts during use, it will not only affect the appearance of the car, but also bring challenges to the freedom of automobile design and lightweight. It is more urgent to reduce the linear expansion coefficient of the material and improve the toughness, rigidity and dimensional stability of the material. At present, glass fiber reinforced PC / ABS or talcum powder filled PC / ABS alloy are usually used to reduce the linear expansion coefficient of the material. The former will cause problems such as warping, floating fiber, and paint falling off. Filling talcum powder will significantly reduce the impact of the material. Therefore, it is necessary to develop a material that has both dimensional stability and high impact strength to meet actual production and use needs. Summary of the invention

[0004] One of the purposes of the present invention is to provide a high-impact, low linear expansion coefficient PC / ABS material to solve the problems of warping, deformation and poor toughness of low linear expansion coefficient PC / ABS alloy materials in the prior art, and to achieve a material with high toughness on the basis of low linear expansion coefficient;

[0005] The second object of the present invention is to provide a method for preparing a high-impact, low-linear expansion coefficient PC / ABS material.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] In the first aspect, a high impact, low linear expansion coefficient PC / ABS material comprises the following raw materials in parts by weight:

[0008] PC (polycarbonate) resin 53-68 parts,

[0009] ABS (acrylonitrile-butadiene-styrene copolymer) resin 10-32 parts,

[0010] Silane modified talc 10-20 parts,

[0011] 3-6 parts of toughening agent,

[0012] 0.5 parts of compatibilizer,

[0013] 0.5 parts of antioxidant,

[0014] 0.5 parts of lubricant,

[0015] 0.5 parts of carbon black.

[0016] Furthermore, the PC resin is a bisphenol A polycarbonate resin, and its melt index at 300° C. / 1.2 kg is 10-20 g / 10 min.

[0017] Furthermore, the relative molecular weight of the ABS resin is 120,000-130,000 g / mol, and the acrylonitrile content is 24-28%.

[0018] Furthermore, the silane-modified talc is prepared by the following steps:

[0019] The talc powder is added into a silane coupling agent aqueous solution with a mass percentage of 13-15%, stirred for 30-80 minutes, dried at 80-120° C., and then ball-milled to obtain silane-modified talc powder with a mesh size of 4000-6000.

[0020] The surface of talc contains hydrophilic groups and has a high surface energy. As an inorganic filler, it has great differences in chemical structure and physical form with organic polymer molecular materials, and lacks affinity. The talc particles need to be surface treated to improve the interfacial bonding between the talc and the polymer, and to improve the uniform dispersion and compatibility of the talc particles and the polymer. By using the surface modification method of silane coupling agent, the functional groups in the silane coupling agent react with the hydroxyl groups on the surface of talc to form a stable chemical bond. This modification method can significantly improve the compatibility of talc with the polymer matrix, improve its dispersion state in the polymer, and thus enhance the physical and mechanical properties of the composite material.

[0021] Furthermore, the usage ratio of the talcum powder and the silane coupling agent aqueous solution is 25g:75g.

[0022] Furthermore, the silane coupling agent includes but is not limited to KH550, KH560, and KH570.

[0023] Furthermore, the compatibilizer is a ternary random copolymer of styrene-acrylonitrile-glycidyl methacrylate. The ternary random copolymer of styrene-acrylonitrile-glycidyl methacrylate is a copolymer formed by free radical polymerization of styrene (St), acrylonitrile (AN) and glycidyl methacrylate (GMA), which can significantly improve the phase structure and mechanical properties of the alloy, while improving the heat resistance and thermal stability of the material.

[0024] Furthermore, the toughening agent is a terpolymer of styrene, butadiene and methyl methacrylate.

[0025] Furthermore, the antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphate, tris(2,4-di-tert-butylphenyl)phosphite, and bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

[0026] Furthermore, the lubricant is one or more of silicone, ethylene bis stearamide, and pentaerythritol stearate.

[0027] In a second aspect, a method for preparing a high-impact, low-linear expansion coefficient PC / ABS material comprises the following steps:

[0028] The components are weighed according to the weight proportions, and PC resin, ABS resin, toughening agent, compatibilizer, antioxidant, lubricant and carbon black are uniformly mixed. The obtained mixture is fed through the main feeding port of the twin-screw extruder, and the silane-modified talc is fed through the side feeding port. After extrusion, granulation, cooling and drying, a high-impact, low-linear expansion coefficient PC / ABS material is obtained.

[0029] Furthermore, the process parameters of the twin-screw extruder are as follows: feeding section 220-230°C, compression section 230-240°C, metering section 240-250°C, die head 260°C, screw speed 350-450rpm.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention provides a high-impact, low-linear expansion coefficient PC / ABS material and a preparation method thereof. By introducing silane-modified talcum powder into the PC / ABS material, the linear expansion coefficient of the material is reduced. At the same time, the talcum powder is modified by silane to improve the interface bonding force between the talcum powder and the copolymer material, improve the uniform dispersibility and compatibility of the talcum powder particles and the polymer, and achieve a dynamic balance between the material performance, the linear expansion coefficient and the impact strength. In addition, the main material is fed from the main feeding port, the auxiliary material silane-modified talcum powder is fed from the side feeding port, and then melted and co-extruded, which can avoid the wear of the screw on the talcum powder. The prepared PC / ABS material has high tensile strength, bending modulus and extremely low linear expansion coefficient, has excellent physical properties, and excellent dimensional stability, and can simultaneously meet the requirements of good dimensional stability and good appearance performance. For complex home appliances and automobile fields, not only will the overall performance of the material not be affected, but also products with excellent appearance can be obtained. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the following embodiments and comparative examples:

[0034] PC resin is Shenma SPC 1013L;

[0035] ABS resin uses Gaoqiao Petrochemical ABS275;

[0036] The compatibilizer is Fin-B l end (Jia Yi Rong polymer) SAG-002;

[0037] The toughening agent is Rohm and Haas EXL-2620;

[0038] The antioxidant is tris(2,4-di-tert-butylphenyl)phosphite (antioxidant 168 Aladdin) and bis(2,4-dicumylphenyl)pentaerythritol diphosphite (antioxidant 9228 Dufu Chemical) in a ratio of 1:1.

[0039] The lubricant used is ethylene bis stearamide (McLean);

[0040] The particle size of carbon black is 100-200 μm.

[0041] Preparation Example 1

[0042] Silane-modified talc is prepared by the following steps:

[0043] The talc powder was added to a 14% by mass aqueous solution of a silane coupling agent, the amount ratio of the talc powder to the silane coupling agent aqueous solution was 25g:75g, the mixture was stirred at 200rpm for 60min, and dried at 100°C; and then ball milled to obtain a silane-modified talc powder with a mesh size of 5000.

[0044] The silane-modified talc in the following examples and comparative examples was prepared according to this preparation example.

[0045] Examples 1-4

[0046] A high impact, low linear expansion coefficient PC / ABS material, the weight parts of the raw materials are shown in Table 1;

[0047] Table 1

[0048] Example 1 Example 2 Example 3 Example 4 PC resin 54 54 68 60 ABS resin 31 27 10 20 Toughening agent 3 6 3 5 Compatibilizer 0.5 0.5 0.5 0.5 Antioxidants 0.5 0.5 0.5 0.5 Lubricants 0.5 0.5 0.5 0.5 Carbon Black 0.5 0.5 0.5 0.5 Silane modified talc 10 11 17 13

[0049] The preparation method of the high-impact, low-linear expansion coefficient PC / ABS material comprises the following steps:

[0050] Weigh each component according to the weight proportion, mix PC resin, ABS resin, toughening agent, compatibilizer, antioxidant, lubricant and carbon black uniformly, feed the obtained mixture through the main feeding port of the twin-screw extruder, feed the silane-modified talc powder through the side feeding port, and obtain a high-impact, low-linear expansion coefficient PC / ABS material after extrusion, granulation, cooling and drying;

[0051] The process parameters of the twin-screw extruder are as follows: feeding section 225°C, compression section 235°C, metering section 245°C, die head 260°C, screw speed 400rpm.

[0052] Comparative Example 1-2

[0053] A PC / ABS material, which is different from the embodiment in that talcum powder with a conventional mesh size of 5000 is used, and the specific weight parts of the raw materials are shown in Table 2;

[0054] Table 2

[0055] Comparative Example 1 Comparative Example 2 PC resin 54 60 ABS resin 31 20 Toughening agent 3 5 Compatibilizer 0.5 0.5 Antioxidants 0.5 0.5 Lubricants 0.5 0.5 Carbon Black 0.5 0.5 talcum powder 10 13

[0056] In the preparation method of the PC / ABS material, an equal amount of silane-modified talc powder is replaced with conventional talc powder, and the remaining steps and parameters are consistent with those in Example 4.

[0057] Comparative Example 3

[0058] A PC / ABS material, whose raw material components and weight parts are the same as those in Example 4, except that the preparation method of the PC / ABS material comprises the following steps:

[0059] Weigh each component according to weight, mix PC resin, ABS resin, toughening agent, compatibilizer, antioxidant, lubricant, carbon black and silane-modified talc evenly, feed the obtained mixture through the main feeding port of a twin-screw extruder, and obtain PC / ABS material after extrusion, granulation, cooling and drying;

[0060] The process parameters of the twin-screw extruder are as follows: feeding section 225°C, compression section 235°C, metering section 245°C, die head 260°C, screw speed 400rpm.

[0061] Comparative Example 4

[0062] A PC / ABS material, which is different from Example 4 in that silane-modified talc is not added, and correspondingly, is not added in the preparation method, and other components and parameters remain the same.

[0063] The PC / ABS materials prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were injection molded into specimens according to GB standard, and their mechanical properties were tested after conditioning in a constant temperature and humidity environment of 23° C. and 50% RH for 24 hours;

[0064] The density is tested according to GB / T 1033 standard method;

[0065] The tensile strength is tested according to GB / T 1044 standard method;

[0066] Bending strength is tested according to GB / T 9341 standard method;

[0067] The simply supported beam notched impact strength is tested according to GB / T 1043.1 standard method;

[0068] Vicat softening temperature is tested according to GB / T 1633 standard method;

[0069] The test results are shown in Table 3:

[0070] Table 3

[0071]

[0072]

[0073] From the test results in Table 3, it can be seen that the linear expansion coefficient of the material can be significantly reduced by adding talc, but the impact strength of the material will also be significantly reduced; after adding silane-modified talc, the linear expansion coefficient of the material is significantly lower than that of the material with conventional talc; while surface-modified talc reduces the linear expansion coefficient of the material, it retains the impact strength of the material to a certain extent, so that the material performance, linear expansion coefficient and impact strength can reach a balanced level.

[0074] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0075] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high impact, low linear expansion coefficient PC / ABS material, characterized in that: According to weight parts, it includes the following raw materials: 53-68 parts of PC resin, ABS resin 10-32 parts, Silane modified talc 10-20 parts, 3-6 parts of toughening agent, 0.5 parts of compatibilizer, 0.5 parts of antioxidant, 0.5 parts of lubricant, 0.5 parts of carbon black.

2. A high impact, low linear expansion coefficient PC / ABS material according to claim 1, characterized in that: The PC resin is a bisphenol A polycarbonate resin, and has a melt index of 10-20 g / 10 min at 300° C. / 1.2 kg.

3. The high impact, low linear expansion coefficient PC / ABS material according to claim 1, characterized in that: The relative molecular weight of the ABS resin is 120,000-130,000 g / mol, and the acrylonitrile content is 24-28%.

4. The high impact, low linear expansion coefficient PC / ABS material according to claim 1, characterized in that: The silane-modified talc is prepared by the following steps: The talc powder is added into a silane coupling agent aqueous solution with a mass percentage of 13-15%, stirred for 30-80 minutes, dried at 80-120° C., and then ball-milled to obtain silane-modified talc powder with a mesh size of 4000-6000.

5. The high impact, low linear expansion coefficient PC / ABS material according to claim 4, characterized in that: The usage ratio of the talcum powder and the silane coupling agent aqueous solution is 25g:75g.

6. The high impact, low linear expansion coefficient PC / ABS material according to claim 1, characterized in that: The toughening agent is a terpolymer of styrene, butadiene and methyl methacrylate.

7. The high impact, low linear expansion coefficient PC / ABS material according to claim 1, characterized in that: The antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphate, tris(2,4-di-tert-butylphenyl)phosphite and bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

8. The high impact, low linear expansion coefficient PC / ABS material according to claim 1, characterized in that: The lubricant is one or more of silicone, ethylene bis stearamide, and pentaerythritol stearate.

9. A method for preparing the high impact, low linear expansion coefficient PC / ABS material as claimed in claim 1, characterized in that: The following steps are involved: PC resin, ABS resin, toughening agent, compatibilizer, antioxidant, lubricant and carbon black are mixed uniformly, and the obtained mixture is fed through the main feeding port of the twin-screw extruder, and the silane-modified talc powder is fed through the side feeding port. After extrusion, granulation, cooling and drying, a high-impact, low linear expansion coefficient PC / ABS material is obtained.

10. The method for preparing a high impact, low linear expansion coefficient PC / ABS material according to claim 9, characterized in that: The process parameters of the twin-screw extruder are as follows: feeding section 220-230°C, compression section 230-240°C, metering section 240-250°C, die head 260°C, screw speed 350-450rpm.

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