Wear-resistant ABS composition and preparation method thereof

Abstract

The invention discloses a wear-resistant ABS (Acrylonitrile Butadiene Styrene) composition which comprises the following components in percentage by weight: 30-50% of ABS; 5 to 20% of polycarbonate; 5 to 20% of a styrene-acrylonitrile copolymer; 1 to 15% of polybutylene terephthalate; 1-5% of an organosilicon modifier; 1-10% of inorganic mineral powder; 10 to 30% of glass fiber; and 0.5-5% of other additives. The invention also discloses a preparation method of the wear-resistant ABS composition. The ABS composition provided by the invention can achieve good balance between mechanical properties and wear resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymer materials, and particularly relates to a wear-resistant ABS composition and a preparation method thereof. BACKGROUND

[0002] ABS plastic is copolymerized from three monomers of acrylonitrile (A), butadiene (B) and styrene (S), and has rigidity, hardness and impact resistance, and also has good chemical corrosion resistance, radiation resistance and ethylene oxide sterilization performance. In the medical field, it is widely used for manufacturing surgical tools, roller clamps, plastic needles and hearing aid shells. Medical devices need to bear certain mechanical action in use, and therefore the plastic material should have sufficient mechanical strength, rigidity and wear resistance. Especially for parts that need to be frequently operated, the wear resistance should be particularly concerned. For example, when manufacturing medical devices, the plastic is required to reduce friction and wear in use, so as to reduce the frequency of maintenance and replacement of parts and save medical costs.

[0003] Therefore, there is still a need to provide an ABS composition having an excellent combination of good processing performance, mechanical performance and wear resistance. SUMMARY

[0004] The present application utilizes the synergy between different components in ABS blending modification to obtain a wear-resistant ABS composite material with excellent comprehensive performance.

[0005] The present application aims to provide a wear-resistant ABS composition.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a wear-resistant ABS composition, made from the following components in the weight parts, based on the total amount of 100 parts: ABS 30-50 parts, polycarbonate 5-20 parts, styrene-acrylonitrile copolymer 5-20 parts, polybutylene terephthalate 1-15 parts, organic silicon modifier 1-5 parts, inorganic mineral powder 1-10 parts, glass fiber 10-30 parts, and other additives 0.5-5 parts.

[0007] As a preference, in the composition, the weight percentage content of the styrene-acrylonitrile copolymer is 8-15%; the weight percentage content of the polybutylene terephthalate is 5-10%; and the weight percentage content of the organic silicon modifier is 2-3%.

[0008] In the composition, the ABS is a copolymer of acrylonitrile-butadiene-styrene, which is prepared by bulk polymerization and / or emulsion polymerization method; further, the ABS is a mixture of bulk ABS (ABS prepared by bulk polymerization method) and emulsion ABS (ABS prepared by emulsion polymerization method).

[0009] As a preference, the weight ratio of the bulk ABS and the emulsion ABS in the composition is 3 / 2 to 5 / 2.

[0010] wherein the emulsion ABS is a high rubber graft acrylonitrile-butadiene-styrene copolymer, can have a butadiene content of between 25% and 85% by weight, and a ratio of styrene to acrylonitrile of between 90:10 and 60:40. Further, the high rubber graft acrylonitrile-butadiene-styrene copolymer has a rubber content (i.e., butadiene content) of greater than or equal to about 50 wt% of the graft polymer by weight. For example, the high rubber graft acrylonitrile-butadiene-styrene copolymer can have a rubber content of greater than or equal to about 60 wt% of the graft polymer by weight.

[0011] In a further aspect, the high rubber graft acrylonitrile-butadiene-styrene copolymer has an average rubber particle size of 0.1 microns to about 3 microns. For example, the high rubber graft acrylonitrile-butadiene-styrene copolymer can have an average rubber particle size of about 0.4 microns.

[0012] The polycarbonate in the composition comprises a homopolycarbonate having repeating structural carbonate units, and can be an aliphatic polycarbonate, a cycloaliphatic polycarbonate, or a mixture of one or two of an aromatic polycarbonate. In the present invention, suitable polycarbonates can be prepared by, for example, interfacial polymerization and melt polymerization. In a particular embodiment, the polycarbonate is a linear homopolymer derived from bisphenol A, i.e., a polycarbonate containing bisphenol A structures. The polycarbonate has high flow characteristics, with a melt index of 300 o C, 1.2 Kg, 25-60 g / 10 min.

[0013] The styrene-acrylonitrile copolymer in the composition can be prepared by bulk, suspension, or emulsion polymerization, and is substantially free of impurities, residual acid, residual base, or residual metals that can catalyze hydrolysis of the polycarbonate. In one aspect, the styrene-acrylonitrile copolymer is prepared by bulk polymerization.

[0014] In various aspects, the styrene-acrylonitrile copolymer has an acrylonitrile monomer content of about 10 to 50 wt%. For example, the styrene-acrylonitrile copolymer has an acrylonitrile monomer content of about 25 wt%.

[0015] The polybutylene terephthalate in the composition has an intrinsic viscosity of 0.6 to 1.4 g / dl, preferably 0.7 to 1.3 g / dl.

[0016] In the composition, the organosilicon modifier includes one or more of polyester-modified organosilicon, polyether-modified organosilicon, and ultra-high molecular weight siloxane. More preferably, the organosilicon modifier is a combination of at least two of polyester-modified organosilicon, polyether-modified organosilicon, and ultra-high molecular weight siloxane.

[0017] Preferably, the polyester-modified organosilicon has a graft-modified structure. Further, the polyester-modified organosilicon is a compound in which polyester chains are introduced into the side chains of a polysiloxane (e.g., polydimethylsiloxane). Preferably, the polyether-modified organosilicon has a graft-modified structure; further, the polyether-modified organosilicon is a compound in which polyether chains are introduced into the side chains of a polysiloxane (e.g., polydimethylsiloxane), such as ethylene oxide-propylene oxide copolyether.

[0018] In the composition, the ultra-high molecular weight siloxane can be directly synthesized by conventional synthesis methods or compounded with inorganic powders. Preferably, the carrier of the ultra-high molecular weight siloxane in this invention is fumed silica.

[0019] Preferably, the polyester-modified organosilicon is polyester-modified polydimethylsiloxane. The polyether-modified organosilicon is polyester-modified polydimethylsiloxane.

[0020] In the composition, the inorganic filler includes one or a mixture of two of talc, mica, kaolin, and wollastonite.

[0021] In the composition, the glass fiber is alkali-free glass fiber, and the average diameter of the glass fiber in the composition is ≤13μm.

[0022] In the composition, other additives include one or more of the following: stabilizers, release agents, colorants, antistatic agents, UV absorbers, metal deactivators, etc. In various embodiments, the stabilizer is present in the system in an amount from 0.01 wt% to about 0.5 wt%. In further embodiments, the stabilizer may comprise heat stabilizers and light stabilizers. Suitable heat stabilizers include hindered phenols, organophosphites, phosphates, or combinations comprising at least one of the above heat stabilizers. Suitable release agents in this invention may comprise metal stearates, polyethylene waxes, silicones, etc., or combinations comprising at least one of the above release agents.

[0023] The beneficial effects of the present invention are that the ABS composition has good processing performance and can achieve a good balance between mechanical properties and wear resistance. Detailed Implementation

[0024] To illustrate the invention in more detail, specific embodiments are described below.

[0025] The ABS used in the comparative examples and embodiments include Shanghai Gaoqiao 8391 (bulk method) and Kumho HR181 (emulsion method).

[0026] The polycarbonate (PC) used in the comparative examples and embodiments is Wanhua high-flow grade, with an MFR of 35 g / 10min at 300°C and 1.2 kg.

[0027] The styrene-acrylonitrile copolymer used in the comparative examples and examples is Kumho SAN320 (abbreviated as SAN in Table 1).

[0028] The polybutylene terephthalate used in the examples is Changchun Chemical PBT-1200 (abbreviated as PBT in Table 1).

[0029] The organosilicon modifiers used in the examples include Evonik Tegomer H-Si 6441P (Si-1, polyester grafted modified organosilicon), TEGOPREN 5840 (Si-2, polyether modified organosilicon), and Wacker GENIOPLAST® Pellet S (Si-3, ultra-high molecular weight siloxane).

[0030] The wollastonite used in the comparative examples and embodiments is WFC5-21-1 from Hubei Fengjiashan Silicon Fiber Co., Ltd.

[0031] The glass fiber used in the comparative examples and embodiments is Jushi ECS13-03-510.

[0032] Referring to Table 1, in the comparative examples and embodiments, the total amount of material is 10 kg. The table shows the weight percentage of each component. The remaining components in the formulation include antioxidants (antioxidant 1076 or / and antioxidant 168) and release agents, etc. The amount added is all in the prior art (for example, in the embodiments and comparative examples, the weight ratio of antioxidant 1076 and antioxidant 168 is 1:1).

[0033] Weigh out the following components according to the specified proportions: ABS, polycarbonate, styrene-acrylonitrile copolymer, polybutylene terephthalate, silicone modifier, inorganic mineral powder, and other additives. Add these components to a high-speed mixer and premix at high speed for 5 minutes. Add the premixed raw material mixture to the hopper of a twin-screw extruder (glass fiber is added via side feeding) for melting, mixing, extrusion, cooling, drying, and pelletizing. Maintain the screw temperature of the twin-screw extruder between 230-250°C, the screw speed at approximately 300 rpm, and the torque at approximately 50% to 60%, operating under standard processing conditions well known to those skilled in the art. Afterward, dry the extruded pellets in a forced-air environment at 90°C for 2 hours, then injection mold them for various performance tests. The testing standards used are as follows:

[0034] Table 1. Ingredients and performance test results for the examples and comparative examples.

[0035]

[0036] Impact performance test: ASTM D4812

[0037] Bending performance test: ASTM D790

[0038] Wear resistance: Reciprocating friction tests were conducted using internal control simulation. The sample was injection molded into a sleeve and mandrel structure of a specific shape and subjected to reciprocating friction at a frequency of 50 times per minute, with a friction distance set at 20 mm. After 1000 cycles, the surface wear of the sample was inspected. Wear resistance was evaluated based on surface scratches and wear debris. More plus signs ("+") indicate better wear resistance. Additionally, the smoothness of the sample to the touch was also evaluated with more plus signs ("+"), indicating better performance.

[0039] As shown in Table 1, the test results indicate that in Comparative Example 1, where the composition system contained only ABS, SAN, and inorganic fillers, the material exhibited poor wear resistance, with noticeable fine wear debris generated during the friction test. In Comparative Example 2, the introduction of a certain amount of high-flow polycarbonate significantly improved the mechanical properties of the material, but the wear resistance remained similar to that of Comparative Example 1. In Examples 1-2, the addition of a certain amount of polybutylene terephthalate improved the wear resistance of the material, resulting in reduced wear debris, but noticeable scratches were still observed. In Examples 3-7, the introduction of an organosilicon modifier resulted in excellent wear resistance and mechanical properties in the ABS composite system. Furthermore, based on the evaluation of the sample's tactile smoothness and wear resistance, the combination of ultra-high molecular weight siloxane with polyester or polyether organosilicon showed a better overall effect.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wear-resistant ABS composition, characterized in that, It mainly includes ABS, polycarbonate, styrene-acrylonitrile copolymer, polybutylene terephthalate, silicone modifier, inorganic mineral powder, glass fiber, and other additives. The weight percentages of each component are as follows: ABS: 30-50%; polycarbonate: 5-20%; styrene-acrylonitrile copolymer: 5-20%; polybutylene terephthalate: 1-15%; silicone modifier: 1-5%; inorganic mineral powder: 1-10%; glass fiber: 10-30%; other additives: 0.5-5%.

2. The wear-resistant ABS composition according to claim 1, characterized in that, The ABS is a copolymer of acrylonitrile-butadiene-styrene, prepared by bulk polymerization and / or emulsion polymerization; wherein the rubber weight percentage of the ABS prepared by emulsion polymerization is more than 50%.

3. The wear-resistant ABS composition according to claim 1, characterized in that, The ABS includes ABS prepared by bulk method and ABS prepared by emulsion method, with a weight ratio of 3 / 2 to 5 / 2.

4. The wear-resistant ABS composition according to claim 1, characterized in that, The polycarbonate has a melt index of 300. o C. The test result at 1.2 kg was 25-60 g / 10 min.

5. The wear-resistant ABS composition according to claim 1, characterized in that, The intrinsic viscosity of the polybutylene terephthalate is 0.6-1.4 g / dl.

6. The abrasion-resistant ABS composition according to claim 1, characterized in that, The organosilicon modifier includes one or more of polyester-modified organosilicon, polyether-modified organosilicon, and ultra-high molecular weight siloxane.

7. The abrasion-resistant ABS composition according to claim 1, characterized in that, The inorganic mineral powder includes one or more of talc, mica, kaolin, and wollastonite.

8. The abrasion-resistant ABS composition according to claim 1, characterized in that, The other additives include one or more of stabilizers, release agents, colorants, and antistatic agents.

9. The abrasion-resistant ABS composition according to claim 1, characterized in that, The organosilicon modifier includes at least two of polyester-modified organosilicon, polyether-modified organosilicon, and ultra-high molecular weight siloxane.

10. A method for preparing the abrasion-resistant ABS composition according to any one of claims 1-9, characterized in that, According to the metering ratio, ABS, polycarbonate, styrene-acrylonitrile copolymer, polybutylene terephthalate, organosilicon modifier, inorganic mineral powder, glass fiber and other additives are premixed evenly, and then melt-blended and extruded into granules through an extruder to obtain wear-resistant ABS composite material.

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