A PC / PS alloy material and its preparation method and application

Abstract

The present invention discloses a PC / PS alloy material, its preparation method, and application. The PC / PS alloy material comprises the following components, by weight: 30-80 parts PC resin; 10-40 parts PS resin; 3-20 parts silica; and 3-8 parts compatibilizer. By adding a certain proportion of PS resin to the PC resin, along with specific silica and a compatibilizer, the present invention effectively reduces the material's linear expansion coefficient and wear, resulting in a PC / PS alloy with both high dimensional stability and excellent wear resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a PC / PS alloy material and a preparation method and application thereof. Background Art

[0002] Polycarbonate (PC) is an excellent engineering plastic with excellent overall properties, including high mechanical strength, good impact toughness, good heat resistance, and good electrical insulation. It is widely used in home appliances, digital products, IT products, and other fields. However, the paper feed components of printers require high dimensional stability and resistance to wear caused by rotation and sliding (i.e., they require a low linear expansion coefficient and low abrasion). Existing PC materials struggle to meet the printer industry's requirements.

[0003] Chinese patent application CN110564129A discloses a low linear expansion coefficient, flame retardant polycarbonate composite material by Sc2W3O 12 Compounding with polyborosiloxane can achieve both linear expansion coefficient and flame retardancy, but it does not improve wear resistance. Existing technologies have attempted to improve the wear resistance of PC materials by adding fluoropolymers (such as ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, and polyvinylidene fluoride) as wear modifiers. For example, Chinese patent application CN108047677A discloses a highly wear-resistant, high-strength polycarbonate composite material. By adding fluoropolymer micropowder wax to PC resin, the material's friction coefficient and wear rate are reduced. However, fluoropolymers are relatively expensive, and generally require a large addition amount to improve wear resistance, resulting in high material costs. Furthermore, because fluoropolymers are non-polar and have poor compatibility with polar resins, they can only improve the material's wear resistance to a certain extent, failing to effectively reduce wear and failing to simultaneously achieve dimensional stability. Currently, there are no reports on modifications that simultaneously address both dimensional stability and wear resistance in PC materials. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a PC / PS alloy material having both high dimensional stability and excellent wear resistance.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned PC / PS alloy material.

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

[0007] A PC / PS alloy material, comprising the following components in parts by weight:

[0008] 30-80 parts of PC resin;

[0009] 10-40 parts of PS resin;

[0010] 3-20 parts of silicon dioxide;

[0011] 3-8 parts of compatibilizer.

[0012] The weight parts of the PC resin can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts or 80 parts.

[0013] The weight proportion of the PS resin may be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts or 40 parts.

[0014] The weight parts of the silicon dioxide can be 3 parts, 6 parts, 9 parts, 12 parts, 15 parts, 18 parts or 20 parts.

[0015] The weight proportion of the compatibilizer may be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts or 8 parts.

[0016] Preferably, the reflectivity of the silicon dioxide to ultraviolet light is ≥70% (for example, 71%, 73%, 75%, 78% or 80%, and specific values ​​between the above points), and the reflectivity to visible light is ≥85% (for example, 83%, 85%, 87% or 90%, and specific values ​​between the above points). By adopting silicon dioxide with a specific reflectivity, the present invention can make the material have a low linear expansion coefficient and wear at the same time. The reflectivity of the silicon dioxide described in the present invention can be tested by a microspherical reflectivity tester, and the test conditions are: the wavelength of ultraviolet light is 380nm, and the wavelength of visible light is 600nm. The specific operating steps of the reflectivity test are: place an appropriate amount of silicon dioxide sample on a glass slide, adjust the wavelength of the incident light, and then automatically analyze the reflectivity at the wavelength through the receiver, and output the result after the reading stabilizes.

[0017] The surface of the silicon dioxide of the present invention may be modified by a silane coupling agent.

[0018] Preferably, the average particle size of the silicon dioxide of the present invention is 0.005 μm to 3 μm. The average particle size is measured using a laser particle size analyzer.

[0019] Preferably, the weight content of silicon dioxide in the PC / PS alloy material is 5%-20%, more preferably 8%-15%.

[0020] Preferably, the weight average molecular weight of the PC resin is greater than 20,000, and more preferably, the weight average molecular weight of the PC resin is 23,000-35,000. The weight average molecular weight of the PC resin can be measured by gel permeation chromatography (GPC).

[0021] Preferably, the mass percentage of the PC resin in the PC / PS alloy material is not less than 40%.

[0022] Furthermore, the PC resin is preferably selected from bisphenol A polycarbonate. The PS resin is preferably selected from atactic polystyrene.

[0023] The present invention incorporates a certain ratio of PS to PC to form an alloy, which fills the gaps between PC chains. This reduces PC molecular rigidity and creates a denser molecular weight distribution, thereby reducing the material's linear expansion coefficient and wear. A PS content that is too low will not effectively improve the material's linear expansion coefficient and wear. A PS content that is too high will accumulate on the surface, hindering the formation of a uniform phase and increasing material wear. Preferably, the weight ratio of the PC resin to the PS resin is (1-4):1.

[0024] Preferably, the weight average molecular weight of the PS resin is 300,000-450,000. The weight average molecular weight of the PS resin can be measured by gel permeation chromatography (GPC).

[0025] Preferably, the compatibilizer is selected from one or more of maleic anhydride grafted styrene, oxidized polyethylene wax, maleic anhydride modified polyethylene wax, polyol ester with a weight average molecular weight of less than 500, methyl methacrylate-butadiene-styrene terpolymer, ethylene-acrylic acid copolymer or ethylene-methacrylic acid-glycidyl methacrylate terpolymer; more preferably, the compatibilizer is selected from one or more of methyl methacrylate-butadiene-styrene terpolymer, ethylene-acrylic acid copolymer or ethylene-methacrylic acid-glycidyl methacrylate terpolymer; more preferably, the compatibilizer is selected from ethylene-methacrylic acid-glycidyl methacrylate terpolymer.

[0026] To meet flame retardancy requirements, the PC / PS alloy material of the present invention further includes 5-20 parts by weight (e.g., 5, 8, 10, 12, 15, 18, or 20 parts) of a phosphorus-based flame retardant. Preferably, the phosphorus content of the phosphorus-based flame retardant is 8-20%. Furthermore, the phosphorus-based flame retardant is selected from a phosphate ester. This improves the material's flame retardancy while maintaining a low linear expansion coefficient and abrasion resistance.

[0027] The present invention also provides a method for preparing the above-mentioned PC / PS alloy material, comprising the following steps: after uniformly mixing the components according to the proportion, extruding and granulating through a twin-screw extruder to prepare the PC / PS alloy material; wherein the screw temperature is 200-250°C and the rotation speed is 180-500r / min.

[0028] The present invention also provides application of the PC / PS alloy material in a paper transfer component of a printer.

[0029] The present invention has the following beneficial effects:

[0030] The present invention adds a certain proportion of PS resin to PC resin, and simultaneously adds specific silica and a compatibilizer, which can effectively reduce the linear expansion coefficient and wear of the material, and prepare a PC / PS alloy with both high dimensional stability and excellent wear resistance.

[0031] The PC / PS alloy material of the present invention has a low linear expansion coefficient, excellent dimensional stability, and small deformation during use, which reduces the interference between the workpiece and the wear part, thereby further reducing the wear during use and effectively extending the service life of the workpiece. It has good application prospects in printer paper transfer components. Implementation Method

[0032] 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 are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0033] The raw materials used in the examples and comparative examples of the present invention are described below, but are not limited to these materials:

[0034] PC resin 1: bisphenol A polycarbonate, weight average molecular weight of 25,000, brand name PC1300 10 NP, LG, South Korea.

[0035] PC resin 2: bisphenol A polycarbonate, weight average molecular weight of 17,000, brand name PC FN1700, Idemitsu, Japan.

[0036] PS resin: atactic polystyrene, weight-average molecular weight 350,000, brand PS 350K, Guoheng Plastics.

[0037] Silicon dioxide 1: The reflectivity of ultraviolet light is 76%, and the reflectivity of visible light is 88%, DK-SiO2-H30, Beijing Dekedaojin Technology Co., Ltd.

[0038] Silicon dioxide 2: reflectivity of ultraviolet light is 73%, reflectivity of visible light is 87%, SH100, Guangzhou Xinxi Metallurgical Chemical Co., Ltd.

[0039] Silicon dioxide 3: reflectivity of ultraviolet light is 75%, reflectivity of visible light is 85%, SH101, Guangzhou Xinxi Metallurgical Chemical Co., Ltd.

[0040] Silicon dioxide 4: The reflectivity of ultraviolet light is 71%, and the reflectivity of visible light is 83%, DK-SiO2-T30, Beijing Dekedaojin Technology Co., Ltd.

[0041] Silicon dioxide 5: The reflectivity of ultraviolet light is 64%, and the reflectivity of visible light is 78%, DK-SiO2-X30, Beijing Dekedaojin Technology Co., Ltd.

[0042] Compatibilizer 1: methyl methacrylate-butadiene-styrene terpolymer, EM500, LG Chem.

[0043] Compatibilizer 2: ethylene-methacrylic acid-glycidyl methacrylate terpolymer, AX8900, Arkema.

[0044] Compatibilizer 3: Ethylene acrylic acid copolymer, EAA Primacor® 3460, Dow.

[0045] Compatibilizer 4: Maleic anhydride grafted styrene, SMA 700, Huawen.

[0046] Compatibilizer 5: styrene-butadiene-acrylonitrile terpolymer, ABS POW HR181, Kumho, Korea.

[0047] Phosphorus-based flame retardant: phosphate ester, phosphorus content 8.9%, WSFR-BDP-N2, Zhejiang Wansheng.

[0048] Preparation methods of PC / PS alloy materials of Examples and Comparative Examples:

[0049] After uniformly mixing the components according to the ratio, the PC / PS alloy material is prepared by extruding and granulating through a twin-screw extruder; wherein the screw temperature is 200-250°C and the rotation speed is 180-500r / min.

[0050] Related performance test methods:

[0051] (1) Linear expansion coefficient: tested using ISO 11359-2-1999 standard.

[0052] (2) Wear: The test is carried out using a Taber abrasion tester. The sample is placed in the machine and the weight loss after 2500 rotations is compared. The unit is mg.

[0053] Table 1: Distribution ratios of each group in Examples 1-12 (by weight) and related performance test results

[0054]

[0055] Continued from Table 1:

[0056]

[0057] Table 2: Distribution ratios of each group in Comparative Examples 1-9 (by weight) and related performance test results

[0058]

[0059] As can be seen from the results of the above embodiments and comparative examples, the present invention adds a certain proportion of PS resin to PC resin, and at the same time adds specific silica and a compatibilizer, which can effectively reduce the linear expansion coefficient and wear of the material, and prepare a PC / PS alloy with high dimensional stability and excellent wear resistance, whose linear expansion coefficient is ≤6.60E-5 and wear loss is ≤72 mg.

Claims

1. A PC / PS alloy material, characterized in that: Calculated by weight, it includes the following components: 30-80 parts of PC resin; 10-40 parts of PS resin; 3-20 parts of silicon dioxide; 3-8 parts of compatibilizer; The reflectivity of the silicon dioxide to ultraviolet light is ≥70%, and the reflectivity to visible light is ≥85%; The compatibilizer is selected from one or more of maleic anhydride grafted styrene, oxidized polyethylene wax, maleic anhydride modified polyethylene wax, polyol ester with a weight average molecular weight lower than 500, methyl methacrylate-butadiene-styrene terpolymer, ethylene-acrylic acid copolymer, and ethylene-methacrylic acid-glycidyl methacrylate terpolymer.

2. The PC / PS alloy material according to claim 1, characterized in that The weight content of silicon dioxide in the PC / PS alloy material is 5%-20%.

3. The PC / PS alloy material according to claim 2, characterized in that: The weight content of silicon dioxide in the PC / PS alloy material is 8%-15%.

4. The PC / PS alloy material according to claim 1, characterized in that The weight ratio of the PC resin to the PS resin is (1-4):

1.

5. The PC / PS alloy material according to claim 1, characterized in that: The weight average molecular weight of the PC resin is greater than 20,000.

6. The PC / PS alloy material according to claim 5, characterized in that: The weight average molecular weight of the PC resin is 23,000-35,000.

7. The PC / PS alloy material according to claim 1, characterized in that: The PC resin is selected from bisphenol A polycarbonate.

8. The PC / PS alloy material according to claim 1, characterized in that The PS resin is selected from atactic polystyrene.

9. The PC / PS alloy material according to claim 1, characterized in that: Calculated by weight, the invention also includes 5-20 parts of phosphorus-based flame retardant.

10. The PC / PS alloy material according to claim 9, characterized in that: The phosphorus content of the phosphorus-based flame retardant is 8-20%.

11. The PC / PS alloy material according to claim 9, characterized in that: The phosphorus-based flame retardant is selected from phosphate esters.

12. The PC / PS alloy material according to claim 1, characterized in that: The compatibilizer is selected from one or more of methyl methacrylate-butadiene-styrene terpolymer, ethylene-acrylic acid copolymer or ethylene-methacrylic acid-glycidyl methacrylate terpolymer.

13. The PC / PS alloy material according to claim 12, characterized in that: The compatibilizer is selected from ethylene-methacrylic acid-glycidyl methacrylate terpolymer.

14. The method for preparing a PC / PS alloy material according to any one of claims 1 to 13, characterized in that: The method comprises the following steps: uniformly mixing the components according to a proportion, and then extruding and granulating the components through a twin-screw extruder to prepare a PC / PS alloy material; wherein the screw temperature is 200-250° C., and the rotation speed is 180-500 r / min.

15. Use of the PC / PS alloy material according to any one of claims 1 to 13 in a paper transfer component of a printer.

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