High-dimensional-stability carbon-fiber-reinforced PC material, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are a high-dimensional-stability carbon-fiber-reinforced PC material, and a preparation method therefor and the use thereof. The high-dimensional-stability carbon-fiber-reinforced PC material comprises the following components in parts by weight: 50-90 parts of a PC resin, 30-40 parts of carbon fibers, 3-5 parts of a toughening agent and 0.1-0.3 parts of a transesterification inhibitor. The surface of the carbon fibers is provided with a sizing agent, and the sizing agent is a polyurethane or a polyamide; and the mass percentage of the sizing agent in the carbon fibers is 2-5%. In the carbon-fiber-reinforced PC material of the present invention, the content of the carbon fiber sizing agent is reduced, and dimensional stability of the material is improved; in addition, it is ensured that the notch impact strength of the material is high, and the bending resistance is high, such that the carbon-fiber-reinforced PC material can be widely applied to the fields of electronic appliances, automobiles, machinery, musical instruments, etc., which have relatively high requirements for dimensional stability and require workpiece assembling.

Description

A carbon fiber reinforced PC material with high dimensional stability and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a carbon fiber reinforced PC material with high dimensional stability, a preparation method thereof, and an application thereof. Background Art

[0002] Polycarbonate (PC) is gaining increasing attention for its excellent mechanical properties, impact resistance, and heat resistance. To meet the needs of various applications, PC can be modified. For example, by adding carbon fiber to a PC matrix, a PC-reinforced material with high strength and stiffness can be produced. Compared to PC reinforced with the same amount of glass fiber, the modulus of carbon fiber-reinforced PC can be increased by approximately 50%.

[0003] However, traditional carbon fiber precursors have poor bonding properties with resins. Therefore, the surface of carbon fibers typically used in thermoplastic materials contains a large amount of sizing agents. The presence of sizing agents can cause degradation of the PC matrix. Slight fluctuations in process and equipment conditions can lead to significant variations in the overall material degradation, resulting in unstable and volatile melt indexes. During the production process, differences in fluidity can lead to significant dimensional fluctuations in the finished product, impacting the subsequent assembly of other parts.

[0004] Therefore, there is an urgent need for a carbon fiber reinforced PC material that reduces the sizing agent content and improves the dimensional stability of the material to meet the needs of areas such as parts assembly that require high dimensional stability. Summary of the Invention

[0005] In view of the defects in the prior art, the present invention proposes a carbon fiber reinforced PC material and a preparation method and application thereof.

[0006] The present invention provides a carbon fiber reinforced PC material, which comprises the following components in parts by weight:

[0007] The surface of the carbon fiber has a sizing agent, and the type of the sizing agent is polyurethane (PU) or polyamide (PA); the type of the sizing agent can be detected by X-ray photoelectron spectroscopy (XPS);

[0008] The mass percentage of the sizing agent in the carbon fiber is 2% to 5%. The content of the sizing agent can be measured by TGA, where the mass loss is the sizing agent content when the temperature is raised from 30°C to 750°C under a nitrogen atmosphere. Alternatively, the sizing agent content can be measured by solvent dissolution method, where the mass loss before and after the dissolution test is the sizing agent content. The solvent type can be selected. By controlling the mass percentage of the carbon fiber sizing agent to 2% to 5%, the effect of the carbon fiber sizing agent on PC degradation is reduced.

[0009] The weight proportion of the PC resin can be 50, 60, 70, 80, or 90 parts;

[0010] The minimum mass percentage of the PC resin in the carbon fiber reinforced PC material composition is preferably 50%, more preferably 70-90%;

[0011] Furthermore, the PC of the present invention is preferably bisphenol A type PC, and the melt index of PC is preferably 10 to 30 g / 10 min (300° C., 1.2 kg), and the test standard is ISO 1133-2022.

[0012] The weight proportion of the carbon fiber can be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40 parts per weight; and the diameter of the carbon fiber is preferably 5 to 7 μm.

[0013] The weight proportions of the toughening agent can be 3, 3.5, 4, 4.5, 3, or 5.

[0014] The weight portion of the transesterification inhibitor can be 0.1, 0.15, 0.2, 0.25, or 0.3.

[0015] Furthermore, the present invention does not contain polybutylene terephthalate (PBT); when PBT is not contained, the material has strong bending resistance and high notched impact strength.

[0016] Furthermore, the transesterification inhibitor is one or more of triphenyl phosphite, sodium acid pyrophosphate, and sodium dihydrogen phosphate.

[0017] Furthermore, the weight ratio of the sizing agent to the transesterification inhibitor is (2.5-5): 1. The addition of the transesterification inhibitor prevents transesterification between the carbon fiber sizing agent and the PC matrix, further ensuring the melt index stability of the material and improving the dimensional stability of the product.

[0018] Furthermore, the toughening agent is one or more of methyl methacrylate-butadiene-styrene copolymer (MBS), styrene-butadiene-styrene copolymer (SBS), and ethylene copolymer, preferably MBS, which has good compatibility with PC. The addition of the toughening agent is beneficial to improving the impact performance of the material, while ensuring that the performance balance of the material is achieved while reducing the content of the carbon fiber sizing agent.

[0019] Furthermore, the carbon fiber reinforced PC material further comprises 0 to 5 parts by mass of an auxiliary agent, wherein the auxiliary agent is one or more of an antioxidant and a lubricant.

[0020] Furthermore, the antioxidant comprises a first antioxidant and a second antioxidant; the first antioxidant is one or more of phenolic antioxidants and hindered amines; the second antioxidant is one or more of phosphites and sulfuric acid-containing antioxidants; the lubricant is one or more of fluorides, fatty acids and their esters, fatty acid amides, metal soaps, hydrocarbons, and organosilicon compounds.

[0021] The present invention also provides a method for preparing the carbon fiber reinforced PC material, comprising the following steps:

[0022] Each component, excluding the carbon fiber, is weighed by weight and mixed, and then directly fed into a twin-screw extruder for processing. The carbon fiber is fed into the twin-screw extruder through a side feed port near the die end of the double-side machine. After extrusion, cooling, and pelletization, the carbon fiber-reinforced PC material is produced. The temperature of each zone of the twin-screw extruder barrel is maintained at 220-260°C.

[0023] The present invention also provides applications of the carbon fiber reinforced PC material in electronic appliances, automobiles, machinery, and musical instruments; the electronic appliances include communication equipment, televisions, office electronic equipment, medical electronic equipment, etc.; the machinery includes engines and power transmissions, hydraulic and pneumatic systems, transmission systems, mechanical materials, etc.

[0024] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0025] (1) The carbon fiber reinforced PC material of the present invention successfully solves the problems of unstable melt index and large fluctuations in finished product size caused by excessive addition of sizing agent.

[0026] (2) The carbon fiber reinforced PC material of the present invention has strong bending resistance and high notched impact strength. DETAILED DESCRIPTION

[0027] In order to help those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described 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 those skilled in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0028] Example

[0029] The present invention is further described below with reference to specific examples and comparative examples. The following specific examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples, and are particularly not limited to the types of the various component raw materials used in the following specific examples.

[0030] 1. The sources of raw materials for the embodiments and comparative examples are as follows:

[0031] PC resin: brand PC 2220, Wanhua Chemical Company;

[0032] Carbon fiber A: average sizing agent (PU) content is 4.5%, the raw fiber is from Zhongfu Shenying Company;

[0033] Carbon fiber B: average sizing agent (PU) content is 3.5%, the raw fiber is from Zhongfu Shenying Company;

[0034] Carbon fiber C: average sizing agent (PU) content is 2.5%, the raw fiber is from Zhongfu Shenying Company;

[0035] Carbon fiber D: The average sizing agent (PA) content is 2.5%, and the precursor is from Zhongfu Shenying Company. The above four carbon fibers are all the same carbon fiber precursor, with only the sizing agent content and type being different;

[0036] Toughener A: MBS toughener, brand M-521, produced by Nakabuchi Co., Ltd., Japan;

[0037] Toughener B: SBS toughener, brand SBSD1101 ASM, Kraton Polymers;

[0038] Toughener C: maleic anhydride grafted ethylene copolymer toughening agent, brand FUSABONDN493, DuPont;

[0039] Ester exchange inhibitor A: disodium dihydrogen pyrophosphate, brand DHPP, Nagase Co.;

[0040] Ester exchange inhibitor B: sodium dihydrogen phosphate, brand MSP2040, Lianyungang Xidu Biochemical Company;

[0041] Additives: Antioxidant: The main antioxidant is hindered phenol antioxidant, brand SONOX 1076, Sanfeng Chemical Company;

[0042] The secondary antioxidant is phosphite, brand YFK-168, Fengguang Chemical Company;

[0043] The mass ratio of primary antioxidant to secondary antioxidant was 1 to 2:1; the same substances were used in parallel experiments.

[0044] Lubricant:

[0045] Internal lubricant: pentaerythritol stearate, Guangzhou Jiadele Biochemical Technology Co., Ltd.;

[0046] External lubricant: Fluoride, fluoropolymer processing aid (PPA), FX-5911, 3M Company. Parallel experiments used the same substance.

[0047] The preparation method of the carbon fiber reinforced PC material of the embodiment of the present invention and the comparative example comprises the following steps:

[0048] After the PC, toughening agent, and additives are evenly mixed, they are directly fed into a twin-screw extruder for processing. The carbon fibers are fed into the twin-screw extruder through a side feed port. To ensure that the carbon fibers retain a high retained length after processing, a double-side feed port near the die head is used. The finished particles are obtained through extrusion, cooling, and granulation. The temperature of each zone of the twin-screw extruder is maintained at 220-260°C.

[0049] 2. Various performance test methods

[0050] (1) The flexural modulus test method refers to the test standard ISO 178-2019;

[0051] (2) Melt index of five batches: The melt index of each batch is tested, and five batches are tested. The difference between the maximum and minimum melt index values ​​of the five batches is the melt index difference of the five batches; the test method of the melt index refers to the test standard of ISO 1133-2022;

[0052] (3) The Izod notched impact strength test method refers to the test standard ISO 180-2019.

[0053] Table 1 Example technical solutions and effects (units are parts by weight)

[0054] Table 2 Comparative Examples Technical Scheme and Effects (Units are parts by weight)

[0055] Compared with Example 1, Comparative Example 1 did not include a toughening agent; Comparative Example 2 did not include a transesterification inhibitor; Comparative Example 3 included an excessive amount of transesterification inhibitor; and Comparative Example 4 included an excessive amount of toughening agent. None of the above comparative examples were able to maintain stable material flowability while maintaining high impact toughness and flexural resistance.

[0056] Based on the test data of flexural modulus, five batches of melt index difference and notched impact strength in Table 1 and Table 2, the carbon fiber reinforced PC material prepared by the embodiment has a five-batch melt index difference of less than 10, a flexural modulus of more than 17500 MPa, and a notched impact strength of 12 KJ / m 2 Under the premise that the notched impact strength can meet the requirements, the melt index stability of the material is improved, the dimensional stability of the final product is high, and the qualified rate of the product is improved.

[0057] 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 in the scope of protection of the present invention.

Claims

1. A carbon fiber reinforced PC material, characterized in that, Comprising the following components by weight parts: The surface of the carbon fiber has a sizing agent, and the type of the sizing agent is polyurethane or polyamide; The mass percentage of the sizing agent in the carbon fiber is 2% to 5%.

2. The carbon fiber reinforced PC material according to claim 1, characterized in that, The transesterification inhibitor is one or more of triphenyl phosphite, sodium acid pyrophosphate, and sodium dihydrogen phosphate.

3. The carbon fiber reinforced PC material according to claim 1, characterized in that, The weight ratio of the sizing agent to the transesterification inhibitor is (2.5 to 5):

1.

4. The carbon fiber reinforced PC material according to claim 1, wherein The toughening agent is one or more of methyl methacrylate-butadiene-styrene copolymer, styrene-butadiene-styrene copolymer, and ethylene copolymer, and preferably methyl methacrylate-butadiene-styrene copolymer.

5. The carbon fiber reinforced PC material according to claim 1, wherein The carbon fiber reinforced PC material further includes an auxiliary agent, and the auxiliary agent is one or more of an antioxidant and a lubricant.

6. The carbon fiber reinforced PC material according to claim 5, characterized in that, The antioxidant includes a first antioxidant and a second antioxidant; the first antioxidant is one or more of phenolic antioxidants and hindered amines; the second antioxidant is one or more of phosphite esters and sulfur-containing antioxidants; the lubricant is one or more of fluorides, fatty acids and their esters, fatty acid amides, metal soaps, hydrocarbons, and silicone compounds.

7. The preparation method of the carbon fiber reinforced PC material according to any one of claims 1 to 6, characterized in that, It includes the following steps: Weigh each component by weight. The components other than the carbon fiber are mixed and directly fed into a twin-screw extruder for processing. The carbon fiber enters the twin-screw extruder through a side feeding port for processing, and the carbon fiber reinforced PC material is obtained through extrusion, cooling, and pelletizing.

8. Application of the carbon fiber reinforced PC material according to any one of claims 1 to 6 in electronic appliances, automobiles, machinery, and musical instruments.

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