Composite board with low friction coefficient and preparation method thereof

Abstract

The invention relates to the technical field of composite boards, in particular to a low-friction-coefficient composite board and a preparation method thereof.The low-friction-coefficient composite board is prepared by selecting epoxy resin as a composite board base material, selecting light carbon fibers with high strength and good high and low temperature resistance as reinforcing fibers and introducing lubricating filler into the composite board; the preparation method comprises the following steps: compounding different types of epoxy resin to prepare prepreg resin, hot-melting the prepreg resin, coating release paper with the prepreg resin, covering a PE film to obtain resin films, flattening unidirectional carbon fibers, placing the unidirectional carbon fibers between two layers of resin films, carrying out hot pressing, slitting and rolling to obtain single-layer prepreg, laminating the single-layer prepreg, and carrying out compression molding to obtain the composite material. Preparing to obtain a composite board; the preparation method comprises the following steps: carrying out modification treatment on a filler, treating blocky molybdenum disulfide by using sodium alginate as an assistance and adopting a liquid phase stripping method to prepare a functionalized molybdenum disulfide nanosheet of which the surface contains a large amount of hydroxyl groups and carboxyl groups, and then grafting an amino-containing melamine derived flame retardant.

Description

Technical Field

[0001] The present invention relates to the technical field of composite plates, in particular to a low-friction-coefficient composite plate and a preparation method thereof. Background Art

[0002] For objects that contact each other by sliding or rolling, friction and wear are important causes of energy consumption and material failure. All surfaces that move against each other will produce friction and wear. The economic losses caused by friction are huge every year. The development of low-friction wear-resistant materials suitable for multiple fields and working conditions has economic significance and practical value.

[0003] In order to reduce the material loss caused by wear between two contact surfaces, lightweight and easy-to-process resin wear-resistant plates have been rapidly developed compared to traditional metal materials. Generally, fillers with self-lubricating and wear-resistant properties such as graphite, carbon fiber, molybdenum disulfide, etc. are added to the resin to improve the wear resistance of the resin plate. However, there are also problems such as poor strength, poor flame retardancy, and limited corrosion resistance. Summary of the Invention

[0004] The object of the present invention is to provide a low friction coefficient composite plate and a preparation method thereof, so as to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: S1: bisphenol A epoxy resin, novolac epoxy resin, bisphenol F epoxy resin, and modified epoxy resin are mixed and stirred, heated to melt, vacuum degassed, and cooled for standby use to obtain component A; S2: Mixing, stirring, grinding and dispersing the epoxy resin, curing agent, accelerator, filler, silane coupling agent and dispersant to obtain component B; S3: Mixing components A and B, stirring and dispersing, and cooling to obtain a prepreg resin; S4: The prepreg resin is hot-melted and coated on a release paper, which is then covered with a PE film to obtain a resin film; S5: placing the unidirectional carbon fiber between two layers of resin film, performing a single hot pressing process, slitting and winding, and obtaining a single-layer prepreg; S6: The single-layer prepreg is stacked and subjected to secondary hot pressing to obtain a composite plate with a low friction coefficient.

[0006] Furthermore, in step S1, the working conditions for heating to melting are: temperature 150-160°C, time 0.5-1.5h; the working conditions for vacuum degassing treatment are: vacuum degree 0.2-0.4MPa, time 0.5-1.5h; and cooling to 80-95°C for standby use.

[0007] Furthermore, in step S2, the mixing and stirring rate is 300-500 rpm, and a three-roll mill is used for grinding and dispersion, and grinding is performed 3-4 times.

[0008] Furthermore, in step S3, the working conditions for mixing and dispersing the mixture are: vacuum degree of 0.2-0.4 MPa, stirring rate of 20-30 rpm, dispersion rate of 200-400 rpm, and temperature of 70-85°C.

[0009] Furthermore, the mixing ratio of component A and component B is (75-113): (35-65).

[0010] Furthermore, in step S5, the working conditions of the primary hot pressing treatment are: temperature of 90-105° C. and pressure of 1-1.5 MPa.

[0011] Furthermore, in step S6, the working conditions of the secondary hot pressing treatment are: temperature of 140° C.-160° C., pressure of 0.5-2 MPa, and time of 90-120 min.

[0012] Furthermore, the raw material composition of component A is, in parts by weight, 45-50 parts of bisphenol A epoxy resin, 15-25 parts of novolac epoxy resin, 0-8 parts of bisphenol F epoxy resin, and 15-30 parts of modified epoxy resin.

[0013] Furthermore, the raw material composition of component B is as follows, in parts by weight: 18-30 parts of epoxy resin, 5-10 parts of curing agent, 1-2 parts of accelerator, 10-30 parts of filler, 1-1.5 parts of silane coupling agent, and 0-1 part of dispersant.

[0014] Furthermore, the bisphenol A epoxy resin is one or a combination of NPEL-128, NPES-901, and KF41.

[0015] Furthermore, the phenolic epoxy resin is one of NPCN-704 and NPPN-638S, or a combination thereof.

[0016] Furthermore, the modified epoxy resin is one or a combination of carboxyl-terminated nitrile rubber modified epoxy resin, phenoxy modified epoxy resin, and polyurethane modified epoxy resin.

[0017] Furthermore, the modified epoxy resin is one or a combination of carboxyl-terminated nitrile rubber modified epoxy resin R341, phenoxy modified epoxy resin, and polyurethane modified epoxy resin 102C-5H.

[0018] Furthermore, the epoxy resin is one of bisphenol A epoxy resin and bisphenol F epoxy resin, or a combination thereof.

[0019] Furthermore, the epoxy resin is one or a combination of bisphenol A epoxy resin NPEL-128, bisphenol A epoxy resin NPEL-127, and bisphenol F epoxy resin NPEF-170.

[0020] Furthermore, the curing agent is dicyandiamide, and the accelerator is one of an organic urea accelerator and an imidazole accelerator, or a combination thereof.

[0021] Furthermore, the organic urea accelerator is one or a combination of UR500, UR300, and UR700.

[0022] Furthermore, the filler is one or a combination of molybdenum disulfide, kaolin, graphite, titanium dioxide, zirconium dioxide, aluminum oxide, and calcium carbonate.

[0023] Furthermore, the dispersant is an alkyl ammonium salt copolymer.

[0024] Furthermore, the filler is a composite molybdenum disulfide, and the preparation includes the following steps: (1) Sodium alginate and deionized water were mixed, heated to 48-52°C and kept warm for 1-2 hours, molybdenum disulfide was added, and ultrasonic treatment was performed for 5-6 hours. During the ultrasonic treatment, stirring was performed for 1 minute every 20 minutes. The mixture was centrifuged, washed, and freeze-dried to obtain functionalized molybdenum disulfide. (2) Under a nitrogen atmosphere, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide, functionalized molybdenum disulfide, and DMSO are mixed, and an amino-containing melamine-derived flame retardant is added. The mixture is kept at 35-37°C for 6-8 hours, cooled, filtered, washed, and dried to obtain composite molybdenum disulfide.

[0025] Furthermore, the preparation of the amino-containing melamine-derived flame retardant comprises the following steps: 1) Under a nitrogen atmosphere, melamine, allyl bromide, and DMSO were mixed, sodium carbonate was added, and the mixture was stirred at 18-25°C for 2 hours. The mixture was heated to 118-122°C and kept warm for 5-6 hours. The mixture was rotary evaporated, cooled, filtered, washed, and dried to obtain double-bonded melamine. 2) Mix 3-mercaptopropylmethyldimethoxysilane, decamethylcyclopentasiloxane, and hexamethyldisiloxane, add trifluoromethanesulfonic acid and deionized water, keep warm at 75-80°C until transparent, cool to 18-25°C, wash, and distill to obtain mercapto silicone oil; 3) Under a nitrogen atmosphere, double-bonded melamine, mercapto silicone oil, and DMSO are mixed, a photoinitiator is added, the temperature is raised to 50-60°C, and irradiated with 365nm ultraviolet light for 10-12 hours to obtain an amino-containing melamine-derived flame retardant.

[0026] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a low-friction coefficient composite plate and a preparation method thereof. Through raw material and process design, a high-strength, corrosion-resistant, highly flame-retardant, low-friction coefficient composite plate is prepared.

[0027] In the present invention, epoxy resin is selected as the base material of the composite board. Compared with other thermosetting resins, it has better mechanical properties, insulation properties, bonding properties and processing flexibility. Lightweight, high-strength, and high and low temperature resistant carbon fiber is selected as the reinforcing fiber, and one of the lubricating fillers graphite and molybdenum disulfide is introduced into the composite board to reduce the friction coefficient. Prepreg resin is prepared by controlling different types of epoxy resins for compounding, and then the prepreg resin is hot-melted and coated on release paper, and then covered with PE film to obtain a resin film, and the unidirectional carbon fiber is flattened and placed between two layers of resin film, hot-pressed to melt the resin and impregnate the carbon fiber, slit and rolled to obtain a single-layer prepreg, and the single-layer prepreg is stacked and pressed to prepare a composite board, which has a greatly reduced friction coefficient compared with the common carbon fiber reinforced epoxy resin composite board on the market.

[0028] In order to further improve the wear resistance and strength of the composite board, nano-scale fillers are selected for improvement. At the same time, in order to make the nano-scale fillers evenly dispersed in the composite board without the addition of additional dispersants, the fillers are modified. With the assistance of sodium alginate, the bulk molybdenum disulfide is treated by liquid phase exfoliation method to prepare functionalized molybdenum disulfide nanosheets containing a large number of hydroxyl and carboxyl groups on the surface. Then, the functionalized molybdenum disulfide nanosheets containing amino groups are grafted under the action of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide. While improving the uniformity of the filler dispersion in the epoxy resin, the bonding strength between the filler and the base glue is improved, preventing the filler from falling off under conditions such as external force impact, and giving the composite board halogen-free high flame retardancy and corrosion resistance.

[0029] The amino-containing melamine-derived flame retardant is prepared by first preparing double-bonded melamine with melamine and allyl bromide, and then reacting it with mercapto silicone oil for a click reaction. The mercapto silicone oil is prepared by hydrolysis copolymerization of 3-mercaptopropylmethyldimethoxysilane, decamethylcyclopentasiloxane and hexamethyldisiloxane. The introduction of mercapto silicone oil gives the composite board excellent stability, high and low temperature resistance and water resistance, thereby extending the service life of the composite board. DETAILED DESCRIPTION

[0030] The following will provide a clear and complete description of the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, and back, such directional indications are only used to explain a specific posture, such as the relative position relationship between components, the movement status, etc. If the specific posture changes, the directional indication will also change accordingly. In addition, the technical solutions between the various embodiments may be combined with each other, but they must be based on the premise that they can be implemented by ordinary technicians in this field. If the combination of technical solutions is mutually inconsistent or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0032] The technical solutions of the present invention are further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely used to explain the present invention and are not intended to limit the present invention.

[0033] Example 1: A method for preparing a low-friction composite plate, comprising the following steps: S1: bisphenol A epoxy resin, novolac epoxy resin, and modified epoxy resin are mixed and stirred, heated to melt, vacuum degassed, and cooled for standby use to obtain component A; In step S1, the working conditions for heating to melting are: temperature 150°C, time 1.5 hours; the working conditions for vacuum degassing treatment are: vacuum degree 0.3MPa, time 1 hour; cooling to 90°C for standby use; In parts by weight, the raw material composition of component A is: 45 parts of bisphenol A epoxy resin, 22 parts of novolac epoxy resin, and 19 parts of modified epoxy resin; The bisphenol A epoxy resin is a compound of NPEL-128 and NPES-901 at a mass ratio of 6:39; the phenolic epoxy resin is a compound of NPCN-704 and NPPN-638S at a mass ratio of 10:12; the modified epoxy resin is a compound of carboxyl-terminated nitrile rubber modified epoxy resin R341, phenoxy modified epoxy resin, and polyurethane modified epoxy resin 102C-5H at a mass ratio of 9:5:5; S2: Mixing, stirring, grinding and dispersing the epoxy resin, curing agent, accelerator, filler, silane coupling agent and dispersant to obtain component B; In parts by weight, the raw material composition of component B is: 26 parts of epoxy resin, 6.8 parts of curing agent, 1 part of accelerator, 10 parts of filler, 1.3 parts of silane coupling agent, and 0.5 parts of dispersant; The epoxy resin is a mixture of bisphenol A epoxy resin NPEL-128 and bisphenol A epoxy resin NPEL-127 in a mass ratio of 10:16; the curing agent is dicyandiamide; the accelerator is an organic urea accelerator and an imidazole accelerator PN-23 in a mass ratio of 0.7:0.3; the organic urea accelerator is UR500, UR300, and UR700 in a mass ratio of 0.2:0.2:0.3; the filler is flake graphite; and the dispersant is an alkyl ammonium salt copolymer. In step S2, the mixing and stirring speed is 400 rpm, and the grinding and dispersion is performed using a three-roll mill, and the grinding is performed three times; S3: Mixing components A and B, stirring and dispersing, and cooling to obtain a prepreg resin; In step S3, the working conditions for mixing, stirring and dispersing the materials are as follows: vacuum degree of 0.3 MPa, stirring rate of 25 rpm, dispersion rate of 300 rpm, temperature of 85°C, and a mixing ratio of component A to component B of 86:45.6; S4: The prepreg resin is hot-melted and coated on a release paper, which is then covered with a PE film to obtain a resin film; S5: Flattening the unidirectional carbon fiber and placing it between two layers of resin film, performing a single hot pressing process, slitting and winding, and obtaining a single-layer prepreg; The working conditions of the primary hot pressing treatment are: temperature 100°C, pressure 1.2 MPa; S6: stacking the single-layer prepregs and performing a secondary hot pressing treatment to obtain a composite plate with a low friction coefficient; the working conditions of the secondary hot pressing treatment are: temperature of 160° C., pressure of 2 MPa, and time of 90 min.

[0034] Example 2: A method for preparing a low-friction composite plate, comprising the following steps: S1: bisphenol A epoxy resin, novolac epoxy resin, and modified epoxy resin are mixed and stirred, heated to melt, vacuum degassed, and cooled for standby use to obtain component A; In step S1, the working conditions for heating to melting are: temperature 150°C, time 1.5 hours; the working conditions for vacuum degassing treatment are: vacuum degree 0.2MPa, time 1.5 hours; cooling to 80°C for standby use; In parts by weight, the raw material composition of component A is: 45 parts of bisphenol A epoxy resin, 15 parts of novolac epoxy resin, and 15 parts of modified epoxy resin; Bisphenol A epoxy resin is a mixture of NPEL-128 and NPES-901 in a mass ratio of 6:39; phenolic epoxy resin is a mixture of NPCN-704 and NPPN-638S in a mass ratio of 7:8; modified epoxy resin is a mixture of carboxyl-terminated nitrile rubber modified epoxy resin R341, phenoxy modified epoxy resin, and polyurethane modified epoxy resin 102C-5H in a mass ratio of 7:4:4; S2: Mixing, stirring, grinding and dispersing the epoxy resin, curing agent, accelerator, filler and silane coupling agent to obtain component B; In parts by weight, the raw material composition of component B is: 18 parts of epoxy resin, 5 parts of curing agent, 1 part of accelerator, 10 parts of filler, and 1 part of silane coupling agent; The epoxy resin is bisphenol A epoxy resin NPEL-128 and bisphenol A epoxy resin NPEL-127, mixed at a mass ratio of 12:6; the curing agent is dicyandiamide; the accelerator is an organic urea accelerator and an imidazole accelerator PN-23, mixed at a mass ratio of 0.7:0.3; the organic urea accelerator is UR500, UR300, and UR700, mixed at a mass ratio of 0.2:0.2:0.3; In step S2, the mixing and stirring rate is 300 rpm, and the grinding and dispersion is performed using a three-roll mill, and the grinding is performed three times; S3: Mixing components A and B, stirring and dispersing, and cooling to obtain a prepreg resin; In step S3, the working conditions for mixing, stirring and dispersing the materials are as follows: vacuum degree of 0.2 MPa, stirring rate of 20 rpm, dispersion rate of 200 rpm, temperature of 70°C, and a mixing ratio of component A to component B of 75:35; S4: The prepreg resin is hot-melted and coated on a release paper, which is then covered with a PE film to obtain a resin film; S5: Flattening the unidirectional carbon fiber and placing it between two layers of resin film, performing a single hot pressing process, slitting and winding, and obtaining a single-layer prepreg; The working conditions of the primary hot pressing treatment are: temperature 90°C, pressure 1.5MPa; S6: stacking the single layers of prepreg and performing a secondary hot pressing treatment to obtain a composite sheet with a low friction coefficient; the working conditions of the secondary hot pressing treatment are: temperature 140°C, pressure 2 MPa, and time 120 minutes; The filler is composite molybdenum disulfide, and its preparation comprises the following steps: (1) Mix 5 g of sodium alginate and 100 mL of deionized water, heat to 48 °C and keep warm for 2 h, add 1 g of molybdenum disulfide, and ultrasonicate for 5 h. During the ultrasonication process, stir for 1 min every 20 min, centrifuge, wash, and freeze-dry to obtain functionalized molybdenum disulfide. (2) Under nitrogen atmosphere, 0.3 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.4 g of N-hydroxysuccinimide, 1.2 g of functionalized molybdenum disulfide, and 20 mL of DMSO were mixed, and 0.8 g of amino-containing melamine-derived flame retardant was added. The mixture was kept at 35 ° C for 8 h, cooled, filtered, washed, and dried to obtain composite molybdenum disulfide; The preparation of the amino-containing melamine-derived flame retardant comprises the following steps: 1) Under nitrogen atmosphere, 15 g of melamine, 14.4 g of allyl bromide, and 90 mL of DMSO were mixed, 0.2 g of sodium carbonate was added, and the mixture was stirred at 18°C ​​for 2 h. The mixture was heated to 118°C and kept for 6 h. The mixture was rotary evaporated, cooled, filtered, washed, and dried to obtain double-bonded melamine. 2) Mix 0.4 mol of 3-mercaptopropylmethyldimethoxysilane, 0.8 mol of decamethylcyclopentasiloxane, and 0.01 mol of hexamethyldisiloxane, add 7.4 g of trifluoromethanesulfonic acid and 11.5 mL of deionized water, and heat at 75°C until transparent. Cool to 25°C, wash, and distill to obtain mercapto silicone oil. 3) Under nitrogen atmosphere, 1.4 g of double-bonded melamine, 0.5 g of mercaptosilicone oil, and 15 mL of DMSO were mixed, 0.02 g of a photoinitiator was added, the mixture was heated to 50°C, and irradiated with 365 nm UV light for 10 h to obtain an amino-containing melamine-derived flame retardant.

[0035] Example 3: A method for preparing a low-friction composite plate, comprising the following steps: S1: bisphenol A epoxy resin, novolac epoxy resin, and modified epoxy resin are mixed and stirred, heated to melt, vacuum degassed, and cooled for standby use to obtain component A; In step S1, the working conditions for heating to melting are: temperature 155°C, time 1 hour; the working conditions for vacuum degassing treatment are: vacuum degree 0.3MPa, time 1 hour; cooling to 90°C for standby use; In parts by weight, the raw material composition of component A is: 47 parts of bisphenol A epoxy resin, 22 parts of novolac epoxy resin, and 19 parts of modified epoxy resin; The bisphenol A epoxy resin is a mixture of NPEL-128 and NPES-901 at a mass ratio of 8:39; the phenolic epoxy resin is a mixture of NPCN-704 and NPPN-638S at a mass ratio of 10:12; the modified epoxy resin is a mixture of carboxyl-terminated nitrile rubber modified epoxy resin R341, phenoxy modified epoxy resin, and polyurethane modified epoxy resin 102C-5H at a mass ratio of 9:5:5; S2: Mixing, stirring, grinding and dispersing the epoxy resin, curing agent, accelerator, filler and silane coupling agent to obtain component B; In parts by weight, the raw material composition of component B is: 30 parts of epoxy resin, 8 parts of curing agent, 1.6 parts of accelerator, 20 parts of filler, and 1.2 parts of silane coupling agent; The epoxy resin is bisphenol A epoxy resin NPEL-128 and bisphenol A epoxy resin NPEL-127, mixed at a mass ratio of 18:12; the curing agent is dicyandiamide; the accelerator is an organic urea accelerator and an imidazole accelerator PN-23, mixed at a mass ratio of 1.1:0.5; the organic urea accelerator is UR500, UR300, and UR700, mixed at a mass ratio of 0.3:0.3:0.5; In step S2, the mixing and stirring rate is 400 rpm, and the grinding and dispersion is performed using a three-roll mill, and the grinding is performed 4 times; S3: Mixing components A and B, stirring and dispersing, and cooling to obtain a prepreg resin; In step S3, the working conditions for mixing, stirring and dispersing the materials are as follows: vacuum degree of 0.3 MPa, stirring rate of 25 rpm, dispersion rate of 300 rpm, temperature of 80°C, and a mixing ratio of component A to component B of 88:66.1; S4: The prepreg resin is hot-melted and coated on a release paper, which is then covered with a PE film to obtain a resin film; S5: Flattening the unidirectional carbon fiber and placing it between two layers of resin film, performing a single hot pressing process, slitting and winding, and obtaining a single-layer prepreg; The working conditions of the primary hot pressing treatment are: temperature 100°C, pressure 1.2 MPa; S6: The single layer prepreg is stacked and subjected to secondary hot pressing to obtain a low friction coefficient composite sheet; the working conditions of the secondary hot pressing treatment are: temperature of 150 ° C, pressure of 1 MPa, and time of 110 min; The filler is composite molybdenum disulfide, and its preparation comprises the following steps: (1) Mix 5 g of sodium alginate and 100 mL of deionized water, heat to 50 °C and keep warm for 1.5 h, add 1 g of molybdenum disulfide, and ultrasonicate for 5.5 h. Stir for 1 min every 20 min during the ultrasonication process, centrifuge, wash, and freeze-dry to obtain functionalized molybdenum disulfide; (2) Under nitrogen atmosphere, 0.3 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.4 g of N-hydroxysuccinimide, 1.2 g of functionalized molybdenum disulfide, and 20 mL of DMSO were mixed, and 0.8 g of an amino-containing melamine-derived flame retardant was added. The mixture was kept at 36 ° C for 7 h, cooled, filtered, washed, and dried to obtain composite molybdenum disulfide; The preparation of the amino-containing melamine-derived flame retardant comprises the following steps: 1) Under nitrogen atmosphere, 15 g of melamine, 14.4 g of allyl bromide, and 90 mL of DMSO were mixed, 0.2 g of sodium carbonate was added, and the mixture was stirred at 20°C for 2 h. The mixture was heated to 120°C and kept at this temperature for 5.5 h. The mixture was rotary evaporated, cooled, filtered, washed, and dried to obtain double-bonded melamine. 2) Mix 0.4 mol of 3-mercaptopropylmethyldimethoxysilane, 0.8 mol of decamethylcyclopentasiloxane, and 0.01 mol of hexamethyldisiloxane, add 7.4 g of trifluoromethanesulfonic acid and 11.5 mL of deionized water, and heat at 78°C until transparent. Cool to 20°C, wash, and distill to obtain mercapto silicone oil. 3) Under nitrogen atmosphere, 1.4 g of double-bonded melamine, 0.5 g of mercaptosilicone oil, and 15 mL of DMSO were mixed, 0.02 g of a photoinitiator was added, the mixture was heated to 55°C, and irradiated with 365 nm UV light for 11 h to obtain an amino-containing melamine-derived flame retardant.

[0036] Example 4: A method for preparing a low-friction composite plate, comprising the following steps: S1: bisphenol A epoxy resin, novolac epoxy resin, and modified epoxy resin are mixed and stirred, heated to melt, vacuum degassed, and cooled for standby use to obtain component A; In step S1, the working conditions for heating to melting are: temperature 160°C, time 0.5h; the working conditions for vacuum degassing treatment are: vacuum degree 0.4MPa, time 0.5h; cooling to 95°C for standby use; In parts by weight, the raw material composition of component A is: 50 parts of bisphenol A epoxy resin, 25 parts of novolac epoxy resin, and 30 parts of modified epoxy resin; The bisphenol A epoxy resin is a compound of NPEL-128 and NPES-901 at a mass ratio of 7:43; the phenolic epoxy resin is a compound of NPCN-704 and NPPN-638S at a mass ratio of 12:13; the modified epoxy resin is a compound of carboxyl-terminated nitrile rubber modified epoxy resin R341, phenoxy modified epoxy resin, and polyurethane modified epoxy resin 102C-5H at a mass ratio of 15:7.5:7.5; S2: Mixing, stirring, grinding and dispersing the epoxy resin, curing agent, accelerator, filler and silane coupling agent to obtain component B; In parts by weight, the raw material composition of component B is: 30 parts of epoxy resin, 10 parts of curing agent, 2 parts of accelerator, 30 parts of filler, and 1.5 parts of silane coupling agent; The epoxy resin is bisphenol A epoxy resin NPEL-128 and bisphenol A epoxy resin NPEL-127, mixed at a mass ratio of 18:12; the curing agent is dicyandiamide; the accelerator is an organic urea accelerator and an imidazole accelerator PN-23, mixed at a mass ratio of 1.4:0.6; the organic urea accelerator is UR500, UR300, and UR700, mixed at a mass ratio of 0.4:0.4:0.6; In step S2, the mixing and stirring rate is 500 rpm, and the grinding and dispersion is performed using a three-roll mill, and the grinding is performed 4 times; S3: Mixing components A and B, stirring and dispersing, and cooling to obtain a prepreg resin; In step S3, the working conditions for mixing and dispersing the materials are: vacuum degree of 0.4 MPa, stirring rate of 30 rpm, dispersion rate of 200 rpm, temperature of 85°C, and a mixing ratio of component A to component B of 105:73.5; S4: The prepreg resin is hot-melted and coated on a release paper, which is then covered with a PE film to obtain a resin film; S5: Flattening the unidirectional carbon fiber and placing it between two layers of resin film, performing a single hot pressing process, slitting and winding, and obtaining a single-layer prepreg; The working conditions of the primary hot pressing treatment are: temperature 105°C, pressure 1MPa; S6: stacking the single-layer prepregs and performing a secondary hot pressing treatment to obtain a composite sheet with a low friction coefficient; the working conditions of the secondary hot pressing treatment are: temperature 160°C, pressure 2 MPa, and time 90 minutes; The filler is composite molybdenum disulfide, and its preparation comprises the following steps: (1) Mix 5 g of sodium alginate and 100 mL of deionized water, heat to 52 °C and keep warm for 1 h, add 1 g of molybdenum disulfide, and ultrasonicate for 6 h. Stir for 1 min every 20 min during the ultrasonication process, centrifuge, wash, and freeze-dry to obtain functionalized molybdenum disulfide; (2) Under nitrogen atmosphere, 0.3 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.4 g of N-hydroxysuccinimide, 1.2 g of functionalized molybdenum disulfide, and 20 mL of DMSO were mixed, and 0.8 g of an amino-containing melamine-derived flame retardant was added. The mixture was kept at 37 ° C for 6 h, cooled, filtered, washed, and dried to obtain composite molybdenum disulfide; The preparation of the amino-containing melamine-derived flame retardant comprises the following steps: 1) Under nitrogen atmosphere, 15 g of melamine, 14.4 g of allyl bromide, and 90 mL of DMSO were mixed, 0.2 g of sodium carbonate was added, and the mixture was stirred at 25°C for 2 h. The mixture was heated to 118°C and kept for 6 h. The mixture was rotary evaporated, cooled, filtered, washed, and dried to obtain double-bonded melamine. 2) Mix 0.4 mol of 3-mercaptopropylmethyldimethoxysilane, 0.8 mol of decamethylcyclopentasiloxane, and 0.01 mol of hexamethyldisiloxane, add 7.4 g of trifluoromethanesulfonic acid and 11.5 mL of deionized water, and heat at 80°C until transparent. Cool to 18°C, wash, and distill to obtain mercapto silicone oil. 3) Under nitrogen atmosphere, 1.4 g of double-bonded melamine, 0.5 g of mercaptosilicone oil, and 15 mL of DMSO were mixed, 0.02 g of a photoinitiator was added, the mixture was heated to 60°C, and irradiated with 365 nm UV light for 12 h to obtain an amino-containing melamine-derived flame retardant.

[0037] Comparative Example 1: Taking Example 1 as the control group, wherein, in parts by weight, component A: 31 parts of NPEL-128 epoxy resin, 65 parts of NPES-901 epoxy resin, 10 parts of NPCN-704 phenolic epoxy resin, 3 parts of R341 carboxyl-terminated nitrile rubber modified epoxy resin, and 3 parts of phenoxy-modified epoxy resin; in parts by weight, component B: 20 ​​parts of NPEL-128 epoxy resin, 7.1 parts of dicyandiamide curing agent, 0.55 parts of UR500 accelerator, 0.25 parts of PN-23 accelerator, 0.25 parts of fumed silica, and 0.5 parts of KH-560 coupling agent; the mixing ratio of component A and component B is 112:28.65, and the other processes are normal.

[0038] Comparative Example 2: Taking Example 4 as the control group, functionalized molybdenum disulfide was used to replace the composite molybdenum disulfide, and the other processes were normal.

[0039] In the embodiment and the comparative example, the number of layers is 40, and the thickness of the prepreg resin after hot-melt cooling is 0.5 μm.

[0040] In the examples and comparative examples, the phenoxy-modified epoxy resin is prepared by compounding phenoxy resin and bisphenol A epoxy resin NPEL-128 in a mass ratio of 1:2.

[0041] Sources of raw materials used (for demonstration purposes only): Carboxyl-terminated nitrile rubber-modified epoxy resin R341: Shenzhen Chuchuang Applied Materials Co., Ltd.; phenoxy resin YX4000: Mitsubishi Chemical; polyurethane-modified epoxy resin 102C-5H: Taizhou Hengchuang Insulation Materials Co., Ltd.; imidazole accelerator PN-23: Ajinomoto Fine Chemicals Co., Ltd.; flake graphite: Qingdao Jintao Graphite Co., Ltd.; alkyl ammonium salt copolymer BYK-9076: BYK Chemical; bisphenol A epoxy resins (NPEL-128, NPEL-127, NPES-901) and novolac epoxy resins (NPCN-704, NPPN-638S): Nan Ya Epoxy Resins (Kunshan) Co., Ltd.; organic urea accelerators (UR500, UR300, UR700): Azcon, Germany; carbon fiber STS40-24K: Toho, Japan; PE film (0.02 mm): Wuxi Jiayou Packaging Materials Co., Ltd.; photoinitiator (2-hydroxy-2-methylpropiophenone, 99%): Shanghai Tongyuan Chemical Co., Ltd.; allyl bromide (99%): Zouping Mingxing Chemical Co., Ltd.; dicyandiamide S26828: Shanghai Yuanye Biotechnology Co., Ltd.; silane coupling agent γ-(2,3-epoxypropoxy)propyltrimethoxysilane G134407, sodium alginate S100128, molybdenum disulfide M104967, 1-ethyl -(3-Dimethylaminopropyl)carbodiimide hydrochloride E106172, N-hydroxysuccinimide H109330, melamine M108433, 3-mercaptopropylmethyldimethoxysilane M158195, decamethylcyclopentasiloxane D135850, hexamethyldisiloxane H105443, trifluoromethanesulfonic acid T398955: Aladdin reagent; sodium carbonate, dimethyl sulfoxide, analytical grade, commercially available.

[0042] Performance testing: The composite panels prepared in the examples and comparative examples were tested: Friction coefficient: The friction coefficient was measured using a friction coefficient meter; flame retardancy: The UL-94 vertical burning rating test was performed; corrosion resistance: The sample was placed in a 10% sodium chloride aqueous solution and kept at 100°C for 12 hours. If there was no cavitation, peeling, or damage, it was considered qualified; otherwise, it was considered unqualified. The results are shown in Table 1. Table 1 The present invention provides a low-friction coefficient composite plate and a preparation method thereof. Through raw material and process design, a high-strength, corrosion-resistant, highly flame-retardant, low-friction coefficient composite plate is prepared.

[0043] By comparing Example 1 with Comparative Example 1, it can be seen that epoxy resin is selected as the composite board base material in the present invention. Compared with other thermosetting resins, it has the characteristics of better mechanical properties, insulation properties, bonding properties and processing flexibility. Lightweight, high-strength, high and low temperature resistant carbon fiber is selected as the reinforcing fiber, and one of the lubricating fillers graphite and molybdenum disulfide is introduced into the composite board to play a role in reducing the friction coefficient. Prepreg resin is prepared by controlling different types of epoxy resins for compounding, and then the prepreg resin is hot-melted and coated on release paper, and then covered with PE film to obtain a resin film, and the unidirectional carbon fiber is flattened and placed between two layers of resin film, hot pressed, slit and rolled to obtain a single-layer prepreg, and the single-layer prepreg is stacked and pressed to prepare a composite board, which has a greatly reduced friction coefficient compared with the common carbon fiber reinforced epoxy resin composite board on the market.

[0044] By comparing Example 4 with Comparative Example 2, it can be seen that in order to further improve the wear resistance and strength of the composite board, nano-scale fillers are selected for improvement. At the same time, in order to make the nano-scale fillers uniformly dispersed in the composite board without the addition of additional dispersants, the fillers are modified. With the aid of sodium alginate, the blocky molybdenum disulfide is treated by liquid phase exfoliation to prepare functionalized molybdenum disulfide nanosheets containing a large number of hydroxyl and carboxyl groups on the surface. Then, the functionalized molybdenum disulfide nanosheets containing amino groups are grafted under the action of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide. While improving the uniformity of the dispersion of the filler in the epoxy resin, the bonding strength between the filler and the base glue is improved, and the filler is prevented from falling off under conditions such as external force impact, thereby giving the composite board halogen-free high flame retardancy and corrosion resistance.

[0045] The amino-containing melamine-derived flame retardant is prepared by first preparing double-bonded melamine with melamine and allyl bromide, and then reacting it with mercapto silicone oil for a click reaction. The mercapto silicone oil is prepared by hydrolysis copolymerization of 3-mercaptopropylmethyldimethoxysilane, decamethylcyclopentasiloxane and hexamethyldisiloxane. The introduction of mercapto silicone oil gives the composite board excellent stability, high and low temperature resistance and water resistance, thereby extending the service life of the composite board.

[0046] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the present invention specification under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing a low friction coefficient composite plate, characterized in that: The following steps are involved: S1: bisphenol A epoxy resin, novolac epoxy resin, bisphenol F epoxy resin, and modified epoxy resin are mixed and stirred, heated to melt, vacuum degassed, and cooled for standby use to obtain component A; S2: Mixing, stirring, grinding and dispersing the epoxy resin, curing agent, accelerator, filler, silane coupling agent and dispersant to obtain component B; S3: Mixing components A and B, stirring and dispersing, and cooling to obtain a prepreg resin; S4: The prepreg resin is hot-melted and coated on a release paper, which is then covered with a PE film to obtain a resin film; S5: placing the unidirectional carbon fiber between two layers of resin film, performing a single hot pressing process, slitting and winding, and obtaining a single-layer prepreg; S6: stacking the single-layer prepregs and performing a secondary hot pressing process to obtain a composite plate with a low friction coefficient.

2. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: In step S1, the working conditions for heating to melting are: temperature 150-160°C, time 0.5-1.5h; the working conditions for vacuum degassing treatment are: vacuum degree 0.2-0.4MPa, time 0.5-1.5h; and cooling to 80-95°C for standby use.

3. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: In step S2, the mixing stirring rate is 300-500 rpm, and a three-roll grinder is used for grinding and dispersion, and grinding is performed 3-4 times; in step S3, the working conditions for mixing, stirring and dispersing are: vacuum degree of 0.2-0.4 MPa, stirring rate of 20-30 rpm, dispersion rate of 200-400 rpm, temperature of 70-85°C, and the mixing ratio of component A to component B is (75-113): (35-65).

4. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: In step S5, the working conditions for the primary hot pressing treatment are: temperature of 90-105°C, pressure of 1-1.5 MPa; in step S6, the working conditions for the secondary hot pressing treatment are: temperature of 140-160°C, pressure of 0.5-2 MPa, and time of 90-120 min.

5. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: In parts by weight, the raw material composition of component A is: 45-50 parts of bisphenol A epoxy resin, 15-25 parts of novolac epoxy resin, 0-8 parts of bisphenol F epoxy resin, and 15-30 parts of modified epoxy resin; In parts by weight, the raw material composition of component B is: 18-30 parts of epoxy resin, 5-10 parts of curing agent, 1-2 parts of accelerator, 10-30 parts of filler, 1-1.5 parts of silane coupling agent, and 0-1 part of dispersant.

6. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: The modified epoxy resin is one or a combination of carboxyl-terminated nitrile rubber modified epoxy resin, phenoxy modified epoxy resin, and polyurethane modified epoxy resin.

7. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: The epoxy resin is one of bisphenol A epoxy resin and bisphenol F epoxy resin or a combination thereof; the curing agent is dicyandiamide; the accelerator is one of organic urea accelerator and imidazole accelerator or a combination thereof; the filler is one of molybdenum disulfide, kaolin, graphite, titanium dioxide, zirconium dioxide, aluminum oxide, and calcium carbonate or a combination thereof; and the dispersant is an alkyl ammonium salt copolymer.

8. The method for preparing a low friction coefficient composite plate according to claim 1, characterized in that: The filler is composite molybdenum disulfide, and its preparation comprises the following steps: (1) Sodium alginate and deionized water were mixed, heated to 48-52°C and kept warm for 1-2 hours, molybdenum disulfide was added, and ultrasonic treatment was performed for 5-6 hours. During the ultrasonic treatment, stirring was performed for 1 minute every 20 minutes. The mixture was centrifuged, washed, and freeze-dried to obtain functionalized molybdenum disulfide. (2) Under a nitrogen atmosphere, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-hydroxysuccinimide, functionalized molybdenum disulfide, and DMSO are mixed, and an amino-containing melamine-derived flame retardant is added. The mixture is kept at 35-37°C for 6-8 hours, cooled, filtered, washed, and dried to obtain composite molybdenum disulfide.

9. The method for preparing a low friction coefficient composite plate according to claim 8, characterized in that: The preparation of the amino-containing melamine-derived flame retardant comprises the following steps: 1) Under a nitrogen atmosphere, melamine, allyl bromide, and DMSO were mixed, sodium carbonate was added, and the mixture was stirred at 18-25°C for 2 hours. The mixture was heated to 118-122°C and kept warm for 5-6 hours. The mixture was rotary evaporated, cooled, filtered, washed, and dried to obtain double-bonded melamine. 2) Mix 3-mercaptopropylmethyldimethoxysilane, decamethylcyclopentasiloxane, and hexamethyldisiloxane, add trifluoromethanesulfonic acid and deionized water, keep warm at 75-80°C until transparent, cool to 18-25°C, wash, and distill to obtain mercapto silicone oil; 3) Under a nitrogen atmosphere, double-bonded melamine, mercapto silicone oil, and DMSO are mixed, a photoinitiator is added, the temperature is raised to 50-60°C, and irradiated with 365nm ultraviolet light for 10-12 hours to obtain an amino-containing melamine-derived flame retardant.

10. A low friction coefficient composite plate, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 9.

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