Epoxy resin binder material suitable for steel bridge deck

Abstract

The invention discloses an epoxy resin binder material suitable for a steel bridge deck, which is prepared by taking bisphenol A / novolac epoxy resin as a matrix and matching with a modified amine hardener, a rigid-flexible composite flexibilizer (carboxyl-terminated nitrile rubber / nano silicon dioxide), an interfacial active filler (graphene modified calcium carbonate) and a compound weather-proof additive. And an interface chemical bonding-rigid-flexible cooperation-multi-mechanism weather resistance system is constructed. According to the preparation process, efficient synergy among the components is realized through filler surface activation, vacuum dispersion and low-temperature curing. The material has the bonding strength larger than or equal to 8 MPa, wide-temperature adaptability of-30 DEG C to 80 DEG C, over 106 times of fatigue-resistant cycles and excellent weather resistance, and the pavement service performance of a steel bridge deck is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering materials, specifically to an epoxy resin binder suitable for steel bridge deck pavement and its preparation method. Through synergistic component modification and process optimization, this material constructs a rigid-flexible composite reinforcement system, significantly improving the bonding performance between the steel bridge deck and the pavement layer, as well as weather resistance, fatigue resistance, and adaptability to a wide temperature range. Background Art

[0002] Steel bridge deck pavement must withstand complex service environments such as alternating loads, temperature cycles, and ultraviolet radiation, placing stringent demands on binder materials. Traditional epoxy resin binders have the following core defects:

[0003] Risk of interfacial bonding failure: The bond between the steel surface and the epoxy resin mainly relies on physical adsorption, lacks chemical bonding, and is prone to peeling under long-term loads. The bond strength at room temperature is usually less than 7MPa;

[0004] Significant temperature sensitivity: at -20°C, the elongation at break is less than 10%, indicating brittle fracture; at 60°C, the shear strength drops sharply to below 3MPa, making it difficult to resist rutting deformation;

[0005] Multi-factor aging attenuation: Ultraviolet radiation causes the epoxy resin molecular chain to break, and the bond strength retention rate after 1000 hours of UV aging is only 60%-70%. At the same time, uneven dispersion of fillers accelerates the propagation of microcracks;

[0006] Insufficient fatigue life: Existing toughening modification methods (such as adding ordinary rubber particles) only achieve physical toughening, and the number of fatigue cycles (10MPa stress amplitude) is generally less than 8×10 5 Second, it is difficult to meet the long-term service requirements of the bridge.

[0007] While existing technologies have attempted modification through the use of nanofillers or coupling agents, they haven't yet achieved a synergistic modification system combining "interface strengthening, structural toughening, and weathering protection," and their specificity for the unique service environment of steel bridge decks is insufficient. Therefore, there is an urgent need to develop a specialized epoxy resin binder that integrates multi-dimensional performance enhancements. Summary of the Invention

[0008] The purpose of the present invention is to provide an epoxy resin tack coat material suitable for steel bridge deck repair. By combining component design with process innovation, an epoxy resin binder material with interface chemical bonding strengthening, synergistic toughening of rigid and flexible phases, and multi-mechanism weathering protection is achieved, thereby solving the problems of insufficient bonding strength, strong temperature sensitivity, poor weathering resistance, and weak fatigue resistance of traditional materials.

[0009] In order to achieve the above object, the present invention is implemented through the following technical solution: an epoxy resin binder material suitable for steel bridge decks, comprising the following components in percentage by weight:

[0010] Epoxy resin 40%-60%,

[0011] Curing agent 20%-30%,

[0012] Toughener 5%-15%,

[0013] Filler 10%-20%,

[0014] Coupling agent 1%-3%,

[0015] Additives 1%-5%;

[0016] The toughening agent and filler form a rigid-flexible composite reinforcement system, so that the elongation at break of the binder material in the range of -30°C to 80°C is not less than 15%, and the fatigue resistance cycle number is not less than 106 times under a stress amplitude of 10MPa.

[0017] As a further improvement of the technical solution of the present invention, the epoxy resin is a bisphenol A epoxy resin or a novolac epoxy resin, and the epoxy value of the bisphenol A epoxy resin is 0.45-0.55eq / 100g, and the epoxy value of the novolac epoxy resin is 0.50-0.60eq / 100g.

[0018] As a further improvement of the technical solution of the present invention, the curing agent is a polyamide curing agent or a modified amine curing agent, the amine value of the polyamide curing agent is 200-300 mgKOH / g, and the modified amine curing agent is a fatty amine modified with cashew nut shell oil, and its amine value is 250-350 mgKOH / g.

[0019] As a further improvement of the technical solution of the present invention, the toughening agent is carboxyl-terminated nitrile rubber, liquid polysulfide rubber or nano-silica dispersion, wherein the particle size of the nano-silica dispersion is 5-20 nm and an acrylic coupling agent is grafted on the surface.

[0020] As a further improvement of the technical solution of the present invention, the filler includes silicon powder, talc or graphene-modified calcium carbonate, wherein the graphene-modified calcium carbonate is obtained by grafting 0.5-1.5 parts by weight of graphene oxide on the surface of calcium carbonate by in-situ polymerization, and the particle size thereof does not exceed 50 μm and the specific surface area is not less than 5 m 2 / g.

[0021] As a further improvement of the technical solution of the present invention, the coupling agent is γ-aminopropyltriethoxysilane or a titanate coupling agent, the silane or titanate group of the coupling agent forms a covalent bond with the hydroxyl group on the surface of the filler, and the amino group undergoes a pre-crosslinking reaction with the epoxy group of the epoxy resin.

[0022] As a further improvement of the technical solution of the present invention, the auxiliary agent includes a defoamer, a leveling agent and a UV absorber in a mass ratio of 1:1-3:0.5-1.5, and the UV absorber is a compound of 2-hydroxy-4-methoxybenzophenone and a hindered amine light stabilizer, and the compound mass ratio is 1:0.5-1.

[0023] As a further improvement to the technical solution of the present invention, the bonding strength of the binder material on the steel surface at room temperature of 25°C is not less than 8MPa, and according to GB / T 5210 standard, the bonding strength retention rate is not less than 85% after 1000 hours of UV aging, and the shear strength at 60°C is not less than 5MPa.

[0024] As a further improvement to the technical solution of the present invention, a method for preparing an epoxy resin binder material suitable for steel bridge decks comprises the following steps:

[0025] (1) Heat the epoxy resin to 50-70°C, stir at 300-500 rpm, add the toughening agent in 2-3 times, with an interval of 5 minutes between each addition, and stir to form a uniform elastomer dispersion phase;

[0026] (2) Add filler and coupling agent, raise the temperature to 80-90°C and maintain a vacuum degree of -0.08-0.05 MPa, and stir at 400-600 rpm for 30-40 minutes to form a coupling agent coating layer on the filler surface;

[0027] (3) Cool to 30-40°C, add curing agent and additives, stir at 100-200 rpm for 15-20 minutes, and finally degas under vacuum conditions for 5-10 minutes.

[0028] As a further improvement of the technical solution of the present invention, the mass ratio of the filler to the coupling agent in step (2) is 5-10:1, and the coupling agent is pre-dissolved in anhydrous ethanol (accounting for 3-5 times the mass of the coupling agent) and then sprayed into the reaction system in an atomized manner.

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

[0030] Interface bonding strengthening mechanism:

[0031] The coupling agent increases the bonding strength of the steel surface to over 8MPa (GB / T 5210) through the "filler surface hydroxyl-silaneoxy" condensation reaction (bond energy ≥ 400kJ / mol) and "amino-epoxy" pre-crosslinking reaction, which is 23% higher than that of traditional materials.

[0032] The lamellar structure of graphene-modified calcium carbonate increases the interfacial contact area, and the oxygen-containing groups of graphene oxide form hydrogen bonds with the amino groups of the coupling agent, further strengthening the interfacial bonding.

[0033] Synergistic toughening of rigidity and flexibility:

[0034] The carboxyl groups of the carboxyl-terminated nitrile rubber react with the amine groups of the curing agent to form a chemically cross-linked network of "rubber particles-resin matrix". The elongation at break at -30°C reaches 18%, which is 125% higher than that of traditional materials (8%).

[0035] Nano-silica dispersion uses the "crack deflection-energy dissipation" mechanism to increase the fatigue cycle resistance (10MPa) to 1.2×106 times, which is double that of commercially available products (5×105 times).

[0036] Multi-mechanism weather protection:

[0037] The UV absorber (2-hydroxy-4-methoxybenzophenone) absorbs 290-400nm UV light and converts it into heat energy, while the hindered amine light stabilizer captures oxidative free radicals. After compounding, the UV aging strength retention rate is ≥85% after 1000 hours, which is 13% higher than that of a single absorber (75%).

[0038] The layered structure of silica powder and talc prevents oxygen and moisture penetration, and the corrosion resistance time in the salt spray test (5% NaCl) exceeds 1000 hours without peeling or rust.

[0039] Balanced performance over a wide temperature range:

[0040] The cross-linked network of phenolic epoxy resin and polyamide curing agent has a glass transition temperature (Tg) of 120°C and maintains a shear strength of over 5 MPa at 60°C, which is 67% higher than the traditional E-51 / ethylenediamine system (3 MPa).

[0041] The flexible toughening agent reduces the brittle transition temperature of the system to below -40°C, and still maintains an elongation at break of more than 15% at -20°C, meeting the use needs in extremely cold areas. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below with reference to specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0043] In the present invention, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, "connection" can mean fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two elements, or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0044] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one such feature. Furthermore, the technical solutions of various embodiments may be combined with each other, but only on the basis that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions contradicts or cannot be implemented, it shall be deemed that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this disclosure.

[0045] An epoxy resin binder material suitable for steel bridge decks, comprising the following components in percentage by weight:

[0046] Epoxy resin 40%-60%,

[0047] Curing agent 20%-30%,

[0048] Toughener 5%-15%,

[0049] Filler 10%-20%,

[0050] Coupling agent 1%-3%,

[0051] Additives 1%-5%;

[0052] The toughening agent and filler form a rigid-flexible composite reinforcement system, so that the elongation at break of the binder material in the range of -30°C to 80°C is not less than 15%, and the fatigue resistance cycle number is not less than 106 times under a stress amplitude of 10MPa.

[0053] Specifically, in this embodiment, the epoxy resin is a bisphenol A epoxy resin or a novolac epoxy resin, and the epoxy value of the bisphenol A epoxy resin is 0.45-0.55 eq / 100 g, and the epoxy value of the novolac epoxy resin is 0.50-0.60 eq / 100 g.

[0054] Specifically, in this embodiment, the curing agent is a polyamide curing agent or a modified amine curing agent, the amine value of the polyamide curing agent is 200-300 mgKOH / g, and the modified amine curing agent is a fatty amine modified with cashew nut shell oil, and its amine value is 250-350 mgKOH / g.

[0055] Specifically, in this embodiment, the toughening agent is carboxyl-terminated nitrile rubber, liquid polysulfide rubber or nano-silica dispersion, wherein the nano-silica dispersion has a particle size of 5-20 nm and an acrylic coupling agent is grafted on the surface.

[0056] Specifically, in this embodiment, the filler includes silicon powder, talc or graphene-modified calcium carbonate, wherein the graphene-modified calcium carbonate is obtained by grafting 0.5-1.5 parts by weight of graphene oxide on the surface of calcium carbonate by in-situ polymerization, and the particle size thereof does not exceed 50 μm and the specific surface area is not less than 5 m 2 / g.

[0057] Specifically, in this embodiment, the coupling agent is γ-aminopropyltriethoxysilane or titanate coupling agent, the silane or titanate group of the coupling agent forms a covalent bond with the hydroxyl group on the surface of the filler, and the amino group undergoes a pre-crosslinking reaction with the epoxy group of the epoxy resin.

[0058] Specifically, in this embodiment, the auxiliary agent includes a defoamer, a leveling agent and a UV absorber in a mass ratio of 1:1-3:0.5-1.5, and the UV absorber is a compound of 2-hydroxy-4-methoxybenzophenone and a hindered amine light stabilizer, and the compound mass ratio is 1:0.5-1.

[0059] Specifically, in this embodiment, the bonding strength of the binder material on the steel surface at room temperature of 25°C is not less than 8 MPa. According to the GB / T 5210 standard, the bonding strength retention rate is not less than 85% after 1000 hours of UV aging, and the shear strength at 60°C is not less than 5 MPa.

[0060] Specifically, in this embodiment, a method for preparing an epoxy resin binder material suitable for steel bridge decks includes the following steps:

[0061] (1) Heat the epoxy resin to 50-70°C, stir at 300-500 rpm, add the toughening agent in 2-3 portions, each time with an interval of 5 minutes, and stir until a uniform elastomer dispersion is formed;

[0062] (2) Add filler and coupling agent, raise the temperature to 80-90°C and maintain a vacuum degree of -0.08-0.05 MPa, and stir at 400-600 rpm for 30-40 minutes to form a coupling agent coating layer on the filler surface;

[0063] (3) Cool to 30-40°C, add curing agent and additives, stir at 100-200 rpm for 15-20 minutes, and finally degas under vacuum conditions for 5-10 minutes.

[0064] Specifically, in this embodiment, the mass ratio of the filler to the coupling agent in step (2) is 5-10:1, and the coupling agent is pre-dissolved in anhydrous ethanol (accounting for 3-5 times the mass of the coupling agent) and then sprayed into the reaction system in an atomized manner.

[0065] Furthermore, it should be noted that an epoxy resin binder material suitable for steel bridge decks is composed of the following components in percentage by weight:

[0066] Epoxy resin 40%-60%: Bisphenol A epoxy resin (epoxy value 0.45-0.55eq / 100g) or novolac epoxy resin (epoxy value 0.50-0.60eq / 100g) are used. The former provides the basic cross-linking structure, while the latter increases the cross-linking density through multiple epoxy groups.

[0067] Curing agent 20%-30%: polyamide curing agent (amine value 200-300 mgKOH / g) or cashew nut shell liquid modified fatty amine (amine value 250-350 mgKOH / g). The former imparts toughness, while the latter improves interfacial wettability through long-chain alkyl groups.

[0068] Toughening agent 5%-15%: nano-silica dispersion (particle size 5-20nm) of carboxyl-terminated nitrile rubber, liquid polysulfide rubber or surface-grafted acrylate coupling agent to form a flexible toughening phase or nano-reinforcement points;

[0069] Filler 10%-20%: silicon micropowder, talc or graphene-modified calcium carbonate (0.5-1.5 parts by weight of graphene oxide is grafted onto the surface of calcium carbonate by in-situ polymerization, with a particle size of ≤50 μm and a specific surface area of ​​≥5m 2 / g), building a rigid skeleton and improving thermal conductivity;

[0070] Coupling agent 1%-3%: γ-aminopropyltriethoxysilane or titanate coupling agent, the silane / titanate group condenses with the hydroxyl group on the filler surface to form a covalent bond, and the amino group pre-crosslinks with the epoxy group of the epoxy resin to construct a "filler-coupling agent-resin" chemical bridging structure;

[0071] Additives 1%-5%: composed of defoamer (polyether modified silicone), leveling agent (acrylate copolymer) and compound UV absorber (2-hydroxy-4-methoxybenzophenone and hindered amine light stabilizer mass ratio of 1:0.5-1), which inhibit bubble formation, improve construction rheology and block UV-induced oxidation reactions through synergistic effect.

[0072] The preparation method comprises:

[0073] Elastomer dispersion phase construction: Heat the epoxy resin to 50-70°C and add the toughening agent in 2-3 times (5 minutes between each addition) while stirring at 300-500 rpm to form a micron-scale (carboxyl-terminated nitrile rubber) or nano-scale (silica dispersion) dispersed phase;

[0074] Filler interface activation: Add filler and coupling agent (mass ratio 5-10:1), the coupling agent is pre-dissolved in 3-5 times the mass of anhydrous ethanol and sprayed in by atomization, and stirred at 80-90℃ and -0.08 to -0.05MPa vacuum conditions for 30-40 minutes to achieve uniform coating of the coupling agent on the filler surface;

[0075] Low temperature curing and mixing: After cooling to 30-40℃, add curing agent and additives, stir at low speed for 15-20 minutes, and finally vacuum degas for 5-10 minutes to avoid residual bubbles during the curing process.

[0076] Example:

[0077] Example 1 (Basic formula: carboxyl-terminated nitrile rubber toughening)

[0078] Components (wt%):

[0079] Bisphenol A type epoxy resin (E-51, epoxy value 0.51eq / 100g) 50%, polyamide curing agent (650 type, amine value 260mgKOH / g) 25%, terminal carboxyl nitrile rubber 10%, silica powder (particle size 30μm) 12%, KH-550 coupling agent 2%, additives (defoaming agent 0.5%, leveling agent 1.5%, ultraviolet absorber compound 1%) 2%.

[0080] Key preparation parameters: Step (2) vacuum degree -0.07MPa, the coupling agent is dissolved in 4 times anhydrous ethanol and added by atomization.

[0081] Performance data:

[0082] Bond strength (25℃, GB / T 5210): 8.5MPa

[0083] Elongation at break (-30℃): 18%, shear strength (60℃): 6.2MPa

[0084] UV aging 1000h strength retention rate: 86%, fatigue cycle number (10MPa): 1.1×106 times

[0085] Example 2 (Nano-enhanced formulation: toughened with silica dispersion)

[0086] Components (wt%):

[0087] Phenolic epoxy resin (F-51, epoxy value 0.55eq / 100g) 45%, cashew nut shell oil modified fatty amine (T-31 modified, amine value 320mgKOH / g) 28%, nano-silica dispersion (particle size 10nm, surface grafted acrylate) 12%, graphene modified calcium carbonate (graphene oxide grafting amount 1%) 15%, titanate coupling agent 2.5%, additives (defoaming agent 1%, leveling agent 1%, ultraviolet absorber compound 1.5%) 2.5%.

[0088] Performance highlights:

[0089] Bond strength: 9.2MPa, elongation at break (-20℃): 20%

[0090] Salt spray test (5% NaCl): no rust after 1200h, fatigue resistance: 1.2×106 times

[0091] Example 3 (Toughener Replacement: Liquid Polysulfide Rubber)

[0092] Component adjustment: the toughening agent was replaced with 12% of liquid polysulfide rubber (molecular weight 3000), and the rest was the same as in Example 1.

[0093] Performance comparison:

[0094] Low temperature toughness: -30℃ elongation at break 16% (slightly lower than CTBN, but cost reduced by 15%)

[0095] Bond strength: 8.2MPa, UV aging retention rate: 85%

[0096] Example 4 (Filler Optimization: Compounding of Talc and Graphene Calcium Carbonate)

[0097] Components (wt%):

[0098] Silica powder (6%) + talc (6%) composite filler 12%, graphene modified calcium carbonate (graphene oxide grafting amount 1.5%) 8%, the total filler accounts for 20%; the rest is the same as Example 2.

[0099] Performance changes:

[0100] High temperature shear strength (80℃): 5.8MPa (talc layered structure improves high temperature resistance)

[0101] Thermal conductivity: 0.45W / (m·K) (20% higher than single silica powder, accelerating heat dissipation on the bridge deck)

[0102] Example 5 (Curing agent compounding: polyamide + modified amine)

[0103] Component adjustment: the curing agent is a mixture of polyamide (15%) and cashew nut shell liquid modified fatty amine (15%), with an amine value of 280 mgKOH / g. The rest is the same as in Example 1.

[0104] Performance advantages:

[0105] Curing speed: surface drying time is shortened from 4h to 2.5h (modified amine promotes early cross-linking)

[0106] Bond strength (wet steel surface): 7.5 MPa (30% higher than single polyamide, attributed to the hydrophobic interfacial wetting of cashew nut shell oil)

[0107] Example 6 (Assistant Optimization: High Concentration UV Absorber)

[0108] Component adjustment: UV absorber compound (2-hydroxy-4-methoxybenzophenone: hindered amine = 1:1) accounts for 2%, other additives account for 3%, and total additives account for 5%.

[0109] Weather resistance data:

[0110] UV aging 1500h strength retention rate: 83% (still meets the standard after 500h aging time extension compared with Example 1)

[0111] Color difference ΔE: 1.2 (traditional material ΔE=3.5, proving that anti-discoloration ability is significantly improved)

[0112] Comparative Example 1 (lack of coupling agent)

[0113] Component differences: the coupling agent was removed, and the filler was directly added (12% silicon powder). The rest was the same as in Example 1.

[0114] Performance drawbacks:

[0115] Bond strength: 6.0 MPa (decreased by 29%, only physical adsorption at the interface)

[0116] Water boiling peeling test (60℃, 24h): peeling area > 50% (large area peeling occurs)

[0117] Comparative Example 2 (single toughening agent unmodified)

[0118] Component adjustment: the toughening agent is ungrafted nano-silica (particle size 50 nm, no surface treatment) 12%, and the rest is the same as in Example 2.

[0119] Performance comparison:

[0120] Dispersibility: 5-10 μm agglomerates were observed under a microscope (the invention example is uniform nano-dispersion)

[0121] Fatigue resistance times: 7×105 times (decreased by 42% due to insufficient interface bonding strength)

[0122] Comparative Example 3 (unmodified traditional filler)

[0123] Component difference: the filler is ordinary calcium carbonate (ungrafted graphene, particle size 100 μm) 20%, and the rest is the same as Example 2.

[0124] Performance degradation:

[0125] Specific surface area: 2m 2 / g(Inventive Example≥5m 2 / g), bonding strength: 7.0MPa (decreased by 24%)

[0126] High temperature stability: 60°C shear strength 4.0 MPa (33% lower than the embodiment of the invention)

[0127] Comparative Example 4 (without compounding additives)

[0128] Component adjustment: the auxiliary agent contains only defoamer (1%), without leveling agent and ultraviolet absorber, and the rest is the same as Example 1.

[0129] Defect manifestation:

[0130] Construction performance: Pinhole defects appear on the coating surface (poor leveling)

[0131] UV aging retention rate: 65% (decreased by 21%, proving the synergistic weathering effect of the compounded additives).

[0132] Performance comparison table of examples and comparative examples

[0133]

[0134]

[0135]

[0136] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0137] Interface bonding strengthening mechanism:

[0138] The coupling agent increases the bonding strength of the steel surface to over 8MPa (GB / T 5210) through the "filler surface hydroxyl-silaneoxy" condensation reaction (bond energy ≥ 400kJ / mol) and "amino-epoxy" pre-crosslinking reaction, which is 23% higher than that of traditional materials.

[0139] The lamellar structure of graphene-modified calcium carbonate increases the interfacial contact area, and the oxygen-containing groups of graphene oxide form hydrogen bonds with the amino groups of the coupling agent, further strengthening the interfacial bonding.

[0140] Synergistic toughening of rigidity and flexibility:

[0141] The carboxyl groups of the carboxyl-terminated nitrile rubber react with the amine groups of the curing agent to form a chemically cross-linked network of "rubber particles-resin matrix". The elongation at break at -30°C reaches 18%, which is 125% higher than that of traditional materials (8%).

[0142] Nano-silica dispersion uses the "crack deflection-energy dissipation" mechanism to increase the fatigue cycle resistance (10MPa) to 1.2×106 times, which is double that of commercially available products (5×105 times).

[0143] Multi-mechanism weather protection:

[0144] The UV absorber (2-hydroxy-4-methoxybenzophenone) absorbs 290-400nm UV light and converts it into heat energy, while the hindered amine light stabilizer captures oxidative free radicals. After compounding, the UV aging strength retention rate is ≥85% after 1000 hours, which is 13% higher than that of a single absorber (75%).

[0145] The layered structure of silica powder and talc prevents oxygen and moisture penetration, and the corrosion resistance time in the salt spray test (5% NaCl) exceeds 1000 hours without peeling or rust.

[0146] Balanced performance over a wide temperature range:

[0147] The cross-linked network of phenolic epoxy resin and polyamide curing agent has a glass transition temperature (Tg) of 120°C and maintains a shear strength of over 5 MPa at 60°C, which is 67% higher than the traditional E-51 / ethylenediamine system (3 MPa).

[0148] The flexible toughening agent reduces the brittle transition temperature of the system to below -40°C, and still maintains an elongation at break of more than 15% at -20°C, meeting the use needs in extremely cold areas.

[0149] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. An epoxy resin binder material suitable for steel bridge decks, characterized in that: It is composed of the following components in percentage by weight: Epoxy resin 40%-60%, Curing agent 20%-30%, Toughener 5%-15%, Filler 10%-20%, Coupling agent 1%-3%, Additives 1%-5%; The toughening agent and filler form a rigid-flexible composite reinforcement system, so that the elongation at break of the binder material in the range of -30°C to 80°C is not less than 15%, and the fatigue resistance cycle number is not less than 106 times under a stress amplitude of 10MPa.

2. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The epoxy resin is a bisphenol A epoxy resin or a novolac epoxy resin, and the epoxy value of the bisphenol A epoxy resin is 0.45-0.55 eq / 100 g, and the epoxy value of the novolac epoxy resin is 0.50-0.60 eq / 100 g.

3. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The curing agent is a polyamide curing agent or a modified amine curing agent. The amine value of the polyamide curing agent is 200-300 mgKOH / g. The modified amine curing agent is a fatty amine modified with cashew nut shell oil, and the amine value is 250-350 mgKOH / g.

4. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The toughening agent is carboxyl-terminated nitrile rubber, liquid polysulfide rubber or nano-silicon dioxide dispersion, wherein the particle size of the nano-silicon dioxide dispersion is 5-20 nm and an acrylic ester coupling agent is grafted on the surface.

5. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The filler includes silicon micropowder, talc or graphene-modified calcium carbonate, wherein the graphene-modified calcium carbonate is obtained by grafting 0.5-1.5 parts by weight of graphene oxide on the surface of calcium carbonate by in-situ polymerization, and the particle size thereof does not exceed 50 μm and the specific surface area is not less than 5 m 2 / g.

6. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The coupling agent is γ-aminopropyltriethoxysilane or titanate coupling agent. The silane or titanate group of the coupling agent forms a covalent bond with the hydroxyl group on the surface of the filler, and the amino group undergoes a pre-crosslinking reaction with the epoxy group of the epoxy resin.

7. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The auxiliary agent includes a defoamer, a leveling agent and an ultraviolet absorber in a mass ratio of 1:1-3:0.5-1.

5. The ultraviolet absorber is a compound of 2-hydroxy-4-methoxybenzophenone and a hindered amine light stabilizer in a mass ratio of 1:0.5-1.

8. The epoxy resin binder material for steel bridge decks according to claim 1, characterized in that: The bonding strength of the binder material on the steel surface at room temperature of 25°C is not less than 8MPa. According to GB / T 5210 standard, the bonding strength retention rate is not less than 85% after 1000 hours of ultraviolet aging, and the shear strength at 60°C is not less than 5MPa.

9. The method for preparing a binder material according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Heat the epoxy resin to 50-70°C, stir at 300-500 rpm, add the toughening agent in 2-3 portions, each with an interval of 5 minutes, and stir until a uniform elastomer dispersion is formed; (2) Add filler and coupling agent, raise the temperature to 80-90°C and maintain a vacuum degree of -0.08 to -0.05 MPa, and stir at 400-600 rpm for 30-40 minutes to form a coupling agent coating layer on the filler surface; (3) Cool to 30-40°C, add curing agent and additives, stir at 100-200 rpm for 15-20 minutes, and finally degas under vacuum conditions for 5-10 minutes.

10. The preparation method according to claim 8, characterized in that: The mass ratio of the filler to the coupling agent in step (2) is 5-10:1, and the coupling agent is pre-dissolved in anhydrous ethanol and then sprayed into the reaction system in an atomized manner.

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