Ultralow-modulus high-elongation flame-retardant anti-corrosion sealant for suspension bridge profile steel isolation

Abstract

The invention discloses an ultralow-modulus high-elongation flame-retardant anti-corrosion sealant for suspension bridge profile steel isolation, and relates to the technical field of polymer sealing materials, the sealant specifically comprises a component A and a component B. The component A comprises an MS polymer, a plasticizer, aluminum hydroxide, magnesium hydroxide, calcium carbonate and a rheological additive; and the component B comprises the following components: a plasticizer, carbon black, aluminum hydroxide, magnesium hydroxide, an adhesion promoter and a catalyst. The ultralow-modulus high-elongation flame-retardant anti-corrosion sealant for suspension bridge profile steel isolation is of a two-component reaction curing type, the performance is easy to control and adjust, the sealant can be fully attached to the surface of an anchoring system after being cured, the sealing effect is improved, the combustion performance of a rubber body formed after vulcanization can reach the V-0 level, meanwhile, the sealant has excellent adhesive force to paint after vulcanization, and the service life of the sealant is prolonged. The adaptability of the sealant is improved; meanwhile, the ultra-low modulus and flame-retardant performance are considered, the ductility is high, the cracking possibility is reduced in the using process, the service life is prolonged, and the using effect is improved.

Description

Technical Field

[0001] This invention relates to the field of polymer sealing materials technology, specifically to an ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges. Background Technology

[0002] The main cable anchorage system of a suspension bridge consists of a rear anchor beam and front and rear anchor bolts. During concrete pouring, heat is generated, and watering during curing causes water accumulation at the contact points between the concrete and the anchor bolts. This results in internal moisture, inevitable cracks in the large volume of concrete, and external moisture entering the anchor bolts, placing the entire anchorage system in a humid environment, leading to corrosion and posing safety hazards. Dynamic loads from the main cable can also cause high-strength bolts at connection points to loosen, leading to reduced structural performance or even failure. Furthermore, the anchor bolts are encased in large volumes of anchor bolt concrete, making inspection and replacement difficult. Therefore, protection of the suspension bridge anchorage system is necessary. Currently, a method to isolate the anchorage system structure from the anchor bolt concrete is to apply sealant between the anchorage system and the anchor bolt concrete.

[0003] In existing technologies, the sealants used between the anchoring system and the anchor concrete are mostly vulcanized sealants. Vulcanized sealants are flammable and burn intensely. To address this issue, more and more projects require sealants with flame-retardant properties. However, current sealant products on the market cannot resolve the contradiction between flame retardancy and ultra-low modulus. During the operation of suspension bridges, vibrations caused by vehicle traffic and the thermal expansion and contraction of the steel structure itself can lead to micro-cracks or even local failure of the sealant, affecting its performance. Based on this, this application proposes an ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for steel isolation in suspension bridges. Summary of the Invention

[0004] This invention provides an ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges, which solves the problem of the contradiction between flame retardancy and ultra-low modulus in the sealants mentioned in the background art.

[0005] This invention provides the following technical solution: an ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for steel isolation in suspension bridges, comprising component A and component B. Component A consists of: MS polymer, plasticizer, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and rheology modifier. The content of each component in component A is as follows: MS polymer 100 parts; plasticizer 80-100 parts; aluminum hydroxide 200-300 parts; magnesium hydroxide 200-300 parts; calcium carbonate 100-200 parts; rheology modifier 10-20 parts.

[0006] The components of component B are: plasticizer, carbon black, aluminum hydroxide, magnesium hydroxide, adhesion promoter, and catalyst; the content of each component in component B is: plasticizer 100 parts; carbon black 20-50 parts; aluminum hydroxide 100-200 parts; magnesium hydroxide 100-200 parts; adhesion promoter 10-20 parts; catalyst 30-50 parts.

[0007] The mass ratio of component A to component B in the ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for steel isolation of suspension bridges is 10:1.

[0008] Preferably, the MS polymer is selected from silane-modified polyether or α-silane-modified polyurethane, wherein the silane-modified polyether is at least one of S303H, S327 and SAX260, and the α-silane-modified polyurethane is at least one of STP-E35 and XM25.

[0009] Preferably, the plasticizer is selected from at least one of alkyl sulfonate phenyl ester, polyether polyol and TCPP ester.

[0010] Preferably, both magnesium hydroxide and aluminum hydroxide are in particulate form, and the particle size of both magnesium hydroxide and aluminum hydroxide is required to be within 5000 mesh.

[0011] Preferably, the calcium carbonate is selected from at least one of Warner 12 powder, 18 powder, 25 powder and 28 powder.

[0012] Preferably, the rheology modifier is selected from at least one of polyamide wax, hydrogenated castor oil, and polyurea.

[0013] Preferably, the adhesion promoter is selected from at least one of KH550, KH560, KH570, and KH792.

[0014] Preferably, the catalyst is selected from organotin and amine catalysts. The organotin catalyst includes at least one of U-220H, TIB 226, and DBTDL, and the amine catalyst includes at least one of tetraethylenepentamine, diether, and N-ethylmorpholine.

[0015] Preferably, the carbon black is modified carbon black.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for steel isolation in suspension bridges is a two-component reactive curing type. Its performance is easy to control and adjust. After curing, it can fully adhere to the surface of the anchoring system, improving the sealing effect. The rubber body formed after vulcanization can achieve a V-0 combustion rating. At the same time, it has excellent adhesion to paint after vulcanization, improving the adaptability of the sealant.

[0018] 2. This ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for suspension bridge steel structure isolation combines ultra-low modulus and flame-retardant properties. It has high elongation, which reduces the possibility of cracking during use, improves the sealant's protective performance for the suspension bridge steel structure, extends the sealant's service life, and meets the requirements for salt spray and acid spray tests in EU EN15434:2006. Attached Figure Description

[0019] Figure 1 These are schematic diagrams of the formulations for embodiments and comparative examples of the present invention;

[0020] Figure 2 This is a schematic diagram showing the performance test results of the sealants prepared using the formulations in the examples and the comparative formulations. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides an ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges, comprising component A and component B. Component A consists of: MS polymer, plasticizer, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and rheology modifier; wherein: the MS polymer is selected from silane-modified polyether or α-silane-modified polyurethane, the silane-modified polyether being at least one of S303H, S327, and SAX260, and the α-silane-modified polyurethane being at least one of STP-E35 and XM25; preferably, the silane-modified polyether is sourced from Kanekachi, Japan. The chemical composition includes: silane-modified polyether from Wacker Chemie, Germany; plasticizer selected from at least one of alkyl sulfonate phenyl ester (Lanxess Mesamoll, Germany), polyether polyols (PPG2000, PPG4000), and TCPP (tris(2-chloropropyl) phosphate); magnesium hydroxide and aluminum hydroxide are both in particulate form, with a particle size of 5000 mesh required; calcium carbonate selected from at least one of Warner 12, 18, 25, and 28 powders; and rheology modifier selected from at least one of polyamide wax, hydrogenated castor oil, and polyurea. Hydrogenated castor oil and Hemings R powder are preferred.

[0023] The addition of magnesium hydroxide and aluminum hydroxide gives the sealant flame-retardant properties. Aluminum hydroxide reacts with oxygen, reducing the rate at which oxygen corrodes the sealant and slowing its aging. The dense oxide film formed when aluminum hydroxide reacts with oxygen reduces the corrosion of the sealant by acids and alkalis, improving its corrosion resistance and extending its service life.

[0024] The contents of each component in Component A are as follows: MS polymer 100 parts; plasticizer 80-100 parts; aluminum hydroxide 200-300 parts; magnesium hydroxide 200-300 parts; calcium carbonate 100-200 parts; rheology modifier 10-20 parts.

[0025] Component B consists of: plasticizer, carbon black, aluminum hydroxide, magnesium hydroxide, adhesion promoter, and catalyst; wherein: the plasticizer is selected from at least one of alkyl sulfonate phenyl ester (Mesamoll, Germany), polyether polyol (PPG2000, PPG4000), and TCPP (tris(2-chloropropyl) phosphate); the carbon black is modified carbon black, preferably Columbia P5 carbon black, used for color matching; the adhesion promoter is selected from at least one of KH550, KH560, KH570, and KH792; the catalyst is selected from organotin and amine catalysts, the organotin being at least one of Nitto Chemical's U-220H, TIB's 226, and DBTDL, and the amine catalyst being at least one of tetraethylenepentamine, bis(2-dimethylaminoethyl) ether, and N-ethylmorpholine.

[0026] By modifying the carbon black, its surface changes from hydrophilic to hydrophobic, increasing its compatibility with other components of the sealant and improving its mechanical properties. The addition of an adhesion promoter enhances the sealant's adhesion, allowing for paint application and improving its overall versatility.

[0027] The contents of each component in Component B are as follows: 100 parts plasticizer; 20-50 parts carbon black; 100-200 parts aluminum hydroxide; 100-200 parts magnesium hydroxide; 10-20 parts adhesion promoter; and 30-50 parts catalyst.

[0028] This ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel rail separation in suspension bridges is a two-component reactive curing sealant. Component A is the prepolymer of the sealant, and component B is the curing agent. During formulation, the mass ratio of component A to component B is 10:1. Furthermore, the solid raw materials in this sealant formulation have the same particle size, facilitating thorough mixing of solid and liquid raw materials and improving the dispersibility and compatibility of the components.

[0029] The present application will be further described below through some embodiments.

[0030] In Examples 1 to 4, the component contents of the ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for steel isolation of suspension bridges are as specified in the appendix to the instruction manual. Figure 1 As shown, the sealant was prepared using the formulations of Examples 1 to 5 through the following preparation process.

[0031] A preparation process for an ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges includes the following steps:

[0032] Step 1: Add the MS polymer, plasticizer, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and rheology modifier of component A into a vacuum disperser and mix for 30-60 minutes at a temperature of 100℃-110℃ and a vacuum degree of 0.085-0.099MPa to obtain component A.

[0033] Step 2: Add the plasticizer, carbon black, aluminum hydroxide, and magnesium hydroxide of component B to a vacuum disperser and mix for 60-90 minutes at a temperature of 110℃-120℃ and a vacuum degree of 0.085-0.099MPa. Once the moisture content is below 800ppm as determined by Karl Fischer method, cool the mixture down to below 50℃, add the adhesion promoter and catalyst, and disperse under vacuum for 30 minutes to obtain component B.

[0034] Step 3: Mix the prepared components A and B thoroughly at a mass ratio of 10:1 to obtain the sealant.

[0035] Comparative Example 1

[0036] This comparative example provides a sealant, the formulation of which is shown in the attached instructions. Figure 1 As shown, the sealant was prepared using the above-described preparation process.

[0037] Comparative Example 2

[0038] This comparative example provides a sealant, the formulation of which is shown in the attached instructions. Figure 1 As shown, the sealant was prepared using the above-described preparation process.

[0039] The sealants prepared in Examples 1 to 4, Comparative Examples 1 and 2 were subjected to performance tests, and the test results are shown in the appendix to the instruction manual. Figure 2 As shown.

[0040] Included in the instruction manual Figure 2It can be seen that, compared with the sealants prepared in Comparative Examples 1 and 2, the sealants prepared in Examples 1 to 4 have the following characteristics: flame retardant performance can reach V0 level; fracture resistance is significantly enhanced; ultra-low modulus; acid mist and salt spray corrosion resistance; and the content of both magnesium hydroxide and aluminum hydroxide affects the flame retardant performance of the sealant. Within a certain range, the higher the content of both magnesium hydroxide and aluminum hydroxide, the better the flame retardant performance of the prepared sealant.

[0041] The contents not described in detail in this specification are prior art known to those skilled in the art. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges, comprising component A and component B, characterized in that: The components of component A are: MS polymer, plasticizer, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and rheology modifier; the content of each component in component A is: 100 parts of MS polymer; 80-100 parts of plasticizer; 200-300 parts aluminum hydroxide; 200-300 parts magnesium hydroxide; 100-200 parts calcium carbonate; 10-20 parts of rheology modifier; The components of component B are: plasticizer, carbon black, aluminum hydroxide, magnesium hydroxide, adhesion promoter and catalyst; the content of each component in component B is: plasticizer 100 parts; carbon black 20-50 parts; aluminum hydroxide 100-200 parts; magnesium hydroxide 100-200 parts; adhesion promoter 10-20 parts. 30-50 parts catalyst; The mass ratio of component A to component B in the ultra-low modulus, high elongation, flame-retardant, and anti-corrosion sealant for steel isolation of suspension bridges is 10:

1.

2. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The MS polymer is selected from silane-modified polyether or α-silane-modified polyurethane, wherein the silane-modified polyether is at least one of S303H, S327 and SAX260, and the α-silane-modified polyurethane is at least one of STP-E35 and XM25.

3. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The plasticizer is selected from at least one of alkyl sulfonate phenyl ester, polyether polyol and TCPP ester.

4. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: Both magnesium hydroxide and aluminum hydroxide are in particulate form, and the particle size of both magnesium hydroxide and aluminum hydroxide is required to be within 5000 mesh.

5. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The calcium carbonate is selected from at least one of Warner 12, 18, 25 and 28 powders.

6. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The rheology modifier is selected from at least one of polyamide wax, hydrogenated castor oil, and polyurea.

7. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The adhesion promoter is selected from at least one of KH550, KH560, KH570, and KH792.

8. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The catalyst is selected from organotin and amine catalysts. The organotin catalyst includes at least one of U-220H, TIB 226, and DBTDL, and the amine catalyst includes at least one of tetraethylenepentamine, diether, and N-ethylmorpholine.

9. The ultra-low modulus, high elongation, flame-retardant, and corrosion-resistant sealant for steel isolation in suspension bridges according to claim 1, characterized in that: The carbon black is modified carbon black.

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