A rare earth synergistic flame retardant asphalt composition and preparation method thereof

Abstract

The invention discloses a rare earth synergistic flame retardant asphalt composition and a preparation method thereof, comprising the following raw materials in parts by weight: 10 parts of a composite flame retardant and 100 parts of asphalt; wherein the composite flame retardant is composed of magnesium hydroxide, a rare earth synergist, a silane coupling agent KH550 and anhydrous ethanol; the preparation method comprises the following steps: S100: preparing a composite flame retardant intermediate; S200: preparing a composite flame retardant; S300: preparing a flame retardant asphalt. The beneficial effect is that it can not only make the asphalt have high-efficiency flame retardant and smoke suppression performance, but also eliminate the emission of pollutants during the pavement paving process, reduce the emission of toxic substances during the flame retardant process, improve the working environment of the pavement paving construction in the tunnel, reduce the health burden of the construction personnel, and greatly reduce the fire loss and casualties of the highway tunnel, improve driving safety, and extend the service life of the highway tunnel pavement.

Description

Technical Field

[0001] The present invention relates to the technical field of pavement materials, and in particular to a rare earth synergistic flame retardant asphalt composition and a preparation method thereof. Background Art

[0002] With the development of land transportation infrastructure, the total mileage of mountain tunnels has continued to grow, and my country has entered a period of rapid development of tunnel construction. Asphalt concrete pavement has excellent driving comfort and is currently the mainstream form of tunnel paving. However, the main component of asphalt materials is hydrocarbons, which are flammable. The asphalt pavement of the tunnel is in a semi-enclosed space. Once a fire occurs, the asphalt in the asphalt mixture will burn to produce a large amount of toxic and harmful gases, which are not easy to disperse, endangering the life and health of people in the tunnel. Flame retardant asphalt technology came into being. Its application in tunnel asphalt pavement can reduce the possibility of tunnel fire accidents to a certain extent, and reduce the personal injury and property losses caused by fire.

[0003] At present, flame retardant asphalt products are mainly used to improve the flame retardancy and smoke suppression performance of asphalt, but the application of flame retardant asphalt is limited by the problems of poor compatibility between flame retardant and asphalt, poor flame retardancy and smoke suppression effect, high preparation cost, and environmental pollution. Chinese invention patent CN 116218028 A discloses an asphalt flame retardant, wherein the asphalt flame retardant, in parts by weight, includes the following raw materials: metal hydroxide: 30 parts to 60 parts, montmorillonite: 5 parts to 10 parts, hydrotalcite: 5 parts to 10 parts, nitrogen-phosphorus flame retardant: 10 parts to 50 parts, silicon-based flame retardant: 10 parts to 20 parts, and surface modifier: 1 part to 10 parts. Its preparation method includes the following steps: mixing and grinding the raw materials to reach 1000-2000 mesh, then wet-modifying the ground raw materials, filtering, washing, and drying to obtain the finished product. The steps of wet modification are as follows: grind the raw materials, prepare slurry with deionized water, heat to 60-110°C in a reactor under stirring conditions, add surface modifier, and stir and react at this temperature for 30-60min. This patent can play a flame retardant and smoke suppression role, and at the same time control the amount of flame retardant added, but the patent does not demonstrate the effect of the flame retardant on the basic properties of asphalt. Materials such as montmorillonite and hydrotalcite will cause asphalt materials to harden. Patent CN 116218039A proposes a novel asphalt composite flame retardant and a preparation method thereof, comprising 10-30 parts of an organic phosphate metal salt, 20-60 parts of magnesium hydroxide, 2-5 parts of a titanate coupling agent, and 10-30 parts of expandable graphite. The preparation method comprises the following steps: dissolving phenol in an organic solvent, adding phosphorus oxychloride and triethylamine, reacting for a period of time to generate an organic phosphoryl chloride, and then hydrolyzing to obtain an organic phosphate ester; sequentially adding the above-mentioned organic phosphate ester and an alkaline substance containing metal ions to the organic solvent to obtain an organic phosphate metal salt; mixing the titanate coupling agent and the organic solvent to obtain an organic solution, sequentially adding the above-mentioned organic phosphate metal salt, expandable graphite and magnesium hydroxide to the organic solution, soaking the organic solution for a period of time, filtering the obtained filter, and drying and cooling the obtained filter to obtain a novel flame retardant, which can improve the flame retardancy and smoke suppression performance of asphalt, reduce the fire hazard of asphalt pavement, and at the same time improve the compatibility between the flame retardant and the asphalt component. However, the preparation process of the patent is complicated, solution immersion is required, the production is not environmentally friendly, industrial production is difficult to achieve, and the flame retardant effect is general (the oxygen index value of the F-doped flame retardant in Example 5 is 25.7%).

[0004] The above patented flame retardant has a complex preparation process, high production cost, and is difficult to apply and promote. Based on this, the present invention proposes a method for preparing rare earth synergistic flame retardant modified asphalt to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a rare earth synergistic flame retardant asphalt composition and a preparation method thereof in order to solve the above-mentioned problems. The preferred technical scheme among the many technical schemes provided by the present invention has the following technical effects: simple preparation process, little impact on the performance of asphalt materials, and good flame retardant and smoke suppression effects, as described below.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a rare earth synergistic flame retardant asphalt composition, comprising the following raw materials in parts by weight: 10 parts of composite flame retardant, 100 parts of asphalt;

[0008] The composite flame retardant consists of magnesium hydroxide, rare earth synergist, silane coupling agent KH550 and anhydrous ethanol.

[0009] Preferably, the rare earth synergist is one of lanthanum oxide and cerium oxide.

[0010] Preferably, the mass fractions of the components in the composite flame retardant are: 9 parts of magnesium hydroxide, 1 part of rare earth synergist, 0.09 parts of silane coupling agent KH550 and 0.81 parts of anhydrous ethanol.

[0011] A method for preparing a rare earth synergistic flame retardant asphalt composition, characterized in that it comprises the following steps:

[0012] S100: preparing a composite flame retardant intermediate, mixing 9 parts of magnesium hydroxide and 1 part of lanthanum oxide / cerium oxide at room temperature, and then drying them in an oven to obtain a composite flame retardant intermediate;

[0013] S200: preparing a composite flame retardant, taking 0.009 parts of silane coupling agent KH500 and mixing it with 0.81 parts of anhydrous ethanol to prepare 0.9 parts of a treatment liquid, and then spraying the treatment liquid evenly onto the surface of the composite flame retardant intermediate, stirring while spraying to make the two mixed evenly, and drying after mixing evenly to obtain a composite flame retardant;

[0014] S300: Prepare flame retardant asphalt, add the composite flame retardant into 100 parts of heated asphalt, shear and disperse it through a high-speed shearing machine, and heat-preserve and develop for 20 minutes to obtain the flame retardant asphalt.

[0015] Preferably, in step S100, the stirring time of magnesium hydroxide and lanthanum oxide / cerium oxide is 5 min.

[0016] Preferably, in step S100, the oven temperature is 160° C. and the drying time is 30 min.

[0017] Preferably, in step S200, the treatment liquid and the composite flame retardant intermediate are mixed evenly and then dried at 65° C. for 1.5 hours.

[0018] Preferably, in step S300, the asphalt is base asphalt or modified asphalt, wherein the heating temperature and the insulation temperature of the base asphalt are both 160°C, and the heating temperature and the insulation temperature of the modified asphalt are both 180°C.

[0019] Preferably, in step S300, the high-speed shearing machine can be replaced by a colloid mill, and the rotation speed of the colloid mill is 4000 r / min.

[0020] In summary, the beneficial effect of the present invention is that by integrating magnesium hydroxide, nano-lanthanum oxide / cerium oxide synergistic flame retardants with asphalt, not only can the asphalt have high-efficiency flame retardant and smoke suppression properties, but compared with existing flame retardants, it can also eliminate the emission of pollutants during the pavement paving process, reduce the emission of toxic substances during the flame retardant process, improve the pavement paving construction working environment in the tunnel, reduce the health burden of construction personnel, and can also greatly reduce fire losses and casualties in highway tunnels, improve driving safety, and extend the service life of highway tunnel pavements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a real picture of the composite flame retardant of the present invention. DETAILED DESCRIPTION

[0023] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0024] The present invention provides a rare earth synergistic flame retardant asphalt composition, comprising the following raw materials in parts by weight: 10 parts of a composite flame retardant, 100 parts of asphalt;

[0025] The composite flame retardant is composed of magnesium hydroxide, a rare earth synergist, a silane coupling agent KH550 and anhydrous ethanol, wherein the rare earth synergist is one of lanthanum oxide and cerium oxide. The magnesium hydroxide is industrial grade magnesium hydroxide, the effective content of Mg(OH)2 is not less than 90%, the mesh number of magnesium hydroxide is 3000-5000 mesh, the mesh number of lanthanum oxide and cerium oxide is 18000 mesh, the concentration of silane coupling agent KH550 is 97.7wt%, and the analytically pure concentration of anhydrous ethanol is 95wt%;

[0026] The mass fractions of the components in the composite flame retardant are: 9 parts of magnesium hydroxide, 1 part of rare earth synergist, 0.09 parts of silane coupling agent KH550 and 0.81 parts of anhydrous ethanol.

[0027] A method for preparing a rare earth synergistic flame retardant asphalt composition, characterized in that it comprises the following steps:

[0028] S100: preparing a composite flame retardant intermediate, stirring 9 parts of magnesium hydroxide and 1 part of lanthanum oxide / cerium oxide at room temperature for 5 min until they are uniformly mixed, and then drying them in an oven to obtain a composite flame retardant intermediate, the oven temperature is 160° C., and the drying time is 30 min;

[0029] S200: preparing a composite flame retardant, taking 0.009 parts of silane coupling agent KH500 and mixing it with 0.81 parts of anhydrous ethanol to prepare 0.9 parts of a treatment liquid, and then spraying the treatment liquid evenly on the surface of the composite flame retardant intermediate, stirring while spraying to make the two mixed evenly, and drying at 65°C for 1.5 hours after mixing evenly to obtain a composite flame retardant;

[0030] S300: preparing flame retardant asphalt, adding the composite flame retardant into 100 parts of heated asphalt, shearing and dispersing (4000r / min) through a high-speed shearing machine (or colloid mill), and heat-keeping and developing for 20min to obtain flame retardant asphalt; the asphalt is base asphalt or modified asphalt, wherein the heating temperature and heat-keeping temperature of the base asphalt are both 160°C, and the heating temperature and heat-keeping temperature of the modified asphalt are both 180°C.

[0031] The specific embodiments are as follows:

[0032] Embodiment 1:

[0033] It includes 9 parts of magnesium hydroxide, 1 part of lanthanum oxide, 0.09 parts of silane coupling agent KH550, 0.81 parts of anhydrous ethanol and 100 parts of base asphalt;

[0034] Example 2

[0035] It includes 9 parts of magnesium hydroxide, 1 part of cerium oxide, 0.09 parts of silane coupling agent KH550, 0.81 parts of anhydrous ethanol and 100 parts of base asphalt;

[0036] Example 3

[0037] It includes 9 parts of magnesium hydroxide, 1 part of cerium oxide, 0.09 parts of silane coupling agent KH550, 0.81 parts of anhydrous ethanol and 100 parts of modified asphalt;

[0038] After setting base asphalt, 10% magnesium hydroxide + 90% base asphalt and SBS modified asphalt as three groups of comparative examples, the limiting oxygen index test, needle penetration and softening point test were respectively carried out on the comparative examples and the examples. The formula table of the examples is shown in Table 1:

[0039] serial number formula Code Comparative Example 1 Base asphalt ZGar Comparative Example 2 10% magnesium hydroxide + 90% base asphalt 10% M-SDJZ Example 1 10% composite flame retardant (lanthanum oxide synergistic flame retardant) + 90% base asphalt 10% ML-SDJZ Example 2 10% composite flame retardant (cerium oxide synergistic flame retardant) + 90% base asphalt 10% MS-SDJZ Comparative Example 3 SBS modified asphalt SBS Example 3 10% composite flame retardant (lanthanum oxide synergistic flame retardant) + 90% base asphalt 10% ML-SBS

[0040] Table 1

[0041] The experimental results are shown in Table 2:

[0042]

[0043]

[0044] Table 2

[0045] It can be seen from Table 2 that the limiting oxygen index value of Example 1 (10% ML-SDJZ, rare earth synergistic flame retardant asphalt with added lanthanum oxide) is 26.5%, and the limiting oxygen index value of Example 2 (10% MS-SDJZ, rare earth synergistic flame retardant asphalt with added cerium oxide) is 27.8%, which are much higher than those of Comparative Example 1 (SDJZ, base asphalt) and higher than those of Comparative Example 2 (only magnesium hydroxide as flame retardant). The addition of synergistic flame retardants has a significant effect on improving the flame retardant properties of asphalt.

[0046] On the other hand, it can be seen from Table 2 that after the base asphalt is modified with flame retardants, the softening point is slightly improved, which shows that the two flame retardants have a certain improvement effect on the high-temperature stability of asphalt, while the needle penetration is slightly reduced, which shows that the addition of flame retardants will increase the modulus of asphalt to a certain extent and improve the deformation resistance of asphalt.

[0047] At the same time, it can be seen from Table 2 that the limiting oxygen index of Example 3 (10% ML-SBS, rare earth synergistic flame retardant SBS modified asphalt with lanthanum oxide added) is as high as 27.1%, which is much higher than that of Comparative Example 3 (SBS modified asphalt), and the composite flame retardant has excellent flame retardant effect. And the addition of the composite flame retardant has little effect on the basic properties of SBS modified asphalt.

[0048] In summary, the flame retardant asphalt prepared by the scheme in this application has excellent flame retardant effect, has no negative impact on the performance of the asphalt itself, and even has a certain positive promotion on the performance of the base asphalt.

[0049] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A rare earth synergistic flame retardant asphalt composition, characterized in that: The raw materials include the following parts by weight: 10 parts of composite flame retardant and 100 parts of asphalt; Wherein, the composite flame retardant is composed of magnesium hydroxide, rare earth synergist, silane coupling agent KH550 and anhydrous ethanol; The rare earth synergist is one of nano lanthanum oxide or nano cerium oxide; The mass parts of the components in the composite flame retardant are: 9 parts of magnesium hydroxide, 1 part of rare earth synergist, 0.09 parts of silane coupling agent KH550 and 0.81 parts of anhydrous ethanol.

2. A method for preparing the rare earth synergistic flame retardant asphalt composition according to claim 1, characterized in that: The following steps are involved: S100, preparing a composite flame retardant intermediate, stirring 9 parts of magnesium hydroxide and 1 part of nano lanthanum oxide or nano cerium oxide at room temperature, and then placing the mixture in an oven to dry to obtain a composite flame retardant intermediate; S200, preparing a composite flame retardant, taking 0.09 parts of silane coupling agent KH550 and mixing it with 0.81 parts of anhydrous ethanol to prepare 0.9 parts of a treatment liquid, and then spraying the treatment liquid evenly onto the surface of the composite flame retardant intermediate, stirring while spraying to make the two mixed evenly, and drying after mixing evenly to obtain a composite flame retardant; S300, preparing flame retardant asphalt, adding the composite flame retardant into 100 parts of heated asphalt, shearing and dispersing by a high-speed shearing machine, and heat-keeping and developing for 20 minutes to obtain the flame retardant asphalt.

3. The method for preparing the rare earth synergistic flame retardant asphalt composition according to claim 2, characterized in that: In step S100, the stirring time of magnesium hydroxide and nano-lanthanum oxide or nano-cerium oxide is 5 minutes.

4. The method for preparing the rare earth synergistic flame retardant asphalt composition according to claim 2, characterized in that: In step S100, the oven temperature is 160°C and the drying time is 30 minutes.

5. The method for preparing the rare earth synergistic flame retardant asphalt composition according to claim 2, characterized in that: In step S200, the treatment liquid and the composite flame retardant intermediate are mixed evenly and then dried at 65°C for 1.5 hours.

6. The method for preparing the rare earth synergistic flame retardant asphalt composition according to claim 2, characterized in that: In step S300, the asphalt is base asphalt or modified asphalt, wherein the heating temperature and the insulation temperature of the base asphalt are both 160°C, and the heating temperature and the insulation temperature of the modified asphalt are both 180°C.

7. The method for preparing the rare earth synergistic flame retardant asphalt composition according to claim 2, characterized in that: In step S300, the high-speed shearing machine can be replaced by a colloid mill, and the rotation speed of the colloid mill is 4000 r / min.

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