CN1249167C - Preparation method of polymer modified asphalt material with high-temperature storage stability - Google Patents

Abstract

The invention relates to a preparation method of a polymer modified asphalt material for road paving and high-temperature storage stability. The method comprises the steps of premixing a thermoplastic elastomer polystyrene-polybutadiene-polystyrene triblock copolymer (SBS) and a stabilizer silicate inorganic filler by high molecular processing equipment to obtain a master batch for modified asphalt, and fully dispersing the modified master batch into matrix asphalt by a high shear mixer. The asphalt material obtained by the invention has the advantages of excellent performance, stable high-temperature storage, low modification cost and simple production process, and can be used as road paving and waterproof materials.

Description

Preparation method of polymer modified asphalt material with high temperature storage stability

Technical field: the present invention relates to a method for preparing polymer-modified asphalt which can be used for paving roads with high-temperature storage stability.

Background technology: as the main modifier of asphalt materials for roads, polymers are widely used at home and abroad to improve the mechanical properties and service performance of asphalt materials, but there are certain limitations, such as the compatibility between polymers and asphalt Generally, the thermal stability of the modified system is poor, resulting in poor thermal storage stability of the modified system. The dispersed polymer particles aggregate and float to the upper layer. , but this method increases the manufacturing process and increases the production cost.

In order to solve the above problems, Chinese patent 01126386.5 reported that fillers with a core-shell structure were used alone or in combination with polymers as asphalt modifiers to prepare storage-stable modified asphalt, but the preparation process of this method is complicated and the production cost is high. U.S. Patent No. 6,558,462B1 reports that other fillers such as pottery clay are used as stabilizers and put into natural asphalt to shear to prepare storage-stable modified asphalt. The modification method adopted for the melting point is not a method for the storage stability of polymer-modified asphalt at high temperature in the usual sense. US Patent Nos. 6,310,122, 6,429,241, 6,441,065 and 6,444,731 report the use of sulfur and other chemical cross-linking methods to prepare modified asphalt with high temperature storage stability, but these methods have complicated preparation processes and high modification costs.

Summary of the invention: The present invention uses polymer processing equipment to directly pre-blend thermoplastic elastomer polystyrene-polybutadiene-polystyrene triblock copolymer (SBS) and stabilizer silicate inorganic fillers to prepare Modified masterbatch, and then disperse the modified masterbatch into base asphalt to prepare modified asphalt, thereby greatly improving the high-temperature storage stability of SBS modified asphalt. Using this processing technology can have the following effects: the stabilizer silicate inorganic filler changes the density difference between the thermoplastic elastomer SBS and asphalt, and its active particles are embedded in SBS to increase the volume percentage of SBS in asphalt. The light components in the asphalt enter the SBS to form a stable colloidal system, thereby improving the compatibility between asphalt and SBS, and greatly improving the stability of SBS modified asphalt.

The preparation method of modified asphalt of the present invention comprises two processes of preparation of modified masterbatch and preparation of modified asphalt, and concrete steps are as follows:

(1) Preparation process of modified masterbatch: first pass SBS and stabilizer silicate inorganic filler through polymer material processing equipment, such as internal mixer, open mixer, single-screw extruder and twin-screw extruder, etc. , make them mix at 25-200°C for 2-20 minutes, and then pass through the open mill and then pelletize on a flat plate or use a plastic crusher to crush and pelletize, or directly pull strands to pelletize or grind after extruding with a screw extruder. noodle dicing;

The weight percentage of the thermoplastic elastomer SBS in the modified masterbatch is 50-90%, and the weight percentage of the stabilizer is 10-50%.

(2) Modified asphalt preparation process: Use high-shear mixing equipment, such as high-shear mixer, colloid mill, etc., to shear the modified masterbatch and asphalt at 120-200°C for 3-60 minutes , It can also be mixed and dispersed with ordinary shearing and stirring equipment, but the time is longer. The weight percentage of the modified masterbatch in the modified asphalt is 2-30%, and the weight percentage of the asphalt is 70-98%.

The molecular weight of the SBS used in the present invention ranges from 20,000 to 500,000, and its structure includes linear and star structures. One or more combinations of the above-mentioned SBS can be used.

The stabilizer used in the present invention is one or a combination of kaolin, clay, montmorillonite, diatomite or bentonite, wherein their particle size ranges from 0.1 μm to 200 μm. The stabilizer can be treated or untreated. Compared with previous reports, the stabilizer used in the present invention has the characteristics of simple production process and low cost; the modified asphalt obtained by using the stabilizer is stable in high temperature storage, and has better high and low temperature performance, and can be widely used For road paving, waterproof membrane.

Specific embodiments: the following examples are further descriptions of the present invention, rather than limiting the scope of the present invention.

Embodiment 1-6:

Mix 100g of SBS (4303) and different amounts of kaolin (calcined ultra-fine type, 20μm) on a double-roll mill at about 130°C for 5 minutes. The modified masterbatch is prepared by pelletizing. The formula of the modified masterbatch is shown in Table 1 (component contents are all parts by weight, the same below). In comparative example 1 in the table, kaolin was not added, and in comparative example 2 in the table, SBS and kaolin were directly put into the base asphalt to obtain modified asphalt.

Table 1 SBS/kaolin modified masterbatch formula Modified Masterbatch No. SBS Kaolin Comparative example 1 100 0 Comparative example 234567 100100100100100100 352025303540

Add 25.2g, 34.3g, 30.3g, 31.6g, 32.9g, 34.3g and 35.6g of modified materials with formulas 1, 2, 3, 4, 5, 6 and 7 into 600g of 160°C In the hot asphalt, a high-shear mixer was used to stir and disperse for 30 minutes to prepare a modified asphalt with a weight content of 4% SBS.

According to GB/T4508, GB/T4507, JTJ052/T660, ASTM D4402 and GB/T4509 test performance indicators such as elongation, softening point, separation, viscosity and penetration (the same below). The properties of the obtained modified asphalt are shown in Table 2.

Table 2 The effect of kaolin addition on the properties of modified asphalt example Softening point/℃ Penetration/0.1mm Viscosity/cp135℃ Ductility(5℃)/cm Delamination test/℃ before aging after aging superior Down Comparative example 1 72 64 1000 30 17 >95 51 Comparative example 2 73 66 900 31 14 90 51 3 73 69 850 25 15 90 59 4 71 62 850 19 13 78.5 66.5 5 69 69 800 twenty three 12 80 67 6 71 69 875 30 20 70.5 71 7 72 73 833.3 35 14 57 79

Note: Stable storage condition: 163℃×48h

Asphalt: Zhenhai 90# (the same below)

As shown in Table 2, the high-temperature storage stability of modified asphalt was improved to varying degrees compared with that of pure SBS by adding SBS modified masterbatch containing kaolin. With the increase of kaolin content in the modified masterbatch, the modified The storage stability of asphalt increases sequentially. When the SBS modified masterbatch containing 35phr kaolin is added, the modified asphalt is stable in storage. When the amount of kaolin is too much or too little, the storage stability of the modified asphalt system becomes poor. Therefore, for the same SBS, storage-stable modified asphalt can be obtained by adjusting the amount of kaolin in the masterbatch.

Embodiment 8-11:

Mix 100g of SBS (4303) and appropriate amount of different types of kaolin on a double-roller mill at about 130°C for 5 minutes. After mixing evenly, pass through 6 times and then slice it out, and use a flat pelletizer to pelletize to obtain modified Masterbatch. The formula of the modified masterbatch is shown in Table 2 (component contents are all parts by weight, the same below).

Table 3 SBS (4303) / different types of kaolin modified masterbatch formula Modified Masterbatch No. SBS dosage Types of Kaolin Kaolin dosage 891011 100100100100 325 mesh uncalcined type 325 mesh calcined type 800 mesh calcined type 1250 mesh calcined type 30283235

Add 32.9g, 32.4g, 31.7g and 34.3g of modified masterbatches with formulations 8, 9, 10 and 11 to 600g of hot asphalt at 160°C, and stir and disperse with a high-shear mixer for 30 Minutes to prepare modified asphalt with a weight content of 4% SBS. The properties of the obtained modified asphalt are shown in Table 4.

As shown in Table 4, after adding appropriate amount of different types of kaolin to the modified asphalt, the modified asphalt is stable in high temperature storage. Different types of kaolin have different binding forces with SBS. An appropriate amount of kaolin can be added to asphalt to obtain an isodensity modified asphalt system. Therefore, for different types of kaolin, the modified asphalt with high temperature storage stability can be obtained by adjusting the amount of kaolin.

Table 4 Effect of different types of clay on modified asphalt example Softening point/℃ Penetration/0.1mm Viscosity/cp Ductility(5℃)/cm Delamination test/℃ before aging after aging superior Down 8 70 69 844.5 32 18 71 71.5 9 68 72 830.3 28 19 70.5 70 10 72 68 880 30 20 72 72.5 11 71.5 69 875 30 11 70.5 71

Examples 12-15:

Mix 100g of different types of SBS with the same kaolin on a double-roll mill at about 130°C for 5 minutes. After mixing evenly, pass through 6 times and then slice it out. Then, use a flat pelletizer to pelletize to obtain a modified masterbatch. The formulation of the modified masterbatch is shown in Table 5.

Table 5 Formulas of different types of SBS/same kaolin modified masterbatch Modified Masterbatch No. SBS model SBS dosage Types of Kaolin Kaolin dosage 12131415 4303791H801501 100100100100 325 mesh uncalcined type 325 mesh uncalcined type 325 mesh uncalcined type 325 mesh uncalcined type 35303032

Add 34.3g, 32.9g, 32.9g and 31.7g of modified masterbatches with formulations 12, 13, 14 and 15 to 600g of hot asphalt at 160°C, and stir and disperse with a high-shear mixer for 30 Minutes to prepare modified asphalt with a weight content of 4% SBS. The properties of the obtained modified asphalt are shown in Table 6.

As shown in Table 6, after adding different types of SBS modified masterbatches to the modified asphalt, the modified asphalt is stable in high temperature storage. Different types of SBS and kaolin have different binding forces. Adjusting the ratio of SBS and kaolin can obtain an isodensity modified asphalt system. Therefore, for different types of SBS, the modified asphalt with high temperature storage stability can be obtained by adjusting the amount of kaolin.

Table 6 Effect of different types of SBS/same kaolin on modified asphalt example Softening point/℃ Penetration/0.1mm Viscosity/cp Ductility(5℃)/cm Delamination test/℃ before aging after aging superior Down 12 70 69 844.5 32 18 71 71.5 13 55.5 73 866 28 12 61 62.5 14 67 68 925 28 19 67 66 15 56 77 885 33 twenty one 60 60.5

Claims (5)

1. A method for preparing a polymer-modified asphalt material stable in high-temperature storage, characterized in that its preparation method is as follows: (1) Preparation of modified masterbatch Add thermoplastic elastomer polystyrene-polybutadiene-polystyrene triblock copolymer and stabilizer silicate inorganic filler into processing equipment, knead at 25-200°C for 2-20 minutes, and then manufacture granules or pulverized to obtain a modified masterbatch, the thermoplastic elastomer polystyrene-polybutadiene-polystyrene triblock copolymer in the modified masterbatch is 50-90% by weight, and the stabilizer silicate The weight percentage of inorganic filler is 10～50%; (2) Preparation of modified asphalt Use a high-shear mixing equipment to mix the modified masterbatch and asphalt at 120-200°C for 3-60 minutes to obtain a modified asphalt that is stable in high-temperature storage. The weight of the modified masterbatch in the modified asphalt The percentage is 2-30%, and the weight percentage of asphalt is 98-70%. 2. the high temperature storage stable polymer modified asphalt material preparation method according to claim 1 is characterized in that the molecular weight of the thermoplastic elastomer polystyrene-polybutadiene-polystyrene triblock copolymer used is The range is 20,000 to 500,000, and its structure is selected from one of linear and star or a combination of the above two. 3. The polymer-modified asphalt material preparation method of high temperature storage stability according to claim 1, characterized in that the used stabilizer silicate inorganic filler is selected from kaolin, clay, montmorillonite, diatomaceous earth or bentonite One or a combination of several of the above, wherein their particle size ranges from 0.1 μm to 200 μm, and the stabilizer silicate inorganic filler is treated or untreated. 4. the high-temperature storage-stable polymer-modified asphalt material preparation method according to claim 1, is characterized in that described processing equipment is selected from internal mixer, open mill, single-screw extruder or twin-screw extruder machine; the granulation equipment is selected from strand granulation, grinding surface granulation, flat granulation or crusher. 5. The method for preparing high-temperature storage-stable polymer-modified asphalt material according to claim 1, characterized in that the high-shear mixing equipment is selected from high-shear mixers or colloid mills.