KR102003686B1 - Modified asphalt containing vegetable oil and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a polymer composition comprising styrene-butadiene-styrene (SBS), a waste vegetable oil refining agent and a crosslinking agent and, if necessary, a waste rubber powder and / or a styrene butadiene block copolymer / vegetable oil- Modified asphalt and a process for producing the same. The polymer modified asphalt produced according to the production method of the present invention had a low freezing point, an excellent low temperature resistance effect, a high degree of penetration and softness, and a good flexibility and a low cracking effect. Therefore, it can be widely used as all kinds of asphalt pavement materials, especially in cold regions, such as wearable layers, surface layers, base layers, and auxiliary layers of car running roads, parking lots, airport pavements and cargo pavements. In addition, based on vegetable oil, it can contribute to the effective utilization of resources and the reduction of production cost.

Description

Modified asphalt containing vegetable oil and method of producing same [0001]

The present invention relates to a polymer asphalt modified with a vegetable oil, and more particularly to a modified asphalt comprising a vegetable oil and styrene-butadiene-styrene (SBS), optionally containing waste rubber powder and other cross- And a method for producing the same.

Asphalt is the last product from crude oil, a solid or semi-solid black or black-brown hydrocarbon compound that is obtained as a residue when refining petroleum. It can be obtained naturally from oil fields and is rich in plasticity, adhesiveness, elasticity, electrical conductivity and electrical insulation and is used for road pavement, waterproof, moisture proof and waterproof sheet. The chemical composition of asphalt consists of Asphaltenes, Paraffin, Naphthene and Aromatic Resin. However, cracks may occur in the asphalt depending on the environmental conditions, so that the asphalt pavement and the waterproof sheet may not be used properly when used. Particularly in cold regions, cracks in asphalt occur more frequently due to the difference in temperature between summer and winter.

Recently, researches for improving the crack resistance at low temperatures have been actively conducted by developing modified asphalt. The development of conventional rubber modified asphalt contains asphalt in rubber powder (especially waste tire powder) with low Tg (glass transition tempature) characteristics, which has been developed to prevent cracking at low temperatures. Another method, polymer modified asphalt, is made by mixing polymer and cross-linking agent in asphalt, and styrene-butadiene-styrene (SBS) is mainly used. SBS is a copolymer of styrene and butadiene and has the following chemical structure.

SBS has two Tg's, the Tg of styrene is 90-100 ° C, and the Tg of butadiene is -100 to -50 ° C. SBS has good properties at low temperatures, so SBS modified asphalt is considered to be the best among the polymer modified asphalt so far developed, and exhibits excellent crack resistance particularly at low temperatures. However, the use temperature is limited to about -30 to 70 ° C, and cracks are generated under the condition of -40 ° C or less.

To solve this problem, it is necessary to make the modified asphalt more flexible. Accordingly, the present inventors have focused on a method of using vegetable oil to make the modified asphalt flexible, and after confirming that the characteristics of the oil can be absorbed by the asphalt to increase the flexibility and low temperature resistance of the asphalt, .

Accordingly, it is an object of the present invention to provide a polymer-modified asphalt having improved flexibility including an oil component. Another object of the present invention is to provide a method for producing the polymer modified asphalt.

In order to achieve the above object, the present invention provides a vegetable oil composition comprising 3 to 10% by weight vegetable oil; 4 to 8 Phr (parts per hundred) of styrene-butadiene-styrene (SBS); And 0.1 to 1 Phr of a cross-linking agent.

In one embodiment of the present invention, the vegetable oil may be waste cooking oil.

In one embodiment of the present invention, the polymer modified asphalt may further comprise 2 to 5 Phr of waste rubber powder.

In one embodiment of the present invention, the waste rubber powder may be selected from the group consisting of waste rubber powder obtained by pulverizing and pulverizing waste of rubber products such as waste tire powder, waste EPDM powder, and waste tire.

The present invention also provides a method for producing a polymer asphalt modified with a waste vegetable oil. The method for producing an asphalt of the present invention comprises the steps of: 1) melting an asphalt; 2) adding waste vegetable oil to the asphalt melt to homogeneously mix; 3) adding styrene-butadiene-styrene (SBS) to the mixed solution and then homogeneously mixing the mixture; And 4) adding a cross-linking agent to the mixed solution of step 3) and mixing.

In one embodiment of the present invention, the waste vegetable oil may be a waste cooking oil.

In one embodiment of the present invention, the cross-linking agent may be sulfur and phosphate.

In one embodiment of the present invention, the method of the present invention may further comprise the step of adding and mixing the waste rubber powder in the step 2).

In one embodiment of the present invention, in the method of the present invention, 3 to 10 wt% of the waste vegetable oil, 4 to 8 Phr of styrene-butadiene-styrene, and 0.1 to 1 Phr of the crosslinking agent may be mixed have.

In one embodiment of the present invention, the process of the present invention may comprise mixing the SBS-coupled oil with or in place of the steps 2) and 3) above.

The present invention also provides a polymer modified asphalt produced by the process of the present invention.

The polymer modified asphalt produced according to the production method of the present invention has a low freezing point (Tg) and thus has excellent low-temperature resistance effect, has high penetration and softness, and has good flexibility and low cracking effect. Thus, it can be widely used as all kinds of asphalt pavement materials such as abrasion layer, surface layer, base layer and auxiliary layer of vehicle running road, parking lot, airport pavement and cargo bottom. In addition, based on the waste vegetable oil, it can contribute to the effective utilization of resources and the reduction of production cost.

FIG. 1 shows the results of analysis of the molecular weight of the vegetable oil used in one embodiment of the present invention by Gel Permeation Chromatography (GPC).
FIG. 2 shows the results of analysis of chemical structure of vegetable oil used in one embodiment of the present invention by Fourier Transform Infrared Spectrometry (FTIR).
3 is a graph showing the softening temperature change of the polymer modified asphalt according to the oil content change.
4 is a graph showing the change in penetration of the polymer modified asphalt according to the oil content change.
5 is an NMR (nuclear magnetic resonance spectroscopy) graph in which SBS and oil are confirmed to be bonded.

The present invention relates to a method for producing a polymer-modified asphalt having good flexibility and low cracking by mixing constituents of an asphalt and an oil component, and a modified asphalt produced therefrom. The manufacturing method of the present invention includes the following steps.

1) Step of melting asphalt: The melting temperature is from 160 ° C to 180 ° C and the melting time is from 20 to 40 minutes. For homogenous mixing, mix with 3000-4000 RPM using a high shear mixer to prevent degradation of the asphalt.

2) adding vegetable oil to the asphalt melt to homogeneously mix

3) Styrene-butadiene-styrene (SBS) is added to the mixed solution, followed by homogeneous mixing: Mixing is performed at 180 ° C to 190 ° C. In this step, a combination of styrene-butadiene-styrene (SBS) and an oil or a waste rubber may be added as necessary.

4) adding a cross-linking agent to the mixed solution of step 3) and mixing: 0.1 to 0.2 Phr of sulfur and 0.2 to 0.8 Phr of phosphate are mixed and mixed.

5) Transfer the mixed solution from the high shear mixer to the normal mixer and mix the mixture at 150 ° C to 160 ° C and 400RPM for 3 hours to 4 hours.

In one embodiment of the present invention, the styrene-butadiene-styrene is prepared by heating a hydrocarbon solvent selected from n-hexane, n-heptane, iso-octane, cyclohexane and methylcyclopentane to 35 to 45 캜; Administering 30 to 70% by weight of the total amount of styrene monomer to be used for the heated solvent; Administering the initiator to the solvent to which the styrene monomer is administered, and then administering the butadiene monomer; And a step of administering 30 to 70% by weight of the remaining styrene monomer to the solvent to which the butadiene monomer is administered.

In one embodiment of the invention, the oils used in the present invention are vegetable oils and may be selected from the group consisting of canola oil, corn oil, cottonseed oil, flaxseed oil, olive oil, rapeseed oil, soybean oil and sunflower oil However, the present invention is not limited thereto. Also, the vegetable oil of the present invention may be used.

In the manufacturing method according to the present invention, the SBS and the vegetable oil may be connected by a coupling reaction in the step 3). In one embodiment of the present invention, the SBS polymer and the vegetable oil may be mixed at a mixing ratio of 1: 0.2 to 3 based on the molar ratio, preferably 1: 0.5 to 2, 1: 0.7 to 1.2. In one embodiment of the present invention, the coupling reaction step can be carried out at a temperature of 25 to 55 ° C for 30 to 140 minutes, preferably at a temperature of 35 to 45 ° C for 60 to 120 minutes, Preferably at a temperature of 38 to 40 DEG C for 80 to 100 minutes.

Meanwhile, the manufacturing method according to the present invention may further include a step of vulcanizing by mixing sulfur (S) and phosphate after the coupling reaction. Through the vulcanization treatment, separation of asphalt and SBS, which are disadvantages of the polymer modified asphalt, can be prevented, and the temperature range for maintaining elasticity can be widened. In one embodiment of the present invention, the vulcanizing temperature is preferably 140 to 220 占 폚, more preferably 170 to 180 占 폚. In one embodiment of the present invention, sulfur (S) 0.2 Phr (parts per hundred) may be added to the styrene-butadiene-styrene. It is preferable to add 0.1 to 1Phr of phosphate. When sulfur is lower than 0.2 Phr, it is uncrosslinked with SBS, and when it is higher than 0.2 wt%, crosslinking can be formed.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

< Example  1>

Characterization of the vegetable oil of the present invention

In the embodiment of the present invention, waste cooking oil is used as vegetable oil. Gel Permeation Chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) were performed to analyze the characteristics of the waste cooking oil used in the present invention. The molecular weight of the oil was measured by the GPC test, and the structure of the vegetable oil was confirmed by the FTIR test.

As a result, the molecular weight of the vegetable oil was 860 (Fig. 1), and the chemical structure was as shown below.

< Example  2>

SBS  Anion Polymerization of Copolymers and Vegetable Oils

Cyclohexane as the solvent and n-butyllithium as the initiator and the initiation temperature was started at 40 占 폚. 380 ml of cyclohexane was heated to 40 占 폚, 25 ml of styrene monomer was added to cyclohexane heated, and 3 ml of n-butyllithium and 70 g of butadiene monomer were administered in that order. Styrene-butadiene-styrene (SBS) block copolymer was prepared by adding 25 ml of styrene monomer to the solvent to which the butadiene monomer was administered. 3 g of waste soybean oil was injected into the SBS block copolymer prepared above to perform a coupling reaction. After completion of the reaction, 5 ml of methyl alcohol was injected as a reaction terminator to complete the reaction. The reaction scheme is as follows:

Reaction 1: Reaction of Styrene with n-Butyl Lithium

Scheme 2: Styrene-Butadiene diblock copolymer formation

Scheme 3: Styrene-Butadiene-Styrene triblock copolymer formation

Reaction 4: Coupling of Styrene-Butadiene-Styrene with Lung Vegetable Oil

< Example  3>

Preparation and Characterization of Polymer Modified Asphalt of the Present Invention

<3-1> Preparation of polymer modified asphalt

The modified asphalt of the present invention was prepared by the following steps.

1) Asphalt was melted in a high shear mixer at 3,000 RPM at 180 ℃ for 30 minutes.

2) Styrene-butadiene-styrene (SBS) was added to the mixed solution, and the mixture was homogenized by mixing at 190 DEG C and 3,000 RPM for 5 minutes. At this time, the high shear mixer is a mixer required to homogenize the SBS. If the homogenization time is long, the asphalt ages and the physical properties deteriorate. Also, if the mixing time is short, homogenization is not achieved and SBS and asphalt are separated.

3) Phosphate 0.25 ~ 0.75 Phr, S (sulfur) 0.1 ~ 0.2 Phr were added and mixed for 3 minutes at 3,000 RPM. Phosphate cures asphalt and sulfur cures SBS to prevent precipitation and separation.

4) The mixed solution was transferred to a normal mixer and mixed at 150 RPM at 400 RPM for 3 hours to complete the modified asphalt.

<3-2> Characterization of asphalt according to oil type and content

In order to evaluate the effect of the vegetable oil (or the vegetable oil) bound to the vegetable oil or SBS (styrene-butadiene-styrene) block copolymer on the modified asphalt, the modified asphalt prepared by the method of <3-1> The softening temperature and penetration were measured. Petroleum oil (LP) was used as a control group and waste cooking oil was used as a vegetable oil.

The measurements were performed according to standard test methods. In other words, the penetration degree was measured by an intrusion measuring instrument after transferring the mixed solution to a paper cup. The depth of penetration of the needle at 25 ° C and a load of 100 g in 5 seconds was measured in mm, Respectively. The degree of penetration represents the grade of the asphalt. The method of measuring the softening point is as follows. The mixed solution was placed in a cylinder-shaped tube, placed in an oven at 163 ° C, taken out after 48 hours and 72 hours, and cooled to 25 ° C. (upper and bottom) Cut the tube into two parts and put it back into the oven and melt. Put the molten mixed solution into a circular plate. Place the circular plate containing the mixed membrane in an oil bath. A steel ball was placed on the mixed solution and the temperature of the metal ball was measured while raising the temperature of the oil bath.

As a result, the softening point decreased as the oil content (0 wt%, 3 wt%, 6 wt%, 9 wt%) increased (Fig. 3) and the penetration increased with increasing oil content (Fig. In conclusion, we expect that the polymer modified asphalt will have the best characteristics when the vegetable oil content is 3%. The reason for this is that as the oil content of waste cooking oil and paraffin oil increases, the value of penetration increases. Therefore, the rutting effect of asphalt pavement is most effective when the oil content is 3%.

<3-3> SBS  Evaluation of Asphalt Properties by Content

According to the example <3-2>, when the oil content is 3%, it is judged that the asphalt has the most excellent characteristics. Thus, the softening point of the asphalt is measured while changing the SBS content to 3 to 6Phr with 3% Respectively. As a control, paraffinic petroleum oil was used, and vegetable oil was waste cooking oil.

As a result, the softening point increased as the amount of SBS was increased (Table 1). The lower the difference between the upper softening point and the botton softening point, the less separation between SBS and asphalt. The results obtained after 72 hours in this experiment show that 5Phr SBS was better when paraffin oil was used, but only 3Phr when using vegetable oil asphalt. However, SBS 5Phr was measured for low temperature properties in polymer modified asphalt.

Softening point according to SBS content of modified asphalt containing paraffinic oil oil 3% LP-65 / SBS content content Softening point (48 h upper section) 163 ° C Softening point (48 h bottom section) Softening point (72h upper section) Softening point (72h bottom section) 3Phr SBS 48 ° C 44.5 DEG C 47 C 45.6 DEG C 4Phr SBS 53 ℃ 47.1 DEG C 51 ℃ 48 ° C 5Phr SBS 63.2 DEG C 52.8 DEG C 62.8 DEG C 60 ° C 6Phr SBS 66 ° C 52.5 DEG C 72 ℃ 50 ℃

(Phr: mixing amount when considering the mixture of asphalt and oil as 100)

Softening point according to SBS content of modified asphalt containing vegetable oil (waste cooking oil) 3% Food oil / SBS content content Softening point (48 h upper section) 163 ° C Softening point (48 h bottom section) Softening point (72h upper section) Softening point (72h bottom section) 3Phr SBS 42 ° C 43 ℃ 44 ° C 45 ° C 4Phr SBS 48 ° C 48 ° C 53 ℃ 46.5 DEG C 5Phr SBS 54 ℃ 49 ℃ 63 ° C 47 C 6Phr SBS 60 ° C 49 ℃ 75 ℃ 45 ° C

< Example  4>

Characterization of Modified Asphalt According to SBS Bridge

Modified polymer asphalt was prepared by crosslinking the SBS polymer.

SBS 5 Phr, sulfur 0.2 Phr and phosphate 0.25Phr to 0.75Phr were mixed with 94% by weight of asphalt and 6% of oil and the mixture thereof as 100%. In case of using 3% oil, the best results were obtained. However, considering the low temperature characteristics of asphalt, the oil content was considered to be the best at 6%. Paraffin-based oil and lead-based oil were used as the control oil, and closed-type edible oil was used as the vegetable oil.

Modified polymer asphalt was prepared using the above materials according to the above-described manufacturing method. The crosslinking agent was crosslinked at 180 캜 for 40 minutes while varying the sulfur 0.2Phr and the phosphate 0.25Phr to 0.75Phr.

The penetration, softening point and pour point of the asphalt prepared by adding each of the above oils were measured. As a result, the penetration rate of cooking oil, paraffin oil, and lead oil was higher (Table 3). The pour point was also in the order of cooking oil (-37 ° C), paraffin oil (-35 ° C), and lead oil (-30 ° C). Thus, it can be seen that asphalt is the softest when adding cooking oil.

Sample penetration (20 ° C) softing point (72h upper section) softing point (72h bottom section) LP (paraffinic oil oil) 1194 63.5 63.5 cooking oil 1307 58 56 n-oil (lead-based oil oil) 577 67.8 66

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (6)

1) melting the asphalt at 160 ° C to 180 ° C for 20 to 40 minutes;
2) adding waste vegetable oil to the asphalt melt to homogeneously mix;
3) adding styrene-butadiene-styrene (SBS) to the mixed solution and then homogeneously mixing the mixture at 180 ° C to 190 ° C; And
4) adding a cross-linking agent to the mixture of step 3) and mixing the mixture,
The styrene-butadiene-styrene and the waste vegetable oil are connected by a coupling reaction and mixed at a molar ratio of 1: 0.2 to 3,
Wherein the waste vegetable oil is mixed at a ratio of 3 to 10 wt%, styrene-butadiene-styrene is mixed at a ratio of 4 to 8 Phr, and the crosslinking agent is mixed at a rate of 0.1 to 1 Phr. The method according to claim 1,
Wherein the waste vegetable oil is waste cooking oil. The method according to claim 1,
Wherein the crosslinking agent is sulfur and a phosphate. The method according to claim 1,
And adding the waste rubber powder in the step 2) and mixing the waste rubber powder. delete A polymer modified asphalt prepared by the process of any one of claims 1 to 4.

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