KR100572461B1 - Asphalt modifiers and asphalt compositions containing them - Google Patents

Abstract

The present invention relates to an asphalt modifier and a asphalt composition comprising the same, wherein the asphalt modifier contains a polymer material. More specifically, the blowing agent may be azodicarbonamide, modified azodicarbonamide, 4,4-oxybis (benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, p -toluenesulfonylhydrazide and their At least one selected from the group consisting of a mixture relates to an asphalt modifier and an asphalt composition comprising the same, characterized in that the amount of blowing agent has a range of 0.1 to 10 phr (per hundred ratio). When the polymer mixture is applied to asphalt, it is possible to increase the rate of dissolving in asphalt while maintaining mechanical properties at actual temperatures.

Asphalt, Modifier, Foaming Agent, Solubility, Dissolution Rate

Description

Asphalt Modifier Containing Blowing Agent and Asphalt Composition Containing Thereof}

The present invention relates to an asphalt modifier and a asphalt composition comprising the same, wherein the asphalt modifier contains a polymer material. More specifically, the blowing agent may be azodicarbonamide, modified azodicarbonamide, 4,4-oxybis (benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, p -toluenesulfonylhydrazide and their At least one selected from the group consisting of a mixture relates to an asphalt modifier and a modified asphalt composition comprising the same, characterized in that the amount of blowing agent has a range of 0.1 to 10 phr (per hundred ratio).

Asphalt used for road pavement and waterproofing materials has been severely limited in its use range due to problems such as low temperature cracking and high temperature plastic deformation. Therefore, researches and applications for various asphalt modifiers have been actively conducted as a way to improve the disadvantages of such asphalt.

Asphalt modifiers include various polymers such as olefin / acrylic monomer copolymers, vinyl aromatic hydrocarbons / conjugated diene random copolymers and vinyl aromatic hydrocarbons / conjugated diene block copolymers. It is most widely used because it has the effect of dramatically increasing the service temperature range and lifespan of asphalt with only a small amount of addition.

On the other hand, in the asphalt reforming process, it is important to dissolve and disperse the polymer material in asphalt, but the dissolution rate is generally not fast, which directly affects productivity. In order to improve productivity, controlling the molecular weight and molecular structure of the polymer material may increase the solubility of asphalt, but may result in the weakening of the final mechanical properties. In addition, when maintaining the same molecular weight and molecular structure, the solubility of the polymer material is mainly dependent on the final shape, but only by controlling the shape does not have a significant effect on the improvement of the solubility.

Accordingly, in the present invention, as a result of studying the problems of the prior art, by adding a blowing agent to the polymer asphalt modifier, without changing the molecular weight or structure of the polymer mixture of the modifier without damaging the final mechanical properties at room temperature The present inventors have found that the asphalt solubility can be significantly improved.

That is, an object of the present invention is to provide a polymer asphalt modifier excellent in solubility at the time of blending with asphalt as compared to conventional polymer asphalt modifiers.

Another object of the present invention is to provide an asphalt modifier and an asphalt composition containing the same, which do not change the molecular weight or structure of the polymer mixture of the modifier, thereby improving asphalt solubility without damaging the final mechanical properties at room temperature. It is done.

In order to achieve the object of the present invention, the present invention provides an asphalt modifier, characterized in that it contains a blowing agent in an asphalt modifier containing a polymer material.

The blowing agent is used in an amount of 0.1 to 10 phr (per hundred ratio), and the blowing agent includes all organic blowing agents and inorganic blowing agents, and in particular, inorganic blowing agents such as sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, azide compound, and boron hydride. Sodium and organic foaming agents azodicarbonamide, modified azodicarbonamide, 4,4-oxybis (benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, p -toluenesulfonylhydrazide and mixtures thereof At least one selected from the group consisting of is preferable.

The polymeric material contained in the modifier includes a vinyl aromatic hydrocarbon / conjugated diene copolymer. The copolymer comprises a vinyl aromatic block having a molecular weight of 10,000 to 150,000 g / mol and a conjugated diene block having a molecular weight of 10,000 to 150,000 g / mol, and the ratio of the vinyl aromatic hydrocarbon / conjugated diene is 5:95 to 40. Has a range of 60

The vinyl aromatic block is at least one block selected from the group consisting of styrene, methyl styrene and mixtures thereof, and the conjugated diene block is at least one selected from the group consisting of butadiene, isoprene and mixtures thereof.

In another aspect, the present invention provides a modified asphalt composition in which the mixing ratio of the asphalt modifier and asphalt is in the range of 1: 99 to 10: 90.

Hereinafter, the present invention will be described in more detail through application to the vinyl aromatic hydrocarbon / conjugated diene copolymer which is most widely used as an asphalt modifier. However, the present invention is applicable not only to the vinyl aromatic hydrocarbon / conjugated diene copolymer but also to other conventional components, which are not affected by the components of the modifier.

<Production of Modifiers>

As one of the polymer mixtures, a vinyl aromatic hydrocarbon / conjugated diene copolymer composed of a vinyl aromatic hydrocarbon block and a conjugated diene block is polymerized. The average molecular weight ranges from 5,000 to 500,000 and the ratio of vinyl aromatic hydrocarbon / conjugated diene monomers ranges from 5:95 to 40:60.

In the polymerization of the block copolymer, a vinyl aromatic hydrocarbon and a conjugated diene mixed solution are added to a reactor containing an organic lithium and a hydrocarbon solvent, the polymerization is performed until the monomer consumption is 99% or more, and then linear or radial through a coupling reaction. Prepare the block copolymer. Thereafter, water or alcohol is added to the reactor to prepare a polymer in which the activity of the active polymer is removed.

Dispersion of the blowing agent in the polymer is carried out as follows. A fixed amount of blowing agent is administered to the polymer and stirred, and then the solvent is recovered to obtain a block copolymer. The blowing agent is an additive used to form a porous foam by mixing with a polymer. The blowing agent includes sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, azide compound, sodium borohydride and azodicarbon as an organic foaming agent. Amides, modified azodicarbonamides, 4,4-oxybis (benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, p -toluenesulfonylhydrazide and mixtures thereof, and the like, in particular organic foaming agents. Phosphorous azodicarbonamide, modified azodicarbonamide, 4,4-oxybis (benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, p -toluenesulfonylhydrazide and mixtures thereof are mainly used. .

The foaming agent is dispersed in the polymer and the foaming agent is decomposed by external heat to form a gas, and the gas forms pores in the polymer, and thus the gas may have a porosity compared to the polymer without the blowing agent.

For example, azodicarbonamide (ADCA) forms a void while the reaction is carried out as shown in the following scheme.

3ADCA → 2N ₂ + CO NH ₃ + HDCA + 3HCNO

HDCA → Urazole + NH ₃

3HCNO → Biuret + Cyanuric acid

<Production of Asphalt and Measurement of Physical Properties>

The mixing of the block copolymer and the asphalt containing the blowing agent proceeds as follows using a low shear stirrer having a simple stirring function or a high shear stirrer having a grinding and stirring function. 500 g of asphalt were put in a mixing vessel, and the temperature was maintained at 150 ° C. for 5 minutes at a stirring speed of 400 rpm. Next, the stirring speed of the stirrer is raised to 1000 rpm and then the quantitative block copolymer is added. After the temperature rises to 170 ° C. over 3 minutes, the low shear stirrer increases the stirring speed to 2000 rpm and the high shear stirrer to 4000 rpm. Stirring for a period of time to measure the viscosity while dissolving the block copolymer in asphalt. The blend is taken from the low shear stirrer and the softening point of the asphalt / block copolymer blend over time is measured. In a high shear stirrer, the blend in the fully dissolved state is taken to determine the final mechanical properties of the asphalt / block copolymer blend.

As the asphalt, AP-5 asphalt having a softening point of 40 to 60 ° C., penetration of 60 to 70, and low temperature elongation of 5 or less was used. The viscosity and mechanical properties of the asphalt / block copolymer blend were measured by the following method.

Viscosity according to dissolution time was measured based on ASTM4402, and penetration was measured according to ASTM5 by standing at 25 ° C. for 3 hours. Softening point was measured by ASTM36 method and low temperature elongation was measured by ASTM113 method after standing at 5 ℃ for 3 hours.

The blending ratio of the asphalt / block copolymer blend is adjustable in the range of 0.1: 99.9 to 20: 80 and preferably has a range of 1: 99 to 10: 90.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited to Examples.

Example 1

Using a styrene and butadiene as a monomer, a triblock copolymer having a weight ratio of 31/69 was prepared as follows.

9000 g of cyclohexane as a solvent and 465 g of styrene were added to a 20 L reactor filled with nitrogen, and 1.6 g of n-butyllithium was added at a temperature of 60 ° C. to polymerize styrene. After the styrene polymerization, butadiene monomer was again administered 1035 g to produce butadiene block at the end of the polymerized styrene block.

After the completion of the butadiene polymerization, the methylation dichloride silane was administered to proceed with the coupling reaction, and then 0.5 g of water was administered to terminate the polymerization reaction. 7.5 g of antioxidant Irganox 1076 and 15.0 g of TNPP were added to the polymerization solution, and finally, 75 g of modified azodicarbonamide, a blowing agent, was added to disperse and the solvent was recovered to prepare a block copolymer. .

The triblock copolymer prepared as described above had a molecular weight of 110,000 g / mol and a coupling efficiency of 90%. The viscosity of the prepared triple block copolymer was mixed with asphalt for 20 minutes in a low shear stirrer, and the softening point, which is the physical property most sensitive to the blending state of the asphalt / block copolymer blend, was measured and shown in Table 2 below.

Comparative Example 1

After the polymerization solution of the triblock copolymer was prepared in the same manner as above, the addition of the blowing agent, which is the final step, was omitted and the solvent was recovered to be a target of the comparative example. The molecular weight and the coupling efficiency corresponded to the triple block copolymer of Example 1, and had a molecular weight of 110,000 g / mol and a coupling efficiency of 90%. The viscosity and softening point of the block copolymer / asphalt blend were measured in the same manner as in Example 1, and are shown in Table 2 below.

[Examples 2 to 4]

After preparing the triple block copolymer in the same manner as in Example 1, it was blended with asphalt for 30 minutes, 40 minutes, and 60 minutes in a low shear stirrer, and the viscosity and softening point of each were measured and shown in Table 2 below.

Example 5

After preparing the triple block copolymer in the same manner as in Example 1, it was blended with asphalt in a high shear stirrer for 30 minutes and the mechanical properties of the final blend were measured and shown in Table 3 below.

[Comparative Examples 2 to 4]

After preparing the triple block copolymer in the same manner as in Comparative Example 1, the mixture was mixed with asphalt for 30 minutes, 40 minutes, and 60 minutes in a low shear stirrer, and the viscosity and softening point of each were measured and shown in Table 2 below.

[Comparative Example 5]

After preparing the triple block copolymer in the same manner as in Comparative Example 1, it was blended with asphalt in a high shear stirrer for 30 minutes and the mechanical properties of the final blend was measured and shown in Table 3 below.

Dissolution Rate of Block Copolymer in Asphalt by Adding Foaming Agent Blowing agent content (phr) 0 5 Dissolution time (min) 60 30

(The dissolution time is the viscosity of the asphalt / block copolymer at 135 ℃ by the dissolution of the block copolymer when stirring with a low shear stirrer rises to more than the viscosity of the asphalt / block copolymer stirred for 30 minutes in a high shear stirrer Time taken)

Viscosity and Softening Point of Asphalt Compounds According to Mixing Time Asphalt Blend Viscosity (cps) Softening Point (℃) 100 ℃ 120 ℃ 135 ℃ Example 1 14100 3420 1440 60.1 Example 2 17500 3930 1536 61.0 Example 3 19300 4280 1550 63.7 Example 4 28200 5240 1880 66.0 Comparative Example 1 18500 2900 1300 59.6 Comparative Example 2 15680 3515 1200 58.5 Comparative Example 3 18500 3500 1330 61.6 Comparative Example 4 21700 4150 1520 64.4

Viscosity and Mechanical Properties of Final Asphalt Formulations Asphalt Blend Viscosity (cps) Softening Point (℃) Penetration (dm) 100 ℃ 120 ℃ 135 ℃ Example 5 14940 3420 1400 65.5 65 Comparative Example 5 14800 3360 1470 65.7 62

As shown in Table 1, the block copolymer to which the blowing agent was added was found to have a significantly faster rate of asphalt dissolution compared to the block copolymer containing no blowing agent.

In addition, as can be seen in Table 2, it was found that the block copolymer to which the blowing agent is added has a relatively high viscosity and softening point at each dissolution time compared to the triple block copolymer containing no blowing agent. Softening point is an important indicator that directly tells the blending degree of the block copolymers and asphalt, it can be seen that the blending speed of the block copolymer and asphalt increased due to the addition of a blowing agent.

In addition, as can be seen in Table 3, the softening point of the final blend of the asphalt / block copolymer was almost the same regardless of the addition of the blowing agent, the penetration is rather improved the final blend according to the present invention than the conventional Could know.

As described above, the asphalt modifier according to the present invention and the modified asphalt composition containing the same have an effect of increasing the dissolution rate of the asphalt without affecting the final physical properties of the modified asphalt, thereby greatly improving the productivity of the modified asphalt. It is a useful invention that can be.

Although the present invention has been described in detail with reference to the embodiments described above, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the present invention, and such modifications and variations are included in the appended claims. It is natural to belong.

Claims (7)

An asphalt modifier containing a vinyl aromatic hydrocarbon / conjugated diene copolymer, wherein the asphalt modifier contains 0.1 to 10 phr (per hundred ratio) of blowing agent. delete The method of claim 1, The blowing agent is an inorganic foaming agent sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, azide compound, sodium borohydride and organic foaming agent azodicarbonamide, modified azodicarbonamide, 4,4-oxybis (benzenesulfonyl Hydrazide), dinitrosopentamethylenetetramine, p -toluenesulfonylhydrazide, and mixtures thereof. delete The method of claim 1, The copolymer includes a vinyl aromatic block having a molecular weight of 10,000 to 150,000 g / mol and a conjugated diene block having a molecular weight of 10,000 to 150,000 g / mol, and the ratio of the vinyl aromatic hydrocarbon / conjugated diene is 5:95 to 40. : Asphalt modifier having a range of 60. The method of claim 5, wherein The vinyl aromatic block is at least one block selected from the group consisting of styrene, methyl styrene and mixtures thereof, and the conjugated diene block is at least one block selected from the group consisting of butadiene, isoprene and mixtures thereof. Asphalt modifier. The modified asphalt composition according to claim 1, wherein the mixing ratio of the asphalt modifier and the asphalt is in the range of 1:99 to 10:90.