Hard asphalt


Hard asphalt is a peculiar amorphous material which is generally in liquid form when discharged by oxidation plants at a temperature ranging from 240° to 300° C., and becomes solid or pasty at ambient temperatures. While being relatively hot, it is viscous, whereas when in pasty or solid state it possesses a fair degree of elasticity. Both in liquid and in plastic or solid form hard asphalt is a highly insulating material with good adhesion properties with respect to almost any solid material.

ATDM is hard asphalt manufacturer and multi face company based on Iran. We are structured into focused on oxidization of Bitumen division to serve the different needs of our customers worldwide.
We are supplying hard asphalt in various grades including hard asphalt 115/15 hard asphalt 95/25 85/40 , 90/15 , 90/40 , 85/25 , 75/25 and very hard asphalt 150/5 also other all grades of asphalt according to order. Throughout the world, more than 8 types of bitumen that is produced depend on the type of weather conditions one of them is hard asphalt.

Hard asphalt grades (115/15 90/40 90/10 90/15 85/25 105/30 150/5 75/25) are suitable for sealing saw cuts and joints where there is expected to be the minimum amount of moving in the joint. Their wide temperature range prevents bleeding in high temperature applications. Hard asphalt can also be used in industrial applications like roofing, flooring, mastics, pipe coatings, electrical applications.

Most usage of hard asphalt is in ink industrial

An ink contains a petroleum-derived hard asphalt, a colorant, and a carrier for the hard asphalt and colorant. The hard asphalt has a softening point from 105° C. to 155° C. and a saturates content not greater than 32% by weight. Preferably at least 50% by weight of the carrier is a material selected from aliphatic oils, aliphatic solvents, and mixtures thereof. A method of making the ink includes granulating the hard asphalt to a particle size not greater than 2.38 mm (8 mesh), dissolving the hard asphalt in the carrier, and adding a colorant to the carrier.

A suitable hard asphalt has a softening point from about 105° C. to about 155° C., preferably from about 120° C. to about 135° C., and more preferably from about 125° C. to about 130° C. The softening point of the asphalt is measured by the ring and ball method, ASTM D-36. The asphalt preferably has a penetration not greater than about 15 dmm at 25° C., and more preferably not greater than about 10 dmm, as measured by ASTM D-5. Thus, the asphalt is a hard asphalt as opposed to a soft asphalt such as AC grade (road grade) or roofers flux.

It has been found that the hard asphalt is well suited for use in a printing ink, because it produces an ink which dries thoroughly on the substrate instead of remaining tacky. A soft asphalt, on the other hand, would usually produce an ink which remains tacky. It has also been found that the hard asphalt is adapted for granulation to a particle size suitable for manufacturing the ink of this invention. In contrast, a soft asphalt would be very difficult to granulate.

Preferably an asphalt starting material is subjected to an oxidizing process to provide these softening point and penetration properties. As mentioned above, it has been found that an oxidizing process provides uniformity and consistency of the asphalt composition to enable control of the ink viscosity. The hard asphalt starting material preferably has a softening point from about 50° C. to about 100° C., and more preferably from about 65° C. to about 85° C. The oxidizing process comprises blowing air, oxygen or an oxygen-inert gas mixture through the asphalt at an elevated temperature for a time sufficient to harden the asphalt to the desired properties. For example, the asphalt can be air blown in a converter at a temperature from about 175° C. to about 290° C. for a time from about 1 hour to about 12 hours.