US1934315A - Air blown asphalt product - Google Patents

Description

, ing stained and blotched Patented Nov. 7, I933 ENT OFFICE AIR BLOWN ASPHALT PRODUCT Morris Levine, Chicago,

Ill., assighor, by mesne assignments, to The Lehon Company, Chicago,

111., a corporation of Illinois No Drawing.- Application January 25,1932

Serial No. 588,838

This invention relates to air-blown asphalt products and a method of preventing discoloration of the same.

In the production of air-blown asphalt products, and particularly asphalt roofing, it is economically desirable to use asphalt produced from Mid-Continent residuum. Such asphalt, however, has the undesirable characteristic of formareas presenting an unsightly appearance. For example, a roofingcomprising the customary roofing base such as asphalt-saturated felt, coated with air-blown'asphalt derivedirom the Mid-Continent residuum, and covered with a layer of talc or slate, when submitted to the underwriters test, requiring that the roofing be held vertically for two hours at 180 R, will show, after the test, stains and blotches. This staining is apparently due to the emergence of a separable oily portion of the asphalt. As a result, asphalts derived from Mid- Continent residuum, although cheaper than asphalt derived from asphalt base residuums such .as Mexican, are avoided in the manufacture of roofing. Asphalts derived from residuums of the Mid-Continent type, for example, Illinois and Smackover residuums, give rise to the same dimculty.

In accordancewith this invention, the tendency of air-blown asphalts of the Mid-Continent type to stain and discolor is avoided by the use of a relatively thin coating of rosin. For erample, roofing material may be produced-in the customary ,manner by coating an asphalt saturated felt base with air-blown asphalt of the Mid-Continent type and then placing thereon a layer of crushed slate or talc'with which has been admixed 3 to 4% by weight of rosin. The rosin ispreferably comminuted to pass a 200 mesh screen and be caught on a 325 mesh screen.

Instead of admixing the rosin with the stone layer, it may be dissolved in a volatile solvent such as alcohol or benzene and sprayed on the surface of the asphalt, or it may be mixed with a stable asphalt such as Mexican in the proportion of, say, 5 to 20% rosin and preferably 20%, and the roofing coated with a thin layer of the mixture. By stable asphalt is meant asphalts of the type which does not cause discoloration.

A further improvement may be accomplished by adding an inert substance of higher melt point, such as gilsonite, to the rosin. Soaps, for example, either sodium or calcium soaps may likewise be used. These substances preserve the appearance of the roofing under elevated temperature conditions better than the rosin alone.

Instead of rosin, the synthetic resin known as teglac, or the coal tar resin cumar, or benzoic acid may be used, but are somewhat less satisfactory. Pontianak, Indian gum, congo, abietic acid or gum arabic may be used in combination with rosin.

' The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

I claim:

1. The method of preventing discoloration, due to Mid-Continent type air- -blown asphalt, in asphaltic products containing the same, which comprises: coating the surface of said asphaltic products with rosin.

'2. The method of preventing discoloration, due to Mid-Continent type air-blown asphalt, of asphaltic roofing containing the same, which comprises: coating, said roofing with a layer comprising crushedstone and a minor proportion of comminuted rosin.

3. The method as set forth in claim 2 in which the rosin comprises 3 to 4% of the crushed stone mixture.

4. The method as set forth in claim 2 in which the rosin is comminuted to such fineness that it will pass a 200 mesh and be caught upon a 325 mesh screen.

5. The method of preventing discoloration, due to Mid-Continent type air-blown asphalt, of asphaltic roofing containing the same, which comprises: spraying a solution of rosin in a volatile solvent upon the surface of said roofing. I

6. The method of preventing discoloration, due to Mid-Continent type air-blown asphalt, of asphaltic roofing containing the same, which comprises: spraying a solution of rosin in a volatile solvent upon the surface of said roofing, and covering said rosin with a protective layer of crushed stone.

7. The method of preventing discoloration due to Mid-Continent type air-blown asphalt, or asphaltic roofing containing the same, which comprises: coating said roofing with a relatively thin layer comprising a mixture of rosin and a stable asphalt.

8. The method as set forth in claim 7 in which 106 the rosin constitutes 5 to 20% of said rosin and stable asphalt mixture.

' 9. The method of preventing discoloration due to Mid-Continent type air-blown asphalt of asphaltic roofing containing the same, which com- 110 prising a mixture of rosin and a relatively high melt point inert substance.

10. The method as set forth in claim 9 in which said mixture comprises rosin and gilsonite.

11. Asphalt roofing comprising: a roofing base, an air-blown asphalt'of the Mid-Continent type coating said base, and a protective layer thereupon comprising a mixture of comminuted rosin and crushed stone.

12. Asphalt roofing as set forth in claim 11 in which the rosin comprises 3 to 4% of the crushed stone mixture.

13; Asphalt roofing as set forth in claim 11 in which the rosin is comminuted to such fineness that it will pass a 200gmesh screen and be caught upon a 325 mesh screen.

14. Asphalt roofing comprising: a roofing base, an air-blown asphalt of the Mid-Continent type coating said base, and a thin layer of rosin thereupon.

15. Asphalt roofing comprising: a roofing base,

prises: coating said roofing with a layer coman air-blown asphalt of the Mid-Continent type coating said base, and a protective layer of crushed stone upon said rosin layer.

16. Asphalt roofing comprising: a roofing base, an air-blown asphalt of the Mid-Continent type coating said base, and a relatively thin layer thereupon comprising a mixture of rosin and a stable asphalt.

1'7. Asphalt roofing as set forth in claim 16 in which the rosin constitutes 5 to 20% of said asphalt rosin layer.

18. Asphalt roofing comprising: a roofing base, an air-blown asphalt of the Mid-Continent type coating said base, and a layer thereon comprising a mixture of rosin and a relatively high melt' point inert substance.

19.- Asphalt roofing comprising: a roofing base, an air-blown asphalt of the Mid-Continent type coating said base, and a layer thereon comprising a mixture of rosin and gilsonite.

MORRIS