US2764495A - Non-gelling bituminous composition and a method of preparing it - Google Patents

Description

NON-GELLING BITUNIINOUS COMPOSITION AND A METHOD OF PREPARING IT Lewis A. Winkler, Scotch Plains, and Walter E. Waddey,

Roselle, N. .L, assiguors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Application July 17, 1951,

I Serial No. 237,278

3 Claims. (Cl. 106-123) This invention relates to improved protective coating compositions for metal surfaces and more particularly relates to an improved asphalt composition for such purposes.

Specialty cutback asphalts are finding increasing use as protective coatings, particularly as the base material in the manufacture of automobile undercoating compounds. Such coatings are made from oxidized asphalt which have 'the great disadvantage that they tend to gel or thicken excessively during storage, leading to application difliculties.

One object of the present invention is the preparation of an oxidized asphalt composition which remains fluid .during storage.

Another object of this invention is to prepare an oxidized :asphalt composition which has improved properties when used as a rust preventing coating for metals.

These and other objects of this invention are attained 'by the addition to an oxidized asphalt of a mixture of primary aliphatic amines and a fatty acid.

The oxidized asphalt used in this invention may be obtained by any method known to the art, such as by bub- Lbling air or oxygen through hot asphalt.

Suitable amines include those having 16-18 carbon atoms in the chain, such as hexadecyl amine, heptadecyl amine and octadecyl amine or their mixtures. Suitable fatty acids include those having 1519 carbon atoms in the alkyl radical, such as oleic, stearic, palmitic, margaric,

:nondecylic, linoleic and abietic acid or other rosin acids.

The proportion of amines used in the mixture is always larger than that of the acid. A suitable proportion is 60 parts by weight of amine to 40 parts of acid. This mixture is then added to an already gelled oxidized asphalt in proportions of about 0.5-3% by volume, while refluxing the :asphalt with a naphtha diluent to break down the gel :structure. the gel structure from reforming.

The presence of the addition agent prevents The following examples illustrate the improved results =obtained by the composition of this invention.

Example 1 decyl, 25% octadecyl and 45% octadecenyl n-primary amines and 40% of highly refined tall oil (approximately 45 oleic acid, 45 linoleic acid, and rosin acids). The additive containing asphalt was then placed in storage along with a material of the same composition not connited States Patent 2,764,495 Patented Sept. 25, 1956 taining the additive. Viscosity data obtained on the two samples during storage are as follows:

, Outback Outback Viscosity (Poises) After Storage For without with 0.67%

Additive Additive The additive can also be used to lower the viscosity and inhibit future gelling of cutbacks that have already thickened by simple addition in the presence of gentle refluxing.

Example 2 Extent of Busting Observed on Test Panel 1 Rust Preventive Oomposition, Wt. Percent 20% Salt 4% Salt Spray, Humidity Spray, 10 Days Cabinet, 10 Days 28 Days 1. Outback Asphalt Medium Medium Light. 2. 2.5% of a heavy coastal do Trace-Medium Do.

phenol extract in Outback Asphalt. 3. (2) 1.0% amine-acid- None None None.

mixture.

1 280 grit polished, sandblasted, and highly polished steel panels.

The nature of the present invention having been thus fully set forth and specific examples of the same given, what is claimed as new and useful and desired to be secured by Letters Patent is:

1. An improved rust proofing, non-gelling bituminous material which comprises an oxidized cutback asphalt containing 0.5 to 0.75% by weight of a mixture of 60% by weight of a mixture of approximately 30% by weight of hexadecyl, 25% octadecyl, and 45% of octadecenyl normal primary amines and 40% of refined tall oil.

2. A method of breaking down a gelled oxidized asphalt and stabilizing it against regelling which comprises refluxing an already gelled oxidized asphalt with a naphtha 1 The test panels are dipped in the rust preventive formulation and then removed for a four hour drying period. The coated specimens are then placed on a rack so that the significant surface is 15 from the vertical and parallel to the principal direction of the horizontal fiow of the fog through the chamber. The salt solution is atomized by warm humidified air to produce a salt fog of the required concentration at a temperature F. plus 2 or minus 3 F. At the end of the test period the coating is removed and the surface examined for evidence of rusting.

2 Test panels are dipped in the rust preventive and then allowed to dry for four hours. These coated specimens are then suspended on a rotating rack in the humidity cabinet, using stainless steel or Monel hooks and subjected to a continuous flow of moisture-saturated air at F. with continuous condensation on the test panels. At the end of the test period, the panels are removed, the coating dissolved with a suitable solvent, and examined for evidence of rusting.

and stabilizing it against regelling which comprises refluxing an already gelled oxidized asphalt with a naphtha diluent and simultaneously adding 0.5 to 3% by Weight of 30% by weight of hexadecyl, 25% octadecyl, and 45% of octadecenyl normal primary amines and 40% of refined tall oil.

References Cited in the file of this patent a mixture of 60% by Weight of a mixture of approximately 10 2,520,356

UNITED STATES PATENTS Allen Feb. 18, Fischer Feb. 15, Summer Aug. 2, Bishop Aug. 29,

Claims (1)

1. AN IMPROVED RUST PROOFING NON-GELLING BITUMINOUS MATERIAL WHICH COMPRISES AN OXIDIZED CUTBACK ASPHALT CONTAINING 0.5 TO 0.75% BY WEIGHT OF A MIXTURE OF 60% BY WEIGHT OF A MIXTURE OF APPROXIMATELY 30% BY WEIGHT OF HEXADECYL, 25% OCTADECYL, AND 45% OF OCTADECENYL NORMAL PRIMARY AMINES AND 40% OF REFINED TALL OIL.