US2397805A - Base coat for launching grease - Google Patents

Description

Patented Apr. 2, 1946 BASE COAT FOR LAUNCHING GREASE Thomas F. Ott, Berkeley, Calif., assignor to Union Oil Company of California, Los Angeles, Calif., a corporation of California N Drawing. Application March 6, 1942, Serial No. 433,640

17 Claims.

This invention relates to compositions used as base coats for launching greases in the preparation of slips or ways for the launching of seagoing vessels. 1

In preparing for the launching of ships, it is desirable that the slips or ways from which they are launched be pre-coated with a so-called base coat of a composition which will not laminate on application, nor crack or shatter, nor run when exposed to the sun nor be subject to other deformities from atmospheric conditions, nor be displaced or stripped off by water, nor be subject to undue deformity in use, nor strip off the ways in launching and which will at the same time be a suitable base coat for the application thereto of any preferred launching grease or slip coat having a high degree of lubricity for the purpose.

The object of the present invention is to produce base coats for launching greases which will have the above indicated characteristics. The lubricating grease to be applied thereto may be of any suitable composition and its specific composition does not constitute a part of the present invention.

This invention resides primarily in the employment in a base coat composition of a substantial proportion of crystalline paraffin wax with a substantial proportion of each of two or more wax plasticizers of the class consisting of rosin, asphalt and amorphous parafiin wax such as that found in the form of petrolatum. Some paraffin waxes obtained from petroleum in connection with the production of oils contain amorphous wax in appreciable quantities, and if this amorphous wax content were sufiiciently high to plasticize the crystalline Wax properly, this wax source would itself be sufficient to supply both the crystalline wax and the amorphous wax. Where the crystalline wax contains relatively small proportions of amorphous wax, then it is necessary to add either additional amorphous wax, as in the form of petrolatum, or to add asphalt, as a plasticizer. The oil content always found in petrolatum and in the indicated asphalts does not objectionably affect the melting points and consistencies of the composition if used in proper quantities. In addition, it has been found preferable to add in each case a minor proportion. of rosin, for example around of either wood rosin or gum rosin, or equivalent resin.

A particular base coat composition of this invention comprises crystalline wax, amorphous wax, rosin and either asphalt or additional amor- In preparing launching grease base coats of the present invention, preferred compositions normally will contain about two-thirds of a fairly well deoiled parafiin wax containing both crystalline and amorphous waxes, and about onethird of plasticizers for the wax of which perhaps one-tenth of the total composition will be rosin such as wood rosin.

The wax may, however, vary from perhaps 50% to 80% by weight of the total composition depending upon the amorphous wax content of the wax and upon the other constituents. The amorphous wax, whether initially present in the parafiin wax used or added in the form of petrolatum,

increases the flexibility of the composition. As the amorphous wax content of the initial paraffin wax is increased where asphalt is used, the penetration value of the asphalt is preferably required to be greater (that is, the asphalt will be softer) in order to give the product more flexibility. No explanation of this phenomenon is known. Possibly the greater flexibility is due to oil in the asphalt which prevents the melting point from becoming too high.

In selecting, for use inthe present invention, parafiin waxes obtained as by-products in the production of lubricating oils, one wax which has been employed will be here referred to as No. 1 wax, this wax apparently containing a very minor proportion of amorphous wax and a very large proportion of crystalline wax. Another wax will be referred to as No. 2 wax; this wax comes ofi at a higher temperature and contains phous and from blends of these, that the No. 1

wax probably contains in the order of a few percent of amorphous wax (which for the mere purpose of estimation might be said to be in theorder of 5% to 10%), whereas the No. 2 wax used contains a materially larger proportion of amorphous wax (which for purposes of rough estimation might be said to be two or three times as much). The waxes would be as free from oil as commercially obtainable.

Characteristics of these waxes follow. The No. l wax is taken oif as a stream in a petroleum distillation process at about 450 F. under a vacuum of about 28 inches of mercury. This is equivalent to taking the stream ofi at about 700 F at atmospheric pressure. The No. 2 wax used is a higher melting point material, being a stream taken 01f at about 575 F. under a vacuum of about 28 inches of mercury, which is equivalent to about 850 F. at atmospheric pressure. These figures are corrected for partial pressure of steam employed in the process. In view of the fact that the No. 2 wax is taken off at higher temperatures, it is obvious that the amorphous wax in the No. 2 wax has a higher melting point than that in the No. 1 wax. Thus, No. 2 wax contains both a larger proportion of amorphous wax and higher melting point amorphous wax than does No. 1 wax. The No. 1 wax thus has a boiling point of about 700 F. and is of lower molecular weight than the No. 2 wax which has a boiling point of about 850 F. .The crystals of the crystalline wax in the No. 1 wax incline to be smaller or more needle-like than those of the crystalline wax in the No. 2 wax. The larger, plate-like, higher molecular weight crystals in the N0. 2 wax possibly may be considered as of better structure for the present purpose and account in part for the higher melting point of the compositions produced with the No. 2 wax. In any event, the No. 2 wax yields more suitable hot weather compositions than does the No. 1 wax, possibly due also to the higher melting point of No. 2 wax.

The petrolatum employed consists almost entirely of amorphous wax and retained oil. The grade which has been used for these purposes is a commercial grade containing in the order of 25% to 35% of oil.

When selecting asphalts to use with the waxes described, a softer asphalt is used as the melting point or Galician solidification point of the wax increases. Thus, when using No. 1 wax with asphalt, a low penetration asphalt in the -20 Where petrolatum has been used instead of asphalt, and along with rosin, the same petrolatum was employed regardless of whether No. 1 wax or No. 2 wax was used. This petrolatum had about 117 F. Galician solidification point and 145 F. A. S. T. M. melting point. However, the products, diifered in that the product produced with the paraffin wax having the higher amorphous wax content and higher melting point (No. 2 wax), was suitable for hot weather use, whereas that produced with the wax of low amorphous wax content was more desirable for very cold weather use.

Apparently an asphalt-free composition with high amorphous wax content obtained by means of petrolatum, with rosin as an additional plasticizer, produces the best hot weather product; whereas a petrolatum-free composition with a wax of comparatively low amorphous content and lower melting point containing a substantial proportion of asphalt as a plasticizer along with;the rosin, produces a superior very cold weather product.

In general, suitable compositions contain around two-thirds of paraffin wax containing minor but appreciable proportions of amorphous wax, about one-tenth rosin, and about one-fourth petrolatum or asphalt.

In connection with the function of the asphalt, this material has the quality of modifying or controlling paraflin wax crystallization, and it is probably for this reason that the asphalt produces a good cold weather product when using the lower molecular weight No. 1 wax which probably has the smaller crystals. The asphalt possibly also has a binding effect on the crystals and improves flexibility.

Specific compositions which have been used appear in the accompanying table.

BASE Con For: LAUNCHING GREASE Specimen Base coat P-1 A-1 P-2 A-2 A-3 Galician solidification point 141 F l41.5 F 154 F 150 F 140 F Composition (percent by weight):

Paraffin wax- No. 1- 65% 65%, No. 2 65%- 5% Rosin (wood) 10% 10% 10%. 10% Petrolatum. 25% 25% Asphalt (steamed) 25% 35% Galician solidification point of wax 142 F 142 F 156 F 156 F 156 F AS'IM penetration of asphalt at 77 F 12 65 65. ASg VM Ilnelting point of petrolatum (about 145 F 145 F a For cool For very cold weather. Especially good in hot weather. For cool weather. Very flexible at 10 F. Good in cool weather. weather.

(In the above s)ymbols for the specimens, P signifies petrolatum content, A signifies asphalt content, and 1 and 2 signify No. 1 and No. 2

waxes respectively.

range is employed, a specific instance being 12 penetration at 77 F.'; whereas when using No. 2 wax the preferred asphalt has been in the -70 penetration range. These are the A. S. T. M. penetrations of method D5-25. While it does not appear to be essential to vary the asphalts according to penetration as indicated in order to produce acceptable products, nevertheless highly preferable products are obtained by observing these variations. increased asphalt content of greater penetration with the No. 2 wax produces a cool weather product, whereas a smaller asphalt content of lower penetration with the N0. 1 wax produces an excellent cold weather product.

It has been noted that use of Percentage ranges within which the various materials may be used for commercial production are about as follows:

Percent by weight De-oiled parafiin wax 50 to 80 Rosin 5 to 15 Asphalt (steam or air blown) 10 to 40 Petrolatum (contains oil) 10 to 30 With respect to each of the constituents usedin preparing these compositions the following specifications, with indicated approximate limits, are given for materials which may be employed:

Parali'in 'waa:

Galician solidification point F 140 to 165 A. P. I. gravity at 60 -F 38 to 42 Wood or gum rosin Solubility in gasoline, minimum per cent 95 Melting point (drop method) F 165 to 180 Acid number 150 to 1'70 Saponification number 165 to 175 Unsaponifiable matter, maximum per cent 9 The rosin should be largely soluble in the parafiln wax and this is measured by its gasoline solubility.

Steam blown asphalt Penetration at 77 F 10 to 70 Melting point (ball and ring) F 110 to 155 Ductility at 77 F 10 to 100 plus Solubility in CC14, minimum per cent 99 Steam blown asphalt is preferred, but air blown asphalts or natural asphalts within approximately these specifications likewise may be used.

Petrolatum Galician solidification point--- 115 F. or higher Oil content .per cent 20 to 50 Light colored rather than dark colored petrolatum is preferred. Higher melting point petrolatums are preferred over lower melting point petrolatums, and apparently the lower the oil content the better.

In addition to specific products shown above, the following have been made within the limits of the percentage ranges above indicated.

A fairly satisfactory composition has contained 80% No. 2 wax, 15% petrolatum and 5% Wood rosin. Another fair composition contained 80% No. 1 wax, of 10-20 penetration steamed asphalt, and 10% wood rosin. In one instance a fair product Was made containing only 75% No. 1 wax and 25% 10-20 penetration steamed asphalt. This was not so good as composition A-1, in that it was not so flexible at low temperatures, and indicates the advantage of the rosin content. However, at moderate temperatures the product would have considerable value. Other reasonably good compositions are made containing all three of the plasticizers mentioned. For example, suitable compositions would contain around 60% of either indicated paraflin wax, about 10% rosin, about petrolatum and about 15% of asphalt. Preferably, for cool weather uses, a No. 2 type wax would be used with high penetration asphalt, and No. 1 type wax would be used with low penetration asphalt. While good base coats are made employing all three plasticizers with the paraffin wax, the use of either the petrolatum or the asphalt without the other is, at least at present, indicated as preferable.

From the foregoing data, it is apparent that products of the present invention are obtained by employing parailin Waxes having Galician solidification points above about 140 F. and above about 150 F. respectively, and that the products made therefrom possess Galician solidification points above about 140 F., and above about 150 F. respectively, depending upon whether No. 1 wax type or No. 2 wax'type is employed. These products thus all have high melting points and show a general lack of tendency to melt in the sun, except that those containing asphalt are black and show a greater melting tendency than the others which have a light or yellowish brown color. All of them are highly flexible. The combination of high flexibility and high melting point in finished products is unique.

In using the products of the present invention it is important that wooden slips or ways to which the base coat is to be applied be as dry as possible, and in addition it is important that the base coat be heated to a temperature high enough to flash off residual moisture from the ways, so as to insure a tight bond between the wood surfaces and the melted composition. Preferable temperatures are between about 250 F. and 300 F. A temperature of at least 250 F. is important in order to eliminate the moisture sufficiently before the composition congeals, and temperatures above 300' F. are not desirable on account of the difficulty of heating and applying hotter materials at the scene of operations. Successive coats are also applicable at these temperatures without lamination of the various coats. The result is, in efiect, one solid or homogenous coating.

In the light of the above teachings, other variations falling within the scope of the depending claims will be obvious to those skilled in the art.

I claim:

1. A composition for a base coat to receive launching greases, comprising paraflin wax, having a solidification point above about 140 F., approximating two-thirds of the composition and containing both crystalline and amorphous wax, a minor proportion of rosin in the order of onetenth of the composition, and a plasticizer approximating one-fourth of the composition selected from the class consisting of petrolatum and asphalt, the composition having a Galician solidification point above about 140 F. and showing lack of tendency to melt in the sun.

2. A base coat composition for launching greases comprising a major proportion of paraffin wax having a solidification point above about 140 F. and containing amorphous wax, and minor proportions of rosin, petrolatum having a solidification point of about F. and asphalt, the composition having a Galician solidification point above about F.

3. A base coat composition for launching greases comprising a composition of parafiin wax having a solidification point between about F. and about 165 F. and containing amorphous wax, the wax being the major proportion of the composition, and asphalt having a melting point of at least 110 F., but not above F., the product having a Galician solidification point of above about 135 F.

4. A base coat composition for launching greases comprising a major proportion of paraffin wax including both crystalline and amorphous waxes, and a minor proportion of asphalt having a melting point below about 155 F. and an ASTM penetration not exceeding about 70 at 77 F. by the ASTM D5-25 test, said paraflin wax having a Galician solidification point of above about 140 F.

5. A composition according to claim 4 having a Galician solidification point above about 140 F. and not over about 154 F. and showing lack of tendency to melt in the sun.

6. A composition according to claim 4 containing rosin amounting to about one-tenthof the composition, and having Galician solidification point above about 140 F.

7. A base coat composition for launching greases comprising crystalline paraflin wax and amorphous paramn wax, the combined wax content constituting a major proportion of the composition, and having a solidification point above about 140 F., and rosin between about 5% and about 15% of the composition, the composition having a solidification point above 135 F.

8. A composition according to claim 7 containing a minor proportion of petrolatum.

9. A composition according to claim 7 containing a minor proportion of asphalt having. an ASTM penetration at 77 F. no higher than about '70.

10. A composition according to claim 7 containing a minor proportion of petrolatum having a Galician solidification point above about 115 F., and a minor proportion of asphalt having a melting point above about 140 F.

11. A composition comprising between about 50% and 80% of parafiinygax having a Galician solidification point above about 140 F. and containing both crystalline and amorphous wax, be-

tween about 5% and about 15% of rosin, and between about 40% and about 10% of asphalt, the composition having a Galician solidification point above about 140 F.

12. A composition according to claim 11 containing between about 30% and about 15% of petrolatum having a Galician solidification point above about 115 F.

13. A composition comprising between about 50% and 80% of paraffin wax having a Galician solidification point above about 140 F., between about 5% and about 15% of rosin, and between about 10% and about 30% of petrolatum, the composition having Galician solidificationpoint above about 135 F. and within an upper limit of about 154 F. and containing between about and about 10% asphalt.

14. A base coat composition for launching greases comprising relatively large proportions of crystalline parafiin wax having a Galician solidification point above about 140 F., amorphous parafiin wax, the wax being the major proportion of the composition, and asphalt in minor proportion having a melting point between about F. and 155 F.

15. A composition according to claim 14 wherein the asphalt has an ASTM penetration not exceeding about '70 at 77 F.

16. As a base coat for launching grease and applied to launching ways in a relatively thin layer, a, mixture comprising roughly equal proportions of crystalline parafiin' wax having a Galician solidification point of between about F. and 165 F. and asphalt having a melting point between about 110 F. and F.

17. As a base coat for launching grease and applied to launching ways in a relatively thin layer, a mixture comprising roughly equal parts of crystalline paraflin wax having a Galician solidification point above about 140 F. and asphalt having a melting point between about 140 F. and about 155 F. THOMAS FLOTT.