US2995508A - Production of waxes of improved quality - Google Patents

Description

United States Patent 2,995,508 PRODUCTION OF WAXES 0F IMPROVED QUALITY Weldon G. Annable and John W. Walsh, Crystal Lake, 111., assignors to The Pure Oil Company, Chicago, 111., a corporation of Ohio No Drawing. Filed July 21, 19 58, Ser. No. 749,660 4 Claimsl (Cl. '208-21) This invention relates to new and useful improvements of paratfin wax blends and more particularly to a meth- 0d of preparation of improved p araffin waxes of high tensile strength.

In manufacturing lubricating oils, waxes are obtained as by-products. Parafiin waxes are obtained by the solvent dewaxing of lubricating oil distillates while microcrystalline waxes are obtained from the residuum or still bottoms. Paraflin waxes are generally softer and lower in melting point than microcrystalline waxes and are less expensive. To increase the marketability of paraffin waxes having low tensile strength properties, several methods have been heretofore proposed. These methods have involved the addition of a small proportion of microcrystalline wax to a low tensile strength paraffin wax, as in Adams et a1., U.S. Patent 2,127,668, or by distilling a paraffin wax into a number of distillate cuts and blending non-consecutive cuts, as in Bowman et al., U.S. Patent 2,467,959.

It is an object of this invention to provide an improved method of preparing parafiin wax compositions of relatively high tensile strength.

Another object of this invention is to provide an improved process for preparing parafiin wax compositions of improved tensile strength which does not require the addition of microcrystalline wax or the use of non-consecutive cuts of a fractionated, de-oiled parafi'in wax.

A feature of this invention is the provision of a process for preparing parafiin wax compositions of improved tensile strength by fractionating a crude oil to produce a heavy lubricating oil distillate, a medium lubricating oil distillate, and a light lubricating oil distillate, dewaxing each of said distillates, deoiling the waxes, and mixing a small amount of wax obtained from the heavy distillate with wax obtained from a lighter distillate.

Other objects and features of this invention will become apparent from time to time throughout the specification and claims as hereinafter related.

In accordance with our invention, a non-asphaltic crude, i.e., a paraflinic or naphthenic crude, or a deasphalted crude, is fractionated to remove the more volatile fractions (gasoline, naphtha, kerosine, gas oils, etc.) and to produce a heavy lubricating oil distillate, a medium lubricating oil distillate, a light lubricating oil distillate, and a residuum. The heavy lubricating oil distillate is de Waxed, by solvent dewaxing or by refrigerating and filtering, to produce a high-melting parafiin wax, M.P. of 140-l60 F. (preferably about 150 F.). From the medium lubricating oil distillate, there is obtained a paraflin wax having a melting point of about 136. F., while the wax from the light lubricating oil distillate has a melting point of about 123 F. When the wax obtained from the light distillate or the medium distillate, or a mixture thereof, is blended with a small proportion of the wax obtained from the heavy distillate, a wax blend is produced which has a substantially improved tensile strength.

The following non-limiting examples are illustrative of the scope of this invention.

EXAMPLE I A Van Zandt, Texas, crude oil was distilled to remove the more volatile components, e.g., gasoline, naphtha,

kerosine, etc., and heavy, medium, and light wax distillates were obtained. A heavy wax distillate is one having a viscosity of 800-1200 S.U.S. at 100 F., and is used in the production of 650 vis. neutral oil. The medium wax distillate is a less viscous oil from which a 200 vis. neutral oil is obtained. The light wax distillate is a still less viscous oil from which an vis. neutral oil is obtained. The wax distillates which were thus produced were each subjected to methyl ethyl ketone-toluene dewaxing and the resulting waxes de-oiled using the same solvent. The physical properties of the waxes thus obtained are shown in Table I.

Table l Parafiin Wax From 85 Vis 200 Vis 650 Vis Neutral Neutral Neutral Melting Point, F 123.0 136. 8 150. 6

Oil Content, Wt. Percent.-- 0.6 0.2 0.3

Penetration at 77 "F 19 13 21 Tensile Strength, #/sq. in. 308 280 Viscosity, SUS, at 210 F- 36 40. 1 51. 2

Gravity at 190 "F 54. 3 63.0 48.5

Distillation, Fz

- I.B.P 717 735 793 732 751 832 734 760 857 738 802 906 742 827 942 751 848 981 767 885 1, 037 775 898 1, 053 810 920 1, 066

A small amount of the F. M.P. paraflin wax was added to portions of the lower melting waxes and a very substantial improvement in tensile strength of the wax blend was observed. For example, when 150 F. M.P. parafiin wax of 276 p.s.i. tensile strength was added to 136 F. M.P. paraflin wax of 308 p.s.i. tensile strength, a series of blends was obtained having the tensile strengths indicated in Table II. The tensile strengths of the indi- As is apparent from Table II, the addition of very small amounts of 150 F. M.P. wax to a lower melting wax, or mixture of lower melting waxes, will produce a blend having a tensile strength higher than that of any component used in the blend.

We have also found that blends of waxes containing the 150 F. M.P. parafiin wax reach a maximum tensile strength upon addition of 7-11% of the higher melting point wax. Beyond this concentration of the higher melting point wax, blends are obtained which have improved tensile strength but which are of less tensile strength than blends containing 711% of the higher melting point wax. These findings are illustrated by the blends in Table III.

In this series of blends, it is seen that a mixture of 123 F. and 136 F. M.P. waxes has a tensile strength intermediate the individual components. However, the addition of even a small amount of 150 F. M.P. wax, see blend B, produces a wax blend having a tensile strength higher than any component in the blend. As was pointed out above, the addition of further amounts of 150 ,F. M.P. parafiin causes an increase in tensile strength up to a concentration of about 7%. At higher or lower concentrations of the 150 F. M.P. paraffin wax, the tensile strength is lower. Obviously, the'f'amount of 150 F. M.P. wax required to give maximum tensile strength will be different for different wax blends according to the relative proportions of the lower melting point components. The addition of a small amount of the 150. F. M.P. wax produces a similar improvement in the tensile strength of the 123 F. M.P. wax.. 1 I

As previously set forth, this invention doesnot rely on close-cut fractions of a distilled wax or the addition of microcrystalline waxes, but is predicated on the discovery that high tensile strength wax blends may be produced by first fractionating an oil into heavy, medium, and light wax distillates, dewaxing each of said distillates, de-oil- While we have described this invention with particular emphasis upon a preferred embodiment thereof, we wish it understood that within the scope of the appended claims, this invention may be practiced otherwise than as specifically described.

This application is a continuation-in-part of our copending application, Serial No. 576,535, filed April 6, 1956, for Production of Waxes of Improved Quality, now abandoned.

What is claimed is:

1. A high-tensile-strength wax blend consisting essentially of 70 to 99% by weight of waxes of the group consisting of (l) wax having a melting point of about 123 F., a penetration at 77 F. of about 19, and a viscosity at 210 F. of about 36, said wax having been obtained by solvent dewaxing a petroleum traction to produce -a lubricating oil having a viscosity of about 85; and paraffin wax having a melting point of about 136 F., a penetration at 77 F. of about 13, and a viscosity at 210 F. of about 40.1, said wax having been obtained by solvent dewaxing a petroleum to produce a lubricating oil having a viscosity of about 200 (2) and mixtures thereof, said blend containing not less than about 35% by weight of paraflin wax (2), and about 1 to by weight of a paraflin wax having a melting point of about 150 F., a peneration at 77 F. of about 21, and a viscosity at 210 F. of about 51.2, said wax having been obtained by sol- I vent dewaxing a petroleum fraction to produce a lubricatto 20% by weight.

ing the waxes, and mixing the higher melting point wax (150 F. M.P.) with one or more or the lower melting point waxes.

In carrying out this invention, the waxes which are prepared from the individual wax distillates arede-oiled to an oil content of not more than 2% and preferably less than about 0.5 The amount of the high melting point wax used in the blend may vary between 1 and 30% of the blend, but preferably lies between about 5 and 20% of the blend.

Blends made in accordance with this invention have better color and produce a higher gloss than blends made with microcrystalline wax, and have a high melting point and higher tensile strength than microcrystalline wax blends. Additionally, this invention enablesthe use of substantially all the wax from neutral lubricating oil distillate as contrasted with the necessity of discarding a portion thereof when following certain prior art procedures.

3. A wax blend in accordance with claim 1 in which the enumerated waxes are present in the amounts of about 52%, about 41%, and about 7%, by weight, respectively.

4. A wax blend in accordance with claim 1 in which said 136 F. melting point wax is present in the amount of about 91% by weight, and said F. melting point wax is present in the amount of about 9% by weight.

References Cited in the file of this patent UNITED STATES PATENTS 1,439,171 Kennedy Dec. 19, 1922 2,157,625 Page May 9, 1939 2,658,852 Tiedje et a1 Nov. 10, 1953 2,682,523 Talley et a1 -June 29, 1954 2,758,100 Bailly et alI Aug. 7, 1956 2,761,814 Post Sept. 4, 1956 2,825,635 Dooley et al. Mar. 4, 1958 2,906,443 Harvey et a1 Sept. 29, 1959 2,915,451 B-artay et a1. Dec. 1, 1959 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No.;- 2,995,508 August 8,, 1961 Weldon G. Annable et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 line 13, before "wax" insert paraffin column 4, line 17, after "85" 's-t'nik e out the semicolon; same line 17, after "and" insert (2) line 22, for 200(2)" read 200; -=v-; line 26, for "peneration" read penetration (SEAL) Attest:

ESTON G. JOHNSON Attesting Officer DAVID L, LADD Commissioner of Patents

Claims (1)

1. A HIGH-TENSILE-STRENGTH WAX BLEND CONSISTING ESSENTIALLY OF 70 TO 99% BY WEIGHT OF WAXES OF THE GROUP CONSISTING OF (1) WAX HAVING A MELTING POINT OF ABOUT 123* F., A PENETRATION AT 77*F., OF ABOUT 19, AND A VISCOSITY AT 210*F. OF ABOUT 36, SAID WAX HAVING BEEN OBTAINED BY SOLVENT DEWAXING A PETROLEUM FRACTION TO PRODUCE A LUBRICATING OIL HAVING A VISCOSITY OF ABOUT 85; AND PARAFFIN WAX HAVING A MELTING POINT OF ABOUT 136*F., A PENETRATION AT 77*F, OF ABOUT 13, AND A VISCOSITY AT 210* F. OF ABOUT 40.1, SAID WAX HAVING BEEN OBTAINED BY SOLVENT DEWAXING A PETROLEUM TO PRODUCE A LUBRICATING OIL HAVING A VISCOSITY OF ABOUT 200 (2) AND MIXTURES THEREOF, SAID BLEND CONTAINING NOT LESS THAN ABOUT 35% BY WEIGHT OF PARAFFIN WAX (2), AND ABOUT 1 TO 30% BY WEIGHT OF A PARAFFIN WAX HAVING A MELTING POINT OF ABOUT 150*F., A PENETRATION AT 77*F., OF ABOUT 21, AND A VISCOSITY ST 210* F. OF ABOUT 51.2, SAID WAX HAVING BEEN OBTAINED BY SOLVENT DEWAXING A PETROLEUM FRACTION TO PRODUCE A LUBRICATING OIL HAVING A VISCOSITY OF ABOUT 650, EACH SAID WAX HAVING AN OIL CONTENT OF LESS THAN ABOUT 0.5%.