US3496107A

US3496107A - Fire-resistant functional fluids

Info

Publication number: US3496107A
Application number: US807074A
Authority: US
Inventors: Daniel A Lima; James P Hamilfon
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1969-03-13
Filing date: 1969-03-13
Publication date: 1970-02-17
Anticipated expiration: 1987-02-17

Description

United States Patent U.S. Cl. 25249.9 12 Claims ABSTRACT OF THE DISCLOSURE Homogeneous fire-resistant, low cost, functional fluids are disclosed which are composed of 40 to 50% highly chlorinated hydrocarbons containing at least 48% by weight chlorine, 20 to 30% petroleum-base oil, 5 to 20% liquid triaryl phosphate, 8 to 35% trialkyl phosphate which serves as a mutual solvent for the other ingredients and stabilizing amounts of a triorganic phosphite and an epoxy plasticizer.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of United States patent application No. 601,335, filed Dec. 13, 1966, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention Fire-resistant functional fluids.

Description of the prior art Many fire-resistant functional fluids are known. Desirably a functional fluid should have viscosity characteristics such that it may be used over a wide temperature range; it must not adversely affect the materials of construction of the system in which it is used; it must possess adequate lubricity and mechanical stability in order that it may be used in valves, pumps, self-lubricated pumps and other components of hydraulic power systems; and it should not be abnormally toxic or otherwise harmful to personnel who come in contact with it.

Suitable fire-resistant hydraulic fluids and lubricants consisting essentially of a mixture of 2080% triaryl phosphate, 80-20% chlorinated biphenyl, and 02-10% polyalkyl methacrylate as a viscosity index improver are disclosed in United States Patent No. 3,136,726 to D. H. Moreton. Fluids composed of a mixture of primarily triaryl and trialkyl phosphates, and minor proportions of a flame-proofing agent and mineral oil are reported in United States Patent No. 2,549,270, issued to Watson, July 19, 1948. These patented fluids are expensive, because they contain major proportions of expensive ingredients and very little of the cheap mineral oil.

Petroleum-base oils, though good lubricants and economically desirable, are not used in high proportions in fire-resistant functional fluids because of their flammability. Chlorinated hydrocarbons are good flame retardants for petroleum-base oils. The higher the combined chlorine content is, the more effective the chlorinated hydrocarbons are as flame retardants. However, the more highly chlorinated hydrocarbons, those containing at least 48% combined chlorine, are not compatible With mixtures of triaryl phosphates and petroleum-base oils.

Triaryl and trialkyl phosphates are Widely used in fire-resistant functional fluids to provide flame resistance and lubricity. Triaryl phosphates are preferred to trialkyl phosphates in functional fluids for anti-Wear properties because they cost less than trialkyl phosphates.

3,496,107 Patented Feb. 17, 1970 ice SUMMARY OF THE INVENTION We have now discovered that inexpensive homogeneous fire-resistant functional fluids can be prepared which contain major amounts of the inexpensive highly chlorinated liquid hydrocarbons and petroleum-base oils, together with minor amounts of triaryl phosphates, by including in the fluid a minor portion of a trialkyl phosphate as a mutual solvent for the other ingredients, and a heat stabilizing amount of a mixture of a triorganic phosphite and an epoxy plasticizer. Fluids containing (a) 35 to 50 parts by weight of a highly chlorinated liquid hydrocarbon, (b) 20 to 30 parts by weight of a petroleumbase oil, (c) 5 to 20 parts by weight of a triaryl phosphate, and (d) 8 to 40% by weight of a trialkyl phosphate based on the total weight of the other ingredients are homogeneous, compatible, fire-resistant functional fluids. The stabilizing phosphite is added to the functional fluids in an amount of about 0.1 to 1 part by weight per parts by weight of fluid composed of components (a) (b) (c) and (d). The stabilizing epoxy plasticizer is added to the functional fluids in an amount of about 0.5 to about 2 parts by weight per 100 parts by weight of fluid composed of components (a) (b) (c) and (d). Surprisingly, the mixed stabilizers have a stabilizing effect greater than that due to the additive effect of the stabilizers.

DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTS Triaryl phosphates suitable for the purposes of this invention are those phosphates containing 3 hydrocarbon radicals, Where the aromatic nucleus may contain 0 to 3 alkyl substituents, and the alkyl 'substituents may contain one to three carbon atoms. These triaryl phosphates particularly include tricresyl phosphate, cresyl-diphenyl phosphate, xylyl-diphenyl phosphate, phenyl-dixylyl phosphate, trixylyl phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenyl monophenyl phosphate, tris isopropylphenyl phosphate and mixtures thereof, and liquid mixtures of triphenyl phosphate, and tricresyl phosphate, etc. The aromatic phosphate esters particularly suitable for the purpose of this invention may be represented by the formula:

Where R is selected from the group consisting of phenyl, cresyl and xylyl radicals. Trixylyl phosphate was found to be slightly more compatible with the other ingredients of these functional fluids than the other triaryl phosphates listed above, and is therefore the slightly preferred aryl phosphate for use in this invention.

The chlorinated hydrocarbons useful in this invention may be any of the commercially available highly chlorinated paraffins or chlorinated biphenyls. The chlorinated hydrocarbon should be liquid and contain enough chlorine to impart flame resistance to the formulation. Compounds containing at least 48% by weight of combined chlorine are desirable for their flame-resistant properties.

The chlorinated hydrocarbons generally have poor heat stability, but this may be overcome by incorporation of any of a sizeable array of heat stabilizers, The type of heat stabilizers normally used in polyvinyl chloride compositions consisting of metal-organic compounds containing barium, cadmium, zinc, tin, lead, epoxy compounds and organic phosphites may be used. Combinations of organo-phosphites and epoxidized oils were found to be the preferred heat stabilizers for these functional fluids.

The most preferred stabilizer found is a combination of phenyl didecyl phosphite and epoxidized linseed oil containing 9.5% oxirane oxygen.

The petroleum-based oils suitable for the purposes of this invention are mineral oils with a Saybolt Universial Viscosity (ASTM Saybolt Method D-88) in the range of 32-200 SUS at 100 F. and petroleum-base hydraulic oil with a Saybolt Universal Viscosity in. the range of about 140-400 SUS at 100 F. The apparently wide viscosity ranges provide final formulations which meet the different viscosity requirements of various hydraulic pumps, fluid motors, and other components of hydraulic power systems.

The trialkyl phosphate useful for inclusion in the present compositions are those in which the alkyl radical has from 4-12 carbon atoms each and include the following: tributyl phosphates, triamyl phosphates, trihexyl phosphates, triheptyl phosphates, trioctyl phosphates, trinonyl phosphates, tridecyl phosphates, tridodecyl phosphates and particularly branched homologs such as tris(2-ethylhexyl) phosphate, tris(2-ethylbutyl) phosphate and tris (3,5,5-trimethylhexyl) phosphate, and the like.

Heat stabilizing triorganic phosphites useful in practicing this invention include trialkyl phosphites, triaryl phosphites, alkyl-diaryl phosphites, tri(alkylatedaryl) phosphites and mixtures of these phosphites, The organophospite is added in the amount of about 0.1 to about 1, and preferably about 0.4 to 0.6, part by weight per 100 parts by weight of fluid containing major amounts of the highly chlorinated liquid hydrocarbon, petroleum-based oil, triaryl phosphate and trialkyl phosphate. Suitable phosphites include triphenyl phosphite, phenyl-didecyl phosphite, trioctyl phosphite and the like.

Heat stabilizing epoxy plasticizers, of the type used in stabilizing poly(vinyl chloride) compositions, useful in practicing this invention include epoxidized oils such as epoxidized soybean oil and epoxidized linseed oil, and epoxidized esters such as butyl epoxy tallate, octyl epoxy tallate, butyl epoxy stearate, and the like. The epoxy compounds are added in the amount of about 0.5 to about preferably about 1 to about 1.5 parts by weight per 100 parts by weight of functional fluid composed principally of a highly chlorinated hydrocarbon, petroleum-base oil and trialkyl phosphate, Epoxidized compounds with high oxirane oxygen contents are preferred to epoxy compounds with low oxirane oxygen contents.

The novel functional fluids of this invention can be compounded together with conventional functional fluid additives such as heat stabilizers, anti-oxidants, rust preventatives, viscosity index improvers, detergent-dispersion additives and the like.

The following typical examples of formulations pre' pared in accordance with this invention are given by way of illustration and not by limitation. The examples were all prepared by simply stirring the ingredients listed in each example together. All parts and percentages are by weight.

EXAMPLE 1 Parts by weight Chlorinated paraffin (50% chlorine) 49 Petroleum oil 29 Trixylyl phosphate 13 Tris(2-ethylhexyl) phosphate 8.4 Epoxidizedlinseed oil (9.5% oxirane oxygen) 0.6 Triphenyl phosphite 0.25

peated substituting chlorinated biphenyl containing 50% chlorine for the chlorinated parafiin and similar results were obtained.

4 EXAMPLE 2 Parts by weight Chlorinated paraflin (50% chlorine) 49 Petroleum oil 29 Trixylyl phosphate l3 Tris(2-ethylhexyl) phosphate 8.4 Epoxidized linseed oil (9.5% oxirane oxygen) 0.6

This sample is a homogeneous solution with good lubricity, mechanical stability and low toxicity. This sample turned significantly darker than Example 1 after 60 minutes in a 400 F. heat test. The petroleum-base oil of Example 1 was used in this example. This example was repeated substituting chlorinated biphenyl described in Example 1 for the chlorinated paraffin and similar results were obtained.

EXAMPLE 3 Parts by weight Chlorinated paraflin (50% chlorine) 49 Petroleum oil 29 Trixylyl phosphate l3 Tributyl phosphate 9 Epoxidized linseed oil (9.5 oxirane oxygen) 0.6 Triphenyl phosphite 0.25

This sample possesses good lubricity, mechanical stability and is not abnormally toxic or hamful. The sample showed only slight discoloration after 60 minutes in a 400 F. heat test. The petroleum oil of Example 1 was used in this example. This example was repeated substituting chlorinated biphenyl containing 50% chlorine This sample possesses good lubricity, mechanical stability and is not abnormally toxic or harmful. The sample showed only slight discoloration after 60 minutes in a 400 F. heat test. The mineral oil used in this example had a viscosity at F. of -190 SUS and a specific gravity at 15.6 C. of 0.820 to 0.880. This example was repeated substituting chlorinated biphenyl (50% chlorine) for the chlorinated paraffin with similar results.

EXAMPLE 5 Parts by weight Chlorinated paraffin (50% chlorine) 49 Mineral oil 29 Trixylyl phosphate 13 Tributyl phosphate 9 Epoxidized linseed oil 0.6 Triphenyl phosphite 0.25

results.

EXAMPLE 6 v I Parts by weight Chlorinated paraffin (50% chlorine) 40 Mineral oil 29 Trixylyl phosphate 20 Tris(2-ethylhexyl) phosphate 11 Epoxized linseed oil 0.6

Triphenyl phosphite 0.25

This sample possesses good lubricity, mechanical stability and is not abnormally toxic or harmful. The sample that the stabilizing etfect of the epoxidized linseed oil showed only slight discoloration and a very slight iuand triphenyl phosphite is greater than that due to the crease in acidity after 60 minutes in a 400 F. heat test. additive eifect of these two stabilizers.

The mineral oil used in this example had a viscosity at 100 F. of 180-190 SUS and a specific gravity at 155 EXAMPLE 9 C. of 0.820 to 0.880. This example was repeated substituting chlorinated biphenyl (50% chlorine) for the chlorinated paraflin with similar results.

A series of fire-resistant functional fluids were prepared to evaluate the effectiveness of typical epoxy compounds and organo phosphites as heat stabilizers in fire resistant EXAMPLE 7 functional fluids. The following test composition was Parts by weight used in this series of tests:

Chlorinated parafiin (50% chlorine) 40 Parts by weight Mineral oil 20 inated paraffin (50% chlorine) 49 Trixylyl phosphate 30 pefl'oleuln Oil 29 Tris(2-ethylhexyl) phosphate l0 f y y P phate 13 Epoxized linseed oil 0.6 Q- Y EXYI) phOSphate 9 Triphenyl phosphite 0.25

All the samples in the phosphite tests contained This sample possesses good lubricity, mechanical stabil- 0.6 part by weight of expoxidized linseed oil per 100 ity and is not abnormally toxic or harmful. The sample parts of the test composition and the phosphite and phosshowed only slight discoloration and a very slight increase phite amount were varied as indicated in Table III. All in acidity after 60 minutes in a 400 F. heat test. The the samples in the epoxy tests contained 0.25 part by mineral oil used in this example had a viscosity at 100 w ight of triphenyl phosphite per 100 parts by weight F. of 180-190 SUS and a specific gravity at 15.6 C. of of the test composition and the epoxy plasticizers and 0.820 to 0.880. This example was repeated substituting e oxy plasticizer amount were varied in the test comchlorinated biphenyl (50% chlorine) for the chlorinated position as indicated in Table IV. paraffin with similar results. Fifty gram samples of the test compositions with the various heat stabilizer compositions shown in Table III EXAMPLE 8 were heated at 400 F. in an oven and observed for A series of functional fluids were prepared and evalucolor changes at intervals of 10, 20, 30, 45 and 60 minutes ated to determine the effectiveness of various epoxy and d 50 gram samples f t composition ith h phosphite heat stabilizers in functional fluids. The comvarious heat stabilizers shown in Table IV were also position details of the fluids are set forth in Table I and heated at 400 F in an oven, but observed for color the results of a heat test are listed in Table II. change at intervals of 15, 30, and 60 minutes.

TABLE I a b c d e f Chlorinated parafiin chlorine) 49 49 49 49 49 49 Petroleum oil 29 29 29 29 29 29 Trixylyl phosphate 13 13 13 13 13 13 Tris(2-ethylhexyl) phosphate 8.4 8.4 8.4 8.4 8.4 8.4 Epoxidized linseed oil (9.5% oxirane oxygen) 0. 6 0.6 0.3 Triphenyl phosphite 0.25 0.25 0.6 0.3

Fifty gram samples of the functional fluids as shown L above were heated at 400 F. and observed at intervals TAB E In EFFECT OF PHOSPHITES ONHEAT STABILITY of 20, 30, 40, 50 and minutes. The samples were re- Page Minutes at400 F.

moved from the oven after each time interval and ar- 50 10 20 3o 45 60 ranged according to color with number 1 having the a Triphenyl 0 1 9 9 7 7 7 lightest color and number 6 having the darkest color. Tri 11 n iIIjjIjfI ,2 5 4 5 4 c. Triphenyl 0.5 3 2 2 2 The initial color of the test fluids was amber. After 20 Phenymidecyl 0.1 7 6 8 8 minutes, sample a was only slightly darker than the c. Phenyl-didecyL 2 a 4 5 original, b was only very slightly darker, and the remain- No change g g 3 ing four samples had little or no observable color change. 6 8 6 6 Obvious color ditferences began to show after 30 minutes. 5 3 3 o 10 10 10 The arrangement of the samples for each time interval 15 recorded in Table II.

TABLE II 30 min. 40 min. 50 min. 60 min.

6 (v. dark brown)-.- 6 (black) 6 (black). 4... 4.... 3 (brown). 5... 5..-... 5 (v. dk. brown). 2 2 1(dk.amber). 3 3. .1 4 (dark brown). (slightly darker than original) 1 (slight darkening) 1 (slight darkening). 2 (light brown).

The above data indicate that sample d is much better The samples were removed from the oven after each than either b or c and sample 1 is much more resistant time interval and arranged according to color. The data to color change than b or e. The fact that f is much more above indicate the rank of the samples with respect to resistant to color change than either [2 or e clearly shows color, #1 being lightest and #10 darkest.

Sample f was best in all casesinitially amber and turning to a dark amber in 60 minutes.

Sample i was worst in all cases-initially amber and turning dark brown, nearly black, in 60 minutes.

TABLE IV.EFFEOT OF EPOXIES ON HEAT STABILITY Minutes at 400 F.

weight 15 30 45 60 k. Epoxy linseed 1 0. 3 10 11 9 l. Epoxy linseed. 0. 6 3' 4 5 m. Epoxy linseed 1. 1 1 1 n. Epoxy soya 0. 3 12 12 10 o. Epoxy soya 0. 6 4 6 6 p. Epoxy soya 1.0 2 2 2 q. Octyl epoxy tallate 0. 3 N 0 change 9 o 12 r. Octyl epoxy tallate. 0. 6 8 8 8 s. Ootyl epoxy tallate 1.0 6 4 t. Butyl epoxy stearatc 0. 3 11 it u. Butyl epoxy stearate" 0. i 7 7 7 v. Butyl epoxy stearabe 1. 0 5 3 3 w. Control, no epoxy 13 13 13 4 Epoxidized butyl oleate, 3.9 oxirane oxygen (butyl epoxy steal-ate) The samples were removed from the oven after each time interval and arranged according to color.

The data above indicate the rank of the samples with respect to color, #1 being lightest and #13 darkest.

Sample m was consistently best, initially amber and turning to a darker amber color in 60 minutes.

Sample w was consistently worst, initially amber and turning dark brown to black in 60 minutes.

The test results in Tables III and IV show that greater stability was obtained with higher levels of stabilizer in both cases. Expoxidized soybean oil and epoxidized linseed oil were clearly the best heat stabilizers. The mixed aryl-dialkyl phosphite was superior to the other two phosphites.

As will be apparent to those skilled in. the art, numerous modifications and variations of the invention illustrated above may be made without departing from the spirit of the invention.

What is claimed is:

1. A liquid fire-resistant functional fluid composition which comprises: (a) 60 to 80% of a mixture of liquid chlorinated hydrocarbons and petroleum oils, the petroleum oil comprising to of the total composition; (b) 20 to of a mixture of liquid triaryl phosphate and trialkyl phosphate, the triaryl phosphate comprising at least 5% of the total composition, and the trialkyl phosphate comprising at least 8% of the total composition; the liquid chlorinated hydrocarbon being selected from the group consisting of chlorinated parafiins containing at least about 48% by weight chlorine and chlorinated biphenyl containing at least about 48% combined chlorine; the petroleum oil being selected from the group consisting of mineral oils having a viscosity of about 30 to 200 SUS and petroleum base hydraulic oils having a viscosity of about 140 to 400 SUS; the liquid triaryl phosphate being selected from the group consisting of triaryl phosphates represented by the formula where R is selected from the group consisting of phenyl, cresyl, and xylyl radicals and the liquid mixtures of these triaryl phopshates; and the trialkyl phosphate being selected from the group consisting of trialkyll phosphates in which each alkyl radical has from 4 to 12 carbon atoms; (0) 0.1 to 1 part by weight, per 100 parts by weight of the total of (a) and (b), phite; and (d) 0.5 to 2 parts by weight per 100 parts by weight of the total of (a) and (b) of an epoxy plasticizer.

2. A fire-resistant functional fluid according to claim 1 of a triorganic phos- 7 wherein the chlorinated paraffin has a molecular weight I Ingredients: Parts by weight Chlorinated paraffin chlorine) 49 Petroleum oil 29 Trixylyl phosphate 13 Tris(2-ethylhexyl)phosphate 8.4 =Epoxidized linseed oil (9.5 oxirane oxygen) 0.6 Triphenyl phosphite 0.25

8. A fire-resistant functional fluid according to claim 1 consisting of the following ingredients:

Ingredients: Parts by weight Chlorinated paraffin (50% chlorine) 49 Petroleum oil 2-9 Trixylyl phosphate 13 Tributyl phosphate 9 Epoxidized linseed oil (9.5 oxirane oxygen) 0.6 Triphenyl phosphite 0.25

'9. A fire-resistant functional fluid according to claim 1 consisting of the following ingredients:

Ingredients: Parts by weight Chlorinated paraffin (50% chlorine) 49 Petroleum oil 29 Trixylyl phosphate 13 Tributyl phosphate 9 Epoxidized linseed oil (9.5 oxirane oxygen) 0.6 Phenyl didecyl phosphite 0.25

10. The fire-resistant functional fluid of claim 1 in which the triorganic phosphite is selected from the group consisting of triaryl phosphites, trialkyl phosphites and aryl dialkyl phosphites.

11. The fire-resistant functional fluid of claim 1 in which the triorganic phosphite is selected from the group consisting of triaryl phosphites, trialkyl phosphites and phite and trioctyl phosphite.

12. The fire-resistant functional fluid of claim 1 in which the epoxy compound is selected from the group consisting of epoxidized soybean oil, epoxidized linseed oil, butyl epoxy tallate, butyl epoxy stearate and epoxidized octyl tallate.

References Cited UNITED STATES PATENTS 2,175,877 10/1939 Clark 252--49 2,245,649 6/1941 Caprio 252-49 2,509,620 5/1950 Watson et al. 252-78 2,549,270 4/1951 Watson 252-78 2,566,623 9/1951 Moreton 252--78 2,686,760 8/1954 Watson 252--49.8 X 2,900,342 8/1959 Manteuifel et al. 252-57 3,115,465 12/1963 Orlofi et al. 252-498 X 3.136,726 6/1964 Moreton 252-78 X DANIEL E. WYMAN, Primary Examiner W. CANNON, Assistant Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO- 2 W6 107 Dated Fehrnary I 'Z J I 7 Inventor(s) D. A. Lima et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 25, "hamful" should read --harmful-.

Column 4, line 72, "epoxized" should read -epoxidized.

Column 5, line 15, "epoxized" should read --epoxidized.

Column 7, line 18-21, should read Claims 7, 8, & 9, line 9, "9.5" should read "9.5%".

Column 8, line 19 & 50, "triaryl phosphites, trialkyl phosphides and phite and troctyl phosphite" should read -triphenyl phosphite, phenyl didecyl phosphite and trioctyl phosphite--.

Signed and sealed this hth day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTISCHALK Attestinq Officer Acting Commissioner of Patents FORM PO-IOSO (IQ-G9) USCOMM-DC GUSTO-P69 USI GOVERNMKNY FIINYING OFFICE 19.9 O-J65-J34