DE961483C - Synthetic lubricant - Google Patents

Description

ISSUED APRIL 4, 1957

St 7387 IVc j 23 c

In an attempt to obtain better specialty lubricating oils with special properties, new types were created Synthetic substances developed with lubricating properties that are good in comparison with mineral oils Have viscosities at low and high temperatures. This makes them particularly suitable for that Lubrication of machines that have to work within a wide temperature range, such as jet engines and internal combustion engines for aircraft and the like, mineral oils are too low in view of theirs Viscosity indices unsuitable for these purposes.

It was also found that synthetic lubricating oils are also useful in lubricating the usual Automotive engines offer advantages. Various synthetic lubricating oils possess besides the adaptability Their viscosity has a further advantage, especially with very little residue after a long period of operation to be left in the combustion chamber. This has a more efficient fuel economy, one less increase in the octane number requirement of the engine, a reduced tendency to pre-ignition and generally a better working of the engine result.

These novel lubricants can also be used to reduce or remove existing ones Serve combustion residues.

It has now been found that the formals, which can be prepared from a large number of different organic compounds with at least one free alcoholic hydroxyl group and contain at least three —CH ₂ O groups, are used as synthetic lubricating oils or components of synthetic ones

ίο lubricating oils and greases can be used, the excellent lubricity at high and low temperatures have and practically none in the combustion chambers of piston engines Leave combustion residues behind.

It is well known that most acetals are not stable for use as lubricants are enough. The formals of organic oxy compounds which make up the group

- O - [CH ₂ - O

CH ₂ - O

contain, in which χ and η ^ 2 and y S ι, now have excellent stability and have viscosity properties that make them excellent lubricating oil mixtures.

The lubricants of the invention have the general composition

AO [CH ₂ - O (C _n H _2n O) _1], CH ₂ -OB

Here, A and B are alcohol or glycol residues, χ and η fe 2 and y § 1. The residues can be the same or different "and contain 1 to 60 carbon atoms. A and B are selected so that the formal a total of about 20 contains up to 130, preferably about 25 to 100, C. The organic oxy compounds used to introduce the radicals A and B are described in more detail below.

For the lubrication of piston engines, in particular of motor vehicle engines, the lubricant must meet several requirements. In order to be able to form an effective lubricating film and to maintain it at high and low temperatures, certain viscosity properties are required. At low temperatures, the lubricant must be unstable enough to be able to circulate in the system's lubrication system and to allow the lubricated surfaces to move without using excessive force. A lubricant with an ASTM pour point below about 1.7 ° has sufficient instability at low temperatures. At high temperatures, a lubricant must have sufficient consistency to form and maintain a sufficient film of lubricant. It has been found that a lubricant which is satisfactory in this regard must have a viscosity of about 2 to 60 cSt at 98.9 °. In order to avoid excessively high losses of lubricating oil through volatilization and decomposition and to be safe from explosions that can occur at higher temperatures, the lubricating oil should have a flash point of more than 150 °. These requirements are included in the term "lubricant" and the formals of the invention are limited to those having these properties. The substances preferably used have an ASTM pour point below about -26 ^0, a flash point above about 190 ° and a viscosity from 2.6 to 13 cSt at 98.9 °.

The above. Properties are functions of the molecular structure and molecular weight. Therefore it is possible within certain limits to use lubricating oils with similar high and low temperature properties to produce in different ways and to meet the respective requirements to a certain extent To make "to measure"; because the large number of organic, alcoholic containing hydroxyl groups Compounds allow a wide variety of lubricants according to the invention to be prepared.

The manufacture of the complex formals according to the invention, which is not patented here is to be carried out according to the generally accepted technique. There are three general ways to do this.

1. You can put the reactants in the reaction zone Mix and in the presence of a carrier, such as hexane, heptane or the like., To reflux temperature heat. After aborting the theoretical amount of water, the product becomes acidic catalysts Washed free and stripped of unreacted components.

2. Mix χ mol of the glycol with (x - 1) mol of formaldehyde to form the core of the compound, namely the group

HO (C _n R _2n O) ₁ , [CH ₂ - O - (QH _2n O) LH

to obtain. In another reaction zone, equal molar proportions of an alcohol and formaldehyde are heated to about 60 ° in order to obtain the semi-formal of the alcohol, ie R — O — CH ₂ —OH. The two products are now mixed by adding the glycol formal to the alcohol semi-formal, and the mixture is heated to reflux temperature. After the theoretical amount of water has been aborted, the product is washed and stripped as above.

3. First, the semi-formal of the alcohol in question is represented by using equal molar proportions Alcohol and formaldehyde heated. Then add the desired molar proportion of glycol and formaldehyde and heated the mass to reflux temperature, whereby the oxy complex

RO- [CH ₂ -O- (C _n H _2n O) J ₀₅ H

arises. Then 2 moles of this product are reacted with ι moles of formaldehyde and the end product is obtained, which is cleaned as described above.

The compounds that can be used to make these formals must therefore be organic oxy compounds which contain at least one free alcoholic hydroxyl group. The following list give examples of such connections. Other compounds can of course also be used.

I. Unsubstituted alcohols

A. Monohydric alcohols i. Aliphatic alcohols

Methyl alcohol A) isopropyl alcohol

b) ethyl alcohol

c) propyl alcohol

e) n-butyl alcohol

f) isobutyl alcohol

g) secondary butyl alcohol
h) tertiary butyl alcohol
i) η-amyl alcohol
j) isoamyl alcohol
k) n-hexyl alcohol
1) isohexyl alcohol
m) 2-ethyl-i-butanol
η) 2-ethyl-i-hexanol
ο) octyl alcohol
ρ) isooctyl alcohol

q) 2-octyl alcohol

r) isononyl alcohol

s) decyl alcohol

t) lauryl alcohol

u) tetradecyl alcohol

v) pentadecyl alcohol

w) octadecyl alcohol

x) AUyl alcohol

y) crotyl alcohol

z) oleyl alcohol

aa) the terpineole
bb) the alcohols obtained by known synthesis processes or their mixtures

2. Aromatic alcohols

a) Benzyl alcohol

b) phenethyl alcohol

c) 3-phenyl-i-propanol

d) a-naphthylcarbinol

e) cinnamon alcohol

f) diphenylcarbinol

g) furfuryl alcohol h) cumic alcohol

i) Vanillyl alcohol j) Piperonyl alcohol

ι. Glycols

B. Polyhydric alcohols

a) Ethylene glycol d) i, 3-butanediol

b) i, 2-propanediol e) 1,4-butanediol

c) i, 3-propanediol f) 1,5-pentanediol g) the various polyalkylene glycols, e.g. B.

i. Polyethylene glycols 2. polypropylene glycols

a) Diethylene glycol a) Dipropylene glycol

b) triethylene glycol b) tripropylene glycol

c) tetraethylene glycol h) i, 2-C3rclohexanediol

i) Decanediol-i, 10

2. Other polyhydric alcohols

a) glycerin

b) 2-oxymethyl-2-methyl-propanediol-i, 3

c) pentaerythritol

d) sorbitol

e) dipentaerythritol

f) Dulcit

g) trimethylol propane

h) tetramethylolcyclohexanol i) benzotrimethylol

II. Substituted Alcohols A. Monohydric Alcohols

i. Aliphatic alcohols

a) Halogenated alcohols

1. Ethylene chlorohydrin

2. Trifluoroethanol

3. propylene chlorohydrin

4. the various chlorine-substituted monoethers of polyalkylene glycols

b) Ethanolamine, ÄthanohnorphoHn

c) 2-aminopropanol e) 2-nitropropanol

d) 2-nitroethanol f) 2-nitrobutanol

2. Aromatic alcohols

a) p-methoxy-benzyl alcohol

b) the various chlorobenzyl alcohols

c) the various nitrobenzyl alcohols

d) 2-aniline ethanol

3. Glycine ether

a) Ethylene glycol monomethyl ether

b) Propylene glycol monobutyl ether

c) butylene glycol monolauryl ether

d) Polyethylene glycol monoether

e) polypropylene glycol monoether

f) polybutylene glycol monoether

g) polytrimethylene glycol monoether

4. Glycol mono-formal, e.g. B. the mixed formals of glycols and alcohols 80

B. Polyhydric alcohols

1. Glycols

a) Halogenated glycols, e.g. B.

1. 3-chloro-i, 2-propanediol

2. 2-chloro-i, 3-propanediol

b) nitroglycols, e.g. B.

1. 2-Nitro-i, 3-propanediol

2. 2-Nitro-2-methyl-propanediol-i, 3

3. Trimethylol-nitromethane

c) aminoglycols

1. 2-Amino-i, 3-propanediol

2. 2-Amino-2-methyl-1,3-propanediol

3. Diethanolamine

4. Trimethylol aminomethane

2. Glycol monoesters

a) Ethylene glycol monoacetate

b) propylene glycol monobutyrate

c) butylene glycol monolaurate

d) Polyethylene glycol monoester

e) polypropylene glycol monoester

f) polybutylene glycol monoester

C. Other oxy compounds

1. Esters of oxyacids

a) lactic acid ester

b) glycolic acid ester

c) oxystearic acid ester

2. Carbonyl-substituted alcohols

a) oxyketones, ζ. Β.
Oxyacetone

b) oxyaldehydes, e.g. B.

1. α-Oxyadipaldehyde

2. / S-oxypropionaldehyde

3. Oxy-alkyl-cyanide

a) ethylene cyanohydrin

b) a-oxy-isobutyrnitrile

Organic oxy compounds which are particularly useful for the process according to the invention are

highly branched aliphatic alcohols, the can be obtained by the "oxo" synthesis.

Alcohols which are particularly useful for preparing the formals according to the invention can be obtained by applying the oxo synthesis to polymers and copolymers of C ₃ and C ₄ monoolefins, such as are readily available in petroleum refinery streams.

Preference is given to oxo alcohols with 8 to 20 carbon atoms, those from olefin copolymers with 7 to 19 carbon atoms are won.

Monohydric alcohols, glycols and organic are used to prepare the formals according to the invention Acids preferred. These compounds can advantageously be combined with formaldehyde to form molecules of the following Implement compositions, with the individual components instead of the structural formulas of the complex formalities are given:

Alcohol (formaldehyde glycol) ,,,,
Glycol (Formaldehyde Glycol) ^
Glycol monoester (formaldehyde glycol) _a ,
Glycol monoether (formaldehyde glycol) _x .

Where λ is; in all cases an integer greater than i. The acids used for the preparation of the glycol monoesters can be found in the following list: acetic acid, propionic acid, butyric acid, 2-ethylbutyric acid, caproic acid, 2-ethylcaproic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, oleic acid, stearic acid, methoxyethyleneoxyacid , Mono-2-ethylhexyl-adipic acid, mono-C ₈ -o ^ o-sebacic acid, C ₃ - to C ₂₀ -oxo acids, including the acids from soil fractions, acids from the oxidation of petroleum fractions, acids from the alkaline melt of 'Alcohols and / or aldehydes, glycolic acid, lactic acid, oxystearic acid.

To further explain the method of production of the formals used as lubricating oils according to the invention the following examples serve. However, no patent protection is claimed for the manufacturing process.

Example i *

Production of n-butyl-carbitol- (CH ₂ -tripropylene glycol) ₄ , ie

n-C ₄ H ₉ - (OCH ₂ CH ₂ ) ₂ O - (CH ₂ OC ₃ H ₇ OC ₃ H ₇ OC ₃ H ₇ O) ₄ H

It presented the half formal of n-butyl carbitol by half-hour heating of 81.1 g (V ₂ ^{Mo1) Car} "Bitol with 15.1 g of (V ₂ MoI CH ₂ O) of paraformaldehyde, 200 g of heptane and 2 g of NaHSO ₄ to 65 ° her.

The polyformal of tripropylene glycol, so

TPG-CHaO-TPG-CH ₂ O-TPG-CH ₂ O-TPG

long by 90 minutes of heating 384.5 g (2 mol) of tripropylene glycol, 45.5 g (1.5 moich ₂ O) of paraformaldehyde, 200 g of heptane and 3.2 g of NaHSO ₄ to 89-104 ⁰ was obtained at reflux. The volume of the water layer was 28 ecm (theory 27 ecm).

To reduce the formation of the simple formal, the semi-formal of n-butyl carbitol was added dropwise over 70 minutes to the refluxed solution of the polyformal of tripropylene glycol. When the addition of the semi-formal had ended, the reflux treatment was continued for a further 30 minutes at 100 to 102 °. The volume of the water layer was now 37 ecm (theory 36 ecm). The catalyst was removed by decanting, and the mixture was washed three times with 100 ecm 5% Na ₂ CO ₃ solution each time and twice with 100 ecm water each time. After the solvent had been stripped off and the material had not reacted, the product boiled below 0.2 mm above 140 ° (boiler temperature 231 ⁰ ) and had the following characteristics:

Viscosity in cSt

at 98.9 ° 50.86

at 37.8 ° 423.1

at -17.8 ° 59 700.0

Viscosity index 130.0

Pour point at ⁰ C - 31.7

Hydrogen combustion test

Carbon in mg 1.1

Fog in mg 0.7

Example 2

Production of. Polyethylene glycol polyformal HO (CH ₂ CH ₂ O) ₆₁₄ [CH ₂ (OCH ₂ CH ₂ ) _{6) 4} O] .H

This polyformal was prepared by heating 300 g (1 mol) of polyethylene glycol with a molecular weight of about 300, 30 g (1 mol CH ₂ O) paraformaldehyde, 200 g heptane and 3.3 g NaHSO ₄ to 98 ° for two hours. 19.2 ecm of water passed over (theory 18 ecm). After cooling, the heptane layer was separated off. The polyformal layer was treated with 10% animal charcoal at 115 ° for 30 minutes and then suction filtered. The polyformal is compared with the original polyethylene glycol 300 below.

Viscosity in cSt

at 98.9 °

at 37.8 °

Viscosity index ..
Flow point in ⁰ C.
Flash point in ⁰ C
Focal point in ° C.

Polyformal Polyethylene the end glycol 300 Polyethylene glycol 300 5.68 36.4 34. ² 4 290.7 116.0 132.0 - 15.0 - 1.0 204.0 182.0 229.0 238.0

According to another embodiment of the invention by the formulas given above labeled compounds which contain a free hydroxyl group, reacted further with formaldehyde and coupled to another organic compound which is also a free alcoholic compound

Contains hydroxyl group. This series of compounds, each of which contains the group - (formaldehyde glycol) _x -, where χ is greater than ι, can be characterized as follows (the common group being designated as "Z" ):

Alcohol-Z-formaldehyde alcohol Alcohol-Z-formaldehyde glycol monoester Alcohol-Z-formaldehyde glycol monoether Glycol monoester Z-formaldehyde glycol monoester Glycol monoester Z-formaldehyde glycol monoether Glycine ether-Z-formaldehyde glycine ether

By substituting an oxyacid monoester, such as the lactates and glycolates, a different series can be made can be made by compounds shown below:

Oxymonoester-Z-formaldehyde-oxymonoester Oxymonoester-Z-formaldehyde-alcohol Oxymonoester-Z-formaldehyde-glycol monoether ^ao Oxymonoester-Z-formaldehyde-glycol monoester

All of the complex formals mentioned above have the general composition

as A - (formaldehyde glycol) _x - formaldehyde - B or

AO [CH ₂ -O- (C _n H _2n O) ^ CH ₂ -OB

where A and B can be the same or different and are selected from the group of organic radicals which contain 1 to 60 carbon atoms and are derived from organic compounds which contain an alcoholic hydroxyl group, and where χ and η are integers greater than 1 and y is equal to or greater than 1.

Example 3

Preparation of C ₁₃ -Oxoalkohol- (CH ₂ 0-tripropylene glycol) ₃ CH ₂ O - C ₁₃ -OxOaIkOhOl, ie

C ₁₃ H ₂₇ O- [CH ₂ O (C ₃ H ₆ O) ₃ J ₃ -CH ₂ -OC ₁₃ H ₂₇

The core of this polyformal was first presented, i.e.

H (OC ₃ H ₆ ) OCH ₂ (OC ₃ H _G ) ₃ - OCH ₂ (OC ₃ H ₆ ) ₃ OH

by heating 288 g (1.5 mol) of tripropylene glycol, 30 g (1 mol of CH ₂ O) trioxymethylene, 300 g of heptane and 5.5 g of catalyst (NaHSO ₄ ) for 40 minutes under reflux at 89 to 100 °. 19 ecm (theory 18 ecm) of water passed over here. The mixture was cooled the reaction mixture to 70 ^0, and then sat 200 g (1 mole) of C ₁₃ oxo alcohol and 30 g (1 mole of CH ₂ O) to trioxymethylene. Then the reaction mixture was heated for 30 minutes at reflux temperature 90-103 ^0, with 19.5 cc (18 cc theory) passed over water.

The reaction product was decanted from the catalyst and then with 150 cc of a io ° / ₀ solution of Na ₂ CO _3, and finally washed twice with 100 cc of water. The product was then stripped of solvent and light components. The product, which boiled above 152 ° at 0.3 mm and consisted of the _{fraction passing over from 14 to 100 ° / 0} , had the following properties:

Viscosity in cSt

at 98.9 ° 8.91

at 37.8 ° -. 56.67

at -17.8 ° 4657.0

Viscosity index 132.0

Pour point in ° C - 43.0

Flash point at ⁰ C 216.0

Focus at ⁰ C 235.0

Hydrogen combustion test

Carbon in mg 1.3

Fog in mg 0.2

The residue-free burning of this reaction product shows that it is when used as Lubricating oil for motor vehicle engine crankshaft housings would cause practically no increase in the octane requirement.

Example 4

Production of C ₁₃ -oxo alcohol - (CH ₂ O-tripropylene glycol) _a -CH ₂ O - C ₁₃ -OxOaIkOhOl

This complex formula, similar to the one above, was made in order to obtain a lower viscosity product. 520 g (2.6 mol) of C _M oxoalcohol, 117 g of paraformaldehyde (3.9 mol of CH ₂ O), 200 g of heptane and 3.1 g (0.25%) of NaHSO ₄ catalyst were heated to 55 minutes for 45 minutes °. 500 g (2.6 mol) of tripropylene glycol were then added to this semi- _{formal of C ls} -oxo alcohol and the mixture was heated to reflux temperature. After 3 hours the temperature ^{had risen from 95 to 18 ° C.} and 73 ecm of water had collected (theory 70.2 ecm). The product was colored light brown, which is an indication that the low concentration of the catalyst (0.25 ° / ₀ ) prevented severe discoloration, as occurs with catalyst concentrations of 1%. The reaction product was separated from the crystalline catalyst, washed three times with 100 ecm of saturated Na ₂ CO ₃ solution each time and then three times with 100 ecm of water each time and then stripped of the heptane and the small amount of water. The product, which boiled above 153 ⁰ at 0.2 mm Hg and from 6 to 100 ° / ₀ merges fraction consisted of, had the following properties:

Viscosity in cSt

at 98.9 ° 5.82

at 37.8 ° 33.82

at - 17.8 ° 2 286.0

at - 40.0 °> 80,000.0

Viscosity index 125.0 iao

Pour point at ⁰ C - 46.0

Flash point in ° C 199.0

Fire point in ° C 221.0

Hydrogen combustion test

Carbon in mg 0.8

Fog in mg 0.2

Example 5

Production of η-butyl— (OC ₃ H ₆ ) ₂ O (CH ₂ O-polypropylene glycol) ₂ - CH ₂ O - (OC ₃ H ₆ ) ₂ n-buty]

This complex formal was produced according to Example 4. The polypropylene glycol had a average molecular weight of 150.

The product, which at 0.3 mm above i6i ° boiled, had the following properties:

Viscosity in cSt

at 98.9 ° 3.72

at 37.8 ° 17.3

at -17.8 ° 591.7

at - 40.0 ° 12 220.0

Viscosity index 116.0

Pour point at ⁰ C - 57.0

Flash point in ° C 166.0

Fire point in ° C 174.0

The fraction of the product boiling at 0.2 mm above 188 ° had the following properties:

Viscosity in cSt

at 98.9 ° 5.39

at 37.8 ° 29.46

at -17.8 ° 1709.0

at - 40.0 ° 55 849.0

Viscosity dex 129.0

Pour point at ⁰ C - 51.0

Flash point at ⁰ C 177.0

Focus at ⁰ C 199.0

Example 6

Production of C ₁₃ -OxOaIkOhOl- (CH ₂ O-Propylene glycol) _{2) 3} - CH ₂ O - C ₁₃ -OxOaIkOhOl

2 moles of Cjg-oxo alcohol, 3.7 moles of formaldehyde (as paraformaldehyde) and 2.3 moles of tripropylene glycol were mixed with 300 g of heptane and 1.5 g of sodium bisulfate. The mixture was heated to reflux temperature until the theoretical amount of water was driven off. Then the product was decanted from the catalyst and washed three times with 100 ecm sodium carbonate solution and twice with 100 ecm water and nitrated. The mass was then stripped down to a steam temperature of 176 ^° at 10 mm. The product had the following properties:

Viscosity in cSt

at 98.9 ° 8.06

at 37.8 ° 47.81

at -17.8 ° 3 49i, o

at - 40.0 °> no 000.0

Viscosity index 136.0

Pour point at ⁰ C - 46.0

Flash point, at ⁰ C 218.0

Focus at ⁰ C 238.0

Example 7

Production of C _ia -oxo alcohol - CH ₂ O (triethylene glycol _{- CH 2} O) ₂ - C ₁₃ -OxOaIkOhOl

400 g of C ₁₃ oxo alcohol and 67.2 g of formaldehyde were mixed and _{heated with 2.4 g of NaHSO 4} in the presence of 240 g of heptane. The mixture was heated for about 25 minutes at 55 ^0, set to 300 g triethyleneglycol and the mixture was heated about ι hour at 113 °. Now you put the reaction mixture 33.6 g further formaldehyde and heated for another hour at 115 ^0th After this time, 60 g of water (theory 54 g) had passed over.

The product obtained in this way was purified according to the examples and ^{stripped down to a steam temperature of 210 °} at 0.9 mm pressure.

The product had the following properties:

Viscosity in cSt

at 98.9 ° 6.34

at 37.8 ° 33.87

at -17.8 ° 16,049.0

at -40.0 ° 443o6, o ·

Viscosity index 142.0

Pour point at ⁰ C - 51.0

Flash point in ⁰ C 221.0

Focus at ⁰ C 243.0

Example 8 ^8s

Production of C ₁₃ oxo alcohol - O (CH ₂ O pentanediol-i, 5) ₃ CH ₂ - O - C ₁₃ oxo alcohol

This product was prepared according to the example, with the exception that 1.5 pentanediol was used as the glycol instead of triethylene glycol. The product was stripped to a vapor temperature of 182 ⁰ at 10 mm pressure.

It had the following properties:

Viscosity in cSt

at 98.9 ° 12.28

at 37.8 ° 75.56

at -17.8 ° 4035.0

at. -40.0 ° -

Viscosity index 143.0

Pour point at ⁰ C - 37.0

Flash point at ⁰ C 227.0

Focus in f C 252.0

The complex formals described here can also serve as a lubricating oil base for lubricating greases.

These novel synthetic lubricating oils can be mixed with mineral or other synthetic oils be mixed into concentrates or finished lubricating oils. They are with the well-known lubricant additives, such as V.I. improvers, pour point depressants, anti-rust agents, anti-rust agents, antioxidants and the like, compatible.

Claims (9)

Patent claims: i. Use of mixed formals containing at least one alcoholic hydroxyl group of organic compounds of the general structural formula A-O [CH ₂ -O (C ₁₁ Hj _n O) J, CH ₂ -OB in A and B organic radicals with 1 to 60 carbon atoms, χ and η whole numbers equal to or greater than 2, y is an integer equal to or greater than ι and the total number of carbon atoms in the molecule is 20 to 130, as a synthetic lubricant or component of synthetic lubricants with a pour point below 1.7 °, a flash point above 150 ⁰ and a kinematic toughness of 2 to 60 cSt at 98.9 °. 2. Use of formals according to claim 1, in which A and B are oxo alcohol groups of 8 to 20 each C atoms are. 3. Use of formals according to claim 1, in which A is the remainder of a monohydric alcohol and B is the remainder of a glycol. 4. Use of formals according to claim 2, in which χ and η are greater than 2. 5. Use of formals according to claim 2, in which η and y = 3 and χ is preferably also = 3. 6. Use of formals according to claim 2, in which η = 2, y is greater than 1 and χ is greater than 2. 7. Use of formals according to claim 4 and 5, in which A and BC _{13 are} oxo alcohol radicals. 8. Use of formals according to claim 1, in which η = 3, χ - 2, y = approximately 2.28 and A and B are the residues of an ether alcohol. as 9. Use of formals according to claim 1 as the synthetic lubricant has an ASTM pour point below -26 °, a flash point of 177 ⁰ and a viscosity of 2.6 to 13 cSt at 98.9 °. © 609580/438 8.56 (609 853 3.57)