JPS585234B2 - Seizou Hohou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to synthetic hydrocarbon lubricant compositions and methods of making the same.

More particularly, the present invention relates to a method for producing aromatic hydrocarbons substituted with two long-chain alkyl groups by a two-step alkylation process.

linear and with 6 to 18 carbon atoms, preferably 11
The use of dialkylbenzenes containing ~14 alkyl substituents as synthetic lubricants is known.

One of the earliest references to such properties of this compound is US Pat. No. 3,173,965.

It is also known that compositions containing large amounts of aromatic hydrocarbons in which the aromatic moiety is phenyl, tolyl, or xylyl and substituted with two long-chain alkyl substituents are useful as low temperature lubricants. There is.

Synthetic hydrocarbon lubricants generally have a combination of physical properties, particularly pour point, viscosity index, and low temperature viscosity, that make them useful as low temperature lubricants.

US Pat. No. 3,173,965 discloses that dialkylbenzenes suitable as lubricants are prepared by one- or two-stage alkylation of benzene.

According to this patent, suitable alkylating agents include alpha-olefins.

Also suitable catalysts are A I C13, A I B r 3
, F e C13, S n C14, B F 3, H
F.

It is disclosed that they are H2SO4, P2O5 and H3PO4.

However, this patent states that the first alkylation is carried out using HF as a catalyst, and the second step is performed using AlC as a catalyst.
There is no mention or suggestion that alkylation using I3 or AlBr3 results in products with improved physical properties, especially improved low temperature viscosity properties.

The present invention provides an improved method for making synthetic hydrocarbon lubricant compositions consisting essentially of aromatic hydrocarbons substituted with two long chain alkyl groups.

This improved process is a two-step alkylation process for alkylating benzene or alkylbenzenes with linear monoolefins, with the first step using hydrogen fluoride as a catalyst and the second step using aluminum chloride or odor as a catalyst. The improvement is in the use of aluminum chloride.

More specifically, the present invention uses a linear monoolefin as the alkylating agent, hydrogen fluoride as the catalyst in the first stage alkylation, and aluminum chloride or aluminum bromide as the catalyst in the second stage alkylation. Provided is a method for producing di-C6-C18 alkylbenzenes in which the alkyl group is substantially linear by a two-step alkylation process using

This improved process provides better low temperature viscosity properties for the product, which is particularly useful as a low temperature lubricant.

The aromatic hydrocarbons used in this method are benzene,
and alkylbenzenes such as toluene, xylene, and ethylbenzene, with benzene being particularly preferred.

Suitable linear monoolefins used in the present process contain about 6 to 18 carbon atoms, preferably about 10 to 14 carbon atoms.

Pure substances or mixtures of such substances containing the desired number of carbon atoms can also be used.

This olefin is an excellent linear substance, but in small amounts (
For example, about 2-15% by weight) of branched olefins.

This olefin may be an α-olefin or an olefin having an internal double bond.

Branched olefins appear to degrade the physical properties of the product.

Additionally, the olefin alkylating agent can contain paraffins of approximately the same molecular weight, which can be separated from the alkylated product by distillation.

The feedstock used in the second stage alkylation of the present invention typically has the following composition.

Preferred catalysts used in the second stage alkylation are aluminum chloride, aluminum bromide, and mixtures thereof.

Among these, aluminum chloride is relatively preferred in terms of cost.

It is well known in the alkylation art that when using aluminum chloride or aluminum bromide as a catalyst, it is necessary to use a hydrogen donor promoter such as water or hydrogen chloride.

In many cases sufficient amounts of water are present in the materials used.

The type and amount of this accelerator can be readily determined by those skilled in the art without undue experimentation.

First stage alkylation using hydrogen fluoride as a catalyst is well known in the art and is not the core of this invention.

However, in order to gain a more complete understanding of the invention, this alkylation step will be briefly described.

The molar ratio of linear olefin to aromatic hydrocarbon is 1:
The ratio is 1 to 1:15, preferably 1:2 to 1:10.

The amount of hydrogen fluoride is approximately 1 per mole of aromatic hydrocarbon.
~30 moles, preferably about 1-10 moles.

The reaction is carried out at a temperature range of about 100°C to about 100°C,
Reaction times range from 10 to 60 minutes.

At the end of the reaction time, the reaction is stopped by separating the HF from the reaction mixture.

after that. The reaction mixture is washed with NaOH solution and subsequently the excess aromatic hydrocarbons are removed by distillation.

The second stage alkylation uses mono-long chain alkyl-substituted aromatic hydrocarbons produced in the first stage using HF as a catalyst and linear olefins as feedstock. The molar ratio is 1:
The ratio is 1 to 1:10, preferably 1:2 to 1:5.

In the improved process, it is desirable to use harsh reaction conditions for this second step.

This can be achieved by increasing the amount of catalyst or by using higher reaction temperatures, preferably by using both.

Expressed as the amount of aluminum chloride or aluminum bromide in the olefin unit base, the amount of aluminum chloride or aluminum bromide is about 2 to 10% by weight, preferably about 3 to 6% by weight.

Conveniently, this reaction is carried out using a temperature within the range of about 60-90°C.

The reaction temperature is preferably about 70-80°C.

Even if the reaction temperature is as high as about 100°C, it can be used satisfactorily.

The use of low temperatures (eg, up to 50° C.) is less desirable, especially at comparable catalyst levels, due to poor low temperature physical properties of the product.

Knowing the abovementioned catalyst amounts and reaction temperature ranges, one skilled in the art can determine the required reaction time.

Suitable reaction times are about 5 to 360 minutes, preferably about 15 to 360 minutes.
The duration is 90 minutes.

When the required reaction time has elapsed, the reaction is stopped.

The products of the alkylation reaction are directed to a suitable separator for removing catalyst sludge.

The catalyst-free alkylation product is then treated to remove residual acidic components and impurities.

This treatment can be easily accomplished by washing with water and/or caustic solutions or percolating through a bed of bauxite.

Methods for purifying the crude product of this alkylation reaction are well known to those skilled in the art.

After the reaction product has been treated as described above, it is subjected to fractional distillation to obtain the desired product.

The desired product is the bottom fraction.

The cut point for separating the desired bottoms fraction is determined by the molecular weight of the starting material and the required physical properties of the bottoms fraction.

In a preferred product, about 165-2 at 5 mm Hg.
We have found that a cut point of 20°C can be used.

In the most preferred product, 5m, about 175 in Hg
A cut point of ˜190° C. is used.

The products of the invention consist essentially of di-long chain alkyl-substituted aromatic hydrocarbons, where the alkyl groups and aromatic moieties are as defined above in the description of the feedstocks used in the second stage alkylation. Amoto: To avoid misunderstandings, the general formula for long-chain alkyl-substituted aromatic hydrocarbons is as follows, taking as an example the aromatic moiety being toluene.

(wherein R and R1 are substantially linear alkyl groups containing about 6 to 18 carbon atoms, preferably about 10 to 14 carbon atoms).

As may be inferred, the term "long chain" refers to approximately 6 to 6 carbon atoms.
It means a substantially linear alkyl group containing up to 18 alkyl groups.

The products of the present invention preferably contain about 85% or more by weight of di-long chain alkyl-substituted aromatic hydrocarbons, more preferably about 90% or more by weight of di-long-chain alkyl-substituted aromatic hydrocarbons.

The products of the invention may also contain up to about 8% by weight of trialkyl-substituted tetrahydronaphthalenes.

Conventionally, very good low temperature properties, especially very good -40
In order to obtain a °F viscosity, it was considered desirable to contain 8-25% by weight, usually 10-15% by weight, of trialkyl-substituted tetrahydronaphthalene.

However, it has been found that the products of the invention do not require trialkyl-substituted tetrahydronaphthalenes to obtain very good low temperature properties.

It is believed that the products of the invention have very good low temperature properties due to the structural nature of the dialkyl-substituted aromatic hydrocarbons.

As a background, if we use phenyl as the aromatic moiety,
Alkylation of benzene with linear monoolefins produces isomeric mixtures of alkylbenzenes.

When a C1□ linear monoolefin is used, the phenyl radical can be substituted on any carbon atom from the 2nd to the 11th position of the monoolefin.

2-phenyl C12 alkylbenzene can be represented as follows.

Likewise K,3-phenylC02 alkylbenzene would have a phenyl radical on the third carbon atom.

The process of the present invention provides products with a large amount of dialkylbentenes (or aromatics), in which one alkyl group has a large amount of 2-phenyl substitution and the other alkyl group has a large amount of 2-phenyl substitution. Has a small amount of 2-phenyl substitution.

A large amount means 20% by weight or more, and a small amount means 20% by weight or less.

The products of this invention typically have a 140"F viscosity of 15,000 cs or less.

Preferably, the -401 viscosity is 12000 cs or less.

More preferably, the -40'F viscosity does not exceed 10,000 es.

Therefore, the 40'F viscosity range of the product of the present invention can be defined as 15,000 cs or less, preferably 12,000 cs or less, more preferably 10,000 cs or less. The product of the invention also has the following physical properties: viscosity Index of at least 100, preferably at least 110, pour point eclipse at least -50°F, preferably at least -6
01.

It was unexpected that the process of the present invention would provide a product with bed temperature viscosity characteristics as described above.

This is especially true when the product contains up to about 8% by weight trialkyl-substituted tetrahydronaphthalene.

The following examples are given to explain the present invention more clearly.

However, the present invention is not controlled in any way by the following examples.

Example 1 This example shows the results obtained using HF for the first stage alkylation and AlCl3 for the second stage alkylation.

A-HP Alkylation 8000 g of benzene was added to a polyethylene reactor equipped with a stirrer, addition funnel and vent.

The benzene was cooled to 5°C in a water bath and HF was added to the reactor.
4000 g was condensed.

While the mixture was stirred and maintained at 5 DEG C., 3000 g of 1-dodecene was added over about 1 hour.

After the olefin addition was complete, the water bath was removed and the HF was allowed to evaporate overnight.

When the liver was no longer present in the reaction system, the crude alkylated product was washed with a 5% aqueous NaOH solution at about 90°C, allowed to settle, and excess caustic solution was removed.

The crude alkylated product was then separated from the benzene.

B-AIC13 Alkylation To a flask equipped with a stirrer, a thermometer, a condenser, and a dropping funnel were added 6 moles of the monoalkylbenzene obtained in step A above.

A trace amount of HCI and Al as accelerators were added to this flask.
C15 (5% by weight based on the olefin used) was added.

Thereafter, 1 mol of 1-dodecene was added over about 1 hour while maintaining the temperature at 50°C.

After the olefin addition was complete, the mixture was stirred for an additional 30 minutes to settle and remove the sludge.

The crude alkylated product was washed with 5% aqueous NaOH and then distilled to remove unreacted monoalkylated benzene.

The bottom fraction was the desired product. The properties of this product are shown in Table 1.

Example 2 (Comparative Example) This example is for comparison and shows the results obtained using HF as the catalyst in both the first and second stages.

The first step alkylation was the same as in Example 1.

The second stage alkylation was similar to the first stage alkylation except that the benzene was replaced by the first stage monoalkylate.

The amounts were the same in molar quantities. After washing, the crude alkylate was distilled to recover the desired product as a bottom fraction.

The properties of this product are shown in Table 1.

It can be easily seen from the viscosity index and -40°F viscosity that the use of AlCl3 in the second stage provides a product with superior properties.

Example 3 This example is illustrative of the invention and shows the results obtained using the method of Example 1 but using different feedstocks for the second stage alkylation.

This raw material uses HF as a catalyst to convert benzene into CtO
It was a mixed CIO-C14 alkylated benzene prepared by alkylation with a mixture of α-olefins of ~C14.

The monoalkylated benzene had the following homolog distribution:

The product contained 3.0% by weight alkyl-substituted tetrahydronaphthalene along with monoalkylbenzene.

The method used was the same as in Example 10B except that molar ratios of monoalkylate to alpha-olefin of 4:1 and 2:1 were used.

A 4:1 ratio was used in run (A) and a 2:1 ratio in run (B).

The tolualkyl-substituted tetrahydronaphthalene content and the physical properties of the bottom fraction are shown in Table 2.

Example 4 This example illustrates the effect of temperature variation and AlCl3 catalyst amount on the second stage alkylation.

The monoalkylated product used was a C14 monoalkylbenzene containing a small amount of the 2-phenyl isomer.

The operating conditions and product properties are shown in Table 2.

From Table 1, (a) the products of operations B, C and D are A
and (b) operations B, C and D were carried out under more severe reaction conditions than operation A.

It should be understood that changes and modifications may be made to the invention without departing from its spirit and scope.

Claims (1)

[Claims] 1. In a method for producing a synthetic hydrocarbon lubricant composition consisting essentially of long-chain alkyl-substituted aromatic hydrocarbons, the first step uses hydrogen fluoride as a catalyst to convert benzene or alkylbenzene into C6-C18 linear monomers. Alkylation with olefins to obtain mono-long-chain alkylbenzenes or mono-long-chain alkyl-substituted alkylbenzenes, and in the second step aluminum chloride or aluminum bromide is used as a catalyst to convert this mono-long-chain alkylbenzenes or mono-long-chain alkyl-substituted alkylbenzenes to C6 ~CI8
A method for producing the synthetic hydrocarbon lubricant composition described above, characterized by a two-step alkylation process in which alkylation is performed with a linear monoolefin.