JPS6224480B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to lubricating oil compositions comprising a mixture of a hydrocracked lubricating oil as a base oil and certain oil-soluble polyalkyl (meth)-acrylates as a pour point depressant. Hydrocracked lubricating oils such as the oil described in Dutch Patent Application No. 7613854 can be obtained with very high viscosity index (VI) and are therefore suitable for many grades of engine oil formulation. Particularly suitable as base oil, especially many grades of gasoline and diesel engine oil. However, very high viscosity index type hydrogenolyzed base oils (XHVI with a VI of at least 140)
For oils (ASTM D-2270), typically e.g.
Hydrocracked HVI cannot be reduced to a pour point of 15°C to -33°C (ASTM D-97) or even lower as required by modern demands, e.g. for cold climates. including oil
This does not seem to be possible even when using pour point depressants specifically made for use in HVI oils, such as the polyalkyl methacrylates described in GB 1347713. These polyalkyl methacrylates have an average number molecular weight of 2 x ¹⁰³ to 106, an average number of carbon atoms in the alkyl chain containing ^9-18 carbon atoms, and an average number of carbon atoms of 12.4 to 13.7 in the alkyl chain containing 9-18 carbon atoms. It has at least 6 "alkyl chains having different numbers of carbon atoms" among the alkyl chains containing atoms. It has been found that this problem can be solved using a special combination of two poly(meth)acrylates. Thus, the present invention provides hydrocracked lubricating oils as base oils and (a) VI improving properties, with more than 75% w of alkyl chains having 12-15 C-atoms, and wt. 0.001-20% w of oil-soluble polyalkyl (meth)acrylate with an average molecular weight of 10 ³ -10 ⁶ and (b) a pour point depressing property with alkyl chains of at most 75
Oil- ^soluble polyalkyl ⁽ 0.001− of meta)acrylate
Lubricating oil compositions containing 5% w. It has already been disclosed by US Pat. No. 2,655,479 that a synergistic pour point lowering effect can be obtained when using a mixture of two polyalkyl methacrylates. This mixture is, in principle, 8-
It comprises a polyalkyl methacrylate having an alkyl chain containing 18 C-atoms, the average alkyl chain length being about 12.7 and about 13.5 for the two polymers, respectively. This patent is directed to solvent extracted (conventional) oils and is silent on the problem of lowering the pour point of hydrocracked lubricating oils (unconventional oils). Lubricating base oils to which this invention is particularly concerned include:
Dutch patent application No. 7613854 including XHVI oil
may be the hydrogenolyzed base oils described in No.
Preferably it has a VI of at least 120, more preferably at least 140. These base oils may be mixed with other oils such as solvent extracted lubricating oils; animal or vegetable oils; synthetic oils such as polyolefins, ester oils or polyoxyalkylene oils; or residual distillates such as Brightstock; or hydrogenated oils. It may be combined with a distillate or a hydrogenated extract of the residue. Additive (a) may act as a VI improver and proportions of 1-10% w are preferred in the absence of other VI improvers. When other VI improvers are used, typically 0.05-1% w of additive (a) is added to additive (b).
It is sufficient to obtain a synergistic pour point lowering effect with. An alkyl chain containing 12-15 carbon atoms is
By hydroformylation, in particular by reacting a mixture of olefins containing 11-14 carbon atoms with carbon monoxide and hydrogen in the presence of a complex catalyst consisting of cobalt, carbon monoxide and phosphorus compounds. The obtained alcohols are preferably derived from a mixture of branched and unbranched synthetic alcohols.
Usually the latter alcohols contain 5-25%w branched alkyl chains. In additive (a), at most 25%w of alkyl (meth)acrylates,
Other alcohols, especially primary alcohols, such as synthetic (unbranched and branched e.g. 5-25% w branched) C _9-11 -alcohols, synthetic or preferably natural (unbranched) C _16-18 -Alcohols,
It may be derived from lower alcohols having 1-8 carbon atoms or alcohols having more than 18 carbon atoms. Additives (a) which, in addition to one or more of the monomers mentioned above, contain small amounts, for example at most 10% w, of polar monomers, such as substituted or unsubstituted vinylpyridines, substituted or unsubstituted vinylpyrrolidones, or monomers containing hydroxyl groups. may also be used. Additive (a) may have a weight average molecular weight (w) of 2×10 ³ to 10 ⁶ , especially 5×10 ⁴ to 5×10 ⁵ . They preferably have a low molecular weight distribution range to have good shear stability, which is due to the Q
=w/n (n=number average molecular weight) means that it should be low, for example 1.5-5, such as 2-4. If desired, they can be pre-sheared. As mentioned above, suitable additives (a) have VI improving properties. It will be shown that additive (a) alone does not substantially improve the pour point of XHVI oils, although they can also act as pour point depressants. Preferred additives (b) are described in GB 1163807 and in particular GB 1347713. What this means is that the C _12-15 -alkyl chains are preferably of the type described above for additive (a), while the other alkyl chains are preferably synthetic
derived from C _9-11 -alcohols and/or synthetic or preferably natural C _16-18 -alcohols and optionally from C _1-8 -alcohols or alcohols with more than 18 carbon atoms. That's what it means. It is particularly preferred that the C _16-18 -alcohols are present in a proportion of at least 10%w. Small amounts, for example at most 10% w, of polar monomers such as those described for the case of additive (a) may also be present. The preferred proportion of additive (b) is 0.01-2%w. Additive (b) may have a weight average molecular weight (w) of 2×10 ³ to 10 ⁶ , especially 2×10 ⁴ to 5×10 ⁵ . They preferably have low Q values such as 2
It has a value of 1.5-5, such as -4. Additives (a) and (b) can be added to the base oil neat or in the form of a concentrate of (a) and/or (b) in a carrier oil. The concentrate may be present in e.g. 20-75%w in mineral lubricating oil as carrier oil.
(a) and/or (b). Other additives may also be used, such as antioxidants, detergents, other VI improvers, corrosion inhibitors, extreme pressure agents, antifoaming agents, and the like. The invention is illustrated by the following examples. The additive according to the invention was tested in various hydrocracked base oils. Base Oil 1: Hydrocracked lubricating oil with a pour point of -15°C and a VI of 149. Base oil 2: Base oil 1 + commercially available gasoline engine oil additive package. Base oil 3: 88% w Base oil 1 + 12% w Hydrogenated Bright Stock (VI of 95) (mixture
VI is 144). Base oil 4: Package of base oil 3 + base oil 2. Base Oil 5: 89% w Base Oil 1 + 11% w Commercial diesel engine oil additive package containing the above hydrogenated bright stock + VI improver (hydrogenated styrene/isoprene block copolymer). Additives _a1 : branched and unbranched (weight ratio 15:85) synthetic _C12-15 - alcohols (20% _wC12 , 30%
_PolyC12-15 -alkyl methacrylate derived from _wC13 , 30% _wC14 and 20% _wC15 ).
n=1.35×10 ⁵ ; w=5.35×10 ⁵ ; Q=4.0. Additive _A2 : Random copolymer of 92.3% _wC12-15 -alkyl methacrylate (see Additive _A1 ) and 7.1% w2-vinylpyridine. w=63000;
n=223000; Q=2.8. Additive _A3 : 98.0% wC _12-15 -alkyl methacrylate (see Additive A ₁ ), 0.9% wC _9-11 -Alkyl methacrylate (see Additive B ₁ ) and 1.1%
wC _16-18 - alkyl methacrylate (additive b ₁
(see) copolymers. w=310000;n=
93700; Q=3.3. Additive b ₁ : 43.5% w branched and unbranched (weight ratio
15:85) Synthesis C _9-11 - Alcohols (20%
wC ₉ , 50% wC ₁₀ and 30% wC ₁₁ ), 10.0%
wC _12-15 - alcohols (see additive a ₁ ) and 44.5% w natural _{C 16/18} - alcohols (30%
Poly derived from wC ₁₆ and 58% wC ₁₈ )
C _9-18 -alkyl methacrylate. w=
420000; n=55000; Q=7.7. Additive b ₂ : Same composition as additive b ₁ but n=
21200;w=46500;Q2.2. Example (base oil 1)

【table】 Example (Base oil 2)

【table】

【table】

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Claims (1)

Claims: 1 Hydrocracked lubricating oil as a base oil and (a) having improved properties, with more than 75%w of the alkyl chains having 12-15 C-atoms, and having by weight Oil-soluble polyalkyl acrylate or polyalkyl methacrylate with an average molecular weight of 10 ³ −10 ⁶ is used.
0.001-20% w and (b) pour point depressing properties, with at most 75 alkyl chains.
Oil-soluble polyalkyls having %w of 12-15 C atoms and 10-90%w of the alkyl chains having at least 16 carbon atoms and a weight average molecular weight of 10 ³ -10 ⁶ A lubricating oil composition containing 0.001-5% w of acrylate or polyalkyl methacrylate. 2. The composition of claim 1, wherein the hydrocracked base oil has a viscosity index of at least 120. 3. A composition according to claim 1, wherein additive (a) is a branched and unbranched polyalkyl methacrylate having 12-15 carbon atoms. 4 Additives (a) and/or (b) contain at most 10
A composition according to claim 1, which is derived from monomers containing %w polar groups. 5. A composition according to claim 1, wherein additive (b) is a polyalkyl methacrylate having at least 6 different alkyl groups having 9 to 18 carbon atoms. 6. Additive (b) is a polyalkyl methacrylate in which the alkyl groups are branched and unbranched and alcohols with 9-15 carbon atoms and 16
and claim 1 or 5 derived from a straight chain alcohol having 18 carbon atoms.
Compositions as described in Section. 7. Claim 6 in which the alkyl group containing 9-15 carbon atoms has 5-25%w branching
Compositions as described in Section. 8. The composition according to claim 1, wherein the ratio of weight average molecular weight to number average molecular weight (Q-factor) of additives (a) and (b) is from 1.5 to 5.