Lubricating oil
View Patent ↗A lubricating oil suitable for use in α-olefin compressors and a high-pressure ethylene polymerization process is disclosed. The oil comprises a base fluid and a hindered C 6 -C 30 alkyl 4-hydroxybenzoate. The hindered C 6 -C 30 alkyl 4-hydroxybenzoate stabilizes the lubricating oil and does not interfere with the high-pressure α-olefin polymerization.
1. A lubricating oil, suitable for use in α-olefin compressors, said oil comprising a base fluid and a hindered C 6 -C 30 alkyl 4-hydroxybenzoate wherein the base fluid is selected from the group consisting of mineral oil, synthetic oil, and mixtures thereof and wherein the hindered C 6 -C 30 alkyl 4-hydroxybenzoate has the structure:
wherein R is C 6 -C 30 alkyl.
2. The lubricating oil of claim 1 wherein the base fluid is a white mineral oil.
3. The lubricating oil of claim 1 wherein R is C 16 alkyl.
4. The lubricating oil of claim 3 wherein R is n-hexadecyl.
5. The lubricating oil of claim 1 comprising 0.01 to 1.0% by weight of the hindered C 6 -C 30 alkyl 4-hydroxybenzoate.
6. The lubricating oil of claim 1 further comprising 50 to 3000 ppm of a second antioxidant.
7. A process comprising: (a) compressing ethylene in a cylinder with the lubricating oil of claim 1 ; (b) transferring the compressed ethylene to a reactor; and (3) polymerizing the ethylene at a pressure exceeding 70 MPa.