Viscosity index improver, refrigerator oil, and working fluid composition for refrigerators

Patent metadata

Field	Value
Publication number	US-12552889-B2
Application number	US-202218571504-A
Country	US
Kind code	B2
Filing date	Jun 14, 2022
Priority date	Jun 21, 2021
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

The present invention relates to a viscosity index improver containing a copolymer (A) that contains, as essential constituent monomers, a fluorine atom-containing monomer (a) represented by the following formula (1) and a monomer (b) represented by the following formula (2),
wherein the copolymer (A) has a solubility parameter of 8.1 to 10.0 (cal/cm 3 ) 1/2 , and a mass ratio (b/a) of the monomer (b) to the monomer (a) in the monomers constituting the copolymer (A) is 0.01 to 42:

wherein R 1 represents a hydrogen atom or a methyl group; R 2 is a C2-C4 alkylene group; p is an integer of 0 or 1; q is an integer from 0 to 20, each R 2 may be the same as or different from each other when q is 2 or greater; and Y is a monovalent group in which one or more or all of hydrogen atoms in a C1-C40 hydrocarbon group are replaced by fluorine atoms, and

wherein R 3 represents a hydrogen atom or a methyl group; —X 1 — is a group represented by —O— or —NH—; R 4 is a C2-C4 alkylene group; r is an integer of 0 or 1; s is an integer from 0 to 20, and each R 4 may be the same as or different from each other when s is 2 or greater; and R 5 is a C1-C40 hydrocarbon group.

First claim

The invention claimed is:

1 . A viscosity index improver working fluid composition for refrigerating machines, comprising a viscosity index improver and a refrigerant, wherein the viscosity index improver comprises:
a copolymer (A) that contains, as essential constituent monomers, a fluorine atom-containing monomer (a) represented by the following formula (1) and a monomer (b) represented by the following formula (2), and an oxygen atom-containing base oil (B), wherein the copolymer (A) has a solubility parameter of 8.1 to 10.0 (cal/cm 3 )/2, and a mass ratio (b/a) of the monomer (b) to the monomer (a) in the monomers constituting the copolymer (A) is 0.01 to 42, and a mass ratio (A/B) of the copolymer (A) and the oxygen atom-containing base oil (B) is 99/1 to 1/99:

wherein R 1 represents a hydrogen atom or a methyl group; R 2 is a C2-C4 alkylene group; p is an integer of 0 or 1; q is an integer from 0 to 20, each R 2 may be the same as or different from each other when q is 2 or greater; and Y is a monovalent group in which one or more or all of hydrogen atoms in a C1-C40 hydrocarbon group are replaced by fluorine atoms, and

wherein R 3 represents a hydrogen atom or a methyl group; —X 1 — is a group represented by —O— or —NH—; R 4 is a C2-C4 alkylene group; r is an integer of 0 or 1; s is an integer from 0 to 20, and each R 4 may be the same as or different from each other when s is 2 or greater; and R 5 is a C1-C40 hydrocarbon group.

2 . The working fluid composition according to claim 1 ,
wherein a constituent unit derived from the monomer (a) has a solubility parameter of 6.5 to 9.0 (cal/cm 3 ) 1/2 .

3 . The working fluid composition according to claim 1 ,
wherein the copolymer (A) has a weight-average molecular weight of 1,000 to 2,000,000.

4 . The viscosity index improver working fluid composition according to claim 1 ,
wherein the oxygen atom-containing base oil (B) is at least one selected from the group consisting of an ester oil (B1), a polyvinyl ether (B2), and a polyalkylene glycol (B3).

5 . A working fluid composition for refrigerating machines, comprising a refrigerating machine oil and a refrigerant,
wherein the refrigerating machine oil comprises: a lubricant base oil; and a viscosity index improver, wherein the lubricant base oil is an oxygen atom-containing base oil (B), wherein the viscosity index improver comprises: a copolymer (A) that contains, as essential constituent monomers, a fluorine atom- containing monomer (a) represented by the following formula (1) and a monomer (b) represented by the following formula (2):

wherein R 1 represents a hydrogen atom or a methyl group; R 2 is a C2-C4 alkylene group; p is an integer of 0 or 1; q is an integer from 0 to 20, each R 2 may be the same as or different from each other when q is 2 or greater; and Y is a monovalent group in which one or more or all of hydrogen atoms in a C1-C40 hydrocarbon group are replaced by fluorine atoms, and

wherein R 3 represents a hydrogen atom or a methyl group; —X 1 — is a group represented by —O— or —NH—; R 4 is a C2-C4 alkylene group; r is an integer of 0 or 1; s is an integer from 0 to 20, and each R 4 may be the same as or different from each other when s is 2 or greater; and R 5 is a C1-C40 hydrocarbon group,
wherein the copolymer (A) has a solubility parameter of 8.1 to 10.0 (cal/cm 3 ) 1/2 ,
a mass ratio (b/a) of the monomer (b) to the monomer (a) in the monomers constituting the copolymer (A) is 0.01 to 42, and
the content of the copolymer (A) is 1 to 20 mass % based on the total amount of the refrigerating machine oil.

6 . The working fluid composition according to claim 5 ,
wherein the oxygen atom-containing base oil (B) is at least one selected from the group consisting of an ester oil (B1), a polyvinyl ether (B2), and a polyalkylene glycol (B3).

7 . The working fluid composition according to claim 5 ,
wherein an absolute value of a difference between a solubility parameter of the copolymer (A) and a solubility parameter of the oxygen atom-containing base oil (B) is 2.0 (cal/cm 3 ) 1/2 or less.

8 . The working fluid composition according to claim 5 ,
wherein the oxygen atom-containing base oil (B) has a solubility parameter of 8.0 to 10.0 (cal/cm 3 ) 1/2 .

9 . The working fluid composition for refrigerating machines according to claim 1 ,
wherein the refrigerant is at least one refrigerant selected from the group consisting of a saturated fluorinated hydrocarbon refrigerant, an unsaturated fluorinated hydrocarbon refrigerant, and a natural refrigerant, or a mixed refrigerant of two or more of these refrigerants.

10 . The working fluid composition according to claim 1 ,
wherein an absolute value of a difference between a solubility parameter of the copolymer (A) and a solubility parameter of the oxygen atom-containing base oil (B) is 2.0 (cal/cm 3 ) 1/2 or less.

11 . The working fluid composition according to claim 5 ,
wherein a constituent unit derived from the monomer (a) has a solubility parameter of 6.5 to 9.0 (cal/cm 3 ) 1/2 .

12 . The working fluid composition according to claim 5 ,
wherein the copolymer (A) has a weight-average molecular weight of 1,000 to 2,000,000.

13 . The working fluid composition for refrigerating machines according to claim 5 ,
wherein the refrigerant is at least one refrigerant selected from the group consisting of a saturated fluorinated hydrocarbon refrigerant, an unsaturated fluorinated hydrocarbon refrigerant, and a natural refrigerant, or a mixed refrigerant of two or more of these refrigerants.

Assignees

• Sanyo Chemical Ind Ltd
• Eneos Corp

Inventors

• Ogata Kazuki
• Sugiyama Yoshimitsu
• Torii Naohiro
• Goto Satoshi
• MIZUTANI Yuya
• Ogata Hidetoshi
• Seki Yuma
• Nakajima Tatsuki

Classifications

• C10M2213/04

  obtained from monomers containing carbon, hydrogen, halogen and oxygen · CPC title

• C10M171/008

  Lubricant compositions compatible with refrigerants · CPC title

• C10M147/04 Primary

  Monomer containing carbon, hydrogen, halogen and oxygen · CPC title

• C09K5/04 Primary

  the change of state being from liquid to vapour or vice versa · CPC title

• C08F220/24 Primary

  containing perhaloalkyl radicals · CPC title