Compositions and process for use in refrigeration

• US 5,017,300 A
• Filed: 08/03/1989
• Issued: 05/21/1991
• Est. Priority Date: 08/03/1989
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Raynolds, Stuart
• Primary Examiner(s): Willis, Prince E.
• Assistant Examiner(s): McAvoy, E.
• Application Number:
  US07/388,922
• Time in Patent Office: 656 Days
• Field of Search: 252/58, 252/68, 252/67
• US Class Current: 252/67
• CPC Class Codes: C09K 2205/24 Only one single fluoro component present
• CPC Class Codes: C09K 5/045 containing only fluorine as halogen
• CPC Class Codes: C10M 107/28 containing monomers having an unsaturated radical bound to a carboxyl radical, e.g. acrylate
• CPC Class Codes: C10M 171/008 Lubricant compositions compatible with refrigerants
• CPC Class Codes: C10M 2209/0845 used as base material

Abstract

A blend of tetrafluoroethane refrigerant with at least one polymer of the following: (a) an acrylic polymer having the formula ##STR1## where R is at least one alkyl group selected from CH₃, C₂ H₅, C₃ H₇ and C₄ H₉ ; and

x is an integer from 3 to 20;

and (b) random copolymers from at least one alkyl acrylate monomer wherein the alkyl group may be anywhere from CH₃ -- to C₁₈ H₃₇ -- provided that the average chain length of the alkyl groups in a major portion of said copolymer contains from 1 to 4 carbon atoms, and, optionally, with at least one other polar or nonpolar vinyl monomer said polymer (homopolymer or copolymer) having an SUS viscosity at 100° F. of at least 50 and a pour point of less than -20° C. is disclosed for use in compression refrigeration.

Claims

1. A composition for use in compression refrigeration comprising:

(a) a saturated hydrocarbon selected from the group consisting of 1,1,1,2-tetrafluoroethane, 1,1,2,2,-tetrafluoroethane and pentafluoroethane; and

(b) sufficient amount to provide lubrication of at least one polymer selected from the following;

(1) an acrylic polymer having the formula ##STR8## where R is at least one alkyl group selected from CH.sub. 3, C.sub. 2H.sub. 5, C.sub. 3H.sub. 7 and C.sub. 4H.sub. 9, and x is an integer from 3 to 20; and

(2) a copolymer of at least one alkyl acrylate monomer having the formula ##STR9## wherein R.sup. 1 may be anywhere from CH.sub. 3--to C.sub. 18H.sub. 37--, provided that the average chain length of the alkyl groups in a major portion of said polymer contains from 1 to 4 carbon atoms, with at least one other vinyl monomer;

said polymer or copolymer having a SUS viscosity at 100°

F. of at least 50.

2. The composition of claim 1 wherein component (a) is 1,1,1,2-tetrafluoroethane.

3. The composition of claim 1 wherein component (b) is at least one homopolymer selected from the group consisting of poly(methyl acrylate), poly(ethyl acrylate), poly(propyl acrylate) or poly(butyl acrylate), wherein x in formula (b 1) is about 3 to 12.

4. The composition of claim 3 where component (b) is a poly(ethyl acrylate).

5. The composition of claim 3 where component (b) is poly(methyl acrylate).

6. The composition of claim 3 where component (b) is poly(propyl acrylate).

7. The composition of claim 3 where (b) is poly(butyl acrylate).

8. The composition of claim 1 wherein component (b) is a copolymer of methyl acrylate, ethyl acrylate, propyl acrylate or butyl acrylate with ##STR10## wherein R_f is a perfluoroalkyl group from CF.sub. 3--to C.sub. 20F.sub. 41--and n is an integer from 1 to 4.

9. The composition of claim 8 wherein R_f comprises 60% C.sub. 6F.sub. 13--,30% C.sub. 8F.sub. 17--and about 10% C.sub. 10F.sub. 21--and higher and wherein n=2.

10. The composition of claim 8 wherein said copolymer is a copolymer of 75-92% by weight of n-butyl acrylate, n-propyl acrylate methyl acrylate or ethyl acrylate.

11. In a method for compression refrigeration wherein, in combination with a lubricant, a saturated hydrocarbon selected from the group consisting of 1,1,1,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane and pentafluoroethane is used as the refrigerant;

the improvement which comprises using as the lubricant about 10-50% by volume in the combination with said refrigerant of at least one polymer selected from the following

(1) an acrylic polymer having the formula ##STR11## where R is at least one alkyl group selected from CH.sub. 3, C.sub. 2H.sub. 5, C.sub. 3H.sub. 7and C.sub. 4H.sub. 9, and x is an integer from 3 to 20;

(2) a random copolymer from at least one alkyl acrylate monomer having the formula ##STR12## wherein R.sup. 1 may be anywhere from CH.sub. 3--to C.sub. 18H.sub. 37--, provided that the average chain length of the alkyl groups in a major portion of said polymer contains from 1 to 4 carbon atoms; and

(3) a copolymer of at least one alkyl acrylate monomer having the formula ##STR13## wherein R.sup. 1 may be anywhere from CH.sub. 3--to C.sub. 18H.sub. 37--, provided that the average chain length of the alkyl groups in a major portion of said copolymer contains from 1 to 4 carbon atoms, with at least one other vinyl monomer;

said polymer or copolymer having an SUB viscosity of 100°

F. of at least 50 .