EP0694140A1 - Hose for refrigerating systems - Google Patents

Hose for refrigerating systems

Info

Publication number
EP0694140A1
EP0694140A1 EP94902501A EP94902501A EP0694140A1 EP 0694140 A1 EP0694140 A1 EP 0694140A1 EP 94902501 A EP94902501 A EP 94902501A EP 94902501 A EP94902501 A EP 94902501A EP 0694140 A1 EP0694140 A1 EP 0694140A1
Authority
EP
European Patent Office
Prior art keywords
peripheral wall
nylon
hose
butyl rubber
hose according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94902501A
Other languages
German (de)
French (fr)
Other versions
EP0694140A4 (en
Inventor
Timothy S. Dickerson
Roger A. Cassell
Brian J. Walsh
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eaton Aeroquip LLC
Original Assignee
Aeroquip Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aeroquip Corp filed Critical Aeroquip Corp
Publication of EP0694140A1 publication Critical patent/EP0694140A1/en
Publication of EP0694140A4 publication Critical patent/EP0694140A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L11/00—Hoses, i.e. flexible pipes
    • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
    • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
    • F16L11/085—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more braided layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
    • B60H1/00—Heating, cooling or ventilating [HVAC] devices
    • B60H1/00507—Details, e.g. mounting arrangements, desaeration devices
    • B60H1/00557—Details of ducts or cables
    • B60H1/00571—Details of ducts or cables of liquid ducts, e.g. for coolant liquids or refrigerants

Definitions

  • This invention relates to hoses for transporting or otherwise handling refrigerants. More specifically, this invention relates to improved inner tubes and outer covers for these hoses.
  • Prior hoses of this type comprise an inner tube and an outer cover, the inner tube being made up of a polymeric inner wall and a rubbery outer peripheral wall.
  • Certain polymeric materials are known which render the hose highly resistant to refrigeration gases. These materials include polyamides such as nylon-6, nylon-6/66, nylon-1 1 , nylon-12 and the like. Many nylons, however, produce inner walls which are very stiff and not very flexible. Flexibility is highly desirable, particularly in automotive applications for ease of routing and damping of noise transmission. Attempts to modify the nylons through the use of traditional plasticizers such as oils or excess monomer to provide more flexible inner walls have resulted in hoses with higher gas permeability. In addition, normal A/C system use can cause these plasticizers to be extracted from the nylon, stiffening the hose and potentially contaminating the refrigeration system. Normal A/C systems often see temperatures in excess of 200°F. DISCLOSURE OF THE INVENTION
  • the hose has an inner tube with improved flexibility while maintaining low gas permeability without the use of extractable plasticizers.
  • the inner tube includes a resinous inner peripheral wall and a rubbery outer peripheral wall, wherein the resinous inner peripheral wall consisting essentially of nylon and a non-extractable elastomeric plasticizer, and wherein the rubbery outer peripheral wall is a butyl rubber or a halogenated butyl rubber.
  • the non-extractable elastomer plasticized inner wall has numerous positive attributes over traditional plasticized nylons, however, permeability is essentially equivalent.
  • a hose with improved permeation resistance is achieved effectively obtaining all desirable properties in a single hose.
  • the hose also has a reinforcing layer laminated over the outer peripheral wall, and an outer cover laminated over the reinforcing layer.
  • the outer cover is a halogenated butyl rubber.
  • the resinous inner wall has an increased nylon content relative to the elastomeric plasticizer content.
  • the discharge hoses have a smaller diameter than hoses on the low pressure, suction side.
  • the resulting hoses in both embodiments are more flexible with lower gas impermeability.
  • the hoses also have better refrigerant oil resistance, favorable inner wall characteristics, high temperature resistance and maintain their flexibility after prolonged use.
  • Traditional walls have negative swell; i.e., they shrink or decrease in size. Shrinking may contribute to leakage.
  • Our development provides a positive swell and actually creates a tighter, more leak proof seal.
  • Fig. 1 is a perspective view, partly cut away, illustrating a hose according to our invention.
  • Hose 10 is a multi-layered structure which comprises inner tube 20, outer cover 40 and reinforcing layer 30 disposed therebetween.
  • Inner tube 20 includes resinous inner peripheral wall 21 and rubbery outer peripheral wall 22.
  • Inner wall 21 of inner tube 20 is made of the combination of nylon and a non-extractable elastomeric plasticizer, preferably grafted ethylene-propylene-diene rubber (EPDM).
  • the nylon can vary widely and comes from the family of polyamide polymers characterized by the amide radical: -CONH. By far, the most common nylons are nylon 66 and nylon 6.
  • Nylon 66 is a condensation product of adipic acid and hexamethylenediamine.
  • Nylon 6 is a polymer of caprolactam.
  • Nylon 4 is based on butyl-rolactam (2-pyrrolidone).
  • Nylon 1 1 is the self-condensation product of aminoundecanoic acid and nylon 12 is made from butadiene.
  • inner wall 21 is made from a mix of nylon 66 and grafted EPDM.
  • rubbery outer wall 22 of inner tube 20 is made of butyl rubber or halogenated butyl rubber.
  • the butyl rubbers can vary widely. Generally, they are a copolymer of isobutylene and small amounts of a diolefin.
  • a typical butyl rubber is made from isobutylene and isoprene (II R). Typically, the II R copolymer contains 3% isoprene.
  • a typical halogenated butyl rubber is chlorinated butyl rubber (Cl-ll R). In the preferred embodiment of this invention, we use butyl rubber (II R).
  • the resinous inner peripheral wall consisting essentially of 24 to 80 percent by weight nylon and 10 to 60 percent by weight elastomeric plasticizer. Materials for the inner wall are described in U.S. Patent No. 5,091 ,478 which is herein incorporated by reference.
  • the preferred halogenated butyl rubber for outer cover 40 is chlorinated butyl rubber.
  • hose according to the invention may be fabricated by any suitable known methods.
  • One such method involves passing a release-treated mandrel through an extruder equipped with heads from which resins are extruded peripherally on the mandrel and thus form an inner wall.
  • the mandrel is allowed to successively enter a rubber extruder at which time an outer wall of rubbery material is laminated over the plastic wall.
  • a layer of reinforcement is laminated by braiding suitable textile yarns over the outer rubbery wall of the inner tube.
  • An outer cover is disposed outwardly about the braided layer by extrusion of the rubbery material.
  • Braided layer 30 may be made from any number if fibers including glass fibers, polyester fibers, nylon, graphite, rayon and polyamide fibers (Kevlar). We prefer that braided layer 30 be made of polyester fibers.
  • the hoses we tested had an inside diameter, typically 8 to 16 mm.
  • the inner tube was made of 60 to 80 percent by weight nylon
  • the reinforcing layer was braided polyester and the outer cover was chlorinated butyl rubber.
  • the hoses we tested are Type E hoses under SAE J2064.
  • the refrigerant we used was Refrigerant 134A.
  • the gas permeations we measured under SAE J2064 ranged from 0.25 to 0.75 lbs/ft 2 /yr.
  • the material of the inner wall of the hoses of this Example have a flex modulus under ASTM D 790-86 of less than, 100,000 psi.
  • unplasticized nylon typically has a flex modulus ranging from 50,000 psi to 100,000 psi.
  • unplasticized nylon is very stiff and has a flex modulus of 250,000 psi.
  • Conventional oil plasticized nylon 66 have a stiffness of 100,000 to 125,000 psi. Oil, however, extracts from the conventional oil plasticized nylons at usual operating temperature in excess of 200°F.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)
  • Laminated Bodies (AREA)

Abstract

Our development provides a hose (10) suitable for use in transporting refrigerants. The hose has an inner tube (20) with improved flexibility while maintaining low gas permeability without the use of extractable plasticizers. The inner tube includes an inner wall (21) and a rubbery outer wall (22), wherein the inner wall is nylon and a non-extractable elastomeric plasticizer, and the rubbery outer wall is a butyl rubber. The hose also has an outer wall (40) made of a rubber such as chlorinated butyl rubber.

Description

DESCRIPTION
HOSE FOR REFRIGERATING SYSTEMS
TECHNICAL FIELD This invention relates to hoses for transporting or otherwise handling refrigerants. More specifically, this invention relates to improved inner tubes and outer covers for these hoses.
BACKGROUND ART Prior hoses of this type comprise an inner tube and an outer cover, the inner tube being made up of a polymeric inner wall and a rubbery outer peripheral wall. Certain polymeric materials are known which render the hose highly resistant to refrigeration gases. These materials include polyamides such as nylon-6, nylon-6/66, nylon-1 1 , nylon-12 and the like Many nylons, however, produce inner walls which are very stiff and not very flexible. Flexibility is highly desirable, particularly in automotive applications for ease of routing and damping of noise transmission. Attempts to modify the nylons through the use of traditional plasticizers such as oils or excess monomer to provide more flexible inner walls have resulted in hoses with higher gas permeability. In addition, normal A/C system use can cause these plasticizers to be extracted from the nylon, stiffening the hose and potentially contaminating the refrigeration system. Normal A/C systems often see temperatures in excess of 200°F. DISCLOSURE OF THE INVENTION
Our development provides a hose suitable for use in transporting refrigerants. The hose has an inner tube with improved flexibility while maintaining low gas permeability without the use of extractable plasticizers. The inner tube includes a resinous inner peripheral wall and a rubbery outer peripheral wall, wherein the resinous inner peripheral wall consisting essentially of nylon and a non-extractable elastomeric plasticizer, and wherein the rubbery outer peripheral wall is a butyl rubber or a halogenated butyl rubber. The non-extractable elastomer plasticized inner wall has numerous positive attributes over traditional plasticized nylons, however, permeability is essentially equivalent. By combining, however, with a butyl or halobutyl outer wall, a hose with improved permeation resistance is achieved effectively obtaining all desirable properties in a single hose. The hose also has a reinforcing layer laminated over the outer peripheral wall, and an outer cover laminated over the reinforcing layer. In one preferred embodiment, the outer cover is a halogenated butyl rubber.
In another preferred embodiment, the resinous inner wall has an increased nylon content relative to the elastomeric plasticizer content. We prefer this embodiment in hoses on the low or discharge side of a compressor where the refrigeration gases are under high pressure and permeate more readily due to higher temperatures. Typically, the discharge hoses have a smaller diameter than hoses on the low pressure, suction side.
The resulting hoses in both embodiments are more flexible with lower gas impermeability. The hoses also have better refrigerant oil resistance, favorable inner wall characteristics, high temperature resistance and maintain their flexibility after prolonged use. Traditional walls have negative swell; i.e., they shrink or decrease in size. Shrinking may contribute to leakage. Our development provides a positive swell and actually creates a tighter, more leak proof seal. BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 is a perspective view, partly cut away, illustrating a hose according to our invention.
BEST MODE OF CARRYING OUT INVENTION
Referring now to Fig. 1 , we show hose 10 according to this invention. Hose 10 is a multi-layered structure which comprises inner tube 20, outer cover 40 and reinforcing layer 30 disposed therebetween. Inner tube 20 includes resinous inner peripheral wall 21 and rubbery outer peripheral wall 22.
Inner wall 21 of inner tube 20 is made of the combination of nylon and a non-extractable elastomeric plasticizer, preferably grafted ethylene-propylene-diene rubber (EPDM). The nylon can vary widely and comes from the family of polyamide polymers characterized by the amide radical: -CONH. By far, the most common nylons are nylon 66 and nylon 6. Nylon 66 is a condensation product of adipic acid and hexamethylenediamine. Nylon 6 is a polymer of caprolactam. Nylon 4 is based on butyl-rolactam (2-pyrrolidone). Nylon 1 1 is the self-condensation product of aminoundecanoic acid and nylon 12 is made from butadiene.
Preferably, inner wall 21 is made from a mix of nylon 66 and grafted EPDM.
Another key to our invention is that rubbery outer wall 22 of inner tube 20 is made of butyl rubber or halogenated butyl rubber. The butyl rubbers can vary widely. Generally, they are a copolymer of isobutylene and small amounts of a diolefin. A typical butyl rubber is made from isobutylene and isoprene (II R). Typically, the II R copolymer contains 3% isoprene. A typical halogenated butyl rubber is chlorinated butyl rubber (Cl-ll R). In the preferred embodiment of this invention, we use butyl rubber (II R). In one preferred embodiment the resinous inner peripheral wall consisting essentially of 24 to 80 percent by weight nylon and 10 to 60 percent by weight elastomeric plasticizer. Materials for the inner wall are described in U.S. Patent No. 5,091 ,478 which is herein incorporated by reference. The preferred halogenated butyl rubber for outer cover 40 is chlorinated butyl rubber.
To attain firm lamination of the inner tube, suitable bonding adhesives may be applied between the peripheral walls, thereby rendering the resulting hose mechanically strong and durable. The hose according to the invention may be fabricated by any suitable known methods. One such method involves passing a release-treated mandrel through an extruder equipped with heads from which resins are extruded peripherally on the mandrel and thus form an inner wall. The mandrel is allowed to successively enter a rubber extruder at which time an outer wall of rubbery material is laminated over the plastic wall.
A layer of reinforcement is laminated by braiding suitable textile yarns over the outer rubbery wall of the inner tube. An outer cover is disposed outwardly about the braided layer by extrusion of the rubbery material.
The resulting hose body is vulcanized under pressure at elevated temperatures, and subsequently cooled. The mandrel is afterwards pulled out of the vulcanized hose body, whereby a desired hose product is obtained. Braided layer 30 may be made from any number if fibers including glass fibers, polyester fibers, nylon, graphite, rayon and polyamide fibers (Kevlar). We prefer that braided layer 30 be made of polyester fibers. Example
We prepared different hoses according to this invention. Tests were conducted on gas permeability under SAE J2064 and flex modulus under ASTM D790.
The hoses we tested had an inside diameter, typically 8 to 16 mm. The inner tube was made of 60 to 80 percent by weight nylon
66 and 20 to 40 percent by weight grafted-EPDM. The reinforcing layer was braided polyester and the outer cover was chlorinated butyl rubber.
The hoses we tested are Type E hoses under SAE J2064. The refrigerant we used was Refrigerant 134A. The gas permeations we measured under SAE J2064 ranged from 0.25 to 0.75 lbs/ft2/yr.
Acceptable gas permeations under the SAE spec allow for a maximum of 2.0 lbs/ft2/yr.
The material of the inner wall of the hoses of this Example have a flex modulus under ASTM D 790-86 of less than, 100,000 psi.
Typically they have a flex modulus ranging from 50,000 psi to 100,000 psi. Typically, unplasticized nylon is very stiff and has a flex modulus of 250,000 psi. Conventional oil plasticized nylon 66 have a stiffness of 100,000 to 125,000 psi. Oil, however, extracts from the conventional oil plasticized nylons at usual operating temperature in excess of 200°F.

Claims

CLAIMS:
1. A hose suitable for use in transporting refrigerants comprising
(a) an inner tube including a resinous inner peripheral wall and a rubbery outer peripheral wall, wherein the resinous inner peripheral wall consisting essentially of nylon and a non-extractable elastomeric plasticizer, and wherein the rubbery outer peripheral wall is a butyl rubber or a halogenated butyl rubber,
(b) a reinforcing layer laminated over said outer peripheral wall, and
(c) an outer cover laminated over said reinforcing layer wherein the outer cover is a halogenated butyl rubber.
2. A hose according to claim 1 wherein the hose has improved flexibility and high gas impermeability.
3. A hose according to claim 1 wherein the non-extractable plasticizer is grafted ethylene-propylene-diene rubber (EPDM).
4. A hose according to claim 1 wherein the nylon is nylon
66.
5. A hose according to claim 1 wherein the outer cover chlorinated butyl rubber.
6. A hose according to claim 1 wherein the resinous inner peripheral wall consisting essentially of 25 to 80 percent by weight nylon and 10 to 60 percent by weight plasticizer.
7. A hose according to claim 1 wherein the resinous inner peripheral wall consisting essentially of 60 to 80 percent by weight nylon and 20 to 40 percent by weight of a non-extractable elastomeric plasticizer.
8. A hose suitable for use in transporting refrigerants comprising
(a) an inner tube including a resinous inner peripheral wall and a rubbery outer peripheral wall, wherein the resinous inner peripheral wall consisting essentially of 25 to 80 percent by weight nylon and 10 to 60 percent by weight of a non-extractable elastomeric plasticizer, and wherein the rubbery outer peripheral wall is a butyl rubber or a halogenated butyl rubber,
(b) a reinforcing layer laminated over said outer peripheral wall, and (c) an outer cover laminated over said reinforcing layer.
9. A hose according to claim 8 wherein the inner tube (a) has improved flexibility and high gas impermeability.
10. A hose according to claim 8 wherein the non-extractable plasticizer is grafted ethylene-propylene-diene rubber (EPDM).
1 1 . A hose according to claim 8 wherein the outer cover is halogenated butyl rubber.
12. A hose according to claim 8 wherein the outer cover is chlorinated butyl rubber.
13. A hose according to claim 8 wherein the nylon is nylon 66.
14. A hose according to claim 8 wherein the resinous inner peripheral wall consisting essentially of 60 to 80 percent by weight nylon and 20 to 40 percent by weight of a non-extractable plasticizer.
EP94902501A 1993-02-26 1993-12-03 Hose for refrigerating systems Withdrawn EP0694140A4 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US2368893A 1993-02-26 1993-02-26
US23688 1993-02-26
PCT/US1993/011772 WO1994019638A1 (en) 1993-02-26 1993-12-03 Hose for refrigerating systems

Publications (2)

Publication Number Publication Date
EP0694140A1 true EP0694140A1 (en) 1996-01-31
EP0694140A4 EP0694140A4 (en) 1996-07-10

Family

ID=21816618

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94902501A Withdrawn EP0694140A4 (en) 1993-02-26 1993-12-03 Hose for refrigerating systems

Country Status (7)

Country Link
EP (1) EP0694140A4 (en)
JP (1) JPH08507351A (en)
CN (1) CN1098772A (en)
AU (1) AU5685594A (en)
BR (1) BR9307818A (en)
MX (1) MX9401026A (en)
WO (1) WO1994019638A1 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1296416B1 (en) 1997-11-21 1999-06-25 Transfer Oil S P A FLEXIBLE HOSE FOR TRANSPORT OF REFRIGERANT GAS FOR REFRIGERATION AND AIR CONDITIONING SYSTEMS.
FR2781720B1 (en) * 1998-07-31 2000-10-13 Hutchinson THERMOPLASTIC-ELASTOMER COMPOSITE PRODUCT, SUCH AS A REFRIGERANT PIPE FOR AIR CONDITIONING CIRCUIT
FR2857733B1 (en) 2003-07-15 2006-10-20 Hutchinson TUBULAR ELEMENT FOR AIR CONDITIONING CIRCUIT.
ITMI20040155A1 (en) * 2004-02-02 2004-05-02 Parker Hannifin S P A Fluid Co IMPROVED AIR CONDITIONING OR REFRIGERATION SYSTEM AND RELATED CONNECTION PIPE
CN2835759Y (en) * 2005-07-04 2006-11-08 朱均琦 Water pipe
FR2891490B1 (en) * 2005-09-30 2007-11-23 Arkema Sa MULTILAYER STRUCTURE BASED ON RUBBER AND COPOLYMER GRAFT WITH POLYAMIDE BLOCKS, AND ITS USE AS TUBES FOR AIR CONDITIONING CIRCUITS.
CN100498033C (en) * 2006-03-28 2009-06-10 东海橡胶工业株式会社 Resin composite fuel hose
EP2194304A1 (en) * 2008-12-02 2010-06-09 M.B.M. S.r.l. Reinforced sheath for domestic gas pipe
CN101776189A (en) * 2010-04-06 2010-07-14 文谟统 FTPV flexible fluoride air-conditioning pipe for delivery of novel environment-protecting refrigerant
CN103423526A (en) * 2013-07-28 2013-12-04 江苏国农泵业有限公司 Plastic-coated hose easy to pull and resistant to abrasion
IT201700040935A1 (en) * 2017-04-12 2018-10-12 Techinit S R L FLEXIBLE PIPE FOR USE IN THE TRANSPORT OF FRIGORIGEN GAS

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3914011A1 (en) * 1988-04-25 1989-11-02 Yokohama Rubber Co Ltd METHOD FOR PRODUCING A HOSE
US4905734A (en) * 1987-11-28 1990-03-06 Tokai Rubber Industries, Ltd. Refrigerant transporting hose
US5016675A (en) * 1988-10-18 1991-05-21 Tokai Rubber Industries, Ltd. Refrigerant transporting hose

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5091478A (en) * 1986-11-14 1992-02-25 E. I. Du Pont De Nemours And Company Partially grafted thermoplastic compositions
EP0294181B1 (en) * 1987-06-01 1994-01-26 The Yokohama Rubber Co., Ltd. Hose construction
US5156699A (en) * 1987-10-23 1992-10-20 Nishirin Rubber Industrial Co., Ltd. Process for producing a hybrid flexible hose
JPH01141047A (en) * 1987-11-28 1989-06-02 Tokai Rubber Ind Ltd Refrigerant transport hose

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4905734A (en) * 1987-11-28 1990-03-06 Tokai Rubber Industries, Ltd. Refrigerant transporting hose
DE3914011A1 (en) * 1988-04-25 1989-11-02 Yokohama Rubber Co Ltd METHOD FOR PRODUCING A HOSE
US5016675A (en) * 1988-10-18 1991-05-21 Tokai Rubber Industries, Ltd. Refrigerant transporting hose

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9419638A1 *

Also Published As

Publication number Publication date
CN1098772A (en) 1995-02-15
AU5685594A (en) 1994-09-14
BR9307818A (en) 1995-11-14
MX9401026A (en) 1994-08-31
JPH08507351A (en) 1996-08-06
EP0694140A4 (en) 1996-07-10
WO1994019638A1 (en) 1994-09-01

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