U.S. patent application number 10/230035 was filed with the patent office on 2004-03-04 for refrigerant hose.
Invention is credited to Henry, Brian, Wilson, Reji Paul.
Application Number | 20040040607 10/230035 |
Document ID | / |
Family ID | 31495365 |
Filed Date | 2004-03-04 |
United States Patent
Application |
20040040607 |
Kind Code |
A1 |
Wilson, Reji Paul ; et
al. |
March 4, 2004 |
Refrigerant hose
Abstract
A hose suitable for use in refrigerant systems. The hose has a
barrier layer formed of at least two layers of thermoplastic resin.
At least one of the layers is a vinyl resin. The resins are
selected so that the hose has a permeation rate of virtually
zero.
Inventors: |
Wilson, Reji Paul;
(Fairlawn, OH) ; Henry, Brian; (Sun Prairie,
WI) |
Correspondence
Address: |
The Goodyear Tire & Rubber Company
Patent & Trademark Department - D/823
1144 East Market Street
Akron
OH
44316-0001
US
|
Family ID: |
31495365 |
Appl. No.: |
10/230035 |
Filed: |
August 28, 2002 |
Current U.S.
Class: |
138/137 ;
138/125; 138/140; 138/DIG.7 |
Current CPC
Class: |
B32B 1/08 20130101; Y10T
428/1383 20150115; B32B 2323/10 20130101; B60H 1/00571 20130101;
F16L 2011/047 20130101; B32B 2327/06 20130101; B32B 2323/046
20130101; B32B 25/10 20130101; F16L 11/085 20130101; B32B 25/18
20130101; F16L 11/081 20130101; B32B 2398/20 20130101; B32B 25/08
20130101; B32B 25/14 20130101; B32B 2323/043 20130101; B32B 2329/04
20130101 |
Class at
Publication: |
138/137 ;
138/125; 138/140; 138/DIG.007 |
International
Class: |
F16L 011/00 |
Claims
What is claimed is:
1. A hose comprising an inner barrier layer, a radially outer
intermediate layer, a reinforcing layer, and a cover layer, wherein
the barrier layer is formed of at least two resin layer and wherein
the two resin layers are formed of two different materials and at
least one of the resin layers is a vinyl resin.
2. A hose in accordance with claim 1 wherein the hose is further
comprised of an elastomeric layer radially inward of the barrier
layer.
3. A hose in accordance with claim 1 wherein the barrier layer is
the radially innermost layer of the hose.
4. A hose in accordance with claim 1 wherein the barrier layer is
formed of three resin layers.
5. A hose in accordance with claim 4 wherein the radially innermost
resin layer and the radially outermost resin layer are formed of
the same resin material.
6. A hose in accordance with claim 1 wherein the vinyl resin is
selected from the group consisting of vinyl acetate (EVA),
polyvinylalcohol (PVA), vinyl alcohol/ethylene copolymer (EVOH),
polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), vinyl
chloride/vinylidene chloride copolymer, and vinylidene
chloride/methylacrylate copolymer.
7. A hose in accordance with claim 1 wherein the non-vinyl resin
barrier layer is formed of a material selected from the group
consisting of polyolefin thermoplastic resins or polyamide
thermoplastic resins.
8. A hose in accordance with claim 1 wherein the hose has a
permeation rate of not greater than 0.0003 g/cm/day.
9. A hose in accordance with claim 1 wherein each resin layer in
the barrier layer has a radial thickness of 0.001 to 0.005 in
(0.025 to 0.127 mm).
10. A hose in accordance with claim 1 wherein the intermediate
layer is formed of a material from the group consisting of
chloroprene rubbers, nitrile rubbers, ethylene-propylene rubber,
ethylene propylene diene rubber (EPDM), butyl rubbers (IIR, CIIR,
BIIR), chlorosulfonated polyethylene rubber (CSM), ethylene-acrylic
copolymer rubber (AEM), chlorinated polyethylene rubber (CPE),
brominated isobutylene-paramethyls- tyrene (BIMS), thermoplastic
elastomers, and thermoplastic vulcanizates.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to a hose suitable for use
in refrigerant systems such as vehicle, industrial, and residential
refrigerant systems. The hose is a combination of elastomeric
materials to provide flexibility and thermoplastic materials to
provide impermeability.
BACKGROUND OF THE INVENTION
[0002] Hoses are used for transporting refrigerants in vehicle air
conditioning systems, and in industrial and residential refrigerant
systems. The hoses generally have a three-layer laminar
construction consisting of an innermost layer, a reinforcing layer,
and an outermost cover layer. Generally, the inner and outer layers
are formed of rubber, including butyl rubbers (IIR, CIIR, BIIR or
BIMS), ethylene propylene diene rubber (EPDM), chloroprene rubber
(CR), nitrite rubbers (NBR, HNBR), or ethylene acrylic copolymer
rubber (AEM). The reinforcing fiber layer usually is a mesh
structure formed by braided organic yarn such as polyester fiber,
rayon fiber, or nylon fiber. The outer cover typically is formed of
EPDM, CR, butyl rubbers, or AEM. Adhesion layers may be employed
between the layers.
[0003] The hoses discussed above have a high degree of flexibility.
Because of this, the rubber hoses can be handled with ease.
However, rubber materials generally tend to have high gas
permeability. Attempts to improve the resistance of conventional
rubber hoses to refrigerant permeation have been made by
incorporating polyamide layers, such as nylon 6, nylon 66, modified
nylon 6, or alloys of nylon 6, etc, as an inner layer. However, the
use of such polyamide layers, while reducing permeation rates, also
reduces the flexibility of the hoses. To achieve an acceptable
compromise of the required characteristics, the thickness of a
nylon inner core layer is conventionally at least 0.5 mm (0.02"),
see also U.S. Pat. No. 4,633,912 who discloses a polyamide blend
cores tube with a gauge thickness of 1.07 mm and 0.81 mm.
[0004] Hoses may be characterized as barrier or veneer hose, the
distinction between the two being the type of material forming the
innermost layer. Barrier hoses have the innermost layer formed of
an elastomeric material and a barrier layer located outward of the
innermost layer. In hoses where the barrier layer is the innermost
layer, the hose is referred to a veneer hose. Some applications may
use either type of hose, such as fuel hose, while other
applications may require a specific internal material and thus only
one type of hose would be appropriate.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a hose suitable for
transporting refrigerants. The hose has a high resistance to
permeation and high flexibility. The hose comprising has a barrier
layer, an intermediate elastomeric layer, a reinforcing layer, and
a cover layer. To achieve the high resistance to permeation,
producing an almost zero permeation rate hose, the barrier layer is
formed of at least two resin layer wherein at least one of the
resin layers is formed from a vinyl resin.
[0006] In one aspect of the disclosed invention, the hose is a
barrier hose. Radially inward of the multi-layer barrier layer is
an elastomeric layer. The elastomeric layer forms the innermost
layer of the hose and is in direct contact with any fluids or
gasses that will flow through the hose.
[0007] In another aspect of the invention, the hose is a veneer
hose. That is, the barrier layer is the radially innermost layer of
the hose and is in direct contact with any fluids or gasses that
will flow through the hose.
[0008] In another aspect, the barrier layer of the hose is formed
of three resin layers. In such a construction, the material forming
the innermost resin layer is repeated as the radially outermost
resin layer. This construction is the most expeditious regarding
manufacturing; however, the third resin layer may also be formed
from a third resin material.
[0009] In one aspect of the invention, the vinyl resin forming one
of the barrier layers is selected from the group consisting of
vinyl acetate (EVA), polyvinylalcohol (PVA), vinyl alcohol/ethylene
copolymer (EVOH), polyvinylidene chloride (PVDC), polyvinyl
chloride (PVC), vinyl chloride/vinylidene chloride copolymer, and
vinylidene chloride/methylacrylate copolymer.
[0010] In another aspect of the invention, the non-vinyl resin
barrier layer is formed of a material selected from the group
consisting of polyolefin thermoplastic resins or polyamide
thermoplastic resins.
[0011] In another aspect of the invention, the intermediate rubber
layer, and the innermost rubber layer when the hose construction is
a barrier hose, is formed of a material from the group consisting
of chloroprene rubbers, nitrile rubbers, ethylene-propylene rubber,
ethylene propylene diene rubber (EPDM), butyl rubbers (IIR, CIIR,
BIIR), chlorosulfonated polyethylene rubber (CSM), ethylene-acrylic
copolymer rubber (AEM), chlorinated polyethylene rubber (CPE), or
brominated isobutylene-paramethylstyrene (BIMS).
[0012] In another aspect of the invention, each resin layer in the
barrier layer has a radial thickness of 0.001 to 0.005 in (0.025 to
0.127 mm).
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be described by way of example and with
reference to the accompanying drawings in which:
[0014] FIG. 1 is a cross-sectional view of a partial hose in
accordance with the present invention;
[0015] FIG. 2 is another embodiment of the inventive hose;
[0016] FIG. 3 is another embodiment of the inventive hose; and
[0017] FIG. 4 is a graph comparing steady state permeation
rates.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The refrigerant hose 10 of the present invention is
illustrated in FIG. 1. The hose 10 has a core layer 12, relative to
the radial direction of the hose and the longitudinal hose axis.
The core layer 12 is formed from an elastomeric material. Over the
core layer 12 is the barrier layer 14 formed of at least two
thermoplastic layers, 16, 18. Over the barrier layer is an
intermediate elastomeric layer 20, reinforcing layer 22 and a cover
layer 24.
[0019] The core layer 12 is formed from an elastomeric material. As
this layer 12 is adjacent to the veneer barrier layer, it must be
able to bond to the barrier layer 14. Such materials include, but
are not limited to chloroprene rubbers, nitrile rubbers,
ethylene-propylene rubber, ethylene propylene diene rubber (EPDM),
butyl rubbers (IIR, CIIR, BIIR), chlorosulfonated polyethylene
rubber (CSM), ethylene-acrylic rubber (AEM), chlorinated
polyethylene rubber (CPE), or brominated
isobutylene-paramethylstyrene (BIMS). The core layer 12 may also be
formed from thermoplastic elastomers or thermoplastic vulcanizates
such as polyproplene, polyethylene, or other polyolefins blended
with EPDM, IIR, NBR, or acrylic rubber.
[0020] The barrier layer 14 is formed of a first thermoplastic
layer 16, the material having a low permeation rate. Suitable low
permeability materials include polyolefin thermoplastic resins,
such as high density polyethylene (HDPE), ultrahigh molecular
weight polyethylene (UHMWPE), polypropylene (PP), and ethylene
propylene copolymer thermoplastic resin; and polyamide
thermoplastic resins such as nylon 6 (N6), nylon 66 (N66), nylon 46
(N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612
(N612), nylon 6/66 copolymer (N6/66), nylon 6/66/610 copolymer
(N6/66/610), nylon MXD6 (MxD6), nylon 6T, nylon 6/6T copolymer,
nylon 66/PP copolymer, and nylon 66/PPS copolymer. To achieve a low
permeation of the completed hose, when using a polyamide resin, or
a blend of polyamide resins, the polyamide is preferably
non-plasticized. The addition of a plasticizer to the polyamide
improves the flexibility of the material; however, it also
decreases the permeability characteristics of the nylon. Thus,
non-plasticized polyamide are preferred.
[0021] The second layer 18 in the barrier layer 14 is a low
permeability material differing from the first thermoplastic layer
16. The preferred material is a vinyl resin such as vinyl acetate
(EVA), polyvinylalcohol (PVA), vinyl alcohol/ethylene copolymer
(EVOH), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC),
vinyl chloride/vinylidene chloride copolymer, and vinylidene
chloride/methylacrylate copolymer.
[0022] In constructing the barrier layer 14, the first layer 16 may
be the radially innermost layer or the second layer 18 may be the
radially innermost layer. To maintain the required flexibility of
the hose 10, each individual resin layer 16, 18, has a radial
thickness of 0.001 to 0.005 in (0.025-0.127 mm).
[0023] The intermediate layer 20 must be able to bond to the
barrier layer. This layer is formed of the same materials suitable
for the innermost layer 12.
[0024] The reinforcing layer 22 may be formed by braiding,
spiraling, knitting, or helical knitting of yarn. The yarn may be
selected from conventional hose reinforcing yarns such as glass,
steel, cotton, polyester, or aramid fibers, or a blend of any of
these fibers.
[0025] The cover layer 24 is selected from known hose cover layer
materials, including but not limited to nitrile-butadiene rubber
(NBR), chlorosulfonated polyethylene rubber (CSM), EPDM, butyl
rubbers, chlorinated butyl rubber (Cl-IIR), brominated butyl rubber
(Br-IIR), epichlorohydrine rubber, acrylic rubber (AEM),
chloroprene rubber (CR), BIMS, and the like. Similar to the core
layer 12, the cover may also be formed from thermoplastic
elastomers or thermoplastic vulcanizates.
[0026] The hose 10 has a permeation rate of not greater than 0.0003
g/cm/day. A permeation rate this low may be considered to be a zero
permeation rate. Conventionally, to obtain permeation rates this
low, a thin metallic layer is employed in the hose. The present
invention achieves a very low, to zero, permeation rate without the
use of a metallic foil or layer within the hose.
[0027] A second embodiment of the present invention is illustrated
in FIG. 2. The hose 10' has an innermost layer 12, a barrier layer
14, an adjacent elastomeric friction layer 20, a reinforcing layer
22, and a cover layer 24. In this embodiment, the barrier layer 14
of the hose 10' has three layers, 16, 18, 16'. The material
selected for the radially innermost layer is repeated as the third,
and radially outermost layer. Preferably, the middle layer is
formed of the material having the lowest permeation rate.
[0028] A third embodiment of the present invention is illustrated
in FIG. 3. In this embodiment, the hose 10" has no innermost
elastomeric layer 12. Instead, the barrier layer 14 forms the
innermost layer and the hose 10" is a veneer hose. In the
illustrated embodiment, the barrier layer is formed of two barrier
layers, 16, 18 formed of the materials, and in the manner,
discussed above. Similar to the second embodiment, the veneer hose
10" may also have the barrier layer 14 formed of three layers
wherein the innermost barrier layer 16 is repeated, sandwiching the
second barrier layer 18.
[0029] The intended use of the hose, including the intended fluid
or gas that will flow through the hose, will determine which of the
various disclosed barrier or veneer hose constructions is
appropriate.
[0030] Construction of the hose 10 is accomplished in the following
manner.
[0031] The innermost layer is extruded onto either a flexible or
fixed mandrel. The barrier layer is formed by co-extruding the
different layers simultaneously onto the innermost layer. A
multi-layer head is used for the extrusion. When the barrier layer
is formed as a three-layer element, a tri-extrusion head is used.
When forming the barrier layer as a two layer element, a dual
extrusion head or a tri-extrusion, with one silent port, may be
used. No adhesive is applied between the different layers as the
bonding between the layers is accomplished through melt
bonding.
[0032] After the barrier layer is formed, either another
elastomeric layer is applied or the reinforcement layer is
immediately applied. The cover layer is applied last. The formed
hose length is then vulcanized to cure the elastomeric layers. The
hose length may be cut into definitive lengths either before or
after curing. If the hose length is cut prior to curing, then
typically, the hose lengths are cured on fixed curve short length
mandrels designed to impart a fixed and final configuration to the
hose.
Exemplary Hose
[0033] A hose in accordance with the invention was constructed. The
innermost layer was formed of CR. The barrier was formed of three
layers: a non-plasticized copolymer of nylon 6 and nylon 66, a
middle layer of EVOH, and a repeated layer of the non-plasticized
nylon 6,66 copolymer. Each of the barrier layers had a thickness of
about 0.002" (0.007 mm) for a total thickness of about 0.006"
(0.024 mm) Outward of the barrier layer, another layer of CR was
applied. A reinforcing layer of polyester was applied. The cover
layer was formed of a butyl rubber.
Comparative 1
[0034] A commercially available, low-permeation rate hose was
procured. The hose has an innermost layer of CR, a barrier layer of
a plasticized nylon 6-66 copolymer, an NBR friction layer,
polyester reinforcement, and a cover layer of chloro-butyl rubber.
This hose is the Goodyear Galaxy 534-860-013 hose sold by The
Goodyear Tire & Rubber Company.
Comparative 2
[0035] A second commercially available, low permeation hose was
procured. The hose has an innermost layer of CR, a barrier layer of
non-plasticized nylon 6-66 copolymer, a CR friction layer,
polyester reinforcement, and a cover layer of chloro-butyl rubber.
This hose is the Goodyear Galaxy 534-890-013 hose sold by The
Goodyear Tire & Rubber Company.
[0036] The three hoses where cut into sections and tested for
permeation rates. The permeation test was performed by sealing at
least one end of the hose section, introducing a refrigerant fluid
into the hose, and then sealing the open end of the hose. The total
weight of the hose and contained fluid is measured. The hose
section is then left in an ambient environment at 90.degree. C. The
weight of the hose is measured every day for two weeks, and then
every other day for another week. The permeation rate is then
calculated based on the weight loss per section length per day for
the last five days (steady state).
[0037] The results of the permeation rates of the inventive hose
and the two comparative hoses are shown in FIG. 4. Comparative hose
1 showed a permeation rate of 0.0064 g/in/day (2.52.times.10.sup.-3
g/cm/day). Comparative hose 2 showed a permeation rate of 0.0013
g/in/day (5.12.times.10.sup.-4 g/cm/day). The inventive hose showed
a permeation rate of 0.0001 g/in/day (3.94.times.10.sup.-5
g/cm/day). The inventive hose exhibits a significant improvement in
low permeation compared to the other hoses.
[0038] This hose has been described as being useful for
refrigerants, including but not limited to R134A, but is also
useful for other types of fluids or gases, such as CO.sub.2.
[0039] Variations in the present invention are possible in light of
the description of it provided herein. While certain representative
embodiments and details have been shown for the purpose of
illustrating the subject invention, it will be apparent to those
skilled in this art that various changes and modifications can be
made therein without departing from the scope of the subject
invention. It is, therefore, to be understood that changes can be
made in the particular embodiments described which will be within
the full intended scope of the invention as defined by the
following appended claims.
* * * * *