Patent Grant
8800604
The invention relates to a hose with low permeation rate with at least the following layer structure:
An important type of hose of the abovementioned type is a coolant hose. Coolant hoses serve to transport gaseous or liquid coolants, in particular fluorocarbon coolants, in air-conditioning systems, and reference is in particular made in this connection to the following literature: DE 38 20 447 A1; U.S. Pat. No. 5,084,314; DE 42 32 946 A1; U.S. Pat. No. 5,653,475; DE 196 08 318 A1; DE 91 02 495 U1; DE 203 21 380 U1; EP 0 222 323 A1; U.S. Pat. No. 4,905,736; EP 0 826 915 A2; U.S. Pat. Nos. 6,376,036; 5,957,154; and, ATZ Automobiltechnische Zeitschrift 98 (1996) 10, page 541.
Films made of a polymeric material are becoming increasingly important, alongside barrier layers based on resin, for example made of phenolic resin. Monofilms are used here, for example made of a polyamide (PA), as also in particular are multilayer films (film-composite materials), for example made of PA and of a polymer based on ethylene-vinyl alcohol (EVOH).
As far as the internal layer is concerned, materials used are mostly elastomers or thermoplastic elastomers. Further details of the relevant materials technology are provided elsewhere.
Embodiments known hitherto which comply with the most recent requirements relating to compatibility with modern refrigeration lubricants, flexibility, noise attenuation, gas impermeability, and dynamic strength have a braiding material as reinforcement.
The braiding method applies a ply of the yarn-based reinforcement. The braiding machine mostly has respectively 12packages rotating toward the right and toward the left. A package can accept up to eight strands, and up to 96 strands are therefore applied to the hose in one direction, and precisely the same number in the other direction. This process provides a hose with 100% yarn covering. Adhesion between the individual plies, internal layer-yarn-external layer, is produced here via an adhesion promoter, these being present in the polymer mixtures, or via adhesion-promoter solutions applied additionally. This design provides a burst in pressure three times as high as demanded by the standard.
There are also coolant hoses with reinforcement which is not applied by braiding. However, these exhibit reduced pressure resistance and they usually have an intermediate layer made of a polymeric material between the plies of the reinforcement.
An object underlining the invention is then to provide a hose of this generic type which features a particularly low permeation rate for fluorocarbon coolants, high flexibility, a high level of vibration damping, good dynamic properties, and high dynamic pressure resistance.
The object is achieved in that the reinforcement is helical, and specifically forms at least two helical plies, where the region between two helical plies is free from any intermediate layer made of any polymeric material.
Possible designs used in respect of the reinforcement are in particular the following:
Further details of the barrier layer, and also of the internal layer and external layer, are now given below.
The barrier layer, composed of a thermoplastic or of a thermoplastic elastomer, has a thickness of from 0.05 to 0.6 mm, in particular from 0.3 to 0.4 mm.
In particular, the following two variants are used in connection with a barrier layer in the form of a monofilm:
Various film materials are used in the context of a barrier layer in the form of a multilayer film, in particular of a two-layer film: all of the films can be composed of thermoplastic materials, or else can comprise a combination of a thermoplastic with a thermoplastic elastomer. By way of example, in a thermoplastic film composite a first film is composed of the abovementioned PA6 and a second film is composed of a polymer based on ethylene-vinyl alcohol (EVOH).
The polymeric material of the internal layer and external layer of the hose has elastic properties, and two polymer variants in particular used in this connection are the following:
Polymer Variant A
The polymeric material is an elastomeric material based on a vulcanized rubber mixture which comprises an unblended rubber component or a rubber-component blend and conventional mixture ingredients. Particular rubber components that may be mentioned are:
It is also possible to use a blend, in particular in conjunction with one of the abovementioned types of rubber, for example an NR/BR blend.
The preferred rubber components for the internal layer are: EPDM, IIR, BIIR, CIIR, or BIMS, or blends thereof, or blends with other types of rubber. Unblended BIMS is of particular importance here.
The preferred rubber components for the external layer are: ACM, AEM, CM, ETER, EPDM, EPM, EVA, IIR, BIIR, CIIR, BIMS, FKM, or HNBR, or blends thereof, or blends with other types of rubber. Unblended EPDM or EPM is of particular importance here.
The conventional mixture ingredients comprise at least one crosslinking agent or one crosslinking agent system (crosslinking agent and accelerator). Other mixture ingredients are mostly also a filler and/or a processing aid, and/or a plasticizer, and/or an antioxidant, and/or an adhesion promoter, and also optionally other added materials (for example, color pigments). In this connection, reference is made to the general prior art of rubber mixture technology.
Polymer Variant B
The polymeric material is a thermoplastic vulcanizate (thermoplastic elastomer, abbreviated to TPE), comprising at least one thermoplastic component, at least one rubber component, which has been at least partially crosslinked, and also conventional mixture ingredients.
The preferred thermoplastic components are:
Particular rubber components that may be mentioned are EPM, EPDM, SBR, CR, NR, NBR, FKM, ACM, or AEM, where these in particular have not been blended with any other rubber component.
In relation to the conventional mixture ingredients, reference is made to the mixture technology relating to polymer variant A, in particular to the teaching in U.S. Pat. No. 6,774,162.
Polymer variant B is in particular used for the internal layer.
Mixture examples are given below for the internal layer (Table 1) and the external layer (Table 2).
Within the ranges of amounts given in Tables 1 and 2, the entirety of all of the mixture constituents used is always 100% by weight.
The hose of the invention is preferably used as high-temperature coolant hose. This novel high-temperature coolant hose complies with all of the requirements imposed on coolant hoses by the specifications of the automobile industry. The novel hose is capable of universal use for the suction and pressure side of air-conditioning systems.
By using the novel hose design, it is moreover possible to produce molded hose sections, in particular in turn molded coolant hoses.
Another object of the invention consists in providing a process which can be used to produce a hose which features a particularly low permeation rate for fluorocarbon coolants, high flexibility, a high level of vibration damping, good dynamic properties, and high dynamic strength, and specifically with a process sequence that is not only simplified but also cost-effective.
This object is achieved via at least the following process steps:
In respect of the thickness of the barrier layer, of the film materials, of the reinforcement material, and also of the vulcanizable polymer mixtures based on elastomer or on TPE for the internal layer and external layer, reference is made to the details given previously.
The process of the invention, with integration of the novel helical method, without any extruded intermediate layer between two helical plies, can give a continuous sequence of the abovementioned process steps, with high line speed.
One embodiment of the novel helical method comprises the following points:
The following advantages are in turn associated therewith:
The reinforcement is moreover formed in a manner which uses no adhesion promoter between two helical plies, for example by dip coating, spreading, or spraying of a solution or of an aqueous dispersion. The individual strands optionally have an optimized finish which promotes the adhesion of the strands to one another and to the internal and external layer.
The internal layer is also applied to the barrier layer without any adhesion promoter.
The vulcanization of the unvulcanized hose is carried out with steam and/or pressure.
In summary, the following advantages are associated with the novel helical process:
The invention will now be described with reference to the drawings in which:
The hose 1 has the following layer structure:
in contact with the internal layer 3, multiple-ply reinforcement 4 made from yarn 4a and yarn 4b which are arranged in helical form, using a yarn made of a polyaramid and with no use of any intermediate layer made of a polymeric material, and also
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 037 211 | Aug 2010 | DE | national |
This application is a continuation application of international patent application PCT/EP2011/062517, filed Jul. 21, 2011, designating the United States and claiming priority from German application 10 2010 037 211.0, filed Aug. 30, 2010, and the entire content of both applications is incorporated herein by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
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| 4998564 | Igarashi et al. | Mar 1991 | A |
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| 6376036 | Nadkarni et al. | Apr 2002 | B1 |
| 6536479 | Wilson et al. | Mar 2003 | B2 |
| 6774162 | Vortkort et al. | Aug 2004 | B1 |
| 6941975 | Wilson et al. | Sep 2005 | B2 |
| 7086420 | Kahn et al. | Aug 2006 | B2 |
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| 20040040607 | Wilson et al. | Mar 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| 38 20 447 | Dec 1988 | DE |
| 91 02 495.1 | May 1991 | DE |
| 42 32 946 | Apr 1993 | DE |
| 196 08 318 | Aug 1997 | DE |
| 203 21 380 | Jan 2007 | DE |
| 0 222 323 | May 1987 | EP |
| 0 826 915 | Mar 1998 | EP |
| 2006-307987 | Nov 2006 | JP |
| 2007-168104 | Jul 2007 | JP |
| WO 2008071604 | Jun 2008 | WO |
| Entry |
|---|
| International Search Report dated Sep. 21, 2011 of international application PCT/EP2011/062517 on which this application is based. |
| Number | Date | Country | |
|---|---|---|---|
| 20130126031 A1 | May 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2011/062517 | Jul 2011 | US |
| Child | 13740627 | US |
