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EP-4536473-B1 - LOW EXTRACTION HNBR MATERIAL WITH ADHESION TO POLYAMIDES

EP4536473B1EP 4536473 B1EP4536473 B1EP 4536473B1EP-4536473-B1

Inventors

  • CLARK, Aaron David
  • CLARK, Gina Theresa
  • HATHAWAY, COLLEEN MARIE

Dates

Publication Date
20260513
Application Date
20230607

Claims (15)

  1. A hose, comprising a multiplicity of layers including: a hydrogenated nitrile butadiene (HNBR) rubber layer (102, 206) directly bonded to a polyamide (PA) barrier layer (104, 204), wherein the HNBR rubber layer (102, 206) is prepared from a first composition comprising an HNBR rubber, a phenylenedimaleimide, and a maleated compound.
  2. The hose of claim 1, wherein the HNBR layer is covalently bonded to the PA barrier layer (104, 204) without an intervening adhesive layer.
  3. The hose of any one of the preceding claims, wherein the HNBR rubber is at least partially saturated having residual double bonds of no more than 6%, no more than 4%, no more than 2%, or no more than 1% by Infrared (IR) Spectroscopy.
  4. The hose of any one of the preceding claims, wherein the phenylenedimaleimide is a N,N'-1,3-phenylenedimaleimide.
  5. The hose of any one of the preceding claims, wherein the maleated compound is a maleated polybutadiene compound.
  6. The hose of any one of the preceding claims, wherein the first composition comprises the maleated compound in a range of from 1-7 wt%, 2-6 wt%, 3-5 wt%, or 3.5-4.5 wt% compared to the total weight of the first composition.
  7. The hose of any one of the preceding claims, wherein the first composition further comprises a plasticizer, wherein the plasticizer is a high molecular weight plasticizer (> 500 g/mol).
  8. The hose of any one of the preceding claims, wherein the first composition comprises one or more fillers, wherein the one or more fillers is selected from the group consisting of carbon black, silica, silicates, talc, aluminum silicate, calcium carbonate, zinc oxide, titanium dioxide, and stearic acid, and wherein the first composition comprises the one or more fillers in a total amount in a range of from 30-60 wt%, 35-55 wt%, or 35-45 wt% compared to the total weight of first composition.
  9. The hose of any one of the preceding claims, wherein the first composition comprises: a peroxide, wherein the peroxide is selected from the group consisting of dicumyl peroxide, di-t-butyl peroxide, and t-butyl cumyl peroxide, and/or an antioxidant.
  10. The hose of any one of the preceding claims, wherein the HNBR layer is an inner HNBR tube layer (102) or an HNBR backing layer (206).
  11. The hose of any one of the preceding claims, wherein the vulcanized hose exhibits one or more of: a working temperature range of from -40 to 149 °C (-40 to +301 deg F); a maximum working pressure of at least 3.45 MPa (500 psi); a burst rating of at least 4:1 under SAE J1527 burst test conditions; does not exceed a permeation rating of 15 g or less of fuel loss per square meter of interior surface area in 24 hours, 15g/m 2 /24 h, with CE fuel at 23°C as specified in SAE J1527-B1; does not exceed a permeation rating of 15 g or less of fuel loss per square meter of interior surface area in 24 hours, 15g/m 2 /24 h, with E85 fuel at 40°C as specified in SAE 30R9; does not exceed a permeation rating of 15 g or less of fuel loss per square meter of interior surface area in 24 hours, 15g/m 2 /24 h, with fuel C at 40°C as specified in SAE 30R9; exhibits a permeation rate of no more than 5g/m 2 /24 h, with E85 fuel; exhibits a permeation rate of no more than 4g/m 2 /24 h, with fuel C; conforms to SAE J30R9 requirements for a fuel injection hose; and conforms to SAE J1527 requirements for a marine fuel hose.
  12. The hose of any one of the preceding claims, comprising the following layers in a radial direction: an inner HNBR tube layer (102) prepared from the first composition; a polyamide barrier layer (104); a rubber backing layer (106); and a braided reinforcement cover layer (108).
  13. The hose of any one of claims 1 to 11, comprising the following layers in a radial direction: an inner polyamide veneer (204); an HNBR rubber backing layer (206) prepared from the first composition; a braided reinforcement layer (208); and an outer rubber cover layer (210).
  14. The hose of claim 12, wherein the rubber backing layer is an EPDM rubber backing layer (106) prepared from a second composition comprising a low ethylene EPDM rubber, a phenylenedimaleimide, and a maleated compound.
  15. A method of making the hose of any one of claims 1 to 12 or of claim 15, the method comprising: blending an HNBR rubber (304), a phenylenedimalemide (306), and a maleated compound (302) to prepare a first composition; extruding the first composition onto a mandrel to form an HNBR inner tube layer (102); extruding a polyamide composition over the HNBR inner tube layer (102) to form a barrier layer (104); blending a second composition comprising an ethylene propylene diene monomer rubber (EPDM), a phenylenedimalemide, and a maleated compound; extruding the second composition on top of the polyamide barrier layer (104) to form an EPDM rubber backing layer (106); applying a textile braid reinforcement layer (108) over the EPDM rubber backing layer (106) to form a green hose; vulcanizing the green hose; and expelling the hose from the mandrel.

Description

CROSS-REFERENCE TO RELATED APPLICATION BACKGROUND In many multilayer hose designs comprising a barrier or veneer layer, an external epoxy or acrylic glue is applied in the production process to adhere the various layers together. These glues or cements may have sporadic coverage in these applications, constitute a messy process, and may contain Substances of Very High Concern (SVHC) ingredients such as bisphenol A. Improved processes and hose designs which remove the hazards associated with glue adhesives, eliminate a cumbersome process step, and dramatically improve the quality of the adhesion layer and overall hose performance are desirable. SANG JING et. al. "Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent", APPLIED SURFACE SCIENCE, ELSEVIER, AMSTERDAM , NL, vol. 412, 30 March 2017 (2017-03-30) discloses a method to provide a fuel hose comprising a HNBR layer directly bonded to a polyamide barrier layer without applying adhesives, wherein good adhesion between said layers is obtained by the use of a silane coupling agent. SUMMARY The present disclosure relates to a novel rubber formulation specifically designed for fluid conveyance fuel and air conditioning hoses, particularly designs that implement a thermoplastic barrier or veneer layer. This thermoset rubber is hydrogenated nitrile rubber (HNBR) based with a specific peroxide cure system that facilitates strong covalent linkages to polyamide thermoplastic without an intervening adhesive layer. The present technology enables the finished composite to have very low permeation. A hydrogenated nitrile butadiene rubber (HNBR) formulation that is peroxide cured, and that generates strong and consistent adhesion to polyamide thermoplastics during the vulcanization process without the need for glue adhesives is provided. The HNBR formulation is designed with very low volatile ingredients to help avoid any residue extraction in the application that might foul downstream components. The HNBR formulation may be employed in preparation of a tube layer or a backing layer in a fuel hose or refrigerant hose. Hydrogenated nitrile rubber (HNBR) is a synthetic compound prepared by hydrogenation of nitrile rubber (NBR). The hydrogenation process allows for enhanced thermal stability up to about 150 °C. HNBR may also improve fluid compatibility over NBR. In some examples, a 99% saturated hydrogenated nitrile rubber (HNBR) peroxide cure composition is provided including components comprising maleic anhydride and malemide functionalities to generate robust covalent linkages to the N terminal amine and/or the carbon backbone of a polyamide thermoplastic resin. The HNBR composition contains very low extractible content (waxes and plasticizers) to limit the available residue that can be extracted and later create an obstruction with a valve or other downstream component. Applications for this invention include barrier or veneer style fuel or air conditioning hoses that use a material such as a polyamide as a gas or fluid permeation barrier layer. A hose is provided comprising a multiplicity of layers including a hydrogenated nitrile butadiene (HNBR) rubber layer directly bonded to a polyamide (PA) barrier layer, wherein the HNBR rubber layer is prepared from a first composition comprising an HNBR rubber, a phenylenedimaleimide, and a maleated compound. The first composition may further comprise a peroxide. The first composition may further comprise one or more fillers. The first composition may further comprise a high molecular weight plasticizer. The first composition may further comprise an antioxidant. Upon vulcanization, the HNBR layer of the hose may be covalently bonded to a polyamide layer without an intervening adhesive layer. The HNBR rubber may be at least partially saturated having residual double bonds of no more than 6%, no more than 4%, no more than 2%, or no more than 1% by Infrared (IR) Spectroscopy. The first composition may comprise the HNBR rubber in a range of from 20-60 wt%, 30-55 wt%, or 35-45 wt% compared to the total weight of the first composition. In some examples, the first composition comprises a phenylenedimaleimide that is a N,N'-1,3-phenylenedimaleimide. The first composition may comprise the phenylenedimaleimide in a range of from 0.1-5.0 wt%, 0.5-4.0 wt%, 0.8-3.0 wt%, or 1-2 wt% compared to the total weight of the first composition. In some examples, the first composition comprises a maleated compound that is a maleated polybutadiene compound. The first composition may comprise the maleated compound in a range of from 1-7 wt%, 2-6 wt%, 3-5 wt%, or 3.5-4.5 wt% compared to the total weight of the first composition. The first composition may further comprises a plasticizer, optionally wherein the plasticizer is a high molecular weight plasticizer (> 500 g/mol). The high molecular weight plasticizer may have low volatility. The plasticizer may be a tri- C6