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US 2006/0124889 A1Published application
Water resistant encoding material
AssigneeFreudenberg-NOK General Partnership
InventorsEdward Park, Francis Walker
Life of this patent
Estimating the term…
Abstract
A cured magnetizable admixture of elastomeric thermoplastic, dispersed magnetizable particulate, and optional dispersed hydrophobic material (such as ethylene acrylic monomer rubber or ethylene-vinyl acetate copolymer) provides elastic elongation of not less than about 50 percent at break and water swell of not greater than about 10 percent after curing in magnetizable articles such as target wheels. The magnetizable composition beneficially combines mechanical and durability advantages of traditionally-used thermoset elastomer-based magnetic compounds, under the range of conditions needed for vehicle encoder applications, with the processing and manufacturing advantages of engineered thermoplastics.
Claims30
A magnetizable admixture composition, comprising:
- (a) a continuous phase of elastomeric thermoplastic selected from the group consisting of polyester thermoplastic elastomer, polyamide thermoplastic elastomer, acrylic acid ester rubber/polyacrylate rubber thermoplastic vulcanizate, ethylene acrylic rubber thermoplastic vulcanizate, silicone-thermoplastic vulcanizate, thermoplastic polyurethane vulcanizate, thermoplastic polyurethane vulcanizate/polyamide thermoplastic elastomer, and combinations thereof;
- and
- (b) a first dispersed phase of magnetizable particulate dispersed in said continuous phase;
- (c) wherein said composition provides an elastic elongation property of not less than about 50 percent at break and a water swell property of not greater than about 10 percent in cured magnetizable polymer of said composition;
- and
- (d) wherein said first dispersed phase is dispersed in sufficient quantity in said composition such that a first magnetic field in a first portion in a cured block of said composition is differentiated from a second magnetic field in a second portion of said block by not less than about 200 Gauss when measured across an air detection gap of about 1 mm wherein said cured block has a length of about 1 centimeter, a width of about 1 centimeter, and a thickness of about 50 millimeters.
3 more elements
An encoder target wheel, comprising
- (a) a continuous ring of cured magnetizable polymer cured from an admixture comprising
- (i) a continuous phase of an elastomeric thermoplastic selected from the group consisting of polyester thermoplastic elastomer, polyamide thermoplastic elastomer, acrylic acid ester rubber/polyacrylate rubber thermoplastic vulcanizate, ethylene acrylic rubber thermoplastic vulcanizate, silicone-thermoplastic vulcanizate, thermoplastic polyurethane vulcanizate, thermoplastic polyurethane vulcanizate/polyamide thermoplastic elastomer, and combinations thereof, and
- (ii) a first dispersed phase of magnetizable particulate dispersed in said continuous phase;
- (b) at least one first magnetized portion in said continuous ring, said first magnetized portion having a first magnetic field strength;
- and
- (c) at least one second portion in said continuous ring, said second portion having a second magnetic field strength differentiated from said first magnetic field strength by not less than about 200 Gauss when measured across an air detection gap of about 1 mm;
- (d) wherein said admixture provides an elastic elongation property of not less than about 50 percent at break and a water swell property of not greater than about 10 percent in said encoder target wheel.
4 more elements
A method for making a magnetizable admixture composition, comprising
- (a) admixing
- (i) an elastomeric thermoplastic selected from the group consisting of polyester thermoplastic elastomer, polyamide thermoplastic elastomer, acrylic acid ester rubber/polyacrylate rubber thermoplastic vulcanizate, ethylene acrylic rubber thermoplastic vulcanizate, silicone-thermoplastic vulcanizate, thermoplastic polyurethane vulcanizate, thermoplastic polyurethane vulcanizate/polyamide thermoplastic elastomer, and combinations thereof, and
- (ii) magnetizable particulate, such that an admixture is formed of said particulate dispersed as a first dispersed phase in a continuous phase of said elastomeric thermoplastic;
- (b) wherein said admixture provides an elastic elongation property of not less than about 50 percent at break and a water swell property of not greater than about 10 percent in cured magnetizable polymer of said admixture;
- and
- (c) wherein said first dispersed phase is dispersed in sufficient quantity in said admixture such that a first magnetic field a first portion in a cured block of said admixture is differentiated from a second magnetic field in a second portion of said block by not less than about 200 Gauss when measured across an air detection gap of about 1 mm wherein said cured block has a length of about 1 centimeter, a width of about 1 centimeter, and a thickness of about 50 millimeters.
3 more elements
A method for making an encoder target wheel, comprising
- (a) admixing
- (i) an elastomeric thermoplastic selected from the group consisting of polyester thermoplastic elastomer, polyamide thermoplastic elastomer, acrylic acid ester rubber/polyacrylate rubber thermoplastic vulcanizate, ethylene acrylic rubber thermoplastic vulcanizate, silicone-thermoplastic vulcanizate, thermoplastic polyurethane vulcanizate, thermoplastic polyurethane vulcanizate/polyamide thermoplastic elastomer, and combinations thereof;
- and
- (ii) magnetizable particulate, such that an admixture is formed of said particulate dispersed as a first dispersed phase in a continuous phase of said elastomeric thermoplastic;
- (b) forming a continuous ring precursor of said admixture;
- (c) curing said precursor to form a cured continuous ring;
- (d) magnetizing at least one first magnetized portion in said continuous ring such said first magnetized portion has a first magnetic field strength as a remanence;
- and
- (e) providing at least one second portion in said continuous ring, said second portion having a second magnetic field strength differentiated from said first magnetic field strength by not less than about 200 Gauss when measured across an air detection gap of about 1 mm;
- (f) wherein said admixture provides an elastic elongation property of not less than about 50 percent at break and a water swell property of not greater than about 10 percent in said continuous ring.
7 more elements
Dependencies are inferred from the claim text.