Patent Application
20120149828
The present invention generally relates to a chemical composition that provides a low friction coating. More specifically, the invention is a waterborne polyisocyanate chemical composition that provides a low friction coating.
It is an object of the invention to provide a waterborne polyisocyanate chemical composition that provides a low friction coating that is able to crosslink to a substrate utilizing substrate surface chemistry adjustments creating adhesion and cohesion bonds to the substrate and a plurality of hydrogels.
It is an object of the invention to provide a waterborne polyisocyanate chemical composition that provides a low friction coating that includes hydrogels that can crosslink with themselves and/or with the waterborne polyisocyanate and/or a substrate, with the waterborne polyisocyanate, the substrate and the hydrogels preferably crosslinking together.
It is an object of the invention to provide a waterborne polyisocyanate chemical composition that provides a low friction coating that utilizes two or more cross linkers to adjust the final properties of the composition's adhesion, cohesion and friction.
What is really needed is a waterborne polyisocyanate chemical composition that provides a low friction coating that is able to crosslink to a substrate using substrate surface chemistry adjustments creating adhesion and cohesion bonds to the substrate and a plurality of hydrogels, that includes hydrogels that can crosslink with themselves (i.e. adhesion, cohesion, chemical bond), crosslink with the waterborne polyisocyanate and/or a substrate, with the waterborne polyisocyanate, the substrate and the hydrogels preferably crosslinking together and that provides a low friction coating that utilizes two or more crosslinkers to adjust the final properties of the composition's adhesion, cohesion, chemical bonds and friction.
Various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials, and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments.
Various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention, however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.
The phrase “in one embodiment” is used repeatedly. The phrase generally does not refer to the same embodiment, however, it may. The terms “comprising”, “having” and “including” are synonymous, unless the context dictates otherwise.
The present invention is a chemical composition that provides a low friction coating and a low sliding coefficient of friction onto a plastic or metal working part, in accordance with one embodiment of the present invention.
The chemical composition includes a waterborne polyisocyanate such as ureas, urethanes, esters, ethers and tetramethylxylene diisocyanates (TMXDI) in the chemical composition structure and a plurality of cross linkable functional groups and a plastic or metal chemical substrate. The waterborne polyisocyanate must include cross linkable functional groups. Any suitable waterborne polyisocyanate can be utilized with the chemical composition.
The chemical composition also includes one or more materials are that are single linked or multiple linked hydrogels such as polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and polyvinyl alcohol (PVA) that are mixed with the waterborne polyisocyanate and one or more crosslinkers that include aziridines and carbodiimides that link the hydrogels, the waterborne polyisocyanate and the substrates together to form the chemical composition. The cross linkers must be able to crosslink with the waterborne polyisocyanate polymer functional chain, and substrates through surface modification. The surface modification includes functional groups grafted to the surface such as hydroxyl and carboxyl groups as an example the can crosslink with the polyisocyanate polymer. The hydrogels should be chosen to crosslink with themselves and/or with the waterborne polyisocyanate chemistry and/or substrate or have a strong adhesion cohesion the other hydrogels in the formulation. Surface modification of the hydrogels can be used to create functional groups on the surface of the hydrogels capable of crosslinking to the polyisocyante polymer. A best mode for the polyisocyanate composition is to have the hydrogels, waterborne polyisocyanate and functional group substrate cross linkable together to create adhesion, cohesion bond, and chemical bonds for best performance. The preferred surface modifications are to add crosslink able functional groups to the surface of the substrate that will crosslink with the waterborne polyisocyanate creating adhesion bonds and adhesion bonds (examples of cross linkable functional groups added to the substrate but not limited to include carboxyl and hydroxyl groups. Example methods employed to add functional groups include but not limited to plasma or chemical grafting and etching). The plasma gases compositions that can be used noted as an example but not limited include carbon dioxide, ethyl alcohol, acrylic acid Any suitable single linked or multiple linked hydrogels and crosslinkers can be utilized with the chemical composition.
In utilizing the chemical composition, two plastic substrates coated with the chemical composition can rub against each other, a plastic substrate and a metal substrate coated with the chemical composition can rub against each other and two metal substrates coated with the chemical composition can rub against each other. Preferably, the substrates are cross linked to the hydrogels utilizing substrate surface chemistry adjustments creating adhesion and cohesion bonds to the substrate and the hydrogels. The preferred surface modifications are to add functional groups that can be cross linked to the surface of the substrate that will crosslink with the waterborne polyisocyanate creating adhesion bonds.
The waterborne polyisocyanate chemical composition provides a low friction coating that is able to crosslink to a substrate using substrate surface chemistry adjustments creating adhesion and cohesion bonds to the substrate and a plurality of hydrogels. The waterborne polyisocyanate chemical composition provides a low friction coating that includes hydrogels that can crosslink with themselves and/or with the waterborne polyisocyanate and/or a substrate, with the waterborne polyisocyanate, the substrate and the hydrogels preferably crosslinking together. The waterborne polyisocyanate chemical composition provides a low friction coating that also utilizes two or more crosslinkers to adjust the final properties of the chemical composition's adhesion, cohesion and friction. The crosslinkers used can be aziridines or carbodiimides, however any suitable crosslinkers can be used to adjust the final properties of the chemical composition's adhesion, cohesion and friction.
The chemical composition can be utilized in a wide variety of devices that require or would benefit from a low friction coating. For example, the chemical composition can be applied to a medical device to reduce friction upon insertion or implantation of the device into the human body, such as a knee replacement joint, catheters, stents, delivery systems, iol injectors, etc.
While the present invention has been related in terms of the foregoing embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described. The present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. Thus, the description is to be regarded as illustrative instead of restrictive on the present invention.
This application claims priority to U.S. Provisional Application 61/421,152 filed on Dec. 8, 2010, the entire disclosure of which is incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61421152 | Dec 2010 | US |
