Heat curing and subsequent calendering to produce magnetic recording media
View Patent ↗A method for producing a magnetic recording medium includes heat-curing a coated substrate to cure a non-magnetic back coat on the substrate and to cure a magnetic front coat on the substrate, and calendering the heat-cured coated substrate to produce the magnetic recording medium. The calendering optionally is off-line calendering during which the substrate passes between opposed, generally non-compliant rolls. Other methods, and magnetic recording media produced by the disclosed methods, also are disclosed.
1. A method for producing a magnetic recording medium, comprising:
winding a coated substrate into a roll to form a wound roll of coated substrate;
heat-curing the wound roll of coated substrate to cure a non-magnetic back coat on the substrate and to cure a magnetic front coat on the substrate; and
calendering the heat-cured coated substrate to produce the magnetic recording medium.
2. The method of claim 1 , wherein the heat-curing comprises heat soaking the wound roll of coated substrate.
3. The method of claim 2 , wherein the heat soaking comprises immersing the wound roll of coated substrate at an immersion temperature in the range of about 50° C. to about 60° C.
4. The method of claim 1 , further comprising drying the non-magnetic back coat and the magnetic front coat before the heat-curing.
5. The method of claim 1 , wherein the calendering occurs at a calendering temperature of between about 80° C. and about 95° C.
6. The method of claim 1 , wherein the calendering comprises passing the substrate between opposed, generally non-compliant rolls.
7. The method of claim 6 , further comprising calendering the substrate between additional opposed rolls, at least one of the additional opposed rolls being generally compliant.
8. The method of claim 1 , wherein the calendering comprises off-line calendering.
9. The method of claim 8 , further comprising in-line calendering, using at least one generally compliant roll, prior to the heat-curing.
10. The method of claim 1 , wherein the heat-curing before calendering generally eliminates or generally reduces embossing of the magnetic front coat by the non-magnetic back coat.
11. The method of claim 1 , wherein the heat-curing before calendering generally reduces a block error rate of the magnetic recording medium.
12. The method of claim 1 , wherein the heat-curing before calendering generally reduces surface mean peak-to-valley height R z of the magnetic front coat.
13. The method of claim 1 , wherein the heat-curing before calendering generally reduces the amount of negative skew R sk of the magnetic front coat.
14. The method of claim 1 , wherein the heat-curing before calendering generally reduces air bleed of the non-magnetic back coat.
15. The method of claim 1 , wherein heat-curing before calendering generally improves wind quality of the magnetic recording medium.
16. A method for producing a magnetic recording medium, comprising:
winding a coated substrate into a roll to form a wound roll of coated substrate;
heating the wound roll of coated substrate to cure a non-magnetic back coat on the substrate and to cure a magnetic front coat on the substrate; and
calendering the cured coated substrate to produce the magnetic recording medium.
17. The method of claim 16 , wherein the beating comprises heat soaking the wound roll of coated substrate.
18. The method of claim 17 , wherein the heat soaking comprises immersing the wound roll of coated substrate at an immersion temperature in the range of about 50° C. to about 60° C.