Information recording tape
An information recording tape including a data-recording area and a non-data-recording area, with the data-recording area having a center-line average surface roughness Ra smaller than 3 nm and at most 100/mm 2 of protuberances standing at least 20 nm high, and with the non-data-recording area having a center-line average surface roughness Ra greater than 2 nm and more than 100/mm 2 of protuberances standing at least 20 nm high.
1 . An information recording tape comprising a data-recording area and a non-data-recording area, wherein
the data-recording area has a first center-line average surface roughness Ra smaller than 3 nm and first protuberances having at least 20 nm heights at 100/mm 2 or less and
the non-data-recording area has a second center-line average surface roughness Ra greater than 2 nm and second protuberances having at least 20 nm heights at 100/mm 2 or more.
2 . The information recording tape according to claim 1 , wherein a first center-line average surface roughness Ra is 1 to 2.5 nm.
3 . The information recording tape according to claim 1 , wherein a first center-line average surface roughness Ra is 1 to 2 nm.
4 . The information recording tape according to claim 1 , wherein the data-recording area has first protuberances having heights of 20 to 60 nm at 100/mm 2 or less.
5 . The information recording tape according to claim 1 , wherein the data-recording area has first protuberances having heights of 20 to 40 nm at 100/mm 2 or less.
6 . The information recording tape according to claim 1 , wherein the data-recording area has first protuberances having at most 20 nm heights at 1 to 50/mm 2 .
7 . The information recording tape according to claim 1 , wherein the data-recording area has first protuberances having at most 20 nm heights at 1 to 20/mm 2 .
8 . The information recording tape according to claim 1 , wherein a second center-line average surface roughness Ra is 3 to 10 nm.
9 . The information recording tape according to claim 1 , wherein a second center-line average surface roughness Ra is 3 to 7 nm.
10 . The information recording tape according to claim 1 , wherein the non-data-recording area has second protuberances having heights of 20 to 60 nm at 100/mm 2 or more.
11 . The information recording tape according to claim 1 , wherein the non-data-recording area has second protuberances having heights of 20 to 40 nm at 100/mm 2 or more.
12 . The information recording tape according to claim 1 , wherein the data-recording area has second protuberances having at most 20 nm heights at 200 to 500/mm 2 .
13 . The information recording tape according to claim 1 , wherein the data-recording area has second protuberances having at most 20 nm heights at 200 to 300/mm 2 .
14 . The information recording tape according to claim 1 , wherein the information recording tape is a magnetic tape.
15 . The information recording tape according to claim 14 , wherein the magnetic tape comprises a support and a magnetic layer containing a binder and a ferromagnetic powder dispersed in the binder.
16 . The information recording tape according to claim 15 , wherein the magnetic tape further comprises a back layer.
17 . The information recording tape according to claim 15 , wherein the magnetic tape further comprises a non-magnetic layer between the support and the magnetic layer.