MySQL data storage requirements can be found here: MySQL5 storage requirements
There I find this table (L = length of string):
TINYBLOB, TINYTEXT L + 1 bytes, where L < 2^8 = 256b
BLOB, TEXT L + 2 bytes, where L < 2^16 = 65.536 = 65kb
MEDIUMBLOB, MEDIUMTEXT L + 3 bytes, where L < 2^24 = 16.777.216 = 16mb
LONGBLOB, LONGTEXT L + 4 bytes, where L < 2^32 = 4.294.967.296 = 4.3gb
So for 80Mb page, you need a LONGTEXT. For PDF I would advice a LONGBLOB type, since this is binary format.
For the record: Eggyal has a point that it is better NOT to store this PDF in the database, but on disk. So I would advice on no doing it via the database, if you really need to put it in MySQL use a LONGBLOB