Talk about Type90, i got some information from Chinese document which mention about the armor composite used on Type88 which is the prototype for Type90 recently. Not sure the exact truth but i would like to share.
“Japanese Type88 tank's turret and hull composite armor were trying to use different ceramic material (Alumina、Silicon oxide or Silicon carbide ceramic cut in rectangle or hexagon),each layer using binder to bonded together. The protection of this armor can reach up equal to 400mm thick of armour steel (BK) and is capable of defeat 120mm high density KE projectile (muzzle velocity>1600m/s) fired from 200meters at 0 degree, and also capable to protect against the 120mm HEAT shell which capable of penetrating 600mm of armor. Besides, there are many of different type of armor plate, the use of ceramic material and it's ability of protection giving the armor research development a new direction”
image10 Type88 tank's spaced (composite) armor structure.
陶瓷板=Ceramic plate 毫米=mm
Other than this，japan seems are developing some kind of Kevlar composite
It says:"Japan is currently develop a Kevlar fiber with Titanium alloy or aluminum structured multi-layer composite armor "
Of course those are just for the prototype of type90, but we can try guessing the armor from this
<<间隔（复合）装甲——现代坦克的主要装甲结构>>(1982) (Composite armor--the main structure of the armor for modern MBT) (1982)
<<国外复合装甲中非金属材料的应用和研究概况>>(1983) （Summarize of the use and research of non-metallic material in foreign composite armor）（1983）