Calcium carbonate filler for resin, process for producing the same, and resin composition containing the filler

Abstract

A calcium carbonate filler for a resin, in which the content rate of particles having a particle diameter of 0.26 μm or less is 30% or less in a number particle size distribution diameter measured (Mac-VIEW manufactured by Mountech) from an electron micrograph, and which satisfies the following expressions (a) to (c) is provided.5/5≦3  (a)1≦≦8 (m/g)  (b)≦300 (ppm)  (c)whereinDms5: A 5% diameter (μm) accumulated from a small particle side in a volume particle size distribution by a laser diffraction particle size distribution measuring device (MASTERSIZER2000 manufactured by Malvern); Dmv5: A 5% diameter (μm) accumulated from a small particle side in a number particle size distribution in a particle diameter (Mac-VIEW manufactured by Mountech) measured with an electron microscope; Sw: A BET specific surface area (Macsorb manufactured by Mountech) (m/g); Mo: A water amount (ppm) by the Karl Fischer method at 200 to 300° C. The calcium carbonate filler for a resin of the present invention contains less fine powders, has a particle size which has been adjusted to a specific particle size, and contains less volatile components such as water etc. and, even when it is incorporated into a resin having a high processing temperature at a high concentration, problems such as foaming etc. are solved.