▎ 摘　　要

NOVELTY - Preparing submicron active heavy calcium carbonate comprises preparing reinforced compound material comprises e.g. graphene powder, phosphite, silicone elastomer particle and dipropylheptyl phthalate, preparing strengthening modified material comprises taking ethylene propylene diene monomer rubber and silicone elastomer particles, grinding to powder, preparing comprehensive molding heat dissipation material comprises adding graphene powder to a stirring and dispersing machine, stirring the mixed material, obtaining mixed material, taking carbonate dry powder, adding water to make slurry, taking stearic acid, adding to slurry, stirring, mixing to obtain initial modified slurry, taking out, adding graphene powder, stirring, drying, taking modified grinded calcium carbonate block, crushing to obtain an active heavy calcium carbonate dry powder, grinding and taking out heavy calcium carbonate powder, adding mixed powder material, stirring, mixing to obtain product, packaging and storing. USE - The submicron active heavy calcium carbonate is useful in biaxially oriented polypropylene film (claimed). ADVANTAGE - The method ensures that the obtained powder has excellent heat-resistant oxygen aging performance and heat-resistant oxygen photo aging performance; improves the aging resistance of biaxially oriented polypropylene film; improves the mechanical properties of biaxially oriented polypropylene film; avoids the breakage of the film under the action of thermal oxygen and light; improves the durability of the biaxially oriented polypropylene film and improves the service life of biaxially oriented polypropylene film. DETAILED DESCRIPTION - Preparing submicron active heavy calcium carbonate comprises (a) preparing reinforced compound material including 10-12 pts. wt. graphene powder, 100-120 pts. wt. liquid o-methoxyphenol, 10-12 pts. wt. phosphite, 10-12 pts. wt. ethylene propylene diene monomer rubber, 10-12 pts. wt. silicone elastomer particles and 10-12 pts. wt. dipropylheptyl phthalate, (b) preparing strengthening modified material including taking 10-12 pts. wt. ethylene propylene diene monomer rubber and 10-12 pts. wt. silicone elastomer particles, adding in a mixing and grinding kettle, grinding into powder with a grinder, (c) preparing anti-aging material including taking 10-12 pts. wt. phosphite, 10-12 pts. wt. dipropylheptyl phthalate and 100-120 pts. wt. liquid o-methoxyphenol, adding into a stirring and dispersing machine for stirring, (d) preparing comprehensive molding heat dissipation material including adding 10-12 pts. wt. graphene powder to the inside of the stirring and dispersing machine in step (c), continuing stirring the mixed material, obtaining mixed material, (e) taking 100-120 pts. wt. carbonate dry powder with a particle size of 4-7 microm into a stirring reaction kettle, adding pure water to make a slurry with a solid mass fraction of 75%, (f) taking 10-30 pts. wt. stearic acid, adding to the interior of the slurry prepared in step (e), fully stirring, mixing to obtain an initial modified slurry, (g) taking out the initial modified slurry in step (f), adding 10-12 pts. wt. graphene powder to the interior of the initial modified slurry, turning on a stirring and dispersing machine, stirring, (h) stopping the stirring, taking the slurry, drying in a drying oven at 200degrees Celsius, (i) taking the modified grinded calcium carbonate block, crushing at a high speed for 3 minutes to obtain an active heavy calcium carbonate dry powder, grinding calcium carbonate powder to a diameter of 2 microm using a grinder and (j) taking out the heavy calcium carbonate powder in step (i), adding the mixed powder material obtained in step (d), continuing stirring, mixing at a speed of 600revolutions/minute for 240 minutes to obtain product, packaging and storing.