The invention relates to a preparation method of a
battery pack sealant, and belongs to the technical field of
adhesive preparation, and the preparation method comprises the following steps: S1, under protective gas, heating and adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-
oxide, polysiloxane containing
double bond end hydroxyalkyl and an initiator at 90-110 DEG C, and devolatilizing to obtain an intermediate; dehydrating, adding diisocyanate and a catalyst, and reacting to obtain a
prepolymer; dropwise adding glycidyl for blocking until an
isocyanate peak disappears to obtain a modifier; s2, carrying out vacuum dispersion on 100 parts of matrix resin, 15-40 parts of a modifier, 100-300 parts of an insulating heat-conducting filler and 1-5 parts of a
coupling agent to obtain a component A; s3, taking 20-50 parts of a curing agent as a component B; s4, uniformly mixing A and B, primarily curing at
room temperature, and heating and curing to obtain the
sealant, the
sealant solves the problem that a traditional additive
flame retardant is easy to migrate and separate out, and the
battery pack sealant is endowed with long-acting and stable
flame-retardant safety performance.