Resin composition, molded article, master batch, and manufacturing methods therefor
The invention provides a thermoplastic resin composition, a molded article, and production methods therefor. The thermoplastic resin composition can sufficiently exhibit a cellulose addition effect and impart excellent mechanical strength to the molded article, particularly a foam molded article. More specifically, the invention provides a resin composition and a foam molded article thereof. The resin composition contains: a cellulose fiber (A); an amorphous resin (B) having a glass transition temperature of 160° C. or lower; a crystalline resin (C) having a melting point (melting peak temperature) of 80° C. to 150° C. and a melting start temperature lower than the melting point by 30° C. or more; and a thermoplastic resin (D) having a melting point or a glass transition temperature higher than the melting point of the crystalline resin (C) by 5° C. or more.
1 . A production method for a master batch, comprising:
a step of melt-kneading
an aggregate of a cellulose fiber (A),
an amorphous resin (B) having a glass transition temperature of 160° C. or lower,
a crystalline resin (C) having a melting point (melting peak temperature) of 80° C. to 150° C. and a melting start temperature lower than the melting point by 30° C. or more, and
a defibering auxiliary (E) having a boiling point of 120° C. or lower;
wherein:
the amorphous polymer (B) is a polymer having an ester bond, an ether bond, a urea bond, a hydroxyl group, an amino group, or a carboxyl group;
the crystallizable polymer (C) is an olefin-based polymer; and
wherein:
the amorphous resin (B) is present in an amount ranging from 5 parts by mass or more to 100 parts by mass or less based on 100 parts by mass of solid content of the aggregate of cellulose fiber (A); and
the crystalline resin (C) is present in an amount ranging from 10 parts by mass or more to 150 parts by mass or less based on 100 parts by mass of solid content of the aggregate of cellulose fiber (A).
2 . The production method for a master batch according to claim 1 , wherein
the defibering auxiliary (E) is one or more auxiliary selected from a water-soluble alcohol, a ketone, an ether, and water.
3 . A production method for a resin composition, comprising:
a step of producing a master batch by the production method according to claim 1 ; and
a step of melt-kneading a thermoplastic resin (D) having a melting point or a glass transition temperature higher than the melting point of the crystalline resin (C) in the master batch by 5° C. or more;
wherein the thermoplastic resin (D) is polypropylene, a poly acetal, or a polyamide.
4 . A production method for a molded article, comprising:
a step of producing a resin composition by the production method according to claim 3 ; and
a step of molding the obtained resin composition.
5 . The production method for a molded article according to claim 4 , wherein
the step of molding the resin composition is a supercritical molding method.