Composite resin molded product with adjusted decomposition rate, and production method therefor

A production method for a composite resin molded product, comprising:

• a step of preparing a microorganism or an enzyme, natural fibers, a hydrolyzable coating resin, and a main agent resin;
• a step of including the microorganism or the enzyme in the natural fibers;
• a coating resin melt-kneading step of melt-kneading the natural fibers containing the microorganism or the enzyme together with the coating resin, advancing defibration from an end part in a fiber length direction of each of the natural fibers containing the microorganism or the enzyme, and expanding a surface area of a defibrated part of the end part;
• and
• a step of molding the composite resin molded product after kneading coated natural fibers, obtained by coating at least a part of a surface of each of the natural fibers with the coating resin, together with the main agent resin.

A composite resin molded product, comprising:

• a main agent resin;
• and
• a plurality of natural fibers dispersed in the main agent resin,
• wherein the plurality of natural fibers each contain a microorganism or an enzyme,
• when the composite resin molded product is 100% by mass, a content rate of the plurality of natural fibers each containing the microorganism or the enzyme in the composite resin molded product is 10% by mass or more and 99% by mass or less,
• at least one of the plurality of natural fibers is exposed on a surface of the composite resin molded product,
• at least a part of a surface of the at least one of the plurality of natural fibers is coated with a hydrolyzable coating resin, and
• wherein the coating resin is a polyester resin.