Polyester molding for use with a casing
By molding a biodegradable plastic material which is treated with a compound reactive to the active hydrogen in the biodegradable plastic material, a biodegradable plastic material and molding having long-term reliability are obtained.
1. The method for manufacturing a biodegradable plastic molding, comprising;
simultaneously or individually adding and blending a silicate and a compound reactive to active hydrogen to a biodegradable plastic material wherein the biodegradable plastic material comprises a polycaprolactone before, while or after melting the biodegradable plastic material, said compound reactive to active hydrogen comprising a bridging agent having a carbodiimide group comprising diisopropylcarbodiimide;
determining the quantity of active hydrogen contained in the biodegradable plastic material treated with the compound reactive to hydrogen by measuring the amount of residual fatty acids; and
molding said biodegradable plastic material.
2. The method for manufacturing a biodegradable plastic molding according to claim 1 , wherein said molding comprises film molding, extrusion molding or injection molding.
3. The method for manufacturing a biodegradable plastic molding according to claim 1 , wherein a silicon dioxide content of said silicate is 50% or more.
4. The method for manufacturing a biodegradable plastic molding according to claim 1 , wherein said silicate takes the form of particles having an average diameter of 50 μm or less.
5. The method for manufacturing a biodegradable plastic molding according to claim 1 , wherein said measuring the amount of fatty acids is equivalent to determining the amount of carboxyl groups in the biodegradable plastic molding which is equivalent to determining the amount of active hydrogen.
6. The method for manufacturing a biodegradable plastic molding according to claim 5 , wherein measuring the amount of fatty acids employs a 0.02 N KOH-EtOH solution, a phenolphthalein solution, and a phenol red solution as reagents.