Polypropylene resin pre-expanded particles and in-mold foamed articles prepared therefrom
AssigneeKaneka Corporation
InventorsTaro Kiguchi, Tomonori Iwamoto
Life of this patent
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Abstract
An object of the present invention is to provide an in-mold foamed article having good surface appearances and high rigidity produced by using a common molding machine that withstands a pressure of up to 0.4 MPa. The present invention provides polypropylene resin pre-expanded particles containing a base resin which is a resin having a melt flow rate of 5 g/10 min or more and 20 g/10 min or less and a melting point of 140° C. or higher and 155° C. or lower and satisfying the conditional formula below, and an in-mold foamed article produced from molding the pre-expanded particles: [Heat of crystal fusion (J/g)]≧1.2×[Melting point (° C.)]−96.
Claims5
A polypropylene resin pre-expanded particle comprising a base resin that has a MFR of 5 g/10 min or more and 20 g/10 min or less and a melting point of 140° C. or higher and 155° C. or lower,
- wherein the base resin is a mixture containing:
- 70 percent or more and 95 percent or less by weight of a polypropylene resin (A) having a MFR of 10 g/10 min or more and 30 g/10 min or less and a molecular weight distribution Mw/Mn of 6 or less, and containing 1-butene as a comonomer;
- and
- 5 percent or more and 30 percent or less by weight of a polypropylene resin (B) having a MFR of 0.1 g/10 min or more and 3 g/10 min or less, and
- the base resin exhibits a relationship between a heat of crystal fusion and the resin melting point determined with a differential scanning calorimeter satisfying conditional formula (1):
- [Heat of crystal fusion (J/g)]≧1.2×[Melting point (° C.)]−96 (1).
Dependencies are inferred from the claim text.