Kaneka Corporation

Takayuki Goda

Tomonori Iwamoto

Tsuyoshi Mihayashi

Yutaka Yanagihara

Ayaka Fujishita

A novel modified polypropylene resin is provided which makes it possible to provide, by an extrusion expansion method, expanded polypropylene-based resin particles having an expansion ratio which falls within a wide range and having a low open cell ratio. The novel modified polypropylene resin is obtained by a method of producing the modified polypropylene resin where the method includes a melting and kneading step of melting and kneading a particular random polypropylene resin, a conjugated diene compound, and a particular radical polymerization initiator to obtain the modified polypropylene resin.

Modified polypropylene resin and method for producing same, and extruded foam particles that use said modified polypropylene resin and method for their production

The present invention provides polypropylene resin pre-expanded particles having small fluctuation in cell diameter and expansion ratio compared to in the past. The pre-expanded particles are obtained by having as a base resin, a polypropylene resin composition comprising polypropylene resin (A), a compound having a triazine skeleton and molecular weight of at most 300 per triazine skeleton unit (B) and as a random component, hydrophilic polymer (C) and inorganic filler (D) and water as the foaming agent. By using the pre-expanded particles, a polypropylene resin in-mold expanded article having decreased unevenness in color and fluctuation in weight can be obtained.

Polypropylene resin pre-expanded particle and in-mold expanded article thereof

The object of the present invention is to provide an in-mold foaming article of a propylene resin composition having improved productivity and stable quality in internal molding, and simultaneously a compressive strength and a tensile strength thereof at high density range are improved at the same time. The in-mold foaming article is obtained by using a pre-foamed particle having a density of 90 to 300 g/L and an open cell ratio of at most 12%, wherein the pre-foamed particle comprises a resin composition having (A) 100 parts by weight of a polypropylene resin and (B) 0.01 to 20 parts by weight of a hydrophilic polymer as a base material resin, and water as a foaming agent, the pre-foamed particle having at least two endothermic peaks in a DSC curve obtained in differential scanning calorimetry.

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Settsu, Japan

Takayuki Goda