摘要:
A process of producing a foamed molding, wherein expanded, substantially non-crosslinked polypropylene-based resin beads are heated in a mold to fuse-bond the beads together into a unitary body. Each of the expanded beads has been surface-modified with an organic peroxide.
摘要:
A composite foamed polypropylene resin molding including a plurality of sections which are fuse-bonded to each other, at least two of which differ from each other in color, apparent density, composition and/or mechanical strengths, each of which is formed from expanded polypropylene resin beads, and each of which shows a high temperature endothermic peak in a DSC curve thereof. At least one of the sections satisfies conditions (d) to (f) at the same time: (d) to be formed from specific expanded polypropylene resin beads of a base resin having a tensile modulus of at least 1,200 MPa, (e) to have an apparent density D2 of 10–500 g/L, and (f) to have such a high temperature endothermic peak with a calorific of E2 J/g, wherein D2 and E2 have the relationship 20−0.020×D2≦E2≦65−0.100×D2. The composite molding may be prepared by filling expanded polypropylene resin beads in each of a plurality of contiguous spaces defined in a mold cavity and heating the expanded beads to fuse-bond respective expanded beads together into a unitary body. At least one of the spaces is filled with the specific expanded polypropylene resin beads.
摘要:
A process of producing a foamed molding, wherein expanded, substantially non-crosslinked polypropylene-based resin beads are heated in a mold to fuse-bond the beads together into a unitary body. Each of the expanded beads has been surface-modified with an organic peroxide.
摘要:
A process for the production of expanded beads, including kneading a base resin containing a polypropylene resin and having a tensile modulus of at least 1,200 MPa together with a mixture of a coloring agent and a thermoplastic polymer having a tensile modulus lower than that of the base resin to form a kneaded mixture including a matrix of the base resin and a multiplicity of domains dispersed in the matrix and each containing the thermoplastic polymer and the coloring agent. The kneaded mixture is formed into resin particles, then treated with an organic peroxide to modify surfaces of the resin particles therewith. Foaming and expanding of the surface-modified resin particles gives expanded beads having an inside region surrounded by a surface region. The heat of fusion of a high temperature peak of the surface region is lower than that of the inside region.
摘要:
Expanded, substantially non-crosslinked polypropylene resin beads capable of producing a high rigidity foamed molding at a relatively low temperature. The beads are produced by a process including a step of dispersing substantially non-crosslinked polypropylene resin particles in a dispersing medium containing an organic peroxide to obtain a dispersion, a step of heating the dispersion to decompose the organic peroxide and to modify the surface of the surface-modified polypropylene resin particles, and a step of expanding the non-crosslinked, surface-modified polypropylene resin particles using a blowing agent.
摘要:
A composite foamed polypropylene resin molding including a plurality of sections which are fuse-bonded to each other, at least two of which differ from each other in color, apparent density, composition and/or mechanical strengths, each of which is formed from expanded polypropylene resin beads, and each of which shows a high temperature endothermic peak in a DSC curve thereof. At least one of the sections satisfies conditions (d) to (f) at the same time: (d) to be formed from specific expanded polypropylene resin beads of a base resin having a tensile modulus of at least 1,200 MPa, (e) to have an apparent density D2 of 10-500 g/L, and (f) to have such a high temperature endothermic peak with a calorific of E2 J/g, wherein D2 and E2 have the relationship 20−0.020×D2≦E2. ≦65−0.100×D2. The composite molding may be prepared by filling expanded polypropylene resin beads in each of a plurality of contiguous spaces defined in a mold cavity and heating the expanded beads to fuse-bond respective expanded beads together into a unitary body. At least one of the spaces is filled with the specific expanded polypropylene resin beads.
摘要:
A process for the production of expanded beads, including kneading a base resin containing a polypropylene resin and having a tensile modulus of at least 1,200 MPa together with a mixture of a coloring agent and a thermoplastic polymer having a tensile modulus lower than that of the base resin to form a kneaded mixture including a matrix of the base resin and a multiplicity of domains dispersed in the matrix and each containing the thermoplastic polymer and the coloring agent. The kneaded mixture is formed into resin particles, then treated with an organic peroxide to modify surfaces of the resin particles therewith. Foaming and expanding of the surface-modified resin particles gives expanded beads having an inside region surrounded by a surface region. The heat of fusion of a high temperature peak of the surface region is lower than that of the inside region.
摘要:
A composite foamed polypropylene resin molding including a plurality of sections which are fuse-bonded to each other, at least two of which differ from each other in color, apparent density, composition and/or mechanical strengths, each of which is formed from expanded polypropylene resin beads, and each of which shows a high temperature endothermic peak in a DSC curve thereof. At least one of the sections satisfies conditions (d) to (f) at the same time: (d) to be formed from specific expanded polypropylene resin beads of a base resin having a tensile modulus of at least 1,200 MPa, (e) to have an apparent density D2 of 10-500 g/L, and (f) to have such a high temperature endothermic peak with a calorific of E2 J/g, wherein D2 and E2 have the relationship 20−0.020×D2≦E2≦65−0.100×D2. The composite molding may be prepared by filling expanded polypropylene resin beads in each of a plurality of contiguous spaces defined in a mold cavity and heating the expanded beads to fuse-bond respective expanded beads together into a unitary body. At least one of the spaces is filled with the specific expanded polypropylene resin beads.
摘要:
A method for producing expanded polypropylene resin particles wherein polypropylene resin particles impregnated with a physical blowing agent are heated along with an aqueous medium and a dispersant and are released and expanded at reduced pressure from the interior of a pressure-tight vessel, wherein the aforementioned aqueous medium has an electrical conductivity of from not less than 0.00 ms/m to not more than 20.00 mS/m. The resulting particles obtained are without inconsistencies caused by differences in the amount of dispersant adhering to the particles or the amount of dispersant added to prevent the particles from fusing together during the heat treatment step of the method.
摘要:
A process of producing a foamed molding, wherein expanded, substantially non-crosslinked polypropylene-based resin beads are heated in a mold to fuse-bond the beads together into a unitary body. Each of the expanded beads has been surface-modified with an organic peroxide.