Dispersion and process for production of moldings by using the same

Abstract

A shaped article (e.g., a porous material, and a spherical particle) comprising (A) a resin component is produced by kneading the resin component (A) (e.g., a thermoplastic resin) and a water-soluble auxiliary component (B) to prepare a dispersed composition, and eluting the auxiliary component (B) from the dispersed composition. The auxiliary component (B) may comprise 100 parts by weight of an oligosaccharide (B1) and 0.5 to 100 parts by weight of a water-soluble plasticizing component (B2) for plasticizing the oligosaccharide. The oligosaccharide (B1) may comprise a tetrasaccharide. The plasticizing component (B2) may comprise a saccharide or a sugar alcohol. Use of the dispersed composition ensures to form a shaped article having a given shape industrially with advantage even in the case of using a wide variety of resin components.

Description

TECHNICAL FIELD [0001] The present invention relates to a dispersed composition (or a resin composition forming a disperse system) which comprises a resin component and a water-soluble auxiliary component and is useful for shaping the resin component into a figure such as a porous material or a particulate, a process for producing a shaped article by using the dispersed composition, and a water-soluble auxiliary agent to be used in combination with a resin to form a dispersed composition. BACKGROUND ART [0002] For producing a resinous shaped article having a desired shape such as a porous material or a particle, various processes have been utilized. For example, Japanese Patent Application Laid-Open No. 2825 / 2001 (JP-2001-2825A) discloses a process for producing a porous material, comprising melt-kneading a pore-forming agent fusible at a molding temperature and a high molecular substance such as a resin, molding the kneaded matter to make a full (non-porous) shaped article containi...

AI Technical Summary

Benefits of technology

The present invention is about a dispersed composition that can be used to make shaped articles with uniform pore size or particle size. The composition includes a resin component and an auxiliary component. The auxiliary component is made up of at least an oligosaccharide and a plasticizing component. The plasticizing component can effectively plasticize the oligosaccharide even if it is thermally decomposable. The composition can be used with a wide range of resin components and has good viscosity and flow properties. The technical effect of this invention is to provide a stable and effective composition for making shaped articles with uniform pore size or particle size.

Problems solved by technology

However, in the case where a proportion of a pore-forming agent (erythritol having a low melting point or pentaerythritol having a high melting point) in a resin composition is increased, the resin composition is deteriorated in melt-kneading property and the size uniformity of the generated pores is decreased.

More specifically, in kneading of the resin and erythritol, melting of erythritol having a low melting point induces decrease in viscosity of the resin composition and remarkable deterioration in melt-kneading property of the resin composition.

Moreover, a resin composition containing pentaerythritol at a high proportion can be melt-kneaded, however, part of pentaerythritol remains as an unmelted matter and it is impossible to obtain a porous material having a uniform pore size.

In this process, however, it is necessary not only that the dispersed phase and the continuous phase are incompatible with each other, but also that an applicable combination of the resin constituting the continuous phase with the solvent is selected depending on the kind of the resin of the dispersed phase.

Therefore, the combination of the resins should be limited to a specific one, and in addition, the combination of the resin with the solvent should be limited to a specific one.

Further, in a step of cooling the dispersed composition, the resins incompatible with each other tend to form a large phase in the separation.

Therefore, if the dispersed composition is not carefully solidified, the once produced dispersed phases will be gathered or aggregated again, and as a result, it is impossible to obtain a spherical fine particle having a given shape.

However, recovery of the resin in the solution not only is very difficult but also is a caused factor of increase in the production cost of the resin particle.

Moreover, in the case of discarding the resin solution directly as a waste fluid, there is concern about adverse effects on the environment.

Even in these processes, however, since it is necessary that a resin and a water-soluble polymer are incompatible with each other, a selectable combination of the resin is limited, and in addition, the particle size distribution of thus resulting resin particle is insufficient in uniformity.

Further, these water-soluble polymers having small solubilities to water need a large amount of water for dissolution, and in addition, significantly deteriorate productivity of resin particles due to the slow velocity of dissolution.

Furthermore, since such water-soluble polymers are often derived from unnatural products, a waste fluid containing such a water-soluble polymer dissolved therein adversely affects on the environment.

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