JPS62212463A - Production of high-molecular porous article - Google Patents

Abstract

PURPOSE:To obtain the titled porous article easily and inexpensively by controlling the pore size and porosity with relatively high accuracy, by dissolving a resin in a solvent, adjusting the viscosity and the concn. of the soln., molding the resulting resin soln., immersing the molding in a specified solvent bath and taking off it. CONSTITUTION:A resin A (e.g., nylon 6, 6) is dissolved in a solvent B (e.g., formic acid) and the viscosity and the concn. of the soln. are suitably adjusted. The resulting resin soln. 3 is molded by a molding means 1 such as an extruder. The molding 6 is immersed in a bath placed in a bath apparatus 2 for solvent extrusion, said bath containing a solvent C which is compatible with the solvent B and does not dissolve the resin A, whereby only the solvent B in the molding 6 is dissolved out and diffused in the solvent C and the resin A is solidified to form a porous article. The molding 6 in the form of the porous article is taken off through a roller 7 to obtain the titled porous article.

Description

[Detailed description of the invention] Industrial use bone The present invention relates to a method for producing a porous polymer body.

2. Prior Art The conventional manufacturing method of this type is as follows: (1) A resin is dissolved in a solvent, a non-solvent is added thereto, and after molding, the solvent is first evaporated to form a thin film containing a liquid of spherical fine particles of the non-solvent. The non-solvent is then removed at high temperature, leaving traces of it as micropores.

(2) After extrusion molding, the film surface is scratched or holed by fine embossing or punching, and then stretched to create the required cleavage openings.

(3) Solid powder that can be eluted and removed with a certain solvent is mixed into the resin in advance, and after molding, the solid powder is removed to form a porous body.

and so on.

As a similar method to the above (+), a similar operation can also be performed by adding a non-solvent to the monomer or moderately polymerized product.

Regarding the conventional techniques shown in Problems (1) and (3) to be solved by the invention, barometers such as solvent type, concentration, non-solvent (or solid powder) type and concentration, resin molecular weight, temperature, resin extrusion pressure, etc. Because of the complex relationships involved, it is difficult to find the optimal conditions for a single product, and manufacturing management is also extremely difficult.Furthermore, because there are too many parameters, fine control of pore diameter, porosity, etc. is difficult.

Further, in the conventional technique (2) above, it is difficult to control the hole diameter and the strength is reduced because a clutch is intentionally generated. This method also has the disadvantage that it can only be applied to some resins such as polypropylene.

There are other methods for producing porous polymers other than those described above, but in general: (1) Since there are many parameters in product production, detailed control is difficult and production management is troublesome.

■ It is difficult to find the optimal conditions for each product and it is difficult to have many product groups.

■ It is not possible to do the resin molding process and the hole making process at the same time.

There is a common drawback.

Purpose of the Invention The present invention has been made in view of the above circumstances, and the number of parameters for manufacturing porous polymer materials is extremely reduced, and by reducing these parameters, the pore diameter and porosity can be controlled with relative precision. Moreover, it is an object of the present invention to provide a method for producing a porous polymer body in which molding of the porous polymer body and pore formation can be performed simultaneously.

Means and Effects for Solving the Problems In order to achieve the above objects, the present invention provides a method for replacing resin A with solvent B.
After molding the dissolved fat 3 by a molding means, the molded body 6 is immersed in a bath of a solvent C that is compatible with the solvent B and does not dissolve the resin A, and the solvent B is mixed between the resin A and the resin A. It is designed to be diffused and extruded into a bath.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. In the drawings, 1 is an extruder, and 2 is a solvent extrusion bath device.

Said extruder! The molten resin 3 whose viscosity and concentration have been adjusted in advance (for example, (nylon 6.6 as resin A)
(formic acid as solvent B)) is supplied.

The solvent extrusion bath device 2 also contains a solvent C (for example, water).

When the extruder 1 is operated, the molded body 6 made of the melted resin 3 formed into a sheet by the mold 5 at the tip of the extruder 1 is immediately immersed in the bath of the solvent C in the bath device 2 for solvent extrusion. This solvent C has good compatibility with the solvent B in the dissolved resin 3, but does not cause any chemical change or dissolve the resin A in the dissolved resin 3.

Then, of the dissolved resin 3 immersed in the solvent extrusion bath device 2, only the solvent B diffuses into the solvent C bath.

Molecules C of solvent C or molecules of diffused solvent B are inserted into the portions of dissolved resin 3 where molecules of solvent B were present. The concentration is determined by the concentration of solvent B (since it is solvent C, almost all of the molecules of solvent H on the surface are replaced with molecules C of solvent C. In this way, the molecules of solvent B inside the surface gradually change to molecules C.
, and finally all of them are replaced with molecule Q (see Figure 2).

In this process, resin A, which was initially in a sol state, gradually loses its freedom due to the diffusion of solvent H, and finally solidifies completely and contains solvent C, which has no influence on resin A, in the pores. It becomes porous.

The molded body 6 formed into a porous body in this manner is taken up in a four-rough manner.

In the above-described method for producing a porous polymer, any pore size,
The concentration and viscosity of the dissolved resin 3 are determined based on the porosity.

Further, if necessary, a second solvent, a viscosity modifier, a solid powder, etc. may be added.

The shape of the porous polymer body produced by the method for producing a porous polymer body described above is not limited to a sheet, but may be a tube shape or an irregular shape, and the shaping means is not limited to extrusion molding, but may also be dip molding.

That is, as shown in FIGS. 3 to 5, a stainless steel rod 8 is inserted into a bath of melted resin @ 3 and then pulled out of the bath to allow the melted resin 3 to stick to the surface of the stainless steel rod 8 in a film form. .

This stainless steel rod 8 may be immersed in a bath of solvent C to diffuse the solvent B in the dissolved resin 3 and replace the molecules of solvent B with the molecules C of solvent C.

By doing so, a porous tube can be manufactured. FIG. 6 shows a cross section of the porous tube. From FIG. 4, it can be seen that the porous portion 9 has fine and uniform pore diameters.

Effects of the Invention As detailed above, in the method for producing a porous polymer according to the present invention, after molding the melted resin 3 obtained by dissolving resin A in solvent B using a molding means, this molded body 6 is It is characterized in that it is immersed in a bath of solvent C that is compatible with solvent B and does not dissolve resin A, and that solvent B is diffused and extruded from between resin A into the bath.

Therefore, once a resin and a suitable solvent are selected, the porous polymer material is determined approximately by the solvent concentration and the viscosity of the dissolved resin.

In this way, the number of parameters for manufacturing the porous polymer material is extremely reduced, and by reducing these parameters, the pore diameter and porosity can be controlled with relative precision.

Furthermore, the molding of the porous polymer and the formation of pores can be performed simultaneously, the pore diameter of the porous polymer becomes uniform from the surface to the inside, and there is no need for heating, resulting in energy savings.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of one embodiment of the present invention, Fig. 2 is an explanatory diagram of a molecular exchange model of a porous polymer body, @Figs. 3 to 5 are explanatory diagrams of other embodiments of the present invention, and Fig. 6 The figure is a cross-sectional view of a porous polymer body. 3 is a dissolved resin, 6 is a molded article, A is a resin, B is a solvent, and C is a solvent.

Claims (1)

[Claims] After molding the melted resin 3 made by dissolving resin A in solvent B using a molding means, this molded body 6 is immersed in a bath of solvent C that is compatible with solvent B and does not dissolve resin A.
A method for producing a porous polymer material, characterized in that the material is diffused and extruded from between resin A into a bath.