JPH0713124B2 - Radiation graft polymerization equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a graft polymerization method whose effectiveness has recently been confirmed in the modification and functionalization of polymeric materials, and in particular, radiation grafting using ionizing radiation. The present invention relates to a polymerization device.

(Prior Art) Radiation-induced graft polymerization is a polymerization method that has recently attracted attention in the advanced industrial fields for improving the functionality of materials, since it can impart other properties while making the most of the characteristics of the substrate.
In particular, the greatest feature of radiation graft polymerization is that the shape of the substrate does not matter. For this reason, radiation graft polymerization is the best method to combine functions or increase functionality by introducing functional substances into polymer materials that have functions depending on shape. And it is unrivaled by other methods.

The ionizing radiations used here are α rays, β rays, γ rays,
There are ultraviolet rays, electron beams, etc., and although not limited, γ rays and electron beams are relatively suitable for the present invention.

There are various methods for radiation graft polymerization, and different methods are used depending on the irradiation method and the method of contact with the monomer.

Irradiation methods include a simultaneous irradiation method in which radiation is applied in the coexistence of a base material and a monomer, and a pre-irradiation method in which a base material is previously irradiated and then contacted with a monomer. The less pre-irradiation method is more advantageous, and the pre-irradiation method will be described below.

Further, the method of contacting the base material with the monomer may be in the case where the monomer is a solution or in the case of vapor, and the former is called liquid phase graft polymerization and the latter is called gas phase graft polymerization.

As described above, there are various methods for radiation graft polymerization, and the shape of the base material is powder, particles, fibers (single fiber,
Since there is no limitation on long fibers, woven fabrics, non-woven fabrics), membranes (flat membranes, hollow fiber membranes) and the like, even if the irradiation method is limited to the pre-irradiation method, various radiation graft polymerization apparatuses are conceivable.

The only example of the radiation graft polymerization apparatus that has been put to practical use so far relates to the pre-irradiation liquid phase graft polymerization method, and a flat film is used as the shape of the substrate. In this apparatus, the graft reaction employs a method of sequentially sending the irradiated flat membrane to a chemical bath using a roller.

(Problems to be Solved by the Invention) Due to its structure, the above device can be applied only to a liquid-phase film-shaped substrate. When the shape of the substrate changes or when it is desired to carry out gas phase graft polymerization, the reactor must be devised and designed each time. As described above, there is still no apparatus capable of graft-polymerizing substrates having various shapes in both the liquid phase and the gas phase.

An object of the present invention is to provide a general-purpose radiation graft polymerization apparatus capable of easily graft-polymerizing substrates having various shapes in both liquid phase and gas phase.

(Means for Solving the Problems) In the radiation graft polymerization apparatus according to the present invention, one or more rotatable inner cylinders that are concentric with the cylinder are provided inside the cylinder that can be used both vertically and horizontally. Is characterized by.

(Operation) This inner cylinder is variable in the direction of rotation and the number of rotations and is detachable, and in the liquid phase and gas phase graft polymerization,
It has the following roles.

Storage container for base material Filter for solid-liquid separation (liquid phase) Stirring and homogenization of monomer and base material Rolling roll for long base material Increasing monomer evaporation area (gas phase) (Example) Powder, particles, cut fibers, long fibers (including tubes), band-shaped (nonwoven fabric, flat membrane, etc.)
The embodiments of the polymerization apparatus of the present invention for the liquid phase and gas phase graft polymerization in each case will be described with reference to the drawings.

First, FIG. 1 shows an apparatus in which the shape of the substrate is powder, particles, cut fibers, etc. and liquid phase graft polymerization is performed. These substrates can be handled as slurries in the monomer solution. The cylinder 1 is a horizontal type, and the inside thereof is a graft polymerization part. The inner cylinder 2 has a cylindrical shape surrounded by the cylinder 1 and coaxial with the cylinder 1, and has a structure capable of rotating around a shaft 6. The base material 4 irradiated with the radiation is introduced into the inner cylinder 2, and the monomer solution 5 is introduced into the cylinder 1.
As a material for forming the inner cylinder 2, any material can be used as long as it allows a monomer solution to pass but does not pass through a base material, is not deteriorated by the monomer solution, and has appropriate strength. For example, a wire mesh, a saran net, a cloth, etc., which are attached to an aggregate to form a cylindrical shape can be used. Further, baffle plates 3 are arranged at several locations on the inner circumference of the inner cylinder 2. Inner cylinder 2
When is rotated about the axis 6, the base material 4 and the monomer solution 5 are brought into uniform contact with each other due to the stirring effect of the baffle plate 3. Depending on the combination of the material of the base material and the monomer solution, when the reaction is performed in a stationary state, it may be difficult to carry out a uniform reaction due to generation of bubbles or the like, but in the example of FIG. 1, this is not the case at all. Moreover, since the amount of the monomer liquid may be such that the base material is impregnated,
The saving effect is remarkable compared to the conventional liquid phase graft polymerization. Changing the rotation direction during the polymerization is also preferable from the viewpoint of stirring effect. When the grafting reaction is completed, the monomer solution is withdrawn and the washing process is performed. However, if the drain 7 provided at the bottom of the horizontal cylinder 1 is opened to withdraw the monomer solution, the inner cylinder 2 serves as a filter. Also useful for solid-liquid separation. Further, when the base material 4 is in the form of fine powder, it may take a long time to extract the liquid, so that it may be left in the horizontal shape, but as shown in FIG. 2, the cylinder 1 is vertical and the inner cylinder 2 rotates. If the number is increased and solid-liquid separation is performed by centrifugation, the time until the final graft product is obtained can be greatly shortened. That is, here, the inner cylinder 2 is caused to perform the functions of stirring and solid-liquid separation (filtration or centrifugation).

When the shape of the base material is long fiber (including tube shape) and it is subjected to liquid phase graft polymerization, it can be easily graft-polymerized by handling the fiber by the method as shown in Fig. 3 using a horizontal cylinder. You can That is, the long fibers 4, which are the base material, are wound on the outside of the inner cylinder 2 to cause a reaction. In this case, the inner cylinder 2 plays the role of a roll for stirring and winding the fiber, and the constituent material does not necessarily have to be a wire mesh or a saran net, and may be an aggregate as it is.

When the substrate is tubular, it can be wound as shown in FIG. 3, but if that is not possible, it can be placed inside the inner cylinder 2 and reacted as shown in FIG. It can be considered that the lengths of the cylinder 1 and the inner cylinder 2 shown in FIG. 1 are extended to the length of the tube.

When the base material has a strip shape (flat membrane, woven fabric, non-woven fabric) and liquid-phase grafting is performed, the method shown in FIG. 5 can be employed, for example. The irradiated strip-shaped base material 4 is wound around the outer side of the inner cylinder 2 while sandwiching an appropriate spacer 9 therebetween, and is rotated to make contact with the monomer solution 5.
In this case, the inner cylinder 2 plays a role of a roll for winding the base material 4 and a role of uniform contact with the monomer solution by rotation.

On the other hand, in the vapor phase graft polymerization, the monomer vapor and the base material are brought into contact with each other, so that it is necessary to lower the liquid level of the monomer. That is, referring to the example of FIG. 1, the liquid surface of the monomer needs to be positioned below the inner cylinder 2. The base material 4 comes into uniform contact with the monomer vapor due to the rotation of the inner cylinder 2, but when the monomer vapor pressure is low, the monomer supply amount is small compared to the number of radicals, so it takes a long time to obtain a predetermined graft ratio. Required. Since the amount of monomer evaporation also depends on the evaporation area, if an inner cylinder 8 is further provided outside the inner cylinder 2 as shown in FIG. Holds the monomer solution in the
The entire inner cylinder 8 serves as a monomer evaporation surface to increase the grafting rate, and it is possible to make the monomer vapor concentration uniform. A material having a large surface area, for example, a mat-shaped material, a woven material, or a non-woven material is preferable as a constituent material of the inner cylinder 8, and a wire net or the like having good vapor diffusion is preferable as a constituent material of the inner cylinder 2.

Regardless of the shape of the base material such as long fiber, tube shape, band shape, etc., when vapor phase grafting is performed, be careful not to place the monomer liquid surface below the inner cylinder 2 so as to avoid direct contact with the base material. Is as described above, and in addition,
The method of increasing the monomer evaporation area by providing the inner cylinder 8 on the outer side of the inner cylinder 2 can be performed in the same manner as the above-mentioned method. That is, the role of the inner cylinder 2 in the gas phase graft polymerization is to make the base material a container for preventing direct contact with the monomer solution, and at the same time to make uniform contact with the monomer vapor. Increasing the grafting rate by increasing it and homogenizing the monomer vapor concentration.

As mentioned above, if you prepare several kinds of inner cylinders matching the shape of the base material, you can graft-polymerize various base materials not only in the liquid phase but also in the gas phase simply by replacing the inner cylinder. You can

(Experimental example) Porous hollow fiber membrane 5 made of polyethylene with an outer diameter of approximately 1 mm and a length of 15 cm
After irradiating 00 lines with 20 Mrad of accelerated electron beam in a nitrogen atmosphere,
Put it in a cylindrical basket made of 50 mesh wire mesh with a diameter of 15 cm and a length of 20 cm, as shown in Fig. 4, and then insert this basket into a cylinder wrapped with polypropylene non-woven fabric with an inner diameter of 17 cm and a length of 25 cm. Then, it was placed in a horizontal cylinder having an inner diameter of 20 cm and a length of 26 cm as shown in FIG. Styrene was used as the monomer solution, and the two inner cylinders were rotated at 30 rpm to carry out gas phase graft polymerization. The graft ratio after 5 hours was 173%, and no graft unevenness was observed.

Comparative Example A polyethylene porous hollow fiber membrane irradiated under the same conditions as in the experimental example was placed in a glass ampoule having an inner diameter of 15 cm and a height of 25 cm, and styrene was introduced into the bottom of the ampoule to carry out gas phase graft polymerization. In addition, 2 cm above the liquid surface of styrene was partitioned by a wire mesh of 50 mesh to prevent direct contact between the hollow fiber membrane and styrene. The graft ratio after 5 hours was 146%, but the diameters of almost all the hollow fibers were very large on the monomer liquid side, and it was clear that the graft polymerization was not carried out uniformly.

(Effects of the Invention) The present invention has enabled a general-purpose radiation graft polymerization apparatus capable of easily graft-polymerizing substrates of various shapes not only in the liquid phase but also in the gas phase. As a result, it has become possible to meet the expectations from the leading industries involved in radiation graft polymerization in terms of hardware.

[Brief description of drawings]

FIG. 1 is a sectional view of a radiation graft polymerization apparatus of the present invention using a horizontal cylinder, FIG. 2 is a sectional view of a radiation graft polymerization apparatus of the present invention using a vertical cylinder, and FIGS. FIG. 5 is a view showing a state of the base material stored in the inner cylinder according to the shape of the base material, and FIG. 6 is a sectional view showing a radiation graft polymerization apparatus according to the present invention, which is adapted to be used for gas phase graft polymerization. is there. 1 ... Cylinder, 2 ... Inner cylinder 3 ... Baffle plate, 4 ... Substrate 5 ... Monomer solution, 6 ... Shaft 7 ... Drain, 8 ... Inner cylinder 9 ... Spacer

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Kunio Fujiwara, Kunio Fujiwara, 1233 Watanuki-cho, Takasaki-shi, Gunma Japan Atomic Energy Research Institute Takasaki Research Institute (72) Inventor Hideaki Sekiguchi 6-17-8 Aobadai, Ichihara-shi, Chiba (56) Reference Reference Japanese Patent Publication Sho-45-7720 (JP, B1)

Claims (4)

[Claims] 1. A radiation graft polymerization apparatus characterized in that one or more rotatable inner cylinders concentric with the cylinder are provided inside a cylinder that can be used both vertically and horizontally. 2. The apparatus according to claim 1, wherein the inner cylinder is made of a material through which a monomer can easily pass but a substrate cannot pass. 3. The apparatus according to claim 1, wherein the rotation speed and the rotation direction of the inner cylinder are variable. 4. The device according to claim 1, wherein the inner cylinder is removable.