JPH08224735A - Kneading of polymeric substance and liquid - Google Patents

Abstract

PURPOSE: To continuously and stably perform the uniform kneading of a polymeric substance and a liquid in large emitting quantities by using a continuous kneader having self-cleaning action in the kneading of the polymeric substance and the liquid and bringing the interior of the kneader in a liquid supply part and a kneading part to a starvation state. CONSTITUTION: In a kneader kneading a natural polymeric substance such as cellulose, natural rubber or protein, a synthetic polymeric substance such as a thermoplastic resin or a thermosetting resin and a liquid such as mineral oil, an org. solvent or water, at least one liquid supply part 22 is provided on the downstream side of a polymeric substance supply part 21 and the interior of the kneader in the polymeric substance supply part 21 and the liquid supply part 22 is set to a starvation state (a state wherein there is a space where the polymeric substance or the mixture of the polymeric substance and the liquid is not present in the space between a cylinder and a screw). The interior of the kneader performing the kneading of the liquid and the polymeric substance is also set to a starvation state. By this constitution, even if there is no filling state of the polymeric substance on the upstream side of the liquid supply part, the kneaded mixture can be transported to a die 23 without generating the back flow of a fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for kneading a polymer substance and a liquid, and particularly to a solution of the polymer substance by kneading the polymer substance and a suitable liquid such as mineral oil, an organic solvent and water. Or a method for uniformly dispersing a liquid in a polymer substance.

[0002]

2. Description of the Related Art Natural polymers and synthetic polymers are widely used for various purposes. Depending on the application, these polymeric substances may be kneaded with a liquid such as mineral oil, organic solvent, and water to form a solution, or a polymeric material having flexibility and fluidity for processing. There is.

For example, the preparation of a polymer substance solution is usually carried out by kneading a polymer substance and a liquid which is a good solvent in a batch system or a continuous system. In case of batch type kneading,
Put the polymer substance and liquid in an autoclave with a stirrer,
The temperature is raised with stirring to knead the polymer substance and the liquid.
However, the batch method has drawbacks that the kneading time is long, the quality in or between batches is unstable, and manpower is required. Further, there is a problem that a high-viscosity solution cannot be prepared and a pellet-shaped polymer substance composition cannot be used.

Therefore, recently, a continuous kneader having a liquid supply section downstream of the resin supply section has come to be used for producing a polymer solution. However, since the internal pressure of the kneading machine in the liquid supply part is high and the pressure in the liquid supply part is higher than the pressure in the downstream, when the liquid supply amount is increased, the phenomenon of reverse flow to the upstream side is observed, and the liquid supply amount is lowered. I had to hold back. In addition, there is a drawback that heat generation due to shearing is large in the kneading machine region where only the polymer substance exists, and thermal deterioration occurs.

Therefore, an object of the present invention is to provide a method for performing uniform kneading of a polymer substance and a liquid continuously and stably with a high discharge amount.

[0006]

As a result of intensive studies in view of the above-mentioned object, the present inventors have used a continuous kneader having a self-cleaning action and starved the inside of the kneader at the liquid supply part and the kneading part. According to the present invention, it was found that the uniform kneading of the polymer substance and the liquid can be continuously and stably performed with a high discharge amount, and the present invention was conceived.

That is, the kneading method of the polymer substance and the liquid of the present invention uses (1) a continuous kneader having a self-cleaning action, and (2) at least one liquid supply downstream of the polymer substance supply section. (3) The inside of the kneading machine in the liquid supply unit located in the uppermost stream with the polymer substance supply unit is starved, and the liquid and the polymer substance supplied from the liquid supply unit are It is characterized in that the inside of the kneading machine at the part where kneading is first performed is set to be in a starvation state.

The present invention is described in detail below. [1] Polymer substance As the polymer substance, various substances such as a natural polymer substance and a synthetic polymer can be used. Examples of the natural polymer substance include cellulose, natural rubber and protein, and examples of the synthetic polymer substance include synthetic resins such as thermoplastic resins and thermosetting resins. Specific examples of the thermoplastic resin include vinyl chloride resin, vinyl acetate resin, polystyrene, ABS resin, acrylic resin, polyolefin, olefin rubber, thermoplastic elastomer, fluororesin, polyamide resin, acetal resin, polycarbonate resin, polyester resin, Thermoplastic polyurethane resin, thermoplastic styrene rubber, polyphenylene sulfide,
Examples thereof include polyvinyl alcohol. Specific examples of the thermosetting resin include phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin,
Examples thereof include diallyl phthalate resin, polyurethane resin, silicon resin, polyimide resin and polyparabanic acid resin.

If necessary, various point additives such as an antioxidant, an ultraviolet absorbent, an anti-blocking agent, a pigment, a dye, an inorganic filler, an antibacterial agent and a far infrared ray emitting agent may be added to the polymer substance. You can

[2] Liquid As a liquid to be mixed with the polymer substance, a good solvent for dissolving the polymer substance into a solution, a plasticizer having good compatibility with the polymer substance and exhibiting good dispersibility, or a high solvent Examples thereof include those that cause hydrolysis of molecular substances. For example, low-volatile aliphatic or cyclic hydrocarbons, mineral oils having almost the same boiling points as those hydrocarbons, low-volatile alcohols, ethers, esters or water which are liquid at room temperature can be used. . The type of liquid can be appropriately selected depending on the type of polymer substance used.

[3] Continuous Kneader The continuous kneader used for producing the polyolefin solution has a self-cleaning action. When it has a self-cleaning action, the screw thread of another screw or the protrusion of the cylinder passes through the screw groove, so the mixture does not rotate with the screw, and the screw angle or the kneading disc combination angle, etc. It is possible to send in the direction according to. Therefore, when it has a self-cleaning action, the pressure of the liquid supply portion can be set to 10 kg / cm ² or less. The self-cleaning action of the kneading machine does not need to have the self-cleaning action in all parts of the kneading machine, so that the pressure of the liquid supply section becomes 10 kg / cm ² or less.
It is sufficient that at least a part of the portion where the mixture is present has a self-cleaning action. As such a continuous kneader, a twin-screw kneader or a special single-screw kneader is preferable. Specific examples include a co-rotating mesh type twin-screw kneader, a counter-rotating mesh type twin-screw kneader, and a special single-screw kneader such as Bus Co Kneader. Is preferred.

On the other hand, when there is no self-cleaning action, even if the screw thread is in the feeding direction,
The coefficient of friction between the cylinder of the mixture of the polymer substance and the liquid which is not sufficiently kneaded and the cylinder is extremely low, and the mixture only rotates together with the screw and is not sent to the downstream side. Therefore, when there is no self-cleaning action, the liquid supply portion and the portion where the polymer substance and the liquid are first kneaded cannot be starved.

At least one liquid supply unit is provided downstream of the polymer substance supply unit. When two or more liquid supply units are provided, the polymer substance is first kneaded with the liquid in the first liquid supply unit to reduce the viscosity, and then a large amount of liquid is added in the next liquid supply unit to perform strong kneading. To do. An example of an extruder having at least one liquid supply is shown in Figures 1-5. 1st shown in FIGS.
In the example to the fifth example, 1 is provided downstream of the polymer substance supply unit 21.
Up to three liquid supply parts 22, 22a, 22b, 22c are provided. A die 23 is provided downstream of the extruder.

[4] Kneading Conditions (1) State of Kneading Machine Inner The kneading method of the polymer substance and liquid of the present invention is such that the inside of the kneading machine at the liquid supply section and the first kneading section located at the uppermost stream is starved. It is characterized by putting in a state. The starvation state inside the kneading machine is a state in which there is a space in which no polymer substance or a mixture of polymer substance and liquid exists in the space between the cylinder and the screw. In such a starvation state, the pressure (kg / cm ² , gauge pressure) gradient in the liquid supply section becomes zero.
Becomes However, the pressure may not be 0 in a liquid having a large vapor pressure. Due to this starvation state, it becomes possible to transport the mixture of the unkneaded polymer substance and the liquid to the front side without generating the backflow of the liquid even when the polymer substance is not filled upstream of the liquid supply section. . The screw between the liquid supply part located at the most upstream part and the position of the pressure gauge immediately downstream thereof is a kneading part for kneading the polymer substance and the liquid.

In addition, filling at least a part of the inside of the kneading machine between the polymer material supply section and the liquid supply section located at the uppermost stream with the polymer material is effective in supplying an extremely large amount of liquid. preferable. As described above, even when there is a filled portion upstream, the pressure of the liquid supply portion can be lowered, and deterioration due to heat generation in the portion of the polymer substance alone can be prevented.

This is to set the internal pressure of the kneading machine in at least a part between the polymer material supply section and the liquid supply section located in the uppermost stream to be higher than the internal pressure of the kneader in the liquid supply section located in the uppermost stream. Become. That is, a portion having a pressure higher than the internal pressure of the liquid supply portion is provided upstream of the liquid supply portion located at the most upstream portion in the starvation state. With such a pressure distribution, even if the amount of liquid added is increased, backflow to the upstream can be prevented, and as a result, the discharge amount can be increased.

When at least two liquid supply parts are provided, for the same reason, the kneader internal pressure in at least a part between each liquid supply part and the liquid supply part immediately downstream thereof is set to the same as that of the polymer material supply part. It is preferable to set the pressure higher than the internal pressure in the liquid supply section immediately downstream. Furthermore, the kneader internal pressure in at least a portion between each liquid supply section and the supply section immediately downstream thereof is set to be larger than the internal pressure in the two sequential liquid supply sections immediately downstream of the polymer substance supply section. More preferable. As a result, the advantage that the liquid supply amount and the discharge amount are increased can be obtained.

The internal pressure (kg / cm ² , gauge pressure) of the kneading machine in the liquid supply section located at the uppermost stream is preferably 0. Shear heat is generated on the upstream side of the most upstream liquid supply section because a high-viscosity polymer material is kneaded. However, by setting the kneader internal pressure to 0, the shear heat generation is suppressed and thermal deterioration of the polymer material is prevented. be able to.

The above starvation state and pressure distribution can be achieved by changing operating conditions such as the depth of the groove of the screw of the kneading machine and the position of the liquid supply section.

(2) Kneading temperature The kneading temperature is equal to or higher than the melting point or glass transition point of the polymer substance, particularly the melting point or glass transition point of the polymer substance + about 1
The temperature is preferably 0 ° C. If the kneading temperature is lower than the above temperature, sufficient kneading cannot be performed, and if the temperature is significantly higher than the above temperature, deterioration of the polymer substance occurs.

[0021]

In the present invention, the pressure gradient in the liquid supply section can be set to 0 by starving the inside of the kneading machine in the liquid supply section located at the most upstream and the first kneading section. It is possible to obtain a uniform kneaded product of the polymer substance and the liquid at a high discharge amount without causing the backflow of the liquid even if the polymer substance is not filled upstream of the supply section. Further, even when there is a polymer-filled portion upstream of the most upstream liquid supply unit, the pressure can be lowered, heat generation deterioration in the polymer-only portion can be prevented, and a large amount can be prevented. Can supply liquid.

[0022]

The present invention will be described in more detail by the following examples, but the present invention is not limited thereto.

Examples 1 to 4 Twin-screw extruders (TEX54, manufactured by Co., Ltd.) which rotate in the same direction
Made by Japan Steel Works, screw diameter = 58mm, L / D = 4
2) was used, and the polymer substance shown in Table 1 and a liquid were kneaded. In order to measure the internal pressure, the TEX 54 is located at a position 236 mm from the most upstream portion of the cylinder and downstream thereof 94.
A total of 14 pressure gauges were installed at intervals of 5 mm, and numbers 1 to 14 were assigned to each of them from the upstream side. The die attached to the extruder had a slit with a thickness of 3 mm and a width of 104 mm. Polymers and liquids used, and polymer 1
Table 1 shows the amount of the liquid added per 100 parts by weight. Also,
Amount of liquid supplied from each liquid supply hole (polymer material 1
Table 2 shows the pressure inside the extruder and the operating conditions. As shown in Table 1, extruders having different configurations were used for each example.

Further, after measuring the pressure of the extruder, the pressure gauge of the liquid supply portion located at the most upstream and the pressure gauge immediately downstream thereof are removed, and the polymer substance (P
C) When several pellets were dropped, PC pellets immediately entered the extruder. Therefore, the position of the liquid supply portion located at the uppermost stream and the position of the pressure gauge immediately downstream thereof were starved. The screw between the liquid supply part located at the uppermost stream and the position of the pressure gauge immediately downstream thereof is a kneading part for kneading the polymer substance and the liquid. Example 2
In Nos. 3 and 3, the pressure (kg / cm ² , gauge pressure) was a value exceeding 0 at the position of the pressure gauge immediately upstream of the liquid supply section located at the uppermost stream, so that it was confirmed that the inside of the extruder was full. Shows.

As a result, it was found that stable discharge of the kneaded product was obtained in each of the examples. Also, judging from the appearance and touch of the sample extruded from the slit die, it was found that the dispersion of the liquid in the polymer substance was good. No discoloration, heat deterioration, fish eyes, etc. were observed in any of the obtained samples.

Comparative Examples 1 to 3 In the same manner as in Examples, TEX54 was used to knead a polymer substance and a liquid. Table 1 shows the polymer substances and liquids used, and the addition amount of the liquid per 100 weight of the polymer substance. Table 2 shows, as kneading conditions, the amount of liquid supplied from each liquid supply hole (expressed in parts by weight relative to 100 parts by weight of the polymer substance), the pressure inside the extruder, and the operating conditions.
The screws used had different configurations, and as shown in Table 1, extruders having different configurations were used for each comparative example. As shown in Table 2, the pressure (kg / c) was measured at the position of the liquid supply portion located at the most upstream side of each comparative example and the pressure gauge immediately downstream thereof.
m ² and gauge pressure) exceeded 0, the inside of the extruder showed a full state, and was not in a starved state. Further, the discharge amount was stable under the conditions of Table 2, but when the discharge amount was increased, the fluctuation of the discharge amount became severe, and unmixed liquid or water vapor was periodically discharged.

[0027]

Table 1 Table 1 Example NO. Polymeric material Liquid Liquid supply amount ⁽⁵⁾ Extruder type Example 1 EPDM ⁽¹⁾ Paraffin oil ⁽⁴⁾ 50 Figure 1 Example 2 EPDM Paraffin oil 100 Figure 2 Example 3 PC ⁽²⁾ Water 30 Figure 3 Example 4 PPA ⁽³⁾ dimethylformamide 400 Fig. 4 Comparative example 1 EPDM paraffinic oil 50 Fig. 2 Comparative example 2 PC water 30 Fig. 5 Comparative example 3 PPA dimethylformamide 400 Fig. 5 Note: (1) ethylene propylene diene Copolymer rubber (propylene content 28%, iodine value 15, weight average molecular weight 4.1 × 10 ⁵ ) (2) Polycarbonate pellets (weight average molecular weight 3.6 × 10 ⁴ ) (3) Polyparabanic acid powder ( Weight average molecular weight 1.0 × 10 ⁵ ) (4) Paraffin oil (kinematic viscosity (40 ° C.) 380 cst) (5) Unit: parts by weight

[0028]

[Table 2]

[0029]

As described in detail above, by starving the inside of the kneading machine at the liquid supply part located at the most upstream part and the first kneading part, backflow of the liquid is prevented and a uniform polymer substance is provided. It is possible to continuously obtain a kneaded product of liquid and liquid with a high discharge amount. The kneaded product of the polymer substance and the liquid thus obtained can be used for various molded articles and the like.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first example of a pressure gauge installation position and a liquid supply site in an extruder.

FIG. 2 is a schematic diagram showing a second example of the installation position of the pressure gauge and the liquid supply portion in the extruder.

FIG. 3 is a schematic diagram showing a third example of the installation position of the pressure gauge and the liquid supply portion in the extruder.

FIG. 4 is a schematic view showing a fourth example of the installation position of the pressure gauge and the liquid supply portion in the extruder.

FIG. 5 is a schematic diagram showing a fifth example of the installation position of the pressure gauge and the liquid supply portion in the extruder.

[Explanation of symbols]

 1-14 ... Pressure gauge 20 ... Extruder 21 ... Polymer material supply unit 22, 22a, 22b, 22c ... Liquid supply unit 23 ... Die

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Kono 3-1, Chidoricho, Kawasaki-ku, Kawasaki-shi, Kanagawa Tonen Kagaku Co., Ltd. Technology Development Center

Claims (6)

[Claims] 1. In a method of kneading a polymer substance and a liquid, (1) a continuous kneader having a self-cleaning action is used, and (2) at least one liquid supply unit is provided downstream of the polymer substance supply unit. (3) Kneading in a portion where the inside of the kneading machine in the liquid supply section located in the uppermost stream is starved and the kneading of the liquid supplied from the liquid supply section and the polymer substance is performed first A method characterized by setting the inside of the machine to be in a starvation state. 2. The kneading method of a polymer substance and a liquid according to claim 1, wherein the kneader internal pressure in at least a part between the polymer substance supply part and the liquid supply part located at the most upstream is The method is characterized in that the internal pressure of the kneader is set to be higher than the internal pressure of the kneading machine in the liquid supply section located in the most upstream. 3. The method of kneading a polymer substance and a liquid according to claim 1, wherein the continuous kneader having a self-cleaning action is a co-rotating mesh type twin-screw kneader. And how to. 4. The kneading method for mixing a polymer substance and a liquid according to any one of claims 1 to 3, wherein the kneading machine internal pressure (Kg / cm ² , gauge pressure) in the liquid supply section located at the uppermost stream.
Is zero. 5. The method of kneading a polymer substance and a liquid according to claim 1, wherein at least two liquid supply units are provided downstream of the polymer substance supply unit.
(2) The kneader internal pressure in at least a part between each liquid supply part and the liquid supply part immediately downstream thereof is set to be higher than the kneader internal pressure in the liquid supply part immediately downstream of the polymer substance supply part. A method characterized by. 6. The kneading method for mixing a polymer substance and a liquid according to claim 5, wherein the kneader internal pressure in at least a part between each liquid supply part and a liquid supply part immediately downstream thereof is set to the high level. A kneading method of a polymer substance and a liquid, wherein the pressure is set to be higher than the kneader internal pressure in the two liquid supply units immediately downstream of the molecular substance supply unit.