JP3279519B2 - Rubber continuous melting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously dissolving a rubber, and more particularly, to a method for producing a rubber-modified resin, by continuously supplying a rubber to a dissolving tank to form a monomer liquid or a monomer. The present invention relates to a method for continuously dissolving rubber in the presence of a liquid and a solvent.

[0002]

2. Description of the Related Art Rubber-modified polymers, for example, styrene for producing impact-resistant polystyrene, styrene and acrylonitrile for producing ABS resin and the like, in the presence or absence of solvents such as styrene, acrylonitrile, and benzene, ethylbenzene, toluene and xylene. The material obtained by dissolving the rubber in the presence was supplied to the reactor. As a method of dissolving the rubber in the liquid, a predetermined amount of the rubber and the liquid are supplied to a dissolution tank so as to have a desired concentration to be supplied to the reactor, and the rubber is completely dissolved in the liquid. As a method for completely dissolving the rubber, a method for dissolving the rubber in a batchwise manner in a rubber dissolving tank is generally employed. Another proposed method is a method disclosed in Japanese Patent Application Laid-Open No. 4-130111. This publication discloses a method in which a wet pulverizer is provided between two rubber dissolving tanks to make it easier to dissolve rubber.

The concept of the rubber dissolution rate in the above-described conventional dissolution method is shown by a curve b in FIG. As shown by the curve b, in these methods, the rate at which the rubber is dissolved in the monomer liquid or the solvent gradually decreases because the undissolved rubber decreases as the rubber concentration in the rubber solution increases as the dissolution proceeds. It took a considerable time to completely dissolve the rubber. For this reason, the capacity of the dissolution tank was large.

[0004]

Therefore, the prior art has the following problems that need to be improved. (1) In the method of dissolving batchwise in a rubber dissolution tank,
The dissolution tank becomes large and the dissolution efficiency of rubber is not good. (2) In the method disclosed in JP-A-4-130111, two dissolving tanks are required, and the former dissolving tank can be made smaller than that described in the above (1). However, although the dissolving speed is slightly increased in the second dissolving tank at the subsequent stage, completely dissolving the rubber is the same as the batch-type dissolving method, and the dissolving efficiency of the rubber is not good. That is, the rubber concentration in the second dissolving tank needs to be a raw material concentration obtained by dissolving the rubber in a styrene monomer and a solvent, including the undissolved rubber. Therefore, as the rubber concentration increases, the undissolved rubber decreases and the dissolution rate decreases. As a result, in order to dissolve a small amount of undissolved rubber, it is necessary to increase the residence time, the volume efficiency of the dissolution tank is poor, and the total volume of the first and second dissolution tanks must be extremely small. It is difficult.
Furthermore, as a result, when changing the target rubber concentration while operating continuously, a long time is required until the final dissolution tank has the desired rubber concentration. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for continuously dissolving rubber that can reduce the size of a dissolving tank by continuously and efficiently dissolving rubber.

[0005]

The above object is achieved by the following invention. That is, (1) a raw material obtained by dissolving rubber and dissolving rubber in the presence or absence of a monomer having a reactivity with rubber and a solvent is continuously supplied from a dissolution tank to a reactor for producing a rubber-modified polymer. Dissolved rubber solution supplied to the reactor
Of solid rubber corresponding to the amount of dissolved rubber
Is supplied to the solution tank, in a state such that the amount following undissolved rubber undissolved rubber to form larger rubber masses than to stick together is present in the dissolution tank, the rubber dissolved rubber and undissolved dissolver co
To continuously dissolve undissolved rubber.
The amount of rubber required to react with the monomer dissolved
A method for continuously dissolving rubber (hereinafter, referred to as a first embodiment), characterized in that a dissolved rubber solution is obtained and undissolved rubber is removed, and then the dissolved rubber solution is supplied to a reactor. A rubber prepared to a desired size is supplied to a dissolving tank provided with a dissolving means, and when the rubber is dissolved in the presence of a monomer or a monomer and a solvent, the rubber is continuously supplied to the dissolving tank. And the diameter of each hole is 1.0 to 2
A method for continuously dissolving rubber (hereinafter, referred to as a second method), wherein the rubber is continuously dissolved while separating the undissolved rubber and the rubber solution passing through the pores by a separator having a pore having a diameter of 0.0 mm. Of the present invention).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, rubber is natural rubber or synthetic rubber, and as synthetic rubber, polybutadiene, high cis polybutadiene rubber, middle cis polybutadiene rubber, low cis polybutadiene rubber, isoprene rubber, chloroprene rubber, Poly-2-chlorobutadiene rubber, polycyclopentadiene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, isobutylene-isopropylene rubber, acrylonitrile-butadiene rubber, acrylonitrile-isoprene rubber, styrene-butadiene rubber, styrene-isoprene rubber,
Styrene-chloroprene rubber, butadiene-isoprene rubber, butadiene-chloroprene rubber, chloroprene-
Isoprene rubber, styrene- (butadiene-isoprene) rubber, 2-chloro-1-chlorobutadiene rubber, chlorosulfonated polyethylene rubber, ethylene-vinyl acetate rubber, various other acrylic rubbers, organosilicon compound rubber, urethane rubber, Examples include ether-based rubbers and mixtures thereof.

Monomers reactive with rubber include α-alkyl-substituted styrenes such as styrene, α-methylstyrene, α-ethylstyrene, α-methyl-p-methylstyrene, o-methylstyrene, p-methylstyrene, m-
Alkyl-substituted styrene such as methylstyrene, ethylstyrene, 2,4-dimethylstyrene, tert-butylstyrene, pt-butylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, dichlorostyrene, Dibromostyrene, trichlorostyrene,
Halogenated styrenes such as tribromostyrene, tetrachlorostyrene and 2-methyl-4-chlorostyrene, further p-hydroxystyrene, o-methoxystyrene,
Vinylnaphthalene, vinylidene aromatics such as vinylanthracene, acrylonitrile, methacrylonitrile, fumaronitrile, unsaturated nitriles such as α-chloronitrile, methyl acrylate, n-butyl acrylate,
Methyl methacrylate, alkyl acrylates such as methyl methacrylate, maleic anhydride, succinic anhydride, oxymaleic anhydride, itaconic anhydride, oxyitaconic anhydride, citraconic anhydride, phenylmaleic anhydride, anionic acid anhydride, anhydride These include unsaturated dicarboxylic anhydrides such as ethyl maleic acid and chloromaleic anhydride, maleimides such as maleimide and N-phenylmaleimide, unsaturated monocarboxylic acids such as methacrylic acid and acrylic acid, and mixtures thereof.

The solvent is not particularly limited, but aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene and the like, inert substituted aromatic hydrocarbons, heptane, hexane,
Straight-chain saturated aliphatic hydrocarbons such as octane or branched saturated aliphatic hydrocarbons or inert substituted saturated aliphatic hydrocarbons,
Refers to alicyclic hydrocarbons such as cyclohexane or inert substituted alicyclic hydrocarbons and the like, and mixtures thereof.

The curves a and b in FIG. 2 show the concept of the relationship between the dissolution time and the rubber concentration for rubber solutions having different rubber concentrations. Curve a is 1 if the rubber is completely dissolved.
Curve b shows the relationship between rubber dissolution time and rubber concentration by putting rubber and monomer in a dissolution tank so as to be 0% by weight so that the rubber solution becomes 6% by weight. With respect to curve b, the dissolved rubber concentration increases as the rubber concentration approaches 6% by weight, and the undissolved rubber decreases, so that the dissolution rate gradually decreases, and becomes zero at 6% by weight. As a result, the dissolution time is very long, requiring about 260 minutes. Curve a is 6
Since the undissolved rubber is present even at a concentration of weight%, the dissolution rate is as shown by the tangent line c. The operation in the presence of the undissolved rubber to maintain this dissolution rate is a concept of continuous dissolution. is there. When operated continuously at this dissolution rate,
The relationship between the rubber concentration in the melting tank and the residence time of the rubber solution is as shown by a straight line d parallel to the tangent line c and passing through the origin. Therefore, a residence time of about 130 minutes is required to achieve a concentration of 6% by weight, and the size of the dissolving tank may be about half the size of the conventional method. As shown by the curves a and b, the dissolution rate increases as the amount of undissolved rubber increases, and the slope of the tangent line c increases. Therefore, the residence time of the rubber solution is shortened, and the dissolution tank can be small. Also, by increasing the rubber melting temperature, the melting rate can be increased, and the melting tank can be made smaller.

As described above, according to the present invention, the size of the melting tank can be made smaller than that of the conventional one, and the rubber concentration in the melting tank can be changed continuously and in a short time. A first embodiment of the present invention will be described with reference to FIG.
In FIG. 1, the dissolving tank 1 has a stirring function such as a stirrer 14 or the like. Rubber 5 is continuously supplied to dissolution tank 1 through line 11 and monomer 6 is supplied through line 9,
The solvent 7 is supplied through the lines 9 and 10. The rubber and the monomer may be two or more types,
The solvent 7 is not always necessary. Usually, the amount of the solvent used is 50% by weight or less of the total amount of the monomer, rubber and solvent. The rubber 5 is usually supplied to the melting tank 1 in the form of a chip having a size of 0.5 cm to 5 cm. When the rubber is adjusted to a desired size, the rubber may be cut into a predetermined size by a cutter or the like, or a means such as pulverization may be used. Alternatively, granules prepared in advance may be used.

Since a larger amount of rubber 5 than the amount corresponding to the rubber concentration supplied to the reactor 4 has been charged into the dissolving tank 1, the undissolved rubber 8 remains. The amount of undissolved rubber 8 depends on the amount of liquid in dissolution tank 1, the concentration of rubber supplied to reactor 4 and the dissolution temperature of dissolution tank 1. The amount is not more than the amount to be formed, preferably 0.1 to 3.0 times, more preferably 0.1 to 3.0 times the amount of the dissolved rubber present in the dissolving tank 1.
It is determined that 1.0 weight times is selected. If it is less than 0.1 times by weight, the dissolution rate may not be increased as much as the dissolving tank can be made extremely small. If it exceeds 3.0 times by weight, the undissolved rubber sticks to each other in the dissolving tank 1, This is not preferable because a larger rubber mass is formed, and problems such as the dissolution rate not increasing so much as to correspond to the amount of undissolved rubber are likely to occur.

The operating temperature in the dissolving tank 1 is selected to be lower than the polymerization temperature of the reactor to which the monomer is supplied and lower than the boiling point of the solvent. Temperatures above the polymerization temperature or above the boiling point of the solvent are not recommended for safety reasons. After the undissolved rubber is separated by the filter 2, it is supplied to the reactor 4 through the line 12, the pump 3 and the line 13.
The size of the mesh of the filter 2 is usually 20 mm or less, and preferably 1.0 to 20.0 mm. In this embodiment, the residence time of the rubber solution in the dissolution tank is usually 0.1 to 6 hours, preferably 0.5 to 4 hours.

Next, an object of the present invention is to provide a second embodiment, in which a rubber having a desired size is supplied to a dissolving tank provided with a dissolving means such as stirring or the like. And when dissolved in the presence of a solvent, the rubber is continuously supplied to the dissolving tank, and the pores are separated by a separator having pores in a range of 1.0 to 20.0 mm. The rubber is continuously dissolved while separating the rubber solution passing through the rubber from the undissolved rubber. The porous separator used in this embodiment may be, for example, cylindrical or polygonal. Further, the separator having a porosity is provided inside the dissolution tank and / or outside the dissolution tank. The hole diameter may be 1.0 mm or less, but is preferably larger than 1.0 mm for ease of processing of the holes and economic advantages. On the other hand, if the pore size is too large, the undissolved rubber that has passed through the pores is supplied to a reactor in the next step, for example, a polymerization tank, and a filter for removing impurities from the raw materials and a supply pipe are clogged. Further, if a large amount of undissolved rubber is supplied to the polymerization tank, the polymerization reaction is hindered, which is not preferable.

The diameter of each hole of the separator is usually 1.0 to 2 when the separator is provided only inside the dissolving tank.
Although it is within the range of 0.0 mm, when the separator is provided inside the dissolution tank and outside the dissolution tank, the diameter of each hole of the separator provided inside the dissolution tank is such that the separator is provided only inside the dissolution tank. It is preferable to separate the undissolved rubber and the rubber solution that have passed through the holes with a diameter larger than the diameter of the holes to be supplied, and supply them to a separator provided outside the melting tank. The diameter of each hole of the separator provided outside the melting tank is preferably in the range of 1.0 to 20.0 mm. When the separator is provided only outside the dissolution tank, the diameter of each hole is preferably in the range of 1.0 to 20.0 mm, more preferably 1.0 to 10.0 mm. In this embodiment, the opening interval of the holes, that is, the distance between the centers of the holes varies depending on the method of perforation, the surface area of the separator, the diameter of the holes, the number of the holes, etc., but is usually at least 1.2 times the hole diameter, preferably 1. It is 5 to 5.0 times. In this embodiment, the residence time of the rubber solution in the dissolution tank is usually 0.1 to 6 hours,
Preferably, it is 0.5 to 4 hours.

Next, the second embodiment will be described in detail with reference to FIGS. FIG. 3 is an explanatory view of an example of a dissolving tank used in this embodiment, and is an example of a dissolving tank in which a cylindrical separator having a porous wall is provided only inside the dissolving tank. In this example, the dissolution of rubber and the separation of undissolved rubber are performed in the same dissolution tank.
Is provided with a separator 22 and a stirrer 23 formed of a porous cylindrical body. The separator 22 has a diameter of 1.0
A large number of holes 24 of up to 20.0 mm are provided. A predetermined amount of the solvent is supplied from a line 25 and a predetermined amount of a monomer is supplied from a line 26, and the solvent is continuously supplied from a line 27 into the separator 22. The raw rubber is usually prepared to have a size of about 0.5 to 50 mm square, and a predetermined amount is continuously supplied from the line 28 into the separator 22. The rubber and the monomer may be used in two or more types, and the solvent may not be used in some cases. If a solvent is used, it is preferably used in an amount of up to 50% by weight of the total amount of monomers, rubber and solvent.

In the dissolving tank 21, the stirrer 23 rotates to dissolve the rubber in the monomer and the solvent while stirring the solvent, the monomer and the rubber. The rubber is dissolved while swelling and gradually becomes smaller, and the remaining swelled rubber hardly keeps its shape and approaches the concentration of the rubber solution, so that the holes 24 formed in the wall and bottom of the separator 22 are formed. , And is withdrawn from the bottom of the dissolving tank 21 together with the rubber solution having reached a predetermined concentration, and supplied from the line 29 to the polymerization tank in the next step. Undissolved rubber that cannot pass through the hole 24 remains in the separator 22 until passing through the hole 24 and is further dissolved.

A stirrer 2 is provided in the separator 22 of the dissolving tank 21.
3 causes a rotational flow of the rubber solution and the undissolved rubber. The average flow velocity of the rubber solution in the vicinity of the hole 24 in the inner wall of the separator 22 is set in the range of 0.01 to 10.0 m / sec. Clogging of the holes 24 due to undissolved rubber can be prevented. It is preferable to keep the average flow velocity of the rubber solution in order to minimize the passage of undissolved rubber having a size smaller than the diameter of the holes 24 through the holes 24. When the average flow velocity is too slow, the possibility that the holes 24 are clogged by undissolved rubber increases. If this flow rate is too fast, a large stirring driving force is required, which is uneconomical in terms of energy. The flow rate of the rubber solution may be determined by a general flow measurement method such as a particle tracking method. The measurement point is located at a position 5 mm away from the hole 24 in the separator 22 on the flow side of the rubber solution (the center side of the separator 22). May be measured.

A hole 2 provided in the wall of the separator 22 is provided.
The average flow rate of the undissolved rubber and the rubber solution passing from the inside to the outside through 4 is determined by the speed of taking out the rubber solution from the melting tank, and is preferably 0.001 to 0.1 m / sec.
If this is too slow, it is not preferable because a larger number of holes need to be provided. If the speed is too fast, the undissolved rubber blocks the holes 24 and the possibility of clogging increases. In the present invention, the rubber dissolves over time and swells, and dissolves so that the concentration of the rubber becomes almost the same as the surrounding rubber solution. Therefore, the concentration distribution of the rubber solution containing the undissolved rubber, which has become so small that the rubber solution comes out of the hole in the wall of the separator, immediately becomes uniform during the movement.

The amounts of monomer, solvent and rubber continuously supplied into the separator 22 are determined by the amounts corresponding to the monomer concentration, solvent concentration and rubber concentration of the rubber solution supplied to the polymerization tank in the next step. The rubber concentration is stabilized by self-control by extracting the rubber solution so as to maintain the liquid volume of the dissolving tank constant. For example, when the temperature in the separator rises, the dissolution rate increases and the rubber concentration of the rubber solution that is temporarily withdrawn increases, but the amount of undissolved rubber in the dissolution tank decreases and the dissolution rate decreases. Slows and becomes the same as before the temperature rise. When the temperature decreases and the rubber dissolution rate decreases, the undissolved rubber increases and the dissolution rate increases, which is the same as before the temperature decrease. In the present invention, it goes without saying that the rubber concentration in the rubber solution is more stable by keeping the temperature of the dissolving tank as constant as possible.

In this embodiment, the method for starting the operation is to dissolve the rubber solution in the dissolving tank in advance in a batch manner so as to have a target rubber solution concentration, and then to dissolve the monomer concentration to be supplied to the polymerization tank in the next step. If the solvent concentration and the amount corresponding to the rubber concentration are supplied to the dissolving tank and the amount supplied to the polymerization tank in the next step is extracted, the rubber solution concentration and the undissolved rubber amount change unsteadily at the beginning of operation, As the operation is continued, the amount of undissolved rubber in the dissolving tank becomes a steady state, and the rubber concentration in the rubber solution reaches a target rubber concentration and becomes a steady state. At the beginning of the operation, the steady state can be achieved in a shorter time by increasing the rubber charging speed. At this time, as in the case of the first embodiment, the amount of the dissolved rubber corresponding to the rubber concentration supplied to the polymerization tank in the next step is 0.1 to 3.
The rubber in an amount of 0 weight times is held as undissolved rubber so as to coexist with the rubber solution. If it is less than 0.1 times by weight, the dissolution rate may not be increased as much as the dissolving tank can be made extremely small. If it exceeds 3.0 times by weight, the undissolved rubber sticks to each other in the dissolving tank 1, An inconvenient state, such as forming a larger rubber mass and not increasing the dissolution rate so as to correspond to the amount of undissolved rubber, is likely to occur.

Although not shown, when the separator is provided both inside and outside the dissolving tank, the diameter of the hole of the separator provided inside the dissolving tank is adjusted to the hole diameter of the separator when the separator is provided only inside the dissolving tank. To separate the undissolved rubber and rubber solution. Next, the undissolved rubber and the rubber solution are withdrawn from the bottom of the dissolving tank, and supplied by a pump into a double-tube separator provided with a porous separator inside. The diameter of each hole of this separator is in the range of 1.0 to 20.0 mm, and the undissolved rubber is separated from the separating means and circulated to the dissolving tank, where it is further dissolved in the monomer and the solvent. . The undissolved rubber and the rubber solution that have passed through the holes are supplied to the polymerization tank in the next step.

In the second embodiment, a separator may be provided outside the dissolving tank, and the rubber solution may be circulated through the external separator and returned to the dissolving tank. FIG. 4 is an explanatory view showing an example of the dissolving apparatus, in which a cylindrical separator having porosity is provided only outside the dissolving tank. 4, the same reference numerals as those in FIG. 3 indicate the same components. The rubber is melted in the melting tank 21 and the unmelted rubber is separated in the separator 32 provided inside the double pipe 35 provided outside. The separator 32 has a large number of holes 34 each having a diameter of 1.0 to 20.0 mm. A predetermined amount of the solvent is supplied from the line 25 and a predetermined amount of the monomer is supplied from the line 26, and the predetermined amount of the rubber is continuously supplied into the melting tank 21 through the line 27. Supplied to In the dissolving tank 21, the stirrer 23 rotates to remove the solvent and monomer.
The rubber is dissolved in the monomer and the solvent while mixing the rubber and the rubber. The rubber is dissolved while swelling and becomes smaller gradually.

Next, the undissolved rubber and the rubber solution are withdrawn from the bottom of the dissolving tank 21 to a line 33, and are supplied from a line 36 into a separator 32 of a double pipe 35 by a pump 37. Undissolved rubber is separated in separator 32 and
Is returned to the dissolving tank 21 and further dissolved in the monomer and the solvent in the dissolving tank 21. On the other hand, the rubber solution containing the undissolved rubber that has passed through the holes is supplied from the line 39 to the polymerization tank in the next step. The undissolved rubber in the rubber solution is immediately dissolved in the rubber solution during the transfer as described above, and the rubber solution has a uniform concentration distribution.

[0024]

The present invention will be described in more detail with reference to Examples. It is needless to say that the present invention is not limited to this.

Example 1 The operation was performed according to the flow sheet shown in FIG. Dissolution tank 1 is 2
It is a tank having an operating volume of 17 liters and accompanied by a stirrer 14 and a filter 2 of 40 mesh (by a sieve of a tiler). A liquid containing 6% by weight of rubber was continuously supplied to the reactor 4 (polymerization reaction tank). A styrene monomer was added to the dissolving tank 1 as the monomer 6 at a rate of 8 per hour.
2 kg, 12 kg / h of ethylbenzene as a solvent 7,
As the rubber 6, 6 kg / hour of chip-shaped polybutadiene adjusted to a 10 mm square was supplied. The melting tank 1 has a temperature of 30.
Adjusted to ° C. 100 kg / hour of a 6% by weight dissolved rubber solution was withdrawn by the pump 3 and supplied to the reactor 4 so that the average dissolution time was 2 hours. At this time, the amount of dissolved rubber in the dissolved layer was 12 kg, and the amount of undissolved rubber was 6.7 kg. Table 1 shows the results.

Example 2 The operating capacity of the melting tank 1 of Example 1 was increased from 217 liters to 5
The operation was performed in the same manner as in Example 1 except that the dissolution time was changed from 2 hours to 0.5 hour, and the liter was changed to 4 liters. Table 1 shows the results
It is described together.

Comparative Example 1 The operating capacity of the melting tank 1 of Example 1 was increased from 217 liters to 2
The procedure was performed in the same manner as in Example 1 except that the dissolution time was changed from 2 hours to 0.25 hours, and the liter was changed to 7 liters. Result is,
The rubber sticks to each other to form a larger mass, 6% by weight
Cannot be obtained, and continuous operation was impossible.

Example 3 The rubber concentration was changed from 6% by weight to 10% by weight based on a constant operating time of 217 liters and a melting time of 2 hours for the dissolving tank 1 of Example 1. Table 1 shows the operating conditions and results.

[0029]

[Table 1]

Example 4 A dissolving tank 21 of Example 1 was used instead of the dissolving tank 1 shown in FIG.
Was used as shown in FIG. 3, and a cylindrical separator was provided only inside the dissolution tank. The dissolution tank 21 has a diameter of 215 mm, the liquid volume is 7,500 g in weight, and the separator 22 has a diameter of 190 m.
m, having a hole diameter of the vessel wall of 2.5 mm, using a stirrer 23
Has an impeller with a wing diameter of 100 mm.
pm, and a 5 mm square rubber was dissolved. The temperature of the melting tank 21 was adjusted to 30 ° C. The rubber solution to be supplied to the polymerization tank in the next step had a styrene concentration of 85% by weight and an ethylbenzene concentration of 8.0% by weight.
The rubber was continuously melted so as to produce 0% by weight. Undissolved rubber was 3.0% by weight. The operating conditions are shown in Table 2. The average flow linear velocity at a position 5 mm from the hole 24 in the separator 23 on the flow side of the undissolved rubber and the rubber solution was 0.01 m / sec. The residence time of the rubber in the melting tank 21 was 2.0 hours. As a result of continuous operation for 72 hours, good continuous operation was possible without clogging of undissolved rubber and formation of rubber lumps.

Example 5 The operation was carried out in accordance with a dissolving apparatus in which the cylindrical separator shown in FIG. 4 was provided only outside the dissolving tank. The dissolution tank 21 has a diameter of 215
mm, the liquid volume was 7,500 g in terms of weight, the separator 32 provided inside the double tube 35 was 70 mm in diameter, and the stirrer 23 was 300 rpm with an impeller having a blade diameter of 100 mm. The rubber solution to be supplied to the polymerization tank in the next step was made to have the same composition as in Example 4, the residence time of the rubber in the dissolution tank, the diameter of each hole provided in the separator 32, the average flow in the separator. The linear velocity was also the same as in Example 4. The temperature of the dissolution apparatus was adjusted to 30 ° C. The operating conditions are shown in Table 2. As a result of continuous operation for 72 hours, good continuous operation was possible without clogging of undissolved rubber and formation of a rubber mass.

Comparative Example 2 Example 4 except that the cylindrical separator was changed as follows.
The rubber was continuously dissolved in the same manner as described above. The diameter of each hole provided in the separator was 25 mm. The operating conditions are shown in Table 2. The rubber solution to be supplied to the polymerization tank in the next step was intended to have the same composition as that of Example 4. As a result of continuous operation for 72 hours, about 2% by weight of undissolved rubber having a diameter of about 3 to 5 mm was supplied to the next step. . For this reason, the supply pipe to the next step was clogged.

COMPARATIVE EXAMPLE 3 A conventional dissolving tank was used in a conventional batch mode. The diameter of the dissolving tank, the blade diameter of the stirrer, and the number of revolutions were the same as in Example 5, and the following amounts of rubber, monomer and solvent were added at a time so that the liquid volume and the dissolved rubber concentration were the same as in Example 5. It was put into a dissolution tank and the dissolution time was measured. as a result,
Six hours were required to dissolve the rubber. Rubber size: 5 mm square Rubber supply amount: 528 g Monomer supply amount: 6360 g Solvent supply amount: 600 g

[0034]

[Table 2]

[0035]

According to the method for continuously dissolving rubber of the present invention, the following excellent effects can be obtained. (1) The residence time required to obtain a rubber solution having a predetermined rubber concentration can be shortened as compared with the conventional method, and the size of the dissolution tank can be made smaller than that of the conventional method. (2) Further, as a result, it is possible to continuously change the rubber concentration in the product in a short time.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a rubber dissolution time and a rubber concentration in a rubber solution.

FIG. 3 is an explanatory view showing another embodiment of the present invention.

FIG. 4 is an explanatory view of a modification of the embodiment of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dissolution tank 2 Filter 3 Pump 4 Reactor 5, 8 Rubber 6 Monomer 7 Solvent 9-13 Line 14 Stirrer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 279/02 C08F 2/00 C08F 2/06 C08F 2/44

Claims (7)

(57) [Claims] 1. A raw material obtained by dissolving rubber and dissolving rubber in the presence or absence of a monomer having a reactivity with rubber and a solvent is continuously supplied from a dissolution tank to a reactor for producing a rubber-modified polymer. On the other hand, a solid rubber in an amount corresponding to the amount of the dissolved rubber of the dissolved rubber solution supplied to the reactor is continuously supplied to the dissolving tank, and the undissolved rubber adheres to each other to form a larger rubber mass. In a state where the undissolved rubber is present in the dissolution tank, the dissolved rubber and the undissolved rubber are allowed to coexist in the dissolution tank to continuously dissolve the undissolved rubber, and necessary for reacting with the monomer in the reactor. After obtaining a dissolved rubber solution in which the amount of rubber is dissolved and removing the undissolved rubber,
A method for continuously dissolving rubber, comprising supplying the dissolved rubber solution to a reactor. 2. A dissolution rubber for dissolving a rubber solution to be supplied to a reactor.
Amount of solid rubber corresponding to the
Feed, liquid volume of dissolution tank, dissolution temperature of dissolution tank, throw into dissolution tank
Amount of rubber to be used, the size of raw rubber pieces to be put into the melting tank,
By adjusting the rubber concentration supplied to the reactor,
Undissolved rubber sticks together to form a larger rubber mass
Less than the amount of undissolved rubber
The method for continuously dissolving rubber according to claim 1, characterized in that: 3. The amount of undissolved rubber present in the dissolving tank is at least 0.1 times and not more than 3 times the amount corresponding to the amount of dissolved rubber of the dissolved rubber solution supplied to the reactor. The method for continuously dissolving rubber according to claim 1 or 2 , wherein: 4. A rubber prepared to a desired size is supplied to a dissolving tank provided with a dissolving means therein, and when the rubber is dissolved in the presence of a monomer or a monomer and a solvent, the rubber is continuously dispersed. The rubber is continuously supplied while separating the undissolved rubber and the rubber solution passing through the pores by a separator having pores each having a diameter of 1.0 to 20.0 mm. A method for continuously dissolving rubber, characterized by being dissolved. 5. The amount of the undissolved rubber present in the dissolving tank being equal to 0.
The method for continuously dissolving rubber according to claim 4 , wherein the amount is not less than 1 time and not more than 3 times by weight. 6. The method for continuously dissolving rubber according to claim 4 , wherein the separator having porosity is installed inside the dissolving tank and / or outside the dissolving tank. 7. Monomers which dissolve rubber and have reactivity with rubber
Dissolve rubber in the presence or absence of
To produce rubber-modified polymer from melted raw material
Dissolving to be supplied to the reactor for continuous feeding to the reactor
Connect solid rubber in an amount equivalent to the amount of dissolved rubber in the rubber solution.
Continuously supply to the melting tank, unmelted rubber sticks to each other
Undissolved rubber less than the amount that forms a large rubber mass
Makes dissolved rubber and undissolved rubber coexist in the melting tank
To dissolve the undissolved rubber continuously,
The amount of rubber required to react with the monomer dissolved
After obtaining the dissolved rubber solution and removing the undissolved rubber,
Feeding the dissolved rubber solution
Dissolution method.