WO2016158084A1

WO2016158084A1 - Process for producing diene-based polymer

Info

Publication number: WO2016158084A1
Application number: PCT/JP2016/055036
Authority: WO
Inventors: 北村　隆; 誠野瀬; 和也吉並; 山下　博司
Original assignee: 宇部興産株式会社
Priority date: 2015-03-30
Filing date: 2016-02-22
Publication date: 2016-10-06
Also published as: JPWO2016158084A1; JP2017088905A; TWI625338B; CN107428853A; TW201638115A; KR101855605B1; CN107428853B; JP6098859B2; KR20170124434A; JP6429043B2

Abstract

The present invention is capable of attaining a high yield in production of a diene-based polymer. A diene-based-monomer solution is supplied as a starting material to a polymerization tank to produce a diene-based polymer. To the polymerization tank, a diene-based monomer or diene-based-monomer solution which has a lower temperature than the polymerization solution inside the polymerization tank is supplied separately from the supply of the starting material. In particular, in the case where a plurality of polymerization tanks are serially disposed, the lower-temperature diene-based monomer or diene-based-monomer solution is supplied to any of the polymerization tanks other than the first polymerization tank.

Description

Method for producing diene polymer

The present invention relates to a method for producing a diene polymer capable of obtaining a high yield.

Generally, since the polymerization reaction of a diene monomer is an exothermic reaction, temperature control is important in the production of a diene polymer. If the temperature cannot be controlled within the predetermined temperature range, the reaction yield decreases. Furthermore, there is a possibility that desired physical properties cannot be obtained in the diene polymer.

Therefore, in the production of a diene polymer, it is a production requirement to set the polymerization temperature within a predetermined range (for example, Patent Document 1). For example, in consideration of heat generated by the polymerization reaction, the temperature of the monomer solution is controlled before being supplied to the polymerization tank. Through an exothermic reaction, a predetermined polymerization temperature is reached (sensible heat effect). Furthermore, as one of the temperature controls, there is a method of supplying a refrigerant called brine to the periphery of the polymerization tank.

These cooling methods can control the temperature of the polymerization solution in the polymerization tank, improve the reaction rate, and improve the yield.

JP 2006-274010 A

However, since cooling with brine is from the outside of the polymerization tank, even if the polymerization solution can be sufficiently cooled on the wall of the polymerization tank, there is a possibility that the cooling inside the polymerization tank may be insufficient. If the temperature of the polymerization solution is not uniform, a homogeneous polymer may not be obtained. Thus, there is a problem that cooling with brine is insufficient.

Incidentally, a plurality of polymerization tanks may be arranged in series for the purpose of increasing the production amount or obtaining a polymer having complicated physical properties.

At this time, in the first tank polymerization tank, the temperature of the monomer solution before supplying the first tank can be controlled (cooled, sometimes heated) by a heat exchanger. In consideration of temperature rise due to heat generation, the polymerization temperature is controlled to a predetermined temperature (sensible heat effect).

However, the polymerization solution is at a predetermined temperature in the first tank polymerization tank, and it is not easy to cool the polymer solution before supplying it to the second and subsequent polymerization tanks.

Furthermore, in the polymer solution at this point, a part of the monomer is a polymer and the viscosity is high. If it is attempted to cool by the heat exchanger, the heat exchanger may be clogged. Therefore, cooling with a heat exchanger is difficult.

Thus, there is a problem that cooling is difficult particularly in the polymerization tanks other than the first tank. In other words, there is a problem that a sensible heat effect cannot be expected.

On the other hand, a part of the monomer solution has become a polymer after passing through the first tank polymerization tank, and there is a problem that the amount of monomer becomes insufficient in the second and subsequent tanks and the yield may be lowered.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method for producing a diene polymer capable of obtaining a high yield by appropriate cooling. In particular, an object of the present invention is to provide a method for producing a diene polymer that can obtain a high yield by appropriate cooling of a polymerization tank other than the initial tank.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing a diene polymer capable of eliminating a shortage of monomers and obtaining a high yield in a polymerization tank other than the initial tank. To do.

The present invention is a method for producing a diene polymer by supplying a diene monomer solution as a raw material to a polymerization tank. The diene monomer or the diene monomer solution having a temperature lower than that of the polymerization solution inside the polymerization tank is supplied to the polymerization tank separately from the raw material supply.

The present invention is a method for producing a diene polymer through a plurality of polymerization tanks. The diene monomer or the diene monomer solution having a temperature lower than that of the polymerization solution inside the polymerization tank is supplied to any polymerization tank other than the initial tank polymerization tank.

In the above invention, the diene polymer is polybutadiene and the diene monomer is butadiene.

In the said invention, it is the same molecular weight in this initial stage polymerization tank and this polymerization tank.
The monomer concentration of the diene monomer solution is 30 wt% to 70 wt%, and the temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution is 30 ° C. to 100 ° C.,
The supply amount of the diene monomer solution is 5% to 20% of the main flow rate.

In the above invention, in the polymerization tank, a polymer having a lower molecular weight is polymerized than in the initial tank polymerization tank, and the high molecular weight polymer and the low molecular weight polymer are mixed at a weight ratio of 2: 8 to 8: 2. To do.
The monomer concentration of the diene monomer solution is 65 wt% to 75 wt%,
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution is 40 to 105 ° C.,
The supply amount of the diene monomer solution is 5 to 20% of the main flow rate.

In the above invention, a medium molecular weight polymer is polymerized in the initial tank polymerization tank, a plastic resin is polymerized in the polymerization tank, and both are mixed.
The monomer concentration of the diene monomer solution is 100 wt% (monomer),
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer is 50 ° C. to 90 ° C.,
The supply amount of the diene monomer is 5 to 20% of the main flow rate.

In the said invention, it has a 1st process, a 2nd process, and a 3rd process.
In the first step, the high molecular weight polymer is polymerized in the first tank polymerization tank of the first process, the polymerization solution is supplied to a polymerization tank other than the first tank of the first process, and the low molecular weight polymer is polymerized in the polymerization tank. To do.
In the second step, the medium molecular weight polymer is polymerized in the initial tank polymerization tank of the second process, the polymerization solution is supplied to a polymerization tank other than the initial tank of the second process, and the plastic resin is polymerized in the polymerization tank.
In the third step, the product of the first step and the product of the second step are mixed.
In the first step,
The monomer concentration of the diene monomer solution is 30 wt% to 50 wt%,
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution is 40 to 105 ° C.,
The supply amount of the diene monomer solution is 5 to 20% of the main flow rate.
In the second step,
The monomer concentration of the diene monomer solution is 100 wt% (monomer),
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer is 35 ° C. to 90 ° C.,
The supply amount of the diene monomer is 5 to 20% of the main flow rate.

The present invention can obtain a high yield by appropriate cooling. In particular, a high yield can be obtained by appropriate cooling of the polymerization tank other than the initial tank.

The present invention can solve the shortage of monomers in a polymerization tank other than the first tank, and can obtain a high yield.

It is a conceptual diagram of the manufacturing process of a general grade. It is a conceptual diagram of the manufacturing process of a bimodal grade. It is a conceptual diagram of the manufacturing process of resin rubber compound polybutadiene grade. It is a conceptual diagram of the manufacturing process of a multimodal grade. It is a conceptual diagram of the triple series arrangement | positioning of a superposition | polymerization tank. It is a conceptual diagram of the independent arrangement | positioning of a superposition | polymerization tank. It is a conceptual diagram of the parallel arrangement | positioning of a superposition | polymerization tank. It is a figure explaining molecular weight distribution in a bimodal grade.

In the present invention, a diene monomer solution is supplied as a raw material to a polymerization tank to produce a diene polymer.

A polymerization monomer adjusting solution consisting of a diene monomer solution is continuously supplied. Add water in the water dissolution tank. Next, an organoaluminum compound is added as a promoter in an aging tank. The monomer solution is controlled to a predetermined temperature via a heat exchanger, and a transition metal catalyst and a molecular weight regulator are added in a polymerization tank to carry out polymerization.

Next, in the reaction stop tank, a mixed solution of an anti-aging agent and a reaction stop agent is added to stop the polymerization. The polymer solution obtained by these is dried with a hot air drier to obtain a polymer product. In this specification, a series of flow from the raw material to the product is defined as a main flow path, and a flow rate of the polymerized monomer adjustment solution supplied to the main flow path is defined as a main flow rate.

In the present invention, the temperature of the polymerization solution in the polymerization tank is controlled. In consideration of the heat generated by the polymerization reaction, the temperature of the monomer solution is controlled (cooled, sometimes heated) through a heat exchanger and supplied to the polymerization tank. Further, a refrigerant called brine is supplied around the polymerization tank.

In addition, the diene monomer or the diene monomer solution at a lower temperature than the polymerization solution inside the polymerization tank is supplied to the polymerization tank separately from the raw material supply (separate from the main flow path) Cool the polymerization solution.

In particular, when a plurality of polymerization tanks are arranged in series, a diene monomer or a diene monomer solution having a temperature lower than the polymerization solution in the polymerization tank in the second and subsequent polymerization tanks is separated from the main flow path. Supply and cool the polymerization solution inside the polymerization tank.

<Diene monomer>
In the present embodiment, examples of the diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, and the like. These may be used singly or in combination of two or more, and may be used by copolymerizing with other dienes such as 1,3-hexadiene. Of these, 1,3-butadiene is preferred.

<Solvent>
Solvents include aromatic hydrocarbons such as toluene, benzene and xylene, aliphatic hydrocarbons such as n-hexane, butane, heptane and pentane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, 1-butene, cis Examples include olefinic hydrocarbons such as C4 fractions such as -2-butene and trans-2-butene, hydrocarbon solvents such as mineral spirits, solvent naphtha, and kerosene, and halogenated hydrocarbon solvents such as methylene chloride. It is done.

Of these, cyclohexane or a mixture of cis-2-butene and trans-2-butene is preferably used.

Examples of the metal catalyst include a zirconium-based catalyst, a hafnium-based catalyst, a chromium-based catalyst, an iron-based catalyst, a tungsten-based catalyst, a randomoid-based catalyst, an actinoid-based catalyst, and a lithium-based catalyst. A metal catalyst may be used individually by 1 type, and may be used in combination of 2 or more type.

<Transition metal catalyst>
Examples of the transition metal catalyst include a cobalt catalyst, a nickel catalyst, a neodymium catalyst, a vanadium catalyst, a titanium catalyst, and a gadolinium catalyst. Among these, a cobalt catalyst or a nickel catalyst is preferable, and a cobalt catalyst is more preferable. A transition metal catalyst may be used individually by 1 type, and may be used in combination of 2 or more type.

Cobalt catalysts include cobalt halide salts such as cobalt chloride and cobalt bromide; inorganic acid cobalt salts such as cobalt sulfate and cobalt nitrate; cobalt octaate, cobalt octylate, cobalt naphthenate, cobalt acetate, cobalt malonate, etc. And cobalt complexes such as bisacetylacetonate cobalt, trisacetylacetonate cobalt, acetoacetic acid ethyl ester cobalt, cobalt salt pyridine complex, cobalt salt picoline complex, and cobalt salt ethyl alcohol complex. Of these, cobalt octaate is preferable.

The amount of the cobalt-based catalyst added is usually preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ mol of the cobalt-based catalyst with ^respect to 1 mol of the diene monomer, and preferably 1 × 10 ⁻⁶ to 1 × 10 ⁻⁵ mol. Particularly preferred.

<Organic aluminum promoter>
An organoaluminum cocatalyst is used with a transition metal catalyst. The addition amount of the organoaluminum cocatalyst is preferably in the range of 50 to 2000 mol per 1 mol of the transition metal catalyst.

Organic aluminum includes halogen-containing organic aluminum compounds and halogen-free organic aluminum compounds, which may be used in combination.

Examples of non-halogenated organoaluminum compounds include organoaluminum hydrides such as trialkylaluminum, dialkylaluminum hydride, and alkylaluminum sesquihydride. Trialkylaluminum is preferred, and triethylaluminum (TEA) is more preferred.

Examples of the halogenated organoaluminum include dialkylaluminum chloride, dialkylaluminum bromide, alkylaluminum dichloride, alkylaluminum dibromide, alkylaluminum sesquichloride, and alkylaluminum sesquibromide. Of these, organoaluminum chloride is preferable, and diethylaluminum chloride (DEAC) is more preferable.

<Molecular weight regulator>
As the molecular weight regulator, for example, non-conjugated dienes such as cyclooctadiene, allene, methylallene (1,2-butadiene), or α-olefins such as ethylene, propylene, butene-1 can be used. . In order to further suppress the formation of gel during polymerization, a known gelation inhibitor can be used.

<Anti-aging agent>
Typical anti-aging agents are phenol-based 2,6-di-t-butyl-p-cresol (BHT), phosphorus-based trinonylphenyl phosphite (TNP), and sulfur-based 4.6-bis (octylthio). Methyl) -o-cresol, dilauryl-3,3′-thiodipropionate (TPL), and the like.

<Reaction terminator>
As a reaction terminator, a large amount of a polar solvent such as water or an alcohol such as methanol or ethanol is added to the polymerization solution.

<Molecular weight>
Macromolecules, medium molecules, and low molecules are defined according to the molecular weight of the polymer. A polymer having a Mooney viscosity (hereinafter referred to as ML) greatly exceeding 40 or having a molecular weight that is too high to be measured with an ML viscometer is defined as a polymer. A thing around ML = 40 is defined as a medium molecule. Those having a molecular weight much lower than ML = 40 or those having a molecular weight that is too low to be measured with an ML viscometer are defined as low molecules.

<Diene polymer>
There are various types of diene polymers, and the basic production method is common as described in the above outline, but the production process differs slightly depending on each grade. Along with this, the cooling method is also different. The general grade, bimodal grade, resin rubber composite polybutadiene grade, and multimodal grade will be described.

<General grade>
FIG. 1 is a conceptual diagram of a general grade manufacturing process. Specific numerical values will be described in Examples.

General grade is a diene polymer (for example, polybutadiene) having a high cis structure (cis ratio is 95% or more) by a transition metal catalyst. Specifically, it shows the behavior of a unimodal molecular weight distribution. The first tank (R1) and the final tank (R2) produce a polymer having the same physical properties (medium molecule). When a predetermined polymerization rate is reached in the first tank (R1), the polymerization solution is supplied to the final tank (R2).

By the way, in this grade, the activity peak of the Cis reaction is around 70 to 75 ° C., and when it exceeds 80 ° C., the deactivation of the catalyst increases. Therefore, the polymerization temperature is set to 60-80 ° C.

At this time, the polymerization temperature in the first tank (R1) is 60 to 80 ° C., and the sensible heat effect as in the first tank (R1) cannot be expected in the final tank (R2). Moreover, cooling with brine alone is not sufficient. Cooling is required in the final tank (R2).

In addition, the monomer is consumed in the first tank (R1), and the amount of monomer is insufficient in the final tank (R2).

On the other hand, a diene monomer solution having a temperature lower than the polymerization solution inside the polymerization tank is supplied to the final tank (R2) separately from the main flow path (apart from the raw material supply), and the polymerization solution inside the polymerization tank is cooled. .

The monomer concentration of the diene monomer solution supplied separately is 30 wt% to 70 wt%, which is higher than the raw material.

The temperature difference between the polymerization solution in the final tank (R2) and the diene monomer solution supplied separately is suitably 30 ° C to 100 ° C, and preferably 55 ° C to 90 ° C. The temperature of the diene monomer solution supplied separately is -20 ° C to 30 ° C.

The supply amount of the diene monomer solution supplied separately is 5% to 20% of the main flow rate.

Thereby, the polymerization temperature in the final tank (R2) can be uniformly controlled to 60 to 80 ° C.

In addition, the monomer is consumed by the polymerization in the first tank (R1), but the monomer is replenished in the final tank (R2).

Thus, temperature control and monomer replenishment can be realized in a balanced manner in the final tank (R2). As a result, a high yield can be obtained.

<Bimodal grade>
FIG. 2 is a conceptual diagram of a bimodal grade manufacturing process. Specific numerical values will be described in Examples.

The bimodal grade is a diene polymer (for example, polybutadiene) having different molecular weight (high molecular weight and low molecular weight) physical properties. Specifically, the behavior of bimodal molecular weight distribution is shown. A high molecular weight polymer is produced in the first tank (R1), and when a predetermined polymerization rate is reached, the polymerization solution is supplied to the final tank (R2), and a low molecular weight polymer is produced in the final tank (R2).

Generally, the weight ratio of high molecular weight to low molecular weight is set to 2: 8 to 8: 2. Preferably, it is 3: 7 to 7: 3, more preferably 4: 6 to 6: 4. Since the polymerization rate is relatively high in the final tank (R2), it is necessary to react more than the general grade. The reaction rate in the final tank (R2) (reaction heat: 330 Kcal / kg-BR) is large, and cooling is required compared to the general grade. In addition, more monomer replenishment is required.

In contrast, a diene monomer solution having a temperature lower than that of the polymerization solution inside the polymerization tank is supplied to the final tank (R2) separately from the main flow path, and the polymerization solution inside the polymerization tank is cooled.

The monomer concentration of the diene monomer solution supplied separately is 65 wt% to 75 wt%, which is higher than the raw material. Also, the concentration is higher than that of the general grade.

The temperature difference between the polymerization solution in the final tank (R2) and the separately supplied diene monomer solution is suitably 40 ° C to 105 ° C, preferably 73 ° C to 95 ° C. The temperature of the diene monomer solution supplied separately is suitably −20 ° C. to 20 ° C., more preferably −20 ° C. to 15 ° C.

The supply amount of the diene monomer solution supplied separately is suitably 5% to 20% of the main flow rate, and preferably 10% to 20%. 13% to 17% is more preferable.

Thereby, the polymerization temperature in the final tank (R2) can be uniformly controlled to 65 to 85 ° C.

Thus, temperature control and monomer replenishment can be realized in a balanced manner in the final tank (R2). As a result, a high yield can be obtained. Moreover, desired physical properties can be obtained.

<Resin rubber composite polybutadiene grade>
FIG. 3 is a conceptual diagram of a process for producing a resin rubber composite polybutadiene grade. Specific numerical values will be described in Examples.

Resin rubber composite polybutadiene grade is a grade in which a high cis-diene polymer (rubber) and a highly crystalline syndiotactic diene polymer (resin) are combined by continuous polymerization technology, and is a kind of special polymer alloy.

In particular, the highly crystalline syndiotactic diene polymer (resin) is a highly crystalline syndiotactic diene polymer resin (for example, highly crystalline syndiotactic polybutadiene resin (SPB)). The highly crystalline syndiotactic diene polymer resin may contain trans polybutadiene.

A medium molecular weight polymer is produced in the first tank (R1) using a transition metal catalyst. When a predetermined polymerization rate is reached, the polymerization solution is supplied to the final tank (R2). A syndiotactic diene polymer resin is produced using a catalyst obtained from carbon sulfide.

The syndio reaction, which is a reaction of a highly crystalline syndiotactic diene polymer resin (for example, a highly crystalline syndiotactic polybutadiene resin (SPB)), is less likely to react than the Cis reaction and has a low polymerization temperature. The activity peak is low at around 45 ° C. When polymerized at high temperature, the molecular weight decreases and the physical properties deteriorate. On the other hand, the sensible heat effect cannot be expected due to the heat generated by the polymerization reaction in the first tank (R1). Therefore, cooling is more necessary in the final tank (R2).

Also, the syndio reaction is less reactive than the Cis reaction and requires more monomers.

In contrast, a diene monomer having a temperature lower than that of the polymerization solution inside the polymerization tank is supplied to the final tank (R2) separately from the main flow path, and the polymerization solution inside the polymerization tank is cooled.

The monomer concentration of the diene monomer solution supplied separately is 100 wt%. That is, a monomer is supplied. Or the monomer solution according to this may be sufficient.

The temperature difference between the polymerization solution in the final tank (R2) and the separately supplied diene monomer is suitably 50 ° C to 90 ° C, and preferably 55 ° C to 87 ° C. The temperature of the diene monomer supplied separately is suitably −20 ° C. to 0 ° C., more preferably −20 ° C. to −5 ° C.

The supply amount of the diene monomer supplied separately is suitably 5% to 20% of the main flow rate, and preferably 10 to 20%. 11 to 15% is more preferable.

Thereby, the polymerization temperature in the final tank (R2) can be uniformly controlled to 50 to 70 ° C.

<Multimodal grade>
FIG. 4 is a conceptual diagram of an example manufacturing process of a multimodal grade. Specific numerical values will be described in Examples.

The multimodal grade is a diene polymer having a plurality of different molecular weights. For example, it has the physical properties of the bimodal grade and the resin rubber composite polybutadiene grade.

The multimodal grade is manufactured through the first step (bimodal grade), the second step (resin rubber composite polybutadiene grade), and the third step (mixing).

In the first step, a high molecular weight polymer is polymerized in the first tank (R1-1), the polymerization solution is supplied to the final tank (R2-1), and a low molecular weight polymer is produced in the final tank (R2-1). To do.

In the second step, the medium molecular weight polymer is polymerized in the first tank (R1-2), the polymerization solution is supplied to the final tank (R2-2), and the syndiotactic diene-based polymer in the final tank (R2-2). A resin is produced.

In the third step, the product of the first step and the product of the second step are mixed to produce a multimodal grade diene polymer.

In the first step, cooling and monomer replenishment are required in the final tank (R2-1), as in the bimodal grade.

In contrast, a diene monomer solution having a temperature lower than that of the polymerization solution inside the polymerization tank is supplied to the final tank (R2-1) separately from the main flow path, and the polymerization solution inside the polymerization tank is cooled.

The monomer concentration of the diene monomer solution supplied separately is suitably 30 wt% to 50 wt%, preferably 35 to 50 wt%, more preferably 38 to 46 wt%.
It is.

The temperature difference between the polymerization solution in the final tank (R2-1) and the separately supplied diene monomer solution is suitably 40 ° C to 105 ° C, preferably 55 ° C to 95 ° C. The temperature of the diene monomer solution supplied separately is suitably −20 ° C. to 20 ° C.

The supply amount of the diene monomer solution supplied separately is suitably 5% to 20% of the main flow rate, and preferably 10% to 20%. 11% to 15% is more preferable.

Thereby, the polymerization temperature in the final tank (R2-1) can be uniformly controlled to 60 to 85 ° C.

In addition, the monomer is consumed by the polymerization in the first tank (R1-1), but the monomer is replenished in the final tank (R2-1).

In the second step, it is necessary to cool and replenish the monomer in the final tank (R2-2), similar to the resin rubber composite polybutadiene grade.

The temperature difference between the polymerization solution inside the final tank (R2-2) and the separately supplied diene monomer is suitably 35 ° C to 90 ° C, preferably 40 ° C to 86 ° C. The temperature of the diene monomer supplied separately is -20 ° C to 25 ° C.

The supply amount of the diene monomer supplied separately is suitably 5% to 20% of the main flow rate, and preferably 10% to 20%. 10 to 14% is more preferable.

Thereby, the polymerization temperature in the final tank (R2-2) can be uniformly controlled to 55 to 70 ° C.

In addition, the monomer is consumed by the polymerization in the first tank (R2-1), but the monomer is replenished in the final tank (R2-2).

Thus, temperature control and monomer replenishment can be realized in a balanced manner in both the final tank (R2-1) and the final tank (R2-2). As a result, a high yield can be obtained in the product. Moreover, desired physical properties can be obtained.

<Modification>
Although four grades and manufacturing processes have been described as examples of diene-based polymers, various variations are possible.

FIG. 5 shows a modification in which the production of general grade is performed in a series of three series polymerization tanks (R1 to R3).

A diene monomer solution having a temperature lower than that of the polymerization solution is supplied to the second tank (R2) and the third tank (R3) separately from the main flow path, and the polymerization solution inside the polymerization tank is cooled.

The concentration of the diene monomer solution separately supplied to the second tank (R2) is 30 wt% to 70 wt%, which is higher than the raw material.

The temperature difference between the polymerization solution inside the second tank (R2) and the separately supplied diene monomer solution is suitably 30 to 100 ° C. 55 to 90 ° C is preferable. The temperature of the diene monomer solution supplied separately is suitably −20 to 30 ° C.

The amount of diene monomer solution supplied separately to the second tank (R2) is 5 to 20% of the main flow rate.

Thereby, the polymerization temperature can be uniformly controlled to 60 to 80 ° C. in the second tank (R2).

Also, the concentration of the diene monomer solution separately supplied to the third tank (R3) is suitably 30 wt% to 70 wt%, more preferably 36 wt% to 60 wt%, and a higher concentration than the raw material.

The temperature difference between the polymerization solution in the third tank (R3) and the separately supplied diene monomer solution is suitably 30 to 100 ° C., preferably 55 to 90 ° C. The temperature of the diene monomer solution supplied separately is suitably −20 to 30 ° C.

The supply amount of the diene monomer solution separately supplied to the third tank (R3) is suitably 5 to 20% of the main flow rate, preferably 5 to 15%, more preferably 5 to 8%.

Thereby, the polymerization temperature can be uniformly controlled to 60 to 80 ° C. in the third tank (R3).

A trimodal grade may be produced via a series of three series polymerization tanks. The trimodal grade is a diene polymer having different physical properties (high molecular weight, medium molecular weight and low molecular weight). A high molecular weight polymer is produced in the first tank, a medium molecular weight polymer is produced in the second tank, and a low molecular weight polymer is produced in the final tank.

Fig. 6 shows a modification of the general grade. The present invention has a remarkable effect when it is intended for a polymerization tank other than the initial tank polymerization tank, but it can also be applied to the case of only one tank.

Even in the case of only one tank, there is a problem that cooling with brine is insufficient, and this can be solved. It can also be applied when it is difficult to apply a heat exchanger.

∙ Due to the general grade, the conditions and changes of the general grade do not occur.

The monomer concentration of the diene monomer solution supplied separately is suitably 30 wt% to 70 wt%, more preferably 36 wt% to 46 wt%, and the monomer concentration is equal to or higher than that of the raw material.

The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution supplied separately is suitably 30 ° C. to 100 ° C., preferably 55 ° C. to 90 ° C. The temperature of the diene monomer solution supplied separately is -20 ° C to 30 ° C.

Thereby, the polymerization temperature in the polymerization tank can be uniformly controlled to 60 to 80 ° C.

Thus, temperature control and monomer replenishment can be realized in a good balance in the polymerization tank. As a result, a high yield can be obtained.

FIG. 7 shows another modification. The present invention has a remarkable effect when the polymerization tanks are arranged in series, but can also be applied in the case of parallel arrangement.

When the same raw material is supplied to a plurality of polymerization tanks, and only one polymerization tank is cooled, a diene monomer solution having a temperature lower than the polymerization solution is supplied only to the polymerization tank, separately from the main flow path, The polymerization solution inside the polymerization tank is cooled. Furthermore, when all three polymerization tanks arranged in parallel are cooled, a diene monomer solution having a temperature lower than the polymerization solution is supplied to the polymerization tank separately from the main flow path, and the polymerization solution inside the polymerization tank is cooled. In some cases.

Examples with each grade will be described with reference to FIGS. 1 to 4, and the effects of the present invention will be verified through comparison with comparative examples (not applying the present invention).

<Example 1: General grade>
Based on FIG. 1, a general grade embodiment will be described. Unimodal (medium molecular weight) polybutadiene is produced.

A polymerization monomer adjusting solution consisting of 38 wt% of 1,3 butadiene as a monomer, 37 wt% of butene as a solvent and 25 wt% of cyclohexane is continuously supplied as a raw material.

The temperature of the first tank (R1) is controlled to a predetermined polymerization temperature by temperature control (sensible heat effect) by the heat exchanger and cooling by brine.

Here, the polymerization monomer adjusting solution used for cooling is defined as cold shot CS. CS is supplied from the same tank as the polymerization monomer adjustment solution. On the other hand, a monomer shot of 1,3 butadiene 100 wt% is defined as a monomer shot.

In Example 1-1, 8% CS of the main flow rate and MS of 5% of the main flow rate were mixed, and the monomer solution having a monomer concentration of 62 wt% was cooled to -16 ° C. at 13% of the main flow rate, and the final tank (R2) To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 85 ° C.

In Example 1-2, 8% CS of the main flow rate and MS of the main flow rate of 5% were mixed, and the monomer solution having a monomer concentration of 62 wt% was cooled to -12 ° C. at 13% of the main flow rate, and the final tank (R2) To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 74 ° C.

In Example 1-3, 5% CS of the main flow rate and MS of 2% of the main flow rate are mixed, and the monomer solution with a monomer concentration of 54 wt% is cooled to −12 ° C. at 7% of the main flow rate, and the final tank (R2) To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 85 ° C.

In Example 1-4, 8% CS of the main flow rate and MS of the main flow rate of 2% were mixed, and the monomer solution having a monomer concentration of 49 wt% was cooled to 10% of the main flow rate to 5 ° C. and placed in the final tank (R2). Supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 74 ° C.

In Example 1-5, 7% CS of the main flow rate and MS of the main flow rate of 8% were mixed, and the monomer solution with a monomer concentration of 69 wt% was cooled to -16 ° C. at 15% of the main flow rate, and the final tank (R2) To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 90 ° C.

In Example 1-6, 15% CS of the main flow rate is cooled to −16 ° C. and supplied to the final tank (R2). In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 90 ° C.

Table 1 shows a comparison between Example 1 (Examples 1-1 to 1-6) and Comparative Example 1 in which the low-temperature monomer solution was not supplied.

In Comparative Example 1, the yield is 93.4% (Example 1-1 is taken as 100%), and a sufficient yield cannot be obtained. Further, the cis bond content does not satisfy the allowable range, and desired physical properties cannot be obtained.

In Example 1, a high yield can be obtained and desired physical properties can be obtained.

<Example 2: Bimodal grade>
An example of a bimodal grade will be described with reference to FIG. Produces bimodal (high molecular weight and low molecular weight) polybutadiene. The weight ratio of high molecular weight to low molecular weight is 1: 1.

A polymerization monomer adjusting solution consisting of 36 wt% of 1,3 butadiene as a monomer and 32 wt% of butene as a solvent and 32 wt% of cyclohexane is continuously supplied as a raw material.

High molecular weight polymer is produced in the first tank (R1). The initial tank (R1) is controlled to a predetermined polymerization temperature by temperature control (sensible heat effect) by the heat exchanger and cooling by brine.

In Example 2-1, CS having a main flow rate of 7% and MS having a main flow rate of 8% were mixed, and the monomer solution having a monomer concentration of 70 wt% was cooled to -19 ° C at 15% of the main flow rate, and the final tank (R2) To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 93 ° C.

In Example 2-2, CS having a main flow rate of 7% and MS having a main flow rate of 8% are mixed, and the monomer solution having a monomer concentration of 70 wt% is cooled to −10 ° C. at 15% of the main flow rate, and the final tank (R2) To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization temperature and the separately supplied monomer solution is 85 ° C.

In Example 2-3, CS with a main flow rate of 7% and MS with a main flow rate of 6% are mixed, and a monomer solution with a monomer concentration of 65 wt% is cooled to 13% of the main flow rate at 0 ° C. to the final tank (R2). Supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization temperature and the separately supplied monomer solution is 75 ° C.

In Example 2-4, CS having a main flow rate of 7% and MS having a main flow rate of 10% were mixed, and the monomer solution having a monomer concentration of 74 wt% was cooled to -19 ° C. at 17% of the main flow rate, and the final tank (R2). To supply. In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization temperature and the separately supplied monomer solution is 93 ° C.

Table 2 shows a comparison between Example 2 (Examples 2-1 to 2-4) and Comparative Example 2 in which the low-temperature monomer solution was not supplied.

In Comparative Example 2, the yield is 83.8% (Example 2-1 is taken as 100%), and a sufficient yield cannot be obtained. Further, the cis bond content does not satisfy the allowable range, and desired physical properties cannot be obtained.

In Example 2, a high yield is obtained and desired physical properties are obtained.

Furthermore, the molecular weight distribution will be examined. FIG. 8A is a comparison between the theoretical value and the actually measured value in Example 2. FIG. 8B is a comparison between the theoretical value and the actual measurement value in Comparative Example 2.

The horizontal axis is the retention time (minutes), the retention time for polymers is short, and the retention time for low molecules is long. The vertical axis is the amount of polymer of the corresponding molecular weight.

Theoretically, the peak on the low molecular side is higher than the peak on the high molecular side (more polymer amount). On the other hand, in the measured value of Comparative Example 2, the peak value on the low molecule side is lower than the theoretical value. The peak on the low molecular side is lower than the peak on the high molecular side. This is because the yield of the final tank (R2) is reduced. As a result, in Comparative Example 2, a desired molecular weight distribution cannot be obtained.

On the other hand, the actual measurement values of Example 2 are almost the same as the theoretical values. That is, a desired molecular weight distribution is obtained.

<Example 3: Resin rubber composite polybutadiene grade>
An example of a resin rubber composite polybutadiene grade will be described with reference to FIG. A polymer alloy of high cis-polybutadiene (rubber) and highly crystalline syndiotactic polybutadiene resin (plastic) is produced.

A polymerization monomer adjustment solution consisting of 1,3 butadiene 40 wt% as a monomer and butene: 35 wt% and cyclohexane 25 wt% as a solvent is continuously fed as a raw material.

In Example 3-1, MS with a main flow rate of 13% is cooled to -19 ° C. and supplied to the final tank (R2). In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 80 ° C.

In Example 3-2, MS with a main flow rate of 11% is cooled to −10 ° C. and supplied to the final tank (R2). In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 70 ° C.

In Example 3-3, MS with a main flow rate of 15% is cooled to 0 ° C. and supplied to the final tank (R2). In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 55 ° C.

In Example 3-4, MS with a main flow rate of 15% is cooled to −18 ° C. and supplied to the final tank (R2). In combination with cooling with brine, the final tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 87 ° C.

Table 3 shows a comparison between Example 3 (Examples 3-1 to 3-4) and Comparative Example 3 in which the low-temperature monomer solution was not supplied.

In Comparative Example 3, the yield is 56.6% (Example 3-1 is taken as 100%), and a sufficient yield cannot be obtained.

Ηsp / C is an index related to the viscosity measurement of the syndio reaction, and indicates the amount of SPB generated in the VCR or the molecular weight of the syndio reaction. If the molecular weight of SPB is small, the reinforcing effect is small and the product quality cannot be maintained. In Comparative Example 3, the allowable range is not satisfied and desired physical properties cannot be obtained.

HI (wt%) (insoluble in n-hexane) indicates the amount of SPB in the VCR and is an index of the amount of SPB produced. If the amount of SPB is small, the reinforcing effect is small and the product quality cannot be maintained. In Comparative Example 3, the allowable range is not satisfied and desired physical properties cannot be obtained.

In Example 3, a high yield is obtained and desired physical properties are obtained.

<Example 4: Multimodal grade>
Based on FIG. 4, an example of a multimodal grade will be described. As an example, a polymer product containing polybutadiene having a distribution of high molecular weight, medium molecular weight and low molecular weight and SPB will be described.

A polymerization monomer adjusting solution consisting of 43 wt% of 1,3 butadiene as a monomer and 32 wt% of butene: 25 wt% of cyclohexane as a solvent is continuously supplied as a raw material. After passing through the water dissolution tank and the aging tank, 64% of the raw material is supplied to the first step and 36% of the raw material is supplied to the second step.

In the first step, a high molecular weight polymer is produced in the first tank (R1-1). By the temperature control (sensible heat effect) by the heat exchanger and cooling by the brine, the initial tank (R1-1) is controlled to a predetermined polymerization temperature.

In Example 4-1, CS with a main flow rate of 13% is cooled to −20 ° C. and supplied to the final tank (R2-1). Along with cooling with brine, the final tank (R2-1) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 93 ° C.

In the second step, a medium molecular weight polymer is produced in the first tank R1-2. By the temperature control (sensible heat effect) by the heat exchanger and cooling by the brine, the initial tank (R1-2) is controlled to a predetermined polymerization temperature.

In Example 4-1, the main flow rate of 12% MS is cooled to -17 ° C. and supplied to the final tank (R2-2). In combination with cooling with brine, the final tank (R2-2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 80 ° C.

1) The product of the first step and the product of the second step are mixed to produce a multimodal grade diene polymer.

In Example 4-2, CS having a main flow rate of 11% is cooled to 0 ° C. and supplied to the final tank (R2-1) in the first step. Along with cooling with brine, the final tank (R2-1) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 77 ° C.

In Example 4-2, in the second step, MS with a main flow rate of 10% is cooled to 25 ° C. and supplied to the final tank (R2-2). In combination with cooling with brine, the final tank (R2-2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 35 ° C.

In Example 4-3, in the first step, CS with a main flow rate of 11% is cooled to −5 ° C. and supplied to the final tank (R2-1). Along with cooling with brine, the final tank (R2-1) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 65 ° C.

In Example 4-3, in the second step, MS with a main flow rate of 10% is cooled to 25 ° C. and supplied to the final tank (R2-2). In combination with cooling with brine, the final tank (R2-2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 35 ° C.

In Example 4-4, CS having a main flow rate of 15% is cooled to −19 ° C. and supplied to the final tank (R2-1) in the first step. Along with cooling with brine, the final tank (R2-1) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 99 ° C.

In Example 4-4, in the second step, MS with a main flow rate of 11% is cooled to 15 ° C. and supplied to the final tank (R2-2). In combination with cooling with brine, the final tank (R2-2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 40 ° C.

In Example 4-5, CS having a main flow rate of 15% is cooled to −19 ° C. and supplied to the final tank (R2-1) in the first step. Along with cooling with brine, the final tank (R2-1) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 99 ° C.

In Example 4-5, in the second step, MS with a main flow rate of 14% is cooled to −7 ° C. and supplied to the final tank (R2-2). In combination with cooling with brine, the final tank (R2-2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer is 67 ° C.

Table 4 shows a comparison between Example 4 (Examples 4-1 to 4-5) and Comparative Example 4 in which the low-temperature monomer solution was not supplied.

In Comparative Example 4, the yield is 56.6% (Example 4-1 is taken as 100%), and a sufficient yield cannot be obtained. Further, the cis bond content does not satisfy the allowable range, and desired physical properties cannot be obtained.

Furthermore, in Comparative Example 4, HI (wt%) (n-hexane insoluble matter) and ηsp / C do not satisfy the allowable range, and the reinforcing effect by SPB cannot be expected.

In Example 4, a high yield is obtained, and the cis bond content, HI, and ηsp / C are all included in the allowable ranges, and desired physical properties are obtained.
<Example 5: Modification>
Based on FIG. 5, the Example of a series triple polymerization tank is demonstrated. Unimodal (medium molecular weight) polybutadiene is produced. It is a modification of a general grade.

A polymerization monomer adjustment solution consisting of 36 wt% of 1,3 butadiene as a monomer, 39 wt% of butene as a solvent and 25 wt% of cyclohexane is continuously supplied as a raw material.

The first tank (R1) is controlled to a predetermined polymerization temperature by temperature control (sensible heat effect) by the heat exchanger and cooling by brine.

In Example 5, 8% CS of the main flow rate and MS of the main flow rate of 5% were mixed, and the monomer solution with a monomer concentration of 59 wt% was cooled to −12 ° C. at 13% of the main flow rate and placed in the second tank (R2). Supply. In combination with cooling with brine, the second tank (R2) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 84 ° C.

Further, 3% CS of the main flow rate and MS of 2% of the main flow rate are mixed, and the monomer solution having a monomer concentration of 60 wt% is cooled to −12 ° C. at 5% of the main flow rate and supplied to the third tank (R3). In combination with cooling with brine, the third tank (R3) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 86 ° C.

Table 5 shows a comparison between Example 5 and Comparative Example 5 in which the low-temperature monomer solution was not supplied.

In Comparative Example 5, the yield is 92% (Example 5 is 100%), and a sufficient yield cannot be obtained. Further, the cis bond content does not satisfy the allowable range, and desired physical properties cannot be obtained.

In Example 5, a high yield is obtained and desired physical properties are obtained.
<Example 6: Modification>
Based on FIG. 6, the Example of a single tank is demonstrated. In the polymerization tank (R0), monomodal (medium molecular weight) polybutadiene is produced. It is a modification of a general grade.

In addition to temperature control by the heat exchanger (sensible heat effect) and cooling by brine, the polymerization tank (R0) is controlled to a predetermined polymerization temperature by separately supplying the monomer solution.

In Example 6-1, 18% CS of the main flow rate is cooled to −13 ° C. and supplied to the polymerization tank (R0). Along with cooling with brine, the polymerization tank (R0) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 85 ° C.

In Example 6-2, 14% CS of the main flow rate is cooled to −10 ° C. and supplied to the polymerization tank (R0). Along with cooling with brine, the polymerization tank (R0) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 83 ° C.

In Example 6-3, 12% CS of the main flow rate is cooled to −12 ° C. and supplied to the polymerization tank (R0). Along with cooling with brine, the polymerization tank (R0) is controlled to a predetermined polymerization temperature. At this time, the temperature difference between the polymerization solution and the separately supplied monomer solution is 83 ° C.

Table 6 shows a comparison between Example 6 and Comparative Example 6 in which the low-temperature monomer solution was not supplied.

In Comparative Example 6, the yield is 95% (Example 6-1 is 100%), and a sufficient yield cannot be obtained. Further, the cis bond content does not satisfy the allowable range, and desired physical properties cannot be obtained.

In Example 6, a high yield is obtained and desired physical properties are obtained.

Claims

A method for producing a diene polymer by supplying a diene monomer solution to a polymerization tank as a raw material,
A method for producing a diene polymer, characterized in that the diene monomer or the diene monomer solution at a lower temperature than the polymerization solution inside the polymerization tank is supplied to the polymerization tank separately from the raw material supply.
A method for producing a diene polymer through a plurality of polymerization vessels,
In any polymerization tank other than the first tank polymerization tank,
A method for producing a diene polymer, comprising supplying the diene monomer or the diene monomer solution at a lower temperature than the polymerization solution inside the polymerization tank.
The method for producing a diene polymer according to claim 1 or 2, wherein the diene polymer is polybutadiene.
The method for producing a diene polymer according to claim 1 or 2, wherein the diene monomer is butadiene.
In the initial tank polymerization tank and the polymerization tank, the same molecular weight,
The monomer concentration of the diene monomer solution is 30 wt% to 70 wt%,
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution is 30 ° C. to 100 ° C.,
The method for producing a diene polymer according to claim 2, wherein the supply amount of the diene monomer solution is 5% to 20% of the main flow rate.
In the polymerization tank, a polymer having a lower molecular weight than that in the initial tank polymerization tank is polymerized, and the high molecular weight polymer and the low molecular weight polymer are mixed so as to have a weight ratio of 2: 8 to 8: 2.
The monomer concentration of the diene monomer solution is 65 wt% to 75 wt%,
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution is 40 to 105 ° C.,
The method for producing a diene polymer according to claim 2, wherein the supply amount of the diene monomer solution is 5 to 20% of the main flow rate.
Polymerize a medium molecular weight polymer in the initial tank polymerization tank, polymerize a plastic resin in the polymerization tank, mix both,
The monomer concentration of the diene monomer solution is 100 wt% (monomer),
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer is 50 ° C. to 90 ° C.,
The method for producing a diene polymer according to claim 2, wherein the supply amount of the diene monomer is 5 to 20% of the main flow rate.
In the first step, the high molecular weight polymer is polymerized in the first tank polymerization tank of the first process, the polymerization solution is supplied to a polymerization tank other than the first tank of the first process, and the low molecular weight polymer is polymerized in the polymerization tank. And
In the second step, the medium molecular weight polymer is polymerized in the initial tank polymerization tank of the second process, the polymerization solution is supplied to a polymerization tank other than the first tank of the second process, and the plastic resin is polymerized in the polymerization tank,
In the third step, the product of the first step and the product of the second step are mixed,
In the first step,
The monomer concentration of the diene monomer solution is 30 wt% to 50 wt%,
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer solution is 40 to 105 ° C.,
The supply amount of the diene monomer solution is 5 to 20% of the main flow rate,
In the second step,
The monomer concentration of the diene monomer solution is 100 wt% (monomer),
The temperature difference between the polymerization solution inside the polymerization tank and the diene monomer is 35 ° C. to 90 ° C.,
The method for producing a diene polymer according to claim 2, wherein the supply amount of the diene monomer is 5 to 20% of the main flow rate.