WO2006008902A1

WO2006008902A1 - Process for producing polymer

Info

Publication number: WO2006008902A1
Application number: PCT/JP2005/011332
Authority: WO
Inventors: Tomoyuki Yoshimi; Naoki Furukawa
Original assignee: Kaneka Corporation
Priority date: 2004-07-16
Filing date: 2005-06-21
Publication date: 2006-01-26
Also published as: JPWO2006008902A1

Abstract

Resin particles or resin pellets of a polymer, especially an isobutylene block copolymer, are obtained while attaining a reduction in residual solvent amount in the product. In the process, a monohalogenated hydrocarbon solvent in a stripping step is inhibited from decomposing and thus yielding an alcohol in order that the solvent to be recovered can be reused. The solvent of a polymer solution is a mixed solvent comprising a C3-8, primary and/or secondary, monohalogenated hydrocarbon and an aliphatic and/or aromatic hydrocarbon. Before resin particles are obtained from the solution containing an isobutylene block copolymer and obtained after polymerization and catalyst deactivation/removal, a surfactant and water are added to the solution and this mixture is heated to remove the solvent with stirring for liquid-liquid dispersion. In this step (1), the actual pressure of the gas phase part in the tank is regulated so as to be in a specific range.

Description

Specification

Method for producing polymer

Technical field

[0001] The present invention prepares a polymer, particularly an isobutylene block copolymer, as a powdered resin particle or a powdered resin pellet while efficiently removing the solvent contained in the product. Regarding the method.

Background art

[0002] A polymer block mainly composed of isobutylene and an aromatic butyl monomer by cationic polymerization of isobutylene and an aromatic vinyl monomer such as styrene. For example, US Pat. No. 4,946,899 (Patent Document 1) discloses a method for producing an isobutylene block copolymer in a mixed solvent in which methyl chloride and methylcyclohexane are combined. It is disclosed.

[0003] Also, Japanese Patent Publication No. 7-59601 (Patent Document 2) discloses an isobutylene block copolymer having an isobutylene polymer block and a styrene polymer block force in a mixed solvent having methylene chloride and hexane power. A manufacturing method is disclosed.

[0004] Generally, a rubbery polymer recovery method employs a method of pelletizing by a submerged cut method after removing a solvent by a thin film evaporator or an extruder or a method of forming a granular material by steam stripping. There are many cases!

[0005] Regarding a method for removing a solvent from a polymer solution comprising a polymer exhibiting thermoplasticity and a solvent, see, for example, JP-A-8-041123 (Patent Document 3), a uniaxial thin film evaporator. A method has been proposed in which the residual solvent of the styrene-acrylic copolymer is reduced to 1, OOOppm or less without causing thermal and mechanical deterioration of the resin. However, when this method is applied to the isobutylene block copolymer used in the present invention, since the resin is melted and the solvent is evaporated, there are problems such as coloring due to thermal and mechanical deterioration of the resin. It occurs.

[0006] Further, JP 2002-161109 A (Patent Document 4) proposes a solvent removal method using a twin screw extruder for solvent evaporation of an isobutylene block copolymer. The power that can be supplied To reduce the residual solvent to 1, OOOppm or less, the equipment becomes expensive and not necessarily an advantageous method.

[0007] On the other hand, as a method for producing a granular material by steam stripping, a method in which a polymer solution is poured into hot water containing a dispersant, and the solvent is volatilized and recovered is generally used. In the presence of water, it is exposed to high temperatures, and the generation of alcohol is inevitable due to the decomposition of primary and Z or secondary monohalogen 匕 hydrocarbons having 3 to 8 carbon atoms, which dissolves in the solvent.

It is known that polymerization is inhibited when it is used again as a polymerization solvent after recovery.

[0008] This phenomenon is particularly prominent with butyl chloride, which produces butanol. When this accumulated in the solvent and became 50 ppm or more, the solvent could not be used for polymerization after recovery, and there was a problem that a great amount of solvent was lost.

[0009] Thus, there is a demand for development of a production process that solves various problems in producing isobutylene-based block copolymer, resin particles, and resin pellets, and stably produces products with low residual solvent. It was.

Patent Document 1: US Pat. No. 4,946,899

Patent Document 2: Japanese Patent Publication No. 7-59601

Patent Document 3: JP-A-8-041123

Patent Document 4: Japanese Patent Laid-Open No. 2002-161109

Disclosure of the invention

Problems to be solved by the invention

[0010] In view of the above-mentioned situation, the present invention provides a rosin powder granule or cocoon powder of a polymer, particularly an isobutylene block copolymer or cocoon of an isobutylene block copolymer that generates very little alcohol by steam stripping. The object is to provide a method capable of stably producing fat pellets.

Means for solving the problem

[0011] The present invention is a method for producing a coconut powder granule or a coconut pellet by removing the solvent of the polymer solution, and the solvent of the polymer solution is a primary having 3 to 8 carbon atoms and A mixed solvent of Z or secondary monohalogen 匕 hydrocarbons and aliphatic and Z or aromatic hydrocarbons containing a polymer in which the catalyst is deactivated and removed from the solution after completion of polymerization. grain In obtaining the body, a surfactant and water are added to the solution, and the liquid is liquid-dispersed by stirring, and the solvent is removed by heating in step (1). The present invention relates to a method for producing a polymer, characterized by heating in the range represented

(P1 / P2X 1.10

Pl = Actual pressure in the gas phase inside the can (MPa)

P2 = saturated water vapor pressure (MPa) calculated from internal temperature

In a preferred embodiment, the present invention relates to a method for producing a polymer, wherein the polymer is an isobutylene block copolymer.

[0012] A preferred embodiment relates to a process for producing an isobutylene block copolymer, wherein the solvent removal temperature power in step (1) is 70 ° C or higher and lower than 130 ° C.

[0013] In a preferred embodiment, following the step (1), in the steam stripping step (2) in which steam is blown and the residual solvent is removed, the internal temperature is 100 ° C or higher and lower than 160 ° C. The present invention relates to a method for producing a characteristic isobutylene-based block copolymer.

As a preferred embodiment, isobutylene block copolymer force (A) polymer block mainly composed of isobutylene and (B) polymer block force mainly composed of an aromatic vinyl monomer It is related with the manufacturing method of the isobutylene type block copolymer characterized by the above-mentioned.

[0015] Preferably, the present invention relates to a method for producing an isobutylene block copolymer, which is a solvent containing butyl butyl chloride and a solvent power of an isobutylene block copolymer solution.

The invention's effect

[0016] According to the present invention, a monohalogen carbonization in a stripping process is performed in order to obtain a polymer, in particular, an isobutylene block copolymer resin powder or resin pellet, while reducing the residual solvent in the product. The decomposition of the hydrogen solvent can be suppressed. In other words, it is possible to suppress the production of alcohol associated with the decomposition of the monohalogen hydrocarbon solvent, and to make it possible to reuse the recovered solvent.

Brief Description of Drawings FIG. 1 is an explanatory diagram of an apparatus for performing solvent removal and steam stripping according to the present invention. Explanation of symbols

[0018] 1 stirring tank

2 Raw material preparation line

3, 4 Jacket hot water line

5 capacitors

6 Solvent recovery line

7 Steam blowing line

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] The polymer of the present invention is not particularly limited as long as it can be solution-polymerized, but an isobutylene polymer is particularly preferably used.

[0020] The isobutylene polymer of the present invention is not particularly limited as long as it is a polymer containing isobutylene, but (A) a polymer block mainly composed of isobutylene, and (B) an aromatic vinyl system. The polymer block power isobutylene copolymer composed mainly of monomers is preferred. More specifically, monomers such as isoprene and aromatic vinyl monomers are added in the presence of a Lewis acid catalyst. Those obtained by cationic polymerization together with an initiator can be preferably used.

[0021] The polymer block composed mainly of isobutylene in (A) is usually a polymer block containing 60% by weight or more, preferably 80% by weight or more of isobutylene units. In addition, the polymer block composed mainly of the aromatic bulle monomer (B) is usually a polymer containing 60% by weight or more, preferably 80% by weight or more of the aromatic bule monomer unit. It is a block.

[0022] The aromatic bur monomer is not particularly limited, and examples thereof include styrene, o-, m- or P-methylstyrene, a-methylstyrene, and indene. These may be used alone or in combination of two or more. Of these, styrene, p-methylstyrene, _a- methylstyrene or a mixture thereof is particularly preferable from the viewpoint of cost.

[0023] The Lewis acid catalyst in the present invention is not particularly limited as long as it can be used for cationic polymerization, and examples thereof include metal halides such as TiCl, BC1, BF, A1C1, and SnCl. Of these, tetrasalt-titanium (TiCl 3) is preferable.

Four

[0024] As the polymerization solvent used in the cationic polymerization, a mixed solvent of primary and Z or secondary monohalogenated hydrocarbons having 3 to 8 carbon atoms and aliphatic and Z or aromatic hydrocarbons is used. it can.

[0025] The primary and Z or secondary monohalogenated hydrocarbons having 3 to 8 carbon atoms are not particularly limited, and include methyl chloride, methylene chloride, butyl chloride (1 chlorobutane), black benzene, and the like. Can be mentioned. Of these, butyl chloride is preferred in terms of the balance of the solubility of the isobutylene block copolymer, the ease of detoxification by decomposition, the cost, and the like.

[0026] The aliphatic and Z or aromatic hydrocarbons are not particularly limited, and examples thereof include pentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, and toluene. Can be mentioned. One or more selected from the group consisting of methylcyclohexane, ethylcyclohexane and toluene power are particularly preferred.

[0027] As the initiator used in the cationic polymerization, a compound represented by the following formula (I) is preferably used.

[0028] (CR'R'X) R ³ (I)

[Wherein, X represents a halogen atom, an alkoxy group having 1 to 6 carbon atoms or an acyloxy group. R ¹ and R ² are the same or different and each represents a monovalent hydrocarbon group hydrogen atom or 1 to 6 carbon atoms, R ¹ and R ² may be different even in the same. R ³ represents a polyvalent aromatic hydrocarbon group or a polyvalent aliphatic hydrocarbon group. n represents a natural number from 1 to 6. ]

Specific examples of the compound represented by the general formula (I) include 1,4 bis (chloroisopropyl) benzene [CH (C (CH) C1)] [note that 1,4 bis (α-chloromonoiso)

6 4 3 2 2

Propyl) benzene is also called dicumulant mouth ride].

[0029] In the polymerization of the isobutylene block copolymer, an electron donor component may be allowed to coexist if necessary. Examples of such compounds include pyridines, amines, amides, sulfoxides, esters, or metal compounds having an oxygen atom bonded to a metal atom.

[0030] In carrying out the actual polymerization, the respective components are mixed under cooling, for example, at a temperature of 100 ° C or higher and lower than 0 ° C. Especially good for balancing energy costs and polymerization stability. Furthermore, the temperature range is 80 ° C to 1-30 ° C.

[0031] Further, the number average molecular weight of the isobutylene block copolymer is not particularly limited, but the surface strength such as fluidity, calorific properties, physical properties, etc. is preferably 30000-500000. Especially preferred to be between 50000 and 40 0000! /.

[0032] After the polymerization, the polymer solution containing the isobutylene block copolymer is brought into contact with water or alkali water to deactivate the catalyst to stop the reaction, and then washed with water to obtain a catalyst. A refined dope can be obtained by extracting and removing residues and metal ions.

[0033] The temperature for deactivation and washing with water is not particularly limited, but is preferably in the range of room temperature to 100 ° C. The amount of water used for deactivation and rinsing is not particularly limited, but the volume ratio of water to the polymer solution is preferably in the range of 1Z10-10.

[0034] The purified polymer solution obtained in this manner is subsequently subjected to the powder and granule step (1) (also referred to as a crumbization step). The concentration of the resin in the polymer solution is preferably 10-60% by weight by adding the solvent used for polymerization as necessary. When the dope concentration is low, the concentration can be adjusted to a desired concentration by using one or more evaporators such as flash evaporation, thin film evaporation, stirring tank, and wet wall type. In addition, when the polymer solution concentration is high, it can be adjusted to a desired concentration by diluting the solvent.

[0035] A surfactant and water are added to the purified polymer solution thus obtained, that is, the solution containing the isobutylene block copolymer from which the catalyst has been deactivated and removed, and the mixture is stirred. The resin particles can be obtained by the step (1) in which the solvent is removed by heating while liquid-liquid dispersion. The amount of water to be added is not particularly limited, but it is preferable that the liquid-liquid dispersion has a strength of 0.5 to 4 times that of the polymer solution.

[0036] As the surfactant, it is necessary to stably disperse the polymer solution at a high temperature of 70 ° C or higher, and to reduce foaming due to solvent volatilization. It is preferable to use the nonionic surfactant which has. Specific examples include glycerin fatty acid ester, sorbitan ester, propylene glycol fatty acid ester, sucrose fatty acid ester, citrate mono (di or tri) stearate ester, pentaerythritol fatty acid ester, trimethylolpropane fatty acid ester, polyglycerin fatty acid ester. Polyoxyethylene glycerin fatty acid ester, polyester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polypropylene glycol fatty acid ester, polyoxyethylene glycol fatty alcohol ether, polyoxyethylene alkylphenol ether, N, N bis Examples thereof include (2-hydroxyethylene) fatty amines, condensation products of fatty acids and diethanol, block polymers of polyoxyethylene and polyoxypropylene, polyethylene glycol, and polypropylene glycol. These may be used alone or in combination of two or more. The amount of the nonionic surfactant to be added is not particularly limited, but is preferably 0.05 to 5 parts by weight with respect to the polymer. If the amount is less than 0.05 parts by weight, the properties as a surfactant cannot be sufficiently exhibited, and particles are not formed. On the other hand, when the amount exceeds 5 parts by weight, the physical properties of the weight body are deteriorated and the problem of foaming in the granular material becomes remarkable, which is not preferable.

[0037] In the present invention, the refined polymer solution and water are liquid-liquid dispersed in the presence of a nonionic surfactant, and then the solvent is removed by heating (1), whereby fine particles are formed. . A vessel equipped with a stirrer is preferably used as the device used for liquid-liquid dispersion by stirring and solvent removal. Arbitrary blades such as screw blades, propeller blades, anchor blades, paddle blades, inclined paddle blades, turbine blades, and large lattice blades can be used. These can be used for the liquid-liquid dispersion operation and the solvent removal operation using the same stirring tank, or after the liquid-liquid dispersion operation is performed in advance to form the dispersion liquid, the solvent removal is subsequently performed in a plurality of stirring tanks. Can also be used.

[0038] Regarding the pressure in the step (1), it is necessary to heat the actual pressure inside the can in the range represented by the following formula.

(P1 / P2X 1.10

Pl = Actual pressure in the gas phase inside the can (MPa)

P2 = saturated water vapor pressure (MPa) calculated from internal temperature

That is, in the dispensing in step (1), the internal pressure is preferably less than 1.10 times and less than 1.04 times (saturated water vapor pressure calculated from the internal temperature). Since the water is in the can, it cannot be less than 1.000 times. 1. When it is 10 times or more, the mono- and logene 匕 hydrocarbon solvent for the differential pressure with respect to the saturated water vapor pressure is steam stripping process (2) Disassembled by alcohol This is not preferable because a large amount of sulfite is generated.

[0039] The liquid temperature in the step (1) is not particularly limited, but is preferably equal to or higher than the azeotropic point of the solvent and water. However, even below the azeotropic point, the solvent can be easily removed by reducing the pressure in the container. Specifically, it is preferably 70 ° C or higher and lower than 130 ° C, more preferably 80 ° C or higher and less than 110 ° C. If it is less than 70 ° C, the solvent removal rate decreases, which is preferable in terms of production efficiency. If the temperature is 130 ° C or higher, the function of the nonionic surfactant is lost and a stable liquid-liquid dispersion system cannot be formed.

[0040] The aqueous solution containing the obtained rosin powder particles can be further removed by passing through step (2) by a steam stripping operation in which steam is continuously passed through. The vessel used for steam stripping is preferably connected to a pipe for introducing steam, and the method of introducing steam into the stirring vessel is preferably used in the same manner as suspension and solvent removal operations. Further, the steam stripping operation can be carried out by venting steam in the same tank following the removal of the solvent, or can be continued by separately providing a stripping tank. In addition, as a continuous method, when one or more aeration and stirring tanks are connected, stripping can be performed by bringing steam and a resin slurry into contact with each other by a shelf method.

[0041] The liquid temperature in the step (2) is not particularly limited, but is preferably 100 ° C or higher and lower than 160 ° C, more preferably 120 ° C or higher and lower than 160 ° C. If it is less than 100 ° C, the solvent removal rate decreases, which is not preferable in terms of production efficiency. If the temperature is 160 ° C or higher, the fusion between the fats and oils is promoted, and a good granular material cannot be obtained.

[0042] The aqueous solution containing the rosin powder particles after the steam stripping is dehydrated and dried by the step (3) described below. In order to recover the rosin powder particles including the aqueous solution containing the rosin powder particles, dehydration operations using various filters, centrifuges, and the like can be used. The water content of the dehydrated fat particles after dehydration by this operation is not particularly limited, but it is effective to make it 10 to 50% by weight. is there.

[0043] The obtained hydrous greaves powder granule is a conductive heat transfer dryer such as a grooved agitator dryer. The rice cake powder is dried by using a hot air heat receiving dryer such as a fluid dryer, etc. It can be a granule. The moisture content in the product powder is not particularly limited, but less than 1% It is preferable to be full.

[0044] In addition, the above-described dehydrated water-containing greaves powder particles or dried product pulverulent particles can be commercialized as rosin pellets using an extruder having a devolatilization mechanism. As the extruder having a devolatilization mechanism, a single-screw or twin-screw extruder having a vent mechanism can be used. In particular, the twin-screw extruder is preferably used from the viewpoint of solvent removal and monomer removal efficiency. The resin discharged from the extruder can be made into a final product by strand cutting, underwater cutting, hot cutting, etc.

Example

[0045] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[0046] The molecular weight and tensile strength of the block copolymer shown in this example were measured by the following methods.

[0047] Molecular weight: GPC system manufactured by Waters (column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, mobile phase: black mouth form). The number average molecular weight is expressed in terms of polystyrene.

[0048] (Production example)

To a 20 L reactor equipped with a stirrer, 3.70 kg of butyl chloride (water removed by molecular sieves), 1.92 kg of hexane (water removed by molecular sieves), 1.92 kg, and 2.90 g of p-dimethyl milk chloride were added. After the reaction vessel was cooled to -70 ° C, 2.18 g of N, N-dimethylacetamide and 844 g of isobutylene were added. Further, 85 g of titanium tetrachloride was added to initiate polymerization, and the reaction was allowed to proceed for 2 hours while stirring the solution at -70 ° C. Next, 408 g of styrene was added to the reaction solution, and the reaction was further continued for 30 minutes to obtain a polymer solution.

[0049] The obtained polymer solution was poured into a large amount of water to stop the reaction. After the reaction was stopped, the polymer solution phase and the aqueous phase were separated with a separating funnel. After the polymer solution phase was washed twice with the same method, it was confirmed that the aqueous layer was neutral, and the polymer solution phase was discharged with a sufficient force to obtain a polymer solution.

[0050] GPC analysis showed that the number average molecular weight was 100,000 and the molecular weight distribution was 1.14. [0051] (Example 1)

A pressure-resistant stirrer with a tank volume of 50 liters and an inner diameter of 30 cm is charged with 12.5 liters of pure water and 12.5 liters of the polymer solution obtained in the production example, and 5 parts of nonionic surfactant (polyethylene glycol monostearate) is added. Add lg and seal. The stirrer blade was heated by a jacket while stirring at 400 rpm using a two-stage tilted four-paddle paddle with a blade diameter of 15 cm.

[0052] When the internal temperature of the stirring tank reached 90 ° C, solvent gas was introduced into a capacitor attached to the pressure-resistant stirrer, and the solvent was sequentially recovered. The internal pressure was adjusted while paying attention to foaming. When the internal pressure (absolute pressure) reached 0.113 MPa and the internal temperature reached 99 ° C (saturated water vapor pressure 0.0978 MPa), the stirring tank was sealed and steam stripping continued. (Process (2)). For the stripping conditions, steam was blown from the bottom of the stirring tank while maintaining 150 ° C for 60 minutes.

[0053] The concentration of butanol in the solvent of the condensate obtained through these steps (1) and (2) was measured. As shown in Table 1, the butanol concentration in the obtained condensate (recovered solvent) was 2 ppm. there were

[0054] (Example 2)

The same procedure as in Example 1 was performed except that the stripping condition was changed to 160 ° C in the step (2).

[0055] As also shown in Table 1, the butanol concentration in the obtained condensate (recovered solvent) was 18 ppm.

[0056] (Comparative Example 1)

In process (1), internal pressure (absolute pressure) 0.11013 MPa, internal temperature 90 ° C (saturated water vapor pressure 0.0

When the pressure reached 701 MPa, the same procedure as in Example 1 was performed, except that the stirring vessel was sealed and steam stripping was subsequently performed.

[0057] As shown in Table 1, the concentration of butanol in the resulting condensate (recovered solvent) is 136 ppm, which is 7 pieces.

[0058] (Comparative Example 2)

The same procedure as in Comparative Example 1 was performed except that the stripping condition was changed to 160 ° C in the step (2).

[0059] As shown in Table 1, the butanol concentration in the resulting condensate (recovered solvent) was 427p. It was pm.

[0060] [Table 1]

[0061] From Table 1, in the examples according to the present invention, it is possible to obtain a solvent suitable for reuse with less butanol in the recovered solvent than in the comparative example.

Claims

The scope of the claims

[1] The solvent of the polymer solution is a mixed solvent of primary and Z or secondary monohalogenated hydrocarbons having 3 to 8 carbon atoms and aliphatic and Z or aromatic hydrocarbons. In order to obtain a coconut powder granule from the solution after completion of polymerization containing the polymer which has been deactivated and removed, a surfactant and water are added to the solution, and the mixture is dispersed in a liquid and liquid state by stirring, followed by heating. A method for producing a polymer, wherein in the step (1) for removing the solvent, the actual pressure in the gas phase in the can is heated in the range represented by the following formula.

(P1 / P2X 1.10

Pl = Actual pressure in the gas phase inside the can (MPa)

P2 = saturated water vapor pressure (MPa) calculated from internal temperature

2. The method for producing a polymer according to claim 1, wherein the polymer is an isobutylene block copolymer.

[3] The method for producing a polymer according to claim 2, wherein the solvent removal temperature in the step (1) is 70 ° C. or higher and lower than 130 ° C.

[4] In the steam stripping step (2) in which steam is blown after the step (1) to remove the residual solvent, the internal temperature is 100 ° C or higher and lower than 160 ° C. 4. A method for producing a polymer as described in 2 or 3.

[5] Strength of isobutylene-based block copolymer (A) A polymer composed of a polymer block mainly composed of isobutylene and (B) a polymer block mainly composed of an aromatic vinyl monomer. The method for producing a polymer according to any one of claims 2 to 4, wherein:

6. The method for producing a polymer according to any one of claims 2 to 5, wherein the solvent power of the isobutylene block copolymer solution is a solvent containing butyl chloride.