JP2013147529A - Method for producing vinyl polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a vinyl polymer, capable of efficiently removing a halogen originated from the vinyl polymer having the halogen group, an initiator, a metal catalyst, etc., from the reaction system of the vinyl polymer.SOLUTION: A method for producing a vinyl polymer is provided by removing halogens originated from the vinyl polymer, an initiator, a metal catalyst, etc., from their reaction system by heating and stirring the vinyl polymer having the halogen group and a compound containing boron at ≥170°C and ≤250°C.

Description

  The present invention relates to a method for producing a vinyl polymer and a purification method.

  A living radical polymerization method is generally known as a precise synthesis method for vinyl polymers. In recent years, many methods for producing vinyl polymers using atom transfer radical polymerization have been reported (for example, Patent Document 1 and Patent Document 2).

  Assuming industrial use of vinyl polymers produced by the atom transfer radical polymerization method, it is essential to establish a method for removing metal catalysts, amines and other reactants used in the polymerization. It is also important to remove the halogen contained in the halogen-based initiator and the vinyl polymer produced with the halogen-based initiator.

  This is because if the metal catalyst remains in the produced vinyl polymer, the color tone and storage stability are likely to deteriorate, and if halogen remains as a free acid, the storage stability is likely to deteriorate. This is because if it remains as a part of the organic compound, it tends to cause an increase in molecular weight and molecular weight distribution of the vinyl polymer, which originates from thermal radical dissociation of carbon-halogen bonds at high temperatures.

  Many universities and companies are still researching methods for removing metal catalysts, amines, other reactants, initiators, and halogens derived from vinyl polymers, and purifying vinyl polymers. As a method, a purification method using an adsorbent and a purification method using water have been reported so far (for example, Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6). In particular, a high temperature treatment condition has been reported as a treatment method effective as a method for removing a halogen derived from an initiator, a metal catalyst, etc. from a vinyl polymer having a halogen group and its reaction system (for example, Patent Document 7). .

WO96 / 30421 publication WO97 / 18247 JP 2001-323012 A JP 2001-323015 A JP-A-2005-105265 Japanese Patent Laid-Open No. 11-80250 WO03 / 066689

  The present invention provides a vinyl polymer having a halogen group and a method for producing a vinyl polymer capable of efficiently removing halogen derived from an initiator, a metal catalyst, and the like from the reaction system of the vinyl polymer. To do.

  In the present invention, a vinyl polymer having a halogen group and a boron-containing compound are heated and stirred at 170 ° C. or more and 250 ° C. or less, whereby the halogen derived from the vinyl polymer, the initiator, the metal catalyst, etc. The present invention has found a method for producing a vinyl polymer characterized in that it is removed from the system.

That is, a vinyl polymer having a halogen group is mixed with a boron-containing compound represented by the following general formula (1) and heated and stirred at 170 ° C. or higher and 250 ° C. or lower to produce a vinyl polymer. Regarding the method.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.)
The vinyl polymer having a halogen group is preferably a vinyl polymer having a γ-haloester group.

  The vinyl polymer is preferably a polymer obtained by atom transfer radical polymerization.

A purification process with water before and / or after the step of mixing a halogen-containing vinyl polymer with a boron-containing compound represented by the following general formula (1) and heating and stirring at 170 ° C. or higher and 250 ° C. or lower. Is preferably performed.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.)

A vinyl polymer having a halogen group is mixed with a boron-containing compound represented by the following general formula (1), and the mixture is heated and stirred at 170 ° C. or higher and 250 ° C. or lower. It is related with the method of removing.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.)

  Conventional methods for halogen-containing compounds such as halogen initiators, metal halides, and other halogen-containing reactants used in the process of producing a vinyl polymer having a halogen group, such as free halogen, organic halogen compounds and inorganic halogen compounds Can be removed efficiently compared to Also, by efficiently removing the halide, the hydrosilylation activity during the hydrosilylation reaction, which is important for obtaining a silyl group-containing vinyl polymer from the obtained vinyl polymer, is improved. You can lose weight, which is economically advantageous. Further, when the halogen compound is removed from the vinyl polymer, coloring is improved.

  In the present invention, a vinyl polymer having a halogen group and a boron-containing compound are heated and stirred at 170 ° C. or higher and 250 ° C. or lower, whereby a halogen derived from a vinyl polymer, an initiator, a metal catalyst, or the like is converted into the reaction system. It is related with the manufacturing method of the vinyl polymer characterized by removing from.

  Examples of vinyl polymers include hydrocarbon polymers such as polyisobutylene, hydrogenated polyisoprene, hydrogenated polybutadiene, (meth) acrylic monomers, acrylonitrile monomers, aromatic vinyl monomers, fluorine-containing vinyl polymers. A polymer produced mainly by polymerizing a monomer selected from the group consisting of a monomer and a silicon-containing vinyl monomer is preferred. Here, “mainly” means that 50 mol% or more of the monomer units constituting the vinyl polymer is the above monomer, and preferably 70 mol% or more. Furthermore, the vinyl polymer is preferably a (meth) acrylic polymer produced mainly by polymerizing polyisobutylene and a (meth) acrylic monomer, more preferably an acrylic polymer, and a polymerized acrylate monomer. An acrylic ester polymer produced by the above method is more preferable.

  (Meth) acrylic monomers include: (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid n-butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid n-heptyl, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, Isodecyl (meth) acrylate, isobornyl (meth) acrylate, disishi (meth) acrylate Lopentanyl, dodecyl (meth) acrylate, phenyl (meth) acrylate, toluyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, (Meth) acrylate 2-hydroxyethyl, (meth) acrylate 2-hydroxypropyl, stearyl (meth) acrylate, isostearyl (meth) acrylate, glycidyl (meth) acrylate, 2-amino (meth) acrylate Ethyl, γ- (methacryloyloxypropyl) trimethoxysilane, ethylene oxide adduct of (meth) acrylic acid, trifluoromethylmethyl (meth) acrylate, 2-trifluoromethylethyl (meth) acrylate, (meth) acrylic 2-perfluoroethylethyl acid, (meth) a 2-perfluoroethyl-2-perfluorobutylethyl acrylate, 2-perfluoroethyl (meth) acrylate, perfluoromethyl (meth) acrylate, diperfluoromethylmethyl (meth) acrylate, (meth) acrylic acid 2-perfluoromethyl-2-perfluoroethylethyl, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, 2-perfluorohexadecylethyl (meth) acrylate, etc. (Meth) acrylic acid ester monomers and the like.

  Examples of acrylonitrile monomers include acrylonitrile and methacrylonitrile.

  Examples of the aromatic vinyl monomer include styrene, vinyl toluene, α-methyl styrene, chlorostyrene, styrene sulfonic acid and salts thereof.

  Examples of the fluorine-containing vinyl monomer include perfluoroethylene, perfluoropropylene, and vinylidene fluoride.

  Examples of the silicon-containing vinyl monomer include vinyltrimethoxysilane and vinyltriethoxysilane.

  There are many methods for producing vinyl polymers, including radical polymerization. The vinyl polymer having a halogen group in the present invention is preferably produced by atom transfer radical polymerization. First, atom transfer radical polymerization will be described.

[Atom transfer radical polymerization]
Atom transfer radical polymerization is a polymerization method recently developed by Matyjaszewski et al. (J. Am. Chem. Soc. 1995, 117, 5614) and Sawamoto et al. (Macromolecules 1995, 28, 1721). This is one of the techniques for synthesizing a polymer in which molecular weight, molecular weight distribution, etc. are highly controlled by combining various reagents such as a catalyst and an amine, that is, a living polymer.

  Recently, single-electron transfer living radical polymerization (J. Am. Chem. Soc. 2006, 128, 14156, JPPS Chem 2007, 45, 1607) proposed by Percec, V et al. As a polymerization method.

  Examples of atom transfer radical polymerization include organic halides or sulfonyl halide compounds as initiators, and group 7, group 8, group 9, group 10 or group 11 of the periodic table as a central metal as a metal catalyst. And a polymerization system using a metal complex.

  Atom transfer radical polymerization is a polymerization method that highly controls molecular weight, molecular weight distribution, and the like, but has a major problem in the purification of the polymer. In atom transfer radical polymerization, metal catalysts, amines, etc. are used as reactants. If these reactants are not purified and removed from the polymerization system, fatal problems such as strong coloring of polymers and poor storage stability may occur. High nature.

  Further, when polymerization is performed using an organic halide as an initiator, and then the halogen group is replaced with another functional group as a termination treatment, free halogen is generated in the reaction system. On the other hand, if the halogen group is not appropriately substituted with another functional group, a polymer having a halogen end will remain in the reaction system.

  If free halogen remains in the reaction system, it acts as a free acid in the reaction system and tends to cause deterioration of the storage stability of the polymer. Polymers having a halogen end, that is, if halogen remains as a part of the organic compound, the molecular weight and molecular weight distribution of the vinyl polymer, which is caused by thermal radical dissociation of carbon-halogen bonds, are likely to increase at high temperatures. Become.

  An appropriate purification treatment is indispensable in terms of low coloration, maintenance of physical properties, and storage stability of the polymer produced as described above.

  In the present invention, as a method for removing a halogen source from a polymer having a halogen terminal produced by atom transfer radical polymerization, a vinyl polymer having a halogen group and a boron-containing compound are heated and stirred at 170 ° C. to 250 ° C. The method is being implemented. This will be described in detail below.

[Dehalogenation method]
A halogen-containing vinyl polymer produced using atom transfer radical polymerization or the like is dehalogenated by the following method. The halogen-containing vinyl polymer can be dehalogenated by adding a boron-containing compound represented by the following general formula (1) to the halogen-containing vinyl polymer and heating.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.)

  Specific examples of boron-containing compounds include boric acid, phenylboronic acid, methylboronic acid, ethylboronic acid, 2-thiopheneboronic acid, propenylboronic acid, allylboronic acid pinacolalate, 2-phenyl-1,3,2-dioxaborinane , Diisopropylmethylborane, trimethyl borate, borinic acids, borinic esters, and the like, which are preferable in that boric acid is inexpensive and can be easily removed with water.

  In order to enhance the dehalogenation effect by the boron-containing compound, it is preferable to heat-treat the halogen group-containing vinyl polymer at a high temperature, and a higher temperature is preferable for shortening the treatment time. If it is too large, the vinyl polymer will be decomposed or thermally deteriorated, and coloring will be deteriorated, which is considered to be caused by the decomposition or deterioration. Therefore, the vinyl polymer will not be noticeably decomposed or thermally deteriorated. It is preferable to heat-treat the polymer. For this reason, in order to enhance the dehalogenation effect while maintaining low coloration of the vinyl polymer, specifically, heat treatment is preferably performed at 170 ° C. or higher and 250 ° C. or lower. 180 degreeC or more and 220 degrees C or less are more preferable, and 190 degreeC or more and 210 degrees C or less are the most preferable.

  The dehalogenation step is preferably devolatilized under reduced pressure in order to remove low-molecular halides. The degree of vacuum is preferably 100 torr or less, more preferably 20 torr or less, and still more preferably 10 torr or less. When the treatment is performed while heating under reduced pressure, it is easily affected by surface renewal, and therefore, it is preferable to perform the treatment in a good surface renewal state by stirring or the like.

Addition of a large amount of boron-containing compound promotes dehalogenation from halogen-containing vinyl polymers, but adding too much leads to accelerated thermal degradation of the vinyl polymer, and after treatment, If boron remains in the polymer, storage stability is deteriorated. Therefore, it is necessary to purify a compound containing boron under a great economic and time burden.
However, on the other hand, if the amount of the boron-containing compound is too small, the effect is not sufficiently exhibited.

  That is, in order to achieve both a high dehalogenation effect and easy purification, the compound containing boron with respect to the halogen group-containing vinyl polymer is 500 ppm or more and 10,000 ppm or less, preferably 1000 ppm or more and 5000 ppm, in terms of the weight of boron alone. It is preferable to add below.

  The treatment time is not particularly limited, and heat treatment is possible in the range of several minutes to several tens of hours. However, if the heat treatment is performed for a long time at a high temperature, the vinyl polymer will be divided or thermally deteriorated. Treatment is preferably avoided. Since the (meth) acrylic polymer has high heat resistance and a high decomposition initiation temperature, it can be processed at a high temperature. The presence or absence of a solvent in the heating step is not particularly limited, but a heat treatment without a solvent is preferable.

  In the present invention, dehalogenation is preferably carried out by advancing an intramolecular cyclization reaction in a halogen-containing vinyl polymer in order to suppress decomposition of the polymer and the like. In particular, it is preferable to form a lactone ring in the vinyl polymer by an intramolecular cyclization reaction. The dehalogenation is preferably carried out by detaching the organic halide from the halogen-containing vinyl polymer in order to suppress the generation of free acid.

In a particularly preferred embodiment of the present invention, the dehalogenation is performed by forming a lactone ring by an intramolecular cyclization reaction in the halogen-containing vinyl polymer, and desorbing the organic halide accordingly. The vinyl polymer having a group represented by the general formula (2) at the terminal produced by atom transfer radical polymerization of a vinyl monomer is dehalogenated by the above heat treatment.
^{-C (R 3) (R 4} ) (X) (2)
(In the formula, R ³ and R ⁴ represent a group bonded to an ethylenically unsaturated group of a vinyl monomer. X represents chlorine, bromine or iodine.)

Here, R ³ and R ⁴ are groups bonded to the ethylenically unsaturated group of the vinyl monomer, but are preferably groups bonded to the ethylenically unsaturated group of the (meth) acrylic acid monomer. In the case where the release of acid by high-temperature heat treatment, polymer deterioration such as molecular weight jump, or the influence on the functional group of the vinyl polymer becomes a problem, it is preferable to convert it into a specific halogen-containing structure in advance. For example, when a halogen-containing vinyl polymer in which a group represented by the general formula (2) is converted into a group represented by the following general formula (3) is used, the coupling between the polymers is suppressed while quickly. Dehalogenation can proceed.
_{^{-C (R 3) (R 4}} ) -CH 2 -CH (X) -R 5 (3)
(In the formula, R ³ and R ⁴ represent a group bonded to an ethylenically unsaturated group of a vinyl monomer. X represents chlorine, bromine or iodine. R ⁵ represents a hydrogen atom, a hydroxyl group or an organic group.)

Here, R ³ and R ⁴ are groups bonded to the ethylenically unsaturated group of the vinyl monomer, but are preferably groups bonded to the ethylenically unsaturated group of the (meth) acrylic acid monomer. In addition, when the halogen-containing structure is a γ-halocarboxylic acid structure, γ-halocarboxylate structure or γ-haloester structure (hereinafter referred to as γ-halocarboxylic acid structure, etc.), it can be easily dehalogenated by heat treatment. Therefore, it is a more preferable halogen-containing structure in the dehalogenation step. Of these, the γ-haloester structure is preferred because it can be most easily dehalogenated.

R ⁵ is a hydrogen atom, a hydroxyl group or an organic group, and when R ⁵ is an organic group, it may contain one or more ether bonds or one or more ester bonds. Moreover, you may have functional groups, such as an ethylenically unsaturated group, a hydroxyl group, an amino group, and a silyl group.

A vinyl polymer having a γ-halocarboxylic acid structure and the like includes a vinyl polymer having halogen at the terminal produced by atom transfer radical polymerization of a vinyl monomer, and one or more ethylenically unsaturated groups in the molecule. It can manufacture by making the compound which has it react. Although it does not specifically limit as (gamma) -halocarboxylic acid structure etc., The group represented by following General formula (4) is more preferable.
^{_{-C (R 6) (CO 2}} R 7) -CH 2 -CH (X) -CH (R 8) -R 9 (4)
(Wherein X is chlorine, bromine, or iodine, R ⁶ is a hydrogen atom or an organic group having 1 to 10 carbon atoms, R ⁷ is a hydrogen atom, an organic group having 1 to 20 carbon atoms or an alkali metal atom, R ⁸ is Hydrogen atom, hydroxyl group or organic group, R ⁹ is hydrogen atom, hydroxyl group or organic group)

R ⁶ is a hydrogen atom or an organic group having 1 to 10 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom. R ⁷ is a hydrogen atom, an organic group having 1 to 20 carbon atoms, or an alkali metal atom. Examples of the organic group having 1 to 20 carbon atoms include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and the like. An alkoxyalkyl group having 2 to 20 carbon atoms and the like may be exemplified. R ⁷ is preferably a hydrogen atom, an alkali metal atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms, a hydrogen atom, a sodium atom, a potassium atom, an alkyl group having 1 to 20 carbon atoms, An alkoxyalkyl group having 2 to 20 carbon atoms is more preferable, and an alkyl group having 1 to 20 carbon atoms and an alkoxyalkyl group having 2 to 20 carbon atoms are particularly preferable.

R ⁸ and R ⁹ may be a hydrogen atom, a hydroxyl group, or an organic group, and R ⁸ and R ⁹ may be the same or different groups. When R ⁸ and R ⁹ are organic groups, they may contain one or more ether bonds or one or more ester bonds, and functional groups such as ethylenically unsaturated groups, hydroxyl groups, amino groups, and silyl groups. You may have. R ⁸ and R ⁹ may be linked at the other end to form a cyclic skeleton.

R ⁸ is preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and particularly preferably a hydrogen atom or a methyl group. R ⁹ is preferably an organic group having 1 to 20 carbon atoms, and the functional group when R ⁹ has a functional group is preferably an ethylenically unsaturated group or a hydroxyl group.

The vinyl polymer having a group represented by the general formula (4) is dehalogenated through formation of a lactone ring after elimination of halogen X by a heating step. When R ⁷ in the general formula (4) is an organic group having 1 to 20 carbon atoms, generation of free acid can be suppressed because halogen X is eliminated as an organic halide.

  In the case of a vinyl polymer having an ethylenically unsaturated group, hydrosilylation activity generally improves when halogen is removed from the polymer. The “hydrosilylation activity” described in this report refers to the reaction of hydrosilylation reaction when a compound having a hydrosilyl group is added to a compound having an ethylenically unsaturated group in the presence of a transition metal complex such as platinum. This is an illustration. In this addition reaction, it is known that a transition metal complex such as platinum acts as a catalyst for the addition reaction. When the purification state of a compound having a hydrosilyl group or a compound having an ethylenically unsaturated group is poor and impurities are included, the amount of transition metal complex necessary to complete the hydrosilylation reaction is good in a purified state with few impurities. More than the case. This is because impurities present in the reaction system poison the transition metal complex.

  If the halogenated compounds such as organic halides, metal catalysts, and free acids that have been described in this report cannot be completely removed and remain in the vinyl polymer, such as platinum added during hydrosilylation of the vinyl polymer. Toxic transition metal catalyst.

  As the hydrosilylation catalyst, a very expensive transition metal catalyst such as platinum is often used, and when conducting a hydrosilylation reaction of the polymer, polymerization is performed in a purified state in which high hydrosilylation activity is expressed from an economical viewpoint. It is necessary to organize. That is, removing a halogen-containing compound from a vinyl polymer exhibits a great economic advantage in view of the hydrosilylation reaction of the polymer.

  In many cases, halogen group-containing vinyl polymers are polymerized using various types of reactants such as metal catalysts and amines in the polymerization process. In addition to the dehalogenation treatment, residues of the above-mentioned catalysts and reactants such as amines are often used. It is difficult to obtain a high-purity vinyl polymer without properly treating the polymer.

  Therefore, a purification method for efficiently removing various reagents such as metal catalysts and amines used in the step of synthesizing the halogen group-containing vinyl polymer will be described below.

[Method of purifying vinyl polymer]
Purification of the vinyl polymer includes a method using an adsorbent and a method using water, but a method using water is preferred.

  As a purification method using water, first, a vinyl polymer is dissolved in a water-insoluble solvent. The following various solvents can be selected for dissolving the polymer. Examples of water-insoluble solvents include saturated hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and anisole; methylene chloride, carbon tetrachloride, chloroform, and the like. Halogenated hydrocarbon solvents; ester solvents such as ethyl acetate, butyl acetate and isoamyl acetate; alcohol solvents having 4 or more carbon atoms such as n-butanol, n-pentanol and n-hexanol. These may be used alone or in combination of two or more. Among them, preferred solvents are n-butanol, n-hexanol, butyl acetate, toluene, and methylcyclohexane, which are easily available, have low toxicity and environmental burden, and can be easily removed after removal of the metal. More preferred solvents are N-butanol and n-hexanol having high copper extraction efficiency.

  In order to ensure oil-water separation after mixing and stirring, it is preferable to use a water-insoluble solvent for dissolving the polymer. However, by using the electrolyte component described below as an essential component, the water-soluble solvent is n. It is also possible to use -propanol.

  The amount of the solvent used is not particularly limited. Usually, the range of 10 to 2000 parts by weight is preferable with respect to 100 parts by weight of the vinyl polymer, and the range of 50 to 200 parts by weight with respect to the polymer is preferable from the viewpoint of economy and operation.

  For the water used, prevention of polymer contamination must be considered. Water through a filter of 50 μm or less is preferable, and pure water treated with an ion exchange resin is more preferable.

  In the present invention, an electrolyte component may be mixed with water in order to improve the separation from the polymer solution. Examples of electrolyte components that dissolve in water are sodium chloride, sodium sulfate, sodium acetate, sodium acrylate, sodium phosphate, sodium citrate, sodium tartrate, sodium benzoate, sodium sorbate, sodium phthalate, sodium acrylate, and Sodium methacrylate. These sodium salts may be potassium salts or ammonium salts. Among these, sodium sulfate and sodium chloride are preferable, and sodium sulfate is more preferable because it is easily available and is a neutral salt and has a low load in wastewater treatment.

  Although the content of the electrolyte added to water is not particularly limited, it is necessary to completely dissolve the electrolyte. Therefore, it is preferable to adjust the addition amount corresponding to the solubility of the electrolyte. In order to promote the separability after mixing the aqueous electrolyte solution and the polymer solution, the amount of electrolyte added is preferably 1 to 15 parts by weight with respect to 100 parts by weight of water, and the wastewater treatment load is reduced. In order to reduce, it is preferable to set it as 1-10 weight part.

  The amount of water used when the polymer solution is brought into contact with water or an aqueous solution in which an electrolyte component is dissolved is not particularly limited, but is 50 to 1000 parts by weight with respect to 100 parts by weight of the vinyl polymer in terms of economy and operation. A range is preferred.

  Various embodiments are possible for the liquid-liquid contact between the aqueous solution in which water or an electrolyte component is dissolved and the polymer solution. However, in addition to the batch method in which stirring and mixing and liquid-liquid separation are performed by a batch operation, water and a polymer are preferably used. An extraction tower method, a spray tower method, or the like that allows liquid to flow through the container by a flow method can also be used. Furthermore, in addition to mixing and dispersing by stirring, various operations for improving the dispersion efficiency such as shaking of the container and use of ultrasonic waves can be incorporated as necessary. Examples of methods that do not require a driving force for mixing the two phases include methods called flow mixers such as spray towers, packed towers, baffle towers, perforated plate extraction towers, orifice towers, and static mixers. Examples of the method that requires a driving force include a pulsating packed tower, a pulsating perforated plate tower, a vibrating plate tower, a centrifugal extraction device such as a Podovirniak extractor and a Lewesta extractor. There are various types of apparatuses using a stirring system as a driving force, such as a mixer-settler extraction apparatus, a Seibel tower, a rotating disk extraction tower, an Old shoe-Rushton tower, and an ARD tower.

  The temperature at which the aqueous solution in which water or the electrolyte component is dissolved and the polymer solution are brought into contact with each other is not particularly limited, and may generally be 0 to 200 ° C. Preferably it is 20-100 degreeC, More preferably, it is 60-100 degreeC. A higher temperature is preferable because the viscosity of the polymer solution decreases and the number of dispersed oil droplets decreases, so that the contact area with water increases and the extraction of the metal catalyst is promoted. However, if it is too high, the quality of the vinyl polymer may be deteriorated.

  The time for performing the contact is not particularly limited as long as the object of the present invention can be achieved. There is also a combination in which purification is completed by mixing and stirring for about 1 minute by limiting the type of water-insoluble solvent or electrolyte that dissolves the polymer. Other combinations can be usually performed in about 5 to 300 minutes.

  For oil-water separation between an aqueous solution in which water or an electrolyte component is dissolved and a polymer solution, centrifugal separation using a specific gravity difference or stationary separation, or electrostatic oil purification utilizing a difference in electrical properties may be used. I can do it. The time for performing the oil / water separation is not particularly limited as long as the object of the present invention can be achieved. Usually, it can be performed in about 5 to 300 minutes.

  The number of times of contact between the aqueous solution in which the water or electrolyte component is dissolved and the polymer solution and the number of oil-water separations are not particularly limited, and may be one or several times.

  In order to remove the residual catalyst, the above-described method may be used in combination with a purification treatment using a filter agent or an adsorbent. Examples of adsorbents are activated carbon, ion exchange resins (acidic, basic or chelated), and inorganic adsorbents. Examples of the inorganic adsorbent include silica, magnesium oxide, activated alumina, acidic clay, activated clay, zeolite, kaolin, bentonite, diatomaceous earth and the like. When the solid-liquid contact between the ion exchange resin or inorganic adsorbent and the polymer solution is used in combination, a batch method in which stirring and mixing and solid-liquid separation are performed by a batch operation can be used. In addition to this, a fixed bed system in which a container is filled with an adsorbent and the polymer solution is passed, a moving bed system in which the liquid is passed through the moving bed of the adsorbent, a fluidized bed system in which the adsorbent is fluidized with liquid and adsorbed, etc. The continuous method can also be used. Furthermore, if necessary, operations for improving dispersion efficiency, such as shaking of a container or use of ultrasonic waves, can be combined with the mixing and dispersing operation by stirring. After the polymer solution is brought into contact with a filtering agent or an adsorbent, the polymer solution is removed by a method such as filtration, centrifugation, or sedimentation separation, and a washing treatment is performed as necessary to further increase the degree of purification.

  The purification with water may be before or after the dehalogenation treatment, but the purification with water before the dehalogenation treatment suppresses the coloring of the vinyl polymer by the dehalogenation treatment. The purification with water after the dehalogenation treatment is preferable because the generated free halogen can be dissolved in water and removed. For these reasons, it is preferable to perform purification with water both before and after the dehalogenation treatment because a vinyl polymer with a higher degree of purification can be obtained.

  The present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

<Molecular weight measurement method>
The molecular weight shown in this example was measured with a GPC analyzer, and the molecular weight in terms of polystyrene was determined using chloroform as the mobile phase. As a system, a GPC system manufactured by Waters was used, and Shodex K-804 (polystyrene gel) manufactured by Showa Denko Co., Ltd. was used for the column.

<Method for measuring conversion rate of polymerization reaction>
The addition rate of the polymerization reaction shown in this example was measured using the following analyzer and conditions.
Equipment used: Gas chromatography GC-14B manufactured by Shimadzu Corporation
Separation column: J & W SCIENTIFIC INC, capillary column DB-17, 0.32 mmφ × 30 m
Separation conditions: Initial temperature 50 ° C, hold for 3 minutes
Temperature increase rate 40 ° C / min
Final temperature 170 ° C, hold for 1.5 minutes
Injection temperature 250 ° C
Detector temperature 250 ° C
Sample preparation: The sample was diluted about 10 times with toluene, and ethanol was used as an internal standard substance.

<Structural analysis method of polymer>
The structures of the polymers shown in the present production examples and examples were measured using the following analyzers and conditions.
Equipment used: AVANCE ^TM III (400 MHz-NMR) (manufactured by Bruker)
Sample preparation: About 60 mg of a polymer was collected in an appropriately sized vial, and about 1 ml of deuterated chloroform (Cambridge Isotop Laboratories) was added thereto to dissolve the polymer. The whole amount was transferred to a sample tube to obtain a measurement sample.

<Method for measuring halogen content in polymer>
In the following examples, the amount of bromine was quantified by elemental analysis by ion chromatography after preparing a sample by an oxygen flask combustion method.

<Measurement method of degree of coloration of polymer>
The degree of coloration (ΔE ^* ) of the purified vinyl polymer was evaluated using a spectroscopic colorimeter SE-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). A lower ΔE ^* value indicates that the polymer is less colored.

<Hydrosilylation activity evaluation test>
A measurement method for simply evaluating the hydrosilylation activity of the polymer is shown below. Although it is not an absolute activity evaluation method, when this evaluation is performed under the same conditions, a relative evaluation can be performed regarding hydrosilylation activity.
A vinyl polymer (compound having an unsaturated bond) and a chain siloxane (Si-H value: 3.70 mmol / g) containing an average of 5 hydrosilyl groups and an average of 5 α-methylstyrene groups in the molecule. ) And a 1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex toluene solution (platinum concentration 1.3 × 10 ⁻⁵ mmol / μl) of zerovalent platinum at room temperature. A composition was obtained. The amount of chain siloxane used was such that the alkenyl group and hydrosilyl group had a molar ratio of 1 / 1.8, and the platinum catalyst amount was the molar ratio to the alkenyl group. A part of the composition was heated on a hot plate at 130 ° C. with stirring in an air atmosphere, and the gelation time was measured.

Example 1
(Polymerization process)
100 parts by weight of n-butyl acrylate, 10 parts by volume of ethanol (EtOH), 1.76 parts by weight of diethyl 2,5-dibromoadipate and 430 ppm of triethylamine (Et ₃ N) were charged and stirred at 65 ° C. under a nitrogen stream. . To this, copper bromide (II) (CuBr ₂ ) 79 ppm (Cu amount = 22 ppm) hexamethyltris (2-aminoethyl) amine (Me ₆ TREN) 80 ppm (equivalent to Cu) with a purity of 96%, A solution prepared by dissolving 0.75 parts by volume of EtOH and a solution prepared by dissolving 8.3 ppm of ascorbic acid (VC) in 0.09 parts by volume of ethanol were separately prepared, and the reaction was started by adding them. In the middle of the reaction, heating and stirring were continued so that the temperature of the reaction solution became 70 ° C to 85 ° C while appropriately adding a solution in which ascorbic acid was dissolved in ethanol. 160 minutes after the start of polymerization, when the reaction rate of n-butyl acrylate reached 92 mol%, the inside of the reaction vessel was depressurized to remove the volatile matter, thereby obtaining a vinyl polymer (A).
The total addition amount of ascorbic acid so far was 91 ppm, and the total addition amount of ethanol was 0.49 parts by volume. The number average molecular weight of the polymer (A) at this time was 21,600, and the molecular weight distribution was 1.22. The terminal structure of the vinyl polymer (A) at this time is the same as the structure represented by the general formula (3).
Subsequently, 55 parts by weight of EtOH, 16 parts by weight of 1,7-octadiene, and Et ₃ N5727 ppm were added to the vinyl polymer (A), and this was heated and stirred and dissolved at an internal temperature of 40 ° C. in a nitrogen stream. To this solution was added CuBr ₂ 29 ppm (Cu amount = 8 ppm) and 96% pure Me ₆ TREN 29 ppm (equal to Cu) dissolved in 2.1 parts by weight of EtOH under a nitrogen stream, and the mixture was stirred. . Finally, a solution in which ascorbic acid was dissolved in ethanol under a nitrogen stream was added to the vinyl polymer (A) solution maintained at an internal temperature of 40 ° C. to initiate the reaction. After the reaction, the temperature controller was adjusted so that the internal temperature was 40 ° C. Ten hours after the start of the reaction, vacuum devolatilization of the reaction system was performed at 80 ° C. for 2 hours to complete the reaction and obtain a vinyl polymer (B).
The total addition amount of ascorbic acid so far was 676 ppm (total addition amount of 767 ppm of total ascorbic acid when including the first half polymerization), and the total addition amount of ethanol was 2.83 parts by volume. The number average molecular weight of the vinyl polymer (B) at this time was 25100, and the molecular weight distribution was 1.38. The terminal structure of the vinyl polymer (B) at this time is the same as the structure represented by the general formula (4).

(First half water purification)
The polymer (B) solution was obtained by adding and stirring 300 g of n-butanol (made by Kyowa Hakko Chemical Co., Ltd.) to 150 g of the vinyl polymer (B). A 1 L separable flask (with a stirrer and a jacket) was charged with 300 g of pure water, 3 g of anhydrous sodium sulfate (manufactured by Wako Pure Chemical Industries, Ltd., hereinafter referred to as mirabilite) was added, and the mixture was stirred at room temperature. A mirabilite aqueous solution was prepared. The jacket temperature of the separable flask was set to 75 ° C., and the salt water was heated and stirred. Next, the vinyl polymer (B) solution was added dropwise to the salt water, and the whole was added and stirred for about 5 minutes. After the stirring was stopped, the oil phase and the aqueous phase were quickly separated, the oil phase (to the upper phase) remained pale yellow, and the aqueous phase (to the lower phase) changed to pale yellow. After standing for 5 minutes, the oil phase and the aqueous phase were separated and recovered. Drain the water phase, and gently add 1% by weight sodium hydroxide water of the same weight as the discharged salt water to the wall from the upper part of the inner wall of the separable flask so that the water phase comes again in the lower phase and the oil phase comes in the upper phase. The above-described stirring, standing, and separation operations were further performed three times for a total of four purification operations. The oil phase obtained by the last fourth operation was distilled off the solvent and water under reduced pressure using a rotary evaporator to obtain a pale yellow vinyl polymer (B).

(Dehalogenation treatment)
100 parts by weight of the polymer (B) obtained by the above-mentioned first half water purification is placed in a 300 ml separable flask, and 0.2 parts by weight of Sumilizer GS (Sumitomo Chemical Co., Ltd.) and boric acid (Wako Pure Chemical Industries, Ltd.) 1 part by weight (boron corresponds to 1750 ppm of the weight of the vinyl polymer (B)) was added, and the mixture was heated and stirred at an internal temperature of 100 ° C. for 1 hour. Thereafter, the mixture was heated and stirred until the internal temperature reached 190 ° C. under vacuum reduction, and after reaching 190 ° C., stirring was carried out for 14 hours while maintaining the temperature. After 14 hours, the temperature was lowered to an internal temperature of 100 ° C. in a vacuum state, and returned to normal pressure when the temperature was lowered to 100 ° C.

(Second half water purification)
A vinyl polymer (B) solution was obtained by adding 200 g of n-butanol to 100 g of the vinyl polymer (B) after dehalogenation and stirring. 200 g of pure water was charged into a 1 L separable flask (with a stirrer and a jacket), the jacket temperature of the separable flask was set to 75 ° C., and the pure water was heated and stirred. Next, the vinyl polymer (B) solution was added dropwise to the pure water, and the whole was added and stirred for about 5 minutes. After the stirring was stopped, the oil phase and the aqueous phase were immediately separated, and the oil phase (to the upper phase) was pale yellow and the aqueous phase (to the lower phase) remained colorless. After standing for 5 minutes, the oil phase and the aqueous phase were separated and recovered. Drain the aqueous phase, gently add pure water of the same weight as the drained water from the upper part of the inner wall of the separable flask to the wall, so that the aqueous phase is again in the lower phase and the oil phase is in the upper phase, as described above Stirring, standing, and separation operations were further performed once, for a total of two purification operations. The solvent and water were distilled off under reduced pressure from the oil phase obtained in the final second operation using a rotary evaporator to obtain a pale yellow vinyl polymer (B). The amount of boron and the amount of halogen (bromine amount) in the obtained vinyl polymer (B) were measured, and the hydrosilylation activity and coloring of the obtained vinyl polymer (B) were evaluated. The results are shown in Table 1.

(Comparative Example 1)
The same operation as in Example 1 was performed except that boric acid was not added during the dehalogenation treatment, and the results are shown in Table 1.

(Comparative Example 2)
0.1 parts by weight of boric acid (corresponding to 175 ppm of the weight of the vinyl polymer (B) as boron) is added to 100 parts by weight of the vinyl polymer (B), and the dehalogenation treatment is performed at 160 ° C. The same operation as Example 1 was implemented except having implemented.

(Comparative Example 3)
The same operation as in Example 1 was performed except that the temperature during dehalogenation treatment was 160 ° C. and boric acid was not added, and the results are shown in Table 1.

(Comparative Example 4)
The same operation as in Example 1 was carried out except that 0.01 parts by weight of boric acid was added after the latter half purification without adding boric acid during the dehalogenation treatment, and the results are shown in Table 1.

(Comparative Example 5)
The same operation as in Example 1 was performed except that boric acid was not added during the dehalogenation treatment and 0.1 part by weight of boric acid was added after the latter half purification, and the results are shown in Table 1.

[Example 1 and Comparative Example 1]
It can be seen from the gelation time that the amount of bromine contained in the vinyl polymer was reduced and the hydrosilylation activity was improved in Example 1 in which boric acid was added at a treatment temperature of 190 ° C. The effect of improving the hydrosilylation activity of boric acid was confirmed.

[Example 1, Comparative Example 1, Comparative Example 3]
The system of Example 1 in which boric acid was added and the dehalogenation treatment was performed at 190 ° C. was less colored than the system of Comparative Example 1 in which the dehalogenation treatment was performed without adding boric acid. It can be seen that low coloration equivalent to dehalogenation treatment at 160 ° C. is achieved. The coloring improvement effect of boric acid was confirmed.

[Example 1 and Comparative Example 2]
In Comparative Example 2 in which the dehalogenation treatment temperature is 160 ° C. and the boron addition amount is 175 ppm relative to the vinyl polymer, it can be confirmed that the hydrosilylation activity is improved from the curing time. It turns out that it does not express.
From this, it can be seen that when the treatment temperature is 170 ° C. or lower, the effect of improving hydrosilylation activity due to the addition of boron is not sufficiently exhibited.

[Example 1, Comparative Example 4, Comparative Example 5]
In Comparative Examples 4 and 5, boric acid is added to the purified vinyl polymer in order to obtain a highly hydrosilylating vinyl polymer. In Example 1, high hydrosilylation activity was achieved by adding at the time of dehalogenation treatment, but then boric acid was removed from the system by purification. In terms of obtaining a vinyl polymer with few impurities and high hydrosilylation activity, the operating conditions of Example 1 which can be added by boric acid during the dehalogenation treatment and then removed by the latter half purification are effective.

Claims (5)

A method for producing a vinyl polymer comprising a step of mixing a halogen-containing vinyl polymer with a boron-containing compound represented by the following general formula (1), followed by heating and stirring at 170 ° C. or more and 250 ° C. or less.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.) The method for producing a vinyl polymer according to claim 1, wherein the vinyl polymer having a halogen group is a vinyl polymer having a γ-haloester group. The method for producing a vinyl polymer according to claim 1 or 2, wherein the vinyl polymer is a polymer obtained by atom transfer radical polymerization. A purification process with water before and / or after the step of mixing a halogen-containing vinyl polymer with a boron-containing compound represented by the following general formula (1) and heating and stirring at 170 ° C. or higher and 250 ° C. or lower. The method for producing a vinyl polymer according to any one of claims 1 to 3.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.) A vinyl polymer having a halogen group is mixed with a boron-containing compound represented by the following general formula (1), and the mixture is heated and stirred at 170 ° C. or higher and 250 ° C. or lower. How to remove.
B (OR ¹ ) _n R ² _3-n (1)
(Wherein ^{R 1} is an alkyl group, an aryl group of up hydrogen or C1 -C10, ^{R 2} is about .n to an alkyl group, an aryl group of up to C1 -C10 the real number satisfying 1 ≦ n ≦ 3.)