JP2013173877A - Method for producing vinylic polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a vinylic polymer low in coloring and high in hydrosilylation activity, the method being capable of efficiently removing, from the reaction system of the vinylic polymer, reaction agents used for polymerization of the vinylic polymer, such as a metal catalyst, an acidic substance, a basic substance and an ionic substance, and reaction residues.SOLUTION: A method for producing a vinylic polymer includes a step of dissolving a vinylic polymer polymerized by an atom transfer radical polymerization in a nonaqueous solvent, and bringing the polymer solution into contact with washing water, wherein the contact with the washing water is carried out using a washing water of 8≤pH≤14 and a washing water of 0≤pH≤6, respectively once or more.

Description

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

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

  Methods for removing metal catalysts, amines, other reactants, initiators, and methods for removing halogens derived from vinyl polymers are still being studied by many universities and companies. So far, a purification method using an adsorbent and a purification method using water have been reported (for example, Patent Literature 3, Patent Literature 4, Patent Literature 5, Patent Literature 6, Patent Literature 7, Patent Literature 8). .

WO96 / 30421 publication WO97 / 18247 JP 2003-049821 A JP 2001-323012 A JP 2001-323015 A JP-A-2005-105265 Japanese Patent Laid-Open No. 11-80250 JP 2001-323016 A

  The present invention efficiently removes a reaction agent and a reaction residue such as a metal catalyst, an acidic substance, a basic substance, and an ionic substance added to perform atom transfer radical polymerization from the reaction system of the vinyl polymer. The present invention provides a method for producing a vinyl polymer that can be used.

The present invention is directed to overcoming the problems set forth above.
That is, a method for producing a vinyl polymer comprising a step of dissolving a vinyl polymer polymerized by atom transfer radical polymerization in a water-insoluble solvent and bringing the polymer solution into contact with washing water,
Contact with the washing water is
The present invention relates to a method for producing a vinyl polymer, which requires at least one contact each with 8 ≦ pH ≦ 14 washing water and 0 ≦ pH ≦ 6 washing water.

  The atom transfer radical polymerization is preferably carried out using a metal complex having a transition metal (M) of Groups 7, 8, 9, 10, or 11 of the periodic table as a central metal.

  Metal catalysts, acid substances, basic substances, ionic substances and other reactants added in atom transfer radical polymerization systems, and reaction residues are economically, easily and wastefully discharged from the produced vinyl polymers. The vinyl polymer thus obtained is low-colored and has a high hydrosilylation activity.

The present invention is a method for producing a vinyl polymer comprising a step of dissolving a vinyl polymer polymerized by atom transfer radical polymerization in a water-insoluble solvent and bringing the polymer solution into contact with washing water,
Contact with the washing water is
The present invention relates to a method for producing a vinyl polymer in which contact with a wash water of 8 ≦ pH ≦ 14 and contact with a wash water of 0 ≦ pH ≦ 6 are each performed once or more.

  Examples of vinyl polymers include hydrocarbon polymers and monomers selected from the group consisting of (meth) acrylic monomers, acrylonitrile monomers, aromatic vinyl monomers, fluorine-containing vinyl monomers, and silicon-containing vinyl monomers. A polymer produced mainly by polymerizing 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.

  Examples of the hydrocarbon polymer include polyisobutylene, hydrogenated polyisoprene, and hydrogenated polybutadiene.

  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.

  Next, atom transfer radical polymerization will be described. 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 metal catalyst and 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, acids, and the like are used as reactants. If these reactants are not purified and removed from the polymerization system, the molecular weight of the polymer increases, the degree of dispersion decreases, the coloring becomes strong, and the storage stability is poor. There is a high possibility of causing fatal issues such as.

  Appropriate purification treatment is indispensable in terms of maintaining the molecular weight, maintaining the degree of dispersion, low coloration, and ensuring storage stability of the produced vinyl polymer.

  A method for purifying the vinyl polymer will be described. There are various methods for purifying vinyl polymers. There are purification methods using adsorbents, purification methods using ion exchange membranes, etc., but a purification method using water is effective as a purification method that is economically inexpensive, simple, and does not discharge much waste. In the invention, the vinyl polymer is purified using washing water whose pH range is controlled. Hereinafter, this purification method will be described.

  Purification using water is performed after first dissolving the vinyl polymer in a non-water-soluble solvent. The following various water-insoluble solvents can be selected for dissolving the polymer. For example, saturated hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and anisole; halogenated hydrocarbon solvents such as methylene chloride, carbon tetrachloride, and chloroform; Examples thereof include 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 metal extraction efficiency.

  The amount of the solvent mixed with the vinyl polymer 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.

  In order to improve oil-water separation after mixing and stirring, the electrolyte components described below may be mixed with water.

  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 20 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.

  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.

  The present invention is a purification of a vinyl-based polymer using water, and a reactive agent and reaction such as a metal catalyst, an acidic substance, a basic substance, an ionic substance, etc. added to the polymerization system by controlling the pH range of the water. The residue is efficiently removed from the vinyl polymer to obtain a vinyl polymer having high hydrosilylation activity and low color. Hereinafter, the water whose pH is controlled is described as washing water.

  The present invention is a method for producing a vinyl polymer comprising a step of bringing a vinyl polymer solution dissolved in a water-insoluble solvent into contact with washing water, wherein in the contact with the washing water, 8 ≦ pH ≦ 14 It is essential to perform the contact with the washing water and the contact with the washing water of 0 ≦ pH ≦ 6 at least once.

  In order to obtain a vinyl polymer having a high cleaning effect, it is preferable to alternately perform contact with both acidic and basic cleaning water, and in order to obtain a vinyl polymer having a high cleaning effect on a regular basis, The contact with water and basic water is preferably carried out twice or more. In order to maximize the coloring reduction effect, it is preferable that the vinyl polymer is first treated with basic washing water and then treated with acidic washing water.

  The pH range of the wash water is preferably 8 ≦ pH ≦ 10 and 1 ≦ pH ≦ 6 in that the load on the apparatus used for the purification is reduced and the economic load on the wastewater treatment is reduced.

  In order to control the pH range of water used for washing to 8 ≦ pH ≦ 14, a water-soluble basic substance may be added to water. For example, sodium hydroxide, potassium hydroxide, ammonia, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, sodium citrate, potassium citrate, potassium acrylate, sodium acrylate, sodium methacrylate Potassium methacrylate, potassium oxalate, sodium oxalate, sodium borate, potassium borate, sodium acetate, potassium acetate, sodium formate, potassium formate, triethylamine, and the like, but is not limited thereto.

  In order to control the pH range of water used for washing to 0 ≦ pH ≦ 6, a water-soluble acidic substance may be added to water. Examples include, but are not limited to, hydrochloric acid, sulfuric acid, oxalic acid, carbonic acid, citric acid, acrylic acid, methacrylic acid, ascorbic acid, glucose acid, boric acid, acetic acid, formic acid, and the like. .

  The amount of the water-soluble substance added to adjust the washing water is 10 parts by weight with respect to 100 parts by weight of water in that the water-soluble substance derived from the washing water hardly remains in the vinyl polymer and is not economically disadvantageous. The following is preferable, and 5 parts by weight or less is more preferable.

  The temperature at which the water-soluble substance is added to water may be any number of times as long as the water-soluble substance is soluble in water, but is preferably 5 ° C. to 90 ° C. in terms of suppressing the temperature adjustment cost of the equipment. Preferably it is 10 degreeC-85 degreeC, More preferably, 15 to 80 degreeC is good.

  If the vinyl polymer solution is washed with washing water in both pH ranges, there is a risk that acidic and / or basic substances contained as solutes in the washing water may remain in the vinyl polymer. For this reason, it is preferable to wash the vinyl polymer solution with water containing no solute after washing with the washing water in both pH ranges from the viewpoint that the water-soluble substance derived from the washing water does not remain in the vinyl polymer.

  Various embodiments are possible for the liquid-liquid contact between water or washing water and the polymer solution. In addition to the batch method in which stirring and mixing and liquid-liquid separation are carried out by batch operation, water and the polymer are mixed in a countercurrent system. An extraction tower system or a spray tower system that allows liquid to pass through 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 the time of bringing water or washing water into contact with the polymer solution 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 water or washing water and the polymer solution, centrifugal separation or stationary separation using a specific gravity difference, electrostatic oil purification using a difference in electrical properties, or the like can be used. 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.

  In atom transfer radical polymerization, an organic halide or a sulfonyl halide compound is preferably used as an initiator. However, the halogen initiator used in the polymerization and the halogen-containing compound derived from the metal halide catalyst are stored in a vinyl polymer. Since it becomes easy to cause serious defects such as deterioration of stability and increase in molecular weight / molecular weight distribution, it is preferably removed from the reaction system of the vinyl polymer as much as possible.

  In order to increase the halogen removal effect, it is preferable to heat-treat the halogen group-containing vinyl polymer at a high temperature, and in order to shorten the treatment time, a higher temperature is preferable. Heat treatment of the vinyl polymer in a temperature range in which the degradation or thermal degradation of the vinyl polymer does not occur remarkably due to degradation of the polymer or deterioration of coloration that is considered to be caused by the degradation or degradation. Is preferred. For this reason, in order to enhance the halogen removal effect while maintaining low coloration of the vinyl polymer, specifically, heat treatment is preferably performed at 140 ° C. or more and 250 ° C. or less. It is more preferably 160 ° C. or higher and 230 ° C. or lower, and most preferably 180 ° C. or higher and 210 ° C. or lower.

  The halogen removal 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.

  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.

  Halogen removal is preferably carried out by advancing an intramolecular cyclization reaction in the halogen-containing vinyl polymer in order to suppress decomposition of the polymer. In particular, it is preferable to form a lactone ring in the vinyl polymer by an intramolecular cyclization reaction. The halogen removal 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 halogen removal 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 (1) at the terminal produced by atom transfer radical polymerization of a vinyl monomer is halogen-removed by the above heat treatment.
-C (R ¹ ) (R ² ) (X) (1)
(In the formula, R ¹ and R ² represent a group bonded to an ethylenically unsaturated group of a vinyl monomer. X represents chlorine, bromine or iodine.)

Here, R ¹ and R ² 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 (1) is converted into a group represented by the following general formula (2) is used, the coupling between the polymers is suppressed while quickly. The halogen can be removed.
—C (R ¹ ) (R ² ) —CH ₂ —CH (X) —R ³ (2)
(In the formula, R ¹ and R ² represent a group bonded to an ethylenically unsaturated group of a vinyl monomer. X represents chlorine, bromine or iodine. R ³ represents a hydrogen atom, a hydroxyl group or an organic group.)

Here, R ¹ and R ² 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. Further, 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.), the halogen can be easily removed by heat treatment, This is a more preferable halogen-containing structure in the halogen removing step. Of these, the γ-haloester structure is preferred because it can most easily remove halogen.

R ³ is a hydrogen atom, a hydroxyl group or an organic group, and when R ³ 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. The γ-halocarboxylic acid structure and the like are not particularly limited, but a group represented by the following general formula (3) is more preferable.
^{_{-C (R 4) (CO 2}} R 5) -CH 2 -CH (X) -CH (R 6) -R 7 (3)
(Wherein X is chlorine, bromine or iodine, R ⁴ is a hydrogen atom or an organic group having 1 to 10 carbon atoms, R ⁵ is a hydrogen atom, an organic group having 1 to 20 carbon atoms or an alkali metal atom, R ⁶ , R ⁷ is a hydrogen atom, a hydroxyl group or an organic group)

R ⁴ 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 ⁵ 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 ⁵ 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 ⁶ and R ⁷ may be a hydrogen atom, a hydroxyl group, or an organic group, and R ⁶ and R ⁷ may be the same or different groups. When R ⁶ and R ⁷ are organic groups, they may contain one or more ether bonds or one or more ester bonds, and may be functional groups such as ethylenically unsaturated groups, hydroxyl groups, amino groups, and silyl groups. You may have. R ⁶ and R ⁷ may be linked at the other end to form a cyclic skeleton.

R ⁶ is preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, particularly preferably a hydrogen atom or a methyl group. R ⁷ is preferably an organic group having 1 to 20 carbon atoms, and the functional group when R ⁷ has a functional group is preferably an ethylenically unsaturated group or a hydroxyl group.

In the vinyl polymer having the group represented by the general formula (3), the halogen X is eliminated by the heating step, and the halogen is removed through lactone ring formation. When R ⁵ in the general formula (3) 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.

  The above halogen removal at high temperature is preferably performed after washing with controlled pH and / or purification using water from the viewpoint of suppressing coloring of the vinyl polymer, and after halogen removal at high temperature. It is preferable to further purify the vinyl polymer by using water so that free halogen remaining in the reaction system that remains without being removed can be removed by dissolving it in washing water with controlled pH range or water. For these reasons, it is preferable to carry out purification using washing water and / or water whose pH range is controlled both before and after halogen removal at a high temperature in terms of obtaining a vinyl polymer having a higher degree of purification.

  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.

When R ^{7 in the} general formula (3) is an ethylenically unsaturated group as the vinyl polymer of the present invention, the resulting vinyl polymer having an ethylenically unsaturated group is hydrosilylated with a compound having a hydrosilyl group. By the conversion reaction, a vinyl polymer having a silyl group is obtained.

  The higher the degree of purification of the vinyl polymer having an ethylenically unsaturated group, the higher the hydrosilylation activity, and the hydrosilylation reaction proceeds in the presence of a relatively small amount of transition metal catalyst. Conversely, if the degree of purification is low, the hydrosilylation reaction will not proceed unless a relatively large amount of transition metal catalyst is present. This is a reaction agent added to polymerize the polymer; a metal catalyst, an amine, an acid, a reaction residue after polymerization; a transition metal catalyst in which free halogen, organic halogen, ionic compounds, etc. are hydrosilylation reaction catalysts. Because it is poisoned.

  As the hydrosilylation catalyst, a very expensive transition metal catalyst such as platinum is often used. When conducting a hydrosilylation reaction of a polymer, it is necessary to obtain a purified state that exhibits high hydrosilylation activity from an economical viewpoint. There is. In other words, increasing the degree of purification of the vinyl polymer exhibits a great economic advantage in view of the hydrosilylation reaction of the polymer.

  In the present invention, the degree of purification is determined by measuring the hydrosilylation activity of a vinyl polymer having an ethylenically unsaturated group. The hydrosilylation activity was measured by mixing a vinyl polymer having an ethylenically unsaturated group, a chain siloxane containing a hydrosilyl group, and a platinum catalyst at room temperature and mixing a part of the resulting composition with 130 parts. It is obtained by heating on a hot plate at 0 ° C. with stirring in an air atmosphere and measuring the gelation time. If the degree of purification of the vinyl polymer having an ethylenically unsaturated group is high, gelation takes place in a short time with a small amount of catalyst.

  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.

<Measurement method of aqueous solution pH>
The liquid property was evaluated visually using a roll pH test paper.

<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 is such that the molar ratio of alkenyl group and hydrosilyl group is 1 / 1.8. The amount of platinum catalyst used is shown in Table 1 in terms of the weight concentration relative to the weight of the vinyl polymer. . 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.

(Production 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 586 ppm of triethylamine (Et ₃ N) were charged and stirred at 65 ° C. under a nitrogen stream. . To this, copper bromide (II) (CuBr ₂ ) 108 ppm (Cu amount = 30 ppm) hexamethyltris (2-aminoethyl) amine (Me ₆ TREN) 109 ppm (equivalent to Cu) with a purity of 96%, A solution in which 1.02 parts by volume of EtOH was dissolved and a solution in which 8.3 ppm of ascorbic acid (VC) was dissolved in 0.09 parts by volume of ethanol were separately prepared and added to initiate the reaction. 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 93 mol%, the inside of the reaction vessel was depressurized to remove the volatile matter to obtain a vinyl polymer (A1).
The total addition amount of ascorbic acid so far was 150 ppm, and the total addition amount of ethanol was 1.63 parts by volume. At this time, the polymer (A1) had a number average molecular weight of 20,500 and a molecular weight distribution of 1.10. The terminal structure of the vinyl polymer (A1) at this time is the same as the structure represented by the general formula (2).
Subsequently, 57 parts by weight of EtOH, 33 parts by weight of 1,7-octadiene and 573 ppm of Et ₃ N were added to the vinyl polymer (A1), and this was heated and stirred and dissolved at an internal temperature of 40 ° C. in a nitrogen stream. Finally, a solution in which ascorbic acid was dissolved in ethanol under a nitrogen stream was added to the vinyl polymer (A1) 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. Six hours after the start of the reaction, the reaction system was devolatilized at 80 ° C. for 2 hours to complete the reaction and obtain a vinyl polymer (B1).
The total addition amount of ascorbic acid so far was 1995 ppm (total addition amount of ascorbic acid was 2145 ppm when including the first half polymerization), and the total addition amount of ethanol was 23.2 parts by volume. The vinyl polymer (B1) at this time had a number average molecular weight of 24,400 and a molecular weight distribution of 1.31. The terminal structure of the vinyl polymer (B1) at this time is the same as the structure represented by the general formula (3).

(Production Example 2)
(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 586 ppm of triethylamine (Et ₃ N) were charged and stirred at 65 ° C. under a nitrogen stream. . To this, copper bromide (II) (CuBr ₂ ) 108 ppm (Cu amount = 30 ppm) hexamethyltris (2-aminoethyl) amine (Me ₆ TREN) 109 ppm (equivalent to Cu) with a purity of 96%, A solution in which 1.02 parts by volume of EtOH was dissolved and a solution in which 8.3 ppm of ascorbic acid (VC) was dissolved in 0.09 parts by volume of ethanol were separately prepared and added to initiate the reaction. 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 to obtain a vinyl polymer (A2).
The total addition amount of ascorbic acid so far was 1326 ppm, and the total addition amount of ethanol was 14.4 parts by volume. At this time, the polymer (A2) had a number average molecular weight of 21,100 and a molecular weight distribution of 1.18. The terminal structure of the vinyl polymer (A2) at this time is the same as the structure represented by the general formula (2).
Subsequently, 29 parts by weight of methanol, 30 parts by weight of 1,7-octadiene and 143 ppm of Et ₃ N were added to the vinyl polymer (A2), and this was heated and stirred and dissolved at an internal temperature of 40 ° C. in a nitrogen stream. . To this solution was added a solution prepared by dissolving 20 ppm CuBr ₂ (Cu content = 15 ppm) and 96 ppm purity Me ₆ TREN 20 ppm (equal to Cu) in 1.4 parts by weight of methanol under a nitrogen stream, and mixing and stirring. did. A solution in which 2520 ppm of ascorbic acid (VC) was dissolved in 9.59 parts by volume of methanol was separately adjusted under a nitrogen stream, and adjusted to a vinyl polymer (A2) solution maintained at an internal temperature of 40 ° C. under a nitrogen stream. The reaction was started by adding the ascorbic acid-methanol solution previously prepared. After the reaction, the temperature controller was adjusted so that the internal temperature was 40 ° C. After 10 hours from the start of the reaction, vacuum devolatilization of the reaction system was carried out at 80 ° C. for 2 hours to complete the reaction and obtain a vinyl polymer (B2).
The total addition amount of ascorbic acid so far was 8252 ppm (the total addition amount of ascorbic acid was 9578 ppm when including the first half polymerization), and the addition amount of methanol was 40.1 parts by volume. The vinyl polymer (B2) at this time had a number average molecular weight of 25400 and a molecular weight distribution of 1.39. The terminal structure of the vinyl polymer (B2) at this time is the same as the structure represented by the general formula (3).

Example 1
(First half water purification)
A polymer (B1) solution was obtained by adding 300 g of n-butanol (manufactured by Kyowa Hakko Chemical Co., Ltd.) to 150 g of the vinyl polymer (B1) produced in Production Example 1 and stirring. A 1 L separable flask (with a stirrer and a jacket) was charged with 300 g of pure water, 0.03 g of 28 wt% ammonia water (manufactured by Wako Pure Chemical Industries, Ltd.) and anhydrous sodium sulfate (manufactured by Wako Pure Chemical Industries, Ltd. And a basic aqueous solution having a pH of 9.0 was prepared by stirring at room temperature. The jacket temperature of the separable flask was set to 50 ° C., and the adjusted basic aqueous solution was heated and stirred. Next, the vinyl polymer (B1) solution was dropped into the basic aqueous solution, and the whole was dropped 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.
Separately, 0.05 g of 37 wt% hydrochloric acid (manufactured by Wako Pure Chemical Industries) and 3 g of mirabilite were added to 300 g of pure water, and the mixture was heated and stirred at 50 ° C. to prepare an acidic aqueous solution with pH = 1.5. After discharging the aqueous phase, an acidic aqueous solution having a pH of 1.5, which had the same weight as the discharged aqueous phase, was gently added to the inner wall of the separable flask. After the addition, the oil phase and the aqueous phase were stirred for about 5 minutes at a jacket temperature of 50 ° C. After the stirring was stopped, the oil phase and the aqueous phase were promptly separated, and after standing for 5 minutes, the oil phase and the aqueous phase were separated and recovered.
The washing with the basic aqueous solution and the stirring with the acidic aqueous solution were further performed once, and the washing with 1 wt% sodium nitrate water was finally performed twice. After discharging the aqueous phase, the solvent and water were distilled off from the oil phase under reduced pressure using a rotary evaporator to obtain a pale yellow vinyl polymer (B1).

(Halogen removal)
100 parts by weight of the polymer (B1) obtained by the above-mentioned first half water purification is placed in a 300 ml separable flask, 0.2 parts by weight of Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) is added thereto, and the internal temperature is 100 ° C. for 1 hour. Stir with heating. 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 (B1) solution was obtained by adding 200 g of n-butanol to 100 g of the vinyl polymer (B1) 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 (B1) 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 by the last second operation using a rotary evaporator to obtain a pale yellow vinyl polymer (B1). The resulting vinyl polymer (B1) was evaluated for hydrosilylation activity and coloring. The results are shown in Table 1.

(Example 2)
(First half water purification)
A polymer (B1) solution was obtained by adding 300 g of n-butanol (manufactured by Kyowa Hakko Chemical Co., Ltd.) to 150 g of the vinyl polymer (B1) produced in Production Example 1 and stirring. A 1 L separable flask (with a stirrer and jacket) is charged with 300 g of pure water, and 2.7 g of sodium hydrogen carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.3 g of sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) are added. The mixture was stirred at room temperature to prepare a basic aqueous solution having a pH of 9.5. The jacket temperature of the separable flask was set to 75 ° C., and the adjusted basic aqueous solution was heated and stirred. Next, the vinyl polymer (B1) solution was dropped into the basic aqueous solution, and the whole was dropped 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.
Separately, 1.3 g of citric acid (manufactured by Wako Pure Chemical Industries, Ltd.) and 1.8 g of disodium citrate (manufactured by Wako Pure Chemical Industries, Ltd.) were added to 300 g of pure water, and the mixture was heated and stirred at 75 ° C. to pH = 4.5. An acidic aqueous solution was prepared. After discharging the aqueous phase, the same amount as the aqueous phase from which the pH = 4.5 acidic aqueous solution was discharged was gently added to the inner wall of the separable flask. After the addition, the oil phase and the aqueous phase were stirred for about 5 minutes at a jacket temperature of 75 ° C. After the stirring was stopped, the oil phase and the aqueous phase were promptly separated, and after standing for 5 minutes, the oil phase and the aqueous phase were separated and recovered.
Washing with the basic aqueous solution and washing with the acidic aqueous solution were performed once more, and the washing with 1 wt% sodium nitrate water was finally performed twice. After discharging the aqueous phase, the solvent and water were distilled off from the oil phase under reduced pressure using a rotary evaporator to obtain a pale yellow vinyl polymer (B1).
(Halogen removal)
Same as the (Halogen removal) treatment operation of Example 1.
(Second half water purification)
Same as the treatment operation in Example 1 (second half water purification).

(Comparative Example 1)
(First half water purification)
A polymer (B1) solution was obtained by adding 300 g of n-butanol (manufactured by Kyowa Hakko Chemical Co., Ltd.) to 150 g of the vinyl polymer (B1) produced in Production Example 1 and stirring. A 1 L separable flask (with a stirrer and a jacket) was charged with 300 g of pure water, 3 g of mirabilite was added, and the mixture was stirred at room temperature to prepare a mirabilite solution. The jacket temperature of the separable flask was set to 75 ° C., and the salt water was heated and stirred. Next, the vinyl polymer (B1) 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 separated quickly, 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 solvent and water were distilled off under reduced pressure from the oil phase obtained in the last fourth operation using a rotary evaporator to obtain a pale yellow vinyl polymer (B1).
(Halogen removal)
Same as the (Halogen removal) treatment operation of Example 1.
(Second half water purification)
Except that the number of times of washing with pure water is 4, the same operation as that in Example 1 (second-half water purification) is performed.

(Comparative Example 2)
(First half water purification)
The conditions for the first half water purification in Example 2 are the same as in Example 2 except that the vinyl polymer (B1) solution is not washed with a basic aqueous solution, but only with an acidic aqueous solution and a sodium sulfate aqueous solution.
(Halogen removal)
Same as the (Halogen removal) treatment operation of Example 1.
(Second half water purification)
Same as the treatment operation in Example 1 (second half water purification).

(Comparative Example 3)
(First half water purification)
The processing operation is the same as that of Comparative Example 1 except that the vinyl polymer (B2) is used instead of the vinyl polymer (B1).
(Halogen removal)
Same as the (Halogen removal) treatment operation of Example 1.
(Second half water purification)
Except that the number of times of washing with pure water is 4, the same operation as that in Example 1 (second-half water purification) is performed.

(Comparative Example 4)
(First half water purification)
To 150 g of the vinyl polymer (B2) produced in Production Example 2, 300 g of n-butanol (manufactured by Kyowa Hakko Chemical Co., Ltd.) was added and stirred to obtain a polymer (B2) solution. A 1 L separable flask (with a stirrer and a jacket) was charged with 300 g of pure water, 0.3 g of sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) and 3 g of mirabilite were added, and the mixture was stirred at room temperature to adjust the pH to 13. A basic aqueous solution was prepared. The jacket temperature of the separable flask was set to 50 ° C., and the adjusted basic aqueous solution was heated and stirred. Next, the vinyl polymer (B2) solution was dropped into the basic aqueous solution, and the whole was dropped and stirred for about 5 minutes. After the stirring was stopped, the oil phase and the aqueous phase separated quickly, 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. A sodium hydroxide aqueous solution with the same concentration as above is prepared separately, and the same amount as the discharged aqueous phase is gently added to the wall from the upper part of the inner wall of the separable flask. Then, the above-described stirring, standing, and separation operations were further performed twice, for a total of three purification operations.
After discharging the third aqueous phase, a 1% by weight aqueous solution of sodium silicate that was the same weight as the third aqueous phase was gently added to the inner wall of the separable flask. After the addition, the oil phase and the aqueous phase were stirred for about 5 minutes at a jacket temperature of 50 ° C. After the stirring was stopped, the oil phase and the aqueous phase were promptly separated, and after standing for 5 minutes, the oil phase and the aqueous phase were separated and recovered. Washing is further performed twice with a 1 wt% aqueous solution of sodium sulfate, and after the final aqueous phase is discharged, the solvent and water are distilled off from the oil phase under reduced pressure using a rotary evaporator to obtain a pale yellow vinyl polymer (B2). Obtained.
(Halogen removal)
Same as the (Halogen removal) treatment operation of Example 1.
(Second half water purification)
Except that the number of times of washing with pure water is 3, the same operation as that in Example 1 (second half water purification) is performed.

(Example 1, Example 2, Comparative Example 1, Comparative Example 2)
Examples 1 and 2 and Comparative Example 2 that were washed with acidic water in the first half purification were less colored than Comparative Example 1 that was not washed with acidic water, but were washed only with acidic water. In Comparative Example 2, the hydrosilylation activity was lower than in Examples 1 and 2 in which washing was performed with basic water.

(Comparative Example 3, Comparative Example 4)
Comparative Example 4 which was washed with only basic water in the first half purification was more strongly colored and less silylated than Comparative Example 3 which was not washed with basic water or acidic water.

  That is, from the results of Table 1, the vinyl polymer becomes low colored only by washing with acidic water, but the hydrosilylation activity is low, and conversely, washing with basic water alone deteriorates both coloring and silylation activity, It can be seen that only the vinyl polymer washed with both acidic water and basic water has low coloring and high hydrosilylation activity.

Claims (2)

A method for producing a vinyl polymer comprising a step of dissolving a vinyl polymer polymerized by atom transfer radical polymerization in a water-insoluble solvent and bringing the polymer solution into contact with washing water,
Contact with the washing water is
A method for producing a vinyl polymer, wherein the contact with the wash water of 8 ≦ pH ≦ 14 and the contact with the wash water of 0 ≦ pH ≦ 6 are each performed once or more. 2. The atom transfer radical polymerization is carried out using a metal complex having a transition metal (M) of Group 7, 8, 9, 10, or 11 of the periodic table as a central metal as a catalyst. A method for producing a vinyl polymer.