KR0124953B1 - Process for preparation of dispersed polymer with functional groups on surface - Google Patents

Abstract

Styrene monomer (1), acryl monomer (2) or diene monomer were reacted in the presense of alkali metal initiator and nonpolar hydro carbon such as nonpolar solvent, pentane, n-hexane, n-heptane and added with alkylalkali metal initiator and vinyl or diene monomer to give living dispersion polymer which is reacted with a material having carboxyl, hyroxyl or sulfonic acid group to give several group in the surface of polymer.

Description

Method for producing a dispersed polymer having functional groups on its surface

The present invention relates to a method for producing a dispersed polymer having a functional group on its surface.

Until now, dispersion polymers have been produced mainly by radical polymerization. General methods for producing water-soluble dispersed polymers by radical polymerization, reaction conditions, and the like are described in Scientific Methods for the Study of Polymer Colloids and Their Applications, page 35. In particular, the method of synthesizing a water-insoluble dispersed polymer is also described in detail in Dispersion Polymerization in Organic Media (1975).

Non-aqueous dispersion polymers are used in various applications such as reinforcing fillers, organic pigments, grease thickeners and biomedical materials. To use them, functional groups must be introduced to the surface of the dispersion polymer by a second reaction. do.

In the preparation of water-soluble or water-insoluble dispersion polymers, steric stabilizers are used as essential ingredients. Block or graft copolymers are usually selectively used as the steric stabilizer, and these copolymers are generally manufactured by a separate process by anionic polymerization.

On the other hand, a method of preparing such a steric stabilizer together with a dispersed polymer in the same reactor by a radical polymerization method has been proposed, but complicated reaction steps have been pointed out as problems. That is, conventional dispersion polymer production is cumbersome to synthesize the steric stabilizer separately in another reaction system, and then use it for synthesis of the dispersed polymer.

In addition, in order to prepare a dispersed polymer having a functional group such as a carboxyl group, a hydroxyl group, or a sulfonic acid group on the surface of the particle, the above-described dispersed polymer is first synthesized, followed by a purification process such as washing, and then a desired functional group is introduced. There is a disadvantage that it is possible to prepare dispersed polymer particles having a functional group on the surface by performing further reaction with a substance to be added.

The present inventors have intensively studied to solve the above-mentioned problems. As a result, by using an alkyl alkali metal as a polymerization initiator, living polymerization of a vinyl or diene monomer in a suitable solvent is performed. The present invention has been completed by discovering that the dispersed polymer can be prepared simultaneously and that a predetermined functional group can be easily introduced to the particle surface.

Accordingly, it is an object of the present invention to provide a method for producing a steric stabilizer and a dispersed polymer in the same reactor.

Another object of the present invention to provide a method for producing a dispersed polymer that can control the particle size and molecular weight.

Still another object of the present invention is to provide a method for preparing a dispersed polymer capable of introducing various functional groups on the surface of particles.

Another object of the present invention is to provide a functionalized dispersed polymer prepared by the method of the present invention.

These and other objects of the present invention will become apparent from the following detailed description.

According to the present invention, a method for producing a dispersed polymer having functional groups on its surface is provided. The production method of the present invention (a) an alkyl alkali metal initiator in the presence cyclic non-polar solvent and by living polymerization of a vinyl-based or diene-based monomer in a C _n H _{2n + 2} paraffinic non-polar hydrocarbon solvent in the system to obtain a three-dimensional stabilization, ( b) subsequently mixing an alkyl alkali metal initiator and polymerizing a vinyl- or diene monomer in which the steric stabilizer is not dissolved in the solvent to obtain a living dispersion polymer; and (c) the living dispersion polymer in the same reactor. And reacting with a substance having a hydroxyl group or a sulfonic acid group.

Among the monomers used for producing the dispersed polymer of the present invention, the vinyl monomers include styrene monomers represented by the following formula (I) and acrylic monomers represented by formula (II), and the diene monomers include the following formulas (III): The monomer represented by) is mentioned.

Wherein R ₁ is H or CH ₃ and R ₂ is C (CH ₃ ) ₃ or CH ₃

Wherein R ₁ is H or CH ₃ and R ₂ is C (CH ₃ ) ₃ or CH ₃

CR ₁ R ₂ = CR ₃ -CR ₄ = CR ₅ R ₆ (Ⅲ)

(Wherein R ₁ , R ₄ and R ₅ each represent a hydrogen or methyl group, R ₃ represents a hydrogen, chlorine or methyl group, and R ₂ and R ₆ each represent hydrogen)

In the method of the present invention, examples of the polymerization initiator include alkylalkali metals represented by the formula R ^- Mt ⁺ , wherein R represents methyl, n-butyl, sec-butyl, tert-butyl or disopropylamino groups. , Mt represents lithium (Li), sodium (Na), potassium (K), rubidium (Rb) or cesium (Cs).

Examples of the solvent used in the method of the present invention include a paraffinic (C _n H _{2n + 2} ) -based nonpolar hydrocarbon solvent such as pentane, n-hexane and n-heptane, an aromatic solvent such as cyclohexane, benzene and toluene, and tetrahydrofuran and chloroform. And polar solvents such as methylene chloride.

On the other hand, materials used for the desired functionalization of living dispersion polymers are known in the art. For example, dry ice, carbon dioxide gas, etc. may be used as the material for introducing the carboxyl group, and ethylene oxide and various ketone compounds may be used for the introduction of the hydroxyl group, and trialkylamine sulfotrioxide (for the introduction of the sulfonic acid group) R ₃ N.SO ₃ ), sultone, and the like.

It is preferred to have a molecular weight in the range of 10,000 to 100,000 and a concentration in the range of 1.0 × 10 ⁻⁴ to 2.0 × 10 ⁻² mol / liter, which is synthesized in situ according to the method of the present invention and used to prepare the dispersed polymer. . The concentration of solids in the reactor is 5 to 60% by weight, and the polymerization temperature is preferably in the range of -78 ° C to 70 ° C.

On the other hand, according to the present invention, the following advantages are provided.

First, the method of the present invention can be prepared using the living polymerization method of the steric stabilizer and the dispersed polymer in the same reactor.

Second, the method of the present invention can adjust the molecular weight having a great influence on the physical properties of the dispersed polymer by using the living polymerization method, and can also produce a dispersed polymer having a narrow molecular weight distribution.

Third, the method of the present invention can appropriately adjust the particle size of the dispersed polymer in the range of 0.01 μm to 50 μm using the living polymerization method.

Fourth, the method of the present invention facilitates the functionalization of the dispersed polymer by introducing a functional group on the surface by reacting with a suitable reactant having the required functional group, since the terminal portion of the polymer chain is alive after polymerization by the living polymerization method. In addition, the yield of functional group introduction can be obtained quantitatively.

Fifth, the method of the present invention avoids the hassle of having to synthesize the steric stabilizer necessary for synthesizing the dispersed polymer in another reaction system, and synthesizes the steric stabilizer and the dispersed polymer using a living polymerization method in the same reactor. And since the functionalization of the dispersing polymer terminal can be performed at the same time, the manufacturing process can be shortened.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, these Examples are only for illustration of this invention, and do not limit this invention.

(Example 1)

Into the 1 liter flask reactor was injected 0.55 mL (1.6 mol / liter) of 8.8 × 10 ⁻⁴ mol of n-butyllithium (1.6 mol / liter) under an inert gas (argon gas) into the reactor and purified under high vacuum. 500 mL of benzene was distilled under reduced pressure, followed by 50 mL of tert-butyl styrene distilled under reduced pressure into the reactor. After reacting the reaction mixture for 24 hours, 48 mL of purified styrene monomer was charged into the reactor. The reactor was left at room temperature for 24 hours. Subsequently, 2 mL of purified methanol was added under high vacuum to stop the living block copolymer, and the solution was poured into about 5 times the volume of methanol to obtain 90 g of the precipitated poly (tert-butylstyrene) / polystyrene block copolymer. The number average molecular weight of this block copolymer was adjusted to 100,000.

After drying the poly (tert-butylstyrene) / polystyrene block copolymer under high vacuum, 10 g was taken into an ampoule on a high vacuum line and the interior of the ampoule was vacuumed. Subsequently, 48 mL of styrene monomer was distilled into this ampoule.

Into a 1 liter flask reactor, 0.55 mL (1.6 mol / liter) of 8.8 × 10 ⁻⁴ mol of n-butyllithium was added again using a syringe, and 500 mL of purified n-heptane was distilled off under reduced pressure. In this state, 48 mL of styrene monomer in the ampoule was added to the reactor, and reacted for 24 hours while stirring using a stirring rod. A portion of the resulting solution was separated into another flask, separated, and then quenched with degassed methanol.

The number average molecular weight of the dispersed polymer prepared through this reaction was about 50,000 by gel permeation chromatography (GPC), the molecular weight distribution was about 1.2, and the average particle size of the dispersed polymer was about 0.5 μm.

(Example 2)

The living dispersion polymer prepared in Example 1 was poured into dry ice to introduce carboxyl groups on the surface of the dispersion polymer. Alternatively, carbon dioxide gas was blown into the reactor via a vacuum line to introduce a carboxyl group. The average particle size of the produced dispersed polymer was about 0.5 μm, and had a carboxyl group (COOLi) on its surface.

(Example 3)

A portion of the living dispersion polymer prepared in Example 1 was injected with ethylene oxide through a high vacuum line and reacted for 24 hours to introduce hydroxyl groups on the surface of the dispersion polymer. The average particle size of the produced dispersed polymer was also 0.5 µm, and the number average molecular weight was about 50,000 according to the GPC results.

(Example 4)

Into a dispersed polymer solution prepared in the same manner as in Example 1, 0.78 mL of 4.4 × 10 ⁻³ mol of 1,1-diphenylethylene was added under high vacuum to react for 24 hours, followed by 4.4 × 10 ⁻³ mol of 1 After adding 0.39 mL of, 3-propane sultone, the reaction mixture was allowed to react for 24 hours to introduce sulfonic acid groups (SO ₃ Li) on the surface of the dispersed polymer. The average particle size of the produced dispersed polymer was also 0.5 µm, and the number average molecular weight was about 50,000 according to the GPC results.

(Example 5)

After synthesis of poly (tert-butylstyrene) in the same manner as in Example 1, 50 mL (1.0 × 10 ⁻⁴ mol) of a portion of the solution was taken and placed in a 1 liter reactor. 0.2 mL of 4.0 × 10 ⁻⁴ mol of n-butyllithium was injected into the reactor, 500 mL of purified n-heptane was added by distillation under reduced pressure to dilute the living solution, and 40 g of styrene monomer was added under vacuum. . The reaction temperature was raised to 60 ° C. and reacted with stirring for 24 hours. A part of the product was taken and quenched with degassed methanol, and some introduced a carboxyl group (COOLi) on the surface of the dispersed polymer in the same manner as in Example 2. The number average molecular weight of the resulting dispersed polymer was about 100,000, and the average particle size was also 0.5 mu m.

(Example 6)

Ethylene oxide was added to the living dispersion polymer prepared in the same manner as in Example 5 under high vacuum to introduce -OH groups to the surface of the dispersion polymer. The number average molecular weight of the resulting dispersed polymer was also about 100,000, and the average particle size was 0.5 mu m.

(Example 7)

0.35 mL of 2.0 × 10 ⁻³ mol of 1,1-diphenylethylene was added to a living dispersion polymer prepared in the same manner as in Example 5 under vacuum, followed by reaction for 24 hours.

Subsequently, 0.18 mL of 2.0 × 10 ⁻³ mol of 1,3-propane sultone was added to the reaction product to introduce sulfonic acid group (SO ₃ Li) onto the surface of the dispersed polymer. The number average molecular weight of the functionalized dispersed polymer was 100,000, the molecular weight distribution was about 1.2, and the average particle size was about 5 μm, similar to that of Example 6.

(Example 8)

In the same manner as in Example 5, 1.0 grams of purified divinyl benzene was placed in a styrene monomer ampoule, the styrene monomer was distilled under reduced pressure to form an ampoule, and the ampoule was treated under the same reaction conditions to prepare a living dispersion polymer. It was. This reaction was introduced with sulfonic acid groups on the surface in the same manner as in Example 7. At this time, divinyl benzene is crosslinking because it is a monomer which forms a gel. Its molecular weight could not be measured. The molecular weight predicted by the living polymerization method was estimated to be about 100,000, and the particle size was about 5 μm.

(Example 9)

500 mL of n-hexane was used as a solvent, and 10 g of butadiene was added to 0.15 mL (2.0 × 10 ^-4 mol) of n-butyllithium to carry out living polymerization to a molecular weight of 50,000. Subsequently, 0.15 mL (2.0 × 10 ^-4 mol) of n-butyllithium was injected into a syringe, 0.9 mL of 1,1-diphenylethylene was added under high vacuum to react for 24 hours, and then 20 g of methyl methacrylate was added thereto. The reaction was stirred at room temperature for 24 hours. As in Example 2, a carboxyl group (COOLi) was introduced into the reaction product on the surface of the dispersed polymer using carbon dioxide. The resulting dispersed polymer had a molecular weight of 100,000 and had an average particle size of 5 μm.

Claims (10)

(a) an alkyl alkali metal initiator in the presence cyclic non-polar solvent and by living polymerization of a vinyl-based or diene-based monomer in a C _n H _{2n +} paraffinic non-polar hydrocarbon solvent in the _second system to obtain a three-dimensional stabilization, (b) continuously-alkyl alkali Mixing a metal initiator and polymerizing a vinyl- or diene-based monomer in which the steric stabilizer is not dissolved in the solvent to obtain a living dispersion polymer, and (c) converting the living dispersion polymer into a carboxyl group, a hydroxyl group, or Method for producing a dispersed polymer having a functional group on the surface characterized in that consisting of reacting with a substance having a sulfonic acid group. The method according to claim 1, wherein the alkyl alkali metal is a compound represented by the following formula. R ^- Mt ⁺ Wherein R represents methyl, n-butyl, sec-butyl, tert-butyl or diisopropylamino group, Mt represents lithium (Li), sodium (Na), potassium (K), rubidium (Rb) or cesium (Cs ). The method according to claim 1, wherein the vinyl monomer is selected from styrene monomer of formula (I) and acrylic monomer of formula (II). In the formula, R ₁ represents H or CH ₃ , and R ₂ represents C (CH ₃ ) ₃ or CH ₃ . The method according to claim 1, wherein the diene monomer is a monomer represented by the following formula (III). CR ₁ R ₂ = CR ₃ -CR ₄ = CR ₅ R ₆ (Ⅲ) In the formula, R ₁ , R ₄ and R ₅ each represent hydrogen or a methyl group, R ₃ represents hydrogen, chlorine or a methyl group, and R ₂ and R ₆ each represent hydrogen. The process of claim 1 wherein the solvent is a paraffinic nonpolar hydrocarbon solvent selected from the group consisting of pentane, n-hexane and n-heptane. The process of claim 1 wherein the solvent is a cyclic nonpolar solvent selected from the group consisting of cyclohexane, benzene and toluene. The method of claim 1 wherein the steric stabilizer has a molecular weight ranging from 10,000 to 100,000 and a concentration ranging from 1.0 × 10 ⁻⁴ to 2.0 × 10 ⁻² mol / liter. The method of claim 1 wherein the carboxyl group-containing material is selected from the group consisting of dry ice and carbon dioxide. The method of claim 1 wherein the hydroxyl group containing material is selected from the group consisting of ethylene oxide and ketones. The method of claim 1 wherein the sulfonic acid group containing material is selected from the group consisting of trialkylamine sulforioxide and sultone.