JP4889237B2 - Method for producing cationic copolymer - Google Patents

Description

In the present invention, when producing a cationic copolymer of a low molecular weight diallylamine-based monomer and an acrylamide-based monomer useful for applications such as cosmetics and toiletry product feel improvers and pigment dispersants, the average molecular weight is controlled, The present invention also relates to a method for producing a high-purity cationic copolymer.

Conventionally, it is well known that a diallylamine monomer generally gives a polymer having a cyclic structure by a cyclization reaction. In addition, since it has an allyl group in the molecule and causes an allyl-type destructive chain transfer, its polymerization activity is low, and many unreacted diallylamine monomers remain in the reaction system.

Therefore, Patent Document 1 proposes a method of increasing the reaction rate of the diallylamine derivative monomer by performing a polymerization reaction while continuously adding an acrylamide compound to an aqueous solution containing the diallylamine derivative monomer.

In Patent Document 2, a low polymerization activity of the diallylamine derivative monomer is obtained by performing a polymerization reaction while continuously adding an aqueous solution in which the acrylamide compound is at a certain concentration or less to an aqueous solution containing the diallylamine compound at a certain concentration or more. A method of achieving a high reaction rate has been proposed even when the ratio of diallylamine derivative monomer is overcome to obtain a high molecular weight, but the unreacted monomer is sufficiently reduced. I can't say that.

On the other hand, Patent Document 3 discloses a method for adjusting the degree of polymerization of a diallylamine-based polymer using mercaptans, phosphorous acid or derivatives thereof, and Patent Document 4 discloses diallylamine and / or a salt thereof using diallylamine and A polymerization method for adjusting the degree of polymerization of the derivative has been proposed.

In Patent Document 5, an acrylamide compound is continuously added to an aqueous solution containing a diallylamine compound and copolymerized in the presence of hypophosphorous acid or a salt thereof, and the content of unreacted monomer is sufficiently low. In addition, a method with easy molecular weight control has been proposed. As in Patent Document 3, Patent Document 4, and Patent Document 5, by using mercaptans, phosphorous acid or a derivative thereof, hypophosphorous acid or a salt thereof as a polymerization regulator, a change in the initiator concentration that is generally performed is generally performed. Although the molecular weight can be reduced without requiring an increase in the initiator concentration for the purpose of molecular weight control, particularly for the purpose of lowering the molecular weight, there is a drawback that the polymerization regulator remains.

Patent Document 6 proposes a method for producing a low molecular weight aqueous solution polymer in the presence of hydrogen sulfite ion and a photoinitiator in an aqueous solution of a vinyl monomer. Alternatively, a light source that emits visible light must be used, which may cause equipment problems.

On the other hand, Patent Document 7 discloses a method for producing a water-soluble polymer by radical polymerization of an α, β-ethylenically unsaturated monomer in the presence of a chain transfer agent. A method for obtaining a polymer having a narrow molecular weight distribution by using a relatively small amount of a chain transfer agent by supplying it to a reactor in a mixed state with a β-ethylenically unsaturated monomer has been proposed. Only the examples to be used are shown, and there is no mention of an efficient method for removing unreacted monomers in the production of diallylamine-based polymers with low polymerization activity.
Japanese Patent No. 2615681 JP-A-6-192343 JP 63-23911 Patent No. 1900553 JP-A-6-179727 JP 2002-69104 A JP 2002-284806 A

Therefore, the problem to be solved by the present invention is that, in producing a cationic copolymer of a low molecular weight diallylamine monomer and an acrylamide monomer, the average molecular weight is controlled and a high purity cationic copolymer is produced. It is to provide a manufacturing method.

（式中、Ｒ_１およびＲ_２はそれぞれ水素またはメチル基を表し、Ｒ_３およびＲ_４はそれぞれ単独に、水素または炭素数１〜６のアルキル基を表し、Ｘ⁻は有機酸または無機酸の陰イオンを表す）で表されるジアリルアミン系モノマーと、（Ｂ）下記一般式（II）

（式中、Ｒ_５は水素またはメチル基を表し、Ｒ_６およびＲ_７はそれぞれ独立に水素または炭素数１〜６のアルキル基を表す。）で表されるアクリルアミド系モノマーをラジカル重合によりカチオン性共重合体を製造する方法において、以下の各工程を経ることにより高純度の共重合体を得ることを特徴とする平均分子量が１，０００〜５０，０００のカチオン性共重合体の製造方法に関する。
（１）連鎖移動剤として全モノマーに対して１．５〜９．５(質量)倍量の低級アルコールを使用し、当該低級アルコールと重合時使用する水との配合比が質量比で低級アルコール／水＝３０〜９５／７０〜５であり、かつレドックス系開始剤またはレドックス系開始剤およびモノマーの一種または二種以上を反応器に連続的に供給することにより重合する工程。
（２）重合終了後撹拌を止め、モノマー液相と共重合体液相に２相分離した共重合体液相を分取し、分取した共重合体液相を３０〜９５質量％の低級アルコール水溶液で洗浄することにより共重合体液相中からモノマーを除去する工程。 Under such circumstances, the present inventors have intensively studied to solve the above problems, and as a result, the present invention has been completed. That is, the present invention provides (A) the following general formula (I)

(Wherein R ₁ and R ₂ each represent hydrogen or a methyl group, R ₃ and R ₄ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and X ⁻ represents an organic acid or an inorganic acid. A diallylamine-based monomer represented by an anion) and (B) the following general formula (II)

(Wherein R ₅ represents hydrogen or a methyl group, and R ₆ and R ₇ each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms). In a method for producing a copolymer, the present invention relates to a method for producing a cationic copolymer having an average molecular weight of 1,000 to 50,000, wherein a high-purity copolymer is obtained through the following steps. .
(1) 1.5 to 9.5 (mass) times the amount of lower alcohol is used as the chain transfer agent with respect to all monomers, and the mixing ratio of the lower alcohol to water used during polymerization is lower alcohol in terms of mass ratio. / Water = 30-95 / 70-5, and the process of superposing | polymerizing by supplying continuously 1 type, or 2 or more types of a redox-type initiator or a redox-type initiator, and a monomer to a reactor.
(2) After completion of the polymerization, the stirring is stopped, the copolymer liquid phase separated into the monomer liquid phase and the copolymer liquid phase is separated, and the separated copolymer liquid phase is reduced to 30 to 95% by mass. A step of removing the monomer from the copolymer liquid phase by washing with an aqueous alcohol solution.

The present invention provides a method for producing a cationic copolymer of a low molecular weight diallylamine monomer and an acrylamide monomer that is useful for applications such as cosmetics and toiletry product feel improvers and pigment dispersants. In addition, a highly pure cationic copolymer can be produced.

Below, the manufacturing method of the cationic copolymer of this invention is explained in full detail.
The diallylamine monomer (A) used in the present invention is an inorganic salt or organic acid salt of a secondary amine such as diallylamine or dimethallylamine, or an inorganic salt of a tertiary amine such as diallylmethylamine, diallylethylamine or diallylbutylamine. Examples thereof include quaternary ammonium salts such as salts or organic acid salts, diallyldimethylammonium chloride, diallyldimethylammonium bromide, diallyldiethylammonium chloride, diallyldiethylammonium bromide, diallyldibutylammonium chloride, diallyldibutylammonium bromide and the like. Among these, diallyldimethylammonium chloride is particularly preferable. In the present invention, one or more of these diallylamine monomers can be arbitrarily used.

Examples of the (B) acrylamide monomer used in the present invention include (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N , N-dipropyl (meth) acrylamide, N-isopropyl (meth) acrylamide and the like. Of these, (meth) acrylamide is particularly preferred. In the present invention, one or more of these acrylamide monomers can be arbitrarily used.

Examples of the lower alcohol used in the present invention include methanol, ethanol, propanol, isopropyl alcohol, and the like, which can be suitably used as a chain transfer agent or a solvent, or when washing the copolymer. Isopropyl alcohol is preferred because it is easy to do and has low odor.

The amount of lower alcohol used is 1.5 to 9.5 (mass) times the amount of monomer used (mass), and the mixing ratio with water used during polymerization is lower alcohol / water in weight ratio. = 30 to 95/70 to 5, preferably 40 to 60/60 to 40, and when the stirring is stopped after the completion of the polymerization, the monomer liquid phase and the copolymer liquid phase are separated into two phases. If the amount of lower alcohol used is less than 1.5 (mass) times the amount of monomer used (mass), the effect as a chain transfer agent may be poor and the desired molecular weight may not be obtained. Even if it is used in an amount more than 5 times, the monomer concentration at the time of polymerization becomes low, and it is not economical. When the mixing ratio of the lower alcohol and water is lower than the lower alcohol / water = 30/70 by mass ratio, the two phases cannot be separated and the copolymer phase cannot be purified. Further, when the mixing ratio of the lower alcohol and water is lower alcohol / water = 95/5, the copolymer may be precipitated during the polymerization, which may hinder the reaction.

After completion of the polymerization, the stirring is stopped, the copolymer liquid phase separated into two phases is separated, and the separated copolymer liquid phase is washed with 30 to 95% by mass of a lower alcohol aqueous solution to obtain a copolymer liquid. Although the monomer can be removed from the phase to achieve high purity, when the concentration of the lower alcohol aqueous solution is lower than 30% by mass, the copolymer is washed away and the yield decreases, which is not economically preferable. On the other hand, when the content is higher than 95% by mass, polymer is precipitated, which is a problem in the production process. The amount of the lower alcohol aqueous solution used for washing is preferably 0.3 to 2 times that of the copolymer liquid phase fractionated by weight, and if it is less than 0.3 times, washing may be insufficient. In addition, even if the amount is more than twice, the amount of monomer that can be removed does not increase, which is not economical. As the number of times of washing, the larger the number of times, the more the monomer can be removed, but 1 to 3 times of washing is preferable including economy.

Examples of the redox initiator used in the present invention include hydrogen peroxide-ammonia, hydrogen peroxide-ethylamine, hydrogen peroxide-iron (II) salt, peroxodisulfate-sodium sulfite, peroxodisulfate- Sodium bisulfite, peroxodisulfate-triethanolamine, peroxodisulfate-iron (II) salt, sodium perchlorate-sodium sulfite, cerium (IV) sulfate-alcohols, cumene hydroperoxide-iron (II ) Salt, benzoyl peroxide-dimethylaniline and the like. Among these, peroxodisulfate-sodium sulfite, peroxodisulfate-sodium hydrogensulfite, peroxodisulfate-triethanolamine, peroxodisulfate-iron (II) salt, sodium perchlorate-sulfurous acid Sodium is preferable, and peroxodisulfate-sodium sulfite and peroxodisulfate-sodium hydrogensulfite are more preferable. The preferable usage-amount of a polymerization initiator is 0.1 to 20% with respect to a monomer.

The polymerization conditions vary depending on the desired average molecular weight of the target polymer, the chain transfer ability of the chain transfer agent itself, the type of monomer, the amount of polymerization initiator used, and the polymerization temperature, but the outline is as follows.
(A) In the case of an average molecular weight of 15,000 to 50,000, the polymerization step is carried out by charging the reactor with two or more monomers and water other than the lower alcohol chain transfer agent and redox initiator dissolved water. It is preferable to carry out the polymerization by continuously supplying each aqueous solution to the reactor.
(B) In the case of an average molecular weight of 5,000 to 15,000, the polymerization step is performed by charging water other than one or more monomers, a lower alcohol chain transfer agent, redox initiator dissolved water, and monomer-diluted water into a reactor, It is preferable to perform polymerization by mixing each of the redox initiator aqueous solutions and one or more monomers and continuously supplying them to the reactor.
(C) In the polymerization step in the case of an average molecular weight of 1,000 to 5,000, a water other than the lower alcohol chain transfer agent, redox initiator dissolved water and monomer dilution water is charged into the reactor, and a redox initiator aqueous solution. It is preferable to perform polymerization by mixing each of the above and two or more monomers and continuously supplying them to the reactor.
The reaction temperature may be appropriately selected from the range of 10 to 80 ° C. The polymerization time is about 3 to 20 hours, and when the stirring is stopped after the polymerization is completed, the two phases are separated into the monomer liquid phase and the copolymer liquid phase. Polymerize in a homogeneous system. Further, by separating the copolymer liquid phase and washing with a lower alcohol aqueous solution, the monomer can be removed and high purity can be achieved.

In the following examples, “%” is “mass%”, and isopropyl alcohol, acrylamide, dimethyldiallylammonium chloride, peroxodisulfate, and sodium bisulfite are IPA, AAm, DADMAC, and Na ₂ S ₂ O _{8, respectively.} And abbreviated NaHSO ₃ .

[Measurement method of weight average molecular weight]
The weight average molecular weight (hereinafter abbreviated as Mw) was measured by gel permeation chromatography (hereinafter abbreviated as GPC). The measurement conditions were shown below and the results are shown in Table 1.
<< GPC measurement conditions >>
Column OHpak SB-804HQ
OHpak SB-803HQ
OHpak SB-802HQ
(Both made by Showa Denko KK)
Column temperature: 40 ° C
Detector: RI
Solvent: 0.25M acetic acid + 0.05M sodium chloride (pH = 3.5)
Flow rate: 0.7 ml / min Sample concentration: 0.5%
Injection volume: 50 μl
Standard: Pull Run
(Made by Showa Denko; Shodex STANDARD P-82)

(Measurement of residual monomer amount)
The amount of residual AAm before and after washing of the copolymerized liquid phase after completion of the polymerization was measured by gas chromatography (hereinafter abbreviated as GC) and quantified by an external standard method. The measurement conditions are as follows. The amount of residual DADMAC was measured under the GPC measurement conditions of the above weight average molecular weight and quantified by an external standard method.
<< GC measurement conditions >>
Column: 10% PEG-20M Chromosorb WAW
3mm inside diameter x 2m length
Column temperature: 210 ° C
Detector: FID
Sample vaporization chamber temperature: 260 ° C
Detector temperature: 260 ° C
Injection volume: 2 μl
Carrier gas and flow rate
: Nitrogen, 30 ml / min

Example 1
A glass flask having a capacity of 3 liters equipped with a thermometer, a reflux condenser and a stirrer was charged with 834 g of water and 1,172 g of IPA and heated to 60 ° C. Next, a mixed solution of AAm 173 g (2.4 mol), 65% DADMAC aqueous solution 233 g (0.9 mol) and water 92 g, 20% Na ₂ S ₂ O ₈ aqueous solution 97 g, 20% NaHSO ₃ aqueous solution 211 g, Dropped into a reactor with stirring from a separate dropping funnel over 6 hours. After completion of the dropwise addition, the reaction was completed at 60 ° C. for 6 hours to complete the polymerization. After completion of the polymerization, the stirring was stopped and the lower phase copolymer liquid phase separated into two phases was separated. It was washed with an equal amount of 50% IPA aqueous solution to the separated copolymer liquid, allowed to stand and then phase-separated to separate a lower copolymer liquid phase. This washing operation was performed once more to obtain a lower phase copolymer. An equal amount of water was added thereto, IPA was distilled off at 80 ° C. under reduced pressure, and the mixture was adjusted to 8% polymer aqueous solution.

Example 2
The same glass flask as above was charged with 173 g (2.4 mol) of AAm, 631 g of water and 1172 g of IPA, and heated to 60 ° C. Subsequently, 325 g (0.9 mol) of 47% DADMAC aqueous solution, 47 g of 20% Na ₂ S ₂ O ₈ , and 211 g of 20% NaHSO ₃ aqueous solution were dropped into the reactor with stirring from separate dropping funnels over 6 hours. . All subsequent operations were the same as in Example 1.

Example 3
A glass flask similar to the above was charged with 173 g (2.4 mol) of AAm, 233 g (0.9 mol) of 65% DADMAC aqueous solution, 698 g of water and 698 g of IPA, and heated to 60 ° C. Subsequently, 49 g of 20% Na ₂ S ₂ O ₈ and 211 g of a 20% NaHSO ₃ aqueous solution were dropped from a separate dropping funnel into the reactor over 6 hours with stirring. All subsequent operations were the same as in Example 1.

Comparative Example 1
A glass flask similar to the above was charged with 173 g (2.4 mol) of AAm, 233 g (0.9 mol) of 65% DADMAC aqueous solution and 1,396 g of water, and heated to 60 ° C. Subsequently, 49 g of 20% Na ₂ S ₂ O ₈ aqueous solution was dropped into the reactor with stirring over 6 hours from the dropping funnel to obtain an aqueous polymer solution.

Comparative Example 2
A glass flask similar to the above was charged with 173 g (2.4 mol) of AAm, 233 g (0.9 mol) of 65% DADMAC aqueous solution and 1,396 g of water, and heated to 60 ° C. Next, 49 g of a 20% Na ₂ S ₂ O ₈ aqueous solution and 211 g of a 20% NaHSO ₃ aqueous solution were dropped from separate dropping funnels into the reactor over 6 hours with stirring to obtain a polymer aqueous solution.

The molecular weight of the water-soluble polymer produced differs depending on the amount of monomer present in the reactor at the initial stage of polymerization, and Mw tends to increase as the amount of monomer present in the reactor at the initial stage of polymerization increases. Further, when no chain transfer agent is used, the resulting polymer has a large Mw.

Claims (5)

(A) The following general formula (I)

(Wherein R ₁ and R ₂ each represent hydrogen or a methyl group, R ₃ and R ₄ each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and X ⁻ represents an organic acid or an inorganic acid. A diallylamine-based monomer represented by an anion) and (B) the following general formula (II)

(Wherein R ₅ represents hydrogen or a methyl group, and R ₆ and R ₇ each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms). In the method for producing a copolymer, a method for producing a cationic copolymer having an average molecular weight of 1,000 to 50,000, wherein a highly pure copolymer is obtained by the following steps.
(1) using 1.5 to 9.5 (mass) volumes of isopropyl alcohol to the total monomer as chain transfer agent, isopropyl alcohol mixing ratio of the water used during the polymerization with the isopropyl alcohol in a weight ratio / Water = 30-95 / 70-5, and the process of superposing | polymerizing by supplying continuously 1 type, or 2 or more types of a redox-type initiator or a redox-type initiator, and a monomer to a reactor.
(2) After completion of the polymerization, the stirring is stopped, and the copolymer liquid phase separated into a monomer liquid phase and a copolymer liquid phase is separated, and the separated copolymer liquid phase is 30 to 95% by mass of isopropyl. A step of removing the monomer from the copolymer liquid phase by washing with an aqueous alcohol solution. The method for producing a cationic copolymer according to claim 1, wherein the redox initiator is a combination of peroxodisulfate and bisulfite. (A) The method for producing a cationic copolymer according to claim 1 or 2 , wherein the diallylamine monomer is diallyldimethylammonium chloride. (B) The method for producing a cationic copolymer according to any one of claims 1 to 3 , wherein the acrylamide monomer is acrylamide. The method for producing a cationic copolymer according to any one of claims 1 to 4, wherein the total monomer concentration is 10 to 30% by mass.