JP2009051767A - Cationic vinyl monomer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cationic vinyl monomer which is stable with the passage of time and is free from the increase of its viscosity or the occurrence of popcorn polymerization due to exterior temperature, light, impact, a few amount of an ion of a metal such as iron in particular, during production, transportation or storage, and also exhibits satisfactory polymerizability. <P>SOLUTION: The cationic vinyl monomer is prepared by adding 0.1 to 5,000 ppm of a thiol compound or a nitroxyl radical compound as a stabilizer, to a cationic vinyl monomer represented by general formula (1) (R<SB>1</SB>is H or methyl group; R<SB>2</SB>and R<SB>3</SB>are each independently identically or differently a 1-3C alkyl group; R<SB>4</SB>is a 1-3C alkyl group or a benzyl group; A is a 1-3C alkylene group; X is a halogen atom, a methylsulfonyl group, an ethylsulfonyl group or a p-toluene sulfonyl group). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cationic vinyl monomer which can prevent deterioration during storage, transportation and production without impairing polymerizability, and which has dramatically improved stability.

  Cationic vinyl monomers can be easily made into polymers having functions such as cationicity, conductivity, water solubility, and adhesiveness by homopolymerization or copolymerization with other monomers. It is widely used industrially as a raw material monomer for cationic polymers that are highly useful in applications such as pharmaceuticals, antistatic agents, fiber modifiers, adhesives, and cosmetics.

Cationic vinyl monomers are generally produced by adding hydrochloric acid, sulfuric acid, etc. to an unsaturated tertiary amine to neutralize it to give an acid salt, or adding a quaternizing agent to cause a quaternization reaction. .
The cationic monomer is unstable as compared with the unsaturated tertiary amine, and is likely to spontaneously polymerize particularly when it is present in a high concentration in an aqueous solution. During production, transportation and storage, external temperature, light, impact, A very small amount of metal ions (especially iron, etc.) may cause thickening or popcon polymerization, and the production and storage of cationic vinyl monomers and the improvement of stability during polymer production are major issues.

Conventionally, as a stabilizer for a cationic vinyl monomer, a polymerization inhibitor such as hydroquinone (hereinafter abbreviated as HQ), hydroquinone monomethyl ether (hereinafter abbreviated as MEHQ), or t-butylcatechol is added. Has been done. However, such polymerization inhibitors are not always satisfactory for cationic vinyl monomers.
Therefore, more advantageous methods have been studied and various stabilization methods have been proposed. For example, addition of an aromatic nitroso compound (Patent Document 1), addition of a cyclic amine compound (Patent Document 2), a nitroso compound or a quinone compound, ethylenediaminetetraacetic acid (hereinafter abbreviated as EDTA), nitrilotriacetic acid, etc. In combination with a metal sequestering agent (Patent Document 3), in combination with a polymerization inhibitor and a sequestering agent, diethylenetriaminepentaacetic acid (hereinafter abbreviated as DTPA), N- (hydroxyethyl) -ethylenediamine as a sequestering agent. Methods such as the use of aminopolycarboxylic acid types such as triacetic acid and salts thereof (Patent Document 4), or the combined use of a polymerization inhibitor and an alkylenephosphonic acid sequestering agent (Patent Document 5) have been proposed. .

However, aromatic nitroso compounds are much more effective as stabilizers than hydroquinone and the like, but there is a tendency to significantly color the cationic vinyl monomer even when added in a small amount, and also inhibits polymerization of the cationic vinyl monomer. There is a drawback that a polymer having a large amount of residual monomer is easily generated. Further, the cyclic amine compound has an unknown stability in the acidic region or metal ion.
Furthermore, in the combined use of a polymerization inhibitor and a sequestering agent, oxycarboxylic acid and polycarboxylic acid have a weak sequestering power against metal ions such as iron ions, and sequestering agents such as aminopolycarboxylic acid and alkylenephosphonic acid. Has insufficient sequestering power in the acidic region, that is, in the presence of locally high concentrations of metal ions, and completely sequesters metal ions that cause gel formation and coloration during natural polymerization and polymer production. It was difficult to do.
JP-A-53-144519 JP 58-155942 A and 58-99449 Gazette. JP-A-57-109747, JP-A-57-109747 JP-A-10-67720 and JP-A-10-67721 JP 2001-226334 A

  Therefore, the present invention prevents deterioration during production, transportation, and long-term storage without impairing the polymerizability. Furthermore, even in an acidic / oxygen-free region, metal polymerization is performed during metal container storage or during polymer production. It is an object of the present invention to provide a cationic vinyl monomer that suppresses the generation of gel on the surface of the kettle and dramatically improves the polymerization stability, and a method for stabilizing the cationic vinyl monomer.

As a result of intensive studies, the present inventors have found that the problem can be solved by adding a thiol compound or a nitroxyl radical compound, and have reached the present invention.
That is, the present invention
(1) General formula (1) containing 0.1 to 5000 ppm of thiol compound and / or nitroxyl radical compound (wherein R ₁ is a hydrogen atom or methyl group, R ₂ and R ₃ are each independently carbon or different and be identical to one another by the number 1 to 3 alkyl groups, the R ₄ is an alkyl group or a benzyl group having 1 to 3 carbon atoms, a is an alkylene group having 1 to 3 carbon atoms, X is A cationic vinyl monomer represented by a halogen atom, a methylsulfonyl group, an ethylsulfonyl group or a P-toluenesulfonyl group.
(2) The cationic vinyl monomer according to the above (1), wherein the thiol compound is a compound having a mercapto group and a hydroxyl group or a carboxyl group,
(3) The cationic vinyl monomer according to the above (1) or (2), wherein the thiol compound is thioglycolic acid,
(4) The cationic vinyl monomer according to the above (1), wherein the nitroxyl radical compound is a compound having a free radical that can stably exist at room temperature,
(5) The cationic vinyl monomer according to the above (1) or (4), wherein the nitroxyl radical compound is 2,2,6,6-tetramethylpiperidine-1-oxyl,
(6) A general formula (1) characterized by adding 0.1 to 5000 ppm of a thiol compound and / or a nitroxyl radical compound (wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ and R ₃ Are each independently an alkyl group having 1 to 3 carbon atoms, which may be the same or different from each other, R ₄ represents an alkyl group having 1 to 3 carbon atoms or a benzyl group, and A represents an alkyl group having 1 to 3 carbon atoms. An alkylene group, and X represents a halogen atom, a methylsulfonyl group, an ethylsulfonyl group or a P-toluenesulfonyl group, respectively))
Is to provide.

  According to the present invention, external temperature during production, transportation, storage, light, impact, natural polymerization due to a small amount of metal ions (particularly iron, etc.), or alteration due to gelation during polymer production is prevented, and There is provided a cationic vinyl monomer represented by the general formula (1) having high stability, which can obtain a desired polymer without impairing the polymerizability at the time of producing the polymer.

The cationic vinyl monomer of the present invention is a compound represented by the above general formula (1) containing 0.1 to 5000 ppm of a thiol compound and / or a nitroxyl radical compound.
In general formula (1), R ₁ is a hydrogen atom or a methyl group, R ₂ and R ₃ are each independently an alkyl group having 1 to 3 carbon atoms, which may be the same or different, and R ₄ is An alkyl group having 1 to 3 carbon atoms or a benzyl group, A represents an alkylene group having 1 to 3 carbon atoms, and X represents a halogen atom, a methylsulfonyl group, an ethylsulfonyl group, or a P-toluenesulfonyl group.
Specifically, a dialkylaminoalkyl (meth) acrylamide represented by the following general formula (2) was reacted with an alkyl halide as a quaternizing agent, dialkylsulfuric acid or alkyltoluenesulfonate by a known method. Reaction products are mentioned.

In general formula (2), R ₁ is a hydrogen atom or a methyl group, R ₂ and R ₃ are each independently an alkyl group having 1 to 3 carbon atoms, which may be the same or different, and A is carbon Represents an alkylene group of formulas 1 to 3, specifically, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, Examples thereof include N, N-dipropylaminopropyl (meth) acrylamide.
The quaternizing agents include alkyl halides such as methyl chloride, ethyl chloride, methyl bromide and ethyl bromide, aralkyl halides such as benzyl chloride and benzyl bromide, alkyl sulfuric acids such as dimethyl sulfate and diethyl sulfate, and paratoluenesulfonic acid. Examples thereof include alkyltoluenesulfonates such as methyl and ethyl paratoluenesulfonate.

The thiol compound used in the present invention refers to a compound having a mercapto group in its chemical structural formula and functioning as a stabilizer, more preferably a compound having a mercapto group and a hydroxyl group or a carboxyl group, specifically, Alcohols such as mercaptoethanol, mercaptopropanol, thioglycerol, thiodiglycol, thioglycolic acid, ammonium thioglycolate, ammonium dithioglycolate, 2-ethylhexyl thioglycolate, methoxybutyl thioglycolate, monoethanolamine thioglycolate And carboxylic acids such as 3,3′-thiodipropionic acid, mercaptopropionic acid, and thiomalic acid.
Among such thiol compounds, those having 2 to 7 carbon atoms, preferably 2 to 4 carbon atoms are particularly preferable because they exhibit excellent effects.
The thiol compounds may be used alone or in combination of two or more.

The nitroxyl radical compound used in the present invention is a compound having a free radical that can exist stably at room temperature, and is di-tert-butyl nitroxide, 2,2,6,6-tetramethylpiperidine-1-oxyl. And its derivatives, 2,2,5,5-tetramethylpyrrolidine-1-oxide and its derivatives. Specifically, di-tert-butyl nitroxide, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-methoxy-2,2,6, 6-tetramethylpiperidine-1-oxyl, 4-acetoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl Is exemplified. Among these, 2,2,6,6-tetramethylpiperidine-1-oxyl is particularly preferable.
These nitroxyl radical compounds may be used alone or in combination of two or more.

  These compounds are added in an amount of 0.1 to 5000 ppm with respect to the cationic vinyl monomer, preferably 5 to 500 ppm in the case of a thiol compound, and 1 to 50 ppm in the case of a nitroxyl radical compound.

  Examples of the method of adding the thiol compound and the nitroxyl radical compound include a method of adding the cationic vinyl monomer as it is or a method of adding it as an aqueous solution, but it can also be added during the production of the cationic vinyl monomer.

  In the present invention, if necessary, a known polymerization inhibitor that inhibits radical polymerization reaction of unsaturated compounds such as HQ, MEHQ, t-butylcatechol, paraphenylenediamine, phenothiazine and the like may be used in combination.

  The storage stability, which is an effect of the present invention, is exhibited even when the cationic vinyl monomer represented by the general formula (1) is in any form such as solid, solution, emulsion, and slurry. When stored as an aqueous solution, the amount of water added is usually 0.01 to 10 times (weight), preferably 0.1 to 5 times (weight), relative to the cationic vinyl monomer.

The cationic vinyl monomer of the present invention can be converted into a polymer or copolymer by a known method. Other vinyl monomers that can be used in the production of the copolymer include hydrophilic nonionic vinyl monomers such as acrylamide, α-methylacrylamide, N, N-dimethylacrylamide, acrylonitrile, styrene, methyl methacrylate. Examples thereof include oil-soluble vinyl monomers such as acrylate.
The polymerization can be carried out by a known method such as aqueous solution polymerization, emulsion polymerization using water and an organic solvent, suspension polymerization, precipitation polymerization or the like. For these polymerizations, a method using a radical polymerization initiator is preferable. As the radical polymerization initiator, an azo compound catalyst (azobisisobutyronitrile, 2,2′-azobis [2- (2-imidazolin-2-yl) is used. ) Propane] dihydrochloride), peroxide catalysts (ammonium persulfate, sodium persulfate, etc.), redox catalysts (peroxides such as ammonium persulfate, sodium persulfate, etc. and reduction of ferrous ammonium sulfate, sodium bisulfite, etc. And the like).
As an example, aqueous solution polymerization is exemplified. The cationic vinyl monomer is made into an aqueous solution (monomer concentration: 20 to 80% by weight), the inside of the system is replaced with an inert gas, and a radical polymerization initiator is added. The polymerization can be carried out at a polymerization temperature of about 0 ° C. for several hours.

A feature of the present invention is that a thiol compound or a nitroxyl compound is used as a stabilizer for the cationic vinyl monomer. The conventionally proposed aromatic nitroso compound stabilizers are much more effective as stabilizers than hydroquinone and the like, but even with the addition of several tens of ppm, the cationic vinyl monomer is remarkably colored, while it is used for radical polymerization. On the other hand, since it has a very large prohibiting effect, there is a drawback that the addition of a large amount inhibits the polymerizability during the production of the polymer, and it has been difficult to use an effective amount alone for stability.
Further, the cationic vinyl monomer is characterized in that, particularly when an aqueous solution is used, the anionic counter ion X ⁻ may combine with hydrogen ions in the aqueous solution to generate a strong acid, and the pH decreases with time. For example, there has been a risk of corroding the surface of the metal polymerization kettle during storage of the metal container or during production of the polymer. For this reason, it becomes a severe condition in which dissolved oxygen having an effect of preventing polymerization is removed by degassing or nitrogen substitution, particularly at the time of polymer production. It affects the trace amount of gelling substances present in the functional vinyl monomer, and a gel is generated on the surface of the metal container or metal polymerization kettle, resulting in a decrease in the synthesis yield, making it impossible to use the device, etc. In some cases, it was difficult to produce a smooth polymer.
For this reason, various metal sequestering agents have been proposed for stabilizing cationic vinyl monomers, but these metal sequestering agents are originally weak in sequestering power or are extremely weak in the acidic region even if they are strong. The metal sequestering power against the metal ions is insufficient, and it is difficult to completely prevent natural polymerization, gelation and coloration during the production of the polymer. On the other hand, the thiol compound or nitroxyl radical compound used in the present invention is stable over a long period of time even in the presence of a local high concentration of metal ions even in an acidic / anoxic region. And the outstanding effect that the polymerizability is not impaired also at the time of polymer manufacture is produced.

EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this.
Example 1
N, N-dimethylaminopropylacrylamide methyl chloride quaternary salt was made into a 75% aqueous solution and 50 ppm of thioglycolic acid was uniformly dissolved as a stabilizer to obtain an aqueous cationic vinyl monomer solution of the present invention. 20 parts by mass of this monomer aqueous solution was placed in a stainless steel metal container, dissolved in 25 parts by mass of distilled water, and then the pH of the system was forcibly adjusted to 5 with sulfuric acid. Next, nitrogen gas was blown at room temperature, the inside of the system was replaced with nitrogen, and the presence / absence of formation of gel attached to the stainless steel metal container can wall and the coloring of the aqueous solution (both visually) were examined. The results are shown in Table 1.

Example 2
In Example 1, it carried out similarly to Example 1 except having changed the stabilizer into 50 ppm of thioglycolic acid and using 2,2,6,6-tetramethylpiperidine-1-oxyl as 10 ppm. The results are shown in Table 1.

Comparative Examples 1-5
Example 1 is the same as Example 1 except that 100 ppm of t-butylcatechol, phenothiazine, nitroso R salt, and nitroso-N-methylaniline was added in each case without adding a stabilizer, instead of thioglycolic acid. It carried out like. The results are shown in Table 1.

Comparative Examples 6-7
In Example 1, instead of thioglycolic acid, MEHQ 3000 ppm and ethylenediaminetetraacetic acid 2Na salt (EDTA-2Na) or 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) were added except that 100 ppm was added. This was carried out in the same manner as in Example 1. The results are shown in Table 1.

Test example 1
200 parts by mass of distilled water was charged into a reactor equipped with a reflux condenser, a thermometer, a nitrogen gas introduction tube and a stirring device, and the reactor was heated to 50 ° C. after substituting the nitrogen. After adding 0.6 parts by mass of 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride to the reactor, the aqueous cationic vinyl monomer solution of the present invention obtained in Example 1 was used. 47 parts by weight (aqueous solution in which 50 ppm of thioglycolic acid is uniformly dissolved in a 75% aqueous solution of N, N-dimethylaminopropylacrylamide methyl chloride quaternary salt), 53 parts by weight of N, N-dimethylacrylamide, and 80 parts by weight of distilled water Was added and reacted for 3 hours to obtain a copolymer.
The viscosity of a 20% aqueous solution of the obtained copolymer was measured, and the weight average molecular weight was measured. The results are shown in Table 2.
The weight average molecular weight was measured by gel permeation chromatography using polyethylene glycol as a standard substance. The viscosity was measured at 25 ° C. using a B-type viscometer.

Test example 2
In Test Example 1, instead of the cationic vinyl monomer aqueous solution obtained in Example 1, the cationic vinyl monomer aqueous solution of the present invention obtained in Example 2 (N, N-dimethylaminopropylacrylamide methyl chloride quaternary salt 75) The test was conducted in the same manner as in Test Example 1, except that an aqueous solution in which 10 ppm of 2,2,6,6-tetramethylpiperidine-1-oxyl was uniformly dissolved) was used. The results are shown in Table 2.

Comparative Test Example 1
In Test Example 1, instead of the cationic vinyl monomer aqueous solution obtained in Example 1, a 75% aqueous solution of N, N-dimethylaminopropylacrylamide methyl chloride quaternary salt to which no stabilizer was added was used. The same operation as in Test Example 1 was performed. The results are shown in Table 2.

  As described above, the cationic vinyl monomer of the present invention can be used for thickening, popcon polymerization or heavy polymerization due to external temperature, light, impact, trace amount of metal ions (particularly iron, etc.) during production, transportation and storage. There is no alteration due to gelation during the production of coalescence, and it is stable over time. Therefore, it can be suitably used as a raw material for cationic polymers such as polymer flocculants, papermaking chemicals, antistatic agents, transition modifiers, adhesives and cosmetics.

Claims (6)

General formula (1) containing 0.1 to 5000 ppm of a thiol compound and / or a nitroxyl radical compound (wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ and R ₃ each independently represents 1 to 1 carbon atoms) 3 may be the same as or different from each other, R ₄ represents an alkyl group having 1 to 3 carbon atoms or a benzyl group, A represents an alkylene group having 1 to 3 carbon atoms, X represents a halogen atom, A cationic vinyl monomer represented by a methylsulfonyl group, an ethylsulfonyl group or a P-toluenesulfonyl group.

The cationic vinyl monomer according to claim 1, wherein the thiol compound is a compound having a mercapto group and a hydroxyl group or a carboxyl group. The cationic vinyl monomer according to claim 1 or 2, wherein the thiol compound is thioglycolic acid. The cationic vinyl monomer according to claim 1, wherein the nitroxyl radical compound is a compound having a free radical that can stably exist at room temperature. The cationic vinyl monomer according to claim 1 or 4, wherein the nitroxyl radical compound is 2,2,6,6-tetramethylpiperidine-1-oxyl. 0.1 to 5000 ppm of a thiol compound and / or a nitroxyl radical compound is added, wherein R ₁ is a hydrogen atom or a methyl group, and R ₂ and R ₃ are each independently Are alkyl groups having 1 to 3 carbon atoms, which may be the same or different from each other, R ₄ represents an alkyl group having 1 to 3 carbon atoms or a benzyl group, and A represents an alkylene group having 1 to 3 carbon atoms. , X represents a halogen atom, a methylsulfonyl group, an ethylsulfonyl group or a P-toluenesulfonyl group, respectively)).