JPS591699B2 - Fuhouwadai 3 Kiyuu Amin Mataha Sono 4 Kiyu Ammonium Enno Antei Kahou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the stabilization of unsaturated tertiary amines or quaternary ammonium salts thereof. Stabilization of an unsaturated tertiary amine or its quaternary ammonium salt, characterized by adding a salt of N-nitrosophenylhydroxylamine as a stabilizer in stabilizing the unsaturated tertiary amine and its quaternary ammonium salt. It is the law.

R1 represents H or CH3, R2 and R4 represent H or lower alkyl, and R2 and R3 may be combined to form alkylene.

Acrylamide-based polymers are used in a variety of situations because high molecular weight water-soluble polymers can be easily obtained.

Specifically, it can be used as a coagulant to separate and remove suspended solids from wastewater containing suspended solids, such as urban sewage, industrial wastewater, or mining wastewater by elutriation, or as a coagulant for drying and moistening paper in the paper manufacturing industry. This type of polymer has promise for a variety of other uses, including as a treatment agent for paper manufacturing such as a strength improver, and as a soil stabilizer applied to soil prior to civil engineering works such as rivers and tunnels. Due to the existence of such a wide variety of uses, various improvements have been made to polymers in order to make them optimal for each use, resulting in a large number of copolymers and even studies at the monomer stage. has also been done.

Since the monomer represented by the above general formula is also expected to have a wide range of uses as a raw material for cationic polymers, research into its application is also progressing. General formula (1
The monomer represented by ) is generally produced from (meth)acrylic acid or its ester and aminoethanol by esterification or transesterification reaction.

After completion of the reaction, the crude product is purified by distillation to separate it from unreacted raw materials and side reaction products, but since the produced monomer has a high boiling point (for example, 185-190°C in the case of dimethylaminoethyl methacrylate) Even if vacuum distillation is performed, work at considerably high temperatures is required. On the other hand, this produced monomer tends to polymerize easily when heated, so it has the disadvantage that it tends to polymerize during the purification process that involves heated distillation, and therefore the yield is significantly reduced. Furthermore, the monomer represented by the general formula (2) can be obtained from the monomer of the general formula (1) and a quaternization reaction reagent according to a typical Menshyutkin reaction. Ammonium salt monomers are more unstable than unsaturated tertiary amines, which are raw materials, and are more likely to polymerize, especially in highly concentrated aqueous solutions. In order to control the polymerization of monomers represented by the general formulas (1) and (2), hydroquinone, hydroquinone monomethyl ether, phenothiazine, etc. have conventionally been added as stabilizers.

In particular, hydroquinone monomethyl ether is considered to be the most typical stabilizer, as is clear from the fact that it is used in most of these commercially available monomers.
However, in reality, polymerization cannot be completely prevented even though 1000 ppm or more of the stabilizer is used based on the monomer, and on the other hand, it is preferable from the quality of the product to use a large amount of stabilizer in order to obtain a sufficient effect. It has also been shown that using a large amount of this type of stabilizer does not necessarily improve storage stability.

The reason for this is that when hydroquinone monomethyl ether, which exhibits a stabilizing effect based on the phenolic hydroxyl group, is present in these basic monomers, it tends to form a phenoxy anion, which itself has no stabilizing effect. It is considered that the sufficient effect has not been achieved.

Under these circumstances, the present inventors conducted various studies on stabilizers for the monomers mentioned above, and found that extremely remarkable effects can be obtained when a salt of N-nitrosophenylhydroxylamine is used as a stabilizer. This knowledge led to the present invention.

The salts of N-nitrosophenylhydroxylamine as used in the present invention specifically refer to alkali metal salts, alkaline earth metal salts, and ammonium salts, and the amounts added when these are used as stabilizers according to the present invention. varies depending on the type of monomer, but is usually about 0.1 to about 1000 ppm1
Preferably, about 1 to about 500 ppm (all calculated on monomer basis) is used.

Note that when the salt of N-nitrosophenylhydroxylamine is an ammonium salt, this salt is originally used as a scavenger for copper, iron, etc., so if this is used, it will not be used as an original stabilizer. In addition to this effect, it can also be expected to remove metals leached from the equipment material. When using the salt of N-nitrosophenylhydroxylamine as described above as a stabilizer, each individual monomer of the tertiary amine represented by the general formula (1) or the quaternary ammonium salt represented by (2) is used as a stabilizer. Of course, it can be used in the reaction step of producing a quaternary ammonium salt from the tertiary amine, but it is also effective as shown in the Examples below.

It goes without saying that when using the stabilizer of the present invention, the effect will not be impaired in any way even if a conventionally known stabilizer is present. As described above, in the present invention, the salt of N-nitrosophenylhydroxylamine is a monomer represented by the general formula (1) or (2), or the monomer represented by the general formula (1) is used as a quaternary ammonium salt. The monomers represented by general formula (1), which are added during the grading reaction, are aminoethyl (meth)acrylates, more specifically aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylamino Examples include ethyl (meth)acrylate, methylethylaminoethyl (meth)acrylate, piperidylethyl (meth)acrylate, and pyrrolidylethyl (meth)acrylate.

Furthermore, the monomer represented by general formula (2) refers to the 4 used.
Although it varies depending on the grading agent, generally methyl halide,
Refers to the corresponding quaternary ammonium salts obtained using ethyl halide, benzyl halide, etc. This 4
The grading reaction can be carried out at a temperature ranging from room temperature to about 150°C,
In order to prevent the polymerization of the monomers of general formula (1) and the produced monomer (2) as much as possible, the reaction should be carried out at a temperature of 100° C. or lower.

The present invention will be explained below with reference to Examples.

Example 1 Dimethylaminoethyl methacrylate (reagent purified by vacuum distillation under a nitrogen stream) in a hard glass test tube
107, and ammonium salt of N-nitrosophenylhydroxylamine (cuperone) as a stabilizer 0.001
y (100 ppm) and 0.025 y of azobisisobutyronitrile as a polymerization initiator, and after completely purging the system with nitrogen, the system was sealed, placed in a constant temperature water bath at 60°C, and the polymerization behavior was observed. did.

For comparison, the behavior was observed when similar operations were performed using hydroquinone monomethyl ether, phenyl-β-naphthylamine, and phenothiazine, and the results are summarized in the table below. Example 2 30 with reflux condenser, stirrer, thermometer and gas inlet tube
In a 0ml reaction vessel, 157.2y of dimethylaminoethyl methacrylate and 39.37ml of pure water, 0.008f
Cuperon was taken and maintained at 55°C, and methyl salt was introduced through the gas introduction tube while stirring.

The introduction of methyl chloride was carried out at 150 ml/m@-. Since the monomer and water at the start of the reaction separate into two layers when left standing, methyl chloride was introduced and reacted with stirring. The end point of the reaction is when the system becomes completely homogeneous and there is no oil layer. After the quaternization reaction was completed, dissolved methyl chloride was removed by nitrogen bubbles, and the mixture was cooled to room temperature.

The product was a clear solution with a slight yellowish tinge, and its weight was 247.87. The quaternization reaction rate was calculated from the weights before and after the reaction and was 99.5%. Also PHll
．． The pH before the reaction, which was 2, became 67 after the reaction was completed. When this product was allowed to stand at room temperature in a dark place, no signs of polymerization were observed even after one month had passed. Comparative Example: 0.87 hydroquinone monomethyl ether (5000pp relative to amine) instead of 0.008f cuperone
Example 1 was repeated, except that 20% (corresponding to m) was used.

The colorless and transparent solution of the product had a pH of 6.42, and the quaternization reaction rate was 98.4%. When this product was allowed to stand at room temperature in a dark place in the same manner as in Example 1, the viscosity had already become extremely high after one week, indicating that polymerization had clearly progressed. Example 3 Example 2 was repeated except that the indicated amount of polymerization inhibitor was added, a 25% by weight aqueous solution was prepared from the obtained quaternary salt monomer, and 2.
2'-azobis(2-amidinopropane) hydrochloride 500
After adding ppm (per solution), the temperature was maintained at 50°C and the induction period was measured.

Example 4 Using dimethylaminoethyl acrylate (4143.27), pure water (393y), and cuperone (0.007y), methyl chloride was introduced while stirring and maintaining the temperature at 55 to 60°C until the oil layer disappeared.

An almost colorless and transparent aqueous solution with pH 6.5 was obtained (192
．． 17). No signs of polymerization were observed even after one month of standing in a cool, dark place. Example 5 Example 2 was repeated except that 126.6y benzyl chloride was used as the quaternizing agent.

Note that benzyl chloride was added at room temperature over about 30 minutes, and then maintained at a temperature of 50°C to 55°C. The pH of the aqueous solution after the completion of the reaction was 5.4, and no sign of polymerization was observed even after one month had passed when it was left in a dark place at room temperature. Example 6 143.2k dimethylaminoethyl acrylate, 1
Example 5 was repeated except using 2667 benzyl chloride.

The product was a pale yellow and transparent aqueous solution with a pH of 5.5, and no sign of polymerization was observed even though it was left in a dark place at room temperature for one month. Example 7 Example 5 was repeated except that 197.2y of biperidyl ethyl methacrylate was used.

Claims (1)

[Claims] 1. Unsaturated tertiary compound represented by the following general formulas (1) and (2)
A method for stabilizing an unsaturated tertiary amine or its quaternary ammonium salt, which comprises adding a salt of N-nitrosophenylhydroxylamine as a stabilizer in stabilizing the unsaturated tertiary amine and its quaternary ammonium salt. . CH_2=CR_1-COO-CH_2CH_2-N・
R_2・R_3 (1) [CH_2=CR_1-COO
-CH_2CH_2-N・R_2・R_3・R_4〕X
(2) R_1 is H or CH_3, R_2, R_3
and R_4 represents H or a lower alkyl group, and further R_4
2 and R_3 may be combined to form alkylene.