JPS6217992B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for stabilizing cationic vinyl monomers. For more details, please refer to the general formula [In the formula, R ₁ is H or CH ₃ ; R ₂ and R ₃ are each independently an alkyl group having 1 to 4 carbon atoms; R ₄ is H, an alkyl group having 1 to 4 carbon atoms, or a benzyl group; A is oxygen atom or NH; B is an alkylene group having 1 to 4 carbon atoms; X ^- is an anionic counterion. ] This invention relates to a stabilization method that dramatically improves safety by preventing deterioration during storage, transportation, or production without impairing the polymerization reactivity of the cationic vinyl monomer ( ) shown in [ ]. In recent years, water-soluble polymers having cationic groups have been found to be effective as flocculants for clarification of domestic wastewater and dewatering of sludge, and have come to be widely used. In particular, the cationic vinyl monomer represented by the general formula () has excellent radical polymerization reactivity and is relatively easily available industrially, so there are many examples of its use. The cationic vinyl monomer of the general formula () shown here can be obtained by neutralizing the unsaturated tertiary amine shown by the general formula () below by adding hydrochloric acid, sulfuric acid, acetic acid, etc., or by adding methyl chloride, dimethyl sulfate, etc. , diethyl sulfate, benzyl chloride, etc. to carry out a quaternization reaction. [In the formula, R ₁ is H or CH ₃ ; R ₂ and R ₃ are each independently an alkyl group having 1 to 4 carbon atoms; A is an oxygen atom or NH; B is an alkylene group having 1 to 4 carbon atoms. ] However, the obtained cationic vinyl monomer (2) has higher radical polymerizability than the raw material unsaturated tertiary amine (2), and especially when reacting at high concentration in an aqueous solution, it may be difficult to react during the reaction or during transportation or storage. Inside, external temperature, natural light, shock, container material, etc. can easily lead to problems such as unexpected thickening and gelation. Therefore, various stabilization methods have been proposed to solve these problems, but none of them have a sufficient effect of preventing deterioration or have an extremely large inhibiting effect on radical polymerization.
The inherent radical polymerization reactivity of this monomer is often impaired. Therefore, there is a need for a method that improves the stability of cationic vinyl monomers and does not cause adverse effects such as inhibition of polymerization when producing a polymer by radically polymerizing the monomers. In view of the current situation, the inventors of the present invention conducted extensive research and found that the general formulas (), (), ()

【formula】 【formula】 [In the formula, R ₅ , R ₆ , and R ₇ are H, an alkyl group, or an aryl group. ]

Phosphite compound, phosphoric acid ester compound or general formula () [In the formula, R ₈ and R ₉ are H or an alkyl group. ]
By adding a small amount of the phosphoric triamide compound represented by the above to the monomer, it is possible to easily prevent the deterioration of the monomer and to stabilize it, and at the same time, it is possible to improve the polymerizability when subjected to radical polymerization. The present invention was achieved by discovering that there is no or almost no deterioration in the solubility of the obtained polymer. Examples of organic phosphorus compounds to be added to the cationic vinyl monomer represented by the general formula () in the present invention are as follows. (1) Phosphite compounds include triethyl phosphite, tri-n-butyl phosphite, tris(2-ethylhexyl) phosphite, tridecyl phosphite, tris(tridecyl) phosphite, tristearyl phosphite, diphenyl monodecyl Phosphite, diphenyl mono(tridecyl) phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, dilauryl hydrogen phosphite, diphenyl hydrogen phosphite, etc. (2) Phosphate compounds include butyl acid phosphate, butoxy Ethyl acid phosphate, 2-ethylhexyl acid phosphate, di(2-ethylhexyl) phosphate, etc. (3) Examples of phosphoric triamide compounds include hexamethyl phosphoric triamide. These include oxalic acid, citric acid, malic acid, condensed phosphoric acid, and salts thereof (Japanese Patent Application Laid-Open No. 54-46711), derivatives of urea or thiourea (Japanese Patent Application Laid-open No. 147023-1982), In addition to exhibiting a much superior deterioration prevention effect compared to guanidine or its derivatives (Japanese Patent Application Laid-Open No. 56-53638), when subjected to radical polymerization, the desired polymer can be obtained without any or almost no loss in polymerizability. You can get a combination. Examples of the monomers represented by the general formula () in the present invention are as follows. (1) Unsaturated tertiary amines include (A) salts of dialkylaminoalkyl (meth)acrylates [(meth)acrylates refer to acrylates and methacrylates; Same below. ], for example, tertiary amine salts such as 2-dimethylaminoethyl (meth)acrylate, 2-diethylaminoethyl (meth)acrylate hydrochloride, sulfate, acetate, etc. (B) dialkylaminoalkyl (meth)acrylamide Salt [(meth)acrylamide refers to acrylamide and methacrylamide. Same below. ], for example, tertiary amine salts such as hydrochloride, sulfate, acetate of 3-dimethylaminopropyl (meth)acrylamide, etc. (2) Unsaturated quaternary amines include (A) dialkylaminoalkyl (meth); Quaternary ammonium salts of acrylates, e.g.
-Dimethylaminoethyl (meth)acrylate, methyl chloride of 2-diethylaminoethyl (meth)acrylate, quaternary ammonium salts quaternized with dimethyl sulfate, diethyl sulfate, benzyl chloride, etc., (B) dialkylaminoalkyl ( Quaternary ammonium salts of meth)acrylamide, such as quaternary ammonium salts of 3-dimethylaminopropyl(meth)acrylamide quaternized with methyl chloride, dimethyl sulfate, diethyl sulfate, benzyl chloride, etc., these monomers The body may be in any known form such as solid, solution, emulsion, or slurry, but the present invention is most effective when it coexists with water, so it is preferably in a state where it coexists with water. In this case, the amount of water is 0.01 to 10 times, preferably 0.1 to 5 times, more preferably 0.2 times the weight of the cationic vinyl monomer represented by the general formula ().
~3 times the range. In the present invention, the amount of the phosphite, phosphate, or phosphoric triamide compound added is usually 0.001 to 1.0% by weight, preferably 0.01 to 0.5% by weight based on the cationic vinyl monomer represented by the general formula (). %, particularly preferably 0.05
~0.2% by weight. If the amount added is less than 0.001% by weight, the effect will be small;
Moreover, if the amount exceeds 1.0% by weight, the influence on the purity of the cationic vinyl monomer will be greater. In the present invention, the phosphite ester, phosphate ester or phosphoric triamide compound exhibits an excellent effect when used alone, but if necessary, it can also be used in combination with a known polymerization inhibitor such as hydroquinone monomethyl ether. be effective. The cationic vinyl monomer used in the method for stabilizing a cationic vinyl monomer of the present invention can be made into a polymer or copolymer by a known method. When producing a copolymer, vinyl monomers other than the monomers of general formula (), ie, comonomers, include acrylamide, α
- Hydrophilic nonionic vinyl monomers such as methylacrylamide and N.N-dimethylacrylamide; and oil-soluble vinyl monomers such as acrylonitrile, styrene, and methyl methacrylate. Polymerization can be carried out by a known method, such as a method using a radical polymerization initiator, radiation, or the like. Among these methods, a method using a radical polymerization initiator is preferable. Examples of radical polymerization initiators include peroxide catalysts (ammonium persulfate, sodium persulfate, etc.), redox catalysts (peroxide catalysts such as ammonium persulfate, sodium persulfate, etc.). and the first
ammonium iron sulfate, sodium bisulfite, etc.), azo compound catalysts (azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane) hydrochloride, 4,4'-
azobis-4-cyanovaleric acid, etc.)
can be given. Among these, it is preferable to use a redox catalyst or a combination of a redox catalyst and an azo compound catalyst. Polymerization can be carried out by known methods such as aqueous solution polymerization, emulsion polymerization using water and an organic solvent, suspension polymerization, and precipitation polymerization. In the case of aqueous solution polymerization, for example, the monomer is made into an aqueous solution (monomer concentration is, for example, 20 to 80% by weight), the system is purged with an inert gas, and then a radical polymerization initiator is added, usually at a concentration of about 0 to 95%. This can be carried out by polymerizing for several hours at a polymerization temperature of . These polymers produced using monomers to which the cationic vinyl monomer stabilization method of the present invention is applied can be used as water treatment agents, flocculants, dehydrating agents, paper chemicals,
It can be widely used as a fiber modifier, adhesive, etc. According to the method for stabilizing a cationic vinyl monomer of the present invention, the cationic vinyl monomer represented by the general formula () can be stabilized industrially very easily (external temperature, natural light, shock, etc. during storage, transportation, or manufacturing process). (prevention of unexpected thickening or deterioration due to gelation), and can be made into a cationic vinyl monomer that is stable over time. Moreover, when polymerization is performed using this monomer, a high-quality polymer can be obtained with a high polymerization rate very easily without abnormal polymerization or abnormal polymerization time delay. The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. Example 1 388.8 g of an approximately 49% by weight aqueous sulfuric acid solution was placed in a beaker with content 1, and 611.2 g of dimethylaminoethyl methacrylate containing the stabilizer listed in Table 1 was added dropwise while stirring while cooling to carry out a reaction. The beaker was cooled from the outside to remove the heat of neutralization during the reaction, and the reaction was completed by adjusting the dropping rate so that the reaction temperature did not exceed 30°C. Obtained. After the reaction was completed, the reaction mixture was sufficiently saturated with air and cooled to room temperature. The test results are shown in Table-1. (Stability test) Put 50g of sample into a 100ml beaker and seal it.
The samples were placed in constant temperature baths at 25°C and 75°C, and the time required for polymerization of the reaction product dimethylaminoethyl methacrylate sulfate to begin to occur and the presence or absence of coloration of the reaction product were measured over time. The polymerization initiation point of the reaction product was determined to be the point at which a stringy phenomenon occurred when a glass rod was immersed in the reaction mixture and pulled up. The results obtained are shown in Table-1.

【table】

[Table] (Polymerization test) Next, 750g of each of the 70% by weight aqueous solutions of the above monomers were placed in a Jewur bottle, the oxygen in the system was sufficiently replaced with nitrogen, and the system was cooled to 10°C. 250 ppm of 2,2'-azobis(2-amidinopropane) hydrochloride, 30 ppm of ferrous ammonium sulfate, and 20 ppm of ammonium persulfate were added as polymerization initiators to an aqueous solution of the monomers, and the mixture was superimposed. As a result, polymerization started within 10 minutes for both the control example and the invention example, and no damage to polymerization was observed due to the addition of the stabilizer of the invention. Furthermore, the obtained polymer had good water solubility and a solution viscosity equivalent to that without the addition of a stabilizer, and was found to have excellent properties as a flocculant. Example 2 388.8 g of an aqueous sulfuric acid solution of about 49% by weight was placed in a beaker with a content of 1, and 611.2 g of dimethylaminoethyl methacrylate was added dropwise while stirring while cooling.
A % by weight dimethylaminoethyl methacrylate sulfate aqueous solution was obtained. After the reaction was completed, the reaction mixture was sufficiently saturated with air and cooled to room temperature. Stabilizers as listed in Table 2 were added to this, and stability tests were conducted in the same manner as in the Examples to examine stability.

【table】

[Table] Example 3 302.8 g of dimethylaminoethyl methacrylate and pure water were placed in a glass autoclave with an effective volume of 1.
Prepare 100g. After the internal temperature was brought to 20°C, 107.2g of methyl chloride was blown in over 4 hours.
Once the reaction begins, the internal temperature will rise, but the external temperature should be adjusted so that it does not exceed 30°C. After addition of methyl chloride
After reacting for 60 minutes, the system becomes homogeneous, but the reaction must be continued for another 60 minutes to complete the reaction. Excess methyl chloride is removed from the mixture by demethyl chloride under reduced pressure at 30°C. After the reaction was completed, the air was sufficiently saturated and the mixture was cooled to room temperature. 80% by weight of methyl chloride of dimethylaminoethyl methacrylate thus obtained 4
A stabilizing agent as shown in Table 3 was added to an aqueous solution of a grade salt, and a stabilization test similar to that in Example 1 was conducted to examine stability.

【table】

[Table] Example 4 Put 208.6 g of an aqueous solution of hydrochloric acid of about 35% by weight into a beaker with content 1, add the stabilizer listed in Table 4 while cooling and stirring, and then dropwise add 312.4 g of 3-dimethylaminopropylacrylamide. Then, the reaction was completed in the same manner as in Example 1 to obtain 521.0 g of 3-dimethylaminopropylacrylamide hydrochloride having a concentration of 74% by weight. After the reaction was completed, the reaction mixture was sufficiently saturated with air and cooled to room temperature. The thus obtained sample was subjected to the same stabilization test as in Example 1 to examine its stability. The results were as shown in Table 4. Furthermore, when a polymerization test was conducted in the same manner as in Example 1, polymerization started within 10 minutes for all of the stabilizers listed in Table 4, and no polymerization interference was observed due to the addition of the stabilizer of the present invention. Nakatsuta.

[Table] Example 5 In a glass autoclave with an effective volume of 1, 3-
Dimethylaminopropylacrylamide 312.4g
and 141.4g of pure water. After bringing the internal temperature to 20℃, add 253.2g of benzyl chloride until the internal temperature is 30℃.
The reaction was completed by controlling the external temperature so as not to exceed 20% by weight to obtain 707 g of an 80% by weight aqueous solution of benzyl chloride quaternary salt of 3-dimethylaminopropylacrylamide. After the reaction was completed, the air was sufficiently saturated and the mixture was cooled to room temperature. A stabilizing agent as shown in Table 5 was added to the thus obtained 80% by weight aqueous solution of benzyl chloride quaternary salt of 3-dimethylaminopropylacrylamide, and the same stabilization test as in Example 1 was carried out. The stability was investigated. The results were as shown in Table-5. Furthermore, when a polymerization test was conducted in the same manner as in Example 1, polymerization started within 10 minutes for all of the stabilizers listed in Table 5, and no polymerization interference was observed due to the addition of the stabilizer of the present invention. Nakatsuta.

【table】

Claims (1)

[Claims] 1 General formula () [In the formula, R ₁ is H or CH ₃ ; R ₂ and R ₃ are each independently an alkyl group having 1 to 4 carbon atoms; R ₄ is H, an alkyl group having 1 to 4 carbon atoms, or a benzyl group; A is oxygen atom or NH; B is an alkylene group having 1 to 4 carbon atoms; X ^- is an anionic counterion. ] A method for stabilizing a cationic vinyl monomer, which comprises adding a phosphite, a phosphate, or a phosphoric triamide compound to the cationic vinyl monomer. 2. The amount of phosphorous acid ester, phosphoric acid ester or phosphoric triamide compound added is 0.001 to 1.0% by weight based on the cationic vinyl monomer.
A stabilizing method according to claim 1. 3. Claims 1 or 2, wherein the phosphite, phosphoric ester, or phosphoric triamide compound is a compound represented by the following general formula (), (), (), or (). Stabilization method. [In the formula, R ₅ , R ₆ and R ₇ are H, an alkyl group or an aryl group, and R ₈ and R ₉ are H or an alkyl group. 4. The stabilization method according to any one of claims 1 to 3, wherein the cationic vinyl monomer coexists with water. 5. The stabilization method according to claim 4, wherein the amount of water is 0.01 to 10 times the weight of the cationic vinyl monomer.