JPH0576485B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL FIELD OF APPLICATION: The present invention relates to aqueous compositions. More specifically, the present invention relates to an aqueous composition that is composed of a polymer obtained by polymerizing specific monomers in a specific state and water, and whose state changes above and below the cloud point. Conventional technology and its problems: Conventionally, water-soluble polymers have been used as water-based pastes in the fields of thickeners, polymer flocculants, etc. In this case, the higher the molecular weight of the water-soluble polymer, the higher the amount added. It is convenient because it is small. However, when the molecular weight is increased, the viscosity of the aqueous solution becomes extremely high, which poses a major problem in actually producing the polymer in a water-soluble state. On the other hand, one major feature of emulsion polymerization is that the molecular weight of the polymer can be extremely increased, and although polymerization technologies that take advantage of this feature are being developed, application to the production of water-soluble polymers has yet to be found. Not yet. Means for Solving the Problems: In view of the above points, the present inventors have conducted extensive studies on the application of emulsion polymerization technology to the production of water-soluble polymers. The present invention was achieved by discovering that an aqueous composition containing a temperature-sensitive, high-molecular-weight water-soluble polymer can be obtained by polymerizing acrylamide derivatives (abbreviated as acrylamide derivatives) in a specific state. That is, the present invention provides general formula () or general formula () general formula

[Formula] (In the above formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a methyl group or an ethyl group, and R ₃ represents a methyl group or an ethyl group.) General formula

〔Example〕

Reference Example Solution polymerization was performed using the monomers or monomer mixtures shown in Table 1, and the solvent was removed after polymerization to obtain a polymer. Dissolve the polymer in distilled water to a concentration of 10% by weight, put the aqueous solution into a test tube with an inner diameter of 15 mm, insert a standard thermometer into it, and stir the aqueous solution with the thermometer in constant temperature water. , gradually warmed up. The temperature at which the aqueous solution becomes cloudy and the mercury bulb of the thermometer becomes invisible is shown in Table 1 as the cloudy temperature, that is, the cloud point.

[Table] Example 1 11.6 g of N-acryloylpyrrolidine in 58.3 g of water
and 0.47 g of sodium 2-acrylamido-2-phenylpropanesulfonate (hereinafter abbreviated as APPS-Na) were added, the inside of the reactor was purged with nitrogen gas, and then heated to 70°C. Next, 1 ml of an aqueous potassium persulfate solution having a concentration of 7% was added to the reaction solution to initiate polymerization, and the polymerization was continued for 7 hours. As the polymerization progresses, the polymerization solution becomes cloudy and then progresses in an emulsified state.
Sufficient stirring was possible. When the obtained polymerization liquid was cooled, it became transparent and could no longer be stirred.
Therefore, when the polymerization solution was diluted with distilled water to a concentration of 10% and the viscosity was measured, it was found to be 117 cps at 25°C. Note that the cloud point of a polymer having the same monomer composition as this polymer was previously measured in the same manner as in the reference example, and the result was 51°C. Comparative Example 1 45.0 g of distilled water and 5.0 g of N-acryloylpyrrolidine were added to a 100 ml four-necked round-bottomed flask while stirring under nitrogen gas flow. Then 0.5 g of ammonium persulfate and sodium bisulfite
Add 0.23g of N-
A 10% aqueous solution of acryloylpyrrolidine polymer was obtained. When the viscosity of the aqueous solution was measured, it was found that at 25℃
It was 3.5cps. Example 2 4.0 g of N-acryloylpyrrolidine and 0.2 g of APPS-Na were added to 166 g of water, the inside of the reactor was purged with nitrogen gas, and then heated to 60°C. Next, 0.12 g of potassium persulfate was added to the reaction solution to initiate polymerization, and the polymerization was continued for 40 minutes. As the polymerization progressed, the polymerization solution became cloudy, and thereafter proceeded in an emulsified state. Next, leave the polymerization temperature as it is and add N to 20g of water.
-Acryloylpyrrolidine 9.9g, acrylic acid
An aqueous solution containing 0.14 g and 0.2 g of APPS-Na was added by pump over 1 hour. Thereafter, polymerization was further carried out for 6 hours. When the viscosity of the obtained polymerization liquid was measured, it was 23 cps at 50°C, 5900 cps at 25°C, and 16000 cps at 10°C. In addition,
At that time, the polymerization solution was in an emulsified state at 50°C and transparent at 25°C and 10°C. Furthermore, when we repeated the viscosity measurement of the above polymerization solution, we found that it was 23 cps at 50°C.
At 25℃ it was 5900cps and at 10℃ it was 16000cps.
Note that the cloud point of a polymer having the same monomer composition as this polymer was previously measured in the same manner as in the reference example, and the result was 50°C. Example 3 15 g of N-acryloylpiperidine and 1 g of APPS-Na were added to 500 g of water, the inside of the reactor was purged with nitrogen gas, and then heated to 50°C. Then, 0.5 g of potassium persulfate was added to the reaction solution to start polymerization.
Polymerization was carried out for 1 hour. As the polymerization progressed, the polymerization solution became cloudy, and thereafter proceeded in an emulsified state. Next, while leaving the polymerization temperature as it is, add 35 g of N-acryloylpiperidine and 0.5 g of APPS-Na to 100 g of water.
The aqueous solution was added by pump over a period of 1 hour. Thereafter, polymerization was further carried out for 6 hours. When the viscosity of the obtained polymerization liquid was measured, it was found that at 10℃
It was 2.4cps, 4.4cps at 5℃, and 12.5cps at 2℃. The polymerization solution is in an emulsified state at 7°C, and at 0°C
It was transparent. Note that the cloud point of a polymer having the same monomer composition as this polymer was previously measured in the same manner as in the reference example, and the result was 6°C. Example 4 20 g of N-acryloylpiperidine and 1.0 g of APPS-Na were added to 514 g of water, the inside of the reactor was purged with nitrogen gas, and then heated to 50°C. Next, 0.5 g of potassium persulfate was added to the reaction solution to initiate polymerization, and the polymerization was continued for 1 hour. As the polymerization progressed, the polymerization solution became cloudy, and thereafter proceeded in an emulsified state. Then, the polymerization temperature was lowered to 40 DEG C., and an aqueous solution of 25 g of N-acryloylpiperidine, 5.0 g of N-methylolmethacrylamide, and 0.5 g of APPS-Na in 150 g of water was added over 1 hour using a pump.
Thereafter, the temperature was raised to 50°C and polymerization was continued for an additional 6 hours.
When the viscosity of the obtained polymerization liquid was measured, it was 2.7 cps at 10°C, 4.3 cps at 5°C, and 13.9 cps at 2°C. The polymerization solution was in an emulsified state at 10°C and 5°C, and became transparent at 0°C. Note that the cloud point of a polymer having the same monomer composition as this polymer was previously measured in the same manner as in the reference example, and the result was 5°C.

Claims (1)

[Claims] 1 [Formula] represented by general formula () or general formula () (In the above formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom, a methyl group or an ethyl group, and R ₃ is (Represents a methyl group, ethyl group or propyl group.) [Formula] (In the above formula, R ₁ is a hydrogen atom or a methyl group, and A is (-
OH ₂ ) _o -- and n is 4 to 6 or (-OH ₂ ) ₂ --O(
―
OH ₂ ) ₂ -- represents. ) N-alkyl- or N-alkylene-substituted (meth)acrylamide is formed into a radical homopolymer or a copolymer in an emulsion state, or a radical copolymer is formed with another copolymerizable monomer in an emulsion state. 5-60% polymer, 95-40% water, which is soluble in water at temperatures below the cloud point and forms an emulsion at temperatures above the cloud point.
%.