JPS6237645B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an aqueous crosslinked copolymer, in particular a water-soluble crosslinked copolymer which exhibits pseudoplastic flow and hardly loses its viscosity properties even in alkaline conditions. As the polymerization method of aqueous solution copolymer, for example, aqueous solution polymerization of acrylamide and acrylic acid and pearl polymerization are known. A method has been proposed in which a crosslinking agent is added and a polymer is obtained by static polymerization. However, with the above method, it is not possible to obtain a product with high viscosity, and when powdered, there are many insoluble substances, which are not practical. On the other hand, a method in which acrylamide, acrylic acid, and a crosslinking agent are added and polymerized in an organic solvent has been proposed, but currently only products with low viscosity or water-insoluble products can be obtained. In view of the current situation, the inventors of this invention conducted intensive research in an attempt to obtain a highly viscous water-soluble crosslinked copolymer product with less insoluble matter. , a β-unsaturated amide compound, an α,β-unsaturated carboxylic acid and/or its salts, and another vinyl compound copolymerizable with the monomer mixture of a predetermined amount. Similarly, by copolymerizing monomers having two or more vinyl groups in a predetermined quantitative range, a water-soluble crosslinked polymer with high viscosity, little insoluble matter, and little decrease in viscosity even in the presence of alkali can be obtained. The inventors have discovered that a polymer can be easily and economically produced as a powder or an aqueous solution, leading to the completion of this invention. That is, in the present invention, in a water-soluble organic solvent,
The composition per 100 parts (parts by weight; the same applies hereinafter) of the mixed monomer is 10 to 90 α,β-unsaturated amide compounds.
90 to 10 parts of an α,β-unsaturated carboxylic acid and/or its salt, and 0 to 25 parts of another copolymerizable monovinyl compound,
It is characterized by polymerizing 0.5 to 15% (weight %; the same applies hereinafter) of a monomer having two or more vinyl groups. Examples of water-soluble organic solvents that can be used in this invention include alcohols such as methanol, ethanol, propanol, isopropanol, and butanol, which essentially do not dissolve the produced polymer;
Examples include ketones such as acetone and methyl ethyl ketone, tetrahydrofuran, dimethylformamide, and ethyl acetate. In addition, as α,β-unsaturated amide compounds,
Examples include acrylamide, methacrylamide, and crotonic acid amide. Furthermore, as α,β-unsaturated carboxylic acid,
Examples of salts of α,β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, maleic acid, fumaric acid, glutaconic acid, itaconic acid, and sorbic acid. Alkali metal salts of saturated carboxylic acids, such as soda salts, potassium salts, and ammonium salts. On the other hand, the α,β-unsaturated amide compound, α,
Other monovinyl compounds copolymerizable with β-unsaturated carboxylic acids and/or their salts include styrene compounds such as styrene and α-methylstyrene, acrylic esters such as n-propyl acrylate and isobutyl acrylate, and methacrylates. methacrylic acid esters such as ethyl acid, lauryl methacrylate,
There are monovinyl compounds such as allyl acetate, methyl vinyl ketone, and isoprene that have a double bond in one molecule and can be polymerized with a radical polymerization initiator.
In this invention, the use of such a monovinyl compound is not particularly defined as essential. Next, monomers having two or more vinyl groups include most compounds that have two or more active carbon-carbon double bonds in the same molecule and are soluble in water-soluble organic solvents. Specifically, (1) polyacrylates and polymethacrylates of polyhydric alcohols such as butanediol diacrylate, butanetriol trimethacrylate, butanediol dimethacrylate, and diethylene glycol diacrylate; Polyallylic ethers of polyhydric alcohols such as gar allyl ether, maltose allyl ether, lactose allyl ether, butanediol diallyl ether, glycerin triallyl ether, (3) glyogysal tetraallyl ether, glyogysal tetramethallyl ether, etc. (4) Polyvalent metal salts such as aluminum, calcium, magnesium, or iron salts of acrylic acid or methacrylic acid. Therefore, the α,β-unsaturated amide compound,
α, β-unsaturated carboxylic acid and/or its salts,
and other copolymerizable monovinyl compounds (hereinafter simply referred to as mixed monomers)
The α,β-unsaturated amide compound is used in an amount of 10 to 90 parts per 100 parts of
When the amount used is less than 10 parts, a high viscosity product can be obtained, but the alkali resistance, which is a feature of this invention, is lost and the viscosity is reduced to 1/10 by the alkali.
It suddenly decreases below 0. Moreover, if the amount is 90 parts or more, only a low-viscosity product containing a large amount of insoluble matter can be obtained. On the other hand, α,β-unsaturated carboxylic acids and/or their salts also have 10 to
It is used in a range of 90 parts, but if the amount is less than 10 parts, only a low viscosity product containing a large amount of insoluble matter can be obtained, and if it is more than 90 parts, the alkali resistance will be lost. Further, when the monovinyl compound described above is used as a part of the mixed monomer, it is used in an amount of 25 parts or less. Next, the general usage range of a monomer having two or more vinyl groups to be copolymerized with the mixed monomer is 0.5 to 15% with respect to the mixed monomer. When the amount of crosslinking agent is too low, the pseudo-fluidity due to crosslinking is lost at low viscosity, and the liquid properties are similar to those when no crosslinking agent is added. When it is used in excess, the crosslinking density increases. It becomes difficult to dissolve in water and tends to produce a large amount of insoluble matter. In the production of the polymer in this invention, in a water-soluble organic solvent, 0.5 to 0.5 to 0.5 to 0.5 to 0.5 to 0.5 to
Either 15% of the monomers are mixed together, or each monomer is added separately and polymerized using an ordinary polymerization initiator.
Sequential or continuous feeding may be used, and as a result, the water-soluble copolymer is appropriately cross-linked, and the polymer is precipitated in the form of a slurry. It can be easily manufactured by When the thus obtained crosslinked copolymer is dissolved in water, it exhibits a gel-like high viscosity, has pseudoplastic flow characteristics, and exhibits extremely little decrease in viscosity even in strongly alkaline conditions, resulting in a stable solution. is obtained. The water-soluble crosslinked copolymer obtained by this invention can be used as a solid suspension stabilizer for gypsum, cement, sand, etc., and as a sizing agent for warps, printing, laundry, etc. in the textile industry, and as an additive for wallpaper removal agents. As a viscous agent, as a fabric filler in the ceramics industry, as an additive for refractory bricks and refractory mortars, as a thickener for water-soluble paints and emulsion paints in the paint industry, as a pigment dispersant for mold paints, and as a water-based printing agent in the printing ink industry. As a thickening pigment dispersant for ink, as a thickening agent for various latex emulsions in the rubber and resin industries, as a bubble stabilizer, as an excipient for alkaline liquid in dry batteries, as a spill prevention agent, and as a thickening agent for many other fields. Useful as agents, gelling agents, dispersants and adhesives. In addition, the obtained aqueous solution is a transparent gel-like high-viscosity pseudoplastic fluid, and despite its high viscosity, it has excellent fluidity due to low stress, has high shaping power, and has a wide concentration range. It can be used for the various purposes mentioned above. This invention will be described in more detail below with reference to Examples and Comparative Examples, and the methods for measuring physical properties described therein are as follows. (1) Viscosity B-type viscometer 25℃ (2) Flow characteristics Visual observation example 1 10 parts of methacrylic acid, 40 parts of acrylamide,
5 parts of diethylene glycol triacrylate,
After adding 45 parts of isopropyl alcohol and 0.1 part of tert-butyl hydroperoxide, the mixture was stirred at a temperature of 55° C. for 6 hours, cooled, and solid-liquid was separated. The polymer was successively precipitated in the form of a powder during stirring, and finally became a slurry. When this separated powder was dried at a temperature of 98° C. for 6 hours, it became a polymer powder of 98% or more. When this powder was made into a 0.5% aqueous solution and adjusted to pH=7.8 with sodium hydroxide, its viscosity was 8000 cps. Furthermore, sodium hydroxide was added to adjust the pH to 13.5, but the viscosity was 3500 cps and the pseudoplastic flow characteristics were not lost. Comparative Example 1 3 parts of methacrylic acid, 47 parts of acrylamide, and 5 parts of diethlylene glycol triacrylate were added to 45 parts of isopropyl alcohol, and tert-butyl hydroperoxide was added.
After 0.1 part was added and stirred at a temperature of 55°C for 6 hours, the mixture was cooled and solid and liquid were separated. The polymer was successively precipitated in the form of a powder during stirring, and finally became a slurry. The separated powder was dried at a temperature of 98°C for 6 hours, resulting in more than 98% polymer powder. This powder was made into a 0.5% aqueous solution and adjusted to pH=7.6 with sodium hydroxide, but it contained many insoluble substances, its viscosity was 10 cps, and it did not exhibit pseudoplastic flow characteristics. Comparative Example 2 46 parts of methacrylic acid, 4 parts of acrylamide, and 5 parts of diethlylene glycol triacrylate were added to 45 parts of isopropyl alcohol, and tert-butyl hydroperoxide was added.
After 0.1 part was added and stirred at a temperature of 55°C for 6 hours, it was cooled and solid and liquid were separated. The polymer was successively precipitated in the form of a powder during stirring, and finally became a slurry. The separated powder was dried at a temperature of 98°C for 6 hours, resulting in more than 98% polymer powder. When this powder was made into a 0.5% aqueous solution and adjusted to pH=8.2 with water-solubilized sodium, its viscosity was 5000 cps. Furthermore, when sodium hydroxide was added to adjust the pH to 9.5, the viscosity became 25 cps and pseudoplastic flow characteristics were lost. Example 2 24 parts of acrylamide, 16 parts of acrylic acid, 1 part of polyvalent allyl sugar ether, 42.5 parts of butanol
16.5 parts of 48% sodium hydroxide was added, 0.5 part of azobisisobutylnitrile was added in portions every hour for 3 hours, polymerized at a temperature of 80°C, and further polymerized for 2 hours. As it continued, it turned into a slurry. This slurry is separated into solid and liquid, and this powder is heated to 95°C.
It was dried at ℃ for 5 hours to obtain a polymer powder of 98% or more. When this powder was dissolved in water to form a 1% aqueous solution, its viscosity was 18,000 cps. Potassium hydroxide was added to this to adjust the pH to 12.8, but the viscosity remained at 10,000 cps and pseudoplastic flow characteristics were not lost. Comparative Example 3 24 parts of acrylamide and 16 parts of acrylic acid were added to 43.5 parts of butanol, and 48% sodium hydroxide was added.
Add 16.5 parts of azobisisobutylnitrile
0.5 part was divided and added every hour for 3 hours, and polymerization was carried out at a temperature of 80°C. The polymerization was further continued for 2 hours to obtain a slurry-like polymerization liquid. This polymerization liquid was separated into solid and liquid and dried at a temperature of 95° C. for 5 hours to obtain a polymer powder with a content of 98% or more. When this powder was dissolved in water to form a 1% aqueous solution, its viscosity was 500 cps, and it did not exhibit pseudoplastic flow characteristics. Comparative Example 4 24 parts of acrylamide, 16 parts of allyl acid, 8 parts of polyvalent allyl Shugar ether, and 36.3 parts of butanol.
16.5 parts of 48% sodium hydroxide was added, 0.5 part of azobisisobutylnitrile was added in portions every hour for 3 hours, and the temperature was 80°C.
When the polymerization was continued for further 2 hours, it became a slurry. This chiller is subjected to solid-liquid separation, and the obtained powder is
After drying at 95°C for 5 hours, it became a polymer powder with a content of more than 98%. When an attempt was made to dissolve the thus obtained powder in water, it only became a slightly swollen gel and did not dissolve. Example 3 15 parts of acrylamide, 12 parts of acrylic acid, 0.2 parts of iron () acrylate, and 0.3 parts of butanetriol trimethacrylate were mixed, 6 parts of this mixed solution was added to 55.7 parts of ethanol, and 50% water was added to this. Add 2.5 parts of potassium oxide aqueous solution and 0.1 part of benzoyl peroxide to start polymerization at a temperature of 60°C.
21.5 parts of the mixed monomers were continuously added dropwise over 3 hours, and further, 14.3 parts of a 50% aqueous potassium hydroxide solution was added continuously over 3 hours. This polymerization solution was further maintained at a temperature of 60° C. for 3 hours to form a thriller-like polymerization solution. After solid-liquid separation of this polymerization liquid, it was dried at a temperature of 98° C. for 3 hours to obtain a polymer powder of 98% or more. When this powder was made into a 0.5% aqueous solution, the viscosity was 6000 cps and the pH was 7.8. Aqueous ammonia was added to this to adjust the pH to 13, but the viscosity was 2800 cps and pseudoplastic flow characteristics were maintained. Comparative Example 5 23 parts of acrylic acid, 0.2 parts of iron acrylate, and 0.3 parts of butanetriol trimethacrylate were mixed, and 8 parts of this mixed solution and 7.5 parts of a 50% aqueous potassium hydroxide solution were added to 44.2 parts of ethanol. ,
0.1 part of benzoyl peroxide was added to start polymerization at a temperature of 60°C, then 15 parts of the mixed monomer and 24.8 parts of a 50% potassium hydroxide aqueous solution were continuously added dropwise for 3 hours, and then polymerization was continued at a temperature of 60°C for 2 hours. The polymerization solution was kept for a certain period of time to form a slurry-like polymerization solution. After solid-liquid separation, this polymerization liquid was heated to 98℃ for 3
It was dried for several hours to form a polymer powder with a content of 98% or more. When this powder was made into a 0.5% aqueous solution, the viscosity was 10,000 cps and the pH was 8.2. When this was adjusted to pH=10 with ammonia water,
Its viscosity was 100 cps and pseudoplastic flow characteristics were lost. Example 4 Methacrylamide 100Kg, acrylic acid 100Kg,
Prepare a mixture of 50 kg of styrene and 5 kg of glyogyzal tetraallyl ether, put 580 kg of methanol into a 1 m ³ autoclave, divide the monomer mixture into 5 parts, apply 50 kg every 45 minutes, and add benzoyl peroxide powder. While adding 0.2Kg at the same time,
The polymerization reaction was carried out at a temperature of 65°C. After polymerization, the temperature was maintained at 65℃ for another 6 hours, then the internal temperature was cooled to 40℃, 104 kg of 48% sodium hydroxide aqueous solution was added, and this polymerization liquid was separated and dried at a temperature of 98℃ for 5 hours. , a powder with a volatile content of 2% was obtained. When this powder was made into a 0.5% aqueous solution, the viscosity was
The result was 5800cps, and although the pH was set to 13 with alkali, the viscosity was 3200cps and pseudoplastic flow characteristics were maintained. Comparative Example 6 Prepare a mixture of 180 kg of alkaline acid, 50 kg of styrene, and 5 kg of glyogysal tetraallyl ether, put 500 kg of benzene into a 1 m ³ autoclave, divide the above mixture into 5 portions of 47 kg, and pass the mixture every 45 minutes. While sequentially adding 0.2 kg of benzoyl oxide,
The polymerization reaction was carried out at a temperature of 65°C. After polymerization, maintain the temperature at 65℃ for another 6 hours, and
The internal temperature was cooled to 40°C. Then, after adding 275 kg of a 35% methanol solution of sodium hydroxide, this polymerization liquid was separated and dried at a temperature of 110°C for 5 hours to obtain a powder with a volatile content of 1.5%. When this powder was made into a 0.5% aqueous solution, the viscosity was
At 13,000 cps, an aqueous solution with pseudoplastic flow characteristics was obtained, but when the pH was adjusted to 10 with alkali, the viscosity became 280 cps, and the pseudoplastic flow characteristics were apparently lost. Examples 5 and 6 and Comparative Examples 7 to 9 After adding 2000 kg of ethanol to a 3 m ³ autoclave and charging 240 kg of mixed monomers having the respective compositions shown in Table 1, the internal temperature was raised to 65°C. After raising the temperature, 1 kg of azobisvaleronitrile was added in 4 portions every hour, and 560 kg of mixed monomer was added in 3 portions.
The polymerization reaction was carried out at a temperature of 65° C. by continuously adding the solution for an hour. As a result, the reaction was completed in about 6 hours, and a polymer was obtained in the form of a slurry. This slurry-like heavy material was filtered using a centrifuge, and the polymer was obtained as a filter cake having a concentration of 45 to 55%. Then, when the mixture was dried for 5 hours in a ventilation dryer at a temperature of 90 to 98°C, white fine powder polymers with a volatile content of 1.5% or less were obtained. The viscosity and flow characteristics of a 1% aqueous solution of this white fine powder polymer were as shown in Table 1.

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Claims (1)

[Claims] 1. In a water-soluble organic solvent, the composition per 100 parts by weight of mixed monomers is 10 to 90 parts by weight of an α,β-unsaturated amide compound, an α,β-unsaturated carboxylic acid and 0.5 to 15% by weight of a monomer having two or more vinyl groups based on the mixed monomer consisting of 90 to 10 parts by weight of / or a salt thereof and 0 to 25 parts by weight of another copolymerizable monovinyl compound. A method for producing a water-soluble crosslinked copolymer, which comprises polymerizing a water-soluble crosslinked copolymer. 2. The method for producing a water-soluble crosslinked copolymer according to claim 1, wherein the monomer having two or more vinyl groups is one or more glyoxal alkenyl compounds. 3 The monomer having two or more vinyl groups is one or two selected from polyacrylic esters and polymethacrylic esters of polyhydric alcohols.
2. A method for producing a water-soluble crosslinked copolymer according to claim 1, wherein the water-soluble crosslinked copolymer contains at least one species. 4 The monomer having two or more vinyl groups is one or two polyallyl ethers of polyhydric alcohols.
2. A method for producing a water-soluble crosslinked copolymer according to claim 1, wherein the water-soluble crosslinked copolymer contains at least one species. 5. Production of a water-soluble crosslinked copolymer according to claim 1, wherein the monomer having two or more vinyl groups is one or more polyvalent metal salts of acrylic acid or methacrylic acid. Method.