JPS6225165B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides a method for producing a water-soluble polymer useful as a dispersant for various pigments, a chelating agent, a scale inhibitor, a builder for detergents, a polymeric surfactant, an emulsifier, and many other uses. It is related to.

Methods for producing polycarboxylates such as polyacrylates and polymethacrylates have been known for some time, and the polymers obtained by these production methods are useful as dispersants and scale inhibitors for certain pigments. used in However, these polycarboxylates do not exhibit sufficiently satisfactory performance in dispersing special pigments or preventing scale precipitation in circulating water containing a large amount of metal ions. In order to improve the drawbacks of these polycarboxylates, we have developed a combination of (meth)acrylate and hydrophilic hydroxy (meth)acrylate or (meth)acrylamide, or hydrophobic styrene or (meth)acrylate. Polymers, etc. have been proposed, but even with these copolymers,
At present, the required performance is not fully satisfied.

In view of the current situation, the inventors of the present invention have conducted intensive research and have developed a dispersant for various pigments, a chelating agent,
We have developed a method for producing water-soluble polymers that exhibit excellent performance in a wide range of applications such as scale inhibitors, detergent builders, polymeric surfactants, and emulsifiers, leading to the completion of the present invention.

Therefore, an object of the present invention is to provide a method for producing a water-soluble polymer that can be used in these applications and exhibits excellent performance.

That is, the present invention has the following general formula: (However, in the formula, m and n are 0 or positive integers, and m
+n=1 to 100, -(C ₂ H ₄ O-) unit and -(
C ₃ H ₆ O―) units may be bonded in any order. ) Polyalkylene glycol monoallyl ether () represented by the general formula (However, in the formula, R ₁ represents hydrogen or a methyl group, and X represents hydrogen, an alkali metal, or an ammonium group.) Copolymerize using a polymerization initiator at a ratio of () to 0.1% by weight or more and less than 5.0% by weight based on the total, and if necessary, further neutralize with an alkaline substance so that the molecular weight is within the range of 1000 to 200000. The present invention relates to a method for producing a water-soluble polymer characterized by the following.

The polyalkylene glycol monoallyl ether () used in the present invention is represented by the above general formula, and has an added mole number m+n of 1 to 100 of alkylene oxide. Number of moles added m
When +n is 0, the performance of the resulting copolymer, such as dispersibility and chelating ability, is low; on the other hand, when it exceeds 100, the copolymerization reactivity of such polyalkylene glycol monoallyl ether is low.

Polyalkylene glycol monoallyl ether () can be synthesized by a known method of directly adding ethylene oxide and/or propylene oxide to allyl alcohol using an alkali such as KOH or NaOH as a catalyst.

The (meth)acrylic acid monomer () is represented by the above general formula, and specific examples include acrylic acid, methacrylic acid, and alkali metal salts and ammonium salts thereof. One or more of these can be used.

In the method of the present invention, a water-soluble polymer is produced by copolymerizing polyalkylene glycol monoallyl ether () and (meth)acrylic acid monomer () in a specific ratio using a polymerization initiator. However, copolymerization can be carried out by methods such as polymerization in a solvent or bulk polymerization.

Polymerization in a solvent can be carried out either batchwise or continuously, and the solvent used in this case is water;
Lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; benzene,
Examples include aromatic or aliphatic hydrocarbons such as toluene, xylene, cyclohexane and n-hexane; ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; In view of the solubility of the raw material monomer and the resulting copolymer and the ease of use of the copolymer, it is preferable to use at least one selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. . Among the lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, and isopropyl alcohol are particularly preferred.

When polymerization is carried out in an aqueous medium, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide is used as the polymerization initiator. At this time, an accelerator such as sodium hydrogen sulfite can also be used in combination. In addition, for polymerization using lower alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, ethyl acetate, or ketone compounds as solvents, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; Aliphatic azo compounds such as bisisobutyronitrile are used as polymerization initiators. At this time, a promoter such as an amine compound can also be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from among the various polymerization initiators or combinations of polymerization initiators and accelerators mentioned above. The polymerization temperature is appropriately determined depending on the solvent and polymerization initiator used, but it is usually carried out within the range of 0 to 120°C.

When water is used as a solvent, sodium hydrogen sulfite-oxygen may be used as a polymerization catalyst. In this case, the polymerization is carried out by blowing oxygen gas or a mixed gas of oxygen and an inert gas into the solvent while adding sodium hydrogen sulfite to the solvent containing the raw material monomer.
This can be carried out by proceeding the polymerization reaction within a temperature range of ~80°C.

Bulk polymerization is carried out using peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; and aliphatic azo compounds such as azobisisobutyronitrile as polymerization initiators at 50 to 150°C. carried out within a temperature range.

When producing a water-soluble polymer in this way, the charging ratio of polyalkylene glycol monoallyl ether () and (meth)acrylic acid monomer (), the amount of polymerization initiator used, the polymerization temperature,
In the case of polymerization in a solvent, the molecular weight of the resulting water-soluble polymer can be adjusted as appropriate by adjusting the type and amount of the solvent.

The water-soluble polymer thus obtained can be used as it is for various purposes, but it may be further neutralized with an alkaline substance if necessary.

Preferred examples of such alkaline substances include hydroxides, chlorides, and carbonates of monovalent metals and divalent metals, ammonia, and organic amines.

The water-soluble polymer obtained in the present invention is nonionic and contains hydrophilic blocks, and through interaction with the anionic blocks, it can be used as a dispersant for various pigments, a chelating agent, a scale inhibitor, and a builder for detergents. It is used in a wide range of applications such as polymer surfactants, emulsifiers, etc., and exhibits excellent performance. In particular, it exhibits excellent dispersion ability for inorganic pigments such as calcium carbonate, satin white, and aluminum hydroxide, and chelating ability and dispersion ability for polyvalent metal ions such as calcium, magnesium, zinc, and aluminum. be.

Furthermore, since the terminal of the polyalkylene glycol monoallyl ether moiety in the water-soluble polymer is an OH group, foaming occurs very quickly even when the water-soluble polymer is foamed by high-speed stirring. have. Therefore, even when used as a dispersant for inorganic pigments, for example, there is no need to use an antifoaming agent in combination.

In addition, the polyalkylene glycol moiety in the molecule of a water-soluble polymer is bonded to the main chain of the polymer through an ether bond, so it can be used for long periods of time at high temperatures, in boiling water, or in high pH ranges. It also has the feature that no hydrolysis occurs and its performance is not affected in any way.

Examples will be described in more detail below, but it goes without saying that the present invention is not limited only to these examples. In addition, all parts in the examples represent parts by weight, and all % represent weight %. In addition, all viscosities in the examples were measured using a Bismetron viscometer manufactured by Seiki Kogyo Research Institute at 25° C. and 60 rpm. In addition, the molecular weight was measured using gel permation chromatography (manufactured by Waters).
244 type).

Example 1 Polyethylene glycol monoallyl ether (containing on average 5 ethylene oxide units per molecule) was placed in a glass reaction vessel equipped with a thermometer, stirrer, dropping funnel, gas inlet tube and reflux condenser.
7.5 parts and 389.9 parts of water were charged, and the inside of the reaction vessel was purged with nitrogen while stirring, and heated to 95°C in a nitrogen atmosphere. Then, 38% sodium acrylate aqueous solution
506.6 parts and 80 parts of 5% ammonium persulfate aqueous solution were each added over 120 minutes. 16 more after addition
of 5% ammonium persulfate aqueous solution was added over 20 minutes. 95 for 120 minutes after the addition of monomer aqueous solution is completed.
The polymerization reaction was completed while maintaining the temperature at °C to obtain a water-soluble polymer (1). A 40% aqueous solution of this water-soluble polymer (1) obtained by concentrating under reduced pressure has a pH of 7.3 and a viscosity of 267 cps.
It was hot. Also, the molecular weight of this water-soluble polymer (1) is
It was 4100.

Example 2 In the same reaction vessel as in Example 1, 9.8 parts of polyethylene glycol monoallyl ether (containing an average of 10 ethylene oxide units per molecule) and water were added.
After charging 441.7 parts, the inside of the reaction vessel was purged with nitrogen while stirring, and heated to the boiling point in a nitrogen atmosphere. after that
500.5 parts of 38% sodium acrylate aqueous solution and 5%
40 parts of ammonium persulfate aqueous solution and 120 parts each
After the addition was complete, 8 parts of a 5% aqueous ammonium persulfate solution was added over 20 minutes. After the addition of the monomers was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction, yielding a water-soluble polymer (2). The pH of a 40% aqueous solution of this water-soluble polymer (2) is 7.5 and the viscosity is 348 cps.
It was hot. Furthermore, the molecular weight of the water-soluble polymer (2) was 4,700.

Example 3 Into the same reaction vessel as in Example 1, 4 parts of polyethylene glycol monoallyl ether (containing an average of 30 ethylene oxide units per molecule) and 23.0
30% of a mixture of 852 parts of a 5% aqueous sodium methacrylate solution and 30% of a mixture of 120 parts of a 5% ammonium persulfate aqueous solution were charged, and the inside of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated in a nitrogen atmosphere.
Heated to 95°C. The remainder of the above monomer mixture and the remainder of the catalyst solution were then added over a period of 120 minutes each. After the addition was complete, an additional 24 parts of 5% ammonium persulfate aqueous solution was added over 20 minutes. After the addition of the monomer mixture was completed, the temperature was maintained at 95° C. for 120 minutes to complete the polymerization reaction, and a water-soluble polymer (3) was obtained. A 40% aqueous solution of this water-soluble polymer (3) has a pH of 7.8 and a viscosity of
It was 3400cps. Moreover, the molecular weight was 26,000.

Example 4 285 parts of isopropyl alcohol (hereinafter abbreviated as IPA) was charged into the same reaction vessel as in Example 1, the inside of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated to the boiling point in a nitrogen atmosphere. Thereafter, a mixture of 4.5 parts of polyalkylene glycol monoallyl ether (containing an average of 18 ethylene oxide units and 2 propylene oxide units per molecule), 295.5 parts of acrylic acid, 3 parts of benzoyl peroxide, and 300 parts of IPA was added over 120 minutes. After the addition was completed, 0.6 parts of benzoyl peroxide dispersed in 11.4 parts of IPA was added in two portions every 30 minutes. After the addition of the monomer mixture was completed, the temperature was maintained at the boiling point for 120 minutes to complete the polymerization reaction. Thereafter, the mixture was neutralized with 410.1 parts of a 40% caustic soda aqueous solution, and then IPA was distilled off to obtain a water-soluble polymer (4). This water-soluble polymer (4)
The pH of a 45% aqueous solution of was 8.5 and the viscosity was 1920 cps. Furthermore, the molecular weight of the water-soluble polymer (4) was 3,000.

Example 5 367.3 parts of water was charged into the same reaction vessel as in Example 1, and the temperature was set at 25°C. 160 ml of air per minute is blown into this water through a glass sintered porous tube with micropores of about 10 microns, and 20% of polyethylene glycol monoallyl ether (containing an average of 15 ethylene oxide units per molecule) is mixed with stirring. Aqueous solution 40
parts, 505.3 parts of 38% sodium acrylate aqueous solution,
and 87.4 parts of a 10% aqueous sodium bisulfite solution were each added over 120 minutes. The microbubbles that were blown in at the start of polymerization were further refined. During the polymerization reaction, the heat generated by the polymerization was cooled with cold water, and the reaction temperature was maintained at 24-26°C. After the addition of the monomer aqueous solution and the sodium bisulfite aqueous solution was completed, air was continued to be blown for another 30 minutes to complete the polymerization reaction and obtain a water-soluble polymer (5). A 40% aqueous solution of this water-soluble polymer (5) had a pH of 9.0 and a viscosity of 560 cps. Furthermore, the molecular weight of the water-soluble polymer (5) was 4,400.

Example 6 Into the same reaction vessel as in Example 1, 2 parts of polyalkylene glycol monoallyl ether (containing on average 8 ethylene oxide units and 2 propylene oxide units per molecule) and 332.9 parts of water were charged, and the mixture was stirred. The interior of the reaction vessel was purged with nitrogen and heated to 95°C in a nitrogen atmosphere. Thereafter, 521.1 parts of a 38% ammonium acrylate aqueous solution and 120 parts of a 5% ammonium persulfate aqueous solution were each added over 120 minutes.
After the addition was complete, an additional 24 parts of 5% ammonium persulfate aqueous solution was added over 20 minutes. After completion of monomer addition
The temperature was maintained at 95° C. for 120 minutes to complete the polymerization reaction, and a water-soluble polymer (6) was obtained. This water-soluble polymer (6)
The pH of a 40% aqueous solution of was 6.4 and the viscosity was 408 cps. Furthermore, the molecular weight of the water-soluble polymer (6) was 5,200.

Example 7 Cyclohexane was added to the same reaction vessel as in Example 1.
809.5 parts of the reactor was charged, and the inside of the reaction vessel was replaced with nitrogen while stirring, and heated to the boiling point in a nitrogen atmosphere. Next, polyalkylene glycol monoallyl ether (containing an average of 4 ethylene oxide units and 4 propylene oxide units per molecule) 4.5
20% of the monomer solution dissolved in 40.5 parts of cyclohexane, 20% of the 95.5 parts of acrylic acid
% and 20% of a solution of 5 parts of decanoyl peroxide dissolved in 45 parts of cyclohexane were added to carry out initial polymerization. Thereafter, the remaining 80% of each of the above was added over a period of 120 minutes.
After the addition was completed, the temperature was maintained at the boiling point for an additional 120 minutes to complete the polymerization reaction, and the mixture was cooled and filtered to obtain a powder of water-soluble polymer (7). 30 of this water-soluble polymer (7)
% aqueous solution had a pH of 1.2 and a viscosity of 1260 cps.
Furthermore, the molecular weight of the water-soluble polymer (7) was 35,000.

Example 8 613.6 parts of ethyl acetate was charged into the same reaction vessel as in Example 1, the inside of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated to the boiling point in a nitrogen atmosphere. Next, polyethylene glycol monoallyl ether (containing an average of 10 ethylene oxide units per molecule)
20% of the monomer solution of 9.6 parts dissolved in 86.4 parts of ethyl acetate, 20% of the 190.4 parts of acrylic acid
% and 20% of a solution prepared by dissolving 2.0 parts of benzoyl peroxide in 98 parts of ethyl acetate were added to carry out initial polymerization. Thereafter, the remaining 80% of each of the above was added over a period of 120 minutes. After the addition was completed, the temperature was maintained at the boiling point for an additional 120 minutes to complete the polymerization reaction. After completion of the polymerization, neutralization was performed with 264 parts of a 40% aqueous solution of caustic soda, and then ethyl acetate was distilled off to obtain a water-soluble polymer (8). A 20% aqueous solution of this water-soluble polymer (8) had a pH of 8.8 and a viscosity of 440 cps. Further, the molecular weight of the water-soluble polymer (8) was 68,000.

Example 9 Polypropylene glycol monoallyl ether (on average 5 ml of polypropylene glycol monoallyl ether per molecule
(containing 4 propylene oxide units) 4 parts,
96 parts of acrylic acid and azobisisobutyronitrile
0.5 part of each was charged, and the inside of the reaction vessel was sufficiently purged with nitrogen while stirring. Thereafter, the mixture was gradually heated and copolymerized to obtain a solid polymer. This polymer was completely neutralized with an aqueous solution of caustic soda to obtain a water-soluble polymer (9). A 20% aqueous solution of this water-soluble polymer (9) had a pH of 9.0 and a viscosity of 1032 cps. Further, the molecular weight of the water-soluble polymer (9) was 110,000.

Example 10 In the same reaction vessel as in Example 1, 1 part of polyethylene glycol monoallyl ether (containing an average of 2 ethylene oxide units per molecule) and water were added.
After charging 415.3 parts, the inside of the reaction vessel was purged with nitrogen while stirring, and heated to 95°C in a nitrogen atmosphere. Then, 523.7 parts of a 38% sodium acrylate aqueous solution and 60 parts of a 5% ammonium persulfate aqueous solution were added.
Added at 120 minutes. Thereafter, the temperature was maintained at 95° C. for 120 minutes to complete the polymerization reaction, and a water-soluble polymer (10) was obtained. The pH of a 40% aqueous solution of this water-soluble polymer (10) is
7.4, and the viscosity was 402 cps. Also, water-soluble polymer
The molecular weight of (10) was 4,800.

Example 11 517.5 parts of IPA was charged into the same reaction vessel as in Example 1, the inside of the reaction vessel was replaced with nitrogen while stirring, and the mixture was heated to the boiling point in a nitrogen atmosphere. Then polyethylene glycol monoallyl ether (average 5 per molecule)
ethylene oxide units) 7.2 parts,
Acrylic acid 172.8 parts, benzoyl peroxide 4.5 parts
and 180 parts of IPA were added over 120 minutes, and after the addition was complete, an additional 0.9 parts of benzoyl peroxide was added.
A solution dispersed in 17.1 parts of IPA was added twice every 30 minutes. After complete addition of monomer mixture, 120
The temperature was maintained at boiling point for a minute to complete the polymerization reaction. Thereafter, the mixture was neutralized with 240 parts of a 40% caustic soda aqueous solution, and then IPA was distilled off to obtain a water-soluble polymer (11). The pH of a 40% aqueous solution of this water-soluble polymer (11) is
8.5, and the viscosity was 130 cps.

Further, the molecular weight of the water-soluble polymer (11) was 1,500.

Claims (1)

[Claims] 1. General formula (However, in the formula, m and n are 0 or positive integers, and m +
n=1 to 100, -(C ₂ H ₄ O-) unit and -(C ₃ H ₆ O
--) Units may be combined in any order. ) Polyalkylene glycol monoallyl ether () represented by the general formula (However, in the formula, R ₁ represents hydrogen or a methyl group, and X represents hydrogen, an alkali metal, or an ammonium group.) Copolymerized using a polymerization initiator at a ratio such that () is 0.1% by weight or more and less than 5.0% by weight based on the total, and if necessary, further neutralized with an alkaline substance, resulting in a molecular weight of 1000.
200,000. 2 Claim 1 in which the copolymerization is carried out in a solvent
A method for producing a water-soluble polymer as described in Section 1. 3. The method for producing a water-soluble polymer according to claim 2, wherein at least one selected from the group consisting of water and a lower alcohol having 1 to 4 carbon atoms is used as a solvent. 4. The method for producing a water-soluble polymer according to claim 2, which uses water as a solvent and sodium bisulfite-oxygen as a polymerization initiator. 5. The method for producing a water-soluble polymer according to claim 2, wherein at least one selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons is used as a solvent. 6. The method for producing a water-soluble polymer according to claim 2, wherein at least one selected from the group consisting of ethyl acetate and ketone compounds is used as a solvent. 7. The method for producing a water-soluble polymer according to claim 1, wherein the copolymerization is carried out by bulk polymerization.