JPH11349612A - Emulsifier for emulsion polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer (film) having good stability in emulsion polymerization and having significantly improved water resistance, adhesion, heat stability and water resistance by using an emulsifier which has a propenyl group as a polymerizable unsaturated group bonding to its hydrophobic portion. SOLUTION: An emulsifier or formula I is used. In formula I, R<1> is a 6-30C alkyl; R<2> is H or propenyl; M is NH4 , an alkanol amine or an alkali metal; A is a 2-4C (substituted) alkylene; (n) is 1-200; and when (n) is 2 or more, (AO)n may be a homopolymer of a repeating unit of formula II or a block or random polymer of two or more repeating units having different substituents A (A<1> , A<2> or the like) of formula III. For example, an α-olefin epoxide and propenyl phenol are heated and reacted in the presence of a catalyst, to which an alkylene oxide may further be added, sulfated and neutralized as necessary to obtain the emulsifier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an emulsifier for emulsion polymerization.

[0002]

2. Description of the Related Art Conventionally, emulsifiers for emulsion polymerization include, for example, dodecylbenzene sulfonate, alkyl sulfate, alkyl sulfosuccinate, polyoxyalkylene alkyl (aryl) ether sulfate. Nonionic surfactants such as anionic surfactants such as salts, polyoxyalkylene alkyl (aryl) ethers, and polyoxyethylene polyoxypropylene block copolymers are used alone or in combination. Stability, the properties of the polymer film obtained from the emulsion, etc. are not always fully satisfactory,
Many problems remain to be solved.

That is, there are problems in polymerization stability of the emulsion, mechanical stability, chemical stability, freeze-thaw stability, pigment miscibility, storage stability and the like of the obtained emulsion.
Regarding mechanical stability, there remains a problem to be improved. Furthermore, when a polymer film is prepared from an emulsion, the used emulsifier remains in the polymer film in a free state, which causes problems such as poor water resistance and adhesiveness of the film. Also, when the emulsion is destroyed by means of salting out or acid precipitation and the like, and the polymer is taken out, a large amount of emulsifier is contained in the waste water, which causes river pollution, so that a great deal of labor is required for the emulsifier removal treatment. Become.

[0004] From such a viewpoint, many reactive emulsifiers having a copolymerizable unsaturated group have been proposed in order to improve the problems of the conventional emulsifiers. For example, Japanese Patent Publication No. 46-124
No. 72, JP-A-54-14431, JP-B-46-34
894, JP-B-54-29657, JP-A-51-3
No. 0285, JP-B-49-46291 and JP-A-Showa 56
JP-A-1227697 and the like describe anionic reactive surfactants, and JP-A-56-28208 and JP-A-50-98484 describe a nonionic reactive surfactant respectively. Emulsion polymerization of various monomers has been attempted. However, when these reactive emulsifiers are used alone as an emulsifier, the stability at the time of emulsion polymerization is insufficient, and when used, polymerization often does not proceed smoothly unless used in combination with a conventional emulsifier. The fact is that the polymer film obtained from the emulsion has not been sufficiently satisfactory in water resistance, adhesion, heat resistance and weather resistance.

However, among such conventional reactive emulsifiers, generally, a reactive emulsifier having an acrylic or methacrylic group as a copolymerizable unsaturated group has excellent copolymerizability with a monomer. However, on the contrary, there was a problem in stability at the time of emulsion polymerization, and there were problems such as formation of a large amount of aggregates during polymerization, formation of coarse particles, and poor stability with time.

The reactive emulsifier having an allyl group is
In many cases, the copolymerizability with a monomer is inferior, and there has been a problem that a polymer film obtained from a polymer emulsion cannot be sufficiently satisfactory in water resistance, adhesion, heat resistance, and weather resistance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to improve the stability during emulsion polymerization, and to further improve the water resistance of polymers and polymer films. It is an object of the present invention to provide an emulsifier for a reactive emulsion polymerization in which adhesiveness, heat resistance, and weather resistance are significantly improved.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a propenyl group as an unsaturated group having copolymerizability, and a bonding position of the unsaturated group are a part of a hydrophobic group of an emulsifier. Have been found to be suitable as an emulsifier for emulsion polymerization, and have reached the present invention.

That is, the present invention is an emulsifier for emulsion polymerization represented by the following general formula (I).

[0010]

Embedded image Wherein R ¹ is an alkyl group having 6 to 30 carbon atoms, R ²
Is hydrogen or a propenyl group, M is NH ₄ and / or an alkanolamine residue, and an alkali metal atom (NH ₄ , an alkanolamine residue, NH ₄ and an alkanolamine residue, or an alkali metal atom). A has 2 carbon atoms
4 to 4 alkylene groups or substituted alkylene groups;
Is 0 or an integer of 1 to 200, and when n is 2 or more, (AO) _n may be a homopolymer composed of one type of repeating unit represented by the following formula (i), The different substituents A (A ¹ , A ² ,...) Represented by the formula (ii)
It may be a block polymer or a random polymer composed of two or more kinds of repeating units having the following formula: ]

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[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The main items relating to the structure of the present invention will be described separately below.

[0012] In the compounds of the general formula the substituents above general formula in a compound of (I) (I), the substituent R ¹ is an alkyl group having 6 to 30 carbon atoms, e.g., hexyl, heptyl, octyl , Nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, tricosyl, pentacosyl, heptacosyl and the like.

Next, the substituent R ² is a hydrogen atom or a propenyl group. However, the propenyl group includes trans-type and cis-type stereoisomers, and in the present invention, any of the isomers may be used alone or as a mixture, but the trans-isomer is more preferably selected. .

M is an alkali metal atom such as sodium or potassium, NH ₄ or an alkanolamine residue such as monoethanolamine or triethanolamine, or a mixture thereof.

A is an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group, such as an ethylene group, a propylene group, a butylene group or an isobutylene group. n
Is 0 or an integer of 1 to 200, more preferably 2 to 100. When n is 2 or more, (AO) _n in the formula (I) may be a homopolymer composed of one kind of repeating unit (see the above formula (i)) or a different substituent A (A ¹ , A ² ,...) May be a block polymer or a random polymer (see the above formula (ii)) composed of two or more kinds of repeating units. When n is 2 or more, (AO) _n may be a mixture of compounds each of which is a homopolymer, a block polymer, or a random polymer.

Synthetic Method The reaction conditions for obtaining the emulsifier for emulsion polymerization of the present invention are not particularly limited. For example, the reaction is carried out by heating and reacting an α-olefin epoxide and propenylphenol in the presence of a catalyst. The resulting reaction composition, or an alkylene oxide adduct to which an alkylene oxide has been added according to a conventional method, is subjected to sulfation with a sulfating agent such as sulfuric acid or sulfamic acid and, if necessary, neutralized with a basic substance. ,
The emulsifier for emulsion polymerization of the present invention can be obtained.

Monomers for Emulsion Polymerization Examples of monomers applicable to emulsion polymerization using the emulsifier of the present invention include various monomers such as acrylic acid, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. Acrylic monomers such as methyl methacrylate, acrylonitrile, acrylamide and hydroxy acrylate, for example, aromatic monomers such as styrene and divinylbenzene, vinyl ester monomers such as vinyl acetate, and halogenated olefin monomers such as vinyl chloride and vinylidene chloride And conjugated diolefin monomers such as butadiene, isoprene, chloroprene, etc., as well as ethylene, maleic anhydride, methyl maleate and the like. The emulsifier of the present invention can be used for emulsion polymerization or suspension polymerization of one or more of the above monomers.

Polymerization conditions The polymerization initiator used in the emulsion polymerization reaction using the emulsifier of the present invention may be a conventionally known one.
Potassium persulfate, azobisisobutyronitrile, benzoyl peroxide and the like can be used. Further, as the polymerization accelerator, sodium hydrogen sulfite, ferrous ammonium sulfate and the like can be used.

The amount of the emulsifier of the present invention to be used is usually 0.1 to 20% based on all monomers. In addition, more preferably, 0.2 to 5.0% is appropriate. If desired, another emulsifier or a protective colloid may be used in combination.

Action and Others The emulsifier for emulsion polymerization of the present invention has a copolymerizable double bond, a propenyl group at the hydrophobic group in the molecule, and has a copolymerizable monomer, especially a vinyl monomer. Excellent polymerizability and easy to incorporate into polymer composition. Therefore, as a copolymerizable reactive emulsifier, the amount of the emulsifier present in a free state in the polymer film obtained from the polymer emulsion is significantly reduced, and the water resistance, adhesiveness,
Very effective in improving heat resistance and weather resistance. In addition, foaming and mechanical stability of the polymer emulsion are remarkably improved.

The polymer emulsion obtained by adding the emulsifier of the present invention can be applied to wood, metal, paper, cloth, concrete, and the like, for example, as an adhesive, a coating agent, an impregnating reinforcing agent, and the like. Further, the polymer taken out from the emulsion or latex can be used as a resin, a rubber, a polymer modifier and the like.

[0022]

The embodiments and effects of the present invention will be described below with reference to examples and comparative examples. However, the exemplification is merely for explanation, and is not intended to limit or limit the inventive idea. In the following description, “%” and “parts” mean weight basis, respectively.

Production Example 1 In an autoclave, 134 g (1 mol) of propenylphenol and an α-olefin epoxide having 12 or 14 carbon atoms (AOE X24, manufactured by Daicel Chemical Industries, Ltd.) 196
g (1 mol), and reacted at a temperature of 120 ° C. using triethylamine as a catalyst. Then, ethylene oxide was reacted at a pressure of 1.5 kg / cm ² and a temperature of 130 ° C. using potassium hydroxide as a catalyst. 44 for things
0 g (10 mol) and 1320 g (30 mol) were added. (Hereinafter, “ethylene oxide” is also simply referred to as “EO”.) Next, 100 g of sulfamic acid was charged into the adduct of 1 mol of α-olefin epoxide of propenylphenol and 10 mol of EO, and reacted at 120 ° C. for 3 hours to obtain sulfuric acid. The reaction composition from which esterification was performed to remove unreacted sulfamic acid was designated as emulsifier [A] of the present invention.

[0024]

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Further, the EO obtained by the same sulfation method is used.
The 30 mol adduct sulfate ammonium salt was used as the emulsifier [B] of the present invention.

[0026]

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Also, the emulsifier [B] of the present invention is dissolved in isopropyl alcohol, and a neutralized equivalent of sodium hydroxide is added thereto. [C].

[0028]

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Production Example 2 In an autoclave, 134 g (1 mol) of propenylphenol and α-olefin epoxide having 16 or 18 carbon atoms (AOE X68, manufactured by Daicel Chemical Industries, Ltd.) 252
were charged g (1 mole), boron trifluoride ether complex is reacted at a temperature of 80 ° C. as a catalyst, then pressure 1.5 kg / cm ² potassium hydroxide as a catalyst, the temperature 13
Under the condition of 0 ° C., 132 g (3 mol) of ethylene oxide
And 1320 g (30 mol) were added.

Next, 120 g of sulfamic acid was added to the obtained EO 3-mol adduct and reacted at 105 ° C. for 4 hours to carry out sulfuric esterification to remove unreacted sulfamic acid. The reaction composition obtained by summing was designated as emulsifier [D] of the present invention. However, at this time, the emulsifier [D] of the present invention partially includes a sulfate monoethanolamine salt.

[0031]

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Further, EO obtained by the same sulfation method is used.
The ammonium sulfate salt of a 30 mol adduct was used as the emulsifier [E] of the present invention.

[0033]

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Production Example 3 In an autoclave, 134 g (1 mol) of propenylphenol and an α-olefin epoxide having 20 to 30 carbon atoms (AOE Y08, manufactured by Daicel Chemical Industries, Ltd.) 342
g (1 mol) was charged and reacted under the conditions of a pressure of 1.5 kg / cm ² and a temperature of 130 ° C. using potassium hydroxide as a catalyst, and then 4,400 g (100 mol) of ethylene oxide was added.

Next, 135 g of sulfamic acid was charged,
The reaction composition from which unreacted sulfamic acid was removed by reacting with sulfuric acid by reacting at 120 ° C. for 3 hours was designated as emulsifier [F] of the present invention.

[0036]

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Production Example 4 According to Production Example 1, dipropenylphenol and C 1
20 mol of ethylene oxide was added to the reaction product of 2,14 α-olefin epoxide, and a sulfation reaction was carried out using sulfamic acid. The resulting reaction composition was designated as emulsifier [G] of the present invention.

[0038]

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Production Example 5 According to Production Example 1, propenylphenol was used.
First, 5 mol of butylene oxide is added to the reaction product of the 2,14 α-olefin epoxide, and then 80 mol of ethylene oxide is further added, and a sulfation reaction is carried out using sulfamic acid. The emulsifier [H] (hereinafter, “butylene oxide” is simply referred to as “B
O ").

[0040]

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Production Example 6 Propenylphenol and a compound having 1 carbon atom were prepared according to Production Example 1.
25 mol of ethylene oxide and 5 mol of propylene oxide were added to the reactants of the 2,14 α-olefin epoxides at random, and a sulfation reaction was carried out using sulfamic acid, and the resulting reaction composition was emulsifier [I] of the present invention. (Hereinafter, “propylene oxide” is also simply referred to as “PO”).

[0042]

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Production Example 7 Propenylphenol and a compound having 1 carbon atom were prepared according to Production Example 1.
Reacting 2,14 α-olefin epoxides,
Next, a sulfation reaction was performed using sulfamic acid, and the obtained reaction composition was designated as the emulsifier [J] of the present invention.

[0044]

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Use Example 1 A reactor equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel was charged with 294 g of ion-exchanged water, the temperature was raised to 80 ° C., and dissolved oxygen in the water was removed with nitrogen gas. Next, 6 g of the emulsifier of the present invention shown in [Table 1] was dissolved in 200 g of ethyl acrylate.
1.2 g was charged into a reactor, and then 0.5 g of ammonium persulfate was added for pre-polymerization. From 10 minutes after the start of the polymerization, the remaining 164.8 g of a mixed solution of ethyl acrylate and an emulsifier was added dropwise over 3 hours. Polymerized. Subsequently, after aging at the polymerization temperature for 2 hours, the emulsion was taken out and taken out as a test sample. Table 1 shows the test results of the emulsion polymerization stability, the emulsion mechanical stability, the foaming property, and the water resistance and contact angle of the polymer film prepared from this emulsion. In addition, the same test was performed for the conventional emulsifiers shown in Table 1 for comparison.

[0046]

[Table 1] Solid content: After drying 2 g of the emulsion at 105 ° C. for 2 hours,
The weight was measured and expressed as a percentage with respect to the weight of the emulsion. Polymerization stability: The emulsion was filtered through a 150-mesh wire net, and the residue was washed with water and dried, and the weight of the obtained coagulated product was expressed as% with respect to the weight of the charged monomer. Mechanical stability: 50 g of the emulsion was stirred with a Marlon-type tester at a load of 10 kg and a rotation speed of 1,000 rpm for 5 minutes, the formed aggregate was filtered through a 150-mesh wire net, the residue was washed with water, dried, and the weight was measured. It was expressed in% with respect to the solid content of the emulsion. Foaming property: Emulsion was diluted 2 times with water, 30 cc was put into a 100 ml Nessler tube, and inverted 30 times, then left standing 5
The amount of foam after a minute was measured. Water resistance test: A 0.5 mm thick polymer film was prepared on a glass plate, immersed in water, and the time required for 4.5 point characters to become unreadable through the polymer film was measured. Contact angle: A 0.5 mm thick polymer film was formed on a glass plate, and the contact angle of a water droplet was measured with a contact angle measuring device. Use Example 2 100 g of butyl acrylate, 100 g of styrene, 290 g of ion-exchanged water and the emulsifier 1 of the present invention shown in [Table 2]
0 g was mixed to prepare a mixed monomer emulsion, and dissolved oxygen was removed with nitrogen gas. Next, 100 g of the above mixed monomer emulsion was charged into a reactor equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel, the temperature was raised to 80 ° C., and 0.5 g of potassium persulfate was added to perform prepolymerization. . Then, 10 minutes after the start of the polymerization, 400 g of the remaining mixed monomer emulsion was added dropwise over 3 hours and polymerized over 3 hours. Further, after continuously aging at the polymerization temperature for 2 hours, the mixture was cooled and the emulsion was taken out to obtain a test sample. The stability of the emulsion polymerization, the foamability of the emulsion and the quantification of the unreacted emulsifier, and the test results of the water resistance and contact angle of the polymer film prepared from this emulsion are shown in Table 2. In addition, the same test was carried out for a conventional emulsifier and another reactive emulsifier shown in Table 2 for comparison.

[0047]

[Table 2] Polymerization stability: The emulsion was filtered through a 150-mesh wire net, and the residue was washed with water and dried, and the weight of the obtained coagulated product was expressed as% with respect to the weight of the charged monomer. Foaming property: Emulsion was diluted 2 times with water, 30 cc was put into a 100 ml Nessler tube, and inverted 30 times, then left standing 5
The amount of foam after a minute was measured. Unreacted emulsifier amount: Add methanol to the emulsion,
After coagulation of the polymer and centrifugation, the amount of emulsifier was measured by HPLC using the supernatant. Water resistance test: A 0.5 mm thick polymer film was prepared on a glass plate, immersed in water, and the time required for 4.5 point characters to become unreadable through the polymer film was measured. Contact angle: A 0.5 mm thick polymer film was formed on a glass plate, and the contact angle of a water droplet was measured with a contact angle measuring device. * 1: Reactive emulsifier having the following structure

Embedded image * 2: Sulfate ammonium salt of octyl allylphenol EO 10 mol adduct * 3: Acrylic ester of lauryl alcohol EO 15 mol adduct * 4: Polyoxyethylene 8 mol adduct * 5: Emulsion was not obtained and measurement was not possible.

* 6: Not measured due to non-reaction type.

Use Example 3 A reactor equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel was charged with 250 g of ion-exchanged water, the temperature was raised to 80 ° C., and dissolved oxygen in the water was removed with nitrogen gas. Next, 51 g, which corresponds to 20% of a mixed monomer solution obtained by dissolving 5 g of the emulsifier of the present invention shown in [Table 3] in 125 g of butyl acrylate and 125 g of 2-ethylhexyl acrylate, was charged into the reactor. 5 g was added for pre-polymerization, and 204 g of the remaining mixed monomer liquid was dropped and polymerized over 3 hours from 10 minutes after the start of polymerization.
After aging at polymerization temperature for 2 hours,
The emulsion was taken out and used as a test sample. With respect to the emulsion polymerization stability and the prepared emulsion at this time, the quantification of the unreacted emulsifier and the test results of the adhesive strength and heat resistance of the polymer film prepared from the emulsion are shown in Table 3. In addition, for the conventional emulsifier and other reactive emulsifiers shown in Table 3 for comparison,
A similar test was performed.

[0050]

[Table 3] Polymerization stability: The emulsion was filtered through a 150-mesh wire net, and the residue was washed with water and dried, and the weight of the obtained coagulated product was expressed as% with respect to the weight of the charged monomer. Unreacted emulsifier amount: Add methanol to the emulsion,
After coagulation of the polymer and centrifugation, the amount of emulsifier was measured by HPLC using the supernatant. Adhesive strength: 0.1mm emulsion on PET film
After coating with a thickness and heat-treating, a PET film is placed on the coating film, and a roller-pressed sample piece (1 inch width) of 25
The 180 ° peel strength at ° C was measured. Heat resistance: A 0.5 mm thick polymer film was prepared on a glass plate, and heat-treated for 30 minutes in a hot air drier adjusted to 200 ° C., and coloring of the polymer film was examined. (Evaluation Criteria) 着色: No coloring observed at all △: Light yellow coloring ×: Dark brown coloring * 1: Ammonium sulfate ammonium salt of octylallylphenol EO 10 mol adduct * 2: Lauryl alcohol Acrylic ester of EO 10 mol adduct * 3: Emulsion was not obtained and measurement was not possible * 4: Measurement not performed due to non-reaction type.

Use Example 4 As a reactor, 60 g of ion-exchanged water was charged into a pressure-resistant glass bottle, specifically, an empty bottle for carbonated beverages, and dissolved oxygen was removed with nitrogen gas. Next, after the glass bottle was cooled in an ice water bath, the emulsifier 1.2 of the present invention shown in Table 4 was obtained.
g, naphthalenesulfonic acid folimarin condensate 0.12
g, dodecyl mercaptan 0.12 g, styrene 20
g, and potassium persulfate 0.12 g. Then, butadiene was introduced from a cylinder into a graduated sampling tube in a methanol dry ice bath, and 20 g of liquefied butadiene was charged into a glass bottle using a syringe with a stopcock, immediately stoppered, and then shaken. Then, the liquid content in the glass bottle was changed to an emulsion state. Next, a glass bottle was set in a holder in a rotary polymerization tank adjusted to a water temperature of 50 ° C.,
Polymerization was performed at a rotation speed of 50 rpm for 20 hours. After the polymerization reaction was completed, the glass bottle was cooled in an ice water bath, opened, and p-
Emulsion obtained by adding 0.12 g of tert-butylcatechol and removing unreacted butadiene with nitrogen gas was used as a test sample. At this time, the stability of the emulsion polymerization, the quantification of the unreacted emulsifier of the prepared emulsion, and the test results of the mechanical stability and the foaming property are shown in Table 4. Also,
For comparison, the same test was carried out for the conventional emulsifiers shown in [Table 4].

[0052]

[Table 4] Solid content: 2 g of the emulsion was dried at 105 ° C. under reduced pressure for 2 hours, weighed, and expressed as a percentage of the weight of the emulsion. Polymerization stability: The emulsion was filtered through a 150-mesh wire net, and the residue was washed with water and dried under reduced pressure. Mechanical stability: 50 g of the emulsion was stirred with a Marlon-type tester at a load of 10 kg and a rotation speed of 1000 rpm for 5 minutes, the formed aggregate was filtered through a 150-mesh wire net, and the residue was washed with water and dried under reduced pressure. % With respect to the solid content. Foaming property: Emulsion was diluted 2 times with water, 30 cc was put into a 100 ml Nessler tube, and inverted 30 times, then left standing 5
The amount of foam after a minute was measured. Unreacted emulsifier amount: Add methanol to the emulsion,
After coagulation of the polymer and centrifugation, the amount of emulsifier was measured by HPLC using the supernatant. *: Not measured due to non-reaction type.

[0053]

As described above, according to the present invention, the stability during the emulsion polymerization can be improved, the foam trouble during the process can be eliminated, and the water resistance of the polymer and the polymer film obtained from the polymer emulsion can be improved. And an improved emulsifier for reactive emulsion polymerization, which can significantly improve the adhesion, and contribute to the development of related industries and the benefit of consumers.

Claims (1)

[Claims] An emulsifier for emulsion polymerization represented by the following general formula (I). Embedded image Wherein R ¹ is an alkyl group having 6 to 30 carbon atoms;
² is hydrogen or a propenyl group; M is NH ₄ and / or an alkanolamine residue; an alkali metal atom.
A is an alkylene group having 2 to 4 carbon atoms or a substituted alkylene group, n is 0 or an integer of 1 to 200, and when n is 2 or more, (AO) _n is represented by the following formula (i) ,
It may be a homopolymer composed of one type of repeating unit, or a different substituent A (A ¹ ,
A ² ,...) May be a block polymer or a random polymer composed of two or more types of repeating units. ]