JPS59102496A - Scale inhibitor - Google Patents

Abstract

PURPOSE:To obtain the titled agent free from phosphor and capable of using effectively together with well-known anticorrosives, by using a copolymer made from a mixture of specific proportions of an unsaturated carboxylic acid monomer, an unsaturated alcohol monomer and other monomers as a main component. CONSTITUTION:An unsaturated carboxylic acid monomer is shown by the formula I (where, each of A<1>, A<2> shows H, methyl and -COOX<2> independently, but is not -COOX<2> simultaneously. A<3> represents H, methyl and -CH2-COOX<3>. In case of -CH2-COOX<3>, each of A<1>, A<2> respectively shows H or methyl independently. X<1>, X<2> and X<3> respectively represent H, a monovalent metal, a divalent metal, -NH4 and an org. amine independently or simultaneously). An unsaturated alcohol monomer is shown by the formula II. A monomer III is possible to copolymerize with the monomers I and II. A copolymer derived from a mixture consisting of 50-99.5mol%>= one kind of monomer I , 0.5-50mol%>= one kind of monomer II and 0-40% monomer III( I +II+III=100%) is used as the main component of the titled scale inhibitor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to scale inhibitors. Specifically, it relates to a scale inhibitor used in boilers, condensers, heat exchangers, gas scrubbing towers, etc.

The heat transfer surfaces of boilers, condensers, heat exchangers, etc., the filling surfaces and piping of gas scrubbing towers, etc., contain cations such as calcium and magnesium, carbonate ions, etc. present in make-up water, cooling water, and collection water. In addition to anions such as bicarbonate ions, sulfite ions, and sulfate ions, zinc ions and phosphate ions caused by corrosion inhibitors are likely to precipitate and form scale. This phenomenon is particularly noticeable in systems that use a refrigerant with a high Ca content of 11 degrees and a high pH value, so-called brine. Such scale adhesion not only increases operating costs due to decreased heat transfer efficiency and increased flow resistance, but also abnormal readings due to scale adhesion to the sensors of various instruments such as thermometers and pH meters. This causes a delay in response speed.

Furthermore, localized corrosion makes it difficult to continue normal operation. Since the attached scale is hard and difficult to remove, the cost required for stopping the operation, removing the scale, etc. is also large.

Conventionally, lignin-based compounds, phosphorus-based compounds, poly(meth)acrylates, and the like have been used as scale inhibitors for the purpose of preventing such scale adhesion. However, the quality of lignin-based compounds is not constant, and as mentioned above, hydrolyzed phosphate ions, including those added as corrosion inhibitors, become scale components when highly concentrated, and furthermore, they are included in blow water. If they are released into closed water systems such as lakes and inland seas, they can cause serious pollution such as blue-green algae and red tide.

Poly(meth)acrylate has received the best evaluation among these conventionally used scale inhibitors, but when highly concentrated, it generates zinc-based and phosphorus-based scales. There are some easy drawbacks. In order to improve the drawbacks of this poly(meth)acrylate, 1. Copolymerize an unsaturated monomer such as hydroxyethyl acrylate with an unsaturated carboxylic acid, and replace some of the carboxyl groups of the polycarboxylic acid with hydroxyethyl ester. A method has been proposed that uses the However, this type of polymer has the disadvantage that its ester bond portions undergo hydrolysis under conditions such as strong acidity, strong basicity, and high temperature, resulting in a loss of performance.

In addition, a method using a copolymer of unsaturated carboxylic acid and allyl alcohol has been proposed, but it is not sufficiently effective because the copolymerizability of unsaturated carboxylic acid and allyl alcohol is not good. Copolymerization in a ratio requires a lot of effort and expense, and is not easy.

The present inventors discovered that a specific unsaturated carboxylic acid monomer and a specific unsaturated alcohol monomer can be easily copolymerized,
Furthermore, the present invention was completed by discovering that the obtained copolymer can be used as an excellent scale inhibitor without the above-mentioned drawbacks. Therefore, the object of the present invention is to
The object of the present invention is to provide an excellent scale inhibitor with no or low phosphorus, which suppresses scale generation even when used in combination with known corrosion inhibitors such as zinc-based and condensed phosphoric acid-based corrosion inhibitors.

That is, the scale inhibitor of the present invention comprises one or more unsaturated carboxylic acid monomers (1) represented by the general formula, and unsaturated alcohol monomers represented by the general formula %. One or more selected from monomers (II) and a monomer a1p copolymerizable with these monomers are combined with unsaturated carboxylic acid monomer (1) 5
0 to 99.5 molar ratio, unsaturated alcoholic monomer Ql)
o, s~50 molar ratio and monomer (e) 0~40 molar ratio (
However, the total of (1), (6) and the amount is 100 moles. ) The main component is a copolymer matrix obtained by using a ratio of

Examples of the unsaturated carboxylic acid monomer (1) used in the present invention include monovalent metals of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and the like. , divalent metals, ammonia, and partially or completely neutralized products with organic amines.

Monovalent metals include sodium, potassium, etc.
Examples of divalent metals include calcium, magnesium, and zinc. In addition, organic amines include alkylamines such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, and triethylamine; alkanols such as monoethanolamine, jetanolamine, triethanolamine, monoisoglobanolamine, and dimethylethanolamine. Amines: Examples include pyridine.

Further, as the unsaturated alcohol monomer (2) represented by the general formula, for example, 3-methyl-3-butene-1
-ol, 3-methyl-2-buten-1-ol, 2-
Examples include methyl-3-buten-2-ol.

The monomer (11) may be added to the resulting polymer based on the total of the unsaturated carboxylic acid monomer (I), the unsaturated alcohol monomer (II), and the monomer fllD, if necessary. Examples of such monomer (e) include styrene, styrene sulfonic acid, vinyl acetate, (meth)acrylonitrile, ( meth)acrylamide, methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)
acrylate, dimethylamine ethyl (meth)acrylate, diethylaminoethyl β-acrylate, 3-
(meth)acryloxy-1,2-dihydroxypropane, -3-(meth)acryloxy-1,2-di(poly)oxyethylene ether propane-3-(meth)acryloxy-1,2-di(poly)oxypropylene Ni-thylpropane, 113-(meth)acryloxy-1゜2-dihydroxypropane phosphate and its monovalent metal salt,
Divalent metal salt, ammonium salt, organic amine salt, or mono- or diester of an alkyl group having 1 to 4 carbon atoms, -3
-(meth)acryloxy-1,2-dihydroxypropanesulfate and its monovalent metal salt, divalent metal salt, ammonium salt, organic amine salt or ester of an alkyl group having 1 to 4 carbon atoms, -3-(meth) ) Acryloxy-2-hydroxypropanesulfonic acid and its monovalent metal salts, divalent metal salts, ammonium salts, organic amines or carbon atoms 1
Esters of ~4 alkyl groups, 53-(meth)acryloxy-2-(poly)oxyethylene ether propane sulfonic acid and its monovalent metal salts, divalent metal salts, ammonium salts, organic amine salts with a carbon number of 1 ~4 alkyl group ester-3-(meth)acryloxy-2-(poly)oxypropylene ether propane sulfonic acid and its 1
Valent metal salts, divalent metal salts, ammonium salts, organic amine salts and esters of alkyl groups having 1 to 4 carbon atoms 3-allyloxyglopano 1,2-diol, 3-allyloxypropane-1, 2-diol phosphate, 3-allyloxypropane-1,2-diol sulfonate, 3-allyloxypropane-1,2-diol sulfate, 3
-Allyloxy-1,2-di(poly)oxyethylene ether propane, 3-allyloxy-1,2-di(poly)oxyethylene ether propane phosphate, 3
-Allyloxy-1,2-cy(poly)oxyethylene ether propane sulfonate, 3-allyloxy-1,2-
Di(poly)oxypropylene ether propane, 3-allyloxy-1+2-di(poly)oxypropylene ether propane phosphate, 3-allyloxy-1,2-
Di(poly)oxypropylene ether globan phosphate, 6-allyloxyhexane-It 2.3.4.5
-Pentaol, 6-arylokydihexane-1.2.3
．． 4.5-pentaol phosphate, 6-allylokydihexane-1.2.3.4.5-pentaol sulfonate, 6-allyloxy-1,2,3,4,5-penta(
Poly)oxyethylene ether hexane, 6-allyloxy-1,2,3,4,5-penta(poly)oxypropylene ether hexane, 3-allyloxy-2-hydroxypropanesulfonic acid and its monovalent metal salt, divalent metal F13-allyloxy-2- ) Oxyethylenepropanesulfonic acid and its monovalent metal salts, divalent metal salts, ammonium salts, or organic amine salts, or phosphoric acid esters or acid esters of these compounds, and their monovalent metal salts and divalent metals salt, ammonium salt or organic amine salt -3-allyloxy-2-(poly)oxypropylenepropanesulfonic acid and its monovalent metal salt, divalent metal salt, ammonium salt or organic amine salt, or phosphoric acid of these compounds Examples include esters or acid esters and their monovalent metal salts, divalent metal salts, ammonium salts, or organic amine salts, 1, and the like.

The amounts of unsaturated carboxylic acid monomer (1) and unsaturated alcohol monomer (6) are as follows: unsaturated carboxylic acid monomer (I), unsaturated alcohol monomer (Iυ and monomer Quantity f
The amounts are 50 to 99.5 molar and 0.5 to 50 molar, respectively, relative to the sum of f1D.

Even if either the unsaturated carboxylic acid monomer (1) or the unsaturated alcohol monomer (6) is out of the above range, the excellent scale inhibitor of the present invention cannot be obtained.

Unsaturated carboxylic acid monomer (1), unsaturated alcohol monomer (II) and monomer (llj to copolymer (4)
Envy can be obtained by conventionally known methods. Examples include polymerization in a solvent such as water, an organic solvent, or a mixed solvent of a water-soluble organic solvent and water. At this time, persulfate, hydrogen peroxide, etc. are used as a polymerization initiator for polymerization in an aqueous medium, and a promoter such as sodium bisulfite or ascorbic acid may be used in combination. For polymerization in an organic solvent, an azo compound, an organic peroxide, or the like is used as a polymerization initiator, and a promoter such as an amine compound can be used in combination. For polymerization in a mixed solvent of a water-soluble organic solvent and water, an appropriate polymerization initiator or a combination of a polymerization initiator and an accelerator can be selected from among the various polymerization initiators described above.

The copolymer (4) thus obtained can be used as it is as a scale inhibitor, but if necessary, it can be further neutralized with an alkaline substance before use. Examples of such alkaline substances include hydroxides, chlorides, and carbonates of monovalent and divalent metals; ammonia; organic amines, and the like.

As the scale inhibitor of the present invention, copolymer (5) is sufficiently effective when used alone, but it can also be used in combination with other additives used in the art.

For example, it can be combined with a phosphorus-free corrosion inhibitor such as molybdenum to form a phosphorus-free water treatment composition. It is also possible to use it in combination with slime inhibitors and chelating agents depending on the needs.

The scale inhibitor of the present invention may be injected quantitatively or intermittently to maintain a constant concentration in the circulating water, for example.
It can be used in the same manner as ordinary scale inhibitors, and sufficient effects are generally observed when the amount added is 1 to 50 ppm.

Hereinafter, the present invention will be explained in more detail with reference to Reference Examples and Examples. In the examples, unless otherwise specified, all parts are by weight, and all brackets are by weight.

Reference example 1 A 5-day flask with an internal volume of 1 ton equipped with a reflux condenser,
380v of pure water and 85g of 3-methyl-3-buten-1-ol were charged, heated to 95°C and stirred. Monomer aqueous solution obtained by neutralizing acrylic acid aqueous solution 2702 with 65f of sodium hydroxide, 20'l ammonium persulfate aqueous solution 1002 and 20% hydrogen peroxide aqueous solution 10
Of was added dropwise from separate dropping ports over a period of 4 hours to carry out a copolymerization reaction. Thereafter, it was cooled and neutralized by adding 182 mL of a 40#I sodium hydroxide aqueous solution. The molecular weight of the water-soluble copolymer (]) thus obtained was 3,200. Moreover, the yield based on all the monomers charged was 93%.

In order to know the copolymerization ratio of the obtained water-soluble copolymer (1), K
The aqueous solution was dried under reduced pressure at 120° C. to remove unreacted unsaturated alcohol, and the resulting dry water-soluble copolymer (1) was converted into butyl ester using n-butanol and sulfuric acid according to a conventional method. The composition ratio of 3-methyl-3-buten-1-ol in the water-soluble copolymer (1) estimated from the OH group analysis value in the butyl ester compound was 33 moles φ (preparation composition ratio 3
5 moles).

Reference Example 2 In Reference Example 1, pure water 3302.3-methyl-3-buten-1-ol 359.4B acrylic acid aqueous solution 35
A copolymerization reaction was carried out in the same manner as in Reference Example 1 except that 0v and sodium hydroxide 822 were used. Thereafter, 20 f of a 45% sodium hydroxide aqueous solution was added to neutralize the mixture. The molecular weight of the water-soluble copolymer (2) thus obtained was 3.7.
It was 0Q.

The composition ratio of 3-methyl-3-buten-1-ol in the water-soluble copolymer (2) was 14 moles (compared to a charging ratio of 15 moles).

Reference Example 3 Pure water 3302 was charged into the same reaction vessel as used in Reference Example 1, heated to 95°C, and stirred. Mixed monomer aqueous solution in which 3-methyl-2-buten-1-ol 12f was dissolved in a monomer aqueous solution obtained by neutralizing with IJium 911 (hydroxidized to 48 thiacrylic acid aqueous solution 3901), 20 An aqueous ammonium persulfate solution of 507 mm and a hydrogen peroxide aqueous solution of 20 mm were added dropwise from separate dropping ports over a period of 4 hours to carry out a copolymerization reaction.

The molecular weight of the obtained water-soluble copolymer (3) was 4,000. Still, 3-methyl- in the water-soluble copolymer (3)
The composition ratio of 2-buten-1-ol is 5 molar ratio (preparation ratio 5
It was (Moru).

Comparative Reference Example 1 Copolymerization was carried out in the same manner as in Reference Example 1 except that crotyl alcohol (2-buten-1-ol) 857 was used instead of 3-methyl-3-buten-1=ol used in Reference Example 1. The reaction was carried out.

The composition ratio of crotyl alcohol in the obtained water-soluble copolymer (4) was only 19 molar ratio (charged composition ratio: 40 molar ratio).

Comparative Reference Example 2 2-Methyl-4-penten-2-ol 859 instead of 3-methyl-3-buten-1-ol used in Reference Example 1
A copolymerization reaction was carried out in the same manner as in Reference Example 1 except that .

The molecular weight of the obtained water-soluble copolymer (5) was 3,300. Still, 2- in the obtained water-soluble copolymer (5)
The composition ratio of methyl-4-penten-2-ol was only 14 moles (32 moles).

Reference Example 4 In the reaction vessel used in Reference Example 1, pure water 3607, disodium maleate 75f and 3-methyl-3-butene-1-
All 302 was charged, heated to 95°C, and stirred. 4
8. Acrylic acid aqueous solution 230? Sodium hydroxide 55
? A monomer aqueous solution obtained by neutralization by adding 1,502 mm of ammonium persulfate solution, and 100 f of a 20 mm hydrogen peroxide aqueous solution were each added dropwise from separate dropping ports for 4 hours to carry out a copolymerization reaction, and then cooled. , 40% sodium hydroxide aqueous solution 15F was added to neutralize.

The molecular weight of the obtained water-soluble copolymer (4) was 3.500. Furthermore, the composition ratio of 3-methyl-3-buten-1-ol in this water-soluble copolymer (4) was 14.5%A.
1 (composition ratio of 15 moles).

Reference Example 5 3237 of pure water and 239 of 3-methyl-3-buten-1-ol were charged into the reaction vessel used in Reference Example 1, and the mixture was heated to 95°C and stirred. 48 acrylic acid aqueous solution 3062, methyl acrylate 352.50 sodium hydroxide 163
f, 20% persulfuric acid polymerization reaction was performed.

The molecular weight of the obtained water-soluble copolymer (5) was 3,400.

Examples 1-5 Capacity 225 ml! Pour 170f of water into a glass bottle, add 1.56% aqueous solution of calcium chloride dihydrate 109, and water-soluble copolymers (1) to (5) obtained in Reference Examples (1) to (5).
) of 0.02'1 aqueous solution of 1f, 5 or 101
ppm or lOppm), and further add and mix 102 of a trivalent sodium bicarbonate aqueous solution, and then seal the resulting supersaturated aqueous solution of 530 ppm of calcium carbonate.
Heat treatment was performed at 70°C for 3 hours. After cooling, the precipitate was filtered through a 0.45μ membrane filter, and the filtrate was analyzed according to JIS Kolol. The results are shown in Table 1.

Comparative Example l The water-soluble copolymer used in Example 1 had a molecular weight of 5.
Example 1 was repeated except that 000 sodium polyacrylate was used. The results are shown in Table 1.

Comparative Example 2 Example 1 was repeated except that sodium tripolyphosphate was used instead of the water-soluble copolymer used in Example 1.

The results are shown in Table zK.

Comparative Example 3 Example 1 was repeated except that the water-soluble copolymer was not added. The results are shown in Table 1.

Examples 6 to 10 Calcium chloride dihydrate 45.
Add 145f of 6% aqueous solution, then refer to Examples (1) to (
The water-soluble copolymer obtained in 5) (0 of each of υ to (5)
．． 02 aqueous solution at 52.30F or 502 (5 ppm, 30 ppm or 50
ppm), mix, add sodium hydroxide' aqueous solution as needed to adjust the pH to 10.0, and add water to bring the total volume to 200.
f and was used as a test aqueous solution. This was stored at 20° C. for 30 days, and the precipitate was filtered through a 0.1 μ membrane filter, and after drying, the weight of the precipitate was measured. The results are shown in Table 2.

Comparative Example 4 Instead of the water-soluble copolymer used in Example-, molecular weight s,
Example 2 was repeated except that ooo sodium polyacrylate was used. The results are shown in Table 2.

Comparative example 5 Comparative example of the water-soluble copolymer used in Example
6.

Procedural amendment document March 1980/ξ Japan Patent Office Commissioner Kazuo Wakasugi 1, Indication of the case Patent application No. 212718 of 1983 2, Name of the invention Scale inhibitor 3, Person making the amendment Patent applicant Osaka 5-1 Koraibashi, Higashi-ku, Osaka, Japan (462) Representative Director of B Hon Shokubai Chemical Industry Co., Ltd.
Mr. Ishikawa, Department 4, Agent Address: 1-2-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo, Japan 5, Nippon Shokubai Chemical Co., Ltd., Tokyo Branch Office 5, Name of the invention and detailed description of the invention in the specification to be amended Section 6, Contents of the Amendment 111 Mei #I, No. 1, the title of the invention section "Kesur inhibitor" is amended to read "scaling inhibitor".

(2) Page 15, line 10, “jk body ice water solution...” is replaced with “jk body ice water suspension,
"..." I corrected myself.

(31, page 17, line 4, "Mixed monomer aqueous solution, ..." is corrected to "Mixed monomer aqueous suspension, ...".

(4) On page 18, line 17, "monomer aqueous solution, . . ." is corrected to "monomer aqueous suspension, . . .".

(Insert the following statement between the 5th line from the bottom and the 4th line from the bottom on page 19 of 51.

[Reference Example 6 26511 of pure water and 2422 of 3-methyl-3-buten-1-ol were charged into the reaction vessel used in Reference Example 1, and the mixture was heated to 95°C and stirred. 113 y of acrylic acid is reacted with 330 ml of sodium hydroxide, and then 2 y of sodium 2-hydroxy-3-allyloxypropanesulfonate is added.
4f and 3-methyl-3-buten-1-ol 242
mixed monomer liquid, 20% ammonium persulfate aqueous solution 100F and 20% hydrogen peroxide aqueous solution 100F
F was added dropwise from separate dropping ports over a period of 4 hours to carry out a copolymerization reaction. Thereafter, it was cooled and neutralized by adding 209 ml of a 35% sodium hydroxide aqueous solution.

The resulting water-soluble copolymer (6) had a molecular weight of H3500. (6) Page 20, line 4, ``Add 1 liter of the 3rd grade aqueous solution and mix...'' to 13
Add 10F aqueous solution and water to make a total volume of 200F and mix...''.

(7) Insert the following statement below line 7 on page 22.

Examples 11 to 13 50f of water was placed in a glass bottle with a capacity of 225 ml, and each of the water-soluble copolymers (1), (2), and (6) was
．． 02 or 102 (5 ppm or 10 ppm based on the supersaturated aqueous solution obtained), and then 2 or 2 or 0.083% zinc chloride aqueous solution (4 ppm as Zn).
m), calcium chloride 0.222% aqueous solution xof
(40ppm as Ca), orthophosphoric acid 0.0103%
Aqueous solution 1or (5ppm as PO4) and 0.168
4 Sodium bicarbonate (60ppm as C03) 10f
was added and mixed, 0.0IN sodium hydroxide was added to adjust the pH to 8.0, water was added and the total volume was adjusted to 2002
And so.

The obtained supersaturated aqueous solution was sealed and heat-treated at 65° C. for 40 hours. After cooling, the precipitate was reduced to 0.45μ
It was filtered through a membrane filter, and the zinc in the ν liquid was quantified to determine the scale inhibition rate. The results are shown in Table 3.

Comparative Example 7 Examples 11-13 were repeated except that sodium polyacrylate having a molecular weight of 5,000 was used as the base of the water-soluble copolymer used in Examples 11-13. The results are shown in Table 3. (8) In Table 1 on page 23, ``Anti-scaling agent'' in the first row from the top and second column from the left is corrected to ``Anti-scaling agent''.

(9) Insert the following statement below Table 2 on page 24.

"Table 3 Scale suppression effect in highly concentrated cooling water model (Note 2) Suppression rate = -X100 (correspondence) A: Zn concentration in test liquid before heating treatment (=4.0) B
: 210 degrees in F liquid after heating treatment

Claims (1)

[Claims] 1. One or more unsaturated carboxylic acid monomers (1) represented by the general formula %, unsaturated alcohol monomers (1) represented by the general formula One or more selected from 6) and a monomer (a) copolymerizable with these monomers are combined with an unsaturated carboxylic acid monomer (1) of 50 to 99.5 molar proportion, Saturated alcoholic monomer (II) O,, s ~ 50 molar ratio and monomer (ill O ~ 40 molar ratio (however, (I)
, (II) and (III) in a ratio of 100 mol.