JPS58199877A - Composition and method of preventing corrosion of ferrous metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to corrosion protection of ferrous metals in circulating water and recirculation systems such as cooling towers.

The technical field of the present invention is well developed, and the present invention provides a method for preventing corrosion of metals by combining two phosphonates and adding them to a larger amount of sulfonated styrene-maleic anhydride copolymer. The point is that it has been found that it provides a synergistic effect.

The present invention provides a copolymer of styrene sulfonic acid and maleic anhydride or maleic acid, a water-soluble salt of the copolymer; and (1) 2-phosphonobutane-1,2,4-)
ricarboxylic acid and (2) a blend of two phosphonates consisting of a member of the group of (a) aminotrimethylenephosphonic acid and (b) hydroxyethylidene diphosphonic acid, which inhibits corrosion of ferrous metals in an aqueous system. Compositions and methods.

The results of the standard corrosion test on the heat transfer test piece are shown in the example below.
:/-7 to Ia''m#□121 Off (3) Shows excellent effects when used in combination with a blend of honate.

The amount of the component used is 0.01 to 500 ppm of a copolymer obtained by copolymerizing styrene sulfonic acid or sulfonated styrene with maleic anhydride or maleic acid, or a water-soluble salt of the copolymer, preferably about 7 .5pp-
and (1) 2-phosphonobutane-L2,4-1-licarboxylic acid and (2) a mixture of (a) aminotrimethylenephosphonic acid or (b) hydroxyethylidene diphosphonic acid, totaling about 9.5-10. 21) 9m mixed or blended, preferably the dose of component (1) is about 6.
ppm, the dose of the component (2a) is about 3.5 p
pm, the dose of component (2b) above is 4.2 ppm (based on active ingredient).

At doses of 0.01 to 500 ppm, the ratio of styrene sulfonic acid-maleic anhydride or maleic acid component to total phosphonate component is preferably about 1=1, with 7.5 to 7.5 of the sulfonated styrene maleic acid component. Phosphonate (1) component 6, Phosphonate (2a) component 3.
5 and phosphonate (2b) (4) component 4.2. That is, generally speaking, the preferred dosage in the present invention is a copolymer of styrene sulfonic acid or sulfonated styrene copolymerized with maleic anhydride or maleic acid (or a water-soluble salt of said copolymer).
about 7.5 to 15 ppm mixed or blended with 9.5 to 20.4 ppm of a blend of phosphonate compounds, one of the phosphonates being 2-phosphonobutane-
1,2,4-)licarboxylic acid 6-12 ppm, and the other is aminotrimethylenephosphonic acid (AMP) or hydroxyethylidene diphosphonic acid (HEDP) 3.5-s
, 4ppm.

The raw materials for the compositions of the present invention are those known in the art. νersa, manufactured by Broctor Company (a subsidiary of National Starch)
TL-4 is a copolymer of styrene sulfonic acid and maleic anhydride (Hwa U.S. Pat. No. 4,255,259;
Chemd Grace), and the ratio of styrene sulfonic acid to maleic anhydride in this copolymer is as described in U.S. Pat. No. 4,306,991 (Che+gd Carp).
) It has been found that the ratio is 50 to 95 in percent by weight, and in the present invention, the ratio can be implemented in the range of 25 to 95.

In addition, 2-phosphonobutane-1,2,4-tricarboxylic acid (Bayer PBS-AM) is disclosed in U.S. Patent No. 3886204.
listed in the number.

Furthermore, Dequest 20 is manufactured by Monsanto Company of St. Louis, Missouri, USA.
00 or its equivalent Foxtenox (Fox te
x) U is stated to be aminotrimethylene phosphonate (see Henkel US Pat. No. 3,959,168). Deques L 2010, manufactured by Monsanto Company of St. Louis, Missouri, USA, is described as hydroxyethylidene diphosphonic acid (see US Pat. No. 3,959,168).

Additionally, for techniques relating to phosphonate blends, see Germscheid et al., U.S. Pat. No. 3,959,168.
(Henkel & Cie), (a) 1-hydroxyethane-1,1-diphosphonic acid and its alkali metal and ammonium salts;
C) Phosphonopolycarboxylic acids can be blended and synergism is stated.

U.S. Pat. No. 4,288,327 to Godlewski et al.
Bella Laboratories) teaches sulfonated styrene-maleic anhydride copolymers with a styrene/maleic anhydride ratio of 4:1 to 2:1.

Hwa U.S. Pat. No. 4,306,991 teaches a copolymer of styrene sulfonic acid and maleic anhydride or maleic acid together with a water-soluble organic phosphonic acid compound.

The present invention differs from the blends described above in that it includes as an essential component a blend of styrene sulfonic acid or a similar compound and two phosphonate treatment agents.

In some cases, small amounts of tritriazole (Toly-L
riazole) and diazinod (Diacid)
It has been found that it is effective to add 4 surfactants such as 1550 and Pluronic Shi-62 as additives.

(7) Tritriazole is described in Hackh's Chemical Dictionary, 4th edition, page 91 (hensitriazole).

Pluronic Shi-62 is a dispersant consisting of an ethylene oxide condensate formed by the condensation of propylene oxide and propylene glycol, and is manufactured by BASF Wya
Manufactured by ndotte. Pluronic Shi-62
is commercially available and can be used with a part number grade mark closely related to its composition and is used in the present invention in doses of 1 to 5 ppm (preferably 2.5 ppm). Pluronic-62 can be used at particularly high doses, e.g. 12.5 pp
Sulfonated styrene maleic anhydride (νe
act to promote the dispersion of rsa). Thiazid 1
550 is a trimerized tall oil surfactant manufactured by EIIlery.

The styrene polymers and phosphonates used in the present invention are generally water soluble and are used as water treatment agents. Furthermore, the acid is usually utilized in the form of alkali metal and ammonium salts, and as far as the specification and claims of the present invention are concerned, the term "acid"
shall include these salts as part of the term.

The copolymer of styrene sulfonic acid and maleic anhydride or maleic acid is preferably used as a water-soluble polymer in the following range.

Molecular weight: 1500-20000...Broad: 2
000-15000 ... Suitable Near 000-120
00...Optimum Furthermore, it is preferable that the content of the styrene sulfonic acid moiety in the copolymer is 25 to 95% by weight.

The present invention will be described in detail below, but it goes without saying that the scope of the present invention is not limited to these Examples.

Space below (9) Example” - Dose of active substance (ppm) Red test No. A BC-IDE 5
PBS-AM*1 6 6 6 6 6
HEDp*2 0 0 4.2 4.2
4.2AMP*3 3.5 3.5 0 0
0TT *4 2 2 2 2 ・2
l.

Siajid 1550*5 1.5 1.5 1.5 1.5
0.5 Pluronic L-62' to 6 2.5 2.5 2.5 2.
5 0TL-4*7 0 t2. , g 0
12.5 7.5 15*1 nitricarboxylic acid (
Bayer) *2: Hydroxyethylidene diphosphonic acid (Dequ-
est-2010) *3 Niaminotrimethylene phosphonate (Foxtex
-U) 20 (10) *4 Nitritriazole (TT-100) *5: Surfactant *6: Surfactant *7: Sulfonated styrene maleic anhydride (Sersa
TL-4) Table 1 (continued) Test No., C-2FGHI PBS-AM*1 6 0 0 17
178EDP*2 4.2 6.48 6.4
8 0 0^MP*3 0 0 0
0 0TT *4 2 2 2 2 2 siad 155 (lk5 0.5 0.5 0.5
0.5 0.5 Pluronic L-62*6 0 0 0 0 0TL
-4*7 0 7. ri 0 7.
5 0 Example 2 Mild steel corrosion rate (@PV) Table 2 Sample No., 1234567B Average test No., *A 5.96.02.56.15.24.36.5
4.35.1B 1.40.91.71.50.8
1.21.21.0 1.2C-11,22,03,2
2,42,71,51,11,21,9C-2--4,
13,73,43,02,81,13,0D 1.
41.33.32.20.82.10.90.8 1.
5E --1, 31, 71, 11, 41, 21, 3
1,3F --3,31,91,82,01,72
,02,IG--2,83,11,82,418
2,12,3H--1,53,12,63,42,22
, 32, 51--4, 34, 93, 7-3, 44, 64
,2* A: Bayer PBS-AM, IMJ'
andshi-62*B: Bayer PBS-AM,
AMP, L-62 and Versa (50ppm)
20* C1: Bayer PBS-AM, HEDP
, and L-62* C2: Bayer PBS-^h
and HEDP*D: Bayer PBS-AM,
HEDP, L-62 and Versa (50pp+w
)*E: Bayer PBS-8M, HEDP and Versa (30ppm)*F: HE Kano and Versa (301)I)1m)*G:
HEDP*H: Bayer PBS-AM and Versa
(30ppm) *I: Bayer PB
S-^h Patent applicant Nalco Chemical Company Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Ishi 1) Honorable patent attorney Akira Yamaguchi (13)

Claims (1)

[Scope of Claims] 1. A copolymer of styrene sulfonic acid and maleic anhydride or maleic acid, and a water-soluble salt of the copolymer; and (1) 2-phosphonobutane-1,2,4-tricarboxylic acid and (2) A composition for inhibiting corrosion of ferrous metals in an aqueous system consisting essentially of a blend of two phosphonates consisting of a member of the group of (a) aminotrimethylenephosphonic acid and (b) hydroxyethylidene diphosphonic acid. 2. Claim giA1 using an effective dispersion amount of a dispersant consisting of an ethylene oxide condensate formed by condensation of propylene oxide and propylene glycol
The composition described in Section. 3. The amount of styrene sulfonic acid moiety in the copolymer is 2.
5 to 95% by weight, and the molecular weight of the copolymer is about 1500
20,000. (1) Copolymers of styrene sulfonic acid and maleic anhydride or maleic acid in doses of 4,0.01 to 500 ppa+ and water-soluble salts of said copolymers; and (1) 2-phosphonobutane-1,2, 4-tricarboxylic acid and (2)
A method for treating the water system of a cooling tower to prevent corrosion of ferrous metals with a blend of two phosphonates consisting of a member of the group of (a) aminotrimethylenephosphonic acid and (b) hydroxyethylidene diphosphonic acid. 5. The amount of styrene sulfonic acid moiety in the copolymer is 2.
5 to 95% by weight, and the molecular weight of the copolymer is about 1500
5. A method according to claim 4, wherein the amount is .about.20,000. 6. The dosage is (a) 7.5 ppm of a copolymer of styrene sulfonic acid and maleic anhydride or maleic acid and a water-soluble salt of said copolymer, and (b) 2-phosphonobutane-1,2,4-tricarboxylic acid. 6 ppm and either aminotrimethylenephosphonic acid 3.5 ppm or hydroxyethylidene diphosphonic acid 4.2 ppm. (2)