JPS62205183A - Stabilized thick composition for anti-freeze liquid based onphosphoric acid and aqueous cooling liquid composition containing the same - 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 1. Technical Field of the Invention The present invention relates to a phosphoric acid-based antifreeze/coolant concentrate formulation containing an anti-settling stabilizer and an anti-settling agent. Aqueous, phosphoric acid-based antifreeze/coolant formulations containing stabilizers. More particularly, the present invention comprises at least one anti-settling stabilizer, which stabilizer comprises hydrocarbon aminophosphonic acids and/or alkali metal salts of said acids, phosphinopolycarboxylic acids and/or said acids. The present invention relates to a phosphoric acid-based water-soluble liquid alcoholic antifreeze/coolant composition selected from the group consisting of alkali metal salts and polyacrylic or polymaleic acids and/or alkali metal salts of said acids. These stabilizers are particularly useful in preventing precipitation of insoluble alkaline earth metal salts in phosphoric acid-based antifreeze/coolant formulations where the formulations are diluted with hard water.

Automotive engine cooling mechanisms are made of copper, solder, brass,
Comprised of a variety of metals including steel, cast iron and aluminum.

Due to the presence of various ions as well as the high temperatures, pressures and flow rates found in such cooling systems, the potential for corrosion of such metal chains is high; the presence of corrosion products within the cooling system can cause It may also impede heat transfer from the combustion chamber, which in turn may cause engine overheating and damage to engine parts due to excessive increase in metal temperature. To prevent these problems, various organic and inorganic compositions have been used as corrosion inhibitors in engine antifreeze/coolant formulations, including various phosphate compounds. Generally, R, H,
Fay, R, H, ノ ``Anti-Freezes 1・
and the icing fluids” (Kirkuosmah Encyclopedia of Chemical Technology, 1978 edition, Vol. 3, pp. 79-95) [Antif
reezes and deicing fluids,
” In: Kirk-Othmer Enc cl.
O-edia of Chemical Techno
lo (i978ed,).

Vat, 3. pp, 79-95. ] can be referenced.

Antifreeze/coolant formulations are typically diluted with water before use in an automobile engine cooling system. However, in many regions only hard water is available to dilute antifreeze/coolant; water hardness is a function of the concentration of dissolved calcium and magnesium salts contained in the water, and is usually expressed as CaCO3 total hardness. , concentration (ppm)
Indicated by Hard water is defined here as water with a CaCO3 total hardness of more than 150 Pp++.

It has been observed that diluting phosphoric acid based antifreeze/coolant formulations causes the formation of insoluble alkaline earth gold FA salts. Although certain calcium and magnesium silicates also precipitate from aqueous antifreeze solutions, these insoluble salts are primarily calcium and magnesium phosphates. These sediments are caused by two reasons:
First, the precipitates are alkaline earth metal phosphates and/or silicates that adversely affect antifreeze/coolant formulations and engine cooling mechanisms, thereby reducing the corrosion-inhibiting properties of the formulation. Second, the settling solids can form scales that can eventually block the flow passages of the engine cooling system, thereby reducing the amount of power transmitted from the engine combustion chamber. Heat is impeded and the resulting excessive increase in metal temperature can cause engine overheating and damage to engine parts.

Therefore, 1% i% per month of alkaline earth metal insoluble salts in phosphoric acid-based antifreeze/coolant formulations diluted with hard water.
111th floor 1st grade, every eggplant is Dehirada, LF Rokuko II Ya. It is an object of the present invention to provide a phosphoric acid-based antifreeze/coolant formulation that prevents the formation of such insoluble salt precipitates when hard water is used to dilute the antifreeze/coolant mixture. It is about providing.

2. Disclosure of the Prior Art The present invention was diluted with hard water. In phosphoric acid based antifreeze/coolant formulations. Insoluble alkaline earth metal phosphoric acid 1p and/or silicic acid 11! Aminophosphonic acid/aminophosphonate, phosphinopolycarboxylic acid/polycarboxylate, polyacrylic acid/polyacrylate and/or polymaleic acid/polymaleate compositions as stabilizers to prevent the formation of precipitates. or the use of mixtures thereof. References disclosing other uses of similar compounds are:

U.S. Pat. No. 4,387,027 discloses that 6-30 ppm of water-soluble orthophosphate is added to water-soluble acrylic acid/salt or water-soluble hydroxyalkyl acrylic acid 111 copolymer 3
Discloses a method for corrosion inhibition and sedimentation control in iron-containing aqueous systems by adding with ~25 ppm.

U.S. Pat. No. 54,333,843 teaches corrosion 6-, +
j: an effective amount of an alkali metal silicate and an effective amount of an organophosphorus-silicon compound to reduce the amount; (RO) 3
-S i (CH2)n--O-P (0)(CH,
)-OR (wherein R represents an alkyl group of 01 to C4, and n is 1
It is an integer of ~4. ) discloses an anti-gelling aqueous glycol composition comprising:

U.S. Pat. No. 4,329,243 describes glycols, conventional corrosion inhibitors, and phenylene+C1-C6 alkylene, or these groups substituted with hydroxy, amino, PO3R2, or polyamino/polyalkylene groups. A cavitation-inhibiting cooling and/or heat transfer fluid is disclosed comprising a phosphonic acid which may contain phosphonic acids.

U.S. Patent No. 4,328,180 discloses that boriaglylic acid 0
, 3-3, 0 ppm+, tartaric acid o, i-1, 0
ppm, sodium sulfonate dispersant 0.1-2
, 0 ppm, mixture of organic phosphonic acid esters 0
．． 1-1,0 ppm, phosphate ester dispersant 0.
by adding 5-3.0 ppm, 3-40 ppm of inorganic phosphate and 0.1-1 Oppm of aromatic triazole. A method for inhibiting corrosion and controlling settling of calcium carbonate-containing scales in a cooling water system is disclosed.

U.S. Patent No. 4,320,025 discloses water, glycol,
and 0.005 to 0-2% by weight of at least one phosphonocarboxylic acid containing at least two carboxylic acid groups.
A cavitation-inhibiting antifreeze cooling and/or heat transfer fluid is disclosed.

U.S. Pat. No. 4,320,023 contains 50 to 500 ppm of ethylene glycol and alkylene diphosphonic acid useful for inhibiting precipitation of aluminum corrosion products in engine cooling systems. U.S. Pat. No. 4,277.3
No. 59 is a scale and corrosion inhibitor for use in aqueous systems consisting of a water-soluble polyacrylic acid having a molecular weight of about 2,500 or less, phosphorous acid and its salts, and a carboxylic acid chelate having at least one hydroxyl 2'L substituent. Disclosed.

U.S. Pat. No. 4,076.501 discloses a corrosion inhibitor for use in aqueous systems comprising the use of an aminophosphonic acid, wherein the aminophosphonic acid is
1 is a linear C1-C3 alkyl group, a C3-C5 alkenyl group having a double bond not adjacent to N, a tolyl group, a benzyl group, or a cyclohexyl group. ) is disclosed.

U.S. Pat. No. 3,960,576 discloses a scale and corrosion inhibitor for use in aqueous systems consisting of a water-soluble alkali metal oxide/silicate, an organic phosphonate, and a carboxymethyl cellulose. .

``Numa 4 hair loss pit't Q, 112 7Q Kuu deaf l
+ Us now 41^ in corrosion inhibition and scale reduction/mitigation compositions for use in automotive and diesel engine cooling systems using silicates containing anti-corrosion formulations. Discloses a composition comprising an effective amount of a polymeric dispersant which is a water-soluble polycarboxylic acid having an average molecular weight ranging from 1.000 to i,ooo,ooo in an amount of 1 to 10% by weight. There is.

US Pat. No. 3,837,803 comprises a water-soluble organic or inorganic orthophosphate along with a water-soluble organic phosphonic acid or salt thereof. Corrosion inhibiting compositions for use in aqueous systems containing soluble calcium salts are disclosed.

U.S. Pat. No. 3,663,448 consists of about 1 part by weight of an aminophosphonate salt and about 0.5 to 0.5 parts by weight of a water-soluble polyacrylic acid or polyacrylamide having a molecular weight in the range of 500 to 12,000. , discloses compositions useful for inhibiting alkaline earth metal scale sedimentation in aqueous systems.

and APIΦ Oilfield Chemicals Abstracts Volume 29, Paragraph Fl 173 (i9
October 1982) [API 0ilfieldChe
n+1cals Abstract, vat, 2+
3. paragraphF1173 (Oct, 1
982)], German patent DE 3,044, which discloses the use of phosphono-polycarboxylic acids containing unsaturated monocarboxylic and dicarboxylic acid units for use in inhibiting mineral scale formation and sedimentation in aqueous systems. 2
There is a description of No. 14.

The present invention provides novel, anti-settling, phosphoric acid-based antifreeze/coolant e-condensate compositions and aqueous, anti-settling, phosphoric acid-based antifreeze/coolant compositions. The concentrate is hard water (here, 150 p as CaCO3 total hardness).
(defined as water above pm). This novel phosphoric acid-based antifreeze/coolant concentrate, when diluted with hard water, remains a stable composition that inhibits the formation of insoluble precipitates that are detrimental to internal combustion engine cooling mechanisms. was discovered.

The antifreeze/coolant concentrate composition of the present invention comprises a water-soluble liquid alcohol freezing point depressant, preferably 80-99% by weight of ethylene glycol, preferably 90-99L% by weight;
Phosphorus-containing corrosion inhibitors such as H3po, or 2HPO4 from 0.1 to 15.0 LI! Amount%, preferably 0.1-5
．． 0% by weight, and (i) a hydrocarbon aminophosphonic acid and/or an alkali metal aminophosphonate or a mixture thereof, wherein the hydrocarbon aminophosphonic acid represents an alkylene group of the formula: ,OH.

PO(OH)2, NH2, or N[R-PO(OH)
)2 ] 2, and Xz and x3 are N [R-PO
(OH) 2 ] 2 or 4*representing PO(OH) 2 ); , the phosphinopolycarboxylic acid is 200-
2.000, preferably in the range of 300 to 1,500, and of the following formula: where m+n has a value of about 2 to 20, preferably about 4 to 16. n) h, # :! Is 4 gov+, 1&yrfii
i) polyacrylic or polymer 1/in alcohol and/or alkali metal salts of said acids or mixtures thereof, wherein said acids or salts have a molecular weight in the range of 500 to 10,000, preferably 500 to 6,000; 100-5,000 ppm, preferably 100-5,000 ppm of at least one sedimentation-inhibiting stabilizer selected from the group consisting of J, H
Consisting of 2,000 ppm.

The aqueous, phosphoric acid-based antifreeze/coolant composition of the present invention is as described above, diluted with 10-90% by weight of hard water, preferably 25-75% by weight.

It consists of a phosphoric acid-based antifreeze/coolant concentrate composition. The aqueous antifreeze/coolant compositions exhibit improved stability compared to aqueous, phosphoric acid-based antifreeze/coolant Ml acids that do not contain any of the anti-settling stabilizers described above.

The novel, anti-settling, stabilized, phosphoric acid-based antifreeze/cooling concentrate composition of the present invention comprises a liquid alcohol freezing point depressant, a phosphorus-containing corrosion inhibitor, and hydrocarbon aminophosphonic acid and/or alkali gold IN? 5 aminophosphonates or mixtures thereof, phosphinopolycarboxylic acids and/or alkali metal phosphinopolycarboxylic acids or mixtures thereof, or polyacrylic or polymaleic acids and/or alkali metal salts of the acids. It consists of at least one anti-sedimentation stabilizer which is a mixture of these.

The liquid alcohol freezing point depressant component of the antifreeze/cooling application e-condensate composition of description 1& may be a glycol or glycol ether. In the present invention, glycol ethers used as main components include glycols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol, as well as methyl, ethyl, and Includes glycol monoethers such as propyl and butyl ethers. The liquid alcohol freezing point depressant component may be used at a concentration of 80-99% by weight, preferably 90-99% by weight. As a liquid alcohol freezing point depressant component.

Particularly preferred is ethylene glycol.

The phosphorus-containing corrosion-inhibiting component of the antifreeze/coolant composition described above may be any phosphorus-containing compound used in addition to the liquid alcohol freezing point depressant described above. .0% by weight, preferably o
, i may be used at a concentration of ~5.0% by weight* HsP
O4 and 2HP04 are particularly preferred as phosphorus-containing corrosion inhibiting compounds for use in the present invention.

The hydrocarbon aminophosphonic acid component of the antifreeze/coolant composition described above has the following linear formula: (wherein R represents a substituted or unsubstituted alkylene group of 01 to G, and xl is HlOHlPO(OH). N.H.
2, or N [R-PO(OH)2 ] 2 , and x2 and x3 are N [R-PO(OH) 2 ] 2
or PO(OH) 2 ) ゛0 Examples of hydrocarbon aminophosphonic acids suitable for use as anti-sedimentation stabilizers in the present invention are: diethyl 1/triaminebenta Kiss (methylene phosphonic acid); Ethylenediaminetetra (methylene phosphonic acid); N-
(hydroxyethyl)-N-bis(methylenephosphonic acid); hexamethylenediamine-N,N,N',N'-tetra(methylenephosphonic acid); and nitrilotris (methylenephosphonic acid).

It was derived from the 7-minophosphonic acid described above.

Also alkali metal aminophosphonates. They may be used in the antifreeze/coolant compositions of the invention, and sodium aminophosphones are particularly preferred. As l♂ niaminophosphonic acids and aminophosphonates suitable for use, Wayplex 45K (:Wayplex 45K) (
zChilenediami7-N,N.

N',N'-tetra(methylenephosphonic acid)
Co,) to the city 1 roll, and Briquest 543-33 S (Briquest 543-
33S) (diethyleneaminopentakis-(methylenephosphonate)sodium),
Series product name, Albright & Wilson (Teneco Company) (Albright & Wilson)
Wilson (a Ter+neco Compan
y) Approximate concentrations of the above-described hydrocarbon aminophosphonic acids and/or aminophosphonates or mixtures thereof that may be used in the antifreeze/coolant Ml acids of the present invention, including those available from ) is about 100pp
ff1~5. OOOppm, preferably about 100
ppm ~2,000 ppm.

The phosphinopolycarboxylic acid component of the antifreeze/coolant composition described above can be represented by the linear formula: where m+n has a value of about 2 to 20, preferably about 4 to 16. . The molecular weight of 8A phosphinopolycarboxylic acid is 200 to 2.000, preferably 300 to 1
,500. Alkali metal phosphinopolycarboxylic acids 1M derived from the phosphinopolycarboxylic acids described above may also be used in the antifreeze/coolant compositions of the present invention, with sodium phosphinolycarponate being particularly preferred. The polycarboxylic acids and/or salts are contained in an amount of ioo to 5,000 ppm, preferably 1
More tortoise exists in the concentration range of 00 to 2,000 ppm,
Phosphinopolycarboxylic acids and polycarboxylic acid salts suitable for use include Belsper 161 (Belsper
se IEII) and Belcle 500 (Belcle
Ciba-Geigy (Ciba-Geigy) under the product names of the Velsparse and Velklen series, such as
igy Carp, ).

The polymaleic acid stabilizer component of the present invention has a molecular weight of 500 to 10.
000, preferably in the range of 500 to 6,000. Alkali metal polymaleic acid derived from the polymaleic acid described above 147. Polymaleic acids and/or salts may also be used in the antifreeze/coolant of the present invention, with sodium polymaleate being particularly preferred. You can do it.
Polymaleic acid sodium salts are particularly preferred, and polymaleic acid sodium salts suitable for use include Belklein 2
01, which is commercially available from Ciba Geigy under the trade name of the Bergkren series.

The undeveloped polyacrylic acid and/or alkali metal polyacrylate stabilizer component contains about 500 to 10,000
0, preferably polyacrylic acids and/or polyacrylates having a molecular weight in the range of about 500 to 6,000 0 Sodium polyacrylates are particularly preferred for use in the present invention, preferred for use Sodium polyacrylates include Good-rit
e) K-732, Ni-739, Ni-752 and Ni-75
Product names of Gutudrite series such as 9, B, F,
Gutdrich Company (B, F.

Goodrich Company. The approximate concentration of the above-described polyacrylic acid and/or polyacrylate salt that may be used in the present invention is about 100 ppm~s,oo.

ppm, preferably about 100-2. It is OOOppm.

Further corrosion inhibitors suitable for use in the present invention include hydrocarbon azoles, preferably aromatic triazoles or alkyl-substituted aromatic triazoles, such as benzotriazole or tolyltriazole, or
Mercaptobenzothiazole sodium. The most preferred azole for use is tolyltriazole, where the approximate concentration of the hydrocarbon azole component is about 0.1 to 0.5% by weight, preferably about o. i~0.3% by weight.

One or more conventional corrosion inhibitors may also be used in the antifreeze/coolant formulations described above. Such conventional corrosion inhibitors may be used in concentrations of 0.01 to 5.0% by weight and include alkali metal borates, alkali metal silicates, alkali metal benzoates, alkali metal nitrates. , alkali metal nitrites and alkali metal molybdates.

In one embodiment of the present invention, the antifreeze solution/
'Cold power J liquid river condensate M1 composition is hard water defined here as water having a concentration of more than 150 PPm as one hard CaCO3i hard water 10-90% by weight h1%, preferably 25-75%
Diluted by ball amount%. The stabilizer component of the antifreeze/coolant composition described above in 1& acts to stabilize the phosphate and/or silicic acid j1! contained in the antifreeze/coolant formulation. Corrosion inhibitor ions are prevented from forming insoluble precipitates with alkaline earth metal ions (particularly calcium and magnesium ions) introduced into the antifreeze/coolant composition via the hard water.

The method of the present invention will be illustrated more specifically by the following examples, which are not intended to limit the invention, but rather to clearly illustrate the invention. .

Also, most of blood consists of ethylene glycol, H3 PO4
1, l 2Lmffi% and sodium metasilicate 5
0.3% by weight of hydrate and the pH of the formulation was approximately 10.5.
An antifreeze formulation containing a sufficient amount of KOH to correct the conditions was prepared by diluting the formulation with hard water corresponding to approximately 200 ppm of CaCO3 total hardness. Aqueous formulation at 90°C
for 10 minutes and cooled to room temperature. - White flocs settled from aqueous antifreeze formulations after standing overnight
Substance observed.

In the aqueous antifreeze formulation of Example 1, an aminophosphonate, namely diethylenetriaminepentakis-(methylenephosphophone I% I) sodium (Bricues) 543-33S) was added to the aqueous antifreeze formulation of Example 1.
2,000 ppm was added.

The formulation was heated to 90''C for 10 minutes and then cooled to room temperature.-After standing overnight, the formulation was observed to be clear and no flocs or sediments were observed.

The aqueous antifreeze formulation of Example 1 was treated with ethylenediamine aminophosphonate-N,N,N',N'-tetra(methylenephosphonic acid) (heated to Wavelex °C for 10 minutes, then Cooled to room temperature. - After standing overnight, the formulation was observed to be clear and no flocs or sediments were observed.

L51 To the antifreeze formulation of Example 1 was added 200 ppm of sodium polyacrylate (Gudolite -732) having a molecular weight of approximately 5.100. Mixture at 90℃
for 10 minutes, then cooled to room temperature. - After leaving it overnight,
The formulation was slightly cloudy, but no flocs or sediment formed.

To the antifreeze formulation of Example 1 was added 200 ppm of sodium polyacrylate (Gudolite -732) having a molecular weight of approximately 5.100. 1. Bring the aqueous formulation to 90°C. Heated for 0 minutes and then cooled to room temperature. - After standing overnight, the formulation was observed to be clear and no flocs or sediments were observed.

q17 fk lftd Q To the antifreeze formulation of Example 1, add 100 pp of an aminophosphonate, i.e., sodium diethylenetriaminepentakis-(methylenephosphonate) (Brequest 543-33 S).
m, and 50 ppm of sodium polyacrylate (Gutudrite K-739) with a molecular weight of about 5,100,
Polyvinylpyrrolidone with a molecular weight of approximately 10,000 1.00
Added with 0 ppm. The aqueous formulation was heated to 90°C for 10 minutes, then cooled to room temperature. - When the formulation was observed after late fermentation, it was clear and no flocs or sediments were observed.

Disaster Coverage-1 The antifreeze formulation of Example 1 was added with 100 ppm of sodium polyacrylate (Gudolite-732) having a molecular weight of about 5.100 and ethylenediamine aminophosphonate-N,N,N',N'-tetra( methylene phosphonic acid) (Wayplex 45K) 100 pp
Added m. Heat the aqueous formulation to 90°0 for 10 minutes
It was then cooled to room temperature. - After 1δ late growth, the formulation was observed to be clear and no flocs or sediments were observed.

Shohou 1 To the antifreeze formulation of Example 1 was added 400 ppm of a phosphinopolycarboxylic acid (Velspers 161) having a molecular weight of about 1.200. 90% water-based formulation
Heat the IO molecules to 'O' and then cool to room temperature.

- After standing overnight, the formulation was observed to be clear and no flocs or sediments were observed.

Sodium polymaleate (free acid molecular weight approximately 800) (Berklein 201) was added to the antifreeze formulation of Example 1. The aqueous formulation was heated to 90°C for 10 minutes, then cooled to room temperature. - After late incubation, the formulation was slightly cloudy, but no flocs or sedimentation was observed.

Kogobanyu” It consists mostly of ethylene glycol.

K2HPO4 4.0% by weight and tolyltriazole 0.
An antifreeze formulation containing 2% by weight was prepared. The formulation, C
It was diluted with hard water corresponding to about 225 ppm total aCO3 hardness. The aqueous formulation was heated to 90° C. for 10 minutes and then cooled to room temperature. After cooling, large amounts of flocs were observed in the aqueous formulation.

To the aqueous antifreeze formulation of Example 10 was added 500 ppa+ of diethylenetriaminepentakis-(methylenephosphophone#) sodium (Brequest 543-33S).

The formulation was heated to 90°C for 10 minutes and then cooled to room temperature. - After standing overnight, the formulation was observed to be clear and no flocs or sediments were observed.

Fire Muwariyu 1 The aqueous antifreeze formulation of Example 11 had a molecular weight of about 5.100.
Sodium polyacrylate (Gutudrite-732)
) 100 ppm was added. The formulation was heated to 90°C for 10 minutes and then cooled to room temperature. - No flocs or sedimentation was observed after standing overnight.

It is shown that insoluble salts precipitate from the coolant formulation when the formulation is diluted with hard water. This is probably due to ions of phosphorous salts and silicates contained in the antifreeze/coolant and ions of alkaline earth metals (particularly calcium and This is due to the interaction with magnesium ions).

Examples 2.3 and 11 show that when a phosphoric acid-based antifreeze/coolant formulation is diluted with hard water, the presence of the hydrocarbon aminophosphonic acid and/or sodium aminophosphonate reduces the insolubility in the antifreeze/coolant formulation. It has been shown to be effective in preventing the formation of sediment.

Example 8 shows that when a phosphoric acid-based antifreeze/coolant formulation is diluted with hard water, the presence of phosphinopolycarboxylic acid and/or sodium phosphinopolycarboxylate reduces the amount of undissolved precipitate in the antifreeze/coolant formulation. Examples 4 and 5 show that polyacrylic acid with a molecular weight of about 5.100 and/or The presence of the poly-7storium acrylate stabilizer has been shown to be effective in preventing the formation of insoluble precipitates in the antifreeze/coolant.

Example 9 shows that when a phosphoric acid-based antifreeze/coolant formulation is diluted with hard water, the presence of polymaleic acid and/or sodium polymaleate (with an LJ acid molecular weight of approximately 800) increases the It has been shown to be effective in preventing the formation of insoluble precipitates.

Examples 6.7 and 12 show that when phosphoric acid-based antifreeze/coolant formulations are diluted with hard water, hydrocarbon aminophosphonic acids and/or sodium aminophosphonates are added to polyacrylic acid having a molecular weight of about 5.100. The presence in combination with and/or sodium polyacrylate has also been shown to be effective in preventing the formation of insoluble precipitates in the antifreeze/coolant.

[of the present invention] - In the described embodiments, the stabilizing effect of the stabilizer exhibited by the present invention is inhibited even if a conventional corrosion inhibitor such as tolyltriazole polyhinylpyrrolidone is additionally present. It should be noted that this is not the case.

It is clear that the words and expressions used herein are used for elaboration and not for limitation. In the use of these descriptive words and expressions, there is no intention to exclude the described features and expressions, and it is recognized that various modifications may be made within the scope of the claims of the invention. .

Claims (1)

[Scope of Claims] 1. An antifreeze concentrate composition comprising a water-soluble liquid alcohol freezing point depressant and a phosphorus-containing corrosion inhibitor, the composition comprising 80 to 99% by weight of the freezing point depressant and a phosphorus-containing corrosion inhibitor. 0.1 to 15% by weight of an inhibitor, and (i) the following formula: ▲Mathematical formula, chemical formula, table, etc.▼ (In the formula, R represents a substituted or unsubstituted alkylene group having 12 or less carbon atoms, X_1 is a hydrogen atom, a hydroxyl group, an amino group, a -PO(OH) group, or -N[R-PO
(OH)_2]_2 group, and X_2 and X_
3 is -PO(OH)_2 group or -N[R-PO(OH)
_2] represents _2 groups. ) A hydrocarbon aminophosphonic acid and/or an alkali metal aminophosphonate or a mixture thereof; (ii) The following formula: ▲There are numerical formulas, chemical formulas, tables, etc.▼ (In the formula, m + n is a value of 2 to 20 (iii) a phosphinopolycarboxylic acid and/or an alkali metal phosphinopolycarboxylic acid salt having a molecular weight in the range of 200 to 2,000, or a mixture thereof, and (iii) a polyacrylic acid or a polymaleic acid and/or a mixture thereof. or an alkali metal salt of said acid, or a mixture thereof, wherein said acid or salt has a molecular weight in the range of 500 to 10,000. A composition characterized by: 2. An aqueous coolant composition having a depressed freezing point, comprising hard water and 10 to 90% by weight of the antifreeze concentrate composition of claim 1.