COLORANT FOR HEAT TRANSFER FLUID, AND COMPOSITION COMPRISING SAME

Abstract

The present invention relates to a colorant for a heat transfer fluid and a composition comprising same.

Claims

1. An antifreeze composition, comprising: 0.001 to 10.000% by weight of a colorant having the structure of Chemical Formula 1 or 2; 30 to 70% by weight of a glycol compound; and 30 to 70% by weight of water: ##STR00012## wherein, M is a metal or a metalloid, L is —(CH.sub.2)m-, —COO—, —CO—, -MH—, —SO.sub.2—, or —SO.sub.2NH—, X is a hydrophilic polymer, and R.sub.1 to R.sub.12 and R.sub.a to R.sub.p are each independently a hydrogen atom, a halogen atom, a, carboxy group, a sulfonic acid group, an amide group, an ester group, an acetyl group, a siloxane group, an alkyl group of C.sub.1 to C.sub.10, an alkylene group of C.sub.1 to C.sub.10, an alkoxy group of C.sub.1 to C.sub.10, an oxyalkylene group of C.sub.1 to C.sub.10, a fluoroalkyl group of C.sub.1 to C.sub.10, an arylalkyl group of C.sub.4 to C.sub.20, or a derivative thereof.

2. The antifreeze composition of claim 1, wherein M in Chemical Formula 1 is boron (B), silicon (Si), aluminum (Al), gallium (Ga), indium (In), or titanium (Ti).

3. The antifreeze composition of claim 1, wherein M in Chemical Formula is silicon (Si), aluminum (Al), gallium (Ga), indium (In), titanium (Ti), tin (Sn), or ruthenium (Ru).

4. The antifreeze composition of claim 1, wherein the hydrophilic polymer is poly(ethylene glycol), poly(vinyl alcohol), poly(vinyl pyrrolidone), or copolymers of two or more thereof.

5. The antifreeze composition of claim 1, wherein the hydrophilic polymer has a number average molecular weight of 150 to 20,000.

6. The antifreeze composition of claim 1, wherein the colorant has a solubility of 1 g/L or higher in the antifreeze composition.

7. The antifreeze composition of claim 1, wherein the colorant has a weight loss of 10% or less at a temperature of 250° C. or less.

8. The antifreeze composition of claim 1, wherein the glycol compound is at least one selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, polyalkylene glycol, and glycol ether.

9. The antifreeze composition of claim 1, further comprising an antifoaming agent in an amount of 0.005 to 0.100% by weight, based on the total weight of the antifreeze composition.

10. The antifreeze composition of claim 1, further comprising a pH adjuster in an amount of 0.0005 to 0.1% by weight, based on the total weight of the antifreeze composition.

11. The antifreeze composition of claim 10, wherein the pH adjuster is an amine-based compound.

12. The antifreeze composition of claim 11, wherein the amine-based compound is at least one selected from the group consisting of alkanol amine, alkyl amine, and a cyclic amine.

13. The antifreeze composition of claim 11, wherein the amine-based compound is triethanolamine.

14. The antifreeze composition of claim 1, further comprising a metal corrosion inhibitor.

15. The antifreeze composition of claim 14, wherein the metal corrosion inhibitor is an azole-based compound.

16. The antifreeze composition of claim 1, wherein the antifreeze composition is used for internal combustion engines, electric batteries, or fuel cells.

17. The antifreeze composition of claim 1, wherein the antifreeze composition has an electric conductivity of 50.0 uS/cm or less.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] FIG. 1a is a nuclear magnetic resonance (NMR) spectrum accounting for the structure of a colorant according to Example 1 of the present disclosure.

[0081] FIG. 1b shows ultraviolet-visible absorption spectra accounting for the structure of a colorant according to Example 1 of the present disclosure.

[0082] FIG. 2a is a nuclear magnetic resonance (NMR) spectrum accounting for the structure of a colorant according to Example 2 of the present disclosure.

[0083] FIG. 2b shows ultraviolet-visible absorption spectra accounting for the structure of a colorant according to Example 2 of the present disclosure.

[0084] FIG. 3a shows UV-Vis absorption spectra of a colorant according to Example 1 of the present disclosure.

[0085] FIG. 3b is a plot showing the molar absorption coefficient of the colorant according to Example 1 of the present disclosure.

[0086] FIG. 3c shows UV-Vis absorption spectra of a colorant according to Example 2 of the present disclosure.

[0087] FIG. 3d is a graph showing the molar absorption coefficient of a colorant according to Example 2 of the present disclosure.

[0088] FIG. 3e shows UV-Vis absorption spectra of a colorant according to Comparative Example 1.

[0089] FIG. 3f is a graph showing the molar absorption coefficient of a colorant according to Comparative Example 1 of the present disclosure.

[0090] FIG. 3g shows UV-Vis absorption spectra of a colorant according to Comparative Example 2.

[0091] FIG. 3h is a graph showing the molar absorption coefficient of a colorant according to Comparative Example 2 of the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

[0092] Provided is an antifreeze composition comprising: 0.001 to 10.000% by weight of a colorant having the structure of Chemical Formula 1 or 2; 30 to 70% by weight of a glycol compound; and 30 to 70% by weight of water.

DETAILED DESCRIPTION

[0093] A better understanding of the present disclosure may be obtained through the following examples, which are set forth to illustrate, but are not to be construed to limit the present disclosure.

Preparation Example 1. Preparation of Colorant of Example 1

[0094] First, a phthalonitrile immediate having a triethylene as a substituent was synthesized. In brief, 4-nitrophthalonitrile (1 eq) and triethylene glycol monomethylether (1.1 eq) were dissolved in tetrahydrofuran (THF) and stirred in a nitrogen atmosphere. Then, Cs.sub.2CO.sub.3 (5.5 eq) was added, followed by heating 65° C. for 12 hours. Subsequently, the mixture was spontaneously cooled to room temperature and added with 100 ml of water. Extraction was carried out with dichloromethane (DCM). Thereafter, the organic layer was separated using a separating funnel and washed three times with water, followed by drying over MgSO.sub.4. Then, the dichloromethane was removed at room temperature using a rotary evaporator to obtain the synthesized 4-triethylene phthalonitrile intermediate.

[0095] Subsequently, the synthesized phthalonitrile intermediate was used for synthesizing a gallium-containing pigment. In brief, 4-triethylene phthalonitrile (4 eq) and GaCl.sub.3 (1.5 eq) were put in a pressure tube and a solution of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (1.5 eq) in n-hexanol was added before heating 180° C. for 4 hours. The reaction mixture was cooled to room temperature and the supernatant n-hexanol was removed with care. Hexane was added to the remaining reaction mixture and removed again as a supernatant. Afterwards, the reaction mixture was dissolved in DCM, washed once with 10% HCl and then three times with water using a separating funnel, and dried over MgSO.sub.4. DCM was removed using a rotary evaporator. Then, a small amount of DCM was added to the mixture, followed by dropwise adding the solution to diehthylehter which was being stirred to afford a gallium-bearing pigment as a crystal.

[0096] Next, the synthesized gallium-bearing pigment was substituted at the axis with a polyethylene glycol to prepare a colorant according to Example 1. In brief, the synthesized gallium-bearing pigment (1 eq) and polyethylene glycol monomethylether (molecular weight 400 (i.e., PEG.sub.0.4K), 10 eq) were dissolved dry dimethylsulfoxide (DMSO) and stirred in a nitrogen atmosphere. The reaction mixture was added with K.sub.2CO.sub.3 (8 eq), stirred at 150° C. for 12 hours and cooled to room temperature. DCM was added before three rounds of washing with water using a separating funnel. Water was removed with MgSO.sub.4 and DCM was removed using a rotary evaporator. Then, a small amount of DCM was added to the mixture which was then dropwise added to diethylether while stirring, to afford as a crystal the colorant having the structure of the following Chemical Formula 2-4 according to Example 1 of the present disclosure.

##STR00008##

Preparation Example 2. Preparation of Colorant of Example 2

[0097] A colorant according to Example 2 was prepared in the same manner as in Example 1 with the exception of using a pigment bearing silicon instead of gallium. In brief, dry polyethylene glycol monomethyl ether (Mw 400, 3 eq) was put, together with a silicon-bearing pigment (1 eq), to a pressure tube to which dry toluene was then poured. A solution of NaOH (2.5 eq) in n-hexanol was added, followed by stirring in a nitrogen atmosphere. Then, the reaction mixture was cooled to room temperature, dissolved in DCM, and washed four times with water using a separating funnel. Water was removed with MgSO.sub.4 and DCM was removed using a rotary evaporator. A small amount of DCM was added to the reaction mixture which was then added to hexane while stirring, to afford as a crystal a colorant having the structure of the following Chemical Formula 2-5 according to Example 2 of the present disclosure.

##STR00009##

Preparation Example 3. Preparation of Colorant of Example 3

[0098] A boron-bearing pigment was synthesized using a phthalonitrile intermediate. In brief, BCl3 (1 eq, 1M solution in p-xylenes) was added at room temperature to 4-triethylene phthalonitrile (1 eq) in a flask in a nitrogen atmosphere and heated at 150° C. for 1 hour. After being cooled to room temperature, the reaction mixture was subjected to extraction with DCM. The extract thus obtained was washed three times with water and dried over MgSO.sub.4. DCM was removed using a rotary evaporator. Subsequently, a small amount of DCM was added again, and the resulting solution was dropwise added to diethylether while stirring, to afford a boron-bearing pigment as a crystal.

[0099] Then, a polyethylene glycol was introduced into the axis of the gallium-bearing pigment to prepare a colorant having the structure of Chemical Formula 1 according to the present disclosure. In brief, the synthesized gallium-bearing pigment (1 eq) and polyethylene glycol monomethylether (Mw 400 (i.e., PEG.sub.0.4K), 1.5 eq) were dissolved in dry o-dichlorobenzene (o-DCB)) and stirred at 140° C. for 10 hours in a nitrogen atmosphere. The reaction mixture was cooled to room temperature, added with DCM, and then washed three times with water using a separating funnel. Then, water was removed with MgSO.sub.4 and DCM was removed using a rotary evaporator. Afterwards, a small amount of DCM was added to the reaction mixture which was then dropwise added to diethylether while stirring, to afford as a crystal a colorant having the structure of the following Chemical Formula 1-2.

##STR00010##

Experimental Example 1. Structural Identification

Experimental Example 1-1. Nuclear Magnetic Resonance (NMR) Analysis

[0100] Measurement was made in CDCl.sub.3 using an NMR spectrometer (Varian-500 MHz). The results are depicted in FIGS. 1a and 2a.

[0101] For the colorant of Example 1, as shown in FIG. 1a, aromatic hydrogen peaks appeared between 7.0 and 8.0 ppm and many aliphatic hydrogen peaks were detected at 3.0 to 4.2 ppm due to the molecular axial substitution of PEG. This spectral data thus indicate that the axial substitution of PEG successfully occurred.

[0102] As can be seen in FIG. 2a, peaks at 7.5 to 8.0 and 8.3 to 9.7 ppm were accounted for by unsubstituted aromatic hydrogens of the colorant of Example 2. In addition, many aliphatic hydrogen peaks were detected at 3.0 to 4.0 ppm due to the molecular axial substitution of PEG in the colorant. This data indicate that the axial substitution of PEG successfully occurred.

Experimental Example 1-2. Ultraviolet-Visible Absorption Spectroscopy

[0103] UV-VIS absorption spectra were measured using UV-1800 spectrophotometer (Shimadzu). The results are depicted in FIGS. 1b and 2b.

[0104] As shown in FIG. 1b, the colorant prepared according to Example 1 appeared blue green.

[0105] The absorbance data of FIG. 2b indicate the appearance of blue color in the colorant prepared according to Example 2.

Experimental Example 2. Chromatic Characterization

[0106] To identify chromaticity, the colorants of Examples 1 and 2 were each added at the same concentration to an antifreeze composition composed mainly of ethylene glycol, with compounds of the following Chemical Formulas 3-1 to 3-5 used for comparison (hereinafter referred to Comparative Examples 1 to 5), and the solutions were measured for absorbance using a UV-Vis spectrophotometer. The results are depicted in FIGS. 3a to 3g and summarized in Table 1.

A=εlc  [Equation]

[0107] A: absorbance, c: molar absorption coefficient, c: molar concentration

[0108] Chromaticity was graded into: ⊚ (excellent) for absorbance coefficiency >100,000; ∘ (very good) for absorbance coefficiency >50,000; Δ (good) for absorbance coefficiency >20,000; and x (poor) for absorbance coefficiency less than 20,000.

##STR00011##

TABLE-US-00001 TABLE 1 Absorbance Coeffi. Sample (M-1cm-) Chromaticity Color Ex. 1 58,588 ◯ Blue green Ex. 2 102,457 ⊚ Blue C. Ex. 1 21,234 Δ Blue green C. Ex. 2 9,032 X Blue green C. Ex. 3 <1,000 X Blue C. Ex. 4 <3,000 X Red yellow C. Ex. 5 <3,000 X Red

[0109] As seen the data of FIGS. 3a to 3h and Table 1, the color was blue green for Example 1, blue for Example 2, blue green for Comparative Examples 1 and 2, blue for Comparative Example 3, and red yellow for Comparative Example 4, and red for Comparative Example 5.

[0110] In addition, turning to absorbance, the absorbance coefficient was measured to be 58,588 L mol-1 cm-1 for Example 1 and 102,457 L mol-1 cm-1 for Example 2, accounting for excellent and very good chromaticity of Examples 1 and 2, respectively.

[0111] In contrast, the absorbance coefficient was 21,234 L mol-1 cm-1 for Comparative Example 1 and 9,032 L mol-1 cm-1 for Comparative Example 2. Comparative Examples 3 to 5 were measured to have absorbance coefficients of 1,000, 3,000, and less than 3,000, respectively, which are all at poor levels.

[0112] The colorants of Examples 1 and 2 in which hydrophilic polymer substituents are introduced into the molecular axis thereof according to the present disclosure exhibited remarkably higher chromaticity, compared to Comparative Example 3 in which a polymer substituent was neither introduced into the peripheral part, nor into the core.

[0113] Compared to Comparative Example 2 in which a polymer substituent was introduced only into the peripheral part, Examples 1 and 2 were measured to have about 6.52- and about 11.39-fold greater absorbance coefficients, respectively.

[0114] In addition, the absorbance coefficient was about 2.77-fold higher in Example 1 and about 4.84-fold higher in Example 2, compared to Comparative Example 1, which had no a polymer substituent at the molecular axis thereof.

[0115] Therefore, the colorants of Examples 1 and 2 according to the present disclosure were found to exhibit excellent chromaticity in an antifreeze composition composed mainly of ethylene glycol, compared to those of Comparative Examples 1 to 5. Particularly, it was found that a colorant having a polymer substituent at the molecular axis thereof exhibits remarkably high chromaticity, compared to a colorant having a polymer substituent at the peripheral part thereof. Hence, the colorants according to the present disclosure were identified to have excellent color intensity and find applications in antifreeze compositions.

Experimental Example 3. Assay for Physicochemical Stability

[0116] Thermal gravity analysis was made using TA Q600 instrument at a temperature elevation rate of 10° C. per min to 300° C. in a nitrogen atmosphere. An assay was measured for acid/alkali stability. In this regard, the compounds were monitored with the naked eye for degradation in solutions having a pH of 2 to 12 and measured for change in absorbance region and for absorbance intensity by UV-Vis spectroscopy.

[0117] Stability was graded into: ⊚ for excellent acid/alkali stability and a weight change rate of 10% or less at 250° C. or higher as measured by thermal gravity analysis; ∘ for excellent acid/alkali stability and a weight change rate of about 20% at 250° C. as measured by thermal gravity analysis; Δ for excellent acid/alkali stability and a weight change rate of about 30% at 150° C. as measured by thermal gravity analysis; and X for conditions other than the foregoing conditions. The results are summarized in Table 2, below.

TABLE-US-00002 TABLE 2 Sample Physical and Chemical Stability Example 1 ⊚ Example 2 ⊚

[0118] It was understood from the data of Table 2 that Examples 1 and 2 were highly superb in terms of thermal stability as their weight change rates were 3.4% and 8.8%, respectively, at measured by thermal gravity analysis. Particularly, Examples 1 and 2 were both thermally stability at up to about 300° C. and degraded at higher than the temperature. In addition, excellent stability to acid and alkali was detected. That is to say, Examples 1 and 2 were thermally and chemically very stable.

Experimental Example 4. Assay for Solubility

[0119] Solubility was measured as follows: 0.1 g of a compound was added to and completely dissolved in 1 L of an antifreeze at room temperature; the compound was additionally added in an amount of 0.4 g; after complete dissolution was detected, the compound was further added in an amount of 0.5 g; and the solubility was observed with the naked eye. The solubility was graded into: ⊚ for a solubility of 1.0 g/L or higher in a commercial antifreeze composition composed mainly of ethylene glycol; ∘ for a solubility of 0.5 g/L or higher; Δ for a solubility of 0.1 g/L or higher; and X for a solubility less than 0.1 g/L. The results are summarized in Table 3, below.

TABLE-US-00003 TABLE 3 Sample Solubility Example 1 ⊚ Example 2 ⊚

[0120] As shown in Table 3, Examples 1 and 2 exhibited excellent dissolution because their solubilities were 1.1 g/L and 1.2 g/L, respectively, in an antifreeze composition composed mainly of ethylene glycol. That is, Examples 1 and 2 were well dissolved in an antifreeze, compared to conventional other pigments. Therefore, the colorants of the present disclosure can express colors stably and uniformly in antifreeze compositions due to their excellent solubility in the antifreeze compositions.

Example 5. Assay for Electric Insulation

[0121] Antifreeze compositions containing compounds (about 0.001 mM) were measured for electric conductivity using TCX-90.sup.3 instrument. Electric insulation was graded into: ⊚ for an electric conductivity of 3.0 uS/cm in the antifreeze composition; ∘ for an electric conductivity of 3.0 to 10.0 uS/cm; Δ for an electric conductivity of 10.0 to 20.0 uS/cm; and X for an electric conductivity higher than 20.0 uS/cm. The results are summarized in Table 4, below.

TABLE-US-00004 TABLE 4 Sample Electric Insulation Colorant 1 ⊚ Colorant 2 ⊚

[0122] As shown in Table 4, the antifreeze compositions containing Examples 1 and 2 were both very low in electric conductivity for their electric conductivity measured to be 3 uS/cm or less. That is, an antifreeze composition containing the colorant of the present disclosure has excellent electric insulation.

Experimental Example 6. Assay for Ion Exchange Resin Pollution

[0123] Ion exchange resin pollution refers to a degree to which an ion exchange resin for removing ions released from fuel cell stacks and radiators and responsible for continual increase of electric conductivity is polluted with the antifreeze composition. To measure ion exchange resin pollution, an antifreeze composition containing a compound (ca. 0.001 mM) was allowed to pass through an ion exchange resin and conductivity and absorbance were compared between the solution before and after passage. Anti-ion exchange resin pollution was determined to be good for 99% or higher coincidence in conductivity and absorbance intensity between the compositions before and after passage and to be poor for the other conditions. The results are summarized in Table 5, below.

TABLE-US-00005 TABLE 5 Sample Anti-ion exchange resin pollution Example 1 Good Example 2 Good

[0124] As shown in Table 5, Examples 1 and 2 were observed to make no pollution in the ion exchange resin.

INDUSTRIAL APPLICABILITY

[0125] The present disclosure pertains to a colorant for heat transfer fluids and a composition comprising same