JPS59166582A - Absorption refrigerant composition - Google Patents

Abstract

PURPOSE:An absorption refrigerant composition, obtained by adding a specific phosphite compound and a phosphate compound secondarily to a fluorohydrocarbon and a polar organic solvent, having high-temperature stability and rust preventing effect on a coexisting metal, and usable for absorption refrigerators and heat pumps. CONSTITUTION:An absorption refrigerant composition obtained by adding (A) a phosphite compound expressed by the formula (R1O)(R2O)(R3O)P and (B) a phosphate compound expressed by the formula (R4O)(R5O)(R6O)PO (R1-R6 are H, alkyl, alkenyl, phenyl, etc.) secondarily in 0.05-0.5wt% respective phosphorus concentrations to a composition consisting of a fluorohydrocarbon and a polar organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an absorption refrigerant composition used in absorption refrigerators and heat pumps applied to air conditioning.

Conventional Structures and Problems In general, an absorption refrigeration cycle is a closed circuit that contains an absorption refrigerant composition, and the liquefied refrigerant is evaporated in an evaporator, which is part of the circuit, so that the absorption refrigerant can be removed from the outside by evaporating the liquefied refrigerant. Removes heat and freezes. The refrigerant vapor vaporized in the evaporator comes into contact with a low refrigerant concentration solution in the absorber and is absorbed. The high refrigerant concentration solution that has absorbed the refrigerant releases refrigerant vapor by receiving p-heat from an external heat source. The vaporized refrigerant vapor is then condensed in a condenser and sent as liquefied refrigerant to an evaporator. The solution that has released the refrigerant vapor returns to the absorber as a low refrigerant concentration solution and absorbs the refrigerant vapor again.

The highest possible effectiveness for such cooling and heating can only be achieved at high temperatures of the refrigerant-rich solution in the generator.

However, conventionally, monochlorodifluoromethane (
R22), Ni-dimethylformamide (DM
F) Or absorption refrigerant compositions using tetraethylene glycol dimethyl ether (TEGDME)-i have been proposed, but these have only a short lifespan for practical use.

One of the reasons for this is that when all of this is heated, R22 decomposes and produces products such as hydrochloric acid and hydrofluoric acid, which corrode the metals that make up the entire equipment, and the absorbent also decomposes at the same time, causing damage to the equipment. This was because the physicochemical properties of the composition deteriorated, which was fatal and could not be tolerated.

Such deterioration and decomposition reactions are extremely individual and complicated depending on the constituent components and their combinations, so thermal stabilization at high temperatures is extremely difficult.

Therefore, although R22/DMF and R22/TEGDME absorption refrigerant compositions have superior physicochemical properties compared to other compositions, they have not yet been put into practical use due to the drawbacks mentioned above. There isn't one.

The object of the present invention is to provide a composition that is highly stable at high temperatures and can sufficiently achieve the best effects in absorption refrigerators, heat pumps, and the like.

Structure of the Invention The absorption refrigerant composition according to the present invention includes a phosphite compound added to an absorption refrigerant composition consisting of a fluorinated hydrocarbon such as a methane-based or ethane-based organic solvent and a polar organic solvent such as an amide-based or glycol ether-based organic solvent. and a phosphate compound added.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, the absorption refrigerant composition must have good thermal stability and be sufficiently stable against the action of coexisting metals in order to obtain maximum effectiveness. For this purpose, it is partly accepted to use the known antioxidants and the phosphite compounds described. However, although the thermal stability of the composition improved by using all of the additives, there were some cases where sludge was formed or copper plating phenomenon occurred on dissimilar metals, so the results were not satisfactory. It's not. This is because, for example, when a copper plating phenomenon occurs, sliding resistance increases in the moving parts of the refrigerator, resulting in an increase in mechanical loss.

Therefore, from a practical point of view, it is expected to develop an absorbing refrigerant composition that has excellent thermal stability and has an anticorrosive effect on coexisting metals.

In view of these points, the present inventors have conducted various studies]7
As a result, we succeeded in developing an absorption refrigerant composition that meets the above expectations by adding a phosphite compound and a phosphate compound dually.

That is, by adding two elements, the composition of the present invention can withstand stable use at high temperatures by suppressing products accompanying the decomposition of the refrigerant, and can contain coexisting metal ions (e.g., copper).
It has excellent features such as completely suppressing the plating phenomenon by suppressing the catalytic action of . Therefore, it can be said that the absorption refrigerant composition according to the present invention has the same thermal stability as above, and is also sufficiently stable against the effects of coexisting metals.

Fluorinated hydrocarbons related to the present invention include monochlorodifluoromethane, dichloromonofluoromethane (R21), )rifluoromethane, monochlorotetrafluoroethane (R21),
124), monochlorotrifluoroethane (R133)
, monochlorodifluoroethane and mixtures thereof, including all fluorinated hydrocarbons selected as refrigerants depending on the operating conditions of the absorption cycle.

In addition, polar organic solvents include formamide, acetamide, monomethylformamide, monomethylacetamide, tetramethylurea, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide (D
MA), N-dimethylpropionamide (DMP), N
, amide compounds having an intramolecular -〇〇N-bond such as N-diethylformamide, and mixtures thereof;
Ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether (DE
GDME), diethylene glycol, diethylene ether, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether (T3 EGDME), triethylene glycol diethyl ether, triethylene glycol dibutyl ether, TEGDME, tetraethylene glycol diethyl ether, and tetraem It contains a glycol ether compound represented by the chemical formula %, such as rangelicol dibutyl ether, and a mixture thereof, and contains an organic solvent selected in combination with a refrigerant other than those described.

The phosphite compound and phosphate compound described above have the chemical formula (R+0)(R20)(Rso)
It is represented by P and (R40XR50)(R60) PO, and R1 to R6 in the formula each independently represent a hydrogen group, an alkyl group, an alkenyl group, a phenyl group, or an alkylphenyl group.

They are an alkylene phenyl group, an alkylene alkylphenyl group, an alkylene phenyl group and an alkylene alkylphenyl group. In addition, these compounds are characterized by the configuration of IJn with respect to oxygen and the type of substituent, for example, when all R1 to R6 are substituted with an alkyl group such as methyl,
Each is called trimethyl phosphite or trimethyl phosphate. Therefore, the phosphite compounds and phosphate compounds according to the present invention refer to alkyl groups having 1 to 18 carbon atoms such as methyl, ethyl, isopropyl, butyl, 2-ethylhexyl, isooctyl, isodecyl, dodecyldecyl, tridecyl, lauryl, octadecyl, and oleyl. It also includes substituents such as alkylphenyl groups having an alkyl group having 1 to 9 carbon atoms such as nonylphenyl and talesyl. Since in this case phosphorus is considered to be the active group with respect to stabilization, for example in the case of phosphite compounds the size of the constituents R1 to R3 is not critical, and the boiling point, melting point.

As long as solubility in organic solvents and toxicity are taken into consideration, all of R1-R3 are the same or different, or all of the substances in which R1-R3 are the same and the rest are different, including all IJ + or G substances, are phosphate compounds. The same applies to the case of , and this compound further includes mono-. A stabilizing effect can be obtained by dually adding these to the absorbent refrigerant composition, and the addition amount is preferably in the range of phosphorus concentration of 0.06 to 0.6% by weight, and 0.05 to 0.2% by weight. Phosphorus concentration shows an even more pronounced stabilizing effect.

The novel absorption refrigerant composition according to the invention is a significantly more stabilized composition compared to conventional compositions. 200'G
Even at high temperatures above, deterioration and decomposition of fluorinated hydrocarbons and organic solvents are suppressed, yellowing of the composition is slow and small,
It will not solidify to a tarry black color. Furthermore, from the viewpoint of the lifespan of the composition, it is stabilized by about 10 to 20 times, and a long life can be expected when used in equipment.

[Example 1] R22 and DMA were mixed at a ratio of 1=1, the compounds shown in Table 1 were added, copper and stainless steel (SUS-3o4) were made to coexist, the mixture was sealed in a Vilex tube, and heated at 160°C. All heat resistance tests were conducted.

Sample numbers (■) to (■) in Table 1 below are antioxidants, sample numbers (■) are rust inhibitors, and all sample numbers of conventional examples are (■).

As a result, sample ■ already turned green on the 14th day, turned into a tar-like black solution on the 30th day, and samples
Some of the samples exhibited similar discoloration or accelerated deterioration compared to those shown in Table 1, and all of the samples had turned black on the 30th day, whereas samples ■ to ■ had only a green color. On the other hand, the copper and stainless steel of samples ■～■ were entirely blackened, but in sample ■■■■, some of the stainless steel had turned yellow, although the degree of blackening was small. In samples ① and ②, there was no abnormality in copper or stainless steel, and the effect was so remarkable that there was no precipitation of copper powder at all.

In this way, such absorption refrigerant compositions did not show any effect of well-known antioxidants and rust inhibitors, and sample
~■ As in, phosphites and phosphate compounds have thermal stability effects? However, as shown in samples ① and ②, by adding all the phosphite compounds and phosphate compounds in binary form, it not only suppresses the decomposition of the composition, but also has a remarkable stabilizing effect on the rust prevention effect of metals. I discovered that it can be produced.

[Example 2] R22 and DEGDMK were mixed in a ratio of 2:1, a phosphite compound, a phosphate compound, copper powder and stainless steel were added, and a heat resistance test was conducted at 220°C. The results are shown in Table 2.

As a result, sample q-di, to which no phosphite or phosphate compound was added, turned brown after 60 days, and quantitative analysis of the amount of decomposed fluorine revealed that 6 parts of R22 had been decomposed.

In addition, at phosphorus concentrations where the amount of phosphite and phosphate compounds added is 0.05% by weight or less, as in samples σ and σ, the amount of decomposed fluorine,
There were many iron and copper ions liberated, and there was no effect of addition at all, and it was actually worse than sample q]. On the other hand, sample 0 (iN(9
0, such as @σsuσ). O2N2.2% by weight))
In the concentration range, the color of the composition was slightly yellowish and the effect was significant. Furthermore, at an IJ concentration of 0.2 to 0.5% by weight, such as in samples (mC) (D), the color of the composition was yellow, and although there were some fluctuations in the decomposition of R22, an effective effect was obtained. However, as in sample 0Q≧,
When the phosphorus concentration exceeds 0.5% by weight13, there are considerable differences depending on the type of compound, and sometimes unfavorable effects have occurred.

Therefore, considering the influence of composition, price, etc., 1% by weight
At the above phosphorus concentration, a stabilizing effect commensurate with the amount added cannot be expected. If the phosphorus concentration is preferably added within the range of 0.05 to 0.6% by weight, a light stabilizing effect can be expected. Nevertheless, a phosphorus concentration of 0.05 to 2% by weight shows a significant stabilizing effect.

Margin below 147-:.

167, [Example 3] In the same manner as in Example 1, all of the samples Q~■ shown in Table 3 were prepared. Sample (D In addition to thermal stability, we added the effect of preventing copper plating as an evaluation method.In this method, as the sample is heated, copper ions dissolve and become liberated. This was done by measuring all changes in plating over time.

Margin 7-187 As a result, although the samples (S [F] 6) had excellent thermal stability, some of them had a fast copper plating speed on stainless steel, aluminum, etc. , sample (D
(DC2 Su○ was excellent in both properties and exhibited sufficient stabilizing effects.

At the same time, quantitative analysis of Aβ, Fe, Cu, etc. was performed, and the increase in metal ions in the composition corresponded well with the quantitative analysis of free halogen and the qualitative and quantitative analysis of decomposition products by chromatography.

Effects of the Invention The novel stabilized composition according to the present invention is composed of a fluorinated hydrocarbon, an organic solvent, and a phosphite compound and a phosphate compound. Regardless, a sufficient stabilizing effect can be obtained.

Name of agent Patent attorney Toshio Nakao and one other person Procedural amendment January 71, 1980 Patent application No. 40880 filed in 1988 2 Name of the invention Absorbing refrigerant composition 3 Person making the amendment Relationship to the case Patent Application Address: 1006 Kadoma, Kadoma City, Osaka Prefecture Name:
(582) Matsushita Electric Industrial Co., Ltd. Representative Yama
Toshihiko Shimo 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Column 6 for the detailed explanation of the invention in the specification subject to the 5th amendment, page 7, 13 of the detailed description of the amendment Delete "alkalene phenyl group, alkalene alkylphenyl group," from line to line 14.

Claims (2)

[Claims] (1) Binary addition of a phosphite compound and a phosphate compound represented by the chemical formula (R10) (R20)% to an absorption refrigerant composition consisting of a fluorinated hydrocarbon and a polar organic solvent. absorption refrigerant composition. (2) The amount of the phosphite compound and the phosphate compound added to the composition is 0.05 to 0.0.
The absorbent refrigerant composition according to claim 1, wherein the absorption refrigerant composition is 6 wt%.