JPH02242823A - Cyanoethylated polyether polyol and refrigerator oil containing the compound as active component - Google Patents

Abstract

PURPOSE:To provide the subject novel compound expressed by a specific formula and useful as a lubricating oil suitable for using in the compression of chlorine- free fluorocarbons. CONSTITUTION:The objective compound is expressed by formula I (X is 2-12C residue of compound, having 2-8 OH group; R is 1-10C alkyl residue excluding OH; (k) is 1-8; (l) is 0-7; (m) is 0-7; (n) is 0-7; (k)+(l)+(m)+(n)=2-8, (a), (b) and (c) are 4-20; AO is 2-4C oxyalkylene) and is e.g. the compound of formula II.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel cyanoethylated polyether polyol compound and a refrigeration oil containing the compound as an active ingredient. This refrigerating machine oil is suitable for use in lubricating oil for compressors that use Freon as a refrigerant, especially when compressing R134a Freon (1,1,1,2-tetrafluoroethane), which does not contain chlorine among Freon. Used as a lubricating oil.

Traditionally, refrigerators, air conditioners, refrigerators, etc. have used refrigerants that contain fluorine and chlorine as constituent elements. However, in connection with the recent problem of ozone layer depletion, a new type of refrigerant, R134a, has begun to appear as a new type of refrigerant that does not have any effect on the ozone layer depletion problem.

On the other hand, many mineral oil-based and synthetic oil-based lubricants have been known for CFC compressor lubricants, but these have completely poor compatibility with the new R134a CFC at low temperatures. I found it unusable. Therefore, this countermeasure has become an important issue today.

In addition, other properties required for refrigeration oil include lubricity,
These include energy saving properties, wear resistance, sealing properties, heat resistance, and sludge precipitation prevention properties, and these points also need to be taken into consideration.

The fourth reason is that polyether-based synthetic lubricating oil is an example of conventionally known synthetic oil, and this is known as "yukajizume".
Volume 29, No. 9, pp. 336-343 (1980) and Petrotevk Magazine No. 8@, No. 6, No. 562-5
There is an introduction on page 66 (1985). Also, JP-A-61-
281) No. 99 has the following formula: R1-(0-(RtO)-R3).

A mixture of Borig Recall and alkylbenzene represented by
For example, an oil in which an epoxycycloalkyl compound is mixed with a high molecular weight polyoxypropylene monobutyl ether such as 53 moles of addition; High viscosity mixed oils are introduced.

However, none of the above-mentioned known synthetic oil-based lubricating oils could be used as refrigerating machine oil for R134a Freon compressors due to problems such as compatibility.

By the way, in U.S. Patent Publication No. 4.755.316, R
Polyoxyalkylene glycol (hereinafter abbreviated as PAG), which has hydroxyl groups (-OH) at both ends, has been introduced as a refrigerating machine oil for 134a. And the above patent publication is this P
AG is a general PA consisting of a hydroxyl group and an alkyl group at the end.
Compared to G, R134a is compatible with R134a, melting together over a wider temperature range, improving oil return to the compressor in refrigeration systems, and preventing seizure when starting the compressor at high temperatures. teaching.

Furthermore, the compatibility range between PAG and R134a is -40°C to +5°C.
It teaches that the temperature is 0°C.

R134a is attracting attention as a potential alternative refrigerant to R12, and is mainly used in car air conditioners and refrigerators.

In particular, 1. In the case of a car air conditioner, the compressor starts up in the summer, so the temperature can well exceed +50°C. Under these conditions, U.S. Patent Publication No. 4.755
, No. 316 refrigerating machine oil, the oil and refrigerant separate into two layers in the compressor at startup, with the refrigerant with higher specific gravity in the lower layer, causing the compressor to start up without lubricating oil and risk seizing the compressor.

In other words, it can be said that a two-layer separation temperature of +50°C is insufficient.

The present invention has extremely good compatibility over a wide temperature range with fluorocarbon-based refrigerants, especially R L34a fluorocarbon, which has been attracting attention as a new refrigerant in recent years. An object of the present invention is to provide a refrigerating machine oil for fluorocarbon compressors and a novel cyanoethylated polyether polyol compound that is an active ingredient thereof.

The present inventor conducted research targeting various synthetic oils with the aim of solving the above problems, and found that a specific cyanoethylated polyether polyol compound is a fluorocarbon refrigerant containing R134a fluorocarbons. The present inventors have discovered that the present invention exhibits excellent compatibility with .

That is, the feature of the present invention is -S formula (1) [wherein X represents a compound residue having 2 to 12 carbon atoms and having 2 to 8 hydroxyl groups, and R represents an alkyl group having 1 to 10 carbon atoms] Represents a group excluding a hydroxyl group. k represents an integer from 1 to 8, L represents an integer from θ to 7, m represents an integer from 0 to 7, and 1 represents an integer from O to 7, and the sum of k+L+a+n is 2 to 8. Also, a, b, and C are 4 to 20
each represents an integer.

AO represents an oxyalkylene group having 2 to 4 carbon atoms. ]
A refrigerating machine oil containing the cyanoethylated polyether polyol shown by the formula and the compound as an active ingredient and exhibiting excellent compatibility with fluorocarbon refrigerants.

Examples of the compound having 2 to 12 carbon atoms and having 2 to 8 hydroxyl groups represented by X in the above general formula (1) showing the cyanoethylated polyether polyol used as an active ingredient in the present invention include glycerin, diglycerin, poly Glycerin, trimethylolethane, trimethylolpropane, 1.3.5-pentanetriol, erythritol,
Pentaerythritol, dipentaerythritol, sorbitol, sorbitan, sorbite, condensate of sorbitol and glycerin, adonitol, arabitol, xylitol, mannitol, xylose, arabinose,
Ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellbiose,
Examples include maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, melezitose, and the like.

In addition, the oxyalkylene group having 2 to 4 carbon atoms represented by ^0 in general formula (1) is -CI(!-C1lz-0
-CJs However, the active ingredients of the refrigerating machine oil according to the present invention include:
These are polymers (・＾0÷T, +AO+T, -(
It is a polyoxy type as in -AO÷, and -C
A type obtained by copolymerizing H-CFlt-0- may also be used.

-CH-CHi-0- Refrigerating machine oil containing 25% by weight or more has particularly excellent melting stability with chlorofluorocarbons, but on the other hand, AO (+CHz-C)
If the content of lt-0+ polyoxy type increases, the pour point of the refrigerating machine oil will become high, which is not preferable.

Furthermore, when ^0 is butylene oxide, its compatibility with chlorofluorocarbons is lower than when propylene oxide is used, and the melting temperature range is also narrower. Therefore, in the present invention, it can be said that a refrigerating machine oil containing a cyanoethylated polyether polyol in which 80 is propylene oxide is most preferable.

In addition, a, b, c representing the polyoxy type of 80 represent the degree of polymerization of the polyoxyalkylene group, and all are integers in the range of 20≧a, b, c, ≧4, and in this range The stability of fluorocarbons in the refrigerating machine oil is improved.

In the above general formula (1), R representing an alkyl group having 1 to 10 carbon atoms is, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a hexyl group, an octyl group, a 2-
Examples include ethylbutyl group, 2-ethylhexyl group, nonyl group, and decyl group.

Also, in the formula: 1. , a, and n, k is 1
an integer of ~8, at least one -CHt-Cl1
It is important that the terminal contains a z-CN- structure.

When X is a compound having two hydroxyl groups, for example ethylene glycol, one of the hydroxyl groups is -0
+AthCHz-CHx-CN, and since X in the formula may have a maximum of 8 hydroxyl groups, all of them can be changed to →1000AO)-CHz-CIli-CN. In this case, glue, m, and le in the formula are each zero.

In addition, L, m and broom are -0+AO+f-R, -o+Ao
')r can take the form of R and -OH and thus represent the number of each of these groups. That is,
1, a, n are integers from O to 7, and 12+l+@+H
The total is 2 to 8.

Incidentally, it is preferable that the refrigerating machine oil of the present invention contains a compound in which L, m>n, and if a compound having the opposite relationship is contained, the lubricity and fluorocarbon stability of the refrigerating machine oil will be improved. It becomes insufficient.

In view of the above, the following can be shown as specific examples of the moiety bonded to X in general formula (I).

CO, -Of CHi-04 CHi-0-(- CI -0f CHz-0-!1 h[Iio +nCHz-CJ-CN C3■&0÷rbcllz-C!(z-CNCJJ-+
rCHz-CHz-CN CJaO+TC) It-CHx-CN CHz-0+ C! ! 440-)T+C3H60+n+
CFlz-CHz-CNCH-0-H C1fi-Of CJeO-+r+C3H60+nCz-Cut-CN
H H-0-CHi-C-C1□÷ Cd1iO-)I-CHt-CHz-CNCN C1)t-0-Cut-CIli-0(-C1lz-0
-C1l*-CHz-0+C3HiO-)r-CHz-
C1(z CJ60+rCJ? CN and, 0H (:Hz-CH-CHx-0+ CaHsO+rCHz
-C1lz-CN (CtL-0 state) The cyanoethylated polyether polyol compound represented by the general formula (1) according to the present invention has at least one -
This is a new substance with a CHz-CHt-CN group at the end, and by using it as an active ingredient in lubricating oils used in compressors using Freon, especially R134a, as a refrigerant, it can be used in a wide range of low to high temperature ranges. This has the effect of exceptionally improving mutual solubility and greatly improving lubricity and thermal stability.

Therefore, the refrigerating machine oil according to the present invention containing the above cyanoethylated polyether polyol compound can solve the conventional problem of improving the compatibility of R L34a with Freon.

It should be noted that the refrigerating machine oil according to the present invention may contain additives conventionally used in refrigerating machine oil, such as antioxidants and anti-wear agents, as appropriate. It is also possible to use a mixture of PAG (polyalkylene glycol).

The present invention will be specifically explained below using Examples.

Example 1 This example shows the synthesis of a cyanoethylated polyether polyol for inclusion in refrigerating machine oil as an active ingredient.

CHx-0+ C3H&0-+-rCHz'-CHz-
Synthesis of CNCI-0(-C1)1ao+rH C1h-
0+ Cs1laO+r [184 g (2.0 mol) of glycerin and Ig potassium hydroxide are placed in a 151-volume autoclave, replaced with nitrogen gas, and then heated to 100° C. and stirred. When the temperature reached 100℃, the pressure inside the autoclave was set to 1.0kg/-, and
1860 g (32,0 mol) of propylene oxide at °C
was added dropwise over 5 hours to maintain the pressure inside the autoclave at 10 kg/cd or less. 1 hour, 100~1)0℃
After aging while maintaining the temperature, unreacted propylene oxide was distilled off at a pressure of 50 mmHg or less. After cooling to 50°C, it was neutralized with phosphoric acid. Then, it was heated to 100℃ and heated to 50mmH.
Dehydrated for 1 hour at less than
Polyoxypropylene (15) glyceryl ether was obtained. The obtained compound had a hydroxyl value of 175.

960 g (1 mol) of the obtained polyoxypropylene (15) glyceryl ether and 5 g of potassium hydroxide were added to 51
Transfer 4 volumes to a flask, add acetone from 1), and add 3
Stir at 0°C until homogeneous. 60 g (1.1 mol) of acrylonitrile was added dropwise to the dropping funnel over 5 hours. 3
After aging at 0°C for 1 hour, it was neutralized with phosphoric acid and
The mixture was heated to a temperature below ]Omdg, and acetone and unreacted 7-crylonitrile were removed in 1 hour. Hexane from 1) and 500% water were added to the resulting mixture, and after stirring at 50 to 60°C for 30 minutes, the mixture was allowed to stand, and the separated water was removed. Next, 5001R1 water was added and the same operation was performed.

After performing this operation a total of 4 times, at 80-100℃, 1) 0
Hexane and water were distilled off in 12 hours at a temperature of below mmHg.

The slight remaining salt was filtered off and 900 g of CHx-0+ C1)liO+-rC1lz-C1lz
-CNC1l -0(-C2H&O+rH CIlx-Of CJbO'+rH was obtained.

The obtained compound has a hydroxyl value of 1) 0 and a viscosity of 3.4 cs.
t (100℃), and as shown in the infrared absorption chart shown in the attached figure, -CmiN is <2250cIIl-'
was confirmed. Moreover, the results of elemental analysis were as shown below.

Elemental analysis results C60.0% (60.2%) H10,6 (10,0%) 0 2B, 0 (28.4%) Values in parentheses are theoretical values.

Example 2 This example uses refrigeration oil containing each cyanoethylated polyether polyol synthesized according to the procedure shown in Example 1, and the polyoxyl oil disclosed in U.S. Pat. No. 4,755,316 shown above. Alkylene glycol (PAG)
), R134a is added as a refrigerant.
This figure shows the results of comparing and evaluating the performance when using fluorocarbons.

In addition, the test oil Al containing each compound shown in Table 1 as a cyanoethylated polyether polyol
-A3, while commercially available polyoxyalkylene glycol (PAG) 81 shown in Table 2 as a comparative example.
~BS<Unionil series manufactured by Nippon Oil & Fats Co., Ltd.] was used.

The performance of each test oil shown in Tables 1 and 2 as a refrigerating machine oil was evaluated for compatibility and thermal stability under the conditions shown below.

Lubricity In accordance with ASTM-D-3233-73, Falex seizure load was measured in a controlled atmosphere (70 d/n+in) of R134a Freon.

After sealing 0.6 g of compatible test oil and 2.4 g of refrigerant (R134a Freon) in a glass tube, cooling and heating were performed at 1°C per minute to reach the temperature at which two-phase separation occurs, that is, the two-phase The separation temperature was measured.

Thermal stability After sealing 1 g of the test oil, Ig of refrigerant (R134a Freon), and catalyst (iron, copper, and aluminum wires) in a glass tube, it was heated to 175°C, and after 10 days, the hue of the test oil was changed to A.
Judgment was made using STM display.

The results of the above evaluation are shown in Table 3.

As shown in Table 3, the seizure load and thermal stability regarding the performance of the test oil are all good and there are no problems, but the two-layer separation temperature is between the present invention (example) and the comparative example. There are important differences.

In this regard, R134a CFC is a promising refrigerant to replace R12 CFC, and is used in car air conditioners and refrigerators.In particular, in the case of car air conditioners, it is used as a high-temperature oil and refrigerant to start the compressor in the summer. The compatibility of the two is important. Then, at the time of startup, the oil and refrigerant separate into two layers within the compressor, and the refrigerant with a higher specific gravity becomes the lower layer, causing the compressor to seize.

In addition, the two-layer separation temperature shown in Table 3 was adjusted according to the present invention (example).
When comparing this and the comparative example, it is necessary to compare them at the same viscosity level. This is because when using lubricating oil,
This is because the viscosity range is limited depending on the model. for example,
The test oil A-3 of the example and the test oils B-3 and B-5 of the comparative examples have a viscosity of 25 to 30 cs t @ 100°C, which is the same level, but diol type and triol type PAG is not compatible with R134a Freon, whereas the sample oil A-3 containing cyanoethylated polyether polyol is compatible even in the temperature range of -50 to +34°C. In addition, for the test oil A-4 and the test oil B-1, which have the same viscosity of 10 cst @ 100°C, the two-layer separation temperature of A-4 containing cyanoethylated polyether polyol is 20°C higher than that of B-1. It's getting expensive. Furthermore, 12~3cs
Test oils A-5 and A- containing cyanoethylated polyether polyols having a viscosity of t@100°C class
No. 6 has a two-layer separation temperature that is 15° C. or more higher than that of test oils B-2 and B-4.

Accordingly, the refrigeration oil of the present invention containing a cyanoethylated polyether polyol is disclosed in U.S. Pat.
Since it has a sufficiently wider compatible temperature range than the PAG-containing refrigerating machine oil disclosed in No. 5.316, it can be said to be a refrigerating machine oil suitable for R134a Freon refrigerant.

In response to ozone layer depletion caused by CFCs, which has become a major problem on a global scale, R134a, which does not cause much ozone layer depletion, has been highlighted as an alternative to R12, which is widely used as a refrigerant. However, it has the disadvantage of poor compatibility with refrigeration oil, which has been a barrier to developing alternative systems. However, since the refrigerating machine oil of the present invention maintains sufficient compatibility with R134a Freon as a refrigerant and has excellent overall performance, it
Even if R134a Freon is used instead of Freon, the effect is that the conventional system can be used as is.

[Brief explanation of drawings]

The attached figure shows the infrared absorption spectrum of the cyanoethylated polyether polyol (see Example 1) according to the present invention.

Claims (5)

[Claims] (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [However, in the formula, X has 2 to 8 hydroxyl groups and has 2 carbon atoms.
-12 compound residues, R represents an alkyl group having 1 to 10 carbon atoms, excluding a hydroxyl group. k is 1
l represents an integer of 0 to 7, m represents an integer of 0 to 7, and n represents an integer of 0 to 7, but k+l
The total sum of +m+n is 2-8. Also, a, b, and c
represent integers from 4 to 20, respectively. AO has 2 or more carbon atoms
4 represents an oxyalkylene group. ] Cyanoethylated polyether polyol. (2) In the general formula (I) shown in claim (1),
A refrigeration base oil containing as an active ingredient a cyanoethylated polyether polyol in which AO is oxypropylene. (3) In the general formula (I) shown in claim (1),
Refrigeration oil containing as an active ingredient a cyanoethylated polyether polyol in which AO is a copolymer residue of oxypropylene and oxyethylene, and the ratio of oxypropylene to oxyethylene is 100:0 to 25:75 by weight. (4) The following formula ( I ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ( I ) [However, X in the formula ▲ There are mathematical formulas, chemical formulas, tables, etc.
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
▲There are mathematical formulas, chemical formulas, tables, etc.▼ ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, AO represents either ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Mathematical formulas,
There are chemical formulas, tables, etc. ▼, where k represents an integer from 1 to 4, l represents an integer from 0 to 3, m represents an integer from 0 to 3, and n represents an integer from 0 to 3, while k+l+m+n is an integer from 2 to 4. Moreover, a is an integer of 4 to 20, b is an integer of 0 to 20, and c is an integer of 0 to 20, respectively.] A refrigeration base oil containing a cyanoethylated polyether polyol as an active ingredient. (5) Refrigeration oil containing a cyanoethylated polyether polyol having the formula (II) ▲Mathematical formula, chemical formula, table, etc.▼ as an active ingredient.