CA2155166C - Refrigerator oil composition and fluid composition for refrigerator - Google Patents

Abstract

A refrigerator oil for use with an HFC
refrigerant containing HFC-134a and/or HFC-125, which comprises:
(A) 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight (based on the total weight of the component (A)) of alkylbenzenes having a molecular weight of 200 to 350 and (B) 30 to 1% by weight of a synthetic oil containing oxygen. There is also proposed a refrigerator fluid composition comprising the above-mentioned refrigerator oil and an HFC refrigerant containing HFC-134a and/or HFC-125, together with or without an additive such as a phosphorus compound.

Description

~-, r ~ ,s ~ ~' T ITLL? OI~ THE :LNVENT ION
REFRIGFRA'fOR O1. L_, GOMfOSI'1'I0N AND
FLI1ID COMPOSI_TLON FOR REFRI_GERAT'OR
13ACKGBOUNI) OI~ fIIL INVENTION
1 . F f.eld of the lnveni=ion 'This invention relates t:o a refr-i.gerator oil composition and a fluid composition i'or a rei'rigerator, and in part=icular to a-~ refrigerator oil composition and a fluid cornposit;ion containing said oi1_ composition for I_0 use in a refrigerator, the refrigerator oil_ comprising a mixed base oil. consisting essentially oi' an a_Lkyl benzene oil having specific. features and a synthetic oil and being suited for use in combination with an HFC
refrigerant containing 1,1,1,2-tetraf:Luor~oethane (HFC-15 134x) and/or pentafluoroethane (HFG-1.25) .

2. Pior Art Due to the rec~.ent prob:l_ems as to tlhe dest=ruction of the ozone layer, the use of CfC (ch7_orofluorocarbon) and HCFC (hydrochlorof:Luorocarbon) which have been conventionally used as a refrigerant for a refrigerator is now restricted under a regulation. 'Therefore, as a replacement of these materials, HFC (hydrofluorocarbon) has been increasingly employed as a refri~;erant.
Under the circumstances, PAG (p olyalkylene glycol) and esters which are compatib.l_e w~~th HFC. have been studied or used as an oil for a r-efrigerator using an HFC refrigerant. For example, the use of fAG is _ Z_ proposed i.n IJ . S . fal~ent 4 , 7 55 . 316 ; Japanese latent Unexamined fublicat:ions Nos. I-lei I-198694, I-lei 1-256594 , He i 7 -2590)3 , Hei 1-259094 , lief J_-25909 5 , Hei.
1-274191, Ile.i. 2-43290, Ilei 2--55797 and Ilei 2-84491. The use of esters is proposed irr PC'f.l'ubi icat:ion No. fIei 3-505602 as well as in .Japanese I='at.ent Une~s:amirled Publicat ions Nos . 1;(e.i 3-88892 , Ile i 2--128991 , Ilei 3-128992, Hei 3-2(:)0895, Hei 3-227397, liei 4.-20597, Ilei 4-72390 , Iie i 4-21_8592 and Ilei. 4--249593 .
However, PACa i.s rather hi.g~t~ in hyg;roscopicity and poor in electric o.harac:terist;ics (volume resistivity). On the other hand, ester-based oi_Ls are readily hydrolyzed to generate arr acid thus possibly giving rise to various probl.erns. Moreover, these oils are accompanied with s~ ser:ious problem that they are inferior in lubricity as compared with a mineral oil/CFC or a mineral oil/HCI~C.
On the other hand, Japanese Patent Unexamined Publication No. Hei5-157379 describes a refrigerating 2~ system for an HFC-134a refrigerant wherein there is used a refrigerator oil which is incompatible with a refrigerant; as an example of such arr i.ncornpatible oi~_, an alkylbenzene oil. is di_scl.osed t:herei.n. Further, Japanese Patent; Unexamined Publication No. Hei 5-59386 describes a mixed oil comprising a hydrocarbon compound and ester or ether, wltick is useful_ ats a refrigs=rator oil for a refrigerator- using tetrafluoroetlnane.

However, it has been found that if an ordinary alkylbenzene oil is to be used as a refrigerator oil for HF(;-134a and/or HFC-125, some specific means are required to be taken on the side of the system, and that if' an ordinary alkylbenzene oil is used as a refrigerator oil for HFC-134a and/or HFC-125 without taking such specific means, the seizure of a refrigerating compressor used may possibly be caused after a long period of its operation.
1H The present inventors took notice of an alkylbenzene oil (alkylbenzenes) which is free from hydrolysis and hygroscopicity and made an extensive study to finally find out that if a mixture comprising an alkylbenzene oil having a specific property and a 15 specific synthetic oil is used as a refrigerator oil for IIFC-134a and/or HFC-1.2 5 , the seizure of the refrigerating compressor can be avoided, thus indicating an excellent lubricity of the alkylbenzene oil, and that the alkylbenzene oil is capable of maintaining a high reliability for a long period of time. This invention has thus been accomplished :in one aspect.
It has further been found out by the present inventors that when a phosphorus compound is added in 25 a specific ratio to the above mixed base oil compr:is:ing an alkylbenzene oil having a specific property and a synthetic oil and the resulting mixture is used as a ~ ~ ~~ ~3 ~. ~

refrigerator oil composition in a re-1'rigerator, the wear resistance and .Load resistance c>f the refrigerai;or can be improved. ~I'hi.s invention has thus been accomplished in another aspect.
Summary oi' Lhe Invention The object of the present; invention is to provide <i refrigerator- oil composition to be used with an HFC refri geraznt containing HFC-134a and/or HFC-125 , which enables a refrigerati..ng compressor to be prevented from .its seizure, i_s excel.:l-ent in .lubricity and retains high reliability for a long period of time.
Another object of the present: invention is t:o provide a fluid composition for use in a refrigerator, which comprises the above refrigerator o.il composition and an HFC refrigerant containing HFC-139.a and/or HFC-125.
In a first aspect of this invention, there is provided a refrigerator oil for use with an I-IFC
refrigerant- containing HFC-1.34a and/or HfC-125, which comprises (A) 70 to 99% by weight of an alky:lbenzene oil containing at Least 60~ by weight: (b<-rsed on the total weight of the component (A)) of al.ky~lbenzenes having a molecular weight of 200 to 350 and (B) 30 to 1 ~ by weight of a synthetic oil containing oxygen.

_ 5 -In <i second aspect of this invention, there is provided an oil composition for use with an HFC
refrigerant containing HFC-134a and/or HFC-125, which comprises:
a mixed base oil comprising:
(A) 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight (based on the total weight of the component (A)) of alkylbenzenes having a molecular weight of 200 to 350 and (B) 30 to 1% by weight of a synthetic oil containing oxygen, and (C) 0.005 to 5.0 parts by weight (based on 100 parts by weight of the mixed base oil) of a p]losphOrus compound.
1.5 In a third aspect of this invention, there is provided a fluid composition for use in a refrigerator which comprises:
[I] an HFC refrigerant containing HFC-134a and/or HFC-125 and [II] a refrigerator oil comprising:
(A) 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight (based on the total weight of the component (A)) of alkylbenzenes having a molecular weight of 200 to 350, and (B) 30 to 1% by weight of a synthetic oil containing oxygen.

p In a fourth aspect of this invention, there is provided a fluid composition for use in a refriger-at-or which comprises:
[IJ an IIFC refrigerant containing HFC-134a and/or HFC-125 and [II] an oil composition which comprises a mixed base oil comprising (A) 70 to 99~ by weight of an alkylbenzene oil containing at least 60~ by weight (based on the total weight of the component (A)) of alkylbenzenes having a molecular weight of 200 to 350 and (B) 30 to 1% by weight of a synthetic oil containing oxygen, and (C) 0.005 to 5.0 parts by weight (based on 100 Parts by weight of the mixed base oil) of a phosphorus compound.
This invention will be further exp.l.ained in detail with reference to the following preferred embodiments.
The component (A) of the refrigerator oil or oil composition (these expressions wi7_1 hereinafter bc;
collectively referred to simply as a refrigerator oi:l composition) proposed by this invention comprises an alkylbenzene oil containing at least 60o by weight (based on total weight of the component (A)) of alkylbenzenes having a molecular weight of 200 to 350.

To be more specific, it is required for the al.kylbenzene oil to contain, based on total weight of the component: (A) , at: least 60 ~ by weight, preferably at least 65o by weight, more preferably at least 70% by weight, still more preferably at least 80% by weight, most preferably 100 by weight of alkylbenzenes having a molecular weight of 200 to 350. If there is employed an alkylbenzene oil which does not meet the above requirements to the seizure of a refrigerating compressor used may possibly be caused after a Long period of its operation, thus undesirably affecting the reliability of the refrigerator oil.
Further, in view of improving the property for preventing the generation of seizure of a refrigerating compressor during a long period of its operation, the alkylbenzene oil. may desirably be selected from those containing, based on total weight of the component (A), at least 30% by weight, more preferably at least 35% by weight, most preferably at least 40% by weight of alkylbenzenes having a molecular weight of 200 to 300.
As for the alkylbenzene oil const.itut.ing the component (A) of the refrigerator oil composition of this invention, there is no restriction with respect to the molecular structure of the component alkylbenzenes as far as the molecular weight thereof falls within the range of from 200 to 350. However, in view of improving a long-term rel.iabi.lity of a refrigerating system, iL i_s preferable to select <rtt alkyi_benzene oi:l (a) composed of a:l.kya_benzenes ltavi_n~r 1 to 4 alkyl groups , each group c:orttaining 1 t=o l ;) carbon atoms and the Lota_l. amount; of carbon atoms i.n the ~ulky.l. group being 9 to 19, and more preferably 1~u sel.ect alkylbenzenes having 1 t;o 4 a_Lkyl groups, each group containing 1 Lo 15 carbon moms and t:he total amount oi.' carbon atoms in the alkyl group being ,j t.o 1. i .
Examples of alkyl groups cont;ainin.g 1 to 19 carbon atoms are methyl , ethy 1. , propyl ( incl.t.tding all isomers), butyl (including all isomers), pentyl (including all isomers), hexy~_ (.including all isomers), heptyl (including all isomers), octyl. (including all isomers) , nonyl (including all. isomers) , decy=1 (including all i.somers), undecyl (inc:luding all isomers), dodecyl (including all isomers), tridecyl ( including all isomers ) , tet:radecy:l_ ( including all isomers), pentadecyl (including a:L1 isomers), hexadecyl (including all isomers), heptadecyl_ (:including all isomers), octadecyl (incvluding~ all isomers) and nonadecyl (including all isomers).
'These alkyl groups may be st;raig~ht-chain or branched-chain ones. However, i.n view oi' the stability and viscosity oi' the rzlky:Lbenzenes, branched-c:haa:in 2~ a:il{yl groups are preferable, arnd t:he branched--chain alkyl groups drat are derived 1'rorn ol..igorners oi' o7_efins such as propylene, butene and isobutylene in view of availability.
The number of alkyl groups in the a_lkylbenzenes defined in the above (a) is confined to 1 i;o 4.
However, in view of the stability and availability of the alkylbenzenes, it is the most preferable to select.
alkylbenzenes having one or two alkyl groups, i.e., a monoalkylbenzene, a dialkylbenzene or a mixture of them.
It is also possible to employ not only the alkylbenzenes defined in the above (a) which have the same molecular structure, but also those having different molecular structures as long as there are satisfied the conditions that they contain 1 to 4 alkyl 1.5 groups, each group containing 1 to 19 carbon atoms and the total amount of carbon atoms in the alkyl group being 9 to 19.
It is permissible for the alkylbenzene oil constituting the component (A) to contain less than 40%
by weight, preferably less than 35% by weight, or more preferably less than 30% by weight, of alkylbenzenes having a molecular weight of less than 200 or more than 350. However, it i.s preferable that the molecular weight of such alkylbenzenes be confined to a range of more than 350 to 450, more preferably more than 350 to 430 in view of retaining reliability during a long period of operation of a compressor used.

~~.~_)~.~' __ i o -Wi t:h respec:i: t:o t;he alkyl.benze.nes having; a rnol.ecular- wo.ight ranging from more: t;ltrm .'.350 i_.o 450, there are n<~ restri_cL,ions _Ltnposec.l on tlrc~ molecular structure' thereof as L'ar' as the molec:ul_ar we iglats fall within this range. however , itr view o(.' the stability and availabilii~y, of alkylbenzenes i.t; is preferable to select al..kyl.ben.zenes (b) having .l Lo 4 alkyl groups, each groul;~ <:onLaritrirrg 1 to 40 cur'hoir ari.orins acrd the total amount of carbon atoms in t,ho <rlkyl. group being ZO to 40, and more preferably Lo se.lec~. alky:Lbenzenes having 1 to 4 alkyl groups, each group c:ontaining 1 to 30 carbon atoms and the total. amount caf carbon atoms in the alkyl group being 20 to 30.
>Jxarnp:les of al.ky.l. groups conl;ai.n:inrg 1 to 40 carbon atoms arc' tnethyl_, et-hyl, propyl. (i.ncluding all_ isomers) , buty:l (it~cl_ud:itrg al:l i.somors) , pentyl (:inc_ludingr al.l_ isotner:~) , hexy:L ( i m:.l.uc.l:i.ng a.ll_ isomers) , heptyl ( i.nclud.Lng all. isomers ) , oc:ty.t ( including all isomers) , nonyl (inc:luding all isomers) , decyl ( including al l isomers) , undec:yl. ( i.nc:luding all isomers) , dodec:yi ( incvl_uding al.l isomers) , tridecyl_ (including a:l_1. isomers) , tetradecyl. (including all isomers ) , perrtadecyl ( :i nclud ing <i L:1 i somers ) , hexadecyl ( i.nc:luding a:ll i somers ) , Ire~p t~adec.;y:l ( i rtcludi.ng all isomers) , octadecyl. (incl.udirug~ al..l isomers) , nonadecyl ( including all. i sourer s ) , is:osylg~rouys ( i.nc:luding all isomers), henicosyl. groups (including all isomers), docosyl groups (including all isomers), tricosyl groups (inc:Luding all isomers), tetracosyl groups (including all isomers), heptacosyl groups (including a:Ll isomers), hexacosyl groups (inc:luding all. isomers), heptacosyl groups ( i.ncluding all i comers ) , oct<~cosyl_ groups (including all isomers), nonacosyl groups (including all isomers), triacontyl. groups (including all isomers), hentriacontyl groups (including all isomers), dotriacontyl groups (including all i.somers), tritriacontyl groups (including all isomers), tetratriacontyl groups (including all isomers), pentatriacontyl groups (including all isomers), hexatriacontyl groups (including all isomers), heptatriacontyl groups (including all isomers), 1J oc:tatriacontyl groups (including all isomers), nonatriacontyl groups (including all isomers) and tetracontyl groups (including all isomers).
These alkyl groups may be straight-chain or branched-chain ones. However, in view of the stability and viscosity of the alkylbenzene, branched-chain alkyl groups are preferable; and branched-chain alkyl groups that are derived from an oligomer of an olefin such as propylene, butene or isobutylene are preferable in view of their availability.
The number of alkyl groups in the alkylbenzenes defined in the above (b) is confined to 1 to 4.
However, in view of the stability and availability of the alkylbenzenes, it is the most preferable to select alkylbenzenes having one or two alkyl groups, i.e., <~
monoalkylbenzene, a dialkylbenzene and a mixture thereof.
It is also possible to employ not only the alkylbenzenes defined in the above (b) which have the same molecular structure, but also those having different molecular structures as long as there are satisfied the conditions that they contain 1 to 4 alkyl 1.0 group, each group containing 1 to 40 carbon atoms and the total amount of carbon atoms in the alkyl group being 20 to 40.
Although there is no specific restriction imposed on the viscosity of the alkylbenzenes 1.5 constituting the component (A) of the refrigerator oil composition of this invention, it is preferable to select alkylbenzenes having a kinematic viscosity of 3 to 50mm2/s, preferably 4 to 40mm2/s, and preferably 5 to 35mm2/s at a temperature of 40°C.
20 There is no restriction placed on the manufacturing method of the alkylbenzene oil constituting the component (A) of the refrigerator oil composition of this invention, and the alkylbenzene oil can be manufactured according to the following 25 synthesizing methods.
Aromatic compounds which may be used as a raw material include benzene, toluene, xylene, ethyl.benzene, methyl.ethylbenzene, dic:~tlryltoenzene and a mixture thc,reof. f11ky1ating agents, which may be used herein include a 1_ower mono-olefin srtch as ethy:l_ene, propylene, butene or isobutylene: prcefcera.bly an ole-Cin oI' a straight-c:train or branched-ctrai.r~ type having 6 to 40 carbon atoms that is obtained h,y the polyrneri.zation of propylene; an olefin of a straighi.-chain or branched-chain type having f to 40 carbon atoms that is obtained by the thermal decornpos i ti.orr cof wax, heavy oil, a petroleum fraction, polyethylene, polypropylene or the like; an olefin of a straight-chain type having 6 to 40 carbon atoms i;hat is obtai.rred toy separating n-paraffin from a petro:Learn fraction such as kerosi.ne or gas oil and then catal.yt.ical.l.y transforming t;he n-paraffin into an olefin; and a rnixture of these o:Lefins.
An alkylating catalyst for use in tare alkylati_on includes a conventional c:atal.yst exempla Pied by a Friedel-Crafts cater:Lyst such as a l.umi rmrn ~;:h:Loride or zinc chloride; or an acidic c:atal.yst such as sui_furic:
acid, phosphoric acid, s:i:iico-t=ungstic acid, hydrofluoric acid or activated clay.
The al_kylbenzene o.i.l.. c:orrsti.tutir~g the component (A) of the refrigerator <.~il composi.tion of i~his invention may be obtained by mixing separately prepared aa_kylbenzenes having a mol.ecul..ar weight ranging from 200 to 350 wi th alk3~lbenzenes havi ng <i mo7_ec:ular weight - 1~
of less than 200 or more than 350 in a ratio as defined by this invention. However, it is advisable in practice to obtain a distillate containing at least 60~
by weight of alkylbenzenes having a molecular weight;
ranging from 200 to 350 through distillation or chromatography from a mixture of alkylbenzenes which is manufactured according to the~method explained above or is available in the market.
Meanwhile, the component (B) of the refrigerator oil composition of this invention is a synthetic oil containing oxygen. Preferable examples of this component (B) are an ester, polyglycol, ketone, polyphenyl ether, silicone, polysiloxane and perfluOrO ether. Among them , ( c ) ester , ( d ) polyglycol , (~') ketone and a mixture of them are especially preferable.
Examples of (c) esters are a dibasic ester, a polyol ester, a complex ester, a polyol carbonate and a mixture of them.
Examples of dibasic esters are those that can be obtained by reacting a dibasic acid having 5 to 1.0 carbon atoms such as glutamic acid, adipic acid, pimelic acid, suberic acid, azelaic acid or sebaci_c acid with a monohydric alcohol having 1 to 15 carbon atoms and an alkyl group of a straight-chain or branched-chain type, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol , nonanol , decanol , undecanol , dodecanol , trie~e~~anol , tetradecanol or pentadecanol . These esters may also be used as a mixture. More particularly, these esters include ditridecyl glutarate, di 2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di 2-ethylhexyl sebacate and a mixture of them.
Examples of polyol esters are esters between a diol or a polyol having 3 to 20 hydroxyl groups and a 1.0 fatty acid having 6 to 20 carbon atoms. More particularly, such diols include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1, 3-propanediol, 1, 5-pentane di of , necopentyl glycol , 1 , 6- hexanediol, 2-ethyl--2-methyl-1, s- propanediol, 1, 7- heptanediol, 2-methyl-2-propyl-1 > 3- propanediol, 2 , 2-diethyl-1, 3- propanediol, l , g- octanediol, l , 9- nonanediol, ~ , lo- decanediol, l ,11- undecandiol and 1,12- dodecandiol. specifi c' examples of polyol are polyalcohols such as trimet.hylol-. ethane , trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentacrythritol, di-(pentaerythrito_L), tri-(pentaerythritol), glycerin, polyglycerin (glycerin dimer to icosamer), 1,3,5-peritanetr101, sorbitol, sorbitan, sorbitol-glycerin condensate, adonitol, arabitol, xylitol and mannitol; saccharides such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose and melezitose, the partially etherified products of these polyalcohols and saccharides; and methylglucoside. More particularly, such fatty acids include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, oleic acid (these fatty acids may be of a straight-chain or branched-chain type), or a neo acid where a carbon atom thereof is quaternary.
More specifically, valeric acid, isopentanoic acid, caproic acid, enanthic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, caprylic acid, 2-ethylhexanoic acid, pelargonic acid, 3,5,5-trimethylhexanoic acid may be preferably empoyed as a fatty acid. Polyolester may contain a free hydroxyl group. Preferable examples of the pOly01 ester are esters of a hindered al.coho~_ such as neopentyl glycol , trlmethylOletharie, trimethylol-propane , trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol , di-(pentaerythritol) and tri-(pentaerythritol). Specific examples are neopentylglycol 2-ethyl.hexanoate, trimethylolpropane caprate, trimethylolpropane ~~ ~~~ ~~s - L~ -pelargonat;e, pentaerythritol 2-et;hyllrexanoa:rte, pentaerythritol pelargonate or a mixt=ure of them.
A complex ester is an ester obtained by t°cacting a fatty acid and a dibasic acid with a monolrydric alcohol and a polyol.. Lxatnpi.es of l'szt l:y uc i.ds , dibasi <.:
acids, monohydric alcohols and po.lyols useful in this case may be the same rrs exemplif'ie<j above with reference to dibasic: esters and p<alyoi. esters.
A po:lyo:l carbom:rte ester i.s an aster obtained by reacting carbonic acid wit! a monohydr ic: alcohol and a polyol . Examples of mortohydr i c rxl.c:oho Ls and polyols useful in this case tray be not. only the same as exemplified above, but a:Lso polyglycol obtained through homopolymerizat:i_on or copolymerizatiotr of a dio 1. , and products which are obtainable by the addition reaction o.f po7_yglycol wi th the po7_yol rnen t:ioned above .
Lxanrples of polyg.Lyc:ol. (cl) suitable in th:LS case are polya:lkylene glyc:o.ls, Ethers i,hereof and modified compounds thereof.
2p Examples of polyal.kylene glyco:Ls a:re homopolymers or copol_yrners of an alky 1_ene oxide such as ethylene oxide, propylene: oxide or t:~ut~ylene oxide. When a polyalkylene glycol. i.s formed of a <:opolymer of alkylene oxides different; in structure from eacYr other, there is no restrioi;i.on placed on the polymeriza.t:i.on form of oxyalkylene groups, i.e., the form may be random copolymer.ization or block copo.l.ymerization.

- l~ -An ether of the polyalkylene glycol is a compound wherein the hydroxyl group of the polyalkyl_ene glycol i.s etherified. Examples of ethers of the polyalkylene glycol are monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, monopent-yl.
ether, monohexyl ether, monoheptyl ether, monooctyl ether, monononyl ether, monodecyl ether, dimethyl ether, diethyl. ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether and didecyl. ether.
Examples of the modified compounds of 1 polyglycol are an adduct of polyol with an alkylene oxide or an etherified product of polyol. Examples of polyol useful in this case may be the same as those exemplified i.n reference to polyol esters.
Examples of ketones (e) mentioned above are ones which contain in the molecule at least one group represented by the following general formula:
O
-C-C-C-(More particularly, the ketones (e) include ketone compounds represented by the following formulas (1), (2) and (3), and a mixture of these ketone compounds.
(R'-C)m-X-(R2)n ___-_-(1) ,.~ .~ ,~ i ~~
y 4~ ,..
- l S3 -wherein X is au m+n valent. aromatic ring or an al.ky.1-substi tuted <r.r<>mat:i c r i rtg W rv.i.rrg 6 to 5U carbon atoms, preferably E; t-o 20 carbon at;c.~ms; 1~t1 and R~ may be i;lre same or dif:(°er:w:nt: and are eac:lr tr hydrocarbon group having 1to 50 carbon atoms, lrr~:L'c~rably 1 to 3U
carbon atoms, peel'erak~l_e examples thc~reoi' being an alkyl , phenyl or alky:ipltetryl group ; m and n rnay be tyre same or di.i'ferent integers and arse emc:lr 1. to 20, t~reCerably 1. to 10.
Preferable examples oI' the atwomatic r:Lng representi.trg X axre a k~enzene t~ing, a naplrthal_ene ring', an anthracene r:Lng, <r phenanthrene ring acrd an alkyl-substituted arornat.ic ring wherein ai. least one hydrogen atom on said aromati_<:: rings is subst:i tuted by an alkyl L5 group having J to 20 carbon atoms .
Preferable examples caf R1 and R~ are rnethyl, ethyl_ , propy:l ( Lnclud.i rrg al_:l i sonrers ) , butyl ( including all i.sorners) , peutyl ( inclucli_rrg a:Ll isc:nnor~s) , hexyl (including all. isomers), troptyl (i_nc:luding al__L
isomers), octyl (including all isomers), nonyl ( including all isomers ) , dec:yl ( includ i.ng all isomers ) , undecyl. ( .incl.ud.i.ng ~jl..l isomers ) , dodecyl ( including all isomers) , tridecyl. ( i.rrc:lud:ing all. isomers) , tetradecyl ( :inc:luding al:l i comers ) , p~ni~adec.:yl ( including a_l.l Z5 isomers ) , hexadecy:L ( irrc.Ludi.ng a1.1 isomers ) , heptadecyl ( including all isomers ) . oc:tadecy_t( iuc:ludirrg~ all isomers ) , nonadecy_i ( i.ncl_uding al l isomers ) , icosyl ~a, . rJ ~i ~. ~) '~:~
p _ (including al.l isomers) , henic:osyl ( including al_1 isomers), doc:osyl (including al.l isomers), tricosyl ( including all i somers ) , tetrac:osyl ( irtc:luding rzl.l_ isomers ) , hep tac:osy:l ( including al_1 i sortrers ) , hexac:osy l_ ( including a.ll isomers ) , hep t<zcosyl ( includitrg all isomers) , ocl;acosy:l ( ino.luding al 1. isomers) , rtonac:osyl ( including a L.l_ son~ers ) , tar iac~ont:yl ( i.nc:a.udi.ng a:L:L
isomers ) , phony 1. , tol_5~1_ ( itrcl.uding a) 1 i som~rs ) , xyl.yl (including al..l isomers) , ethylptrerty:i_ ( inc,l ud.i.ng all.
isomers) , prc>pylphony.l (incl.uding all i.scuners) , ethylmethylphenyl (i_ncluding al.l isomers), buty:l.phenyl ( including all. isomers) , d.iethy:Lphenyl ( inclu.ding all isomers), pentylphenyl. (inc_Luding all isomers), hexy:Lphenyl ( :i.n<:luding al l i comers ) , hop t.ylphenyl ( including a.11 isomers ) , octylphenyl( .includ:ing all isomers ) , nonylphenyl ( including nllisomers ) , decylphenyl (inc:luding all isomers) , undecylphenyl ( including al_1 isomer s ) , dodecyl_~~henyl ( irrcludi_ng all_ isomers) , tridec:ylphenyl ( inc:l.uding al.l lSOIrrE'.rS) , tetradecylpherryL (inc:luding al_1 isomers) , pentadecylphenyl (inca.uding al. 1. isornc~rs) , hexadecyl.phenyl ( including trl1. i.sconer s ) , heptadecyl.phenyl ( i nclud ing al:L isomers ) , octadecyl.phenyl_ ( inc;ludiug al.l isomers ) , nonadec:ylphenyl. ( inc:lrrdi.ng al:L isomers ) , icosylphenyl ( inc:l.udl.ng al.l isomers ) , hc~n:ic:osy:Ll~henyl ( i.nc:Lulling all isomers ) , doc:osy lphenyl. ( including al l i somers ) , f~
l _ tricosylphenyl (inc:ludirrg all isomers) and tetracosylphenyl_ ( inc:Luding a1.:1_ i sonretvs ) .

IZ'3_(~-[_.1Z4_L~_lL,-R' __.__-_(2) wherein 1Z3 and R' may be i~he same or different and are individual_l.y a hrydroc:arbon group having 1 to 50 carbon acorns , prefe~rrrt~ly 1 to ,30 tarpon acorns , preferab:l y an zt.l_ky.l , a lv>henyl or ao ,:rlkylpltenyl. group ;
R4 is an al.kyl..ene group having 1 t;o 19 carbon atoms, preferably 1 to 1_0 carbon atoms; L, is an integer of 1.
to 5, preferably 1 to 3.
1'referabl.e examples of R'~ anti R' are alkyl, phenyl and alkyl.pheny:l. groups by which are exemplified R1 and R~ in the compounds represeni:ed by the general formula ( 1_ ) .
r'urther, R4 is preferably <zrr al.kylene group which includes tnethylene , ethylene ( i nc:.l.uding a7 1 isomers) , propyl..ene (inc:luding a1 L isomers) , butylene ( inc:luding al.l isomers ) , pentylene ( i ncl_ucling al l isomers) , hexylene (i.ncluding all isomers) , heptylene ( including all isomers ) , oc:tyl.ene ( inc.Luding all isomers ) , nonyl.ene ( including all. isomers ) or decylerre group ( incl.uding~ a1.1 i.sorners ) .
( Ei 7 (~ 5 9 A-[-()-(R. 0)p-l~ -(,-(R 0)c.l-R ~r __._(;1) wherein A i s a monolydric t=o i cosah3ydri.c alcohol residue ; Cti' , 1z7 an<:l R3 may be the sarnc or different arid are indi.vidua:lly ar:c a:Lkylerue group laving 1. to 4 carbon atoms ; R1j is a hydrocarbon group , prel'erabl.y an alkyl , phenyl or a1_ky.Lplretty l group each having 1 t;o 50 carbon atoms, pret'erab7_y 1. t;o 30 c:arbors acorns; F~ and q rnay be' the same or different integers and are individually 0 to 30, prei'erably 0 to 20; and r is an integer of 1 to 20.
A.lcohol_s for the alcohol residue A, include aliphatic monohydric alcohols suc:lr as methanol, ethanol , propanol. ( including all isomers ) , butarrol ( including all. isomers ) , pen t;ano.l. ( i rrc: l.uding all isomers) , hexano.l (i.rm:l.uding all. i.scmers) , heptano:l (including al.i isomers), oct;anol (inc:Luding a:11 i_sotners) , nonanol (inc:luding all isomers) , decanol (including a17. isomers), undecanol. (incl.ud.ing all isomers) , dodecanol ( i.nc:ludirrg a11. isomors) , tridecanol ( including al.l _i.somers) , tei:r~adecvatrol ( including al.l isomers ) , pentadecanol ( i nc:luding sill isomers ) , hexadecanol (including all isomers), heptadecanol ( incl.uding all. isomers ) , octadecano.l ( i.ncludi.ng all isomers) , nonadecanol. (inc:l.ud:ing a.l.:L isomers) , icosanol (including all isomers), tuenicosanol (including all isomers), docosanol_ (inc:luding all isomers), tricosano:L (including al.l isomers) and tetrac:osanol ( .irrc:ludi.rrg all. i comers ) ; cl iols such as ethylene glycol, 1,3-prOparied101, propylene glycol, 1, 4- butanediol, 1, 2- butanediol, 2-methyl-l , 3-propane d.iol, 1,5- peritaned101, neopentyl glycol, l,s-hexane_.
diol, 2-ethyl-2-methyl-1,3- propanediol, 1,7-heptane _ diol, 2-methyl-2-propyl-1,3- propanediol, 2,2-diethyl-l , 3- propanediol, i , g- octanediol, l , s- nonanediol, l , lo- decanediol, 1,11-undecandiol, and 1,12-dodecan -diol; polyols including polyhydric alcohols such as trimethylolethane, trimethylolpropane, trimethylol-butane, di-(trimethylolpropane), tri-(trimethylol-propane), pentaerythritol, di-(pentaerythritol), t=ri-(pentaerythritol), glycerin, polyglycerin (glycerin dimer to icosamer consisting of 2 to 2Q glycerin monomers), 1,3,5- pentanetriol, sorbitol, sorbitan, sorbitol-glycerin condensate, adonitol, arabitol, xylitol and mannitol, and saccharides such as xylose, arabinose, ribose, rhamnose,.glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose and melezitose, the partially etherified products of these polyalcohols and saccharides; and methylglucoside.
Preferable examples of alkylene groups representing R5, R7 and Rg are methylene, ethylene (including all isomers), propylene (including all isomers) and butyl.ene (including all isomers).

a Z~.~~'~~ ~~f~
(referable examples o1' R'~ _are alkyl, phenyl and alkylphenyl groups by which are exernl.~l i.f'ied ftl and R~
i.n the c:ornpouncls reps esented by i=he>, yerrera.7 formulct (1).
'fhe lower .l irni i, o f' tire con t;en t. ca P t;he c;ornponen t (A) i.n a reI'ri.gerator oit. (a rnixecl base oi.l) of this invention comprising the components (A) and (B) is at least 70i by weight, 1:>re('erabl.y azt le<zst 75a by weight, more preferably at Least 80% by weight, bused on the total weight of the components (A) and (l3) , wtii.l_e the upper 1_imit of the content o1' the component (13) is not more than 30~ by weight, preferably nc~l: more Lhan 25%
by weight, more preferab:.l.y not more t;han ;~0°~ by weight, based on the total weight.: of Lhe componE.n~ts (A) and (g), On the other Lrand , the upper' 1 irni t of thc.
content of the component (A) in a refr-igerator oil (a mixed base of l) of t:h.is i anent ion cornlari sing the components (A) and (13) is not more tlrun 99% by weight, preferably not rnore than 95% by weight;, more preferably not more flan 90 ., by weight , based on t;tre total weight:
of the components (A) and (13), while tire lower limit of the content of the component (13) is ai: least. 1% by weight, preferably at least 5~ by wei.g~ht, more preferably at least 10% by weight, based crn the total weight of the components (A) and (B).

If the lower limit of the content of the component (A) is Less than 70% by weight based on the total weight of the components (A) and (B), a long germ reliability of the refrigerator oil composition will undesirably deteriorate. On the other hand, if the upper limit of the content of the component (A) is more than 99% by weight based on the total weight of the components (A) and (B), the return of the refrigerator oil composition in a refrigerating system will to undesirably deteriorate.
The refrigerator oil of this invention comprises (A) an alkylbenzene oil (alkylbenzenes) and (B) a synthetic oil containing oxygen as defined above, which can be suitably used as a refrigerator oil for an HFC
refrigerant containing HFC-134a and/or HFC-125 without accompaniment of an additive. However, it is also possible to use in the form of a refrigerator oil composition containing therein any of various additives as required.
In particular, it is preferable to blend a phosphorus oompound (C) in view of improving the refrigerating apparatus in wear resistance and load resistance by the use of the refrigerator oil c~.omposition. The phosphorus compound (C) means in this case at least one kind of a phosphorus compound selected from the group consisting of phosphoric esters, acidic phosphoric esters, amine salt of acidic phosphoric esters, chlorinated phosphoric esters and phosphorous esters.
These phosphorus compounds are esters obtained by a reaction between phosphoric acid or phosphorous acid and an alkanol or polyether type alcohol, and are also derivatives o'f said esters.
Examples of phosphoric esters are tributyl phosphate, tripentyl phosphate, trihexyl. phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl 1.0 phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, tri.octadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyldiphenyl phosphate and xyleyldiphenyl phosphate.
Examples of acidic phosphoric esters are monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadec:yl acid phosphate, monooctadecyl acid phosphate, monool.eyl acid phosphate, dibutyl acid phosphate, dipentyl acid phosphate, dihexyl acid ,, a A
~~.'~~,~~.~~
7 _ phosphate, d3.ttc~pt;y:L acid phosphate, dioctyl acid phosphate , d inorry 1 ac: i d phosphate , d i.decyl. ac.i cl phosphate, diundecyl. ac:Ld phosphate, didodec:yl acid ptrosphat.e, ditri_dec:yl acvi.d phosphate, ditetradecyl acid phosphate , d ipent=aclec:yl acid phosphate , dioctadecyl.
acid phosphate anti d i « L eyl ac i_d phosphate .
Examples oi' am i ne srzl is oi' acidic: phosphoric esters are methyl. au.rnirre, ethyl arsine, propyl amine, butyl amine , pertty:l. um.i.ne , hrxyl arsine , heptyl amine , oc:tyl. amine, dimet;hyl amine, diethyl_ arsine, dipropyl.
amine, dibutyl arninE , dipentyl arninE;, dihexy:L arsine, diheptyl amine, dioc~t;,yl amine, trirnet:hyl. amine, triethyl amine, tri.propyl. arn.ine, trik~utyl_ amine, tripentyl ami_tie, trihexyl amine, triheptyl amine and trioctyl_ amine of the acidic phosphoric ester.
Examples of chl.or.i.nat;ed phosphoric est;ers are tris-dic:hloropropyl. phosphate, Iris-ch:L.oroethyl phosphate , tr is---chloroplrenyl phosphate and polyoxyalkylene bis I chi ( ~'ltloroalky.l. ) J phosphate .
Examples of phosphorous est;ers arc' dibutyl. phosphite, dipentyl pltosphite, diluexyl pltosphite, ditreptyl_ phosphite, dioctyl phosphite, dinonyl phosphite, didecyl_ pltosphi.te, di.undecyl. phoshhite, didodecyl_ phosphite, diol.eyl phosphite, diphenyl phosphite, di.cresyl phosphate, tributyl phosphate, tr ipentyl phosphi to , tri.ttexyl phosl:>hi t;e , tr iheptyl phosphi to , trioctyl phosphi.te, t;ri.nonyl phosphate, tridec;yl 2g _ phosphite, triundecyl phosphite, tridodecyl phosphit:e, tr.ioleyl phosphite, triphenyl phosphite and tricresyl phosphite. It.is also possible to use a mixture of these compounds.
These phosphorus compounds may be incorporated into a refrigerator oil composition in any desired mixing ratio. However, it is generally preferable to add these phOSphOruS compounds in the ratio of 0.005 to 5.0 parts by weight, more preferably 0.01 to 3.0 L0 parts by weight, based on 100 parts by weight of the total amount of the alkylbenzene oil (A) and the synthetic oil containing oxygen (B).
If the amount of the phosphorus compound added is less than 0.005 part by weight based on 100 parts by weight of the total amount of the components (A) <rnd (B), any substantial effect on the improvement of wear resistance and loading resistance would not be attained by the addition of said compound. On the other hand, if the amount of the phosphorus compound added exceeds 5.0% by weight based on 100 parts by weight of the total amount of the components (A) and (B), it may give rise to undesirable corrosion in a refrigerating system during its use for a long period of time.
The improvement in wear resistance and loading resistance to be attained by the addition of the phOSphOruS compound is one of the features of the '~,~~~a~~~
refrigerator oil cc~tnpositioo ofi' this invention. l_t is eertalnJ_y possible tc'o achieve more or less act improvement; in wear r°esistancc anc.I l.c>adin.g resisi;artee, even wi th i:he use of PAG ( po_l.yal.kyletre g:Lyc:ol.. ) or an ester which is eactr known as use('u_I. I'or a reC'ri.gerator oil used with FI1~(~. However, t;lre ei'I'oci: thazt can be attained by the use of these conventional compounds i.s far less than the el'1'ect i;c~ lae ac:ttieved by the use of the refriger<-zt;or oil composition c~f' t,lti.s ittvc:~nt.ion.
It is also possibie i'or the purpose oI' i_tnprovi_ng stability to incorporate in t:ite refrigerator oil composition of t;his invention at l east one kind of an epoxy compound selected from the group consisting of:
(1) Phenylglycidyl_ ether type epoxy compounds, (~) Alkylglyc:idyl ether type epoxy cc.~utloourzds, (3) Glycidyl ester type epoxy compounds, (4) Aryl oxirane compounds, (5) Alkyl oxirane compounds, (6) Alicyclic epoxy compounds, (7) Epoxidized fatty monoesters, (8) Cpoxid:i~ed vegei:able oils.
Examples of phenyl.glyc:idyl. et;tier type epoxy compounds ( 1 ) are ph.enylg lycidyl ether and alkylphenylglycidyl ether. 'Itze alkylpitertylglycidyl ether used herein may be one Having 1 to ;.. alkyl groups each containing L to 13 carbon atoms, preferably one having one alkyl group containing 4 to 1U carbon acorns .

y, n ~~.~~~~:~.~
- ,30 -Examples o.t' such prei'erabl.e alkylptrc~nylglyc:idyl ethers are n-buty.l_phenylglycidy7. ettrer, i.-buty:l.l:~henylglycidyl.
ether , sec-bra tyl pheny.Lglyc i.dyI ether , tert;-butyl.pheny..l,g.Lycidyl ei;her, pentylphenylglycidyl ether, trexylphenylg~:l_yc.~idylether, hepty.lphenyl.glycidyl ether, octylphenylglycidyl ether, nonylplrenylglycidyl ether and decyl.phenylglycidyl ether.
Exampl.c>s of alky.Lglyci.dyl_ ether type epoxy compounds (2) are decyl.gLycidyl ether, undecylgLycidyl ether, dodecy.l.glyc:idy~.1 ether-, Lri<lecy.L~,rl_ycidyl ether, tetradecylglyc:idyl etLrer, z-ethyltrexy:Lg:l.yci.dyl ether, neopentylglycoldigl:yc:idyl ether, trinrethylolpropane triglycidyl ether, pentac:rythritol tetraglycidyl ether, 1,6-hexadiol diglyc:Ldy:1 tether, sorbitol polygl.ycidyl 1.5 ether , po l_yai_kyl eneg7 ycol. monog.lyc.L.dy L etl:rer and polyalkyleneglycol. d_iglyoidyl ether.
l3xampl.es of gl.ycidyl ester Lype epoxy compounds (3) are phenylglyc:i<kyl ester, alkylglyc:idyl ester and al.kenylglyc:idyl ester. L'rei'erable examples thereof' are gl.yci_dyl 2,2-dimethyloctanoate, glycickyl benzoate, glycidyl acryl.ate and glycidyl methacryl.ai;e.
Ex<~mples of a.ryl_ oxirane compounds (4) are 1,2-epoxystyrene acrd alk.yl.-:1. , z-epoxystyrerze .
Examples of alkyl oxirane compounds (5) are 1,2-epoxybutane , L , 2--epoxypentane , 1 , 2-el>oxyhexane , 7_ , 2-epoxyheptane , 1 , 2-epoxyoctane , 1 , 2-epcaxyno~nane . J_ . 2-~~..:~r~~~~

epoxydecane , 1 , 2-epoxyundec:ane , 1. , 2-cpoxydodecane , 1. , 2-epoxytridecane , 1 , c -epoxyte t:radec:ane , L , 2-epoxypentardecane , 1 , 2-epoxylrexadecar~c: , 1 , 2-epoxyheptadecanc~ , 1 , 2-epoxyoctadec:anc , 1 , 2-epoxynonadecane and 1- , 2-epoxyei c:osmrrc~ .
Examples of a 1 i cyc 1 i c epoxy ccaml:~ounds ( 6 ) are 1 , 2-epOXyC',yclohexato 1. , 2-el~oxycyc:lc.~l>entu.ne , 3 , 4-epoxycyclohexyl_tuethyl.._~3 ~l-c,pc>xycyc.Lolrexane c:arboxylate, bis (;:3, 4-epoxycyc: l.ohexy:Lmetlryl ) ad ipnte , exo-a? , 3-epoxynorbornane , bi s ( 3 , 4-epoxy-6--methylcyclohexylmeth~j.l.) adipate, 2-(7-oxabicyclo[4.1.OJhep(:-3-yl)-spiro(l_,3-clioxane-5,3'-[ 7 ]oxabicyclo [ 4 . 1 . 0 ) ) heptane , 4-- ( 1_' -rnethy.Lepoxyethyl ) -1 , 2-epoxy-2-methylc;yc.v:l_ohexmue and 4-epoxyethy 1.-1 , 2-epoxyc:yclohexane .
Examples of c~poxiciized fatty monoesters (7) are an ester formed by reach ng an epoxidized fatty acid having 1.2 to 20 carbon at:orna wi t:lr au n:l.cohol. having 1.
to 8 carbon atoms, phenol or an a_lkyllpheno7, In particular, epoxystearates such ars L~ut:yl., hoxyl, benzyl , cyclohexyl , methoxyethyl , phenyl_ and butylphenyl esters of epoxyst:earic acid are prei'"erred.
Examples of epoxidized veget:abl_e oils (8) are epoxy compounds oI' a veget=able o:i.l suc:lo as soybeain oil, linseed oil or cottc.~nseed oil.
Among these epoxy compounds, the more preferred ones are plrenylgLycidyl_ ether type epoxy <:ornpounds, glyc:idyl ester type epoxy compounds, alicyclic epoxy compounds and epoxiciized fatty monoester are preferred.
Among them, pheny.Lglycidyl. ether type epoxy compounds and glycidyl ester type epoxy compounds with phenylglycidyl ether, butylphenylglycidyl ether and alkylglycidyl esters being the most preferred.
These epoxy compounds may be incorporated into a refrigerator oil in any desired mixing ratio. However, i.t is generally preferable to incorporated these epoxy compounds in the ratio of 0.1 to 5.0% by weight, more preferably 0.2 to 2.0% by weight, based on 100 parts by weight of the total amount of the alkylbenzene oil (A) and the synthetic oil containing oxygen (B).
1t is of course possible to employ these phosphorus compounds and epoxy compounds jointly.
It is also possible, if required, to use singly or jointly suitable conventional additives in the refrigerator oil for the purpose of improving the properties of the oil composition of this invention.
The suitable additives include, anti-oxidants of a phenol. type such as ci.i-tert-butyl-p-cresol and bisphenol A or of an amine type such as phenyl-a-naphthylamine and N,N-di(2-naphthyl)-p-phenylene diamine; anti.-wear additives such as zinc dithioph osphate; extreme pressure agents such as chlorinated paraffin and sulfur compounds; an oiliness improvers such as a fatty acid; antifoaming agents such 1 ~::) ~~ ~. ~7 as si7...i_cone-tyL~e ones; metal inac;t.ivators such as ben2otriazole; visc:osi.t;y index improvers; pour point depressants; and detergent-dispersant:s. 'These additives may be used singly or in combination. 'These additives can be generally added in <r r°atio c>f not more than 10% by weight, more preferably not more than 5~ by weight, based on 100 parts by weight oi' the total amount of ttte al_ky_iberrzene oi.l (A) and Lhe synthetic oil containing oxygen (B) .
'I he refrigerants used, togettrer with t:he refrigerator oil composition of this invention, in a refrigerator include an alkane fluorid<~ having 1_ to ,3 carbon atoms, preferably 1 to 2 carbon atoms and containing at least 40% by weight of 1,1,1,2-tetrafluoroethane (fIFC-134x) and/or an alltane fluoride having 1 to 3 carbon atoms, preferabay J 1:0 2 carbon atoms and containing at least 20% by weight, preferably at least 30% by weight, more preferably at 1_east 40% by weight of pentafluoroethane (IIFG-125) .
'There is no rest~ric:tion placed con the kinc.I of HFC (hydrofluorocarbon) to be mixed with HFC-134a and/or HFC-125. The IiL~C includes tri.('luoromethane (HFC-23), difluoromethane (HFG-32), 1,1,2,2-tetrafluoroethane (IIFC-134) , 1, 1, 1-trif iuoroethane (HFC-143a) or 1,:1-difl.uoroethane (IiI~C;-l_52a) .
Examples or the HFC refrigerant: containing 1,1,1,2-tetrafluoroethane (I-IF(:-134x) and/or . ;~ :~ ~ ~i ~

pentafluoroethane (HF(>-125) that at:~e uset'u.l. in this invention are I~1FC-134a alone ; HFC-125 alone ; a mixture of IIFC-1.34a/l~F(~-32 irn a rat;i.o of 60-H0~ by wc~ightl40-20% by weight, a mixture of tII~'C-7.~34a/HI~C-32/iIFC-1.25 in a ratio of 40-70% by weight/:15-35'% by weight/5-40 o by weight, a rnixi:ure of III~(~-:125/IiI~C--,32 in a ratio of 30-601 by weight/70-40 a by we:igltt, a mixture of IiFC-125/HFC-143a in a ratio of 40-60~ by wc~.igtrt./Ei0-40% by weight and a rni.xtur~~ c>(' IIhC-7.25/IItO:;-1.34a/EiF(:-143a in a ratio of 35-55% by wei ght/l.-7 5°~ by wc~ ight/40-60°o by weight.
More part;icu_iarly, the III~C refrigerant mixtures are R404A (I-IFC-125/IIFC-143a/IIfC-134a in a ratio of 44%
by weight/52~ by weight/4 o by weight) , t1407C (HfC-32/IihC-125/lil.~C;-.134a in a ratio oI' 2,3'% by weig~Lrt/25% by weight/52'% by weight;) , R410l1 (ILFC-32/IIFC-125 in <r ratio of S0 o by weight/50~~ by weight ) , t1410L3 ( IIFC-32/HFC-l25 in a ratio of 45~ by weight/55% by weight) and 8507 (HFC-125/IIFC-143a in a ratio of 50°~ by weigtzt/50~ by weight.
The refrigerator oil composition according to this invention is generally present in a refrigerator in the form of a fluid composi tiorr in which the refrigerator ail composition is mixed with the al.kane fluoride as mentioned a:rbove. The mixing ratio of the refrigerator oil composition to the refrigerant (alkane fluoride) in i;lris fluid composition may be optionally ~, ~~

determined, but is trenerall.y a rat:i.o of l_ t:o 500 parts by weight, of t;lre re('ri.gerc-zCor o.i.l c:onrposit-ion preferably 2 to 400 par is by weight, ofi' t:he refr igerator o i. L cornpc>s i t ion per 100 parts by weight; of the re rr i ger<>_nt .
5i.ttc;e t:lte refrigerator oi.l <:orrrposit.ion according to this i.nverttion is excell.enl: irr electric: properties and low i.n hygroscopicat,y, i t; is pari,ic;ularl.y suited 1'or use i n mn a i r cond i t i.ortcr or a re l'ri gerat:or provided wi ttt a se<zled compressor of a reciprocating type or rotary t:ype. This rel'rigerat..or oil composition is also suited for case in an air conditioner or dehumidifier for vehicles, a freezer, a refrigerating chamber , an autornat.tc: vending machine , a show-case or a 1.5 cooling system 1'or a chemic<zl p:l.ant. 'I'tri.s refrigerator oi.l composition is also applicable to a c:otnpressor of a centrifugal type.
Brief' Descrit~tion of the f)raw::rn~
l~ig. 1 i.s a schematic view o(' l.he t:esting apparatus used in the tvaJ_uation 'Pest Nos. 4 and 8, wherein the reference trurneraL 1. represent; a refrigerating tank; 2, a copper conduit; 3, a flow meter; 4 and 6, manometers respectively; 5, a thermostatic tatrk; aancl 7, an oil pair.
Descrit~tion ol' t;he Preferred Etnbodirnents This invention will be 1'urttrer explained with referenc;e to the Collow.i.ng examples acrd comparative ., .a ~~ r t a.t y - 3E~ -examples. I-Iowever, it should be noted t=hat: Ltteso examples are not; intended to restrict; in arty manner tire scope of this invention.
Examples 1 to 2F and Comparative Lxarnples 1 to 13 The properti es oi' the Case oi.l s used in t=hese Lxamples and E;onrparat ive Lxampl.es are represented in 'fable 1, and the additives used therein are shown in Table 2. 'ftte distribution of mol ec:ui ar weights of alky~_henzenes i.n mixture was measured by means caf mass sped=rometry.

S

__ 37 -1't3b l o ~._.._. __I<1 __.._ .._....-_- _-.__ nen ._...
it i~~:
__._....

B ase oil i viscosity nloleculurwt. stribution di I 2 ,,, (mrri ~_~ .-.._~.__wt. -_ _. /.> -_ ___ ~, __- _. _~~_.
':._ 40~:' 1.00"(;<200 200-300 3U1--350>350 A Alkyl benzene 8 . 2 _ :> :)3 2 0 (branched- ' chain t ~e i B Alkyl benzene I 5 2 . 4 (>8 1.4 14 . 3 S34 (branched-chain t a ' i Alkyl.. benzene l 6. 3.:15 20 ''0 1~~ 41 (branched-chain t a ~_ _-__ ~ _-___~.._________.._...____.__ .__ D Alkyl benzene l_2.6 2.62 0 83 15 2 ~

(branched-chain t a K Alkyl benzene 29.0 4.30 2 4:) 2~4 25 (branched-chain t a F Alkyl benzene ;35.2 4.52 2 38 35 25 (branched-chain t a . - _.. _ _. _ __~ ._....__ _-_ _..

r G Alkyl benzene 60.8 5.91 3 32 30 35 (branched-c h a i n t;
a ~

__~_._... _...._.
_.-. ___~_ ___.- ___.-____.._...-__-- _-_____ ' H Alkyl benzene 72.6 6.40 3 22 26 49 I

(branched-chain t a ~_-_,_ __-~ _ _ i Alky1 t>anzana 1 5.4 3. 18 0 ~~(>1 i 30 9 l (straight- ' ~, ~ ~' __ ___-.._.._.._ _...- _ .__ _-_ i _ __ _ __ _. _,__ __._,_ J'Alkyl benzene ''S 4 . 1 45 43 11 . 6 33 (straight- i, i c: h a i n t:
y p a ) _'_ _- ~ ... _... _..- ___.._ ._ ...- _-___ ..._.
' K Refined j naphthenic i 32.5 4.71 _.-_ m ineral oil __ ___ v 21~~~~.

'I'abLe 1 (continued) 1(lnematl~ -._-.._ ___. __._._.
Base oil vi.scosit:y Mole>cu:lar w't. clist;ribut;ion ( mrn ~ !~s ) __~ _ ~_. ( w t. . -o 40°(, 100°(; <z00__.._.__2..UU_:..~jUU -_301-3 50 >350 L 'I'etraester (neopentylglyc:ol/ 7.4 2.05 w--2-ethylhexanoic a c i d - _._ _____-_._..__~_- _-_-.__ --M Tetraester (pentaerythritol/ 66.;j 8.18 ---ethylhexanoic acid & 3,5,5-trimethylhexanoic ac i d __ .._u.. _._.. _.____...._-__~_____-_ N Di 2- 11.3 3.19 -----ethylhexyl f sebacate 0 Complex ester 59.'i 9.71 ---P polyethylene pol_yglycol Lf>1 . 3 ~ 32 . 2 5 Number--average Mol .14't . 2500 d i m a t h 1 a t h a r _ -~ ~ -______...-. ~_«__-__ Q Polypropylene glycol 32.5 6.71 Number-average h1o1.1Nt.690 monobut lether _ ' ._ _ .____...----_-R Tetrapropyl-etherified 41..4 7.18 Number--average Mol .11't.950 product of i propyleneox:i.de addition ' i product of ~- [ i m a t h y 1 ~;1 c o s i d a __~_-.~_.r..-____..__. ____. _ _ __._ __... .. __ ._ _-_.-~____-~-___ _.
S Carbonate oU' trimethylol- 42..1 ~i 5.59 ~ _ __ propana/batanol__~_ _-_: _.__.__...-_ __~___~._~-___-_._ T Acetylized 54.,:~ 4.77.
a1k lbanzc.na I __. _~ ____ _ - ~_ __ _ U Alkyl benzene (branched- 15.2 2.90 1. 72 L7 10 chain type ) _.~_.__-.--_. _.._._._____.___. _.. __- -_-__. - -_ [Note]
A, C, D, E, F, H and U: 'these oils were each produced by distilling a rnJ.xt=ure of monoalkylbenzenes and d.ialkylbenzenes which hack hec~n prepared from, as raw materials, benzene and branched-chain olefins consisting of propylene dinners to octamers and having 6 to 24 carbon atoms, by reacting them in the presence of hydrofluoric acid as an alkylating catalyst.
B: A mixture of A and E (50% by weight:50% by weight).
G: A product obatained by the re-distillation of H.
I and J: These oils were produced by distilling a mixture of monoalkylbenzenes and dialkylbenzenes l-5 which had been prepared from, as raw materials, benzene and n-paraffin having 9 to 18 carbon atoms and separated from a kerosene fraction, by reacting them in the presence of hydrofluoric acid as an alkylating catalyst.
p: An ester obtained by reacting adipic acid, neopentyl glycol and 3,5,5-trimethylhexanol together.
T: A product obtained by reacting the alkylbenzenes of A with acetyl chloride in the presence of aluminum chloride.

Table 2 Additive Name of Compound A Tricresyl phosphate B Dioleylhydrogen phosphate C Di(2-ethylhexyl) acid phosphate D Para-tertiarybutylphenylglycidy_1 ether E Neodecanoic glycidyl ester F 2,6-ditertiarybutyl-p-cresol Various kinds of refrigerator oil compositions of this invention have the compositions shown in 'fables 3 and 4, respectively. The refrigerator oil compositions thus obtained were each subjected to an evaluation test for their long-term operability as illustrated in 'fables 3 and 4 (Examples 1-26).
[Evaluation 'test 1]
A household room air conditioner having a refrigerating capacity of 2.5kw was filled with 3508 of a test oil and 10008 of a mixed refrigerant consisting of HF(:-134a/HFC-32 in a ratio by weight of 70o to 30%
was placed in a thermostatic room kept at an atmospheric temperature of 43°(: and then subjected to a continuous operation of 500 hours while setting the air conditioner to maintain the room at 25°C, in order to evalutate the test oil for its operability.
[Evaluation Test 2]

~~ ~ J ~ ~~ ~~

A luc~useh.ol.d three-door type r~~I'riger-ntor having an effective inner volume of :300 liters was Pi.l.ted with 180g of a refr:igera.nt consisting oi' lil~C-1.34a and 1508 of a test oil , housed in a thermostatic: r°oorn kept at: an atmospheric terni~erature of 4;:3c'G and then subjected to m continuous operation of 500 hours wh.iie setting the temperatures of the freezing chamber and the cooling chamber to -18°(~' and 3°C respectively, in order to evaluate the test oil for its oiler°<:rb.i 1 i t;y (or Performance).
[Evaluation Pest 3]
An evaluation test was conducted using tyre same test oils as those which were rec:ogn:i.zed as LSE-~,ing excellent in the above Lval.uation ~l'est~s 1. and 2 by the I5 use of a rolling piston type compressor in which 50g of a refrigerant consisting of 1-lT'C-1.34a <rnd 70g or a test oil were filled. 'Then, t:hc~ compressor so fi.ll.ed was subjected to a continuous operation c>f' 1_000 hours under the conditions ol' a delivery pressure oi' 161cgI'/cmZG, an inlet pressure of Okgf/cm~G, a revolvi_ug :peed o(' 300rpm and a test temperature of 160«(',. After 1..000 hours of the test, t=he surface roughness of sliding surface portion of t-he compressor vanes was measured.
For the purpose of comparison, Che same, evaluation tests as those conducted above were also performed on various rc:fr:ige.rator oil compositions as indicated in Tabl_~ 5 , i. . a . , a composi t.i on comprising ~ ~, ~. ~ ~a .><. '~~ ~31 t~
- 4z -only an a.llcy.ibenzene «i.i c:otrtuirti.ttg Less Lltatt 60'i by weight (based ott the total we.ighL oi.' the component (A) ) of alkylbenzenes having a molecular weight of 200 Lo 350 in the component (A) (Cornparat:ivEe l3xarnpl_es 1 to 4) ;
a eompositi.on comprising a re1'ine~cl rtaphthene--based tn:inera7_ oii as the component: (A) ((;otnp<,trat.iVE', C:xample 5 ) ; a c:ompos i ti.on con i;ai.n:ittg~ on ly t:tte c:oml:~c~nont ( B ) (Comparati.ve Lxarnples 6 to ;3) ; <rrtd a.t composition containing tyre component (f3) in a mixing ratio -i'alling outside the range defined by this invettLion (Comparat.ive Examp:Les lU to 13). The results of these tests are also shown in 'table 5.

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Examples 27 to 30 and Comparative Examples 14 to .17 There were prepared various kinds of the refrigerator oil compositions of this invention having their respective compositions shown in Table 6 (Examples 27 to 30). The refrigerator oil compositions thus prepared were subjected to the following Oil--return Property Test 1 as indicated below. 'L'he results obtained are shown in Table 6.
[Oil-return Property Test 1]
An experimental apparatus shown in Fig. 1 was employed, and 5.Og of an oil was filled into the portion of the thermostatic tank in which the copper conduit of 1.5m in length and 0.0036m in inner diameter was dipped. The temperature of the thermostatic tank was set to -220°C, and HFC-134a was allowed to flow at a flow rate of O.OOlm3. 30 minutes later, the amount of oil collected in the oil pan was measured, and, based on this measurement, an oil-return ratio was calculated according to the following equation.
Oil-return ratio (wt.%) =(Amount (g) of oil collected)/5.0(g) X 700 For the purpose of comparison, the same evaluation test as mentioned above was conducted using a refrigerating oil composition containing only the component (A) as the base oil as indicated in Table 6.
The results obtained are shown in Table 6.

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Examples 31 to 56 and Comparative Examples 1_8 to 30 There were prepared various kinds of the refrigerator oil c.~.ompositions of this invention having their respective compositions shown in Tables 7 and 8 (Examples 31 to 56). The refrigerator oilcompositions thus prepared were subjected to an evaluation test for their long-term operability as indicated below. 'The results obtained are shown in Tables 7 and 8.
[Evaluation Test 4]
A household room air conditioner ~lavirig a refrigerating capacity of 2.5kw was filled with 3508 o.f a test oil and 10008 of a mixed refrigerant consisting of HFC-125/HFC-32/HFC-134a in a ratio of 25~ by weight/52% by weight/23% by weight, was placed :in a 1.5 thermostatic room kept at an atmospheric temperature of 43°C, and then subjected to a continuous operation of 500 hours while setting the air conditioner to maintain the room at 25°C, in order to evaluate the test oilfor its operability (or performance).
[Eval.uation Test 5]
A household three-door type refrigerator having an effective inner volume of 300L was filled with 1508 of a test oil, and 1808 of a mixed refrigerant consisting of HIFC-125/HFC-134a/HFC-143a in a ratio of 44% by weight/4% by weight/52% by weight, placed in a thermostatic room whose atmospheric temperature was kept at 43°C and then subjected to a continuous l ' .! j(~ [/[;;"
~.~~C~.J:.~~

operation of 50t) hours while sett:.ing tile temperatures of the rreez.i.ng chamber <~nd the cc.)ol..i_ng~ charrlber to -18°C and 3°C respectively, i_rl order to evaluate the test oil for operat;i.:l.i ty (per-.Pc)rmancc~) .
[L:valuation 'Pest 6 ~
Arl evaluation lest was eonciuc:t.ed tazsing the same test oils as those which were rec:og-n_i zed as being excellent in the above L;valuation Pests 4 and 5 by the use of a roll i rl~r piston type compressor , i n whictl 70g of a test oil and 5Ug of a mixed refrigerant consisting of HFC-125/HFC-32 in rz ratio of 50 ~ by weighl;/50% by weight were filled. 'Then, the compressor so filled was subjected to a continuous operation of 1000 hours under the conditions of a delivery pressure ol' l6kgi'/crn~(', an inlet pressure of Oikgl.'/cm~G, a revo_Lving speed of 3000rpm and a test temperature of 16U°t;. After 1_000 hours of the test, the surface roughness of sliding surface portion of the compressor vanes wus measured.
For the purpose o:l' <:ompari son , t;he same evaluation tests as conducted above were also performed on various refrigerator oil. coml:)os:itions as i.ndi.cated in 'fable 9, i.e. , a c:ornpc)si.tion comprising only an al.kylbenzene oil al_kylberlzenes c:orltai.ni.ng less than 60~
by weight (based on t;he total weight of the component (A)) of the alkylbenzenes having a molecular weight of 200 to 350 i.n the component (A) (Comparative Cxamples 18 t0 ~~. ) ; ~l C:OCTIpOSl tlOrl CorrlpC Lslrlg a ref l_IlE:d ~' v ~~ f - ~;3 -napLrthene-~asec'1 mir'iera:L c'~il as ttie ~:eonpottent: (A) (Comparat.ive ~xampl.e ~2); a c~.otnpos.ition ooritrzi.nirtg only the componen t ( i3 ) ( Comparative hxamp I es 2,3 to 2Ep ) ; and a composition c: ontarining ttae componc:rrt (Li) in a mixing ratio fall_i.ng outsi.cle the range de('it~ed by ti:ri.s invention ( Comparat:ive Exanrp l es z7 to 30 ) . 'I'h.e resin t=s of these i:ests are also shown in Takr L a 9 .

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r, U oo N I I ~r ~ I
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a a a a O O n t! .Ly N N

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N

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N

a a a N

H

n r~v n N

C, Ca U .G

Y

N H

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O

au Y Y JJ V

H ~ N

N 'p O N N 4-~

fd 'fl E~ E~' E-~(~

.H

id tn V

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i~

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lC

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0. ~ 4r ...-. +, 6 a 4w ~V O

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>

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r~~~ 3.

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n n O O O

O7 . .
N (s, O' O O

a a O

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a ~ ,-, F3 v O , f, ~r ~CN CC '~E I I C/7 (/;~
O O

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o ~I O a a I O
-U r -a n O

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n ~ N

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O

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N

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N

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f3 La i fd N >

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a v S.'tr - E)0 -Examples 57 to 60 and Comparative L:xarr~~les 30 Lo ;34 'i'here wera prepared various k i.nds oi-' the refrigerator oi:l. cornposi dons of LhiS invention leaving i:hei.r respective connposiLions shown irr '1'abl.e 1.0 (Examples 57 to 60) . 'T'hc>, roi'rigcraztcor oi..lc:omposiLions thus prepared wore sut,jected to i.lre t'ol:l.c~win,~,r O:i:L-return Property Test ~ as indi.cat.crd below. The results obtained are shown irz Table 10.
[Oi.:l_-ret;urn Property 'Pest 21 An experimental. apparatus shown itz Fig. 1. was employed, and 5.0g of an o.i...L was I'.il i.ed into the portion of the i;hermostatic tank i.n whic:h the copper conduit, 1..5m in length and 0.003(im in inner diameter, was dipped. The temperature of tire Lhermostatic tank was set to -220°C, and a mixed refrigerant consisting of IIFC-125/HI~'(:-32/HFC-134a ( ~5 v~t . ~/z3 wt . o/5z wt . % ) was allowed to i'low at az f Low rate o i' U . OOl.m'~; . ,30 minutes later , l;he atnounL o1' tire: o:il co_Ilectc:d in the oil pan was measured, and , based orr t lr:i s ;measurement , an oil-return ratio was o.alcul.ated according t;o the following equation.
Oil-return r<~ti.o (wt . a, ) =(Amount (g) of oi:l c:ollecLed)/ >.0(g) x~ 7_00 For tire pt,trpose of comparison, Ltze same evaluation test; ms mentioned above; was conducted using a refrigerating oil composition containing only the ... "~ ~,~ ~ x - Ei l component (A) as the base oil as ind~sated in 'fable J0.
The results ol.~tained azre rilso shown i n 'fa.bl.e 1Ø
to iw. a ~~ ~>
~~3.~.~~~
- Ep2 -o r-~r-, I - ma w M -- O I C7 a. r.

O i O O

a a a N

6 n M I I I eo W M - O I I I

N .--r 7 a N

N n O r~

d N I O I ~C

M d' O I 4' I N

O O 1 .-rI

U .-~ a a n O

I I I e~

M C O I I I N

O I I I

ri a n n O O n n O ~ t!7 .-i tD n...1t7?-., ~t7CO GY M

t0 ~ O O

a a a a r1 O O

z ~ I I M

I I

O a a ~C n n W O O n , o I o0 eC tf ..-a LCD<C I M
J

00 r-i ~i 1 a a a n n O O

.n sC vra.-a wa I I M

I I
a a t, n n n O

C GC U .c7 L ~ a..

O

- -~ a7 O

O

+ y p N c, b td 'd 00 CO ~C C

C

Nn ~ if O

N ~

+' n 4~
i I ~r N

CL ~ O

B v O

U

- Ei:3 -As appaarettt ('rom the resin is oi' tire performance eval.uati.<m t;est=s slrc~wrt itt 'i'ables ;3 anti 4 tts we:l.l as shown in 'fables 7 wand 8, the ret'rig~erator o:i_1 compositions of th:i.s invention dial riot cause the seizure of rel.'ri.geratiny compressor and were ex.cell.ent i.n lubricity, thus making it possible to maintain a high reliabil.i.ty for az L<>ng~ period ol' time.
In partict.tlar, the refrigerator oil c:ompositic>ns o f' t~xazyo l es l ~i t.o ~4 , ~6 , 48 to >4 and 56 , each containing a phosuphorus compound ( (; ) , indic:;~ted a remarkable improvement in the surfao.<~ rouglanc~ss of sliding surface portion of the compressor vanes over the refrigerator oi.l composii;:ions of Examples 1 to 17, 25 , 31 to 47 and 55 , t:hus c;learl_y detnoustrating the retnarkable ef f'e<: t oI' the phosuphorus compound ort the improvement i_n wear resistance.
By cont,rzist , when there were used t:he refrigerator oil compositions of (;omparative l3xamples 1 to 4 and 18 to zl shown respectively i.n Fi.gs. 5 and 9, each comprising, as t;lne cotnpottent (A) , an alkylbenzene oil (alkylbenzenes) containing less than 60% by weight (based on the total weight of the component (A)) of the a:lkylbenzenes having a molecular weight ranging frotn 200 to 350, the seizure oi' a refrigerating compressor used was recognized, thus i.ndicat;i.ng that they cannot be reliably used for a. 7.cong period of time. It was also recognized that t:he gertc:ration of the sei.zure of a.. ... ~ f~
~~~~.~~~>
- Ei4 -the refrigerating compressor could not; bc: ;:zvo:i.ded even of a phosuphorus cornpoutrd was tzdcaeci Lc~ tlae:~e refrigerator oil compositions of the (.;omparative hxamples. 'This tendency wszs also rec:ogn:ized in the cases of the Comparative Examples 5 and '~2 usitrg a naphthene-based mineral oil.. as the component (A).
On the other hand, when tire refril;erator oil compositions ovf' Cornparat;ive F_xamp.les Ei arrd 23, each c;ornlorising only peni;azerythri t<al ester as the component (B) , and of Comp~arat:ive Cxamples 8 and z;i, each comprising only polypropylene glycoi_rnonoalkyl ether as the component (t3), were used, they indicated far poor wear resistance as compared with the refrigerator oil.
composition of this i.nventi.on, even t;hou~;h ttrey did not;
cause the seizure a~i' the refrigerat::i.ng compressor.
Furt;her, the refrigerator oi.l compositions of Comparative Examples 7 , 9 , z4 and 2E3 , which were prepared by adding a phosuphorus compound (C) Lo the same refrigerator oils as Lhose of Comparative Fxamp7es g, g, 23 and 25, respectively, did not; exhibit any substantial improvc~rnerrt in wear resi stance . 'This clearly cienronstrates a synerg~.isti.c ei'i-'ect of the base oil (t;he components (I1) and (l~) ) and a phosuphorus compound (C) in the refrigerator o.il composition of this invention.
On the other hand, as apparent; from the results of oil-return property test shown in Digs. 6 and 10, the refrigerator oil composition of this invention is far excellent in oil-return property of t:he refrigerator oil as compared with those of Comparative Examples 14 to 17 and 31 to 34, each containing only the component (A) as a base oil.
As explained above, the refrigerator oil composition of this invention is suited for use in an HFC$refrigerant containing HFC-134a and/or HFC-125, beCauSe it enables the generation of seizure of the refrigerating compressor to be avoided and 1S
excellent in lubricity, thus making it possible to maintain a high reliability for a long period of time.
'therefore, the refrigerator oil composition of this invention is highly useful as a refrigerator oil composition to be utilized together with an HFC
refrigerant containing HFC-134a and/or HFC-125. As explained above, it has been made possible to provide a refrigerator oil composition suited for use with an HFC
refrigerant containing HFC-134a and/or HFC-125, and to provide a refrigerator fluid composition comprising such a refrigerator oil composition as mentioned above and an HFC refrigerant containing HFC-134a and/or HfC-125.

Claims (18)

1. ~A refrigerator oil composition for use with an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof, which comprises component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350, said alkylbenzenes having a kinematic viscosity of 3 to less than 72.6 mm2/s at a temperature of 40°C., said component (B) being 30 to 1%
by weight of at least one synthetic oil containing oxygen, said synthetic oil being a member selected from the group consisting of a dibasic ester, a polyol ester, a complex ester, a polyol carbonate, a polyalkylene glycol, an alkyl ether of said polyalkylene glycol, an adduct of a polyol with an alkylene oxide, an ester of a polyalkylene glycol, a ketone and a mixture thereof.

2. A refrigerator oil composition according to claim 1, further comprising component (C), said component (C) being 0.005 to 5.0 parts by weight, based on 100 parts by weight of mixed base oil comprising said components (A), (B) and (C), of a phosphorus compound.

3. A refrigerator oil composition according to claim 1, wherein said alkylbenzene oil contains at least 65% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

4. A refrigerator oil composition according to claim 1, wherein said alkylbenzene oil contains at least 70% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

-67-~

5. ~A refrigerator oil composition according to claim 1, wherein said alkylbenzene oil contains at least 80% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

6. ~A refrigerator oil composition according to claim 1, wherein said alkylbenzene oil contains 100% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

7. ~A refrigerator oil composition according to claim 1, wherein said alkylbenzene oil contains at least 30% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 300 and at least 60% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

8. A refrigerator oil composition according to claim 1, wherein said alkylbenzene oil contains at least 35% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 300 and at least 60% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

9. A refrigerator oil composition according to claim l, wherein said alkylbenzene oil contains at least 40% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 300 and at least 60% by weight, based on the total weight of said component (A), of alkylbenzenes having a molecular weight of 200 to 350.

10. A refrigerator oil composition according to claim 1, wherein said alkylbenzenes having a molecular weight of 200 to 350 have 1 to 4 alkyl groups, each group containing 1 to 19 carbon atoms and the total amount of carbon atoms in the alkyl groups being 9 to 19.

11. A refrigerator oil composition according to claim 10, wherein said alkylbenzenes are selected from the group consisting of a monoalkylbenzene, a dialkylbenzene and a mixture thereof.

12. A refrigerator oil composition according to claim 1, wherein said alkylbenzenes having a molecular weight of 200 to 350 have 1 to 4 alkyl groups, each group containing 1 to 15 carbon atoms and the total amount of carbon atoms in the alkyl groups being 9 to 15.

13. A refrigerator oil composition according to claim 1, wherein alkyl groups of said alkylbenzenes having a molecular weight of 200 to 350 are branched-chain alkyl groups.

14. A refrigerator oil composition according to claim 13, wherein said branched-chain alkyl groups are derived from oligomers of olefins.

15. A refrigerator oil composition for use with an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof, which composition comprises component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350, said alkylbenzenes having a kinematic viscosity of 3 to less than 72.6 mm2 /s at a temperature of 40°C, said component (B) being 30 to 1 % by weight of a synthetic oil containing oxygen.

16. A refrigerator fluid composition which comprises:
(I) an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof and (II) a refrigerator oil comprising component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350, said alkylbenzenes having a kinematic viscosity of 3 to less than 72.6 mm2 /s at a temperature of 40C, said component (B) being 30 to 1% by weight of at least one synthetic oil containing oxygen, said synthetic oil being a member selected from the group consisting of a dibasic ester, a polyol ester, a complex ester, a polyol carbonate, a polyalkylene glycol, an alkyl ether of said polyalkylene glycol, an adduct of a polyol with an alkylene oxide, an ester of a polyalkylene glycol, a ketone and a mixture thereof.

17. A refrigerator fluid composition according to claim 16, wherein said refrigerator oil further comprises component (C), said component (C) being 0.005 to 5.0 parts by weight, based on 100 parts by weight of mixed based oil comprising said components (A), (B) and (C), of a phosphorus compound.

18. A refrigerator fluid composition which comprises:
(I) an HFC refrigerant containing HFC-134a, HFC-125 or a mixture thereof and (II) a refrigerator oil comprising component (A) and component (B), said component (A) being 70 to 99% by weight of an alkylbenzene oil containing at least 60% by weight, based on the total weight of component (A), of alkylbenzenes having a molecular weight of 200 to 350, said alkylbenzenes having a kinematic viscosity of 3 to less than 72.6 mm2 /s at a temperature of 40°C, said component (B) being 30 to 1% by weight of a synthetic oil containing oxygen.