FR2792326A1 - NON-TOXIC AND BIODEGRADABLE FUNCTIONAL FLUIDS BASED ON COPOLYMERS OF ETHYLENE OXIDE AND PROPYLENE OXIDE FOR MOTOR VEHICLES - Google Patents

Abstract

The invention relates to the use of copolymers of ethylene oxide (EO) and propylene oxide (PO) as one and the same base fluid for the manufacture of various functional fluids of motor vehicles by the addition of suitable non-toxic and biodegradable functional additives.

Description

The invention relates to non-toxic functional fluids and

  biodegradable for motor vehicles obtained by adding non-toxic and biodegradable functional additives to basic fluids of the copolymer type of ethylene oxide and propylene oxide or of fatty chain ester types of neopolyols. Each motor vehicle currently contains a variety

  fluids fulfilling different functions such as lubricating oils

  engine and / or gear, hydraulic oils such as power steering fluid, brake fluid or shock absorber fluid, and

coolant.

  When a vehicle is permanently put out of use, all of these fluids must be 95% removed and landfilled in containers

  separated or recycled separately resulting in significant costs.

  Among these functional fluids, the most problematic from an ecological point of view is undoubtedly engine oil. Indeed, lubricants

  today mainly use mineral base oils (paraffini-

  or naphthenic) or synthetic little or not biodegradable. For

  meet the requirements of a specification or lubricant standard

  reliably, a set of additives having functions are added to this base oil

  very specific. By way of example, such additives may be indicated as corrosion / rust inhibitors of the metal parts of the engine, - anti-wear (AW) and extreme pressure (EP) agents reducing friction by chemical reaction with the metal surface , - dispersing agents ensuring the dispersion and removal of insoluble solid contaminants, - detergent agents preventing the formation of deposits on the surface of metal parts by dissolution of secondary oxidation or combustion products, - agents increasing the viscosity index (VI), i.e.

  reducing the decrease in the viscosity of the lubricant as a function of the temperature

temperature,

  - anti-oxidation agents inhibiting degradation by oxida-

the lubricant, and

  - agents lowering the pour point.

  Most of these additives have toxicity problems and

  are not biodegradable or are carcinogenic.

  Thus, the current engine oils pose a serious problem for the protection of the environment because oil leaks, emission with exhaust gases and non-control of the collection and recycling of a high tonnage of waste oils (in Germany, up to 20 to 30%

  sales volume) are the source of significant pollution.

  One approach to overcome these problems has been to use

  non-ecotoxic and rapidly biodegradable base fluids.

  Thus, patent application DE A 196 47 554 (Daimler Benz and Fragol Industrieschmierstoffe) discloses a refrigeration and lubrication fluid for life of an internal combustion engine consisting of a fluid

  carrier based on a copolymer of ethylene oxide and propylene oxide

  lene having an average molar mass of between 300 and 700 and an EO / PO weight ratio of between 30/70 and 70/30, and of a mixture

additives.

  However, in this application, only the base fluid has a rapid biodegradability greater than 90% and an absence of ecological toxicity. WO 97/30137 (corresponding to DE 196 OS 162) (Elf Antar) describes a lubricating composition consisting of at least 70% by weight of at least one C2_5 monoalkylene glycol, and up to 30% of a mixture additives. This composition may also contain a small proportion, in particular from 0 to 15% by weight, of a polyalkylene glycol having a molar mass of less than 5000.

  However, due to the high volatility of monoalkylene-

  glycols, the upper temperature limit for the use of these lubricants is at most 165 C. A large part of the additives contained in these

  lubricants are also toxic and not very biodegradable.

  The Applicant has now discovered that it is possible to

  overcoming the problems linked to the ecotoxicity and recycling of lubricants

  prior art fiants, hydraulic fluids and coolants using copolymers of ethylene oxide and propylene oxide or fatty chain esters of neopolyols as the sole

  basic fluid for the various functional fluids and adding uni-

  only non-toxic and rapidly biodegradable additives in one

reduced quantity.

  This use of the same basic fluid makes it possible, when the vehicle is finally put out of use, to landfill with a single waste number or jointly reprocess all of the fluids

  functional made from it.

  In addition, the use of exclusively non-toxic additives

  and biodegradable also solves the problem of ecological nuisances

  ques in the event of accidental leaks or negligence in recovering fluids.

  The present invention therefore relates to the use of copoly-

  mothers of ethylene oxide (EO) and propylene oxide (PO) or fatty chain esters of neopolyols as one and the same base fluid for

  the manufacture of various functional fluids for automotive vehicles

  by adding appropriate non-toxic and bio-functional additives

  degradable. It also relates to a functional fluid for a motor vehicle containing a base fluid consisting of copolymers of ethylene oxide (EO) and propylene oxide (PO) or of fatty chain esters of neopolyols above, and various non-toxic and biodegradable functional additives. Copolymers of ethylene oxide and propylene oxide (hereinafter referred to as EO / PO copolymers) used as the base fluid

  for the production of functional liquids are statistical copolymers

  containing 30 to 90% by weight of units derived from ethylene oxide and 70 to 10% by weight of units derived from propylene oxide and having

  a weight-average molar mass of between 300 and 1,200.

  These basic fluids, due to their macromolecular structure, have high viscosity indices, generally between 140 and

  220, which make the addition of additives having the function of increasing

  mention of the viscosity index.

  The good miscibility with water of these fluids makes it possible to do without

  dispersant and / or detergent additives during the formulation of lubricants

proud.

  The rapid biodegradability (according to CEC L-33-A-94) of these fluids

  des is greater than 70% or even sometimes greater than 80%.

  These copolymers have a good lubricity which can be

  attribute to the formation of films strongly adsorbed on the surface of the parts

  these subject to friction. They also have a very pour point

  low, less than -20 C or even less than -30 C. Their cooling power

  manager is better than that of mineral oils.

  The other group of compounds used according to the present invention

  as base fluid for functional liquids in motor vehicles

  the, includes various fatty chain esters of neopolyols.

  The term “neopolyols” according to the present invention means alcohols

  containing at least three hydroxyl functions and having a neo- structure

  pentylic, that is to say a structure characterized by the absence of a

  hydrogen atom on the carbon atom in position cx of the carbons

  both the hydroxyl functions. This absence of a hydrogen atom in posi-

  tion has alcohol functions is of paramount importance because it gives the esters of these polyols a very high chemical stability, in

  particularly high stability to hydrolysis.

  The neopolyols on the basis of fatty chain esters include, for example, neopentylglycol (diol), trimethylolpropane (triol),

  pentaerythritol (tetraol) and dipentaerythritol (hexaol).

  These polyols are esterified with long chain monoacids, that is to say C8_36 fatty acids, with linear or branched chain, saturated

  or unsaturated, but preferably saturated, or with mixtures of such acids

fat.

  The esterification can be partial or complete. However, to obtain a sufficient kinematic viscosity and a fairly high ignition point, at least two hydroxyl functions must be esterified

by fatty acids.

  There may be mentioned as examples of suitable saturated fatty acids

  caprylic acid, pelargonic acid, capric acid, lauric acid

  that, myristic acid, palmitic acid, stearic acid, ara-

  chidic, behenic acid, lignoceric acid, cerotic acid, and

  branched isomeric forms of these.

  Fatty acids can also have one or more

  double bonds, but these unsaturations are poten- tial oxidation sites

  and affect the chemical stability of the base fluids.

  The number of ethylenic unsaturations of the esters can be characterized by the iodine index, that is to say by the number of grams of iodine (12) which can be fixed per 100 g of material. To guarantee good stability of fatty chain esters of neopolyols, the iodine value must

  be less than 10 and preferably less than 1.

  The chain length, the branching rate and the unsatu-

  ration of fatty acids used influence the physicochemical properties

  of the basic fluids obtained. Thus, a significant branching rate

  reduces the pour point and increases resistance to hydrolysis.

  Long chains with little branching lead to high viscosity indices. The fatty chain esters of neopolyols used as base fluid in the present invention have a viscosity index

at least 140.

  As indicated above, the rate of unsaturation plays a role in the oxidation stability. The appropriate choice of all of these

  parameters must be done according to the different specifications.

  The rapid biodegradability (according to CEC L-33-A-94) of these esters

  fatty acids and neopolyols used as base fluids is superior

less than 90%.

  The two types of molecules described above used according to the present invention as base fluid for functional liquids of motor vehicles must have low volatility. In the engine sector, this volatility is assessed by measuring the loss of

  mass by high temperature evaporation. This loss of mass is deter-

  mined in Europe using the Noack test, of German origin (NF T 161, CEC L-40-A-93, DIN 51-581), which consists of heating 65 g of oil to

  250 C for 1 hour under air depression of 20 mm of water.

  The basic fluids, namely EO / PO copolymers or esters

  with fatty chains of neopolyols, used according to the present invention must

  wind have a volatility (Noack) lower than 7% and preferably inferior

less than 4%.

  Furthermore, as indicated above with regard to the copolymers

  EO / PO, the basic fluids according to the invention must have a flow point

  low enough. By pour point is meant (in English:

  doublet) the lowest temperature at which the oil still flows

  that it is cooled, without stirring, under standardized conditions (NF

T 60-105 / ASTM D 97 / ISO 3016).

  EO / PO copolymers and fatty chain esters of neopo-

  lyols forming the basic fluids used according to the present invention must

  Wind have a pour point below -20 C, and preferably below

  less than -30 C, or even less than -40 C.

  The present invention has set itself the aim of solving the problems

  of ecotoxicity and recycling posed by the functional liquids of

  prior art motor vehicles. For this it offers the use of

  tion of the non-toxic and biodegradable base fluids described above

  in combination with non-toxic and biodegradable additives

  wheat. The interesting physicochemical properties of the non-additive base fluids described above, such as their viscosity index

  high, their low pour point and good lubricity allow

  try to avoid the use of additives whose function is to improve specific properties (anti-wear / extreme pressure additives,

  pour point and agent increasing the viscosity index).

  Additives used for the production of different fluids

  functional agents are chosen from antioxidant agents, anti-

  corrosion / anti-rust, pH regulating agents (buffer), anti-wear agents, anti-hydrolysis agents, dispersing agents and agents

  anti-foam, all non-toxic and biodegradable.

  The non-toxic and biodegradable antioxidants are chosen from zinc dialkyldithiocarbamates, dithiocarbamates

  alkyl such as methyl dithiocarbamate, vitamin E (tocophé-

  rol) and derivatives thereof, sterically hindered phenols such as

  2,6-di-tert-butyl-4-methyl-phenol or similar hindered phenols

  res in which the methyl group in position 4 is replaced by a

  higher aliphatic alkyl group, and dialkyl trisulfides.

  Non-toxic and biodegradable anti-corrosion / anti-rust agents

  dables are chosen from succinic acid derivatives such as acids

  alkylsuccinics and partial esters of succinic acid, and alkylben-

neutral calcium zenesulfonates.

  Poly (aspartic acid) is a peptide polymer of aspartic acid capable of performing both the functions of dispersing agent, buffering agent (pH regulator) and antiwear agent. Preferably, a poly (aspartic acid) having an average molar mass in

  weight between 1000 and 10 000.

  When the base fluid is a neopolyol ester, it is necessary

  Be sure to add an agent to protect it against hydrolysis. Such agents

  non-toxic and biodegradable are for example the steric carbodiimides

only crowded.

  Non-toxic and biodegradable defoaming agents are

  example chosen from polydimethylsiloxanes.

  Although, for most applications, the addition of agents

  anti-wear is not necessary, it can be useful in the formula-

  tion of engine or gear oils. Appropriate anti-wear agents

  are for example zinc dialkyldithiocarbamates, olefins sulfu-

  esters of sulfurized unsaturated fatty acids, sulfurized jojoba oil

  and vegetable oils capable of being sulfurized by trapping and trans-

  sulfur sulfur from the fuel.

  This list of additives is of course not exhaustive and may

  be extended according to the specifications of the different functional fluids

  nels that we wish to manufacture provided that only

  non-toxic and biodegradable functional additives.

  The amounts of these various additives will of course depend on the nature of the base fluid and the role of the additive. In general, the oxidizing agent or agents are used in an amount of 0.2 to 3% by weight, the anti-corrosion / anti-rust agent (s) are present in an amount of 0.05 to 1% by weight, the or anti-wear agents, if present, are added in an amount of 0.1 to 2% by weight, the polyaspartic acid is present in an amount of 0.3 to 3%

  by weight, the anti-foaming agent (s) are present in a lower amount

  less than 0.02% by weight and the anti-hydrolysis agent (s) are present in an amount of 0.2 to 2% by weight, all these values being related to the base fluid. Likewise, the total amount of functional additives

  added will depend on the chemical nature of the base fluid and the application

  tion of the final functional fluid. It is generally between 1 and 20% by weight, preferably between 2 and 12% by weight relative to the base fluid.

  The functional fluid produced by adding functional additives

  non-toxic and biodegradable compounds with copolymers of ethylene oxide and propylene oxide or with esters of neopolyols, can for example be a motor oil, a gear oil, an automatic transmission oil, an oil for power steering, a fluid

  hydraulic for shock absorbers, brake fluid or coolant

  dissement. The functional fluid of the present invention, when it is

  of engine oil, is preferably used in engines whose parts

  these friction - based on new ceramic type materials or

  posites or surface treated with triboactive coatings - are less prone to friction wear than metallic mechanical parts

  conventional internal combustion engines.

  In such types of engines, the functional fluids used as engine oil allow lifetime or long term lubrication

  term of the engine because of functions conventionally assumed by addi-

  gradually consumed (increased viscosity index and anti-wear) are now filled with the base liquid which is available

in unlimited quantity.

Claims (19)

  1. Use of copolymers of ethylene oxide (EO) and propylene oxide (PO) as one and the same base fluid for the manufacture of various functional fluids of motor vehicles   by adding suitable non-toxic and biodegradable functional additives   dimmable. 2. Use according to claim 1, characterized in that the EO / PO weight ratio of said ethylene oxide copolymer and   propylene oxide is between 30/70 and 90/10.   3. Use according to claim 1 or 2, characterized in that the weight-average molar mass of said copolymer of ethylene oxide and propylene oxide is in the range from 300 to 1200.   4. Use according to any one of the preceding claims.   teeth, characterized in that said EO / PO copolymers have a volatility (Noack volatility measured according to DIN 51581) of less than 7%, preferably less than 4%.   5. Use according to any one of the preceding claims.   teeth, characterized in that said EO / PO copolymers have a   viscosity index greater than 140.   6. Use according to any one of the preceding claims.   teeth, characterized in that said EO / PO copolymers have a pour point of less than -20 C, preferably less than -30 C, and   especially below -40 C.   7. Use according to any one of the preceding claims.   teeth, characterized in that said functional additives are chosen   among antioxidants, anti-corrosion / anti-rust agents, pH regulating agents (buffers), anti-wear agents, anti-hydrolysis agents, anti-foaming agents and dispersing agents, all not toxic and biodegradable.   8. Use according to claim 7, characterized in that the non-toxic and biodegradable antioxidants are chosen from zinc dialkyldithiocarbamates, alkyl thiocarbamates such as methyl dithiocarbamate, vitamin E (tocopherol) and   derived therefrom, sterically hindered phenols such as 2,6di-   tert-butyl-4-methyl-phenol or similar hindered phenols in which the methyl group in position 4 is replaced by an alkyl group   higher aliphatic, and dialkyl trisulfides.   9. Use according to claim 7, characterized in that   that the non-toxic and biodegradable anti-corrosion / anti-rust agent (s)   dables are chosen from succinic acid derivatives such as acids   alkylsuccinics and partial esters of succinic acid, and alkylben- neutral calcium zenesulfonates.   10. Use according to claim 7, characterized in that one uses as dispersing agent, buffering agent (pH regulator) and antiwear agent a poly (aspartic acid) having a molar mass   weight average between 1,000 and 10,000.   11. Use according to claim 7, characterized in that zinc dialkyldithiocarbamates, sulfurized olefins, esters of sulfurized unsaturated fatty acids are used as antiwear agent.   sulfurized jojoba oil and vegetable oils likely to be sulphurous   by trapping and transferring sulfur from the fuel.   12. Use according to claim 7, characterized in that   that the non-toxic and biodegradable anti-foaming agent (s) are chosen   located among polydimethylsiloxanes.   13. Use according to any one of the preceding claims.   teeth, characterized in that the content of non-toxic and biodegradable functional additives in the functional liquids prepared from the base liquid is between 1 and 20% by weight, preferably between 2   and 12% by weight based on the base fluid.   14. Use according to any one of the preceding claims.   teeth, characterized in that said functional fluids prepared   are selected from engine oil, gear oil, transmission oil   automatic mission, power steering oil, hydraulic fluid   for shock absorbers, brake fluid and coolant.   15. Functional fluid for a motor vehicle, characterized in that it contains a base fluid consisting of copolymers of ethylene oxide (EO) and propylene oxide (PO) according to any one of   claims 1 to 6, and non-toxic and biodegradable functional additives   dables, including at least one antioxidant agent chosen from dibutyldithio-   zinc carbamate, alkyl thiocarbamates, vitamin E (tocopherol)   and derivatives thereof, sterically hindered phenols and trisul-   dialkyl fures, which antioxidant is present at 0.2 to 3%   by weight based on the base fluid.   16. Functional fluid for a motor vehicle, characterized in that it contains a base fluid consisting of copolymers of ethylene oxide (EO) and propylene oxide (PO) according to any one of   claims 1 to 6, and non-toxic and biodegradable functional additives   dables, including at least one anti-corrosion agent chosen from succinic acid derivatives and neutral calcium alkylbenzenesulfonates,   which anti-corrosion agent is present in an amount of 0.05 to 1% by weight brought to the base fluid.   17. Functional fluid for a motor vehicle, characterized in that it contains a base fluid consisting of copolymers of ethylene oxide (EO) and propylene oxide (PO) according to any one of   claims 1 to 6, and non-toxic and biodegradable functional additives   dables, including a poly (aspartic acid) having a weight-average molecular weight of between 1000 and 10,000, and which is present in an amount of 0.3 to 3   % by weight based on the base fluid.   18. Functional fluid for a motor vehicle, characterized in that it contains a base fluid consisting of copolymers of ethylene oxide (EO) and propylene oxide (PO) according to any one of   claims 1 to 6, and non-toxic and biodegradable functional additives   dables, including at least one anti-wear agent chosen from dialkyldithio-   zinc carbamates, sulfurized olefins, esters of unsaturated fatty acids   sulphurised res, sulphurized dejojoba oil and susceptible vegetable oils   to be sulfurized by trapping and transfer of sulfur from the car-   burant, which antiwear agent is present at 0.1 to 2.0% by weight reported to the base fluid.   19. Functional fluid for a motor vehicle, characterized in that it contains a base fluid consisting of copolymers of ethylene oxide (EO) and propylene oxide (PO) according to any one of   claims 1 to 6, and non-toxic and biodegradable functional additives   dables, including at least one anti-foaming agent chosen from polydimines   thylsiloxanes, present in an amount of less than 0.02% by weight brought to the base fluid.