EP1174489A1

EP1174489A1 - Process for preparing cutting lubricant fluids

Info

Publication number: EP1174489A1
Application number: EP01500194A
Authority: EP
Inventors: Giancarlo Occhiena; Marta Cardona Capdevila; Salvatore Musti; Josep Canals Aubanell; Guillermo Pardo Pascual; Alfio Bonciolini
Original assignee: Nueva Fl Iberica Sa
Current assignee: Nueva Fl Iberica Sa
Priority date: 2000-07-21
Filing date: 2001-07-19
Publication date: 2002-01-23
Also published as: ES2172412B1; ES2172412A1

Abstract

The process starts from A) an oil phase; B) an aqueous phase; C) a bactericidal fungicide; and D) high pressure components, proceeding in situ by successively mixing said components with water, at the site of use, the proportions of the components varying in accordance with the type of machining and metal to be machined. The basic components are divided into composition sub-groups for their allocation to different machining states. It allows mixing of the components to be carried out in the appropriate lubricant reservoir of the cutting machine.

Description

The invention discloses a new and original process for preparing lubricant cutting oils intended for various machining operations, with cutting of metals.
As is known, fluid lubricants and coolants which act between the tool and the workpiece are required in metal machining operations, allowing various effects to be brought about, including cooling of the part and the tool as a consequence of friction and of the work involved in cutting, a lubricating action to reduce the coefficient of friction and other characteristics such as resistance to extremely high pressure, which is important in certain types of machining, as well as bactericidal or fungicidal and other characteristics.
At present coolants are prepared by means of the components required in each application, the user subsequently diluting them in water in the proportion intended to produce the lubricant and coolant which is to be disposed in each cutting machine in accordance with the characteristics of metal, tool, machine, finishing etc..
The problems which arise when using lubricants and coolants in the currently known form principally consist in the need to have available a large variety of said fluids, commonly called "cutting compounds", in order to be able to use one of them in the appropriate operation and machine. Another considerable disadvantage lies in the fact that once the chosen lubricant has been placed in a certain machine the degradation which said lubricant experiences during the operation is difficult to compensate for since adding water from the dilution to compensate for the volume lost will vary the concentrations of the basic products and, therefore, the characteristics of the lubricant/coolant product.
To alleviate the aforementioned disadvantages, the inventor has invented a process for preparing the coolant/lubricant fluid in situ, starting from a basic range of products and proceeding to mix the same in the desired proportions. It is possible by means of the present invention therefore, above all in large machines which only support stocks of the basic range of products which form part of the present invention, to mix and dilute said products in water in the suitable proportions, which also form part of the present invention, in such a way that to achieve the cutting compound necessary for a certain machining operation the user may only proceed to consult the table of compositions in order to ascertain the precise proportions of the different basic components which have to be used in order to achieve said lubricant/coolant liquid.
Application of the process which is the subject of the present invention will also allow easy recuperation of the coolant/lubricant liquid as it will allow the individual components which have been lost during the operation to be replaced by reconstructing the initial conditions of the cutting compound.
To achieve this aim the present invention provides the use of four basic components in different proportions as will be explained hereinafter.
The basic components are the following:
A) oil phase
B) aqueous phase
C) bactericide/fungicide
D) high pressure components

Component A fundamentally consists of the mixture of products soluble in oil with a composition defined as follows:

COMPONENT	PERCENTAGE
	Generic	Preferred
Basic lubricant	20-80	30-65
Dispersant detergents	5-20	5-15
Non-ionic emulsifiers	5-20	5-15
Fatty acids	5-20	5-12
Cosolvents	1-5	1-3
High molecular weight esters	2-25	2-10

We understand the basic lubricant to be the fluid which prevents friction between sliding surfaces and is also the carrier of certain additives which modify the behaviour thereof, behaving in the system like a lipophilic part and which therefore contains the grease-soluble functional additives.
The basic lubricants considered in the process of the invention are:

Paraffin mineral oil with a viscosity at 40°C between 10 and 46 cSt, preferably between 15 and 32 cSt.
Naphthene mineral oil with a viscosity at 40°C between 10 and 45 cSt, preferably between 5 and 32 cSt.
Paraffin mineral oil treated with H2 and high pressure (free of aromatics and S), known as hydrocracking, with a viscosity at 40°C between 10 and 46 cSt, preferably between 15 and 32 cSt.
Alpha polyolefins with a viscosity at 100°C of 4 to 8 cSt, preferably of 4 to 6 cSt.
Internal polyolefins with a viscosity at 100°C of 4 to 8 cSt, preferably of 4 to 6 cSt.
Lubricant esters based on di- or tricarboxylic acids reacted with monoalcohols with a viscosity at 40°C of 10 to 46 cSt, preferably 15 to 32 cSt.
Lubricant esters based on monoacids reacted with monoalcohols with a viscosity at 40°C of 10 to 46 cSt, preferably 15 to 32 cSt.
Polyol esters with natural or synthetic acids with a viscosity at 40°C of 10 to 46, preferably 10 to 32 cSt (all acids and alcohols considered being natural or synthetic and branched or unbranched).

Dispersant detergents are substances which allow the formation of emulsions/micro-emulsions and in the same way as in the final formulation allow cleaning of machines and machined products. They are generally molecules with a hydrophilic/lipophilic balance suitable for the requirements. The most representative are:

Alkanol amides of saturated and unsaturated organic acids C₈ to C₂₄, preferably C₁₄ - C₁₈.
Natural or synthetic sodium or potassium alkyl benzene sulphonates with a mean molecular weight between 400 and 500, preferably between 430 and 470.
Alkyl benzene sulphonic acids with a molecular weight of 370 to 470, preferably 400 to 440 or acylsuccinic acids or the sodium, potassium or amine salts thereof, the acyl group being C₁₂ to C₁₈.

The emulsifiers or non-ionic surfactants are surface-active agents which form emulsions/microemulsions and impart cleaning properties to the machines and machined products. They are generally molecules with OH radicals and ethylene oxide condensates.
The following may be used:
Ethoxylated C₈ to C₂₂, preferably C₁₂ to C₁₆ natural fatty alcohols with ethoxylation value (ethylene oxide moles/product molecule) between 2 and 30, preferably between 2 and 12. Synthesised alcohols, both linear and branched, with the same number of carbon atoms stated and the same ethoxylation value, may also be used.
Amines derived from C₁₂ to C₂₀, preferably C₁₄ to C₁₈, natural or synthetic fatty acids both saturated and unsaturated with ethoxylation value between 2 and 10, preferably between 2 and 8.
Ethoxylated C₈ to C₂₄, preferably C₈ to C₁₀ fatty acids, both natural and synthesised (monocarboxylates) which can be linear or branched and with ethoxylation value between 3 and 10, preferably between 4 and 6.
Ethoxylated C₈ to C₁₀ alkyl phenols with linear or branched alkyl group and with an ethoxylation value between 2 and 12, preferably between 2 and 9.
C₁₂ to C₂₀ preferably C₁₄ to C₁₈ natural or synthetic fatty acid amides with an ethoxylation value between 2 and 10, preferably between 2 and 8.
C₁₂ to C₁₀ fatty acid esters with or without hydroxyl, ethoxylated with an ethoxylation value between 6 and 30.
On reacting the organic acids with some components from the aqueous phase (B) salts or soaps are formed, which impart dispersant detergent and anticorrosive characteristics, in particular the latter, to the emulsion/microemulsion. The monoacids used have C₇ to C₂₀ atoms, preferably C₅ to C₁₈ which can be saturated or unsaturated (with OH^- groups) and linear or branched. Tall oil or synthetic fatty acids.
The cosolvents are substances with the peculiarity of having part of the soluble molecule in a non-polar or slightly polar medium and functional group or groups soluble in very polar substances, for example water.
Characteristic chemical compounds are the glycols, butyl glycol/branched or cyclic butyl glycol alcohols with C₆ to C₂₄ which can have one or more alcoholic groups, preferably between one or two groups.
The principle function of the esters is to impart high pressure, anti-degassing and oiliness properties and to contribute to the stability of the emulsion/microemulsion conferring anti-foaming properties to the same.
Esters derived from the triethanolamine partially reacted with diacids and monoacids. The ratio monocarboxyl/dicarboxyl allows the molecular weight of the polymerised ester to be defined. The following may be mentioned as examples of this group:
HOSTAGLISS-H
HOSTAGLISS-FN
HOSTAGLISS-D
CLARIANT, Trademark
Simple or complex esters obtained from polyols:
NEOPENTYLGLYCOL
GLYCERINE
TRIMETHYLOLPROPANE
PENTAERITHYRITOL
Also reacted with diacids and monoacids in which the ratio monocarboxylics/dicarboxylics allows the molecular weight of the polymeric ester to be defined.

KETJEHLUBE (*)

** SYN ESTER GY-25
** SYN ESTER GY-15
** De BECKER-LUBRIZOL CORP.
Examples of complementary cosolvent additives are:

Alkylbenzenes and dialkylbenzenes with a viscosity at 40°C between 2 to 12 cSt, preferably 2 to 6 cSt.
Linear or cyclical hydrocarbons or their mixtures without aromatic contents with an ignition point of 40 to 110°C, preferably of 60 to 110°C. These products improve the detergent properties of the basic lubricant and fluidise the same, improving the velocity of the emulsification.

The components which are soluble in water and/or which on reacting with other components form soluble salts in water make up the aqueous phase or component B.
They can have substances which, in turn, react with active components from the oil phase and which impart the desired properties to the final product.
The chemical components used in the aqueous/alkaline phase are:

alkaline reserve contributors with increased pH
alkaline metal hydroxides
hydroxylated amines
primary, tertiary or secondary amines
diglycol amines

Products which impart anticorrosive and/or bacteriostatic properties such as:

Lactic acid
Boric acid
Benzoic acid
Sebacic acid*
Alkylated or non-alkylated succinic acid*
Ethyl hexanoic acid
Azelaic acid*
Isononanoic acid
Cyanic acid
Cecanoic acid
Trimellitic acid* products.
Undecylic acid
Phthalic acid
Reocor 190 (CIBA)
IRGACOR 252 FC (CIBA)
HICOR EK/C (CLARIANT)

Examples of metallic passivators which may be mentioned are:

Benzotriazole
Mercaptobenzotriazole
Tolyltriazole
IRGAMET 42 (CIBA);
IRGAMET BTA/M (CIBA);
ANTICOR C-6 (ADD - APT)

The bactericides/fungicides (component C) are used to disinfect and maintain the low concentration level of fungal and yeast bacteria in the operation systems. They can also contribute to bacteriostatic properties.
Salts derived from orthoacids, such as borax (penta- or decahydrated) IRGACOR 252 FC (CIBA) may also be used.
The following are preferably used in this invention:
1. Oxide-2-pyridinethiol-1 sodium salt
2. 1,3,5 triazine 1,3,5-(2H, 4H, 6H triethanol)
3. N,N-methylene-bis-(5-methyloxyzolidine)
4. 2-(2 methoxyethoxy) ethoxy methanol
5. 1-2 ethanediyl-bis (oxi)-bis methanol
6. 5-chloro-2-methyl-(2H)-isothiazolone
7. 2 methyl-(2H)-isothiazolone
8. Hemiformyl propylene glycol
9. Hexahydrotriazine derivatives
10. VANCIDE 51 (VANDERBILT)
Dissolved or neat, mixtures with substances which complex alkaline earth metals, principally:
Citric acid, tartaric acid, diethyldiaminotetraacetic acid or whole or partial sodium or potassium salts thereof Aqueous solution of a polycarboxylic acid having a molecular weight of approximately 1,400:

POCHS 2050 (DEGUSSA);
Acetodiphosphonic acid
Sodium hexametaphosphate
Sodium pyrophosphate
Sodium tripolyphosphate
Nitrile triacetic acid sodium salt
Sodium gluconate

The high pressure (HP) additives (component D) are substances which confer high pressure properties to the emulsions increasing these to those of the basic product (component A).
The HP additive composition is principally represented by:

Chloroparaffins
Sulphurised olefins
Sulphurised organic esters
Phosphoric acid esters
Polyol-derived complex esters
Esterified polyol amines with mono- and dicarboxylic acids
Polyol esters with monocarboxylic acid compounds of P-sulphur
Thiophosphorus compounds.

The formulations for component D are the following:

	D1	D2
Aicoil 125 TD	15	10
Aicoil 10 SM	-	10
TMP oleate	-	25
HICOR BA/V	14	15.50
Emulsogem M	14	14.5
Ricinoleic acid	6	9
Vegetable olein	2	2.5
Nonylphenol 9M OE	4	4
Butyl diglycol	2	2.5
EXXOL D 100	7	5
Nonylphenol 6m OE	1	2
SYN ESTER SE GY 15	15	-
SYN ESTER SE 110	10	-
Trimellitic isodecanol	10	-

Characteristics

	D1	D2
Viscosity at 40°C	45 cSt	37 cSt
Refractive index	1.4785	1.4766
Acid number	16 mgKOH/g	25 mgKOH/g

The composition in detail of component A (oil phase) is as follows:

	A1	A2	A3	A4
Paraffin mineral oil 40°C 20 cSt	55.80	-	-	30.00
Linear hydrocarbon free of aromatics	-	4.50	5.00	3.00
Oleic acid amide	12.00	16.00	18.50	10.00
AICOIL 10 SM	-	-	-	3.50
Fatty alcohol (C18) with 5 M of OE	8.00	13.00	16.00	10.00
Ricinoleic acid	9.50	7.70	2.50	7.80
TMP oleate	3.70	26.00	5.00	12.00
Nonylphenol 9M OE	5.00	-	-	3.50
SYN ESTER SE 110	-	-	-	3.00
AICOIL TD 125	2.00	2.50	2.50	5.00
Vegetable olein	2.00	1.80	0.50	2.20
Butyl diglycol	2.00	2.00	-	2.00
TMP ESTER 18.2 cSt 40°C	-	26.00	-	-
ISOTRIDECANOL	-	0.50	0.50	-
PAO 6 cSt 100°C	-	-	49.50	-
Alkyl benzene sulphonate of Na pm 460	-	-	-	8.00

Characteristics
	A1	A2	A3	A4
Acid number	16.00	17.00	6.40	17.20
Refractive index	1.4758	1.4652	1.4637	1.4682

The composition in detail of component B (water phase) is as follows:

	B1	B2	B3	B4
Water	34.00	35.00	38.00	37.00
Boric acid	30.00	-	-	-
Monoethanolamine	25.00	39.00	-	13.00
Triethanolamine	10.00	11.00	27.00	18.00
IRGACOR 42	1.00	1.00	-	-
Benzoic acid	-	8.00	6.00	-
Lactic acid	-	5.00	600	5.00
Sebacic acid	-	1.00	-	4.00
Potassium hydroxide	-	-	4.00	-
Benzotriazole	-	-	1.00	2.00
Succinic acid	-	-	10.00	-
REOCOR 190	-	-	8.00	-
Cecanoic acid	-	-	-	4.00
Butyl amine	-	-	-	2.00
Mercaptobenzot riazole	-	-	-	1.00
Cinnamic acid	-	-	-	6.00
HICOR EK/C	-	-	-	8.00

Characteristics
	B1	B2	B3	B4
pH 1%	10.2	9.8	10.3	9.5
Alkaline reserve	80	52	58	45
Refractive index	1.4432	1.4393	1.4402	1.4461

In accordance with the present invention, starting from the basic components indicated, the user will be able to make up the cutting coolant which is of interest to his specific application. For this purpose, the supply of anticipated basic components in the present invention will be complemented by instruction tables to suggest individual percentages for each of the components for each particular application.
Some examples of compositions for machining different metallic materials such as aluminium, steel and cast iron by the machining processes indicated are given hereinafter.
To duly observe the effects of the present invention in comparison with a conventional cutting coolant liquid we carried out the following examples:

Example

In this example the aluminium L-216 was machined in drilling, milling and screwing operations. The water was at 25°F and contained 350 ppm chloride. The capacity of the machine's reservoir was 400 litres and the flow of the liquid lubricant and coolant was 150 to 180 litres/minute.
A lubricant compound of: 0.7% A1; 1.4% B2; 0.4% D2; and the remainder (97.5%) water was used.
The cooling lubricant liquid was prepared with addition of B2 and water according to the composition indicated on the reservoir, with recirculation for 10 minutes followed by the slow addition of the proportion of A1 with 15 minutes of recirculation after the end of the addition, the addition of the proportion indicated of D2, also with recirculation and with the final addition of 800 ppm of C1. In this way a lubricant and cooling liquid was obtained for cutting with pH 9.5; alkaline reserve- 84; and a refractive index of 1.3512.
The machined parts are acceptable according to the predetermined quality control specifications for the same.
Machining continued in the machine for a period of three months giving rise to the following measured parameters on the days mentioned, as they are shown in the following table:
As can be seen in the results reflected in the table mentioned, during the three months of the test it has been possible to maintain in a virtually unaltered fashion the initial parameters, the production capacity of the system, correct finishing of the part in different operations without any industrial accidents and the condition of the machine without incidents.
The comparative example was carried out with a conventional cutting lubricant in identical machining operations and otherwise identical conditions. The results are shown in the following table:
As can be seen in the table, in the comparison example the pH was maintained throughout the said period with an increase in the alkaline reserve and with signs of corrosion. There were no odours or dermatosis.
Therefore, the improvement in behaviour brought about by applying the present invention can clearly be seen.

Claims

Process for preparing cutting lubricant fluids in situ, characterised by the following basic components: A)an oil phase; B) an aqueous phase; C) a bactericide/fungicide; and D) high pressure components, proceeding in situ by successively mixing said components with water, at the site of use, the proportions of the components varying in accordance with the type of machining and metal to be machined.
Process for preparing cutting lubricant fluids in situ according to claim 1, characterised in that the basic components are divided into composition sub-groups for their allocation to different machining conditions.
Process for preparing cutting lubricant fluids in situ according to claim 1, characterised in that the components are mixed in the appropriate lubricant reservoir of the cutting machine.
Process for preparing cutting lubricant fluids in situ according to claim 1, characterised in that the oil phase is formed by the following components: Component % by weight Basic lubricant 20-80 Dispersant detergents 5-20 Non-ionic emulsifiers 5-20 Fatty acids 5-20 Cosolvents 1-5 High molecular weight esters 2-25
Process for preparing cutting lubricant fluids in situ according to claim 4, characterised by the use, as basic lubricants, of paraffin mineral oil with a viscosity at 40°C between 10 and 46 cSt, preferably 15 and 32 cSt; naphthene mineral oil with a viscosity at 40°C between 10 and 45 cSt, preferably 15 and 32 cSt; paraffin mineral oil treated with H₂ and high pressure (free of aromatics and S), known as hydrocracking, with a viscosity at 40°C between 10 and 46 cSt, preferably 15 and 32 cSt; alpha polyolefins with a viscosity at 100°C of 4 to 8 cSt, preferably of 4 to 6 cSt; internal polyolefins with a viscosity at a 100°C of 4 to 8 cSt, preferably of 4 to 6 cSt; lubricant esters based on di- or tricarboxylic acids reacted with monoalcohols with a viscosity at 40°C of 10 to 46 cSt, preferably 15 to 32 cSt; lubricant esters based on monoacids reacted with monoalcohols with a viscosity at 40°C of 10 to 46 cSt, preferably 15 to 32 cSt; and polyol esters with natural or synthetic acids with a viscosity at 40°C of 10 to 46, preferably 10 to 32 cSt (all acids and alcohols considered being natural or synthetic and branched or unbranched).
Process for preparing cutting lubricant fluids in situ according to claim 2, characterised by the subdivision of the basic component A from the oil phase into four sub-groups A1, A2, A3, A4 in accordance with the following compositions: A1 A2 A3 A4 Paraffin mineral oil 40°C 20 cSt 55.80 - - 30.00 Linear hydrocarbon free of aromatics - 4.50 5.00 3.00 Oleic acid amide 12.00 16.00 18.50 10.00 AICOIL 10 SM - - - 3.50 Fatty alcohol (C18) with 5 M of OE 8.00 13.00 16.00 10.00 Ricinoleic acid 9.50 7.70 2.50 7.80 TMP oleate 3.70 26.00 5.00 12.00 Nonylphenol 9M OE 5.00 - - 3.50 SYN ESTER SE 110 - - - 3.00 AICOIL TD 125 2.00 2.50 2.50 5.00 Vegetable olein 2.00 1.80 0.50 2.20 Butyl diglycol 2.00 2.00 - 2.00 TMP ESTER 18.2 cSt 40°C - 26.00 - - Isotridecanol - 0.50 0.50 - PAO 6 cSt 100°C - - 49.50 - Alkyl benzene sulphonate of Na pm 460 - - - 8.00
Process for preparing cutting lubricant fluids in situ according to claim 1, characterised in that the aqueous phase B comprises the following components: alkaline reserve contributors to increase pH; alkali metal hydroxides; hydroxylated amines; primary, tertiary or secondary amines; diglycol amines; products which impart anticorrosive and/or bacteriostatic properties such as: lactic acid; boric acid; benzoic acid, sebacic acid; alkylated or non-alkylated succinic acid; ethyl hexanoic acid; azelaic acid; isononanoic acid; cyanic acid; cecanoic acid; trimellitic acid; undecylic acid; phthalic acid; Reocor 190 (CIBA); IRGACOR 252 FC (CIBA); HICOR EK/C (CLARIANT); and, as metallic passivators: benzotriazole, mercaptobenzotriazole; tolyltriazole; IRGAMET 42 (CIBA); IRGAMET BTA/M (CIBA); and ANTICOR C-6 (ADD - APT).
Process for preparing cutting lubricant fluids in situ according to claim 1, characterised by the use, as bactericides and fungicides C, of the following components: oxide-2-pyridine thiol-1 sodium salt; 1,3,5 triazine 1,3,5-(2H, 4H, 6H triethanol); N,N-methylene-bis-(5-methyloxyzolidine); 2-(2 methoxyethoxy) ethoxy methanol; 1-2 ethanediyil-bis (oxy)-bis methanol; 5-chloro-2-methyl-(2H)-isothiazolone; 2 methyl-(2H)-isothiazolone; hemiformyl propylene glycol; hexahydrotriazine derivatives; and VANCIDE 51 (VANDERBILT), dilute or neat, mixtures with complexing agents for alkaline earth metals, in particular citric acid, tartaric acid, diethyldiaminotetraacetic acid or whole or partial sodium or potassium salts thereof, aqueous solution of a polycarboxylic acid having a molecular weight of approximately 1,400; POCHS 2050 (DEGUSSA); acetodiphosphonic acid; sodium hexametaphosphate; sodium pyrophosphate; sodium tripolyphosphate; nitrile triacetic acid sodium salt; and sodium gluconate.
Process for preparing cutting lubricant fluids in situ according to claim 1, characterised in that as high pressure components D): chloroparaffins; sulphurised olefins; sulphurised organic esters; phosphoric acid esters; polyol-derived complex esters; esterified polyol amines with mono- and dicarboxylic acid; monocarboxylic acid polyol ester compounds of P-sulphur; and thiophosphorus compounds are preferably used.
Process for preparing cutting lubricant fluids in situ according to claim 2, characterised by the formation of the following sub-groups for the aqueous component B: B1 B2 B3 B4 Water 34.00 35.00 38.00 37.00 Boric acid 30.00 - - - Monoethanolamine 25.00 39.00 - 13.00 Triethanolamine 10.00 11.00 27.00 18.00 IRGACOR 42 1.00 1.00 - - Benzoic acid - 8.00 6.00 - Lactic acid - 5.00 5.00 5.00 Sebacic acid - 1.00 - 4.00 Potassium hydroxide - - 4.00 - Benzotriazole - - 1.00 2.00 Succinic acid - - 10.00 - REOCOR 190 - - 8.00 - Cecanoic acid - - - 4.00 Butyl amine - - - 2.00 Mercaptobenzotriazole - - - 1.00 Cinnamic acid - - - 6.00 HICOR EK/C -- --- --- 8.00
Process for preparing cutting lubricant fluids in situ according to claim 2, characterised by the sub-division of the group of high pressure components into the following sub-groups: D1 D2 Aicoil 125 TD 15 10 Aicoil 10 SM - 10 TMP oleate - 25 HICOR BA/V 14 15.50 Emulsogem M 14 14.5 Ricinoleic acid 6 9 Vegetable olein 2 2.5 Nonylphenol 9M OE 4 4 Butyl diglycol 2 2.5 EXXOL D 100 7 5 Nonylphenol 6m OE 1 2 SYN ESTER SE GY 15 15 - SYN ESTER SE 110 10 - Trimellitic isodecanol 10 - Viscosity at 40°C 45 cSt 37 cSt Refractive index 1.4785 1.4766 Acid number 16 mgKOH/g 25 mgKOH/g
Cutting lubricant fluids prepared in accordance with the process in the above claims 1 to 11.