New generation of phosphate-esters for MWF: balancing performance, labeling and economics.

Transcription

1 New generation of phosphate-esters for MWF: balancing performance, labeling and economics. Claude-Emmanuel Hédoire 1), 1) Solvay Novecare, Aubervilliers, France 1 Introduction Phosphate-esters are well known multifunctional additives for metalworking fluids. They are emulsifiers for expandable oils, as well as anti-wear additives, corrosion and staining inhibitors. The most currently used phosphate-esters are based on long carbon chains, like cetyl oleyl chain. While providing excellent emulsion stability, good antiwear performance and good staining inhibition, they tend to foam too much and to generate soap in hard water, creating deposits on tools, work-pieces or filters. Besides, their eco-toxicity has been reviewed in 2015 and they are now classified as very toxic to aquatic life. They are no longer a good optimum between performance, regulation and economics and this paper introduces a new generation of phosphate-esters 2. Summary Solvay researchers took a number of steps to optimize the performance, classification of phosphateesters. The first one was the switch to a shorter chain alcohol. This provides a better classification, an enhanced soap formation control and a better security of supply. The second one was propylene oxide insertion into the molecule. This provides similar performance to cetyl oleyl alcohol ethoxylates in terms of emulsion stability as well as anti-wear performance, and enhanced performance in terms of foam control. The result is the development of a new generation of phosphate-esters that optimize performance and economics, and allow milder labeling.

2 New generation of phosphateesters for MWF: balancing performance, regulation and economics v1 STLE annual meeting,las Vegas, May 2016 Claude-Emmanuel Hédoire

3 Agenda Common emulsifiers for MWF Current generation of phosphate-esters: pros and cons Phosphate-esters based on cetyl oleyl alcohol are no longer an optimum between performance, classification and economics Molecular design of phosphate-esters Some chemistry State of the art: what are the tools to improve performance, classification and economics There is no ideal phosphate-ester on the market Development of a new generation of phosphate-ester New optimum between performance, classification and economics 2 0/0/13

4 Common Emulsifier types in MWF Anionics and non-ionics are used in MWF formulations Besides emulsion stability, emulsifiers can provide MWF with other sidebenefits Emulsifier systems are elaborated blends of components to finely balance their benefits and their limitations Low foam Corrosion / staining protection Lubricity Anti-wear Stability in HW Anionics Amine soaps of fatty acids Synthetic and natural sulfonates Amine soaps of phosphate-esters Amine soaps of ether-carboxylates Non-ionics Ethoxylated fatty alcohols Ethoxylated fatty acids Ethoxylated amines and amides

5 Common Emulsifier types in MWF Anionics and non-ionics are used in MWF formulations Besides emulsion stability, emulsifiers can provide MWF with other sidebenefits Emulsifier systems are elaborated blends of components to finely balance their benefits and their limitations Low foam Corrosion / staining protection Lubricity Anti-wear Stability in HW Anionics Amine soaps of fatty acids STLE 2016 Synthetic and natural sulfonates Amine soaps of phosphate-esters Amine soaps of ether-carboxylates Non-ionics Ethoxylated fatty alcohols Ethoxylated fatty acids Ethoxylated amines and amides

6 Phosphate-esters: pros and cons of current generation (1) The current generation is based on phosphate-ester of (cetyl oleyl + 5 EO) Cetyl oleyl: C16-C18:1 Performance: emulsion Performance: hard water stability Clear solution Heavy soap formation Good emulsion stability Low foam in DI water, ultra low-foam in HW due to soap formation No defoaming in DI water, excellent defoaming in hard water due to soap formation 5 Heavy soap formation in HW Soap formation is positive for foam control, but soap precipitates on tools, workpieces, filters

7 Phosphate-esters: pros and cons of current generation (2) The current generation is based on phosphate-ester of (cetyl oleyl + 5 EO) Cetyl oleyl: C16-C18:1 Performance: side benefits Good corrosion / staining inhibition Good AW performance blank 1% PE Classification Labels Regulation H315: Causes skin irritation H318: Causes serious eye damage H410: Very toxic to aquatic life with long-lasting effects 6

8 Pros and cons of current generation: conclusion Cetyl oleyl phosphate-ester Performance Emulsion stability Low foaming Defoaming Hard water stability Staining inhibition AW performance Cetyl oleyl: C16-C18:1 Good DI water: good, Hard water: good through soap formation DI water: good, Hard water: good through soap formation Poor Good Good Classification and labeling Toxicity Eco-toxicity H315, H318 H410 Commercial Raw material availability Supply of cetyl oleyl alcohol is very tight Phosphate-esters based on cetyl oleyl alcohol are no longer an optimum between performance, classification and economics A new optimum has to be found 7

9 Agenda Common emulsifiers for MWF Current generation of phosphate-esters: pros and cons Phosphate-esters based on cetyl oleyl alcohol are no longer an optimum between performance, classification and economics Molecular design of phosphate-esters Some chemistry State of the art: what are the tools to improve performance, classification and economics There is no ideal phosphate-ester on the market Development of a new generation of phosphate-ester New optimum between performance, classification and economics 8 0/0/13

10 Some chemistry The phosphation process leads to a mixture of several substances: Mono-ester: 50 60% Residual non-ionic 3 10% Di-ester: 30 45% When considering performance and classification, it is necessary to take into account noth the phosphate-esters and the residual non-ionic 9

11 Molecular design: state of the art R (CH 2 - CH 2 - O) n (CH 2 - CH 2 - O) m - CH 3 O H Fatty alcohol (ROH) R (CH 2 - CH 2 - O) n Ethylene oxide (EO) CH 3 OH (CH 2 - CH 2 - O) m O P O - Propylene oxide (PO) OH More favorable classification and labelling for short carbon chain vs long carbon chain (CESIO guidelines) More favorable classification and labelling for higher EO and PO degrees (CESIO guidelines) Regulation Cetyl oleyl alcohol supply is very tight Other carbon feedstocks are more available Commercial Higher AW performance with longer chain Better soap formation control with shorter chain Higher EO degree increases foam PO insertion enables a better foam control the challenge is to maintaing good emulsification performance Performance

12 Classification of short chain phosphate-esters is more favorable CESIO guidelines for environmental classification. CESIO is European Committee of Organic Surfactants and Intermediates. Most of the surfactant manufacturers belong to CESIO Chemical name Carbon chain length EO degrees Hazard statement (classification) Hazard phrase (classification) Label C8 C NC None _ NC None _ ic13 3 H400 H411 Very toxic to aquatic life Toxic to aquatic life with long lasting effects 5-20 H412 Harmful to aquatic life with long lasting effects _ H412 Harmful to aquatic life with long lasting effects _ NC NC NC 18 : H400 H : NC Very toxic to aquatic life Harmful to aquatic life with long lasting effects 11 0/0/13

13 Classification of short alcohol ethoxylates is more favorable CESIO guidelines for environmental classification. CESIO is European Committee of Organic Surfactants and Intermediates. Most of the surfactant manufacturers belong to CESIO Environmental classification of surfactant according to 2 nd ATP, public revision 2015 Chemical name Alcohols, C8, ethoxylated Acohols, C10, ethoxylated Alcohols, C12-C16, ethoxylated Alcohols, C14, ethoxylated Alcohols, C16-C18, ethoxylated Saturated and unsaturated 12 0/0/13 Carbon chain length EO degrees Hazard statement (classification) Hazard phrase (classification) 8 All NC None _ 10 All NC None _ < 5 H400 H412 Very toxic to aquatic life Harmful to aquatic life with long lasting effect 5 15 H412 Harmful to aquatic life with long lasting effects _ > 15 NC None _ < 6 H400 H412 Very toxic to aquatic life Harmful to aquatic life with long lasting effects 6-15 H412 Harmful to aquatic life with long lasting effects _ > 15 NC None _ < 5 H411 Toxic to aquatic life with long lasting effects 5 10 H400 H412 Very toxic to aquatic life Harmful to aquatic life with long lasting effects H412 Harmful to aquatic life with long lasting effects > 20 EO NC None _ Label

14 State of the art: short chain phosphate-ester vs cetyl oleyl phosphate-ester Short chain phosphate-ester Cetyl oleyl phosphate-ester Classification Eco-toxicity Commercial Raw material availability Emulsion stability Low foaming Performance Defoaming Hard water stability AW performance 13

15 Commercial: availability depends on the feedstock type and manufacturing Lauryl alcohol Manufactured from palm kernel oil and synthetically from crude oil Commonly and widely available: > 10 suppliers in Asia > 5 suppliers in Europe Approx. 5 suppliers in North America Base feedstock for numerous types of surfactants (home and personal care) Branched alcohols Synthetically manufactured from crude oil Base feedstock for numerous types of surfactants (coatings) Cetyl oleyl alcohol Manufactured from palm kernel oil, with a patented technology Only 3 suppliers in the world, with production sites in Asia and Europe 14 0/0/13

16 State of the art: short chain phosphate-ester vs cetyl oleyl phosphate-ester Short chain phosphate-ester Cetyl oleyl phosphate-ester Classification Eco-toxicity Commercial Raw material availability Emulsion stability Low foaming Performance Defoaming Hard water stability AW performance 15

17 Performance: state of the art Performance: AW Performance: hard water stability Higher AW performance with cetyl oleyl phosphate-ester Heavy soap formation with cetyl oleyl phosphate-ester Lower soap formation with short chain phosphate-ester 16

18 Performance: state of the art Good emulsion stability with cetyl oleyl phosphate-ester and with short chain phosphate-ester Low foam in DI water with cetyl oleyl phosphate-ester and with short chain phosphate-ester Low foam in Hard water with short chain phosphate-ester. Lower foam with cetyl oleyl phosphate-ester, due to soap formation Better defoaming in DI water with short chain phosphate-ester 17

19 State of the art: short chain phosphate-ester vs cetyl oleyl phosphate-ester Short chain phosphate-ester Cetyl oleyl phosphate-ester Classification Eco-toxicity Commercial Raw material availability Emulsion stability Low foaming Performance Defoaming Hard water stability AW performance There is no ideal phosphate-ester for MWF on the market 18

20 Agenda Common emulsifiers for MWF Current generation of phosphate-esters: pros and cons Phosphate-esters based on cetyl oleyl alcohol are no longer an optimum between performance, classification and economics Molecular design of phosphate-esters Some chemistry State of the art: what are the tools to improve performance, classification and economics There is no ideal phosphate-ester on the market Development of a new generation of phosphate-ester New optimum between performance, classification and economics 19 0/0/13

21 Development of a new generation of phosphateester R (CH 2 - CH 2 - O) n (CH 2 - CH 2 - O) m - CH 3 O H Fatty alcohol (ROH) R (CH 2 - CH 2 - O) n Ethylene oxide (EO) CH 3 OH (CH 2 - CH 2 - O) m O P O - Propylene oxide (PO) OH Eco-toxicity: Must be a short chain More favorable classification and labelling for higher EO and PO degrees (CESIO guidelines) Regulation Raw material availability: Must be a short chain Soap formation control: must be a short chain EO and PO distribution fine-tuning in order to improve the AW performance. The challenge is not to loose the emulsion performance Commercial Performance

22 Best candidate; Improved Overall Performance Naphthenic oil Stable emulsions, with paraffinic and naphthenic oil based formulations, in soft and hard water Low foaming, without soap formation Outstanding defoaming, especially for DI water emulsions Water hardness: 400 ppm Emulsion stability: 40 C Foam test: CNOMO 21

23 Best candidate: good AW performance Nytex 810 with 2% of additive Falex Pin and Vee blocks, ASTM D2670 (700 lbs, 10 min) Higher AW performance 22 0/0/13

24 Best candidate: limited soap formation Clear solution Limited soap formation Clear solution Water hardness: 400 ppm Heavy soap formation 23 0/0/13

25 Best candidate: good aluminum staining inhibition Water hardness: 0 ppm 40 C Weight uptake (mg) Al 2024 Al 6061 Al 7075 No additive 30,6 34,8 30,5 Best candidate (1%) Cetyl oleyl phosphate-ester (1%) 24 0/0/13 0,1 0,1 0,1 0,3 0,2 0,1

26 Best candidate versus Cetyl Oleyl phosphate-ester Best candidate Cetyl oleyl phosphate-ester Emulsion stability Good Good Low foaming Good Good Performance Defoaming Excellent Good Hard water stability Good Poor Staining inhibition Good Good AW performance Good Good Toxicity H315, H318 H315, H318 Classification Eco-toxicity Not classified H400, H412 Commercial Raw material availability Globally available raw material Supply of cetyl oleyl alcohol is very tight 25

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28 Common Emulsifier types in MWF Anionics and non-ionics are used in MWF formulations Besides emulsion stability, emulsifiers can provide MWF with other sidebenefits Emulsifier systems are elaborated blends of components to finely balance their benefits and their limitations Low foam Corrosion / staining protection Lubricity Anti-wear Stability in HW Anionics Amine soaps of fatty acids STLE 2016 Synthetic and natural sulfonates Amine soaps of phosphate-esters Amine soaps of ether-carboxylates STLE 2015 Non-ionics Ethoxylated fatty alcohols Ethoxylated fatty acids Ethoxylated amines and amides

29 STLE 2015: introduction of new non-ionic emulsifiers Sustainability benefits Low eco-toxicity (no dead fish label) Readily biodegradable Based on commonly and globally available raw materials Performance benefits Low foam to ultra-low foam Outstanding defoaming Excellent low temperature stability Cetyl oleyl 5 EO Short chain alcohol Low EO/PO degree Short chain alcohol Medium EO/PO degree Short chain alcohol High EO/PO degree 28 Emulsion stability Low foam Defoaming Labels 0/0/13

30 Emulsifiers for MWF Emulsifiers are backbone additives for water soluble MWF: soluble oils and semi-synthetic fluids They stabilize the oil in water emulsions The oil droplet size distribution is a result of the choice of emulsifiers Some of them bring valuable side benefits With corrosion inhibitors, emulsifiers are the type of additives the most used in MWF They represent 140 kt/y out of a global additive consumption of 600 kt/y Additives for MWF (WW), 600 kt WW MWF market (million MT) CAGR = 2,3 %/y Antiwear 3% Others 12% Buffer 6% Corrosion inhibitors 24% 2,5 Extreme pressure 13% Emulsifiers 23% 2, % additives 60-90% base oil Friction modifiers 19% (Kline) 29 0/0/13

31 Trends in MWF and challenges for emulsifiers Trends in MWF Challenges for emulsifiers Performance New generation of high speed machine tools require much improved foam control Development of a new generation of emulsifiers with ultra low foam and enhanced defoaming, without defoamer addition and without soap formation Regulation GHS in place for substances and formulations More and more stringent regulations for biocides (boric acid, formaldehyde releasers ) Change in classification and labelling for some emulsifiers Development of a new generation of emulsifiers with millder labelling Development of biostable emulsifiers Commercial Cost-effectiveness of RM and MWF WW availability of RM New generations of emulsifiers should be based on commonly and globally available raw materials A lot of challenges faced by MWF formulators and emulsifiers suppliers! 30 0/0/13

32 Emulsifiers; Performance Evaluation Concentrate Oil 80% Emulsifier 20% solubility stability Emulsion Oil Cream Emulsion Water Concentrate 10% DI water 90% or hard water (400 ppm) MEA ph=9 Short term stability: 30 min Long term stability: 40 C, 7 days Foaming: recycling test (CNOMO), NF T Droplet size

33 The CNOMO Foam Test The CNOMO foam test D describes a fluid circulation test using a centrifugal pump and a waterjacketed 2000 ml graduated cylinder with an outlet on the side, near the bottom A formulation is added to the cylinder to the 1000 ml level. It is then pumped from the bottom of the cylinder at a rate of 250 L/h and cascaded backed upon itself from a height of 390 mm above the 1000 ml mark. The test is run for a maximum of 5h or until the foam level reaches the 2000 ml mark. The pump is then stopped. Collected data are: Volume of foam above the 1000 ml mark immediately after the pump is stopped (5h). Time to reach the 2000 ml mark (if reached) Volume of foam above the 1000 ml mark 15 minutes after the pump is stopped This test simulates fluid flow in a machine sump or central system, but is much more severe due to the extremely high turnover rate

34 MWF: CNOMO Foam Test Low foam MWF High amount of foam is generated rapidely: 1000 ml within 2 to 15 minutes The pump is then stopped for defoaming evaluation Ultra Low foam MWF Low amount of foam is generated: the test can be run for 5 hours without reaching 1000 ml of faom The pump is then stopped for defoaming evaluation Low foam Ultra Low foam

35 Spiders; An overall Evaluation of Performance Higher Emulsion stability Lower foam Improved defoaming 34 0/0/13

36 Results; An overall Evaluation of Performance Emulsion stability index volume of oil phase 5 volume of water phase 1 volume of cream Foam profile indexes Initial foam level index: (1 + log ) Defoaming index: 100 x Emulsion stability Short term DI Water 100 Lower initial foam level and better defoamning 35 0/0/13 Defoaming DI water Defoaming Hard water Initial foam level Hard water Initial foam level DI water Emulsion stability Short term Hard Water Emulsion stability Long term DI Water Emulsion stability Long term Hard Water Higher Emulsion stability