GB2083059A

GB2083059A - High Viscosity Fluids

Info

Publication number: GB2083059A
Application number: GB8124269A
Authority: GB
Original assignee: Texaco Development Corp
Current assignee: Texaco Development Corp
Priority date: 1980-09-02
Filing date: 1981-08-07
Publication date: 1982-03-17
Also published as: ES8206581A1; DE3134494A1; ES505121A0; FR2489344A1; GB2083059B; IT1139417B; IT8123724A0; FR2489344B1; NL8103916A; BE890158A; JPS5774329A; CA1153356A

Abstract

Functional fluids having higher viscosity than those known in the art can be prepared by a) reacting one or more monohydric or dihydric alcohol initiators with one or more alkylene oxides, and b) terminating the reaction, preferably when the alkylene oxide adduct of the monohydric or dihydric initiators has a molecular weight in the range from 2,000 to 20,000, with a quantity of epoxy resin such that the ratio of hydroxyl to epoxy resin equivalents is in the range from 2 to 1 to 5 to 1.

Description

SPECIFICATION High Viscosity Fluids The invention relates to high viscosity fluids and, more particularly, relates to high viscosity fluids that are produced by terminating the base catalyzed reaction of alkylene oxides with mono- and polyhydric initiators by the addition of epoxy resins. The resulting fluids are suitable for use as functional fluids.

Prior art functional fluids have been typically prepared by the reaction of mixtures of ethylene oxide and propylene oxide together with polyoxyalkylene glycol initiators that have molecular weights greater than 5000. Typical ratios range from 2:1 to 4:1 in proportions of oxide mixture to initiator.

Undiluted viscosities of the resultant products range between 1 00,000 SUS (Saybolt Universal Seconds) and 200,000 SUS at 380C. Representative prior art fluids are the Jeffox synthetic functional fluids manufactured by Texaco Chemical Co. Preferably, undiluted viscosities should be greater than 200,000 SUS. As more and more of the alkylene oxides are added and the product becomes more viscous, a point of diminishing returns is reached due to the shearing action of the reactor agitator on the product. As a result, large additions of ethylene oxide and propylene oxide are required to obtain significant changes in viscosity. This method significantly increases the cycle time and costs for these products.

Therefore, it is an object of this invention to produce water soluble fluids with viscosities preferably in excess of 200,000 SUS at 380C by an economical method. It is expected that the fluids would be particularly useful as thickening agents for fire resistant glycol-water hydraulic fluids for use in refineries, coal mines, steel mills, machine shops and military equipment. Functional fluid uses as brake fluids, lubricants and starting materials for surfactants, plasticizers and resins are also anticipated.

It is anticipated that the fluids of this invention would be found useful in applications for which the typical functional fluids would not be suited, but which require high viscosity water soluble fluids.

Other patents disclose reactions involving polyols and epoxy resins. Japanese Patent 71-24,255 concerns the reaction of glycerine-based 3,000 molecular weight triol with 2% Bisphenol A epoxy resin to produce flexible polyurethane foams with increased hardness.

U.S. Patent 3,012,984 describes how hydroxyl terminated polyesters, epoxy resins and isocyanate terminated prepolymers may be reacted in an inert organic solvent to produce metal primers and coatings. U.S. Patent 3,010,940 discloses how phenol, epoxy resins, polyisocyanates and alpha-methylbenzyldimethylamine react to produce various polyurethane coatings. U.S. Patent 3,448,046 describes how polyols containing chlorine are mixed with epoxy resins before reaction with an isocyanate. The free epoxides scavenge the HCI in the polyol and do not contribute to the functionality of the polyol. The reaction of an epoxide with an alcoholic hydroxyl group is set out in U.S.

Patent 3,317,609. Further, British Patent 968,102 describes how polyols suitable for polyurethane foams may be prepared from the reaction of a polyol, and an epoxy resin in the presence of an acidic catalyst.

The preparation of an emulsion of epoxy diacrylate from hydroxyethylacrylate, the diglycidyl ether of Bisphenol A, benzophenone, deionized water, N-butylcarbamoyloxyethyl and oxyethylenepropylene diol is described in U.S. Patent 4,125,503. U.S. Patent 4,108,922 discloses the preparation of antistatic fibers that contain multiple branched propoxylated ethoxylated polyalkylenepolyamines and monoamines as well as the chain-extended reaction products from these materials. Elastomers made from a 5000 molecular weight capped triol, a diol and a liquid polyepoxide over a quaternary ammonium or phosphonium catalyst are the subject of U.S. Patent 4,118,373.

Further prior art compositions include those described in German Offenlegungschrifft 2,056,080.

This patent describes how epoxy adhesives may be made by the reaction of epoxy resins with 4mercaptobutanol-blocked urethane prepolymers which are made from toluene diisocyanate and various polyols. A uretinedione derivative of diisocyanatotoluene sulfonic acid has been treated with a polyol and an epoxide to prepare sulfonate ester groups containing urethane which were found to be water resistant, according to the disclosure in German Offenlegungschrifft 2,735,047. German Offenlegungschrifft 1,905,696 discloses how polyurethane latices may be produced by chainextending a urethane prepolymer by using the reaction product of polyethylene glycols of a molecular weight of about 5,000 to 10,000, and an aromatic diglycidyl ether. The modification of epoxy resins by heating them with added polyalkoxylated disaccharides is described in Belgium Patent 785,020.

The invention concerns high viscosity fluids prepared by reacting one or more monohydric or dihydric alcohol initiators with one or more alkylene oxides. The reaction is then terminated by the addition of a quantity of epoxy resin such that the ratio of hydroxyl equivalents in the reaction product to epoxy equivalents in the resin is in the range of about 2 to 1 to about 5 to 1. The invention also concerns methods of making the fluids and the fluids in aqueous solutions.

This invention is the modification of ethylene oxide/propylene oxide (EO/PO) adducts of alcohols, glycols, and other polyhydric initiators to prepare high viscosity functional fluids. Water soluble EO!PO adducts of the above initiators are particularly useful as thickening agents for fire resistant glycol-water hydraulic fluids for use in refineries, coal mines, steel mills, machine shops, and military equipment. To be useful as thickeners for these type applications, the materials must be water soluble and have an undiluted viscosity of greater than 100,000 SUS at 380 C. and preferably, greater than 200,000 SUS at 380C.

In this invention, large increases in product viscosity were obtained by terminating the reaction of the EO/PO addition to the polyoxyalkylene glycol initiator with 1 4% of an epoxy resin such as the diglycidyl ether of Bisphenol A. A source of this resin is the EPON 828 product manufactured by Shell Chemical Co. It is preferred that the ratio of hydroxyl to epoxy equivalents be 2/1 to 5/1. Functional fluids prepared as described in this invention have viscosities of 200,000-400,000 SUS at 380C.

Due to their high viscosity and excellent water solubility, they can be diluted with larger quantities of water to prepare fluids of comparable viscosity to less viscous prior art materials. This results in a more economical and fire resistant system.

It is well known that the polyoxyalkylene glycol initiators used in this invention may be prepared by, for example, the base catalyzed reaction of ethylene oxide or propylene oxide with an initiator having a low hydroxyl functionality, that is, containing less than three reactive hydrogen atoms. An example of a suitable initiator is propylene glycol. If base catalysis is used, the alkaline catalysts normally employed are sodium hydroxide and potassium hydroxide. The polyols that are preferred for this invention should be monohydric or dihydric, that is, the alcohol initiator should have a hydroxyl functionality of less than three. Other techniques to prepare polyols are known to those skilled in the art.

Polyether polyols having equivalent weights of up to about 750 are normally prepared in a onestep process by the reaction of propylene oxide or ethylene oxide with such an initiator. For example, the starting material for the examples herein is Jeffox PEG-600, a product of Texaco Chemical Co., that is a 600 molecular weight polyethylene glycol. For the preparation of larger molecules, a two-step process is usually employed. In the first step, a product having an equivalent weight of from about 1 50 to about 750 is prepared, and in the second step this is reacted further with propylene oxide and ethylene oxide to prepare the higher molecular weight product.

Ultimately, the alkylene oxide adducts of the alcohols, glycols and other polyhydric initiators should be in the 2,000 to 20,000 molecular weight range. In this invention, the growing polyether chain is terminated with epoxy resins to produce the high viscosity functional fluids instead of using more alkylene oxides to build up viscosity as in the prior art. Although the epoxy resin is added at the end of the alkylene oxide adduct reaction, the epoxy resin ends up in the middle of a chain formed by two adduct molecules and the product has a functionality of approximately four. In a similar manner, when a monohydric initiator is used, the epoxy resin is positioned in the center of a diol.

The alkylene oxides useful in this invention are ethylene oxide, propylene oxide and 1,2-butylene oxide. Ethylene oxide and propylene oxide are preferred for this invention, and these reactants are used in the examples herein. More than one alkylene oxide may be added to the reaction mixture as deemed necessary by one skilled in the art practicing this invention.

It is anticipated that a wide variety of epoxy resins would be useful in practicing this invention.

The vicinal polyepoxide containing compositions are organic materials having an average of at least 1.8 reactive 1,2-epoxy groups per molecule. These polyepoxide materials can be monomeric or polymeric, saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or heterocyclic, and may be substituted if desired with other substituents besides the epoxy groups, e.g., hydroxyi groups, ether radicals, aromatic halogen atoms and the like.

Preferred polyepoxides are those of glycidyl ethers prepared by epoxidizing the corresponding allyl ethers or reacting, by known procedures, a molar excess of epichlorohydrin and an aromatic polyhydroxy compound, i.e., isopropylidene bisphenol, novolak, resorcinol, etc. Examples of specific preferred epoxy resins for the purposes of this invention are the diglycidyl ether of Bisphenol A, the polyglycidyl ether of phenolformaldehyde novolac resin, the hydrogenated diglycidyl ether of Bisphenol A, 1,4-butanediol diglycidyl ether, the diglycidyl ether of propylene glycol, vinylcyclohexanediepoxide, halogenated diglycidyl ethers of Bisphenol A and aromatic amine-based epoxy resins. The epoxy derivatives of methylene or isopropylidene bisphenols are especially preferred. The diglycidyl ether of Bisphenol A is used in the examples herein.Some of these epoxy resins are known in the trade as "Epon" resins and may be obtained from Shell Chemical Co.

A widely used class of polyepoxides which are useful according to the instant invention includes the resinous epoxy polyethers obtained by reacting an epihalohydrin, such as epichlorohydrin, and the like, with either a polyhydric phenol or a polyhydric alcohol. An illustrative, but by no means exhaustive, listing of suitable dihydric phenols includes 4,4'-isopropylidene bisphenol, 2,4'- dihydroxydiphenylethylmethane, 3,3'-dihydroxydiphenyldiethylmethane, 3,4'- dihydroxydiphenylmethylpropylmethane, 2,3'-dihydroxydiphenylethylphenylmethane, 4,4'- dihydroxydiphenylpropylphenylmethane, 4,4'-dihydroxydiphenylbutylphenylmethane, 2,2'- dihydroxydiphenylditolylmethane, 4,4'-dihydroxydiphenyltolylmethylmethane and the like. Other polyhydric phenols which may also be cq-reacted with an epihalohydrin to provide these epoxy polyethers are such compounds as resorcinol, hydroquinone, substituted hydroquinones, e.g., methylhydroquinone, and the like.

Among the polyhydric alcohols which can be coreacted with an epihalohydrin to provide these resinous epoxy polyethers are such compounds as ethylene glycol, propylene glycols, butylene glycols, pentane diols, bis(4-hydroxycyclohexyl)dimethylmethane, 1 ,4-dimethylolbenzene, glycerol, 1,2,6- hexanetriol, trimethylolpropane, mannitol, sorbitol, erythritol, pentaerythritol, their dimers, trimers and higher polymers, e.g., polyethylene glycols, polypropylene glycols, triglycerol, dipentaerythritol and the like, polyallyl alcohol, polyhydric thioethers, such as 2,2'-, 3,3'-tetrahydroxydipropylsulfide and the like, mercapto alcohols such as monothioglycerol, dithioglycerol, and the like, polyhydric alcohol partial esters, such as monostearin, pentaerythritol monoacetate, and the like, and halogenated polyhydric alcohols such as the monochlorohydrins of glycerol, sorbitol, pentaerythritol and the like.

Another class of polymeric polyepoxides which can be amine cured and are in accordance with the instant invention includes the epoxy novolak resins obtained by reacting, preferably in the presence of a basic catalyst, e.g., sodium or potassium hydroxide, an epihalohydrin, such as epichlorohydrin, with the resinous condensate of an aldehyde, e.g., formaldehyde, and either a monohydric phenol, e.g., phenol itself, or a polyhydric phenol. Further details concerning the nature and preparation of these epoxy novolak resins can be obtained in Lee, H. and Neville, K., Handbook of Epoxy Resins, McGraw Hill Book Co., New York, 1 967.

It will be appreciated by those skilled in the art that the polyepoxide compositions which are useful according to the practice of the present invention are not limited to those containing the above described polyepoxides, but that these polyepoxides are to be considered merely as being representative of the class of polyepoxides as a whole.

The reaction conditions of temperature and pressure may be selected by the invention practitioner to meet certain specifications required by the functional fluid for a particular use. The examples herein use a pressure of about 4.4 bars and a temperature of about 50 to 1 500C as representative conditions for the making of functional fluids that would be useful as brake fluids, lubricants, starting materials for surfactants, plasticizers and resins and thickening agents for hydraulic fluids. Other uses of the high viscosity fluids of this invention are anticipated wherever there is a need for fluids having good water solubility and high viscosity. The amount of epoxy resin to be added to the reaction mixture should be such that the ratio of hydroxyl equivalents to epoxy equivalents ranges from about 2:1 to about 5:1.Too many epoxy equivalents in relation to the hydroxyl equivalents may cause the epoxy resin to gel by cross-linking with itself. The functional fluids resulting from the method of this invention would preferably have a viscosity in the range of 200,000 to 400,000 SUS at 380C.

The following examples demonstrate how prior art functional fluids and the high viscosity functional fluids of this invention may be prepared. Examples are also presented which demonstrate the properties of aqueous solutions of the high viscosity functional fluids as well as the limits on the hydroxyl to epoxy functionality ratio.

Example I This example will illustrate the preparation of prior art functional fluids. It will further show the multiple processing steps required to prepare high viscosity functional fluids.

Step A Preparation of 5000 m.w. EO/PO diol.

Reaction Charge Kg/Kg. of product

600 m.w. polyethylene glycol (Jeffox PEG-600, a product of Texaco Chemical Co.) 0.1018 Potassium hydroxide, 90% flake 0.00223 Ethylene oxide X mixed 0.6875 Propylene oxide t mixed 0.2288 Hydroxyanisole 0.00007 Jeffox PEG-600 was first charged to the kettle. The kettle was evacuated and purged with nitrogen and then heated to 500 C. Potassium hydroxide was added and the mixture was stirred until the KOH was solubilized. The reactor was heated to 1 200C to strip the initiator to a water content of less than 0.3%.The mixed EO/PO was reacted at 1 15--1200C at 4.4 bars. Approximately 1 5 hours were required for addition of the mixed EO/PO. The reaction mixture was then digested to an equilibrium pressure and stripped to a water content of less than 0.06%. The hydroxyanisole was then added as a stabilizer and antioxidant and the product was transferred t6 a rundown tank. The finished product had the following properties: Properties Alkanility, mg KOH/g 1.9 Corrected Hydroxyl No., mg KOH/g 22.6 Water, wt. % 0.03 Viscosity Centistokes 380C 1903 990C 254 Step B Preparation of 13000 m.w. EO/PO diol.

KgIKg.

Reaction Charge product

5000 m.w. EO/PO diol from Step A 0.2208 Potassium hydroxide, 90% flake 0.00122 Ethylene oxide q 0.5982 Propylene oxide I mixed 0.2001 Hydroxyanisole 0.00013 Prqcedure The 5000 m.w. EO/PO diol was charged to the kettle which was then evacuated and purged with nitrogen. The reactor was heated to 500 C. Potassium hydroxide was added and stirred until solubilized.

The mixture was heated to 1 200C and stripped to a water content of less than 0.08%. Mixed EO/PO was reacted at 11 5-1 200C at 4.4 bars. Approximately 22 hours were required for addition of the mixed oxides. The reaction mixture was digested to an equilibrium pressure and the hydroxyanisole added. The product was transferred to a storage tank. The finished product had the following properties.

Properties Alkalinity, mg KOH/g 1.65 Corrected hydroxyl No., mg KOH/g 8.7 Water, wt. % 0.637 Viscosity, c.s.

38"C 19900 990C 2522 Viscosity, 380C., SUS 921 77 Step C Preparation of 200,000 SUS functional fluid Kg/Kg.

Reaction Charge product

13,000 m.w. EO/PO diol from Step B 0.5 Potassium hydroxide, 90% flaked 0.00008 Ethylene oxide ) . 0.375 Propylene oxide, I mixed 0.125 Procedure The 13,000 m.w. EO/PO diol was charged to the kettle which was then purged with nitrogen. The reactor was heated to 500C and potassium hydroxide was added. The mixture was heated to 100 C., maintaining nitrogen purge to strip to a water content of less than 0.08%. Mixed EO/PO was reacted at 1 15--1200C at 3 bars over a three hour period. The reaction mixture was digested to an equilibrium pressure, stripped and drained from the kettie.The resultant product had the following properties.

Properties Alkalinity, mg KOH/g 1.26 Corrected Hydroxyl No., mg KOH/g 6.68 Water, wt. % 0.09 Viscosity, c.s.

380C 43118 990C 5537 Viscosity, 380C. SUS 199273 Example II This example will illustrate the preparation of the high viscosity functional fluids of this invention.

It will further show the excellent water solubility, thickening power, and shear stability of the resultant fluids.

Into a 40 litre reactor were charged 4.5 Kg of the EO/PO diol from Step B in Example 1, 25 g water, and 45 g of diglycidyl ether of Bisphenol A (EPON 828). The reactor was then evacuated and purged with prepurified nitrogen. The reactants were then heated to 1 000C and stripped to a water content of less than 0.05%. After a one to two hour digestion period, the product was drained from the kettle. The product had the following properties: Properties Alkalinity, mg KOH/g 1.51 Corrected Hydroxyl No., mg KOH/g 9.2 Water, wt. % 0.014 Viscosity, c.s.

380C 65425 990C 7957 Viscosity, 380C., SUS 303049 Cloud point, OC. (1% aqueous) 64.5 Table I Properties of Aqueous Solutions of High Viscosity Functional Fluids Sample No. A* B* C Composition, pbw Functional fluid 80 70 50 Water 20 30 50 Properties Viscosity, 380C., c.s. 12306 5235 720 Viscosity, 380C., SUS 57743 24249 3335 Shear stability (five minutes on Waring blender at liquify speed) Viscosity, 380C., c.s. 862 Viscosity, 380 C., SUS 3993 *Shear stability not tested for these formulations Example Ill This example will further illustrate the preparation of the high viscosity functional fluids of this invention.It will also further illustrate the excellent water solubility, thickening power and shear stability of the resultant fluids In addition, the reproducibility of the procedure is demonstrated.

Into a 40 litre reactor were charged 4.5 kg of the EO/PO diol from Step B, Example I, and 45 g diglycidyl ether of Bisphenol A(EPON 828). The reactor was then evacuated and purged with prepurified nitrogen. The reactants were then heated at 100 C., for one hour, stripped and drained from the kettle. The product had the following properties: Properties Alkalinity, mg KOH/g 1.48 Corrected Hydroxyl No., mg KOH/g 9.5 Water, wt. % 0.02 Viscosity, c.s.

380C. 65621 990C. 6490 Viscosity, 380 C., SUS 303956 Cloud point, OC. (1% aqueous) 64 Table II Properties of Aqueous Solutions of Functional Fluids Sample No. D* E* F Composition, pbw Functional Fluid 80 70 50 10 Water 20 30 50 90 Properties Viscosity, 38"0., c.s. 13000 5600 1065 7.4 Viscosity,380C.,SUS 60190 25928 4933 50.1 Shear stability (five minutes in Waring blender at liquify speed) Viscosity, 380C., c.s. - - 1119 - Viscosity, 38"0., SUS - - 5183 - *Shear stability not tested for these formulations.

Example IV This example will illustrate the reaction of Epon 828 (diglycidylether of Bisphenol A) with the 12mole ethylene oxide adducts of nonyl phenol (Surfonic N-1 20, Texaco Chemical Co.).

The increase in viscosity of monofunctional polyol initiators is hereby illustrated. Into a 500 ml three-necked flask equipped with a stirrer, thermometer, nitrogen source and condenser was charged 250 g Surfonic N-1 20 (0.334 eq.); 30.8 9 Epon 828 (0.167 eq.) and 1.25 g 45% aqueous potassium hydroxide. The mixture was then heated at 90-100"C for three hours. The reaction mixture was then dewatered by vacuum stripping. The resultant product had the following properties: For comparison, properties of the original Surfonic No120 are included: Surfonic N- 120 Reaction monofunctional Description Product polyol initiator Properties Alkalinity, mg KOH/g 106 Hydroxyl No., mg KOH/g 72.6 73.5 Water, wt. % 0.01 0.05 Viscosity, c.s.

250C. 1687 254 380C. 668 122 Cloud point, OC. (1% aqueous) 17.1 54 Surface tension, dynes/cm.

1% aq. 39.2 38.6 0.1% aq. 39.3 38.3 0.001% aq. 40.9 37.6 Example V This example will illustrate the reproducibility of this invention with respect to monohydric initiators. Using the procedure of Example IV, 250 g (0.14 eq.) of a propylene oxides ethylene oxide adduct of methanol was reacted with 13.2 g Epon 828 (0.07 eq.) in the presence of 1.45 g 45% aqueous potassium hydroxide. The resultant product had the following properties: Methanol-propylene Reaction oxide-ethylene Description Product oxide adduct Properties Alkalinity, mg KOH/g 2.03 0.01 Hydroxyl No., mg KOH/g 34.9 32.2 Water, wt. % 0.01 0.01 Viscosity, c.s.

25"C. 1018 251 380C. 511 138 Example VI This example is intended to show the preferred ratios of hydroxyl/epoxy resin equivalents to prepare the high viscosity functional fluids of this invention. In these experiments a 13,000 molecular weight EO/PO diol (Step B, Example I) was reacted with varying quantities of the diglycidyl ether of Bisphenol A (EPON 828) using the procedure of Example Ill. The data indicate that the preferred hydroxyl/epoxy ratio should be in the range of 2/1 to 5/1. Lower ratios caused a gelation of the product, while higher ratios did not increase the viscosity enough.

Table Ill Effect of Hydroxyl/Epoxy Ratios on Functional Fluid Properties Charge, pbw 13000 m.w. EO/PO diols 100 100 100 from Step B, Ex. I Diglycidyl ether of 0.5 1.0 2.0 Bisphenol A Hydroxyl/epoxy ratio 5.74 2.87 1.44 Properties Viscosity, c.s.

380C. 34824 65621 Gelled 990C. 4019 6490 Viscosity,380C. SUS 161305 303956

Claims

1. A process for the preparation of a high viscosity fluid which comprises a) reacting one or more monohydric or dihydric alcohol initiators with one or more alkylene oxides, and b) terminating the reaction with a quantity of epoxy resin such that the ratio of hydroxyl to epoxy resin equivalents is in the range from 2 to 1 to 5 to 1.

2. A process as claimed in Claim 1 wherein the alkylene oxide adduct of the monohydric or dihydric initiators has a molecular weight in the range from 2,000 to 20,000 before the addition of the epoxy resin.

3. A process as claimed in Claim 1 or 2 wherein the viscosity of the resulting high viscosity fluids is in the range from 200,000 to 400,000 SUS at 380C.

4. A process as claimed in any preceding Claim wherein the alkylene oxide is ethylene oxide, propylene oxide, butylene oxide, or a mixture thereof.

5. A process as claimed in any preceding Claim wherein the epoxy resin is diglycidyl ether of Bisphenol A, a polyglycidyl ether of phenolformaldehyde novolac resin, a hydrogenated diglycidyl ether of Bisphenol A, 1,4-butanediol diglycidyl ether, the diglycidyl ether of propylene glycol, vinyl cyclohexanediepoxide, a halogenated diglycidyl ether of Bisphenol A, or an aromatic amine-based epoxy resin.

6. A process as claimed in any preceding Claim wherein the components are heated at a temperature of 50 to 1200 C. during the reaction of making the high viscosity fluids.

7. A process as claimed in Claim 1 and substantially as herein before described with reference to any of Examples II to VI.

8. A high viscosity fluid produced by a process as claimed in any of Claims 1 to 7.

9. An aqueous solution of a high viscosity fluid comprising water and a high viscosity fluid as claimed in Claim 8. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~