US 20110315929A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2011/0315929 A1 Datta et al. (43) Pub. Date: Dec. 29, 2011 (54) SOLVENT BLEND FOR REPLACEMENT OF Publication Classi?cation KETONES (51) Int. Cl. B01F 1/00 (2006.01) (76) Inventors: Rathin Datta, Chicago, IL (U S); (52) US. Cl. ...................................................... .. 252/364 James E. Qpre, Downers Grove, IL (57) ABSTRACT (US); Kevin L. Monti, Aurora, IL (Us) A three-part solvent composition that contains A) a C l to C4 lactate ester, B) ethyl 3-ethoxy propionate and C) a C7-Cl2 hydrocarbon mixture is disclosed that is a homogeneous liq (21) App1.No.: 12/826,239 uid at Zero degrees C. A contemplated solvent blend provides performance properties that can replace toxic ketones, but (22) Filed: Jun. 29, 2010 does not contain any ketone groups in any of the components. US 2011/0315929 A1 Dec. 29, 2011 SOLVENT BLEND FOR REPLACEMENT OF contemplated blend contains three components: A) a Cl-C4 KETONES aliphatic ester of lactic acid, B) ethyl 3-ethoxy propionate, and C) a mixture of C7-Cl2 hydrocarbons that includes aro BACKGROUND ART matic hydrocarbons and up to about 70 Weight percent ali [0001] Ketones are a speci?c group of chemicals that are phatic hydrocarbons and provides enhanced properties com used as solvents in a Wide variety of applications. Simple pared to each component. A contemplated mixture of C7-Cl 2 ketones such as acetone, methyl ethyl ketone (MEK), and hydrocarbons preferably has a distillation range of about 150° methyl iso-butyl ketone (MIBK) are commonly used for gen to about 230° C. at one atmosphere, a Tagliabue (Tag) closed eral cleaning and Wiping solvents and sometimes as formu cup (TCC) ?ash point of about 100° F. or greater, and can be lation ingredients for inks and coatings. substantially all (about 95% or more) aromatic compounds, [0002] Generally however, complex ketones are used in or aromatics plus Zero to about 70 Weight percent aliphatic many such formulations because they impart many desirable compounds. A mixture of about equal Weights of each type of properties simultaneously, such as viscosity reduction, dis C7-Cl2 hydrocarbon (aromatic and aliphatic) is preferred. persion of dyes and pigments, consistent phase behavior, Each of the three ingredients (A, B and C) can itself be present desirable ?oW characteristics, consistent drying behavior and at about 10 to about 80 Weight percent of the total. A contem many other properties. One such complex ketone is Isophor plated composition is a homogeneous liquid at Zero degrees one (3,5,5-trimethyl-2-cyclohexen-1-one, CAS number (78 C. 59-1)). Isophorone is manufactured by catalyZed self-con [0008] Ethyl lactate is a preferred is a preferred Cl-C4 densation of acetone by a multi step processimesityl oxide aliphatic ester of lactic acid. Other Cl-C4 aliphatic lactate is the initial product of the aldol self-condensation. Mesityl esters include methyl lactate, n-propyl lactate, iso-propyl lac oxide formation is folloWed by a Michael reaction of acetone tate, n-butyl lactate, iso-butyl lactate and t-butyl lactate. In With the mesityl oxide folloWed by intramolecular aldol con preferred embodiments, the Cl-C4 aliphatic ester of lactic densation to eventually obtain the six-membered ring of iso acid such as ethyl lactate (EL) is present at about 50 to about phorone. The process is complex and loW yielding but 70 Weight percent, the ethyl 3-ethoxy propionate (EEP) is because of the desirable product properties, fairly large quan present at about 15 to about 35 Weight percent, and the C7-Cl 2 tities are manufactured and used. hydrocarbon mixture (HC) constitutes about 15 to about 35 [0003] Ketones generally have a much higher toxicity than percent. More preferably, the solvent blend contains each of other simpler solvents such as esters and alcohols, and com the three ingredients in a ratio of about 3:1:1, ELzEEPzHC. plex ketones have particularly high toxicities. Isophorone for [0009] The present invention has several bene?ts and example, in tests conducted by the National Toxicology Pro advantages. One bene?t of a contemplated blend is that the gram (NTP) has shown some evidence of carcinogenicity in performance in formulations exceeds that of isophorone. male rats and equivocal evidence of carcinogenicity Was [0010] An advantage is that the solvents in the blend con noted in male mice. In repeated expo sure of isophorone to rats tain no ketone groups and thus a contemplated blend avoids and guinea pigs, increases in mortality, groWth retardation, the inherent physiological toxicity that many ketones display. kidney, lung and liver toxicity and blood cell changes Were observed. Hence, isophorone is considered a Hazardous Air [0011] Another bene?t is that the primary components of Pollutant as Well as a SARA reportable substance and many these blends4ethyl lactate, ethyl 3-ethoxy propionate are countries are banning or regulating its large-scale usage. environmentally benign, non-toxic and are derived at least in [0004] Furthermore, ketones especially the complex part, from reneWable resources. ketones, are not readily manufactured from reneWable [0012] Still further bene?ts and advantages of the present resources and given the desirability of sustainable products invention Will be apparent to the skilled Worker from the and processes, there is a clear need for ?nding suitable sub disclosure that folloWs. stitutes for such solvents. [0005] Ethyl lactate and other lactate esters are environ DETAILED DESCRIPTION OF THE INVENTION mentally benign, non-toxic solvents derived from reneWable carbohydrates via fermentation and separation processes. [0013] It has been unexpectedly found that a solvent blend Ethyl lactate for example, has very good solvent properties that contains no ketone group and that contains esters of lactic and a characteristic odor. Chemically, this ester has an active acid, particularly ethyl lactate, When blended With ethyl hydroxyl group in addition to the carboxylic ester group. 3-ethoxy propionate and a mixture of hydrocarbons provides Lactate esters can also be blended With other solvents to properties that permit the blend to replace a complex ketone provide biosolvent blends With enhanced properties. such as isophorone in a variety of applications [0006] Other ester solvents such as ethyl 3-ethoxy propi onate available from Eastman Chemical Company of King [0014] Because of its toxicity, many attempts have been sport, Tenn. (CAS #763-69-9) have an ether group in addition made to replace isophorone as a solvent in formulations With to the carboxylic ester group. Another generally used solvent non-toxic, environmentally benign ingredients. The results, in coating formulations is a mixture of aromatic hydrocar hoWever, have not been successful. As a matter of fact the bons (A 150 or AR 150) available from Shell Chemical Com three solvent components described in this invention if tested pany or Exxon Mobil Company. These mixtures are a blend of individually, do not give good results. The unexpected result aromatic compounds (>99% aromatic hydrocarbons) that fall of this invention illustrates that these solvents that have a very Within a range of boiling points. The primary components are diverse group of chemical functionalities can be successfully C1O to C l 1 alkyl benZenes With a total range of C7 to C12 alkyl blended and provide not only very uniform properties but also benZenes. It shouldbe noted thatAR 150 is available in grades very good performance properties in the ?nal coatings for that have very loW contents of naphthalene as a loW-toxicity mulations Where isophorone Would normally be used. solvent. [0015] A contemplated blend contains three components: A) a Cl-C4 aliphatic ester of lactic acid, B) ethyl 3-ethoxy BRIEF SUMMARY OF THE INVENTION propionate, and C) a mixture of C7-Cl2 hydrocarbons that [0007] The present invention contemplates a solvent blend provides enhanced properties. Each of the three ingredients that can replace isophorone in a variety of applications. A (A, B and C) can be present at about 10 to about 80 Weight US 2011/0315929 A1 Dec. 29, 2011 percent of the total. A contemplated composition is a homo distillation range of about 183° C. to about 207° C., a TCC geneous liquid at room temperature (about 25° C.) and at Zero ?ash point of 66° C., is 99 volume percent aromatics, and has degrees C. a CAS Registry No. 64742-94-5. Another illustrative com [0016] Ethyl lactate is a preferred is a preferred Cl-C4 mercial solvent mixture is sold under the name AtosolTM 150 aliphatic ester of lactic acid. Other lactate esters include methyl lactate, n-propyl lactate, iso-propyl lactate, n-butyl that is available from Total Petrochemicals USA, Inc. That lactate, sec-butyl lactate, iso-butyl lactate and tert-butyl lac product has CAS Registry No. 64742-94-5, exhibits a distil tate. lation range of about 182° C. to about 210° C., and a TCC [0017] A contemplated mixture of C7-Cl2 hydrocarbons ?ash point of 150° F. or greater (>65.6° C.). Illustrative ingre (HC) can be comprised of aromatic hydrocarbons (AM) or a dients listed for AtosolTM 150 are as folloWs: mixture of both aromatic and Zero to about 70 Weight percent aliphatic (AC) hydrocarbons. A contemplated mixture of C7-Cl2 hydrocarbons has a distillation range of about 150° to about 230° C. at one atmosphere, and a Tagliabue (Tag) Component Amount (%) closed cup (TCC) ?ash point of about 100° F. or greater, and 1,2-Dimethyl-4-ethylbenzene 10-20 more preferably about 150° F. or greater (>65.6° C.). 1,2,3 ,5-Tetramethylbenzene 10-20 [0018] It is to be understood that commercially available 1,2,4,5—Tetramethylbenzene 5-15 aromatic hydrocarbons and aliphatic hydrocarbons are them 1,3 -Dimethyl—4-ethylbenzene 2-10 selves typically mixtures of distillation products obtained 1,3-Dimethyl-5-ethylbenzene 2-10 from oil re?ning, and When designated “aromatic” or “ali 1,4-Dimethyl-2-ethylbenzene 2-10 phatic” can contain up to about 5 Weight percent of the other 1-Methyl-3 —propylbenzene 2-10 Naphthalene <10 type of solvent.