WO2020075152A2

WO2020075152A2 - A composition and uses thereof

Info

Publication number: WO2020075152A2
Application number: PCT/IB2019/059546
Authority: WO
Inventors: Rendert Jan Wiersma
Original assignee: Shell Oil Company; Shell Internationale Research Maatschappij B.V.
Priority date: 2018-10-11
Filing date: 2019-11-06
Publication date: 2020-04-16
Also published as: WO2020075152A3

Abstract

A composition comprising diethyl carbonate and an ingredient selected from the group consisting of paints, dyes, coatings, inks, adhesives, resins, agricultural formulations, personal care formulations, fuels and pharmaceutical compositions.

Description

A COMPOSITION AND USES THEREOF

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of pending U.S. Provisional Patent Application Serial No. 62/744,442, filed on 11 October 2018, the entire disclosure of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a composition comprising diethyl carbonate and one or more uses of that composition.

BACKGROUND

US 2018/0187315 describes a process for degreasing a chemical plant where vessels and lines are rinsed with a solvent comprising at least 50 wt% of dialkyl carbonate, based upon the weight of the solvent.

Several solvents are known, including xylene, 1 -butanol, methyl isobutyl ketone, and butyl acetate, but each of these solvents has drawbacks to its use. It would be desirable to identify a sustainable solvent that could replace these solvents. The solvent preferably has an improved carbon footprint and is preferably not considered a volatile organic compound. SUMMARY OF THE INVENTION

The invention provides a composition comprising diethyl carbonate and an ingredient selected from the group consisting of paints, dyes, coatings, inks, adhesives, resins, agricultural formulations, personal care formulations, fuels and pharmaceutical compositions. The invention also provides a method of purifying a pharmaceutical composition comprising contacting the composition with diethyl carbonate.

The invention further provides a method of extracting metal from a metal-containing composition comprising contacting the metal-containing composition with diethyl carbonate. The invention provides a method of treating base oil to remove n-paraffins comprising contacting the base oil with diethyl carbonate to reduce the viscosity and filtering the base oil to remove n-paraffins. BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows the evaporation rate of the paint formulations of Example 2.

Figure 2 shows the effect of shear rate on viscosity of the paint formulations of Example 2.

Figure 3 shows the evaporation rate of the paint formulations of Example 3.

Figure 4 shows the effect of shear rate on viscosity of the paint formulations of

Example 3.

Figure 5 shows the evaporation rate of the paint formulations of Example 4.

Figure 6 shows the effect of shear rate on viscosity of the paint formulations of Example 4.

DETAILED DESCRIPTION

The invention provides a composition comprising diethyl carbonate (DEC). In the composition, diethyl carbonate may act as a solvent. The diethyl carbonate may be made by one of a number of processes as further described.

Production of DEC

Transesterification of ethanol with ethylene carbonate

One process to produce diethyl carbonate comprises the transesterification reaction of ethylene carbonate and ethanol in the presence of a catalyst. This process produces diethyl carbonate and ethylene glycol. This process may be carried out at a temperature of 10 to 200 °C and a pressure of 0.5 to 50 bara. The process may be carried out in any suitable reactor, including a reactive distillation column, a plug flow reactor, or a continuously stirred tank reactor. Embodiments of such a process are further described in US 7,563,919; US

7,718,820; US 7,732,630; and US 7,763,745, the disclosures of which are incorporated by reference. Carbonylation of ethanol using CO?

Another process to produce diethyl carbonate comprises the reaction of ethanol and carbon dioxide to produce diethyl carbonate and water. Diethyl carbonate produced using this method has a lower net product carbon footprint (including end-of-life emissions) than butyl acetate.

Ethanolysis of urea

Another process to produce diethyl carbonate comprises the reaction of an alcohol with urea or alkyl carbamate in the presence of a catalyst. The process may include the use of an organic Group IV complex, for example, a dibutyltin dimethoxide complex.

Embodiments of such a process are further described in US 5,902,894 and US 7,074,951, the disclosures of which are incorporated by reference.

Use of DEC

Diethyl carbonate is a versatile solvent with a favorable environmental profile, low toxicity and valuable chemical and physical properties. Diethyl carbonate may be used in a variety of solvent applications and may be combined with one or more ingredients to provide a composition comprising diethyl carbonate and an ingredient selected from paints, dyes, coatings, inks, adhesives, resins, agricultural formulations, personal care formulations, fuels or pharmaceutical compositions. In addition, diethyl carbonate may be used in batteries, as an extractant and as a dewaxing or reactive agent.

Typical solvent and functional fluid applications are for example described in“The Index of Solvents”, Michael Ash, Irene Ash, Gower publishing Ltd, 1996, ISBN 0-566- 07884-8 and in“Handbook of Solvents”, George Wypych, Willem Andrew publishing, 2001 , ISBN 0-8155-1458.

Diethyl carbonate is especially suitable as a solvent in the applications described in more detail herein.

Paints and Coatings

Diethyl carbonate may be combined with nitrocellulose lacquers, vinyl coatings, alkyd coatings, epoxy coatings, urethane coatings or acrylic coatings.

In one embodiment, the diethyl carbonate may be combined with polyurethane or polyols, isocyanates or mixtures thereof. The diethyl carbonate in this embodiment is used as a solvent for a polyurethane paint or coating. The polyurethane paint or coating may be applied as two compounds which react to form a polyurethane paint or coating. In this case, the diethyl carbonate may be used as a solvent for the polyols and/or for the isocyanates. The polyols may be polyesters, polyethers, acrylics and mixtures thereof. The isocyanates may be aliphatic diisocyanates, aromatic diisocyanates, aliphatic polyisocyanates, aromatic polyisocyanates or mixtures thereof.

One embodiment of polyurethane paints and coatings that can be combined with diethyl carbonate are 2 K polyurethane topcoats which are typically used in a variety of outdoor applications for their versatility, durability and weatherability. These paints and coatings may be used in automotive, marine, aerospace, agricultural, and construction applications. The diethyl carbonate is expected to be a suitable solvent as it does not have active hydrogen groups that would react with the isocyanates in the paint or coating.

In another embodiment, the diethyl carbonate may be combined with epoxy resin components to form an epoxy coating. These epoxy coatings may be used as corrosion resistant primers for a variety of applications. The diethyl carbonate is expected to be a suitable solvent as it will not negatively impact the rate of curing.

In another embodiment, the diethyl carbonate may be combined with a combination of bifunctional acrylic oligomers and multifunctional acrylic monomers to form a UV-curable coating. Diethyl carbonate is expected to be a suitable solvent as it will not impact the free radical chemistry that occurs during the curing process.

The paints and coatings may further comprise additional paint components, including pigments, flattening agents, leveling agents, thickening agents, air release agents, modifying agents, catalysts or resins. In some embodiments, the concentration of water in diethyl carbonate may affect the performance of the paint or coating. In these embodiments the concentration of water may be limited during production or purification steps.

Dyes

Diethyl carbonate may also be combined with organic colorants, e.g. dyes. The high solvency power of diethyl carbonate allows dissolution of a variety of dyes.

Printing Tnks

Diethyl carbonate may be combined with ink ingredients, including gravure inks, flexography inks and screen printing inks. Adhesives

Diethyl carbonate may be combined with adhesive components including epoxies, polyurethanes and polyvinyl resins for structural or flexible applications.

Resins

Diethyl carbonate may be combined with resin components, either as a solvent or during the manufacture of the resins. When the manufacture involves an azeotropic distillation step, diethyl carbonate can be used as a suitable solvent. The diethyl carbonate dissolves the resin and acts as an azeotropic component where it can replace the harmful and commonly used xylene.

Agricultural formulations

Diethyl carbonate may be combined with agricultural and/or agrochemical formulations. Due to its favorable solvency properties diethyl carbonate will enable dissolution of many different types of agrochemical ingredients, potentially replacing aromatic solvents. Moreover, in the soil, diethyl carbonate easily biodegrades.

Personal care formulations

Diethyl carbonate may be combined with personal care compositions used for cosmetics or nailcare. In addition, diethyl carbonate may be used as a carrier for fragrances. Fuels

Diethyl carbonate may be combined with fuels to provide improved performance, including cleaner diesel fuel combustion.

Pharmaceutical compositions

Diethyl carbonate may be combined with pharmaceuticals to form injectable solutions, for example for erythromycin injections.

Battery fluids

Diethyl carbonate may be used as an electrolyte in batteries, specifically Li-Ion batteries.

Pharmaceutical extraction and purification

Diethyl carbonate may be used as an extractant to extract valuable substances from plants and other (bio) sources and to purify pharmaceutical components and actives. Metal extraction

Diethyl carbonate may be used as an extractant to extract valuable metals from metal- containing solutions obtained from leaching ore, electronic waste, metal production waste streams or any other metal source. For example, diethyl carbonate may be used to extract niobium, tantalum or gold. In addition, diethyl carbonate can replace aromatics or other more harmful solvents in rare earth metal solvent extraction processes where it acts as a gel breaker when acidic complexants are applied.

Dewaxing agent

Diethyl carbonate may be combined with base oils to lower the viscosity before filtering the base oil to remove n-paraffins. This improves the filterability of the base oil. Ethylating, carbonylating agent in organic synthesis

Diethyl carbonate can be used in a variety of chemical synthesis reactions where it can act as an ethylation or carbonylation agent.

Cleaning applications

Due to its high solvency power, diethyl carbonate is also very suitable in a variety of cleaning applications, including electronic resist cleaning. The high solvency power also makes diethyl carbonate suitable in paint stripper formulations where it can replace harmful aromatics and chlorinated type solvents.

Examples

Example 1 (Compatibility of Diethyl carbonate)

Several resins were combined with diethyl carbonate to test compatibility. The resins and the results of the test are shown in Table 1. A small quantity of each resin

(approximately 0.5 ml) was added to a transparent glass vial. Two milliliters of diethyl carbonate were added to the vial and the vial was mixed by shaking. The vial was examined after 30 minutes and again after 24 hours. The resins all appeared to be compatible with diethyl carbonate except possibly Aradur 115. This resin is typically used in formulations containing xylene/butanol mixtures and those solutions are reducible in representative quantities with diethyl carbonate. Table 1

Example 2 (DEC in UV curing paints)

In this example, two paint formulations were prepared, A and B. Formulation A was prepared with the ingredients shown in Table 2. Formulation B contained the same ingredients except that the butyl acetate was replaced with diethyl carbonate. Table 2

The ingredients were weighed into an amber glass bottle and hand-mixed with a spatula. Due to the high viscosity of some ingredients, dissolution did not take place immediately, so the formulation was allowed to sit overnight and was re-mixed in the morning. The formulations were stored in the dark until required.

Solvent Evaporation Rate

A 100 pm wet film of each paint formulation was applied to a glass slide using a cube applicator and its mass was automatically monitored for a period of up to several hours until constant mass was achieved.

The evaporation rate of butyl acetate and DEC from formulations A and B respectively is shown in Figure 1. The initial rate of mass loss appears to be very similar for both formulations, however, mass loss plateaued for formulation B earlier than that for formulation A, despite having nominally the same solids content.

High Shear Viscosity

The high shear viscosity of the formulation (to mimic the shear rate of spraying application processes) was measured using a Research Equipment Ltd cone and plate viscometer, equipped with a 19.5 mm/0.5 ° cone, at 23 °C and a shear rate of 9038 s ¹. The cone and plate viscosity values are shown in Table 3. Table 3

Rheology

The viscosity was measured as a function of shear rate using a TA Instruments AR2000 controlled stress rheometer equipped with a 40 mm 2° truncated cone with a solvent trap to minimize evaporation on the timescale of the test. The test temperature was 23 °C.

The sample was allowed to equilibrate for 2 mins at the measurement temperature and the measurement was performed using a continuous shear rate ramp from 0.1-2000 s ¹. The rheology sweep data is shown in Figure 2.

The data obtained at low-moderate shear rates on the controlled stress rheometer are consistent with data obtained at high shear rates on the cone and plate viscometer. The diethyl carbonate containing formulation, B, had slightly higher viscosity than the butyl acetate containing formulation, A. This is consistent with the apparently slightly higher solids content of formulation B as shown by the evaporation experiments. The recommended viscosity range for sprayable formulations is approximately 60-100 mPa- s (or 0.06-0.10 Pa· s), therefore both formulations would be suitable for spray application. In the rheology experiment, the viscosity is unaffected by shear rate across most of the measurement range, therefore the formulation can be said to have Newtonian characteristics.

Example 3 (DEC in 2K PU curing paints)

In this example, two paint formulations were prepared, C and D. Formulation C was prepared with the ingredients shown in Table 4. Formulation D contained the same ingredients except that butyl acetate was replaced with diethyl carbonate.

Table 4

The formulations were prepared by mixing parts 1 and 2 at a ratio of 1 :0.85 by mass respectively (for 1 : 1 stoichiometry). The VOC of the mixture is 517 g/L, the pot life is 7 hours at ambient temperature, the solids content is 48.0 wt% solids and the full curing time is 7 days at ambient temperature or 45 minutes at 60 °C.

Solvent Evaporation Rate

A 100 pm wet film of each paint formulation was applied to a glass slide using a cube applicator and its mass was automatically monitored for a period of up to several hours until constant mass was achieved. The evaporation rate of butyl acetate and DEC from formulations C and D respectively are shown in Figure 3. The substitution of butyl acetate with DEC seems to have little effect on the initial evaporation rate.

High Shear Viscosity

The high shear viscosity of the formulation (to mimic the shear rate of spraying application processes) was measured using a Research Equipment Ltd cone and plate viscometer, equipped with a 19.5 mm/0. ° cone, at 23 °C and a shear rate of 9038 s ¹. The cone and plate viscosity values are shown in Table 5.

Table 5

Rheology

The viscosity was measured as a function of shear rate using a TA Instruments

AR2000 controlled stress rheometer equipped with a 40 mm 2° truncated cone with a solvent trap to minimize evaporation on the timescale of the test. The test temperature was 23 °C.

The sample was allowed to equilibrate for 2 mins at the measurement temperature and the measurement was performed using a continuous shear rate ramp from 0.1-2000 s ¹. The rheology sweep data is shown in Figure 4.

The diethyl carbonate containing formulation, D, had very slightly higher viscosity than the butyl acetate containing formulation C. The recommended viscosity range for sprayable formulations is approximately 60-100 mPa- s (or 0.06-0.10 Pa- s), therefore both formulations would be suitable for spray application. In the rheology experiment, the viscosity is unaffected by shear rate across most of the measurement range, therefore the formulation can be said to have Newtonian characteristics.

Example 4 (DEC in epoxy curing paints)

In this example, two paint formulations were prepared, E and F. Formulation E was prepared with the ingredients shown in Table 6. Formulation F contained the same ingredients except that the methyl isobutyl ketone was replaced with diethyl carbonate. Table 6

The Part 1 ingredients were mixed and left in a sealed container overnight at room temperature for the solid epoxy resin to dissolve. The Let-down solvent mixture was prepared separately. The resin solution was then stirred at 500 rpm using a Dispermat high speed dissolver mixer fitted with a 30 mm Cowles blade. Other ingredients were added sequentially in aliquots with pauses to ensure full incorporation into the resin solution. The solvent mixture was also added in aliquots to aid pigment / extender incorporation when viscosity increased too much. Solvent Evaporation Rate

A 100 mpi wet film of each paint formulation was applied to a glass slide using a cube applicator and its mass was automatically monitored for a period of up to several hours until constant mass was achieved.

The evaporation rate of MIBK and DEC from formulations E and F respectively is shown in Figure 5. Some differences were noted in the evaporation of solvents from the MIBK and DEC based formulations; DEC appeared to evaporate faster from formulation. High Shear Viscosity

The high shear viscosity of the formulation (to mimic the shear rate of spraying application processes) was measured using a Research Equipment Ltd cone and plate viscometer, equipped with a 19.5 mm/0. ° cone, at 23 °C and a shear rate of 9038 s ¹. The cone and plate viscosity values are shown in Table 7.

Table 7

Rheology

The viscosity was measured as a function of shear rate using a TA Instruments AR2000 controlled stress rheometer equipped with a 40 mm 2° truncated cone with a solvent trap to minimize evaporation on the timescale of the test. The test temperature was 23 °C. The sample was allowed to equilibrate for 2 mins at the measurement temperature and the measurement was performed using a continuous shear rate ramp from 0.1-2000 s ¹. The rheology sweep data is shown in Figure 6.

A significantly lower viscosity was noted for the DEC formulation than for the MIBK formulation. This might be explained by the fact that the rheology modifier Bentone SD2 particularly is designed for use in polar solvents and that the higher polarity of the DEC formulation is activating the Bentone to a higher extent. Example 5 - cured coating performance

The following paint tests were performed with the formulations described above and the respective performance of different formulations is compared in Table 8.

Pot-Life

The pot-life is typically defined as the time taken for a mixed 2-part coating to double in viscosity. It was evaluated at 23+2 °C using a high shear viscometer. Viscosity was measured immediately after mixing and then at regular intervals until the pot-life had been determined. The containers were kept sealed between measurements to minimise viscosity changes due to solvent evaporation.

Pendulum Damping Test

The pendulum damping hardness was tested according to BS EN ISO 1522:2006, using a Kdnig pendulum. 100 x 150 mm aluminium panels were hand abraded and solvent- cleaned prior to application of the coating using a 50 (UV-cure) or 100 pm (polyurethane) wire-wound bar. For the 2-part coatings, the first test was performed after 24 hours curing, and they were then tested at regular intervals for 2 weeks. For the UV-cure coatings, the pendulum damping was measured as a function of applied curing energy. All testing was performed at 23+2 °C and 50+5 %RH. The time taken for the pendulum amplitude to reduce from 6° to 3° was recorded in triplicate for each sample and averaged.

Gloss

The gloss was tested according to BS EN ISO 2813:2014 using a calibrated Rhopoint

IQ handheld glossmeter. 100 x 150 mm steel panels were hand abraded and solvent-cleaned prior to application of the coating using a 50 (UV-cure) or 100 pm (polyurethane) wire- wound bar. For the clear-coat systems, additional Leneta black and white sealed card test charts were used as received and coated at the same wet film thickness. The coatings were cured and conditioned at the test conditions (23+2 °C and 50+5 %RH) overnight prior to testing. For high gloss coatings, gloss measurements were recorded at 60° and 20°. For semi gloss coatings, gloss measurements were recorded only at 60°. It should be noted that for transparent coatings, the gloss measurement may be influenced by the substrate, therefore gloss readings on different substrates cannot be directly compared. Cross-cut Adhesion

The cross-cut adhesion was tested according to BS EN ISO 2409:2013. 100 x 150 mm aluminium panels were hand abraded and solvent-cleaned prior to application of the coating using a 50 (UV-cure) or 100 pm (polyurethane) wire-wound bar. The coatings were cured and conditioned at the test conditions (23+2 °C and 50+5 %RH) overnight prior to testing. A hand-held multi-blade cutter with 1 mm spacer was used to create the cross-cut pattern and any loose fragments of coating were removed using adhesive tape pulled off at a 60° angle. Coating removal was compared to pictorial standards to determine classification.

Abrasion Resistance

The Taber abrasion resistance was measured according to BS EN ISO 7784-2, using a lkg load and CS-17 type abrasive rubber wheels. 100 x 100 mm steel panels were hand abraded and solvent-cleaned prior to application of the coating using a 50 (UV-cure) or 100 pm (polyurethane) wire-wound bar. The coatings were cured and conditioned at the test conditions (23+2 °C and 50+5 %RH) overnight prior to testing. Each sample was weighed before testing and then every 250 abrasion cycles until wear-through of the coating occurred. The abrasion wheels were re-surfaced every 500 cycles.

Scratch Resistance

The scratch resistance was assessed according to BS EN ISO 1518-1 :20l 1. 100 x 150 mm aluminium panels were hand abraded and solvent cleaned before application of coating using a 100 pm wire-wound bar. Coatings were allowed to cure/condition for at least 7 days at 23+2 °C/50+5% RH and testing was performed under the same conditions. A

hemispherical hard metal stylus was used, and increasing loads were applied until penetration of the coating occurred (as indicated by electrical contact of the stylus to the substrate). The “minimum load to cause penetration” of the coating was recorded after testing on triplicate panels.

Chip Resistance

The chip resistance was assessed according to BS AU 148: Part 15: 1969. 100 x 150 mm aluminium panels were hand-abraded and solvent cleaned before application of the coating using a 100 pm wire-wound bar. Coatings were allowed to cure/condition for at least 7 days at 23+2 °C/50+5% RH. Testing was performed outside the controlled conditions laboratory, but samples were tested within 30 minutes of removal from the controlled conditions. The panel was supported at an angle of 45° with coated surface uppermost while impacted by 100 of ¼ inch hexagon nuts (gravel simulant) dropped from a height of 4.5 m. The degree of chipping was assessed as a grade of 1-6 by comparison with pictorial examples in the standard test method

Tmpact Resistance

The impact resistance was tested according to BS EN ISO 6272-1 :2011. 100 x 150 mm aluminium panels were hand abraded and solvent cleaned before application of coating using a 100 pm wire-wound bar. Coatings were allowed to cure/condition for at least 7 days at 23+2 °C/50±5% RH and testing was performed under the same conditions. The classification method was used, with a drop weight of lkg and the coated side of the panel facing up. No stops were used to limit the penetration of the indenter. The lowest drop height required to cause failure (cracks or peeling of the coating) in at least 3 out of 5 impacts was recorded.

Flexibility (Cylindrical Mandrel)

The coating flexibility was tested using a cylindrical mandrel bend test according to

BS EN ISO 1519:2011 and using a type 2 tester with interchangeable mandrels. 100 x 150 mm aluminium panels were hand abraded and solvent cleaned before application of coating using a 100 pm wire-wound bar. Coatings were allowed to cure/condition for at least 7 days at 23+2 °C/50+5% RH and testing was performed under the same conditions. Each coated panel was cut lengthways into 30-35 mm strips before testing. The diameter of the first mandrel to cause failure (cracking or delamination, as observed with normal corrected vision) was recorded, having repeated the procedure on a fresh panel to confirm the failure.

Table 8

Claims

1. A composition comprising diethyl carbonate and an ingredient selected from the group consisting of paints, dyes, coatings, inks, adhesives, resins, agricultural formulations, personal care formulations, fuels and pharmaceutical compositions.

2. The composition of claim 1 wherein the paint or coating ingredient is selected from the group consisting of nitrocellulose lacquers, vinyl coatings, alkyd coatings, epoxy coatings, urethane coatings and acrylic coatings.

3. The composition of claim 2 wherein the urethane coating ingredient is a)

polyurethane; or b) one or more polyols and/or one or more isocyanates.

4. The composition of claim 3 wherein the one or more polyols are selected from the group consisting of polyesters, polyethers, acrylics and mixtures thereof.

5. The composition of any of claims 3-4 wherein the one or more isocyanates are

selected from the group consisting of aliphatic diisocyanates, aromatic diisocyanates, aliphatic polyisocyanates, aromatic polyisocyanates and mixtures thereof.

6. The composition of any of claims 2-5 further comprising additional paint ingredients selected from the group consisting of pigments, flattening agents, leveling agents, thickening agents, air release agents, modifying agents, catalysts and resins.

7. The composition of any of claims 1-6 wherein the diethyl carbonate contains from 0 to 0.05 wt% water.

8. The composition of claim 1 wherein the coating ingredients comprise bifunctional acrylic oligomers and multifunctional acrylic monomers.

9. The composition of claim 1 wherein the ink ingredients are selected from the group consisting of gravure inks, flexography inks and screen printing inks.

10. A method of purifying a pharmaceutical composition comprising contacting the composition with diethyl carbonate.

11. A method of extracting metal from a metal-containing composition comprising

contacting the metal-containing composition with diethyl carbonate.

12. The method of claim 11 wherein the metal is selected from the group consisting of niobium, tantalum and gold.

13. A method of treating base oil to remove n-paraffins comprising contacting the base oil with diethyl carbonate to reduce the viscosity and filtering the base oil to remove n-paraffins.