WO1995031510A2

WO1995031510A2 - A carrier solvent coating composition and method to enhance the performance of an organic coating

Info

Publication number: WO1995031510A2
Application number: PCT/US1995/005703
Authority: WO
Inventors: Nancy H. Morris; Douglas K. Pollock
Original assignee: The Dow Chemical Company
Priority date: 1994-05-12
Filing date: 1995-05-05
Publication date: 1995-11-23
Also published as: WO1995031510A3

Abstract

A carrier solvent in an organic coating composition that contains a propylene glycol alkyl ether acetate and a diether additive. The diether provides a synergistic effect with the propylene glycol alkyl ether acetate by enhancing the hardness development of an applied film of the organic coating composition. The carrier solvent finds preferable use in polyol/polyisocyanate systems and acrylic/polyol/polyisocyanate systems. The diether is characterized by two terminal alkoxy groups. A highly preferred propylene glycol alkyl ether acetate is propylene glycol methyl ether acetate.

Description

A CARRIER SOLVENT COATING COMPOSITION AND METHOD TO ENHANCE THE PERFORMANCE OF AN ORGANIC COATING BACKGROUND OF THE INVENTION

This invention generally pertains to organic coating compositions and more particularly to carrier solvents that contain propylene glycol alkyl ether acetates, and that are used in organic coating compositions.

During the early 1980's, a great deal of time and money was expended by the coatings industry to find a suitable alternative to ethylene glycol ethyl ether acetate (EEA) to use as the carrier solvent in organic coating compositions, investigators sought an alternative o solvent that could similarly serve as the active solvent in high solids, solvent-based, coating applications. The reformulation effort was primarily driven by EEA toxicity studies conducted on laboratory animals. The studies demonstrated that EEA has teratogenic and fetotoxic effects at relatively low exposure levels. The studies even prompted The Occupational Safety and Health Administration and The American Conference of Governmental Industrial 5 Hygienists to establish very low worker exposure guidelines for EEA. As a result of the investigations, propylene glycol methyl ether acetate (PMA) is now the practical alternative to EEA and finds widespread acceptance in the marketplace. PMA is highly similar to EEA in both molecular structure and physical properties; however, PMA has radically different toxicity. In general, the performance of PMA as a substitute for EEA in a coating 0 composition has been acceptable, although one property, hardness development, is not typically similar to that achieved when EEA is used in the carrier solvent in a coating composition. The common concern expressed by many industrial coating manufacturers is that PMA encourages under-curing and softening of an applied film. Softening leaves the film susceptible to marring and environmental fallout, and the film may ultimately require repair. It 5 is believed the softening is due to the retention of PMA in the applied film after curing of the coating composition. SUMMARY OF THE INVENTION

In one aspect, the present invention is a carrier solvent for a coating composition that includes propylene glycol alkyl ether acetates to address health concerns, but also 0 produces a film with a hardness development that is closer to that achieved when ethylene glycol ethyl ether acetate (EEA) is used in the carrier solvent. The carrier solvent of the present invention includes a particular diether as an additive to the propylene glycol alkyl ether acetate. The carrier solvent containing this diether additive with propylene glycol alkyl ether acetate provides an organic coating that has improved hardness development above that seen 5 when propylene glycol alkyl ether acetate is used, alone, as a carrier solvent. Furthermore, the present invention, by comparison, offers surprising hardness development above that seen when a monoether additive, such as a propylene glycol monoether, is used in the coating formulation. The carrier solvent of the present invention is useful to solvate organic binders to form organic coating compositions. Thus, another aspect of the present invention is an organic coating composition that includes the carrier solvent of the invention and one or more organic binders. The carrier solvent insures f lowability and prevents premature hardening of the organic binder before it is placed on an appropriate surface. The organic coating composition is formulated by combining pigments, if desired, an organic binder, and the carrier solvent of the present invention. Typically, all that is required is to provide these ingredients in user- defined amounts and thoroughly mix them before application upon an article of manufacture. Other conventional coating additives may also be included in the coating composition. Yet another aspect of the present invention is a process for coating an article of manufacture with an organic coating composition that includes the carrier solvent of the present invention. The article to be coated by the coating composition is coated by any conventional coating means, such as printing, screening, spraying, drawing down, and the like, to provide a coating which, upon curing, provides a layer or film upon the article. Due to the presence of the carrier solvent of the present invention, the article of manufacture is coated with an organic binder that has improved hardness development over that seen in the common practice of using propylene glycol alkyl ether acetate, alone, as the carrier solvent.

One embodiment of the present invention is a carrier solvent for use in an organic coating composition that includes at least one propylene glycol alkyl ether acetate, and at least one diether corresponding to the formula:

R" I R-0-(CHCH20)n-R'

where R and R' are independently a Ci to C₄ alkyl, R" is H, -CH3, or -C₂H₅, and n is a whole number from 1 to 3.

Another embodiment of the present invention is an organic coating composition that includes an organic binder, at least one propylene glycol alkyl ether acetate, and at least one diether corresponding to the formula:

R" I

R-0-(CHCH20)n-R'

where R and R' are independently a C1 to C4 alkyl, R" is H, -CH3, or -C₂Hs, and n is a whole number from 1 to 3. In a preferred embodiment, the organic binder forms a polyurethane film or an acrylic, polyurethane film.

Yet another embodiment of the present invention is a process to apply the coating composition of the present invention upon an article of manufacture. DESCRIPTION OF THE FIGURES in the accompanying drawings, forming a part of this specification, and in which like abbreviations are employed to designate identical compounds throughout these drawings, Figure 1 illustrates relative evaporation rates of the example formulations; Figure 2 illustrates relative viscosities of the example formulations;

Figures 3, 4, and 5 illustrate the hardness development of the example formulations; and

Figure 6 illustrates the hardness development of a comparative example formulation. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Specific language is used to describe several embodiments of the present invention for the purpose of promoting an understanding of the principles of the invention.

However, it must be understood that no limitation of the scope of the present invention is intended by using this specific language. Any alteration and further modification of the described carrier solvent, coating composition, or coating process and any application of the principles of the present invention are also intended that normally occur to one skilled in the art to which the present invention pertains.

Generally, the preferred embodiments of the present invention include a carrier solvent, an organic coating composition, and a process for coating an article of manufacture. The carrier solvent of the preferred embodiment to date is formed from mixing propylene glycol alkyl ether acetate, and a specific diether described below. The carrier solvent of the preferred embodiment is combined with an organic binder to form an organic coating composition. This organic coating composition is useful to create an organic film upon an article of manufacture. The organic coating composition is applied to the article of manufacture and the carrier solvent of the preferred embodiment is allowed to evaporate.

Upon evaporation, a film of the organic binder is left on the article. Due to the use of the carrier solvent of the preferred embodiment, the organic coating has improved hardness development. The hardness development resembles that achieved when ethylene glycol ethyl ether acetate is used in the carrier solvent. The term diether is used within this specification to generally describe a molecule with terminal alkoxide groups on each end of a molecule.

Carrier Solvent

One embodiment of the present invention is a carrier solvent for use in an organic coating composition. A first component included in the preferred carrier solvent of the present invention is a propylene glycol alkyl ether acetate, and preferably propylene glycol methyl ether acetate (PMA). PMA is graphically represented in Formula I.

Formula I

Propylene glycol methyl ether acetate is a widely used commercial product and is available from such sources as the Aldrich Chemical Company, Inc. The compound is typically produced by the well-known catalyzed reaction of propylene oxide under basic conditions with methanol to initially produce a propylene glycol methyl ether (PM) intermediary. Should other monoalkyls be desired, the corresponding alcohol is simply used instead of methanol, for example, ethanol is used to place an ethyl group, propanol for a propyl group, or butanol for a butyl group. The PM intermediary is then reacted with acetic acid to form the propylene glycol alkyl ether acetate.

A second component included in the carrier solvent of the preferred embodiment is a diether of Formula II.

R" I R-0-(CHCH20)n-R'

Formula II

In this formula, R and R' are each a Ci to C₄ alkyl, R" is H, -CH3, or -C₂Hs, and n is a whole number from 1 to 3. The term "C1 to C₄ alkyl" denotes such radicals as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl.

The preferred R and R' groups are each methyl or n-butyl; however, most preferably both the R and R' groups are methyl. The preferred R" group is methyl. The preferred whole number, n, is 1 or 2. The most preferred diether in work completed to date has been propylene glycol dimethyl ether (MM) or dipropylene glycol dimethyl ether (DMM). Both MM and DMM are products available from The Dow Chemical Company.

The diethers usable in the preferred embodiments of the present invention can be made by the well-known catalyzed reaction of propylene oxide with an alcohol under basic conditions. Where it is desired for R to be methyl, methanol is used; for ethyl, ethanol; for propyl, propanol; or for butyl, butanol. For example, if methanol is used, the reaction forms propylene glycol methyl ether as illustrated in Formula III.

Here, both R and R" are methyl. Further reaction of the propylene glycol methyl ether with propylene oxide produces dipropylene glycol methyl ether (n = 2), and further reaction of the O R»

H2C-CH-CH3 + R-OH ► ROCHCH20H

Formula III

dipropylene glycol methyl ether with propylene oxide forms tripropylene glycol methyl ether (n = 3). Here R" is routinely methyl; however, should it desired to be hydro, ethylene oxide is used in that step instead of propylene oxide; or should it desired to be ethyl, butylene oxide is used in that step instead of propylene oxide. The wide difference in the boiling points of these glycol ethers (that is, n = 1 , 2, or 3) enables their separation to be achieved by distillation. Finally, to remove the terminal hydrogen and to form the diether, the Williamson synthesis is used. The mono-, di-, or tri- propylene glycol alkyl ether is first reacted with sodium metal to form an alkoxide:

RO( rCHCH20)nH + Na ► RO( rCHCH20)n-Na +

Then, the alkoxide is reacted with an alkyl halide to form the diether:

RO(C rHCH20)n-Na+ + XR ► RO( rCHCH20)nR'

Typically, X is usually chloro or bromo and R' is methyl, ethyl, propyl, or butyl, depending on the desired R' group. The Williamson synthesis is well-known to the practitioner in this art and is described in such references as Morrison and Boyd, Organic Chemistry, Third Ed., (Allyn and Bacon, Inc. 1980) pp. 556-558, which is incorporated into this specif ication by reference. The carrier solvent of the preferred embodiment of the present invention is made by combining propylene glycol alkyl ether acetate and a diether identified in Formula II. The two components can be combined in about any manner. For example, they can be combined by converging individual component streams or by mixing premeasured volumes of each. What is important is the relative amount of the diether that is present in relation to the Q amount of propylene glycol alkyl ether acetate present.

The relative proportions of the diether of Formula II and the propylene glycol alkyl ether acetate can vary over a relatively wide range. In respect to a combination of the two, from the work completed to date, it is recommended that the diether comprise no more than about 25 wt. % and that the propylene glycol alkyl ether acetate comprise no less than c about 75 wt. % . Preferable relative proportions have been up to about 15 wt. % of the diether with no Jess than.about 85 wt. % being propylene glycol alkyl ether acetate. However, most preferable relative proportions to date have been from about 5 wt. % to about 10 wt. % of the diether with the balance being from about 90 wt. % to about 95 wt. % propylene glycol alkyl ether acetate.

Organic Coating Composition

Another preferred embodiment of the present invention is an organic coating composition that contains the carrier solvent of the present invention and an organic binder. The carrier solvent of the present invention is mixed with an organic binder to make the binder f lowable over an appropriate surface upon application and to prevent the organic binder from prematurely hardening before this application. The carrier solvent is combined with the organic binder in user-defined amounts and mixed with the binder in typically the same fash ion as the user would use EEA or PMA in a formulation.

A polyurethane is an example of an organic binder that is practicable with the carrier solvent of the present invention. An isocyanate, diisocyanate, or polyisocyanate used to form a particular polyurethane may be dissolved in the carrier solvent of the present invention. Likewise, the macroglycol, also known as polyol, of the particular polyurethane may also be combined with the carrier solvent of the present invention. Pigments and flow enhancers may also be combined with the isocyanate, diisocyanate, or polyisocyanate and/or the polyol, as desired. The isocyanate, diisocyanate, or polyisocyanate mixture and the polyol mixture are then combined, mixed, and the resulting formulation applied to an article of manufacture. Upon combination, the isocyanate, diisocyanate, or polyisocyanate mixtures and the polyol mixtures react to form a polyurethane, and a film of polyurethane is deposited upon the article of manufacture. As the carrier solvent evaporates from the applied film, the film hardens. By using of the carrier solvent of the present invention, the hardness development of that film is better than that achieved when PMA is used, alone or with a mono-ether additive, as the carrier solvent. Additional organic binders practicable in the present invention include acrylics, polyesters, epoxies, alkyds, and mixtures of these organics including mixtures with polyols and isocyanates, diisocyanates, or polyisocyanates. Although preferably, the organic binder is a polyurethane coating formed from polyisocyanates and polyols or an acrylic, polyurethane coating formed from acrylics, polyisocyanates, and polyols. Process for Coating an Article of Manufacture

Another embodiment of the present invention is a process for coating an article of manufacture with an organic coating composition that contains the carrier solvent of the present invention. The article to be coated by the composition may be coated by any conventional coating means, such as printing, screening, spraying, drawing down, and the like, to provide a coating which, upon curing, provides a layer or film upon the article. Typically no special equipment or technique is required. The user may apply the coating composition containing the carrier solvent described in this specification as it would be applied if the composition contained PMA, alone, or PMA and a mono-ether additive. EXAMPLE I

Table I Coating Formulation Used in the Following Example I

Component 1

Grind Wt.% Grams

ACRYLOID^® AU-608X 10.26 20.52

Test Solvent 10.26 20.52

Titanium Dioxide 23.82 47.64

Letdown

ACRYLOID^® AU-608X 36.50 73.0

Test Solvent 5.53 11.06

BYK 300 0.08 0.16

Component 2

DESMODUR^® N-100 9.08 18.16

Test Solvent 3.02 6.04

Test Solvent 1.45 2.9

(The second addition of test solvent in component 2 was made to account for additional solvent that might be added with a pigment in a commercial application.) Procedure

All the components of Table I are commercially available. ACRYLOID^® is an acrylic polyol commercially available from the Rohm & Haas Company. DESMODUR^® is an aliphatic polyisocyanate commercially available from Mobay Corporation. BYK 300 is a flow-aid commercially available from the Byk-Mallinckrodt Company. T-12 is a dibutyltin dilaurate catalyst commercially available from the Air Products Corporation. In the Examples that follow, "MM" is an abbreviation for propylene glycol dimethyl ether and "DMM" is an abbreviation for dipropylene glycol dimethyl ether. Both MM and DMM are available from The Dow Chemical Company.

Formulations listed in Table I were prepared and evaluated with each of the following Test Solvent blends:

1. 100% PMA 4. 90% PMA, 10% MM

2. 100% EEA 5. 95% PMA, 5% DMM

3. 95% PMA, 5% MM 6. 90% PMA, 10% DMM

The grind ingredients of Component 1 were each weighed into a polished quart paint can. Stainless steel diagonals (250 grams) were added and the sealed cans were placed on a ball mill overnight The mean particle size of the grind was checked with a Hegman gauge. All grind ingredients for all test formulations were 6-8 microns after 16 hours. The letdown ingredients of component 1 were added directly to the grind ingredients and the cans were resealed and returned to the ball mill for an additional four hours to ensure complete mixing. The stainless steel diagonals were removed by passing the contents of each can through a large mesh filter and into a glass container.

Component 2 was prepared by weighing the ingredients into a glass jar and mixing them overnight on a platform shaker.

The Components 1 and 2 were manually mixed together just prior to use. If the formulation was to be tested with a catalyst, 0.04 grams of T12 catalyst (dibutyltindilaurate) was added to Component 2 before combining the two Components.

Relative evaporation rate profiles were generated for each Test Solvent used in the formulation using the Quintel EV-1 Evaporometer. The sample size used was 0.5 grams and the instrument was held at a constant temperature of 30 °C The viscosities of the catalyzed formulations were taken one hour after Components 1 and 2 were combined. The measurements were taken utilizing a Brookf ield RVT microvisometer equipped with a Cp-51 spindle and a temperature controlled (25°C) sample cup.

The effect of each Test Solvent on the hardness development of the urethane film was evaluated as a function of time. Ten 0.5m1 (wet) drawdowns on BONDERITE^® 1000 panels were performed for each formulation. When the panels were dry to the touch, hardness measurements were taken using the Sward Rocker Hardness Tester. This instrument was calibrated to give 50 oscillations (rocks) on a clean glass plate. The test panels were tested at hourly intervals the first day and then once a day thereafter until the values plateaued. Three sets of triplicate readings were taken at different locations on each panel and the average of the nine measurements were recorded for the given time point. Results

Figure 1 illustrates the relative evaporation rates of EEA, PMA, and 10% MM or 10% DMM in PMA. PMA evaporates significantly faster than EEA, and the effect of the diethers in PMA correlates with the evaporation rates of pure MM and DMM. MM evaporates much faster than PMA, which results in a fast initial evaporation rate until the MM is gone. DMM evaporates significantly slower than PMA, which results in a traditional tailing solvent profile.

Figure 2 contains the results of the viscosity measurements taken one hour after Component 1 , Component 2, and catalyst were mixed together. PMA showed almost three times the viscosity of EEA after one hour. The propylene glycol diethers were effective at lowering the one hour viscosities when blended with PMA. DMM was slightly more effective than MM.

Figure 3 contains the hardness development rates for the PMA and EEA formulations. As shown, the hardness development achieved with EEA is much more desirable. Figures 4 and 5 contain the results of the PMA/MM and PMA/DMM formulations. The incorporation of either of the propylene glycol diethers, MM or DMM, into the PMA formulation showed an improvement in the hardness development rate and the final hardness when compared to PMA, alone. Interestingly, the addition of MM at 5% outperformed the MM at the 10% level. There were no significant differences in performance of DMM blends at the two levels tested, which is supported by the data showing that the hardness of the diether/PMA blends approached that of the EEA formulation. COMPARATIVE EXAMPLE II

Using the identical coating system, the identical method of preparation, and the o identical film evaluation as the Example I, propylene glycol methyl ether (PM) was tested as a 10 wt. % blend with propylene glycol methyl ether acetate. The propylene glycol methyl ether used was DOWANOL^® PM, a product of The Dow Chemical Company. Figure 6 illustrates the results. The use of the monoether, instead of a diether, has a significant negative effect on the hardness development of the film. The negative effect is a significant contrast to the positive 5 effect observed from using the diethers of the present invention. Conclusions

Results from the Examples suggest that the use of the propylene glycol diethers of the present invention as solvent additives to propylene glycol alkyl ether acetates results in a film hardness development rate and final film hardness that is comparable to formulations o based on ethylene glycol alkyl ether acetate. The use the diethers of the present invention provide better results than the use of propylene glycol alkyl ether acetates, alone, as a carrier solvent.

While the present invention is described in detail in this specification, these details are to be considered as illustrative and not restrictive in character. It should be 5 understood that only the preferred embodiment is described and that all changes that come within the spirit of the present invention are protected.

0

5

Claims

We claim:

I . A carrier solvent for use in an organic coating composition, comprising:

(a) at least one propylene glycol alkyl ether acetate; and

(b) at least one diether corresponding to the formula:

5 R"

I R-0-(CHCH20)n-R'

where R and R' are independently a Ci to C₄ alkyl, R" is H, -CH3, or -C2H5 and n is a whole number from 1 to 3. ¹⁰

2. The carrier solvent of Claim 1 , wherein the propylene glycol alkyl ether acetate is propylene glycol methyl ether acetate.

3. The carrier solvent of Claim 1 , wherein the alkyl substituent in said propylene glycol alkyl ether acetate is an alkyl substituent selected from the group consisting of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl. ' ⁵

4. The carrier solvent of Claim 1 , wherein the diether is propylene glycol dimethyl ether.

5. The carrier solvent of Claim 1 , wherein the diether is dipropylene glycol dimethyl ether.

6. The carrier solvent of Claim 1 , wherein the diether is propylene glycol ²⁰ dibutyl ether.

7. The carrier solvent of Claim 1 , wherein the diether is dipropylene glycol dibutyl ether.

8. A carrier solvent for use in an organic coating composition, comprising: propylene glycol methyl ether acetate; and " propylene glycol dimethyl ether.

9. A carrier solvent for use in an organic coating composition, comprising: propylene glycol methyl ether acetate; and dipropylene glycol dimethyl ether.

10. The carrier solvent of Claim 1 , wherein said propylene glycol alkyl ether ^3u acetate is present in an amount of no less than about 75 wt. % and said diether is present in an amount of no more than about 25 wt. %.

I I . The carrier solvent of Claim 1 , wherein said propylene glycol alkyl ether acetate is present in an amount of no less than about 85 wt. % and said diether is present in an amount of no more than about 15 wt. % .

³⁵ 12. The carrier solvent of Claim 1 , wherein said propylene glycol alkyl ether acetate is present in an amount from about 90 wt. % to about 95 wt. % and said diether is present in an amount from about 5 wt. % to about 10 wt. % .

13. An organic coating composition, comprising:

(a) at least one propylene glycol alkyl ether acetate; and

(b) at least one diether corresponding to the formula:

R" I R-0-(CHCH20)n-R'

where R and R' are independently a Ci to C₄ alkyl, R" is H, -CH₃, -C₂H₅ and n is a whole number from 1 to 3; and (c) an organic binder. 0

14. The organic coating composition of Claim 13, wherein the propylene glycol alkyl ether acetate is propylene glycol methyl ether acetate.

15. The organic coating composition of Claim 13, wherein the alkyl substituent in said propylene glycol alkyl ether acetate is an alkyl substituent selected from the group consisting of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl. 5

16. The organic coating composition of Claim 13, wherein the diether is propylene glycol dimethyl ether.

17. The organic coating composition of Claim 13, wherein the diether is dipropylene glycol dimethyl ether.

18. The organic coating composition of Claim 13, wherein the diether is ⁰ propylene glycol dibutyl ether.

19. The organic coating composition of Claim 13, wherein the diether is dipropylene glycol dibutyl ether.

20. The organic coating composition of Claim 13, wherein the organic binder is a combination of polyols and an isocyanato radical source, wherein the isocyanato radical ⁵ source is an isocyanate, diisocyanate, or polyisocyanate.

21. The organic coating composition of Claim 13, wherein the organic binder is a combination of acrylics, polyols, and an isocyanato radical source, wherein the isocyanato radical source is an isocyanate, diisocyanate, or polyisocyanate.

22. The organic coating composition of Claim 13, wherein said organic binder ^υ is selected from the group consisting of acrylics, polyesters, epoxies, alkyds, polyols, isocyanates, diisocyanates, and polyisocyanates and mixtures of these binders.

23. An organic coating composition, comprising: propylene glycol methyl ether acetate; propylene glycol dimethyl ether; and a combination of polyols and diisocyanates. 5

24. An organic coating composition, comprising: propylene glycol methyl ether acetate; dipropylene glycol dimethyl ether; a combination of polyols and diisocyanates.

25. The organic coating composition of Claim 13, wherein said propylene glycol alkyl ether acetate is present in an amount of no less than about 75 wt. % and said diether is present in an amount of no more than about 25 wt. %, wherein said amounts are measured in respect to the weight of the combination of the propylene glycol alkyl ether acetate present and the diether present.

26. The organic coating composition of Claim 13, wherein said propylene glycol alkyl ether acetate is present in an amount of no less than about 85 wt. % and said diether is present in an amount of no more than about 15 wt. %, wherein said amounts are measured in respect to the weight of the combination of the propylene glycol alkyl ether acetate present and the diether present.

27. The organic coating composition of Claim 13, wherein said propylene glycol 5 alkyl ether acetate is present in an amount from about 90 wt. % to about 95 wt. % and said diether is present in an amount from about 5 wt. % to about lO wt. %, wherein said amounts are measured in respect to the weight of the combination of the propylene glycol alkyl ether acetate present and the diether present.

28. A process for coating an article of manufacture with an organic coating composition having improved hardness development, comprising:

(a) providing an article of manufacture;

(b) mixing an organic binder, propylene glycol alkyl ether acetate, and at least one diether of the formula:

R" ⁵ R-0-(CHCH20)n-R'

where R and R' are independently a Ci to C₄ alkyl, R" is H, -CH_, or -C₂H₅, and n is a whole number from 1 to 3; and

(c) coating the article of manufacture with the mixture of said mixing step. ⁰ 29. The process for coating an article of manufacture of Claim 28, wherein the propylene glycol alkyl ether acetate is propylene glycol methyl ether acetate.

30. The process for coating an article of manufacture of Claim 28, wherein the alkyl substituent in the propylene glycol alkyl ether acetate is an alkyl substituent selected from the group consisting of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl. ^

31. The process for coating an article of manufacture of Claim 28, wherein the diether is propylene glycol dimethyl ether.

32. The process for coating an article of manufacture of Claim 28, wherein the diether is dipropylene glycol dimethyl ether.

33. The process for coating an article of manufacture of Claim 28, wherein the diether is propylene glycol dibutyl ether.

34. The process for coating an article of manufacture of Claim 28, wherein the diether is dipropylene glycol dibutyl ether.

35. The process for coating an article of manufacture of Claim 28, wherein the organic binder is a combination of polyols and an isocyanato radical source, wherein the isocyanato radical source is an isocyanate, diisocyanate, or polyisocyanate.

36. The process for coating an article of manufacture of Claim 28, wherein the organic binder is a combination of acrylics, polyols, and an isocyanato radical source, wherein the isocyanato radical source is an isocyanate, diisocyanate, or polyisocyanate.

37. The process for coating an article of manufacture of Claim 28, wherein said organic binder is selected from the group consisting of acrylics, polyesters, epoxies, alkyds, polyols, isocyanates, diisocyanates, polyisocyanates, and mixtures of these binders.

38. The process for coating an article of manufacture of Claim 28, wherein said coating step is a method selected from the group consisting of printing, screening, spraying, drawing down, and a combination of these methods.