CA2493185C

CA2493185C - Improved color in film-forming compositions

Info

Publication number: CA2493185C
Application number: CA2493185A
Authority: CA
Inventors: Paul D. Bloom; Peter K. Fuge; George B. Poppe; Teodora R. Tabuena-Salyers
Original assignee: Archer Daniels Midland Co
Current assignee: Archer Daniels Midland Co
Priority date: 2004-01-16
Filing date: 2005-01-14
Publication date: 2012-07-10
Anticipated expiration: 2025-01-14
Also published as: US20050182168A1; AU2005200152B2; JP2005200654A; US7875664B2; AU2005200152A1; US20080015296A1; CA2493185A1; MXPA05000645A; US7271210B2

Abstract

This invention relates to a composition comprising, consisting of or alternatively consisting essentially of a stabilized glycol ester of a vegetable oil fatty acid and butylated hydroxy toluene. This invention also relates to latex film-forming compositions containing stabilized glycol esters, such as a stabilized propylene glycol monoester (PGME) mixture. This invention is also directed to methods of stabilizing glycol esters of a vegetable fatty acid by combining butylated hydroxy toluene. This invention also includes methods of preparing film-forming compositions comprising a stabilized glycol ester, such as the stabilized PGME mixture disclosed herein.

Description

IMPROVED COLOR IN FILM-FORMING COMPOSITIONS
BACKGROUND OF THE INVENTION

Field of the Invention [0001] This invention relates to a composition containing stabilized glycol esters of a vegetable oil fatty acid and butylated hydroxy toluene. Such a composition is useful, for example, as an additive in latex film-forming compositions. This invention also relates to latex film-forming compositions containing a stabilized glycol ester. This invention is also directed to methods of stabilizing glycol esters of a vegetable oil fatty acid by combining butylated hydroxy toluene with glycol esters to maintain a low peroxide value or prevent a high peroxide value from developing. This invention also includes methods of preparing film-forming compositions comprising the stabilized glycol esters such as the stabilized PGME mixtures disclosed herein.

Related Art [0002] A coating composition is generally film-forming. "Film-forming", as used herein, means that the coating composition has a minimum Film Forming Temperature (MFT) at, or below, the ambient temperature, to allow for fusion of the polymer into a continuous film. Volatile organic compounds (VOCs), such as coalescents, can be used to temporarily lower the MFT of a coating composition, allowing the polymer to form a film at a temperature below the glass transition temperature (Tg) of that polymer.

[0003] Water-based latex paint is comprised of an aqueous dispersion of pigments and latex particles that impart substrate hide, water resistance, and durability to the solid paint film. Other components such as dispersants, surfactants, and thickeners are added to the liquid paint to maintain a stable I

dispersion and suspension of the pigments and latex particles. Solvents, bases, defoamers, and biocides are also incorporated to improve liquid stability, application performance and film formation properties. The chemical composition of water-base latex paints is designed to allow dispersion of components in water, yet maintain water resistance upon curing and forming a dry paint film. Essentially, the compositions are designed to contain a hydrophobic component for water resistance as a paint film, and a hydrophilic component to improve stability, solubility, and dispersion in the liquid aqueous phase.

[0004] A latex polymer is a high molecular weight component which imparts water resistance and durability to the dry paint film. These latex polymers include polymerization and co-polymerization products of: vinyl acetate, acrylic acid, methacrylic acid styrene, alpha-methyl styrene, butadiene, acrylates, methacrylates, vinyl chloride, vinylidene chloride and acrylonitrile containing monomers. Particularly important are polymers and co-polymers of alkyl acrylates, alkyl methacrylates, styrene, and vinyl acetate.

[0005] Latex polymers are the film-forming portions of the paint film, and are prepared by an emulsion polymerization reaction. Aggregation of polymer particles is typically discouraged by including a stabilizing surfactant in the polymerization mix. In general, the growing latex particles are stabilized during emulsion polymerization by one or more surfactants such as an anionic or nonionic surfactant, or a mixture thereof, as is well known in the polymerization art. Many examples of surfactants suitable for emulsion polymerization are given in McCutcheon's Detergents and Emulsifiers (MC
Publishing Co., Glen Rock, N.J.), published annually. Generally, emulsion polymerization consists of using nonionic surfactants to create monomer micelles within the water phase.

[0006] The effectiveness of the latex polymer in forming a film after the paint has been deposited upon a surface depends upon the Tg of the polymer and the temperature at which the paint film is allowed to dry. Coalescing aids, compounds compatible with the polymer, have been used in latex paints to plasticize (soften) the latex polymer to allow the formation of a continuous film with optimum coating properties once the water has evaporated. Without the coalescing aid, the coatings may crack and fail to adhere to the substrate when dry. Traditionally, such coalescing aids (generally alcohol esters and ethers) are volatile and leave the film after they have enabled the polymer to coalesce into an integral film. Once the coalescing aids are gone, the original hardness of the polymer, defined by its initial Tg, returns yielding a tougher and more resistant coating.

[0007] One problem encountered by the coatings manufacturers is the development of formulations containing low VOC-coalescing aids or plasticizers. For instance, emulsion polymers are currently formulated with coalescing aids or plasticizers in order to form films at and below ambient conditions yet dry to films of sufficient Tg to perform adequately at and above room temperature. In general, the ability of emulsion polymers to form or coalesce into film is governed by the MFT of the polymer in question, which typically approximates Tg of that polymer. Thus, there is a dilemma, i.e., low MFT polymers are required in order to exhibit coalescence, flow, and surface wetting properties. However, if the polymer remains soft and tacky, the coatings are not usable. Therefore, it is necessary to develop a technology in which coating formulations contain suitable ingredients with an initial low MFT, followed upon application forms nontacky, durable, hard, and water resistant surfaces having a Tg significantly above their MFT.

[0008] In contrast to latex compositions, oil-based compositions, e.g., oil-based paints, commonly employ vegetable oils such as linseed oil or tung oil and/or vegetable oil co-reacted with other compounds (such as alkyd resins) as a component of the vehicle in the paint. The vegetable oils, which are also referred to in the art as "drying oils", form crosslinked films upon exposure to air. Like all vegetable oils, these drying oils are triesters of various fatty acids and glycerol. However, unlike most vegetable oils, the fatty acids in drying oils have a very high degree of unsaturation (high iodine value), are high in polyunsaturated fatty acids, and generally have a majority of fatty acids that contain 3 or more double bonds (such as linolenic [cis-9-cis-12-cis-15-Octadecatrienoic] acid, eleostearic [cis-9-trans- 11 -trans- 13 -Octadecatrienoic]
acid, and 4-Oxo-cis-9-trans-1l-trans-l3-Octadecatrienoic acid). Semi-drying oils have moderate to high degrees of unsaturation, and are high in polyunsaturated fatty acids, but contain lower levels of fatty acids that have or more double bonds. The use of such reactive drying oils in oil based paints helps to provide a paint film which is hard and durable. Thus, the drying oils and co-reacted vegetable oil products (alkyds) are desirable components of oil-based compositions. However, oil based compositions typically comprise large proportions of VOCs as solvents or additives, e.g., 380 to 450 grams per liter (g/1) or more. Such high concentrations of VOCs are environmentally undesirable.

[0009] Latex compositions, on the other hand, typically comprise very low concentrations of VOCs, e.g. less than about 250 g/l, and thus are more environmentally compatible. Accordingly, it would be desirable to incorporate the drying oils of oil-based compositions into latex compositions to promote crosslinking of the latex compositions. However, the drying oils used in oil-based compositions are not water-soluble and accordingly cannot readily be used in latex compositions.

[0010] A latex or emulsion composition containing drying oils is disclosed in U.S. Pat. Nos. 6,203,720 and 6,174,948. The compositions disclosed in these patents contain crosslinkable monomers having a fatty acid residue derived from semi-drying or non-drying oils and chemically attached to ethylenically unsaturated carboxylic acids. The monomers are polymerized to yield a latex polymer resin with oxidative cross-linking capability.

[0011] It is desirable to develop a latex paint formulation which incorporates components that can react during the curing process, and thereby help form a durable, water-resistant paint film. It is also desirable to reduce the amounts of VOCs, such as coalescing solvents, which are environmentally undesirable.

[0012] PGME mixtures can be used to replace traditional coalescing solvents such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Trade name:

Texanol) (N. Jiratumnukul and M.R. Van De Mark, J. Am. Oil. Chem. Soc., 2000, 77, 691-697). Traditional coalescing solvents are VOCs. Thus, it is desirable to minimize the use of these solvents or replace them entirely with non-volatile compounds. PGME mixtures behave as coalescing solvents, but such PGMEs are non-volatile. Thus, PGME remains in the dried film.

[0013] The yellowing of dried,films containing PGME has been attributed to the presence of PGME in the dried film. Further, in these paints, in-can yellowing is also attributed to the presence of PGME. It is desirable to formulate a latex film-forming composition that contains PGME mixtures as coalescing solvents but exhibit yellowing similar to coatings containing traditional coalescing solvents.

SUMMARY OF THE INVENTION

[0014] This invention relates to a composition comprising, consisting of or alternatively consisting essentially of a stabilized glycol ester of a vegetable oil fatty acid and butylated hydroxy toluene. This invention also relates to latex film-forming compositions containing stabilized glycol esters, such as a stabilized propylene glycol monoester (PGME) mixture. This invention is also directed to methods of stabilizing glycol esters of a vegetable fatty acid by combining . butylated hydroxy toluene. This invention also includes methods of preparing film-forming compositions comprising a stabilized glycol ester, such as the stabilized PGME mixture disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

[0015] Figures 1 and 2 depict yellowing of coatings which contain specified latex resins and stabilized or non-stabilized PGME, or commercial coalescent.

[0016] Figure 3 depicts yellowing of coatings which contain specified biocides and stabilized or non-stabilized PGME, or commercial coalescent.

DETAILED DESCRIPTION OF THE INVENTION

[00171 The present invention is based on the finding that a glycol ester composition such as a PGME can be stabilized by combining with butylated hydroxy toluene (BHT). Although not wishing to be bound by theory, the BHT may act to maintain a low peroxide value or prohibit the peroxide value from increasing to a high value. The BHT stabilized PGME has been incorporated into latex film-forming compositions where the formulation exhibits a higher resistance to in-can yellowing and yellowing in the dried film coating than formulations with non-stabilized PGME.
[0018] In one aspect the present invention is directed to a stabilized glycol ester composition. Such a composition comprises, consists essentially of or alternatively consists of a glycol ester of a vegetable oil fatty acid to which an amount of butylated hydroxy toluene (BHT) has been incorporated. A glycol ester composition comprises monoesters, residual diesters, monoglycerides and other impurities depending on the starting materials used in preparing a glycol ester composition.
[0019] The amount of BHT combined with the glycol ester composition is sufficient to maintain a low peroxide value or prohibit the peroxide value from increasing to a high value. Although any amount of BHT that produces this effect falls within the scope of this invention, it has been discovered that an amount of BHT from about 1.0 percent to about 0.05 percent by weight of the glycol ester provides a sufficiently stabilized glycol ester composition. More preferably, the amount is between about 0.5 percent to about 0.20 percent. It has been discovered that the peroxide value of a glycol ester composition can be maintained or inhibited from rising to an unacceptable level for commercial purposes by combining with BHT. A stabilized glycol ester composition, such as a stabilized PGME mixture, has been successfully incorporated into latex film-forming compositions. Preferably, the stabilized glycol ester composition has a peroxide value below about 50. Most preferably, the peroxide value is below about 10.
[0020] Prior to stabilization, the glycol ester composition is prepared by combining a glycol with a vegetable oil fatty acid through means that are known in the art. Preferably, the glycol ester composition is a monoester mixture. A monoester mixture is a composition comprising a high percentage of monoester in terms of the ratio of mono- to diesters comprising the product.
A monoester mixture can contain some residual diesters, monoglycerides and other impurities depending on the starting materials. Preferably, the stabilized glycol ester composition is composed of at least about 50 percent monoesters.
More preferably, the stabilized glycol ester composition is composed of at least about 80 percent monoesters.
[0021] The glycol is selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and the like. The preferred polyol is propylene glycol, which includes individual isomers and d, l-propylene glycol.
[0022] The vegetable oil fatty acid is derived from a vegetable oil. The vegetable oils suitable for preparing the fatty acid portion of the glycol ester composition include a genetically modified oil, soybean oil, linseed oil, corn oil, sunflower oil, canola oil, rapeseed oil, coconut oil, palm kernel oil, palm oil, cottonseed oil, peanut oil, coconut oil, tong oil and safflower oil and derivatives and mixtures thereof. Preferably the vegetable oil is a polyunsaturated vegetable oil. Most preferably, the polyunsaturated vegetable oil is low in C18:3 or higher fatty acids. Although any polyunsaturated oil that has sufficiently low levels of C18:3 or higher fatty acids is suitable, preferably, the vegetable oil is safflower oil, sunflower oil or corn oil.
Preferably, the polyunsaturated vegetable oil contains less than about 2 percent of C18:3 or higher polyunsaturated fatty acids. Also preferred are polyunsaturated vegetable oils containing less than about 2 percent linolenic acid. More preferably, the linolenic content is less than about 1 percent.
Most preferably, this oil is safflower, sunflower or corn oil.
[0023] In a most preferred embodiment, the stabilized glycol ester composition is a stabilized propylene glycol monoester (PGME) mixture. A
PGME mixture is a composition comprising monoesters, diesters, monoglycerides, polyols and alcohols. A monoester mixture is a composition comprising a high percentage of monoester in terms of the ratio of mono- to diesters comprising the product. A monoester mixture can contain some residual diesters, monoglycerides and other impurities depending on the starting materials. Preferably, the stabilized PGME mixture is composed of at least about 50 percent PGMEs. More preferably, the stabilized PGME
mixture is composed of at least about 80 percent PGMEs.
[0024] Preferably, the stabilized glycol ester composition has a Lovibond color below about 0.6 Red and below about 1.5 Yellow. Most preferably, the color is below about 0.4 Red and below about 1.0 Yellow.
[0025] The stabilized glycol ester composition can additionally contain a UV
stabilizer. Such stabilizers are known in the art and examples include: Cytek -Cyasorb UV-24, UV-1164, UV-531, UV-5357, UV-2337, UV-5411 and the like.
[0026] In another aspect, the present invention is directed to a latex film-forming composition comprising a stabilized glycol ester composition.
Suitable stabilized glycol ester compositions are described above.
[0027] A stabilized glycol ester composition is formed by the combination of a glycol and a vegetable oil fatty acid. Suitable and preferred glycols and vegetable oil fatty acids are described above. For incorporation into latex film-forming compositions, there are several advantages disclosed herein for incorporating a stabilized glycol ester composition. Further, the preferred stabilized glycol ester compositions outlined above are also preferred for incorporation into latex film-forming compositions.
[0028] Preferably, the latex film-forming composition comprises a stabilized glycol ester composition composed of at least about 50 percent monoesters.

More preferably, the stabilized glycol ester is composed of at least about 80 percent monoesters. A monoester mixture is a composition comprising a high percentage of monoester in terms of the ratio of mono- to diesters comprising the product. A monoester mixture can contain some residual diesters, monoglycerides and other impurities depending on the starting materials.
[0029] Preferably the vegetable oil used for preparing the glycol ester composition is a polyunsaturated vegetable oil. The polyunsaturated fatty acid moiety promotes a more desirable dry film due to oxidative crosslinking at the sites of unsaturation. Most preferably, the polyunsaturated vegetable oil is low in C18:3 or higher fatty acids. It has been discovered that lower levels of C18:3 or higher fatty acids yields a superior film-forming composition in terms of resistance to yellowing. Although any polyunsaturated oil that has sufficiently low levels of C18:3 or higher fatty acids is suitable, preferably, the vegetable oil is safflower oil, sunflower oil or corn oil. Preferably, the polyunsaturated vegetable oil contains less than about 2 percent of C 18:3 or higher polyunsaturated fatty acids. Also preferred are polyunsaturated vegetable oils containing less than about 2 percent linolenic acid. More preferably, the linolenic content is less than about 1 percent. Most preferably, this oil is safflower, sunflower or corn oil.
[0030] The stabilized glycol ester composition should have a peroxide value that is appropriate for commercial use in a latex film-forming composition.
Preferably, the peroxide value is below about 50. More preferably, the peroxide value is below about 10.
[0031] , In a most preferred embodiment, the latex film-forming composition comprises a stabilized PGME mixture. Preferably, the stabilized PGME
contains at least about 80 percent monoesters. The latex film-forming compositions incorporating a stabilized PGME mixture have been shown to have lower yellowing in the can and in the dry film when compared to formulations using non-stabilized PGME.
[0032] For incorporation into a latex film-forming composition, the stabilized glycol ester composition should be light in color so that the final color of the latex film-forming composition is not adversely affected by combining with a stabilized glycol ester composition. In preferred embodiments, the stabilized glycol ester composition has a Lovibond color of less than about 0.6 Red and about 1.5 Yellow. More preferably, the latex film-forming composition comprises a glycol ester having a Lovibond color of less than about 0.4 Red and about 1.0 Yellow.
[0033] In all embodiments, the preferred stabilized glycol ester composition is a stabilized PGME mixture as described above.
[0034] The stabilized glycol ester composition can additionally contain a UV
stabilizer. Such stabilizers are known in the art and examples include: Cytek -Cyasorb UV-24, UV-1164, UV-531, UV-5357, UV-2337, UV-5411 and the like. When used as an ingredient in the stabilized glycol ester component of a latex film-forming formulation, the UV stabilizers may further minimize any yellowing that may occur in the can or in the dry film.
[0035] The latex film-forming composition can also include a biocide.
Biocides are known in the art. They are especially useful, but are not limited to, coatings for exterior surfaces, such as exterior house paint. It has been found that certain biocides when used in combination with a stabilized glycol ester provide the latex film-forming composition with better resistance to yellowing. Preferable biocides include Fungitrol 820, Fungitrol 720, Polyphase CST, Rozone 2000 and Polyphase 678.
[0036] The latex film-forming composition can also include one or more pigments. When formulated with pigments, the latex film-forming composition can be = used to visually conceal a substrate. In this aspect the latex film-forming composition is essentially paint. While the formulation benefits from lower VOC because the stabilized glycol ester, such as a stabilized PGME mixture, replaces a typical coalescing solvent, the formulation resists the typical yellowing that is attributed to the presence of non-stabilized PGME.
[0037] The latex film-forming composition may further contain additives such as thickeners, dispersants, surfactants and rheologic modifiers necessary to produce an end product with the desirable characteristics such as in-can stability, gloss, etc.
[0038] In yet another aspect, the present invention is directed to a method of stabilizing a glycol ester of a vegetable oil fatty acid ester comprising combining an amount of BHT to the glycol ester composition to maintain a low peroxide value or prohibit the peroxide value from increasing to a high value.
[0039] Suitable glycol ester compositions and preferred embodiments are as described above.
[0040] The amount of BHT combined with the glycol ester composition is sufficient to maintain a low peroxide value or prohibit the peroxide value from increasing to a high value. The BHT can be combined at any time while the peroxide value is at an acceptable level. Generally, the BHT will be combined as soon as possible after providing a glycol ester composition so that the peroxide value does not rise to an unacceptable level. It is desirable to combine BHT immediately after synthesis to provide or maintain the lowest peroxide value. Although any amount of BHT that produces this effect falls within the scope of this invention, it has been discovered that an amount of BHT from about 1.0 percent to about 0.05 percent provides a sufficiently stabilized glycol ester composition. More preferably, the amount of BHT is between about 0.5 percent and 0.20 percent.
[0041] Preferably, prior to stabilization, the glycol ester composition has a peroxide value below about 50. Most preferably, the peroxide value is below about 10.
[0042] The method of stabilizing a propylene glycol ester of a vegetable oil fatty acid can further include additionally combining a UV stabilizer. Such stabilizers are known in the art and examples include: Cytek - Cyasorb W-24, UV-1164, UV-531, UV-5357, UV-2337, UV-5411 and the like. As used herein the UV stabilizers may provide for additional maintenance of peroxide values. When used as part of the stabilized propylene ester composition where the composition is an ingredient in a paint formulation, the LTV stabilizers may further minimize any yellowing.
[0043] In another aspect, the present invention is directed to a method of preparing a latex film-forming composition comprising combining a stabilized glycol ester of a vegetable oil fatty acid to a film-forming formulation.
[0044] In a preferred embodiment, the method comprises combining a stabilized PGME mixture, wherein all suitable and preferred PGME mixtures are as described above. Most preferably, the PGME mixture combined during the method of preparing a latex film-forming composition contains at least 80% monoesters. Further, it is equally desirable that the PGME mixture has a peroxide value below about 50. Also the PGME mixture preferably has a Lovibond color below about 0.6 Red and below about 1.5 Yellow. Most preferably, the Lovibond color is less than about 0.4 Red and about 1.0 Yellow.
[0045] The present invention is based on the discovery that stabilized PGME
mixtures are more resistant to yellowing than non-stabilized PGME mixtures.
Formulations containing the stabilized PGME mixture can rival formulations containing traditional coalescing solvents in terms of minimizing in-can yellowing and yellowing of the dried film.

EXAMPLES

[0046] Film-forming compositions consisting of a resin, coalescent and biocide were formulated to test yellowing in latex coatings. Approximately 88g of AC-2508 (Rohm and Haas acrylic resin), 3.3g of coalescent and 2.7g of biocide as identified in Figure 1, were blended together, mixed and allowed to stand in an oven at 140 F for 10 days. After this time, the mixtures were removed from the oven, cooled to room temperature and applied to Lenetta drawdown charts with a 3 mil applicator bar. The films were allowed to dry for several hours and then read with a colorimeter. The color of the films ()b value in LAB color system) was monitored over time in the cast films held at room temperature. The standard use for all color measurements was AC-2508 and Texanol (Eastman) with no biocide, that was mixed and immediately cast as a film with no heat aging. PGMEs such as Archer RC containing BHT at 0.2% and high peroxide value PGME (peroxide value = 185) with no BHT
were compared. Higher )b values represent increased yellowing.
[00471 As seen in Figure 1, initial yellowing was most severe with Polyphase AF-1 (Troy) and high peroxide value PGME containing no BHT. Higher initial yellowing was observed in all PGME containing examples in comparison to the Texanol/Polyphase AF-1 sample. High peroxide value PGME containing no BHT in combination with Fungitrol 820 (ISP) showed improved recovery over time in the film. Even lower yellowing was observed when low peroxide value, BHT stabilized PGME (Archer RC 4298-171-0903) was used in conjunction with Fungitrol 820. In fact, the )b value of this film after 5 days was lower than that of the Texanol/Polphase AF-1 sample.
Therefore, the combination of BHT stabilized PGME in combination with Fungitrol 820 is a preferred formulation. However, Fungitrol 720 (ISP) and 678 (Troy) both showed lower yellowing than compositions containing PGME
and Polyphase AF-1. The improved performance of the film-forming composition containing the Fungitrol 820 may be attributed to the UV
stabilizer contained in 820 because 720 does not contain such a stabilizer.
PGME inherently had higher yellowing than Texanol in combination with AC-2508.

[00481 Similar experiments were carried out as in example 1 with a different resin, SG-IOM (Rohm & Haas, acrylic latex polymer). Approximately 88g of SG-10M, 3.3g coalescent and 2.7g of biocide, as identified in Figure 2, were blended together, mixed and allowed to stand in an oven at 140 F for 6 days.
After this time, the mixtures were removed from the oven, cooled to room temperature and applied to Lenetta drawdown charts with a 3 mil applicator bar. The films were allowed to dry for several hours and then read on a colorimeter. The color of the films Qb value in LAB color system) was monitored over time in the cast films held at room temperature. The standard use for all color measurements was SG-10M and Texanol (Eastman) with no biocide, that was mixed and immediately cast as a film with no heat aging.
PGMEs (Archer RC) containing BHT at 0.2% and high peroxide value PGME
(peroxide value = 185) with no BHT were compared.
[0049] Initial yellowing was highest with SG-10M containing high peroxide value PGME with no BHT in combination with Polyphase AF-1 (Troy).
Reduction of yellowing in comparison to the Texanol/Polyphase AF-1 was observed when BHT stabilized PGME was used in combination with Fungitrol 820 (ISP), Polyphase CST (Troy), Polyphase 678 (Troy) and Fungitrol 720 (ISP). The Fungitrol 720 sample continued to show an increase in yellowing over time in contrast to the Fungitrol 820 samples that maintained their )b values. The difference was again attributed to the UV stabilizer contained in the Fungitrol 820 that is not present in the Fungitrol 720. The levels of several biocides were doubled and are indicated by a (2x) in Figure 2. In "2x"
samples, PGME again showed reduced yellowing in comparison to Texanol/Polyphase AF-1 after 2 days. For Fungitrol 820, 720 and Polyphase 678, the )b values were consistently lower than Texanol/Polyphase AF-1 at all reported times.

[0050] A gloss paint was formulated and tested with various coalescing solvents (Texanol, Archer RC, etc.) and biocides. Archer RC stabilized with 0.2% BHT was combined with paint containing a specific biocide. The formulation containing the Polyphase AF-1 (Figure 3, AF-1, left column) exhibited the most yellowing. The histogram of Figure 3 shows that preferred biocides in combination with stabilized Archer RC are Fungitrol 720, Polyphase CST, Polyphase 678 and Rozone 2000. The Figure 3 histogram shows the comparable yellowing of stabilized PGME containing formulations to formulations containing Texanol. Archer RC without BHT (non-stabilized Archer RC) exhibits the highest yellowing as indicated by the data set on the right third of the histogram. The peroxide value of non-stabilized Archer RC
was 313 in this experiment.

[0051] The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

1. A stabilized glycol ester composition consisting essentially of a glycol ester of a vegetable oil fatty acid and butylated hydroxy toluene.

2. The composition of claim 1, wherein said composition has a peroxide value below about 50.

3. The composition of claim 1, wherein said composition has a peroxide value below about 10.

4. The composition of claim 1, wherein said vegetable oil fatty acid is derived from a vegetable oil which is a genetically modified vegetable oil, soybean oil, linseed oil, sunflower oil, corn oil, canola oil, rapeseed oil, palm kernel oil, cottonseed oil, peanut oil, coconut oil, palm oil, tung oil, safflower oil, a derivative thereof, or a mixture thereof.

5. The composition of claim 1, wherein said vegetable oil fatty acid is derived from a polyunsaturated vegetable oil.

6. The composition of claim 5, wherein said polyunsaturated vegetable oil contains less than about 2 percent of C 18:3 or higher polyunsaturated fatty acids.

7. The composition of claim 6, wherein said polyunsaturated vegetable oil is safflower oil, sunflower oil or corn oil.

8. The composition of claim 1, wherein said butylated hydroxy toluene is present from about 1.0 percent to about 0.05 percent by weight of said glycol ester of a vegetable oil fatty acid.

9. The composition of claim 1, wherein said glycol ester is derived from a glycol which is ethylene glycol, propylene glycol, diethylene glycol or dipropylene glycol.

10. The composition of claim 9, wherein said glycol is propylene glycol.

11. The composition of claim 1, wherein said glycol ester of a vegetable oil fatty acid is a glycol monoester mixture comprising at least about 50 percent glycol monoesters by weight.

12. The composition of claim 11, wherein said glycol monoester comprises at least about 80 percent glycol monoesters by weight.

13. The composition of claim 12, wherein said glycol monoester is a propylene glycol monoester.

14. The stabilized glycol ester composition of claim 1 further comprising a UV stabilizer.

15. A latex film-forming composition comprising, the stabilized glycol ester of a vegetable oil fatty acid of claim 1.

16. The latex film-forming composition of claim 15, wherein said stabilized glycol ester has a peroxide value below about 50.

17. The latex film-forming composition of claim 15, wherein said stabilized glycol ester is a stabilized propylene glycol monoester.

18. The latex film-forming composition of claim 17, wherein said stabilized propylene glycol monoester contains at least about 80 percent monoesters.

19. The latex film-forming composition of claim 18, wherein said stabilized propylene glycol monoester has a Lovibond color below about 0.6 Red and below about 1.5 Yellow.

20. The latex film-forming composition of claim 15, wherein said vegetable oil fatty acid is derived from a vegetable oil which is a genetically modified oil, soybean oil, linseed oil, sunflower oil, corn oil, canola oil, rapeseed oil, palm kernel oil, cottonseed oil, peanut oil, coconut oil, palm oil, tung oil, safflower oil, a derivative thereof, or a mixture thereof.

21. The latex film-forming composition of claim 15, wherein said vegetable oil fatty acid is derived from a polyunsaturated vegetable oil.

22. The latex film-forming composition of claim 21, wherein said polyunsaturated vegetable oil contains less than about 2 percent of C18:3 or higher polyunsaturated fatty acids.

23. The latex film-forming composition of claim 22, wherein said polyunsaturated vegetable oil is safflower oil, sunflower oil or corn oil.

24. The latex film-forming composition of claim 15, wherein said stabilized glycol is a stabilized propylene glycol monoester containing at least about 80 percent monoesters, wherein said monoester is derived from a polyunsaturated vegetable oil containing less than about 2 percent of C18:3 or higher polyunsaturated fatty acids.

25. The latex film-forming composition of claim 24, wherein said propylene glycol monoester has a peroxide value below about 50.

26. The latex film-forming composition of claim 25, wherein said stabilized propylene glycol monoester has a Lovibond color below about 0.6 Red and below about 1.5 Yellow.

27. The latex film-forming composition of claim 26, wherein said propylene glycol monoester is derived from safflower oil, sunflower oil or corn oil.

28. The latex film-forming composition of claim 15 further comprising a biocide.

29. The latex film-forming composition of claim 28, wherein said biocide is Fungitrol 820, Fungitrol 720, Polyphase CST, Rozone 2000 or Polyphase 678.

30. The latex film-forming composition of claim 15 further comprising one or more pigments.

31. A method of stabilizing a glycol ester of a vegetable oil fatty acid comprising, combining an amount of butylated hydroxy toluene between about 1.0 percent to about 0.05 percent by weight of said glycol ester with said glycol ester, wherein a stabilized glycol ester is produced.

32. The method of claim 31, wherein said glycol ester has a peroxide value below about 50.

33. The method of claim 32, wherein said glycol ester has a peroxide value below about 10.

34. The method of claim 33, wherein said glycol ester is derived from a glycol ethylene glycol, propylene glycol, diethylene glycol or dipropylene glycol.

35. The method of claim 31, further comprising combining a UV stabilizer with said latex film-forming composition.

36. A method of preparing a film-forming composition comprising, combining the stabilized propylene glycol monoester composition of claim 13 with a film-forming composition.

37. The method of claim 36, wherein said stabilized propylene glycol monoester has a peroxide value below about 50.

38. The method of claim 37, wherein said stabilized propylene glycol monoester has a Lovibond color below about 0.6 Red and below about 1.5 Yellow.