WO1995014528A1

WO1995014528A1 - Bis-oxazolidine compounds and their use

Info

Publication number: WO1995014528A1
Application number: PCT/US1994/013492
Authority: WO
Inventors: Chih-Yueh Chou; Pattabhi K. Raman; Thomas L. Johnson; Marina D. Hoffman
Original assignee: Angus Chemical Company
Priority date: 1993-11-22
Filing date: 1994-11-22
Publication date: 1995-06-01
Also published as: AU1292995A

Abstract

Methods of using a compound as a corrosion inhibitor, moisture of formaldehyde scavenger, reactive diluent, rheological modifier, thermoplastic foam inhibitor, antifreezing agent, decolorizing agent, drying agent, agent for minimizing bubble formation or agent for minimizing downglossing in a coating. The compound has structure (I) wherein R1 and R1' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, R2', R3' and R4' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

Description

BIS-OXAZOLIDINE COMPOUNDS AND THEIR USE

This application is a continuation-in-part of copending patent application serial number 07/624,062, filed December 4, 1990. Background Of The Invention Field Of The Invention The present invention is generally related to methods of using bis-oxazolidine compounds. In particular, the present invention relates to methods of using the compounds as a corrosion inhibitor, moisture or formaldehyde scavenger, reactive diluent, rheological modifier, thermoplastic foam inhibitor, antifreezing agent, decolorizing agent, drying agent, agent for minimizing downglossing in a coating, or an agent for minimizing bubble formation in a coating, sealant or adhesive. Background Of The Art

Moisture curable polyurethane coatings are extensively used as commercial and industrial protective and/or decorative coatings. Polyurethane coatings, known in the industry as one of the toughest coatings available, are routinely applied as protective coatings on exterior walls of buildings, industrial machinery, military equipment and vehicles, commercial and passenger vehicles, and any other surface requiring a protective coating. Moisture curable polyurethane systems are also used extensively as sealants and adhesives.

Moisture curing polyurethane coating systems include a polyisocyanate component which reacts with atmospheric water at room temperature to form useful films. These systems also include pigments, organic solvents, and a variety of adjuvant components, e.g., surface active agents, dispersants, diluents, and fillers. Since the polyisocyanate component reacts with even trace amounts of moisture, extreme care must be taken so that the polyisocyanates do not contact water until they are applied to a surface to be coated. Water is, however, unintentionally and unavoidably introduced into the formulation process in the form of dissolved water in solvents, adsorbed and absorbed moisture on the surfaces of fillers and pigments, and atmospheric moisture. Subsequent reaction of the water with the polyisocyanate component of the system results in an irreversible reaction which will harden the product, making it unusable before it can be applied to the surface to be coated. This water must be removed in order to produce an acceptable product. The existing methods for preparing color- pigmented moisture curable polyurethane coatings require expensive equipment to dry the pigments, solvents, and fillers. In the alternative, moisture scavenging agents are added to the coating preparation or are added to the pigments, solvents and other raw materials prior to preparing the coating.

One group of moisture scavenging compounds are the molecular sieves. Molecular sieves adsorb water into their pores, thereby binding the water and preventing it from reacting with the polyisocyanate component. An example of a molecular sieve is sodium potassium aluminosilicate, available from the Mobay Corp., Pittsburgh, Pennsylvania, under the tradename designation Baylith L Powder. One disadvantage of using molecular sieves is that they reduce the gloss of the cured coating. Another disadvantage of molecular sieves is that they will sometimes plasticize or embrittle the cured coating.

A second group of water scavenging agents widely used to prevent moisture contamination of moisture curable polyurethane coating systems is the monomeric isocyanates. A typical monomeric isocyanate, such as p-toluenesulfonyl isocyanate (Vanchem, Inc. Lockport, Connecticut), reacts with water to generate carbon dioxide and the corresponding sulfonamide, e.g., p-toluenesulfonamide. The carbon dioxide diffuses from the pigment grind during the dehydration phase as carbon dioxide gas. A disadvantage of monomeric isocyanates is that they are harmful if swallowed, inhaled, or absorbed through the skin and are extremely corrosive to the tissues of the mucous membranes, upper respiratory tract, and skin.

There is a need for a moisture scavenger which efficiently, cost effectively, and safely removes water from moisture curable coating systems and from any other preparation where residual water is a problem, without seriously detracting from the performance of the cured coating. Coating, adhesive or sealant formulations also may include rheological modifiers to reduce viscosity, disperse pigments and improve solvency and flow. Formulations which do not contain rheological modifiers may exhibit a rapid increase in viscosity for a relatively small increase in solids content. The increased viscosity causes the formulation to set quickly resulting in striations in the formulation. Addition of a rheological modifier enables the formulation to flow into a smooth layer before it sets. Conventional rheological modifiers include polyethylene glycols such as Carbowax and polyethylene oxides such as Poly ox. There is a need for a rheological modifier to reduce viscosity and volatile organic content, disperse pigments, and improve the solvency and flow properties of a coating, adhesive or sealant.

Restrictions on solvent content in the atmosphere have increased efforts to provide coatings which do not contain any volatile components, but instead include components which form either the whole or a part of the hardened film itself. Reactive diluents are used to lower the volatile content of the coatings by reducing the loss of organic solvents into the atmosphere. For purposes of the present invention, reactive diluents are compounds of low volatility which reduce the viscosity and VOC of a coating, adhesive, elastomer, epoxy or sealant formulation and become a permanent part of the formulation through chemical reaction. Accordingly, reactive diluents are added to coatings not only as a diluent, but to reduce viscosity, copolymerize with the oligomers and polymers to form a part of the coating, and contribute to the final properties of the cured film. Some reactive diluents pose problems which limit their use in coatings. The diluents are known to produce brittle films with severe shrinkage and poor adhesion to substrates, exhibit slow cure response, poor solvency effects or color instability, ineffectively reduce viscosity, or cause serious skin irritancy problems.

There is a need for a reactive diluent which exhibits good cure response, color stability, an adequate potlife, low intrinsic viscosity, low film shrinkage, and excellent solvating or viscosity reducing properties.

When polyurethane coatings are applied under conditions of high humidity, a phenomenon known as downglossing can occur. Downglossing is caused by the reaction of water with isocyanate, resulting in microbubbles on the surface of the coating which reduce gloss. Downglossing affects air dry systems more severely than forced dry or baked systems. The iminoalcohol-oxazolidine mixtures described in U.S. Patent No. 5,223,174 have been used as agents for minimizing downglossing because these mixtures react with moisture more rapidly than does isocyanate.

When water reacts with isocyanate within a preparation, it forms bubbles which create pinholes within the preparation. The mixtures described in U.S. Patent No. 5,223,174 have also been used to minimize the formation of bubbles in a coating. Bubbles have been visually eliminated from the coating, improving the film integrity by providing improved abrasion resistance and impact resistance.

There is a need for an agent which can minimize downglossing in coating systems. An agent that can minimize or visually eliminate bubble formation in a coating, adhesive or sealant is also required. Formaldehyde is a raw material frequently used in polymeric systems including phenol-formaldehyde, urea-formaldehyde, and melamine-formaldehyde. Exposure to formaldehyde vapors in the workplace is stringently controlled by the use of formaldehyde scavengers. Formaldehyde scavengers capture formaldehyde and hold it in a form having significantly lower formaldehyde vapor pressure. Products such as textiles and plywood typically contain a formaldehyde scavenger to reduce free formaldehyde levels without changing the physical properties of the products. Known formaldehyde scavengers include nitroparaffins such as nitromethane (NM™), nitroethane (NE™), 1-nitropropane (NiPar S-10™) and 2-nitroproρane (NiPar S-20™), and amino alcohols such as 2-amino-2-methyl-l-propanol (AMP™), 2-amino-2-ethyl-l,3-propanediol (AEPD^®) and tris(hydroxymethyl)aminomethane (TRIS AMINO^®), which are manufactured by ANGUS Chemical Company.

There is a need for a formaldehyde scavenger which efficiently, cost effectively, and safely removes formaldehyde from polymeric systems and from any other preparation where free formaldehyde is a problem, without seriously detracting from the performance or physical properties of the system.

Corrosion is often prevalent in engine cooling systems. Metals such as copper, iron, steel, aluminum, magnesium and the like are often exposed to high temperatures, pressures and flow rates in these cooling systems. These conditions corrode metal forming corrosion products which may cause engine overheating or engine failure. Lightweight metals in engine components such as aluminum and magnesium are subject to pitting of radiator tubes, crevice corrosion at hose connections, and deposit corrosion from deposition of corrosion products. Corrosion inhibitors are added to antifreeze/coolant compositions and functional fluids which contact metal to prevent and control corrosion in engine cooling systems and other machinery. U.S. Patent No. 4,282,108 describes oxazolidine derivatives which are used as chelants, anti-copper- corrosion additives and frictional modifiers in automatic transmission fluid, and oxidation inhibitors in middle distillate fuels. There is a need for a corrosion inhibitor which effectively reduces the incidence of corrosion of metals or alloys, and which may be applied to a surface of a metal or alloy or may be incorporated in a functional fluid which contacts a surface of a metal or alloy. Phenol-based peroxide inhibitors have been suggested as a substitute for 2,6-di-t- butyl-p-cresol for use in polyol formulations because of the limited supply of the conventional p-cresol inhibitor. However, the phenol-based inhibitors cause discoloration of the polyol. N-(2-hydroxyalkyl)oxazolidines are known decolorizing agents for removing color-forming bodies from a mixture of alkyl substituted phenols. There is a continuing need for a decolorizing agent which removes the color from a phenol, amine or other discolored preparation. Summary Of The Invention

The present invention provides a method of scavenging formaldehyde from a preparation by admixing with the preparation an effective amount of an oxazolidine compound having the formula:

R, R, R₄

R . R .

Ri ' R₂ ' R, R,

wherein: R_j and R_j ' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, R2'. R3'. and R ' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group. An effective amount of the formaldehyde scavenging compound as described above is intimately admixed with the preparation. In a preferred embodiment, the effective amount of the compound includes from about 1 to about 100 moles of the compound for every mole of formaldehyde in the preparation. A second aspect of the invention is directed to a method of scavenging moisture from a preparation. According to the method, an effective amount of the compound as described above is intimately admixed with the preparation. In a preferred embodiment, the effective amount of the compound includes from about 1 to 100 moles of the compound for every mole of water in the preparation. The preparation is preferably a composite, sacrificial pigment, gas, ink, industrial fluid, coating, adhesive, sealant, or coating component.

A third aspect of the present invention is a method of inhibiting corrosion of a metal or alloy. An effective amount of the compound as described above intimately contacts the metal or alloy. In a preferred embodiment, the metal or alloy is coated with the compound. Alternatively, the compound is admixed with an industrial fluid.

Preferably, from about 1 to about 100 moles of the compound is added for every mole of water in the industrial fluid. A fourth aspect of the present invention is a method of reducing volatile organic content of a preparation and improving rheological properties of the preparation using a reactive diluent. An effective amount of the compound as described above is admixed with the preparation. Preferably, from about 1 to about 50 wt. % of the compound is added based on the total weight of the preparation. Another aspect of the present invention is a method of modifying the rheology of a preparation. An effective amount of the compound as described above is admixed with the preparation. Preferably, from about 1 to about 50 wt. % of the compound is added based on the total weight of the preparation.

A further aspect of the invention is a method of reducing foaming of a thermoplastic. An effective amount of the compound as described above is admixed with the thermoplastic. Preferably, from about 1 to about 100 moles of the compound is added for every mole of water in the thermoplastic.

Still another aspect of the invention is directed to a method for preventing the formation of ice crystals and for depressing the freezing point of a preparation. According to the method, an effective amount of the compound as described above is intimately admixed with the preparation. The preparation is preferably an industrial fluid. In a preferred embodiment, the effective amount of the compound includes from about 1 to 100 moles of the compound for every mole of water in the preparation. If the preparation does not contain water, the effective amount of the compound is from about 1 to about 50 wt. % of the compound based on the total weight of the preparation. Another aspect of the present invention is a method of obtaining a stable dispersion, suspension or solution. An effective amount of the compound as described above is admixed with the dispersion, suspension or solution. Preferably, from about 1 to about 50 wt. % of the compound is added based on the total weight of the dispersion, suspension or solution.

An additional aspect of the present invention is a method of minimizing formation of bubbles in a preparation. An effective amount of the compound as described is admixed with the preparation. Preferably, from about 1 to about 80 wt. % of the compound is added based on the total weight of the preparation.

Yet another aspect of the invention is a method of minimizing gloss reduction in a preparation when the preparation is exposed to heat and humidity. An effective amount of the compound as described is admixed with the preparation. Preferably, from about 1 to about 30 wt. % of the compound is added based on the total weight of the preparation. Detailed Description Of The Invention

The present invention provides a compound which can be advantageously used in the formulation of specialty systems including sealants, adhesives, elastomers, epoxy resin formulations and coatings. For the purposes of the present invention, a coating is any polyurethane coating, including both one and two component coatings. These coatings are typically cured by moisture, ambient, thermal, forced dry, radiation or bake curing. The compound acts as a rheological modifier, drying agent, decolorizing agent, dispersant, and reactive diluent in these systems. Additionally, the compound is a corrosion inhibitor, a reactive diluent in inks, a drying agent in inks, composites, sacrificial pigments, radiation cure coatings and industrial gasses, a foam inhibitor in thermoplastics, an antifreezing agent in functional fluids, and a formaldehyde scavenger in preparations such as polymeric systems, textiles and plywood. It has been discovered that a class of compounds including substituted bicyclic oxazolidines are excellent moisture and formaldehyde scavengers, decolorizing agents, drying agents, corrosion inhibitors, reactive diluents, thermoplastic foam inhibitors, antifreezing agents, dispersants, and rheological modifiers. Oxazolidine compounds have been used as curing and crosslinking reagents, reacting with polyfunctional isocyanates in the presence of polyols or water to form polymeric coatings. United States Patent No. 4,101,527 discloses an equimolar reaction of an oxazolidine with a polyfunctional isocyanate in the presence of water to form a polyurethane coating. United States Patent No. 3,941,753 describes pre-polymers for coating formation prepared from the reaction of a ketiminoalkanol with an isocyanate.

The bicyclic oxazolidine compounds of the present invention have the formula:

R. R< R.

R , R .

R, R₂ ' Rι R-

wherein: R_j and R_j' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, R2', R3', and R4' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

Referring to the bicyclic oxazolidines of the present invention, the preferred R group substituents are those which increase the reactivity of the compound to water. Without limiting the invention, it has been discovered that aliphatic or aromatic R group substituents increase the reactivity of the ring to water. The bicyclic oxazolidine compounds of the present invention react chemically with water in the following manner:

As shown above, the reaction products are an amino alcohol and carbonyl compounds. One mole of bicyclic moisture-scavenging oxazolidine will react with and remove two moles of water. Therefore, it is preferred that the moisture-scavenging compositions of the invention containing bicyclic oxazolidines include at least one-half mole of the bicyclic moisture-scavenging oxazolidine for each mole of water to be removed. However, since a perfectly efficient reaction environment cannot be guaranteed in industrial settings, it is preferable that from 0.5 to about 10 moles of the moisture-scavenging bicyclic oxazolidine be included in the inventive composition for every mole of water to be removed. Some applications require that only from 0.5 to about 3 moles of the moisture scavenging bicyclic oxazolidine be included for every mole of water to be removed from the preparation. Greater amounts of the oxazolidine can be added to reduce the viscosity and/or volatile organic content of the preparation. As much as 100 moles of the compound for every mole of water may be required to effect the desired change in the physical properties of the preparation. R group substituents which facilitate the reaction of water with the bicyclic moisture-scavenging oxazolidines of the present invention are preferred. According to one preferred embodiment, the R_j and R_j' substituents are, individually, a methyl group or a (C2 - C5) straight or branched chain alkyl or alkanol group; the R2, R2' R3, R3', R4 and R4' substituent groups are hydrogen atoms; and the R5 substituent group is a methyl group or a (C2 - C5) straight or branched chain alkyl or alkanol group.

According to another preferred embodiment, the R _j and R_j ' substituents are isopropyl groups.

The preferred R group substituents of the oxazolidine compounds of the present invention are also those which increase the reactivity of the compound to formaldehyde. The formaldehyde scavenging compounds of the present invention react with formaldehyde regardless of the presence of water in the preparation from which the formaldehyde is to be removed. One mole of formaldehyde scavenging oxazolidine will react with and remove two moles of formaldehyde. Therefore, it is preferred that at least 0.5 mole of the formaldehyde scavenging compound is used for each mole of formaldehyde to be removed from a preparation. However, since a perfectly efficient reaction environment cannot be guaranteed in industrial settings, it is preferable that from 0.5 to about 10 moles of the formaldehyde scavenging compound be included for every mole of formaldehyde to be removed from a preparation. Some applications require that only from about 1 to about 3 moles of the formaldehyde scavenging oxazolidine be included for every mole of formaldehyde to be removed from the preparation. Greater amounts of the oxazolidine can be added to reduce the viscosity and/or volatile organic content of the preparation. As much as 100 moles of the compound may be required to effect the desired change in the physical properties of the preparation.

The structure of the R substituents in the bicyclic oxazolidines is determined by the selection of the reactant precursor compounds. The oxazolidines of the present invention are prepared by reacting a primary amino alcohol with a carbonyl compound as described in U.S. patent application serial no. 07/624,062 which is incorporated herein by reference.

A further aspect of the invention is directed to a method of dehydrating a preparation. In one embodiment the preparation includes at least one pigment and at least one organic solvent. According to the method, an effective amount of the moisture scavenging compound as described above is intimately admixed with the preparation. In a preferred embodiment, the effective amount includes from about 1 to about 10 moles of the compound for every mole of water in the preparation to be dehydrated. Most preferably, from about 1 to about 3 moles of the compound is added to the preparation for every mole of water in the preparation to be dehydrated.

According to one embodiment of the invention, catalysts are added in combination with the oxazolidine compounds of the present invention to facilitate the reaction with water. The addition of a preferred catalyst will, in some instances, minimize the amount of the oxazolidine compound required to remove water from a preparation by increasing the efficiency of the reaction. Furthermore, a preferred catalyst will, in certain circumstances, increase the rate at which the moisture scavenging compounds react with water. Preferred catalysts include the organometallic catalysts, such as dibutyltin dilaurate, the mineral acid catalysts and the organic acid catalysts, such as acetic acid.

According to another embodiment of the invention, the reaction between the moisture scavenging compounds and water occurs at temperatures from ambient to about the boiling point of the preparation being dehydrated. Preferably, this range is from about 40 to about 180 degrees Fahrenheit. Increasing the temperature at which the reaction occurs increases the rate and the efficiency of the reaction.

The moisture scavenging compounds of the present invention are advantageously used in preparations including urethane coating, sealant and adhesive systems to remove moisture during the formulation, packaging and application steps. The present invention provides the producer of specialty polyurethane systems with an expedient and efficient alternative to the physical methods of dehydration, exemplified by molecular sieves and drying machinery, and the potentially toxic prior chemical methods, exemplified by the monomeric isocyanates presently available. The compounds also provide the coatings with improved consistency and application properties by improving the solvency effects (i.e., the degree to which a solvent holds a resin or other paint binder in solution) in the urethane coatings. The moisture scavenging compounds of the present invention are further provided for the storage stabilization of moisture curable polyurethane systems. A still further intended use of the invention is the dehydration of surfaces onto which moisture curable coatings are to be applied. Furthermore, the compounds improve the pot life of two component polyurethane coating systems.

The compounds of the present invention are also useful in scavenging moisture from radiation cure coatings such as UV cure coatings. The addition of the moisture scavenging compound to a radiation cure coating reduces hazing, cloudiness and brittleness that is caused by the presence of moisture. The moisture scavenging compounds also act as a reactive diluent in reducing the volatile organic content to impart improved flow and film properties to the coating.

Composites and gasses are also dried using the compounds of the present invention. Composites are elastomers which are considerably thicker than films, such as sealants, construction materials, shoe soles, extruded plastics, and aerospace panels. Composites, like urethane coatings, may be adversely affected by water prior to curing. The moisture scavenging compounds are added to a composite prior to curing to reduce brittleness of the elastomer which results from moisture. Gasses are dehumidified for use in industrial processes through the use of the moisture scavenging compounds. For example, forced air flow over a urethane coating serves to dehumidify the air. The moisture scavenging compounds are also useful in drying inks. During the process of forming an ink, a pigment slurry is commonly mixed with resins or vehicles to drive water out of the slurry. After this flushing stage, any residual water is removed by subjecting the ink to a two to six hour vacuum stripping process. The compounds of the present invention are added to the slurry either alone or with a resin to scavenge the water from the ink after flushing of the ink so that the conventional vacuum stripping process can be eliminated or minimized.

The invention provides an anhydrous composition including the moisture scavenging compounds described above and an organic solvent. Solvents used in the formulation of one and two-component systems are rapidly dehydrated by treating them with the moisture scavenging compound of the invention. This anhydrous composition is useful in any application where water is preferably avoided, e.g., preparing moisture curable polyurethane coatings, or dehydrating surfaces prior to applying moisture curable coatings. The quantity of moisture scavenger in the composition will vary with the water content of the solvent. The amount of water in the organic solvent being dehydrated can be determined by gas chromatography or Karl Fischer technique. The solvents generally used in the formulation of specialty polyurethane systems are compatible with the moisture scavenging compositions of the present invention. Solvents generally used in the preparation of polyurethane moisture scavenging preparations include aprotic solvents, such as ketones, esters, ethers, nitroparaffins, glycol esters, glycol ether esters, halogenated hydrocarbons, and alkyl and aromatic hydrocarbons.

Pigments, fillers, poly isocyanates, and adjuvants are suspended in organic solvents. For the purposes of this invention the term "fillers" is intended to include those materials added to a coating preparation to increase the solids content of the coating. The term "adjuvants" is intended to include those materials which are added to the coating formulation to aid application or formation, such as surface active agents, anti-settling agents, diluents, suspending agents, dispersants, flow additives, UV inhibitors and the like. Pigments, fillers, poly isocyanates and adjuvants can also be dehydrated with the water scavenging compositions of the present invention. Sacrificial pigments, for example, are added to coatings so that the pigment will corrode for the sake of protecting an underlying metal substrate from corrosion. Conventional sacrificial pigments include chromium oxide, zinc oxide, and strontium oxide. The addition of the moisture scavenging compounds of the present invention to the sacrificial pigment prevent corrosion of the pigment prior to its use in a coating formulation.

One aspect of the present invention is a substantially anhydrous composition including pigments, fillers, organic solvents, and the moisture scavenging compounds described above. It has been determined that a reaction period of from 30 minutes to about twenty-four hours is preferred to ensure substantially complete dehydration of pigment preparations. The amount of the moisture scavenger composition required to dehydrate the pigment or filler will vary with the total water content. Through the addition of the moisture scavenging composition of the invention, an anhydrous composition is produced including pigments, organic solvents, fillers, poly isocyanates and adjuvants. Alternatively, any of the above-listed components can be deleted, depending on the needs of the ultimate user. This anhydrous composition is useful in applications where water is preferably avoided, e.g., in the formulation of moisture curable polyurethane coatings. A further aspect of the invention is directed to a method of scavenging formaldehyde from a preparation. In one embodiment, the preparation is a phenol- formaldehyde, urea-formaldehyde, or melamine-formaldehyde polymeric system. According to the method, an effective amount of the oxazolidine compound of the present invention is intimately admixed with the preparation. An effective amount of the formaldehyde scavenging compound is an amount of the compound which removes free formaldehyde in the preparation. In a preferred embodiment, the effective amount includes from about 1 to about 10 moles of the compound for every mole of formaldehyde in the preparation. Most preferably, from about 1 to about 3 moles of the compound is added to the preparation for every mole of formaldehyde in the preparation. The compounds of the present invention will scavenge formaldehyde regardless of the presence of water in the preparation. However, the presence of a catalyst or water may facilitate the reaction of the oxazolidine compound with formaldehyde.

Another aspect of the present invention is directed to a method of inhibiting corrosion of a metal or alloy. According to the method, an effective amount of the oxazolidine compound of the present invention as described above contacts the surface of a metal or alloy. An effective amount of the corrosion inhibiting compound is an amount of the compound sufficient to prevent the formation of corrosion in a preparation. In one embodiment, the compound is applied directly to the metal or alloy by coating the metal or alloy with the compound. Alternatively, the compound may be incorporated into a paint formulation or other coating formulation which is to be applied to the metal or alloy. In a second embodiment, the compound is intimately admixed with a functional fluid which contacts a metal or alloy. The term "functional fluid" is defined for purposes of the present invention to include any industrial fluid such as a lubricant, hydraulic fluid, hydrocarbon fuel or jet fuel. Additional examples of functional fluids include but are not limited to transmission fluid, motor oil, gasoline, diesel fuel, kerosene, greases, and synthetic oils such as polyethylene oils, polysilicones, fluorohydrocarbon oils, and esters of dicarboxylic acids, poly glycol and alcohol. The functional fluid may also be an aqueous system such as a cooling water system, an air conditioning system, or a steam generating system. In a preferred embodiment, the effective amount includes from about 1 to about 10 moles of the compound for every mole of water in the functional fluid. Most preferably, from about 1 to about 3 moles of the compound is added to the preparation for every mole of water in the functional fluid.

Yet another aspect of the present invention is directed to a method for preventing the formation of ice crystals and for lowering the freezing point of an industrial fluid while removing moisture from the preparation. Conversely, conventional antifreezing agents lower the freezing point of an industrial fluid without removing moisture from the fluid. According to the method of the invention, an effective amount of the oxazolidine compound of the present invention as described above is intimately admixed with an industrial fluid which may be exposed to low temperatures during use in automobiles, airplanes or other machinery. An effective amount of the antifreezing agent is an amount of the compound which prevents an industrial fluid from freezing. The term "industrial fluid" is defined for the purposes of this invention to include any lubricant, hydraulic fluid, hydrocarbon fuel, jet fuel and the like. In a preferred embodiment, the effective amount includes from about 1 to about 10 moles of the compound for every mole of water in the industrial fluid. Most preferably, from about 1 to about 3 moles of the compound is added to the preparation for every mole of water in the industrial fluid. If the preparation does not contain water, the effective amount of the compound is from about 1 to about 30 wt. % of the compound based on the total weight of the preparation. Most preferably, from about 1 to about 10 wt. % of the compound based on the total weight of the preparation is added to the preparation. A further aspect of the present invention is directed to a method of reducing volatile organic content of a preparation and improving rheological properties of the preparation using a reactive diluent. The preparation is preferably a coating, ink, adhesive, elastomer, sealant or epoxy resin formulation in which an effective amount of the reactive diluent compound is intimately admixed with the formulation as a substitute for volatile organic solvents. The reactive diluent oxazolidine compound reacts to form a part of a high solids formulation while reducing the release of volatile organics into the atmosphere. An effective amount of the reactive diluent compound of the present invention is an amount sufficient to reduce the viscosity and volatile organic content of the preparation and provide an acceptable potlife or stability and cure rate while maintaiiiing or improving the film properties of the preparation. The quantity of reactive diluent in the composition will vary with the viscosity and volatile organic content of the formulation. Generally, the effective amount will range from about 1 to about 80 weight percent based on the total weight of the formulation. In a preferred embodiment, the effective amount includes from about 5 to about 50 weight percent of the compound based on the total weight of the formulation. Most preferably, from about 5 to about 30 weight percent of the compound based on the total weight of the formulation is added. Film properties which may be improved by the reactive diluent compounds of the present invention include, but are not limited to, color stability, gloss, hardness, impact resistance, flexibility, chemical resistance, abrasion resistance, exterior durability, humidity and salt fog resistance.

An aspect of the present invention is directed to a method of mimmizing bubble formation in a preparation. The preparation is preferably a coating, adhesive, elastomer, sealant or epoxy resin formulation in which an effective amount of the oxazolidine compound is intimately admixed with the formulation to remove moisture. An effective amount of the compound for minimizing bubble formation is an amount of the compound sufficient to visually eliminate bubbles from the preparation. Generally, the effective amount will range from about 1 to about 80 weight percent based on the total weight of the formulation. In a preferred embodiment, the effective amount includes from about 5 to about 50 weight percent of the compound based on the total weight of the formulation. Most preferably, from about 5 to about 30 weight percent of the compound based on the total weight of the formulation is added. Film properties which may be improved by addition of the compounds of the present invention include, but are not limited to, impact resistance and abrasion resistance.

Another aspect of the present invention is directed to a method of minimizing downglossing in a preparation. The preparation is any one component or two component coating, elastomer or sealant of low, medium or high gloss. The coatings include polyurethanes and epoxies, and are preferably polyurethanes such as automotive refinish coatings. Downglossing may also be minimized in melamine systems. An effective amount of the oxazolidine compound is intimately admixed with the coating to prevent the formation of microbubbles on the surface of the coating which reduce gloss. An effective amount of the compound for minimizing downglossing is an amount of the compound sufficient to stabilize the gloss of a coating when exposed to high humidity. Generally, the effective amount will range from about 0.5 to about 30 weight percent based on the total weight of the coating. In a preferred embodiment, the effective amount includes from about 1 to about 15 weight percent of the compound based on the total weight of the coating. Most preferably, from about 1 to about 5 weight percent of the compound based on the total weight of the coating is added. Although the compound can be added to the coating at any stage of preparation, it is most common to add the compound during the grind phase and/or the let down phase.

Another aspect of the present invention is directed to a method of obtaining a stable dispersion, suspension or solution. According to the method, an effective amount of the oxazolidine compound of the present invention as described above is intimately admixed with the dispersion, suspension or solution. An effective amount is an amount of the compound which provides sufficient solvency or pigment dispersabihty. Solvency is the ability of an additive to hold a resin or other binder in solution. Dispersabihty is the ability of an additive to increase the stability of a suspension of pigments in a liquid medium. In a preferred embodiment, the effective amount includes from about 1 to about 30 weight percent of the compound based on the total weight of the dispersion, suspension or solution. Most preferably, from about 1 to about 10 weight percent of the compound based on the total weight of the dispersion, suspension or solution is added. Another aspect of the invention is directed to a method of reducing the foaming of a thermoplastic to improve processing and quality of the thermoplastic. Foaming during formation of urethane and urethane/polyurea thermoplastics is produced by the formation of carbon dioxide from the reaction of water with an isocyanate. According to the method, an effective amount of the oxazolidine compound of the present invention as described above is intimately admixed with the thermoplastic. An effective amount is an amount of the compound which will react with water in the thermoplastic to prevent the formation of carbon dioxide. In a preferred embodiment, the effective amount includes from about 1 to about 10 moles of the compound for every mole of water in the thermoplastic. Most preferably, from about 1 to about 3 moles of the compound is added to the thermoplastic for every mole of water in the thermoplastic.

A further aspect of the invention is directed to a method of modifying the rheology of a preparation. Rheology is the deformation and flow of the preparation. Rheological properties which may be modified by the compound of the present invention include sagging, flow and film build. In an embodiment of the method, the preparation is a coating, adhesive or sealant which has improved flow and film properties as a result of reduced viscosity. According to the method, an effective amount of the oxazolidine compound of the present invention as described above is intimately admixed with the preparation. An effective amount is an amount of the compound which is sufficient to reduce the viscosity and improve the rheological properties of the preparation. In a preferred embodiment, the effective amount includes from about 1 to about 30 weight percent of the compound based on the total weight of the preparation. Most preferably, from about 1 to about 10 weight percent of the compound based on the total weight of the preparation is added. Although the compound can be added to the preparation at any stage, it is most common to add the compound during the grind phase and/or the let down phase. When the compound is added during the grind phase, the compound also acts as a pigment dispersant to prevent agglomerate formation. Accordingly, addition of the compound to a coating, adhesive or sealant assures that the pigment particles are finely divided and stabilized.

Another aspect of the invention is directed to a method of decolorizing a preparation. According to the method, an effective amount of the oxazolidine compound of the present invention as described above is intimately admixed with the preparation. An effective amount is an amount of the compound which will sufficiently remove the color from a preparation. In a preferred embodiment, the effective amount includes from about 1 to about 30 weight percent of the compound based on the total weight of the preparation. Most preferably, from about 1 to about 10 weight percent of the compound based on the total weight of the preparation is added. The preparations which may be decolorized include phenols and amines.

Greater amounts of the oxazolidine compound can be added in the methods of the present invention to reduce the viscosity and/or volatile organic content of the preparation. In excess of 100 moles of the compound for every mole of water or formaldehyde in a preparation may be required to effect the desired change in the physical properties of the preparation. Likewise, in excess of 50 weight percent of the compound based on the total weight of the preparation may be required in decolorant, antifreeze, reactive diluent or rheological modifier applications.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example and were herein described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Any R group substituents which increase the reactivity of a compound of the present invention to water or formaldehyde are within the scope of the present invention. For example, alkenyl and alkynl groups or substituent R groups may be selected as R group substituents if these groups increase the reactivity of the compound to water or formaldehyde. Likewise, any R group substituents which increase the reactivity of a reactive diluent compound to the active material whose concentration is to be reduced are within the scope of the present invention. Additionally, any R group substituents which improve the ability of a compound of the present invention to lower the freezing point of a preparation, provide improved solvency or pigment dispersability in a dispersion, suspension or solution, reduce the viscosity and improve the rheological properties of a preparation, minimize bubble formation in a preparation, minimize downglossing in a coating, or remove the color from a preparation are also preferred.

Claims

WE CLAIM:

1. A method of scavenging formaldehyde from a preparation containing formaldehyde, wherein the method comprises admixing with the preparation at least 0.5 mole of a formaldehyde scavenging compound for every mole of formaldehyde to be scavenged from the preparation, the formaldehyde scavenging compound having the structure:

R, R₂ ' Rι R.

wherein: R^ and R_j' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R₂, R3, R4, R₂', R3', and R₄' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

2. The method of claim 1 wherein the preparation is a resin.

3. The method of claim 2 further including the step of curing the resin after the formaldehyde scavenging compound is admixed with the resin.

4. The method of claim 1 including from about 1 mole to about 100 moles of said formaldehyde scavenging compound for every mole of formaldehyde to be removed from the preparation.

5. The method of claim 1 including from about 1 mole to about 10 moles of said formaldehyde scavenging compound for every mole of formaldehyde to be removed from the preparation.

6. The method of claim 1 including from about 1 mole to about 3 moles of said formaldehyde scavenging compound for every mole of formaldehyde to be removed from the preparation.

7. A method of scavenging moisture from a preparation, wherein the method comprises admixing with the preparation from about 1 mole to about 100 moles of a moisture scavenging compound for every mole of water to be dehydrated from the preparation, the moisture scavenging compound having the structure:

R₄ ' R, R₄

R. R .

O N O

R i ' R₂ ' R ι R-

8. The method of claim 7 wherein the preparation is selected from the group consisting of a composite, sacrificial pigment, gas, ink, industrial fluid, coating, adhesive, sealant, and coating component.

9. The method of claim 7 wherein the preparation is a composite, and further including the step of curing the composite after the moisture scavenging compound is admixed with the composite.

10. The method of claim 7 wherein the preparation is an ink, and the moisture scavenging compound is admixed with the ink after flushing of the ink.

11. The method of claim 7 wherein the preparation is a coating component selected from the group consisting of polyols, solvents, pigments, wetting agents, dispersants, flow additives, and fillers.

12. The method of claim 7 including from about 1 mole to about 10 moles of said moisture scavenging compound for every mole of water to be dehydrated in the preparation.

13. The method of claim 7 including from about 1 mole to about 3 moles of said moisture scavenging compound for every mole of water to be dehydrated in the preparation.

14. A method of inhibiting corrosion of a metal or alloy, wherein the method comprises contacting the metal or alloy with at least one mole of a corrosion inhibiting compound for every mole of water to be removed from a surface of the metal or alloy, the corrosion inhibiting compound having the structure:

R₂ ' R_! R₂

wherein: R^ and R_j' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, R2', R3', and R4' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

15. The method of claim 14 wherein the corrosion inhibiting compound is admixed with an industrial fluid.

16. The method of claim 14 further including the step of coating the metal or alloy with the corrosion inhibiting compound.

17. The method of claim 15 including from about 1 mole to about 100 moles of said corrosion inhibiting compound for every mole of water to be removed from the industrial fluid.

18. The method of claim 15 including from about 1 mole to about 10 moles of said corrosion inhibiting compound for every mole of water to be removed from the industrial fluid.

19. The method of claim 15 including from about 1 mole to about 3 moles of said corrosion inhibiting compound for every mole of water to be removed from the industrial fluid.

20. A method of reducing volatile organic content of a preparation and improving rheological properties of the preparation, comprising admixing with the preparation a compound having the structure:

i ' ₂ ' i R2

21. The method of claim 20 wherein the effective amount of the compound is from about 1 to about 80 wt. % of the compound based on the total weight of the preparation.

22. The method of claim 20 wherein the effective amount of the compound is from 5 to about 50 wt. % of the compound based on the total weight of the preparation.

23. The method of claim 20 wherein the effective amount of the compound is from 5 to about 30 wt. % of the compound based on the total weight of the preparation.

24. The method of claim 20 wherein the preparation is a coating, ink, adhesive or sealant.

25. The method of claim 20 wherein the preparation is an epoxy resin.

26. A method of modifying rheology of a preparation, comprising admixing with the preparation an effective amount of a rheology modifying compound having the structure:

R i ' R₂ ' R ι R.

27. The method of claim 26 wherein the preparation is a coating, adhesive or sealant.

28. The method of claim 26 wherein the effective amount of the rheology modifying compound is from about 1 to about 50 wt. % of the rheology modifying compound based on the total weight of the preparation.

29. The method of claim 26 wherein the effective amount of the rheology modifying compound is from about 1 to about 30 wt. % of the rheology modifying compound based on the total weight of the preparation.

30. The method of claim 26 wherein the effective amount of the rheology modifying compound is from about 1 to about 10 wt. % of the rheology modifying compound based on the total weight of the preparation.

31. A method of reducing foaming of a thermoplastic comprising admixing with the thermoplastic at least one mole of an antifoamant for eveiy mole of water to be reacted in the thermoplastic, the antifoamant having the structure:

R- R< R-

R, R .

R i R₂ ' R ι R^

32. The method of claim 31 including from about 1 mole to about 100 moles of said antifoamant for every mole of water to be reacted in the thermoplastic.

33. The method of claim 31 including from about 1 mole to about 10 moles of said antifoamant for every mole of water to be reacted in the thermoplastic.

34. The method of claim 31 including from about 1 mole to about 3 moles of said antifoamant for every mole of water to be reacted in the thermoplastic.

35. A method of preventing the formation of ice crystals and depressing the freezing point of a preparation, wherein the method comprises admixing with the preparation an effective amount of an antifreezing agent having the structure:

R- R$ R<

α ' Ri R-

wherein: R_j and R_j' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, 2', R3', and ₄' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

36. The method of claim 35 wherein the preparation is an industrial fluid.

37. The method of claim 35 wherein the effective amount of the antifreezing agent includes from about 1 mole to about 100 moles of said antifreezing agent for every mole of water to be removed from the preparation.

38. The method of claim 35 wherein the effective amount of the antifreezing agent includes from about 1 mole to about 10 moles of said antifreezing agent for every mole of water to be removed from the preparation.

39. The method of claim 35 wherein the effective amount of the antifreezing agent includes from about 1 mole to about 3 moles of said antifreezing agent for every mole of water to be removed from the preparation.

40. The method of claim 35 wherein the effective amount of the antifreezing agent is from about 1 to about 50 wt. % of the antifreezing agent based on the total weight of the preparation.

41. The method of claim 35 wherein the effective amount of the antifreezing agent is from about 1 to about 30 wt. % of the antifreezing agent based on the total weight of the preparation.

42. The method of claim 35 wherein the effective amount of the antifreezing agent is from about 1 to about 10 wt. % of the antifreezing agent based on the total weight of the preparation.

43. A method of obtaining a stable dispersion, suspension or solution, comprising admixing with the dispersion, suspension or solution an effective amount of an additive having the structure:

R 1 ' α 'Ri

wherein: R_j and R_j' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, R2', 3', and 4' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R5 is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

44. The method of claim 43 wherein the effective amount of the additive is from about 1 to about 50 wt. % of the additive based on the total weight of the dispersion, suspension or solution.

45. The method of claim 43 wherein the effective amount of the additive is from about 1 to about 30 wt. % of the additive based on the total weight of the dispersion, suspension or solution.

46. The method of claim 43 wherein the effective amount of the additive is from about 1 to about 10 wt. % of the additive based on the total weight of the dispersion, suspension or solution.

47. A method of minimizing the formation of bubbles in a preparation, comprising admixing with the preparation an effective amount of a compound having the structure:

wherein: _j and R_j' are, individually, a methyl group, or a branched or straight chain alkyl or alkanol group; R2, R3, R4, R2', R3', and R ' are, individually, a hydrogen atom, a methyl group, a straight chain or branched chain alkyl or alkanol group, a cyclic alkyl or an aryl group; and R is a methyl or methylol group, or a branched chain or straight chain alkyl or alkanol group.

48. The method of claim 47 wherein the preparation is a coating, elastomer, adhesive or sealant.

49. The method of claim 47 wherein the effective amount of the compound is from about 1 to about 80 wt. % of the compound based on the total weight of the preparation.

50. The method of claim 47 wherein the effective amount of the compound is from 5 to about 50 wt. % of the compound based on the total weight of the preparation.

51. The method of claim 47 wherein the effective amount of the compound is from 5 to about 30 wt. % of the compound based on the total weight of the preparation.

52. A method of minimizing downglossing in a preparation which is exposed to heat and humidity, comprising admixing with the preparation an effective amount of a compound having the structure:

53. The method of claim 52 wherein the effective amount of the compound is from 0.5 to about 30 wt. % of the compound based on the total weight of the preparation.

54. The method of claim 52 wherein the effective amount of the compound is from about 1 to about 15 wt. % of the compound based on the total weight of the preparation.

55. The method of claim 52 wherein the effective amount of the compound is from about 1 to about 5 wt. % of the compound based on the total weight of the preparation.

56. The method of claim 52 wherein the preparation is a coating, sealant or elastomer.