US3192061A - Coating vehicle - Google Patents

Description

United States Patent 3,192,061 COATING VEHICLE Samuel G. Wilson, Minnetonka Village, and Morris R.

Olson and David E. Tweet, Minneapolis, Minn., assignors to Cargill, Incorporated, Wilmington, Del., a corporation of Delaware No Drawing. Filed Mar. 22, 1962, Ser. No. 181,804

8 Claims. (Cl. 196-252) The present invention generally relates to a coating vehicle and more particularly relates to a vehicle, com prising substantially 100 percent solids, for use in coatings, such as paints, varnishes and the like.

Various types of vehicles are conventionally used in the preparation of coatings, such as paints. In addition, various attempts have been made in the past to successfully employ drying oils, such as linseed oil and soybean oil, in the absence of other constituents, as vehicles for coatings. The drying oils set to a hardened state, i.e., dry upon exposure to air and/or heat, due to oxidation and/ or polymerization. However, drying oils by themselves generally are not satisfactory alone as vehicles since they do not impart to coating formulations suitable characteristics including a sufficient degree of physical hardness, weather resistance and chemical resistance.

Accordingly, in order to obtain desirable characteristics, it is conventionalto provide in the vehicles of coating formulations, such as paints, various other constituents. Among these constituents is a suitable thinner. The thinner is a volatilizable material, such as water or an organic thinning agent such as benzene, turpentine or other light organic solvent which cooperates with the drying oils and other constituents in providing the desired characteristics. When such coating formulation is applied to a surface, evaporation of the water or organic thinner occurs, exposing the drying oils in the vehicle in a controlled manner to the atmosphere in order to facilitate the desired drying of the paint to a hard, resistant coating.

However, there are substantial disadvantages in providing a coating vehicle which includes vaporizable constituents. In this connection, the vaporizable portion of the vehicle may comprise a substantial portion of the vehicle and is lost during drying thereby not contributing to the ultimate body of the dried coating. Moreover, the thinner usually presents certain problems. Thus, undue evaporation of the thinner before formulating the coating and also after such formulating and before use of the coating must be prevented. In the case of organic thinners, problems of shipping and storage also arise due to their bulk and often their potentially dangerous nature,

both as a health hazard to personnel and as a fire hazard.

Accordingly, it would be desirable to provide a 100 percent solids vehicle for coating formulations, i.e., a.

vehicle containing no normally vaporizable components. Such vehicle should provide desired hardness in the coating when applied, and should also provide suitable Weather resistance and chemical resistance.

A highly satisfactory 100 percent solids vehicle has now been discovered which is particularly useful in the preparation of coating formulations which are to be baked to provide the desired dried coating, i.e., baking enamels and the like. The 100 percent solids vehicle contains no normally volatilizable components and, accordingly, all of the vehicle contribute to the body and characteristics of the coating. Problems connected with prevention of loss of volatilizable components, health and fire hazards and the like are avoided. The vehicle can be readily prepared at low cost utilizing available constituents and con- "ice tributes hardness, weather resistance and chemical resistance to the dried coating. Pigmented coating formulations containing the vehicle of this invention are somewhat thixotropic in nature so that they can be easily spread upon vertical surfaces Without running down such surfaces. Moreover, the vehicle is easily spread and brushed on a surface to provide a thin uniform coating with improved coverage.

It is the principal object of the present invention to provide an improved vehicle for coating formulations. It is a further object of the present invention to provide a percent solids vehicle for coating formulations. It is also an object of the present invention to provide a 100 percent solids vehicle which contributes to desired coating hardness, and weather and chemical resistance. It is also an object of the present invention to provide a 100 percent solids vehicle which is suitable for use in paints, lacquers and varnishes, and is particularly suitable in baking enamels and the like. 7

Further objects and advantages of the present invention will be apparent from a study of the following detailed description.

The vehicle of the present invention comprises an unsaturated drying oil or mixture of drying oils, together with specific non-volatile esters which, in combination with oil, impart to the improved vehicle its improved characteristics. Other non-volatile constituents designed to modify and/ or augment the characteristics of the vehicle may also be present in varying concentrations. Referring more particularly to the vehicle of the invention, it includes dicyclol maleate and/ or dicyclol furnarate, in a specific range of concentration, together with a cyclol ester of drying oil and an unsaturated oil or mixture of unsaturated oils, such as are conventionally used in vehicles for coating formulations, usually known as drying oils. Various other non-volatile cyclol esters may also be present, as may non-volatile unsaturated fatty acids and certain other non-volatile constituents.

The dicyclol maleate and/or dicyclol fumarate is derived from a product sold under the trade name Cyclol, which is 2-hydroxymethyl-5-norbornene and which is available from the Interchemical Corporation. This product is an unsaturated alcohol having the following physical properties:

Table I Molecular weight 124. Color, APHA Maximum 20. Boiling point (760 mm. Hg) 205 C. Freezing point 1l.5 C. Flash point, open cup 84 C. Specific gravity (25 C.) 1.022. Refractive index, N d 1.4994. Viscosity 55 cps. Solubility Miscible with most organic solvents; insolu ble in cold water; slightly soluble in hot water.

Dicyclol maleate can be prepared in any conventional manner from the Cyclol product. In this connection, it can be prepared by a fusion type esterification, reacting 2 moles of the Cyclol product with one mol of maleic anhydride at 400 degrees F. The reaction can also be carried out in xylene using an excess of the Cyclol product. The acid value reduces to 5.0 or below in 4 to 5 hours, andthe product thus prepared has a viscosity of 20 to 25 poises, and a 2 to 3 Gardner color (standard colordetermination) The product is miscible with alkalirefined linseed oil and also with soybean oil at an approximately l:l ratio. It is not miscible with regular mineral spirits, but is soluble in high KB (kauri-butanol) value hydrocarbon solvents having KB values of more than 90. It is also soluble in xylol.

Dicyclol fumarate can be prepared in a generally similar manner, from the Cyclol product and fumaric acid to a product having generally similar characteristics as dicyclol maleate, since fumaric and maleic acids are isomers. Howeven dicyclol fumarate is a low melting point compound, which is solid at room temperature (70 F.)

The dicyclol maleate or dicyclol furnarate is not suitable for use alone as the 100 percent solids vehicle, since alone it does not possess the ability to form a smooth coating of film with the other constituents which are usually utilized in a coating formulation, i.e., pigments, fillers, etc. Instead, in order to achieve the benefits of the present invention, it is necessary that the dicyclol maleate or dicyclol furmarate, or mixture thereof be present in the vehicle of this invention together with an effective concentration of one or more drying oils, i.e., an unsaturated oil, or mixture of such oils, and also with a cyclol ester of fatty acids of a drying oil. The unsaturated (drying) oil may comprise one or more of the following drying oils: saifiower, linseed, soybean, corn, and other drying (unsaturated) oils conventionally utilized for coating vehicles.

The cyclol ester or esters of one or more fatty acids of drying oils, required in the solids vehicle, can be prepared by direct reaction of the fatty acids obtained from any. drying oil with the vCyclol product. Thus, for example, one mole of the Cyclol product can be heated with one mole of fatty acids obtained from linseed oil to 400 degrees F. and held at that temperautre for about 89 hours, that is, until an acid value of less than It) is reached. The temperature can then be raised to 440 degrees F. to drive oh. the .unreacted Cyclol product. Similar esters can be prepared utilizing, for example, soybean oil rather than linseed oil in the reaction with the Cyclol product. So also with other drying oils. However, it has been found that the cyclol esters of fatty acids of linseed oil and soybean oil are preferred, the cyclol ester of soybean oil fatty acids being particularly suitable.

The concentration of dicyclol maleate or dicyclol fumarate can vary in the vehicle of the invention, depending upon the results desired. Thus, it can comprise between about 10 and about 8t) percent of the total weight of the vehicle. However, it has been found that in order to provide the vehicle with sufficient hardness when baked, it is necessary to have present'in the vehicle a concentration of at least about 50 percent by weight of dicyclol maleate or dicyclol furnarate. Moreover, at least about 50 percent concentration of the dicyclol maleate or dicyclol fumarate is needed in order to provide the vehicle with effective chemical resistance (i.e., resistance to impairment by alkalies, acids, etc.). Particularly suitable vehicles have been prepared utilizing between about 50 and about 60 percent dicyclol maleate or dicyclol fumarate, the requisite hardness and chemical resistance of the coating being obtained while still substantially retaining other desirable characteristics. Within the range of 50 to 60 percent by weight, an increase in the concentration of the dicyclol maleate or dicyclol fumarate results in increases in hardness, chemical resistance and gloss, While somewhat reducing impact resistance. In such formulations, the drying oil is present in a concentration of up to about 40 percent preferably at least about percent, by weight of the vehicle, in order to impart sufiicient flexibility to the film. The cyclol ester or esters of drying oil fatty acids, hereinafter referred to as cyclol. esters of drying oils or cyclol-drying oil esters, should normally be present in a concentration of at least about 10 percent by weight of the vehicle. They can be used eliectively in concentrations of up to about 20 percent, by weight of the vehicle, and can contribute to the vehicle desirable properties, particularly impact resistance and chemical resistances. Such cyclol esters are particularly important when the vehicle is to be used in baking formulations.

In the event that it is desirable in a given coating formulation to provide a high gloss, a proportion of the cyclol esters of drying oil can'be replaced with suitable fatty acids, for example, soy fatty acids. However, impact resistance and chemical resistance are somewhat lowered thereby. In any event, some cyclol esters of drying oil, at least about 5 percent by weight of the vehicle, should be present.

It will also be understood that, in accordance with the present invention, minor amounts of suitable non-volatile addends, such as coupling agents can also be added to this vehicle. Such coupiing agents should be mutual solvents or emulsifying agents or the like.

Gther non-volatile additives may also be used in minor amounts, for example, unsaturated fatty acids and the like.

The indicated constituents for the vehicle of the invention can be added together in any sequence by simple mixing and stirring in order to provide the finished vehicle. Such constituents in proper combination and concentration readily blend together to provide a homogeneous vehicle which does not separate into a plurality of phases upon standing, and which does not contain volatile constituents.

As previously indicated, pigmented coating formulations incorporating the vehicle of this invention exhibit the highly desirable and unusual property of thixotropy so that when, for example, the vehicle is present in a baking enamel formulation, the enamel can be applied as a film on a vertical surface, for example, a steel plate, in a suitable thickness, for example, 1-1.5 mil thick, and will not runoff such surface before being baked thereon. The coating is easy to apply in a thin film, provided the vehicle is present in an effective concentration.

It has been found that when the vehicles are prepared utilizing constituents other than those specified for the present vehicle, various advantages of the present invention are not enjoyed. Thus, one or more properties of the vehicle may be seriously depreciated, for example, color, hardness, flexibility, impact resistance, weather resistance, chemical resistance, spreadability, smoothness, coverage and the like.

Table II sets forth properties of various IOOpercent solids vehicle formulations.

10 cyclol-soy bean oil, 5 cyclol-soy bean oil,

5 soy ac ds 10 soy acids. Z0 70. 0 V h o00 300 2 r. 1% 1. 10.-.. 26. 10 40.

Fail.

Percent oil 36 soy 30 soy. Percent DGM O 10 s0y acids.

' pebble mill.

Table IIContinued Samples Characteristics Percent oil. '40 soy 45 soy. Percent DOM 50.-." 50. Percent other 5 cyclol-soy bean oil 5 soy acids.

esters, 5 soy acids. Pigment, g./l veh 70 7 Bake 250 1% hrs. 300, hr Film (mil) 1% 1 3. Hard 28 14. Imprint 25 80. 20% NaOH Res -1 hr -1 hr. ellow .013. Gloss 84.. 79.

Percent oil 40 soy 30 lin. Percent DCh 50. Percent other 6 s y acids, 4 y 1o soy acids, 10 cyclolsoy bean oil esters. soy bean oil esters.

Pigment, g./100 veh 50 Q 300, hr. Film (11111). 11 1% W1 30. ct 20. 20% NaOH 11%..

Percent other I.

Pigment, g./100 veh 50 Fire V esters, 10 soy acids. Pigment, g./100 veh 700 90. Bake 300, hr.

For the above tests, the constituents dicyclol maleate and the cyclol soybean oil esters'and cyclol-linseed oil esters were prepared as previously described. In preparing the vehicles, the Constituents were merely mixed together with stirring until uniformly distributed. A quantity of pigment (titanium dioxide) was then mixed with the vehicle and themixture was ground overnight in a Approximately 0.2 percent by weight of the mixture, of manganese drier was added to the ground mixture and films of the indicated thickness were preppared on steel panels and baked 30 minutes at 300 de- 6 and gloss were determined on a photovoltmeter. Resistance to sodium hydroxide was determined by placing the caustic on the film for 1.25 hours, and checking at intervals to determine the time required for breakdown. A plus sign (-1-) in Table II above indicated that the film was not destroyed in the test time.

As seen from Table II above, several particularly suitable 100 percent solids vehicles for baking purposes have been discovered.

Accordingly, an improved vehicle which can be utilized in various coating formulations including baking enamels is provided in accordance with the present invention. The vehicle imparts thixotropy to pigmented coating formulations, is stable, i.e., does not separate, contains no vaporizable components under ambient conditions and imparts requisite hardness, impact resistance, color, weather resistance and chemical resistance to the coating formulations. If desired, the vehicle can also provide high gloss in the coating. Moreover, the vehicle is simple to prepare, is economical, and is free of difficulties with evaporation, storage and transportation usually present with volatile vehicles.

Various of the features of the present invention are set forth in the appended claims.

What is claimed is:

' 1. An improved vehicle for coating comprising, a mixture of from about 30 to 40 percent by weight of said vehicle of an unsaturated drying oil, from about 50 percent to 60 percent by weight of said vehicle of a member selected from the group consisting of the reaction product of Z-hydroxyrnethyl-S-norborene with maleic acid, the reaction product of Z-hydroxymcthyl-S-norborene with maleic anhydride and the reaction product of 2- hydroxymethyl-S-norborene with fumaric acid, and from about 10 percent to about percent by weight of said vehicle of an adduct of 2-hydroxymethyl-5-norborene with an unsaturated drying oil fatty acid. v 2. An improved vehicle for coating comprising, a mixture of from about to percent by weight of said vehicle of an unsaturated drying oil, from about per cent to 60 percent by weight of said vehicle of a member selected from the group consisting of the reaction product of Z-hydroxymethyl-5-norborene with maleic acid, the reaction product of Z-hydroxymethyl-S-norborene with maleic anhydride and the reaction product of 2-hydroxymethyl-5-norborene with fumaric acid, from about 10 percent to about 20 percent by weight of said vehicle of an adduct of Z-hydroxymethyl-5-norborene with an unsaturated drying oil fatty acid, and an unsaturated fatty acid in an amount sufficient to substantially increase the gloss imparted by said vehicle.

3. An improved vehicle for coating comprising, a mixture of from about 30 to 40 percent by weight of said vehicle of an unsaturated drying oil, from about 50 percent to 60 percent by Weight of said vehicle of a member selected from the group consisting of the reaction product of Z-hydroxymethyl-S-norborene with maleic acid, the reaction product of Z-hydroxymethyl-S-norborene with maleic anhydride and the reaction product of 2-hydroxy methyl-S-norborene with fumaric acid, from about 10 percent to about 20 percent by Weight of said vehicle of an adduct of 2-hydroXymethyl-5-norborene with an unsaturated drying oil fatty acid and up to about 10 percent by weight of an unsaturated fatty acid.

4. An improved vehicle for coating compositions comprising, a mixture of about 35 percent by weight of said vehicle of a drying oil, about percent by weight of a member selected from the group consisting of the reaction product of Z-hydroxymethyl-S-norborene with maleic acid, the reaction product of Z-hydroxymethyl-S-norborene with maleic anhydride and the reaction product of 2-hydroXymethyl-5-norborene with furnaric acid, and about 10 percent by weight of said vehicle of an adduct of Z-hydroxymethyl-S-norborene and a drying oil fatty acid.

5. An improved vehicle for coating compositions comprising a mixture of a drying oil, said drying oil being present in a sufiicient amount to impart flexibility up to about 40 percent by weight of said vehicle, from about 10 percent to about 80 percent by weight of said vehicle of a member selected from the group cosisting of the reaction product of 2-hydr0Xymethyl-5-norborene with maleic acid, the reaction product of Z-hydroxymethyl-S- norborene with maleic anhydride, and the reaction product of 2-hydroxymethyl-S-norborene with fumaric acid, and from about 5 percent to about 20 percent by weight of said vehicle or an adductof Z-hydroxymethyl-S-norborene and a drying oil fatty acid.

6. An improved vehicle for coating compositions comprising a mixture of a drying oil, said drying oil being present in a suificient amount to impart flexibility up to about 40 percent by weight of said vehicle, from about 50 to 60 percent by Weight of a member selected from the group consisting of the reaction product of Z-hydroxymethyl-S-norborene with maleic acid, the reaction product of 2-hydroxymethyl-S-norborene with maleic anhydride and the reaction product of Z-hydroXymethyl-S- norborene with fumaric acid, and from about 5 percent to about 20 percent by Weight of said vehicle of an adduct of 2-hydroxymethyl-S-norborene and a drying oil fatty acid.

*7. An improved vehicle for coating compositions comprising a mixture of an unsaturated drying oil, said drying oil being present in a sufficient amount to impart flexibility up to about 40 percent by weight of said vehicle from about 50 percent to 60 percent by Weight of said vehicle of a member'selected from the group consisting of the reaction product of Z-hydroxyrnethyl-5-norborene with maleic acid, the reaction product of 2-hydroxymethyl-S-norborene with maleic anhyd-ride and the react-ion product of Z-hydroxymethyl-S-n-onborene with fumaric acid, and from about percent to about percent by weight of said vehicle of an adduct of Z-hydroxyrnethyl- 8 S-norborene with a drying oil fatty acid, said drying oil fatty acid being a member selected from the group consisting of the fatty acids of soy-bean oil, linseed oil, safflower oil, and mixtures thereof.

8. An improved vehicle for coating compositions comprising a mixture of an unsaturated drying oil, said drying oil being present in a suflicient amount to impart flexibility up to about percent by Weight of said vehicle, from about percent to percent by Weight of said vehicle of a member selected from the group consisting of the reaction product of 2-nydroxymethyl-5-norborene with maleic acid, the reaction product of Z-hydroivmethyl-S-norborene with maleic anhydride and the reaction product of 2-hydroxyrnethyl-S-norborene with fumaric acid, and from about 1O percent to about 20 percent by weight of said vehicle of an adduct of 2-115 droxymethyl-S-norborene With a drying oil fatty acid,

said drying oil fatty acid being a member selected from.

References Cited by the Examiner UNITED STATES PATENTS 5/52 Nichols et al. 260617 1/59 Dean et al. 260-22 OTHER REFERENCES Condensed Chemical Dictionary, 6th edition (1961), page 327.

Cyclol, Interchemical Corp. Product Bulletin, New York, NY, February 1960, pages 15-18.

MORRIS LIEBMAN, Primary Exmniner.

JOSEPH REBOLD, JOHN R. SPECK, ALEXANDER H. BRODMERKEL, Examiners.

Claims (1)

1. AN IMPROVED VEHICLE FOR COATING COMPRISING, A MIXTURE OF FROM ABOUT 30 TO 40 PERCENT BY WEIGHT OF SAID VEHICLE OF AN UNSATURATED DRYING OIL, FROM ABOUT 50 PERCENT TO 60 PERCENT BY WEIGHT OF SAID VEHICLE OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF THE REACTION PRODUCT OF 2-HYDROXYMETHYL-5-NORBORENE WITH MALEIC ACID, THE REACTION PRODUCT OF 2-HYDROXYMETHYL-5-NORBORENE WITH MALEIC ANHYDRIDE AND THE REACTION PRODUCT OF 2HYDROXYMETHYL-5-NORBORENE WITH FUMARIC ACID, AND FROM ABOUT 10 PERCENT TO ABOUT 20 PERCENT BY WEIGHT OF SAID VEHICLE OF AN ADDUCT OF 2-HYDROXYMETHYL-5-NORBORENE WITH AN UNSATURATED DRYING OIL FATTY ACID.