CA1063746A - Solid paint - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Solid paint compositions having dimensional stability based on ion bonding and gel strengths ranging from 100 to 200 millimeter pen?tration are formed by interaction of certain polymers having acid group functionality with a sub-stantial excess in the order of 100-600 mole percent of a cross-linking reactant formed by solution of a metal hydroxide in a high dielectric polar solvent, said polymers being selected from (1) a polymer having a molecular weight ranging from 25,000 to 1,000,000 and sufficient reactive acid functional groups selected from the group consisting of carboxylic, sulfonic and phosphonic to provide an acid number from 25 to 6?? and (2) a mixture of a non-bonding NAD resin comprising a polymer having a molecular weight ranging from 25,000 to 1,000,000 dispersed as a 25 to 90 weight percent suspension in a non-polar non-solvent, and having no reactive functional group sites, with an ion-bonding curable resin having a molecular weight ranging from 1,000 to 7,000 and sufficient reactive acid functional groups selected from the group consisting of carboxylic, sulfonic and phosphonic to provide an acid number from 20 to 80.

Description

The present invention relates to a new type of paint product, namely, a solid paint having dimensional stabillty based on ~on bonding.
Various resin compositions consisting of homopolymers and co-polymers having partially neutral-ized carboxylic acid groups are known. These contain between 3% and 20% of carboxylic acid residues of which less than 50% of the carboxylic acid groups are neutralized with monovalent, divalent or trivalent cations. The prior art resins, known as ionomers, are desirable in industry be-cause they combine the utility of a thermoset polymer with the mobility and workability of the thermoplastic resin. Ionomers have lower densities than vinyl or cellulosic plastics and because of their similarity to polyethylenes find use as protective films in the food packaging industry. Ethylene-meth-acrylic acid co-polymers are discussed in U.S. Patents 3,266,272, 3,338,739 and in Belgium Patents 674,595 and 600,397. Ethylene~sodium acrylate copolymers are described in Netherlands Patent 6,511,920. Many of the desirable properties of these polymers such as stress-crack resistance, transparency, grease and abrasion resistance, low permeability, high elongation, high tensile strength, ; and low modulus are attributed in part to a type of ionic bonding.
It has now been discovered that solid paints having effective gel properties necessary to provide dimensional stability can be prepared by cross-linking certain reactive polymers with 'lion clusters" having polar molecule com-ponents. This type of ion bonding differs substantially from the solvent-free ionic bonding of the prior art compounds.
The present invention provides a solld paint composition having a gel strength ranging from 100 to 200 millimeter penetration and a dimensional stabil-ity based on ion bonding comprising the admixture of (a~ a polymer composition .~. . . . . . . - . . . . . ..................... . . . . .
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selected from the group consi ting of a (1) a stabilized non-aqueous di~persion of a polymer having a molecular weight ranging from 25,000 to 1,000,000 and sufficient reactive acid functional groups selecte~ ~rom the group consi~tlng of carboxylic, sulfonic, and phosphonic groups to provide an acid number from 25 to 60, said polymer dispersed in a non-polar non-sol~ent as a 25 to 90 weight percent suspension;
and t2) a mixture of a non-bonding NAD resin comprising a stabilized di~persion of a polymer having a molecular weight ranging from 25,000 to 1,000,000 dispersed as a 25 to 90 weight percent suspension in a non-polar non~
solvent, sald polymer having no reactive functional group sites, with an ion-bonding resin ~olu~ion of a curable polymer re~in having a molecular weight ranging- from 1,000 to 7,000 and sufficient reactive acid functional groups selected from the -group cc~nsisting of . .

carboxylic, sulfonic and phospho~ic to provide an acid number from 20 to 80, said resin dissolved in a non-polar solvent to provide a 25 to 90 weight percent solution;
the proportion by weight of non-bonding ~D resin to ion-bonding being from 2:1 to 8:1; (b~ an ionic cross-linking agent selected from the group consisting of metal hydroxide, metal oxide, metal alkoxide, ammonium hydroxide, or an organic cation former dissolved or suspended in a polar solvent of high dielectric strength to provide a 10-50 weight percent solution or suspension;said metal hydroxide preferably selected from the group consisting of sodium, potassium, lithium, barium, calcium, manganese and mag-nesium hydroxides; (c) a metallic drier in amounts from about 0 to 5 weight percent based on the total weight of polymer in composition (a)(l) and about 0.2 to 5 weight percent based on the total weight of polymer in composition (a)(2); and (d) an opacifying pigment or colorant wherein said composition contains from about 100 to 600 mole percent of ionic cross-linking agent per mole of aci~ func-tional group.
The invention further provides a process for ; preparing a solid paint having dimensional stability based on ion bonding and a gel strength from about 100 to 200 millimeter penetration which comprises (a) dissolving or suspending a polymer resin of the type shown in a(l) or(2) above to form the respective polymer composition or : mixtures thereof in such proportion to provide sufficient ; reactive acid functional groups necessary for the indicated ;; dimensional stability when cross-linked by ionic cross-30 linking agents; (b) mixing pigments, fillers, or colorants : 4 . . . . .
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and 0 to 5 weight percent of a metallic drier into the resin solution or disperslon; (c) adding thereto under vigorous stirring a 20 to 30 weight percent solution or suspension of an ionic cross-linking agent as defined above in a polar solvent of high dielectric strength to provide a 10-15 weight percent solution or suspension containing 100 to 600 mole percent of the amount of ionic cross-linking agent required to neutralize said reactive acid groups of the resin. The process may be followed by aging the mixture for 3 to 25 hours at a temperature between 15 and 70 degrees CentigradeO
The invention further provides paint sticks encased in a removable skin or bars based on the above compositions and processes.
Solid paint compositions having dimensional stability and desirable paint characteristics result fxom the inter-action of certain polymers~ having reactive functional groups, with certain cross-linking agents formed by dissolving an ionic cross-linking agent in a high dielectric polar solvent.
Cross-linking of the p~lymer chains takes place through 'lion clusters" composed of multiple ions associated with polar solvent moleculesO By the term solid paint is meant a paint which has sufficient dimensional stability under storage conditions, i.eO, is self-supporting, yet could be utilized as a stick of paint (analagous to a segment of hard bu~ter or cheese). Such solid paint can advantageously be applied by hand to the surfaces usually protected by paint and coating products without the use of a brush or roller.
For practic~l and protective purposes, such stick of paint will generally be contained in a skin or covering suitable ,!
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for storage. Advantageously such protective cover will have a closeable opening, said covering being distinct ~rom the nature of an applicator in the usual sense. The solid paint can be used by placing the paint stick in contact with the surface to be painted followed by the usual vertical and lateral movements across the substrate whereby a non-sagging air-curable paint film is deposited thereon. The shear provided by drawing the paint stick over the surface to be painted is sufficlent to cause the solid paint to deform to a flowable coating at the point of contaatO Such a solid paint coating is one that possesses the desirable properties of adhesion, flow and uniform converage of the surface. It ; is assumed that the solid paint of the present invention will contain the usual pigments, fillers, driers, bondin~
agents, and other additives to provide films havin~ desirable properties of gloss, color, and hiding power. It is anti-cipitated that such a solid paint could be fabricated in blocks or sticks having widths ranging from 1/8" to about 8 feet or larger, thus, also allowing use in industrial applications such as, for example, coil coating of metal~
When the curable resin is a stabilized dispersion of a polymer in a non-polar non-solvent medium as shown in a~l) above, the resins useful in the present invention include homopolymers and copolymers and mixtures thereof having appropriate functional groups either built into the polymer chain or grafted thereto by the usual graft techniques. Such resins include but are not limited to polyethers, unsaturated polyesters, polyurethanes, poly-acrylates, vinyl resin and chlorin~-substituted vinyls as well as other combinations known to the art. The '~:
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particular reactants and quantities are chosen to produce a resin havlng pendant functional substituents which are capable of further reactions with ionic reagents to form gels of proper dimensional stability and gel strength.
Desirable application properties result when the gel strength is from about 130 to 210 and preferably from 150 to 195 mm when measured 25 hours after gelling. Gel strength is recorded in mlllimeter units using a Universal *
penetrometer - lower the penetrcmeter reading, the higher the gel strength.
For the a~l) type of resin formulation used in the practice of this invention, it is essential that the particular resin be insoluble or only lightly swelled by the non-solvent, as is necessary for any non-aqueous dispersion, and that the resin have pendant reactive groups which are readily ionizable. Such ionizable groups include both cationic and anionic reactive functions. PreferaDl~, anionic functional groups used to modify the resin are the sulfonic, phosphonic, and carboxylic types. The carb-oxy~ic acid functionality is especially preferred since a varlety of polymers having such reactive ionizable groups can be readily purchased or synthesized. Preferred resins are copolymers of unsaturated hydrocarbons and unsaturated acids having molecular weights in the range of 100,000 to 25 300,000. Especially useful resins for the practice of this invention are acrylic acid esters and vinyl polymers having a particle size range of from 0.01 to 30 microns.
Acrylate and methacrylate copolymers having terminal carboxy functionality are especially preferred and are illustrated in the best mode examples. ~on-aqueous ~ Trademark . - . .-~ 7~

dispersions (NADs) known to the art and partlcularly u~e~ul in the practice o~ this invention tif these are modified to have ionizable sites on the ~urface) include those described by Dowbenko and Hart, Ind. Eng. Chem. ProdO Res. Develop., Vol.
12, No. 1, 1973 at pages 14-28. ~n the ~ormation of such NADs the choice and level of stabilizer is eminently important to provide solld paints having desirable application flow and coalescense characteristics. Other u~eful NAD resin include those derived from poly(methyl methacrylate), polyacrylate 1~ and polymeth_acrylate resin and copolymers of these derived through addi~ion polymerization with oleins, such as ethylene, vinyl ethyl ether, vinyl acetate, hydroxyethyl acrylate an~ 2-hydroxypropyl methacrylate.
The polymer resins use~ul in thls aspect of the inven-tion can be prepared by solution polymerlzation followed by dispersion in a non-solvent or by dlspersion polymerization.
The first meth~d involves polymerizing the monomer or co-mono- -mers and other intermediates under free radical conditions at a temperature ~f about -50 to ~250F. to yield a resin

2~ hæving an acid value (AV) ranging from 20 to 80 and preferably from 25 to 60. The second and pre~erred method in~olves poly-merizing the monomer or comonomers and other intermediates in - a non-solvent under free radical conditions at a temperature of about -50 to +250F~ to yield a resin dispersion with the desirable acid value.
- The abové described polymers having ionizable reactive groups are dispersed in a non-polar non-solvent to provlde a dlspersion ~aving non-volatile ~N/~) content .
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of from about 10 to 90 and prefexabLy from 30 to 60 welght percentO Especlally preferred are dlspersions of 50% N/V.
Suitable non-~olvents include both aroma~ic and allphatic type hydrocarbons which are sele~ted based on the particu-lar resin, the functlonality on Isaid resin and the nature ofthe ionic reactant. In general suitable non-solvents are hydrocarbons having a boiling polnt of about 100 to 400F.
and which contain up to twelve carbon atom90 These include hexane, heptane, octane, nonane, decane, dodecane and mix-tures thereof. Preferred hydrocarbons are the various octane~because o thelr suitable evaporation rate~O Mineral spirits is an especially preferred solvent because of its availability and the desirable properties of the resultant solid palnt.
For some resin systems aromatic hydrocarbons such as toluene or xylene may be usedO
It i~ recognized that NAD resins can be suitably formulated with ~arious stabilizers known to the artO The func~ion of these stabilizers is primarily to prevent the ; resin particle from coalescing on storage and during ~ormu-lation into solid paint products~ Useful stabilizers include those described and referenced in the above noted article by Dowbenko and ~artO Polyene stabilizers which are useful for certain solid paint compositions include low molecular weight polybutadiene, grafted to a backbone of an acrylic copolymer.
For the instant solid paints NAD resin stabllized by copolymer~
of methyl methacry`late and glycldyl methacrylate and further reacted with 12-hydroxystearic acid andfor poly t~au~Yl me~h-acrylate) are especially preferredO
It is unde~stood that the non-solvent, resin~

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and proportions of each will vary and depend on the type of resins, stabilizers, non-solvent, illers and other addi-tives needed for a particular end-product solid paint.
The additives, driers and other u3ual dispersant aids are preferably blended with the r~esin dispersion using a Cowles agitatorO The order of addition is usually not critical. ~he typical solid paint formulations as described herein are of the latex type non-aqueous resin dispersion and do not usually require specific drier components to give suitable film properties; when driers are added they are used in quantities less than 2 percent and preferably less than 1 percent per weight of total composition. The drlers are added for the small amount of oil or alkyd that is normally added to the formulation to aid dispersion of the pigment and to ai,d in the coalescence of the film.
~fter application the resin particles coalesce and fuse to give a dry film in matter of minutes~
The curable polymer resins useful in the present invention in mixture (a)(2) include h~mopolymers and ao-polymers and mixtures thereof having appropriate functionalgroups either built into thepolymer chain or grafted thereto by the usual ~ra~t techniques. Useful resins include but are not limited to polyethers, polyesters, unsaturated polyesters, polyurethanes, polyolefins, polyacrylates, polyhydrocarbons derived from aliphatic and aromatic hydrocarbons having ~ unsaturation, vinyl resins and chlorine-substituted vinyls as well as other combinations known to the art. The particluar reactants and quantities ; are chosen to produce resins having pendant and/or terminal ,~
functional substituents which are capable of further ~' ~ .
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reaction with ionic reagents to form yels of proper dimensional stability and gel strength. Desirable application properties result when the gel strenyth is from about 100 to 190 and preferably from 135 to 180 when measured 25 hours after gelling. Gel strength is recorded in millimeter units using a Universal Penetrometer* - the lower the pentrometer reading the higher the gel strength. Reyardless of the type of resin used in the practice of this invention, it is essential that the particular resin be soluble in a non-polar solvent and that the resin have pendant and/or terminal functional reactive groups which are readily ionizable. Such ionizable groups include both cationic and anionic reactive functions.
Preferably, anionic functional groups used to modify the resin are the sulfonic, phosphonic and carboxylic types. The carb-oxylic acid functionality is especially preferred since a variety of polymers having such reactive ionizable groups can be readily purchased or synthesized. Preferred reaction products are those obtained from the combination of carboxylic acid substituted polyesters and alkyd polyesters having molecular weights in the range of from about 1000 to 7000 which contain from about 1 to 4 reactive functional groups per each 2~0pO unit of molecular weight. Polyesters and p~lyether5 . ~,.,~
having molecular weights in the range of 400-2000 and,whic~ y:i~ld solid paint~ of desirable gel properties are especially preferred. Alkyd resins m~fie~ with fatty acid groups and having terminal carb~xylic func-tionality are exemplified in the best mode Examples. In the case of polyolefins, polyacrylates and other systems where no air-curing will occur, a higher molecular weight of the order of lOO,ooo is usually necessaryO However, 1 to 4 reactlve functional groups are still required per *Trademark .. .

2,000 unit of molecular weight. The alkyd resins useful in the practice of this invention are prepared by polymerizing the polymer monomers and ~ther intermediates in a fusion cooX at a temperature of about 400-600F. to yield resins having an acid value (A.V.) ranging from 30 to 55 and pre-ferably 41 + 2. Certain 'longer' oil resins as exemplified hereafter in Examples l and 2 are polymerized at 450F. to an A.V. of 43Ø
The above described polymers having ionizable reactive groups are dissolved in sufficient non-polar solvents to provide solutions ha~ing non-volatile (N.V.) contents of from about lO to 90 and preferably from 35 to 60 weight percent. Expecially preferred are solutions of 50~ N~V.
Suitable non-polar solvents for dissolving the polymer 15 include both aromatic and aliphatic-type hydrocarbons and ;~
are selected based on the particular resin used, the ~unc-tionality on said resin, and the nature of the ionic reactant.
In general, suitable solvents are hydrocarbons having a boiling point of about 125 to 400F. and which contain up to twelve carbon atoms. These include hexane, heptane, oc~ane, nonane, decane and mixtures thereof. Preferred hydrocarbons are the various octanes because of their suitable evaporation rates. Mineral spirits is an especially preferred solvent because of its availability and the desirable properties of the resultant solid paint. In certain cases aromatic `~ hydrocarbons such as toluene and xylene can advantageously be used and are especially valuable in dissolving the higher molecular polymers.
The polymer formulations shown in a(l) (stabilized dispersion in a non-polar non-solvent~ or the mixture of a~2) . .

are next combined with the ionic cross-linking agents dissolved in a high dielectric polar solvent~
Suitable ionic cross-linking reactants are usually of the inorganic salt variety which produ_e on solution specific cations or anions capable of combining with the terminal reactive groups of the resin to form ion clusters responsible for gel formation. Such clusters, s~hich contain the high dielectric polar solvent molecules, act as reversible cross-links to join the reactive resin molecules in webs thus imparting gel strength and dimen-sional stability to the resultant solid paint. ~hen the reactive terminal sites on the polymer are carboxylic acid groups (-COQH), the preferred cross-linking reactants are alcoholic solutions of mono, di and txivalent metal hydroxides.
Such cross-linking reactants include the oxides and hydrox-ides of sodium, potassium, lithium, barium, calcium, manganese and magnesium. Equally effective cr~ss-linking agents are the corresponding metal alkoxides i.e. sodium methylate.
In some cases ammonium hydr~xide and organic cation formers such as tetramethyl-ammonium hydroxide can be used as cross-linking reactants. The cross-linking gelation derived by reacting ~odium hydroxide with the above described resin molecules having terminal or pendant carboxyl groups is especially preferredO Suitable gels result when an effective amount of the cationic base combines with the free carboxylic acid functionality. In every case an amount of base substantially in excess of ~he amount required for neutralization is necessary to be effective.
By substantial excess is meant from about 100-600 mole 0 percent of ionic reactant dissolved in the polar solvent.

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Although the amount of excess varies with each particular resin system and depends upon the molecular weight of the resin, the number and type of the ionizable functional group and on the valence of the metal hydroxide, satisfactory gels result when the ionic reagent is used at 100-600 mole percent excess. When amounts less than 100 mole p~rcent are used the resins do not exhibit the required dimensional stability. When amounts greater than 600 mole percent are used the resins do not exhibit the ~esired flow and surface characteristics. For gel formation the metal hydroxide or other ionic cross-linking reactant is added as a 10-50 weight percent solution in the high dielectric polar solvent to the pQlymer resin formulations. Preferred s~lid paints were obtained by using 100 to 250 mole percent sodium hydroxide based on the molar content of the reactive functional group i.e. moles free COOH.
The polar solvents useful in dissolving the ionic cross-linking agents are generally those solvents having a dielectirc constant greater than 10, include aliphatic alcohols containing one to ten carbGn atoms and one to two hydroxy groups. Although Cl 8 aliphatic alcohols are usually preferre~, gIycols containing the similar carbon chains are sometimes useful in producing desirable gel properties in the resultant solid paint. Useful alcohols include methanol, ethanol, isopropanol, n-pro-panol, the normal and isomeric butanols, pentanols, ` hexanols, heptanols, octanols, as well as the corresponding glycols derived therefrom~ Methanol is the preferred alcohol because of its costs, availability and the favorable solubility of the ionic reagents therein, In .~

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certain applications it is preferred to use glycols or mixtures of glycols and alcohols as the plasticizer carrier for the ionic reactant. Preferred glycols are ethylene glycol and propylene glycol although for certain resins the higher glycols such as pentanediol and hexanediol act in the nature of a plasticizer and pxovide desirable lubricity. Additional high dielectric polar solvents useful in the practice of thi~ invention include, water, formamide, dimethylformamide, and d~methylsulfoxide.
The metal driers suitable for the instant solid paint compositions are those known to the art and include the metal salts and/or esters of various organic carboxylic acids containing up to 30 carbon atoms and mixtures thereof.
The metal salts of cobalt, zinc, zirconium, magnesium, aluminum and manganese prepared from branched chain C8 12 carboxylic acids are preferred driers. The typical paint formulations, as described herein, required unusually high amounts of metal drier of the order of about 0.5 to 5 percent based on the weight of the resin. The amount of drier needed depends to some extent on the oil or other source of double bonds used in the paint system i.e. number and type of double bonds available.
A further aspect of this~invention m~ludes the use of resins having pendant and/or terminal functional reactive groups other than the acid or carboxylate groups. When the ionizable group on the polymer is a cationic group precursor instead of an acid or carboxylate group, the ionic cross-linking reactant will be an anion precursor. Examples of cation formers are (1) primary, secondary, tertiary and cyclic amines, which react with hydrogen halides and .

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~ 7~hydrocarbon halides to give quarternary halide~ to givs quarternary salt~; (2) substituted phosphines which com-bine with halides to give phosphonium salts; (3) sulfides which react with alkyl halides give sulfonium salts;
(4) cyclic ethers which react with acids give oxonium salts. Examples of anion source cross-linking agents include acetic acid, nitric acid, hydrochloric acid, sul-furic acid, and relatively short chain organic multibasic acids such as oxalic, malic, succinic, maleic, a~ipic acids and corresponding anhydrides.
For industrial coating purposes, the block of solid paint i9 advantageously contained in conventional holding and applicator devices. Such devices, which will vary with the nature of the substrate to be coated and will be adaptable to continuou~ application, usually include a device for holding the solid paint and a mechanism fox adjusting the pressure placed on the paint block to allow proper deformation to provide a fluid coating and film of required thickness. Increasing the pressure applied to the solid paint will result in the deposit of a heavier coating. Although the instant solid paints are capable of air drying, it is contemplated that for industrial coating applications curing o~ the film may be accele~ated by the use of heat, and other energy techniques known to the art.
The following specific examples illustxate only a limited number of embodiments; accordingly, the invention is not limited thereto. All parts and percentages being by ~eight unless otherwise indicated. The driers used were commercially available conventional driPrs. The .~

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"mineral spirits" and the "odorle!ss mineral spirits" had a boiling range of 300-400F. and 345-410F, respectively.
Molecular weights reported are nul~er average molecular weights unless otherwise specifie!d. Examples 1 through 7 S exemplify the (a)(l) type polymer dispersion formulations.
Examples 8 through 12exemplify mixtures of the (a)(2) type of polymer solution formulations used in conjunction with non-bonding (no reactive acid functionality) non-aqueous dispersions. PREPARATION OF N~D RESINS
The NAD resins 1, 2, 2A, 3 and 4 were prepared by addition polymerization of various monomers in the presence of non-solvents, free radical initiators and various stabilizers in the rela~ive proportions shown in Table III.
A small portion of the monomers is charged to the polymer-ization kettle with the non-solvent and about 50 percent of the desired stabilizer and polymerization is initiated by heating to a reflux temperature in the order of 70-80C.
Thereafter the remaining monomers, stabilizer (30%) and free radical initiator are added with ethyl acrylate in one feed stream while the acidic component i.e. methacrylic acid and remaining stabilizer (20~) is added in a separate feed stream over a two to three hour addi~ion period at the reflux temperature. Additional initiator (1/4 total amount) is introduced in ethyl acetate in two portions over a further period of 2 hours. After refluxing for an additional two hours, low boiling solvent is removed by heating to approximately 90C. For this present invention it is important that the NAD be prepared with the carboxylic sites (or other ionizable sites) at the surface of the particle (or at least the majority be available to the '~ ' : ~, . - . . , ~ . .
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surface) in order to provide the external acid sites on the suspended polymer particles. In this case the acid feed was started 10 minutes after the other monomer feed was commenced; and the acid feed was completed approximate~y 10 minutes after the other monomer feed wa~ terminate~.
Variants of the condit~on~ shown in this example may be used as long as a stable NAD is produced where the acid sites are available for gelling and not buried in the body of the particle. It is recommended that an acid value determination be made on the NAD.
TABLE I~I - GENERAL MAKEUP OF NAD POLYMERS
(PARTS BY WEIG~TS) NAD-l NAD-2 NAD-2A NAD 3 NAD-4 Vinyl Acetate 227 142 14~ 142142 Ethyl Acrylate 104 212 237 237212 NAD Stabilizer 76.4 76 76 57.5 58 Methacrylic Acid 28 26 ^38 3018 Mineral Spirits 300 300 300 300300 Hexane 300 300 300 300300 Azobisisobutyronitrile7.5 7.5 7.5 7.5 6 Ethylacetate 25 25 25 2525 Non-Volatile Content (final1 42.447.5 49 49.8 58.1 Acid Value NAD 44.739O5 55.5 43.7 28.5 P~EPARATION OF NAD STAB~LIæER
1000 Parts 12-hydroxystearic aci~, 3.5 parts tetra-i30propyl titanate and 60 parts xylene were heated togetker at 200C. under a nitrogen atmosphere. The reaction was monitored by collecting the by-product water. The resulting product had an acid value of 34.2 (calculated 33).

This product was further reacted at 90C. under nitrogen with 82.3 parts glycidyl methacrylate using 400 parts methyl ethyl ketone and 10 parts triethylamine to yield a - second intermediate having an acid value of 4.3 and a non-volatile content of 93.4. (The methyl ethyl ketone is stripped off at the end of the reaction). This second intermediate (321 parts1 was polymerized under free radical '~
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conditions with 225 parts methyl methacrylate in the presence of ethyl acetate (500 parts), dodecyl ercaptan (1.5 parts) and azobisisobutyronitrile (3.0 parts) free-radical initiator.
The stabilizer was obtained in 98 percent yield.
PREPARATION OF ALKYD MODIFIER
A polyester alkyd conden3ation polymer was prepared by condansing 136 parts pentaerythritol, 560 part3 dehydrated ca~tor oil fatty acid, 135 parts Azelaic 1110 dimer acid, and 168 Parts Empol 1014 dimer acid in a fusion cook at 460F. to produce an alkyd resin having reactive carboxylic acid functionality, acid value of 41~ and a molecular weight of 1500.

Resin NAD-2 (87 parts of 50 N~V suspension in mineral spirits) was formulated and blended to a #6 Hegman grilld with 30 parts of alkyd modifier and 120 parts titanium dioxide No driers were used in the formulation.
In a similar fashion resin NAD-2A (94 parts of 50 N/V in mineral spirits) was blended with 25 parts alkyd modifier and 115 parts titanium dioxide. Various weights of sodium hydroxide (25% solution in methanol) were then adde~ to form the solid paints identified in Table I as Experiment lA, and lB. Solid paints lA and lB with respective gel strengths of 164 and 185 exhibited dimensional stability, had good application characteristics and gave a satisfactory dry coating on application to a test panel. By good application characteristics it is implied that on drawing the paint across the test panel a uniform film of paint is transferred to the panel ancl the work required to accomplish this is not excessive.
~n a third palnt, resin NAD-2 (94 parts of 50 -lg -. ' : . :

N/V in mineral spirits) was blend~d with 25 parts alkydmodifier, 115 parts titanium dioxide, 0.5 parts cobalt drier (12 percent cobalt), 0.5 parts mangane~e drier (8 percent metal), 4.0 parts zirconium drier (12 percent metal); the driers are added for the alkyd modifisr.
16.1 Parts sodium hydroxide (25% solution in methanol) were then added to form the solid paint identified in Table I
as experiment IC. This product exhibited dimensional stability, had good application characteristics and exhibited an excellent dry on application to a test panel.
TABLE I Percent Neutralization Gel Exp. Parts NaOH Calculated on Moles Strength*
NO. Resin Added Carboxylic Acid (24 hours) 15 IA NAD-2 15.8 175 164 IB NAD-2A 16.1 175 185 IC NAD-2A 16.1 175 183 IIA NAD-l 12.8 200 135 IIB NAD-l 12.8 200 195 IIC NAD~l 12.8 200 221 20IIIA NAD-2 11.2 200 240 IIIB NAD-2 14.0 250 190 IVA NAD-3 14.0 225 150 IVB NAD-3 16.2 225 2~0 25VIA NAD-2 15.3 175 160 *Average of three readings .
Resin NAD-l (110 parts) was formulated and blended to a ~6 He~man grind with 100 parts titanium dioxide, 0.015 -~ 30 parts cobalt drie~r (12% cobalt), 0.10 parts zirconium drier (12~ zirconium) in three formulations A, B and C containing 5, 10 and 15 parts of tall oil alkyd (100% solids) respective-ly. Various weights of sodium hydroxide were than added a8 a 25 weight percent solution in methyl alcohol to form the . .

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solid paints identified in Table I as Experiment IIA, IIB
and IIC. Solid paints IIA and IIEI with gel strengths of 135 and 195 respectively exhibited satisfactory application characteristics. Solid paint IIC exhibited poor application characteristics. All three solid paints exhibited dimensional stability and gave a satisfactory dry coating on application to a test panel.

Resin NAD-2 (105 parts) was ~ormulated and blsnded to a #6 Hegman grind with 100 parts titanium dioxide, 0.015 parts cobalt drier (12~ cobalt), 0.10 parts zirconium drier (12% zirconium) and 10 parts tall oil alkyd (100%). Various weights of sodium hydroxide were added as a 25 weight percent solution in methyl alcohol to form solid paints`identified in Table I as Experiments IIIA and IIIB. Solid paint IIIA with a gel strength of 240 had inferior application characteristics (tQo soft, heavy drag) as opposed to the good characteristics of solid paint IIIB having a gel strength of 190. Although the paints exhibited dimensional stability the film appearance was poor due to unsatisfactory coalescence.

Resin NAD-3 (101 paxts) was formulated as indicated for NAD-2 in Example 1 above using 10 parts tall oil in one case and replacing the tall oil with 15 parts of the polyester alkyd modifier in the second case. The corre-sp~ing solid paints prepared by the addition of a 25 weight percent solution of sodium hydroxide in methanol are iden-tified in Table I as solid paints IVA and IVB respectively.
Solid paints IVA and IVB with gel strengths of 150 and 200 e~bited d~hsional stab~l~ty and satisfactory-application and film ,~, .........
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characteristics.

Paint blocks of approximate ize 4" x 6" formed from the above described solid paint were stored using a thin Saran (Trademark of the Dow Chemical Company) envelope for a period of six months. Application of these paints to a test panel after the storage period showed no detecta~le deterioration of the application and film characteristics. Additionally solid paints prepared from the same resins but having acid values in the range of from 25 to 60 gave acceptable solid paint characteristics. The best application properties were obtained when the gel strength as measured by the Universal penetrometer was between 130 and 195 mm. although formulations having gel 15 strength of from 100-130 and 195-200 gave effective solid paints with somewhat less desirable characteriStics.

Resin NAD-4 ~94 parts of 50 N/V suspension in mineral spirits) was formulated and blended to a #6 Hegman 20 grind with 30 parts of alkyd modifier, 100 parts titanium dioxide, 15 parts calcium carbonate, 0.65 parts cobalt drier (12 percent cobalt), 0.65 parts manganese drier (8 percent met~l~, and 6.0 parts zirconium drier (12 per-cent zirconiumi. Sodium hydroxide (25% solution in methanol) was then added to form the solid paint identified in Table I as experiment VIA. This solid paint had good application characteristics r exhibited dimensional stability and gave a dry film on a test panel.

A 'non-aqueous dispersion' was prepared without :`

.. ..

t7~;

using added stabilizer. A monomer ~ystem was chosen ~o that it would be partially swelled in the non-polar solvent, this being enough to maintain stability of the dispersion.
In this case, 780 parts butyl acrylate, 100 parts 5 methacrylic acid, 8 parts dodecyl mercaptan, 12 parts azobisisobutyronitrile, and 600 parts mineral spirlts were charged to a reactor. The charge was brouqht to and held at 80C. for 5 hours. Conversion was 97%, the acid value of the dispersion was 43.7. The theoretical acid value is 72, 10 i.e. a certain amount of the acid is buried when this method of preparation is used.
Two aliquots each of 180 parts (60 percent N/V
resin) were mixed with 25.0 parts (200% neutralization) and 37.5 parts (300% neutralization3 of sodium hydroxide as 15 a 25 percent solution in methanol. Both products exhibited dimensional stability; however, the application character-istics were poor.
~ This product is not a true NAD and could best be descirbed as a very coarse dispersion. This does point 20 out, however, the possibility of internal stabilization through a judicious choice of monomers. This system is not as stable and many of the ionizable sites are buried.

PREPARATION OF NON BONDING NAD RESIN NON AQUEOUS DISPERSION
NAD resins of the non~onding type (i~e. wlthout 25 reactive functional sites - no gelling sites) were prepared by the addition polymerization of various monomers in the presence of non-solvents, free ra~ical initiators a~d stabilizers, one example of which is given in the table shown below. A small portion of the monomers is charged f 30 to the polymeri~ation kettle with the non-solvent (mineral ' :" :' , , . , " . ' ' : ' ' . . . . ~ ' " ` ` ' 37~

spirits etc.) and about 50 percen1: of the desired stabilizer and polymerization is initiated by heating to 75-80C. After approximately 15-30 minutes, feeding of the remaining mono-mers, stabilizers, etc., is commenced and continu~d over

3-4 hours. The batch, held at reacting temperature for an additional hour, is then cooled to yield a milky dispersion having a low viscosity (100-200 cps~ and a 46 percent by weight non-volatile content.
Materi~l Char~ Feed 10 ethyl acrylate 46 253 ~;
methyl methacrylate 9 64 ``
odorless minera~ spiritsa 300 76 mineral spirits 40 10 stabilizer (38%) 37.5 37.5 15 azobis isobutyronitrile 1.5 4.0 a) boiling range 174-210C.
b) boiling range 149-204C.

Although a wide variety of NAD Stabilizers of the type exemplified in Examples 1-7 are suitable for the pre-paration of Non-bonding NAD re~ins the following illustrates the preparation of a particularly de~irable and useful stabilizer:
goo Parts 12-hydroxystearic acid, 3.1 parts tetra-isopropyl titanate and 90 parts odorless mineral spirits were heated together at 210C und~r a nitrogsn atmosphere.
The reaction was monitored by collecting the by-product water.
The resulting product had an acid value of 36 (calculated 33?- -The product was further reacted at 190F. under nitrogen 30 with 97.6 parts glycidyl methacrylate using 10 parts tri-ethylamine as a catalyst. This rea~tion product had an acid value-of 1.8 and a non-volatile content of 91Ø This ., ..

,.. . ,, ~ .

-j 37 LR~ ~

second intermediate (440 part~) was polymerized under free radical conditions at 85C. using 2.0 parts azobis isobutyro-nitrile with 300 parts methyl methacrylate in the presence of odorless mineral spirits (800 parts~. The product was reduced wîth 300 parts odorless mineral spirits. The final non-volatile content by weight was 38%.

Alkyd Resin J, having bonding sites and particularly useful in preparing solid paints in combination with the non-bonding NAD Resin NON-AQUEOUS DISPERSIONS shown in Example 8, was prepared by polymerizing a mixture of 295 parts trimethylol propane, 690 parts dehydrated castor oil fatty acid, 340 parts Azelaic dimer (AZELAIC 1110) and 423 parts EMPOL 1014 at a temperature of 250C. to an acid value of 42.
15 The resulting resin gives a Gardner-Holt viscosity of Z2 ,~ EXAMPLE 11 Solid paints were prepared from Resin J using the following formulations:
Materials Parts Experiment No. 1 2 Non-bondin~ NAD Resin 100 100 Ion-Bonded Resin J 25 30 Rheox 1 1 1.2 Titanium Dioxide 100 100 Min-U-Sil 10 10 10 Celite 499 10 10 Cobalt drier (12.0 percent metal)0.65 0.70 Manganese drier (9.0 percent metal)0.65 0.3 ' 30 . Zirconium ~rier (12.0 percent metal) 2.5 3.0 Methanol 2.0 1.0 Sodium hydroxide-methanol 6.0 7.0 (24 percent sodium hydroxide) % neutralization 195 195 ; gel strength (mm.) 160 150 The materials were added in the order shown, except that : .

~.
'' ; 'C~

half of the quantity of NAD (50 parts) were held out until after the grind was achieved (i.e. all the pigments were added). Grind was 5 1/2 hegman. After the remaining NAD
was added and the batch cooled, the driers were addedO The S driers were allowed to mature fox 1/2 hour before the sodium hydroxide - methanol was added with agitation under reduced pressure in a 'vacuum Cowles' to form a solid paint.
This manner of addition diminishes the chances of entrapping air into the 'final' solid paint.
Both paints exhibited dimensional stability. When rubbed (by hand) on a substrate, paint was transferred to the substrate forming a film. Both films exhibited dry over night.
The solid paints formed by combining Non-Bonding NAD resins with lesser quantities of ION-bonded resins of the IA type exemplified in Examples 1-12 and 22 are par-ticularly for the trade sales (consumer) segment of the coating industry as well as for commercial coating applications such as for maintenance coatings and coil 2~ coatingO The particular advantage of such combination and intercombination of ion-bonding and NAD resins (both bonding and bonding types) is that dimensional stability is retained withjless bonding sites while application and film characteristics are greatly improved.
~ 25 EXAMPLES 12 ., .
The change in the proportion of Non-~onding NAD
resins shown in Example 11 from 75 to 200 parts NAD resin per 25 parts of ion-bonded resin will yield equally ~atisfactory dimensionally stable solid paints.
3U The above Examples are illustrative of the best mode for the practice of this invention and are not to be construed as limitations thereon.

. i : .' . ~ :' . ' ,

Claims (13)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A solid paint composition having a gel strength ranging from 100 to 200 millimeter penetration and a dimensional stability based on ion bonding comprising the admixture of:
a) a polymer composition selected from the group consisting of:
(1) a stabilized non-aqueous dispersion of a polymer having a molecular weight ranging from 25,000 to 1,000,000 and sufficient reactive acid functional groups selected from the group consisting of carboxylic, sulfonic and phosphonic to provide an acid number from 25 to 60, said polymer dispersed as a 25 to 90 weight percent suspension in a non-polar non-solvent; and (2) a mixture of a non-bonding NAD resin comprising a stabilized dispersion of a polymer having a molecular weight ranging from 25,000 to 1,000,000 dispersed as a 25 to 90 weight percent suspension in a non-polar non-solvent, said polymer having no reactive functional group sites, with an ion-bonding resin solution of a curable polymer resin having a molecular weight ranging from 1,000 to 7,000 and sufficient reactive acid functional groups selected from the group consisting of carboxylic, sulfonic and phos-phonic to provide an acid number from 20 to 80, said resin dissolved in a non-polar solvent to provide a 25 to 80 weight percent solution; the proportion by weight of non-bonding NAD resin to ion-bonding being from 2:1 to 8.1;
b) an ionic cross-lingking agent selected from the group consisting of metal hydroxide, metal oxide, metal alkoxide, ammonium hydroxide, or an organic cation former dissolved or suspended in a polar solvent of high dielectric strength to provide a 10-50 weight percent solution or suspension;
c) a metallic drier in amounts from about 0.2 to 5 weight percent based on the total weight of polymer in composition (a)(2) and 0 to 5 weight percent based on the total weight of polymer in composition (a)(1); and d) an opacifying pigment or colorant;
wherein said composition contains from about 100 to 600 mole percent of ion cross-linking agent per mole of acid functional group.

2. The composition of claim 1, wherein the cross-linking agent is a metal hydroxide selected from the group consisting of sodium, potassium, lithium, barium, calcium, manganese and magnesium hydroxides, the polar solvent is selected from the group consisting of a C1-8 aliphatic alcohol, formamide and water; and the functional group is a carboxylic acid group.

3. The compositions of claim 1 and 2, wherein the polar solvent is methanol and the cross-linking agent is sodium hydroxide.

4. The composition of claim 1, having from 1 to 3 weight percent of organic acid metal salt drier, said metal being selected from the group consisting of cobalt, zinc, magnesium, aluminum, manganese and zirconium.

5. The composition of claim 1, wherein the polymer composition comprises a non-aqueous dispersion of a resin having a molecular weight of 100,000 to 300,000 and acid number 30-40 suspended in mineral spirits and the ionic cross-linking agent is sodium hydroxide which is present at 120-280 mole percent.

6. The composition of claim 5, wherein the non-aqueous dispersion is formed from a vinyl acetate-ethyl acrylate methacrylic acid terpolymer resin having a molecular weight of 100,000 to 300,000 and an acid number of 25 to 80 is reacted with 210-250 mole percent of sodium hydroxide as a weight percent solution in methanol.

7. The composition of claim 1, wherein the polymer com-position comprises a mixture of a non-bonding non-aqueous dispersion wtih an ion-bonding resin solution, the proportion of the former to the latter being from 2:1 to 4:1.

8. A process for preparing a solid paint having dimensional stability based on ion bonding and a gel strength from 100 to 200 millimeter penetration which comprises:
(a) dissolving or suspending a polymer resin of the type shown in claim 1, to form the respective polymer composition or mixtures thereof in such proportion to provide sufficient reactive acid functional groups necessary for the indicated dimensional stability when cross-linked by ionic cross-linking agents;
(b) mixing thereto pigments, fillers, or colorants and 0.5 to 5 weight percent of an organic acid metal salt drier into the resin solution;
(c) adding thereto under vigorous stirring a 20 to 30 weight percent solution or suspension of metal hydroxide in a C1-8 aliphatic alcohol containing 100 to 600 mole percent of the amount of metal hydroxide required to neutralize said reactive acid group of the resin.

9. The process of claim 8, wherein the resin of claim 1 (a) is a homopolymer or copolymer selected from the group consisting of polyester, unsaturated polyester, polyvinyl-chloride, polymethacrylate, polyacrylate, or mixtures thereof, wherein said reactive acid group is a carboxylic acid group.

10. The process of claim 8, wherein the resin is dis-persed in a non-polar non-solvent at a content of 30 to 60 weight percent in the presence of a stabilizer, said resin having a molecular weight of 25,000 to 1,000,000 and sufficient pendant or terminal reactive acid function-ality selected from the group consisting of carboxylic, sulfonic and phosphonic to yield an acid value in the range of 25 to 60.

11. The process of claim 10, wherein the resin is a homopolymer or copolymer selected from the group consisting of polyester, unsaturated polyester, polyvinylchloride, polymethacrylate, polyacrylate, or mixtures thereof, wherein said reactive acid group is a carboxylic acid group present in amounts from about 1 to 4 per 2,000 units of molecular weight.

12. The process of claim 8, wherein the resin composition of claim 1, (a) (2) comprises a non-bonding non-aqueous dispersion mixed with an ion-bonding resin solution wherein the ratio of ion-bonding resin is from 2:1 to 4:1.

13. A paint stick which comprises the solid paint according to claims 1 or 2, encased in a removable skin.