US2731375A - Metal building material - Google Patents

Description

Jan. 17, 1956 H. A. TOULMIN, JR 2,731,375

METAL BUILDING MATERIAL Filed Aug. 19, 1953 INVENTOR Heir/2y A T 0111mm JP:

ATTORNEY METAL BUILDING MATERIAL.

Harry A. Toulmin, Jr., Dayton, Ohio, assignor to Mid.-

landChemi cal Corporation, Dayton, Ohio, 3 corporation of Delaware r Application August 19, 1953, Serial No. 375,089 3 Claims. (Cl.15445.9)

Thisinventionmelates to protected metal articles and more -particularly to pgotected metal building sheets Protected metal building sheets comprising .a steel sheet enveloped in; an outer Weatherproofing coating of a bituminous or.,asphaltic composition are known. Some of these sheets are made by applying the outer weatherproofing,coating overfelt layers saturated with a bi tuminouspimpregnant and adhered to the metal base. Other types ofprotected metal building sheets comprise a steel sheetprotected by;a galvanizing or equivalent coatingpfnfusible metal adhesiveon which the fibrous layer isj disposed and which serves, to anchorsthefibrous or felt layer to: thejmetal base. The fibrous, layers are impregnated withwa bituminous composition and, usually, an, outer weatherproofing coatingof bituminous character is appliedontoppf the impregnated felt layers.

Asphalt or similar bituminous compositions are very desirableforusewas thetimpregnant but, asisknown, whentthey are used as the outer or topcoating, a limitation is imposed on the color and appearance of thefinal building sheets, only dark colors being possible. Therefore, it is desirable to provide the sheets with outer weatherproofing coating that is: light colored and maybe decorative.

Various synthetic resins have been tried but these generallyhave to be applied in conjunction with a solvent which penetrates into the fibrous layers during application ofnthe resin and; thengescapes over a long period of time through., the. resin coating, renderingthe resin, coating porous and permitting bleeding through or migration of the, ,oily constituents. of; the bituminous impregnantl The result has been that the resin coating becomes ,badly dis: colored in the course of time.

It has been proposed, also, to provide these conventionalzmetal building sheets, with an outer coatingof certain-.polyester resins applied in liquid condition without ELSOIVGHL, Howeverythe resins which have beensuggested do not combine dye-receptivity with the required properties of-high impact strength and rigidity coupled with suflicientflexibility to permit fitting and bendingof the, sheets without cracking of the resin coating.

Theobject of this invention is to provide new building sheets protected by fibrous or felt layers which may be impregnated with a bituminous composition and carry, as the exterior coating, a new dye-receptive resin blend which, in thermoset condition, combines high impact strength and practical rigidity with a capacity to withstand bending stress without cracking whether the outer protective resinous coating is relatively thin or relatively The new building sheets are obtained by coating an assembly comprising a metal sheet having a bituminousimpregnatedfibrous material adhesively bonded to a surface thereof with a polymerizable composition comprising a' blend of unsaturated polyester or alkyd resin .precon densate. and a vinyl-substituted heterocyclic tertiary amine id monomeric or at least still polymerizable condition,

and curingthe blend on :the sheet to ahardened insoluble,

and infusible state.

The unsaturated polyester component oftthe: polymerize,

able blend is an unmodified or modifiedpolyhydric alcohol 1 polyester of an alphaunsaturated alpha, beta-polycar-:

boxylic, acid or ester-forming derivative thereof such as;-

may also include alcohols having a-functionafity.greaterr than two, suchas glycerol and \pentaerythritoL:

Examples of the alpha-unsaturated-alpha-beta-polycars boxylic acids, to be reacted with the polyhydricalcohols are maleic,. fumaric,.chloromaleic, chlorofumaric, citra conic, methylethyl maleic, diethylmaleim. chloromethyl-. maleic, and mesaconic acids. 7

In making the unmodified alkyd or unsaturated p o1y-, ester component of the blend, one or more ofthe fore-. going alcohols is heated with, the. desired amount, usuallyaroughly equivalent proportion, of one or moreofnhe. acids or their ester-forming derivatives for a time sufficient .to effect condensation to the, stage at whichthe condensate, occurs as. a liquid resinous, flowable polyester having the desired molecularweight, When the polyester. component istobe of themodified type, a part, or even; nearly all,.of the unsaturated polycarboxyl ic acid may be. substituted by. saturated monoor polycarboxylic acid. suchas succinic, adipic, phthalic, sebacicor l2ehydroxy-r stearicacids. Monobasic acidsihavingfrom 10-20 carbon, atoms may, be preferred. These acids, mayvbemixed fatty ,acids, derived from vegetable oilsorthe individual. acids present therein. When desired, thetvegetable ,oils; themselves may be incorporated by conventional methods; such as by the so-called alcoholysis. method.. As ex: amples of suitable vegetable oils may be mentioned. linseed,-perilla, soybean, castor, dehydratedncastor,palm. kernel, cocoanut and thclike. Resins of both thesesunw modified andmodified types are ,known in, the art and. available commercially under the different trade names;

The unsaturated polyesteris made ,up of. repeating, groupings containing alcohol andacid. units and may have. a-molecular weight, as measured by the acid value,of the resin, or over 500, molecular Weights of 1,000 or over,' such ,as,1,000 to..10 ,000 being generallypreferred. The molecular weight may .vary'but should be such that the, liquid. resinous polyester is, capable of being blended, uniformly with. the. vinyl-substituted amine in convene, tional typemixing apparatus.

Examples of the it vinyl-substituted heterocyclicttertiary amines. whichmay be used include the, vinylpyridines,,for, instance,.. 2-.vinylpyridine, 5 vinyl-2-methylpyridine,.. 5- ethyl-Z-vinylpyridine, and. :the vinylpyridines and .their, alkyl nuclearlysubstituted derivatives generallyin which, the alkyl. radicals contain from .1 to 4 carbonatoms, the. vinylimida'zoles, the vinylquinolines, the ,vinyl-isoquinm lines, the vinylthiazoles, the vinyl ,oxaz oles, the. .vinyl benzooxazoles, etc,

The vinyl-substituted amine functions, initially, as a diluent for the unsaturated polyester and subsequently, on, heating of the mix tocuring temperature, as a crosslinkr, ing agent forthe polyester chains.

The eventual hardening to thermoset. condition and simultaneous cross linking of the polyester chains by the; amine are best, accomplished in the presence of a catalyst. Introduction .of "the catalyst may be achieved in various. ways calculated to prevent premature polymerizationof the composition to the insoluble, infusible state, as during Patented n-v such as, ethylene s peroxides.

storage or shipping. One method of accomplishing this is to incorporate in the blend, during preparation thereof, a latent catalyst which does not exert its catalytic action, at least to any appreciable extent, until the building sheet coated'or impregnated with the blend is heated to curing temperature. Another method is to mix the catalyst with the blend immediately before the latter is coated onto the building sheet or to apply the catalyst concurrently with the blend, as by spraying. Particularly preferred catalysts for this purpose are organic peroxides such as benzoyl peroxide, succinic peroxide, and especially peroxides derived from fatty acids having from l20 carbon atoms, including lauroyl peroxide, stearoyl peroxide, and peroxides made from vegetable oil acids such as cocoanut oil droperoxide and terpeneoxides such as ascaridole, may also be used. Organic ozonides are also useful catalysts for this reaction, including di-isopropylene ozonide and di-isobutylene ozonide. The catalyst may be used in very small amounts from about 1.1% to about 2% of the blend by weight.

If the mixture of polyester resin and vinyl-substituted hcterocyclic tertiary amine is to be stored for long periods of time, it is desirable to include a polymerization inhibitor with it. Suitable inhibitors include guaiacol, paraquinone, para tertiary butyl catechol, hydroquinone, ortho trinitro phenols, and the like. From about 0.2% to 1.0% of the inhibitor by weight of the blend is generally suflicient to inhibit or retard polymerization for substantial periods of time.

Under certain circumstances, as when the blend includes a substance which inhibits the polymerization under normal storage and shipping conditions even in the presence of a peroxide or ozonide catalyst, these catalysts may be incorporated in the blends at the time of their preparation.

Agents which stabilize the compositions against any marked polymerization on standing under normal conditions include alkoxy-substituted hydroxybenzoic acid in which the alkoxy radical contains up to 18 carbon atoms and not more than one oxygen atom is joined to the hydroxybenzoyl nucleus by an atom other than a carbon atom.

Typical of these stabilizers is the substance 4-hydroxy-3,5- dimethoxybenzoic acid.

The relative proportions of the unsaturated polyester and vinyl-substituted amine in the blend may be varied and the blend may even comprise from 5 to 95 parts of the one component to, conversely, from 95 to 5 parts of the other, by weight. However, blends comprising from 5 to 50 parts of the vinyl-substituted 'heterocyclic tertiary amine such as a 2-vinylpyridine or 5-vinyl-2-methylpyridine for each 100 parts of the unsaturated polyester will generally be found satisfactory for the present purposes.

Preferred compositions for use as the outer or weatherproofing coating for the building sheets are those obtained by coating the sheet with a polymerizable composition comprising the vinyl'substituted amine and apolyester obtained from a glycol, particularly propylene glycol, and a mixture of an unsaturated dicarboxylic acid with a saturated acid, or the acid anhydrides and especially a mixture of maleic and phthalic acids or anhydrides in which the molecular ratio of saturated acid to unsaturated acid is not greater than 60:40. The acid (or anhydride) mixtures may desirably comprise the acids (or anhydrides) in such proportions that the molecular ratio of saturated acid to unsaturated acid is :90, :75 or 50:50.

The unsaturated polyester component of the blends may be further modified by including with the polyester-forming constituents an alcohol having a terminal CH2=C group, including allyl alcohol and others of that class having from 3 to 10 carbon atoms. This includes methallyl alcohol, methyl vinyl carbinol, allyl carbinol, beta-allyl ethyl alcohol, monoallyl and monomethallyl ethers of ethylene glycol and the like. Such modified polyesters are known and contain, in addition to the acid and polyhydric alcohol residues, residues of the unsaturated alcohol.

Alcohol peroxides such as tertiary butyl hy- The polyester may also be one produced in the presence of a monohydric aliphatic alcohol such as l-butanol, and other saturated lower aliphatic alcohols having straight or branched chains, particularly alcohols having 3-6 carbon atoms such as propanol, l-pentanol, 2-methyl-1- butanol, 2-pentanol, 2-methyl-2-butanol, Z-propanol, 2- butanol, 2-methyl-2-propanol and the like. The final polyester may, therefore, also contain residues of the saturated monohydric alcohol, preferably in an amount up to l10% of the total ester linkages.

These blends are clear, essentially colorless resinous liquids. They may be modified by the inclusion of suitable pigments to provide the building sheets with a decorative weatherproofing outer coating, pigments being selected which are capable of withstanding the temperature at which the blend is ultimately cured. One distinguishing feature of the blends is that the vinyl-substituted heterocyclic tertiary amine is strongly receptive of the acid dyestuflfs and can be dyed with those dyestufis to provide the building sheets with a surface coating colored uniformly to any desired depth of shade by an acid dye which is particularly fast because of the attraction for it exhibited by the tertiary nitrogen atom of the vinyl-substituted amine component distributed uniformly throughout the blend. Although the unsaturated polyester componentof the blend may be prepared by reacting substantially equal parts of the polyhydric alcohol and polycarboxylic acid, considerable variation may be achieved in the properties of the blend, not only by conducting the esterification reaction in the presence of unsaturated allyl-type alcohols and/ or saturated monohydric alcohols, but also by variations in the relative proportions of the primary reactants, and particularly by selecting these reactants so that there is a slight preponderance of either the polyhydric alcohol or of the polycarboxylic acid.

The following examples illustrate the preparation of typical blends for use in coating building sheets in accordance with the invention.

Example I A modified unsaturated resinous polyester resin was prepared by heating a mixture of 0.5 mol. (49 parts) maleic anhydride, 0.5 mol. (74 parts) phthalic anhydride and 1.2 mol. (92 parts) of propylene glycol to 190C. until a clear resinous liquid was obtained.

A suflicient amount of monomeric 2-vinylpyridine was mixed, at room temperature, with the resinous polyester to obtain a mass comprising, on a Weight basis, the equivalent of 40 parts of the vinylpyridine per each parts of polyester. J

Example II An unmodified resinous polyester was prepared by heating together equimolecular proportions of triethylene glycol and maleic acid until a partial condensate having the form of a resinous liquid was obtained.

The polyester was mixed, at room temperature, with a sufiicient amount of 5-vinyl-2-methylpyridine to produce a blend containing the equivalent, on the weight basis, of about 15 parts of the 5-vinyl-2-methyl-pyridine per 100 parts of the polyester.

Example III 2-.vinylpyridine with the polyester in amounts of 5, 10, 20,..i30.ar1d 50 partsper 100 parts of the polyester. Similarcompositions in which Z-methyl-S-vinylpyridine was substituted for the2-.vinylpyridine were also prepared. All these blends were clear, liquid but viscous, products which could be polymerized to hardened condition.

When these clear resinous liquids are applied to the bituminous-saturated felt layers of building sheets as describedherein, and owed to the hardened condition on the sheets, the latter are provided with a dyeable, durable filinlthat-isinsoluble, infusible, resistant to deterioration on. exposure to changing whether conditions, and which, though hard and sufiiciently rigid for this purpose, has enough flexibility to permit bending and flexing of the building sheet without cracking of the protective outer coating. The polymerized vinylpyridine cross-links impart rigidity to the resin coating Without depriving it of flexibility, and the balance between flexibility and rigidity can be controlled and varied by varying the amount of polymerizable vinyl amine blended with the liquid resinous polyester. The blends may be converted to the hardened condition at temperatures varying over a wide range and even including room temperature if time is not an important factor of production. However, it is generally preferred to use higher temperatures permitting shorter curing cycles, such as temperatures between 50 C. and 200 C. A cure .of ten minutes at 100 C. in a conventional baking oven is generally satisfactory.

Since the liquid blend is applied directly to the metal sheet or other article carrying thhe fibrous or felt layers as such and without the use of a solvent, there is no seepage of solvent from the finished product and, therefore, no tendency for the oily constituents of the bituminous material to migrate through the top coating and discolor the outer or exposed surface of the building sheet.

The liquid polymerizable blend adheres to the fibrous material bonded to the metal base and is cured in contact with it so that the cured blend is permanently anchored to the metal base through the intermediate fibrous layer, to provide a strong coherent laminated structure, the laminae of which, including the top surface or film of cured resin, do not tend to separate even when the building sheet is subjected to bending stress. The resin blend also adheres to bituminous impregnant occurring at the surface of the fibrous layers.

If desired, during the curing the assembly may be subjected to pressure, such as pressures of from 0.5 pound per square inch above atmosphere to 20 pounds per square inch (gauge) or even higher, and up to 300- 500 pounds per square inch.

The building sheet provided with the coating or top film of the polymerizable blend may comprise a sheet of steel or other metal having bonded thereto a layer of fibrous material impregnated with bituminous material. Bituminous material may also be coated on the fibrous layer, the blend being applied over such coating. Bonding of the fibrous layer to the metal sheet may be by means of the usual adhesives commonly employed for this purpose or by a galvanized or equivalent coating of fusible metal adhesive disposed on the metal sheet. The fibrous layer and cured blend may occur at only one major surface of the metal sheet, or the sheet may be sheathed in the fibrous material and the surface thereof completely covered with the cured resin blend.

The attached drawing is illustrative of the invention. In the drawing:

Figure l is a perspective view of a protected metal building sheet according to the invention,

Figure 2 is a sectional view of the sheet taken on line 2-2 of Figure l, and

Figure 3 is an enlarged fragmentary view of another embodiment.

Referring to Figures 1 and 2, there is shown a protected metal building sheet comprising the steel sheet 2 sheathed in a felt formed of asbestos or equivalent fibers 3j secured thereto by bituminous material... The assembly comprises the topor outer coating 4 of pplyrneriz edy.

polymerized viriylpolyester resin cross-linked by the substituted heterocyclic tertiary amine.

Figure 3 illustrates asomewhat different form of structure in which the, steel sheet 5 has a, feltfllayer 6'of cross-linked by the vinyl-substituted heterocyclic tertiary amine is cured and bonded .to the asbestos layer.

Various embodiments. and specific: details, havebeen given in the above discussion of the invention. Instead of flowing the polymerizable blend onto the fibrous layer or sheath adhered to the metal base, or applied directly to the fibrous layer or sheath in any other suitable way, the polymerizable composition may be deposited on a suitable base to which it does not adhere and which may be heated to a temperature such that the condensation or polymerization is advanced to a stage at which the composition sets to a condition in which it can be handled, but short of complete curing or hardening, the sheet thus obtained may be dyed to any desired color and shade using an acid dyestuff, and thereafter the dried, dyed sheet may be deposited on the asbestos or other fibrous layer adhered to the metal building sheet and brought to the completely cured and hardened condition. In this embodiment the fibrous layer may be provided With a coating of the liquid polymerizablle blend before the preformed dyed sheet is deposited on it, the final heating serving to cure both the liquid blend and the preformed sheet to thermoset condition and bond the preformed sheet to the fibrous layer through the interposed initially liquid coating on the fibrous layer.

Other methods of obtaining the preformed partially cured sheet to be deposited on the fibrous layer may be used, such as a method in which the liquid polymerizable blend is coated onto a metal conveyor or belt which travels through a heating zone in which the blend is heated at a controlled temperature such. that the conversion of the blend to a coherent sheet is effected. The polymerizable liquid blend coated on the surface of the fiber layer before the preformed sheet is deposited thereon may be a blend which has been heated to a stage of advanced condensation such that further heating to convert the preformed sheet to final cured condition also induces condensation of the interposed coating to the hardened fusible insoluble state.

It will be understood that it is not intended to limit or circumscribe the invention by the details given since modifications may be made in practicing the invention without departing from the spirit and scope of the disclosure and appended claims.

I claim:

1. As a new article of manufacture, metal building material comprising a metal sheet, a layer of bituminouscarrying fibrous material covering and bonded to a surface of the metal sheet, and an outer, weatherproofing layer self-adhered to the surface of the fibrous layer removed from the metal sheet and formed by depositing on said fibrous layer surface a blend consisting of (a) a liquid, resinous condensate of components consisting essentially of a polyhydric alcohol and a substance selected from the group consisting of straight-chain alphaunsaturated-alpha, beta-dicarboxylic acids and anhydrides thereof with (b) from 5 to 50 parts by weight of a monovinylpyridine per parts of the condensate, and curing the blend on the fibrous layer to set it in hard, infusible, insoluble condition.

2. As a new article of manufacture, metal building material comprising a metal sheet, a layer of bituminouscarrying fibrous material covering and bonded to a surface of the metal sheet, and an outer, weatherproofing layer self-adhered to the surface of the fibrous layer re- 3. As a new article of manufacture, metal building material comprising a metal sheet, a layer of bituminouscarrying fibrous material covering and bonded to a surface of the metal sheet, and an outer, weatherproofing layer self-adhered to the surface of the fibrous layer removed from the metal sheet and formed by depositing on said fibrous layer surface a blend consisting of (a) a 8 liquid, resinous partial condensate of triethylene glycol and maleic acid, with (b) from 5 to 50 parts by weight of Swinyl-Z-methylpyridine per 100 parts of the condensate, and curing the blend on the fibrous layer to set it in hard, infusible, insoluble condition.

References Cited in the file of this patent UNITED STATES PATENTS 2,073,334 Coifman Mar. 9, 1937 2,472,963 Singleton et al. June 14, 1949 2,491,409 Kropa et al. Dec. 13, 1949 2,600,457 Wynstra June 17, 1952

Claims (1)

1. AS A NEW ARTICLE OF MANUFACTURE, METAL BUILDING MATERIAL COMPRISING A METAL SHEET, A LAYER OF BITUMINOUSCARRYING FIBROUS MATERIAL COVERING AND BONDED TO A SURFACE OF THE METAL SHEET, AND AN OUTER, WEATHERPROOFING LAYER SELF-ADHERED TO THE SURFACE OF THE FIBROUS LAYER REMOVED FROM TEH METAL SHEET AND FORMED BY DEPOSITING ON SAID FIBROUS LAYER SURFACE A BLEND CONSISTING OF (A) A LIQUID, RESINOUS CONDENSATE OF COMPONENTS CONSISTING ESSENTIALLY OF A POLYHYDRIC ALCOHOL AND A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF STRAIGHT-CHAIN ALPHAUNSATURATED-ALPHA, BETA-DICARBOXYLIC ACIDS AND ANHYDRIDES THEREOF WITH (B) FROM 5 TO 50 PARTS BY WEIGHT OF A MONOVINYLPYRIDINE PER 100 PARTS OF THE CONDENSATE, AND CURING THE BLEND ON THE FIBROUS LAYER TO SET IT IN HARD, INFUSIBLE, INSOLUBLE CONDITION.

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