US2421892A - Seal-down composition shingle - Google Patents

Description

Patented June 10, 1947 UNITED SEAL-DOWN CQWQSITEQN SGLE Lester Kirschbraun, Leonie, N. 3., assignor to The Patent and Licensing Corporation, New York, N. Y., a corporation of Massachusetts Application June 8, 1945, Serial No. 598,411

7 Claims. 1

This invention relates to improvements in asphalt composition shingles of the flexible type and more particularly to the'provision in such shingles of improved means for efiecting'the self sealing of the free butt or exposed portions thereof when laid on a roof or side wall."

More specifically, the present invention con-' templates improvements in the means provided, as set forth in my U. S- Patent No.- 2,210,209, issued August 6, 1940, for causing flexible-type composition shingles to become self-adherent and pressure sensitivity possessed by'an asphalt such as is employed in the practice of my prior invention, and thus will prevent the singles from sticking to one another in the bundles in which they arepackaged for storage and shipment from the manufacturer tothe user.

upon exposure on a roof or side wall. As stated tree butts or exposed portions of the shinglesto be lifted or elevated from the underlying surface under the action of winds, particularly of high force and continuing nature. In the attainmerit of this objective, use was madeof certain When shingles provided with the aforedscribed' self-sealing means are applied to a roof or side wall in the usual manner, 1. e., in successive courses with the butts or tabs of the singles'of one course partially overlapping and left free of the shingles of the immediately preceding courses, the water that creeps upwardly between the shingles with the first moderatelyheavy rain that occurs after the shingles are applied will cause thewater soluble fugitive material to dissolve asphalts which arerelatively non-adhesive at normal atmospheric temperatures, butwhose adhesive qualities are energizable or activated at a temperature of'about 125 F. As a specific example of asphalts possessing heat sensitivity to the extent just mentioned, I described an asphalt having a melting point between 160-170" F. and a penetration at '27 F. within. the range of 5 to 8. Asphalt of such heat sensitivity was applied to the bottom face of an individual shingle or strip in the form of a relatively narrow band extending along the butt edge thereof.

Since the asphalt employed for the band is possessed of some pressure sensitivity as well as heat sensitivity, these characteristics must be counteracted or rendered unable to'cause stickin together of the shingles during the period when they are packed in bundles and stacked and stored for shipment. Accordingly, the asphalt layer or band was covered or coated with a fueltive material which will be decomposed or otherwise removed as by sublimation, or by being dissolved by dew or by the first rain that occurs after the thus treated shingles are laid in place on a roof or sidewall. ,Among the examples of water soluble substances that were suggested for use as the fugitive masking material to prevent sticking together of the shingles in their bundles were such substances as common salt crystals, glycerine, sugar crystals, ammonium chloride, trisodium phosphate. The protective cover that is provided bythe application of any one of the foregoing fugitive materials to the asphaltic layer or band is sufliclent to mask effectively the heat or "decompose along the surface of the asphaltlc layer or band. As soon thereafter as a temperature of the order. of 125 F. occurs on the roof, the adhesive qualities of the band will become energized or activated sufllciently to seal the tabs or butts down to the underlying singles.

While the employment of an asphalt having the aioredescribed melt point and penetration properties in the formation of the heat energizable self-sealing band has proven fairly satisfactory whenever and wherever temperatures of the order of 125 F. occur on the roof, a more universal application of shingles provided with such self-sealing means and a more prompt and more efiective adhesion of the sealing medium may be accomplished ii the sealing band could be activated or energized at temperatures acquired by the roofing, which, in northerly climates particularly, occurs more frequently above F. than 'above F. Thus, particularly in such climates,

sealing conditions will occur during most of the outdoor construction period even at air temperatures as low as 40 F., as the incidence of a bright sun on a calm day will bring the temperature of the roofing within the above sealing temperature range. l

Such improvement may be accomplished, in accordance with the present invention, by employing for the sealing band a softer, tackierasphalt or equivalent hydrocarbon, say an asphalt having a melting point of approximately F. and a penetration at 77 F. between 20-30, in lieu of the F. melting point asphalt employed in the practice of my previous invention.

With the employment of the softer thermoplastic possessing greater heat sensitivity than the asphalt heretofore employed in the formation of the sealing layer or band, the problem of providing adequate masking protection for such layer or hand, during the time the shingles on which it is applied are packaged in bundles for storage or shipment, is aggravated by the fact that it is more tacky and possesses greater pressure sensitivity than the harder asphalt. I have found that the water soluble materials of the character mentioned in the patent as a fugitive masking material for the harder, less pressure sensitive asphalt are ineffective when used in conjunction with a sealing band composed of the softer and tackier thermoplastic above mentioned.

In order to take advantage of the greater and more rapidly heat energizable adhesive qualities possessed by these softer asphalts, as compared to the harder 160 F. melting point asphalt heretofore employed, and, at the same time, prevent shingles having sealing layers or bands composed of the softer asphalt from sticking together in the bundles, there is employed, according to my invention, as the fugitive masking material for the rapidly heat energizable sealing band of the asphalt, a continuous film of a water soluble substance of suflicient strength and toughness to provide adequate protection for the highly pressure sensitive sealing band. Such material should form a continuous film immiscible with or impermeable to the asphalt or similar hydrocarbon but readily affected by rain or moisture.

A preferred material which may be employed as the fugitive or parting medium for the sealing band comprises polyvinyl .alcohol in sheet form, approximately .001" thick. 'This substance is available in pre-formed sheets of high strength and toughness and is water soluble and thus readily disintegrated and dissolved by the action of rain or moisture.

If desired, in order to accelerate the rate of solution of the polyvinyl alcohol, there may be incorporated in the aqueous solution of the polyvinyl alcohol, before the substance is extruded or otherwise produced in sheet form, say 30-40% .005" to .015" which I have found satisfactory in practice to furnish an amount of adhesive ample for firmly sealing down the tabs when the adhesive qualities of the band become energized.

Immediately after the band of heat energizable adhesive is deposited, a continuous film of the polyvinyl alcohol is applied thereto in any convenient fashion. This film or ribbon is at least of a width sufiicient to cover the band of adhesive. The fugitive medium is firmly adhered to the underlying band. Since the polyvinyl alcohol will generally be employed in the form of continuous films or ribbons of desired width, it may be fed from a reel, thus affording a ready means of application, in addition to its other advantages as above described, as compared with the inconvenience of handling care and control required formerly in the application of water soluble fugitive materials in liquid form or discrete particles. Nevertheless, under certain conditions, it maybe desirable to apply the film of polyvinyl alcohol .to the asphaltic band from a water solution thereof, which upon drying in situ, will be firmly adhered to the underlying band.

, There is thus provided, by means of the present invention, an improvement in self-sealing shingles wherein the free butts or exposed portions of the shingles will be scaled down to the underlying shingles more promptly than heretofore possible and with more effective adhesion at lower roof temperatures and yet such shingles are prevented most effectively from sticking to one another in (on the total weight) of a water soluble substance,

such as common salt, sugar, or the like. Also, if desired, there may be incorporated with the polyvinyl alcohol a suitable plasticizer or softener, examples of which may include glycerine, or a water-soluble synthetic wax, such as polyethylene glycol, known commercially as Carbowax. A highly water-soluble plasticizer or softener, such as one of those just mentioned, is particularly suitable for this purpose, as its presence in the dry film of the polyvinyl alcohol' will serve to accelerate the rate of dissolution and disintegration of the latter in the presence of moisture, thus rendering it unnecessary to add, in addition water-soluble salts as the accelerant. Sheet material produced from water-soluble waxes such as Carbowax" may be employed in lieu of polyvinyl alcohol, although the film formed does not possess the strength and toughness of the latter substance.

The layer of adhesive may be applied in any suitable manner, such as described in my foregoing patent, either before or after the shingles are cut from the parent sheet so as to be presented in the form of a band of say /g" width on the bottom or rear face of each finished shingle or strip and extending along the butt edge of the shingle or of the strip. This band may be deposited'in continuous form, or may be disrupted at spaced intervals. In the latter case, any water which may lodge in back of the seal will find means of egress through the spaces in the adhered areas. The thickness of the continuous or disrupted band may vary within a range of say the bundlesin which they are packaged In the accompanying drawings:

Fig. 1 is a view of the bottom face of one form of shingle embodying the invention;

Fig. 2 is an enlarged cross-sectional view taken along the line 22 of Fig. 1;

Fig. 3 is a view showing the shingles of Fig. 1, laid in successive courses;

Fig. 4 is a view in elevation showing a number of the shingles of Fig. 1 as they appear when assembled in bundles for storage or shipment;

Fig. 5 is a view similar to Fig. 1 showing another embodiment of the invention; and

Fig. 6 is an enlarged cross sectional view taken along line 6-6 of Fig. 5.

In Fig. 1, the invention is shown embodied in a so-called square butt strip shingle of wellknown form. The shingle strip, indicated at l0, and provided with tab-defining slots II and end notches l2, has applied to the bottom face thereof, along its lower or butt edge M, a relatively narrow band l5 of a heat energizable asphaltic material of the character hereinabove set forth, to serve as the sealing band to cause the butts of the shingles to become sealed to the underlying shingles when subjected to temperatures of the order of 90 F. or above. Adhering to the sealing band I5 is a thin ribbon l6 of fugitive material in the form of a continuous film of polyvinyl alcohol or the like, this ribbon being applied to the asphaltic film immediately after the latter is deposited on the sheet from which the strips are formed, and being of a width at least as wide as the sealing band l5: As will be understood,

the shingle is of the flexible type, such as made from a sheet of fibrous felt impregnated with relatively low melting point asphalt and provided on its top or exposed surface with a weather protective layer l8 of relatively high melting point asphalt in which is partially embedded a layer 20 of surfacing material such as mineral granules or the like;

In the embodiment. illustrated in Fig. l, the

. V I v sealing band l5 extends over the full length of each of the tabs. formed by the tab-defining slots In Figs. 5 and 6, a modifled form of the invention is illustrated, wherein the sealingband of asphalt, instead of extending along the full length of the butt edge of the'shingle, is deposited in discontinuous form at spaced intervals along this edge, as indicated at 22. These discontinuous bands 22 of sealing-asphalt are likewise covered with a ribbon 23 of fugitive material such as polyvinyl alcohol. Since this fugitive material is sufilciently water soluble to be substantially dissolved and washed away upon the occurrence of the first moderately heavy rain, it may be applied so as to extend continuously along the full length of thebutt edge of the shingle. When this ribbon has thus been dissolved, the discontinuous bands 22 of the sealing asphalt will become exposed for energizing by solar heat, causing the butts of the shingles to seal to the surface of the underlying shingles, while leaving the intervening spaces 24 between the bands 22 as avenues for escape of any water which may lodge up behind the upper edge of the bands 22.

Fig. 4 depicts a number of strip shingles of the form shown in Figs. 1 and 5, assembled in bundles for storage or shipment. As will be observed, the ribbons it of the fugitive material, such as polyvinyl alcohol, adhering to the bands of heat energizable asphalt it, serve to mask the latter and prevent these bands from sticking to the face of the adjoining shingle in the bundle under the pressure prevailing when the bundled shingles are stacked in storage or during shipment.

, While I have mentioned above an asphalt having specific physical properties rendering it suitable in the practice of my invention, it will be appreciated that the physical properties of the thermoplastic material selected for the adhesive band need not be as closely controlled as formerly required, since the more effective functioning of the aforedescribed fugitive masking materials in preventing adhesion of. the shingles to one another in the bundles permits the use of any other asphalt or equivalent thermoplastic hydrocarbon, such as cumar resin, that is capable of being energized by solar heat to the extent and under the conditions specified.

I claim:

1. A flexible shingle of the asphalt composition type having along the bottom surface of its butt portion a band of thermoplastic characterized by adhesiveness sufficient to efiect sealing down oi the butt portion of the shingle to its underlying surface after a number of such shingles are applied in overlapping courses and exposed to solar Heat, the pressure sensitivity of the adhesive being such as would normally cause sticking together of adjacent shingles packed in bundles, said band of thermoplastic adhesive being covered by a thin sheet material sufi'iciently strong and tough to prevent being ruptured or permeated by said adhesive whereby sticking together of adjacent shingles packed in bundles for storage and shipment is avoided, yet sufliciently soluble in water to be readily removed by the action of moisture upon exposure of the applied shingles to the'weather.

2. A flexible shingle of the asphalt composition type having along the bottom surface of its butt portion an interrupted band oi! thermoplastic hydrocarbon characterized by adhesiveness sufiicient to effect sealing down of the butt portion of the shingle to its underlying surface after a number of such shingles are applied in overlapping courses and exposed to solar heat, the

cent shingles packed in bundles, said band of thermoplastic hydrocarbon adhesive being covered by a thin sheet material sufilciently strong and tough to prevent being ruptured or permeated by said adhesive whereby sticking together of adjacent shingles packed in bundles for storage and shipment is avoided, yet sufficiently soluble in water to be readily removed by the action of moisture upon exposure of the applied shingles to the weather.

3." A flexible shingle of the asphalt composition type having along the bottom surface of its butt portion a band of thermoplastic characterized by adhesiveness sufficient to effect sealing down of the butt portion of the shingle to its underlying surface after a number of such shingles are applied in overlapping courses and have acquired a temperature above about 90 F., the pressure sensitivity of the adhesive being such as would normally cause stickin together of adjacent shingles packed in bundles, said band of thermoplastic adhesive being covered by a thin sheet materialsufliciently strong and tough toprevent being ruptured or permeated by said adhesive whereby sticking together of adjacent shingles packed in bundles for storage and shipment is avoided, yet sufliciently soluble in water to be readily removed by the action of moisture upon exposure of the applied shingles to the weather.

4. A flexible shingle of the asphalt composition type and of a form in which its exposed butt is normally free to be elevated by wind when a number of such shingles are laid in overlapping courses, said shingle having a narrow band of a heat-sensitive asphalt on the bottom face of said butt portion adjacent the lower edge thereof, the said asphalt beingrelatively non-' in overlapping courses the said adhesive proper ties of the asphalt will become activated promptly upon the occurrence of temperatures above about 90 F. to effect sealing down of the said buttportion to its underlying surface, the pressure sensitivity of the asphalt being such as would normally cause sticking together of adjacent shingles packed in bundles, said band being covered with a continuous solid film of non-adhesive, asphalt impermeable, water-soluble sheet'material to prevent the said band of asphalt from causing sticking together of adjacent shingles packed in bundles for storage and shipment, said film being suficiently water-soluble to be readily disintegrated and dissolved by the action of moisture.

5. In a flexible shingle which is laid with its exposed butt normally free to be elevated by wind and having atthe margin of the rear face of its butt portion a layer of heat sensitive thermo plastic which assumes adhesive properties at acquired temperatures above normal atmospheric temperatures sufiicient to cause said butt portion to adhere to an underlying shingle, said thermoplastic being relatively non-adhesive at normal atmospheric temperatures yet pressure sensitive, the improvement which comprises a film of polyv yinyl alcohol applied over the said layer of during storage and shipment, said film being sufiiciently water-soluble to be readily disintegrated and dissolved by the action of moisture.

6. A flexible shingle of the asphalt composition type having along the bottom surface of its butt portion a band of thermoplastic characterized by adhesiveness sufllcient to eifect sealing down of the butt portion of the shingle to its underlying\ surface after a number of such shingles are appliedwin overlapping courses and exposed to solar heat, the pressure sensitivity of the adhesive being such as would normally cause sticking together of adjacent shingles packed in bundles, said band of thermoplastic adhesive being covered by an adherent film f p01yviny1 alcohol, said film preventing the said band of adhesive from causin sticking together of adjacent shingles packed in bundles for storage and shipment and having incorporated therewith additional water-soluble material regulating its rate of solution whereby said film will be readily disintegrated and dissolved by the action of moisture.

7. A flexible shingle of the asphalt-composition type havingalong the bottom surface of its butt portion an interrupted band of thermoplastic characterized by adhesiveness suflicient to eifect 30 2,

8 sealing down of the butt portion or the shingle to its underlying surface after a number 01. such shingles are applied in overlapp n courses and exposed to solar heat, the pressure sensitivity 01 the adhesive being such as would normally cause sticking together of adjacent shingles packed in bundles, said 'band of thermoplastic adhesive being covered by an adherent film of polyvinyl alcohol, said film preventing the said band of adhesive from causing sticking together of adjacent shingles packed in bundles for storage and shipment and having incorporated therewith additional water-soluble material regulating its rate of solution whereby said film will be readily disintegrated and dissolved by the action of moisture.

' LESTER KIRSCHBRAUN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date OTHER REFERENCES British Plastics, March 1944, age 126, column

Images