US1948979A

US1948979A - Weather resisting material

Info

Publication number: US1948979A
Application number: US619522A
Authority: US
Inventors: Philip W Codwise
Original assignee: Certain Teed Products Corp
Current assignee: Certainteed LLC
Priority date: 1932-06-27
Filing date: 1932-06-27
Publication date: 1934-02-27
Anticipated expiration: 1951-02-27

Description

'Patented Feb. 27,

UNITED STATES PATENT OFFICE 1,948,979 WEATHER BESISTING MATERIAL Philip W. Codwise, Kenmore, N. Y., assignorto Y Certain-Iced Products Corporation, New York, N. Y., a corporation of Maryland No Drawing. Application June 2'7, 1932 Serial No. 619,522

12 Claims.

This invention relates to covering material and especially to covering material having weatherproofing or waterproofing qualities. More particularly the invention relates to prepared roof- Prepared roofing as commonly understood comprises a sheet of fibrous material which has been felted, the felted sheet being saturated with a mastic or bituminous material. A well known lo form of this material is made by using as a base material aso-called wool felt which is made of waste in the form of rags which have been reduced to the constituent fibres by well known processes. With such wool felts for roofing purposes frequently admixtures of papers or paper pulps or other fibrous materials have been used in order to lessen the cost or modify the felting characteristics.

As the mastic material, asphalt has commonly been used of such consistency as to provide for saturation of the felt with the asphalt to produce a product commonly known as saturated felt. To produce prepared roofing, saturated felt is commonly coated with an applied coating or layer of asphalt upon one or both sur- Sid faces of the sheet. To produce mineral surfaced roofing, as is well known, granular slate or other granular mineral material is applied upon the asphalt coating so as to adhere thereto.

In felts used prior to my'invention certain fibrous materials, either alone or in mixtures with rags, have been used for the purpose of increasing the amount of the mastic or bituminous material which could be absorbed by the felt. l'nall such roofing products it is desirable that the felt shall carry as much of the saturant as possible, thus reducing the amount of felt necessary to carry a givenamount of the waterproofing mas tic or bituminous material. Felts which have been proposed prior to the present invention have included those which have utilized resinous wood fibres, such as yellow southern pine fibres produced in a chemical process. Also in my prior Patents Nos. 1,857,432 and 1,857.433, dated May 1c, 1932, I have described a felt utilizing bundles of fibres to produce the desired porous or open structure of the felt necessary for high saturat ing capacity. The fibre used according to said patent also is prepared by a chemical process using caustic soda in which the separation of the individual fibres is incomplete, thus producing the. fibre bundles and utilizing the absorbent character of the fibre bundles as well as of the felted form of said bundles.

According to the present invention I have discovered that the desirable high absorptive quality of a felt for roofing purposes and the high capacity of such a felt for a saturant such as a bituminous material, for example, asphalt, may be producedby using a felt comprising or containing a substantial amount of the fibres of wood which are produced by the so-called soda pulp" process. Such a felt may be made in the usual manner of producing felts on a paper machine or by other felting process and I have discovered that when so felted the absorptive capacity of such a felt is much higher than that obtained previous to my invention by the use of individual wood fibres and that this absorptive capacity, that is, the saturation capacity of the felt, is nearly equivalent to that which is obtained by the use of rags alone and exceeds that of the usual rag fibre combinations with wastepapers as is common practice.

The process of manufacturing soda pulp depends upon the solvent power of caustic soda for certain constituents of the wood, converting them into soluble salts of soda. The reactions are very complicated but the degradation of the woody constituents is in. general greater than that which occurs for the same constituents'when the wood is treated by the so-called sulphite process. in. the soda pulp process the wood is barked and chipped as is customary in various chemical pulping processes. It is then furnished to a digester together with the proper amount of caustic soda solution and with careful regulation of the total amount of water introduced. The time required for a cock. is 5 to 8 hours and the steam pressure is usually between 100 pounds and 120 pounds per square inch. At completion of the cool: the pulp is blown into pit, washed, and, if white pulp is desired, is then bleached. In order to produce soda pulp 18% to oi caustic soda (NaOli) based on dry weight of the wood is required.

The known characteristics which in general distinguish soda pulse from, other chemical pulps are its softness and. bulking properties. T. have also discovered that said pulps, perhaps due the softness and bulking properties, have a high absorptive capacity for asphalt and bituminous saturants. the theory that the destruction or degradation of the woody constituents mentioned above has gone so far in the manufacture of this particular type of wood pulp as to open upthe cell structure, thus swelling the individual fibres and rendering them highly absorbent to asphalt or bituminous saturants. This absorptive quality is greater than that possessed by individual fibres prepared by I account for this characteristic on other processes. While papers of various degrees of compactness of the felting have been known.

the treatment with caustic soda which aifects the According to the statement in the patent to Ed":

fibres themselves both as to their cell structure and as to swelling of the individual fibres, is more highly absorbent to asphalt and similar bituminous saturants than other paper fibres. I propose to use fibres which are so treated according to commercial practice as to retain sufficient strength of the fibre while securing the opened or swelled condition of the fibre for the purpose of obtaining the absorptive quality.

Of the wood fibres whichhave been used, I am aware that southern yellow pine rich in resinous substances has been treated in a chemical process.

ward J. Schroeder, 1,188,495, in a chemical process of producing wood pulp southern resinous woods containing relatively large resin ducts have been treated so as substantially to empty these ducts of resin. The product is designated in said patent as chemicalresinous wood fibre or chemical fibre of southern yellow pine. While the fibrous product suggested in the patent to Schroeder was intended to be used for roofing felts. to replace wool felt, the fibres and the felt made from said fibres are a different product from that which I propose to utilize in my invention.

' These fibres do not have the soft character of the fibres of soda pulp and are not swelled as are the soda pulp fibres. The fibres which I utilize in my invention .are those whichresult from the treatment of wood with strong solutions of caustic soda which open up thecell structure in the woods which are so treated and do not merely remove the resinous material from the ducts.

Moreover, for the most part soda pulp is made from non-resinous woods or the hard woods such as poplar, gum, maple and other woods of relatively short fibres. The process of treatment contributes to the characteristic softness of the pulp and to the felting quality which assists in giving the felt a high absorptive capacity.

My invention therefore consists in the discovcry of the high absorptive capacity of soda pulp and of soda pulp felts for mastic or bituminous materials, particularly bituminous saturants, such as asphalt, which are used in prepared roofing. My invention in its practical form resides in the combination with a felt containing soda pulp of such a saturant, particularly asphalt.

I have found that the advantage afforded by the use of soda pulp in roofing felt may be obtained to a considerable degree when other materials, such as paper or paper pulps and other fibrous materials are admixed with the soda pulp. Moreover, while in some cases felts made of rags may have higher 'absorptive capacity than felts made of soda pulp alone or of mixtures of soda pulp and rags, nevertheless the admixture of the soda pulp with the fibre obtained from rags produces a felt of much higher absorptive capacity and one capable of saturating more rapidly than mined by tests the amount of asphalt which will be absorbed by the felt which I utilize in my invention and also I have determined the relative rate of absorption of saturating materials of the sodapulp felt as compared with other felts used particularly in the manufacture of prepared roofing. A felt of usual thickness consisting of 100% soda pulp was found to saturate readily with asphalt and to take up 177% of its weight in asphalt. This felt showed a kerosene saturation test of 195% and an oil penetration test of -10 seconds. These tests compare very favorably with those obtained with commercial rag felt of equivalent thickness.

To show the comparison between mixtures of rags and soda pulp and mixtures of rags and paper as commonly used tests were made with the following results:

50%soda 50%mixed 50%newspul and papers and papers and Caliper .045" .047"; .047". Kerosene. 159% 111 147%. Oil netration 10sec-.- 2sec.- 67m. Astp u)lt saturation (labora- 132% 104% 118%.

ory

In connection with these tests it is to be noted that the rate of oil penetration is a measure of the rapidity with which the felt absorbs the saturant, which quality in roofing felts is highly important, as felts which rapidly absorb the saturant may be treated more quickly in the process of manufacturing the roofing than those which require a longer time-for the penetration of the saturant into the felt. It will be noted that the soda pulp accelerates the penetration when substituted for the papers usually used in mixtures. It will also be clear that a high percentage of saturation by the asphalt is obtained with the soda pulp as compared with pulps of ordinary mixtures using rags and paper. As has been explained above, this is a valuable feature of a felt for roofing purposes, because a larger amount of the weatherproofing or waterproofing material may be carried for a given thickness of fin ished roofing or a thicker, heavier and more durable roofing may be produced with the same weight of felt as is now used for the normal product.

What I claim is:

1. As an article of manufacture a weather resisting material comprising a sheet of felt containing a substantial amount of soda pulp, and a water proofing saturant impregnating said felt.

2. As anarticle of manufacture a weather resisting material comprising a sheet of felt composed for the most part of soda pulp and saturated with asphalt.

3. As an article of manufacture a weather resisting material comprising a sheet of felt containing a substantial amount of the wood fibers resulting from the process of treating wood with caustic soda to produce individual fibers known as soda pulp, and a bituminous saturant impregnating said felt.

4. A roofing material comprising a base in the form of a sheet of felted soda pulp wood fibers, and asphalt saturating said felt sheet.

5. A roofing material comprising a sheet of felted fibers containing at least 25% of soda pulp wood fibers and saturated with asphalt.

6. As an article of manufacture a weather resisting material comprising a sheet of felt containing soda pulp, rag fibers, and a water proofing saturant impregnating said felt.

7. As an article of manufacture a weather resisting material comprising a sheet of felt contaming a. substantial eimount of individual cellulose fibers substantial y unbound (for the most part) by natural incrustations soluble in strong solutions of caustic alkali and having their cell structure opened and swelled by said alkali treatment but substantially retaining the integrity of v the individual fibers, and a waterproofing saturant impregnating said felt.

' 8. As an article of manufacture, a weather resisting material comprising a sheet of .felt containing soda pulp, paper stock, and a water proof saturant impregnating said felt.

9. As an article of manufacture a sheet of felted cellulose fibers which are the proluct of "a process using caustic soda in strong water solution at high temperature and pressure for producing a primauv pulp from wood. said fibers being substantially individual and substantially freefrom the materials binding them together when in the wood and as a result of said process being soft and of such opencell structure as markedly to increase the bulk of the individual fibers with respect to their bulk when in the wood but substantially retaining the integrity of the individual fibers, and a water proofing saturant claim 9 in which the fibers comprise a substantial amount of fibers of gum wood.

PHILIP W. CODWISE.