US3608606A

US3608606A - Rubber structures containing glass

Info

Publication number: US3608606A
Authority: US
Inventors: Alfred Marzocchi
Original assignee: Owens Corning Fiberglas Corp
Current assignee: Owens Corning
Priority date: 1969-12-29
Filing date: 1969-12-29
Publication date: 1971-09-28
Anticipated expiration: 1988-09-28

Abstract

Vulcanizable elastomeric stock material in sheet, tubular and spiral form featuring interiorly thereof substantially inextensible cord assemblies in spaced relationship with each other and in aggregate defining a plane closer to one of the surfaces of the sheet or closer to the interface of the spiral member than the other; the stock material in the several forms being adapted to incorporation into tire manufacturers providing placement of the inextensible cord reinforcement in desired preselected disposition.

Description

United States Patent Alfred Marzocchi Cumberland, RJ.

Dec. 29, 1969 Sept. 28, 1971 Owens-Corning Flberglas Corporation Continuation of application Ser. No. 562,216, J y 1, 1966, now abandoned.

Inventor Appl. No. Filed Patented Assignee RUBBER STRUCTURES CONTAINING GLASS 21 Claims, 20 Drawing Figs.

us. 01 152/361, 152/356,l56/117,156/123,161/60,161/144 Int.

Field of Search 161/47, 60, 143,144,175;156/1l7,123,126,l28,131,137,

[56] References Cited UNITED STATES PATENTS 2,577,843 12/1951 Crosby etal 16l/144X 3,002,546 10/1961 Limmer 152/361 3,205,931 9/1965 Keefe, Jr. 152/361 X 3,237,673 3/ 1966 Ward 152/354 3,252,278 5/1966 Marzocchi et a1. 1 17/72 X Primary Examiner-Robert F. Burnett Assistant Examiner-Linda M. Carlin Atromeys--Staelin & Overman and Paul F. Stutz ABSTRACT: Vulcanizable elastomeric stock material in sheet, tubular and spiral form featuring interiorly thereof substantially inextensible cord assemblies in spaced relationship with each other and in aggregate defining a plane closer to one of the surfaces of the sheet or closer to the interface of the spiral member than the other; the stock material in the several forms being adapted to incorporation into tire manufacturers providing placement of the inextensible cord reinforcement in desired preselected disposition.

PATENIED ssr'zsum SNIII 1 0F 4 INVENTOR- ALFRED MARZOCCHI BY MA @116 ATTORNEYS mzmm'm an INVENTOR- 5 4 FIG.5'

ALFRED MARZOCCHI BY )& QM

ATTORN EYS mimsusgrzsnn $608,606

' sum 3m 4 INVENTOR. ALFRED MAPZOCCHI ATTORNEYS PATENTED SEP28 m7:

SHEET & UF 4 5 20K 2 9. km; 9 9. m wm RUBBER STRUCTURES CONTAINING GLASS This is a continuation of Ser. No. 562,216 filed July 1, 1966, now abandoned. The present invention relates both to the arts of rubber and glass. More particularly, the present invention relates to structures including both rubber and glass components and, as well, methods of forming these structures.

The present invention is concerned with techniques for incorporating glass, specifically fiber glass, and most particularly, assemblies of individual filaments, commonly referred to as strands, cords, rovings, fabrics, etc., into an elastomeric matrix as to ultimately yield a vulcanized structure which is improvedly reinforced by reason of the proper location and the technique employed in locating the reinforcement in the elastomeric matrix.

Traditionally in the past, textile materials such as cotton, rayon, the polyamides (more popularly referred to as NYLON) and polyesters (more popularly referred to as DACRON) have been employed in various rubber structures as reinforcement. Examples include tires, both automotive and off-the-road (as well as aircraft), wherein various textile reinforcements are employed in carcasses as well as in special reinforcements, e. g. so-called breaker strips and tread reinforcing plies. Additionally, textile reinforced elastomers and rubbers are exemplified by hoses, V-belts, conveyor belts, gaskets, and the like.

The use of glass fibers as a reinforcement material for rubber has been often thought of in the past. Each of the known textiles contribute their own particular advantage dependent to a degree upon the inherent properties of the basic filament, strand or thread in the particular advantage dependent to a degree upon the inherent properties of the basic filament, strand or thread in the particular fabric and, as well, to a degree upon the successful translation of that property into ultimate performance when embodied in a rubber matrix. The properties of glass, as illustrated by the properties exhibited by a single filament, represent a very desirable combination. These properties, considered qualitatively, include relative imperviousness to moisture, high modulus, low percent elongation, high dimensional stability and relative inertness to temperature. The translation of these desirable properties into a vulcanized or cured rubber product reinforced with glass fiber in one form or another has proven to be very difficult of attainment. Thus, in prior applications for Letters Patent as signed to the same assignee as the assignee of the present ap plication, the difficulty has been pinpointed as being due to the character of the glass fiber. Thus, textile fibers known heretofore have a degree of surface porosity and/or surface irregularity, e.g., projecting hairlike tendrils, for example, which provide mechanical securement to the rubber matrix. Glass fibers, on the other hand, are perfectly smooth. These various patent applications, such as Ser. Nos. 750,253; 218,723; 398,305; 505,564; 406,501; and 424,790, have as their object the overcoming of the bonding problem as between the smooth glass surface and the ultimate elastomeric matrix and disclose a variety of size materials and impregnating formulations as are designed to provide adhesiveness or a bonding relationship between the smooth glass surface and the elastomer. Application Ser. No. 750,253 filed on July 22, 1958 stands abandoned in favor of application Ser. No. 470,407 filed on July 8, 1965, which issued on June 11, 1968 as U.S. Pat. No. 3,387,990, and Ser. No. 714,297 filed on Mar. 19, 1968 and, additionally, continuation-in-part application Ser. No. 729,566 filed on May 16, 1968. Application Ser. No. 218,723 filed on Aug. 22, 1962 issued on May 24, 1966 as U.S. Pat. No. 3,252,278. Application Ser. No. 398,305 was filed on Sept. 22, 1964 and is still pending. Application Ser. No. 505,564 was filed on Oct. 28, 1965 and is still pending. Application Ser. No. 406,501 filed on Oct. 26, 1964 issued on July 2, 1968 as U.S. Pat. No. 3,391,052. Application Ser. No. 424,790 filed on Jan. 11, 1965 was abandoned on Jan. 30, 1969.

A "filament" of glass is an individual fiber or solid rod, as it were; which fiber may vary from 0.00005 to 0.00060 inches in diameter. A strand" is a collection or assembly composed of a plurality of individual filaments, usually numbering from 104, 208 and even up to 500 to 2,000 individual filaments, gathered together in a manner well known in the art and technology of glass fiber manufacture. A cord or bund1e" comprises a plurality of strands, for example, from two to about 30 and sometimes even up to 50 strands, plied, plaited or otherwise assembled together continuously. The strands in the bundle or cord may be possessed of twist, reverse twist, or no twist at all. Additionally, a number of strands of several ply constructions, e.g., three strands, may be combined to yield an ultimate cord having a total number of strands equal to the product of the number of strands in the first assembly times the number of these assemblies that are combined to make up the final cord. As will be appreciated, a cord is composed of a large number of individual filaments in the neighborhood of 300 to 2,000. By way of illustration, a cord construction may feature three strands of continuous filaments gathered together with or without twist. Additionally, ten of the justmentioned three-ply strand assemblies may be joined together with or without twist to form, in effect, a 30-strand assembly; each strand being composed of to 200 filaments, yielding therefore a 3,000 to 6,000 filament cord or bundle assembly. By way of further illustration, a 30,000 filament assembly cord may be achieved by first forming an assembly composed of 10 strands, then combining five of these lO-strand (each strand containing 200 filaments) assemblies to form a 50-strand as sembly and lastly combining three of the latter to yield a strand cord. The accepted cord designation for the latter construction would be a l0/5/3 cord assembly.

Another difficulty encountered in considering glass fibers, in one form or another, as a reinforcement for rubber resides in the proper manner in which to combine the two and to orient the spatial attitude of the glass fiber strand, cord, fabric, or the like, within the rubber matrix in order to achieve the maximum in achievement of reinforcement, as well as convenient incorporation into existing manufacturing techniques employed in the production of rubber products.

In accordance with the present invention, it is believed that proper location of the glass component would provide the optimum in terms of the translation of the capability of the basic glass fiber or filament into improved performance of the finished reinforced product.

With the foregoing understandings, it is a general object of the present invention to provide methods for combining glass and rubber into an integral unit.

It is another object of the present invention to provide a method for combining glass elements and rubber vulcanizable rubber stock material as to yield a component which tends to provide the glass in a desired preselected relationship within the ultimate molded rubber product.

It is still another object of the present invention to provide structures embodying rubber and glass elements in preselected relationship with each other as to insure the retention of this preselected relationship during the vulcanization of the product into which the glass rubber structures are incorporated as building elements for purposes of lending reinforcement at desired locations or positions needing such reinforcing.

It is a particular object of the present invention to provide vulcanizable rubber elements containing glass elements distributed therein in a highly desirable fashion and maintained in spaced, noncontacting relationship as will substantially preclude interelement destruction of the glass elements as might occur if such elements were allowed to come into contacting relationship.

It is additionally an object of the present invention to provide vulcanizable structures including a combination of glass and rubber; which structures are ideally suitable for incorporation into existing rubber manufacturing operations as to lend a particular degree of reinforcement where needed.

It is also an object of the present invention to provide methods for combining vulcanizable rubber stock material and glass elements which have been previously coated with appropriate bonding sizes and compatibly adhesive impregnating systems.

The foregoing, as well as other objects of the present invention, will become apparent to those skilled in the art from the following more detailed description and recitation of examples taken in conjunction with the annexed sheets of drawings on which there are presented, for purposes of illustration only, a number of variant embodiments of the present invention.

It is a particular object of the present invention to provide a vulcanizable rubberlike sheet, band or strip material containing, embedded therein in particular offset relationship with respect to the central plane of said sheet, band or strip, a plurality of mutually parallel cords composed in each case of a plurality of strands of individual glass fibers assembled together and held in a binding matrix.

IN THE DRAWINGS FIG. 1 is a schematic side elevation view with portions broken away and serving to illustrate a manner of combining glass elements and vulcanizable elastomeric stock material in accordance with one embodiment of the present invention;

FIG. 2 is a cross-sectional view, partially broken away for simplicity of illustration, of a structure embodying cords of glass and a rubber matrix in accordance with the present invention and representing a product of the process illustrated in FIG. 1;

FIG. 3 is a view of the encircled left end segment of the structure shown in FIG. 2, but greatly enlarged;

FIG. 4 is a schematic side elevation view, partially broken away, illustrating a technique for combining elastomeric stock material and glass elements in accordance with another embodiment of the present invention;

FIG. 5 is a top plan view taken on the line 5-5 of FIG. 4;

FIG. 6 is a sectional view of the product of the technique illustrated in FIG. 4 and taken on the line 6-6 of FIG. 4;

FIG. 7 is a schematic view of a multiple-ply structure including glass and rubber elements in each ply in accordance with another embodiment of the present invention;

FIG. 8 is a top plan view schematically illustrating production of a particular structure, including elastomer and glass, and representing another embodiment of the present invention;

FIGS. 9 through 13 are schematic sectional views taken on the lines, respectively, 9-9, 10-10, 11-11, 12-12 and 13-13 in FIG. 8, but with portions broken away;

FIG. 14 is a schematic perspective view of the multiple-ply product of the technique illustrated in FIG. 8;

FIG. 15 is a schematic side elevation view, partly in section, illustrating a process and/or technique for producing a vulcanizable rubber structure containing glass strand in a particular location in accordance with another embodiment of the present invention;

FIG. 16 is a sectional view taken on the line 16-16 of FIG. 15;

FIG. 17 is a sectional view taken on the line 17-17 of FIG. 15;

FIG. 18 is a sectional view taken on the line 18-18 of FIG. 15;

FIG. 19 is a sectional view taken on the line 19-19 of FIG. 15; and

FIG. 20 is a schematic perspective view of a tire construction with portions broken away for purposes of illustrating one embodiment of the present invention, specifically a tire construction including a glass/rubber structure representing a preferred embodiment of the present invention.

In its simplest embodiment, the present invention envisions vulcanizable structures composed of glass and rubber in particular form as to be most desirably incorporated into the layup in a building of rubber products prior to vulcanization. It is envisioned that the reinforcement of elastomeric items, such as tires, hose, belts, etc., can be most expeditiously accomplished utilizing a preassembled rubber containing glass cord structure in which the glass, in the form of cords, are preselectively located as to contribute the optimum in reinforcement of the ultimate vulcanized product.

The present invention particularly envisions structures, for example, a sheet, a strip or a band, formed of rubber and glass wherein (as viewed in cross section) the glass is located primarily in that portion of the band as is characterized by the existence of tension forces, whereas the remaining portion of the band is, from the standpoint of statics, characterized by the existence of compressive forces.

The present invention additionally envisions structures of glass and rubber wherein, in section, the rubber exhibits gradient properties or is, in part, of gradient composition due to selection of recipe, choice and amount of particular elastomer, filler and cure system, etc.

The precise nature and, as well, the general concept of the present invention will become more self-evident from the following description of the techniques illustrated in the drawings; it, of course, being understood that such are included herein primarily for the purpose of compliance with the patent statutes requiring the setting forth of the manner of practicing the invention, as well as preferred modes thereof.

Referring now more specifically to FIG. 1, there is disclosed one technique for producing a glass and rubber containing structure in accordance with the present invention. A reel 20 contains an array of mutually parallel strands 21; each composed of an assembled multiplicity of glass fibers. A spool of strands of this type is frequently referred to in the textile trade as a beam. The strands 21, in mutually parallel relationship, are passed horizontally from the spool, about a roller 22, into a tank 24 containing a bath of impregnant 23 of a composition to be hereinafter disclosed in more detail. The tank 24 also contains three pairs of

opposed rollers

25, 26 and 27. The rollers are disposed to maintain the array of mutually parallel strands or cords within the bath of irnpregnant and, additionally, to subject the strand to a sharp bend to increase the efficiency of impregnation of the impregnant into the interstices or voids between the individual fibers. Opposed rollers 26 subject the parallel array of cords to some compression as to also increase the impregnation or pickup of impregnant. From the rightmost pair of counterrotating rollers 27, the impregnated strand passes vertically upward out of the bath, between adjustably spaced wiping members 27a and 27b and into a chamber 28, thence reversely downwardly about roller 29. The chamber 28 includes an inlet 30 for introduction of hot air for drying the impregnated strand or, in the case of a thermally active impregnant, to at least partially advance the polymerization or vulcanization of the impregnant components, as the case may be. The strands proceed downwardly from roller 29 and through a four-roll calender stack, identified by the reference numeral 31. The calender stack 31 is composed of horizontally disposed

rollers

32 and 33 and vertically disposed

rollers

34 and 35 situated directly below roller 33. Elastomeric stock material S is fed to the upper nip between spaced

horizontal rollers

32 and 33. Similarly, elastomeric stock S-l is fed into the nip between vertically situated

rollers

34 and 35, in the manner illustrated, and as assisted by a guide shoe 36. The parallel array of strands proceed about roller 32a and .between

rollers

33 and 34 as urged by the windup roll 38. The calender setup 31 is operated in typical manner, that is, with appropriate temperature control of the individual rolls, rotational speed and spacing as to effect pickup on roll 33 of a layer of stock S and, similarly, a pickup of a layer of stock S-l on roll 34 which merges at the nip of counterrotating rolls 33 and 34 together with the array of strands. As a consequence, there emerges from the calender a continuous length of a sheet of elastomer having a thickness corresponding closely to the spacing of the surfaces of

rolls

33 and 34 and said sheet containing therewithin an array of mutually parallel strands or cords of glass yielding a structure 41, as shown in FIG. 2. The windup roll 38 urges the structure 41 over an idler roll 39 and, contemporaneously, winds it upon the roll 38 together with a continuous length of polyethylene or cotton duck 40a proceeding from a supply roll 40. The latter is wound between layers of the vulcanizable structure 41 and serves to prevent the rolled product from sticking to adjacent layers above and below. The reference numeral 39a identifies a vertically adjustable movable support for the idler roller 39. The latter and the windup roller 38 are shown in dotted outline in an alternative position to that shown in solid-line outline.

In operation, the continuous array of strands or cords 21 are drawn in sequence into the impregnant bath 23, up through the drying chamber 28 and through the calender setup 31 to produce a sheet of vulcanizable elastomeric containing, internally thereof, cords of glass maintained in mutually parallel array. Particularly in accordance with this invention, the windup roll 38 and idler roller 39 are positioned so that the array of strands will be located closer to one facing surface of the structure 41 than the other. Thus, as can be seen in FIG. 2, the array or cords are located closer to the one facing surface 410 than to the other facing surface 411:. An individual cord is shown in sectional enlarged view in FIG. 3. It can be seen that it is composed of a plurality of strands 21a; each of which is itself composed of a plurality of 200 to 1,000 individual filaments as hereinbefore defined. The strands 214 are surrounded by the impregnant substance picked up during immersion in the impregnant bath 23.

Referring now to FIG. 4, there is shown a method and apparatus for forming, in a different fashion, a rubber structure containing glass cords which are located in a preselected spatial array. The reference numeral 50 identifies a spool or beam" from which is unreeled a plurality of mutually parallel cords composed of strands of glass fiber; the parallel cords being drawn vertically downwardly between

opposed rollers

52 and 53 and further downwardly between

opposed rollers

54 and 55. Extruder nozzle 57 includes an internal throat 58 from which issues, as controlled by revolving barrel 59, a thin band 60 of vulcanizable rubber; which band is entrained over roller 53 to pass downwardly in converging relationship with the mutually parallel array of cords 51. Similarly, extruder nozzle 57a includes an internal throat 58a from which issues, by reason of revolving barrel 590, a band 60a of vulcanizable elastomer which passes about roller 52 and downwardly into merging relationship with the mutually parallel array of strands and, as well, the sheet or band of rubber 60. Band 60a is somewhat greater in thickness than band 60. The assembly of face-to-face bands 60 and 60a, having therebetween mutually parallel array of strands 51, passes between c0unterrotating rolls 54 and 55. The counterrotating rolls 54 and 55 press the assembly together into an essentially integral structure 61, shown in sectional view in FIG. 6. Spray nozzles 62 situated above the individual bands 60 and 601; as they issue from the extruder heads serve to apply to their upper faces an effective amount of a plasticizer or softener for the rubber stock material as to accentuate and assist the knitting together of the two stock materials at the interface 62 (FIG. 6). As can be seen from FIG. 6, the array of individual strands 51 define in aggregate a plane which is located closer to the one surface 60 than the other 60a of the integral structure 61.

In FIG. 7, there is disclosed a plied up construction 70 formed of a structure such as structure 61 of FIG. 6 or structure 41 of FIG. 2. The construction 70 is composed of outer ply 71, intermediate ply 72 and inner ply 73. The plies may be continuous; that is, formed of a single length of the structure 61 spirally sound about a mandrel or core, not shown. In the alternative, structure 70 may be formed of three or more separate lengths of varying longitudinal dimension. The firstis wrapped about a core or mandrel, not shown, with the two ends of the first lengths butted together. The second longer length is wrapped about the first, with its mating ends in ofiset relationship with respect to the butt end or seams of the lower ply. Finally, a third still longer length is wrapped about the second, likewise with its mating ends offset with respect to the seam of the second ply. As can be seen, the plies, as viewed in section, are similarly disposed; that is, so that the array of 75 cords is closest to the outer face which is the region of the individual band which would be in tension in the cylindrical construction as shown. This type of construction may, for example, be used in the building of a tire wherein the structure 61 constitutes breaker strips or plies. (See element 102 in FIG. 20.)

Another embodiment of the present invention as particularly relates to a glass cord and rubber structure and method for making same is shown in FIGS. 8 through 14. As shown in FIG. 8, a continuous length -of a l/64 to H8 thick band measuring l to 8 inches in width and constituting a structure such as 61 (FIG. 6), that is, composed of vulcanizable rubber and containing mutually parallel array of cords of glass 51 arranged in offset relationship therein, is drawn from a continuous supply thereof and passed through and in-series array of dies 80, 81, 82, 83 and 84. The dies have respective orifices, as illustrated in FIGS. 9 through 13, whereby one lateral edge of the strip 61 is rolled upon itself by reason of the configuration of the first die 80, as at 80a. The successive die configurations urge successive rolling of the band 61 into spiral configuration, leading ultimately to the construction illustrated in FIG. 14 and identified by the reference numeral 91. The structure 91, as can be seen, is continuous and of tubular or cylindrical configuration. It contains, uniformly distributed therethrough, an array of reinforcing cords in accordance with preferred aspects of the present invention. The array of cords define (in section) a spiral located closer to one surface of the roller up band. This vulcanizable structure can be incorporated in various rubber manufacturing operations. For example, it can be adapted into a bead construction. It can be slightly flattened and incorporated in the shoulder region of a tire supplementing or complementing the lateral side regions of a tread reinforcing or a breaker strip construction.

FIG. 20 discloses a tire construction composed of spaced rim-contacting beads joined by a toroidal carcass 106 and a connected tread portion 104 extending circumferentially about the carcass. The tire includes, between the carcass 106 and tread 104a, a tread reinforcing band 102 or breaker strip desirably formed of a plurality of structures in accordance with this invention; that is, the structure 61 of FIG. 6 or the structure 41 of FIG. 2. The tire 100 may also include the structure 91 either as a bead reinforcement or as a supplemental reinforcement in selective regions beneath the tread, particularly in the shoulder region at the lateral edges of the breaker strips. The structure 91 at this location provides greater dynamic stability than obtained by the breaker strip alone.

A method and apparatus for producing glass reinforced vulcanizable rubber structures, in accordance with still another embodiment of the present invention, is illustrated in FIGS. 15 through 19. In the process illustrated, a continuous tubular element 110 formed of vulcanizable rubber stock proceeds horizontally via conveyor arrangement 111. A continuous band 112 of vulcanizable rubber stock having embedded therein, in mutually ofiset relationship, a plurality of spacedapart parallel cords of glass (structure 61 or 41) is passed downwardly about roller 109 into tangential relationship with the upper side of the tubular element 110. The two are immediately passed through die member 115. After emerging from this die, the assembly 114 is merged tangentially with another similar band or strip 116 of vulcanizable rubber stock material containing, embedded therein in mutually offset relationship, a plurality of spaced parallel cords of glass (structure 41 or 61), proceeding inclinedly upwardly about roller 117. This combination is immediately passed through a die 120 from which the product, in the form of a laminated tubular assembly 130, is delivered. The die comprises a fore portion 115:: and an aft portion 115b and, viewed in section, the die is seen to be of split construction; that is, composed of two halves 1150 and 115d. The die halves define a principal central passageway 115e, which is of variable contour, extending from the inlet end 115) in fore portion 115a to the outlet end 115g in the aft portion 115b. Referring to FIG. 16, it can be seen that the passageway lle at the inlet 1l5f defines a rectangular opening on top of and contiguous to a circular opening which together easily receives the strip or band 1 12 in contacting overlying relationship with the tubular element 110. Referring to FIG. 17, the die passageway 115a has gradually changed in contour in proceeding through the die to define a circle at the outlet end 115g. As a consequence, the lateral side edges of the band 112 have been gradually urged downwardly and about the tubular element 110 in such fashion that its lateral edges ultimately meet end-to-end, as indicated by the reference numeral 130a. The fore and aft portions 115a and 11512 of the die member 115 are each provided with an upper inlet 115m and a lower outlet l15n between which extends, in surrounding relationship with the die passageway, a circuitous canal 115p for circulation of a heat exchange media. In this respect, fore portion 115a is desirably furnished with a heated medium (steam, water or oil) whereby the rubber asernbly introduced thereto is easily deformable by the inner surface configuration of the die passageway l 15e. Similarly, it is usually desirable that the aft portion 1l5b have circulated therethrough cool water so as to tend to solidify or rigidify the assembly 114 as it emerges from the exit 115g. The die 115 also includes an elongate central region 115: between the fore-and-aft portions, accommodating the gradual change in the passageway 115a from that as illustrated in FIG. 16 to that illustrated in FIG. 17. The region 1151 may be refractory to provide insulation between the different halves.

The die 120 is very similar in construction to the die 115, excepting for the initial contour of the die passageway and the gradual change. Thus, as viewed in section in FIG. 18, the die passageway in the fore end 120f is of a configuration as will easily accommodate the tubular assembly 114 atop the rectangular band 116 proceeding upwardly about the guide roller 1 17. The die passageway 120a gradually changes in configuration in proceeding from the inlet end l20f to the exit end 120g in that it assumes the configuration shown in FIG. 19, which is essentially a circle, from which the ultimate assembly 130 emerges as shown. As in the previous die 115, heat exchange media is circulated through similar component parts to assist in the formability of the assembly in the fore region and to tend to rigidify the elastomeric stock material as it emerges from the aft portion and as viewed in FIG. 19. The seam 150 defining the juncture of the lateral edges of the band 116 is at the top of the assembly 130, as seen in FIG. 19.

A fine stream of a solvent or softener for the rubber stock composition can be applied to the upper side of the assembly 130 emerging from die 120 via a nozzle 140. The assembly 130 is then passed between counter-rotating rolls 141; the upper one of which is provided with a knurled region in contacting relationship with the butt end seam (lateral meeting edges of band 116) in order to better knit these two lateral edges together. The finished assembly is thus seen to be a laminated structure comprising a central core and two successive outer larninants; each of the latter characterized by an embedded circular array of cords of glass which are arranged equidistantly from the center of the assembly and particularly located in the outer peripheral regions of the particular band. Consequently, the array of strands is located in those regions characterized by tension forces. The inner regions of the individual bands, on the other hand, are characterized by compressive forces.

A continuous length of this material is conveniently cut into convenient lengths and stored on leaf trucks" for later incorporation into various rubber products desiring reinforcement in critical regions. The diameter of these structures produced, as illustrated in FIGS. 15 to 19, may range from one quarter inch up to an inch or more in diameter. It should also be appreciated that these sizes can be conveniently provided for by suitable selection of the size of the central core 112 and the thickness and width of the

bands

110 and 116. The

bands

110 and 116, of course, can be produced in the manner previously illustrated in FIG. I, for example, in which case the finished sheet good 41 is subdivided by dividing the width of the sheet 41 into appropriate smaller width bands. Similarly, the product 61 shown in FIG. 6 may be produced, in accordance with the extrusion techniques shown, in the desired width or the extrudate may be subdivided into a plurality of strips of appropriate size. The tubular element in the assembly may be a solid vulcanizable rubber element as described above, or it may be formed of the structure 91 shown in FIG. 14, or it may be an assembly of one or more cords gathered together in contiguous relationship and thereby adapted in accordance with the process shown in FIG. 15 to be enclosed within successive peripheral wraps or layers of the

bands

112 and 116.

The individual glass fibers or filaments as described above and used in assembling strands and/or cords used in the rubber/glass structures of the present invention are preferably sized just subsequent to being drawn from the filament forming bushing. A number of suitable sizes are disclosed in the copending patent applications as mentioned hereinbefore. By way of illustration, the following are representative of size compositions:

EXAMPLE I 0.5-2.0 percent by weight gamma-aminopropyltriethoxy silane 0.3-0.6 percent by weight glycerine Remainder water EXAMPLE 2 8.0 percent by weight partially dextrinized starch l.8 percent by weight hydrogenated vegetable oil 0.4 percent by weight lauryl amine acetate (wetting agent) 0.2 percent by weight nonionic emulsifying agent 1.0 percent by weight glycylato chromic chloride EXAMPLE 3 3.2 percent by weight saturated polyester resin 0.1 percent by weight polargonate amide solubilized with acetic acid 0.1 percent by weight tetraethylene pentamine stearic acid 0.1 percent by weight polyvinyl alcohol 3.0 percent by weight polyvinyl pyrrolidone 0.3 percent by weight gamma-aminopropyltriethoxy silane 0.1 percent by weight acetic acid 93. I percent by weight water.

The liquid size is applied to the glass fiber filaments as they are gathered together into strands and then the assembled strand of fibers bearing the size is allowed to dry in ambient air.

In FIG. 1 described hereinbefore, the beam" of parallel strands or cords of fibers was described as being directed into a bath of impregnant 23. A number of formulations of suitable impregnants is also disclosed in the referred-to pending applications assigned to the same assignee as the present application. For purpose of illustration, the following examples 4-7 are representative of the compositions containing an elastomeric material which may be used as the bath of impregnant 23 into which the cords or strands are introduced before combining with the rubber stock material as described hereinbefore and herein stated in the drawings.

EXAMPLE 4 100 parts by weight neoprene rubber 4 parts by weight powdered magnesium oxide 5 parts by weight powdered zinc oxide 15 parts by weight Channel Black 1 part by weight Thiate B (trialkyl thiourea accelerator) The foregoing ingredients are mixed on the mill, sheeted off and dissolved in a suitable rubber solvent such as Xylene or methyl ethyl ketone to form a 20 percent solids solution which constitutes the impregnating bath.

9 EXAMPLE 100 parts by weight Paracril C rubber (Buna N) 25 parts by weight SRF carbon black 5 parts by weight powdered zinc oxide 5 0.5 parts by weight Aminox (reaction product of diphenyl EXAMPLE 6 60 parts by weight Lotol 5440U.S. Rubber Company Lotol 5440 is a 38 percent dispersed solids system including a butadiene-styrene-vinyl pyridine terpolymer latex, a butadiene styrene latex and a resorcinol-fonnaldehyde resin.

39 parts by weight water EXAMPLE 7 '2 parts by weight resorcinol formaldehyde resin 1 parts by weight Formalin (37 percent solution) 2.7 parts by weight concentrated ammonium hydroxide 25 parts by weight vinylpyridine terpolymer (42 percent latex) 4] parts by weight neoprene rubber latex (50 percent solids) 5 parts by weight butadiene latex (60 percent solids) 0.05 parts by weight sodium hydroxide 1 part by weight gamma-aminopropyltriethoxy silane 1 part by weight vulcanizing agent 1,100 parts by weight water.

It will be appreciated that the selection of impregnant will be guided by knowledge of the nature of the rubber stock material in which the impregnated strand or cord is to be embedded in several methods disclosed herein.

The elastomeric component of the rubber/glass structures (assemblies) of the present invention may be (a) natural Hevea rubber, (b) synthetic rubber; the latter including GR-S rubber (butadiene-styrene copolymer), nitrile rubber, butyl rubber, neoprene rubber (also known as polychloroprene), polychlorobutadiene rubber, polysulfide rubber, polyisoprene rubber, Cis-4 polybutadiene rubber, polyisobutylene rubber, polyurethane rubber, etc., and (c) as well, the rubberlike resins such as polyesters, vinyl polymers, and copolymers, polystyrene, silicones, chlorostyrenes, polyvinylacetals, polyethylene, polypropylene and the fluorocarbons.

Typical recipes for a natural rubber and a synthetic GR-S rubber are given in table 1.

Philrich 5 TABII 1 Continued 1 0 Pine tar Sulfur 2.25 NOBS Special 0.5 Santocure L2 Pepton 22" 0.5 Retarder w" a l.t ut adiene -styrene coime r rubber. also known as GR-S rubber s when s a c. a highly aromatic oil d. N- oxy diethylene benzo thiazole 2 -sulfonaniide, marketed by American C yanamid e. N-cyclohexyl benzothiazol i -Eult'omimide, marketed by Monsanto Chemical C o.. S t. Lo uis. Missouri f. di O berEamidQ phenyl disul fide marketed by Ameri an Cyanamid fs'biic iib' acid marketed b E. l. duPont Table 2 below lists typical recipes for a butyl rubber, a neoprene rubber (polychloroprene) and a nitrile rubber.

TABLE 2 RECIPES OF LOADED STOCKS Butyl Neoprene Nltrile Polysar Butyl 30l Neoprene W Hycar I042 Stesric acid Zinc Oxide Light magnesia Butyl phthalate Circo light process oil Dibenzothiazyl disulfide Telramethylthiuram disulfide Diphenylguanidine 0.8 Z-Mercaptoimidazoline (NA-22) 0.5 Sulfur Phenyl-B-nsphthylamine MPC black 20 vol.

20 vol.

20 vol. vulcanization, min,

35 nt l53 C.

at I53 C.

at l53 C.

b. a channel class carbon black, whole particles have a mean diameter of 25 millimicrons The rubbers given in either of table 1 or table 2 are workable on a mill, calender or extruder and therefore are readily combinable with cords and strands (formed of fiber glass) of essentially inextensible material in the manner as described earlier herein. These rubbers are also vulcanizable to a cured state in which the glass structure will be fixed within the elastomeric matrix, as described, and therefore ideally located for effective reinforcement of the cured part in which contained.

The multiple-ply construction of this invention as illustrated, for example, in FIGS. 2 and 6, finds particular utility in the manufacture of tires as described earlier herein. In such case, the sheet material 41 is desirably bias cut and incorporated into a tire as a peripheral band or belt beneath the tread region. Usually, I prefer to employ at least two such belts bias cut at an angle as will yield a vulcanized structure in which the cords will define an angle of from to 28, most preferably, 24, with the peripheral centerline of the tire. The cords in the adjacent belts should be oppositely inclined so that they will define an included angle of 48. In each belt, the cords will be located closest to the outer surface or, in other words, in the tension region of each. The individual belt plies can be fabricated of relatively thin stock but providing the maximum in separation of the cords in abutting belt plies. This feature is illustrated in FIG. 7, for example. The carcass plies of such a tire may be also formed of glass or of NYLON (polyamide), DACRON (polyester), rayon, etc.

From the foregoing, it is seen that the present invention provides novel glass reinforced rubber structures having a wide adaptability in terms of combining with a wide variety of rubber products needing reinforcement of the type herein concerned. The structures are of a configuration as to permit their easy incorporation into a variety of products.

It is additionally and particularly desirable that the methods of invention herein disclosed are adaptable to produce structures of the invention of various dimensional sizes.

Modifications may be resorted to without departing from the spirit and scope of the present invention.

1 claim:

1. A tire tread reinforcing band construction comprising a plurality of layers in substantially coextensive face-to-face abutting relationship, said layers each comprising a matrix component comprising a vulcanizable elastomeric stock composition having located interiorly therein a plurality of mutually parallel strands of substantially inextensible character, said strands in each layer being therefore in parallel relationship with strands in the adjacent layer, said strands in a given 1 layer being definitive of a common plane offset with respect to the central plane of said layer.

2. A construction as claimed in claim 1, wherein said strands in adjacent layers are similarly offset on the same side of their respective central plane and said strands are formed of glass filaments.

3. A tire construction which includes the multiple-ply construction claimed in claim 1.

4. In a tire construction including spaced circular bead portions, a connecting carcass portion proceeding in toroided configuration from bead to bead and a ground-contacting tread portion encircling said carcass portion, all of said components including an elastomeric composition holding them a central generally cylindrical core comprising an elongate tubelike member formed of vulcanizable elastomeric stock,

a first layer abuttingly surrounding said core along the length of said core, said layer having abutting edges defining a meeting line along said length, said layer including a vulcanizable matrix of elastomeric stock material, said layer in section defining an annulus having an outer surship with the outer cylindrical surface of said core, said layer including a plurality of strands of substantially inextensible material in annular array substantially equidistantly spaced from the central axis of said core, said strands each including a multiplicity of continuous glass fibers or filaments held together by a common impregnant substance in substantially noncontacting relationship, said annular array of strands being closer to one of the outer and inner surfaces of said layer than the other, and

a second layer abuttingly surrounding said first layer, said second layer having the same structure as the first layer but having the abutting-edge-defined line offset to the line defined by the abutting edges of said first layer.

6. An elongate spiral construction comprising an elongate band of elastomeric material, said band having spaced edges, one constituting the center of said spiral and the other edge lying in the outer periphery of said spiral, said band including an array of strands of glass filaments in parallel relationship .between said edges and spaced closer to one surface of the band than the other.

7. An elongate tubelike member of convoluted cross sectional configuration and formed of elastomeric material, said convolution being of generally uniform thickness, said member including therein a plurality of mutually parallel, closely spaced strands of glass filaments, said strands in sectional aggregate defining a spiral which is offset with respect to the spiral which is equidistant from the lines constituting the interface of said convoluted structure.

8. An elongate band of vulcanizable elastomeric material, said band being folded upon one lateral edge into convoluted spiral configuration as viewed in section, said band having ,spaced surfaces and, embedded therebetween but closer to one surface than the other, an array of strands of substantially inextensible material, said strands being in mutually parallel relationship, each strand including a multiplicity of individual continuous glass filaments separated by a common continuous impregnant, said strands being in equispaced relationship from the surface in closest proximity.

9. An annular body formed of vulcanizable elastomeric material, said body including a plurality of concentric layers, each layer having a facing surface in substantially coextensive abutting relationship with the facing surface of the adjacent layer, said layers each including a plurality of spaced cords defining, in aggregate array, an imaginary cylinder, the surface of which is closer to one of the surfaces of the layer containing same than the other, said cords each consisting essentially of a gathered plurality of continuous glass fibers embedded in an elastomeric matrix.

10. The body as claimed in claim 9, wherein the cylinder defined by the cords in each layer is closer to the outer surface of the layer containing same.

11. The vulcanized body of claim 9.

12. A tire construction having an annular vulcanized body in accordance with the construction of claim 9.

13. An annular body fonned of vulcanizable elastomeric material, said body being defined by a sheet of said material wound in spiral configuration upon itself but as to leave a central void, said sheet having lateral edges and facing surfaces, said sheet material including embedded therein a plurality of cords in mutually closely spaced parallel relationship with each other and the said lateral edges, and spaced closer to one facing surface of said spirally wound sheet than the other, said cords each consisting essentially of a gathered plurality of continuous glass fibers substantially physically insulated one from the other.

14. The body as claimed in claim 13, wherein said cords are spaced closer to the radially outer facing surface of said sheet.

15. The vulcanized body as claimed in claim 13.

16. A tire construction including a vulcanized annular body construction as claimed in claim 14.

17. An elongate, vulcanizable, elastomeric member, said member including, as viewed in section, a central generally cylindrical core, and a first enveloping layer along the length face and an inner surface, the latter in abutting relationof said core, said layer having an inner surface abutting said 18. A tire construction which includes the construction as defined in claim 2.

19. A tire construction as claimed in claim 18, wherein said construction is located just beneath the tread in the form of a pair of peripheral belts.

20. A tire construction as claimed in claim 19, wherein the strands define an angle of 20 to 28 with the peripheral centerline of the tire.

21. An elongate, vulcanizable, elastomeric member, said member including, as viewed in section:

a central generally cylindrical core,

a first enveloping layer along the length of said core, said layer having an inner surface abutting said core and an outer surface, said layer being of uniform thickness and having embedded interiorly therein a plurality of essentially inextensible cords, said cords defining, in aggregate, an annulus concentric with the axis of said core and located closer to the said outer surface, said cords each consisting essentially of a gathered plurality of glass fibers substantially physically insulated from each other by an elastomeric impregnant, and

a second layer along the length of said first layer and having an inner surface abutting said first layer and otherwise having the structure of said first layer, and said first and second layers having meeting edges in oflset relationship.

Claims

1. A tire tread reinforcing band construction comprising a plurality of layers in substantially coextensive face-to-face abutting relationship, said layers each comprising a matrix component comprising a vulcanizable elastomeric stock composition having located interiorly therein a plurality of mutually parallel strands of substantially inextensible character, said strands in each layer being therefore in parallel relationship with strands in the adjacent layer, said strands in a given layer being definitive of a common plane offset with respect to the central plane of said layer.

4. In a tire construction including spaced circular bead portions, a connecting carcass portion proceeding in toroided configuration from bead to bead and a ground-contacting tread portion encircling said carcass portion, all of said components including an elastomeric composition holding them together as an integral whole, the improvement which comprises a peripheral breaker strip or ply assembly situated between said tread and the outer periphery of said carcass, said breaker strip or ply assembly including the construction claimed in claim 2.

5. An elongate multiple-ply construction comprising: a central generally cylindrical core comprising an elongate tubelike member formed of vulcanizable elastomeric stock, a first layer abuttingly surrounding said core along the length of said core, said layer having abutting edges defining a meeting line along said length, said layer including a vulcanizable matrix of elastomeric stock material, said layer in section defining an annulus having an outer surface and an inner surface, the latter in abutting relationship with the outer cylindrical surface of said core, said layer including a plurality of strands of substantially inextensible material in annular array substantially equidistantly spaced from the central axis of said core, said strands each including a multiplicity of continuous glass fibers or filaments held together by a common impregnant substance in substantially noncontacting relationship, said annular array of strands being closer to one of the outer and inner surfaces of said layer than the other, and a second layer abuttingly surrounding said first layer, said second layer having the same structure as the first layer but having the abutting-edge-defined line offset to the line defined by the abutting edges of said first layer.

6. An elongate spiral construction comprising an elongate band of elastomeric material, said band having spaced edges, one constituting the center of said spiral and the other edge lying in the outer periphery of said spiral, said band including an array of strands of glass filaments in parallel relationship between said edges and spaced closer to one surface of the band than the other.

8. An elongate band of vulcanizable elastomeric material, said band being folded upon one lateral edge into convoluted spiral configuration as viewed in section, said band having spaced surfaces and, embedded therebetween but closer to one surface than the other, an array of strands of substantially inextensible material, said strands being in mutually parallel relationship, each strand including a multiplicity of individual continuous glass filaments separated by a common continuous impregnant, said strands being in equispaced relationship from the surface in closest proximity.

11. The vulcanized body of claim 9.

13. An annular body formed of vulcanizable elastomeric material, said body being defined by a sheet of said material wound in spiral configuration upon itself but as to leave a central void, said sheet having lateral edges and facing surfaces, said sheet material including embedded therein a plurality of cords in mutually closely spaced parallel relationship with each other and the said lateral edges, and spaced closer to one facing surface of said spirally wound sheet than the other, said cords each consisting essentially of a gathered plurality of continuous glass fibers substantially physically insulated one from the other.

15. The vulcanized body as claimed in claim 13.

17. An elongate, vulcanizable, elastomeric member, said member including, as viewed in section, a central generally cylindrical core, and a first enveloping layer along the length of said core, said layer having an inner surface abutting said core and an outer surface, said layer being of uniform thickness and having embedded interiorly therein a plurality of essentially inextensible cords, said cords defining, in aggregate, an annulus concentric with the axis of said core and located closer to the said outer surface, said cords each consisting essentially of a gathered plurality of glass fibers substantially physically insulated from each other by an elastomeric impregnant.

18. A tire construction which includes the construction as defined in claim 2.

20. A tire construction as claimed in claim 19, wherein the strands define an angle of 20* to 28* with the peripheral centerline of the tire.

21. An elongate, vulcanizable, elastomeric member, said member including, as viewed in section: a central generally cylindrical core, a first enveloping layer along the length of said core, said layer having an inner surface abutting said core and an outer surface, said layer being of uniform thickness and having embedded interiorly therein a plurality of essentially inextensible cords, said cords defining, in aggregate, an annulus concentric with the axis of said core and located closer to the said outer surface, said cords each consisting essentially of a gathered plurality of glass fibers substantially physically insulated from each other by an elastomeric impregnant, and a second layer along the length of said first layer and having an inner surface abutting said first layer and otherwise having the structure of said first layer, and said first and second layers having meeting edges in offset relationship.