CA2024973A1 - Recycled rubber compositions and products - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A novel molding composition is provided herein. The molding composition comprises 90% ? 5% by weight shredded spent rubber tires and correspondingly 10% ? 5% by weight of a resin system comprised either wholly of a formaldehyde/resorcinol resin, or of a mixture of the formaldehyde/resorcinol resin with a resin cross-linking agent system with or without a conventional sulfur vulcanization system and/or a fire retardant agent. The resin cross-linking agent system may be combined with a conventional sulfur vulcanization system for cross-linking the rubber. The molding composition is adapted to be placed, e.g., by extrusion, into forms or molds and cured at, e.g., a minimum temperature of 300°F, e.g., at 360°F ? 25°F, for a minimum time of 1 minute.

Description

, This invention relates to the reuse of rubber tires.
In the United States and Canada, society is disposing of hundreds of millions of spent automotive tires and the so-called "TOWMOTOR" tires, (e.g., a solid rubber tire adhered to a steel wheel), every year. Some of the tires may be returned to a rub-ber tire factory where the rubber can be reclaimed as an additivefor the manufacture of new tires. A small number of worn-out automobile tires are used for making some low cost rubber arti-cles, e.g., doormats, for example.
The great majority of such spent rubber tires are now being dumped along with junked autos along roads and highways and in all possible places all over the countryside, where they pollute the landscape. This happens because there is no economical incentive for anybody to collect such spent tires as no large use has been developed for them thus far.
In addition, rubber tires may be shredded, chopped, ground, burned, buried, dumped in the ocean or exported to the Third World. They can be turned into ~ogging tracks, crash barriers, ~ungle gyms, mud flaps, sandals, doormats and hockey pucks. Yet, despite all of this and a flurry of regulations from government agencies worldwide, less than 4 percent are recycled. The rest are still accumulating in heaps, embarrassing environmental ~-protection authorities and inviting arsonists.
Such tires are banned from half of the landfills in the U.S.A. and are being shut out of more such landfills every week ~` 202~3 because they take up too much valuable space. When dumped into bodies of water, they trap air, causing them to resurface.
With the U. s. Environmental Protection Agency projecting a 50 percent reduction in landfill space by the end of the twen- -tieth century, and an 80 percent reduction by the year 2010, such tires appear to be headed for universal banishment from the fam-ily of ordinary garbage. In 1990, there are now three billion of such tires stockpiled throughout the U.S.A. 240 million passenger and 650 million truck tires are generated annually in the U.S.A. There are thousands of piles across the United States and some cover several acres of land.
Lying about, they attract not only arsonists, rats and com-mon mosquitoes, but also the Asian Tiger Mosquito, a known vector of dengue fever in the Far East. Such mosquito has been shown in the laboratory to transmit encephalitis and a number of less dan-gerous viral infections.
Contrary to popular notions, however, scrap tires are not worthless. Tires are essentially petrochemical products and when ignited, usually by lighting, piles have burned for months.
Tires are an excellent source of energy, and pollution-free incineration of whole tires can be accomplished. One such plant exists in California and converts 4-5 million tires annually into enough electricity to heat 15,000 homes. One tire contains the equivalent of 2.5 gallons of oil, enough to heat a medium-sized house for one day. Techno:Logy has kept apace. Machines are now av~ilable to slicQ through the entire rubber tire including the -~` 2024973 steel belts, to turn rubber into the consistency of crumbs, sand, or baby powder.
Using ground-up tires in the compounding of rubberized asphalt as a road building material has shown promise, but it has yet to be approved by many highway departments. Nevertheless, a growing list of States of the United States have been experi-menting with crumb rubber for road paving and patching, and advo-cates of the practice maintain that rubber/asphalt mixes will outlast conventional asphalt and perhaps provide better traction.
Paving a mile with a rubber asphalt mixture can use the equiva-lent of 16,000 ~unked rubber tlres.
Numerous advantages have been suggested for incorporating various rubbers, or rubber-like polymers into paving asphalt.
The added rubber can give the asphalt improved tensile strength, lS elastlcity, and ductility, and can reduce its susceptibility to cracking and disintegration due to mechanical stress and/or extreme temperature changes. The extent to which these advan-tages can be realized, however, depends upon the proportion and type of rubber which is utilized, and the extent to which it is ao di~solved or uniformly dispersed in the asphalt.
Until very recently, the art has contemplated the use of rubberized asphalt primarily as the cement for asphalt concretes and for this particular use economics dictated that no more than ;~
5 weight-percent of rubber could be used. These small pro- ;;;
portions wére said to give some benefit, primarily in the area of ` -~;improved ductility (as disclosed for example in U.S. Patent No.

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~ 2~24973 :

3,779,964), but gave little improvement in other physical pro-perties.
One such cement is disclosed in Japanese Patent No. 50087121 patented July 14, 1978 by Hamano Industries XK, which disclosed an impact-absorbing cement rubber pavement containing natural and/or synthetic rubber, and a synthetic resin emulsion.
It has also been found difficult under practical conditions to obtain a uniform solution or dispersion of rubber in the asphalt. One known procedure was the addition of a latex emul-sion, but this procedure was found to be impractical because ofthe necessity of flashing the water from the asphalt mixture thus formed. In addition, asphalt viscosity was often reduced adver~ely by aqueous latex emulsions.
In U.S. Patent No. 3,891,585 to McDonald, some progress was ;
said to be made toward achieving more of the potentially avail-able bene~its from the addition of rubber to asphalt. In this patent, relatively large proportions of ground, reclaimed rubber, ranging between 25% and 33% by weight, were utilized in the a~phalt mix, and the mixture was used in the form o~ relatively thin layers or membranes applied over old pavements, the mem-branes then being dressed with mineral aggregate or rock chips.
The asphalt/rubber mixture was prepared by heating the granulated rubber with the asphalt at temperatures between 350F and 500F, to form a "~ellied" composition which provided a coating of excellent elasticity, tensile strength and durability under adver~e weather conditions.

-:` 2~4973 Winters et al in their U.S. Patent No. 3,919,148, suggest adding, to the mixture, a light hydrocarbon solvent, e.g., kero-sene. This was said to bring about a temporary reduction in vis-cosity for up to 1 hour, during which time the mixture could be applied to the roadway and the application of rock chips eompleted. However, problems were encountered in using the rub-ber-rich mixture. Firstly, the adhesive qualities of the asphalt-rubber blend were not as good as most other liquid asphalt and it was therefore generally necessary to make a light applieation of a liquid asphalt first, as a tack coat to the pavement being treated, to act as a "glue" to assure that the rubberized asphalt will stick. It was also generally necessary to use elean, dry high quality rock chips to cover the hot asphalt-rubber membrane; wet or dirty ehips did not adeguately lS adhere. These faetors inereased the eost of any pro~eet, and at timeo traffie was tied up longer due to the need for the appliea-tlon of a taek eoat.
Moreover, the high viseosity and gel-like nature of the rubber/asphalt mixture usually meant that the hot blend would not ~20 flow readily into pavement eraeks when such cracks were being ealed. This meant either that the cracks eould be sealed over by a bridging aetion, or that it was necessary to rout out the !' eraeks first to widen them. Sealing would then be aecomplished ~ ' in a separate operation, whieh was an added ineonvenienee and ~ ;;
as expense. Also, in applying membranes of the mixture by eonven- ~;
tlonal ~praying methods, the high viseosity of the mixture made : ':
r~ ~ b~

~ 2~4~3 it more difficult to obtain an even, smooth spray pattern from the asphalt distributor bar. "Roping~ or ~ridging~ could more easily occur, which reduced the smoothness of the pavement. It could also be unsightly and the ridges could pose tire tracking problems for a vehicle.
Finally, the use of a light hydrocarbon solvent, e.g., kero-sene in itself presented additional problems. Since kerosene generally has a flash point of 130F - 150F, a fire hazard was presented. Further, some of the lighter fractions of the kero-sene were released to the atmosphere, creating an air pollution problem.
One general solution to the problem of re-use of rubber tires was provided by U.S. Patent No. 4,068,023, patented January 10, 1978 by D. L. Nielsen et al, in the form of facilitating the dissolving and/or disper9ing of relatively large proportions of reclaimed rubber into molten paving asphalt by incorporating, into tho asphalt, a minor proportion of a highly aromatic, high-boiling, high-flash-point mineral oil. The resulting mixtures could be held at temperatures above 300F for substantial periods ~
ao of time without becoming too viscous for convenient handling, ;
thereby facilitating the application thereof to roadways. The rubberized asphalt mixtures were said to be particularly useful in the form of stress-absorbing membrane interlayers between old, damaged pavement 9urfaces and an overlayer of new asphalt con-cr~te, for providing chip-seal coatings over old pavement, as .

crack fillers in Portland Cement concrete or asphalt concrete pavements, and bridge deck waterproofing membranes.
Another general solution to the problem of re-use of rubber tires was provided by U.S. Patent No. 3, 567,660 patented March 2, 1971 by J. Winkler, in the form of a method of conversion of oil ~ -spills into improved rubberized, fiber fortified asphaltic mater-lals by coagulating oil spills with previously ground, spent automotive rubber tires which have preferably been previously premixed with powdery polystyrene or asphalt. That patentee provided a proces~ for the preparation of reinforced asphaltic compositions including rubber, carbon blacks, and fibrous mater- ;~ial, while simultaneously removing spilled oils from water sur-~aces, by using coarsely-shredded, spent automobile rubber tires. : -~
. :. .: . ., The procedure included the steps of contacting coarsely-shredded lS ~pent automobile tire having a particle sizQ from one to ten h, with the spilled oils to sorb the oil on the particles of ;~
pent automobile rubber tire~; harvè~ting the resulting conglo- ;
merates; and reacting and concentrating the asphaltic composition ;~
by distilling o~f the volatile components at elevated tempera-ao ture, at least one of the spilled oils and the particles of spent ~ - automobile rubber tires including an asphaltic component. .'I''~
Rubber/resin compositions are also known in the art. For '~ ` example, Japanese Patent No. 2115264 patented April 27, 1990 by ; Nitta KK provided a polyamide resin composition suitable for 2S automobilo hoses, containing hydrogenated nitrile rubber and a :~
cross-linking agent.
~, ,.

. -r r Japanese Patent No. 2113028 patented April 25, 1990 by Human Industry Corporation KK provided a polymerized body which con-sisted of rubber and a coal tar derivative powder obtained by distillation o~ low grade oil in the presence of metal, then mixin~ the residue with clay and calcining.
Japanese Patent ~o. 2110155 patented April 23, 1990 by Nippon Oils & Fats KK provided a heat-resistant vinyl chloride-type resin composition which included a rubber-modified resin obtained from a monomer mixture of a maleimide compound, an alkyl (meth)acrylate, vinyl cyanide and styrene.
Japanese Patent No. 63128048 patented May 31, 1988 by Idemltsu Petrochemical KK provided a resin composition used as a hot melt adhesive and comprised of a hydrogenated copolymer of a cyclopentadiene monomer and an aromatic vinylic compound and an EVA copolylner.
Japanese Patent No. 54083090 patented July 2, 1979 by Asahi Chemical Industrie~ KK provided an impact-resistant polystyrene resin product produced by using a butadiene-isoprene copolymer o~
specified isoprene content dissolved in a vinyl monomer mixture containing styrene, and then polymerising.
Japanese Patent No. 49098446 patented September 18, 1974 by Asahi Dow KK provided a thermoplastic resin composition contain-ing rubber particles, a vinyl polymer and an oligo(phenylene ether) grafted with vinyl monomers.
as u.s. Patent No. 4,218,361 patented August 19, 1980 by W. H.
Searfoss et al provided a heat and wear resistant friction mater-2024973 ~ ~
. ~, g . ~:
ial comprising in approximate percent by weight; asbestos fibers, 20% - 60%; phenolic resin, 15% - 33%; spun blast furnace slag fibers, 1% - 15%; rubber particles, 3% - 9%; fillers, 10% - 35%;
and metallic oxide, 2% - 12%.
U.S. Patent No. 4,923,924 patented May 8, 1990 by T. S.
Grant et al provided a thermoplastic blend composition, compris-ing a specified proportion of a polyamide, a specified proportion , . ., , .,:
of a carboxylated polyphenylene ether resin which is the product ~ -of melt mixing a mixture of a polyphenylene ether resin and an : . ...
ethylenically unsaturated carbocylic acid compound, and a speci-fied proportion of an impact modifier selected from the group con~isting of grafts of a vinyl aromatic polymer on a diene rub-,, ::
ber substrate, vinyl aromatic-con~ugated diene-vinyl aromatic triblock polymers, carboxylated vinyl aromatic-conjugated diene-vinyl aromatic triblock polymers, carboxylated hydrogenated vinyl aromatic-con~ugated diene-vinyl aromatic triblock polymers, ~;
. ~ ~,.. ......
copolymer~ of an alpha-olefin compound and an unsaturated car-boxylic compound, grafts of an acrylic polymer on acrylate rubber ~ ;
: . ~ , . .,:
substrate, linear low density polyethylene, and mixtures thereof. ;
~20 ~ In spite of these general procedures for the provision of ~-rubber/resin andlor rubber/asphalt composition and for the re-use . . .~
of rubber tires, there still exists the need to find other uses of such old rubber tires.
Accordingly, principal ob~ects of aspects of this invention 2S are to provide novel compositions and novel products derived from recycled rubber tires prepared by a novel process.
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2~24973 This invention therefore in one aspect provides a molding composition comprising 90~ + 5% by weight shredded spent rubber tires and correspondingly 10% + 5% by weight of a resin system comprised either wholly of a formaldehyde/resorcinol resin, or of a mixture of the formaldehyde/resorcinol resin with a resin cross-linking agent system with or without a conventional sulfur vulcanization system and/or a fire retardant agent, in which such molding composition is specially adapted to be placed, e.g., extruded, into molds or forms, and cured at a minimum temperature of 300F for a minimum time of 1 minute.
This invention, in a second aspect, also provides a block comprising a solid formed substantially entirely from a molding composition comprising 90% + 5% by weight shredded spent rubber tires and correspondingly 10% ~ 5% by weight of a resin system compri~ed either wholly of a formaldehyde/resorcinol resin, or of a mixture of the formaldehyde/resorcinol resin and a resin cross-llnking agent system with or witho~t a conventional sulfur vulcanization system and/or a fire retardant agent, such molding composition having been placed, e.g., extruded, into molds or ao ~orms, and cured at a minimum temperature of 300F, for a minimum time o~ 1 minute.
This invention, in a third aspect, also provides a method for molding a block, comprising the steps of: mixing 90% + 5% by weight shredded spent rubber tires and correspondingly 10% + 5%
a5 by weight of a resin system comprised either wholly of a formal-dehyde/resorcinol resin or a mixture of the formaldehyde/resor-2~24373 cinol resin with a resin cross-linking agent system with or without a conventional sulfur vulcanization system and/or a fire retardant agent; placing, e.g., extruding that mixture into a mold or form; and curing the mixture in the mold or form at a minlmum temperature of 300F. for a minimum time of 1 minute.
The temperature of curing preferably is 360F ~ 25F.
The shredded spent rubber tires should preferably have a particle size of from 1 micron to 1/2 inch, and preferably from one to ten mesh. The preferred amount of the shredded rubber is 90% by weight and the preferred amount of the resin system is 10%
by weight.
The Sormaldehyde/resorcinol resin in the resin system can have many chemical compositions. It can comprise the reaction product of formaldehyde with resorcinol and containing resorcinol polymers but no free formaldehyde. Alternatively, the formalde- ;
hyde/resorclnol resin can comprisQ an acidic aqueous solution o~
a formaldehyde/~esorcinol condensation product.
The resin system preferably also includes a resin cross-linXing agent system. Examples of such resin cross-linking agent ~ -9y9tem include, for example, formaldehyde, or hexamethyltetra- :-mine, or any other suitable resin cross-linking agent system, e.g., diphenylguanidine, mercaptobenzothiazole, N-cyclohexyl~
benzothiazolesulfenamide, N-oxydiethylenebenzothiazolesulfen-:.,, j,; :. ~
amidQ~ tetramethyl- and tetraethylthiuram disulfides, thiocar-banilide, or zinc dimethyldithiocarbamate. The amount of suchresin cross-linkin~ agent system is generally the stoichiometric amount.
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The resin cross-linking agent system may be combined with a conventional sulfur vulcanization system for cross-linking the rubber.
The resin system preferably also includes a fire retardant agent. Examples of such fire retardant agents include water-soluble, inorganic salts, including ammonium bromide, borax, boric acid, phosphates, e.g., diammonium phosphate of sodium phosphate, sodium tungstate and ammonium sulfamate, and mixtures of these. Other fire retardant agents include mixtures of anti-mony oxide, or oxychloride, and chlorinated organic. Still othersuch fire retardant agents include phosphorus çompounds, e.g., tho polymer resin formed by tetrakis(hydroxymethyl)Phosphonium chloride, melamine and brominated triallyl phosphate. The amount of ~uch fire retardant agent is generally up to 7% ~y weight based on the weight of the resin system.
The block o~ one preferred embodiment of this invention may be in th~ form o~ a square cross-section post, to be used as part o~ a cable-type barrier, or as part o~ a guard-rail-type barrier.
Alternatively, the block of this preferred embodiment Or this invention may be in the form of a generally-rectangular, ~inite-length block, the base of which is provided with a pair of spaced-apart lifting slots, one end face of which is provided with a vertical Xey, the other face of which is provided with a vertical, mating slot, the cross-sectional shape being an upper 2S trapezoidal shape superposed on a lower rectangular shape, to be usQd on a movable barrier block.

2~2~973 Still further alternatively, the block of this preferred embodiment of this invention may be in the form of a generally -rectangular block of indefinite length, the cross-sectional shape ~:
being an upper trapezoidal shape superposed on a rectangular shape, to be used as a permanent, cast-in-place barrier wall.
The block of another preferred embodiment of the present invention may be in the form of a solar collector. In one such embodiment of solar collector, the solar collector comprises a .
heat storage slab formed of the molding composition previously described, which had been placed into forms or molds and cured at a minimum temperature of 300F for a minimum time of 1 minute, the heat storage slab being formed with a number of metal tubes embedded ln spaced relationship in the slab, each of the tubes being adapted for passage therethrough of a heat transfer medium and including an exterior wall portion, the exterior wall portion ~ `
forming a heat collecting surface for the unit.
In another such embodiment of solar collector, the solar collector may be in the form which includes a support surface formed of the molding composition previously described, which had ao been placed into forms or molds and cured at a minimum ~:
temperaturQ of 300F for a minimum time of 1 minute, the support ..
surface being formed with a heat transfer fluid channel adapted ~ :
to contain a circulatable heat transfer fluid, and also being formed with a chamber disE~osed about the upper side of the chan- :.
2S n~l, below a light-transmitting cover, the chamber having an air '.
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` 2~24973 inlet and an air outlet providing contact between t~.e chamber and the surrounding air.
In order to provide additional strength to the blocks, steel cords, nylon cords or any other usual reinforcing cord may be added to the rubber/resin system compositions, or may be disposed within the molds before the addition of the molding composition.
The method of forming the blocks of a preferred embodiment of this invention preferably includes the step of providing a release agent in the form or mold, e.g., a silicone material.
The method may also include the step of cutting the molded pro-duct to a desired length.
The rubber/resin system compositions of aspects of this invention have many uses. In one general type of such use, they may be used as a road paving material, of the same general character as disclosed in U.S. Patent Nos. 3,567,660, 3,779,964, 3,891,585, 3,919,148 and 4,068,032.
Another use of the rubber/resin system composition of this inventlon i8 as a guard-rail or barrier walls, to be used instead of concrete, the guard-rail or barrier wall being of the type disclosed in the following typical Canadian patents:
559,969 issued July 8, 1958 to J. Hogue et al for "Guard Rail and Block Therefor";
656,155 issued January 22, 1963 to M. Trief et al for "Safety Barrier for Roads";

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'``` 2024~73 844,863 issued June 23, 1970 to P.E.L.A. Gravisse for "Security Barrier for Expressways and Constructive Works";
931,403 issued August 7, 1973 to E. Glasesener for "Guard Rail for Vehicular Roadways";
997,607 issued September 28, 1976 to E. Glaesener for "Vehicular Guardrail With Metal Line"; and 1,141,579 issued February 22, 1983 to P. F. Trent et al for "Median Barrier Construction".
Yet another use of the rubber/resin system composition of this invention is as the base of a solar collector. Such solar oollector can be installed where it is sub~ected to solar radia-tion. As a result the collector will be heated, and the heat collected is transferred by the collector to a flowing medium, ~5 e.g., air, whereby the heat i8 transported either to a storage unlt or to the various rooms in the building. The collector should preferably be one whlch has a cover.
one important requirement which such a collector should s~tlsfy is that the msterial to be heated by solar radiation ao should be of low heat capacity, in order that it is rapidly heated up when irradiated, which is especially of importance during periods of intermittent sunshine. Another important requlrement is that the material heated by the sun rays must be in contact with the flowing medium over as large an area as ~S po~ible.

202~973 Two structures of such solar collectors which are be taken as examples only and not to be considered as limiting to any extent, are disclosed in the following patents:
Canadian Patent No. 1,095,792 patented February 17, 1981 by J. M. Van Heel; and Canadian Patent No. 1,203,133 patented April 15, 1986 by H.
Kirchmayer.
When used as the block to form the base of a solar collec-tor, the rubber/resin sy~tem compositions of this invention pro-vide a collector for collecting solar heat and transferring heatto a medium, e.g., air, which is of simple and relatively inex-penslvo construction. The solid block provides a combined solar heat collector and storage unit which makes it possible, on the one hand, to transfer collected heat rapidly to a heat transport-ing medium, e.g., air, and on the other hand, to store a possiblesurplus o~ energy in an inexpensive and simple manner.
The resin component of the resin system o~ this invention is a rubber solubilizing ~ormaldehyde/resorcinol resin. Prererably, the resin used is that known by the trade-mark PENACOLITE of a O Indspec Chemical Corporation.
Among the PENACOLITE resins useful in this invention are the following:
I. Penacolite Resin B-18-S, which is a reaction product of for-maldehyde with rQsorcinol and resorcinol polymers supplied in ~5 fl~ke form. The product contains no ~ree formaldehyde. It has very low vapor pressure. A non-staining naphthenic process oil 2~2~73 .
17 . ;is incorporated into the resin to reduce dusting. Such resin has the following specifications: .

~r~ MethodofT~t S~cntlon ::
Softcning Point, C INDSP~C No. 495 100-114 Moisture Content, % Ma1~imum INDSPEC No, 493 1.0 Typical Prop~rtles Appearance ..................................................... dark brown flakes :; ;
Softcning Po~t, C.............................................. 104 Moisture Content, 70............................................ 0.5pH, 50 ~ Aqucous Solution....................................... 4.7 ~
F~e Resorcinol, q~.............................................. 18 ~; -.
Specific Gravi~y, 23/25C ..................................... 1.36 ` ~ ..
Bulk Dcnsity, 3~g/m3 (Ib.lf~?) Loose........................................................ 480 (30) Tappcd....................................................... ~20 (45) Solu'oility, in tcr ................... ; ............. Complet~ :
Alcohols .................................................... Complete Kctones...................................................... Complete ~ Aromatic Solvcnts ........................................... Nil 2û
.

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II. Penacolite Resins R-2170 and R-2200, which are orange-red, : ..
aqueous solutions of a resorcinol-formaldehyde condensation pro-~5 duct~ The resins are acidic and must be stored and handled in . :.
acid resistant equipment. They are stable and will not polymer- :

~` 2~24973 I

ize during storage. They differ only in percent resin solids.
Penacolite Resin R-2200, the more dilute resin, is fluid and can be pumped at 15.50C (60F). Such resins have the following Qpeci~ications:
Sp~lnc?3tl0ns Propert~ M?2thod of ~st }~--2170 R--2200 -Color ~lsual orsnge-red orange-xd Rk~in Solids, % nN~SPEC No. 4S7 75 i 1 70 ~ I
pH INDSPEC No. 439 0.5 - 1.5 0.6 - 2.0 V~lscosity, poisc at 23 C INI)SPEC No. 478 40 _ ?~0 8 -- 18 Typicnl Propertle~
Res;n Solids, % ................................ 75 70 pH ............................................. 0.9 1.2 Viscosity -- poise ~ 23~C ....................... 50 13 Preo Reso~cinol Specinc G~aYity 23 123 C ....................... I .24 Dcnsit~ -- poundsf?gallon ............ ........; ..... 10.3 Plash Poiot, C CleYeland Open Cup ............. > 225 SolubUi~, in:
lS Wate~ ~ pH of 2 ............................. Par~a~
Water e~ P~ of7.5...... -.-.-.-... -.............. Completely Soluble Alcohols .................................... Completely Soluble Ketona ...................................... Completely Soluble ~;
Aromatic Solven~ ............................ Nil : ' .
ao ~ ~

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Penacolite Resin ~-18-S is packaged in multiwall paper bags With a moisture barrier. The bags are palletized on two-way . .:

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~` 2024~73 entry pallets. Penacolite Resin B-18-S is hygroscopic and must be protected from exposure at high relative humidity. A poly- ~ -ethylene lined paper bag will protect B-18-S; however, the bag must be kept closed except when withdrawing resin.
S Penacolite Resins R-2170 and R-2200 are shipped in lined, closed-head, drums with three-quarter inch and two-inch threaded openings on one head. Bulk quantities are shipped in stainless steel tank trucks and railroad cars. Penacolite Resins R-2170 and R-2200 are stable at elevated temperatures; however, pre-cautions must be taken to prevent evaporation of water and con-centration of resin solids. The resins are not damaged by alter-nate freezing and thawing.
When ussd as a paving material, the rubber/resin system com-position of one aspect of this invention may be used as a complete or partial substitute for aggregate, to satisfy, for example, the Ontario Provincial Standard Specification (~TO) for aqgregates for asphaltic concrete, which is hot mixed and hot ~;
laid.
Aggregates used in con~unction with the rubber/resin system composition of one aspect of this invention may be gravels, quarried rock or slags, provided the source is of such a nature and extent as to ensure acceptable processed aggregates of a con-sistent gradation and quality.
Fine aggregate preferably should be consistently graded and should preferably meet the gradation requirements in Table 1.
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~ 2~2~973 . .

T~LE 1 au~T ~ ~ ~TAL
FIIIE ~mtEc~Tp I~T0 PEACE~IT~CE PASSi~ ~.
St~v~ . . .
D~slgn~tlon HL 1 11 3 NL 2 NL 4 9 . 5 ~100 100 100 .75 ~ 90-100 t5-100 ~5-~00 ~:
2 . 36 _ 70- 100 70-90 60- 100 . ;
1.1~ _50-90 50-7~ 3~-90 ,~
600 1l~30-70 30-55 17-70 .3001~15-40 ~5-35 9-40 ; 1~0 yS 5-1~ 5-15 3-15 ; ~ ~
~5 1~ 0~5 3~~ 0~7 ~ i TO Li~ T -t No. LS 602. , . . :.~ ~

~ The gradatlon envelope~ represent the extreme limits. It i8 "4~ thor-fore preferred that the gradation should be rea~onably con~
~ t-nt and not be sub~ect to the extreme percentage of gradation peci~$ed in Table 1. The fraction retained between any two con-~; secutive sieves (excluding the 75 ~m sieve) should not be less ~ ,~
than 5 percent~
~P"~ Tho fine aggregate should pre~erably be composed of clean, ~ 5 h~rd, durable partlcle~ and preferably ~hould meet the phyisical i~ xequirement shown below.
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20~73 Soundness: When the fine aggregate is subjected to five cycles of a standard magnesium sulphate soundness test, the loss :
by mass shall not exceed the following:
HL 1 and 3.............................. 16%
HL 2, 4 and R........................... 20%
Material Passing 75 ~m Sieve: In any fine aggregate, not more than 20 percent of the material passing the 75 ~m sieve should be finer than 2 ~m in size.
Plasticity Index: The plasticity index should be 0, as~ ~ :
determined by MT0 Test Method LS 704.
Coarse aggregate should preferably be consistently graded, and preferably should meet the gradation requirements shown in Table 2. . ;

lS

T~E 2 CO~ ~iEC~TEt ~70 PERC6NTAGE P,~SS I 1 ao ~lgnatl3n UL 1 ~ 3 H~ L J
26.5 ~- ___ ~ 100 19.0 ~- ___ 10090-loo 16.0~ loO 96-lOo I 6~-90 13.2 ~ 96~100 67-S6 ¦ ---. _ 9.~-- 50~73 1 29-52 20-55 .7~ o-10 1 o~ o-10 \IT0 L-b 7~t No. LS 602.

The gradation envelope represents the extreme limits. It is therefore preferred that the gradation should be reasonably con-sistent and not be subject to the extreme percentages of grada-tion specified in Table 2.
~ .
S Coarse aggregates should preferably conform to Table 3.

r~uE 3 al~E ~T,E
_ I
~0tiL TY~E ::
~ro usTEsr W
TEST J 1 3 ~ 3 ~o~g~ . `: ' ~Or~elon, LS 603 15 3S 35 3S
X l~-K~-U~ ~0~ --gno~lu- Sulphnto _ Soundnoe~,~ Cyol-- S 60~ S 12 12 lS
X ~KI U~ Lo~ _ ~b orptlon, _ x~ u- LS 60q 1 0 1 7~ 2 0 2 0 Potrogrophlc Nu~Oor, H~ ~K. 609 100 135 160 160 _ :',',: ' ,:,. :'~
~ Lo-~ Oy ~nln9 i~
`~ ~P~vlng 7S ~ LS 601 ~1.0 1.3~ 1 3~ 1 3~ ~, ~;: Sl~v~), X ~ xl-u- . _ _ ' "'''~'.'~':'' ;", Fl~t ~nd Elongnte , P~rtlcl~j, X ~x. LS 60J 20 20 20 20 P~reont~go Cru~h- i;
X ~Inl~u~ ~S 607 100 60 60 60 ~ wn~n qu~rrlod rock lo u--d ~o ~ ~ouroo o~
eo-r~- oggrcgoto, ~ ooxl~uo ot 2 poreont p~
sing th- 7S po ~l~vo n-ll bo p~roit~od ,.' " ,~ ~ ' '."
. .: .: .: -: .

:,., :, . :::

~`` 2~ 3.

Filler should consist of mineral filler, hydrated lime, -portland cement, or other material as designated and currently approved for use in asphaltic concrete. Mineral filler should consist of thorou~hly dry dust produced from rock sources accep-table for coarse aggregates approved under physical requirements listed in Table 3, and should preferably meet the following gradation requirements:
Passing 600 ~m Sieve......................... 100%
Passing 75 ~m Sieve - not less than.......... 80%
In the rubber/resin system composition of an embodiment of this invention, the amount of rubber can range from about 85% to about 95% by weight, while the amount of the resin system can oorrespondingly range from about 15% to about 5% by weight.
In the accompanying drawings of solid blocks made using the rubber/resin system compositions of embodiments of this inven-tlon, Flg. 1 19 a front elevational view of one embodiment of such solid block in the form of a cable type barrier;
Fig. 2 i8 a front elevational view of one embodiment of such solid block in the form of a guard rail type;
Fig. 3 is a top plan view of the guard rail type of Fig. 2;
Fig. 4 is a side elevational view of the guard rail type of Fig. 2;
Fig. 5 is a front elevational view of one embodiment of such solid block in the form of a movable barrier block type;

~- 2~24~73 Fig. 6 is a top plan view of the movable barrier block type of Fig. 5;
Fig. 7 is a side elevational view of the movable barrier block type of Fig. 5;
Fig. 8 i9 a front elevational view of one embodiment of such solid block in the form of a permanent cost in place barrier wall;
Fig. 9 is a side elevational view of the permanent cast in place barrier wall of Fig. 8; and Fig. 10 is a cross-sectional perspective view of one embodi-ment of such solid block in the form of a combined collector-storage unit according to an embodiment of the present invention;
and Fig. 11 is a vertical cross-section through one embodiment lS of i~uch solid block ln the ~orm of a collector element according , ,. ::
to another embodiment of this invention.
As ~een in Fig. 1, the rubber/resin system composition o~
one embodlment of the present inventlon has been either molded or cast into square cross-section posts 11, e.g., o~ dimensions 10"
x 10", (by the procedures and conditions described in general terms above), and these posts have been buried below grade 12 by ;;
a suitable amount, 13, e.g., up to 4 feet, so that it extends a suitable amount 14, e.g., up to 3 feet above grade. The cables ~ . :. .
15 for the guard rail include three spaced-apart, horizontally-2 extending ~teel cables which are held to the post 11 by ~ ;
galvanizQd fasteners 16. The steel cables 15 are provided with '.
,. ',. ' "' ~ , -- 20~4973 ~ ~
.,, tensioners 17, are combined at a union 18, and are then secured to a buried anchor block 19 of a size which varies to suit the required weight. The anchor block 19 can likewise be formed of the rubber/resin system composition of one aspect of this invention.
As seen in Figs. 2, 3 and 4, the 10" x 10" square cross-sec-tlon posts ll as described with respect to Fig. 1 are buried below grade 12, as described for Fig. 1. The posts 11 are each -provided with an associated 10" x 10" stand-off block 20 and the guard rail 21, which is, in general, 4" x 16" x 24' is secured to ;
such stand-off' block by galvanized fasteners 22 and asso~ciated hardware. One of' the posts i9 provided with a splice block 23 who~e dimensions are lO"xlO"x24", instead of the stand-off block 20. The post 11 may be buried up to 4 feet below grade and may extend above grade by up to 3 feet. --A~ seen in Figs. 5, 6 and 7, the rubber/resin system rom-po~ition of one embodiment of' thl~ invention is molded or cast lnto a movable barrler blook 50, (by the procedures and condl-tions described in general terms above). The barrier block 50 i8 ,, ~0 generally-rectangular in elevational shape, but, in vertical cross-section, has a generally-rectangular base 51, upper con-verging faces 52, and a flat top 53 to provide a generally-trape-zoldally-shaped upper portion 54. The base 55 of the block 50 is --~
provided with a pair of li~'ting slots 56. One end of the block ls provided with a vertically-extending key 57, and the other end i9 provided with a vertically-extending mating slot 5a, so that ' ; .: ~, ''.f ... :'~`

2~24973 .

two ad~acent similar blocks 50 may be interlocked together. The block 50 may suitably be up to about 3 feet high, and at the base may suitably be up to 3 feet wide. The length is suitably up to 8 feet.
S As seen in Figs. 8 and 9, the rubber/resin system composi-tion Or this invention is formed into a variable length block 100, (by the procedures and conditions described in general terms ~ `
above), by being continuously cast into a form (not shown) in a ;;~
compacted trench 101 below the grade 12. The lower portion 102 of the block 100 has the cross-sectional shape of a rectangle, while the upper portion 103 of the block 100 has the cross-sec- ;
tional shapo of a trapezoid. It i~ preferred that the form also ;; ;-.. .. .
inalude be provided with reinforcing ~teel bars 104 therein. ~ i . . ~ : . "~, .-Periodically, the block is provided with a terminus 105, provided " " ,., , ,. . ~ .,.
lS with a con~truction ~oint or expansion ~oint 106. The height of ~ ~ ;
, . ,. ~ .. :.:the block 100 is up to 4 feet, while the amount the block 100 is burled below grade is variable. ;~
As ~een in Fig. 10, the collector-storage unit may, for ;;
example, be 5 metres long, 1 metre wide, and have a total ~20 thickness of 0.25 metre. In one useful environment it may be one ~; -;
Or a plurality of units to form at least part of the roof of a bouse.
As shown, the collector-storage unit comprises a plurality -~
of parallel metal tubes 10,21 of square cross-sectional con-~, . . .
~ ~ as ~lgur~tion, dispo9ed in spaced relationship to each other. Tubes l ~
~, , 1021 are embedded in a slab 1023 of the molded block formed from .. ~- , - , , , -- 202~973 the molding composition of one aspect of this invention using the procedures and conditions described in general terms above so ;
that wall portions 1024 of the tubes 1021 are flush with the outer sur~ace of the concrete 1023. These wall portions 1024, together with the surface 1025 of the block slab 1023 between them ~orm the collector surface to be subjected to solar radiation. This surface is inherently black since it is formed from reclaimed rubber from tires which increases the heat absorbing capacity.
Block 1023 i9 provided with a rebate 1026 for receiving a glass pane 1027, which may be a double glass pane, and with a rQc-ss 1028 for guiding a screen (not shown) which can be drawn between glass pane 1027 and collector surface 1024, 1025.
At both ends of the collector-storage unit, the tubes 1021 lS can b- connected, in a conventional manner, to supply and dls-charge conduits for air as the heat transporting medium to be pa~ed through tube~ 1021. Air can be blown through the tubes by mQans of a blower (not shown).
The collector-storage unit shown i8 particularly advantage-ao ous since the heat collected is effectively utilized. In the ; collector-storage unit as shown, as soon as the sun shines, wall portions 1024 of tubes 1021 will be heated, and owing to the high heat conductivity of the metal, the heat will spread throughout the tube walls. This makes it possible to discharge the required ~S amount of heat through the air flowing through the tubes, rela-tively soon after the sun begins to shine. The amount of heat 20~73 discharged can be controlled by controlling the rate of flow of the air through tubes 1021.
Heat not discharged will be passed through the metal of tubes 1021 directly to the storage slab 1023 in the periods when the sun does not shine. For example, at night, the slab 1023 will give off heat through tubes 1021 to the air flowing therein, to an extent depending on the velocity of the air through the tubes.
Owing to the relatively high heat-conductivity coefficient of the metal, the sun rays will rapidly heat up the entire metal tubes, so that the heat transporting medium within the tubes can be rapidly heated up. Accordingly, the collector reacts fast, i.e., shortly after the sun has begun to shine a maximum of heat ;~ ~
can be carried off if such heat is needed for direct heating. ~ ~-.
lS The quantity of heat to be carried off can be regulated, for ~ `
example, by controlling the rate of flow of the heat transporting medium. The heat not carried away can simultaneously be con-ducted through the metal of the tubes to the heat storage slab 1023.
The metal tubes 1021 are embedded in the slab 1023 so as to be flush therewith and in spaced interrelationship, i.e., the ~ ~;
interspaces between the tubes are filled with the slab 1023. ~ ~-$his ensures that the tubes 1021 are properly secured in the slab 1023 and that there is a large area of contact between the slab 1023 and the metal of the tubes 1021.

, ~. , , ,"' ,, '~, .

, :
; -, , ",~

2~4973 As seen in Fig. 11, a single collector element 1111 has its heat transfer fluid channel 1112 directly connected to a suitable fluid circulating pump (not shown) so that fluid can be pumped through fluid channel 1112 to where the heat therefrom is to be used (not shown) and then circulated back to be reheated.
Channel 1112 of the collector element 1111 is mounted on a base 1113 which is a molded block formed from the molding compo-sition of one embodiment of this invention using the procedures and conditions described in general terms above. A light-trans-mitting cover 1114 is disposed at a distance over the channel1112. The cover 1114 rests on an upper projection 1115 and a lower pro~ection 1116 of the base 1113. The upper projection 1115 provides the top closure of the chamber 1117 bounded by the cover 1114 and the channel 1112. There are two slots in the lower pro~ection 1116, which slots communicate with the bottom end of the chamber: the first slot 1118 is at a distance from the channel 1112, and the second ~lot 1119 is close to the channel 1112.
Because of the inherent characteristics of the base 1113 (as ao described above with reference to slab 1023) the same useful results accrue. ~ -~.

Claims (41)

1. A molding composition comprising 90% ? 5% by weight shredded spent rubber tires and correspondingly 10% ? 5% by weight of a resin system comprised either wholly of a formalde-hyde/resorcinol resin, or of a mixture of the formaldehyde/resor-cinol resin with a resin cross-linking agent system and/or a fire retardant agent; said molding composition being adapted to be placed into forms or molds and cured at a minimum temperature of 300°F for a minimum time of 1 minute.

2. The molding composition of claim 1 wherein said curing temperature is 360°F ? 25°F.

3. The molding composition of claim 1 wherein said resin system consists essentially of said formaldehyde/resorcinol resin.

4. The molding composition of claim 1 wherein said resin system comprises a major amount of said formaldehyde/resorcinol resin and a minor amount of a resin cross-linking agent system which is sufficient to complete the cross-linking of said resin system which acts as an adhesive for the shredded rubber.

5. The molding composition of claim 4 wherein said resin cross-linking agent system comprises formaldehyde, hexamethylene-tetramine, diphenylguanidine, mercaptobenzothiazole, N-cyclo-hexylbenzothiazolesulfenamide, N-oxydiethylenebenzothiazole-sulfenamide, tetramethyl- and tetraethylthiuram disulfides, thiocarbanilide, or zinc dimethyldithiocarbamate, in an amount which comprises up to the stoichiometric amount by weight of said resin system.

6. The molding composition of claim 5 wherein said resin cross-linking agent system includes a sulfur vulcanization system therein.

7. The molding composition of claims 5 or 6 including a minor, fire-retarding amount of a fire retardant comprising a water-soluble, inorganic salt, ammonium bromide, borax, boric acid, phosphates, diammonium phosphate, sodium phosphate, sodium tungstate, ammonium sulfamate, mixtures of antimony oxide and oxychloride, chlorinated organic, phosphorus compounds, or the polymer resin formed by the polymerization of tetrakis(hydroxy-methyl)- phosphonium chloride, melamine, and brominated triallyl phosphate.

8. The molding composition of claim 1 wherein said shredded spent rubber tires have a particle size of from one micron to 1/2 inch.

9. The molding composition of claim 8 wherein said shredded spent rubber tires have a particle size of from one to ten mesh.

10. The molding composition of claim 8 wherein the amount of shredded rubber is 90% ? 5% by weight and the amount of formaldehyde/resorcinol resin is 10% ? 5% by weight.

11. The molding composition of claim 10 wherein said for-maldehyde/resorcinol resin comprises the reaction product of formaldehyde with resorcinol, said reaction product containing resorcinol polymers but substantially no free formaldehyde.

12. The molding composition of claim 10 wherein said for-maldehyde/resorcinol resin comprises an acidic aqueous solution of a formaldehyde/resorcinol condensation product.

13. The molding composition of claim 1 including reinforc-ing materials therein.

14. The molding composition of claim 13 wherein said rein-forcing materials are steel cords or nylon cords.

15. A solid block formed substantially entirely from a molding composition comprising 90% ? 5% by weight shredded spent rubber tires and correspondingly 10% ? 5% by weight of a resin system comprised either wholly of a formaldehyde/resorcinol resin, or of a mixture of the formaldehyde/resorcinol resin with a resin cross-linking agent system and/or a fire retardant agent;
said molding composition having been placed into forms or molds and having been cured at a minimum temperature of 300°F for a minimum time of 1 minute.

16. The solid block of claim 15 wherein said curing tem-perature is 360°F ? 25°F.

17. The solid block of claim 16 wherein said resin system consists essentially of said formaldehyde/resorcinol resin.

18. The solid block of claim 14 wherein said resin system comprises a major amount of said formaldehyde/resorcinol resin and a minor amount of a resin cross-linking agent system which is sufficient to complete the cross-linking of said resin system which acts as an adhesive for the shredded rubber.

19. The solid block of claim 15 wherein said resin cross-linking agent system comprises formaldehyde, hexamethylene-tetramine, diphenylguanidine, mercaptobenzothiazole, N-cyclo-hexylbenzothiazolesulfenamide, N-oxydiethylenebenzothiazole-sulfenamide, tetramethyl- and tetraethylthiuram disulfides, thiocarbanilide, or zinc dimethyldithiocarbamate, in an amount which comprises the stoichiometric amount by weight of said resin system.

20. The solid block of claim 19 wherein said resin cross-linking agent system includes a sulfur vulcanization system therein.

21. The solid block of claims 15, 19 or 20 including a minor, fire-retardant amount of a fire retardant comprising a water-soluble, inorganic salt ammonium bromide, borax, boric acid, phosphates, diammonium phosphate, sodium phosphate, sodium tungstate, ammonium sulfamate, mixtures of antimony oxide and oxychloride, chlorinated organic, phosphorus compounds, or the polymer resin formed by the polymerization of tetrakis(hydroxy-methyl)phosphonium chloride, melamine, and brominated triallyl phosphate.

22. The solid block of claim 15 wherein said shredded spent rubber tires originally had a particle size of from one micron to 1/2 inch.

23. The solid block of claim 22 wherein said shredded spent rubber tires originally had a particle size of one to ten mesh.

24. The solid block of claim 22 wherein the amount of shredded rubber is 90% ? 5% by weight and the amount of formalde-hyde/resorcinol resin is 10% ? 5% by weight.

25. The solid block of claim 15 wherein said formaldehyde/-resorcinol resin comprises the reaction product of formaldehyde with resorcinol, said reaction product containing resorcinol polymers but substantially no free formaldehyde.

26. The solid block of claim 15 wherein said formaldehyde/-resorcinol resin comprises an acidic aqueous solution of a for-maldehyde/resorcinol condensation product.

27. The solid block of claim 15 wherein said molding com-position includes reinforcing materials therein.

28. The solid block of claim 27 wherein said reinforcing materials are steel cords or nylon cords.

29. The solid block of claim 15 in the form of a square cross-section post, to be used as part of a cable-type barrier or as part of a guard-rail-type barrier.

30. The solid block of claim 15 in the form of a generally-rectangular, finite-length block, the base of which is provided with a pair of spaced-apart lifting slots, one end face of which is provided with a vertical key, the other face of which is pro-vided with a vertical, mating slot, the cross-sectional shape of said block comprising a trapezoidal upper shape superposed on a rectangular lower shape, to be used as a movable barrier block.

31. The solid block of claim 15 in the form of a generally-rectangular block of indefinite length, the cross-sectional shape of which comprises a trapezoidal upper shape superposed on a rec-tangular lower shape, to be used as a permanent cast-in-place barrier wall.

32. The solid block of claim 15 in the form of a solar collector comprising a heat storage slab formed of the molding composition of claim 1, which had been placed into forms or molds and cured at a minimum temperature of 300°F for a minimum time of 1 minute, said heat storage slab being formed with a number of metal tubes embedded in spaced relationship in said slab, each of said tubes being adapted for passage therethrough of a heat transfer medium and including an exterior wall portion, the exterior wall portion forming a heat collecting surface for the unit.

33. The solid block of claim 15 in the form of a solar collector having support surface formed of the molding composi-tion of claim 1, which had been placed into forms or molds and aured at a minimum temperature of 300°F for a minimum time of 1 minute, said support surface being formed with a heat transfer fluid channel adapted to contain a circulatable heat transfer fluid, and also being formed with a chamber disposed about the upper side of the channel, below a light-transmitting cover, said chamber having an air inlet and air outlet means providing con-tact between said chamber and the surrounding air.

34. A method for molding a solid block comprising the steps of: mixing 90% ? 5% by weight shredded spent rubber tires and correspondingly 10% ? 5% by weight of a resin system comprised either wholly of a formaldehyde/resorcinol resin, or of a mixture of the formaldehyde/resorcinol resin with a resin cross-linking agent system with or without a conventional sulfur vulcanization system and/or a fire retardant agent to form a mixture; placing said mixture into a form or mold; and curing said mixture in said form or mold at a minimum temperature of 300°F for a minimum time of 1 minute.

35. The method of claim 34 wherein said mixture is extruded into said form or mold.

36. The method of claim 34 wherein said curing temperature is 360°F ? 25°F.

37. The method of claim 34 including the step of providing a release agent in the form or mold.

38. The method of claim 37 wherein the said release agent is a silicone material.

39. The method of claim 34 including the step of adding a reinforcing material to said rubber/resin system composition prior to said step of extruding.

40. The method of claim 39 wherein said reinforcing mater-ials are steel cords or nylon cords.

41. The method of claim 34 including the step of cutting the molded product to a desired length.