Document G5w4v4rkMbQpDJvjY9bqbgBrn

ALLENTGWN PENN;'.:.'. ANlA oIP1 ""6-~5CC ax. n-w* DOYLESTCWN. PENNSYLVANIA ;215' 3-*e-:6l! FAX. iLlSt 346-5439 HARRISBURG. PENNSYLVANIA wl7) 232-1022 FAX: (717) 232-1349 LANCASTER. PENNSYLVANIA (717) 399-1845 FAX: (717 ) 399-1853 NORRISTOWN, PENNSYLVANIA (610) 292-4440 FAX: (610) 292-0410 ERIE, PENNSYLVANIA (814) 454-4360 FAX (814) 459-4340 NEWTOWN SQUARE. PENNSYLVANIA (610) 325-2210 FAX: 4610) 325-2238 LAW OFFICES Marshall, Dewehey, Warxea Coleman g Gogcin PITTSBURGH. PENNSYLVANIA .412' ''94-4CC FAX: 412: 5P4-JC95 A PROFESSIONAL CORPORATION PLAINTIFF'S EXHIBIT 1845 WALNUT STREET PHILADELPHIA, PENNSYLVANIA 19103-4797 (215) 575-2600 CABLE ADDRESS -- MARSHALL FAX: (215) 575-0856 SCRANTON. PENNSYLVANIA (717) 342-1999 FAX. ,717) 342-4999 MARLTON, NEW JERSEY (609 ) 985-3900 FAX: (609) 983-4358 LIVINGSTON, NEW JERSEY (2C1) 994-0303 FAX: (201) 994-1965 April 17, 1997 WILLIAMSPORT, PENNSYLVANIA (717) 326-9091 FAX: (717) 326-5507 WILMINGTON, DELAWARE (302) 651-7900 FAX: (302) 651-7905 Direct Dial 575-2740 Robert E.- Paul, Esquire PAUL, REICH & MYERS, P.C. 1411 Walnut Street, Ste. 500 Philadelphia, PA 19102 RE: Interrogatory Answers of Railroad Friction Product Corporation in the Derrick Case Dear Bob: In reviewing the Interrogatory Answers filed on behalf of Railroad Friction Product Corporation on or about July 30, 1981 which were signed by Ed David who was then counsel for Railroad Friction Product Corporation we have discovered a few mistakes. Although I believe that I may have provided you with accurate information with respect to Cobra brake shoes in the past, I enclose for your review two patents wherein it is clear that although composition brake shoes were first patented in 1958, those particular shoes did not contain asbestos as an ingredient. The second patent dated June 25, 1968 demonstrates that this was the first date in which asbestos was used as an ingredient in Cobra brake shoes. Thus to the extent that the interrogatory answers state that asbestos was used as an ingredient in Cobra brake shoes from 1955 to 1980 this should be corrected to 1968 to 1980. Robert E April 17 Page 2 Paul, Esquire 1997 If you would like a formal amendment to the answers, I will be more than happy to do so. You will be receiving shortly an Affidavit attached to Summary Judgments filed on behalf of Westinghouse Air Brake in your May Group which makes reference to the fact that asbestos was not an ingredient in Cobra brake shoes or to our knowledge any brake shoes until 1968. Although the Federal Register refers to Cobra brakes shoes made by Manville from 1892 to 1989 it is mistaken to our knowledge that asbestos was in the Cobra brake shoe before 1968. Therefore I believe that my client should be dismissed in the upcoming mesothelioma cases because there is no evidence that any of these plaintiffs worked with or around any asbestos containing products made by my clients. We will call Dave Kerr and possibly others as fact witnesses in these cases if necessary. DJR/smw Enclosures philal9/doc#209676 / Very t^ruly yours, A / v. x~\ ____- DANIEL J. RYAN, JR. Unit o ijuc Patent Offic 2. if d' \ vv * /w -A ) V, V 4/ " Piler.ted Nov, 23, 1S3S bJ-Vl the undesirable characteristic of uttevec wear on the wit::.1 tread. 2.S6I.964 With this object in view, the inventic; consists of the improved molded composition brake blnci. which is bere COMPOSITION BRAKE BLOCK ft inafter described and more particularly defined tr. the ap Charles L. E. 6c Gaugue,.Jr., Coltsbury, tad Ralph T. Halstead, Somerville, N. J., assignors lo Johns-Manviile Corporation, New York, N. Y, a corporation of New York - pended claims. la the accompanying drawings, in which preferred em bodiments of the invention are illustrated, and wherein like reference characters designate like parts: Application November 17,1953, Serial No. 392,764 10 Fig. I ibows in cross-section a molded composition brake block shaped for mounting on an arcuate brake n Claims. (CL 260--->tf.4) ` ahoc; ' Fig. 2 Is an enlarged cross-sectionai view taken along the line 2--2 of the embodiment of the invention shows 15 in Fig. 1; This invention relates to composition brake blocks and' Fig. 3 .is a fragmental perspective view of a modified more particular])' to a molded brake block of novel com-' metal lath reinforced brake block, with pan of the face position adapted particularly for braking heavy railway broken away to ibow a metal lath reinforcing element in equipment. position; and, This application contains subject matter in common 20 Fig. 4 is an attempted plan view portrayal of a wearing with coprsdizg U. S. paten: application, Charles L. E. face of the brake block portrayed in Fig, 3, Showing worn de Gaugue. J:., Serial No. 2'?.417. filed March 29, 1952, portions of an embedded reinforcing lath exposed. issued August 10, 1954, as Patent No. 2,656,140, which In that embodiment of the invention which is illustrated is a cooiinuation-io-pan of U. S. patent application Serial in Figs. 1 and 2, the numeril 10 designates a molded com- No. 217,790, filed March 27, 1951, and .now abandoned, 25 position brake block of arcuate shape firmly affixed to, or which in turn v-as a contio-tat.-or.-ic-pan of U. S. patect molded integral with, a metal shot 12 w-hich is adapted pplic2:.rc Serial No 127,;c, filed November 17, 1949, and no* icacdccrd. for operation by compressed air actuating mechanism (not shown). It will be understood that the invent.; is On: of ti; cocvesaional means, p_( .braking .railway - - not limited as to the shape'of the shoe or block, or as to equipment is by brake shoes of cast iron applied against 30 the means for affixing or anchoring the block facing to the the steel treads of the wheels, whereby a meial-to metal shoe. engagement is effected under sufficient applied force to As in the aforementioned application, the present in effect deceleration. Compressed air actuated mechanism vention is directed to a molded brake block of novel com is usually employed lo force the brake ihoe into braking position having a high friction coefficient level preferably engagement with the wheel tread. 35 approximating 0.300, as compared to 0.050 for cast iron An alteroatiye form of railway brake employs engage- under comparable railway braking conditions. Another able rotor aod stator discs, the rotor discs being con important feature of the present brake block composition nected to the wheels to rotate therewith, and the stator is that it exhibits a frictional coefficient w-htn wet which discs being connected to the stationary frame of the equip is not substantially less than its dry friction coefficient. ment. Brake blocks may be affixed to the face of the 40 Thus, for molded brake blocks formed its accordance stator and applied to the rotor to effect decleration. with this invention the ratio of wet to dry stopping The brakieg of heavy railway equipment using cast iron distance under the same initial speed and braking ahoes requires application of high braking force to hold effectiveness does not usually exceed 1.25. Molded brake the shoes in brakiog contact with the wheel: or rotor blocks within the widest composition range herein dis- discs, and efficient and effective deceleration develops a t5 closed have a friction coefficient level at least triple that high rate of wear for east iron brake shoes. While the of cast iron under high speed braking conditions, and friction coefficient of a cast iron brake shoe is relatively have a friction coefficient when wet which is not less than low- aod the service life short, it is notable that the fric 73% of the dry friction coefficient. tion coefficient of such shoe remains substantially con- It is also a particular feature of the present brake bloek aunt in either dry or wet weather. In other words, the g0 competition that tbe coefficient of friction of these blocks presence of moisture doet not have a serious adverse is relatively constant over the entire range of wheel speeds effect on the braking efficiency of cast iron shoes. during the braking activity; whereas the coefficient of In copending application Serial No. 279,417, there is friction of cast iron brake shoes increases greatly as the disclosed a molded composition brake block having prop wheel speed decreases. Accordingly, a much smoother erties adapting it for braking heavy railway equipment. gg braking action is obtained when utilizing brake blocks As specifically disclosed therein, the molded brake block fabricated according to this invention than is obtained has characteristics of high friction level and low rate of when conventional cast iron shots ate employed; that is wear with a wet-to-dry friction coefficient ratio approxi brake blouks formed in accordance with this invention do mating that of cast iron. The block claimed in that appli not cause the typical jerky stops commonly experienced cation preferably contains fixed proportions of eatt iron gQ with railway equipment using east iron shoes. particles, long-wearing orginic friction panicles, and While possessing the aforementioned characteristics in staple reinforcing fiber, preferably asbestos, all in a binder common with the preferred molded friction elements matrix comprising an in situ vuleanited elastomer matrix. described in application Serial No, 279,417, brake blocks While the preferred friction element disclosed therein ex formed in accordance w'ith this invention possess the hibited excellent characteristics adapting it for use as a Sj further advantageous characteristic of more ever. earing railway brakeblock, it also exhibited one adverse charac of the wheel tread against which they coa::. Thr pre teristic in that it had a tendency towards uneven wearing vention of uneven tread wear is, of course, a most de of the tread of the ear wheel. sirable characteristic in the blocks hereinafter described, It is an object of this invention to provide a molded and they also possess a totally unexpected characteristic brake bloek having all of tbe outstanding characteristics of longer wear life than bloeks containing asbestos fiber of the preferred friction element described and claimed in u is exemplified in application Serial No. 279.417. This ipplicatifc Serial No. 279,417, but which does cot exhibit characteristic would be unexpected since elimination of O. 2,se: ,se 4 3 4 4or: v'3: zz :h: wns:i tread would be expected to re- (Buna GR-S), together with 4-20% by weigh; of the ru.: j: .z:wiuti *:a: ca -be other eoacucg body, tie block of inorganic and organic fillers and vul.-ardring it- bn>.e gredients such as sulfur, litharge, ZnO, carnon blicL, Tie acc.ded railway bral.e blocks formed in accord- barytes, etc., which rubber matrix may be stiffened with ansa with the presen! invention essentially comprise hard1 S up to 6% by weight of the block of a thermosetting resin ferrous metal particles, preferably granulated cr chipped1 such as pheaolaldebyde or cishew nut shell oil resins, cist iron; loeg-wearieg organic friction particles, such ass etc. common heavily filled bard vulcanized rubber friction! The characteristics of the composition brake blocks particles or conventional resinous friction particles such1 for railway service formed in accordance with this in as granules of cured thermosetting resins as exemplified1 10 vention primarily result from the presence in the composi kiy polymerized cashew nut shell oil; t vulcanized in situ1 tion cl high proportions of bard cat iron granules or hard rubber matrix formed from an elastomer composi chips and of the hard vulcanized rubber matrix and its tion containing a relatively large amount of conventiona1l non-ferrous fillers, and organic fiber reinforcement, which fillers and vulcanizing ingredients; and. as distinguished1 matrix has good resistance to heat-softening. " The from the preferred blocks claimed In application Seria1l IS presence of 25-75% by weight of hard ferrous metal Vo. 279,417, a substantial proportion of a staple organic chiefly in the form of cast iron particles, and at least reinforcing fiber, ^samples of staple organic reinforc 50% by volume (75-25% by weight) of non-fenous in ing fibers wbicb may be used in accordance with this in organic and organic filler and organic binder materials in .vention are cellulose fibers such as wood fiber, cellulose> cluding the organic reinforcing fiber and a binder matrix flock (exemplified by the commercial product Solka-floc), 20 of relatively heat-stable vulcanized rubber, is necessary viscose ind acetate rayon fiber, cotton fiber, etc.; proteinl to develop a suitably high friction coefficient, a satisfac fibers such as wool, silk, etc; regenerated protein fibersE tory rau'o between the wet and dry braking performance (e,-g. Vicara); alginate fibers; and synthetic polymeric for heavy duty railroad service, good resistance to gen j-fibers such as polyamide fibers (e. g. nylon), polyethylene and polyhiloethylen: fibers (e. g. Polythene, Velon, etc.), erated heat, even tread wearing characteristics and a long service life. Preferably, the total ferrous metal content polyester fibers (e. g. Dacron), polytetrahaloethylene is in the form of cast iron chips, and, when so used, the fibers (e. g. Teficn), polyacrylonitrile fibers (e. g. Orion)I iron content will usually not exceed 65% by .weight. including thermally modified acrylonitrile fibers as, for While a greater percentage'may be employed, an increase example, these obtained from the procedure disclosed ins in iron chip content over 65% does not result in any the copending application of Irvin Barnett, Serial No. 30 significant improvement of wet/dry ratio, and slightly de- 345,682. filed March 30. 1953, etc. _______________ .creases the desirable -long wear life of the block. The --It is apparent from test results'that the excellent fric cast iron particles used in this invention should have the tional characteristics and long service life of the railwayt brake blocks formed in accordance with this invention1 characteristics of those defined in Serial So. 279.417. In order that the present molded composition brake are due to a pronounced cooperation between the cast 35 block have a high coefficient of frietion and long wear iron particles forming a substantial proportion thereof characteristics, it is preferred that it contain a compara and the bard, tough elastomer matrix and non-ferrouss tively high percentage of long wear friction particles of the inorganic and organic filler materials incorporated there types described in-the aforementioned application. in. considering the organic fiber and resinous or rubber An alternative form of molded composition brake block friction particles as such fillers. The cooperation of thesee <0 may be formed, as illustrated in Figs. 3 and 4 wherein ingredients lends the block characteristics of long lifee several layers of expanded steel grid lath 22 or equivalent and frictional efficiency, both wet and dry, not attained1 hard ferrous metal reinforcing fabric are incorporated in in any molded friction materials heretofore proposed or the block. While these reinforcing grids obviously com fabricated, nor exhibited by conventional cast iron rail prise a part of the total ferrous metal content of these way brake blocks. 45 blocks in which they are incorporated, by far the great The staple organic reinforcing fiber cooperates with thee est part of the ferrous metal will be present in the form organic and inorganic fillers and elastomer matrix to re of cast iron chips. The ferrous metal content due to the sult in the extremely desirable characteristic in the block grids alone should comprise no more than about 15% by of less wear on the wheel tread and yet a longer lifee weight of the total block-composition. when compared to the prior blocks in a manner whichh 60 When the hard ferrous metal chips comprise up to is most noticeable when employing a eeliulosic reinforcingt 50% by weight of the block, it will be noted that this fiber and particularly when using a eeliulosic fiber of thet tfietal content does not exceed on the average 25% by chemically modified wood fiber type, such as that markett- volume at the exposed wear face of the block, with the re ed under the name Solka-floc. That such staple organic reinforcing fibers could be used in such molded braket blocks and would lend the bodies such desirable char acteristics is totally unexpected, since investigations have shown that temperatures as high as 1450* F., well abovee the destructive temperatures for such fibers, are generated 55 sult that the block develops a much higher coefficient of friction than, and exhibits a wear life substantially great er than, that of a standard cast iron shoe. In the molded and cured block the cast iron panicles, staple organic reinforcing fibers and long wear friction particles are dis at the friction surfaces under service conditions. Preferably, the railway brake block 10 (Figs. 1 and 2) formed in accordance with this invention will comprise approximately 25-75% by weight of hard ferrous metal1,, 80 tributed uniformly throughout the hard rubber binder matrix. In other words, the oganic fiber and long wear friction particles may be considered to make up a part of the filler content of the bard rubber, supplementing at least 50% of which is in the form of cast iron chips o>rr granules 14; 10-60% by weight of long wear friction particles 16 comprising either particles of hard vulcanized 65 the content of conventional filler and vulcanizing ma terials. Brake blocks of the type Illustrated may be manu rubber containing, for example, 50-70% by weight of ina- factured substantially as follows: A suitable molding com organic fillers and vulcanizing ingredients, or conven5- position for Lite block is first prepared in accordance with tional resinous particles as exemplified by granules o>fr the formulas heretofore set forth. After thoroughly mix cured theromseuing resins such as polymerized cashew 70 ing the paniculate.ingredients, the mixture is charged into nut shell oil; up to 30%. preferably 2 to 10%, stapl!ee a mold of suitable shape. In the event that expanded organic reinforcing fiber 18; from 8-32% of a vulcanized metal lath or equivalent metal reinforcing fabric is to be in situ rubber matrix 20 formed from a composition coma* used, layers of such reinforcing fabric are introduced prising 2-12% by weight of the block of a natural or syni- into the mold at spaced intervals paralleling the block thetic rubber such as a butadiene-styrene copolyme:r 75 face during the operation of charging the mold with the O"S '~X--T~ ' -6. cnr.pcsii.'en material. After-jBLUing the mold to prtdettr .'inversion or softening point during :hea't hardening cure mined depth witn the plastic moldiog'mixture, with or .or in use. -'iris'preferred to reinforce'iihe-vulcanized' without metal reinforcing fabric,-the uncured and plastic i rubber matrix' with up to 6% by weight of the block block is beatified, hardened, and cured .within the mold of a thermosetting resin of the pheaoiicaldehyde or cashew . : by simultaneous application of high temperature and pres .6 nut shell oil type.. - _ ' sure. Such curing may, for example, take place under a pressure of 2000-5000 (preferably 2500-3000) lbs. per It will be understood that the de'tails given are (or the purpose of illustration, not restriction, and that variations square inch at a temperature equivalent to the temperature of steam at 90 lbs. pressure.- In,this manner the block within the spirit of the invention are intended to be in cluded in the scope of theappended claims/ is molded to final dimensions and shape, and the various 10 . What I claim is:' :: ingredients of-the composition are strongly -bonded to - -1. A .molded .^composition .brake^block .having good y 4J each other to form a strong unitary bloek.ivi^h^ r- .wet' and dry 'friction charjcteristics -acd ;a'-long service A The following are examples of various molded com .life, comprising 25-75% by weightof hard ferrous metal position brake blocks for use in railway brake systems, at least 50%-of-which Is in the (firm..offcast iron par---; and their general method of preparation-^It is understood, IS .tides,"'staple organic ^reinforcing `fiber/jn-amount - from of course, that the compositions of, and methods for pro -2-to 30%. by weight,-.and at least 50%'-by volume of ducing. these blocks are exemplary and/are. not to be non-ferrous inorganic and organic filler aod organic bin considered toriimit the invention to the particular com der materials including a binder matrix comprising a positions and operating conditions outlined." All per beat resistant hard vulcanized-, in situ .`rubber selected centages indicated in the examples are by weight ' to from the group consisting of natural rubber,, polychlor- Example I butadiene, and butadiene-styrene-and butadiene-acrylo nitrile copolymers,. A railway brake block was prepared by thoroughly 2. A molded composition brake block having good mixing a composition comprising: ' wet and dry friction characteristics and a long service Cast iron Percent chips--____________________ -___ ....... 32 5 life, comprising 25-75% by weight of hard ferrous metal t least 50% of which is in the form of cast iron par Hard rubber friction panicles_____________ __ .___ 46 ticles, cellulosie reinforcing fiber in amount from 2 to Cellulose fiber (Solka-Floc) 6' Hard rubber matrix.-...... 16 Butadiene-styrene (Buna GR-S), 3% Polymerizable cashew nut shell oil resin.. 2%______ 30% by weight, and at least 50% by volume of nonferrous inorganic and organic filler and organic binder 30 materials including a binder matrix comprising a heat resistant hard vulcanized in situ rubber-selected-from-- 'the group consisting of natural rubber,.polyeblorbutadi- SnlfST""_________________ 1.4% ene, aod butadiene-styrene and. butadiene-acrylonitrile litharge_______ ________________ 4.3% Zinc oxide3.6% \10% copolymers. 85 3. A molded composition brake block having good Carbon black_________________ 0.5% wet and dry friction characteristics and a long service Hexamethylenetetramine______ _ 0.2% life, comprising 25-75% by weight of hard fenous metal and molding said composition to the desired dimensions with a pressure of approximately 300Q Ibs./tq. in. and at a temperature of approximately 300* F. The block ex hibited a coefficient of friction of 0.300 as compared to 0.1 SO for a cast iron shoe under the same, braking con ditions, bad a wet/dry stopping distance ratio of sub stantially 1.0 at high speeds, and had a wear life approxi mately 3J to 4 times that of a standard cast iron railway 40 45 at least .50% of which is in the form of cast iron par ticles, cellulosie reinforcing fiber in amount frem 2 to 30% by weight, and at,least 50% by volume of nonferrous inorganic and organic filler and organic binder materials including a binder matrix comprising a heat resistant bard vulcanized in situ butadiene-styrene co polymer synthetic rubber. 4. A molded composition brake block having good wet and dry friction characteristics and a long service block. life, comprising 25-75% by weight of bard ferrous metal Example II at least 50% of which is in the form of cast iron par- A railway block was prepared in the same manner as tides, cellulosie reinforcing fiber in amount from 2 to that in Example I from a composition containing: 60 30% by weight, and at least 50% by volume of non- ~ Percent Cast iron chips______________ ___ _____ .......___ 33 ferrous inorganic and organic filler and organic binder materials including a binder matrix comprising a heat Hard rubber friction panicles..........__________ 47 resistant hard vulcanized in situ natural rubber. Thermally modified acrylonitrile fiber ... Hard rubber matrix....________ ________ ... Butadiene-styrene (Buna GR-5). 3% Polymerizable cashew nut shell oil resin, 2% Sulfur1.4% Litharge ___________________ 4J% Zinc oxide ____________________ 3.6% 10% Carbon black___.....____ ..... 0.5% Hexamethylenetetramine'________ 0.2% 5 15 65 5. A molded composition brake block having good wet and dry friction 'characteristics and a long service life comprising 25-75% by weight of hard ferrous metal at least 50% of which is in the form of cast iron particles, staple organic reinforcing fiber in amount from 2 to 30% by weight, and at least 50% by volume of 60 non-ferrous inorganic and organic filler and organic binder materials including a binder matrix comprising a heat resistant vulcanized in situ' rubber selected from the group consisting of natural rubber, poiychlorbu'adi- Il The resultant block exhibited frictional characteristics sub eoe and butadiene-styrene and butadiene-acrylonitrile co stantially similar to those exhibited by the block formed 65 polymers, said binder matrix containing up to 6% by in accordance with the preceding example. weight of the block of a thermosetting resin stiffener. The invention disclosed herein is not limited to the use 6. A molded composition brake block having good \ of the butadiene-styrene rubber defined in the above ex wet and dry friction characteristic! and a long service amples for the heat resistant vulcanized elastomer matrix. life, comprising 25-75% by weight of hard ferrous metal A satisfactory matrix may comprise in place of butadiene- 70 at least 50% of which is in the form of cast iron par r styrene, oatunl rubber or a synthetic rubber of the Buna N type, i. e., butadiene-acrylonitrile. An alternative, but ticles, cellulosie reinforcing fiber in amount from 2 to 30% by weight, and at least 50% by volume of non- somewhat less satisfactory, matrix may comprise a poly- ferrous inorganic and organic filler and organic binder chloroprtne such as chlorbutadiene, or any other heat re- materials including a binder matrix comprising a beat aistint vulcanized rubber which will not pass through an 75 resistant vulcanized in situ rubber selected from the group -- . 7 * "TV'',r'-\. "*>.. - ; - :**: ' o *'-' - earn:::.:* aatunl rubber, polychlorbutadiene rand ' and a high proportion of inorganic fillers and vuIcaniScj'1-' fc-.".a;.:a: f.yreat and butadiene-acrylonitrile copolymers, ingredients. ...." ' i'%2'4^-5 Hid bmder matrix containing up to 6% by weight of 13. A molded composition brake block having;gcxxF'; the block of a thermosetting resin stiffener. - "" ..wet and dry friction characteristics and a long service 7. A molded composition brake block having good life, comprising 25-73% by weight of hard ferrous meul wet and dry friction characteristics and a long service at least 50% of which is in the form of cast iron par life, comprising 2 3-75% by weight of bard ferrous ticles, from 10-60% by weight of long wearing organic metal at least 50% of which is in the form of cast iron friction particles, cellulosic reinforcing fiber in amount panicles, cellulosic reinforcing fiber in amount from 2 . from 2 to 30%-by .weight,,ahd from 8-32%"of a binder to 30% by weight, and at least 50% by .volume-of non- 10 matrix comprising- the- is situ vulcanization product-of ferrous inorganic and .organic filler and.organicbinder.'V;.* composition comprising a. natural-rubber and a'high materials including .a binder, matrix comprising a;heat V- .proportion of inorganic fillers and vulcanizing ingredients. - resistant bard vulcanized in situ butadiene-styrene-co-1H. A molded composition brake block having..good .polymer synthetic rubber, .taid binder-matrix, containing..--i.'wet and dp''friction-.characteristics and a long service . up to 6% by weight of the block of a thermosetting resin IS life, comprising 25-75% by weight of hard ferrous metal stiffener. at least 50% of which- is in the form of cast iron par 8. A molded composition brake block having -good ticles, from 10-60%- by weight of long wearing organic wet and dry friction characteristics and a Jong-service ' friction particles,' staple organic reinforcing fiber in life, comprising 25-75% by weight of hard ferrous metal - amount from 2 to 30% by weight, and from 8-32%' of at least 50% of which is in the form of cast iron par- 20 a binder matrix comprising the in situ vulcanization tides, cellulosic reinforcing fiber in amount from 2 to product of a composition comprising a rubber selected 30% by weight, and at least 50% by volume of non- from the group consisting of a natural rubber, poly ferrous inorganic and organic filler and organic binder chlorbutadiene. and butadiene-styrene and butadiene- materials including a binder matrix comprising a heat acrylonitrile copolymers and a high proportion of in- resistant bard vulcanized in situ natural rubber, said 23 organic fillers and vulcanizing ingredients, said binder binder matrix containing up to 6% by weight of the block matrix containing up to 6% by weight of the block of of a thermosetting resin stiffener. a thermosetting resin stiffener. 9. A molded composition brake block having good 15. A molded composition brake block having good wet and dry friction characteristics and a long service wet and dry friction characteristics aDd a long service li/e, comprising 25-75% by weight of hard ferrous metal 30 life, comprising 25-75% by weight of hard ferrous metal ...at least .50% ..of .wbichlis_in_the..form-o_cast-iron^par--------at least 50% of which is in the form of cast iron par- tides, from 10-60% by weight of long weiring organic tides, from 10-60% by weight of long wearing organic friction panicles, staple organic reinforcing fiber is friction panicles, cellulosic reinforcing fiber in amount amount from 2 to 30% by weight, and from 8-32%' from 2 to 30% by weight, and from 8-32% of a binder of a kinder matrix comprising the in situ vulcanization 35 matrix comprising the in situ vulcanization product of product of a composition comprising a rubber selected a composition comprising a rubber selected from the from the group consisting of a natural rubber, poly- group consisting of a natural rubber, polychlorbutadiene ehlorbutadiene and butadiene-styrene and butadiene- and butadiene-styrene and- butadiene-acrylonitrile co acrylonitrile copolymers and a high proportion of in polymers and a high proportion of inorganic fillers and organic fillers and vulcanizing ingredients. 40 vulcanizing ingredients, said binder matrix containing 10. A molded composition brake block having good up to 6% by weight of the block of a thermosetting resin wet and dry friction characteristics and a long service stiffener. life, comprising 25-75% by weight of bard-ferrous metal 16. A molded composition brake block having good at least 50% of which is in the form of cast iron par- wet and dry friction characteristics and a long service tides, from 10-60% by weight of long wearing organic life, comprising 25-75% by weight of hard ferrous metal friction particles, cellulosic reinforcing fiber in amount at least 50% of which is in the form of cast iron par- from 2 to 30% by weight, and from 8-32% of a binder tides, from 10-60% by weight of long wearing organic matrix comprising the in situ vulcanization product of friction particles, thermally modified acrylonitrile rein a composition comprising a rubber selected from the forcing fiber in amount from 2 to 30% by weight, and group consisting of a natural rubber, polychlorbutadiene 50 from 8-32% of a binder matrix comprising the in situ and butadiene-styrene and butadiene-acrylonitrile co vulcanization product of a composition comprising a polymers and a high proportion of inorganic fillers and rubber selected from the group consisting of a natural vulcanizing ingredients. rubber, polychlorbutadiene and butadiene-styrene and 11. A molded composition brake block having good butadiene-acrylonitrile copolymers and a high propor- wet and dry friction characteristics and a long service 55 tion of inorganic fillers and vulcanizing ingredients, said life, comprising 25-75% by weight of a hard ferrous binder matrix containing up to 6% by weight of the block metal at least 50% of which is in the form of cast iron of a thermosetting resin stiffener. particles, from 10-60% by weight of loog wearing or 17. A molded composition brake block having good ganic friction particles, thermally modified acrylonitrile wet and dry friction characteristics and a long service reinforcing fiber in amount from 2 to 30% by weight, 0 life, comprising 25-75% by weight of hard ferrous metal and from 8-32% of a binder matrix comprising the at least 50% of which is in the form of cast iron par- in situ vulcanization product of a composition compris- tides, from 10-60% by weight of long wearing organic ing a rubber selected from the group consisting of a friction particles, cellulosic reinforcing fiber in amount natural rubber, polychlorbutadiene and butadiene-styrene " from 2 to 30% by weight, and from 8-32% of a binder aod butadiene-acrylonitrile copolymers and a high pro- 33"comprising the in aitu vulcanization product of portion of inorganic fillers and vulcanizing ingredients. a composition comprising a butadiene-styrene copolymer 12. A molded composition brake block bavin; good. and a high proportion of inorganic fillers and vulcanizing wet and dry friction characteristics and a long service ingredients, said binder matrix containing up to 6% by life, comprising 25-75% by weight of hard ferrous metal weight of the block of a thermosetting resin stiffener. at leest 50% of which is io the form of east iron par 70 18. A molded composition brake block having good ticles, from 10-60% by weight of long wearing organic wet and dry friction characteristics and a Ion; service friction panicles, cellulosic reinforcing fiber in amount lift, comprisin; 25-75% by weight of hard ferrous metal from 2 to 30% by weight, end from 8-32% of a binder at least 50% of which is in the form of cast iron par matrix comprising the in situ vulcanization product of ticles, from 10-60% by weight of long wearing organic a composition comprising a butadiene-styrene copolymer 73 friction partielex, cellulosic reinforcing fiber in amount < < ' >' V 1-. l' ' .t \ : ; I l. t _ .. '' S.aei.O 64 10 from 2 to 30% by weight, and from 8-32% of a binder ..23. A molded composition brake block having good matrix comprising the in titu vulcanization product of wet and dry friction characteristics and a lor.; service life, a composition comprising a natural rubber and a high comprising 25-75% by wei [ of hard ferrous metal at proportion of inorganic fillers and vulcanizing ingredients, least 50%-of which is in the form of cast iron particles, laid binder matrix containing up to 6% by weight of from 10--609> by weight of long wearing organic friction the block of a thermosetting resin stiffener. particles, cellulosic reinforcing fiber in amount from 2 19. A molded composition brake block having good to 30% by weight, and from 8-32% by weight of a binder wet and dry friction characteristics and a long service matrix comprising the in situ vulcanization product of a life, comprising 25-75% by weight of hard ferrous metal composition comprising a butadiene-acrylonitrile .copoly- at least 50% of which is in the form of cist ironpar-! 10 mer and a high -proportion of inorganic fillers and vul- tides, from 10--609& by weight of long wearing organic'.- .canizing ingredients.'; .it'.^ ..............r'-fe- friction particles, staple organic reinforcing -fiber .La -2,24. A.molded composition brake block having good amount from 2 to 30% by weight, and from' 8-32% -i^wet and dry friction characteristics and a long service life, of a binder matrix comprising j^c in situ vulcanization: - --comprising 25-75% by weight of hard-ferrous;metal at product of a composition comprising .a rubber selected 15 least 50% of which is in the form of cast iron'particles, from the group consisting of a natural rubber,.-poly- - from-10-50% by weight of long wearing organic friction chlorbutadlene ^*od : butadiene-styrene and butadiene- ' panicles, cellulosic reinforcing fiber in amount from 2 acrylonitrile copolymers and a high proportion of inor* to 30% by weight, and from 8-21% of a binder matrix ganic fillers and vulcanizing ingredients, said block'being comprising the in situ vulcanization product of a com- reinforced with a hard ferrous metal grid sheet disposed 20 position, comprising, butadiene-acrylonitrile copolymer in spaced relation substantially parallel to the friction and a high proportion of inorganic fillers and vulcaniz face of the element. ing ingredients, said-binder matrix containing up to 6% 20. A molded composition brake block having good by weight of the block of a thermosetting resin stiffener. wet and dry friction characteristics and a long service 25. A molded composition brake block having good life, comprising 25-75% by weight of hard ferrous 5 wet and dry friction characteristics and a long service metal at least 50% of which is in the form of cast iron life, comprising approximately 32% by weight of cast particles, from 10-60% by weight of long wearing or iron chips, approximately 46% by weight of hard rubber ganic friction particles, cellulosic reinforcing fiber in friction particles, approximately 6% of cellulosic rein amount from 2 to 30% by weight, and from 8-32% forcing fiber, and approximately 16% of a binder matrix of a binder matrix comprising the in situ vulcanization 50 comprising the in situ vulcanization product of a compost- product of a coJmposnion_cpmp.risiDg_a_nihber_$elccted____ tion comprising rubber -selected from the group consisting from the group consisting of a natural rubber, poly* of a natural rubber, polychlorbutadiene, butadiene-styrene chlorbutadierst and butadiene-styrene and butadiene- -and butadiene-acrylonitrile copolymers, and a high pro- acrylonitrile copolymers and a high proportion of in- portion of inorganic fillers and vulcanizing ingredients, organic fillers and vulcanizing ingredients, said, binder 55 26. A molded composition brake block having good matrix containing up to 6% by weight of the block of wet and dry friction characteristics and a long service a tbermosettng resin stiffener, and said block being re life, comprising approximately 32% by weight of cast inforced with a bard ferrous metal grid sheet disposed iron chips, approximately 46% by weight of hard rubber in spaced relation substantially parallel to the. frieuon friction particles, approximately 6% of cellulosic rein- face of the element. 40 forcing fiber, and approximately 16% of a binder matrix 21. A molded composition brake block having good comprising the in situ vulcanizauon product of a compo wet and dry friction characteristics and a long service sition comprising natural rubber and a high proportion life, comprising 25-75% by weight of hard fenous metal of inorganic fillers and vulcanization ingredients. at least 50% of which is in the form of cast iron particles, ' 27. A molded composition brake block having good cellulosic reinforcing fiber in amount from 2 to 30% 45 wet and dry (ricu'on characteristics and a long s'erviee life, by weight, and at least 50% by volume of non.fetTOUS Inorganic and organic filler and organic binder materials including a binder matrix comprising a heat resistant comprising approximately 32% by weight of cast iron chips, approximately 46% by weight of hard rubber fric tion particles, approximately 6% of cellulosic reinforc hard vulcanized in situ butadiene.aeryionitrile copolymer ing fiber, and approximately 16% of a binder matrix synthetic rubber. 50 comprising the in situ vulcanization product of a compo 22. A molded composition brake block having good sition comprising a. butadiene-styrene copolymer and a ' wet and dry friction characteristics and a long service. high proportion of inorganic fillers and vuleanizitien in life, comprising 25-75% by weight of hard fenous metal gredients, said binder matrix containing approximately 2% at least 50% of which is in the form of cast iron particles, by weight of the block of thermosetting resin stiffener. cellulosic reinforcing fiber in amount from 2 to 30% by 55 weight, and at least 50% by volume of non-fenous in References Cited in the file of this patent organic and organic filler and organic binder materials UNITED STATES PATENTS including a binder matrix comprising a heat resistant hard vulcinized in situ butadiene-acrylonitrile copolymer syn thetic rubber, said binder matrix containing up to 6% by 60 weigbt of the block of a thermosetting resin stiffener. 2,460,367 2,663.693 2,673,146 2,686,140 Sharpe_____________________Feb. 1, 1949 Hess et al.........................Dec. 22,1953 Kuzmick et al.......................Mar. 23, 1954 De Gaugue ________ Aug. 10,1954 a a XJ o m '~y Co-position Friction Hater for Erake Shoos, Brake Bon Disc, Brakes, etc, Nov. 25, 1958 r? C. L. E. DE GAUGUE, JR.. ET AL CQUPOSITION BRAKE BLOCK Fllad Kov. 17. 1953 2,861,964 i i li i TW^A/TOA C//ARL5 L. atGA&Gu? Ja XALPh T. HALSTAD ffy " a rroRHcy * 4 r.O liiLu TU j oRps.jn\j, 113 Patented uu- nt 25, 1553 12 of tl is. in-.cr.i.---. Iilc' ihu-sr of the P.ve.v.. No 2.,r0 !-'* ? .390.1 11 brut r.Lncix- comi'ush io\s coMrrtiMVG \ U.CAMtXi) HALOCLNaTLD BUTYL ULlliiCK end Nc 2.v61.!'f4. tsp::r.l'y ec--tprre a" to 7$'.i b; si or.'.: of hr.td ferrott, n:r:. I a: i-.-a*-t 5i*r. of which is in the fotm of east iron prrticlos to-jet.irr v. Charles Louis Ernest it Gaucue. Califon, NJ.. assignor, j nf least 5`JT- by volume of non-ferrous inorearar ar.d to Joluis-Mam illt- Corporation, New YorL, N.Y-, u cot* . organic filler ar.d the orpr.i; binder. If,: cffcctt-.c bi-Jc* pofflliou ot New Yeti, ; -- . systems of this invention ccnjist of haloycnatcd butyl rub- PLAINTIFFFSSgffj teownr mo. ''ntidmtatian-ir.-p-an of application Scr. No. 19S.15G, May 28, 19G2. This application 3an. 27, 19G7, Scr. No. 632,120 12 Claims. (Cl. 260--23.7) 'ber elastomer contnininf a hdlopen eomprisin; chlorine and/or bromine such as chlorobutyl rubber and brontoj0 butyl rubber. The preferred rubber material, primari.1; due to its superior moldinr characteristics, con-ists of a chlorobutyl rubber or elastomeric i*or,,:yler.e isopw.e |0ATE:l.g^TH:LC4i ABSTRACT Of THE DISCLOSURE cop.-lymer contnininj 3bc,.,t 1.1 to 1.352 cf reactisc ch.crinc and produced pursuant to the disclotutc of U.S. Lct- heavy du'.y brake bloc). composition containing hard 15 ters Patent No. 2.944.57E. ferrous metal particles. non-ferrous ir.or'.anie ar.d otgnniz Objects and advantages c-f this imp'oved compositior. fillets, a-.,-t ar. organic binder matrix ror.tpri.-ing a heat for brrd.c blocks or elements of this ir.seriiior. comprise rcsuiar.:, sal.-ar.-e.J i:. .l.-l.-..r,..:v.t butyl rut;--.-:. greater bin.!, or element wear life of up to ai-ct.t three limes crcuier than prior cor. p.ui:ior.; ssi:b.out an increr.se 20 in ss-ear of the cooperating brakir.; surface of the wheel CROSS-REFERENCE TO RELATED APPLICATION trend or brr.he drum, and imp.ri.ved hither and more uni- This a,"hr of in- ct-:--. f.-.j : - it a cr-ti.-trnt.er. in-gar. application U 5 r-'-.a: a "/ :.,,ar Sr:. No. IF'.-.Ifa, r. - Or- fornt friction, props-rties alone- ssiib read net cr.d sirs frirtio.-.a! el.aractrnsiics co.Tpurr.cle tc- .-.tior br.l-.r blocks A.tr.oJuh tr.ctc niiiibutes ate piestr.t ss.-..-. t ;. . tty sceid, i.ncy are me-1! p*c'o.rr..: ur..-.- 'pr.-;. BACKGROUND C* THE INVENTION crnditions cf up tc 150 r.t.p b. Mo'cc--.:: th: my tor- ----- position brake blocks'O; elemer.ts'of t.-is jr,vcr.ii.;.- bo --------------------------- This ir.-.cmij:- re: c Tc "ir.Tpfe ITTcoThpo'CTTor. brake blocks, ar.a r-er. r-rt.ralarr; to enhanced mold.-.' brake no: en*.:: or produce typical or cbararr.-rii:;: brakir,; sq-j.-als o: the like diiagrceabie noise ar J sicr.tiom sx-ncr. block compr-mor-s ct to.- gene::-.! type disrlcicd tml 20 cc.r.actmt nnd/or coir.prrsved upon the cooperating claimed in U S. Letters Patent No. 2.6S6.140 and No. 2.P.61,96-t ssfcicb. are peca'i-iN adt-pintle for fctr.l.ir.j v;.' re! tread or brake drum surface. ' Tne above and ether object' ar.d ads am ace-- cf thr heavy ca ?e:h :> r -.i-vraa' ruil-rr stock. ir.-.proved composition or r.ra bi.nJcr system cf i'i: ir- Pater.t! N; 2 i: ;,rd No. 2.161,66-' arc cor.rcrrrd vension will become more apparent in.the bereir.after dr- with a n:-< cr;:e-t in rutl-md fcr. kc blocks, a tintr-pie conibirat-r*. cf cat*, i'er. px::..ifs end organ.- cont'.ittra.V.s 3d tailed description, and drawir.; whcrcir. the FIGS. 1 aad 2 illtixtrate comparable rctnrd.tia.-. ra*cs or cr.:!.*...-:.-:- bonded ui:.-. r filed, ha'd. rurerrs c-f the given com position; ssprosier d;::Je.'.;. improved ads:.r.'..ig:; istics ttpur. brakinc fre.r. speeds cf N-k mile- per hear and 40 miles per hour with brake tierks of tr.:; ir.-.en. including enhanced b::k:-.g and friction pror-rnics ssith lion and with the preferred and commercial composition both ler.ger block or friction eler.er.; and wheel it cad ct brake blocks of the prior art consisting of the product drum wear o\cr the lor; utilized soiid east ito-.t brake of Example 1 of Patent No. 2.61,964. FIG. 3 com- blr-cks for railroad r-ppl:::.tic.-.. This ir.ve.-.tior. comprises tbe discos cry of a r.ew com ` prises a graph illustrating the relative wear rates of the composition cf Example I of this invention with that of position for raiitoad brake biocl.s of the gtr.cr.il type and/or genera! corrprr.cnfs described ir. Patents No. 2.6E6.140 and-er 2.SGI,964, which results in further marked enhancements ansi improvements of certain basic properties of the- former composttu.".; brake Weeks cf either ol the said patents. In particular, the modified and Example I of Patent Nc. 2.PC3.964 constituting a pie<-" ferrrd. commercial p.rodt-c; of the prior art. All braking conditions were the same nd the abscissa axis denotes spied and the ordinate axis the rate of wear in cubic inches in logarithmic scale. improved composition brake blocks of this invention, DESCRIPTION OF PREFERRED EMBODIMENTS primarily attributable to and constituting a new and en The composition brake block products of this invention hancing binder pharc or matrix, exhibit general overall arc prcdurcJ by utilizing halogcr.atrd butyl rubbers of the properties *t least equivalent to those of the prior art type* specified ir. amount of about 5 tc 12CE and pref as re; resented by the aforementioned patents and dc- erably abn.it C to 1051 by weigh; ol the cu-rtll bh:i cidcdis impro'ed properties eomprts:r.r n suh-iarwi':!1;. i,-,. dd which arc vulcjr.izcJ or cured in situ with curing agent1, creased v.er.r life, more uniform and ciet-tct fnctioo cit.v- fillers, etc. tc form the bonding phase or system cor.- actetistics, and the ieduction of loud a.-.u.-'ur disapicceblc tiiiuiing art encompassing matrix for other components. noise; durin; or resulting ficm braking whiv.lt is of con- The overall binder systems or phases include along v-th tidcroMe impartanec ir. p.a.-senper scrsice, partieul.vly the rubber approximately 2 to 20T by weigh: of the , in subway or intcruiban passenger service vyber-rir. stops CO Hock of inorganic and organic fillers and vuh.zr.irin; in- ` arc frequent and the noise of braking confined or ecu- prrdients sitch as sulfur, or (ctramrthylihiuram disulfide ccnttatcd by the tsmbient conditions. or potymethylo! phenol resin cr other apt curing seer.:*, SUMMARY CT THE INVENTION n:'-ne-irm oxide, rinc oxide, carbon bk.rh. t*-:\:v* e-r j.. ...... a L-ortwi.-g a.id cnco;.:pa'>- g r.:.::.-- ... ...... In pcn.r.-r!. this invention compircs in:prt"cd cor:ipO:i- i.`, k t.i 35% by weight of the total Hock.'And i-i atljition tion o, r.ke thick* of me same general construction at-.d to the fundamental haloeenntcd bt-tyi ri.-brcr ir. the '-eci- co"s-,*oitions as those of Patents No. 2.f>>6.140 ar..'. N`o- l-.:' .-mo:i-.t*. these brake blocks may aNo include other 2.801,564 contc.ii.inp i binder phase c.r matrix cor.-.;::i>. rfl-'ncr Cyir.rovitions in the binder xyvt.r.-. such as butyl ! ir.p halo'c.i.-rrd b:::;-l n.hhcr, or r.toie precise)-, a i. :r compatible but iJiene-sijrcr.c rubber and other ^ ier.:-ud elastomer rroauc.d b> cup-sisr.scri/, tior. cf iso- TO t:-::-pj;ible cluMoniers When combined with oilier rub- butylene ssith lel.iitsely sni-1! amounts of isopren: at loss ! *-r c'js'i'nteri, the hx!..-cr.a:.-d hu.i rubber of the lcmp.-r..;urs-s The babr.ee of the friction cn:r.-..::ion b: of tl-i invention inu.-l consist of ai Ic.-s; pr bu. J> r 4 r" '.a." S':'.7 Noe.. ;.-d tr.e imu! rubber binder "`'Exemplary brake blocks ccmpiisir.g the ne'er, .her cc.-.:p sr.ej.J -cl excc.-d about 157.' bj weight of given formul.itionv were prepared asJollcw;- Tl.c ag;-:,'- tbc block -pri.Me `-identified halogenatcd 'butyl rubber crmpo.-.cr.i- The method or means of producing and/or molding were combined on a rubber mill with the given ptvppN (he sur-ect crake fciocxs of this invention arc not ur.likc 5 tions of a conventional curing agent comprising ei'.i.rr sul those of tnc foregoing mentioned patents and arc pursuant fur or tetramethjlthiuram disulfide or poiymcth>!olp!:enol to established render compounding and brake block manu resin accelerators, stearic acid, zinc oxide or tbc like ap facturing procedures and techniques. For example, tiie propriate rubber compounding constituents given. Tne re rubber component with the fillers and/or. suleanuers anj sultant-compounded rubber sheelAvas chopped and turn- the like are blended on a rubber-miff and cut bach v.ith fated with gasoline until a smooth' consistent cement was. a suitable solvent such as gasoline to form a uniform and formed which was placed in a sigma-blade mixer and com- workable fluid-lil.e consistency whereupon the other con ' bined7 with the balance of the`constituents of tiic rar* stituents are combined and blended-.therewith. ..The ad 2 Jicular-^formulation producing ':!!, dough-like extrudablc mixture of the complete formulation is then formed into "mass...Upon pelleting the mixture! or*chopping or slicing" small particles or pellelswhich are dried at "a relatively 13 tbc Imaterial into small bodiev'tbe particles thereof were low tcmpcratuie if necessary to provide a convenient and thoroughly dried at a temperature just under about 130* har.dlcabic particulate furnish for molding. The material F.To provide a convenient particulate furnish for charg is then molded at high pressures and elevated tempera ing and molding in compression type molds such as ate tures, e.g.. about 2000-5000 p.s.i. and. 300-400* F., to frequently utilized in the production of composition shape and integrate the brake block article whereupon it 20 blocks. The dried pellets were compression molded for a is baked at an appropriate temperature, e.g., about 250- period of about I hour at mold temperatures of approxi 400' F., to complete the cure or. vulcanization. mately 300* F. and unit 'compressive loads of approxi Molded composition btaka biocks of a formulation in mately 3000 pounds per square inch. Upon removal from accordance with this invention, viz. composition brake the mold, the resulting shaped and consolidated brake blocks such as generally disclosed in Patent No. 2,656,140 25 blacks were subjected to an after-bake of about 12 hours and/or No. 2.SCI.9G4, but comprising taerem a vulcan at approximately 300* F, to complete the vulcanization or ized in situ halogcr.ated puts I rubber in amount of at least cure. about 2 up to about 1272 by weight of the product In each of the hereinafter examples the composition is selected from the group consisting of chlorobutyl rubber, given in percentages based upon weight. anJ acditicnal- -and-bromobutyl rubber, teres thereof, exhibit im- ;p ly in some cases by parts by weight, or percent by volume. proved higher and more uniform frictional characteristics, significantly greater wear resistance or service iife without EXAMINE I a commensurate increased rate of wear or reduced service life on the cooperating or brake contacting wheel tread, brake drum or other contacting brake surface, and ex 25 Pi rc*r.t by wt. re.-:; by i. Apr*u:. Tv:- Krc'r.i ceptionally quiet braking properties without incurring ad ChHrANityl ru*>fccr (Enjay JIT- verse qualities of materially diminishing other essential lOC-j'-............................................... Aecii-r-tof. vuinr'.lnkUiufam di* properties of comparable prior art products. As is ap parent these improved properties render such a brake lulfid.*rTuiJ.O......................... Aml-'Mior. Umoil.i-uy! duulftdc rA:ui"K.,..*.............................. block particularly advantageous and useful in high speed 40 St-artc eid........................................ passenger service and on subway and interurfcan service Zinc ,-viJe.......................................... Carbon blsct. iiuw-diwU.................. systems. Ci>t iron cb:ps i>ub:-.mi;hlly IO> eoom-sh)....................................... The organic friction panicles and thermosetting resin Trtctwo iiar.telrs (hard. brtrUy stiffener referred to throughout this specification comprise fiile-nUfU rubber).............. CcUulovcfloe..................................... conventional frictional material constituents such as de 45 scribed and illustrated in Patents Nos. 2.S6S.140 and TotJl........................................ 7.6-* 0.0S 0.0$ 0.G> o.:s <K 30.50 (S.W 7.W 1M.00 1ft? 20 11 1J l1 51 Ct! C <?: <; oto yICl is >; 1.312 ................ 2.S61.964, and related prior art. For example, the organic friction particles may comprise common heavily filled, EXAMPLE II hard, prevuleanized rubber friction particles, or conven Percent by weight tional resinous friction particles such as granules of cured 50 Chlorobutyl rubber (Enjay MD-551)------------- thermosetting resins as exemplified by polymerized ca Sulfur___---------------------------------------------------- ' shew nut shell oil. Such organic friction particles are Accelerator, tellurium dicthyldithiocarbamate 7.57 0.15 preferably included in amounts of from approximately ("Tellurac") ....................................................... 10 to 6092 by weight of the composition and typically Accelerator, bcnzoihizzyl disulfide ("Altax")___ in amount of about 40 to 5092. And the rubber matrix or 65 Stearic acid 0.0S binder phase can be stiffened with up to about 692 by Zinc oxide_______________ weight of the overall block with a thermosetting resin Carbon black, powdered 4.60 such as phenolic resins, polymethjlol phenol resins or Cast iron chips (substantially 100-200mesh) .. halogenatcd butyl compatible resins. The friction par Friction particles (hard, heavily filled, ticles of the herenzfter specific examples consist of the 00 vulcanized rubber) 48.50 heavily filled hard vulcanized-rubber variety of a com Cellulose floeTj_______________________________ position approximating that illustrated in Patent No. 2,- 0.0S 0.08 0.75 30.33 7.86 686,140. The compositions also preferably include rein forcing fiber in amounts up to approximately 3092 by Total............................................................. 1C0.00 weight of the composition. 05 The following examples illustrate suitable and preferred EXAMPLE III Percent by weight railroad brake block compositions including various haln- Bromcoutyi rubber (Hycnr 2202)_____________ 7.57 genated butyl rubbers in accordance with this invention. Sulfur 0.15 It is to be ur.lirv.vwi that the manufacturing or process Accelerator, tellurium dicthyldilhiocarhamatc ing means and techniques, and the particular constituents 70 ("Te'iiuK-c") ---------------------- --------- -............. 0f-c of the illustrated brake blocks, other than the rovel halo- Accelerator, benzoihiazyl disulfide ("Altax") s. 0.0S genaicd butyl elastomer binders, arc exemplary and are Stearic acid----- -------------- 0.0a not to be considered to limit this invention to any specific Zina oxide -_...--------- ------------------------------ 0.75 product, formulation, or comrosiiiun recited in the here Carbon hl<ick, ppwdcrcd ----------------------- --- 4 60 inafter examples. 73 Cast hen chips (rubsiauliuily 100-200 mesh) -- 30.3? k.xau-'i.j: in roui.i.u..1 "`th-d given in Example I of Patent No. d.KolNo-i on rail Frictioo particles (bird, heavily filled, road rolling stock under substamially identical service vulcanized rubber) 4S.50 load r.r.d braking conditions were of superior wear life, Cellulose fior 7.SO comp: ruble wet-to-dry friction ratios and of improved 0 -and more uniform friction or retarding qualities. Total ............. 100.00 ; :A number of dry. stops and wet stops made from 4(1 //miles per hour established the wet-to-dry friction ratio KXAUl'LU IV Percent by weight -fr'of the improved composition brake blocks to be 1.123 Chlorobutyl rubber (EnjayMD-55I)-.:___________ S.50 ' / which is comparable lo the, typical ratios of 1.25 for the Sulfur......................... .................. ........................... .. 0.20 j'(l .said prior commercial products. Accelerator, tellurium dicihyldiihlocarbamaie - - -..vTCharacteristic retardation curves for the brake blocks (Tellurac").............. 0.10 V of the composition of Example II. above and the brake Accelerator, benzothiiryl disulfide("Altai")____ 0.10 blocks of the composition-of Example I of Patent No. Stearic acid 0.10 - 2,S61,954 are given fog stops made from speeds of 100 Zinc oxide________________ _______________ 1.00 13 miles rer hour and 40 miles per hour in FIG. 3 and FIG. Carbon black, powdered _________ _____________ J.00 2 of the drawing, the curves produced by the composi Cast iroo chips (substantially100-200 mesh) ___30.00 tion of this invention being presented in heavy solid Friction panicles (bard, heavily filled, lines designated A and the curses produced by the prior vulcanized rubber) 43.00 compositions under comparable railroad car braking con Asbestos f.ba:_________ ,, 12.00 20 ditions being presented in heavy broken lines designated' B, superimposed upon each other. Retardation bring Total............................................................. 100.00 directly proportional to fticiioual characteristics, it isapparent from these curves that the improved friction rsamplev materials comprising halogenaied butyl rubber, or brake Pererni 25 blocks thereof, exhibit substantially more uniform and by *i Uv u i. consistent friction characteristics o\cr a broad rar.ee of n.:...c' A?rs ".Er.-I V IIT-li-C.: . ... 8 Ofi ICO TS N-C--1--UiS I-- ------ . 1C------------- 3-- Arr*duyUidc .OS 1 --The- prc.nourrecd improvement in pro!onged''wear' liTe of products of the halogenaied butyl rubber bonded com oxide............. .................. ................. Zinc cv/5?... ...................................................... >Mh-i>o.*: r-rn <luru 1.CS7).................... .......... Car(>o*. ................................ ....................... t\v; .................................................... Ftfciv.: (hard. btivUy filled, tul r3::aJi'J foij;.- *................ ............................... Avista* I.Uf 7-D-c*.\. ....................................... . 1C l.w l. 4 tt 2.0 a.uo 6 40 30 positions of this invention is demonstrated by the com*, parative data illustrated in the graph comprising FIG. 3 34 CO 3u> of the thawing. The data presented in the graph of FIG. 3 w-as derived from idectical braking conditions extend fiCO fO ing over a range of initial speeds of from 40 m.p.h. up to O-/ 150 m.p.h. applied to like brake shoes composed of each Tec el............................................................ 100 00 I.SW the composition of Example I of this application and of the preferred and a comrneicial product of the formula EXAMPLE VI of Example I of U.S: Patent No. 2.S61,954, carried out on a large scale dynamometer with a conventional 36 perm Ly wt. Parts by 40 inch railroad car wheel under the equivalent of one wheel load of a stanJaid passenger car and all conditions CUlorcbuyl rubUr >Ti\jy UT-UGC ......... Uronuicj^d K.!\;..e:liy.ol ptuiioi itaifl tScli.S-Kiney SP-IUXS)................. ................... Zinc oxv>>............................................................ Cftrb^o bi.ck............. ............................. ............ I'ut l/-*c err................. ....................................... Tunx<i pvtirlt* (hard. U*jrj|x filled. tuI* Cellulate floe....................... .............................. TotL.......................................................... *. * SI .6O i.a 3d. SI 4S.34 7.5*6 100.00 1W comparable to and simulating ojerational railroad brak \2 ing. In the graph the abscissa axis seu forth the initial i cn 4CO speed ir. milts per hour at which braking is commenced, 45 and (he ordinate axis, in logarithmic scale, gives the shoe wear from braking under like, simulated railroad operat 640 104 ing conditions from the initial speeds for each the im proved composition of this invention and. lo applicant's 1.3J4 knowledge, the bust and most closely akin composition EXAMPLE VII 60 of the prior art. From the graph and data provided thereby wherein the solid line, identified as A, represents the rerr.ni by *i. by *-i. average wear rate of the preferred composition of Ex ample I of this invention and the broken line, identified {'lilervLutyt ruUUr tEnlov UT-10C6*................ Aud-ewe. u;;ju.cJh>J;ruuiwn d^ul/idc i*`T o uli ')......................................................... Afo i'C..u.r.iu..m...d.i.e..ij...................... Atrrlrmnr. Uniuhiuyt duuSttCs vAIim"").. . Siear.c scid........................................................... ................. ........................................ Ck/ltcn ............................................. . UC fill.......................,,........................ . YtKtU'n (turd, hcanjv OKed, ?ul e................ ......................... . AiIa-Jih Cll iTitX)........................... .07 .o: .o: .o: .3(4 4.30 n, tc IC 00 13.10 100 as B, represents the average wear rate of the composition I 55 of Example 1 of U.S. Patent No. 2.S6I.964, under identi cal braking conditions, it is clearly evident that through 1 1 out the extended range of speeds of from 40 m.p.h. up 1 to 150 m.p.h.. the wear rate from braking of the im 3 CO proved composition of this invention is in the order of iw 2.5 lo 3 times less than that of the prior an and com Wu mercial product. 1M ~~ The most significant improvement and attribute of this Tuj............................................................ HD 00 1.3VO invention, that of reduced wear rate, has hcer. found to be primarily, if not so'ety attributable to the utilization As stated hereinbefore, the halogenatcd but) I rubber containing molded composition brake blocks of this in- Go of haloarn.-itcd bu'sl rubber ns the principal binder com ponent of the bonding system or phase of the product as vertitm rrmid: certain decided adsc-ta-er* or ir rroved is {`fifnr-'rrtcd by the following relative ev.n'unt'-n o' properties, including such fundamental qualities as en the wear r.ue ui Identical compodlionv rune1' im-"' m hanced frictional chc.tie'.eris'Jcs and marked!, greater of ?.v"-cri H--'crx. cures, end proportions thr-r'nr. To wc.i life over like projects divtUs-cd b> the piw ait evaluate r.ur.rcr ci centra-.-..vat: and/or employed in commerce. For instance, brake blocks cxpvJiti.'ms test procedure was employed rather than the of the approximate composition of Example II, an porcfcrct.s, ccMly and lime consuming railroad scale optimum formulation due to its relative ease of produc dynamometer. The test apparatus consisted of a revolving ing or maiding, when compared with commercial com- arm cor.sttucted to carry a friction comp-svition sample C i- 1 ' ` - j 5rX3J! <' ;; 3,300,113 :S be made io cur.tact a dal steel fin; o', a comrodtiun iden A full her ami dcciJeJ improvement ir. ccttam opera tical to a railroad car wheel. Comae: time and speed is variable as desired and can b; intermittent or con tions such as subway and interurban service u the virtually noiseless operation or bruiting of * the compo-.tions of tinuous, as curn. Contact pressure in all tests was ICO this invention which eliminate stih>tsn:i:.l!v all braking p.s.n The tes: conditions and sequence were as follows: squeals or the like noises other than .tito-c produced bv the mechanical action of the brake actuating mechanism. 1............ Hmc........ Irri \\ct Krond 17.6 46 R TV 4 , Ccnl.t'*; 1 >i r "|H.r App.ir.iuou AlMdr pcrpti.v? 1$ ............ ................. . 20 mfrrnnftrnf. 15imn *............. .. 1 enm It .will be undcrsiod.'that ..the foregoing dtiaitx arc given.for the purpose of illustration, not restriction, and . the variations within the spirit of this invention arc in 10 , tended to claims.s - be - included within the scope -;-jy , -- of the appended Phases 1 and 2 simulate"`intermittent stopping from I claim: ` * . different speed levels and the drag phase continuous down 1. An improved molded composition brake block hav hill drag under brsking load. All phases are carried out ing good wet and-dry fricticn eharacteristes and long in connnuu.is sequence for each sample tested. Equities- 15 service, life, comprising approximately 20 to 75% bv rium temperatures reached during the tests average ^ap weight of hard ferrous metal at.least 50%. of which is proximately 250* F. for phase I. approximately 4UU* F. in the form of cast iron particles, and at Ica't 50% by for phase 2, and 500* F. to 700* F. for the simulated volume of the block of non-ferrous inorganic and organic downhill drag phase. It should be appreciated that the filler and organic binder matrix comprising it least about "continuous downhill drag conidiions of uninterrupted 20 2 to'up to about 12% by weight of the block of heat braking over a 1J minute' period constitutes an unduly resistant vuiennizej in situ litiiogenatcd but,! rubber demanding test of rigorous terms exceeding the require which is a halojcnated isobutjleue-isoprer.e copolymer. ments of apical passenger or freight service and is ap 2. The improved molded composition brake block of plicable to mountainous terrain. claim 1 whcicin the Mr.a'cr matrix cor.tproes about 5 to The jromrrt.ti-m of Example I. evaluated in simulated 25 about 12% by w-eich: of the block of lie::: res'vtnn: vul railroad sc-tc ;uns and in the field, served as the stand canized in situ halogen:-ted hut;.I rubber which iv a ard to determine the relative wear rates of rubber bonds, halogennud isobutylene isaprcn: eo|iolvn-.ei. _ciires thc:f.fojL.jnd_vjirichtc-proportion^-thcreo(--in-prod-------..... 3--An impioved-moi-ded-composition hr: ' - block hav-` uc:s of otherwise identical composition or components. ing good we: and dty friction characteristics and Ion: All tes: friction materials are of the same composition as 30 service life. comp.ri'-.ug apptoxtm.v.ch 2(: to 75% by Example 1 except as indicated, wherein the given changes weight of hard ferrous m-rtr.l at least 50 a of which is consist of the identified variations in the percentage of in the form of east iron pnrti.lis. from approximately 10 rubber content of binder phase, cure systems, substitu to fiO% by weight of long wearing oi panic friction tions of butvl rubbers, and the testing of the composi particles, and from S to 35 k; by v eig.'.t of a htr.tlcr mztrix tions of Examples V ar.d VII in the thetein staled amount 33 comprising the in situ vulcanization piockic: of a compost- of rubber and the given increased amount. Derived data lion comprising at least about 2 to up to about 12% by consist of average cocffic'cnt of friction, average rate of weight of the block of hiilogi-i.c-jtvi nth-rcr which is wear in cubic inches per horsepower hour. The so-called a halogenated isobuiyler.e-isuptv.'e copo!;.mcr. "standard cure" consists of a thiuram-thiazole" sulfuriess 40 4. The improved molded composition brake block of cure (tctramcthylthiurnm disulfide. "Tuadn" and benzo- claim 3 wherein the bi-der mv.ti.*. coir.p'.'idr.j the in situ thiazyl disulfide, "Altax") as recommended by the vendor vulcanization produci comprises about 5 to about 12% of HT-1066, and as illustrated in Example I. The "resin by weight of the block of at lot one hnlogcnated butyl cure" consists of polymeth>lo!phenol resin is in Ex rubber which is a halogeitat.-d isohutylene-isoprenc ample VI. 45 copolymer selected from tbe group consisting of chloro- TABLJt I Bond Content, petwtu Volumetric mi 6.2 1 2 Drat Cl lorobuiyl Bond Standard Cure Rtxln Cure A*r. Arp. No. Arf. Art. No. Fne. Hilt TtfU Wwr its. Hite We Tis .a: .wo . .00:1 .22 .MM H:on:n Siattdurrt Cuff Arc. its. Arc. Rule \V? No Tc*t$ Nmil !.': Cere Arc. Atr Yr.r. K .r Ti-r.r V. i Examptr 1--Siindn/d Etamplc V! 7.6 1 .12 .0W2 7 2 .20 .0<l 7 .29 .cm2 .22 .uyv> I X .96 .Gvr 2 .92 .<*n> . 2 .17 . r-v j. J *1 Drac .22 . ocn 7 .26 . 2670 1 .24 .0T7`1 .27 .( . 24 t.t 1 .40 .0M0 .11 .0^0 r>re .24 .tlx 27 11.3 1 . 40 2 .96 .0016 r*c . .29 . 7t4D IGl-j 6.2 ) 2 Dr.ic 7 7 1 I 1 J J Pr-i UamMpid m/m.-in ,3< .0X4 ,iv .aoi S .4120 *` 2 2 1 Dauucvd in ruiWii F%auV V .1..... .11 .a- : .20 1 H .* !. \ 1 2 VtAt DtMrotfd XU 3 I 7 liras o -3,399,113; 9 10 butvI ruracr, and bror.rwu: s! tui r.-r. and a high propor 10. The improved molded composition brake block of tion of inorganic siiierv and \uic.ir.i. .rt~ mgicdicnls. claim 8 wherein the fiber comprises a-bestus. 5. The improved molded comp.isi .-on brake Hock of 11. The improved molded composiuon brake block of claim < whetem the comi'-.-si'.icn ccmpnws asbrstos fiber. claim wherein the fiber comprises organic fiocr. 6. The improved molded eompP'itru.i brake block of J2.,The improved molded ..compos.non brake block I claim 4 wherein the composition luir.gnocs organic fiber. 5 "of claim 8 comprising the following in approximate parts 7. An iniprovcj muided icmp'situc. brjl.c.block bav '.' by weight:; in; gooJ wet and dry fiietion characteristics and Ion; service life, comprising approximately 20 to 75% by weigh! of bard ferrous n:e::ij al le^st 5GT of which is in titc form of cast iron paMi-elcs, from appro.\ir.iaic!y..lO to 60% by weight of long wearing organic friction par- Cblorobutyl rubber which is a halogenated isobutvl.Icnc-ixoprcnc copolymer ----- ------------ ----- ,, 10 Accelerators " Stearic acid------------------------------------------------- 7.62 0.16 0.08 tides, up to approximate^ 30% by weight of fiber, and Zinc -oxide 0.38 from approximately $ to .'5% bv weight of a binder matrix "Carbon black 4.56 comprosing the in situ vidca.-.izaii-./.i pioduct of a com Cast iron chips -______________________________ 30.50 position composing at leas; about 2 to up to about. 12% 5 -Organic friction particles-------------------------------- 48.80 by weight of the block of liaioeen.iiui butyl rubber which is a Italogcnatcd i-obut^lettr-ijoprcne copolymer and a Reinforcing fiber 7.90 high proportion of inorganic fillers anJ vulcanizing in gredients. S. The irr.pro'eJ compc'dior. brake block of 20 References Cited UNITED STATES PATENTS claim 7 wherein the bi>i(L; r.-trt' comprising the in situ 2,861,964 1 1/1958 De Gauciic,ct al. .. 260--17.4 vulcanization pioduct comprises about 5 to about 12% 2,933,117 4/1960 Baldwin ct al............... 260--11.5 by weight of the block of c; hast c..c halocrncted butyl 3,152.099 10/1964 De Gaucue................... 260--3R rubber which is a h.il gfeted isobutviene-isoprene 2- 3.344,094 eopolvmer selected from c.oup consisting of chloro- basts 1 rubber, .iu.1 l-ro.r.trur-.tr, and a high propor 9/1967 De Gaucue..................... '260--5 FOREIGN PATENTS tion of inorganic filters .v-J 'c':c..r:i:-g incrcdlehts. " '"9rTRf improvcT"ivTi'-.-d cor. p '-:i:rn "brake block of claim S wherein the binder metric contains up to ap- _.,,700,18I....1 1/1953 Great .Britain. DONALD E. CZAJA, Primary Examiner. pro.si.T^tfh 6c: b;. wci.:.: c-f the Hack of li:-rr.:o.-ottmg resin stifiener. R. A. WHITE, Assistant Examiner. ( 1 o * . * ^ > 1* -* 7j CA/ M < 4 June 25, 1968 c. l e. de gaugue 3,390,113 BRAKE BUCK COMPOSITIONS CCMPR 1 S : KG VULCAN I ZED h'ALOGENAl ED BUTYL RUBBER Filed Jan. 27, 1957 2 Sheets-SBeex l MPHPS j? / . / June 25, 1968 c l e de gaugue 3,390,1 13 BRAKE BLOCK co.v.: 05 : : :a .s CCVPMSilO VULCAN 1 IE'J Filed Jan. 2.7, 1957 KALOOENATEO BUTYL RUBBER Sheels-Sheei 2 T o m L -S>/<?- c?_"7