Document DDYGeqEQZvpVOpeV09wRBp8yo

,3 428,309 9 10 dividing the sulphurized product thus obtained The compositions Illustrated in the foregoing Into relatively small particles or granules which Examples Nos. 1 and 2 may be converted Into may be dispersed with substantial uniformity heavy duty type friction elements by intimately throughout friction elements' of the character mixing the ingredients thereof and forming the herein contemplated. 5 resulting mixture Into friction element shapes A suitable formula which may be followed in and then effecting the cure of the %organlc bond making friction elements for normal heavy duty ing agent, as by the application of heat alone, service. In the practice of the present invention. or by the application of' both heat and pressure. Is the following, in which all parts indicated are Thus, In the manufacture of friction elements by weight: 10 employing . fee composition which is Illustrated Example No. 1 \ In the foregoing Example No. 2, a temperature Parts by weight Heat polymerized vegetable drying oil (lin of from about 300 F. to about 325 F., and the application of a pressure of about two thousand pounds per square Inch, for about four hours, seed) 8.4 Oil modified phenol-formaldehyde resin___ Lead formate* 9.0 Potassium dlchromate 1.0 8.4 15 are suitable, It being understood that the pre ferred or optimum temperature, pressure and ap plication time stated above may be varied some what depending in part upon the particular com Vulcanized butadiene-acrylonitrile copoly position and the specific temperature, pressure mer synthetic rubber-like elastoprene (flnel^ divided dust-like particles, vulcan 20 and application time employed. However, in the manufacture of friction elements employing either ized wife ten percent sulphur, by weight) -- 4.0 Pyrobitumlnous material (soft coal, finely the composition which is Illustrated In the fore going Example No. 1, or the composition which divided) 15.0 is Illustrated in the foregoing Example No. 3, the Asbestos fiber _65.0 Sulphur 2.5 25 application of heat alone Is sufficient to effect the cure of the bond and a typical example of A suitable formula which may be followed, in suitable progressively Increasing temperatures the practice of the present Invention, In making and application times which may be employed is friction elements which may be subjected to ex as follows: Three hours at 225 F.; three horns ceptionally severe heavy duty service. Is the fol lowing, In which all parts Indicated are by weight: 30 at 275 F.; three hours at 315 F. hours at 300 F.; and three As pointed out hereinbefore, the hardness and Example No. 2 heat resistance and related properties and char Crude (natural) Parts by weight rubber__________________ 5.76 35 acteristics of the finely divided or dust-like par ticles of the butadiene-acrylonitrile copolymer Reclaimed rubber 8.00 friction-stabilizing material, which are referred Sulphur________________________________ 3.25 to in the foregoing Examples Nos. 1 to 3, Inclu Rubber accelerator (benzothlazyl disul sive, may be readily varied and controlled by phide) ------------------------------------------------ 0.25 selecting and employing In the making of said Zinc oxide 2.0 40 finely divided friction-stabilizing particles, for a Carbon black 4.0 given sulphur content, a synthetic rubber-llke Graphite 7.0 elastoprene material of the butadlene-acryloni- Lead sulphate------------------------------------------- 16.0 trlle copolymer type containing a predetermined Blanc fixe 7.5 or preselected percentage of acrylonitrile as a Phenol-formaldehyde resin________________ 12.0 45 component of the copolymer material. Thus, the Vulcanized butadiene-acrylonitrile copoly mer synthetic rubber-like elastoprene (finely divided dust-like particles, vul relative hardness and heat resistance of said finely divided or dust-like particles of frletion-stabillzing material may be Increased by employing in, canized with ten per cent sulphur, by weight)______ 3.0 , Powdered lead_J-_________________ '_____ t the making of said particles a butadiene-acrylo-' 8.0 60 nitrile copolymer containing a relatively high percentage of acrylonitrile as a component of Brass chips.___ 110.0 the copolymer material as Is true, for example, Asbestos fiber____________________________ 28.0 In the case of "Hycar OR" (5-15 or 25), "Chenii- gum" (X and I), and in certain of the mate A suitable formula which may be followed, in the practice of the present invention, In making 55 rials known as "Stanco" and in the materials known as "Standard" and "Perbunan." On the friction elements for use as brake linings upon other hand, If desired, the relative hardness and passenger automobiles, light trucks, and fee like, heat resistance of said finely divided particles of Is the following, In which all parts Indicated are friction-stabilizing material may be decreased by by weight: Example No. 3 60 employing in the making thereof a butadieneacrylonitrile copolymer containing a relatively Parts by weight Crude (natural) rubber cement13.25 low percentage of acrylonitrile as a component of the copolymer material as In the case, for ex Oil modified phenol-formaldehyde flexible ample, of "Hycar Nlnene B," and In certain of resin__________________________________ 12.0 65 the materials known as "Stanco." White lead 7.5 It may be added, at this point, that the per Pyrobitumlnous material (soft coal, finely centage of acrylonitrile In the vattous butadiene- divided) 10.0 acrylonitrile copolymer materials or elastoprenes Sulphur------------------------------------------------- 1.5 referred to above, varies from a lower range of Vulcanized butadiene-acrylonitrile copoly mer synthetic rubber-like elastoprene 70 the order of approximately fifteen per cent, by weight, in the case of "Hycar Nlnene B" and in (finely divided, dust-like particles, vul certain of the materials known as "Stanco," to an canized with ten per cent sulphur, by weight)3.0 Asbestos fiber_________65,0 upper range of the order of approximately fifty per cent, or slightly less, by weight. In the case of n "Hycar OR" (5) and in certain of the materials