Document 3NDV0GV93mvNgx0EQpmmLBVey

PATENT SPECIFICATION ()_ 1235 100 1235 100 DRAWINGS ATTACHED (21) Application No. 53608/69 (22) Filed 31 Oct. 1969 (31) Convention Application No. 81999 (32) Filed 9 Nov. 1968 in (33) Japan (JA) (45) Complete Specification published 9 June 1971 (51) International Classification C 09 k 3/14 (52) Index at acceptance C3R IA 101 '1015 1022 1029 102A 1C5QB1 1C6X 1C8P 1'LIB 1L2CX 1L4D 21A 21'Cl 21C15 21022 21029 21C2A 21C5B1 21C6X 21C8P 21L1B 21L2CX 21L4D C4X 4 (54) BRAKE OR CLUTCH LININGS (71) We, Kabushiki Kaisha Toyota Chuo Kenkyusho, a Corporation duly organized under the laws of Japan, of 2--12, Hisakata, Showa-ku, Nagoya-shi, Aichi-ken, 5 Japan, do hereby declare the invention for which we pray that a patent may be granted' to us, and the method by which it is to be performed, to be particularly described in and by the following statement: -- 10 The present invention relates to an im proved brake lining, dutch facing and the like (hereinafter called a lining). The optimum properties required of a good lining are: an adequate coefficient of friction 15 for expected usage, ability to retain a constant coefficient of friction under varying conditions such as rubbing surface temperature and pres sure, and little wear or scoring on its own and on an opposed rubbing surface. 20 Conventional linings have not been adequate to fulfil the requirements for a desired lining as listed above. The friction materials forming said conventional linings are mainly composed of asbestos with one or more agents in 25 amounts ranging from several percent to ten percent and higher, added for raising and stabilising the coefficient of friction and the wear resistance: for example, oxides, e.g. silicon dioxide and alumina; sulfates and sul30 fid'es, barium sulfate and lead sulfide, and heat resisting resins added as binders for sub sequent compression, heating and molding. None of these conventional friction materials satisfy the described requirements because 35 some have poor wear resistance although having stable coefficient of friction at high temperatures, and because others have poor or unstable coefficients of friction, although having good wear resistance. Other disadvan40 tages of conventional friction materials are a decrease of coefficient of friction and reduc tion of braking force and a marked increase in wear at the high temperature of 200-- 300C very frequently encountered in practical 45 use. ][Price 2Sp It is a primary object of the present inven tion to provide an improved lining. According to the invention, there is provided a brake or clutch lining comprising an organic binder and from 40 to 70% by weight of frictional force-imparting material selected from the group consisting of iron sand, iron powder, copper powder, asbestos and mixtures thereof, and from 2 to 25% by weight of a metal halide selected from the group consisting of cryolite, aluminum fluoride, calcium fluoride, magnesium fluoride, barium fluoride, copper iodide, lead iodide, lead chloride, and mixtures thereof. Iron sand, so called Iserine, is a black sand which consists mainly of magnetic iron ore, or ferrosoferric oxide, Fe3Ot. When asbestos is used, a particularly strong friction material is obtained because of the bonding force thereof. When 20' to 50% by weight of iron sand, iron powder, or copper powder are mixed with the asbestos, an even, strong material of excellent quality is obtained. When iron sand, which is cheaper than asbestos, is added to the asbestos, a less expensive friction material is obtained. The cost of fabrication of a brake or clutch lining in accordance with the invention is certainly not greater than, but usually far less than, that of fabricating conventional linings. For organic binders, the material of the invention includes one or more kinds of con ventional heat resisting resins,. for example phenol aldehyde res'ns and modified phenol aldehyde resins. Adequate amounts of conven tional fillers and additives are also used for the purpose of increasing the total amount of friction and to lessen fading. The invention will become more readily apparent from the following detailed descrip tion of examples the test results of which are shown in the accompanying drawings, in which: Fig, 1 is a diagram showing the relation 50 55 go 65 70 75 go 85 90