Impregnating method for the production of wound coupling coatings

1. A process for producing a friction lining for clutches, produced from at least one winding, where the winding is wound from at least one yarn impregnated with an impregnation dispersion comprising at least resin, a hardener, a rubber system, fillers and a vulcanization system,

wherein the resin is a low-melting, water-free and solvent-free novolak resin and the rubber system has a high to medium viscosity of greater than 5000 mPas and can be homogenized with other constituents of the impregnation dispersion, and

wherein the impregnation dispersion consists of formulation 1 or formultion 2, where

formulation 1 consists of 52% novoiak, 3% hexamethylenetetramina 10% NBR rubber, 3% kaolin,10% barite, 10%tricalcium phosphate, 5% graphite, 1% sulfur, and 1% vulcanization accelerator, and

formulation 2 consists of 35% novolak, 3% hexamethylenetetrarnine, 26% NBR rubber, 2% kaolin, 10% barite, 7% tricalcium phosphate, 9% carbon black, 2%tin sulfide, 3% sulfur, and 3% vulcanization accelerator,

where percentages are percentages by weight based in the impregretion dispersion.

2. The process of claim 1 , wherein the novoiak resin has a melting point ranging from less than 50° C. to 100° C.,

3. The process of claim 2 , wherein the melting point of the heated, liquefied novolak resin is 70° C.

4. The process of claim 1 , wherein the hardener becomes reactive only above an initiation temperature and than cross-links the resin, the novolek resin has a melting point, and the hardener is selected so that an initiation temperature is above the melting point of the novolak resin.

5. The process of claim 4 , wherein the hardener is hexamethylenetetramine and has an initiation temperature at or above 110° C.

6. The process of claim 1 , wherein at least the rubber system, the fillers and the vulcanization system are mixed into a heated, liquefied novolak resin.

7. The process of claim 6 , wherein the hardener is added in a subsequent further step of the process.

8. The process of claim 6 , wherein the novolak resin has a melting point, the heated, liquefied novolak resin has a temperature ranging from 50° C. to 100° C., which is at or above the melting point of the novolak resin, but below an initiation temperature of the hardener.

9. The process of claim 8 , wherein the temperature of the heated, liquefied novolak resin is 70° C.

10. The process of claim 1 , wherein all constituents of the impregnation dispersion are mixed into a heated, liquefied novolak resin.

11. The process of claim 1 , wherein the impregnation of the yarn with the impregnation dispersion is carried out by means of an impregnation bath.

12. The process of claim 1 , wherein the impregnation of the yarn with the impregnation dispersion is carried out by means of a pultrusion process.

13. The process of claim 1 , further comprising a step of bringing the temperature above an initiation temperature of the hardener, and allowing cross-linking of the novolak resin to occur.

14. A friction lining for clutches, comprising:

at least one yarn impregnated with an impregnation dispersion having at least resin, a hardener, a rubber system, fillers and a vulcanization system,

wherein the resin is a low-melting, water-free and solvent-free novolak resin and the rubber system is of high to medium viscosity of greater than 5000 mPas and can be homogenized with other constituents of the impregnation dispersion, and

wherein the impregnation dispersion consists of formulation 1 or for 2 where

formulation 1 consists of 52% novolak, 3% hexamethylenetetramine,10% NBR rubber, 3% kaolin , 10% barite tricalcium phosphate, 5% graphite,

formulation 2consists of 35% novolkak, 3% hexamethylenetetramine, 26% rubber, 2% kaolin, 10% barite, 7% tricalcium phosphate, 9% carbon black, 2% tin sulfide, 3% sulfur, and 3% vulcanization accelerator,

where percentages are percentages by weight based on the impregnation dispersion.