Adhesive tape with polyurethane carrier

Abstract

The present invention relates to an adhesive tape of thickness 40 to 300 μm that can be redetached without residue or destruction by stretching essentially in the plane of the bond, comprising at least one carrier of thickness 10 to 150 μm comprising at least one layer based on preferably uncrosslinked thermoplastic polyurethane that has typically been produced by means of extrusion and has a Shore A hardness of not more than 87, where the carrier has a ratio of force at 400% elongation F400% to breaking force Fbreak of not more than 45%, and on which a pressure-sensitive adhesive layer is disposed on at least one side, and wherein the adhesive tape has a ratio of stripping force Fstrip to breaking force Fbreak of less than 60%. The invention also relates to an adhesive tape of thickness 40 to 300 μm that can be redetached without residue or destruction by stretching essentially in the plane of the bond, comprising at least one carrier of thickness 10 to 150 μm comprising at least one layer based on preferably uncrosslinked polyurethane that has been produced from a dispersion and has a modulus at 100% elongation of not more than 1.8 MPa, where the carrier has a ratio of force at 400% elongation F400% to breaking force Fbreak of not more than 30%, and on which a pressure-sensitive adhesive layer is disposed on at least one side, and wherein the adhesive tape has a ratio of stripping force Fstrip to breaking force Fbreak of less than 60%. The invention also relates to a process for producing the adhesive tapes and to the use thereof for bonding of components in electronic devices.

1 . An adhesive tape having a thickness of 40 to 300 μm that can be redetached without residue or destruction by stretching essentially in the plane of the bond, comprising
 at least one carrier of thickness 10 to 150 μm comprising at least one layer based on preferably uncrosslinked thermoplastic polyurethane that has typically been produced by means of extrusion and has a Shore A hardness of not more than 87, where the carrier has a ratio of force at 400% elongation F 400%  to breaking force F break  of not more than 45%, 
 on which a pressure-sensitive adhesive layer is disposed on at least one side, 
 wherein the adhesive tape has a ratio of stripping force F strip  to breaking force F break  of less than 60%. 
 
     
     
         2 . to The adhesive tape of  claim 1 , wherein the thermoplastic polyurethane is a reaction product of a mixture comprising at least one diisocyanate, at least one polyester polyol and optionally at least one chain extender, for example butanediol. 
     
     
         3 . t wherein the carrier contains less than 0.3% by weight of processing auxiliaries. 
     
     
         4 . An adhesive tape having a thickness 40 to 300 μm that can be redetached without residue or destruction by stretching essentially in the plane of the bond, comprising
 at least one carrier of thickness 10 to 150 μm comprising at least one layer based on preferably uncrosslinked polyurethane that has been produced from a dispersion and has a modulus at 100% elongation of not more than 1.8 MPa, where the carrier has a ratio of force at 400% elongation F 400%  to breaking force F break  of not more than 30%, on which a pressure-sensitive adhesive layer is disposed on at least one side, 
 wherein the adhesive tape has a ratio of stripping force F strip  to breaking force F break  of less than 60%. 
 
     
     
         5 . The adhesive tape of  claim 4 , wherein the polyurethane is aliphatic polyester polyurethane or aliphatic polyether polyurethane. 
     
     
         6 . The adhesive tape of  claim 1  wherein the carrier has a thickness of 20 to 100 μm. 
     
     
         7 . The adhesive tape of  claim 1  wherein the carrier consists of the at least one layer based on polyurethane. 
     
     
         8 . The adhesive tape of  claim 1  wherein the carrier does not have a crystalline superstructure. 
     
     
         9 . The adhesive tape of  claim 1  wherein the carrier has been foamed. 
     
     
         10 . The adhesive tape of  claim 1  wherein a pressure-sensitive adhesive layer has been disposed on each side of the carrier, such that the adhesive tape is a double-sided adhesive tape. 
     
     
         11 . The adhesive tape of  claim 1  wherein the at least one pressure-sensitive adhesive layer consists of a pressure-sensitive adhesive based on vinylaromatic block copolymer. 
     
     
         12 . The adhesive tape of  claim 1  wherein the at least one pressure-sensitive adhesive layer has been foamed. 
     
     
         13 . The adhesive tape of  claim 1  wherein the adhesive tape has a stripping force F strip  of less than 20 N/cm. 
     
     
         14 . A process of producing an adhesive tape according to  claim 1  in which a carrier based uncrosslinked thermoplastic polyurethane as defined in  claim 1 , in which the carrier
 (i) is extruded onto a temporary carrier and combined at least on one side, preferably on both sides, with a pressure-sensitive adhesive, or 
 (ii) is extruded onto a pressure-sensitive adhesive layer, and the carrier is preferably combined with a further pressure-sensitive adhesive on the opposite side from the pressure-sensitive adhesive layer, 
 so as to result in an adhesive tape. 
 
     
     
         15 . A process of producing an adhesive tape according to  claim 4  in which a dispersion
 (i) is coated onto a temporary carrier and dried, and the resultant carrier as defined in  claim 4  is combined with a pressure-sensitive adhesive on at least one side, or 
 (ii) is coated onto a pressure-sensitive adhesive layer and dried, so as to result in a carrier as defined in  claim 4 , 
 so as to result in an adhesive tape. 
 
     
     
         16 . The process of claim in which the carrier is combined with the pressure-sensitive adhesive by laminating the carrier with a pressure-sensitive adhesive layer consisting of the pressure-sensitive adhesive. 
     
     
         17 . The process of  claim 14  in which the carrier is applied to a temporary carrier and then laminated with a pressure-sensitive adhesive layer consisting of a pressure-sensitive adhesive on at least one side, preferably on both sides. 
     
     
         18 . The process of  claim 14  in which the carrier is applied to a pressure-sensitive adhesive layer and the carrier is simultaneously combined with a further pressure-sensitive adhesive layer on the opposite side from the pressure-sensitive adhesive layer. 
     
     
         19 . The process of  claim 14  in which the carrier is combined with the pressure-sensitive adhesive by coating the pressure-sensitive adhesive directly onto the carrier, where the pressure-sensitive adhesive is
 (a) coated onto the carrier as a solution and dried, or 
 (b) extruded onto the carrier as a plastic melt. 
 
     
     
         20 . A method of bonding of components in electronic devices, the method comprising the use of the adhesive tape of  claim 1 .