Prelaminate pressure-sensitive adhesive constructions

Abstract

Prelaminate pressure-sensitive adhesive (PSA) constructions comprise, a first substrate, a coating or release material on a surface of the first substrate, a PSA layer disposed on the coating of release material, and a detackified layer (DL) disposed on a surface of the PSA layer to form a continuous film covering the PSA layer. In first and second embodiments of the construction the DL is activatable to form a tacky layer on top of the PSA layer for lamination with a second substrate. In a third embodiment, the DL includes constituents that when activated migrate into the PSA layer to expose the PSA layer tacky surface for lamination with a second substrate. The prelaminate PSA constructions are completely nonblocking to a minimum 24 hour blocking temperature of about 50° C. at pressure of about 40 kilopascals, thereby allowing such prelaminate PSA construction to be collected, stored, and or transported before being laminated without adhesive interference occurring between continuous layers. The DL in each embodiment is activatable in less than five seconds to provide a tacky layer having a sufficient open tack time to permit lamination at less than about 100° C.

What is claimed is:  
     
         1 . A detackified pressure-sensitive adhesive construction comprising: 
 a flexible substrate;    a coating of release material disposed on a surface of the flexible substrate;    a layer of pressure-sensitive adhesive material disposed on the release material; and    a layer of detackifying material in the form of a continuous film disposed on a surface of the pressure-sensitive adhesive forming a nonblocking surface having a minimum blocking temperature of at least 50° C. for a period of 24 hours at a pressure of about 40 kilopascals, wherein the detackifying material is heat activatable to provide a tacky surface for lamination.    
     
     
         2 . The construction as recited in  claim 1  wherein the detackifying material is heat activatable in less than about five seconds to provide a tacky surface for lamination without being removed from the construction.  
     
     
         3 . The construction as recited in  claim 1  wherein the detackifying material is heat activatable to provide a tacky surface having an open tack time of at least 0.25 seconds to facilitate lamination at a temperature below about 100° C.  
     
     
         4 . The construction as recited in  claim 3  wherein the detackifying material is heat activatable to form a second tacky layer on top of the layer of pressure-sensitive adhesive material for lamination with a face stock.  
     
     
         5 . The construction as recited in  claim 4  wherein a bond formed between the activated detackifying material and the pressure-sensitive adhesive is greater than a bond formed between the pressure-sensitive adhesive and the flexible substrate.  
     
     
         6 . The construction as recited in  claim 4  wherein the detackifying material is selected from the group consisting of heat-seal adhesives, modified heat-seal adhesives, delayed action heat-seal adhesives, and mixtures thereof that are heat activatable in less than about five seconds to form the second tacky layer.  
     
     
         7 . The construction as recited in  claim 4  wherein the detackifying material has a hot melt viscosity that is within a factor of about two times a hot melt viscosity for the pressure-sensitive adhesive.  
     
     
         8 . A nonblocking pressure-sensitive adhesive construction comprising: 
 a first flexible substrate;    a coating of release material disposed on a surface of the first flexible substrate;    a pressure-sensitive adhesive layer disposed on the release material; and    a continuous film layer disposed on a surface of the pressure-sensitive adhesive layer to render the pressure-sensitive adhesive layer nontacky, the continuous film layer being formed from a material that is heat activatable within five seconds without being removed from the construction to provide a tacky surface independent of the pressure-sensitive adhesive having a sufficient open tack to facilitate lamination at a temperature below about 100° C. with a second substrate.    
     
     
         9 . The construction as recited in  claim 8  wherein the continuous film layer forms a nonblocking surface over the pressure-sensitive adhesive that has a minimum blocking temperature of at least 50° C. for a period of 24 hours at a pressure of about 40 kilopascals.  
     
     
         10 . The construction as recited in  claim 8  wherein a bond formed between the continuous film layer and the pressure-sensitive adhesive is greater than a bond formed between the pressure-sensitive adhesive and the first flexible substrate to facilitate preferential removal of the pressure-sensitive adhesive and continuous film layer therefrom.  
     
     
         11 . The construction as recited in claims  8  wherein the continuous film layer forms a nonblocking surface that has a minimum blocking temperature of at least 50° C. for a period of 24 hours at a pressure of about 40 kilopascals.  
     
     
         12 . A detackified prelaminate pressure-sensitive construction comprising: 
 a first flexible substrate    a coating of release material disposed on a surface of the first flexible substrate;    a layer of pressure-sensitive adhesive material disposed on the coating of release material; and    a layer of detackifying material in the form of a self-supporting continuous film disposed on a surface of the pressure-sensitive adhesive material having a minimum blocking temperature of at least 50° C. for a period of 24 hours at a pressure of about 40 kilopascals, and being heat activatable in less than about five seconds without being removed from the construction to provide a tacky surface independent of the pressure-sensitive adhesive for lamination with a second substrate at temperature less than a heat activation temperature.    
     
     
         13 . The construction as recited in  claim 12  wherein the detackifying material is activatable to provide a tacky surface having open tack time of at least 0.25 seconds to facilitate lamination at a temperature below about 100° C.  
     
     
         14 . The construction as recited in  claim 12  wherein the detackfying material has a hot melt viscosity that is within a factor of about two times a hot melt viscosity for the pressure-sensitive adhesive.  
     
     
         15 . The construction as recited in  claim 12  wherein the detackifying material is selected from the group consisting of heat-seal adhesives, modified heat-seal adhesives, delayed action heat-seal adhesives, and mixtures thereof that are heat activatable in less than about five seconds to form the second tacky layer.  
     
     
         16 . The construction as recited in  claim 12  wherein the detackifying material is a polyamide resin.  
     
     
         17 . A method for forming a detackified pressure-sensitive adhesive construction comprising the steps of: 
 a) depositing a layer of pressure-sensitive adhesive material onto a coating of release material disposed on a surface of a first flexible substrate; and    b) applying a detackifying material onto a surface of the pressure-sensitive adhesive layer to form a continuous film thereon that occludes the pressure-sensitive adhesive layer and that has a minimum 24 hour blocking temperature of about 50° C. at a pressure at about 40 kilopascals, wherein the detackifying material has an open tack time of at least 0.25 seconds.    
     
     
         18 . The method as recited in  claim 17  further comprising, after the step of applying, the step of heat treating the detackifying material.  
     
     
         19 . The method as recited in  claim 17  further comprising the step of heating the detackified pressure-sensitive adhesive construction to an activation temperature to form a tacky surface for lamination independent of the pressure-sensitive adhesive.  
     
     
         20 . The method as recited in  claim 19  wherein during the step of heating, the tacky surface for lamination is provided in less than about five seconds.  
     
     
         21 . The method as recited in  claim 19  further comprising, between the steps of applying and heating, the steps of: 
 collecting the detackified pressure-sensitive adhesive construction by placing the detackified pressure-sensitive adhesive construction against a contiguous first flexible substrate surface; and  
 removing the collected detackified pressure-sensitive adhesive construction from the contiguous first substrate surface.  
 
     
     
         22 . The method as recited in  claim 21  further comprising, between the steps of collecting and removing, the step of transporting the detackified pressure-sensitive adhesive construction to a geographic location different than that where the steps of depositing, applying and collecting are carried out.  
     
     
         23 . The method as recited in  claim 17  wherein the step of applying and depositing are carried out simultaneously.  
     
     
         24 . The method as recited in  claim 17  wherein, the detackifying material has a hot melt viscosity that is within a factor of about two times a hot melt viscosity for the pressure-sensitive adhesive.  
     
     
         25 . The method as recited in  claim 19  further comprising, between the steps of applying and heating, the steps of: 
 die cutting the detackified pressure-sensitive adhesive construction to form cut patterns of detackifying material and pressure-sensitive adhesive material; and  
 stripping away detackifying material and pressure-sensitive adhesive material from the detackified pressure-sensitive adhesive construction to leave the cut patterns on the first flexible substrate.  
 
     
     
         26 . A method for forming a detackified pressure-sensitive adhesive construction comprising the steps of: 
 a) depositing a layer of pressure-sensitive adhesive material onto a coating of release material disposed on a surface of a first flexible substrate; and    b) simultaneously applying a detackifying material onto a surface of the pressure-sensitive adhesive layer to form a continuous film layer thereon that occludes the pressure-sensitive adhesive construction and that, in combination with the pressure-sensitive adhesive, is sufficient self supporting to facilitate printing, converting and dispensing, the detackifying material being heat activatable without removal from the construction within less than about five seconds to form a tacky surface independent of the pressure-sensitive adhesive for lamination to a second substrate at a temperature less than an activation temperature.    
     
     
         27 . The method as recited in  claim 26  wherein the during the step of applying, the continuous film layer has a minimum blocking temperature of about 50° C. at a pressure at about 40 kilopascals.  
     
     
         28 . The method as recited in  claim 26  wherein the detackifying material is selected from the group consisting of heat-seal adhesives, modified heat-seal adhesives, delayed action heat-seal adhesives, and mixtures thereof that are heat activatable in less than about five seconds to form the tacky surface for lamination.  
     
     
         29 . The method as recited in  claim 26  the detackifying material is selected from the group of materials having a hot melt viscosity within a factor of about two times a hot melt viscosity of the pressure-sensitive adhesive.  
     
     
         30 . The method as recited in  claim 26  further comprising the step of heating the detackifying material to an activating temperature to form the tacky surface on top of the pressure-sensitive adhesive for lamination.  
     
     
         31 . A laminated pressure-sensitive adhesive construction comprising: 
 a first flexible substrate;    a coating of release material disposed on a surface of the first flexible substrate;    a layer of pressure-sensitive adhesive material disposed on the coating of release material;    a layer of detackifying material in the form of a continuous film disposed on a surface of the pressure-sensitive adhesive, the detackifying material being heat activatable to provide a tacky surface independent of the pressure-sensitive adhesive for lamination at a temperature below an activation temperature; and    a second substrate laminated to the tacky surface of the activated detackifying material, wherein the second substrate, layer of detackifying material, and layer of pressure-sensitive adhesive material are adapted to be preferentially removed together from the first flexible substrate.    
     
     
         32 . The construction as recited in  claim 31  wherein the detackifying material forms a nonblocking surface having a minimum blocking temperature of at least 50° C. for a period of 24 hours at a pressure of about 40 kilopascals.  
     
     
         33 . The construction as recited in  claim 31  wherein the detackifying material is heat activatable in less than about five seconds to form the tacky surface for lamination.  
     
     
         34 . The construction as recited in  claim 31  wherein the detackifying material is heat activatable to provide a tacky surface having an open tack time in the range of from 0.25 to 5 seconds to facilitate lamination at a temperature below about 100° C.  
     
     
         35 . The construction as recited in  claim 31  wherein a bond formed between the pressure-sensitive adhesive and the detackifying material is greater than a bond formed between the tacky surface of the detackifying material and the second substrate.  
     
     
         36 . The construction as recited in  claim 31  wherein the detackifying material is selected from the group consisting of heat-seal adhesives, modified heat-seal adhesives, delayed action heat-seal adhesives, and mixtures thereof.  
     
     
         37 . The construction as recited in  claim 31  wherein the detackifying material has a hot melt viscosity that is within a factor of about two times a hot melt viscosity of the pressure-sensitive adhesive.  
     
     
         38 . The construction as recited in  claim 31  further comprising an object interposed between the second substrate and the layer of detackifying material.  
     
     
         39 . A laminated pressure-sensitive adhesive construction comprising: 
 a first flexible substrate;    a coating of release material disposed on a surface of the first flexible substrate;    a layer of pressure-sensitive adhesive material disposed on the coating of release material;    a continuous film layer disposed over a surface of the pressure-sensitive adhesive material that, in combination with the pressure-sensitive adhesive, is sufficient self supporting to provide structural reinforcement to the construction, the continuous film layer being heat activatable to produce a tacky surface for lamination independent of the pressure-sensitive adhesive; and    a second substrate laminated to the tacky surface of the continuous film layer.    
     
     
         40 . The construction as recited in  claim 39  wherein the continuous film layer provides increased tensile strength to the construction of up to about 20 percent.  
     
     
         41 . A repulpable pressure-sensitive adhesive construction comprising: 
 a first substrate having a release surface;    a pressure-sensitive adhesive disposed on the release surface;    a continuous film disposed on a surface of the pressure-sensitive adhesive, the continuous film being formed from a material that when heated to an activation temperature provides a tacky surface independent of the pressure-sensitive adhesive for lamination;    a second substrate laminated to the tacky surface of the continuous film, wherein the continuous film is more strongly bonded to the pressure-sensitive adhesive than to the second substrate to permit preferential removal of the pressure-sensitive adhesive and continuous film together from the second substrate for recovery and recycling of the second substrate.    
     
     
         42 . A method for forming a laminated pressure-sensitive adhesive construction comprising the steps of: 
 a) depositing a layer of pressure-sensitive adhesive material onto a coating or release material that is disposed on a surface of a first flexible substrate; and    b) applying a detackifying material onto a surface of the pressure-sensitive adhesive layer to occlude the pressure-sensitive adhesive layer and form a nonblocking detackified pressure-sensitive adhesive construction, the detackifying material being heat activatable;    c) heating the detackifying material to an activation temperature to provide a tacky surface independent of the pressure-sensitive adhesive for lamination; and    d) laminating a second substrate to the tacky surface of the detackifying material at a temperature less than about 100° C. to form a laminated pressure-sensitive adhesive construction having the second substrate, detackifying material, and pressure-sensitive adhesive layer adapted to be preferentially removed together from the first flexible substrate.    
     
     
         43 . The method as recited in  claim 42  wherein during the step of heating, the tacky surface has an open tack time in the range of from 0.25 to 5 seconds.  
     
     
         44 . The method as recited in  claim 42  wherein before the step of heating, the detackifying material is heat treated by heating to a temperature below an activation temperature.  
     
     
         45 . The method as recited in  claim 42  further comprising, between the step of applying and heating, the steps of: 
 collecting the detackified pressure-sensitive adhesive construction by placing the detackified pressure-sensitive adhesive adjacent to a contiguous surface of the first flexible substrate; and  
 removing the collected detackified pressure-sensitive adhesive from the contiguous first flexible substrate surface.  
 
     
     
         46 . The method as recited in  claim 42  wherein the steps of applying and depositing are done simultaneously.  
     
     
         47 . A method for forming a laminated pressure-sensitive adhesive construction comprising the steps of: 
 a) heating a detackified prelaminate pressure-sensitive adhesive construction to an activation temperature form a tacky surface for lamination, said pressure-sensitive adhesive construction comprising: 
 a first substrate comprising a coating of release material disposed thereon;  
 a pressure-sensitive adhesive disposed on the coating of release material; and  
 a continuous film layer disposed on a surface of the pressure-sensitive adhesive to occlude the pressure-sensitive adhesive layer, the continuous film layer being, in combination with the pressure-sensitive adhesive, self supporting and forming a tacky surface independent of the pressure-sensitive adhesive upon heating to an activation temperature; and  
   b) laminating a second substrate to the tacky surface at a temperature below about 100° C. to form a laminated pressure-sensitive adhesive construction.    
     
     
         48 . The method as recited in  claim 47  wherein the continuous film layer forms a bond with the pressure-sensitive adhesive that is stronger than a bond formed with the second substrate to facilitate preferential removal of the second substrate from the continuous film layer and pressure sensitive adhesive during paper reclamation.  
     
     
         49 . The method as recited in  claim 47  wherein the during the step of heating, the tacky surface is formed in less than about five seconds.  
     
     
         50 . The method as recited in  claim 47  wherein the step of laminating takes place in the range of from 0.25 to 5 seconds after the step of heating.  
     
     
         51 . The method as recited in  claim 47  further comprising between the steps of heating and laminating, placing an object on the tacky surface.