Adhesive composition

Abstract

An adhesive composition which allows for preventing misalignment when mutually laminating adherends, mutually strongly bonding the adherends when correction of lamination is not required, as well as peeling the adherends without causing any damage thereto when correction of lamination is required. The adhesive composition includes an adhesive base agent consisting of a monomer and a polymerization initiator. Adhesive strength of the adhesive composition changes to take a local maximum value, a local minimum value and a value greater than the local maximum value along with increase of irradiation amount of the electromagnetic wave or particle beam irradiated to the adhesive composition under a predetermined temperature environment.

1 . An adhesive composition which intervenes between at least two adherends and develops adhesive strength for mutually laminating the at least two adherends by irradiation of electromagnetic wave or particle beam, comprising:
 (a) an adhesive base agent consisting of at least one type of monomer; and   (b) at least one type of polymerization initiator for generating polymerization of the adhesive base agent,   wherein the adhesive strength changes to take a local maximum value, a local minimum value and a value greater than the local maximum value along with increase of irradiation amount of the electromagnetic wave or particle beam irradiated to the adhesive composition under a predetermined temperature environment.   
     
     
         2 . An adhesive composition which intervenes between at least two adherends and develops adhesive strength for mutually laminating the at least two adherends by irradiation of electromagnetic wave or particle beam, comprising:
 (a) an adhesive base agent consisting of at least one type of monomer; and   (b) at least one type of polymerization initiator for generating polymerization of the adhesive base agent,   wherein the adhesive strength changes to take a local maximum value and a local minimum value along with increase of irradiation amount of the electromagnetic wave or particle beam irradiated to the adhesive composition under a predetermined temperature environment, and   wherein the adhesive changes to take a value greater than the local maximum value by further maintaining the adhesive composition under a temperature environment higher than the predetermined temperature environment after the adhesive strength taking the local minimum value.   
     
     
         3 . An adhesive composition as defined  claim 1 , the adhesive composition indicates viscoelastic state which develops adhesive strength by pressure when the adhesive strength is at least the local maximum value, and indicates cured state which is sufficient to allow for peeling at least one of the at least two adherends and a layer consisting of the adhesive composition at an interface therebetween without damaging the adherends when the adhesive strength is at least at the local minimum value. 
     
     
         4 . An adhesive composition as defined by  claim 1 , wherein time required for the adhesive strength reaching to the local maximum value, time required for the adhesive strength changing from the local maximum value to the local minimum value and time required for the adhesive strength changing from the local minimum value to the value greater than the local maximum value is shortened along with increase of irradiation intensity of electromagnetic wave or particle beam and/or rise of temperature for adhesion. 
     
     
         5 . An adhesive composition as defined by  claim 1 , the adhesive composition is fluid when electromagnetic wave or particle beam has not been irradiated under the predetermined temperature environment. 
     
     
         6 . An adhesive composition as defined by  claim 1 , wherein the at least one type of monomer included in the adhesive base agent is a photo-polymerizing vinyl monomer having at least one of hydroxyl group, carboxyl group, cyano group, amino group, alicyclic hydrocarbon group, heterocyclic group, amido group or carboxylate ester group. 
     
     
         7 . An adhesive composition as defined by  claim 1 , wherein the at least one type of polymerization initiator is a photo-polymerization initiator. 
     
     
         8 . An adhesive composition as defined by  claim 7 , wherein electromagnetic wave absorption wavelength of the photo-polymerization initiator is a wavelength of electromagnetic wave which transmits through either one of the at least two adherends. 
     
     
         9 . An adhesive composition as defined by  claim 1 , wherein the adhesive strength decreases to a value at least smaller than the local maximum value when the adhesive composition is immersed in water after the adhesive strength increased the value greater than the local maximum value. 
     
     
         10 . An adhesive composition as defined by  claim 1 , wherein one of the at least two adherends is an optical film and the other of the at least two adherends is a substrate. 
     
     
         11 . An adhesive composition as defined by  claim 1 , wherein one of the at least two adherends is an optical film and the other of the at least two adherends is a glass substrate or a plastic substrate. 
     
     
         12 . An adhesive composition as defined by  claim 1 , wherein both of the at least two adherends are optical films. 
     
     
         13 . An adhesive composition as defined by  claim 1 , wherein both of the at least two adherends are glass substrates or plastic substrates. 
     
     
         14 . An adhesive composition as defined by  claim 10 , wherein the optical film is a polarizing film, a polarizer, an anti-glare film, a hard-coat film, an anti-reflection film, an optical compensation film, a conductive film, a UV-cut film, a diffusion film, a prismatic film, a light distribution film, a heat ray cut film, a hand-cut filter or an electromagnetic wave shield film. 
     
     
         15 . A viscoelastic body adapted to develop adhesive strength by pressure along with increase of irradiation amount of electromagnetic wave or particle beam irradiated to the adhesive composition defined by  claim 1  under a predetermined temperature environment. 
     
     
         16 . An optical film wherein a layer of the adhesive composition defined by  claim 1  is provided on at least one of surfaces thereof. 
     
     
         17 . A polarizing film wherein a layer of the adhesive composition defined by  claim 1  is provided on at least one of surfaces thereof. 
     
     
         18 . A panel for an optical display unit wherein a layer of the adhesive composition defined by  claim 1  is provided on at least one of surfaces thereof. 
     
     
         19 . A liquid crystal cell wherein a layer of the adhesive composition defined by  claim 1  is provided on at least one of surfaces thereof. 
     
     
         20 . An optical display unit comprising:
 a layer of the adhesive composition defined by  claim 1 ;   an optical film bonded to one of surfaces of the layer and a panel for an optical display unit bonded to the other of the surfaces of the layer by irradiation of electromagnetic wave or particle beam under a predetermined temperature environment.   
     
     
         21 . An optical display unit defined by  claim 20 , wherein the optical film is a polarizing film and the panel for an optical display unit is a liquid crystal cell. 
     
     
         22 . An optical display unit defined by  claim 21 , wherein a protection film of a polarizer of the polarizing film is laminated on a surface opposite to the surface which the layer of the polarizing film is bonded thereto.