Optical transparent dual core adhesives composition

Abstract

The present invention relates to an optical transparent dual cure adhesive, and process for preparing this dual cure adhesive, and uses thereof. More particularly, the present invention relates to optical transparent adhesive, which is both capable of being UV-light cured and thermal cured, for example, it can be used for the bonding of touch screen of an electronic device and substrate.

What is claimed is: 
     
         1 . An optical transparent dual cure adhesive composition, based on the total weight of the adhesive composition, the composition comprises:
 10-90 wt % of photo curable oligomer or polymer having (meth)acryloxy group or vinyl group;   5-55 wt % of (meth)acrylate;   0-50 wt % of liquid polybutadiene;   0.5-5 wt % of UV-photoinitiator; and   0.5-5 wt % of thermal initiator.   
     
     
         2 . The composition according to  claim 1 , characterized in that,
 said photo curable oligomer or polymer having (meth)acryloxy group or vinyl group has an average degree of functionality of (meth)acryloxy group or vinyl group of more than 0 and equal to or less than 3;   said oligomer or polymer has an number average molecular weight of about 300 to 50000 Daltons, preferably 1000 to 35000 Daltons, and the glass transition temperature T g  thereof is preferably from −100° C. to 20° C.   
     
     
         3 . An optical transparent dual cure adhesive composition, based on the total weight of the adhesive composition, the composition comprises:
 40-90 wt % of urethane oligomer having (meth)acryloxy group;   5-55 wt % of (meth)acrylate;   0.5-5 wt % of UV-photoinitiator; and   0.5-5 wt % of thermal initiator.   
     
     
         4 . The composition according to  claim 3 , characterized in that,
 said urethane oligomer having (meth)acryloxy group has an average degree of functionality of more than 0 and equal to or less than 3, preferably from 0.5 to 2.5; and the glass transition temperature T g  thereof is from −80 to 0° C., preferably from −60 to 0° C., and the Brookfield viscosity thereof at the temperature of 25° C. preferably is from 1000 cps to 190000 cps, more preferably from 2000 cps to 150000 cps.   
     
     
         5 . The composition according to  claim 3 , characterized in that, based on the total weight of the adhesive composition, the composition comprises 50-80 wt % of urethane oligomer having (meth)acryloxy group, preferably 60-70 wt %; 10-50 wt % of (meth)acrylate, preferably 20-40 wt %; 1-4 wt % of UV-photoinitiator, preferably 2-3 wt %; 1-4 wt % of thermal initiator, preferably 2-3 wt %. 
     
     
         6 . The composition according to  claim 3 , characterized in that, said urethane oligomer having (meth)acryloxy group has number average molecular weight of 1000-25000 Daltons, preferably 1500-10000 Daltons. 
     
     
         7 . An optical transparent dual cure adhesive composition, based on the total weight of the adhesive composition, the composition comprises:
 10-80 wt % of polyisoprene having (meth)acryloxy group or vinyl group;   10-55 wt % of (meth)acrylate;   0-50 wt % of liquid polybutadiene,   0.5-5 wt % of UV-photoinitiator, and   0.5-5 wt % of thermal initiator.   
     
     
         8 . The composition according to  claim 7 , characterized in that,
 said polyisoprene having (meth)acryloxy group or vinyl group has an average degree of functionality of 0.5-3, a number average molecular weight of 10000-50000 Daltons, preferably 12000-40000 Daltons, more preferably 15000-35000 Daltons; and   said liquid polybutadiene preferably has a number average molecular weight of 1000-30000 Daltons; more preferably 1500-25000 Daltons, even more preferably 2000-20000 Daltons, particularly preferably 3000-10000 Daltons.   
     
     
         9 . The composition according to  claim 7 , characterized in that,
 based on the total weight of the adhesive composition, the adhesive composition comprises 20-70 wt % of polyisoprene having (meth)acryloxy group or vinyl group, preferably 30-60 wt %; 10-40 wt % of liquid polybutadiene, preferably 20-35 wt %; 20-45 wt % of (meth)acrylate, preferably 25-40 wt %; 1-4 wt % of UV-photoinitiator, preferably 2-3 wt %; and 1-4 wt % of thermal initiator; preferably 2-3 wt %.   
     
     
         10 . The composition according to  claim 1 , wherein said UV-photoinitiator is selected from the group consisting of: benzophenone and substituted benzophenone, acetophenone and substituted acetophenone, benzoin and alkyl ester thereof, diethoxy acetophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, N-methyl-diethanolamine-benzophenone, 2-hydroxy-methyl-1-phenylpropan-1-one, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide, and combination thereof. 
     
     
         11 . The composition according to  claim 10 , wherein said UV-photoinitiator is selected from: 2-hydroxy-2-methyl-1-phenyl-propan-1-one, diphenyl (2,4,6-trimethyl-benzoyl)phosphine oxide, and combination thereof. 
     
     
         12 . The composition according to  claim 1 , wherein said thermal initiator is organic peroxide, preferably selected from the group consisting of: ester peroxide, alkyl peroxide, and combination thereof, in particular said organic peroxide is selected from the group consisting of 1,1-bis(tert-butylperoxy)-3,3,5-trimethyl cyclohexane, tert-butyl peroxy benzoate, and combination thereof. 
     
     
         13 . The composition according to  claim 1 , wherein said (meth)acrylate is selected from the group consisting of alkyl(meth)acrylate, alkenyl(meth)acrylate and heterocyclic(meth)acrylate,
 wherein the alkyl group preferably is an optionally substituted alkyl group having 1 to 20 carbon atoms, the alkenyl group is preferably an optionally substituted alkenyl having 4 to 20 carbon atoms, and the heterocyclic group is preferably an optionally substituted heterocyclic group having 4 to 20 carbon atoms, in which the hetero atom is selected from nitrogen or oxygen atom,   wherein the substituent preferably being selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an epoxy group having 4 to 10 carbon atoms, and a hydroxyl group.   
     
     
         14 . The composition according to  claim 13 , wherein said (meth)acrylate is selected from the group consisting of: methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, tetrahydrofurfuryl(meth)acrylate, lauryl acrylate, isooctyl acrylate, isodecyl acrylate, 2-phenoxy ethyl acrylate, 2-ethylhexyl(meth)acrylate, isobornyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentadienyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, caprolactone acrylate, morpholine(meth)acrylate, hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetrahydrofuran(meth)acrylate, hydroxylpropyl(meth)acrylate, ethylene glycol dicyclopentenyl ether(meth)acrylate, and any combination thereof. 
     
     
         15 . Use of the adhesive composition according to  claim 1  for bonding a touch screen of a liquid crystal display and substrate of a electronic device, wherein said substrate is preferably selected from the group consisting of glass and polymeric material, wherein said polymeric material is preferably selected from the group consisting of polyester film, such as polyethylene terephthalate (PET) film polycarbonate film, and polyacrylate film, such as polymethyl methacrylate film; and cycloolefin polymeric film.