Embodiment
Below describe embodiment of the present invention in detail.The invention provides the light solidified tackiness agent for the bonding protective membrane of being made by transparent resin on the polarizer being made by the polyvinyl alcohol resin film.The present invention also provides and uses this light solidified tackiness agent, the protective membrane that laminating is made by transparent resin on above-mentioned polarizer and polaroid, further be provided on this polaroid stacked other optical layers and laminated optical component.These light solidified tackiness agents, polaroid and laminated optical component are described successively.
[light solidified tackiness agent]
In the present invention, for the light solidified tackiness agent of the bonding protective membrane of being made by transparent resin on the polarizer being made by the polyvinyl alcohol resin film, contain following (A) and (B) two kinds of compositions.
(A) light cation-curable composition and
(B) light cationic polymerization initiators.
(light cation-curable composition)
Be the principal constituent of light solidified tackiness agent, the light cation-curable composition (A) of giving bounding force by polymerizing curable contains following three kinds of compounds.
(A1) the ester ring type di-epoxy compounds shown in above formula (I),
(A2) diglycidyl compounds shown in above formula (II) and
(A3) monofunctional epoxy compound shown in above formula (III).
The amount of the ester ring type di-epoxy compounds (A1) in light cation-curable composition (A) is that to take the total amount of light cation-curable composition (A) be benchmark, is the 60-75 % by weight.By contain the ester ring type di-epoxy compounds (A1) more than 60 % by weight in light cation-curable composition (A); storage modulus after the light solidified tackiness agent that can make to contain it solidifies improves; for example can make the storage modulus under 80 ℃ is 1; more than 000MPa; even the polaroid laminating of polarizer and protective membrane formed via this tackiness agent is subject to violent temperature history, also can prevent breaking of polarizer.And if this amount surpasses 75 % by weight; the relative minimizing of amount of the diglycidyl compounds of the following stated (A2) and monofunctional epoxy compound (A3), low viscosity and the closing force between polarizer/protective membrane of the light solidified tackiness agent that is difficult to simultaneously to realize that the present invention is desired improve.The total amount of light cation-curable composition (A) of more preferably take is benchmark, more than ester ring type di-epoxy compounds (A1) contains 70 % by weight.
The amount of the diglycidyl compounds (A2) in light cation-curable composition (A) is the 5-35 % by weight.By coordinate the diglycidyl compounds (A2) more than 5 % by weight in light cation-curable composition (A); storage modulus after the light solidified tackiness agent that can make to contain it solidifies keeps high value, and the while can be improved the closing force between polarizer and protective membrane.And if this amount surpasses 35 % by weight, the closing force deficiency between polarizer and protective membrane, simultaneously, the storage modulus after the light solidified tackiness agent solidifies also has the tendency of reduction.In order to make the storage modulus after closing force between polarizer and protective membrane or light solidified tackiness agent solidify, be preferred value, more preferably making the amount of the diglycidyl compounds (A2) in light cation-curable composition (A) is below 25 % by weight.
And the amount of the monofunctional epoxy compound (A3) in light cation-curable composition (A) is the 2-15 % by weight.By coordinate the monofunctional epoxy compound (A3) more than 2 % by weight in light cation-curable composition (A); can make the reduced viscosity of light solidified tackiness agent; show good coating, show the effect that improves the closing force between polarizer and protective membrane simultaneously.And if this amount surpasses 15 % by weight, the storage modulus of light solidified tackiness agent after solidifying fully improves, polaroid polarizer and protective membrane laminating obtained via this tackiness agent when being subject to violent temperature history polarizer easily generation break.
Mean in the above formula (I) of ester ring type di-epoxy compounds (A1) R
1and R
2independent separately, be the alkyl of hydrogen atom or carbonatoms 1-6, the carbonatoms of alkyl is 3 when above, can have alicyclic structure.Take the position of the cyclohexane ring of being combined with X in formula (I) as the 1-position (thus, the position of the epoxy group(ing) in two cyclohexane rings is 3,4-position), and this alkyl can be in the optional position combination of 1-position~6-position.This alkyl can be straight chain certainly, and carbonatoms is 3 when above, can be side chain.As mentioned above, carbonatoms is 3 when above, can have alicyclic structure.Exemplary with alkyl of alicyclic structure is cyclopentyl or cyclohexyl.
In formula (I), connect two 3 equally, the X of 4-epoxy-cyclohexane ring is the divalent group shown in any one in Sauerstoffatom, carbonatoms alkane two bases that are 1-6 or above formula (Ia)-(Id).Here, alkane two bases are the concepts that comprise alkylene base or alkylidene, and alkylene base can be straight chain, and carbonatoms is 3 when above, can be side chain.
X is in above formula (Ia)-(Id) during the divalent group shown in any, the linking group Y in various
1, Y
2, Y
3and Y
4be respectively carbonatoms 1-20 alkane two bases, the carbonatoms of these alkane two bases is 3 when above, can have alicyclic structure.These alkane two bases can be straight chain certainly, and carbonatoms is 3 when above, can be side chain.As mentioned above, carbonatoms is 3 can have alicyclic structure when above.Exemplary with alkane two bases of alicyclic structure is cyclopentylidene or cyclohexylidene.
Ester ring type di-epoxy compounds (A1) shown in formula (I) is illustrated, X in formula (I) is the divalent group shown in above formula (Ia), the compound that a in this formula is 0 is 3,4-epoxy group(ing) hexahydrobenzyl alcohol (can be on this cyclohexane ring in conjunction with carbonatoms 1-6 alkyl) is with 3, the carboxylate of 4-epoxy-cyclohexane formic acid (can be on this cyclohexane ring in conjunction with carbonatoms 1-6 alkyl).Exemplifying its object lesson, is 3,4-epoxy-cyclohexane formic acid 3, and 4-epoxy group(ing) cyclohexyl methyl esters [in formula (I) (the divalent group shown in the formula that X is a=0 (Ia)), R
1=R
2the compound of=H], 3,4-epoxy group(ing)-6-methylcyclohexane formic acid 3,4-epoxy group(ing)-6-methylcyclohexyl methyl esters [has in the formula (I) of X same as described above R
1=6-methyl, R
2the compound of=6-methyl], 3,4-epoxy group(ing)-1-methylcyclohexane formic acid 3,4-epoxy group(ing)-1-methylcyclohexyl methyl esters [has in the formula (I) of X same as described above R
1=1-methyl, R
2the compound of=1-methyl], 3,4-epoxy group(ing)-3-methylcyclohexane formic acid 3,4-epoxy group(ing)-3-methylcyclohexyl methyl esters [has in the formula (I) of X same as described above R
1=3-methyl, R
2the compound of=3-methyl] etc.
The compound that X in formula (I) is the divalent group shown in formula (Ib) is the carboxylate of alkylene base glycols and 3,4-epoxy-cyclohexane formic acid (can be on its cyclohexane ring in conjunction with carbonatoms 1-6 alkyl).The compound that X in formula (I) is the divalent group shown in formula (Ic) is the carboxylate of aliphatic dicarboxylic acid class and 3,4-epoxy group(ing) hexahydrobenzyl alcohol (can be on its cyclohexane ring in conjunction with carbonatoms 1-6 alkyl).The compound that X in formula (I) is the divalent group shown in formula (Id) is 3, the ether body (during b=0) of 4-epoxy group(ing) hexahydrobenzyl alcohol (can be on its cyclohexane ring in conjunction with carbonatoms 1-6 alkyl), or the etherate of alkylene base glycols or poly-alkylene base glycols and 3,4-epoxy group(ing) hexahydrobenzyl alcohol (can be on its cyclohexane ring in conjunction with carbonatoms 1-6 alkyl) (b > 0 o'clock).
Mean in the above formula (II) of diglycidyl compounds (A2) alkylene base that Z is carbonatoms 1-9, carbonatoms 3 or 4 alkylidene, divalent ester ring type alkyl or formula-C
mh
2m-Z
1-C
nh
2n-shown in the divalent group, here ,-Z
1-be-O-,-CO-O-,-O-CO-,-SO
2-,-SO-or-CO-, m and n are independent separately, are the integer more than 1, both add up to below 9.The exemplary of divalent ester ring type alkyl is cyclopentylidene or cyclohexylidene.
In formula (II), the compound that Z is alkylene base is the diglycidyl ether of alkylene base glycol.Providing its object lesson, is ethylene glycol bisthioglycolate glycidyl ether, 1,3-propane diol diglycidyl ether, Isosorbide-5-Nitrae-butanediol diglycidyl ether, 1,6-hexane diol diglycidyl ether etc.
In formula (II), Z is formula-C
mh
2m-Z
1-C
nh
2n-shown in the situation of divalent group be equivalent to: Z is the alkylene base of carbonatoms more than 2, the C-C key quilt-O-of this alkylene base ,-CO-O-,-O-CO-,-SO
2-,-SO-or-CO-cuts off.
Mean in the above formula (III) of monofunctional epoxy compound R
3alkyl for carbonatoms 1-15.This alkyl can be straight chain certainly, and carbonatoms is 3 when above, can be also side chain.The carbonatoms of this alkyl is many, for example is preferably more than 6, further the preferred scope at carbonatoms 6-10.The preferred alkyl of side chain wherein.The exemplary of the monofunctional epoxy compound shown in formula (III) can be enumerated 2-ethylhexyl glycidyl ether.
The light cation-curable composition (A) that forms the light solidified tackiness agent contains ester ring type diepoxide described above (A1), diglycidyl compounds (A2) and monofunctional epoxy compound (A3) according to ratio discussed above respectively.For the raising of the storage modulus of the lowering viscousity of the light solidified tackiness agent before more effectively realize solidifying, its cured article and the raising of the closing force between polarizer and protective membrane; the total amount of light solidified tackiness agent of take is benchmark, and preferably the total amount of diglycidyl compounds (A2) and monofunctional epoxy compound (A3) is more than 25 % by weight.
Ester ring type di-epoxy compounds (A1), diglycidyl compounds (A2) and monofunctional epoxy compound (A3) are under the condition of the scope of amount discussed above, and light cation-curable composition (A) can contain other cationically polymerizable compound.
(light cationic polymerization initiators)
In the present invention, the cationoid polymerisation undertaken by the irradiation of active energy beam solidifies above-mentioned smooth cation-curable composition, forms binder layer, therefore will in Photocurable adhesive composition, coordinate light cationic polymerization initiators (B).The light cationic polymerization initiators is irradiation generation positively charged ion or the Lewis acid by the active energy beam as visible ray, ultraviolet ray, X ray or electron rays, causes the material of the polyreaction of light cation-curable composition (A).The light cationic polymerization initiators is to bring into play katalysis by light, and therefore, even mix with light cation-curable composition (A), its storage stability, operability are also excellent.Irradiation generation positively charged ion or lewis acidic compound by active energy beam for example can be enumerated: aryl diazonium salt; Salt as aromatics salt compounded of iodine or aromatics sulfonium salt and so on; Iron-arene complex etc.
Aryl diazonium salt for example can be enumerated following compound.
The hexafluoro-antimonic acid diazobenzene,
The phosphofluoric acid diazobenzene,
Hexafluoro boric acid diazobenzene etc.
The aromatics salt compounded of iodine for example can be enumerated following compound.
Phenylbenzene iodine four (pentafluorophenyl group) borate,
Diphenyl iodine hexafluorophosphate,
Phenylbenzene iodine hexafluoro antimonate,
Two (4-nonyl phenyl) iodine hexafluorophosphate etc.
The aromatics sulfonium salt for example can be enumerated following compound.
The triphenylsulfonium hexafluorophosphate,
The triphenylsulfonium hexafluoro antimonate,
Triphenylsulfonium four (pentafluorophenyl group) borate,
The two hexafluorophosphates of 4,4 '-bis-[phenylbenzene sulfonium] diphenyl sulfide,
The two hexafluoro antimonates of 4,4 '-bis-[two (beta-hydroxy oxyethyl group) phenyl sulfonium] diphenyl sulfide,
The two hexafluorophosphates of 4,4 '-bis-[two (beta-hydroxy oxyethyl group) phenyl sulfonium] diphenyl sulfide,
7-[bis-(p-methylphenyl) sulfonium]-the ITX hexafluoro antimonate,
7-[bis-(p-methylphenyl) sulfonium]-ITX four (pentafluorophenyl group) borate,
4-phenylcarbonyl group-4 '-phenylbenzene sulfonium-diphenyl sulfide hexafluorophosphate,
4-(to the tert-butyl-phenyl carbonyl)-4 '-phenylbenzene sulfonium-diphenyl sulfide hexafluoro antimonate,
4-(to the tert-butyl-phenyl carbonyl)-4 '-bis-(p-methylphenyl) sulfonium-diphenyl sulfide four (pentafluorophenyl group) borate etc.
Iron-arene complex for example can be enumerated following compound.
Dimethylbenzene-cyclopentadienyl iron (II) hexafluoro antimonate,
Cumene-cyclopentadienyl iron (II) hexafluorophosphate,
Imines etc. between dimethylbenzene-cyclopentadienyl iron (II) three (trifluoromethyl sulfonyl).
These light cationic polymerization initiators can be used alone, can also be 2 or more kinds in combination respectively.Wherein, particularly near the wavelength region may of aromatics sulfonium salt 300nm also has the ultraviolet radiation absorption characteristic, and therefore the cured article that therefore can obtain the solidified nature excellence, have good physical strength and bond strength is preferably used.
The use level of light cationic polymerization initiators (B) is all with respect to 100 weight part light cation-curable compositions (A), is the 1-10 weight part.Every 100 weight part light cation-curable compositions (A) coordinate the above light cationic polymerization initiators of 1 weight part, can make thus light cation-curable composition (A) fully solidify, and make the gained polaroid have high mechanical strength and bond strength.On the other hand, if its amount increases, the ionic substance in cured article increases, thus, the water absorbability of cured article improves, may make the endurance quality of polaroid reduce, therefore, the amount of light cationic polymerization initiators (B) is to be below 10 weight parts with respect to every 100 weight part light cation-curable compositions (A).The use level of light cationic polymerization initiators (B) is preferably more than 2 weight parts with respect to every 100 weight part light cation-curable compositions (A), also is preferably below 6 weight parts.
(can be matched with other composition in the light solidified tackiness agent)
Light solidified tackiness agent of the present invention, except the above the light cation-curable composition (A) that contains epoxy compounds and light cationic polymerization initiators (B), can also contain known other composition be matched with in conventional light-cured resin or tackiness agent.The applicable example of other composition can be enumerated photosensitizers and photosensitizer additive.Photosensitizers is the compound that the wavelength place longer at the maximum absorption wavelength more shown than light cationic polymerization initiators (B) shows the polymerization initiation reaction that maximum absorption, promotion light cationic polymerization initiators (B) produce.Photosensitizer additive is the compound that further promotes the effect of photosensitizers.Preferably according to the kind of protective membrane, coordinate such photosensitizers, further coordinate photosensitizer additive.
Photosensitizers is preferably the compound that the light display that contrasts the long wavelength of 380nm is shown maximum absorption.Near above-mentioned smooth cationic polymerization initiators (B) short wavelength place 300nm or than it shows maximum absorption, respond near the light of its wavelength, generate positively charged ion or Lewis acid, cause the cationoid polymerisation of light cation-curable composition (A), if but coordinated above-mentioned photosensitizers, also could respond to the wavelength longer than it, the particularly light of longer wavelength than 380nm.Described photosensitizers can effectively utilize the anthracene based compound.Anthracene is that the object lesson of photosensitizers is as following compound.
9,10-dimethoxy anthracene,
9,10-diethoxy anthracene,
9,10-dipropoxy anthracene,
9,10-diisopropoxy anthracene,
9,10-dibutoxy anthracene,
9,10-, bis-pentyloxy anthracenes,
9,10-, bis-hexyloxy anthracenes,
9,10-bis-(2-methoxy ethoxy) anthracene,
9,10-bis-(2-ethoxy ethoxy) anthracene,
9,10-bis-(2-butoxy oxyethyl group) anthracene,
9,10-bis-(3-butoxy propoxy-) anthracene,
The 2-methyl-or EDMO,
The 2-methyl-or 2-ethyl-9,10-diethoxy anthracene,
The 2-methyl-or 2-ethyl-9,10-dipropoxy anthracene,
The 2-methyl-or 2-ethyl-9,10-diisopropoxy anthracene,
The 2-methyl-or 2-ethyl-9,10-dibutoxy anthracene,
The 2-methyl-or 2-ethyl-9,10-bis-pentyloxy anthracenes,
The 2-methyl-or 2-ethyl-9,10-bis-hexyloxy anthracenes etc.
By coordinate above-mentioned photosensitizers in the light solidified tackiness agent, with ill-matched situation, to compare, the solidified nature of tackiness agent improves.With respect to 100 weight part light cation-curable compositions (A), by coordinating the photosensitizers more than 0.1 weight part, can show above-mentioned effect.On the other hand, if the use level of photosensitizers increases, have the problem that low temperature when keeping separate out etc., so it measuring preferably with respect to 100 weight part light cation-curable compositions (A), is below 2 weight parts.From the viewpoint of the neutral gray that keeps polaroid, consider; within the bounding force of polarizer and protective membrane keeps appropriate scope; the use level that reduces photosensitizers is comparatively favourable; for example; with respect to 100 weight part light cation-curable compositions (A); the amount that can make photosensitizers is the 0.1-0.5 weight part, the scope of further preferred 0.1-0.3 weight part.
Below photosensitizer additive is described.Photosensitizer additive also has various, can effectively utilize naphthalene series compound.Naphthalene is that the object lesson of photosensitizer additive has the following stated compound.
4-methoxyl group-1-naphthols,
4-oxyethyl group-1-naphthols,
4-propoxy--1-naphthols,
4-butoxy-1-naphthols,
4-hexyloxy-1-naphthols,
Isosorbide-5-Nitrae-dimethoxy-naphthalene,
1-oxyethyl group-4-methoxynaphthalene,
Isosorbide-5-Nitrae-diethoxy naphthalene,
Isosorbide-5-Nitrae-dipropoxy naphthalene,
Isosorbide-5-Nitrae-dibutoxy naphthalene etc.
Be photosensitizer additive by the light solidified tackiness agent, coordinating naphthalene, compare with ill-matched situation, the solidified nature of tackiness agent improves.With respect to 100 weight part light cation-curable compositions (A), by coordinating the above naphthalene of 0.1 weight part, be photosensitizer additive, can show above-mentioned effect thus.On the other hand, if the use level that naphthalene is photosensitizer additive increases, occur that low temperature when keeping the problem such as separate out, so it is measured preferably with respect to 100 weight part light cation-curable compositions (A), be below 5 weight parts, further preferably below 3 weight parts.
(physical property of light solidified tackiness agent)
Light solidified tackiness agent of the present invention as described above, for protective membrane being fitted in to the polarizer of being made by the polyvinyl alcohol resin film.On at least one binding face in these polarizers and protective membrane, this tackiness agent of coating, then make both superimposed via this binder layer, and tackiness agent is solidified.In order to improve the coating suitability to polarizer and/or protective membrane, preferably the viscosity of this tackiness agent is low.In the present invention, by usining specific 3 kinds of compounds that the regulation ratio coordinates above-mentioned explanation as light cation-curable composition (A), the reduced viscosity of light solidified tackiness agent, the coating suitability improves.Specifically, the viscosity of this light solidified tackiness agent under 25 ℃ can be for 100MPa below second.
In addition, aspect the adaptation improved between polarizer and protective membrane, make the storage modulus of the curing binder layer obtained of this tackiness agent more high more preferred.In the present invention, remain by usining specific 3 kinds of compounds that the regulation ratio coordinates above-mentioned explanation as light cation-curable composition (A), as mentioned above, the viscosity before making to solidify keeps lower value, keep the coating suitability, can improve the storage modulus of cured article simultaneously.Specifically, the cured article of this light solidified tackiness agent can show the storage modulus that 1,000MPa is above under 80 ℃.
[polaroid]
In the present invention, via light solidified tackiness agent described above, the protective membrane that laminating is made by transparent resin at least one face of the polarizer of being made by the polyvinyl alcohol resin film, solidify this light solidified tackiness agent, makes polaroid.As mentioned above, can improve the storage modulus as the binder layer of the cured article of light solidified tackiness agent in the present invention, improve the adaptation between polarizer and protective membrane.Therefore, to obtain bond strength can be more than 0.6N/25mm to the stripping test of 180 between polarizer and protective membrane degree.Here, 180 degree stripping tests are carried out according to JIS K 6854-2:1999 " tackiness agent-2 ones of peel adhesion strength test method-: 180 degree are peeled off ".
Below polarizer and the protective membrane that forms polaroid of the present invention described, further to the manufacture method simple declaration of polaroid.
(polarizer)
Polarizer consists of the polyvinyl alcohol resin film that has adsorbed dichroic dye orientation.The polyvinyl alcohol resin that forms polarizer is that the resin saponification obtains by making polyvinyl acetate base ester.Polyvinyl acetate base ester is resin except the homopolymer of vinyl-acetic ester-polyvinyl acetate base ester, can be also vinyl-acetic ester and can with the multipolymer of other monomer of its copolymerization.With other monomer of vinyl-acetic ester copolymerization such as enumerating: unsaturated carboxylic acid class, olefines, vinyl ethers, unsaturated sulfonic acid class etc.The saponification deg of polyvinyl alcohol resin is generally the scope of 85-100 % by mole, preferred 98-100 % by mole.Polyvinyl alcohol resin can further be modified, such as the polyvinyl formal that can use the modification of use aldehydes or polyvinyl acetal etc.The polymerization degree of polyvinyl alcohol resin is generally 1,000-10, and 000, preferably 1,500-5,000 scope.
Polarizer is via following operation manufacture: by the operation of above-mentioned polyvinyl alcohol resin film uniaxial extension; The polyvinyl alcohol resin film is dyeed with dichroic dye, make the operation of this dichroic dye absorption; The operation that the polyvinyl alcohol resin film that has adsorbed dichroic dye is processed with boric acid aqueous solution.
Uniaxial extension can carry out before utilizing dichroic dye dyeing, also can carry out with utilizing dichroic dye dyeing simultaneously, can also after utilizing dichroic dye dyeing, carry out.While after utilizing dichroic dye dyeing, carrying out uniaxial extension, this uniaxial extension can carry out before boric acid is processed, and also can during boric acid is processed, carry out.Certainly, also can in these a plurality of stages, carry out uniaxial extension.For uniaxial extension, can be between the roller different at peripheral speed along uniaxial extension, also can use hot-rolling along uniaxial extension.Can also be the dry type stretching stretched in atmosphere, can be also that the wet type stretched under the state with solvent-swollen stretches.Stretching ratio is generally doubly left and right of 4-8.
For the polyvinyl alcohol resin film is dyeed with dichroic dye, for example the polyvinyl alcohol resin film can be soaked in the aqueous solution that contains dichroic dye.Dichroic dye specifically can be used iodine or dichroism organic dye.
While using iodine as dichroic dye, usually adopt and soak the method that the polyvinyl alcohol resin film is dyeed in the aqueous solution that contains iodine and potassiumiodide.In this aqueous solution, the content of iodine is normally 0.01-0.5 weight part left and right with respect to 100 weight parts waters, and the content of potassiumiodide is normally 0.5-10 weight part left and right with respect to 100 weight parts waters.The temperature of this aqueous solution is generally 20-40 ℃ of left and right, and in addition, the soak time in this aqueous solution (dyeing time) is generally 30-300 about second.
And while using the dichroism organic dye as dichroic dye, usually adopt the polyvinyl alcohol resin film is soaked in to the method dyeed in the aqueous solution that contains water miscible dichroism organic dye.The content of the dichroism organic dye in this aqueous solution is normally 1 * 10 with respect to 100 weight parts waters
-3-1 * 10
-2the weight part left and right.This aqueous solution can contain the inorganic salt of sodium sulfate etc.The temperature of this aqueous solution is generally 20-80 ℃ of left and right, and in addition, the soak time in this aqueous solution (dyeing time) is generally 30-300 about second.
Utilizing boric acid after dichroic dye dyeing to process to be polyvinyl alcohol resin film by having dyeed to be soaked in carries out in boric acid aqueous solution.The content of the boric acid in boric acid aqueous solution is normally 2-15 weight part left and right with respect to 100 weight parts waters, preferably 5-12 weight part left and right.While using iodine as dichroic dye, preferably this boric acid aqueous solution contains potassiumiodide.The content of the potassiumiodide in boric acid aqueous solution is normally 2-20 weight part left and right, preferably 5-15 weight part with respect to 100 weight parts waters.Soak time in boric acid aqueous solution is generally 100-1, and about 200 seconds, preferably 150-600 is about second, and further preferred 200-400 is about second.The temperature of boric acid aqueous solution is generally more than 50 ℃, preferably 50-85 ℃.
Polyvinyl alcohol resin film after boric acid is processed is washed processing usually.Washing is for example processed and can is soaked in water and carry out by the polyvinyl alcohol resin film after boric acid is processed.Implement drying treatment after washing, obtain polarizer.The temperature of water when washing is processed is generally 5-40 ℃ of left and right, and soak time is generally 2-120 about second.The drying treatment of carrying out is afterwards used hot air dryer or far infra-red heater to carry out usually.Drying temperature is generally 40-100 ℃.The time of drying treatment is generally 120-600 about second.
The thickness of the polarizer of being made by the polyvinyl alcohol resin film obtained above can be 10-50 μ m left and right.
(protective membrane)
Via the light solidified tackiness agent illustrated before, the protective membrane of fitting on the polarizer of being made by the polyvinyl alcohol resin film described above, solidify the light solidified tackiness agent, makes polaroid.The cellulose acetate resin film that protective membrane can be representative by the most widely used triacetyl cellulose of protective membrane of take at present as polaroid or low resin molding forms than triacetyl cellulose Water Vapour Permeability.The Water Vapour Permeability of triacetyl cellulose is approximately 400g/m
2about/24 hours.
In a preferred scheme, the protective membrane of fitting with at least one face of polarizer consists of acetyl fibre prime system resin.Particularly with the protective membrane of face laminating of polarizer, can be formed by the acetyl fibre prime system resin that is combined with UV light absorber.In another preferred version, resin molding, for example Water Vapour Permeability low by the Water Vapour Permeability than triacetyl cellulose with the protective membrane of at least one face laminating of polarizer are 300g/m
2resin molding below/24 hours forms.The resin that forms the resin molding that above-mentioned Water Vapour Permeability is low can be enumerated: noncrystalline polyolefin is resin, polyester based resin, acrylic resin, polycarbonate-based resin, chain polyolefin-based resins etc.Wherein, preferably using noncrystalline polyolefin is resin, polyester based resin and chain polyolefin-based resins.In a further preferred scheme; the protective membrane that the face laminating is become by acetyl fibre prime system resin via above-mentioned binder layer at polarizer; similarly, the another side laminating protective membrane that low transparent resin is made by above-mentioned Water Vapour Permeability at polarizer via above-mentioned binder layer.
Acetyl fibre prime system resin is the resin that at least a portion of the hydroxyl in Mierocrystalline cellulose is obtained by acid esterification, can be make a part by acid esterification, another part by the mixed ester of other acid esters.The object lesson of acetyl fibre prime system resin can be enumerated: triacetyl cellulose, diacetyl cellulose, cellulose ethanoate propionic ester, cellulose acetate butyrate etc.
Noncrystalline polyolefin be resin be have as norbornylene or tetracyclododecane (another name dimethyl bridge octahydro naphthalene) or on them, be combined with so substituent compound, the polymkeric substance of the polymerized unit of cyclic olefin, can be the multipolymer that chain alkene and/or aromatic vinyl compound and cyclic olefin copolymerization are obtained.During for the multipolymer of the homopolymer of cyclic olefin or two or more cyclic olefin, residual due to ring-opening polymerization have two keys, and therefore, it is resin that the product of its hydrogenation is typically used as to noncrystalline polyolefin.Wherein representational for thermoplastic norbornene be resin.
Polyester based resin is the polymkeric substance that the polycondensation by diprotic acid and dibasic alcohol obtains, and representational is polyethylene terephthalate.Acrylic resin is to take the polymkeric substance that methyl methacrylate is principal monomer, except the homopolymer of methyl methacrylate, can also be methyl methacrylate and the multipolymer of acrylate as methyl acrylate or aromatic vinyl compound etc.Polycarbonate-based resin is the polymkeric substance that main chain has carbonic acid ester bond (O-CO-O-), and it is representational is the resin that dihydroxyphenyl propane and phosgene polycondensation obtain.The chain polyolefin-based resins is the polymkeric substance that the chain alkene of take as ethene or propylene is principal monomer, can be homopolymer or multipolymer.Wherein, representational is the homopolymer of propylene or a small amount of ethene of copolymerization obtains in propylene multipolymer.
Said protection film can have the various surface-treated layers as hard coat, anti-reflection layer, antiglare layer or antistatic layer on the opposite face of the face with the polarizer laminating.Protective membrane comprises the situation that has formed such surface-treated layer, and its thickness can be 5-150 μ m left and right.Its thickness is preferably more than 10 μ m, also preferably below 120 μ m, further preferably below 100 μ m.
(manufacture method of polaroid)
When polaroid is manufactured; the coating layer of the light solidified tackiness agent of above-mentioned explanation is formed to a side or two sides of the binding face of polarizer and protective membrane; via this coating layer; by polarizer and protective membrane laminating; irradiation by active energy beam is solidified the coating layer of the uncured light solidified tackiness agent of formation like this, makes the protective membrane secure fit on polarizer.The coating layer of light solidified tackiness agent can form on the binding face of polarizer, also can on the binding face of protective membrane, form.The formation of coating layer is such as utilizing takeoff knife, wire bar applicator, mould to be coated with the various coating methods such as machine, unfilled corner wheel coating machine, intaglio plate coating machine.Can also adopt and polarizer and protective membrane be take to both binding face supply with continuously as inboard form, make the mode of tackiness agent curtain coating between it simultaneously.Each coating method all has best separately range of viscosities, and therefore, using solvent to carry out viscosity adjustment is also effective technology.For this reason, but solvent will adopt the optical property that can not make polarizer to reduce the solvent of excellent dissolution light solidified tackiness agent, and its kind is not particularly limited, and such as using, take the hydro carbons that toluene is representative, the organic solvents such as ester class that the ethyl acetate of take is representative.The thickness of binder layer is generally below 20 μ m, preferably below 10 μ m, further preferably below 5 μ m.If the binder layer thickening, the reactivity of tackiness agent reduces, and the humidity resistance of polaroid has the tendency of variation.
By polarizer and protective membrane when bonding; before forming the coating layer of tackiness agent, can to both binding face a side or two sides implement as Corona discharge Treatment, Cement Composite Treated by Plasma, flame treating, prime treatment or anchoring coating processing easy adhesion process.
The coating layer of light solidified tackiness agent is irradiated to the light source that active energy beam uses so long as produce the light source of ultraviolet ray, electron rays, X ray etc. and get final product.Be particularly suitable for using below wavelength 400nm, have luminescence distribution, such as low pressure mercury lamp, medium pressure mercury lamp, high voltage mercury lamp, ultrahigh pressure mercury lamp, chemical lamp, black lamp, microwave-excitation mercury lamp, metal halid lamp etc.Active energy beam is determined according to every kind of objective composition the exposure intensity of light solidified tackiness agent, is not particularly limited, and to the exposure intensity of the effective wavelength region may of activation of light cationic polymerization initiators, be preferably 0.1-100mW/cm
2.If the rayed intensity to the light solidified tackiness agent is too small, the reaction times long, and if this rayed intensity is excessive, the heating during by the light and heat curing adhesive polymerization of lamp radiation may cause the deteriorated of the xanthochromia of light solidified tackiness agent or polarizer.To rayed time of light solidified tackiness agent be subject to every kind will be curing the control of composition, also be not particularly limited, be preferably set to: the accumulated light of product representation of exposure intensity and irradiation time of take is 10-5,000mJ/cm
2.If the accumulated light to the light solidified tackiness agent is too small,, from the generation deficiency of the spike of light cationic polymerization initiators, the curing of gained binder layer may be insufficient, and if increase its accumulated light, irradiation time is very long, and productivity raising aspect is unfavorable.
When the two sides of polarizer laminating protective membrane; the irradiation of active energy beam can be undertaken by protective membrane side arbitrarily; for example; when the protective membrane that contains UV light absorber, opposite side at the protective membrane of a side does not contain UV light absorber; irradiate active energy beam by the protective membrane side that does not contain UV light absorber; this can effectively utilize irradiated active energy beam, improves curing speed, preferably.
[laminated optical component]
The optical layers with optical function of polaroid of the present invention beyond can the laminated polarizing sheet, make laminated optical component.Be typically via tackiness agent or tackiness agent; stacked laminating optical layers on the protective membrane of polaroid; make thus laminated optical component; in addition; for example can be via the light solidified tackiness agent; the protective membrane of fitting on a face of polarizer, via tackiness agent or tackiness agent, stacked laminating optical layers on the another side of polarizer.In the latter's situation, if use light solidified tackiness agent given to this invention for the tackiness agent of fit polarizer and optical layers, this optical layers also becomes protective membrane given to this invention simultaneously.
The example that is laminated in the optical layers on polaroid can be enumerated: with respect to the polaroid that is disposed at the liquid crystal cell back side one side, be laminated in reflecting layer, Transflective layer, light diffusion layer, light collecting plate, raising brightness film of this polaroid and contrary towards liquid crystal cell one a side side etc.And for the polaroid that is disposed at liquid crystal cell front one side be disposed at the random polarization sheet of the polaroid of the liquid crystal cell back side one side, be laminated in addition the phase retardation film etc. that this polaroid is intended for liquid crystal cell one side.
Reflecting layer, Transflective layer or light diffusion layer are established for the polaroid (optical component) of making reflection-type, the polaroid (optical component) of Transflective or the polaroid (optical component) of dispersion pattern respectively.The liquid crystal indicator of the type that the incident light that the polaroid of reflection-type is recognized side for considering oneself as by reflection is shown, can omit the light source backlight of Denging, therefore easily makes the liquid crystal indicator slimming.And the polaroid of Semitransmissive at bright place as reflection-type, in the dark use the liquid crystal indicator of the type shown from light backlight.Such as being to set up paper tinsel or the vapor-deposited film formed by metals such as aluminium on the protective membrane of polarizer, form reflecting layer as the optical component of reflection type polarizer.As the optical component of Semitransmissive polaroid, be that half-mirror is made in above-mentioned reflecting layer, or will contain pearly pigment, show that reflector and the polaroid-bindnig of half transmitting form.On the other hand, as the optical component of dispersion pattern polaroid, be for example to adopt the protective membrane on polaroid is implemented to the method that delustring is processed; Coating is containing the method for the resin of particulate; The whole bag of tricks such as method of the bonding film containing particulate, form the micro concavo-convex structure on surface.
Also can further form the optical component of the effect of the dual-purpose polaroid of performance reflection diffusion, in this case, such as adopting the method that the reflecting layer of having reflected this concaveconvex structure etc. is set on the micro concavo-convex structural plane of dispersion pattern polaroid.The reflecting layer of micro concavo-convex structure have advantages of by scattering make incident light diffusion, prevent directivity or dazzle, can to suppress light and shade unequal.In addition, containing fine-grained resin layer or film, when incident light and reflected light thereof see through the layer containing particulate, spread, also have advantages of that can to suppress light and shade unequal.The reflecting layer of reflecting surperficial micro concavo-convex structure is such as can be by vacuum evaporation, ion plating or the methods such as the evaporation as sputter or coating, and the surface of directly metal being located to the micro concavo-convex structure forms.The particulate coordinated in order to form surperficial micro concavo-convex structure such as can be as the inorganic of the median size silicon-dioxide that is 0.1-30 μ m, aluminum oxide, titanium oxide, zirconium white, stannic oxide, Indium sesquioxide, Cadmium oxide, weisspiessglanz etc. be particulate, as organic system particulate of crosslinked or noncrosslinking polymkeric substance etc.
Light collecting plate be take light path control etc. and is used as purpose, therefore can make the form of the plate etc. of prism array sheet or lens array plate or attachment point.
The purpose that improves the brightness film is the raising for the brightness of liquid crystal indicator, so its example can be enumerated: be designed to the anisotropy of specific refractory power stacked, the anisotropic reflective polarizing light separate sheet that produces reflectivity of different film multi-disc mutually; Circularly polarizing separation sheet formed at alignment films or this aligned liquid-crystal layer of film base material upper support cholesteric liquid crystal polymkeric substance etc.
On the other hand, the purpose of the above-mentioned phase retardation film of performance optical layers effect is for the phase difference compensation of liquid crystal cell etc.Its example can be enumerated: the birefringence film formed by stretched film of various plastics etc., orientation and fixedly discotic mesogenic or nematic liquid crystal film, formed the material of above-mentioned liquid crystal layer etc. on film base material.While forming liquid crystal layer on film base material, preferably use the cellulose-based resin molding such as triacetyl cellulose as film base material.
The plastics of form dielectric grid film for example can be enumerated: as noncrystalline polyolefin is the chain polyolefin-based resins of resin, polycarbonate-based resin, acrylic resin, polypropylene and so on, and polyvinyl alcohol, polystyrene, polyarylate, polymeric amide etc.Should illustrate, stretched film can be processed and obtain by suitable modes such as single shaft or twin shafts.The purpose of phase retardation film is to carry out the control of the optical characteristics such as broadband, can will more than 2, be used in combination.
In laminated optical component, contain phase retardation film as the optical layers beyond polaroid, this can effectively carry out the optics guarantee when being applied to liquid crystal indicator, therefore preferably uses.The phase difference value of phase retardation film (face in and thickness direction) can be selected optimum value according to applied liquid crystal cell.
Laminated optical component can be by polaroid, with according to application target, from above-mentioned various optical layers, select more than 1 layer or 2 layers the combination, make the duplexer more than 2 layers or 3 layers.In this case, the various optical layers that form laminated optical component are used tackiness agents or tackiness agent, with polaroid, form one, as long as for this reason and the tackiness agent or the tackiness agent that use can well form binder layer or adhesive layer, are not particularly limited.From the simplicity of bonding operation or prevent the considerations such as generation of optical aberration, preferably use tackiness agent (also referred to as pressure sensitive adhesive).Tackiness agent can be used usings the material as stock polymer such as acrylic acid polymer or silicon-type polymkeric substance, polyester, urethane, polyethers.Wherein, as acrylic pressure-sensitive adhesive, preferably select optical transparence excellent, keep appropriate wetting property or aggregation force, also excellent and there are weathering resistance or thermotolerance etc., under the condition of heating or humidification, perk occur or peel off etc. to peel off problem and use with the binding property of base material.In acrylic pressure-sensitive adhesive, acrylic copolymer can be used as stock polymer, this acrylic copolymer has coordinated the acrylic monomer containing functional group that has (methyl) acrylic acid alkyl ester that methyl or the carbonatomss such as ethyl or butyl are the alkyl below 20 and made by (methyl) vinylformic acid or (methyl) Hydroxyethyl Acrylate etc., its second-order transition temperature is preferably below 25 ℃, further preferably below 0 ℃, weight-average molecular weight is more than 100,000.
Form binder layer on polaroid, such as carrying out in the following manner: in the organic solvents such as toluene or ethyl acetate, dissolve or the dispersion agent adhesive composition, the solution of preparation 10-40 % by weight, directly coat the mode on polaroid by it; Perhaps form in advance adhesive layer on protective membrane, by its transfer lamination to mode on polaroid etc.The thickness of adhesive layer is according to decisions such as its bounding forces, and the scope of 1-50 μ m left and right is comparatively suitable.
Also can as required, coordinate the weighting agent of being made by glass fibre or granulated glass sphere, resin bead, metal powder or other inorganic powder etc., pigment or tinting material, antioxidant, UV light absorber etc. in adhesive layer.UV light absorber has: salicylate based compound or benzophenone based compound, benzotriazole based compound, cyanoacrylate based compound, nickel complexing salt based compound etc.
The configurable one or both sides at liquid crystal cell of laminated optical component.The liquid crystal cell used is arbitrarily, such as for take that film transistor type is representative active matrix drive-type, simple matrix that the super-twist nematic of take is representative is driving etc., can use various liquid crystal cells to form liquid crystal indicators.The bonding common use of laminated optical component and liquid crystal cell and above-mentioned same tackiness agent.
Embodiment
Below provide embodiment, further illustrate the present invention, but the present invention is not subject to the restriction of these embodiment.In example, as be not particularly limited, mean that the % of content and usage quantity and part are weight basis.The light cation-curable composition and the light cationic polymerization initiators that in following example, use are as follows, with following symbol, mean respectively.
(A) light cation-curable composition
(a1) 3,4-epoxy-cyclohexane formic acid 3,4-epoxy group(ing) cyclohexyl methyl esters [in above formula (I), R
1=R
2=H, X=-COOCH
2-compound]
(a2) Isosorbide-5-Nitrae-butanediol diglycidyl ether [in above formula (II), Z=-(CH
2)
4-compound]
(a3) 2-ethylhexyl glycidyl ether [in above formula (III), R
3=CH
3(CH
2)
3-CH (CH
2cH
3)-CH
2-compound].
(B) light cationic polymerization initiators (in table referred to as " initiator ")
(b1) triaryl matte hexafluorophosphate.
[embodiment 1 and 2 and comparative example 1-9]
(1) preparation of light solidified tackiness agent
According to proportioning shown in table 1 (unit is part), each composition is mixed, then deaeration, prepare light solidified tackiness agent liquid.Should illustrate, light cationic polymerization initiators (b1) coordinates with the form of 50% polypropylene carbonate ester solution, and table 1 is with its solid matter quantity representation.
[table 1]
(2) viscosimetric analysis of tackiness agent liquid under 25 ℃
For each tackiness agent liquid of above-mentioned preparation, the rotary determination of viscoelasticity device " Physica MCR 301 " that uses Anton Paar society to manufacture, measure the viscosity at 25 ℃ of temperature.Result is as shown in table 2.
(3) mensuration of the storage modulus of cured article under 80 ℃
Use coating machine [metering bar coater, the first physics and chemistry (strain) is manufactured], in polyethylene terephthalate film [trade(brand)name " エ ス テ Le Off ィ Le system E7002E7002 spins in Japan ", Japan weaving (strain) is manufactured] a face on each tackiness agent liquid of preparation in coating above-mentioned (1), the thickness after making to solidify is about 30 μ m.Then, " D バ Le Block " irradiation ultraviolet radiation of manufacturing with フ ュ ー ジ ョ Application UV シ ス テ system ズ society, accumulated light is 3,000mJ/cm
2, tackiness agent is solidified.Its cutting is become to 5mm * 30mm size, peel off the polyethylene terephthalate film, obtain the cured film of tackiness agent.Use ア イ テ ィ ー instrumentation to control the Measurement of Dynamic Viscoelasticity device " DVA-220 " that (strain) manufactures, clamp this cured film with grip separation 2cm, making its long limit is draw direction, the frequency of draw and shrink is 1Hz, heat-up rate is set as to 3 ℃/minute, obtains the storage modulus at 80 ℃ of temperature.Result is as shown in table 2.
(4) manufacture of polaroid
Tri acetyl cellulose membrane [trade(brand)name " コ ニ カ タ ッ Network KC8UX2MV " to the thickness 80 μ m that contain UV light absorber, コ ニ カ ミ ノ Le タ オ プ ト (strain) manufactures] surface implement Corona discharge Treatment, with the excellent coating machine of coiling, each tackiness agent liquid of the above-mentioned preparation of coating on this Corona discharge Treatment face, the thickness after making to solidify is 2 μ m approximately.On this binder layer, polyvinyl alcohol-iodine of coating thickness 28 μ m is polarizer.Also to the phase retardation film [trade(brand)name " N-TAC KC4FR-1 " of the thickness 40 μ m that become by acetyl fibre prime system resin, コ ニ カ ミ ノ Le タ オ プ ト (strain) manufactures] surface implement Corona discharge Treatment, use metering bar coater, with above-mentioned similarly coating adhesive liquid on this Corona discharge Treatment face, the thickness after making to solidify is 2 μ m approximately.Polarizer one side that the tri acetyl cellulose membrane of above-mentioned preparation is fitted in to a polarizer on face is fitted on this binder layer, makes sandwich.Use is with the UV irradiation equipment (" D バ Le Block " that lamp is used Off ュ ー ジ ョ Application UV シ ス テ system ズ society to manufacture) of travelling belt, and by the acetyl fibre prime system phase retardation film one side irradiation ultraviolet radiation of this sandwich, accumulated light is 250mJ/cm
2, tackiness agent is solidified.Like this, made the polaroid of the protective membrane of having fitted on the polarizer two sides.
(5) 180 degree stripping tests
Size by the polaroid cutting growth 200mm of making in above-mentioned (4) * wide 25mm.The adhesive layer of acrylic acid series is set in acetyl fibre prime system phase retardation film one side, as for measuring the test film of the stripping strength between this acetyl fibre prime system phase retardation film and polarizer, therewith mutually independently, the adhesive layer of acrylic acid series is set, as the tri acetyl cellulose membrane for measuring thickness 80 μ m and the test film of the stripping strength between polarizer in tri acetyl cellulose membrane one side of thickness 80 μ m.The adhesive layer of each test film is pasted on sheet glass; insert the blade of cut-off knife between the protective membrane (tri acetyl cellulose membranes of acetyl fibre prime system phase retardation film or thickness 80 μ m) of polarizer and tackiness agent one side; by end strip off 30mm along its length, the clamp portion clamping by the part of this strip off with trier.By the test film of this state in the atmosphere of 23 ℃ of temperature and relative humidity 55%, according to JIS K6854-2:1999 " tackiness agent-2 ones of peel adhesion strength test method-: 180 degree are peeled off ", within 300mm/ minute, carry out 180 degree stripping tests with the fixture translational speed, obtain the average peeling force of the 170mm length outside the 30mm that removes clamp portion.Result is as shown in table 2.In 180 degree stripping strength items of table 2, " N-TAC/PVA " list shows that above-mentioned acetyl fibre prime system phase retardation film and polyvinyl alcohol-iodine are the stripping strength between polarizer, and " TAC/PVA " list shows that the tri acetyl cellulose membrane of above-mentioned thickness 80 μ m and polyvinyl alcohol-iodine are the stripping strength between polarizer.
(6) estimate the weather resistance of polaroid by cold shock testing
The polaroid cutting of making in above-mentioned (4) is become to the size of 170mm * 110mm, the adhesive layer of acrylic acid series is set in acetyl fibre prime system phase retardation film one side, this adhesive layer is pasted on sheet glass, carries out cold shock testing (thermal shock test).Cold shock testing is that the polaroid sample fitted on above-mentioned sheet glass is kept 1 hour under-35 ℃, then is warming up to 70 ℃, keeps 1 hour, using this operation as 1 cycle, it is added up to 300 cycles repeatedly.Respectively each 6 polaroid samples are carried out to this test, after test, to observe polarizer, have the number broken to be estimated with respect to the ratio of all sample numbers (6).Result is as shown in table 2.
[table 2]
From table 1 and table 2; in the comparative example 1-2 that is (a1) and two component system (a2) at light cation-curable composition (A); for the stripping strength between protective membrane and polarizer, all be no more than 0.6N/25mm between N-TAC/PVA and between TAC/PVA.In comparative example 3, the Young's modulus of tackiness agent cured article is low, and in cold shock testing, polarizer has and breaks.In the comparative example 4 and 5 that is (a1) and two component system (a3) at light cation-curable composition (A), the Young's modulus of tackiness agent cured article is low, and in cold shock testing, polarizer breaks.In the situation that light cation-curable composition (A) is (a1) and three component system (a2) and (a3), coordinated the Young's modulus that 20 parts of [being 20% in light cation-curable composition (A)] comparative examples 8 and 9 (a3) are also the tackiness agent cured articles low, therefore in cold shock testing, polarizer breaks.And in the comparative example 6 and 7 that use level (a1) is [being more than 80% in light cation-curable composition (A)] more than 80 parts, more than the stripping strength between protective membrane and PVA does not reach 0.6N/25mm.On the other hand, as embodiment 1 and 2, with the regulation ratio, coordinate (a1) and (a2) be low viscous with tackiness agent (a3), this cured article has high elastic coefficient, so polarizer is difficult to break, and can obtain the polaroid that adaptation is high.