CN109917507A - The manufacturing method of polarizability stacked film and the manufacturing method of polarizing film - Google Patents

Abstract

The present invention relates to the manufacturing methods of the manufacturing method of polarizability stacked film and the polarizing film for having used the polarizability stacked film obtained using this method, the manufacturing method of the polarizability stacked film has following process: being coated with the coating fluid containing polyvinyl alcohol resin on base material film and obtains the resin layer formation process of stacked film, stacked film is longitudinally uniaxially stretched and obtains the stretching process of stretched film, the polyvinyl alcohol resin layer of stretched film is dyed and is made with dichroism pigment the dyeing process of polarizer layer；Stretching process includes 2 stretch processing the process more than stage, and the ratio between stretching ratio in stretching ratio and the stretch processing process in the 2nd stage in the stretch processing process in the 1st stage is 0.5 or more, and total stretching ratio of polarizer layer is more than 5 times.

Description

The manufacturing method of polarizability stacked film and the manufacturing method of polarizing film

It is on October 22nd, 2013 that present patent application, which is for the applying date, application No. is 201380054755.3, hairs The divisional application that the application of bright entitled " manufacturing method of polarizability stacked film and the manufacturing method of polarizing film " proposes.

Technical field

The present invention relates to the manufacturing methods of the manufacturing method of polarizability stacked film and polarizing film.

Background technique

Feed element of the polarizing film as the polarised light in liquid crystal display device, and the detecting element as polarised light is wide General use.In the past, it as polarizing film, is mainly used in the light polarizing film being made of polyvinyl alcohol resin and is bonded via bonding agent Polarizing film made of the protective film be made of triacetyl cellulose etc., it is in recent years, electric to notebook along with liquid crystal display device Development in the mobile devices such as brain, mobile phone, and the development into large-scale tv machine etc., it is desirable that the thin-walled of polarizing film is light Type.

However, light polarizing film is by the film raw material (Off ィ Le system is former anti-) (in general, 75 μm of thickness or so) of polyvinyl alcohol resin It stretches and dyes and manufacture, the thickness of the film after stretching is usually 30 μm or so.Filming more than it exists when stretching Film such as is easily broken off at the productivities the problem of, therefore highly difficult.

Therefore, it is proposed to the manufacturing method of the stacked film (polarizing film) with polarizer layer: by being coated on base material film Coating fluid containing polyvinyl alcohol resin forms polyvinyl alcohol resin layer after obtaining stacked film, implements to the stacked film It stretches and to assign polarised light function to polyvinyl alcohol resin layer polarizer layer (such as patent document is made in dyeing processing 1~3).

Patent document 1: Japanese Unexamined Patent Publication 2009-93074 bulletin

Patent document 2: Japanese Unexamined Patent Publication 2011-150313 bulletin

Patent document 3: Japanese Unexamined Patent Publication 2012-159778 bulletin

Summary of the invention

According to being recorded in above patent document 1~3 and the coating of the coating fluid containing polyvinyl alcohol resin The method for forming polarizer layer can obtain thin compared with the case where light polarizing film is made by the film raw material of polyvinyl alcohol resin Polarizer layer, therefore be advantageous from the viewpoint of the thin-walled lightness of polarizing film.

However, the film deposited after the stretch generates when carrying out stretch processing to the stacked film with polyvinyl alcohol resin layer Fold generates in the film that film width direction generates after stretching uneven (non-uniform stretching) or stretching in film width direction The problem of uneven thickness.

Therefore, the purpose of the present invention is to provide it is a kind of manufacture polarizability stacked film or polarizing film method, be by After coating liquid containing polyvinyl alcohol resin forms polyvinyl alcohol resin layer on base material film and obtains stacked film, Polyvinyl alcohol resin layer is made polarizer layer using the stretching and dyeing processing of the stacked film, manufacture polarizability stacked film or The method of person's polarizing film, this method can stretch above-mentioned stacked film while the generation, stretching for inhibiting fold are uneven, Manufacture appearance, optical characteristics good thin polarizability stacked film or polarizing film well hereby it is possible to yield rate.

The present invention includes following the description.

[1] a kind of manufacturing method of polarizability stacked film, has:

Resin layer formation process makes after at least one face of base material film is coated with the coating fluid containing polyvinyl alcohol resin It is dried, to form polyvinyl alcohol resin layer, obtains stacked film,

Above-mentioned stacked film is carried out longitudinal direction and is uniaxially stretched, obtains stretched film by stretching process, and

Dyeing process is dyed with polyvinyl alcohol resin layer of the dichroism pigment to above-mentioned stretched film, and formation is polarized Device layer, to obtain polarizability stacked film；

Above-mentioned stretching process includes 2 stretch processing the process more than stage,

The stretching ratio of the stretch processing process in the 1st stage and the ratio between the stretching ratio of the stretch processing process in the 2nd stage It is 0.5 or more,

Using the polyvinyl alcohol resin layer of above-mentioned stacked film as benchmark, total stretching ratio of above-mentioned polarizer layer is more than 5 Times.

[2] manufacturing method for the polarizability stacked film recorded according to [1], wherein in above-mentioned resin layer formation process, The two sides of above-mentioned base material film forms above-mentioned polyvinyl alcohol resin layer.

[3] manufacturing method recorded according to [1] or [2], wherein the thickness of the polyvinyl alcohol resin layer of above-mentioned stacked film It is 3 μm~30 μm.

[4] manufacturing method recorded according to any one of [1]~[3], wherein the stretch processing process in above-mentioned 1st stage Stretching ratio less than 5 times.

[5] manufacturing method recorded according to any one of [1]~[4], wherein above-mentioned base material film is by polypropylene-based resin structure At.

[6] a kind of manufacturing method of polarizing film, has following process:

Prepare the process of the polarizability stacked film obtained by the manufacturing method that any one of [1]~[5] are recorded,

The process for being bonded protective film in the polarizer layer of above-mentioned polarizability stacked film and obtaining laminating film, and

From the process of the above-mentioned above-mentioned base material film of fitting film stripping.

According to the method for the present invention, the generation of fold, film width direction can be effectively inhibited when stretching stacked film Stretch uneven (therefore, the uneven thickness of film width direction), thus can yield rate to manufacture appearance, optical characteristics well good Polarizability stacked film or polarizing film.

Detailed description of the invention

Fig. 1 is the preferred implementation of the manufacturing method for indicating polarizability stacked film of the invention and the manufacturing method of polarizing film The flow chart of mode.

Fig. 2 is the schematic diagram for an example for indicating that the multistage in stretching process S20 stretches.

Fig. 3 is the schematic diagram for another example for indicating that the multistage in stretching process S20 stretches.

Fig. 4 is the schematic diagram for illustrating that the longitudinal direction of chuck has been used to be uniaxially stretched mode.

Specific embodiment

Hereinafter, showing the manufacturing method of embodiment and manufacturing method and polarizing film to polarizability stacked film of the invention It is described in detail.

The manufacturing method > of < polarizability stacked film

Fig. 1 is the preferred implementation of the manufacturing method for indicating polarizability stacked film of the invention and the manufacturing method of polarizing film The flow chart of mode.The manufacturing method of the polarizability stacked film of present embodiment successively includes following processes:

Resin layer formation process S10 is coated with the coating fluid containing polyvinyl alcohol resin at least one face of base material film After make it dry, to form polyvinyl alcohol resin layer, obtain stacked film,

Stretching process S20, stacked film is longitudinally uniaxially stretched and obtains stretched film,

Dyeing process S30 is dyed with polyvinyl alcohol resin layer of the dichroism pigment to stretched film, forms the polarizer Layer, to obtain polarizability stacked film.

As described later, polarizing film can obtain as follows in present embodiment, that is, until being implemented into dyeing process S30 and Protective film is bonded in the polarizer layer of obtained polarizability stacked film and obtains laminating film (bonding process S40), then from fitting Film stripping removes base material film (stripping process S50).

Hereinafter, being carried out to each process S10~S30 that the manufacturing method of the polarizability stacked film of present embodiment has detailed Explanation.

(1) resin layer formation process S10

This process is in the process that at least one face of base material film forms polyvinyl alcohol resin layer and obtains stacked film.It should Polyvinyl alcohol resin layer is the layer via stretching process S20 and dyeing process S30 and as polarizer layer.Polyethenol series tree Coating fluid containing polyvinyl alcohol resin can be by being coated on the single side of base material film or two sides and making coating layer by rouge layer It dries and is formed.Using such method, the thickness of polyvinyl alcohol resin layer and polarizer layer can be reduced, therefore to polarization The thin-walled lightness of property stacked film and polarizing film is advantageous.

(base material film)

Base material film can be made of thermoplastic resin, wherein preferably by the transparency, mechanical strength, thermal stability, draftability It is constituted etc. excellent thermoplastic resin.The concrete example of such thermoplastic resin, it may for example comprise chain polyolefin-based resins, ring The polyolefin-based resins of shape polyolefin-based resins (norbornene resin etc.) etc；Polyester based resin；(methyl) acrylic acid series Resin；The cellulose esters system resin of cellulose triacetate, cellulose diacetate etc；Polycarbonate-based resin；Polyethenol series Resin；Polyvinyl acetate system resin；Polyarylate system resin；Polystyrene resin；Polyether sulfone system resin；Polysulfones system Resin；Polyamide resin；Polyimides system resins；And their mixture, copolymer etc..

Base material film can be the single layer constituted with a resin layer being made of a kind or thermoplastic resin of more than two kinds Structure, be also possible to the resin layer that will be made of a kind or thermoplastic resin of more than two kinds it is multilayer laminated obtained by multilayer knot Structure.

As chain polyolefin-based resins, the homopolymer of the chain olefins such as polyvinyl resin, acrylic resin can be enumerated And the copolymer being made of chain olefin of more than two kinds.From the aspect of being readily and stably drawn into high magnification, preferably by chain The base material film that shape polyolefin-based resins are constituted.Wherein, base material film more preferably by polypropylene-based resin (homopolymer as propylene Acrylic resin, the copolymer based on propylene), polyethylene-based resin (as the homopolymer of ethylene polyvinyl resin, with Copolymer based on ethylene) etc. constitute.

Belong to and is suitable as constituting the copolymer based on propylene of one of example of thermoplastic resin of base material film and is The copolymer of propylene and the other monomers that can be copolymerized with it.

As the other monomers that can be copolymerized with propylene, for example, ethylene, alpha-olefin can be enumerated.As alpha-olefin, preferably The alpha-olefin that the alpha-olefin for the use of carbon atom number being 4 or more, more preferably carbon atom number are 4~10.Carbon atom number is 4~10 The concrete example of alpha-olefin, it may for example comprise 1- butylene, 1- amylene, 1- hexene, 1- heptene, 1- octene, the straight-chain of 1- decene etc Monoene hydro carbons；3-methyl-1-butene, 3- Methyl-1-pentene, the branched monoene hydro carbons of 4-methyl-1-pentene etc；Vinyl Hexamethylene etc..The copolymer of propylene and the other monomers that can be copolymerized with it can be random copolymer, be also possible to block copolymerization Object.

In the copolymer, the content of above-mentioned other monomers is, for example, the 0.1 weight % of weight %~20, preferably 0.5 weight Measure the weight of %~10 %.The content of other monomers in copolymer can be by the way that according to " macromolecule analysis handbook ", (nineteen ninety-five records The distribution of her Guo Wu bookstore) the record of page 616 method, carry out infrared ray (IR) spectroscopic assay to find out.

Among the above, as polypropylene-based resin, preferably using the homopolymer of propylene, Propylene-ethylene random copolymer, third Alkene -1- butene random copolymer or propylene-ethylene -1- butene random copolymer.

The stereospecificity of polypropylene-based resin is substantially preferably isotactic or rule.Substantially by with isotactic or Between the base material film that constitutes of the polypropylene-based resin of stereospecificity advised, operability is better, also, under hot environment Mechanical strength.

Base material film can be made of a kind of chain polyolefin-based resins, can also be by chain polyolefin-based resins of more than two kinds Mixture constitute, can also be made of the copolymer of chain polyolefin-based resins of more than two kinds.

Cyclic polyolefin hydrocarbon system resin is the general name for the resin for polymerizeing cyclic olefin as polymerized unit, for example, can lift Japanese Unexamined Patent Publication 1-240517 bulletin, Japanese Unexamined Patent Publication 3-14882 bulletin, Japanese Unexamined Patent Publication 3-122137 bulletin etc. out The resin of middle record.It is open loop (co) polymer, the ring-type alkene of cyclic olefin if enumerating the concrete example of cyclic polyolefin hydrocarbon system resin The copolymer of the chain olefin of addition polymer, cyclic olefin and the ethylene of hydrocarbon, propylene etc (is typically random copolymerization Object) and by they with unsaturated carboxylic acid, its it is derivative modified obtained by graft polymers and their hydride etc..Its In, preferably using the drop ice that the orbornene-baseds monomers such as norbornene, polycyclic orbornene-based monomer are used as to cyclic olefin Piece alkene system resin.

Cyclic polyolefin hydrocarbon system resin is commercially available various products.The example of the commercially available product of cyclic polyolefin hydrocarbon system resin, with quotient The name of an article indicate when, including " Topas " (TOPAS ADVANCED POLYMERS GmbH corporation, can be from Polyplastics Co., Ltd. obtains), " ARTON " (JSR Corp.'s system), " ZEONOR " (Japanese Zeon Co. Ltd. system), " ZEONEX " (day This Zeon Co. Ltd. system), " APEL " (Mitsui Chemicals, Inc's system).

In addition, " ESCENA " (Sekisui Chemical Co., Ltd's system) can be used when indicating with trade name, " SCA40 " (Sekisui Chemical Co., Ltd's system), " ZEONOR Film " (Japanese Zeon Co. Ltd. system) etc. are film-made The commercially available product of cyclic polyolefin resin film is as base material film.

Base material film can be made of a kind of cyclic polyolefin hydrocarbon system resin, can also be by cyclic polyolefin hydrocarbon system resin of more than two kinds Mixture constitute, can also be made of the copolymer of cyclic polyolefin hydrocarbon system resin of more than two kinds.

Polyester based resin is the resin with ester bond, usually by the condensation polymer of polybasic carboxylic acid or derivatives thereof and polyalcohol The resin of composition.As polybasic carboxylic acid or derivatives thereof, 2 yuan of dicarboxylic acids or its derivative can be used, such as can enumerate Terephthalic acid (TPA), M-phthalic acid, dimethyl terephthalate (DMT), naphthalene diformic acid dimethyl ester etc..As polyalcohol, it can be used 2 The glycol of member, such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol can be enumerated etc..

As the typical example of polyester based resin, can enumerate as the poly- to benzene two of the condensation polymer of terephthalic acid (TPA) and ethylene glycol Formic acid glycol ester.Polyethylene terephthalate is crystalline resin, but before crystallization processing in the state of poly- pair Ethylene terephthalate is easy to implement the processing such as stretching.If it is required, then when can use stretching or stretch after heat at Reason etc. carries out crystallization processing.In addition, it also may be preferable for using by further on the skeleton of polyethylene terephthalate It is copolymerized the monomer of other types and reduces copolyester obtained by crystallinity (alternatively, forming amorphism).As such resin Example, for example, copolymerization cyclohexanedimethanol, resin made of M-phthalic acid etc. can be enumerated.Also draftability is excellent for these resins It is different, it is possible to appropriate to use.

If enumerating the concrete example of the polyester based resin other than polyethylene terephthalate and its copolymer, for example, can Enumerate polybutylene terephthalate (PBT), polyethylene naphthalate, polybutylene naphthalate, poly terephthalic acid third Diol ester, polytrimethylene naphthalate, polycyclohexylene's dimethyl ester, poly- naphthalenedicarboxylic acid cyclohexane dicarboxylates etc..

Base material film can be made of a kind of polyester based resin, can also be by the mixture structure of polyester based resin of more than two kinds At can also be made of the copolymer of polyester based resin of more than two kinds.

(methyl) acrylic resin is the tree using the compound with (methyl) acryloyl group as main composition monomer Rouge.The concrete example of (methyl) acrylic resin, it may for example comprise poly- (methyl) acrylic acid of polymethyl methacrylate etc Ester；Methyl methacrylate-(methyl) acrylic copolymer；Methyl methacrylate-(methyl) acrylate copolymer；Methyl Methyl acrylate-acrylic acid ester-(methyl) acrylic copolymer；(methyl) acrylate-styrene copolymer (MS resin Deng)；The copolymer of methyl methacrylate and the compound with alicyclic alkyl is (for example, methyl methacrylate-methyl-prop Olefin(e) acid hexamethylene ester copolymer, methyl methacrylate-(methyl) acrylic acid norbornyl ester copolymer etc.).It is preferable to use with poly- (first Base) methyl acrylate etc poly- (methyl) acrylic acid C_1-6Arrcostab is the polymer of principal component, and more preferable use is with methyl-prop E pioic acid methyl ester is the methyl methacrylate of principal component (the 50 weight % of weight %~100, the preferably 70 weight % of weight %~100) Ester system resin.

Base material film can be made of a kind of (methyl) acrylic resin, can also be by (methyl) acrylic acid series of more than two kinds The mixture of resin is constituted, and can also be made of the copolymer of (methyl) acrylic resin of more than two kinds.

Cellulose esters system resin is the ester of cellulose and fatty acid.The concrete example of cellulose esters system resin includes triacetic acid fibre Tie up element, cellulose diacetate, three cellulose propionates, dipropyl acid cellulose etc..In addition, their copolymer, hydroxyl can also be enumerated A part resin etc. obtained by the modification of other substituent groups.Wherein, particularly preferred cellulose triacetate (triacetyl cellulose). Cellulose triacetate is commercially available bulk article, also advantageous in terms of obtaining easiness, cost.As the commercially available of cellulose triacetate The example of product when indicating with trade name, can enumerate " FUJITAC TD80 " (Fuji Film Co. Ltd. system), " FUJITAC TD80UF " (Fuji Film Co. Ltd. system), " FUJITAC TD80UZ " (Fuji Film Co. Ltd. system), " FUJITAC TD40UZ " (Fuji Film Co. Ltd. system), " KC8UX2M " (Konica Minolta Opto Co. Ltd. system), " KC4UY " (Konica Minolta Opto Co. Ltd. system) etc..

Base material film can be made of a kind of cellulose esters system resin, can also be by the mixed of cellulose esters system of more than two kinds resin It closes object to constitute, can also be made of the copolymer of cellulose esters system of more than two kinds resin.

Polycarbonate-based resin is the engineering plastics by constituting via polymer obtained by carbonate group binding monomer unit, It is the resin with high-impact, heat resistance, anti-flammability, the transparency.The polycarbonate-based resin for constituting base material film can be The resin for being referred to as modified polycarbonate of modified polymer skeleton, wavelength dependency is improved to reduce photoelastic coefficient Copolymerization polycarbonate etc..

Polycarbonate-based resin is commercially available various products.The example of commercially available product as polycarbonate-based resin, with quotient When the name of an article indicates, " PANLITE " (Teijin Chemicals, Ltd.'s system), " Iupilon " (Mitsubishi can be enumerated Engineering-Plastics Co. Ltd. system), " SD POLYCA " (Sumitomo Dow Co. Ltd. system), " CALIBRE " (Dow Chemical Co. Ltd. system) etc..

Base material film can be made of a kind of polycarbonate-based resin, can also be by the mixed of polycarbonate-based resin of more than two kinds It closes object to constitute, can also be made of the copolymer of polycarbonate-based resin of more than two kinds.

In base material film other than above-mentioned thermoplastic resin, any suitable additive can also be added.As in this way Additive, for example, ultraviolet absorbing agent, antioxidant, lubricant, plasticizer, release agent, coloring agent, resistance can be enumerated Fire agent, nucleating agent, antistatic agent, pigment and colorant etc..The content of thermoplastic resin in base material film is preferably 50 weights The weight % of %~100, the more preferably 50 weight % of weight %~99, the further preferably 60 weight % of weight %~98 are measured, it is special It You Xuanwei not 70 weight of weight %~97 %.When the content of thermoplastic resin in base material film is less than 50 weight %, it may not be possible to Fully demonstrate the high transparency etc. of thermoplastic resin inherently.

The thickness of base material film can suitably determine, generally from the aspect of the workability such as intensity, operability, preferably 1 μm ~500 μm, more preferable 1 μm~300 μm, further preferred 5 μm~200 μm, most preferably 5 μm~150 μm.

(coating fluid containing polyvinyl alcohol resin)

Obtained from above-mentioned coating fluid is preferably dissolved in the powder of polyvinyl alcohol resin in good solvent (such as water) Polyvinyl alcohol resin solution.As polyvinyl alcohol resin, for example, polyvinyl alcohol resin and its derivative can be enumerated.As The derivative of polyvinyl alcohol resin, can enumerate polyvinyl formal, polyvinyl acetal etc. and by polyvinyl alcohol resin Derivative made of being modified with the olefines of ethylene, propylene etc；With the insatiable hunger of acrylic acid, methacrylic acid, crotonic acid etc Derivative made of being modified with carboxylic acids；With the alkyl of unsaturated carboxylic acid it is ester modified made of derivative；With acrylic amide modified Made of derivative etc..Modified ratio is preferably smaller than 30 moles of %, more preferably less than 10 moles of %.It is performed for more than 30 moles of % Modification when, can generate and be not easy to adsorb dichroism pigment, the unfavorable condition that polarization property is lower.Above-mentioned polyvinyl alcohol resin In, it is preferable to use polyvinyl alcohol resin.

The average degree of polymerization of polyvinyl alcohol resin preferably 100~10000 range, more preferably 1000~10000 Range, further preferably 1500~8000 range, most preferably 2000~5000 range.Average degree of polymerization can benefit The method specified in JIS K 6726-1994 " polyvinyl alcohol test method " is found out.If average degree of polymerization less than 100, It is difficult to obtain satisfactory polarization property, if it exceeds 10000, then dissolubility in a solvent deteriorates, it is difficult to form poly- second Enol resin.

Polyvinyl alcohol resin is preferably the saponification product of polyvinyl acetate system resin.Ranging preferably from for saponification degree 80 rubs You are % or more, more preferably 90 moles of % or more, particularly preferably 94 moles of % or more.If saponification degree is too low, it is made Water resistance when polarizability stacked film, polarizing film, a possibility that humidity resistance is insufficient.In addition, though can be fully saponified Product (saponification degree is 100 moles of %), but if saponification degree is excessively high, dyeing kinetics are slack-off, it is adequately inclined sometimes for assigning Vibration performance and cause manufacturing time elongated, or according to circumstances, cannot have the polarizer layer of sufficient polarization property.Cause This, saponification degree is 99.5 moles of % hereinafter, more preferably 99.0 moles of % or less.

Saponification degree is will be as the acetate contained in the polyvinyl acetate system resin of the raw material of polyvinyl alcohol resin (acetoxyl group :-OCOCH₃) value that the ratio of hydroxyl is indicated with unit ratio (mole %) become by saponification process, with following formula Definition:

Saponification degree (mole %)=

((number of hydroxyl) ÷ (number+acetate number of hydroxyl)) × 100

Mean that saponification degree is higher, then the ratio of hydroxyl is more, therefore, it is intended that hindering the ratio of the acetate of crystallization It is few.Saponification degree can the method as specified in JIS K 6726-1994 " polyvinyl alcohol test method " find out.

As polyvinyl acetate system resin, other than as the polyvinyl acetate of the homopolymer of vinyl acetate, The copolymer etc. of vinyl acetate Yu copolymerizable other monomers can also be illustrated.As can be with other lists of vinyl acetate copolymerization Body, for example, unsaturated carboxylic acid class, olefines, vinyl ethers, unsaturated carboxylic acid class, the acrylamide with ammonium can be enumerated Class etc..

The example of the commercially available product of the polyvinyl alcohol resin preferably used, when being indicated with trade name, including strain formula meeting " PVA124 " (saponification degree: 98.0 moles of %~99.0 mole %) of society Kuraray, " PVA117 " (saponification degree: 98.0 rub Your %~99.0 mole %), " PVA117H " (saponification degree: 99.5 moles of % or more), " PVA624 " (saponification degree: 95.0 moles of % ~96.0 moles of %) and " PVA617 " (saponification degree: 94.5 moles of %~95.5 mole %)；Japanese synthetic chemical industry strain formula " AH-26 " (saponification degree: 97.0 moles of %~98.8 mole %) of commercial firm, " AH-22 " (saponification degree: 97.5 moles of %~ 98.5 moles of %), (saponification degree: 98.0 rub by " NH-18 " (saponification degree: 98.0 moles of %~99.0 mole %) and " N-300 " You are %~99.0 mole %)；" JC-33 " (saponification degree: 99.0 moles of % or more) of JAPAN VAM&POVAL Co. Ltd. system, " JM-33 " (saponification degree: 93.5 moles of %~95.5 mole %), " JM-26 " (saponification degree: rub 95.5 moles of %~97.5 Your %), " JP-45 " (saponification degree: 86.5 moles of %~89.5 mole %), " JF-17 " (saponification degree: 98.0 moles of %~99.0 Mole %), " JF-17L " (saponification degree: 98.0 moles of %~99.0 mole %) and " JF-20 " (saponification degree: 98.0 moles of % ~99.0 moles of %).

Coating fluid can contain the additives such as plasticizer, surfactant as needed.As plasticizer, can be used more First alcohol or its condensation product etc., such as glycerol, two glycerol, triglycerin, ethylene glycol, propylene glycol, polyethylene glycol can be illustrated etc..Addition The use level of agent is preferably the 20 weight % or less of polyvinyl alcohol resin.

(coating of coating fluid and the drying of coating layer)

The method that above-mentioned coating fluid is coated on base material film, can be from bar rubbing method；Reverse coating, intaglio plate coating etc Rolling method；Die coating method；Comma rubbing method；Die lip rubbing method；Spin-coating method；Silk screen rubbing method (Screen coating)；Fountain Formula rubbing method (Fountain Coating)；Infusion process；It is properly selected in method well known to spray-on process etc..

The drying temperature of coating layer (the polyvinyl alcohol resin layer before dry) and drying time are contained according in coating fluid The type of solvent set.Drying temperature is, for example, 50 DEG C~200 DEG C, preferably 60 DEG C~150 DEG C.Solvent contains water When, drying temperature is preferably 80 DEG C or more.Drying time is, for example, 2 minutes~20 minutes.

Polyvinyl alcohol resin layer can be formed only in a face of base material film, can also be formed on two sides.If two Face is formed, then is able to suppress the curling of producible film when the manufacture of polarizability stacked film, polarizing film, further, it is possible to partially from 1 Vibration property stacked film obtains 2 polarizing films, therefore also advantageous in terms of the production efficiency of polarizing film.

The thickness of polyvinyl alcohol resin layer in stacked film is preferably 3 μm~30 μm, more preferably 5 μm~20 μm.Such as Fruit is the polyvinyl alcohol resin layer with the thickness within the scope of this, then via aftermentioned stretching process S20 and dyeing process S30, can obtain dichroism pigment dyeability is good and polarization property is excellent and thickness is sufficiently small polarizer layer.Such as The thickness of pectin/polyvinyl alcohol resin is more than 30 μm, then the thickness of polarizer layer is more than 10 μm sometimes.In addition, such as fruit polyethylene The thickness of alcohol resin then has the tendency that becoming too thin after stretching and dyeability deteriorates less than 3 μm.

It, can be at least in order to improve the adaptation of base material film and polyvinyl alcohol resin layer before being coated with coating fluid Substrate film surface in the side for forming polyvinyl alcohol resin layer implements sided corona treatment, corona treatment, flame (flame) Processing etc..

It, can be in order to improve the adaptation of base material film and polyvinyl alcohol resin layer in addition, before being coated with coating fluid Polyvinyl alcohol resin layer is formed across priming coat, adhesive layer on base material film.

(priming coat)

After priming coat can be by being coated on substrate film surface with coating fluid for priming coat formation, makes it dry and formed. Priming coat formation coating fluid, which contains, plays a degree of strong closing force to base material film and this two side of polyvinyl alcohol resin layer Ingredient.Priming coat formation usually contains the resin component and solvent for assigning such closing force with coating fluid.As resin at Point, it is preferable to use the excellent hot castable resin such as the transparency, thermal stability, draftability, for example, (methyl) acrylic acid series can be enumerated Resin, polyvinyl alcohol resin etc..Wherein, it is preferable to use giving the polyvinyl alcohol resin of good closing force.

As polyvinyl alcohol resin, for example, polyvinyl alcohol resin and its derivative can be enumerated.As polyvinyl alcohol resin Derivative can also enumerate other than polyvinyl formal, polyvinyl acetal etc. by polyvinyl alcohol resin second Derivative made of the olefines of alkene, propylene etc is modified；With the unsaturated carboxylic of acrylic acid, methacrylic acid, crotonic acid etc Derivative made of acrylic modified；With the alkyl of unsaturated carboxylic acid it is ester modified made of derivative；It is formed with acrylic amide modified Derivative etc.., it is preferable to use polyvinyl alcohol resin in above-mentioned polyvinyl alcohol resin.

As solvent, in general, general organic solvent, the water solvent that can dissolve above-mentioned resin component can be used. If enumerating the example of solvent, for example, for the aromatic hydrocarbon of benzene,toluene,xylene etc；Acetone, methyl ethyl ketone, methyl are different The ketone of butyl ketone etc；The esters of ethyl acetate, isobutyl acetate etc；The halogen of methylene chloride, trichloro ethylene, chloroform etc For hydro carbons；The alcohols of ethyl alcohol, 1- propyl alcohol, 2- propyl alcohol, n-butyl alcohol etc.But if use the priming coat containing organic solvent Formation forms priming coat with coating fluid, then also dissolves base material film sometimes, thus preferably also consider base material film dissolubility and Select solvent.If also considering the influence to environment, priming coat is preferably formed by the coating fluid taken water as a solvent.

It, can be in priming coat formation with adding crosslinking agent in coating fluid in order to improve the intensity of priming coat.About crosslinking agent, According to the type of the thermoplastic resin used, suitable friendship is properly selected from crosslinking agent well known to organic system, inorganic system etc. Join agent.If enumerating the example of crosslinking agent, for example, for epoxy, isocyanates system, dialdehyde system, metal system crosslinking agent.

As epoxy crosslinking agent, single solution curing type, biliquid curing type be can be used, and can enumerate ethylene glycol diglycidyl Ether, polyethyleneglycol diglycidylether, glycerol two-or three-glycidol ethers, 1,6 hexanediol diglycidylether, three hydroxyls Methylpropane triglycidyl ether, diglycidylaniline, diglycidyl amine etc..

As isocyanates system crosslinking agent, toluene di-isocyanate(TDI), hydrogenated toluene diisocyanate, trihydroxy methyl can be enumerated Propane-tolylene diisocyanate adduct, triphenylmethane triisocyanate, di-2-ethylhexylphosphine oxide (4- phenylmethane) three isocyanic acids Ester, isophorone diisocyanate and their ketoxime block object or phenol block object etc..

As dialdehyde system crosslinking agent, glyoxal, malonaldehyde, butanedial, glutaraldehyde, maleic dialdehyde (Maleic can be enumerated Dialdehyde), phthaladehyde (Phthaldialdehyde) etc..

As metal system crosslinking agent, for example, metal salt, metal oxide, metal hydroxides, organometallic can be enumerated Close object.As metal salt, metal oxide, metal hydroxides, for example, can enumerate magnesium, calcium, aluminium, iron, nickel, zirconium, titanium, silicon, Salt, oxide and the hydroxide of the metal with valence more than divalent of boron, zinc, copper, vanadium, chromium, tin etc.

Organo-metallic compound refer in the molecule have at least one on metallic atom Direct Bonding organic group or Via the compound of the structure of the bonding organic group such as oxygen atom, nitrogen-atoms.Organic group refer at least containing carbon one The group of valence or multivalence, for example, can be alkyl, alkoxy, acyl group etc..In addition, bonding is not only to refer to covalent bonding, it can also To be the coordination bonding formed by the coordination of chelate shape compound etc..

The preference of organo-metallic compound includes organic titanic compound, organic zirconate, organo-aluminum compound, organic Silicon compound.Organo-metallic compound can only be used alone a kind, and also two or more kinds may be used.

As organic titanic compound, for example, tetra-n-butyl titanate can be enumerated, tetraisopropyl titanate, butyl titanate dimer, The ortho-titanic acid esters of metatitanic acid four (2- ethylhexyl) ester, tetramethoxy titanate ester etc；Titanium acetylacetone, four titanium acetylacetones, poly- second Acyl acetone titanium, octamethylene glycolic titanium, lactic acid titanium, triethanolamine close the titanium chelate class of titanium, oacetic acid titanium etc；It is more Acrylic acid titanium class of hydroxy stearic acid titanium etc etc..

As organic zirconate, for example, n Propanoic acid zirconium, n-butyric acie zirconium, four acetylacetone,2,4-pentanedione zirconiums, single acetyl acetone can be enumerated Double oacetic acid zirconiums of zirconium, bis-acetylacetonate zirconium, acetylacetone,2,4-pentanedione etc..

As organo-aluminum compound, for example, aluminium acetylacetonate, aluminium organic acid chelate etc. can be enumerated.As siliconated Object is closed, for example, chemical combination made of the ligand bonded silica illustrated in organic titanic compound and organic zirconate before can enumerating Object.

Other than above low molecule system crosslinking agent, methylolated melamine resin, polyamide ring can also be used The macromolecular crosslinking agent of oxygen resin etc.If enumerating the example of the commercially available product of Polyamide Epoxy, for by field ridge chemistry " Sumirez resin 650 (30) ", " Sumirez resin 675 " (being trade name) etc. of Industrial Co., Ltd's sale.

, it is preferable to use Polyamide Epoxy, hydroxyl when polyvinyl alcohol resin is used as the resin component for forming priming coat Methylated melamine resins, dialdehyde system crosslinking agent, meal chelate compounds system crosslinking agent etc. are used as crosslinking agent.

Relative to 100 parts by weight of resin component, priming coat forms the ratio with resin component and crosslinking agent in coating fluid It is the range of 0.1 parts by weight~100 parts by weight or so from crosslinking agent, it is suitable according to the type of resin component, type of crosslinking agent etc. Locality determines, particularly preferably selects from the range of 0.1 parts by weight~50 parts by weight or so.In addition, priming coat is formed with painting Cloth liquid preferably its solid component concentration is 1 weight of weight %~25 % or so.

Preferably 0.05 μm~1 μm or so of the thickness of priming coat, more preferably 0.1 μm~0.4 μm.If thinner than 0.05 μm, The effect for then improving base material film and the closing force of polyvinyl alcohol resin layer is small, if than 1 μ m-thick, to polarizability stacked film, The filming of polarizing film is unfavorable.

It can be with polyvinyl alcohol resin layer formation with the method that coating fluid is coated on base material film by priming coat formation Coating fluid is identical.Priming coat is coated on the face (single side of base material film for being coated with polyvinyl alcohol resin layer formation coating fluid Or two sides).The drying temperature for the coating layer being made of priming coat formation with coating fluid and drying time contain according in coating fluid The type of some solvents is set.Drying temperature is, for example, 50 DEG C~200 DEG C, preferably 60 DEG C~150 DEG C.Solvent contains water When, drying temperature is preferably 80 DEG C or more.Drying time is, for example, 30 seconds~20 minutes.

(2) stretching process S20

This process is longitudinally to be uniaxially stretched the stacked film being made of base material film and polyvinyl alcohol resin layer and drawn Stretch the process of film.In the present invention, carried out stretching process S20 points are 2 stretch processing the process more than stage.That is, stretching work Sequence S20 is stretched by the multistage and is constituted, the stretch processing process including 2 more than the stage.Here, " including at 2 the stretching more than stage Science and engineering sequence " refers to the stretching at least with the 1st stage (initial) for being longitudinally uniaxially stretched stacked film with certain stretching ratio Treatment process；Section (period) with by not stretching and (not extending in film carry direction) stacked film, will carry out for the 1st stage Stretch processing the stretch processing process in the 2nd stage that is longitudinally uniaxially stretched with certain stretching ratio again of stacked film.It draws Stretching process S20 may include 3 stretch processing the process more than stage, in this case, not stretch the section (time of stacked film Section) also between the stretch processing process in each stage.

Longitudinal direction in each stage stretch processing process, which is uniaxially stretched, can for example stretch between roller, roll, hot-rolling stretches, makes With the stretching etc. of chuck.The stretching mode in each stage can be all identical, can also combine different stretch mode.But example It such as, sometimes can not be to by being polarized obtained from dyeing process S30 when low necking down rate in the case where stretching ratio height Device layer assigns sufficient polarization property, therefore in order to ensure sufficient necking down rate, the stretch processing process at least one stage is preferred To utilize the process for stretching progress between the roller stretched as free end.

Above-mentioned necking down rate, is defined with following formula:

Necking down rate (%)=((W1-W2) ÷ W1) × 100

W1 is supplied with the width of the stacked film before stretching process S20.W2 is stacked film have been carried out at whole stretchings The minimum widith of film after reason.For example, W2 is to draw in the case where only implementing stretch processing to stacked film in stretching process S20 Stretch the minimum widith of finally obtained stretched film in process S20.In addition, as described later, can also implement in dyeing process S30 Additional stretch processing, but at this moment, W2 are the minimum widiths for carrying out the polarizability stacked film after the stretch processing of the addition.Contracting Neck rate is preferably 50% or so or more.

It is illustrated referring to several examples that attached drawing stretches the multistage in stretching process S20.In each figure, arrow is indicated The carry direction of film.

Fig. 2 is to indicate that stretching process S20 includes the stretch processing process in 2 stages and these stretch processing processes are between roller Stretching mode, that is, the figure of the example the case where mode stretched between the different niproll of peripheral speed (nip roll). It illustrates, the stacked film 10 being handled upside down is heated and in the heating furnace 20 for being set to desired temperature first, together When be stretched (the stretch processing process in the 1st stage) between the mutually different niproll 1- niproll 2 of peripheral speed.Carry out The film of the stretch processing in 1 stage is further carried by deflector roll 5, and in the heating furnace 30 for being set to desired temperature by Heating, while it being stretched (the stretch processing process in the 2nd stage) between the mutually different niproll 3- niproll 4 of peripheral speed, As stretched film 15.Substantially in the peripheral speed and niproll 3 for from niproll 2 to the section niproll 3, making niproll 2 Peripheral speed it is identical, therefore film is not stretched.

Fig. 3 be indicate include stretching process S20 be 3 stages stretch processing process, these stretch processing processes are heat Roller stretching mode, i.e., the figure of the example of the mode situation stretched between the roller being heated.It illustrates, the stacking being handled upside down The surface first of film 10 is adjusted to desired temperature, during between the hot-rolling 6- hot-rolling 7 mutually different by peripheral speed Be stretched (the stretch processing process in the 1st stage).Then, via the section for not generating stretching, i.e., the section contacted with hot-rolling 7, Surface is adjusted to desired temperature, be stretched during between the hot-rolling 7- hot-rolling 8 mutually different by peripheral speed (the The stretch processing process in 2 stages).The film for having carried out the stretch processing in the 2nd stage, via the section for not generating stretching, i.e., with heat The section that roller 8 contacts, surface are adjusted to desired temperature, between the hot-rolling 8- hot-rolling 9 mutually different by peripheral speed During be stretched (the stretch processing process in the 3rd stage), become stretched film 15.

Fig. 4 be for the schematic diagram that illustrates that the longitudinal direction of chuck (pressing plate) has been used to be uniaxially stretched mode, be seen from above by The figure when stacked film of stretching.As shown in the drawing, it has used the longitudinal direction of chuck to be uniaxially stretched mode and has referred to width in stacked film 10 It spends direction both ends and (usually certain intervals) multiple chucks 40 is installed, on one side to the stacked film for being heated to desired temperature 10 carry distance R and the mode that is stretched between film carry direction slowly widens chuck on one side.Although not shown, but in order to It carries out multistage stretching in the way of having used the longitudinal direction of chuck to be uniaxially stretched, widen distance R between chuck and carries out stretch processing After (the stretch processing process in the 1st stage), by the section for carrying stacked film 10 in the state that fixed chuck spacing is from R, It is widened between chuck again and distance R and carries out stretch processing (the stretch processing process in the 2nd stage).Drawing after 3rd stage It is also same for stretching treatment process.

The control method of distance R is not particularly limited between chuck when stretching, and various methods can be used.For example, each Chuck can independently drive, and can control chuck spacing from R with independent control each chuck；Chuck is connected to each other, and can be passed with 1 Dynamic system controls multiple chucks to control chuck spacing from R.Either method can be applicable in the present invention.

As the independent specific method for driving each chuck, it can enumerate and use magnetic representated by linear motor driven mode The method of power, the method for setting up rotation drive motor etc. in each chuck etc..It should be noted that not being the whole card of independent driving Disk, but independent driving only is carried out to the chuck of a part, for remaining chuck without particularly controlling.

As the specific method for controlling multiple chucks with 1 transmission system, representative is pantogragh mode etc..Scaling side Formula is by way of controlling the distance between 2 guide rails and switching pantogragh and control chuck spacing from R.

Referring to Fig. 2~4, the winding that the above-mentioned multistage of illustration stretches the film for being not accompanied by each stretch processing process is opened Volume.Such embodiment is preferred from the aspect of productivity.But, it is not limited to above-mentioned example, it can be whenever 1 Wound film at the end of the stretch processing process in stage implements uncoiling again when next stretch processing process.

In the present invention, in the stretching ratio and the stretch processing process in the 2nd stage in the stretch processing process in the 1st stage The ratio between stretching ratio is (hereinafter also referred to as " stretching ratio ratio ".) it is 0.5 or more." the stretching of the stretch processing process in the 1st stage Multiplying power " is the longitudinal direction (side being stretched for the polyvinyl alcohol resin layer having for the stacked film before stretching process S20 To) length be 1 when, the length of the longitudinal direction of polyvinyl alcohol resin layer at the end of the stretch processing process in the 1st stage Degree.For example, the longitudinal direction for the polyvinyl alcohol resin layer having for the stacked film before stretching process S20 length (or The some portion of length of polyvinyl alcohol resin layer) it is 1, pass through the stretch processing process polyvinyl alcohol resin in the 1st stage When the length (or above-mentioned some portion of length) of layer is 2, the stretching ratio in the stretch processing process in the 1st stage is 2 times.

" stretching ratio in the stretch processing process in the 2nd stage " is poly- at the end of the stretch processing process in the 1st stage The polyethenol series when length of the longitudinal direction of vinyl alcohol resin layer is 1, at the end of the stretch processing process in the 2nd stage The length of the longitudinal direction of resin layer.

Stretching process S20 points are carried out for 2 stretch processing the process more than stage, by meet above-mentioned stretching ratio The mode of ratio implements the stretch processing process in the 1st stage and the 2nd stage, thus stretching stacked film until desired total stretching During multiplying power, stacked film, therefore, energy can be stretched while the necking down caused by stretching is maintained degree appropriate Enough generations for effectively inhibiting fold when stretching, and can effectively inhibit uneven (non-uniform in the stretching of film width direction It stretches).

The generation of fold not only can lead to the dyeing in dyeing process S30 uneven and bad order, polarization property, thoroughly The unevenness of the optical characteristics of rate etc is penetrated, and becomes the reason of yield rate reduces.Stretch the uneven thickness with film width direction Uneven form performance, similarly will lead to the unevenness of the optical characteristics of polarization property, transmissivity etc.

According to the method for the present invention, the thickness difference of film width direction can be formed in less than 5 μm, and then the drawing less than 4 μm Film is stretched, therefore the uniform polarizability stacked film of polarization property, transmissivity and polarizing film can be made." in the thickness of film width direction It is poor to spend " refer to in 1 point of film thickness determination for playing the position of 50mm from one end of film width direction and in the film width side To film thickness determination 1 of center when their film thickness absolute value of the difference.

In order to more effectively obtain above-mentioned effect, above-mentioned stretching ratio ratio is preferably 0.6 or more, more preferable 0.7 or more, Particularly preferably 1.0 or more.If stretching ratio ratio less than 0.5, can generate the stretching unevenness in film width direction.In addition, If stretching ratio ratio is too big, be easy to produce fold, thus stretching ratio than preferably 5 hereinafter, more preferably 4 hereinafter, special It You Xuanwei 3 or less.

Stretching ratio in the stretch processing process in the 1st stage is preferably smaller than 5 times, more preferably 4 times or less.If the drawing Stretching multiplying power is 5 times or more, then is easy to produce fold.That is, in order to good to being assigned by polarizer layer obtained from dyeing process S30 Good polarization property preferably makes 5 times of total stretching ratio or more of the stretch processing carried out to stacked film, but such as described later Fruit carries out such powerful stretch processing with 1 stage, then generates fold.Also such situation is considered in the present invention, divides 2 More than the stage carry out stretch processing.

Above-mentioned " total stretching ratio " refers to the stretch processing process by each stage (as described later, in dyeing process S30 Additional stretch processing can be implemented, at this moment, also include the addition stretch processing process) in stretching ratio adduction obtained by In other words final stretching ratio is the long side for the polyvinyl alcohol resin layer having for the stacked film before stretching process S20 Polyvinyl alcohol resin layer at the end of stretch processing when the length in direction (direction being stretched) is 1, whole, that is, be polarized The length of the longitudinal direction of device layer.

As described above, total stretching ratio of the polarizer layer when polyvinyl alcohol resin layer that stacked film has is benchmark Preferably greater than 5 times.If stretching ratio be 5 times hereinafter, if the insufficient orientation of polyvinyl alcohol resin layer, therefore have polarizer layer The insufficient trend got higher of degree of polarization.In addition, total stretching ratio is preferably 8 times or less.If total stretching ratio is more than 8 times, The fracture of film is easy to produce when then stretching, also, the thickness of stretched film is beyond thinning, the processability and operation of rear process as needed Property may be decreased.

Draft temperature in each stage of stretching process S20 be set to polyvinyl alcohol resin layer and base material film it is whole with Stretchable degree shows the temperature of mobility or more, preferably -30 DEG C of the fusing point of base material film~+30 DEG C of fusing point range, More preferably -30 DEG C of the fusing point~+5 DEG C of fusing point range, further preferably -25 DEG C of the fusing point~+0 DEG C of fusing point model It encloses.When base material film is made of multiple resin layers, above-mentioned fusing point refers to highest fusing point in fusing point that multiple resin layer is shown.

If draft temperature is made to be lower than -30 DEG C of fusing point of base material film, have that the mobility of base material film is too low and stretch processing The trend become difficult.If draft temperature is more than+30 DEG C of fusing point, the mobility of base material film is excessive, equally there is stretch processing The trend become difficult.In view of the easiness of stretch processing, draft temperature within the above range, further preferably 120 DEG C with On.

As the heating means of the stacked film in the stretch processing in each stage, have area's heating (for example, be blown into hot wind and The method heated in the drawing zone of the heating furnace of temperature as defined in being adjusted to etc.Referring to Fig. 2)；It is stretched using roller When, method (referring to Fig. 3) that roller itself is heated；Heater heating is (by infrared heater, halogen heater, face The method of stacked film heated up and down and using radiant heat is arranged in board heating apparatus etc.) etc..From the sight of the uniformity of draft temperature Point sets out, preferred area heating in stretching mode between roller.At this moment, 2 niprolls are to can be set in temperature controlled drawing zone It is interior, also it can be set outside drawing zone, but the adhesion of stacked film and niproll in order to prevent, it is preferably provided at outside drawing zone (referring to Fig. 2).

It should be noted that draft temperature in the case where area's heating, refers in area the atmosphere temperature of (such as in heating furnace), When also being heated in furnace in heater heating, refer to the atmosphere temperature in furnace.In addition, being heated to roller itself In the case where method, refer to the surface temperature of roller.

Before stretching process S20, the pre-heat treatment process preheated to stacked film can be set.As preheating side Method identical with the heating means in stretch processing can be used in method.When stretch processing mode stretches between roller, preheating can be with Before through the niproll of upstream side, pass through in, carried out by any opportunity in rear.Stretch processing mode is hot-rolling stretching When, opportunity of the preheating preferably before through hot-rolling carries out.When stretch processing mode is the stretching for having used chuck, preheating preferably exists Opportunity between broadening chuck before distance carries out.Preheating temperature is preferably -50 DEG C of draft temperature~draft temperature ± 0 DEG C range, More preferably -40 DEG C of draft temperature~-10 DEG C of draft temperature range.

In addition, heat fixation treatment process can be set after the stretch processing of the final step in stretching process S20.Thermosetting Fixed processing is to maintain tense situation in the state that one side holds the end of stretched film using pressing plate, on one side crystallized temperature with On the processing that is heat-treated.It is handled by the heat fixation, promotes the crystallization of polyvinyl alcohol resin layer.Heat fixation processing Temperature is preferably -0 DEG C of draft temperature~-80 DEG C of draft temperature range, more preferably -0 DEG C of draft temperature~draft temperature -50 DEG C range.

(3) dyeing process S30

This process be the polyvinyl alcohol resin layer of stretched film is dyed with dichroism pigment and make its gas absorption quantity, The process that polarizer layer is made.By this process, it can be obtained and be laminated with the inclined of polarizer layer in the single side of base material film or two sides Vibration property stacked film.

As dichroism pigment, specifically, iodine or dichroic organic dye can be enumerated.The tool of dichroic organic dye Body example, it may for example comprise red BR, red LR, red R, pink LB, magenta (Rubin) BL, purplish red (Bordeaux) GS, sky blue (Sky Blue) LG, lemon yellow, indigo plant BR, indigo plant 2R, navy blue RY, green LG, purple LB, purple B, black H, black B, black GSP, Huang 3G, Huang R, orange LR, Orange 3R, scarlet GL, scarlet KGL, Congo red, brilliant violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, Direct sky blue (Direct Sky Blue), direct everbright fast orange (Direct Fast Orange) S, resistance to tanned (Fast Black) Deng.Dichroism pigment can only be used alone a kind, and also two or more kinds may be used.

Dyeing process can be by carrying out stretched film mass-impregnation in the solution (staining solution) containing dichroism pigment. As staining solution, can be used solution obtained by the dissolution in a solvent of above-mentioned dichroism pigment.As the molten of staining solution Agent generally uses water, but can further add organic solvent having a miscibility with water.Dichroism color in staining solution The concentration of element is preferably the 0.01 weight % of weight %~10, the more preferably 0.02 weight % of weight %~7, further preferably 0.025 weight of weight %~5 %.

When using iodine as dichroism pigment, dyeing efficiency can be further increased, therefore preferably in the dyeing containing iodine Solution further adds iodide.As iodide, for example, can enumerate potassium iodide, lithium iodide, sodium iodide, zinc iodide, silver iodide, Lead iodide, cupric iodide, barium iodide, calcium iodide, stannic iodide, titanium iodide etc..The concentration of iodide in staining solution is preferably 0.01 weight of weight %~20 %.In iodide, potassium iodide is preferably added.When adding potassium iodide, the ratio of iodine and potassium iodide with Weight ratio meter, preferably in the range of 1:5~1:100, more preferably in the range of 1:6~1:80, further preferably in 1:7~1:70 Range.

Dip time of the stretched film in staining solution is usually 15 seconds~15 minutes ranges, and preferably 30 seconds~3 points Clock.In addition, the temperature of staining solution is preferably in 10 DEG C~60 DEG C of range, more preferably in 20 DEG C~40 DEG C of range.

It should be noted that further stretch processing can be implemented to stretched film in dyeing process S30.As reality in this case Mode is applied, can be enumerated in 1) above-mentioned stretching process S20, after carrying out stretch processing with the multiplying power lower than target, dyeing process S30 Dyeing processing in, in such a way that total stretching ratio carries out stretch processing in the way of target multiplying power；As described later, at dyeing When carrying out crosslinking Treatment after reason, 2) it in above-mentioned stretching process S20, after carrying out stretch processing with the multiplying power lower than target, is dyeing In the dyeing processing of process S30, stretch processing is carried out, until the degree of total stretching ratio miss the mark multiplying power, then, with The mode that final total stretching ratio becomes target multiplying power carries out the mode etc. of stretch processing in crosslinking Treatment.

Dyeing process S30 may be embodied in the crosslinking Treatment process implemented after dyeing processing.Crosslinking Treatment can by The film being colored is impregnated in solution (crosslinker solution) containing crosslinking agent and is carried out.As crosslinking agent, can be used previous known Substance, for example, the boron compound of boric acid, borax etc, glyoxal, glutaraldehyde etc. can be enumerated.Crosslinking agent only can individually make With a kind, also two or more kinds may be used.

The solution by crosslinking agent dissolution in a solvent specifically can be used in crosslinker solution.As solvent, such as can be with Using water, organic solvent having a miscibility with water can also be contained.The concentration of crosslinking agent in crosslinker solution is preferably 1 weight Measure the range of the weight of %~20 %, the more preferably range of 6 weight of weight %~15 %.

Crosslinker solution can contain iodide.By adding iodide, the polarization property in the face of polarizer layer can be made More evenly change.As iodide, such as potassium iodide, lithium iodide, sodium iodide, zinc iodide, silver iodide, lead iodide, iodate can be enumerated Copper, barium iodide, calcium iodide, stannic iodide, titanium iodide etc..The concentration of iodide in crosslinker solution is preferably 0.05 weight %~15 Weight %, more preferably 0.5 weight of weight %~8 %.

Dip time of the film being colored in crosslinker solution is usually 15 seconds~20 minutes, preferably 30 seconds~15 points Clock.In addition, the temperature of crosslinker solution is preferably in 10 DEG C~90 DEG C of range.

It should be noted that crosslinking Treatment can be carried out and the cooperation crosslinking agent in staining solution with dyeing processing simultaneously. Furthermore it is possible to carry out stretch processing in crosslinking Treatment.The specific mode for implementing stretch processing in crosslinking Treatment is as described above.

It is preferred that after dyeing process S30, carrying out cleaning process and drying process before aftermentioned bonding process S40.Scavenger Sequence generally includes water cleaning process.Water cleaning treatment can be contaminated by impregnating in the pure water of ion exchange water, distilled water etc Film of the color after treated or crosslinking Treatment carries out.Water cleaning temperature is usually 3 DEG C~50 DEG C, preferably 4 DEG C~20 DEG C Range.Dip time in water is usually 2 seconds~300 seconds, preferably 3 seconds~240 seconds.

Cleaning process can be the combination of water cleaning process and the cleaning process carried out using iodide solution.In addition, water It, in addition to water, can also be appropriate in cleaning process and/or the cleaning solution as used in the cleaning treatment of iodide solution progress Liquid alcohol containing methanol, ethyl alcohol, isopropanol, butanol, propyl alcohol etc.

As the drying process carried out after cleaning process, it is arbitrary that natural drying, air-supply drying, heat drying etc. can be used Proper method.Such as when heat drying, drying temperature is usually 20~95 DEG C, and drying time is usually 1~15 minute or so.Such as On obtained polarizability stacked film can be used directly as polarizer, also, as being made by polarizer layer and guarantor The intermediary for the polarizing film that cuticula is constituted is also useful.

The polarizer layer that polarizability stacked film has with a thickness of 10 μm hereinafter, preferably 7 μm or less.By making the polarizer Layer with a thickness of 10 μm hereinafter, slim polarizability stacked film can be constituted.

The manufacturing method > of < polarizing film

The manufacturing method of polarizing film of the invention successively includes preparing the process of above-mentioned polarizability stacked film；In polarizability layer It is bonded protective film in the polarizer layer of folded film and obtains the bonding process S40 of laminating film；Base material film is removed from fitting film stripping Stripping process S50.

(4) bonding process S40

This process is in the polarizer layer of polarizability stacked film, that is, the side opposite with base material film side of polarizer layer Face paste close protective film and the process that obtains laminating film.Bonding agent can be used in protective film, adhesive fits in polarizer layer.Partially Vibration property stacked film is when the two sides of base material film has polarizer layer, in general, being bonded protective film respectively in the polarizer layer on two sides. At this moment, these protective films can be the protective film of identical type, be also possible to different types of protective film.

(protective film)

Protective film for example can be by chain polyolefin-based resins (polypropylene-based resin etc.), cyclic polyolefin hydrocarbon system resin The polyolefin-based resins of (norbornene resin etc.) etc；The cellulose esters of cellulose triacetate, cellulose diacetate etc It is resin；The Polyester of polyethylene terephthalate, poly- naphthoic acid glycol ester, polybutylene terephthalate (PBT) etc Resin；Polycarbonate-based resin；(methyl) acrylic resin；Or the film of the compositions such as their mixture, copolymer.It is cyclic annular The example of the workable commercially available product of polyolefin-based resins and its film and cellulose triacetate etc. is as described above.

Protective film is also possible to have both the protective film of the optical function of phase difference film, brightness raising film etc..For example, by pair The resin film being made of above-mentioned material is stretched (be uniaxially stretched or biaxial stretch-formed etc.) or forms liquid crystal layer on the film Deng the phase difference film for assigning arbitrary phase difference value can be made.

On the surface of the side opposite with polarizer layer of protective film, hard conating, antiglare layer, antireflection layer can be formed Etc. optical layers.It is not particularly limited in the method that protection film surface forms these optical layers, well known method can be used.Optics Layer can be previously formed on protective film before implementing bonding process S40, can also be after implementing bonding process S40 or real It is formed after applying aftermentioned stripping process S50.

When being bonded protective film in polarizer layer, in order to improve the cementability with polarizer layer, protective film can be risen Inclined device layer side surface carries out corona treatment, sided corona treatment, ultraviolet treatment with irradiation, flame (flame) processing, saponification process Deng surface treatment (easy bonding processing), wherein preferably progress corona treatment, sided corona treatment or saponification process.Such as it protects When cuticula is made of cyclic polyolefin hydrocarbon system resin, corona treatment, sided corona treatment are usually carried out.In addition, by cellulose esters system When resin is constituted, saponification process is usually carried out.As saponification process, the alkalinity in sodium hydroxide, potassium hydroxide etc can be enumerated The method impregnated in aqueous solution.

The thickness of protective film is preferably thin, but if excessively thin, strength reduction, poor in processability.On the other hand, if mistake Thickness, then generating the transparency reduces or the problems such as necessary curing time is elongated after fitting.Therefore, the thickness of protective film is preferred For 90 μm hereinafter, more preferably 5 μm~60 μm, further preferably 5 μm~50 μm.In addition, the sight of the filming from polarizing film Point set out, the aggregate thickness of polarizer layer and protective film be preferably 100 μm hereinafter, more preferably 90 μm hereinafter, further preferably It is 80 μm or less.

(bonding agent)

As bonding agent, water system bonding agent or Photocurable adhesive agent can be used.As water system bonding agent, can enumerate Bonding agent, water system two liquid type polyurethane system emulsion adhesive for being made of polyvinyl alcohol resin aqueous solution etc..In particular, to When saponification process etc. is surface-treated the cellulose esters resin film of (hydrophilicity-imparting treatment) as protective film, it is preferable to use by The water system bonding agent that polyvinyl alcohol resin aqueous solution is constituted.

As polyvinyl alcohol resin, in addition to the polyvinyl acetate of the homopolymer of vinyl acetate will be used as to be saponified Other than alcotex obtained from processing, the copolymerization of vinyl acetate and the other monomers that can be copolymerized with it can also be used Object is modified poly- obtained by carrying out polyvinyl alcohol based copolymer obtained from saponification process or being modified their hydroxylic moiety Vinyl alcohol system polymer etc..Water system bonding agent can containing polyaldehyde, soluble epoxide compound, melamine based compound, The additives such as zirconia compound, zinc compound.When using water system bonding agent, the thickness of adhesive layer therefrom is usually 1 μm or less.

Water system bonding agent is coated in the polarizer layer of polarizability stacked film and/or on protective film, via adhesive layer These films are bonded, it is preferable to use the pressurizations such as doubling roller keep its closely sealed, to implement bonding process.Water system bonding agent is (solid for light Change property bonding agent it is also the same) coating method be not particularly limited, can be used the tape casting, bar rubbing method, gravure coating process, The known method of comma rubbing method, scraper method, die coating method, dip coating, spray-on process etc..

It is real in order to remove the water contained in water system bonding agent after above-mentioned fitting is preferably implemented when using water system bonding agent Apply the drying process that film is dried.It is dry for example to be carried out and film is imported drying oven.Drying temperature (drying oven Temperature) be preferably 30 DEG C~90 DEG C.If it is less than 30 DEG C, then have the tendency that protective film is easy to remove from polarizer layer.In addition, If drying temperature is more than 90 DEG C, the polarization property deterioration of polarizer layer may be caused because of thermal conductivity.Drying time can be 10 seconds ~1000 seconds or so, from the viewpoint of productivity, preferably 60 seconds~750 seconds, more preferably 150 seconds~600 seconds.

After drying process, the temperature in room temperature or a little higher than room temperature, such as 20 DEG C~45 DEG C or so of temperature can be set The curing step of the lower curing 12 hours~600 hours or so of degree.Curing temperature is generally set to lower than drying temperature.

Above-mentioned Photocurable adhesive agent refer to by irradiate the cured bonding agent of ultraviolet light isoreactivity energy line, for example, The curing agent containing polymerizable compound and Photoepolymerizationinitiater initiater can be enumerated, the curing agent containing light reactive resin, contained Adhesive resin and the curing agent of photoreactivity crosslinking agent etc..As polymerizable compound, photo-curable epoxy can be enumerated The photopolymerization monomers such as monomer, light-curable acrylic system monomer, photo-curable polyurethane series monomer come from photopolymerization monomer Oligomer etc..As Photoepolymerizationinitiater initiater, can enumerate in generating containing the irradiation by ultraviolet light isoreactivity energy line The Photoepolymerizationinitiater initiater of the substance of the reactive species of free love base, radical anion, radical cation etc.As containing poly- The Photocurable adhesive agent of conjunction property compound and Photoepolymerizationinitiater initiater is, it is preferable to use contain photo-curable epoxy monomer and light sun The Photocurable adhesive agent of cation polymerization initiator.

When using Photocurable adhesive agent, after implementing above-mentioned fitting, as needed, process (photo-curable is dried When bonding agent contains solvent etc.), it then carries out making the cured solidification work of Photocurable adhesive agent by irradiating active energy ray Sequence.The light source of active energy ray is not particularly limited, but has the active-energy for the distribution that shines preferably below wavelength 400nm Line, specifically, it is preferable that using low pressure mercury lamp, medium pressure mercury lamp, high-pressure sodium lamp, ultrahigh pressure mercury lamp, chemical lamp, black light lamp, microwave Excite mercury lamp, metal halide lamp etc..

The photo-irradiation intensity of Photocurable adhesive agent is suitably determined according to the composition of Photocurable adhesive agent, preferably Exposure intensity with the effective wavelength region of activation to polymerization initiator is 0.1mW/cm²~6000mW/cm²Mode set. Exposure intensity is 0.1mW/cm²When above, the reaction time becomes too long, is 6000mW/cm²When following, it is possible to create by from light source The xanthochromia of Photocurable adhesive agent caused by fever when the light and heat curability bonding agent of radiation solidifies, polarizer layer it is bad Change.

The light irradiation time of Photocurable adhesive agent is also suitably determined according to the composition of Photocurable adhesive agent, preferably It is 10mJ/cm with the accumulative light quantity of the product representation of above-mentioned exposure intensity and irradiation time²~10000mJ/cm²Mode set It is fixed.Accumulative light quantity is 10mJ/cm²When above, an adequate amount of active material from polymerization initiator can be generated and more reliable Ground carries out curing reaction, is 10000mJ/cm²When following, irradiation time will not become too long, be able to maintain that good productivity.

It should be noted that the thickness of the adhesive layer after active energy ray irradiation is usually 0.001 μm~5 μm or so, preferably It is 0.01 μm~2 μm, further preferably 0.01 μm~1 μm.

(adhesive)

It can be used for the adhesive of the fitting of protective film usually by by acrylic resin, phenylethylene resin series, organic silicon-type As basic polymer and thereto addition isocyanate compound, epoxide, the aziridine cpd etc such as resin Adhesive composition obtained by crosslinking agent.It can also further be made containing particle and show light scattering adhesive phase.

The thickness of adhesive phase can be 1 μm~40 μm, but in the range of not damaging the characteristic of processability, durability, It is preferred that being thinly coated with, specifically preferably 3 μm~25 μm.3 μm~25 μm of thickness, which has, is well set as processability, and It is also preferred in terms of the change in size of control polarizer layer.If adhesive phase, less than 1 μm, caking property reduces, if More than 40 μm, then a problem that adhesive squeezes out is easy to produce.Protective film is fitted in the side of polarizer layer using adhesive In method, polarizer layer can be fitted in, adhesive can also be set in polarizer level after protection film surface setting adhesive phase After layer, it is bonded protective film on it.

Formed adhesive phase method be not particularly limited, can protection film surface or the polarizer level coating containing with Above-mentioned base polymer is the adhesive composition (binder solution) of each ingredient of representative, it is dry and after forming adhesive phase, It is bonded protective film and polarizer layer；After adhesive phase can also being formed on spacer (stripping film), which is transferred In protection film surface or polarisation film surface, spacer is removed from adhesive phase, is then bonded protective film and polarizer layer.By adhesive Layer is formed in protection film surface or when polarizer level, as needed, can to protection film surface or polarised light polarizer level or The one or two sides of person's adhesive phase implements surface treatment, such as sided corona treatment etc..

(5) stripping process S50

This process is from the process that fitting film stripping removes base material film obtained from fitting protective film.By the process, energy Access the polarizing film that protective film is laminated in polarizer layer.It is to have to be polarized on the two sides of base material film in polarizability stacked film Device layer and the polarizer layer of this two side be bonded protective film when, by stripping process S50, obtain 2 from 1 polarizability stacked film Open polarizing film.

Removing remove base material film method be not particularly limited, can with carried out in the common polarizing film with adhesive The identical method of stripping process of spacer (stripping film) removed.Base material film can be directly vertical after bonding process S40 Removing is carved, roll can also be once wound into after bonding process S40, be removed in process behind in uncoiling.

Polarizing film manufactured as above is also used as that the optical film of other optical layers has been laminated in practical application.In addition, Protective film can have the function of such optical layer.As other optical layers, it can enumerate and transmit certain polarised light and will show The reflection type polarizing film of the polarised light reflection of opposite to that property；There is the film with anti-dazzle function of concaveconvex shape on surface； Belt surface reflects the film for preventing function；There is the reflectance coating of reflection function on surface；Have both the half of reflection function and transmission function Transflective film；Field angle compensation film etc..

As with transmit certain polarised light and will show opposite to that property polarised light reflection reflection type polarizing film Comparable commercially available product, for example, " DBEF " (3M corporation can be obtained from Japanese Sumitomo 3M Co., Ltd.) can be enumerated, " APF " (3M corporation can be obtained from Japanese Sumitomo 3M Co., Ltd.).

As field angle compensation film, the optics benefit for coating liquid crystal compounds in substrate surface and being orientated, fixing can be enumerated Repay film, the phase difference film being made of polycarbonate-based resin, the phase difference film being made of cyclic polyolefin hydrocarbon system resin etc..

Liquid crystal compounds and the comparable commercially available product of optical compensation films that is orientated, fixes are coated as in substrate surface, It can enumerate " WV film " (Fuji Film Co. Ltd. system), " NH film " (JX Nippon Oil&Energy Co. Ltd. system), " NR Film " (JX Nippon Oil&Energy Co. Ltd. system) etc..

As with the comparable commercially available product of phase difference film that is made of cyclic polyolefin hydrocarbon system resin, " ARTON film " can be enumerated (JSR Corp.'s system), " ESCENA " (Sekisui Chemical Co., Ltd's system), " ZEONOR Film " (Japanese Zeon plants of formula meeting Society's system) etc..

Embodiment

Hereinafter, showing embodiment further the present invention to be specifically described, but the present invention is not limited by these examples.

1 > of < embodiment

(1) production of base material film

By using the co-extrusion modling of multilayer extrusion molding machine, it is produced on the ethylene unit by containing about 5 weight % Propylene/ethylene random copolymer (" the Sumitomo Noblen W151 " of Sumitomo Chemical Co, fusing point Tm= 138 DEG C) constitute resin layer two sides configuration by propylene the homopolymer (" Sumitomo of Sumitomo Chemical Co Noblen FLX80E4 ", Tm=163 DEG C of fusing point) constitute resin layer made of 3-tier architecture strip substrate film.Base material film Aggregate thickness is 100 μm, and the thickness ratio (FLX80E4/W151/FLX80E4) of each layer is 3/4/3.

(2) production (resin layer formation process) of stacked film

By pva powder, (" Z-200 " of the Nippon Synthetic Chemical Industry Co., Ltd, average degree of polymerization 1100 are put down 99.5 moles of % of equal saponification degree) it is dissolved in 95 DEG C of hot water, the polyvinyl alcohol water solution that preparation concentration is 3 weight %.? To aqueous solution in relative to 2 parts by weight of pva powder with ratio mixed cross-linker (the field ridge chemical industry strain of 1 parts by weight " the Sumirez resin 650 " of formula commercial firm), obtain priming coat formation coating fluid.

In addition, by pva powder (" PVA124 " of Co., Ltd. Kuraray, average degree of polymerization 2400, average soap 98.0 moles of %~99.0 mole % of change degree) it is dissolved in 95 DEG C of hot water, the polyvinyl alcohol for preparing 8 weight % of concentration is water-soluble Liquid, as polyvinyl alcohol resin layer formation coating fluid.

The base material film made in one side continuous transport above-mentioned (1) implements sided corona treatment to its single side on one side, uses dimple version Coating machine is continuously coated with above-mentioned priming coat formation coating fluid in the face of progress sided corona treatment, 3 minutes dry at 80 DEG C, by This forms 0.2 μm of thickness of priming coat.Then, film is carried on one side, is continuously coated on priming coat using comma coating machine on one side Above-mentioned polyvinyl alcohol resin layer, which is formed, uses coating fluid, 1 minute dry at 90 DEG C, 3 minutes dry at 70 DEG C, then dry at 60 DEG C Dry 4 minutes, 10.0 μm of thickness of polyvinyl alcohol resin layer is thus formed on priming coat.

In turn, the substrate film surface of the side opposite with the face for foring polyvinyl alcohol resin layer is implemented same as described above Processing, sequentially form priming coat and polyvinyl alcohol resin layer, base material film two sides formed 0.2 μm of thickness priming coat and 10.0 μm of thickness of polyvinyl alcohol resin layer is obtained by polyvinyl alcohol resin layer/priming coat/base material film/priming coat/poly- second The layer of enol resin constitutes the stacked film to be formed.

(3) production (stretching process) of stretched film

Using stretching device shown in Fig. 2, the stacked film made in one side continuous transport above-mentioned (2) passes through clamping on one side The longitudinal direction that stretching mode carried out for 2 stages between roller is uniaxially stretched processing (being uniaxially stretched to the free end of film carry direction), and production is drawn Stretch film.Draft temperature (atmosphere temperature in heating furnace 20,30) in the stretch processing in 2 stages is 160 DEG C.1st stage and Stretching ratio in the stretch processing in the 2nd stage by adjusting the peripheral speed of niproll 1,2,3,4, be set to 2.00 times, 2.90 again.Total stretching ratio is 5.80 times.The thickness of polyvinyl alcohol resin layer in stretched film, a side are 4.6 μm, another party It is 4.8 μm.

It can't see the fold caused by stretching in obtained stretched film.It is wide that film as defined above is measured to obtained stretched film The thickness difference in direction is spent, result is 3 μm, it is thus identified that stretched with generally uniform thickness distribution in film width direction.

(4) production (dyeing process) of polarizability stacked film

The stretched film made in one side continuous transport above-mentioned (3), is become on one side in 60 DEG C of tepidarium with the residence time After 60 seconds modes impregnate, with the residence time as 150 seconds or so in staining solution of 30 DEG C containing iodine and potassium iodide Mode impregnates to carry out the dyeing of polyvinyl alcohol resin layer processing, then, with the extra staining solution of 10 DEG C of pure water rinsing. Then, it impregnates in crosslinker solution of 76 DEG C containing boric acid and potassium iodide in such a way that the residence time becomes 600 seconds to carry out Crosslinking Treatment.Thereafter, it is cleaned 4 seconds with 10 DEG C of pure water, it is 300 seconds dry at 80 DEG C, thus make polarizability stacked film.

(5) production (bonding process and stripping process) of polarizing film

Pva powder (" KL-318 " of Co., Ltd. Kuraray, average degree of polymerization 1800) is dissolved in 95 DEG C Hot water in, prepare 3 weight % of concentration polyvinyl alcohol water solution.Relative to pva powder 2 in obtained aqueous solution Parts by weight with the ratio mixed cross-linker (" the Sumirez resin 650 " of Taoka Chemical Industries Co. Ltd.) of 1 parts by weight, Bonding agent aqueous solution is made.

Next, the polarizability stacked film made in one side continuous transport above-mentioned (4), on one side by above-mentioned bonding agent aqueous solution After being coated in the polarizer layer on two sides, protective film (triacetyl cellulose (TAC) structure of saponification process will be implemented to binding face At transparent protective film (" KC4UY " of Konica Minolta Opto Co. Ltd. system), 40 μm of thickness) be fitted in the polarizer On layer, pass through between a pair of of doubling roller, thus pressed, production by TAC/ polarizer layer/priming coat/base material film/priming coat/ Polarizer layer/TAC layer constitutes the laminating film to be formed (bonding process).

Then, base material film is removed from fitting film stripping, obtains being made of and TAC/ polarizer layer/priming coat in polarizer layer On 2 polarizing films of the transparent protective film being made of TAC have been laminated via adhesive layer.In the process for removing above-mentioned base material film, A problem that not producing fracture.

2 > of < embodiment

The stretching ratio of the stretch processing in the 1st stage and the 2nd stage is set to 2.50 times, 2.32 times of (total stretchings times 5.80 times of rate), in addition to this, polarizing film is made similarly to Example 1.The thickness of polyvinyl alcohol resin layer in stretched film Degree, a side are 4.8 μm, and another party is 5.0 μm.It can't see fold in stretched film, the thickness difference in film width direction is 2 μm, is drawn Stretch uniform progress.Bonding process and stripping process also there is no problem ground carry out, the polarizing film for being laminated with protective film can be obtained.

3 > of < embodiment

Stretching ratio in the stretch processing in the 1st stage and the 2nd stage is set to 2.80 times, 2.07 times of (total stretchings 5.80 times of multiplying power), in addition to this, polarizing film is made similarly to Example 1.The thickness of polyvinyl alcohol resin layer in stretched film Degree, a side are 5.2 μm, and another party is 5.4 μm.It can't see fold in stretched film, the thickness difference of film width direction is 2 μm, is stretched Uniformly carry out.Bonding process and stripping process also there is no problem ground carry out, the polarizing film for being laminated with protective film can be obtained.

4 > of < embodiment

The stretching ratio of the stretch processing in the 1st stage and the 2nd stage is set to 3.40 times, 1.70 times of (total stretchings times 5.78 times of rate), in addition to this, polarizing film is made similarly to Example 1.The thickness of polyvinyl alcohol resin layer in stretched film Degree, a side are 5.1 μm, and another party is 5.3 μm.It can't see fold in stretched film, the thickness difference of film width direction is 2 μm, is stretched Uniformly carry out.Bonding process and stripping process also there is no problem ground carry out, the polarizing film for being laminated with protective film can be obtained.

1 > of < comparative example

Stretching ratio in the stretch processing in the 1st stage is set as 5.80 times, without the stretch processing in the 2nd stage, is removed Other than this, stretched film is made similarly to Example 1.Obtained stretched film generates serious fold in draw direction.

<comparative example 2>

Stretching ratio in the stretch processing in the 1st stage and the 2nd stage is set to 1.54 times, 3.80 times of (total stretchings 5.85 times of multiplying power), in addition to this, stretched film is made similarly to Example 1.The thickness of polyvinyl alcohol resin layer in stretched film Degree, a side are 4.7 μm, and another party is 5.2 μm.It can't see fold in obtained stretched film, the thickness difference of film width direction is greatly to 7 μm, it stretches uneven.

By the stretching ratio in the stretch processing in the 1st stage and the 2nd stage, the stretching ratio ratio (stretch processing in the 1st stage The ratio between the stretching ratio in stretching ratio and the stretch processing process in the 2nd stage in process), total stretching ratio and about The fold of stretched film and the measurement result of the thickness difference in film width direction summarize shown in table 1.

[table 1]

[table 1]

Industrial availability

According to the method for the present invention, the generation of fold can effectively be inhibited when film stretching is laminated, in film width direction Stretch uneven (therefore, the uneven thickness in film width direction), thus can yield rate to manufacture appearance, optical characteristics well good Good polarizability stacked film or polarizing film.

Symbol description

1,2,3,4 niproll, 5 deflector rolls, 6,7,8,9 hot-rollings, 10 stacked films, 15 stretched films, 20,30 heating furnaces, 40 chucks.

Claims (7)

1. a kind of manufacturing method of polarizability stacked film, has:

Resin layer formation process keeps it dry after at least one face of base material film is coated with the coating fluid containing polyvinyl alcohol resin It is dry, to form polyvinyl alcohol resin layer, stacked film is obtained,

The stacked film is carried out longitudinal direction and is uniaxially stretched, obtains stretched film by stretching process, and

Dyeing process is dyed with polyvinyl alcohol resin layer of the dichroism pigment to the stretched film, forms polarizer layer, To obtain polarizability stacked film；

The stretching process includes 2 stretch processing the process more than stage,

The stretch processing process in the 2nd stage is the mode being stretched in the temperature that draft temperature is 120 DEG C or more,

The ratio between the stretching ratio in stretching ratio and the stretch processing process in the 2nd stage in the stretch processing process in the 1st stage For 0.6 or more and be 5 hereinafter,

Using the polyvinyl alcohol resin layer of the stacked film as benchmark, total stretching ratio of the polarizer layer is more than 5 times.

2. the manufacturing method according to claim 1, wherein the stretch processing process in the 2nd stage is by being set To be heated in the heating furnace of the draft temperature, while being stretched between 2 mutually different niprolls of peripheral speed Mode.

3. manufacturing method according to claim 1 or 2, wherein in the resin layer formation process, in the base material film Two sides form the polyvinyl alcohol resin layer.

4. manufacturing method described in any one of claim 1 to 3, wherein the polyvinyl alcohol resin of the stacked film Layer with a thickness of 3 μm~30 μm.

5. manufacturing method according to any one of claims 1 to 4, wherein in the stretch processing process in the 1st stage Stretching ratio less than 5 times.

6. manufacturing method according to any one of claims 1 to 5, wherein the base material film is by polypropylene-based resin structure At.

7. a kind of manufacturing method of polarizing film, has following process:

Prepare the process of the polarizability stacked film obtained by manufacturing method according to any one of claims 1 to 6,

The process for being bonded protective film in the polarizer layer of the polarizability stacked film and obtaining laminating film, and

From the process of base material film described in the fitting film stripping.