WO2016056600A1 - Film polarisant - Google Patents

Film polarisant Download PDF

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Publication number
WO2016056600A1
WO2016056600A1 PCT/JP2015/078519 JP2015078519W WO2016056600A1 WO 2016056600 A1 WO2016056600 A1 WO 2016056600A1 JP 2015078519 W JP2015078519 W JP 2015078519W WO 2016056600 A1 WO2016056600 A1 WO 2016056600A1
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WIPO (PCT)
Prior art keywords
polarizing film
film
int
pva
mass
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PCT/JP2015/078519
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English (en)
Japanese (ja)
Inventor
沙樹 今林
達也 大園
修 風藤
Original Assignee
株式会社クラレ
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 株式会社クラレ filed Critical 株式会社クラレ
Priority to CN201580054575.4A priority Critical patent/CN106796319B/zh
Priority to JP2016553140A priority patent/JP6655544B2/ja
Priority to KR1020177003263A priority patent/KR102432418B1/ko
Publication of WO2016056600A1 publication Critical patent/WO2016056600A1/fr

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements

Definitions

  • the present invention relates to a polarizing film having excellent moisture and heat resistance.
  • a polarizing plate having a light transmission and shielding function is a basic component of a liquid crystal display (LCD) together with a liquid crystal that changes a polarization state of light.
  • LCD liquid crystal display
  • Many polarizing plates have a structure in which a protective film such as a cellulose triacetate (TAC) film is bonded to the surface of a polarizing film.
  • TAC cellulose triacetate
  • a polarizing film constituting the polarizing plate a uniaxially stretched polyvinyl alcohol film (hereinafter referred to as a polarizing film) , "polyvinyl alcohol” and may be abbreviated as "PVA”) to iodine dye (I 3 - and I 5 -, etc.) has become mainstream those adsorbed.
  • PVA uniaxially stretched polyvinyl alcohol film
  • Such a polarizing film can be obtained by uniaxially stretching a PVA film preliminarily containing an iodine pigment, adsorbing an iodine pigment simultaneously with uniaxial stretching of a PVA film, or adsorbing an iodine pigment after uniaxially stretching a PVA film. Or manufactured.
  • LCDs are widely used in small devices such as calculators and watches, notebook computers, liquid crystal monitors, liquid crystal color projectors, liquid crystal televisions, in-vehicle navigation systems, mobile phones, and measuring instruments used indoors and outdoors.
  • a polarizing film that is more durable than conventional products, in particular, has excellent heat and humidity resistance under high temperature and high humidity.
  • a polarizing film excellent in wet heat resistance for example, a film containing PVA, a dichroic dye and a specific organic acid is known (see Patent Document 1).
  • JP2011-237580A International Publication No. 2014/065140
  • the polarizing film of Patent Document 1 also has room for further improvement in improving the heat and moisture resistance.
  • an object of this invention is to provide the polarizing film excellent in the moisture heat resistance in which the fall of the polarization performance under high temperature and high humidity was suppressed, and its manufacturing method.
  • a polarizing film excellent in an external appearance etc. reference patent document 2
  • the improvement of the heat-and-moisture resistance made into the objective in this invention cannot be achieved also by the said polarizing film.
  • the present inventors have made a cross-section by bringing a treatment liquid containing a reducing agent in a specific ratio into contact with the surface of the polarizing film on which the iodine dye is adsorbed. It is found that an unprecedented polarizing film excellent in moisture and heat resistance can be easily obtained by satisfying a specific relationship between the measurement results in the thickness direction center part and the surface vicinity of the film obtained by Raman spectroscopy measurement. Based on this, further studies were made to complete the present invention.
  • the present invention is [1] a polarizing film in which an iodine dye is adsorbed on a PVA film, and is obtained by measuring the cross section of the polarizing film by Raman spectroscopy at 310 cm ⁇ 1 in the center in the thickness direction of the film.
  • the ratio (Int 310 / Int 210 ) between the signal intensity (Int 310 ) and the signal intensity (Int 210 ) at 210 cm ⁇ 1 is L, and 10% of the thickness from the one side of the film to the inside in the thickness direction.
  • the ratio of the signal intensity at 310 cm -1 in the entrance portion signal intensity at (Int 310) and 210cm -1 (Int 210) to (Int 310 / Int 210) is M, the thickness direction from the other surface of the film Signal intensity at 310 cm ⁇ 1 (Int 310 ) And the signal intensity (Int 210 ) at 210 cm ⁇ 1 (Int 310 / Int 210 ) is N (where M ⁇ N), 2 ⁇ L / (M + N) is 1.2. [2] Absorption at a wavelength of 610 nm in a crossed Nicol state before the test when the polarizing film was subjected to a heat and humidity resistance test for 12 hours at 60 ° C.
  • the absorbance (B) at a wavelength of 610 nm in the crossed Nicol state after the test (B / A) is 0.12 or more; [3] the thickness is 30 ⁇ m or less.
  • Iodine color A method for producing a polarizing film, comprising the step of bringing the surface of the polarizing film adsorbed on the surface of the polarizing film into contact with a treatment liquid containing 0.5 to 10% by mass of a reducing agent; [6] The contact time in the contacting step is 1 minute [7] The production method of the above [5]; [7] The production method of the above [5] or [6], wherein the temperature of the treatment liquid is 5 to 50 ° C .; [8] The reducing agent is ascorbic acid.
  • the polarizing film excellent in wet heat resistance in which the fall of the polarization performance under high temperature and high humidity was suppressed is provided.
  • the manufacturing method of the polarizing film which can manufacture the said polarizing film easily is provided.
  • an iodine dye is adsorbed on a PVA film (typically a uniaxially stretched PVA film).
  • a PVA film typically a uniaxially stretched PVA film.
  • Such a polarizing film can be obtained by stretching a PVA film containing an iodine pigment in advance, adsorbing an iodine pigment simultaneously with the stretching of the PVA film, or forming a matrix by stretching the PVA film. It can be manufactured by adsorbing.
  • the polarizing film of the present invention the cross-section of the polarizing film obtained by Raman spectrophotometry, the signal intensity (Int 210 in signal intensity (Int 310) and 210 cm -1 in the 310 cm -1 in the thickness direction central portion of the film )) (Int 310 / Int 210 ) and L, and the signal intensity (Int 310 ) at 310 cm ⁇ 1 and 210 cm ⁇ at a portion that enters 10% of the thickness in the thickness direction from one side of the film.
  • the ratio (Int 310 / Int 210 ) to the signal intensity at 1 (Int 210 / Int 210 ) is M, and the signal at 310 cm ⁇ 1 in the portion that enters 10% of the thickness in the thickness direction from the other side of the film the ratio of the intensity signal intensity at (Int 310) and 210cm -1 (Int 210)
  • the Int 310 / Int 210) upon the N is 2 ⁇ L / (M + N ) is 1.2 or more.
  • Raman spectrophotometry may be performed with a Raman spectrophotometer using a sample obtained by slicing the target polarizing film in the thickness direction.
  • a laser Raman spectrometer such as a microscopic laser Raman spectrometer “LabRAM ARAMIS VIS”
  • the measurement target portion of the sample may be irradiated with laser light having a wavelength of 532 nm to perform Raman spectroscopy.
  • the ratio (Int 310 / Int 210 ) is calculated.
  • specific measurement methods or conditions for obtaining the ratio (Int 310 / Int 210 ) in each part of the film those described later in the examples can be employed.
  • the corresponding portion is each surface of the polarizing film.
  • the ratio (Int 310 / Int 210 ) in each part of the film is considered to depend on the ratio of the amount of I 5 ⁇ to the amount of I 3 ⁇ in that part. It is done.
  • the above 2 ⁇ L / (M + N) is 1.2 or more.
  • the polarizing film is excellent in moisture and heat resistance.
  • 2 ⁇ L / (M + N) is preferably 1.5 or more, more preferably 1.7 or more, and even more preferably 1.9 or more because the polarizing film is more excellent in heat and humidity resistance.
  • 2 * L / (M + N) is 3.0 or less, and 2.6 or less. It is more preferable that
  • vinyl esters such as vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl benzoate, isopropenyl acetate Or what is obtained by saponifying the polyvinyl ester obtained by superposing
  • vinyl esters vinyl acetate is preferable from the viewpoints of ease of production of PVA, availability, cost, and the like.
  • the above-mentioned polyvinyl ester may be obtained using only one or two or more kinds of vinyl esters as a monomer. It may be a copolymer of two or more kinds of vinyl esters and other monomers copolymerizable therewith.
  • Examples of the other monomer copolymerizable with the vinyl ester include ⁇ -olefins having 2 to 30 carbon atoms such as ethylene, propylene, 1-butene, and isobutene; (meth) acrylic acid or a salt thereof; (Meth) methyl acrylate, (meth) ethyl acrylate, (meth) acrylate n-propyl, (meth) acrylate i-propyl, (meth) acrylate n-butyl, (meth) acrylate i-butyl, ( (Meth) acrylic acid esters such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate; (meth) acrylamide, N-methyl ( (Meth) acrylamide, N-ethyl (meth) acrylamide, N,
  • Vinyl ether vinyl cyanide such as (meth) acrylonitrile; halogenated vinyl such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride; vinegar Allyl compounds such as allyl acid and allyl chloride; maleic acid or its salt, ester or acid anhydride; itaconic acid or its salt, ester or acid anhydride; vinylsilyl compound such as vinyltrimethoxysilane; unsaturated sulfonic acid be able to.
  • Said polyvinyl ester can have a structural unit derived from 1 type, or 2 or more types of an above described other monomer.
  • the proportion of structural units derived from the other monomers described above in the polyvinyl ester is preferably 15 mol% or less based on the number of moles of all structural units constituting the polyvinyl ester, and is preferably 10 mol%. Hereinafter, it may be 5 mol% or less.
  • the other monomer described above is a monomer that may promote the water solubility of the obtained PVA, such as (meth) acrylic acid or unsaturated sulfonic acid
  • the proportion of structural units derived from these monomers in the polyvinyl ester is 5 mol% or less based on the number of moles of all structural units constituting the polyvinyl ester. It is preferable that it is 3 mol% or less.
  • the PVA may be modified with one or two or more types of graft copolymerizable monomers as long as the effects of the present invention are not impaired.
  • examples of the graft copolymerizable monomer include unsaturated carboxylic acids or derivatives thereof; unsaturated sulfonic acids or derivatives thereof; ⁇ -olefins having 2 to 30 carbon atoms, and the like.
  • the proportion of structural units derived from the graft copolymerizable monomer in PVA (structural units in the graft modified portion) is preferably 5 mol% or less based on the number of moles of all structural units constituting PVA. .
  • a part of the hydroxyl groups may be cross-linked or may not be cross-linked.
  • said PVA may react with aldehyde compounds, such as acetaldehyde and a butyraldehyde, etc. to form an acetal structure, and the said PVA does not react with these compounds and does not form an acetal structure. May be.
  • the average degree of polymerization of the PVA is preferably in the range of 1,000 to 9,500.
  • the average degree of polymerization is more preferably 1,500 or more, and further preferably 2,000 or more. Moreover, it is more preferable that it is 9,200 or less, and it is further more preferable that it is 6,000 or less.
  • the average degree of polymerization is 1,000 or more, the polarizing performance of the polarizing film is improved.
  • the productivity of PVA is improved.
  • the average degree of polymerization of PVA can be measured according to the description of JIS K6726-1994.
  • the saponification degree of the PVA is preferably 95 mol% or more, more preferably 98 mol% or more, and further preferably 98.5 mol% or more from the viewpoint of the polarizing performance of the polarizing film. preferable.
  • the degree of saponification is less than 95 mol%, PVA tends to be eluted during the production process of the polarizing film, and the eluted PVA may adhere to the film and reduce the polarizing performance of the polarizing film.
  • the degree of saponification of PVA refers to the total number of moles of structural units (typically vinyl ester units) that can be converted into vinyl alcohol units by saponification and the vinyl alcohol units of PVA. The proportion (mol%) occupied by the number of moles of vinyl alcohol units.
  • the degree of saponification can be measured according to the description of JIS K6726-1994.
  • the iodine-based dye As the iodine-based dye, I 3 -, and the like - and I 5, examples of these counter cations include alkali metals such as potassium.
  • the iodine dye can be obtained, for example, by bringing iodine (I 2 ) into contact with potassium iodide.
  • the thickness of the polarizing film of this invention is preferably 30 ⁇ m or less, more preferably 15 ⁇ m or less, and may be 10 ⁇ m or less.
  • the thickness of the polarizing film is, for example, preferably 1 ⁇ m or more, more preferably 2.5 ⁇ m or more, and 8 ⁇ m or more. Is more preferable.
  • the polarizing film of the present invention is superior in moisture and heat resistance, it preferably contains 1% by mass or more, more preferably 2% by mass or more, more preferably 3% by mass with respect to the mass of PVA contained therein. % Or more, more preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 4% by mass or less.
  • the content of boron atoms in the polarizing film can be adjusted by changing the content of boron atoms in the treatment bath used in the crosslinking step, stretching step, washing step, etc. in the polarizing film production method described later.
  • the polarizing film of the present invention is excellent in moisture and heat resistance.
  • the moisture and heat resistance can be evaluated by subjecting the polarizing film to a moisture and heat resistance test. Specifically, the polarizing film is subjected to a moisture and heat resistance test that is allowed to stand for 12 hours at 60 ° C. and 90% RH. Can be evaluated.
  • the degree of wet heat resistance of the polarizing film of the present invention is the ratio of the absorbance (A) at a wavelength of 610 nm in the crossed Nicol state before the test and the absorbance (B) at the wavelength of 610 nm in the crossed Nicol state after the test ( B / A) is preferably 0.12 or more, more preferably 0.15 or more, and further preferably 0.25 or more.
  • a ratio (B / A) is 0.5 or less, for example.
  • said moisture-heat resistance test can be measured by the method mentioned later in an Example.
  • the single transmittance of the polarizing film of the present invention is preferably in the range of 40 to 50% from the viewpoint of polarization performance, and the single transmittance is more preferably 41% or more, and 42% or more. More preferably, it is more preferably 45% or less.
  • the single transmittance of the polarizing film can be measured by the method described later in Examples.
  • the degree of polarization of the polarizing film of the present invention is preferably 99% or more from the viewpoint of polarization performance, the degree of polarization is more preferably 99.9% or more, and 99.95% or more. Is more preferable.
  • the degree of polarization of the polarizing film can be measured by the method described later in the examples.
  • the method for manufacturing the polarizing film of the present invention is not particularly limited, the following manufacturing method of the present invention is preferable because the polarizing film of the present invention can be easily manufactured.
  • the production method of the present invention includes a step of bringing the surface of the polarizing film on which the iodine dye is adsorbed into contact with the treatment liquid containing 0.5 to 10% by mass of the reducing agent.
  • the polarizing film to which the iodine dye used in the production method of the present invention is adsorbed can be obtained by subjecting the PVA film to a dyeing process and a stretching process using an iodine dye.
  • the PVA film to be used may be a single layer or may be laminated on a substrate such as a thermoplastic resin substrate, but a single layer is preferred.
  • a PVA film contains a plasticizer from a viewpoint of the extending
  • the plasticizer include polyhydric alcohols such as ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, and trimethylol propane.
  • One or more of the agents can be included. Among these, glycerin is preferable from the viewpoint of the effect of improving stretchability.
  • the content of the plasticizer in the PVA film is preferably in the range of 1 to 20 parts by mass with respect to 100 parts by mass of PVA contained therein. When the content is 1 part by mass or more, the stretchability of the PVA film can be further improved. On the other hand, when the content is 20 parts by mass or less, it is possible to prevent the PVA film from becoming too flexible and handling properties from being lowered.
  • the content of the plasticizer in the PVA film is more preferably 2 parts by mass or more with respect to 100 parts by mass of PVA, further preferably 4 parts by mass or more, particularly preferably 5 parts by mass or more, The amount is more preferably 15 parts by mass or less, and further preferably 12 parts by mass or less.
  • the PVA film may further contain components such as an antioxidant, an antifreezing agent, a pH adjusting agent, a masking agent, an anti-coloring agent, an oil agent, and a surfactant as necessary.
  • the content of PVA in the PVA film is preferably in the range of 50 to 99% by mass in view of ease of preparation of the desired polarizing film, and the content is preferably 75% by mass or more. More preferably, it is more preferably 80% by mass or more, particularly preferably 85% by mass or more, more preferably 98% by mass or less, further preferably 96% by mass or less, 95 It is particularly preferable that the content is not more than mass%.
  • the thickness of the PVA film used in the manufacturing method of this invention can adjust suitably.
  • the thickness of the PVA film can be, for example, 200 ⁇ m or less, and further 100 ⁇ m or less.
  • the moisture and heat resistance is likely to decrease in a thinner polarizing film, and the effect of the present invention is more remarkable in such a polarizing film. Therefore, the thickness of the PVA film is preferably 60 ⁇ m or less, more preferably 30 ⁇ m or less, and may be 20 ⁇ m or less.
  • the thickness of the PVA film is, for example, preferably 2 ⁇ m or more, more preferably 5 ⁇ m or more, and 15 ⁇ m or more. Further preferred.
  • the shape of the PVA film is not particularly limited, but is preferably a long PVA film because it can be used continuously when producing a polarizing film.
  • the length of the long PVA film (length in the long direction) is not particularly limited, and can be set as appropriate according to the use of the polarizing film to be produced. For example, the length is in the range of 5 to 20,000 m. It can be.
  • the width of the PVA film is not particularly limited and can be set as appropriate according to the application of the polarizing film to be produced.
  • the PVA film has been increasing in screen size for liquid crystal televisions and liquid crystal monitors. If the width is set to 0.5 m or more, more preferably 1.0 m or more, it is suitable for these applications.
  • the width of the PVA film is 7 m or less. Is preferred.
  • the polarizing film to which the iodine dye used in the present invention is adsorbed can be obtained by subjecting the PVA film to a dyeing process and a stretching process using an iodine dye, as described above.
  • a swelling step, a crosslinking step and the like can be further included as necessary.
  • the order of each process may be changed as needed, each process may be performed twice or more, and different processes may be performed simultaneously.
  • the PVA film is subjected to a swelling process, and then subjected to a dyeing process using an iodine dye, and further if necessary.
  • crosslinking process and using for a extending process after that is mentioned.
  • the swelling step can be performed by immersing the PVA film in water.
  • the temperature of the water when immersed in water is preferably within a range of 20 to 40 ° C., more preferably 22 ° C. or higher, further preferably 25 ° C. or higher.
  • the temperature is more preferably 38 ° C. or lower, and further preferably 35 ° C. or lower.
  • the time for immersion in water is preferably within a range of 0.1 to 5 minutes, and more preferably within a range of 0.5 to 3 minutes. By making it within the range of 0.1 to 5 minutes, the PVA film can be efficiently swollen.
  • the water at the time of immersing in water is not limited to pure water, The aqueous solution in which various components melt
  • the dyeing step with an iodine pigment can be performed by immersing the PVA film in an aqueous solution containing iodine (I 2 ) and potassium iodide. By mixing the iodine and potassium iodide and water, I 3 - and I 5 - such can generate iodine dye.
  • the concentration of iodine and potassium iodide in the dyeing bath is not particularly limited, but the iodine concentration is within a range of 0.01 to 2% by mass as a ratio of the mass of iodine used to the mass of the resulting dyeing bath.
  • the concentration of potassium iodide is preferably in the range of 0.02 to 0.5% by mass, and the concentration of potassium iodide is the amount of potassium iodide used relative to the mass of iodine used.
  • the mass ratio is preferably in the range of 10 to 200 times by mass, and more preferably in the range of 15 to 150 times by mass.
  • the dyeing bath may contain a boron compound such as borate such as boric acid and borax.
  • the temperature of the dyeing bath is preferably in the range of 20 to 50 ° C., particularly preferably in the range of 25 to 40 ° C.
  • the crosslinking step is preferably performed after the dyeing step and before the stretching step.
  • the crosslinking step can be performed by immersing the PVA film in an aqueous solution containing a crosslinking agent as a crosslinking bath.
  • a crosslinking agent one or more of boron compounds such as boric acid and borate such as borax can be used.
  • the concentration of the crosslinking agent in the crosslinking bath is preferably in the range of 1 to 15% by mass, more preferably 2% by mass or more, more preferably 7% by mass or less, and 6% by mass or less. More preferably. Sufficient stretchability can be maintained when the concentration of the crosslinking agent is in the range of 1 to 15% by mass.
  • the crosslinking bath may contain an auxiliary agent such as potassium iodide.
  • the temperature of the crosslinking bath is preferably in the range of 20 to 50 ° C., particularly preferably in the range of 25 to 40 ° C. By setting the temperature within the range of 20 to 50 ° C., crosslinking can be performed efficiently.
  • the wet stretching method is preferable from the viewpoint of the uniformity of the thickness in the width direction of the obtained polarizing film, and it is more preferable to stretch in a boric acid aqueous solution.
  • the concentration of boric acid in the boric acid aqueous solution is preferably in the range of 0.5 to 8.0% by mass, more preferably 1.0% by mass or more, and 1.5% by mass. More preferably, it is more preferably 7.0% by mass or less, and still more preferably 6.0% by mass or less.
  • the boric acid concentration is in the range of 0.5 to 6.0% by mass, a polarizing film having excellent thickness uniformity in the width direction can be obtained.
  • the aqueous solution containing the boron compound may contain potassium iodide, and its concentration is preferably in the range of 0.01 to 10% by mass.
  • concentration of potassium iodide is in the range of 0.01 to 10% by mass, a polarizing film with better polarizing performance can be obtained.
  • the temperature at which the PVA film is stretched is preferably in the range of 5 to 90 ° C., more preferably 10 ° C. or more, and more preferably 80 ° C. or less. More preferably, it is not higher than ° C.
  • a polarizing film having excellent thickness uniformity in the width direction can be obtained.
  • the stretching ratio at the time of stretching the PVA film is preferably 4 times or more, more preferably 5 times or more, and further preferably 6 times or more.
  • the upper limit of the draw ratio of the PVA film is not particularly limited, but is preferably 8 times or less. Stretching of the PVA film may be performed at one time or divided into a plurality of times, but when performed in a plurality of times, the total stretching ratio obtained by multiplying the stretching ratio of each stretching is within the above range. I just need it.
  • the draw ratio in this specification is based on the length of the PVA film before extending
  • the stretching of the PVA film is preferably uniaxial stretching from the viewpoint of the performance of the obtained polarizing film.
  • Uniaxial stretching in the longitudinal direction is preferred. Uniaxial stretching in the longitudinal direction can be performed by changing the peripheral speed between the rolls using a stretching apparatus including a plurality of rolls parallel to each other. On the other hand, lateral uniaxial stretching can be performed using a tenter type stretching machine.
  • the production method of the present invention includes a step of bringing the surface of the polarizing film on which the iodine dye is adsorbed into contact with a treatment liquid containing 0.5 to 10% by mass of a reducing agent.
  • a treatment liquid containing 0.5 to 10% by mass of a reducing agent.
  • the contact method in the said contact process For example, using the said process liquid as a processing bath (reducing agent bath), the method of immersing the polarizing film in which the said iodine type pigment
  • a method of immersing a polarizing film on which an iodine dye is adsorbed is preferable.
  • the treatment bath is preferably an aqueous solution.
  • the concentration of the reducing agent in the treatment liquid is preferably 1% by mass or more, more preferably 2% by mass or more, preferably 8% by mass or less, and preferably 7% by mass or less. More preferred.
  • concentration of the reducing agent in the treatment liquid is not more than the above lower limit, it becomes difficult to obtain a target polarizing film.
  • concentration of the reducing agent in the treatment liquid is equal to or higher than the above upper limit, it becomes difficult to obtain a polarizing film having excellent polarization performance.
  • the type of the reducing agent is not particularly limited, and a reducing compound can be used. Since the affinity with PVA is excellent, the reducing agent is preferably a water-soluble antioxidant. Therefore, the reducing agent is more preferably at least one selected from the group consisting of ascorbic acid or a salt thereof, erythorbic acid or a salt thereof, thiosulfate, and sulfite. Preferably, it is thiosulfate.
  • the reducing agent is a salt
  • examples of the salt include lithium salt, sodium salt, potassium salt, calcium salt, ammonium salt, and the like, and sodium salt is preferable.
  • the contact time in the contacting step is preferably 1 minute or less, more preferably 40 seconds or less, 15 seconds or less, and even 5 because the polarizing film of the present invention can be obtained more easily. It may be less than a second. The shorter the contact time, the easier it is to obtain the intended polarizing film. However, if the contact time is too short, the operation may be difficult. Therefore, the contact time is preferably 0.1 seconds or longer.
  • the temperature of the treatment liquid is preferably in the range of 5 to 50 ° C., since the polarizing film of the present invention can be more easily obtained.
  • the temperature is more preferably 10 ° C. or more, and 20 ° C. More preferably, it is more preferably 40 ° C. or lower.
  • a fixing treatment step, a washing step, a drying step and the like are further included after the contacting step.
  • the fixing treatment step is mainly performed in order to strengthen the adsorption of the iodine dye to the polarizing film.
  • the fixing treatment step can be performed by immersing the polarizing film in a fixing treatment bath.
  • a fixing treatment bath an aqueous solution containing one or more of boron compounds such as boric acid such as boric acid and borax can be used.
  • the concentration of the boron compound in the aqueous solution containing the boron compound used as the fixing treatment bath is generally within the range of 0.1 to 15% by mass, and particularly preferably within the range of 1 to 10% by mass.
  • the concentration of the iodine-based dye can be further strengthened.
  • the temperature of the fixing treatment bath is preferably in the range of 10 to 60 ° C, particularly preferably in the range of 15 to 40 ° C. By setting the temperature within the range of 10 to 60 ° C., it is possible to further strengthen the adsorption of the iodine dye.
  • the washing process is often performed to remove unnecessary chemicals and foreign matters on the film surface and to adjust the optical performance of the finally obtained polarizing film.
  • the cleaning step can be performed by immersing the polarizing film in a cleaning bath or by spraying a cleaning liquid on the polarizing film. Water can be used as the washing bath or the washing liquid, and potassium iodide may be contained therein.
  • the drying conditions in the drying step are not particularly limited, but it is preferable to perform the drying at a temperature in the range of 30 to 150 ° C, particularly in the range of 50 to 130 ° C.
  • a polarizing film excellent in dimensional stability can be easily obtained by drying at a temperature in the range of 30 to 150 ° C.
  • the polarizing film is usually used as a polarizing plate by attaching a protective film on both sides or one side.
  • the protective film include those that are optically transparent and have mechanical strength. Specifically, for example, cellulose triacetate (TAC) film, acetic acid / cellulose butyrate (CAB) film, acrylic film, and polyester film.
  • TAC cellulose triacetate
  • CAB acetic acid / cellulose butyrate
  • acrylic film acrylic film
  • polyester film polyester film.
  • a film or the like can be used.
  • examples of the adhesive for bonding include a PVA adhesive and a urethane adhesive, and a PVA adhesive is preferable.
  • the sample to be measured is irradiated with a laser beam having a wavelength of 532 nm on the cross-section to be measured on the cross section produced by the microtome. performed, among the signals observed at that time, because the intensity of the signal at 310cm intensity of the signal at -1 (Int 310) and 210cm -1 (Int 210), the ratio in that portion (Int 310 / Int 210 ) was calculated.
  • said measurement object part shall be the part which penetrated 10% with respect to thickness inside the thickness direction center part of a polarizing film and the thickness direction of a film from each surface of a polarizing film from the thickness direction center part of a polarizing film.
  • the obtained ratios (Int 310 / Int 210) is L, also two ratios obtained from 10 percent penetration portion of the thickness inside from each side of the polarizing film in the thickness direction of the film (Int 310 / For Int 210 ), each value was set to M or N so as to satisfy M ⁇ N, and 2 ⁇ L / (M + N) was calculated using these L, M, and N.
  • Example 1 100 parts by mass of PVA (saponified copolymer of vinyl acetate and ethylene, average polymerization degree 2,400, saponification degree 99.4 mol%, ethylene unit content 2.5 mol%), A PVA film having a thickness of 30 ⁇ m obtained by casting a film using a film-forming stock solution consisting of 10 parts by mass of glycerin as a plasticizer, 0.1 part by mass of sodium polyoxyethylene lauryl ether sulfate as a surfactant and water.
  • PVA saponified copolymer of vinyl acetate and ethylene, average polymerization degree 2,400, saponification degree 99.4 mol%, ethylene unit content 2.5 mol%
  • a PVA film having a thickness of 30 ⁇ m obtained by casting a film using a film-forming stock solution consisting of 10 parts by mass of glycerin as a plasticizer, 0.1 part by mass of sodium polyoxyethylene lauryl ether sulfate as a surfactant and
  • a polarizing film adsorbed with iodine dye is obtained by performing a swelling process, a dyeing process with iodine dye, a crosslinking process, and a stretching process, and this is brought into contact with a treatment liquid containing a reducing agent, and further washed.
  • the objective polarizing film was manufactured by performing a process and a drying process. That is, after the above PVA film was uniaxially stretched (MD) in the length direction (MD) up to 1.6 times the original length while being immersed in water at a temperature of 30 ° C. for 1 minute, The amount of the original length is 2 while being immersed in a dyeing bath at a temperature of 30 ° C.
  • iodine is mixed with water at a concentration of 0.053% by mass and potassium iodide at a concentration of 5.3% by mass for 1 minute.
  • MD length direction
  • second-stage stretching Uniaxially stretched in the length direction (MD) up to 7 times (second-stage stretching), and then placed in a crosslinking bath at a temperature of 30 ° C. containing 3% by weight of boric acid and 3% by weight of potassium iodide for 2 minutes While immersed, the film is uniaxially stretched in the length direction (MD) up to three times the original length (stretching at the third stage), and further boric acid is 4.5% by mass and potassium iodide is 6% by mass.
  • Example 2 Example 1 except that the boric acid concentration and temperature in the stretching bath, the concentration of sodium thiosulfate in the reducing agent bath, and the immersion time in the reducing agent bath were changed as shown in Table 1.
  • a polarizing film was produced in the same manner. Using the obtained polarizing film, 2 ⁇ L / (M + N), boron atom content, single transmittance, polarization degree, and heat and humidity resistance were measured or evaluated by the method described above. The results are shown in Table 1.
  • Example 1 The immersion in the reducing agent bath (the step of bringing into contact with the treatment liquid containing the reducing agent) is omitted, and the content of boron atoms and the single transmittance in the obtained polarizing film are substantially the same as in Example 1.
  • a polarizing film was produced in the same manner as in Example 1 except that the iodine concentration and potassium iodide concentration in the dyeing bath, and the boric acid concentration and temperature in the stretching bath were changed as shown in Table 1. did.
  • 2 ⁇ L / (M + N) boron atom content, single transmittance, polarization degree, and heat and humidity resistance were measured or evaluated by the method described above. The results are shown in Table 1.
  • Example 2 A polarizing film was produced in the same manner as in Example 1 except that the concentration of sodium thiosulfate in the reducing agent bath was changed as shown in Table 1. Using the obtained polarizing film, 2 ⁇ L / (M + N), boron atom content, single transmittance, polarization degree, and heat and humidity resistance were measured or evaluated by the method described above. The results are shown in Table 1.

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  • Chemical & Material Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Polarising Elements (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)

Abstract

La présente invention concerne un film polarisant dans lequel un colorant à base d'iode est adsorbé sur un film de PVA. Lorsque le rapport (Int310/Int210) de l'intensité de signal à 310 cm-1 (Int310) à l'intensité de signal à 210 cm-1 (Int210), dans une section centrale du film, dans le sens de son épaisseur, telle que mesurée par spectroscopie Raman, d'une section transversale dudit film, est désigné par L, lorsque le rapport (Int310/Int210) dans une partie du film atteinte en se déplaçant vers l'intérieur de 10 % de l'épaisseur dudit film à partir d'une surface du film est désigné par M, et lorsque le rapport (Int310/Int210), dans une partie du film atteinte en se déplaçant vers l'intérieur de 10 % de l'épaisseur dudit film depuis l'autre surface du film, est désigné par N (où M ≤ N), 2×L/(M+N) est égal à 1,2 ou plus. Ce film polarisant a pour effet de présenter une excellente résistance à l'humidité et à la chaleur et de réduire au minimum les pertes de performances de polarisation aux hautes températures et aux taux d'humidité élevés.
PCT/JP2015/078519 2014-10-08 2015-10-07 Film polarisant WO2016056600A1 (fr)

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WO2019188779A1 (fr) * 2018-03-28 2019-10-03 日東電工株式会社 Polariseur, film polarisant, film polarisant multicouche, panneau d'affichage d'image, et dispositif d'affichage d'image
JP7005803B1 (ja) 2020-10-26 2022-01-24 住友化学株式会社 積層体
WO2023286702A1 (fr) * 2021-07-15 2023-01-19 住友化学株式会社 Polariseur, plaque de polarisation, et dispositif d'affichage d'image
KR20240087665A (ko) 2021-10-25 2024-06-19 주식회사 쿠라레 폴리비닐알코올 필름

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KR102327242B1 (ko) * 2016-07-26 2021-11-16 주식회사 쿠라레 편광 필름 및 그 제조 방법
KR102593640B1 (ko) * 2020-03-10 2023-10-24 삼성에스디아이 주식회사 편광판 및 이를 포함하는 광학표시장치

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JPS55126202A (en) * 1979-03-20 1980-09-29 Nitto Electric Ind Co Ltd Polarizing film
JP2013156621A (ja) * 2012-01-05 2013-08-15 Nitto Denko Corp ヨウ素系偏光子、偏光板、光学フィルムおよび画像表示装置
JP2013231938A (ja) * 2012-04-04 2013-11-14 Nitto Denko Corp 偏光板用接着剤、偏光板、その製造方法、光学フィルムおよび画像表示装置
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Publication number Priority date Publication date Assignee Title
WO2019188779A1 (fr) * 2018-03-28 2019-10-03 日東電工株式会社 Polariseur, film polarisant, film polarisant multicouche, panneau d'affichage d'image, et dispositif d'affichage d'image
JPWO2019188779A1 (ja) * 2018-03-28 2020-12-17 日東電工株式会社 偏光子、偏光フィルム、積層偏光フィルム、画像表示パネル、および画像表示装置
JP2021185414A (ja) * 2018-03-28 2021-12-09 日東電工株式会社 偏光子、偏光フィルム、積層偏光フィルム、画像表示パネル、および画像表示装置
JP2021185415A (ja) * 2018-03-28 2021-12-09 日東電工株式会社 偏光子、偏光フィルム、積層偏光フィルム、画像表示パネル、および画像表示装置
JP7005803B1 (ja) 2020-10-26 2022-01-24 住友化学株式会社 積層体
JP2022070192A (ja) * 2020-10-26 2022-05-12 住友化学株式会社 積層体
WO2023286702A1 (fr) * 2021-07-15 2023-01-19 住友化学株式会社 Polariseur, plaque de polarisation, et dispositif d'affichage d'image
KR20240087665A (ko) 2021-10-25 2024-06-19 주식회사 쿠라레 폴리비닐알코올 필름

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TW201617652A (zh) 2016-05-16
TWI686630B (zh) 2020-03-01
CN106796319A (zh) 2017-05-31
KR20170068427A (ko) 2017-06-19

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