JP2001215326A - Manufacturing method for polarizing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a manufacturing method for a polarizing member by which a overlapping layer of a cross-linked resin excellent in adhesion strength to a polarizing plate can be attached. SOLUTION: In forming a cross-linked resin layer superposed on at least one side of a polarizing plate in two or more layers, a crosslinking processing is performed so that an upper layer is recoated on a lower layer whose crosslinking reaction is controlled to 10-50% and the rate of crosslinking reaction of the lower layer becomes 80% or more with the upper layer. The lower layer and the upper layer form a cross-linked structure mutually at the boundary face.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の技術分野】本発明は、偏光板に密着力に優れる
架橋樹脂の重畳層を付設できる偏光部材の製造方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a polarizing member which can be provided with a superposed layer of a crosslinked resin having excellent adhesion to a polarizing plate.

【０００２】[0002]

【発明の背景】従来、液晶表示装置の視認側偏光板の表
面に防眩層やハードコート層、透明導電層や帯電防止層
等からなる架橋樹脂の重畳層を設ける場合、各層を完全
キュアさせつつ重畳する各層を順次積み重ねて行く方法
が採られてきた。しかしながら上下の層の密着力に乏し
い問題点があった。2. Description of the Related Art Conventionally, when a superposed layer of a crosslinked resin comprising an antiglare layer, a hard coat layer, a transparent conductive layer, an antistatic layer and the like is provided on the surface of a polarizing plate on the viewing side of a liquid crystal display device, each layer is completely cured. A method of sequentially stacking layers to be superimposed has been adopted. However, there is a problem that the adhesion between the upper and lower layers is poor.

【０００３】[0003]

【発明の技術的課題】本発明は、偏光板に密着力に優れ
る架橋樹脂の重畳層を付設できる偏光部材の製造方法の
開発を課題とする。SUMMARY OF THE INVENTION An object of the present invention is to develop a method for manufacturing a polarizing member in which a superposed layer of a crosslinked resin having excellent adhesion can be provided on a polarizing plate.

【０００４】[0004]

【課題の解決手段】本発明は、偏光板の少なくとも片側
に２層以上が重畳した架橋樹脂層を形成するにあたり、
架橋反応率を１０〜５０％に制御した下層の上に上層を
重ね塗りしてその上層と共に下層を架橋反応率が８０％
以上となるように架橋処理することを特徴とする偏光部
材の製造方法を提供するものである。The present invention relates to forming a crosslinked resin layer in which two or more layers are overlapped on at least one side of a polarizing plate.
The upper layer is overcoated on the lower layer whose cross-linking reaction rate is controlled to 10 to 50%, and the lower layer together with the upper layer has a cross-linking reaction rate of 80%
An object of the present invention is to provide a method for producing a polarizing member, which comprises performing a crosslinking treatment as described above.

【０００５】[0005]

【発明の効果】本発明によれば、下層と上層がその界面
で相互に架橋構造を形成して密着力に優れる架橋樹脂の
重畳層を偏光板に付設することができる。According to the present invention, the lower layer and the upper layer form a crosslinked structure at the interface therebetween, and a superposed layer of a crosslinked resin having excellent adhesion can be provided on the polarizing plate.

【０００６】[0006]

【発明の実施形態】本発明による製造方法は、偏光板の
少なくとも片側に２層以上が重畳した架橋樹脂層を形成
するにあたり、架橋反応率を１０〜５０％に制御した下
層の上に上層を重ね塗りしてその上層と共に下層を架橋
反応率が８０％以上となるように架橋処理して偏光部材
を得るものである。BEST MODE FOR CARRYING OUT THE INVENTION In the production method according to the present invention, when forming a crosslinked resin layer in which two or more layers are superposed on at least one side of a polarizing plate, an upper layer is formed on a lower layer whose crosslink reaction rate is controlled to 10 to 50%. The polarizing member is obtained by repeatedly coating and cross-linking the lower layer together with the upper layer so that the cross-linking reaction rate becomes 80% or more.

【０００７】偏光板としては、偏光フィルムを透明保護
層で保護したもの、それと位相差板を積層した楕円偏光
板などの液晶表示装置等の形成に使用される適宜なもの
を用いることができ、その種類について特に限定はな
い。ちなみに前記偏光フィルムの例としては、ポリビニ
ルアルコール系フィルムや部分ホルマール化ポリビニル
アルコール系フィルム、エチレン・酢酸ビニル共重合体
系部分ケン化フィルムの如き親水性高分子フィルムにヨ
ウ素及び／又は二色性染料を吸着させて延伸したもの、
ポリビニルアルコールの脱水処理物やポリ塩化ビニルの
脱塩酸処理物の如きポリエン配向フィルムなどがあげら
れる。As the polarizing plate, a polarizing film protected with a transparent protective layer, and an appropriate one used for forming a liquid crystal display device such as an elliptically polarizing plate obtained by laminating the polarizing film and a retardation plate can be used. There is no particular limitation on the type. By the way, as an example of the polarizing film, iodine and / or a dichroic dye is added to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, and an ethylene / vinyl acetate copolymer-based partially saponified film. Stretched by adsorption,
Polyene oriented films such as dehydration products of polyvinyl alcohol and dehydrochlorination products of polyvinyl chloride are exemplified.

【０００８】また偏光フィルムの片側又は両側に設ける
透明保護層の形成には、例えばアセテート系樹脂やカー
ボネート系樹脂、アリレート系樹脂やスルホン系樹脂、
ポリエチレンテレフタレートやポリエチレンナフタレー
トの如きポリエステル系樹脂、ポリエーテルスルホン系
樹脂やポリアミド系樹脂、ポリイミド系樹脂やスチレン
系樹脂、環状ポリオレフィンの如きオレフィン系樹脂や
アクリル系樹脂、フッ素系樹脂などの適宜な透明樹脂を
用いうる。透明保護層は、樹脂液の塗布方式やフィルム
としたものの接着剤等を介した積層方式などの適宜な方
式にて形成することができる。For the formation of the transparent protective layer provided on one side or both sides of the polarizing film, for example, an acetate resin, a carbonate resin, an arylate resin, a sulfone resin,
Appropriate transparent materials such as polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone resins and polyamide resins, polyimide resins and styrene resins, olefin resins such as cyclic polyolefins, acrylic resins and fluorine resins. Resins may be used. The transparent protective layer can be formed by an appropriate method such as a method of applying a resin liquid or a method of forming a film through an adhesive or the like.

【０００９】一方、偏光板と積層して楕円偏光板を得る
ための位相差板の例としては、ポリカーボネートやポリ
ビニルアルコール、ポリスチレンやポリメチルメタクリ
レート、ポリプロピレンやその他のポリオレフィン、ポ
リアリレートやポリアミドの如き適宜なポリマーからな
るフィルムを延伸処理してなる複屈折性フィルム、配向
処理した液晶ポリマーやその配向層を透明フィルム基材
で支持したものなどがあげられる。位相差板は、２種以
上の位相差フィルム等を積層して位相差等の光学特性を
制御したものであってもよい。On the other hand, examples of a retardation plate for obtaining an elliptically polarizing plate by laminating a polarizing plate include an appropriate retardation plate such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene and other polyolefins, polyarylate and polyamide. Birefringent films formed by stretching a film made of a suitable polymer, liquid crystal polymers having been subjected to an alignment treatment, and those having an alignment layer supported by a transparent film substrate. The retardation plate may be one in which two or more kinds of retardation films or the like are laminated to control optical characteristics such as retardation.

【００１０】偏光板と位相差板との積層には光学特性の
維持性等の点より粘着層が好ましく用いうるがその粘着
層の形成には、例えばアクリル系重合体やシリコーン系
ポリマー、ポリエステルやポリウレタン、ポリエーテル
や合成ゴムなどの適宜なポリマーをベースポリマーとす
る粘着剤を用いることができ、特に限定はない。就中ア
クリル系粘着剤の如く光学的透明性に優れ、適度な濡れ
性と凝集性と接着性等の粘着特性を示すものが好まし
く、それに加えて耐候性や耐熱性などにも優れるものが
特に好ましい。For laminating a polarizing plate and a retardation plate, an adhesive layer can be preferably used from the viewpoint of maintaining optical characteristics. For example, an acrylic polymer, a silicone polymer, a polyester, An adhesive having an appropriate polymer such as polyurethane, polyether or synthetic rubber as a base polymer can be used, and there is no particular limitation. Among them, those having excellent optical transparency such as acrylic pressure-sensitive adhesives and exhibiting adhesive properties such as appropriate wettability, cohesiveness and adhesiveness are preferable, and those having excellent weather resistance and heat resistance in addition to the above are particularly preferable. preferable.

【００１１】ちなみに前記のアクリル系粘着剤の例とし
ては、メチル基やエチル基、ブチル基やエチルヘキシル
基等の炭素数が２０以下のアルキル基を有する（メタ）
アクリル酸のアルキルエステルの１種又は２種以上を主
成分に用いたアクリル系重合体やそれに必要に応じて粘
着特性の改質等を目的にアクリル酸系アルキルエステル
以外の適宜なモノマー成分の１種又は２種以上を共重合
したものをベースポリマーとするものなどがあげられ
る。Incidentally, examples of the acrylic pressure-sensitive adhesive include an alkyl group having 20 or less carbon atoms such as a methyl group, an ethyl group, a butyl group, and an ethylhexyl group (meth).
Acrylic polymer using one or more alkyl ester of acrylic acid as a main component, and one of appropriate monomer components other than acrylic acid alkyl ester for the purpose of improving adhesive properties as required. Examples of the base polymer include those obtained by copolymerizing a kind or two or more kinds.

【００１２】偏光板や位相差板への粘着層の付設は、例
えば粘着剤液を流延方式や塗工方式等の適宜な展開方式
で偏光板等の上に直接付設する方式、あるいは前記に準
じセパレータ上に粘着層を形成してそれを偏光板等の上
に移着する方式などの適宜な方式で行うことができる。
粘着層の厚さは、接着力等に応じて適宜に決定でき一般
には１〜５００μmとされる。粘着層には、必要に応じ
て例えば天然物や合成物の樹脂類、就中、粘着性付与樹
脂、充填剤や顔料、着色剤や酸化防止剤などの適宜な添
加剤を配合でき、透明粒子を配合して光拡散性を示す粘
着層とすることもできる。また粘着層は、異なる組成又
は種類等のものの重畳層として設けることもできる。The attachment of the pressure-sensitive adhesive layer to the polarizing plate or the retardation plate may be performed, for example, by directly applying the pressure-sensitive adhesive liquid on the polarizing plate or the like by an appropriate developing method such as a casting method or a coating method. An appropriate method such as a method in which an adhesive layer is formed on a separator and then transferred onto a polarizing plate or the like can be used.
The thickness of the pressure-sensitive adhesive layer can be appropriately determined according to the adhesive strength and the like, and is generally 1 to 500 μm. If necessary, the adhesive layer may contain, for example, natural or synthetic resins, especially, tackifying resins, fillers and pigments, and appropriate additives such as coloring agents and antioxidants. Can be added to form an adhesive layer exhibiting light diffusion. Further, the adhesive layer can be provided as a superimposed layer of different compositions or types.

【００１３】偏光板の片側又は両側に設ける重畳層の形
成には、例えばアクリル系やウレタン系、アクリルウレ
タン系やエポキシ系、シリコーン系などの熱や紫外線等
で硬化する適宜な樹脂の１種又は２種以上を用いること
ができる。就中、透明性や硬度等に優れるものが好まし
く用いられる。重畳層は、２層又は３層以上のものとし
て形成されるが、その重畳の各層を形成する硬化型樹脂
は、同種のものであってもよいし、異種のものであって
もよい。密着力や密着界面での反射を防止する点などよ
りは同種のものであることが好ましい。The formation of the superimposed layer provided on one side or both sides of the polarizing plate may be performed by, for example, one of an appropriate resin such as an acrylic resin, a urethane resin, an acrylic urethane resin, an epoxy resin, and a silicone resin which is cured by heat, ultraviolet light, or the like. Two or more types can be used. Among them, those excellent in transparency and hardness are preferably used. The superposed layers are formed as two or three or more layers, and the curable resins forming the superposed layers may be of the same type or different types. It is preferable that they are of the same type rather than to prevent adhesion at the contact force or reflection at the contact interface.

【００１４】重畳層の形成は、例えば硬化型樹脂の塗工
液を重ね塗りする方式などにより行いうるが、その場合
に本発明においては先に塗工形成した下層の架橋処理を
その架橋反応率が１０〜５０％、就中２０〜４５％、特
に３０〜４０％となった状態で一旦停止し、その架橋制
御した下層の上に上層を重ね塗りしてその上層と共に下
層を架橋反応率が８０％以上、就中８５％以上、特に９
０％以上となるように架橋処理される。これにより下層
の皮膜強度を抑制して上層の馴染み性を向上でき上下の
層の密着力に優れると共に、硬度に優れる重畳層とする
ことができる。The superposed layer can be formed by, for example, a method in which a coating liquid of a curable resin is overcoated. In this case, in the present invention, the cross-linking treatment of the lower layer previously formed by coating is carried out by the cross-linking reaction rate. Is temporarily stopped at 10 to 50%, especially 20 to 45%, especially 30 to 40%, and the upper layer is overcoated on the lower layer whose crosslinking is controlled, and the lower layer together with the upper layer has a cross-linking reaction rate. 80% or more, especially 85% or more, especially 9
Crosslinking treatment is performed so as to be 0% or more. As a result, the film strength of the lower layer is suppressed, the conformability of the upper layer can be improved, and the superposed layer having excellent adhesion between the upper and lower layers and excellent hardness can be obtained.

【００１５】なお３層以上の重畳層の場合、前記の下層
は最上層よりも下層の中間層を含む全体として定義され
る。すなわち更に上層を形成する必要のある内は、前記
の重ね塗りの対象となる下層が５０％以下の架橋反応率
にあることが優先され、従って当該下層よりも更に下層
は架橋反応率が８０％未満であってもよく、最終の上層
が形成された場合にその全ての下層が８０％以上の架橋
反応率にあればよい。In the case of three or more superposed layers, the lower layer is defined as a whole including an intermediate layer lower than the uppermost layer. That is, while it is necessary to further form the upper layer, it is preferred that the lower layer to be overcoated has a cross-linking reaction rate of 50% or less, so that the lower layer further than the lower layer has a cross-linking reaction rate of 80%. When the final upper layer is formed, all the lower layers may have a crosslinking reaction rate of 80% or more.

【００１６】上記において架橋樹脂の重畳層を形成する
各層は、例えば防眩層やハードコート層、透明導電層や
帯電防止層などの適宜な目的を有するものであってよ
い。ちなみに前記の防眩層は、表面での反射光を散乱さ
せて蛍光灯の外景の映り込みによる視認阻害を防止する
ことを目的とし通例、透明微粒子を含有して表面に微細
凹凸構造を有する架橋樹脂層として形成される。In the above, each layer forming the superposed layer of the crosslinked resin may have a suitable purpose such as, for example, an antiglare layer, a hard coat layer, a transparent conductive layer or an antistatic layer. Incidentally, the anti-glare layer is intended to scatter reflected light on the surface to prevent visual disturbance due to reflection of the external view of the fluorescent lamp, and usually contains transparent fine particles and has a fine uneven structure on the surface. It is formed as a resin layer.

【００１７】また透明導電層や帯電防止層は、電磁波の
遮蔽や帯電防止等を目的とし透明導電材や界面活性剤等
を含有する架橋樹脂層などとして形成される。従って架
橋樹脂層には、目的とする機能に応じて当該透明微粒子
などの適宜な添加剤を配合することができる。かかる架
橋樹脂層の形成は、それを形成するモノマー系の架橋型
樹脂に必要な添加剤を配合して塗工しそれを硬化処理す
る方式などにより行うことができる。The transparent conductive layer and the antistatic layer are formed as a crosslinked resin layer containing a transparent conductive material, a surfactant and the like for the purpose of shielding electromagnetic waves and preventing static charge. Therefore, an appropriate additive such as the transparent fine particles can be added to the crosslinked resin layer according to the intended function. Such a crosslinked resin layer can be formed by, for example, a method in which a necessary additive is mixed with a monomeric crosslinkable resin forming the same, and the mixture is applied and cured.

【００１８】なお前記した透明微粒子や透明導電材に
は、例えばシリカやアルミナ、チタニアやジルコニア、
酸化錫や酸化インジウム、インジウム・錫混合酸化物や
酸化チタン、酸化カドミウムや酸化アンチモン等からな
る、導電性のこともある無機系粒子、架橋又は未架橋の
ポリマー等からなる有機系粒子などの適宜なものを用い
うる。The transparent fine particles and the transparent conductive material include, for example, silica, alumina, titania, zirconia,
As appropriate, such as inorganic particles that may be conductive, such as tin oxide, indium oxide, indium-tin mixed oxide, titanium oxide, cadmium oxide, and antimony oxide, and organic particles that include a crosslinked or uncrosslinked polymer. Can be used.

【００１９】また上記したハードコート層は、表面の傷
付き防止などを目的とし、特に指紋等の汚れを付着しに
くくし、また付着した汚れを払拭しやすくする場合など
にはフッ素系の架橋型樹脂などが好ましく用いられる。The above-mentioned hard coat layer is used for the purpose of preventing the surface from being scratched, etc. In particular, when the stains such as fingerprints are hardly adhered and the adhered stains are easily wiped off, the fluorine-based cross-linking type is used. Resins and the like are preferably used.

【００２０】なお重畳層を形成する各架橋樹脂層の厚さ
は、その機能等に応じて適宜に決定されるが一般には、
５０μm以下、就中０．１〜３０μm、特に０．５〜２０
０μmとされる。重畳層を設ける偏光板の表面には、密
着力の向上等を目的にコロナ処理や紫外線照射処理、プ
ラズマ処理やスパッタエッチング処理、アンダーコート
処理等の適宜な処理を施すことができる。The thickness of each crosslinked resin layer forming the superposed layer is appropriately determined according to its function and the like.
50 μm or less, especially 0.1 to 30 μm, especially 0.5 to 20
0 μm. Appropriate treatment such as corona treatment, ultraviolet irradiation treatment, plasma treatment, sputter etching treatment, and undercoat treatment can be applied to the surface of the polarizing plate provided with the superposed layer for the purpose of improving the adhesion.

【００２１】また偏光部材を形成する偏光板や架橋樹脂
層等の各層には、例えばサリチル酸エステル系化合物や
ベンゾフェノン系化合物、ベンゾトリアゾール系化合物
やシアノアクリレート系化合物、ニッケル錯塩系化合物
等の紫外線吸収剤で処理する方式などにより紫外線吸収
能をもたせることもできる。本発明による偏光部材は、
液晶表示装置等の各種表示装置などに好ましく適用する
ことができ、その実用に際しては液晶セル等の他部材と
の接着を目的とした粘着層を予め設けることもできる。Each layer such as a polarizing plate and a crosslinked resin layer forming the polarizing member is provided with an ultraviolet absorbent such as a salicylic acid ester compound, a benzophenone compound, a benzotriazole compound, a cyanoacrylate compound, a nickel complex salt compound, or the like. UV-absorbing ability can be imparted by a method of treating with UV light. The polarizing member according to the present invention,
The present invention can be preferably applied to various display devices such as a liquid crystal display device, and in practical use, an adhesive layer for the purpose of bonding to another member such as a liquid crystal cell can be provided in advance.

【００２２】[0022]

【実施例】実施例１ 紫外線硬化型の多官能オリゴマー１００部（重量部、以
下同じ）に光重合開始剤１部を配合して偏光板の片面に
バーコータにて塗布し高圧水銀灯を介し紫外線で架橋反
応率が５０％以下となるように硬化処理して厚さ１０μ
mの予備下層を形成した後、その上に前記多官能オリゴ
マー１００部に光重合開始剤５部を配合してそれをバー
コータにて塗布し高圧水銀灯を介し紫外線で硬化処理
し、さらに加熱による後キュア処理を加えて厚さ１μm
の上層を形成し、偏光部材を得た。Example 1 One part of a photopolymerization initiator was mixed with 100 parts (parts by weight, the same applies hereinafter) of an ultraviolet-curable polyfunctional oligomer, applied to one surface of a polarizing plate with a bar coater, and irradiated with ultraviolet light through a high-pressure mercury lamp. Curing treatment to reduce the cross-linking reaction rate to 50% or less
After forming a preliminary lower layer of m, 100 parts of the polyfunctional oligomer is mixed with 5 parts of a photopolymerization initiator, applied with a bar coater, cured with ultraviolet light through a high-pressure mercury lamp, and further heated. 1μm thick with cure
Was formed to obtain a polarizing member.

【００２３】前記の偏光部材における架橋反応率を、Ｆ
Ｔ−ＩＲ−ＡＴＲ法によるスペクトルにて調べた結果、
上下層共に８４％であった。また上下層のスクラッチ
性、密着性を調べた結果、その両者に優れていた。The cross-linking reaction rate of the polarizing member is expressed by F
As a result of examining the spectrum by the T-IR-ATR method,
Both the upper and lower layers were 84%. Further, as a result of examining the scratch property and the adhesion of the upper and lower layers, both were excellent.

【００２４】比較例１ 光重合開始剤の配合量を５部として架橋反応率が８０％
の予備下層を形成したほかは実施例１に準じて偏光部材
を得た。その偏光部材における架橋反応率は、上下層共
に８４％で上下層のスクラッチ性に優れていたが、密着
性が不良であった。Comparative Example 1 The crosslinking reaction rate was 80% when the amount of the photopolymerization initiator was 5 parts.
A polarizing member was obtained in the same manner as in Example 1 except that the preliminary lower layer was formed. The cross-linking reaction rate of the polarizing member was 84% for both the upper and lower layers, indicating that the upper and lower layers were excellent in the scratch property, but the adhesion was poor.

【００２５】比較例２ 実施例１に準じて架橋反応率が上下層共に６８％の偏光
部材を得たが、これは上下層の密着性に優れていたがス
クラッチ性が不良であった。Comparative Example 2 A polarizing member having a cross-linking reaction rate of 68% for both the upper and lower layers was obtained according to Example 1. This polarizing plate had excellent adhesion between the upper and lower layers but had poor scratching properties.

フロントページの続き (72)発明者 松永 卓也 大阪府茨木市下穂積１丁目１番２号日東電 工株式会社内 (72)発明者 正田 位守 大阪府茨木市下穂積１丁目１番２号日東電 工株式会社内 Ｆターム(参考） 2H049 BA02 BA04 BA06 BA26 BB23 BB24 BB25 BB26 BB27 BB28 BB34 BB36 BB43 BB51 BB62 BB63 BB67 BC09 4F100 AK01B AK01C AR00A BA03 BA07 BA10A BA10C BA13 CC00B EH461 EH462 EJ05B EJ05C EJ051 EJ052 EJ541 EJ542 GB41 JA20B JA20C JB14B JB14C JK06 JN10A YY00B YY00C Continuing from the front page (72) Inventor Takuya Matsunaga 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Tomomori Masada 1-1-2 Shimohozumi, Ibaraki-shi, Osaka F-term in TEPCO (reference) 2H049 BA02 BA04 BA06 BA26 BB23 BB24 BB25 BB26 BB27 BB28 BB34 BB36 BB43 BB51 BB62 BB63 BB67 BC09 4F100 AK01B AK01C AR00A BA03 BA07 BA10A BA10C BA13 CC00BEJ05 E05 EB01 541 JB14B JB14C JK06 JN10A YY00B YY00C

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 偏光板の少なくとも片側に２層以上が重
畳した架橋樹脂層を形成するにあたり、架橋反応率を１
０〜５０％に制御した下層の上に上層を重ね塗りしてそ
の上層と共に下層を架橋反応率が８０％以上となるよう
に架橋処理することを特徴とする偏光部材の製造方法。When forming a crosslinked resin layer in which two or more layers are overlapped on at least one side of a polarizing plate, the crosslinking reaction rate is 1
A method for producing a polarizing member, comprising coating an upper layer on a lower layer controlled at 0 to 50%, and subjecting the lower layer together with the upper layer to a crosslinking treatment so that a crosslinking reaction rate becomes 80% or more.