JPH06298957A - Light-reflecting sheet - Google Patents
Light-reflecting sheetInfo
- Publication number
- JPH06298957A JPH06298957A JP5084411A JP8441193A JPH06298957A JP H06298957 A JPH06298957 A JP H06298957A JP 5084411 A JP5084411 A JP 5084411A JP 8441193 A JP8441193 A JP 8441193A JP H06298957 A JPH06298957 A JP H06298957A
- Authority
- JP
- Japan
- Prior art keywords
- light
- film
- resin
- sheet
- reflecting sheet
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光反射シートおよびこれ
を用いてなる液晶表示のためのバックライト装置に関す
る。詳しくは本発明は、無機充填剤を含む合成樹脂フィ
ルムを延伸してなる光反射シートおよびこれを用いてな
る液晶表示のためのバックライト装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light reflecting sheet and a backlight device for liquid crystal display using the same. More specifically, the present invention relates to a light reflection sheet formed by stretching a synthetic resin film containing an inorganic filler and a backlight device for liquid crystal display using the light reflection sheet.
【０００２】本発明の光反射シートは、ワードプロセッ
サーやパーソナルコンピューター、カラー型液晶テレビ
の液晶表示パネルのバックライト、照明器具や複写機、
プロジェクター方式のディスプレイ等に使用するのに適
している。The light reflecting sheet of the present invention is applied to a word processor, a personal computer, a backlight of a liquid crystal display panel of a color liquid crystal television, a lighting device, a copying machine,
Suitable for use in projector type displays.
【０００３】[0003]
【従来の技術】近年、液晶表示装置はあらゆる分野で使
用されてきており、特に、ワードプロセッサーやパーソ
ナルコンピューター、テレビ等の電子産業分野で数多く
使用されており、薄型で省電力であることを特徴として
いる。この特徴を生かすために使用するバックライトも
薄型で省電力であることが要求されている。2. Description of the Related Art In recent years, liquid crystal display devices have been used in all fields, especially in the electronic industry fields such as word processors, personal computers, and televisions, and are characterized by being thin and power saving. There is. The backlight used to take advantage of this feature is also required to be thin and to save power.
【０００４】バックライトから供給する光量を大きくす
るためには、バックライトに用いる光反射シートの光の
反射率が問題となり、反射率が高く、高輝度が得られる
バックライト用の反射シートが要求されている。In order to increase the amount of light supplied from the backlight, the light reflectance of the light reflection sheet used for the backlight becomes a problem, and a reflection sheet for a backlight having high reflectance and high brightness is required. Has been done.
【０００５】バックライトには図１で示した様に、光源
を透明な導光板の横に配置する方式（サイドライト方
式）と直接光源を液晶部の後部に配置する方式とがあ
る。液晶表示装置を薄型化するためにはサイドライト方
式が適している。しかし、導光板を用いたバックライト
は、導光板を経由する光の一部を液晶部に伝え、更に導
光板を経由する光の残部を光反射シートで反射せしめて
再び導光板に戻して光を有効に利用するものであるた
め、導光板と光反射シート間の光の漏れや、導光板，反
射シートによる光の吸収等により、直接光源を液晶部の
後部におく方式よりも液晶部に伝わる光量が少なくな
る。従って、導光板の下におく光反射シートは、光の反
射率がより高く、吸収率の低いものが要求されている。As shown in FIG. 1, the backlight has a system in which a light source is arranged beside a transparent light guide plate (sidelight system) and a system in which a light source is directly arranged in the rear part of a liquid crystal section. The sidelight method is suitable for reducing the thickness of the liquid crystal display device. However, in a backlight using a light guide plate, a part of the light passing through the light guide plate is transmitted to the liquid crystal part, and the remaining part of the light passing through the light guide plate is reflected by the light reflecting sheet and returned to the light guide plate again to emit light. Since the light source is effectively used, the light source is placed in the liquid crystal part more than the method in which the light source is directly placed in the rear part of the liquid crystal part due to light leakage between the light guide plate and the light reflection sheet and absorption of light by the light guide plate and the reflection sheet. Less light is transmitted. Therefore, the light reflection sheet placed under the light guide plate is required to have a higher light reflectance and a lower absorptance.
【０００６】また、一方で、現在、液晶表示面のカラー
化や大型化が望まれており、さらに液晶の表示品位を向
上させる必要がでてきており、この要望に応えるために
も、液晶表示装置に用いるバックライトには少しでも多
くの光を液晶部に供給することが強いられている。On the other hand, at present, there is a demand for colorization and size increase of the liquid crystal display surface, and it is necessary to further improve the display quality of the liquid crystal. In order to meet this demand, the liquid crystal display is required. The backlight used in the device is required to supply as much light as possible to the liquid crystal part.
【０００７】従来の光反射体として用いられてきた、ア
ルミ等の金属板の表面に銀を主成分とする金属薄膜層を
有する光反射フィルムを貼合わせた光反射板では光の反
射率は極めて高いが、拡散反射率が低いためバックライ
ト用反射シートとして用いると輝度むらが生じ、特開平
２−１３９２５号に示されるようなアルミ等の金属板上
に白色顔料を塗布した反射板、特開昭５９−８７８２号
に示されるような白色の無機充填剤を含有するポリエチ
レンテレフタレート（以下ＰＥＴと略す）シートからな
る反射シートでは、光の反射が顔料でのみ起こっている
ために十分な光の反射が得られなかった。また、特開昭
６３−１６１０２９号に示されるような、炭酸カルシウ
ムを含有するＰＥＴシートやＰＥＴを主成分とする樹脂
シートを延伸させた反射シートでは、顔料による光の反
射の他に延伸時に形成される空孔による光の反射も得ら
れるが、ＰＥＴと空孔との界面での光の反射が十分では
なく、かかる要請に応えるには不十分であった。A light reflection plate, which has been used as a conventional light reflector, has a light reflection film having a metal thin film layer containing silver as a main component bonded to the surface of a metal plate such as aluminum, and has a very high light reflectance. Although it has a high diffuse reflectance, it has uneven brightness when used as a reflective sheet for a backlight, and a reflector having a white pigment coated on a metal plate such as aluminum as disclosed in JP-A-2-13925, In a reflective sheet made of a polyethylene terephthalate (hereinafter abbreviated as PET) sheet containing a white inorganic filler as shown in JP-A-59-8782, sufficient reflection of light occurs because reflection of light occurs only with a pigment. Was not obtained. Further, in a reflection sheet obtained by stretching a PET sheet containing calcium carbonate or a resin sheet containing PET as a main component as shown in JP-A-63-161029, in addition to the reflection of light by the pigment, it is formed at the time of stretching. Although the reflection of light by the pores can be obtained, the reflection of light at the interface between PET and the pores is not sufficient, and it was insufficient to meet such a request.
【０００８】[0008]
【発明が解決しようとする課題】本発明の目的は、これ
らの問題を解決し、従来の光反射シートに比べて、光の
反射率が大幅に向上せしめられ、しかも、輝度むらのな
い、高輝度が得られる、優れた光反射シート、その製造
方法および前記光反射シートを用いてなる液晶表示のた
めのバックライト装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and to significantly improve the light reflectance as compared with the conventional light reflecting sheet, and to have a high brightness without uneven brightness. An object of the present invention is to provide an excellent light-reflecting sheet capable of obtaining brightness, a method of manufacturing the same, and a backlight device for liquid crystal display using the light-reflecting sheet.
【０００９】[0009]
【課題を解決するための手段】本発明者らは、屈折率が
小さい樹脂に白色の無機充填剤を含有させ、延伸を行な
うと、光の反射が無機充填剤だけでなく、延伸時に形成
される空孔と樹脂の界面で効率的に行なわれることを見
出した。更に無機充填剤の量が２５〜７５重量部でかつ
延伸倍率が１．２〜１５倍である場合に相乗的に反射率
が向上することを見出し、本発明を完成させるに至っ
た。Means for Solving the Problems The present inventors have made a resin having a small refractive index contain a white inorganic filler, and when stretching is performed, light reflection is formed not only in the inorganic filler but also in the stretching. It has been found that this is done efficiently at the interface between the holes and the resin. Further, it was found that the reflectance is synergistically improved when the amount of the inorganic filler is 25 to 75 parts by weight and the draw ratio is 1.2 to 15 times, and the present invention has been completed.
【００１０】即ち本発明の要旨は、第一に屈折率が１．
６未満である樹脂７５〜２５重量部と無機充填剤２５〜
７５重量部からなり、かつ、面積延伸倍率が１．２〜１
５倍であることを特徴とする光反射シート、第二に屈折
率が１．６未満である樹脂７５〜２５重量部と無機充填
剤２５〜７５重量部からなる樹脂組成物を製膜後、面積
延伸倍率が１．２〜１５倍となるように少なくとも一軸
方向に延伸することを特徴とする光反射シートの製造方
法、および第三に前記光反射シートを用いることを特徴
とする液晶表示のためのバックライト装置にある。That is, the gist of the present invention is that the refractive index is 1.
75 to 25 parts by weight of resin which is less than 6 and inorganic filler 25 to
It consists of 75 parts by weight and the area draw ratio is 1.2 to 1.
5 times the light reflection sheet, secondly, after forming a resin composition consisting of 75 to 25 parts by weight of a resin having a refractive index of less than 1.6 and 25 to 75 parts by weight of an inorganic filler, A method for producing a light-reflecting sheet, which comprises stretching in at least a uniaxial direction so that an area stretching ratio is 1.2 to 15 times, and thirdly, a liquid crystal display characterized by using the light-reflecting sheet. There is a backlight device for.
【００１１】本発明で使用する樹脂の屈折率は１．６未
満が好ましく、１．５６未満が更に好ましい。屈折率が
１．６未満である樹脂としては、ポリエチレン、ポリプ
ロピレンおよびこれらのコポリマーが例示される。樹脂
の屈折率がこの範囲内にある場合、無機充填剤を含む樹
脂からなるフィルムを延伸した場合、延伸時に形成され
る空孔と樹脂自体の界面での光の乱反射が効率良く行わ
れるために光の反射率の高いフィルムが得られる。一
方、屈折率が１．６以上である樹脂を用いた場合、フィ
ルムの延伸を行っても、空孔と樹脂の屈折率の差が大き
いために界面での光の反射が十分に得られず、光の反射
率の高いフィルムとはならない。The refractive index of the resin used in the present invention is preferably less than 1.6, more preferably less than 1.56. Examples of the resin having a refractive index of less than 1.6 include polyethylene, polypropylene and copolymers thereof. When the refractive index of the resin is within this range, when a film made of a resin containing an inorganic filler is stretched, diffuse reflection of light at the interface between the pores formed during stretching and the resin itself is efficiently performed. A film having a high light reflectance can be obtained. On the other hand, when a resin having a refractive index of 1.6 or more is used, even if the film is stretched, sufficient reflection of light at the interface cannot be obtained due to the large difference in refractive index between the holes and the resin. , The film does not have high light reflectance.
【００１２】無機充填剤としては、炭酸カルシウム、硫
酸バリウム、酸化チタン、炭酸マグネシウム等が挙げら
れ、これらは単独で、または二種類以上混合して使用す
ることが出来る。該充填剤の含有量は、通常、樹脂７５
〜２５重量部に対して、２５〜７５重量部である。該充
填剤の含有量がこの範囲内にある場合は、延伸により、
空孔が形成されるために白色度が増加する。逆に該充填
剤の含有量が２５重量部未満の場合、延伸時に形成され
る空孔が少ないために、フィルムの延伸による白色度の
増加も少なくなり、逆に７５重量部を超えると、白色度
は増すが、延伸後のフィルム強度が極端に低下する。Examples of the inorganic filler include calcium carbonate, barium sulfate, titanium oxide, magnesium carbonate and the like, and these can be used alone or in combination of two or more kinds. The content of the filler is usually 75
25 to 75 parts by weight with respect to 25 parts by weight. When the content of the filler is within this range, by stretching,
The whiteness increases due to the formation of holes. On the other hand, when the content of the filler is less than 25 parts by weight, the number of pores formed during stretching is small, so that the increase in whiteness due to the stretching of the film is also small. However, the film strength after stretching is extremely reduced.
【００１３】本発明に使用する光反射シートは、該充填
剤を含む樹脂組成物を製膜後、少なくとも一軸方向に延
伸することにより得られる。The light-reflecting sheet used in the present invention is obtained by forming a resin composition containing the filler into a film and then stretching the resin composition in at least one axial direction.
【００１４】該樹脂と該充填剤の混合は製膜前にあらか
じめ行なっておくことが好ましく、例えば、重合時添加
法やドライブレンド法がある。混合後の樹脂組成物の形
態はポリマチップ状、粉末状等、溶融製膜を行ないやす
い形状が好ましい。また、分散の際にステアリン酸カル
シウム等の分散安定剤を少量添加してもよい。製膜法と
しては、押出法、カレンダー法、インフレ法等公知の製
膜法が挙げられる。The resin and the filler are preferably mixed in advance before film formation, and examples thereof include an addition method during polymerization and a dry blending method. The form of the resin composition after mixing is preferably a polymer chip form, a powder form, or the like that facilitates melt film formation. A small amount of a dispersion stabilizer such as calcium stearate may be added during dispersion. Examples of the film forming method include known film forming methods such as an extrusion method, a calendar method and an inflation method.
【００１５】フィルムの延伸は、一軸延伸、二軸延伸
等、公知の方法が適宜採用できる。一軸延伸法として
は、例えば、ロール延伸法がある。For stretching the film, known methods such as uniaxial stretching and biaxial stretching can be appropriately adopted. Examples of the uniaxial stretching method include a roll stretching method.
【００１６】ポリエチレンフィルムを延伸する場合を例
にとって説明する。まず、２００℃〜２４０℃の温度で
Ｔダイ法により製膜したフィルムを３０℃〜６０℃の冷
却ドラムで冷却せしめ、未延伸フィルムとした後に、６
０℃〜１００℃に加熱した余熱ロール群に導き、２０℃
〜３０℃の冷却ロール群で冷却した後、巻き取る。この
際、余熱ロール群の回転速度と冷却ロール群の回転速度
の差によりフィルムの延伸を行なう。延伸時の延伸倍率
は面積延伸倍率で通常１．２〜１５倍である。面積延伸
倍率がこの範囲内にある場合は、延伸によってフィルム
に塑性変形を起こさせ、空孔が生じるために白色度が増
加し、より高い輝度をもたらす光反射シートになる。し
かし、面積延伸倍率が１．２倍未満の場合、フィルムの
塑性変形が生じにくく、空孔の形成が少ないために、反
射率の高い光反射シートは得られない。一方、面積延伸
倍率が１５倍を超える場合、フィルムの強度が低下し、
破れ等が生じ易くなる。The case of stretching a polyethylene film will be described as an example. First, the film formed by the T-die method at a temperature of 200 ° C. to 240 ° C. is cooled by a cooling drum of 30 ° C. to 60 ° C. to obtain an unstretched film, and then 6
Lead to a group of preheated rolls heated to 0 ℃ to 100 ℃, 20 ℃
After being cooled by a cooling roll group at -30 ° C, it is wound up. At this time, the film is stretched by the difference between the rotation speed of the residual heat roll group and the rotation speed of the cooling roll group. The stretching ratio during stretching is usually 1.2 to 15 times in area stretching ratio. When the area stretching ratio is within this range, the film is plastically deformed by stretching, and voids are generated to increase whiteness, resulting in a light reflecting sheet that provides higher brightness. However, when the area stretch ratio is less than 1.2 times, the film is less likely to be plastically deformed and the number of pores formed is small, so that a light reflecting sheet having a high reflectance cannot be obtained. On the other hand, when the area stretch ratio exceeds 15 times, the strength of the film decreases,
Tear easily occurs.
【００１７】ポリプロピレンフィルムを延伸する場合適
宜ポリエチレンフィルムを延伸する場合にならって条件
が決定される。In the case of stretching a polypropylene film, the conditions are determined appropriately according to the case of stretching a polyethylene film.
【００１８】本発明で使用する光反射シートの厚みは通
常２０〜８００μｍであり、５０〜５００μｍが更に好
ましい。厚みが２０μｍ未満の場合、光の反射率が劣る
傾向にあり、逆に８００μｍを超えても光の反射率は変
わらないが、生産効率が悪くなる。The thickness of the light reflecting sheet used in the present invention is usually 20 to 800 μm, more preferably 50 to 500 μm. When the thickness is less than 20 μm, the light reflectance tends to be poor, and on the contrary, when it exceeds 800 μm, the light reflectance does not change, but the production efficiency deteriorates.
【００１９】また、本発明により得た、フィルム１枚を
光反射シートとして用いてもよいが、複数枚積層して用
いても良く、強度を補うため等の理由により適宜他のフ
ィルムと積層して用いても良い。しかし、他のフィルム
を積層して用いる場合は、本発明により得たフィルムを
上面（導光板に面した面）になるように積層しなければ
ならない。Further, one film obtained according to the present invention may be used as a light reflecting sheet, but a plurality of films may be laminated and used, and may be appropriately laminated with another film for the reason of supplementing strength. You may use it. However, when other films are laminated and used, the film obtained by the present invention must be laminated so as to be the upper surface (the surface facing the light guide plate).
【００２０】以下、本発明の光反射シートを図１の液晶
表示のためのバックライト装置に使用した場合について
説明する。無機充填剤を含む光反射シート１は本発明の
光反射シートである。光源部２は通常使用される光源で
ある。ランプハウス用光反射板３として、通常銀フィル
ムが使用され、白色顔料入りポリエチレンテレフタレー
トシートまたはフィルムが使用される場合もある。導光
板４としてポリメチルメタアクリレート（ＰＭＭＡ）が
汎用される。光拡散フィルム５としてポリエチレンテレ
フタレートシートまたはフィルムの表面処理品（エンボ
ス加工品）が汎用される。The case where the light reflecting sheet of the present invention is used in the backlight device for liquid crystal display of FIG. 1 will be described below. The light reflecting sheet 1 containing an inorganic filler is the light reflecting sheet of the present invention. The light source unit 2 is a light source that is normally used. As the light reflection plate 3 for a lamp house, a silver film is usually used, and a polyethylene terephthalate sheet or film containing a white pigment may be used in some cases. Polymethylmethacrylate (PMMA) is commonly used as the light guide plate 4. As the light diffusion film 5, a polyethylene terephthalate sheet or a film surface-treated product (embossed product) is generally used.
【００２１】[0021]
【実施例】以下、実施例により本発明を詳しく説明す
る。 実施例１ ７０重量％の炭酸カルシウムＳＳＴ−４０（同和カルフ
ァイン（株）製）を含む屈折率が１．５３であるポリエ
チレン（三井石油化学工業（株）製、ウルトゼックス２
０２１Ｌ）樹脂を２２０℃でＴダイ法により押し出し製
膜後、５０℃の冷却ロールで冷却せしめ未延伸フィルム
とした後、８０℃に加熱した余熱ロール群に導き、縦一
軸に面積延伸倍率で５倍に延伸を行い、次いで３０℃の
冷却ロールで冷却した後巻取り、厚み３１０μｍの光反
射シートを作成した。このシートを導光板方式のバック
ライト装置（富士通（株）製）の光反射シートの位置に
設置し、導光板上での輝度を測定した。その結果を表１
に示す。輝度測定には、ミノルタカメラ（株）製、輝度
計ＬＳ−１１０型を用いた。このフィルムの光線反射率
も合わせて表１に示す。光線透過率は、日立製作所
（株）製、分光光度計Ｕ−３４００を用いて測定し、波
長５５０ｎｍの光の反射率を代表値として用いた。The present invention will be described in detail below with reference to examples. Example 1 Polyethylene containing 70% by weight of calcium carbonate SST-40 (manufactured by Dowa Calfine Co., Ltd.) and having a refractive index of 1.53 (manufactured by Mitsui Petrochemical Industry Co., Ltd., Ultzex 2)
(021 L) The resin was extruded at 220 ° C by the T-die method to form an unstretched film by cooling with a cooling roll at 50 ° C, and then led to a preheated roll group heated to 80 ° C to give a longitudinal uniaxial stretch ratio of 5 The film was stretched twice, then cooled with a cooling roll at 30 ° C. and then wound up to form a light reflection sheet having a thickness of 310 μm. This sheet was placed at the position of a light reflecting sheet of a light guide plate type backlight device (manufactured by Fujitsu Limited), and the brightness on the light guide plate was measured. The results are shown in Table 1.
Shown in. A luminance meter LS-110 type manufactured by Minolta Camera Co., Ltd. was used for the luminance measurement. The light reflectance of this film is also shown in Table 1. The light transmittance was measured using a spectrophotometer U-3400 manufactured by Hitachi Ltd., and the reflectance of light having a wavelength of 550 nm was used as a representative value.
【００２２】実施例２ ５０重量％の硫酸バリウムＨＤ（バライト工業（株）
製）を含むポリエチレンのポリマチップを使用した以外
は実施例１と同様にして、厚み３７０μｍの光反射シー
トを作成した。このシートの光反射率及びこのシートを
用いた場合の導光板上での輝度を測定した。その結果を
表１に示す。Example 2 50% by weight of barium sulfate HD (Barite Industry Co., Ltd.)
A light-reflecting sheet having a thickness of 370 μm was prepared in the same manner as in Example 1 except that a polyethylene polymer chip containing polyethylene was used. The light reflectance of this sheet and the brightness on the light guide plate when this sheet was used were measured. The results are shown in Table 1.
【００２３】実施例３ ７０重量％の炭酸カルシウムＳＳＴ−４０（同和カルフ
ァイン（株）製）を含む屈折率が１．５０であるポリプ
ロピレン（三井東圧化学（株）製）のポリマチップを２
００℃で押し出し製膜後、余熱ロールの温度を８０℃、
延伸倍率を３倍とした以外は実施例１と同様にして、厚
み４１０μｍの光反射シートを作成した。反射率、輝度
を実施例１と同様にして測定した。結果を表１に示す。Example 3 Two polymer chips of polypropylene (manufactured by Mitsui Toatsu Chemicals, Inc.) having a refractive index of 1.50 and containing 70% by weight of calcium carbonate SST-40 (manufactured by Dowa Calfine Co., Ltd.) were used.
After extrusion film formation at 00 ℃, the temperature of the preheat roll is 80 ℃,
A light reflecting sheet having a thickness of 410 μm was prepared in the same manner as in Example 1 except that the stretching ratio was set to 3 times. The reflectance and the brightness were measured in the same manner as in Example 1. The results are shown in Table 1.
【００２４】実施例４ ポリエチレンに含有する無機充填剤を炭酸カルシウムＳ
ＳＴ−４０と硫酸バリウムＨＤとし、各々の割合を２０
重量％と４０重量％とした以外は、実施例３と同様の方
法で、厚み５１０μｍの光反射シートを作成した。反射
率、輝度を実施例１と同様にして測定した。結果を表１
に示す。Example 4 The inorganic filler contained in polyethylene was calcium carbonate S
ST-40 and barium sulphate HD, each ratio 20
A light-reflecting sheet having a thickness of 510 μm was prepared in the same manner as in Example 3 except that the content was 40 wt% and 40 wt%. The reflectance and the brightness were measured in the same manner as in Example 1. The results are shown in Table 1.
Shown in.
【００２５】実施例５ ポリプロピレンに含有する炭酸カルシウムの量を３０重
量％とし、溶融製膜後の面積倍率を１０倍にした以外は
実施例３と同様にして、厚み１６５μｍの光反射シート
を得た。反射率、輝度を実施例１と同様にして測定し
た。結果を表１に示す。Example 5 A light reflecting sheet having a thickness of 165 μm was obtained in the same manner as in Example 3 except that the amount of calcium carbonate contained in polypropylene was 30% by weight and the area ratio after melt film formation was 10 times. It was The reflectance and the brightness were measured in the same manner as in Example 1. The results are shown in Table 1.
【００２６】実施例６ 延伸時の倍率を４倍とした以外は、実施例１と同様にし
て、厚み５５０μｍの光反射シートを得た。反射率、輝
度を実施例１と同様にして測定した。結果を表１に示
す。Example 6 A light reflecting sheet having a thickness of 550 μm was obtained in the same manner as in Example 1 except that the stretching ratio was 4 times. The reflectance and the brightness were measured in the same manner as in Example 1. The results are shown in Table 1.
【００２７】比較例１ ５０重量％の炭酸カルシウムＳＳＴ−４０を含むポリエ
チレンンのポリマチップを２１０℃で押し出し製膜後、
延伸を行なわずに厚み５１０μｍの光反射シートを作成
した。この反射シートの反射率及びこの反射シートを用
いた場合の導光板上での輝度を表１に示す。Comparative Example 1 A polyethylene polymer chip containing 50% by weight of calcium carbonate SST-40 was extruded at 210 ° C. to form a film.
A 510 μm-thick light reflecting sheet was prepared without stretching. Table 1 shows the reflectance of this reflection sheet and the brightness on the light guide plate when this reflection sheet is used.
【００２８】比較例２ ポリエチレンに含まれる炭酸カルシウムＳＳＴ−４０の
割合を６０重量％とし、押し出し製膜後、余熱ロールの
温度を８０℃、延伸倍率を１００倍とした以外は実施例
１と同様にして延伸を行ったところ、フィルムが裂け
て、光反射シートが得られなかった。Comparative Example 2 The same as Example 1 except that the proportion of calcium carbonate SST-40 contained in polyethylene was 60% by weight, the temperature of the preheating roll was 80 ° C. and the draw ratio was 100 times after extrusion. When the film was stretched as described above, the film was torn and a light reflection sheet could not be obtained.
【００２９】比較例３ ポリプロピレンに含有する無機充填剤を硫酸バリウムＨ
Ｄとし、含有量を１０重量％とした以外は、実施例３と
同様の方法で、厚み５１０μｍの光反射シートを作成し
た。反射率、輝度を実施例１と同様にして測定した。結
果を表１に示す。Comparative Example 3 The inorganic filler contained in polypropylene was barium sulfate H.
A light reflection sheet having a thickness of 510 μm was prepared in the same manner as in Example 3 except that the content was D and the content was 10% by weight. The reflectance and the brightness were measured in the same manner as in Example 1. The results are shown in Table 1.
【００３０】比較例４ ポリエチレンに含まれる炭酸カルシウムＳＳＴ−４０の
割合を８０重量％とし、押し出し製膜後、余熱ロールの
温度を８０℃、延伸倍率を４倍とした以外は実施例１と
同様にして延伸を行ったところ、フィルムが裂けて、光
反射シートが得られなかった。Comparative Example 4 The same as Example 1 except that the proportion of calcium carbonate SST-40 contained in polyethylene was set to 80% by weight, the temperature of the preheating roll was set to 80 ° C. and the stretching ratio was set to 4 times after the extrusion film formation. When the film was stretched as described above, the film was torn and a light reflection sheet could not be obtained.
【００３１】比較例５ ７０重量％の炭酸カルシウムＳＳＴ−４０（同和カルフ
ァイン（株）製）を含む屈折率が１．６４であるポリエ
チレンテレフタレート（帝人（株）製）のポリマチップ
を２７０℃で押し出し製膜後、余熱ロールの温度を１２
０℃、延伸倍率を５倍とした以外は実施例１と同様にし
て延伸を行って、厚み２１０μｍの光反射シートを作成
した。反射率、輝度を実施例１と同様にして測定した。
結果を表１に示す。Comparative Example 5 Polymer chips of polyethylene terephthalate (manufactured by Teijin Ltd.) having a refractive index of 1.64 and containing 70% by weight of calcium carbonate SST-40 (manufactured by Dowa Calfine Co., Ltd.) were extruded at 270 ° C. After film formation, the temperature of the residual heat roll is set to 12
Stretching was carried out in the same manner as in Example 1 except that the stretching ratio was 0 ° C. and the stretching ratio was 5 times to prepare a light reflection sheet having a thickness of 210 μm. The reflectance and the brightness were measured in the same manner as in Example 1.
The results are shown in Table 1.
【００３２】比較例６ 無機充填剤を含まないポリエチレンのポリマチップを１
５０℃で押し出し後、実施例１と同様にして２．５倍に
延伸を行って、厚み３００μｍのフィルムを得た。反射
率、輝度を実施例１と同様にして測定した。結果を表１
に示す。Comparative Example 6 A polyethylene polymer chip containing no inorganic filler was used.
After extruding at 50 ° C., it was stretched 2.5 times in the same manner as in Example 1 to obtain a film having a thickness of 300 μm. The reflectance and the brightness were measured in the same manner as in Example 1. The results are shown in Table 1.
Shown in.
【００３３】[0033]
【表１】 ＰＰ：ポリプロピレン、 ＰＥ：ポリエチレン PET ：ポリエチレンテレフタレート 含有量＝〔（充填剤）／（充填剤＋樹脂）〕×１００ （重量％） 厚み：μｍ 光線反射率：％ 輝度：ｃｄ／ｍ2 その他の単位は無次元である。[Table 1] PP: polypropylene, PE: polyethylene PET: polyethylene terephthalate Content = [(filler) / (filler + resin)] × 100 (weight%) Thickness: μm Light reflectance:% Luminance: cd / m 2 Other units Is dimensionless.
【００３４】[0034]
【発明の効果】本発明の無機充填剤を含有する延伸フィ
ルムは、液晶表示のためのバックライト装置用光反射シ
ートとして使用すると、光反射率が従来の光反射シート
に比べて高く、これまで以上に明るいバックライトが実
現した。EFFECT OF THE INVENTION The stretched film containing the inorganic filler of the present invention has a higher light reflectance than conventional light reflecting sheets when used as a light reflecting sheet for a backlight device for liquid crystal display. A bright backlight has been realized.
【図１】光源部を透明な導光板の横に配置する、液晶表
示のためのバックライト装置の一実施例を示す。FIG. 1 shows an embodiment of a backlight device for liquid crystal display in which a light source unit is arranged beside a transparent light guide plate.
１ 無機充填剤を含む光反射シート ２ 光源部 ３ ランプハウス用光反射板 ４ 導光板 ５ 光拡散フィルム 1 Light Reflecting Sheet Containing Inorganic Filler 2 Light Source Section 3 Light Reflecting Plate for Lamp House 4 Light Guide Plate 5 Light Diffusing Film
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｇ０２Ｂ 5/08 Ａ 9224−2Ｋ Ｇ０２Ｆ 1/1335 ５３０ 7408−2Ｋ // Ｂ２９Ｋ 23:00 Ｂ２９Ｌ 7:00 4Ｆ (72)発明者 吉開 正彰 愛知県名古屋市南区丹後通２丁目１番地 三井東圧化学株式会社内 (72)発明者 佐野 明美 愛知県名古屋市南区丹後通２丁目１番地 三井東圧化学株式会社内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification code Internal reference number FI technical display location G02B 5/08 A 9224-2K G02F 1/1335 530 7408-2K // B29K 23:00 B29L 7: 00 4F (72) Inventor Masaaki Yoshikai 2-1-1, Tango-dori, Minami-ku, Aichi Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Akemi Sano 2--1, Tango-dori, Minami-ku, Aichi Prefecture Mitsui Toatsu Inside Chemical Co., Ltd.
Claims (6)
５重量部と無機充填剤２５〜７５重量部からなり、か
つ、面積延伸倍率が１．２〜１５倍であることを特徴と
する光反射シート。1. A resin 75-2 having a refractive index of less than 1.6.
A light reflection sheet comprising 5 parts by weight and 25 to 75 parts by weight of an inorganic filler, and having an area stretching ratio of 1.2 to 15 times.
ロピレンまたはポリエチレンであることを特徴とする請
求項１の光反射シート。2. The light reflecting sheet according to claim 1, wherein the resin having a refractive index of less than 1.6 is polypropylene or polyethylene.
リウム、酸化チタンおよび炭酸マグネシウムの群から選
ばれる１種または２種類以上の混合物であることを特徴
とする請求項１の光反射シート。3. The light reflection sheet according to claim 1, wherein the inorganic filler is one kind or a mixture of two or more kinds selected from the group consisting of calcium carbonate, barium sulfate, titanium oxide and magnesium carbonate.
とを特徴とする請求項１の光反射シート。4. The light reflecting sheet according to claim 1, wherein the sheet has a thickness of 20 to 800 μm.
５重量部と無機充填剤２５〜７５重量部からなる樹脂組
成物を製膜後、面積延伸倍率が１．２〜１５倍となるよ
うに少なくとも一軸方向に延伸することを特徴とする光
反射シートの製造方法。5. A resin 75-2 having a refractive index of less than 1.6.
A light-reflecting sheet, which is obtained by forming a resin composition comprising 5 parts by weight and 25 to 75 parts by weight of an inorganic filler, and then stretching the resin composition in at least one axial direction so that an area stretching ratio is 1.2 to 15 times. Manufacturing method.
特徴とする液晶表示のためのバックライト装置。6. A backlight device for liquid crystal display, comprising the light reflection sheet according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5084411A JPH06298957A (en) | 1993-04-12 | 1993-04-12 | Light-reflecting sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5084411A JPH06298957A (en) | 1993-04-12 | 1993-04-12 | Light-reflecting sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06298957A true JPH06298957A (en) | 1994-10-25 |
Family
ID=13829854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5084411A Pending JPH06298957A (en) | 1993-04-12 | 1993-04-12 | Light-reflecting sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06298957A (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0724181A2 (en) * | 1995-01-27 | 1996-07-31 | MITSUI TOATSU CHEMICALS, Inc. | Light reflective sheet and light reflector using it |
| WO1998005984A1 (en) * | 1996-08-05 | 1998-02-12 | Teijin Limited | Orientated film having pores |
| KR19980021185A (en) * | 1996-09-13 | 1998-06-25 | 김광호 | Backlight of liquid crystal display |
| US5991080A (en) * | 1996-03-14 | 1999-11-23 | Kimoto Co., Ltd. | Light reflecting material |
| JP2002031704A (en) * | 2000-04-26 | 2002-01-31 | Yupo Corp | Light reflector |
| WO2003014778A1 (en) * | 2001-08-06 | 2003-02-20 | Yupo Corporation | Light reflector |
| JP2005202349A (en) * | 2003-12-19 | 2005-07-28 | Yupo Corp | Light reflector and surface light source device using the same |
| WO2005116699A1 (en) | 2004-05-31 | 2005-12-08 | Yupo Corporation | Light reflector and surface light source device using the same |
| JP2006018244A (en) * | 2004-05-31 | 2006-01-19 | Yupo Corp | Light reflector and surface light source device using same |
| WO2007052609A1 (en) | 2005-10-31 | 2007-05-10 | Yupo Corporation | Light reflector, planar light source and illumination device using the same |
| KR100837348B1 (en) * | 2007-06-14 | 2008-06-12 | 제일모직주식회사 | Composition for backlight unit optical member of display device and backlight unit optical member |
| US7413799B2 (en) | 2004-11-16 | 2008-08-19 | Mitsubishi Plastics, Inc. | Reflective film and reflective plate |
| KR100871095B1 (en) * | 2007-07-19 | 2008-11-28 | 인하대학교 산학협력단 | Glass and ceramic compositions for information display |
| WO2010010729A1 (en) | 2008-07-24 | 2010-01-28 | 株式会社ユポ・コーポレーション | Light reflector, and planar light source device and illuminating device using light reflector |
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-
1993
- 1993-04-12 JP JP5084411A patent/JPH06298957A/en active Pending
Cited By (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0724181A3 (en) * | 1995-01-27 | 1996-08-21 | Mitsui Toatsu Chemicals | |
| US5710856A (en) * | 1995-01-27 | 1998-01-20 | Mitsui Toatsu Chemicals, Inc. | Light reflective sheet and light reflector using it |
| EP0724181A2 (en) * | 1995-01-27 | 1996-07-31 | MITSUI TOATSU CHEMICALS, Inc. | Light reflective sheet and light reflector using it |
| US5991080A (en) * | 1996-03-14 | 1999-11-23 | Kimoto Co., Ltd. | Light reflecting material |
| US6177153B1 (en) | 1996-08-05 | 2001-01-23 | Teijin Limited | Orientated film having pores |
| WO1998005984A1 (en) * | 1996-08-05 | 1998-02-12 | Teijin Limited | Orientated film having pores |
| KR19980021185A (en) * | 1996-09-13 | 1998-06-25 | 김광호 | Backlight of liquid crystal display |
| JP2002031704A (en) * | 2000-04-26 | 2002-01-31 | Yupo Corp | Light reflector |
| JP4688339B2 (en) * | 2000-04-26 | 2011-05-25 | 株式会社ユポ・コーポレーション | Light reflector |
| KR100854233B1 (en) * | 2001-08-06 | 2008-08-25 | 가부시키가이샤 유포 코포레숀 | Light reflector |
| WO2003014778A1 (en) * | 2001-08-06 | 2003-02-20 | Yupo Corporation | Light reflector |
| US6914719B2 (en) | 2001-08-06 | 2005-07-05 | Yupo Corporation | Light reflector |
| JP2008203877A (en) * | 2001-08-06 | 2008-09-04 | Yupo Corp | Light reflector |
| JP2010191436A (en) * | 2003-06-19 | 2010-09-02 | Yupo Corp | Light reflector and planar light source apparatus using the same |
| JP2005202349A (en) * | 2003-12-19 | 2005-07-28 | Yupo Corp | Light reflector and surface light source device using the same |
| JP2006018244A (en) * | 2004-05-31 | 2006-01-19 | Yupo Corp | Light reflector and surface light source device using same |
| US7548372B2 (en) | 2004-05-31 | 2009-06-16 | Yupo Corporation | Light reflector and planar light source device |
| WO2005116699A1 (en) | 2004-05-31 | 2005-12-08 | Yupo Corporation | Light reflector and surface light source device using the same |
| US7413799B2 (en) | 2004-11-16 | 2008-08-19 | Mitsubishi Plastics, Inc. | Reflective film and reflective plate |
| JP2012077311A (en) * | 2004-11-16 | 2012-04-19 | Mitsubishi Plastics Inc | Reflective film and reflector plate |
| WO2007052609A1 (en) | 2005-10-31 | 2007-05-10 | Yupo Corporation | Light reflector, planar light source and illumination device using the same |
| US8408774B2 (en) | 2005-10-31 | 2013-04-02 | Yupo Corporation | Light reflector, planar light source and illumination device using the same |
| KR100837348B1 (en) * | 2007-06-14 | 2008-06-12 | 제일모직주식회사 | Composition for backlight unit optical member of display device and backlight unit optical member |
| KR100871095B1 (en) * | 2007-07-19 | 2008-11-28 | 인하대학교 산학협력단 | Glass and ceramic compositions for information display |
| WO2010010729A1 (en) | 2008-07-24 | 2010-01-28 | 株式会社ユポ・コーポレーション | Light reflector, and planar light source device and illuminating device using light reflector |
| US8950920B2 (en) | 2008-07-24 | 2015-02-10 | Yupo Corporation | Light reflector, and planar light source device and illuminating device using the light reflector |
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