JP2006045259A5

JP2006045259A5 -

Info

Publication number: JP2006045259A5
Application number: JP2004224156A
Authority: JP
Filing date: 2004-07-30
Publication date: 2007-03-15
Anticipated expiration: 2024-07-30

Description

［実施例１］
光学用アクリル樹脂（住友化学（株）スミペックスＭＧＳＳ）を予め１２０℃の条件で４時間加熱したものを原料とし、これを１段目として３５ｍｍ、Ｌ／Ｄが３４の単軸押出機、２段目として５０ｍｍ、Ｌ／Ｄが２８の単軸押出機のタンデム構成押出機に供給し、さらに押出機の機外に設置した高圧ガス供給装置から、超臨界条件を越える３８℃、１５ＭＰａにて、炭酸ガスを１段目押出機の溶融圧縮部のシリンダ部に設けたノズルに供給し、樹脂中に溶解、混錬させた。このときの炭酸ガスの供給量は、押出機の吐出量１４．７ｋｇ／ｈに対して、炭酸ガスの割合を０．３８ｋｇ／ｈとした。このときの押出温度は、１段目２４０℃、２段目２００℃であった。
これをスリット幅１５０ｍｍ、スリット間隙０．８ｍｍのダイから吐出させてシート化したところ、平均厚み２３０μｍ、８８ｍｍ幅の白色発泡シートが得られた。
このシートをミクロトームにてフィルム断面を潰すことなく切断し、切断した断面を走査型電子顕微鏡Ｓ−２１００Ａ型（（株）日立製作所製）を用いて、５００倍にて観察したところ、気泡径は中心が１４μｍで気泡の８０％以上が２０μｍ以下の範囲の気泡径を有していた。気泡による空隙率は密度から計算して７６％であった。
表面の荒れている部分を削り取った後、このシートの可視光範囲の反射率を測定したところ８５％で、かつ全光線透過率は６％であった。
さらにフィルム強伸度自動測定装置（オリエンテック（株）製テンシロンＡＭＦ／ＲＴＡ−１００）を用い、試料サイズ：幅１０ｍｍ×試長間１００ｍｍ、温度１００℃、引張速度：３００ｍｍ／分の条件で測定したところ、引張破断伸度は１４１％、１００℃、１００％伸度における引張応力は１２．０ＭＰａであった。念のため、簡易成形テストを実施したところ、成形性は良好であった。 [Example 1]
Optical acrylic resin (Sumitomo Chemical Co., Ltd. Sumipex MGSS) heated in advance at 120 ° C for 4 hours is used as a raw material. This is the first stage, 35mm, L / D is 34 single screw extruder, 2 stages 50 mm, L / D is supplied to a tandem configuration extruder of 28 single screw extruder, and further from a high pressure gas supply device installed outside the extruder at 38 ° C. and 15 MPa exceeding the supercritical condition, Carbon dioxide gas was supplied to a nozzle provided in the cylinder part of the melt compression part of the first stage extruder, and dissolved and kneaded in the resin. At this time, the supply amount of carbon dioxide gas was 0.38 kg / h with respect to the discharge amount of the extruder 14.7 kg / h. The extrusion temperature at this time was 240 ° C. for the first stage and 200 ° C. for the second stage.
When this was discharged from a die having a slit width of 150 mm and a slit gap of 0.8 mm to form a sheet, a white foam sheet having an average thickness of 230 μm and a width of 88 mm was obtained.
This sheet was cut with a microtome without crushing the film cross section, and the cut cross section was observed at 500 times using a scanning electron microscope S-2100A type (manufactured by Hitachi, Ltd.). The center was 14 μm, and 80% or more of the bubbles had a bubble diameter in the range of 20 μm or less. The porosity due to bubbles was 76% calculated from the density.
After shaving off the rough surface, the reflectance of this sheet in the visible light range was measured and found to be 85% and the total light transmittance was 6%.
Furthermore, using a film strength and elongation automatic measuring device (Orientec Co., Ltd. Tensilon AMF / RTA-100), sample size: width 10 mm × sample length 100 mm, temperature 100 ° C., tensile speed: 300 mm / min. When measured, the tensile elongation at break was 141%, 100 ° C., and the tensile stress at 100% elongation was 12.0 MPa. As a precaution, when a simple molding test was performed, the moldability was good.

Claims

An unstretched foam sheet comprising a thermoplastic resin, wherein 80% or more of the bubbles contained in the sheet have a cell diameter in the range of 0.1 to 20 μm, and the porosity is 20 to 80%. There is a foam sheet.

The foamed sheet according to claim 1, wherein the tensile elongation at break measured in an atmosphere of 100 ° C is 100% or more, and the tensile stress at 100 ° C and 100% elongation is 50 MPa or less.

The foamed sheet according to claim 1 or 2, wherein the thermoplastic resin has a melted fluidity (according to ASTM D1238-98) of 0.5 to 44 g / 10 min.

The foam sheet according to claim 1, wherein the thermoplastic resin is an acrylic resin and / or a methacrylic resin.

The foam sheet according to any one of claims 1 to 4, comprising 0 to 3% by weight of a nucleating agent.

The foam sheet according to any one of claims 1 to 5, wherein an embossed pattern is transferred on at least one side.

It is a laminated sheet of two or more layers, Comprising: The laminated sheet by which at least 1 layer of the foam sheet in any one of Claims 1-6 is arrange | positioned.

The laminated sheet according to claim 7, wherein at least one non-foamed layer is disposed.

The sheet according to any one of claims 1 to 8, wherein the reflectance in the visible light range is 85% or more and the total light transmittance is 10% or less.

The light reflection board using the sheet | seat in any one of Claims 1-9.

The light reflection board by which the shaping | molding process is given to the sheet | seat of Claim 10.

A display device using the light reflecting plate according to claim 10.

The manufacturing method of the sheet | seat in any one of Claims 1-9 including the process made to foam by extruding the thermoplastic resin in which gas melt | dissolved.

A step of forming a molten polymer of a thermoplastic resin in which a gas is dissolved into a non-foamed state;
Generating bubbles by exposing the sheet to a vacuum at a temperature of 50 to 200 ° C.,
A method for producing a foam sheet.

A step of forming a molten polymer of a thermoplastic resin in which a gas is dissolved into a non-foamed state;
Generating bubbles by exposing the sheet to a vacuum at a temperature of 50 to 200 ° C.,
The manufacturing method of the sheet | seat in any one of Claims 1-9 containing.

The method for producing a sheet according to any one of claims 1 to 9, and 13 to 15, wherein a thermoplastic resin in which gas is dissolved and a thermoplastic resin in which gas is not dissolved are coextruded.

An extruder equipped with a screw, a cylinder, and a temperature control mechanism for the cylinder, and a nozzle for introducing gas supplied from a high-pressure gas supply unit provided outside the cylinder into an inner surface of a part of the cylinder An extrusion apparatus for producing foamed sheets, comprising:

An extruder equipped with a screw, a cylinder, and a temperature control mechanism for the cylinder, and a nozzle for introducing gas supplied from a high-pressure gas supply unit provided outside the cylinder into an inner surface of a part of the cylinder The extrusion apparatus for sheet manufacture according to any one of claims 1 to 9, characterized by comprising:

The extrusion apparatus according to claim 17 or 18, wherein the nozzle is made of a ring-shaped metal or ceramic having fine holes.

The extrusion apparatus according to claim 19, wherein the ring-shaped metal is made of a material obtained by sintering metal powder or metal fiber.

Production of foamed sheet, in which a vacuum chamber apparatus having a chamber capable of reducing the pressure inside and a sealing mechanism, and a vacuum generator attached to the vacuum chamber apparatus are arranged after the casting roll and / or casting roll of the sheet forming machine apparatus.

The vacuum chamber apparatus provided with the chamber which can depressurize an inside, and the sealing mechanism, and the vacuum generator accompanying this vacuum chamber apparatus are arrange | positioned after the casting roll of a sheet forming machine and / or a casting roll. The sheet manufacturing apparatus according to claim 9.

23. The manufacturing apparatus according to claim 21 or 22, wherein the vacuum chamber device is capable of reducing the pressure inside the chamber capable of being reduced to 30 KPa or less.