JP2004278010A

JP2004278010A - Decorative interior and exterior finishing material composed of styrene resin foamed molding

Info

Publication number: JP2004278010A
Application number: JP2003066963A
Authority: JP
Inventors: Makoto Machida; 誠町田; Hiroyuki Yamagata; 裕之山形
Original assignee: Sekisui Plastics Co Ltd
Current assignee: Sekisui Kasei Co Ltd
Priority date: 2003-03-12
Filing date: 2003-03-12
Publication date: 2004-10-07
Anticipated expiration: 2023-03-12
Also published as: JP3987444B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide decorative interior and exterior finishing materials wherein a resin foam is used as a core material, wherein a decorative coating film is formed on the surface of the resin foam, which enhance safety by shortening self-extinguishing time of the resin foam, which enhance the property of being recycled as a raw material, and which decrease a coefficient of dimensional contraction of a foamed molding with time. <P>SOLUTION: In this foamed molding 1, prefoamed particles, which are obtained by prefoaming a self-extinguishing type expandable styrene resin particles, are foamed and molded so as to be used as the core material. In the self-extinguishing type expandable styrene resin particles, a 1-7 pts.wt. composite flame retarder, which comprises a 90-40 wt% frame retardant composed of tris (2,3-dibromopropyl) isocyanurate, and a 10-60 wt% flame retardant assitant composed of 2,3-dimethyl-2,3-diphenylbutane or 3,4-dimethy-3,4-diphenylhexane, is included in styrene resin particles based on the 100 pts.wt. styrene resin particles. A synthetic resin paint or a cement-based paint is applied as a decorative layer 3 to the surface of the foamed molding 1. Preferably, carbon dioxide is used as a foaming agent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明はスチレン系樹脂発泡成形体からなる装飾用内外装材、さらに詳しくは、特定の難燃剤と難燃助剤とからなる複合難燃剤を含む自己消火型スチレン系樹脂発泡成形体を芯材として使用した装飾用内外装材に関する。
【０００２】
【従来の技術】
各種建造物の屋内外に、構造物としてではなく装飾等のために造形物が設けられる場合がある。例えば、屋内では、柱の上端で天井への継ぎ目となる部分に装飾用の造形物が付設され、屋外では、外壁に装飾用の造形物が設けられることがある。このような装飾用内外装材は、軽量化の目的で芯材として合成樹脂発泡体を用い、その表面の一部あるいは全部に合成樹脂塗料あるいはセメント系塗料を塗布して、合成樹脂発泡体の表面保護と同時に装飾性を高めるようにしたものが多く用いられる。また、図２に示すように、所定形状に成形した合成樹脂発泡体（例えば、スチレン系樹脂発泡成形体１）を基材とし、その表面に耐アルカリ性のグラスファィバーメッシュのようなネット状物２を貼り付けた後、その上からモルタル組成物のような表面材を表面補強層あるいは装飾層３として塗布した装飾用内外装材４も知られている。
【０００３】
一方、建築廃棄処分・再資源化に関する規則、建設リサイクル法規制等が年々厳しくなっており、この種の装飾用内外装材を分別回収・再資源化を可能とすることが急務となっている。さらに、スチレン系樹脂発泡成形体を芯材とする装飾建材は、ＪＩＳＡ９５１１に規定する自己消火性が求められる。そのために、難燃剤を発泡性樹脂粒子に含浸させることが行われる。特許文献１（特開平９−２５５８７９号公報）には、難燃剤としてトリス（２，３−ジブロモプロピル）イソシアヌレートを使用したスチレン系難燃性樹脂組成物が記載され、特許文献２（特開平１１−１３０８９８号公報）には、難燃剤としてテトラブロモビスフェノールＡジアリルエーテルを、難燃助剤としてジクミルパーオキサイドやクメンヒドロパーオキサイドを使用した発泡ポリスチレン樹脂粒子が記載されている。
【０００４】
【特許文献１】
特開平９−２５５８７９号公報
【特許文献２】
特開平１１−１３０８９８号公報
【０００５】
【発明が解決しようとする課題】
発泡性スチレン系樹脂粒子、それから得られた予備発泡粒子及び発泡成形体に自己消火性を付与するために、難燃剤はそれら粒子や成形体中に均一に分散していることが望まれる。ところで、前記トリス（２，３−ジブロモプロピル）イソシアヌレートは、融点が低く含浸法でも発泡性スチレン系樹脂粒子に比較的均一に含浸させることができるが、これ単独ではテトラブロモシクロオクタン等に比べて難燃性が低く、効果的に自己消火性を発揮することができない。そのために、難燃助剤としてジクミルパーオキサイドやクメンヒドロパーオキサイドのような有機過酸化物を添加することが行われる。その作用として、燃焼時にラジカルを発生させることで、より少量で効率よく自己消火性を発泡成形体に付与していると考えられる。しかし、このような有機過酸化物は、当該発泡成形品のリサイクル時に溶融混練されると、ラジカルが発生し、そのラジカルがスチレン系樹脂を分解して分子量の低下をまねき、リサイクルされた樹脂の強度等の品質を悪化させるという課題がある。
【０００６】
別の課題として、一般的に使用されているスチレン系樹脂発泡成形体は、ブタンやペンタン等の有機化合物を発泡剤として含む発泡性樹脂粒子を蒸気等により加熱して得た予備発泡粒子を型内発泡成形用型の型窩内に充填し、蒸気等で加熱して該予備発泡粒子を型内発泡成形することによって製造されるが、このような発泡成形体は、発泡剤にブタンやペンタン等を用いているため、経時的に大きな（通常、１．５％程度の）寸法収縮を起こす。そのために、装飾材の全長を長くした場合、中央部に引っ張り応力が発生し、表面に形成した化粧用塗膜に亀裂が発生しやすい。そのために装飾材自体を短くする必要があり、建造物への取り付け時に装飾材間に目地を多数設けなければならないことから、現場作業量がどうしても多くなる。
【０００７】
本発明は上記のような事情に鑑みてなされたものであり、十分な自己消火性を備えながら、リサイクル時に溶融混練されたときに、樹脂の強度低下等の品質悪化を招くことがなく、有効に再資源化することができるスチレン系樹脂発泡成形体からなる装飾用内外装材を提供することを目的とする。また、スチレン系樹脂発泡成形体の経時的な寸法収縮率を小さいものとし、長さの長いものとしても表面に塗布した化粧用塗材に亀裂等が発生しないようにしたスチレン系樹脂発泡成形体からなる装飾用内外装材を提供することを目的とする。それにより、現場での作業量を低減することができる。
【０００８】
【課題を解決するための手段】
本発明の発明者等は、種々の難燃剤と難燃助剤の組合せを検討した結果、下記種類の難燃剤と難燃助剤とを特定の比率で含む複合難燃剤が、発泡樹脂成形体用の難燃剤として、リサイクル時に分子量低下を起こしにくく、かつ優れた自己消火性を発揮できることを見い出し本発明に至った。
【０００９】
すなわち、本発明による装飾用内外装材は、スチレン系樹脂粒子中に、トリス（２，３−ジブロモプロピル）イソシアヌレートからなる難燃剤９０〜４０重量％と、２，３−ジメチル−２，３−ジフェニルブタン又は３，４−ジメチル−３，４−ジフェニルヘキサンからなる難燃助剤１０〜６０重量％とからな複合難燃剤を、スチレン系樹脂粒子１００重量部に対して、１〜７重量部含む自己消火型発泡性スチレン系樹脂粒子を予備発泡させて得られた予備発泡粒子を発泡成形して得た発泡成形体の表面の一部あるいは全部に合成樹脂塗料あるいはセメント系塗料を塗布してなることを特徴とする。
【００１０】
上記、トリス（２，３−ジブロモプロピル）イソシアヌレート（以下、ＴＤＩＣとも称する）は融点１１５℃、分解温度２８５℃であり、２，３−ジメチル−２，３−ジフェニルブタン（ビスクミルと呼ばれることから、以下ＢＣとも称する）は、融点１１３℃、分解温度２０５℃である。また、３，４−ジメチル−３，４−ジフェニルヘキサンは、融点１４２℃、分解温度２３０℃である。上記難燃剤と難燃助剤は、融点が比較的近いため、それらを混合した複合難燃剤は、融点がほぼ一つのピークを形成する（この温度を融点ピーク温度と称する）。また、複合難燃剤の融点ピーク温度は、融点降下により、難燃剤及び難燃助剤単独の融点より低いことを発明者等は見い出している。
【００１１】
上記難燃剤と難燃助剤は、９０〜４０重量％と１０〜６０重量％の割合で使用される。難燃助剤の割合が１０重量％未満の場合、自己消火性の発現には複合難燃剤を多量に使用する必要が生じ、その結果リサイクル性が阻害される。また、融点ピーク温度があまり低下せず、含浸温度又は混練温度を高くしなければならない。一方、６０重量％を超える場合、難燃剤の割合が減るため、自己消火性が劣ることとなる。より好ましい難燃剤と難燃助剤の割合は、９０〜６０重量％と１０〜４０重量％である。
【００１２】
複合難燃剤の含有割合は、スチレン系樹脂１００重量部に対して、１〜７重量部である。１重量部未満では、十分な自己消火性が得られない。一方、７重量部を超える場合、自己消火性効果は飽和し、経済的でない。より好ましい含有割合は、１〜５重量部である。
【００１３】
本発明に使用できるスチレン系樹脂粒子は、スチレン系であれば特に限定されない。例えば、スチレン単独重合体であっても、スチレンとそれと共重合可能な他のモノマーとの共重合体であってもよい。他のモノマーとしては、α−メチルスチレン、ビニルトルエン、アクリロニトリル、メチルメタクリレート、グリシジルメタクリレート、ブチルアクリレート、メタクリル酸、ジビニルベンゼン、アルキレングリコールジメタクリレート等が挙げられる。なお、本明細書では、スチレン及びスチレンと共重合可能なモノマーもスチレン系モノマーと称している。更に、スチレン系樹脂は、他樹脂との混合樹脂であってもよい。他樹脂の例としては、ポリエチレン、ポリプロピレン、ポリフェニレンエーテル及びゴム変性スチレン系樹脂が挙げられる。混合の方法としては、押出機での押出ブレンドの他、重合ブレンド（水性媒体中でポリエチレン樹脂粒子等のスチレン系樹脂以外の樹脂粒子にスチレンモノマーを含浸させて重合させる方法）が挙げられる。
【００１４】
上記スチレン系樹脂粒子に含浸させる発泡剤としては、炭酸ガス、窒素ガス等の無機発泡剤、プロパン、ブタン、ペンタン、ヘキサン、それらの異性体等の脂肪族炭化水素、シクロブタン、シクロペンタン等の脂環式炭化水素、ジフルオロエタン、テトラフルオロエタン等のフッ化炭化水素等が挙げられる。特に好ましい発泡剤は、炭酸ガスである。その場合、炭酸ガス１００％でもよいが、本発明の効果を阻害しない範囲で、他の発泡剤を加えてもよい。他の発泡剤としては、空気、窒素などの無機発泡剤、プロパン、ブタン、ペンタン、ヘキサンなどの脂肪族炭化水素、シクロブタン、シクロペンタン、シクロヘキサンなどの脂環族炭化水素、フッ化炭化水素などの有機発泡剤を混合することもできる。フッ化炭化水素としては、オゾン破壊係数がゼロであるジフルオロエタン、テトラフルオロエタンなどを使用することが好ましい。ここで、有機発泡剤は、発泡剤の全体量の２０重量％を超えない範囲で使用することが好ましい。発泡性樹脂粒子中の炭酸ガスの含有割合は、１〜１５重量％が好ましい。
【００１５】
スチレン系樹脂粒子中に炭酸ガスを含浸させるには、例えば、耐圧密閉容器に樹脂粒子を入れた後、炭酸ガスを圧入して、樹脂粒子を加圧された炭酸ガスと接触させることによって行うことができる。含浸温度は、樹脂粒子どうしが互いに合着して団塊化しない温度まで高くしてもよいが、通常０〜４０℃である。樹脂粒子に炭酸ガスを含浸させるときの圧力は、１０ｋｇ／ｃｍ^２Ｇ以上であることが好ましく、より好ましくは１５〜４０ｋｇ／ｃｍ^２Ｇである。含浸時間は、樹脂粒子が前記の炭酸ガス含有量となるように適宜調整することができ、１〜２０時間が好ましく、２〜８時間がより好ましい。
【００１６】
一方、他の発泡剤の含浸方法としては、懸濁重合時又は懸濁重合とは別に含浸させる方法が挙げられる。含浸に用いられる水性媒体には、含浸時のスチレン系樹脂粒子同士の結合を防止するために、懸濁安定剤を添加することが好ましい。
懸濁安定剤としては、従来から懸濁重合において一般に使用されている公知のポリビニルアルコール、メチルセルロース、ポリアクリルアミド、ポリビニルピロリドン等の水溶性高分子や、第三リン酸カルシウム、ハイドロキシアパタイト、ピロリン酸マグネシウム等の難水溶性無機化合物等が挙げられる。難水溶性無機化合物を用いる場合には、通常アニオン界面活性剤が併用される。アニオン界面活性剤としては、例えば脂肪酸石鹸、Ｎ−アシルアミノ酸又はその塩、アルキルエーテルカルボン酸塩等のカルボン酸塩、アルキルベンゼンスルホン酸塩、アルキルナフタレンスルホン酸塩、ジアルキルスルホコハク酸エステル塩、アルキルスルホ酢酸塩、α−オレフィンスルホン酸塩等のスルホン酸塩；高級アルコール硫酸エステル塩、アルキルエーテル硫酸塩、ポリオキシエチレンアルキルフェニルエーテル硫酸塩等の硫酸エステル塩；アルキルエーテルリン酸エステル塩、アルキルリン酸エステル塩等のリン酸エステル塩等が挙げられる。
【００１７】
発泡性スチレン系樹脂粒子には、更に添加剤が含まれていてもよい。添加剤としては、高級脂肪酸アマイド、芳香族ビスアマイド、エチレンビスステアリルアマイド、高級脂肪酸、パラフィン、ワックス、動植物硬化油等の滑剤、トルエン、シクロヘキサン、ジイソブチルアジペート等の発泡助剤、可塑剤、気泡調整剤、気泡安定剤、充填剤、着色剤、酸化防止剤、紫外線吸収剤等が挙げられる。これら添加剤は、粒子の製造時や、複合難燃剤の含浸又は混練時に粒子に含ませることができる。
【００１８】
発泡性スチレン系樹脂粒子の平均粒径は、用途に応じて適宜選択でき、例えば、０．３〜３ｍｍの平均粒径のものを使用することができる。より好ましい平均粒径は、０．５〜２ｍｍである。
【００１９】
本発明における発泡成形体に使用する発泡性スチレン系樹脂粒子の製造方法としては、懸濁重合法や、押出機でスチレン系樹脂と複合難燃剤とを溶融混練した後、押し出したストランドをペレタイズする方法が挙げられる。このうち、生産効率の観点から懸濁重合法が好ましい。
【００２０】
懸濁重合法において、前記した複合難燃剤を樹脂粒子に含浸させる方法としては、重合転化率が９９．８％以上の段階又は、重合完了後の水性媒体中に添加して含浸させる方法が挙げられる。重合転化率が９９．８％以上のときに含浸させることで、所定の分子量の発泡性スチレン系樹脂粒子を簡便に得ることができるので好ましい。
【００２１】
複合難燃剤の添加方法は、例えば、水性媒体中に難燃剤と難燃助剤を別々に又は同時に投入する方法、難燃剤と難燃助剤をスーパーミキサー等で混合してから粉体状態のままで水性媒体中に投入する方法、撹拌装置を備えた予備分散槽内で均一に分散させた懸濁液を水性媒体に投入する方法が挙げられる。更に、発泡剤及び／又は上記添加剤と同時に含浸させることが好ましい。含浸をより円滑に行うために、水性媒体を加温することが好ましい。具体的には、７０〜１２０℃の温度で、１〜６時間加温することが好ましい。
複合難燃剤及び発泡剤が含浸された自己消火型発泡性スチレン系樹脂粒子は、必要に応じて水性媒体から取り出される。取り出した粒子は、洗浄及び脱水乾燥させてもよい。
【００２２】
上記自己消火型発泡性スチレン系樹脂粒子には適当な表面処理剤による処理がなされていてもよい。表面処理剤には、結合防止剤、帯電防止剤、滑剤、融着促進剤、ハイサイクル剤、離型剤等の公知のものを用いることができる。この他にも紫外線吸収剤、防錆剤、木材用防腐剤、防蟻剤、防黴剤、抗菌剤、香料、着色剤等の公知の添加剤を表面処理剤と併用してもよい。表面処理の方法は、タンブラーミキサー、ナウターミキサー、レディゲミキサー、プロシェアミキサーリボンブレンダー等の混合機を用いた公知の方法を用いることができる。
【００２３】
上記自己消火型発泡性スチレン系樹脂粒子を予備発泡させて自己消火型スチレン系予備発泡粒子とする。予備発泡方法は、公知の方法をいづれも使用することができる。例えば、発泡ポリスチレンビーズ用予備発泡機を用いて、通常の条件で、製造することができる。特に、スチレン系樹脂粒子に炭酸ガスを含浸させて発泡性スチレン系樹脂粒子とし、次工程で、蒸気投入ラインと排気ラインを備えた予備発泡機内に、前記発泡性スチレン系樹脂粒子を投入し、蒸気投入ラインから蒸気を０．５〜５．０ｋｇ／ｃｍ^２Ｇの投入圧力で供給すると共に、排気ラインから蒸気を含む雰囲気ガスを排気し、かつその間、発泡機内圧力を蒸気の投入圧力より０．０５〜１．０ｋｇ／ｃｍ^２Ｇ低く維持しながら予備発泡させてスチレン系樹脂予備発泡粒子を得る方法は、得られた予備発泡粒子を発泡成形して作られる成形品の寸法収縮率をきわめて小さくすることができるので有効である。
なお、この方法において、炭酸ガスを含浸させる工程に次いで、直ちに予備発泡を行うことが好ましい。なお、予備発泡粒子の嵩密度は、０．０１〜０．２ｇ／ｃｍ^３の範囲であることが好ましい。
【００２４】
上記のスチレン系樹脂予備発泡粒子を製造するのに使用できる予備発泡機の一例を、図１により説明する。図中、１００は予備発泡機、１０２は撹拌モーター、１０３は撹拌翼、１０４は邪魔棒、１０５は発泡槽上面検出器、１０６は発泡性粒子輸送器、１０７は発泡性粒子計量槽、１０８は発泡性粒子投入器、１０９は蒸気吹込制御弁、１１０は蒸気チャンバー、１１１は凝縮水排出弁、１１２は排気制御弁、１１３は予備発泡粒子排出口、１１４は予備発泡粒子一時受器、１１５は空気輸送設備、１１６は内圧検出・制御装置、１１７は蒸気吹込孔、１１８は蒸気投入圧力計、１１９は減圧弁、１２０は蒸気元圧力計を意味する。
【００２５】
詳細には、一定量の蒸気が常に予備発泡機１００内に供給されるように排気制御弁１１２等で予備発泡機１００内の圧力（内圧検出・制御装置１１６で圧力検出）が常に供給圧力を下回るように制御を行う。例えば、蒸気の投入圧力を１．２ｋｇ／ｃｍ^２Ｇ（蒸気投入圧力計１１８で検出）、予備発泡機内の圧力を０．８ｋｇ／ｃｍ^２Ｇに設定した場合、予備発泡機１００内の圧力を内圧検出・制御装置１１６にて検出し、制御信号が排気制御弁１１２へ送られ、排気ラインから０．４ｋｇ／ｃｍ^２Ｇ圧分の圧力を抜きながら圧力の制御を行う。このように、予備発泡機１００内圧力と排気制御弁１１２とをリンクさせて制御することにより、予備発泡機１００内圧力の調整することができる。
【００２６】
上記の方法において、投入圧力と予備発泡機内圧力との差が、０．０５ｋｇ／ｃｍ^２Ｇ未満であると低密度の予備発泡粒子が得られ難いばかりか、発泡成形体の外観、内部融着が悪く、非常に商品価値の低いものになってしまう。また、１．０ｋｇ／ｃｍ^２Ｇを超えると予備発泡時の結合が増加するばかりか、発泡体表面の凹凸も大きくなり好ましくない。より好ましい圧力差は、０．１〜０．５ｋｇ／ｃｍ^２Ｇである。
【００２７】
予備発泡機内の発泡性樹脂粒子は、通常１１０〜１６０℃程度に加熱されることが好ましく、より好ましい加熱温度は１１０〜１３０℃である。加熱温度が１１０℃を下回ると、嵩密度０．５ｇ／ｃｍ^３以下の予備発泡粒子は得られ難いので好ましくない。また、加熱温度が１６０℃を上回ると予備発泡粒子同士が合着する傾向が強くなるので好ましくない。
【００２８】
上記の自己消火型スチレン系樹脂予備粒子を発泡成形することで得られる発泡成形体は、自己消火性が良好であることに加えて、長期にわたる寸法収縮率にも優れており、寸法収縮率を０．５％以下にすることができる。また、揮発性有機化合物の含有量を１０００ｐｐｍ以下ときわめて少なくすることができる。
【００２９】
発泡成形法は、特に限定されず、公知の方法をいづれも使用することができる。例えば、自己消火型スチレン系予備発泡粒子を成形用型窩内に充填し、蒸気により加熱する。蒸気との接触によって予備発泡粒子が加熱されると、予備発泡粒子は膨張するが、成形用窩型によって発泡できる空間が限定されているので、互いに密着すると共に融着一体化して所望の発泡成形体を得ることができる。発泡成形体の密度は、０．０１５〜０．５ｇ／ｃｍ^３程度が好ましい。所望の形状の一例として、図２に示すような形状の装飾材が挙げられる。
【００３０】
上記発泡成形体は、難燃剤の含まれていない一般のポリスチレン発泡成形体と同様に押出機で減容や溶融混練してリサイクルしても、従来の自己消火型発泡性スチレン系樹脂粒子から得られる発泡成形体をリサイクルするよりも樹脂の劣化が少なく、リサイクル性の高い成形体となる。
【００３１】
本発明によるスチレン系樹脂発泡成形体からなる装飾用内外装材は、このようにして得た発泡成形体の表面の全部もしくはその一部に塗装を施すことによって製造できる。本発明では塗装として樹脂塗装やモルタル塗装等を施すことができる。樹脂塗装として、水性塗料を使用したもの、溶剤塗料を使用したもの等いづれも使用することができる。水性塗料を使用した塗装には、アクリル系樹脂、ウレタン系樹脂、エポキシ系樹脂、シリコン系樹脂等を使用することが好ましく、スプレー、エアーガン、刷毛塗り等の方法により塗装すればよい。また、溶剤塗料を使用した塗装を施す場合には、塗装する発泡成形体部分に下地処理を施すことが好ましい。また、モルタル系塗料とは、例えばＪＩＳ６９０９，ＪＩＳＡ６９１６に規定されるようなセメントモルタルであり、水及び／又は合成樹脂エマルジョンと共に攪拌したものを使用することが好ましい。塗装を施す場合には、こて、吹き付け機、ローラー、刷毛などを使用して塗装することができる。
【００３２】
さらに、芯材としての自己消火型スチレン系樹脂発泡成形体の表面に、耐アルカリ性のガラス繊維、炭素繊維等の無機系繊維、またアクリル繊維等の合成樹脂繊維から選ばれた一種又は数種類を織る又は編み込まれたネット状物を接着剤を用いて貼り付けた後、その上からモルタル組成物のような上記塗装を表面補強層あるいは装飾層として塗布することが好ましい。このようなネット状物を貼り付けることにより、塗装面に亀裂がはいるのを阻止することができる。
【００３３】
本発明の好ましい態様による装飾用内外装材（発泡剤として炭酸ガスを使用したスチレン系樹脂予備発泡粒子からの成形体）では、長期にわたる寸法収縮率がきわめて小さい。そのために、長尺状の装飾材としても表面に塗布した化粧用塗装に芯材の収縮に起因して亀裂等が入るのを回避できる。また、短い装飾材を多数繋ぎ合わせる場合と比較して、現場での作業量を低減することができる。
【００３４】
【実施例】
以下、本発明を実施例及び比較例に基づき更に詳しく説明するが、本発明はこれらにより限定されることはない。なお、実施例、比較例において、圧縮強さ、自己消化性、寸法収縮率、ＭＦＲ（メルトフローレート）、及び、重量平均分子量の評価は以下のようにして行った。
【００３５】
＜寸法収縮率＞
ＪＩＳＡ６９１６（建築用下地調整塗材）の長さ変化試験に準じて試験を実施した。すなわち、発泡成形型から取り出した発泡成形体（実際には、１６０ｍｍ×４０ｍｍ×４０ｍｍの平板）を乾燥し、その後、温度２３℃、相対湿度５０％の恒温恒湿室（ＪＩＳ−Ｋ７１００の標準温湿度状態）に２４時間放置した後、発泡成形体の全面に各仕上げ材（ウレタン又はモルタル）を２ｍｍ厚みに塗布し、さらに、２０℃の恒温室で６時間乾燥させた。その後、ＪＩＳＡ１１２９（モルタル及びコンクリートの長さ変化試験方法）に準じ、供試体に所定の間隔（１００ｍｍ）でゲージプラグを埋め込み、供試体作成直後の間隔と２０℃、６５％の恒温恒湿室で４週間経過した後の間隔をコンタクトゲージにて測定した値の差を供試体作成直後の間隔測定値で除した値から求めた。
＜圧縮強さ＞
ＪＩＳＡ９５１１の試験方法に準じて行った。すなわち、テンシロン万能試験機ＵＣＴ−１０Ｔ（株式会社オリエンテック製）を用いて、発泡成形型から取り出した発泡成形体から得た試験体（サイズ５０ｍｍ×５０ｍｍ×５０ｍｍ）で圧縮速度を１０ｍｍ／ｍｉｎとして５％圧縮時の圧縮強さを測定した。
＜自己消火性＞
ＪＩＳＡ９５１１の燃焼試験Ａ法に準じて発泡成形型から取り出した発泡成形体の燃焼性（自己消火時間）を測定した。なお、このＪＩＳ規格では自己消火時間が３．０秒以内である必要がある。
【００３６】
＜ＭＦＲの測定＞
ＪＩＳＫ７２１０に基づき下記の条件で行った。試験試料には、実施例及び比較例にて得られた発泡性ポリスチレン樹脂粒子を、５０℃のオーブン中で到達圧力１．０ｋｇ／ｃｍ^２Ｇで真空吸引しながら２４時間保持し、樹脂粒子中の揮発性有機化合物を除去したものを用いた。なお、押出機で溶融混練しストランド化することでリサイクルが可能なポリエチレン樹脂のＭＦＲは、２０ｇ／１０分以下、好ましくは１５ｇ／１０分以下である。
測定装置：東洋精機製作所社製メルトインデクサー
測定温度：２００℃
測定荷重：５．０ｋｇｆ
オリフィス径：２．０９ｍｍ
【００３７】
＜重量平均分子量＞
スチレン樹脂粒子の重量平均分子量（Ｍｗ）は、ＧＰＣ（ゲルパーミエイションクロマトグラフィー）によって、以下の条件で測定した。なお、重量平均分子量の測定に際して、測定試料の有する分子量分布が、数種の単分散ポリスチレン標準試料により作成された検量線の分子量の対数とカウント数が直線となる範囲内に包含される測定条件を選択した。また、検量線は、重量平均分子量が２．７４×１０^３、１．９１×１０^４、１．０２×１０^５、３．５５×１０^５、２．８９×１０^６、４．４８×１０^６である東ソー社製の６個のポリスチレン標準試料（ＴＳＫスタンダードポリスチレン）を用いて以下の条件で作成した。
ＧＰＣ：東ソー社製高速ＧＰＣ装置ＨＬＣ−８０２０
カラム：積水ファインケミカル社製ＨＳＧ−６０Ｓ×２本、ＨＳＧ−４０Ｈ×１本、ＨＳＧ−２０Ｈ×１本
カラム温度：４０℃
移動相：ＴＨＦ（テトラヒドロフラン）
流量：１．０ｍｌ／分
注入量：５００ｍｌ
検出器：東ソー社製ＲＩＤ−６Ａ
【００３８】
なお、重量平均分子量の測定は、上記ＭＦＲ測定処理の前と後で行った。重量平均分子量は熱処理（ＭＦＲ測定処理）の前後においてできるだけ変化しないことがリサイクルの観点から望まれる。大きく低下すると、押出機で溶融混練した後にストランドとして押し出せない又はストランドの切断が頻繁に起こり、リサイクルが困難である。
【００３９】
［実施例１］
撹拌機を具備した内容積１００リットルの反応器に、脱イオン水３８リットル、ピロリン酸マグネシウム７５ｇ、ドデシルベンゼンスルホン酸ナトリウム７ｇを入れた後に、重合開始剤としてベンゾイルパーオキサイド１１７ｇとｔ−ブチルパーオキシベンゾエート２７ｇを溶解したスチレン４４ｋｇを反応器に入れ撹拌し、９０℃に昇温してから６時間保持した後、１２５℃に昇温し３時間保持して重合を行った。重合終了時における重合転化率は９９．９％であった。その後、冷却して内容物を取り出し、洗浄及び脱水乾燥した後に、篩い機に掛け粒子径０．９〜１．２ｍｍのポリスチレン樹脂粒子を得た。
【００４０】
内容積５リットルの撹拌機付き圧力容器に、水２リットルにドデシルベンゼンスルホン酸ナトリウム０．５ｇと、ピロリン酸マグネシウム６ｇと、トルエン２０ｇを懸濁させた懸濁液を入れ、撹拌しながら上記ポリスチレン樹脂粒子２ｋｇと、トリス（２，３−ジブロモプロピル）イソシアヌレート（難燃剤：ＴＤＩＣ）１．６重量％及び２，３−ジメチル−２，３−ジフェニルブタン（難燃助剤：ＢＣ）０．３重量％からなる複合難燃剤を入れて容器を密閉し、引き続き撹拌しながら１００℃まで昇温した後に、１００℃の含浸温度でノルマルブタン９５ｇとイソブタン４４ｇを圧入し３時間保持した。次いで、２５℃まで冷却し、圧力容器から樹脂粒子を取り出した後、樹脂粒子の洗浄及び脱水乾燥を行うことで、自己消火型発泡性ポリスチレン樹脂粒子を得た。この自己消火型発泡性ポリスチレン樹脂粒子のＭＦＲと重量平均分子量とを上記評価方法により評価した。その結果を表１に示す。
【００４１】
この発泡性樹脂粒子を２０℃の恒温室で５日間保持した後に、予備発泡機で発泡し、予備発泡粒子を得た。予備発泡６時間後、寸法収縮測定用サンプル作成として、長さ１６０ｍｍ×幅４０ｍｍ×厚さ４０ｍｍの、及び、リサイクル性確認試験用サンプル作成として、長さ３００ｍｍ×幅１５０ｍｍ×厚さ３０ｍｍの型窩をもった成形用金型内に予備発泡粒子を充填し、この金型内に蒸気を吹き込んで、再び膨張させて密度０．０２０ｇ／ｃｍ^３の装飾用内外装材の芯材を得た。
【００４２】
得られた発泡成形体を５０℃の恒温室で７日間乾燥させた後、該装飾用内外装材の芯材の表面全体に、ウレタン樹脂（商品名：エフレタンＳＨ−４０００（日本合成化学工業株式会社製／速硬化及び無溶剤タイプのウレタン樹脂））を塗布厚み１ｍｍ程度で２回に分けて吹き付け、ウレタン樹脂皮膜の塗装を行い、２０℃の恒温室で１時間乾燥させた。
【００４３】
塗装後の長さ１６０ｍｍ×幅４０ｍｍ×厚さ４０ｍｍの装飾材について、上記した評価方法により寸法変化率を評価すると共に、自己消火性を装飾用内外装材の芯材についてＪＩＳＡ９５１１に従って評価した。さらに、リサイクル性を検討するため、長さ３００ｍｍ×幅１５０ｍｍ×厚さ３０ｍｍの装飾材からウレタン樹脂皮膜を剥がし、芯材発泡ポリスチレンを取り出した。この芯材を減容し、φ３０ｍｍの単軸押出機（押し出し温度１８０℃）にて、ストランド化を行い、得られた回収原料を上記と同様な方法により発泡成形し、得られた発泡成形体の圧縮強さを上記評価方法により測定した。その結果を表１に示す。
【００４４】
［実施例２］
実施例１と同様に、装飾用内外装材の芯材を得、その表面全体に粘着材を予め吹き付けた耐アルカリガラスファイバーメッシュ（商品名：ＣＣＸＦｉｂｅｒｇｌａｓｓＰｒｏｄｕｃｔ社製、品番Ｓｔｙｌｅ１３５０）を巻き付け、さらにセメント系塗料（商品名：積水化成品株式会社製セキスイボンモルコートうすぬり）を２ｍｍ厚にて塗布した後、２０℃の恒温室で６時間乾燥させ、装飾用内外装材を得たこと以外は実施例１と同様な測定評価を行った。その結果を表１に示す。
【００４５】
［実施例３］
実施例１と同じポリスチレン樹脂粒子１ｋｇに対し、発泡時結合防止剤として炭酸カルシウム微粉末１．５ｇと、帯電防止剤としてステアリン酸モノグリセライト０．５ｇを樹脂粒子表面に均一に付着させた後に圧力容器に入れ密閉し、次いで圧力容器内に炭酸ガスを圧入して、２０℃、３０ｋｇ／ｃｍ^２Ｇに６時間保って樹脂粒子内に炭酸ガスを含浸させ、発泡性スチレン樹脂粒子を得た。
【００４６】
こうして得られた発泡性スチレン樹脂粒子を耐圧容器から取り出し、次工程で攪拌機付き発泡機内に投入した後、投入圧力が１．２ｋｇ／ｃｍ^２Ｇの蒸気を発泡機内に導入した。この時の発泡機内の圧力は０．８ｋｇ／ｃｍ^２Ｇになるように、排気制御弁の開度を電気信号でコントロールしながら、排気ラインを使って余分な圧力を外部に逃がした（投入圧力と発泡機内圧力との差は０．４ｋｇ／ｃｍ^２Ｇ）。このように、蒸気を発泡機内に連続して導入しながら予備発泡させてスチレン樹脂予備発泡粒子を得たこと以外は、実施例１と同様な測定評価を行った。その結果を表１に示す。
【００４７】
［比較例１］
トリス（２，３−ジブロモプロピル）イソシアヌレートをテトラプロモシクロオクタン３０ｇ、２，３−ジメチル−２，３−ジフェニルブタンをジクミルパーオキサイト６．０ｇとしたこと以外は、実施例１と同様な方法で発泡性スチレン樹脂粒子を得、該発泡性スチレン樹脂粒子のＭＦＲと重量平均分子量とを実施例１と同様にして評価した。その結果を表１に示す。
【００４８】
この発泡性樹脂粒子を２０℃の恒温室で５日間保持した後に、実施例１と同様にして予備発泡機で発泡し、予備発泡粒子を得た。予備発泡６時間後、実施例１と同様にして２種の装飾用内外装材の芯材を得た。
【００４９】
以下、実施例１と同様にして、表面塗装を行い、塗装後の長さ１６０ｍｍ×幅４０ｍｍ×厚さ４０ｍｍの装飾材については、実施例１と同様にして、寸法変化率を評価すると共に、自己消化性を該装飾用内外装材の芯材をＪＩＳＡ９５１１に従って評価した。長さ３００ｍｍ×幅１５０ｍｍ×厚さ３０ｍｍの装飾材についても、リサイクル性を検討すべく、実施例１と同様にウレタン樹脂皮膜を剥がし、芯材発泡ポリスチレンを取り出して減容し、φ３０ｍｍの単軸押出機（押し出し温度１８０℃）にてストランド化を行った。しかし、得られた回収原料を実施例と同様な方法により発泡成形しようとしたが、発泡成形できるような回収原料は得られなかった。
【００５０】
【表１】

【００５１】
［考察］
実施例１〜４は、本発明に固有の複合難燃剤を用いていることから、自己消火時間は短く、また、ＭＦＲ測定前後での重量平均分子量の変化も小さい。そのために、回収原料を用いて発泡成形品を得るとができ、得られ発泡成形品は高い圧縮強さを示している。実施例３は、発泡剤として炭酸ガスを用いたために、寸法収縮率が０．１３と小さくなっている。
【００５２】
比較例１は従来の難燃剤を使用しており、自己消火時間が実施例のものよりも長くなっており、さらに、ＭＦＲ測定前後での重量平均分子量の変化が非常に大きいことから、回収原料を用いて発泡成形品を得ることもできない。
【００５３】
【発明の効果】
本発明によるスチレン系樹脂発泡成形体からなる装飾用内外装材は、固有の複合難燃剤を用いていることから、自己消火時間は短く、また、ＭＦＲ測定前後での重量平均分子量の変化も小さい。そのために、樹脂の強度低下等の品質悪化を招くことがなく、有効に再資源化することができる。発泡剤として炭酸ガスを用いる場合には、発泡成形体の経時的な寸法収縮率をきわめて小さな値とすることができ、長さの長いものとしても表面に塗布した化粧用塗材に亀裂等が発生しない装飾用内外装材を得ることができる。それにより、現場での作業量を低減することができる。
【図面の簡単な説明】
【図１】本発明で使用できるスチレン系樹脂予備発泡粒子を製造するのに用いられる予備発泡機の概略説明図である。
【図２】装飾用内外装材の一例を示す図。
【符号の説明】
１芯材としての発泡成形体
２ネット状物
３表面塗装
４装飾用内外装材
１０２撹拌モーター
１０３撹拌翼
１０４邪魔棒
１０５発泡槽上面検出器
１０６発泡性粒子輸送器
１０７発泡性粒子計量槽
１０８発泡性粒子投入器
１０９蒸気吹込制御弁
１１０蒸気チャンバー
１１１凝縮水排出弁
１１２排気制御弁
１１３予備発泡粒子排出口
１１４予備発泡粒子一時受器
１１５空気輸送設備
１１６内圧検出・制御装置
１１７蒸気吹込孔
１１８蒸気投入圧力計
１１９減圧弁
１２０蒸気元圧力計[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a decorative interior / exterior material comprising a styrene resin foam molded article, and more specifically, a self-extinguishing type styrene resin foam molded article containing a composite flame retardant comprising a specific flame retardant and a flame retardant aid. The present invention relates to a decorative interior / exterior material used as a material.
[0002]
[Prior art]
In some cases, a shaped object is provided for decoration and the like, not as a structure, inside and outside of various buildings. For example, indoors, decorative moldings may be attached to the upper ends of pillars at seams to the ceiling, and outdoor, decorative moldings may be provided on outer walls. Such decorative interior and exterior materials use a synthetic resin foam as a core material for the purpose of weight reduction, and apply a synthetic resin paint or a cement-based paint to a part or all of the surface thereof to form a synthetic resin foam. Those that enhance the decorativeness while protecting the surface are often used. As shown in FIG. 2, a synthetic resin foam (for example, a styrene-based resin foam 1) formed into a predetermined shape is used as a base material, and a net-like material 2 such as an alkali-resistant glass fiber mesh is formed on the surface thereof. There is also known a decorative interior / exterior material 4 in which a surface material such as a mortar composition is applied thereon as a surface reinforcing layer or a decoration layer 3 after being attached.
[0003]
On the other hand, regulations on construction waste disposal and recycling, construction recycling laws and regulations are becoming stricter year by year, and it is urgently necessary to be able to separate and collect and recycle this kind of decorative interior and exterior materials. . Further, a decorative building material having a styrene-based resin foam molded body as a core material is required to have self-extinguishing properties specified in JIS A9511. For this purpose, impregnating the foamable resin particles with a flame retardant is performed. Patent Document 1 (Japanese Patent Application Laid-Open No. 9-255879) describes a styrene-based flame-retardant resin composition using tris (2,3-dibromopropyl) isocyanurate as a flame retardant. JP-A-11-130898) describes expanded polystyrene resin particles using tetrabromobisphenol A diallyl ether as a flame retardant and dicumyl peroxide or cumene hydroperoxide as a flame retardant aid.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-255879 [Patent Document 2]
Japanese Patent Application Laid-Open No. H11-130898
[Problems to be solved by the invention]
In order to impart self-extinguishing properties to the expandable styrene-based resin particles, the pre-expanded particles obtained therefrom, and the foamed molded article, it is desired that the flame retardant is uniformly dispersed in the particles and the molded article. The tris (2,3-dibromopropyl) isocyanurate has a low melting point and can be relatively uniformly impregnated into expandable styrene resin particles even by an impregnation method. Low flame retardancy and cannot effectively exhibit self-extinguishing properties. For this purpose, an organic peroxide such as dicumyl peroxide or cumene hydroperoxide is added as a flame retardant aid. As an effect thereof, it is considered that self-extinguishing properties are efficiently imparted to the foamed molded article with a smaller amount by generating radicals during combustion. However, when such an organic peroxide is melted and kneaded at the time of recycling the foamed molded product, radicals are generated, and the radicals decompose the styrene-based resin, leading to a decrease in molecular weight. There is a problem that quality such as strength is deteriorated.
[0006]
Another problem is that a commonly used expanded styrene-based resin molded product is obtained by heating pre-expanded particles obtained by heating foamable resin particles containing an organic compound such as butane or pentane as a foaming agent with steam or the like. The pre-expanded particles are manufactured by filling in the mold cavity of the inner foam molding die and heating with steam or the like to foam the pre-expanded particles in the mold. And the like, a large (typically about 1.5%) dimensional shrinkage occurs over time. Therefore, when the overall length of the decorative material is increased, a tensile stress is generated at the center, and a crack is easily generated in the decorative coating film formed on the surface. Therefore, it is necessary to shorten the decoration material itself, and a large number of joints must be provided between the decoration materials at the time of attachment to a building.
[0007]
The present invention has been made in view of the above-described circumstances, and has sufficient self-extinguishing properties, and when melt-kneaded at the time of recycling, does not cause deterioration in quality such as deterioration in resin strength and is effective. It is an object of the present invention to provide a decorative interior / exterior material made of a styrene resin foam molded article which can be recycled. In addition, the styrene-based resin foam molded article has a small dimensional shrinkage rate over time of the styrene-based resin foam molded article, and prevents cracks or the like from being generated in the cosmetic coating material applied to the surface even if the length is long. It is an object to provide a decorative interior / exterior material comprising: Thereby, the amount of work on site can be reduced.
[0008]
[Means for Solving the Problems]
The inventors of the present invention have studied combinations of various flame retardants and flame retardant auxiliaries, and as a result, a composite flame retardant containing the following types of flame retardants and flame retardant auxiliaries in a specific ratio has been obtained. As a flame retardant for use, it has been found that the molecular weight does not easily decrease at the time of recycling and that excellent self-extinguishing properties can be exhibited, and the present invention has been accomplished.
[0009]
That is, the interior / exterior material for decoration according to the present invention comprises 90 to 40% by weight of a flame retardant composed of tris (2,3-dibromopropyl) isocyanurate and 2,3-dimethyl-2,3 in styrene resin particles. 1 to 7 parts by weight of a composite flame retardant comprising 10 to 60% by weight of a flame retardant auxiliary comprising -diphenylbutane or 3,4-dimethyl-3,4-diphenylhexane with respect to 100 parts by weight of the styrene resin particles. Applying a synthetic resin paint or a cement paint to part or all of the surface of the foam molded article obtained by foaming the pre-expanded particles obtained by pre-expanding the self-extinguishing type expandable styrene resin particles including It is characterized by becoming.
[0010]
The above-mentioned tris (2,3-dibromopropyl) isocyanurate (hereinafter, also referred to as TDIC) has a melting point of 115 ° C. and a decomposition temperature of 285 ° C., and is based on 2,3-dimethyl-2,3-diphenylbutane (because it is called biscumyl). , Hereinafter also referred to as BC) has a melting point of 113 ° C and a decomposition temperature of 205 ° C. Further, 3,4-dimethyl-3,4-diphenylhexane has a melting point of 142 ° C. and a decomposition temperature of 230 ° C. Since the above-mentioned flame retardants and flame retardant auxiliaries have relatively close melting points, the composite flame retardant obtained by mixing them has a melting point with almost one peak (this temperature is referred to as a melting point peak temperature). In addition, the present inventors have found that the melting point peak temperature of the composite flame retardant is lower than the melting points of the flame retardant and the flame retardant auxiliary alone due to a decrease in the melting point.
[0011]
The flame retardant and the flame retardant are used in a proportion of 90 to 40% by weight and 10 to 60% by weight. When the proportion of the flame retardant auxiliary is less than 10% by weight, it is necessary to use a large amount of the composite flame retardant in order to exhibit self-extinguishing properties, and as a result, recyclability is impaired. Further, the melting point peak temperature does not decrease so much, and the impregnation temperature or kneading temperature must be increased. On the other hand, when the content exceeds 60% by weight, the proportion of the flame retardant decreases, so that the self-extinguishing property is deteriorated. More preferred ratios of the flame retardant and the flame retardant auxiliary are 90 to 60% by weight and 10 to 40% by weight.
[0012]
The content ratio of the composite flame retardant is 1 to 7 parts by weight based on 100 parts by weight of the styrene resin. If the amount is less than 1 part by weight, sufficient self-extinguishing properties cannot be obtained. On the other hand, if it exceeds 7 parts by weight, the self-extinguishing effect is saturated and is not economical. A more preferable content ratio is 1 to 5 parts by weight.
[0013]
The styrene resin particles that can be used in the present invention are not particularly limited as long as they are styrene. For example, it may be a styrene homopolymer or a copolymer of styrene and another monomer copolymerizable therewith. Other monomers include α-methylstyrene, vinyltoluene, acrylonitrile, methyl methacrylate, glycidyl methacrylate, butyl acrylate, methacrylic acid, divinylbenzene, alkylene glycol dimethacrylate, and the like. In this specification, styrene and monomers copolymerizable with styrene are also referred to as styrene monomers. Further, the styrene-based resin may be a mixed resin with another resin. Examples of other resins include polyethylene, polypropylene, polyphenylene ether, and rubber-modified styrene resins. Examples of the mixing method include extrusion blending with an extruder and polymerization blending (a method of impregnating resin particles other than styrene-based resin such as polyethylene resin particles with a styrene monomer in an aqueous medium and polymerizing).
[0014]
Examples of the foaming agent to be impregnated into the styrene resin particles include inorganic foaming agents such as carbon dioxide gas and nitrogen gas, aliphatic hydrocarbons such as propane, butane, pentane, hexane and isomers thereof, and fats such as cyclobutane and cyclopentane. Examples include cyclic hydrocarbons, fluorinated hydrocarbons such as difluoroethane, and tetrafluoroethane. A particularly preferred blowing agent is carbon dioxide. In that case, carbon dioxide gas may be 100%, but other foaming agents may be added as long as the effects of the present invention are not impaired. Other blowing agents include air, inorganic blowing agents such as nitrogen, aliphatic hydrocarbons such as propane, butane, pentane, and hexane; alicyclic hydrocarbons such as cyclobutane, cyclopentane and cyclohexane; and fluorocarbons. Organic blowing agents can also be mixed. As the fluorinated hydrocarbon, it is preferable to use difluoroethane, tetrafluoroethane, or the like having an ozone depletion potential of zero. Here, the organic foaming agent is preferably used in a range not exceeding 20% by weight of the total amount of the foaming agent. The content ratio of carbon dioxide in the expandable resin particles is preferably 1 to 15% by weight.
[0015]
To impregnate the styrene-based resin particles with carbon dioxide gas, for example, after putting the resin particles in a pressure-tight container, press-fit the carbon dioxide gas and contact the resin particles with the pressurized carbon dioxide gas. Can be. The impregnation temperature may be raised to a temperature at which the resin particles do not coalesce and agglomerate with each other, but are usually 0 to 40 ° C. The pressure at which the resin particles are impregnated with carbon dioxide gas is preferably 10 kg / cm ² G or more, and more preferably 15 to 40 kg / cm ² G. The impregnation time can be appropriately adjusted so that the resin particles have the above-mentioned carbon dioxide content, and is preferably 1 to 20 hours, more preferably 2 to 8 hours.
[0016]
On the other hand, as another impregnating method of the foaming agent, a method of impregnating at the time of suspension polymerization or separately from suspension polymerization may be mentioned. It is preferable to add a suspension stabilizer to the aqueous medium used for impregnation in order to prevent the styrene-based resin particles from binding to each other during the impregnation.
As the suspension stabilizer, known polyvinyl alcohol, methyl cellulose, polyacrylamide, water-soluble polymers such as polyvinylpyrrolidone and the like, commonly used in suspension polymerization, tribasic calcium phosphate, hydroxyapatite, magnesium pyrophosphate and the like Examples thereof include poorly water-soluble inorganic compounds. When a poorly water-soluble inorganic compound is used, an anionic surfactant is usually used in combination. Examples of the anionic surfactant include fatty acid soap, N-acyl amino acid or a salt thereof, carboxylate such as alkyl ether carboxylate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, dialkyl sulfosuccinate, and alkyl sulfoacetic acid. Sulfonates such as salts and α-olefin sulfonates; sulfates such as higher alcohol sulfates, alkyl ether sulfates and polyoxyethylene alkylphenyl ether sulfates; alkyl ether phosphates and alkyl phosphates Phosphate salts such as salts are exemplified.
[0017]
The expandable styrene resin particles may further contain an additive. Additives include higher fatty acid amides, aromatic bisamides, ethylene bisstearyl amides, higher fatty acids, paraffins, waxes, lubricants such as hardened animal and plant oils, foaming aids such as toluene, cyclohexane, diisobutyl adipate, plasticizers, and foam regulators. , A foam stabilizer, a filler, a coloring agent, an antioxidant, an ultraviolet absorber and the like. These additives can be included in the particles during the production of the particles or during the impregnation or kneading of the composite flame retardant.
[0018]
The average particle size of the expandable styrene-based resin particles can be appropriately selected according to the application. For example, an average particle size of 0.3 to 3 mm can be used. A more preferred average particle size is 0.5 to 2 mm.
[0019]
The method for producing expandable styrene resin particles used in the foamed molded article in the present invention includes suspension polymerization, melt kneading a styrene resin and a composite flame retardant with an extruder, and then pelletizing the extruded strands. Method. Among them, the suspension polymerization method is preferred from the viewpoint of production efficiency.
[0020]
In the suspension polymerization method, as a method for impregnating the resin particles with the above-described composite flame retardant, a method in which the polymerization conversion is 99.8% or more, or a method in which the resin is impregnated by adding it to an aqueous medium after the polymerization is completed. Can be Impregnation when the polymerization conversion rate is 99.8% or more is preferable because expandable styrene resin particles having a predetermined molecular weight can be easily obtained.
[0021]
The method of adding the composite flame retardant is, for example, a method of separately or simultaneously adding a flame retardant and a flame retardant aid into an aqueous medium, a method of mixing the flame retardant and the flame retardant aid with a super mixer, etc. A method in which the suspension is poured into an aqueous medium as it is, and a method in which a suspension uniformly dispersed in a preliminary dispersion tank provided with a stirring device is charged into the aqueous medium. Furthermore, it is preferable to impregnate simultaneously with the foaming agent and / or the additive. In order to perform the impregnation more smoothly, it is preferable to heat the aqueous medium. Specifically, it is preferable to heat at a temperature of 70 to 120 ° C. for 1 to 6 hours.
The self-extinguishing foamable styrenic resin particles impregnated with the composite flame retardant and the foaming agent are removed from the aqueous medium as needed. The removed particles may be washed and dehydrated and dried.
[0022]
The self-extinguishing foamable styrene resin particles may be treated with an appropriate surface treatment agent. As the surface treatment agent, known agents such as a binding inhibitor, an antistatic agent, a lubricant, a fusion promoter, a high cycle agent, and a release agent can be used. In addition, known additives such as an ultraviolet absorber, a rust inhibitor, a wood preservative, a termiticide, a fungicide, an antibacterial agent, a fragrance, and a coloring agent may be used in combination with the surface treatment agent. As a method of the surface treatment, a known method using a mixer such as a tumbler mixer, a Nauter mixer, a Loedige mixer, a proshare mixer ribbon blender, or the like can be used.
[0023]
The self-extinguishing styrene-based resin particles are pre-expanded into self-extinguishing styrene-based pre-expanded particles. As the pre-foaming method, any known method can be used. For example, it can be manufactured under normal conditions using a prefoaming machine for expanded polystyrene beads. In particular, styrene-based resin particles are impregnated with carbon dioxide to form expandable styrene-based resin particles, and in the next step, the foamable styrene-based resin particles are charged into a pre-foaming machine equipped with a steam input line and an exhaust line, Steam is supplied from the steam input line at an input pressure of 0.5 to 5.0 kg / cm ² G, and an atmosphere gas containing the steam is exhausted from the exhaust line. The method of obtaining pre-expanded styrene-based resin particles by pre-expanding while maintaining the styrene-based resin pre-expanded particles at a low value of 0.05 to 1.0 kg / cm ² G can reduce the dimensional shrinkage of a molded product formed by expanding and molding the obtained pre-expanded particles. This is effective because it can be made smaller.
In this method, it is preferable that prefoaming be performed immediately after the step of impregnating with carbon dioxide gas. The bulk density of the pre-expanded particles is preferably in the range of 0.01 to 0.2 g / cm ³ .
[0024]
An example of a prefoaming machine that can be used to produce the styrene resin prefoamed particles will be described with reference to FIG. In the figure, 100 is a prefoaming machine, 102 is a stirring motor, 103 is a stirring blade, 104 is a baffle, 105 is a foaming tank upper surface detector, 106 is a foaming particle transporter, 107 is a foaming particle measuring tank, and 108 is Expandable particle input device, 109 is a steam blowing control valve, 110 is a steam chamber, 111 is a condensed water discharge valve, 112 is an exhaust control valve, 113 is a pre-expanded particle outlet, 114 is a pre-expanded particle temporary receiver, 115 is Pneumatic transportation equipment, 116 is an internal pressure detection / control device, 117 is a steam injection hole, 118 is a steam input pressure gauge, 119 is a pressure reducing valve, and 120 is a steam source pressure gauge.
[0025]
In detail, the pressure in the prefoamer 100 (pressure detected by the internal pressure detection / control device 116) is always set to the supply pressure by the exhaust control valve 112 or the like so that a fixed amount of steam is always supplied into the prefoamer 100. Control is performed so as to fall below. For example, when the input pressure of steam is set to 1.2 kg / cm ² G (detected by the steam input pressure gauge 118) and the pressure in the prefoaming machine is set to 0.8 kg / cm ² G, the pressure in the prefoaming machine 100 is set to Detected by the internal pressure detection / control device 116, a control signal is sent to the exhaust control valve 112, and the pressure is controlled while the pressure of 0.4 kg / cm ² G pressure is removed from the exhaust line. As described above, the pressure in the prefoamer 100 can be adjusted by linking and controlling the internal pressure of the prefoamer 100 and the exhaust control valve 112.
[0026]
In the above method, if the difference between the charging pressure and the pressure in the prefoaming machine is less than 0.05 kg / cm ² G, not only is it difficult to obtain low density prefoamed particles, but also the appearance and internal fusion of the foamed molded article Is bad and has a very low commercial value. On the other hand, if it exceeds 1.0 kg / cm ² G, not only the bonding at the time of prefoaming increases, but also the unevenness of the foam surface becomes large, which is not preferable. A more preferable pressure difference is 0.1 to 0.5 kg / cm ² G.
[0027]
It is preferable that the expandable resin particles in the prefoaming machine are usually heated to about 110 to 160 ° C, and a more preferable heating temperature is 110 to 130 ° C. If the heating temperature is lower than 110 ° C., pre-expanded particles having a bulk density of 0.5 g / cm ³ or less are not easily obtained, which is not preferable. On the other hand, if the heating temperature is higher than 160 ° C., the tendency of the pre-expanded particles to coalesce increases, which is not preferable.
[0028]
The foamed molded article obtained by foaming the above self-extinguishing styrene-based resin preliminary particles has excellent self-extinguishing properties, and also has an excellent long-term dimensional shrinkage rate, and has a high dimensional shrinkage rate. It can be 0.5% or less. Further, the content of the volatile organic compound can be extremely reduced to 1000 ppm or less.
[0029]
The foam molding method is not particularly limited, and any known method can be used. For example, self-extinguishing styrene-based pre-expanded particles are filled in a molding cavity and heated by steam. When the pre-expanded particles are heated by contact with steam, the pre-expanded particles expand, but because the space in which the foam can be expanded is limited by the molding cavity, the pre-expanded particles adhere to each other and are fused and integrated to obtain the desired foamed molding. You can get the body. The density of the foam molded article is preferably about 0.015 to 0.5 g / cm ³ . An example of the desired shape is a decorative material having a shape as shown in FIG.
[0030]
The foamed molded article can be obtained from conventional self-extinguishing foamable styrene-based resin particles even when recycled by volume reduction or melt-kneading with an extruder, similarly to a general polystyrene foamed molded article containing no flame retardant. The resin is less deteriorated than when the foamed molded article is recycled, and the molded article has high recyclability.
[0031]
The interior / exterior material for decoration comprising the styrenic resin foam molded article according to the present invention can be produced by coating the whole or a part of the surface of the foam molded article thus obtained. In the present invention, a resin coating, a mortar coating, or the like can be applied as a coating. As the resin coating, any one using a water-based paint, one using a solvent paint, and the like can be used. It is preferable to use an acrylic resin, a urethane resin, an epoxy resin, a silicone resin, or the like for the coating using the water-based paint, and the coating may be performed by a method such as spraying, an air gun, or brushing. Further, in the case of applying a coating using a solvent paint, it is preferable to apply a base treatment to a foam molded body portion to be coated. The mortar-based paint is, for example, a cement mortar defined in JIS 6909 and JIS 6916, and it is preferable to use a mortar-based paint that is stirred with water and / or a synthetic resin emulsion. When applying the coating, the coating can be performed using a trowel, a spraying machine, a roller, a brush, or the like.
[0032]
Further, on the surface of the self-extinguishing styrenic resin foam molded body as a core material, one or several kinds selected from alkali-resistant glass fibers, inorganic fibers such as carbon fibers, and synthetic resin fibers such as acrylic fibers are woven. Alternatively, it is preferable to apply the above-mentioned coating such as a mortar composition thereon as a surface reinforcing layer or a decoration layer after attaching the woven net-like material using an adhesive. By sticking such a net-like object, it is possible to prevent a crack on the painted surface.
[0033]
The decorative interior / exterior material according to a preferred embodiment of the present invention (a molded article of a styrene-based resin pre-expanded particle using carbon dioxide as a foaming agent) has an extremely small long-term dimensional shrinkage. For this reason, it is possible to avoid a crack or the like caused by shrinkage of the core material in the decorative coating applied to the surface even as a long decorative material. In addition, the amount of work on site can be reduced as compared with a case where a large number of short decorative materials are connected.
[0034]
【Example】
Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, evaluation of compressive strength, self-digestibility, dimensional shrinkage, MFR (melt flow rate), and weight average molecular weight was performed as follows.
[0035]
<Dimension shrinkage>
The test was performed according to the length change test of JIS A6916 (coating material for building base adjustment). That is, the foam molded product (actually, a flat plate of 160 mm × 40 mm × 40 mm) taken out of the foam molding die is dried, and thereafter, a constant temperature / humidity room (standard temperature of JIS-K7100) at a temperature of 23 ° C. and a relative humidity of 50%. After leaving for 24 hours in a humidity state), each finishing material (urethane or mortar) was applied to a thickness of 2 mm on the entire surface of the foamed molded product, and further dried in a constant temperature chamber at 20 ° C for 6 hours. Thereafter, according to JIS A1129 (mortar and concrete length change test method), a gauge plug is embedded in the specimen at a predetermined interval (100 mm), and the interval immediately after the preparation of the specimen and the constant temperature and humidity chamber at 20 ° C and 65%. The difference after 4 weeks had elapsed was calculated from the value obtained by dividing the difference between the values measured with a contact gauge by the measured interval immediately after the preparation of the specimen.
<Compression strength>
The test was performed according to the test method of JISA9511. That is, using a Tensilon universal testing machine UCT-10T (manufactured by Orientec Co., Ltd.), the compression speed was set to 10 mm / min with a test piece (size: 50 mm × 50 mm × 50 mm) obtained from a foam molded article taken out of a foam mold. The compression strength at 5% compression was measured.
<Self-extinguishing>
The flammability (self-extinguishing time) of the foam molded article taken out of the foam mold was measured according to the combustion test A method of JIS A9511. According to this JIS standard, the self-extinguishing time needs to be within 3.0 seconds.
[0036]
<Measurement of MFR>
The measurement was performed under the following conditions based on JIS K7210. In the test sample, the expandable polystyrene resin particles obtained in Examples and Comparative Examples were held in an oven at 50 ° C. for 24 hours while vacuum-sucking at an ultimate pressure of 1.0 kg / cm ² G for 24 hours. From which volatile organic compounds were removed. The MFR of the polyethylene resin that can be recycled by melting and kneading with an extruder to form a strand is 20 g / 10 min or less, preferably 15 g / 10 min or less.
Measuring device: Melt indexer manufactured by Toyo Seiki Seisakusho Co., Ltd. Measurement temperature: 200 ° C
Measurement load: 5.0kgf
Orifice diameter: 2.09 mm
[0037]
<Weight average molecular weight>
The weight average molecular weight (Mw) of the styrene resin particles was measured by GPC (gel permeation chromatography) under the following conditions. When measuring the weight-average molecular weight, the measurement conditions are such that the molecular weight distribution of the measurement sample falls within a range in which the logarithm of the molecular weight and the count number of a calibration curve prepared from several types of monodisperse polystyrene standard samples are linear. Was selected. The calibration curve shows that the weight average molecular weight is 2.74 × 10 ³ , 1.91 × 10 ⁴ , 1.02 × 10 ⁵ , 3.55 × 10 ⁵ , 2.89 × 10 ⁶ , 4.48 × 10 5. ^The sample was prepared under the following conditions using 6 polystyrene standard samples (TSK standard polystyrene) manufactured by Tosoh Corporation.
GPC: Tosoh Corporation high-speed GPC device HLC-8020
Column: HSG-60S x 2, HSG-40H x 1, HSG-20H x 1 manufactured by Sekisui Fine Chemical Co., Ltd Column temperature: 40 ° C
Mobile phase: THF (tetrahydrofuran)
Flow rate: 1.0 ml / min Injection volume: 500 ml
Detector: Tosoh RID-6A
[0038]
The measurement of the weight average molecular weight was performed before and after the MFR measurement treatment. It is desired from the viewpoint of recycling that the weight average molecular weight does not change as much as possible before and after the heat treatment (MFR measurement treatment). If it is significantly reduced, it cannot be extruded as a strand after melt-kneading with an extruder, or the strand frequently breaks, making recycling difficult.
[0039]
[Example 1]
38 l of deionized water, 75 g of magnesium pyrophosphate and 7 g of sodium dodecylbenzenesulfonate were charged into a reactor having an inner volume of 100 l equipped with a stirrer. 44 kg of styrene in which 27 g of benzoate was dissolved was stirred in a reactor, heated to 90 ° C. and maintained for 6 hours, then heated to 125 ° C. and maintained for 3 hours to carry out polymerization. At the end of the polymerization, the polymerization conversion was 99.9%. After cooling, the contents were taken out, washed and dehydrated and dried, and then passed through a sieving machine to obtain polystyrene resin particles having a particle diameter of 0.9 to 1.2 mm.
[0040]
A suspension prepared by suspending 0.5 g of sodium dodecylbenzenesulfonate, 6 g of magnesium pyrophosphate, and 20 g of toluene in 2 liters of water was placed in a pressure vessel equipped with a stirrer having an internal volume of 5 liters. 2 kg of resin particles, 1.6% by weight of tris (2,3-dibromopropyl) isocyanurate (flame retardant: TDIC), and 0.1% of 2,3-dimethyl-2,3-diphenylbutane (flame retardant auxiliary: BC). After the composite flame retardant consisting of 3% by weight was charged and the container was closed, the temperature was raised to 100 ° C. with continuous stirring, and 95 g of normal butane and 44 g of isobutane were injected at an impregnation temperature of 100 ° C. and held for 3 hours. Next, after cooling to 25 ° C. and taking out the resin particles from the pressure vessel, the resin particles were washed and dehydrated and dried to obtain self-extinguishing foamable polystyrene resin particles. The MFR and the weight average molecular weight of the self-extinguishing type expandable polystyrene resin particles were evaluated by the above evaluation method. Table 1 shows the results.
[0041]
After keeping the expandable resin particles in a constant temperature room at 20 ° C. for 5 days, the expandable resin particles were foamed with a prefoaming machine to obtain prefoamed particles. After 6 hours of prefoaming, a 160 mm long x 40 mm wide x 40 mm thick as a sample for dimensional shrinkage measurement, and a 300 mm long x 150 mm wide x 30 mm thick cavity as a sample for recyclability confirmation test The pre-expanded particles were filled in a molding die having the same, and steam was blown into the die to expand again to obtain a core material of the decorative interior / exterior material having a density of 0.020 g / cm ³ .
[0042]
After drying the obtained foamed molded article in a constant temperature room at 50 ° C. for 7 days, a urethane resin (trade name: Efretane SH-4000 (Nippon Synthetic Chemical Industry Co., Ltd.) A company-made / rapid-curing and solvent-free urethane resin)) was sprayed in two portions with a coating thickness of about 1 mm to apply a urethane resin film and dried in a constant temperature chamber at 20 ° C. for 1 hour.
[0043]
For the decorative material having a length of 160 mm, a width of 40 mm and a thickness of 40 mm after coating, the dimensional change rate was evaluated by the above-described evaluation method, and the self-extinguishing property was evaluated for the core material of the interior and exterior materials for decoration in accordance with JIS A9511. Further, in order to examine the recyclability, the urethane resin film was peeled off from the decorative material having a length of 300 mm × a width of 150 mm × a thickness of 30 mm, and a core material expanded polystyrene was taken out. The volume of the core material was reduced, and the core material was formed into strands using a single-screw extruder having a diameter of 30 mm (extrusion temperature: 180 ° C.). Was measured by the above evaluation method. Table 1 shows the results.
[0044]
[Example 2]
In the same manner as in Example 1, the core material of the interior / exterior material for decoration was obtained, and an alkali-resistant glass fiber mesh (trade name: CCX Fiberglass Product Co., Ltd., product number Style 1350) was sprayed on the entire surface in advance, and further wound. After applying a cement-based paint (trade name: Sekisui Chemical Co., Ltd. Sekisui Bon Molcoat Lightweight) at a thickness of 2 mm, and drying in a constant temperature room at 20 ° C. for 6 hours to obtain decorative interior and exterior materials Performed the same measurement and evaluation as in Example 1. Table 1 shows the results.
[0045]
[Example 3]
To 1 kg of the same polystyrene resin particles as in Example 1, 1.5 g of calcium carbonate fine powder as a bonding inhibitor during foaming and 0.5 g of monoglycerite stearate as an antistatic agent were uniformly adhered to the resin particle surfaces. The container was sealed in a pressure vessel, and then pressurized with carbon dioxide gas, and kept at 20 ° C. and 30 kg / cm ² G for 6 hours to impregnate the resin particles with carbon dioxide gas to obtain expandable styrene resin particles. .
[0046]
The expandable styrene resin particles thus obtained were taken out of the pressure-resistant container and charged in a foaming machine equipped with a stirrer in the next step, and then steam having a charging pressure of 1.2 kg / cm ² G was introduced into the foaming machine. At this time, while the opening of the exhaust control valve was controlled by an electric signal so that the pressure in the foaming machine was 0.8 kg / cm ² G, excess pressure was released to the outside using the exhaust line (input pressure). Is 0.4 kg / cm ² G). As described above, the same measurement and evaluation as in Example 1 were performed except that pre-expanded styrene resin particles were obtained by pre-expanding while continuously introducing steam into the foaming machine. Table 1 shows the results.
[0047]
[Comparative Example 1]
Same as Example 1 except that tris (2,3-dibromopropyl) isocyanurate was 30 g of tetrabromocyclooctane and 2,3-dimethyl-2,3-diphenylbutane was 6.0 g of dicumyl peroxide. Expandable styrene resin particles were obtained by the following method, and the MFR and the weight average molecular weight of the expandable styrene resin particles were evaluated in the same manner as in Example 1. Table 1 shows the results.
[0048]
After keeping the expandable resin particles in a constant temperature room at 20 ° C. for 5 days, the expanded resin particles were expanded with a pre-expanding machine in the same manner as in Example 1 to obtain pre-expanded particles. Six hours after the prefoaming, two kinds of core materials for the interior and exterior materials for decoration were obtained in the same manner as in Example 1.
[0049]
Hereinafter, surface coating is performed in the same manner as in Example 1, and for the decorative material having a length of 160 mm × width 40 mm × thickness 40 mm after coating, the dimensional change rate is evaluated in the same manner as in Example 1, The self-extinguishing property was evaluated according to JIS A9511 for the core material of the interior / exterior material for decoration. As for the decorative material having a length of 300 mm, a width of 150 mm, and a thickness of 30 mm, the urethane resin film was peeled off in the same manner as in Example 1 to reduce the volume of the expanded polystyrene core, and the volume was reduced to a uniaxial diameter of 30 mm. Stranding was performed with an extruder (extrusion temperature 180 ° C.). However, although the obtained recovered raw material was subjected to foam molding by the same method as in the example, no recovered raw material capable of foaming was obtained.
[0050]
[Table 1]

[0051]
[Discussion]
In Examples 1 to 4, since the composite flame retardant unique to the present invention was used, the self-extinguishing time was short, and the change in the weight average molecular weight before and after the MFR measurement was small. Therefore, a foam molded article can be obtained by using the recovered raw material, and the obtained foam molded article shows high compressive strength. In Example 3, since carbon dioxide was used as the foaming agent, the dimensional shrinkage was as small as 0.13.
[0052]
In Comparative Example 1, the conventional flame retardant was used, the self-extinguishing time was longer than that of the Example, and the change in the weight average molecular weight before and after the MFR measurement was very large. Cannot be used to obtain a foam molded article.
[0053]
【The invention's effect】
The decorative interior / exterior material made of the styrene-based resin foam molded article according to the present invention has a short self-extinguishing time and a small change in the weight average molecular weight before and after the MFR measurement because the unique composite flame retardant is used. . Therefore, it is possible to effectively recycle the resin without deteriorating the quality such as a decrease in the strength of the resin. When carbon dioxide gas is used as the foaming agent, the dimensional shrinkage over time of the foamed molded article can be made extremely small, and even if the length is long, cracks and the like are generated in the decorative coating material applied to the surface. A decorative interior / exterior material that does not generate can be obtained. Thereby, the amount of work on site can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view of a prefoaming machine used to produce styrene resin prefoamed particles that can be used in the present invention.
FIG. 2 is a view showing an example of an interior / exterior material for decoration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Foam molding as a core material 2 Net-like material 3 Surface coating 4 Decorative interior / exterior material 102 Stirrer motor 103 Stirrer blade 104 Baffle bar 105 Foaming tank upper surface detector 106 Foaming particle transporter 107 Foaming particle measuring tank 108 Foaming Injecting device 109 Steam injection control valve 110 Steam chamber 111 Condensed water discharge valve 112 Exhaust control valve 113 Pre-expanded particle discharge port 114 Pre-expanded particle temporary receiver 115 Air transport facility 116 Internal pressure detection / control device 117 Steam injection hole 118 Steam Input pressure gauge 119 Pressure reducing valve 120 Steam source pressure gauge

Claims

90 to 40% by weight of a flame retardant composed of tris (2,3-dibromopropyl) isocyanurate in styrene resin particles, and 2,3-dimethyl-2,3-diphenylbutane or 3,4-dimethyl-3, A self-extinguishing foamable styrene resin particle containing 1 to 7 parts by weight of a composite flame retardant of 10 to 60% by weight of a flame retardant aid composed of 4-diphenylhexane with respect to 100 parts by weight of the styrene resin particle. A decorative interior / exterior material obtained by applying a synthetic resin paint or a cement-based paint to a part or all of the surface of a foam molded article obtained by foam molding pre-expanded particles obtained by pre-expanding.

The decorative interior / exterior material according to claim 1, wherein the styrene-based resin pre-expanded particles use carbon dioxide gas as a foaming agent.

The pre-expanded styrene resin particles used for molding the core material for interior and exterior decoration materials are made by impregnating the styrene resin particles with carbon dioxide to form expandable styrene resin particles, and equipped with a steam input line and an exhaust line in the next process The expandable styrenic resin particles are charged into the pre-expansion machine, steam is supplied from a steam charging line at a charging pressure of 0.5 to 5.0 kg / cm ² G, and an atmosphere gas containing the steam is discharged from an exhaust line. Pre-expanded styrene-based resin particles obtained by pre-expanding while exhausting and maintaining the pressure inside the foaming machine at 0.05 to 1.0 kg / cm ² G lower than the pressure of steam during that time. Item 3. An interior / exterior material for decoration according to Item 2.

The decorative interior / exterior material according to claim 2 or 3, wherein the content of the volatile organic compound contained in the styrenic resin foam molded article is 1000 ppm or less.