JP3805422B2

JP3805422B2 - Laminate for pachinko base plate

Info

Publication number: JP3805422B2
Application number: JP07307696A
Authority: JP
Inventors: 光臣長田; 敏彦兼岩; 厚至竹内; 勲甲斐
Original assignee: Asahi Organic Chemicals Industry Co Ltd
Current assignee: Asahi Yukizai Corp
Priority date: 1996-03-05
Filing date: 1996-03-05
Publication date: 2006-08-02
Anticipated expiration: 2016-03-05
Also published as: JPH09239918A

Description

【０００１】
【発明の属する技術分野】
本発明は、木材系材料の代替材料として用いられる積層体、特に古紙を有効活用して成る軽量な積層体及びこれを用いたパチンコ台に関する。
【０００２】
【従来の技術】
パチンコ業界においては、顧客の安定確保のため、従前より新旧パチンコ台の入れ替えが頻繁に行われており、毎年膨大な数のパチンコ台が生産されている。そして、このパチンコ台盤面板には従来合板が用いられてきたが、世界的な木材資源の枯渇及び自然環境の保護の観点から木材の入手が困難になるとともに合板の価格高騰が予測される。一方、ＯＡ機器の普及や情報化社会に伴う新聞・雑誌・書籍等の増大により多量の紙が使用されているが、これら使用済古紙は約６割近く回収再利用されているものの約４割は廃棄されている。かかる状況のもと古紙の再資源化促進及び木材系材料（合板）の代替材料の出現が強く待ち望まれている。
【０００３】
【発明が解決しようとする課題】
本発明は、上述のような事情に鑑み、木材系材料、特にパチンコ台盤面板用合板の代替材料として要求される特性、すなわち軽量性、強度、釘引き抜き抵抗値（以下「保釘力」という）及び加工性（鋸作業性、ドリル孔空け性等の切削性及び釘打ち性）を有し、かつ安価な古紙を有効利用して成る積層体及びこれを用いたパチンコ台を提供することを目的としてなされたものである。
【０００４】
【課題を解決するための手段】
上記の課題を解決するため、本発明はパチンコ台盤面板用積層体に関するもので、本発明では、コスト、軽量さ、強度及び加工性の観点から（Ａ）粉砕ないし離解処理された古紙主体の繊維質基材９０〜５０重量％と（Ｂ）熱硬化性樹脂１０〜５０重量％から構成され、かつ層間剥離防止の観点から坪量（熱硬化性成形体１ｍ²当たりの重量）を３００ｇ／ｍ²以上とした熱硬化性成形体を、保釘力確保及び反り防止の観点から同種又は異種組み合せて積層後熱硬化させて成り、かつパチンコ台盤面板用合板の代替材料として適用可能とするため、密度が５００〜９００ｋｇ／ｍ³、曲げ強度が２００ｋｇ／ｃｍ²以上及び保釘力が１５ｋｇ／ｃｍ以上に設定されている積層体又は該積層体を層状に接合して成る積層体としている。以下、本発明を詳細に説明する。
【０００５】
【発明の実施の形態】
本発明において用いられる繊維質基材は、例えばパルパー、ヘンシェルミキサー等の離解叩解機により粉砕ないし離解処理された古紙を主体とするものであって、必要に応じて有機質、無機質又は金属質繊維の少なくとも１種を繊維質基材全量の５０重量％未満、好ましくは３０重量％以下、さらに好ましくは２０重量％以下で併用することができる。前記古紙は繊維系であればよく特に制限はない。このような古紙の例としては、木材パルプ、リンターパルプ、麻パルプ、わらパルプ等の植物繊維系古紙の他、レーヨン繊維、ナイロン繊維、塩化ビニリデン繊維、ポリエステル繊維、アラミド繊維、フェノール繊維等の合成繊維系古紙、炭素繊維、ガラス繊維、セラミックス繊維等の無機繊維系古紙などが挙げられるが、中でも特に植物繊維系古紙が好ましい。これらは１種で用いてもよく、２種以上組み合せて用いてもよい。好ましい植物繊維系古紙の品種としては、例えば新聞紙、雑誌紙、電話帳、書籍紙、商業印刷紙、図画紙、タオル紙、パルプ紙、包装紙、記録紙等の紙類、段ボール紙、白板紙、黄板紙等の板紙類などが挙げられる。また、必要に応じて併用できる前記有機質、無機質又は金属質繊維としては、例えば木粉、パルプ類、木綿、レーヨン繊維、ポリアセテート繊維、ポリプロピレン繊維、ポリ塩化ビニリデン繊維、ポリエステル繊維、ナイロン繊維、アラミド繊維、フェノール繊維、ガラス繊維、炭素繊維、セラミック繊維、炭化珪素繊維、アルミニウム繊維、銅繊維などが挙げられるがこれらに限定されるものではない。これらは１種で用いてもよく、２種以上組み合せて用いてもよい。
【０００６】
本発明において用いられる熱硬化性樹脂は、架橋剤の存在下又は不存在下で熱硬化して繊維質基材を結合保持する結合剤機能を有するものであり、このような熱硬化性樹脂の例としては、フェノール樹脂、エポキシ樹脂、不飽和ポリエステル樹脂、メラミン樹脂、尿素樹脂などが挙げられる。中でも耐熱性、耐燃性及び剛性に優れるフェノール樹脂が好ましい。これらは１種で用いてもよく、２種以上を組み合せて用いてもよい。熱硬化性樹脂は、通常、粉末状ないし繊維状固体で使用されるが必要に応じて溶液や樹脂液で又は固液組合せで用いられる。
【０００７】
ここでいうフェノール樹脂とは、フェノール類とアルデヒド類との縮合生成物又はその変性物で架橋剤の存在下又は非存在下で熱硬化性を発現するものであって、このようなフェノール樹脂の例としては、ノボラック型フェノール樹脂、メチロール基含有ノボラック型フェノール樹脂、レゾール型フェノール樹脂、含窒素レゾール型フェノール樹脂、ベンジリックエーテル型フェノール樹脂及びこれらのフェノール樹脂とエポキシ系化合物、キシレン系化合物、メラミン系化合物、尿素系化合物、アクリル系化合物、酢酸ビニール系化合物等の熱硬化性もしくは熱可塑性化合物とを混合ないし反応させて得られる変性フェノール樹脂などが挙げられる。これらは１種で用いてもよく、２種以上を組み合せて用いてもよい。前記ノボラック型フェノール樹脂を単独で使用する場合には、例えばヘキサメチレンテトラミンのような架橋剤を用いて熱硬化性を付与する必要がある。
【０００８】
前記フェノール樹脂の中でもメチロール基含有ノボラック型、レゾール型、含窒素レゾール型及びベンジリックエーテル型フェノール樹脂は、積層体の臭気及び製造し易さの点で架橋剤を用いるノボラック型フェノール樹脂より有利であるが、特にベンジリックエーテル型フェノール樹脂は、他の樹脂より優れた熱安定性及び着色安定性を有し、後述の湿潤成形体乾燥時の変質、特に硬化の進行を抑制できることから好適に用いられる。
【０００９】
本発明に係る積層体は、木材系材料の代替材料を考慮しているため、コスト、軽量性、強度及び加工性の観点から（Ａ）粉砕ないし離解処理された古紙主体の繊維質基材５０〜９０重量％と（Ｂ）熱硬化性樹脂５０〜１０重量％、好ましくは（Ａ）６０〜８５重量％と（Ｂ）４０〜１５重量％から構成され、かつ層間剥離防止の観点から坪量を３００ｇ／ｍ²以上、好ましくは４００ｇ／ｍ²以上、より好ましくは５００ｇ／ｍ²以上とした熱硬化性成形体を、保釘力確保及び反り防止の観点から同種又は異種組み合せて積層し一体化させて成る積層体、又は該積層体をさらに層状に接合して成る積層体である。また、該積層体はパチンコ台盤面板用合板の代替材料として適用可能とするため、密度５００〜９００ｋｇ／ｍ³、好ましくは６００〜８００ｋｇ／ｍ³、曲げ強度２００ｋｇ／ｃｍ²以上、好ましくは２００〜７００ｋｇ／ｃｍ²、より好ましくは３００〜５００ｋｇ／ｃｍ²及び保釘力１５ｋｇ／ｃｍ以上、好ましくは２０ｋｇ／ｃｍ以上に設定されている。
【００１０】
ここで（Ａ）繊維質基材の配合量が５０重量％未満で（Ｂ）熱硬化性樹脂が５０重量％を越えると加工性の悪化及びコストの上昇を招き、逆に（Ａ）が９０重量％を越えて（Ｂ）が１０重量％未満であると強度及び保釘力が低く実用に供し得ない。また、坪量が３００ｇ／ｍ²未満であると層間剥離を生じ易く不都合である。また、密度が５００ｋｇ／ｍ³未満であると目標の強度及び保釘力の確保が困難であり、逆に９００ｋｇ／ｍ³を越えると重過ぎるし加工性も悪化して好ましくない。また、曲げ強度が２００ｋｇ／ｃｍ²未満では木材系材料の代替材料として実用に供し得ない。また、保釘力が１５ｋｇ／ｃｍ未満であるとパチンコ台用盤面板としては釘の耐震性及び玉の弾け具合が十分でなく好ましくない。
【００１１】
本発明に係る積層体は、一般に次のような抄造法を適用した方法により製造される。先ずはじめに、離解叩解機（例えばパルパー、ヘンシェルミキサー）内に多量の水と古紙及び必要に応じて有機質及び／又は無機質繊維を投入後、高速攪拌処理して古紙を粉砕ないし離解状態としたスラリーを得る。次いで、該スラリーを攪拌翼付混合槽に移送し、熱硬化性樹脂を投入して十分に混合し、必要に応じて各種添加物、例えば定着剤、架橋剤、硬化促進剤、充填材（軽量骨材や中実骨材）、難燃剤、可塑剤、防虫・殺菌剤、顔料、香料等を投入し、さらに混合して抄造用スラリーを得る。
【００１２】
次に、前記工程で得た抄造用スラリーを長網型又は円筒型抄造機（連続式又はバッチ式）により所望厚み、例えばシート状ないし薄板状の湿潤成形体に抄造し、ろ過、減圧、圧搾等により脱水し、その後乾燥装置、例えばドラム乾燥機、熱風通気乾燥機、誘電加熱乾燥機、遠赤外線乾燥機、減圧乾燥機等により乾燥させて所望の坪量を有する未硬化状態の熱硬化性成形体を得る。なお、前記湿潤成形体には必要に応じて架橋剤（例えばヘキサメチレンテトラミンや水溶性レゾール型フェノール樹脂）、硬化促進剤等を例えばスプレー含浸により定着させてもよい。また、かかる熱硬化性成形体の製作に際しては、適当な粉砕機で粉砕ないし離解処理した古紙主体の繊維質基材と熱硬化性樹脂及び必要に応じて前記各種添加物をミキサーにより均一混合して得られた混合物を、例えばフリース製造機等の賦形機により所望坪量のマット状フリースに賦形し、これを焼成機やプレス機等により樹脂の硬化を抑制しつつ所望厚み（例えはシート状、薄板状、マット状）に調整して未硬化状態の熱硬化性成形体を得る乾式法を採用してもよい。
【００１３】
次に、前記工程で得た熱硬化性成形体は、所望の性状（厚み、密度、密度差構成、密度傾斜等）に応じて同種又は異種組み合せて積層し、これを熱圧成形装置、例えば圧縮成形機、引き抜き成形機、押出機等で加熱加圧して一体化すると同時に硬化させて積層体に賦形される。また、得られた該積層体は、さらにその複数を例えばネジ、クギ、接着剤等の接合固定化手段、好ましくは接着剤とりわけ硬化型接着剤（例えばフェノール樹脂、尿素樹脂、メラミン樹脂、エポキシ樹脂、ウレタン樹脂等）で層状に接着（部分ないし全面）して接合固定して成る積層体とすることもできる。
【００１４】
かくして得られた本発明に係る積層体は、上述した如く特定坪量の熱硬化性成形体を用いて成る強力な層間結合性を有する多数積層構造体であるため、優れた保釘力を発現するのみならず、単層構造体より温度や湿度の変化に伴う反りを防止できるという利点を有する。さらには、積層構造中に高密度層を設けることにより積層体特性（反り防止、保釘力、強度）を一層向上させることができる。具体的には、例えば低密度芯層の上下面側に高密度表層を設けるとか又は同種の熱硬化性成形体を積層成形する際の圧縮速度調節（圧縮速度を速くすれば相対的に表面層密度が高く、逆に圧縮速度を遅くすれば相対的に芯層密度が高くできる）によって得られる表層部と芯層部とで異なる密度を有する積層体である。
【００１５】
本発明に係る積層体には、その表面部及び／又は芯部に必要に応じてアクリル樹脂、塩化ビニール樹脂等のプラスチックシート類又はボード類、メラミン樹脂化粧紙、クラフト紙、アルミクラフト紙、プリント紙等の紙類、アルミニウム薄板、ステンレス薄板、エンボス加工金属薄板等の金属系薄板類、コルクシート、天然木ツキ板等の木質系薄板類、無機質繊維又は有機質繊維の織布又は不織布などを設けてもよい。
【００１６】
【実施例】
次に、本発明を実施例により説明するが、本発明はこれらの実施例に限定されるものではない。なお、密度はＪＩＳＺ−２１０１、曲げ強さはＪＩＳＫ−６９１１及び保釘力はＪＩＳＺ−２１０１に準拠して測定した。また、加工性については、比較対照用パチンコ台盤面板用合板を基準に評価し、遜色のない場合は「〇」、劣るため実用に供し得ない場合は「×」で表示した。
【００１７】
実施例１
２００リットルパルパー（回転数３５００回転／分）内に水１２０リットルと新聞古紙７００ｇを投入し５分間攪拌処理して古紙を粉砕ないし離解状態としたスラリーを得た。次いで、このスラリーを攪拌翼付混合槽（回転数６００回転／分）に全量移送し、ベンジリックエーテル型フェノール樹脂粉末３００ｇを投入して１０分間攪拌混合し、さらにポリアクリルアミド系定着剤を添加後攪拌混合して抄造用スラリーを得た。次いで、この抄造用スラリーを角型バッチ式抄造機（抄造網１５０メッシュ、１０００×１０００ｍｍ）に全量投入し、ろ過し、吸引圧搾脱水を行ってシート状湿潤成形体を得た。次いで、この湿潤成形体を８０℃のオーブン内で乾燥させて未硬化状態で坪量９５０ｇ／ｍ²の熱硬化性成形体を得た。引続き、前述同様の操作を繰り返して同種の熱硬化性成形体を１４枚作製した。次いで、高さ１９ｍｍの金枠内に前記熱硬化性成形体１４枚を積層載置し、温度１８０℃及び圧力６ｋｇ／ｃｍ²で３５分間加熱加圧して厚み１９ｍｍの積層体を作製した。得られた積層体については、冒頭記載の方法により密度、曲げ強さ、保釘力及び加工性を調べた。その結果を表１に示す。なお、曲げ強さ及び保釘力の測定時には積層体の層間剥離現象は全く観察されなかった。
【００１８】
比較例１
実施例１において、新聞古紙を１４０ｇ及びベンジリックエーテル型フェノール樹脂粉末を６０ｇに変更した以外は、実施例１と同様に操作して坪量１８５ｇ／ｍ²の熱硬化性成形体を７０枚作製した。次いで、高さ１９ｍｍの金枠内に前記熱硬化性成形体７０枚を積層載置し、温度１８０℃及び圧力６ｋｇ／ｃｍ²で３５分間加熱加圧して厚み１９ｍｍの積層体を作製した。得られた積層体については、冒頭記載の方法で密度、曲げ強さ、保釘力及び加工性を調べたが、保釘力測定のため積層体に釘を打ち込んだところ一部で層間剥離を生じ、又曲げ強さ測定の際テストピースは層間剥離を伴って破壊した。
【００１９】
比較例２
実施例１において、新聞古紙を３６０ｇ及びベンジリックエーテル型フェノール樹脂粉末を４４０ｇに変更した以外は、実施例１と同様に操作して坪量７５０ｇ／ｍ²の熱硬化性成形体を１２枚作製した。次いで、高さ１９ｍｍの金枠内に前記熱硬化性成形体１２枚を積層載置し、温度１８０℃及び圧力６ｋｇ／ｃｍ²で３５分間加熱加圧して厚み１９ｍｍの積層体を作製した。得られた積層体については、冒頭記載の方法で密度、曲げ強さ、保釘力及び加工性を調べた。その結果を表１に示す。なお、曲げ強さ及び保釘力の測定時には積層体の層間剥離現象は観察されなかったが釘打ち及び切削時に欠け易いという欠点が確認された。
【００２０】
比較例３
パチンコ台盤面板に使用されている合板については、冒頭記載の方法で密度、曲げ強さ及び保釘力を調べた。その結果を表１に示す。
【００２１】
応用例
実施例１で得た積層体を用いて実機同様の試作パチンコ台を作成した後、長期間に亘る玉打ち評価を行ったところ、玉の弾け具合及び釘の耐震性は良好であり、しかもパチンコ台の反りは認められなかった。この結果から本発明に係る積層体はパチンコ台盤面板用合板の代替材料として使用できることが確認された。
【００２２】
【表１】

【００２３】
【発明の効果】
本発明に係る積層体は、強い層間結合性を有する古紙主体熱硬化性成形体を用いて成る多数積層構造体であるため、低コストかつ軽量で保釘力に優れ、しかも合板と遜色のない強度及び加工性を有するなどの効果を奏し、加えて温度や湿度の変化に伴う反りを防止できるという利点を有する。このような優れた性質を有する本発明に係る積層体は、木材系材料、特にパチンコ台盤面板用合板の代替材料として実用性を有するが、その他型枠用・梱包用・パレット用・家具用板など幅広い用途にも適用することができる。また、木材系材料の代替材料として実用可能なことから古紙の再資源化促進や木材資源の節減による自然環境の保護に大きく寄与することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminate used as an alternative material for a wood-based material, particularly a lightweight laminate obtained by effectively using waste paper, and a pachinko machine using the same.
[0002]
[Prior art]
In the pachinko industry, replacement of old and new pachinko machines has been frequently performed to ensure the stability of customers, and a huge number of pachinko machines are produced every year. Conventionally, plywood has been used for the pachinko base plate. However, it is difficult to obtain timber from the viewpoint of global depletion of wood resources and protection of the natural environment, and the price of plywood is expected to rise. On the other hand, a large amount of paper is used due to the spread of OA equipment and the increase in newspapers, magazines, books, etc. accompanying the information society, but about 40% of these used paper is collected and reused by about 60%. Has been discarded. Under such circumstances, there is a strong demand for promoting the recycling of waste paper and the emergence of alternative materials for wood-based materials (plywood).
[0003]
[Problems to be solved by the invention]
In view of the circumstances as described above, the present invention has characteristics required as an alternative material for wood-based materials, particularly plywood for pachinko base plate, that is, lightness, strength, nail pulling resistance (hereinafter referred to as “holding force”). ) And workability (cutability such as sawing workability, drilling ability and nailability), and a laminated body made by effectively using inexpensive waste paper and a pachinko machine using the same It was made as a purpose.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention relates to a laminate for a pachinko base plate, and in the present invention, from the viewpoint of cost, light weight, strength and workability, (A) a waste paper mainly processed by pulverization or disaggregation It is composed of 90 to 50% by weight of a fibrous base material and 10 to 50% by weight of (B) a thermosetting resin, and has a basis weight (weight per 1 m ^{2 of} thermosetting molded body) of 300 g / weight from the viewpoint of preventing delamination. m ² or more and the thermosetting moldings, made by Hokugi force providing and after the viewpoint laminated combination homologous or heterologous from warping prevention thermosetting or Tsupa dick base board applicable as a substitute material for plywood plate Therefore, a laminate having a density of 500 to 900 kg / m ³ , a bending strength of 200 kg / cm ² or more, and a nail holding force of 15 kg / cm or more, or a laminate obtained by joining the laminates in layers. It is said. Hereinafter, the present invention will be described in detail.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The fibrous base material used in the present invention is mainly composed of waste paper that has been pulverized or disaggregated by a disaggregation beater such as a pulper or a Henschel mixer, and is made of organic, inorganic or metallic fibers as necessary. At least one kind can be used in combination with less than 50% by weight of the total amount of the fibrous base material, preferably 30% by weight or less, more preferably 20% by weight or less. The waste paper is not particularly limited as long as it is fiber-based. Examples of such used paper include synthetic fiber fibers, nylon fibers, vinylidene chloride fibers, polyester fibers, aramid fibers, phenol fibers, etc. in addition to plant fiber-based used paper such as wood pulp, linter pulp, hemp pulp, straw pulp, etc. Examples include inorganic waste paper such as fiber waste paper, carbon fiber, glass fiber, and ceramic fiber. Among them, plant fiber waste paper is particularly preferable. These may be used alone or in combination of two or more. Preferred types of plant fiber-based waste paper include, for example, newspapers, magazine papers, telephone books, book papers, commercial printing papers, graphic papers, towel papers, pulp papers, wrapping papers, recording papers, etc., cardboard papers, white paperboards And paperboards such as yellow paperboard. Examples of the organic, inorganic or metal fibers that can be used together as necessary include wood flour, pulps, cotton, rayon fibers, polyacetate fibers, polypropylene fibers, polyvinylidene chloride fibers, polyester fibers, nylon fibers, and aramids. Examples thereof include, but are not limited to, fiber, phenol fiber, glass fiber, carbon fiber, ceramic fiber, silicon carbide fiber, aluminum fiber, and copper fiber. These may be used alone or in combination of two or more.
[0006]
The thermosetting resin used in the present invention has a binder function of binding and holding the fibrous base material by thermosetting in the presence or absence of a crosslinking agent. Examples include phenolic resins, epoxy resins, unsaturated polyester resins, melamine resins, urea resins and the like. Among them, a phenol resin excellent in heat resistance, flame resistance and rigidity is preferable. These may be used alone or in combination of two or more. The thermosetting resin is usually used in the form of a powder or a fibrous solid, but is used as a solution, a resin liquid, or a solid-liquid combination as necessary.
[0007]
The term “phenolic resin” as used herein refers to a condensation product of phenols and aldehydes or a modified product thereof that exhibits thermosetting properties in the presence or absence of a crosslinking agent. Examples include novolak-type phenol resins, methylol group-containing novolak-type phenol resins, resol-type phenol resins, nitrogen-containing resol-type phenol resins, benzylic ether-type phenol resins, and these phenol resins and epoxy-based compounds, xylene-based compounds, melamine Examples thereof include modified phenolic resins obtained by mixing or reacting with thermosetting or thermoplastic compounds such as system compounds, urea compounds, acrylic compounds, and vinyl acetate compounds. These may be used alone or in combination of two or more. When the novolac type phenol resin is used alone, it is necessary to impart thermosetting property using a cross-linking agent such as hexamethylenetetramine.
[0008]
Among the phenol resins, the methylol group-containing novolac type, resol type, nitrogen-containing resol type, and benzylic ether type phenol resin are more advantageous than the novolak type phenol resin using a crosslinking agent in terms of the odor of the laminate and ease of production. However, the benzylic ether type phenol resin is particularly suitable for use because it has better thermal stability and coloring stability than other resins, and can suppress deterioration during drying of the wet molded body, which will be described later, particularly the progress of curing. It is done.
[0009]
Since the laminated body according to the present invention considers alternative materials for wood-based materials, from the viewpoint of cost, lightness, strength, and workability, (A) a pulverized or disaggregated fiber-based fibrous base material 50 ~ 90 wt% and (B) 50 to 10 wt% of thermosetting resin, preferably (A) 60 to 85 wt% and (B) 40 to 15 wt%, and basis weight from the viewpoint of preventing delamination A thermosetting molded body having a thickness of 300 g / m ² or more, preferably 400 g / m ² or more, and more preferably 500 g / m ² or more, is laminated by combining the same type or different types from the viewpoint of securing nail force and preventing warpage. Or a laminated body obtained by further joining the laminated body in layers. Moreover, in order to make this laminated body applicable as an alternative material of the plywood for pachinko base plate, the density is 500 to 900 kg / m ³ , preferably 600 to 800 kg / m ³ , the bending strength is 200 kg / cm ² or more, preferably 200 ˜700 kg / cm ² , more preferably 300 to 500 kg / cm ² and nail holding force 15 kg / cm or more, preferably 20 kg / cm or more.
[0010]
Here, when the blending amount of (A) the fibrous base material is less than 50% by weight and (B) the thermosetting resin exceeds 50% by weight, the workability is deteriorated and the cost is increased. If it exceeds wt% and (B) is less than 10 wt%, the strength and the nail holding force are so low that it cannot be put to practical use. Further, if the basis weight is less than 300 g / m ² , delamination is likely to occur. On the other hand, if the density is less than 500 kg / m ^3, it is difficult to ensure the target strength and nail holding force. Conversely, if the density exceeds 900 kg / m ³ , it is too heavy and the workability deteriorates. Further, if the bending strength is less than 200 kg / cm ^2, it cannot be put to practical use as a substitute material for wood-based materials. Further, if the nail holding force is less than 15 kg / cm, the nails are not preferable because the nail's seismic resistance and the ball bounce are not sufficient as a board surface plate for a pachinko machine.
[0011]
The laminate according to the present invention is generally produced by a method to which the following papermaking method is applied. First, after adding a large amount of water and waste paper and, if necessary, organic and / or inorganic fibers into a disaggregation beater (for example, a pulper or a Henschel mixer), a slurry that pulverizes or disaggregates the waste paper by high-speed stirring treatment. obtain. Next, the slurry is transferred to a mixing vessel equipped with a stirring blade, and a thermosetting resin is added and mixed well. Various additives such as a fixing agent, a crosslinking agent, a curing accelerator, a filler (lightweight) Aggregates and solid aggregates), flame retardants, plasticizers, insecticides / bactericides, pigments, fragrances, etc. are added and mixed to obtain a papermaking slurry.
[0012]
Next, the papermaking slurry obtained in the above step is made into a desired thickness, for example, a sheet-shaped or thin-plate-shaped wet molded body, using a long net type or cylindrical papermaking machine (continuous or batch type), and filtered, decompressed, and compressed. And then dried by a drying device such as a drum dryer, hot air ventilation dryer, dielectric heating dryer, far-infrared dryer, vacuum dryer, etc., and has an uncured thermosetting property having a desired basis weight. A molded body is obtained. In addition, a crosslinking agent (for example, hexamethylenetetramine or a water-soluble resol type phenol resin), a curing accelerator, or the like may be fixed to the wet molded body by spray impregnation, for example. In the production of such a thermosetting molded body, a fibrous base material mainly composed of waste paper, pulverized or disaggregated by an appropriate pulverizer, a thermosetting resin and, if necessary, the above-mentioned various additives are uniformly mixed by a mixer. The resulting mixture is shaped into a mat-like fleece having a desired basis weight using a shaping machine such as a fleece manufacturing machine, and the desired thickness (for example, A dry method for obtaining an uncured thermosetting molded body by adjusting to a sheet shape, a thin plate shape, or a mat shape may be employed.
[0013]
Next, the thermosetting molded body obtained in the above step is laminated in the same kind or different kind according to the desired properties (thickness, density, density difference configuration, density gradient, etc.), and this is laminated with a hot press molding apparatus, for example, It is heated and pressed by a compression molding machine, a pultrusion molding machine, an extruder, etc. to be integrated and simultaneously cured to be shaped into a laminate. In addition, the obtained laminate may be further bonded and fixed by means such as screws, nails, adhesives, etc., preferably adhesives, especially curable adhesives (eg phenol resins, urea resins, melamine resins, epoxy resins). , Urethane resin or the like) can be laminated (partially or entirely) and bonded and fixed.
[0014]
The laminate according to the present invention thus obtained is a multi-layered structure having strong interlayer bonding formed using a thermosetting molded article having a specific basis weight as described above, and thus exhibits excellent nail retention. In addition, the single-layer structure has the advantage of preventing warping associated with changes in temperature and humidity. Furthermore, by providing a high-density layer in the laminated structure, it is possible to further improve the laminate properties (warp prevention, nail retention, strength). Specifically, for example, a high-density surface layer is provided on the upper and lower surfaces of the low-density core layer, or the compression rate is adjusted when the same type of thermosetting molded body is laminated (if the compression rate is increased, the surface layer is relatively The surface layer portion and the core layer portion obtained by a high density and, conversely, the core layer density can be relatively increased by lowering the compression speed).
[0015]
In the laminate according to the present invention, the surface portion and / or the core portion, if necessary, plastic sheets or boards such as acrylic resin and vinyl chloride resin, melamine resin decorative paper, craft paper, aluminum craft paper, print Paper such as paper, metal thin plates such as aluminum thin plate, stainless steel thin plate, embossed metal thin plate, wooden thin plates such as cork sheet and natural wood veneer, woven fabric or non-woven fabric of inorganic fiber or organic fiber, etc. May be.
[0016]
【Example】
EXAMPLES Next, although an Example demonstrates this invention, this invention is not limited to these Examples. The density was measured according to JIS Z-2101, the bending strength was measured according to JIS K-6911, and the nail retention strength was measured according to JIS Z-2101. Further, the processability was evaluated with reference to a plywood for a pachinko base plate for comparison and the reference was “◯” when there was no inferiority, and “×” when it could not be put to practical use because it was inferior.
[0017]
Example 1
120 liters of water and 700 g of waste newspaper were put into a 200 liter pulper (rotation speed: 3500 rpm) and stirred for 5 minutes to obtain a slurry in which the waste paper was crushed or disaggregated. Next, this slurry was transferred to the mixing tank with a stirring blade (rotation speed: 600 rpm), and 300 g of benzylic ether type phenol resin powder was added and stirred for 10 minutes. Further, after adding a polyacrylamide-based fixing agent. By stirring and mixing, a papermaking slurry was obtained. Next, the entire amount of this papermaking slurry was put into a square batch type papermaking machine (papermaking mesh 150 mesh, 1000 × 1000 mm), filtered and subjected to suction squeezing dehydration to obtain a sheet-like wet molded body. Next, the wet molded body was dried in an oven at 80 ° C. to obtain a thermosetting molded body having a basis weight of 950 g / m ² in an uncured state. Subsequently, the same operation as described above was repeated to produce 14 thermosetting molded bodies of the same kind. Next, 14 thermosetting molded bodies were laminated and placed in a metal frame having a height of 19 mm, and heated and pressed at a temperature of 180 ° C. and a pressure of 6 kg / cm ² for 35 minutes to produce a laminate having a thickness of 19 mm. About the obtained laminated body, the density, bending strength, nail force, and workability were investigated by the method described at the beginning. The results are shown in Table 1. Note that no delamination phenomenon of the laminate was observed at the time of measuring the bending strength and the nail holding force.
[0018]
Comparative Example 1
In Example 1, 70 thermosetting molded articles having a basis weight of 185 g / m ² were produced in the same manner as in Example 1 except that 140 g of used newspaper and benzylic ether type phenol resin powder were changed to 60 g. did. Next, 70 thermosetting molded bodies were laminated and placed in a metal frame having a height of 19 mm, and heated and pressed at a temperature of 180 ° C. and a pressure of 6 kg / cm ² for 35 minutes to produce a laminate having a thickness of 19 mm. The obtained laminate was examined for density, bending strength, nail force and workability by the method described at the beginning, but when the nail was driven into the laminate for measuring the nail force, some delamination occurred. As a result, the test piece broke with delamination when measuring the bending strength.
[0019]
Comparative Example 2
In Example 1, twelve thermosetting molded articles having a basis weight of 750 g / m ² were produced in the same manner as in Example 1 except that the newspaper used paper was changed to 360 g and the benzylic ether type phenol resin powder was changed to 440 g. did. Next, 12 thermosetting molded bodies were laminated and placed in a 19 mm high metal frame, and heated and pressed at a temperature of 180 ° C. and a pressure of 6 kg / cm ² for 35 minutes to produce a 19 mm thick laminated body. About the obtained laminated body, the density, bending strength, nail force, and workability were investigated by the method described at the beginning. The results are shown in Table 1. In addition, the delamination phenomenon of the laminate was not observed when measuring the bending strength and the nail holding force, but it was confirmed that the laminate was easily chipped during nailing and cutting.
[0020]
Comparative Example 3
About the plywood used for the pachinko base plate, the density, the bending strength, and the nail holding force were examined by the method described at the beginning. The results are shown in Table 1.
[0021]
After creating a prototype pachinko machine similar to the actual machine using the laminate obtained in Application Example 1 and performing a ball hitting evaluation over a long period of time, the ball bounce condition and the earthquake resistance of the nail are good. Moreover, there was no warping of the pachinko machine. From this result, it was confirmed that the laminate according to the present invention can be used as an alternative material for the plywood for the pachinko base plate.
[0022]
[Table 1]

[0023]
【The invention's effect】
The laminated body according to the present invention is a multi-layered structure using a waste paper-based thermosetting molded body having strong interlayer bonding properties, so it is low in cost, lightweight, excellent in nail retention, and inferior to plywood. There are advantages such as having effects such as strength and workability, and in addition, warping associated with changes in temperature and humidity can be prevented. The laminate according to the present invention having such excellent properties has utility as an alternative material for wood-based materials, particularly plywood for pachinko base plate, but for other forms, packaging, pallets, furniture. It can be applied to a wide range of uses such as plates. In addition, since it can be used as a substitute material for wood-based materials, it can greatly contribute to the protection of the natural environment by promoting the recycling of waste paper and saving wood resources.

Claims

(A) 90% to 50% by weight of a pulverized or disaggregated waste paper-based fibrous base material and (B) 10 to 50% by weight of a thermosetting resin, and a basis weight of 300 g / m ² or more Or a laminated body obtained by laminating different thermosetting molded bodies and then thermosetting , or a laminated body obtained by joining the laminated bodies in layers, and has a density of 500 to 900 kg / m ³ and a bending strength of 200 kg / cm. ^{2. A} laminate for a pachinko base plate having a nail pulling resistance value of 15 kg / cm or more.