JP3698492B2

JP3698492B2 - Manufacturing method of resin-based material

Info

Publication number: JP3698492B2
Application number: JP19582596A
Authority: JP
Inventors: 康夫中井; 正樹塚田
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 1996-07-25
Filing date: 1996-07-25
Publication date: 2005-09-21
Anticipated expiration: 2016-07-25
Also published as: JPH1036533A

Description

【０００１】
【発明の属する技術分野】
本発明は、樹脂系材料そのものを始めとして、木材合板、パーティクルボード、ＭＤＦ等の木質材料、ＦＲＰ等の樹脂系材料であって、その中に含有されるホルムアルデヒド量を低減させた樹脂系材料の製造方法に関するものである。
【０００２】
【発明が解決しようとする課題】
木材合板を例にとると、層間の接着剤として低価格で接着力の高いフェノール樹脂、尿素・ホルムアルデヒド樹脂が従来より多用されてきた。しかし、これら接着剤用の樹脂は経時的にホルムアルデヒド（ホルマリン）を発散するため、ホルマリン臭がする、目に痛みを感じる（特に高濃度の場合）等の欠点があることから、これを改善するべく次に挙げるような試みがなされている。
▲１▼尿素・ホルマリン系、メラミン系、フェノール系等の接着剤を酢酸ビニル系エマルジョン、レゾルシノール樹脂、エポキシ樹脂等のホルムアルデヒドを発散しないものに変更する。
▲２▼接着剤中にホルムアルデヒド捕獲剤を混合する（例えば、特公平７−１１０４８４号公報参照）。
▲３▼ホルムアルデヒド捕獲剤、或いは捕獲剤を混入した樹脂を木質材料の表面に塗布する（例えば、特公昭５１−４２１６４号公報参照）。
▲４▼化粧板の裏面にホルムアルデヒド捕獲剤を含浸させた紙、不織布等を貼着する（例えば、特開昭５６−１２１７１３号公報参照）。
【０００３】
しかしながら、上記したもののうち▲１▼の方法では、使用する接着剤のコストが尿素・ホルマリン系等の接着剤に比べて高い上に、仮接着性が悪く、製造時の良品数が低下するという欠点があり、また接着剤ごとに加工条件を変更する必要がある。また、▲２▼〜▲４▼の方法は何れもコストが高くなるばかりか、▲２▼の方法では、製造工程中に吸着、放出したホルムアルデヒドは捕獲できないと言った問題や、グレードにより配合量を変える必要があるため接着剤の種類が増える、端面処理が難しいと言った欠点があり、▲３▼の方法では、表面に貼着する化粧シートとの密着性を考慮する必要があり、また端面処理が難しいという欠点があり、▲４▼の方法では、含浸基材に印刷する場合に印刷適性が悪いという欠点がある。
【０００４】
また、メラミン樹脂含浸紙とフェノール樹脂含浸紙の積層体からなる所謂メラミン樹脂化粧板やアミノアルキッド樹脂塗装木板の場合も同様に樹脂分からホルムアルデヒドが発散される。そこでこの場合にも対策として、樹脂自体に、或いは化粧板を他の基材に積層する際の接着剤中に、ホルムアルデヒド捕獲剤を添加するという工夫を行うことは提案されていた。しかしながら、ホルムアルデヒドを接着剤中に混合すると、接着力の低下、接着剤の配合変更、接着条件の変更、原価高騰という問題が起こり、さらには化粧板表面に吸着されたホルムアルデヒドの発散が防げないと言った問題がある。また、ホルムアルデヒドを塗料に混入すると、表面物性（硬度等）の低下、硬化条件の変更、原価高騰という問題が発生する。
【０００５】
本発明は、上記のような問題点に鑑みてなされたものであり、その目的とするところは、フェノール樹脂等のホルムアルデヒド発散性樹脂を含む樹脂系材料であって、ホルムアルデヒドの発散を少なくした樹脂系材料の製造方法を提供することにある。
【０００６】
【課題を解決するための手段】
上記の目的を達成するため、本発明に係る樹脂系材料の製造方法は、ホルムアルデヒド発散性樹脂を成分として含有する樹脂系材料に、不活性ガス雰囲気下で電子線を照射して発散ホルムアルデヒド量を低減させることを特徴とするものである。
【０００７】
上記の樹脂系材料は、▲１▼ホルムアルデヒド発散性樹脂単体、▲２▼ホルムアルデヒド発散性樹脂を層間の接着剤として用いた木材合板（所謂集成材も含む）、▲３▼ホルムアルデヒド発散性樹脂をバインダーとするパーティクルボード又は木質繊維板（ＭＤＦ等）、▲４▼ホルムアルデヒド発散性樹脂を繊維質材料と混練又は含浸して複合化したもの（広義のＦＲＰ）、▲５▼各種基材にホルムアルデヒド発散性樹脂を成分とする接着剤層を間に介して各種化粧シートを貼着してなる化粧板の何れの形態であっても構わない。
【０００８】
上記の製造方法によれば、樹脂系材料の種類に関わらず、特殊な添加剤が不要で、厚み方向均一に、端面処理も同時に、瞬時に樹脂系材料中のホルムアルデヒド量を低減させることができる。
【０００９】
【発明の実施の形態】
ホルムアルデヒド発散性樹脂としては、フェノール（石炭酸）とホルムアルデヒドとの縮重合から得られるフェノール樹脂、尿素とホルマリンとの重合で得られる尿素（或いは尿素・ホルムアルデヒド）樹脂、アルキド樹脂にメラミン樹脂、尿素樹脂、グアナミン樹脂等を添加してなるアミノアルキド樹脂、メラミン樹脂等がある。ホルムアルデヒドが樹脂系材料中に存在するのは、主に次の原因によると考えられている。すなわち、▲１▼樹脂の未反応物として残る場合、▲２▼硬化反応中（加熱・加圧）に遊離したものとして残る場合、▲３▼樹脂以外の材料（木材、紙等）に捕捉されたものとして残る場合、等である。このように樹脂系材料中に存在していたものが徐々に遊離し放出される。
【００１０】
ホルムアルデヒド発散性樹脂単体としては、ホルムアルデヒド発散性樹脂からなる成形品、板状、シート状、各種立体形状等の形状のものがある。木材合板、パーティクルボード又は木質繊維板に用いられる木材としては、楢、杉、松、欅、樫、ラワン、チーク等通常使用されているものを用いる。
【００１１】
ホルムアルデヒド発散性樹脂を混練又は含浸する繊維質材料としては、上質紙、クラフト紙、チタン紙、和紙等の紙、硝子繊維、炭素繊維、石綿等の無機物繊維、麻、木綿、ビニロン等の有機物繊維からなる織布又は不織布があり、さらには前記無機物又は有機物繊維を１〜１０ｍｍ程度に切断した短繊維等がある。これら繊維材料に該樹脂を混練又は含浸し硬化させてなるものは所謂ＦＲＰと呼称されるものであり、メラミン樹脂化粧板もこれに包含される。
【００１２】
各種基材と各種化粧シートを接着剤層を間に介して接着してなる化粧板において、各種基材としては、木質板（単板、或いは前記の木質合板、パーティクルボード、木質繊維板であってもよい）、金属板、セメント板、硅酸カルシウム板、セラミック板等である。各種化粧シートとしては、紙、不織布、合成樹脂シート等のシートに塗装、絵柄印刷、凹凸模様エンボス等の装飾処理を施したものを用いる。
【００１３】
本発明で使用する不活性ガスの種類は問わないが、価格、入手の容易さから窒素ガスが好ましい。その他、ヘリウムガス、ネオンガス、アルゴンガス等の不活性ガス元素（希ガス元素）の気体を用いてもよい。そして、樹脂系材料に電子線を照射するに際し経済性を考慮する場合は、樹脂系材料を密閉性のある容器に入れた後、容器内の気体を窒素ガス等の不活性ガスに置換し、栓をした状態にして、容器ごと照射するのが好ましい。
【００１４】
本発明で使用する電子線は、高エネルギータイプの電子線である。すなわち加速電圧が１ＭｅＶ以上のものを用いる。照射装置としては、コッククロフトウォルトン型、バンデグラフ型、共振変圧器（テスラコイル等）型、線型加速器型等の電子線加速器を用いる。
【００１５】
本発明の樹脂系材料には、必要に応じて絵柄印刷、金属薄膜の蒸着、化粧シートの貼着、凹凸模様のエンボス等の装飾処理を施してもよい。
【００１６】
本発明の樹脂系材料は、シート、板（平板、曲面板等）、各種立体形状に成形し、さらに必要に応じて各種寸法、形状に切断した後、切削、Ｖカット加工等の加工や各種素材との積層を行った上、天井、床、壁等の建築物内装材、箪笥、机等の家具、テレビジョン受信機等の弱電機器のキャビネット、箱等の容器、自動車、電車等の車輛内装材、航空機の内装材等に用いられる。
【００１７】
【実施例】
（実施例１）
材種はラワン材を使用し、総厚み５．５ｍｍになるように熱プレスで積層して合板を作製した。積層枚数は３枚で、層間接着剤として尿素・ホルムアルデヒド系樹脂を使用した。この合板に次の条件で電子線の照射を行った。
照射装置：コッククロフトウォルトン型電子加速器
加速電圧：２ＭｅＶ
照射線量：１５ｋＧｙ
照射回数：１回
照射雰囲気：窒素ガス中
【００１８】
（実施例２）
坪量１００ｇ／ｍ²のチタン紙にメラミン樹脂を含浸したもの１枚を、フェノール樹脂含浸紙２枚と重ね合わせ、１００ｋｇ／ｃｍ²の圧力で加圧したまま室温から１３０℃まで昇温させて１０分間加熱した後、室温まで冷却して樹脂積層板（ＦＲＰ）を得た。このＦＲＰに実施例１と同条件で電子線の照射を行った。
【００１９】
（実施例３）
フェノール樹脂の熱硬化物からなる厚さ５ｍｍの板を作製し、次いでこれに実施例１と同条件で電子線の照射を行った。
【００２０】
（実施例４）
尿素・ホルマリン系樹脂をバインダーとして用い、木材粉を結合して厚さ１０ｍｍのパーティクルボードを用意した。このパーティクルボードに実施例１と同条件で電子線の照射を行った。
【００２１】
（実施例５）
厚さ１０ｍｍの杉の単板に、尿素・ホルマリン系樹脂接着剤を３０ｇ／ｍ²塗布し、その表面に印刷模様を有する坪量５０ｇ／ｍ²の化粧紙を印刷模様が外面となるようにして重ね、熱プレスで貼着して化粧板を得た。これに実施例１と同条件で電子線の照射を行なった。
【００２２】
＜ホルムアルデヒド量の評価＞
実施例１〜５で電子線の照射工程を行わなかった樹脂系材料をそれぞれ比較例１〜５とし、実施例１〜５と比較例１〜５の樹脂系材料に対して臭覚評価とＪＡＳ特殊合板に記載のある「ホルムアルデヒド放散量試験」に従った定量評価を行い、表１に示す結果を得た。この結果から、電子線の照射工程を経たものはホルムアルデヒド量が低減していることが分かる。
【００２３】
【表１】

【００２４】
【発明の効果】
以上説明したように、本発明の製造方法によれば、樹脂系材料中に存在するホルムアルデヒドを瞬時に低減することができ、経時的なホルムアルデヒドの発散を十分に低減することができる。また、電子線を照射するだけでよく、余分な添加剤は不要である。[0001]
BACKGROUND OF THE INVENTION
The present invention includes resin-based materials themselves, wood-based materials such as wood plywood, particle board, and MDF, and resin-based materials such as FRP, in which the amount of formaldehyde contained therein is reduced. It relates to a manufacturing method.
[0002]
[Problems to be solved by the invention]
Taking wood plywood as an example, phenolic resins and urea / formaldehyde resins that are inexpensive and have high adhesive strength have been widely used as adhesives between layers. However, since these adhesive resins emit formaldehyde (formalin) over time, there are disadvantages such as smell of formalin and pain in the eyes (especially in the case of high concentration). The following attempts have been made as much as possible.
(1) Change the urea / formalin type, melamine type, phenol type adhesive, etc. to those that do not emit formaldehyde, such as vinyl acetate emulsion, resorcinol resin, epoxy resin.
(2) A formaldehyde scavenger is mixed in the adhesive (see, for example, Japanese Patent Publication No. 7-110484).
(3) A formaldehyde scavenger or a resin mixed with a scavenger is applied to the surface of the woody material (see, for example, Japanese Patent Publication No. 51-42164).
(4) A paper, non-woven fabric or the like impregnated with a formaldehyde scavenger is attached to the back surface of the decorative board (see, for example, JP-A-56-121713).
[0003]
However, in the method (1) among the above, the cost of the adhesive to be used is higher than that of the urea / formalin adhesive, and the temporary adhesiveness is poor, resulting in a decrease in the number of good products at the time of manufacture. There are drawbacks, and it is necessary to change the processing conditions for each adhesive. In addition, the methods (2) to (4) are not only costly, but the method (2) does not capture formaldehyde adsorbed and released during the manufacturing process, and the amount added depending on the grade. There is a drawback that the type of adhesive increases and the end face treatment is difficult because it is necessary to change the surface. In the method (3), it is necessary to consider the adhesion with the decorative sheet to be attached to the surface, There is a drawback that the end face treatment is difficult, and the method (4) has a disadvantage that the printability is poor when printing on the impregnated substrate.
[0004]
In the case of a so-called melamine resin decorative board or an aminoalkyd resin-coated wood board made of a laminate of melamine resin-impregnated paper and phenol resin-impregnated paper, formaldehyde is also emitted from the resin component. Therefore, in this case, as a countermeasure, it has been proposed to devise adding a formaldehyde scavenger to the resin itself or to the adhesive when the decorative plate is laminated on another base material. However, when formaldehyde is mixed in the adhesive, problems such as a decrease in adhesive strength, changes in the composition of the adhesive, changes in the bonding conditions, and cost increases occur, and further, the formaldehyde adsorbed on the surface of the decorative board cannot be prevented. There is a problem I said. In addition, when formaldehyde is mixed in the paint, problems such as a decrease in surface physical properties (hardness and the like), a change in curing conditions, and an increase in cost occur.
[0005]
The present invention has been made in view of the above-described problems, and the object of the present invention is a resin-based material containing a formaldehyde-emitting resin such as a phenol resin, and a resin that reduces formaldehyde emission. It is providing the manufacturing method of a system material.
[0006]
[Means for Solving the Problems]
To achieve the above object, a manufacturing method of a resin-based material according to the present invention, the resin-based material containing formaldehyde divergent resin as the component divergent amount of formaldehyde is irradiated with electron beam in an inert gas atmosphere It is characterized by reducing.
[0007]
The above resin materials are: (1) formaldehyde-emitting resin alone, (2) wood plywood (including so-called laminated material) using formaldehyde-emitting resin as an interlayer adhesive, and (3) formaldehyde-emitting resin as a binder. Particle board or wood fiber board (MDF, etc.), (4) Formaldehyde-dispersing resin mixed with fiber material or impregnated into composite (FRP in a broad sense), (5) Formaldehyde-diffusing property on various substrates Any form of a decorative board formed by sticking various decorative sheets with an adhesive layer containing a resin as a component may be used.
[0008]
According to the above manufacturing method, no special additive is required regardless of the type of the resin material, and the amount of formaldehyde in the resin material can be instantaneously reduced at the same time in the thickness direction and simultaneously with the end face treatment. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Formaldehyde-emitting resin includes phenol resin obtained by condensation polymerization of phenol (coal acid) and formaldehyde, urea (or urea / formaldehyde) resin obtained by polymerization of urea and formalin, alkyd resin and melamine resin, urea resin, There are amino alkyd resins and melamine resins to which guanamine resins and the like are added. The presence of formaldehyde in the resin-based material is considered to be mainly due to the following causes. That is, (1) when it remains as an unreacted resin, (2) when it remains as a free product during the curing reaction (heating / pressurization), and (3) it is captured by materials other than resin (wood, paper, etc.) If it remains as a Thus, what was present in the resin material is gradually released and released.
[0010]
Examples of the formaldehyde-emitting resin alone include molded products made of formaldehyde-emitting resin, plates, sheets, and various three-dimensional shapes. As wood used for wood plywood, particle board, or wood fiber board, wood, cedar, pine, firewood, firewood, lauan, teak, or the like that are usually used are used.
[0011]
Examples of fiber materials for kneading or impregnating formaldehyde-emitting resins include paper such as fine paper, kraft paper, titanium paper, and Japanese paper, inorganic fibers such as glass fiber, carbon fiber, and asbestos, and organic fibers such as hemp, cotton, and vinylon. There are woven fabrics or nonwoven fabrics made of, and further, there are short fibers obtained by cutting the inorganic or organic fibers into about 1 to 10 mm. What is obtained by kneading or impregnating the resin into these fiber materials and curing is called a so-called FRP, and includes a melamine resin decorative board.
[0012]
In a decorative board formed by bonding various base materials and various decorative sheets with an adhesive layer interposed therebetween, the various base materials include wooden boards (single board or the above-mentioned wooden plywood, particle board, and wooden fiber board). Or a metal plate, a cement plate, a calcium oxalate plate, a ceramic plate, or the like. As the various decorative sheets, sheets such as paper, non-woven fabric, and synthetic resin sheets that have been subjected to decoration treatment such as painting, pattern printing, and uneven pattern embossing are used.
[0013]
The type of the inert gas used in the present invention is not limited, but nitrogen gas is preferable from the viewpoint of cost and availability. In addition, an inert gas element (rare gas element) such as helium gas, neon gas, or argon gas may be used. Then, when considering the economics upon irradiation with the electron beam resin material was placed in a resin-based material in a container with a sealing property, to replace the gas in the container to an inert gas such as nitrogen gas It is preferable to irradiate the whole container in a state where it is plugged.
[0014]
Electron beam used in the present invention, Ru electron beam der high energy type. That is, the acceleration voltage is 1 MeV or more. As the irradiation device, an electron beam accelerator such as a cockcroft Walton type, a bandegraph type, a resonant transformer (such as a Tesla coil) type, or a linear accelerator type is used.
[0015]
The resin-based material of the present invention may be subjected to decoration treatment such as pattern printing, vapor deposition of a metal thin film, sticking of a decorative sheet, embossing of a concavo-convex pattern, if necessary.
[0016]
The resin-based material of the present invention is formed into a sheet, a plate (a flat plate, a curved plate, etc.), various three-dimensional shapes, and further cut into various dimensions and shapes as necessary, followed by various processes such as cutting and V-cut processing. Laminated with materials, building interior materials such as ceilings, floors, walls, furniture such as walls, desks, cabinets for light electrical devices such as television receivers, containers such as boxes, vehicles such as cars and trains Used for interior materials and aircraft interior materials.
[0017]
【Example】
(Example 1)
Lauan was used as the material type, and laminated by hot pressing so that the total thickness was 5.5 mm to produce a plywood. The number of laminated layers was 3, and urea / formaldehyde resin was used as an interlayer adhesive. It went the irradiation of the electron beam under the following conditions to the plywood.
Irradiation device: Cockcroft-Walton-type electron accelerator Acceleration voltage: 2 MeV
Irradiation dose: 15 kGy
Irradiation frequency: Once Irradiation atmosphere: In nitrogen gas
(Example 2)
One sheet of titanium paper impregnated with 100 g / m ² basis weight and impregnated with melamine resin is overlapped with two sheets of phenol resin impregnated paper and heated from room temperature to 130 ° C. with pressure of 100 kg / cm ^2. After heating for 10 minutes, it cooled to room temperature and obtained the resin laminated board (FRP). It was irradiated in electron beam under the same conditions as in Example 1 to the FRP.
[0019]
(Example 3)
To prepare a thick plate 5mm consisting of thermoset phenolic resin, followed by irradiation of the electron beam under the same conditions as in Example 1 to this.
[0020]
(Example 4)
Using a urea / formalin resin as a binder, a wood board was bonded to prepare a particle board having a thickness of 10 mm. It was irradiated in electron beam under the same conditions as in Example 1 to the particle board.
[0021]
(Example 5)
Apply a 30g / m ² urea / formalin resin adhesive to a 10mm thick cedar veneer, and make a decorative paper with a printed pattern on the surface with a basis weight of 50g / m ² so that the printed pattern is the outer surface. Then, they were laminated and stuck with a heat press to obtain a decorative board. It was performed irradiation of electron ray under the same conditions as in Example 1 this.
[0022]
<Evaluation of formaldehyde content>
The resin materials that were not subjected to the electron beam irradiation process in Examples 1 to 5 were referred to as Comparative Examples 1 to 5, respectively. Quantitative evaluation was performed according to the “formaldehyde emission test” described in the plywood, and the results shown in Table 1 were obtained. This result, which has passed through the irradiation step of the electron beam it can be seen that the amount of formaldehyde is reduced.
[0023]
[Table 1]

[0024]
【The invention's effect】
As described above, according to the production method of the present invention, the formaldehyde present in the resin-based material can be instantaneously reduced, and the emission of formaldehyde over time can be sufficiently reduced. Moreover, it is only necessary to irradiate the electron beam, excess additive is not required.

Claims

A resin-based material containing formaldehyde divergent resin as the component manufacturing method of the resin-based material, characterized in that reducing the divergence amount of formaldehyde by irradiating sagittal electrodeposition in an inert gas atmosphere.

Tree fat-based material, manufacturing method of the resin-based material according to claim 1 formaldehyde divergent resin alone.

Tree fat-based material, manufacturing method of the resin-based material according to claim 1 formaldehyde divergent resin is wood plywood used as an adhesive between the layers.

Tree fat-based material, manufacturing method of the resin-based material according to claim 1 formaldehyde divergent resin is particle board or wood fiber board and a binder.

Tree fat-based material, manufacturing method of the resin-based material according to claim 1 formaldehyde divergent resin fibrous material and kneading or impregnation to those complexed.

Tree fat-based material, manufacturing method of the resin-based material according to claim 1 through between the adhesive layer is a veneer formed by bonding the decorative sheet on a substrate which formaldehyde divergent resin component .