JP2009262521A

JP2009262521A - Transfer foil

Info

Publication number: JP2009262521A
Application number: JP2008140155A
Authority: JP
Inventors: Masahiro Sugimoto; 優弘杉本; Hideyuki Sawada; 英之澤田
Original assignee: Kotobuki Seihan Printing Co Ltd
Current assignee: Kotobuki Seihan Printing Co Ltd
Priority date: 2008-04-28
Filing date: 2008-04-28
Publication date: 2009-11-12

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer foil can obtain a variety of sharp embossed patterns by using the same die in an in-mold transfer molding. <P>SOLUTION: On one surface of a flexible film, a mold release layer, a protective layer, a pattern layer, and a bonding layer are formed, and on the opposite surface, an embossed pattern layer is installed for this transfer foil. In the transfer foil, the protective layer is constituted of an ultraviolet ray or electron beam curing type resin. Before the resin is molded, the curing degree is adjusted to have a glass transition temperature of 30 to 150°C, and the transfer foil is re-cured after the resin is molded. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、樹脂のインモールド成型で用いられる転写箔において、種々のパターンの凹凸表現が可能となる転写箔に関するものである。 The present invention relates to a transfer foil that can express unevenness of various patterns in a transfer foil used in in-mold molding of a resin.

樹脂成型品は、成型が容易であること、軽量であること、さまざまな装飾が可能であることより、家庭電化製品、携帯電話、自動車等の部品に多用されている。従来樹脂成型品の表面加工は塗装により行われていたが、作業性が悪くまた綺麗な装飾に向いていなかった。更に有機溶剤の使用により作業環境も悪かった。 Resin-molded products are widely used for parts such as home appliances, mobile phones, and automobiles because they are easy to mold, lightweight, and can be decorated in various ways. Conventionally, the surface treatment of resin molded products has been performed by painting, but the workability is poor and it is not suitable for beautiful decoration. Furthermore, the working environment was poor due to the use of organic solvents.

その改良として、プラスチックフイルムに離型層を設け、その上に、保護層、絵柄層、接着層を設け、樹脂成型用の金型に挿入し、接着層側に樹脂を挿入し成型を行うと共に、フイルムを剥がし保護層以下を樹脂成型品に転写させる成型法が広く用いられるようになってきた。このことにより、樹脂成型と同時に表面加工が可能となり、作業性がアップすると共に、種々の高意匠インキ、例えば金属光沢インキ、パールインキ等が使用可能となり、高意匠の加工が可能となる。更に、有機溶剤の使用がなくなるため作業環境もよくなるとの利点があり、近年使用が増加している。 As an improvement, a release layer is provided on the plastic film, and a protective layer, a picture layer, and an adhesive layer are provided on the plastic film. The mold is inserted into a mold for resin molding, and the resin is inserted into the adhesive layer side for molding. The molding method in which the film is peeled off and the portion below the protective layer is transferred to a resin molded product has been widely used. Thus, surface processing can be performed simultaneously with resin molding, workability is improved, and various high-design inks such as metallic gloss ink and pearl ink can be used, and high-design processing is possible. Furthermore, there is an advantage that the working environment is improved because the use of the organic solvent is eliminated, and the use is increasing in recent years.

特に転写箔の反対面に別途樹脂層を設け、その絵柄によって一つの金型を用いて、種々のバリエーションを有した凹凸表現を得ることもなされている。例えば、特開平０１−１１４４９９には、フイルムに、保護層、絵柄層、接着層を設けその反対面に凹凸層を形成する樹脂層を設け、同一の金型で種々の凹凸表現が容易にできることが開示されている。フイルムとして、ＰＥＴ、ＰＰ、ナイロン等を用い、保護層としてビニル系樹脂、環化ゴム塩化ゴム系樹脂、アクリル樹脂等熱可塑性樹脂を用い、あるいは紫外線や電子線硬化樹脂を用いる場合が開示されている。この方法を用いることにより、種々のバリエーションの凹凸表現を同一の金型で行うことが可能となり、小ロット生産に有利となる。 In particular, a resin layer is separately provided on the opposite surface of the transfer foil, and an uneven expression having various variations is obtained by using a single mold depending on the pattern. For example, in JP-A-01-114499, a film is provided with a protective layer, a picture layer, an adhesive layer and a resin layer that forms an uneven layer on the opposite surface, and various uneven expressions can be easily expressed with the same mold. Is disclosed. A case is disclosed in which PET, PP, nylon, etc. are used as the film, a thermoplastic resin such as vinyl resin, cyclized rubber chlorinated rubber resin, acrylic resin, or ultraviolet ray or electron beam curable resin is used as the protective layer. Yes. By using this method, it is possible to express various variations of unevenness with the same mold, which is advantageous for small lot production.

この場合の保護層については、樹脂成型時の高温で変形しないこと、使用中に傷がつきにくいこと、油、有機溶剤、洗剤などがかかっても変化しないことが望まれる。従って、通常の熱可塑性樹脂では高温で変形しやすく、硬度も低く傷がつき易く、種々の耐性に富む保護層が得られにくい難点があった。一方、紫外線または電子線硬化型樹脂を用いる場合は、高温で変形しにくく、傷がつきにくく、種々の耐性に富む保護層が得られるが、反面樹脂が硬くなりすぎて成型加工時に凹凸追随できず、ひび割れが生じたり成型樹脂との密着が低下したり細かな凹凸表現ができなかったりする。 The protective layer in this case is desired not to be deformed at a high temperature during resin molding, to be hard to be damaged during use, and to remain unchanged even when oil, organic solvent, detergent, etc. are applied. Therefore, ordinary thermoplastic resins are easily deformed at high temperatures, have low hardness and are easily damaged, and it is difficult to obtain protective layers having various resistances. On the other hand, when UV or electron beam curable resin is used, it is difficult to be deformed at high temperatures, scratches are difficult, and various protective layers can be obtained. However, the resin is too hard to follow unevenness during molding. In other words, cracks may occur, adhesion with the molding resin may decrease, or fine unevenness may not be expressed.

発明が解決しようとする課題Problems to be solved by the invention

このように、転写箔の反対側に凹凸絵柄層を設け、紫外線または電子線硬化型樹脂を保護層に用いると優れた耐熱性、表面硬度、種々の耐性を持った樹脂成型品が得られるが、細かな凹凸表現を得るには問題があった。本発明の課題は、紫外線または電子線硬化型樹脂を保護層に用い、細かな凹凸表現を得られる転写箔を提供することである。 As described above, when an uneven pattern layer is provided on the opposite side of the transfer foil and an ultraviolet ray or electron beam curable resin is used for the protective layer, resin molded products having excellent heat resistance, surface hardness, and various resistances can be obtained. There was a problem in obtaining fine irregularities. An object of the present invention is to provide a transfer foil that can obtain a fine concavo-convex expression using an ultraviolet ray or an electron beam curable resin as a protective layer.

そこで、本発明者らは鋭意に研究を重ね、電離硬化型樹脂の硬化度合いをコントロールし、成型時には容易に凹凸に追随し、成型後更に硬化度合いを増せばよいとの発想を得、本発明を完成に至った。 Therefore, the present inventors have earnestly studied and obtained the idea that the degree of curing of the ionizing curable resin is controlled, can easily follow irregularities at the time of molding, and can further increase the degree of curing after molding. Was completed.

課題を解決するための手段Means for solving the problem

本発明の請求項１に係わる転写箔は、可とう性フイルムの片面に、離型層、保護層、絵柄層、接着層を設け、その反対面に凹凸絵柄樹脂層を形成させ、次いで、樹脂成型金型に装着し、金型に樹脂を充填しインモールド成型を行う転写箔において、保護層が紫外線もしくは電子線硬化型樹脂で形成され、その硬化度合いを調整することで、樹脂のガラス転移温度が３０〜１５０℃の保護層から成ることを特徴とするものである。 In the transfer foil according to claim 1 of the present invention, a release layer, a protective layer, a pattern layer, and an adhesive layer are provided on one side of a flexible film, and an uneven pattern resin layer is formed on the opposite side. In a transfer foil that is mounted on a molding die, filled with resin in the die, and in-mold molding is performed, the protective layer is formed of ultraviolet light or electron beam curable resin, and the degree of curing is adjusted to change the glass transition of the resin. It is characterized by comprising a protective layer having a temperature of 30 to 150 ° C.

本発明の請求項２に係わる転写箔は、請求項１の転写箔において、紫外線並びに電子線硬化型樹脂が、アクリル系樹脂、スチレンアクリル系樹脂、スチレン系樹脂、エポキシアクリル系樹脂から成ることを特徴とするものである。 The transfer foil according to claim 2 of the present invention is the transfer foil according to claim 1, wherein the ultraviolet ray and the electron beam curable resin are made of an acrylic resin, a styrene acrylic resin, a styrene resin, or an epoxy acrylic resin. It is a feature.

以下、本発明の実施の形態を説明する。 Embodiments of the present invention will be described below.

図１は本発明の実施の形態を示すもので、１は可とう性フイルムで、２は離型層、３は保護層、４は絵柄層、５は接着層であり、６はフイルムの反対側に設けられた凹凸絵柄層である。 FIG. 1 shows an embodiment of the present invention, wherein 1 is a flexible film, 2 is a release layer, 3 is a protective layer, 4 is a pattern layer, 5 is an adhesive layer, and 6 is the opposite of the film. It is the uneven | corrugated pattern layer provided in the side.

可とう性フイルムは、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレイト、ナイロン、塩化ビニール、塩化ビニリデン等種々のものが用いられる。成型樹脂により、耐熱性を考慮し選定すると良い。また、厚みは１５〜７０μｍが良い。 As the flexible film, various materials such as polyethylene, polypropylene, polyethylene terephthalate, nylon, vinyl chloride, and vinylidene chloride are used. It is better to select the resin considering the heat resistance depending on the molding resin. The thickness is preferably 15 to 70 μm.

離型層は、メラミン樹脂、アクリル樹脂、シリコン樹脂、ワックス等が用いられる。塗布は、グラビアコーター、ロールコーター、スクリーンコーター、フレキソコーター、リバースコーター等種々のものが用いられる。塗布厚みは、０．５〜５μｍである。 For the release layer, melamine resin, acrylic resin, silicon resin, wax or the like is used. Various coatings such as a gravure coater, a roll coater, a screen coater, a flexo coater, and a reverse coater are used for coating. The coating thickness is 0.5-5 μm.

保護層は、紫外線硬化樹脂もしくは電子線硬化樹脂が用いられる。分子中に不飽和結合を有するプレポリマー並びにオリゴマー、モノマーを有する。紫外線硬化樹脂を用いる場合は、光重合開始剤を入れておくと良い。樹脂としてはアクリル系樹脂、スチレンアクリル系樹脂、スチレン系樹脂、エポキシアクリル系樹脂等が上げられる。 For the protective layer, an ultraviolet curable resin or an electron beam curable resin is used. It has a prepolymer having an unsaturated bond in the molecule, an oligomer, and a monomer. When using an ultraviolet curable resin, a photopolymerization initiator is preferably added. Examples of the resin include an acrylic resin, a styrene acrylic resin, a styrene resin, and an epoxy acrylic resin.

硬化度合いは、紫外線または電子線の強度を調整し、ガラス転移温度が３０〜１５０℃にすると良い。温度が低いと、成型時に樹脂の熱で柔らかくなり、樹脂の移動に引っ張られる場合がある（いわゆるゲート飛びが発生する）。また、再硬化しても優れた耐性が得られない場合もある。高すぎると、樹脂が硬くなり成型時にひび割れや樹脂本体との密着不良が発生する。 The degree of curing is preferably adjusted by adjusting the intensity of ultraviolet rays or electron beams so that the glass transition temperature is 30 to 150 ° C. If the temperature is low, the resin heats up during molding and may be pulled by the movement of the resin (so-called gate jump occurs). Moreover, even if recured, excellent resistance may not be obtained. If it is too high, the resin becomes hard and cracks and poor adhesion to the resin body occur during molding.

保護層の厚みは、０．５〜１５μｍが好ましく、特に強い耐性を得るためには、５〜１５μｍがより好ましい。薄いと強度が得られにくくなり、厚いと凹凸に追随しにくくなり、綺麗な凹凸表現が得られなくなる。 The thickness of the protective layer is preferably from 0.5 to 15 μm, and more preferably from 5 to 15 μm in order to obtain particularly strong resistance. If it is thin, it will be difficult to obtain strength, and if it is thick, it will be difficult to follow unevenness, and it will not be possible to obtain beautiful unevenness expression.

絵柄層は、グラビア印刷機、オフセット印刷機、スクリーン印刷機、凸版印刷機、フレキソ印刷機等種々の印刷方式が用いられる。インキの耐熱性を保持するために、紫外線硬化型樹脂や２液硬化型樹脂が好ましい。 For the pattern layer, various printing methods such as a gravure printing machine, an offset printing machine, a screen printing machine, a letterpress printing machine, and a flexographic printing machine are used. In order to maintain the heat resistance of the ink, an ultraviolet curable resin or a two-component curable resin is preferable.

接着層は、成型樹脂との相性を考慮し選定すると良い。塩ビ樹脂、エチレン酢ビ樹脂、アクリル樹脂、塩ビ酢ビ樹脂等が用いられる。厚みは、１〜３μｍが好ましい。成型温度が接着層樹脂の耐熱性温度よりも高い場合は、成型時の絵柄層のインキ流れ（いわゆるゲート飛び）を防ぐために、２液硬化型の耐熱層を設けても良い。 The adhesive layer is preferably selected in consideration of compatibility with the molding resin. A vinyl chloride resin, an ethylene vinyl acetate resin, an acrylic resin, a vinyl acetate vinyl resin, or the like is used. The thickness is preferably 1 to 3 μm. When the molding temperature is higher than the heat resistance temperature of the adhesive layer resin, a two-component curable heat-resistant layer may be provided in order to prevent ink flow (so-called gate jump) of the pattern layer during molding.

凹凸絵柄樹脂層は、グラビア印刷機、スクリーン印刷機、オフセット印刷機、凸版印刷機、フレキソ印刷機等種々の印刷方式が可能である。インキは耐熱性を考慮し、電離放射線インキもしくは２液硬化型インキが好ましい。厚みは１〜３０μｍと種々の厚みを設けることができる。特に厚みを大きくする場合はスクリーン印刷が適している。 Various printing systems such as a gravure printing machine, a screen printing machine, an offset printing machine, a letterpress printing machine, and a flexographic printing machine can be used for the concavo-convex pattern resin layer. In consideration of heat resistance, the ink is preferably ionizing radiation ink or two-component curable ink. Various thicknesses of 1 to 30 μm can be provided. Screen printing is particularly suitable for increasing the thickness.

上記のように製造された転写箔を用い、樹脂整形用金型に挿入し、樹脂成型を行う。図２に成型の手順を示す。７は樹脂成型金型で８は樹脂を挿入する部分（一般にはゲートと呼ばれる）。９は転写箔で、凹凸絵柄印刷層を樹脂が挿入されるゲートとは反対側になるようにセットし、接着層側が成型される樹脂層と接するようにする。熱溶融した樹脂を、所定の圧で金型に挿入し、冷却後成型樹脂を金型から取り出し、フイルムを離型層から剥がし絵柄を樹脂層に転移させる。その際、凹凸絵柄層が有る部分は、凹部となる。 Using the transfer foil produced as described above, it is inserted into a resin shaping mold and resin molding is performed. FIG. 2 shows the molding procedure. 7 is a resin molding die, and 8 is a portion into which resin is inserted (generally called a gate). Reference numeral 9 denotes a transfer foil, in which the concavo-convex pattern printed layer is set so as to be opposite to the gate into which the resin is inserted, and the adhesive layer side is in contact with the molded resin layer. The heat-melted resin is inserted into the mold at a predetermined pressure, and after cooling, the molded resin is taken out from the mold, the film is peeled off from the release layer, and the pattern is transferred to the resin layer. At that time, the portion having the concavo-convex pattern layer becomes a concave portion.

その後、保護層の硬化を十分に行うため、紫外線もしくは電子線を再照射し、最終樹脂成型品が得られる。 Thereafter, in order to sufficiently cure the protective layer, the final resin molded product is obtained by reirradiating with ultraviolet rays or electron beams.

次に、実施例で本発明を説明する。 Next, an Example demonstrates this invention.

可とう性フイルムは、市販のＰＥＴフイルムを用いた。厚みは、２５μｍ、３８μｍ、５０μｍを用いた。 As the flexible film, a commercially available PET film was used. Thicknesses of 25 μm, 38 μm, and 50 μm were used.

可とう性フイルムにシリコン系離型剤をグラビアコーターで塗布した。乾燥後１８０℃の熱風で焼付け加工を施した。塗布厚みは０．５μｍで有る。 A silicone release agent was applied to the flexible film with a gravure coater. After drying, it was baked with hot air at 180 ° C. The coating thickness is 0.5 μm.

離型処理済みのフイルムに保護層を塗布する。保護層の樹脂としては、アクリル系の紫外線硬化型の樹脂を用いた。塗布厚みは２μｍ並びに１０μｍである。 A protective layer is applied to the release-treated film. As the resin for the protective layer, an acrylic ultraviolet curable resin was used. The coating thickness is 2 μm and 10 μm.

硬化度合いと凹凸表現、表面物性との関係を明確にするため、ＵＶランプの照度を変化させ試験を行った。照射エネルギーの測定は、積算光量計で行った。比較例として、紫外線照射を行わない場合、並びに完全硬化させた場合のサンプルも作成した。硬化度合いの確認のため、ガラス転移温度を測定した。 In order to clarify the relationship between the degree of curing, the unevenness expression, and the surface properties, the illuminance of the UV lamp was changed and the test was performed. The irradiation energy was measured with an integrating light meter. As a comparative example, samples were also prepared in the case where ultraviolet irradiation was not performed and in the case of complete curing. In order to confirm the degree of curing, the glass transition temperature was measured.

作製した転写箔は以下の表１の通り。

The produced transfer foil is as shown in Table 1 below.

この保護層の上に、絵柄層を印刷する。印刷はグラビア印刷機で行った。インキは市販の水性アクリルインキを使用した。また、接着層もグラビア印刷機で行った。使用した接着剤は水性アクリル樹脂である。 A pattern layer is printed on the protective layer. Printing was performed with a gravure printing machine. As the ink, a commercially available water-based acrylic ink was used. Moreover, the adhesive layer was also performed with the gravure printing machine. The adhesive used is a water-based acrylic resin.

上記転写箔の反対面に、凹凸絵柄層をスクリーン印刷機で印刷した。２液硬化型のビニールウレタン系インキを使用した。絵柄層の印刷との見当をあわすため、チタン酸化物の顔料を添加したインキを使用した。 On the opposite surface of the transfer foil, an uneven pattern layer was printed with a screen printer. A two-component curable vinyl urethane ink was used. In order to give an idea of printing the picture layer, an ink added with a titanium oxide pigment was used.

以下の転写箔を樹脂成型機を用いて成型した。使用した樹脂はＰＭＭＡである。成型した樹脂から、フイルムを剥がし転写させた後、紫外線を照射し再硬化させた。その照射エネルギーは、５００ｍｊで有る。 The following transfer foil was molded using a resin molding machine. The resin used is PMMA. The film was peeled off from the molded resin, transferred, and then re-cured by irradiation with ultraviolet rays. The irradiation energy is 500 mj.

成型した最終成型品の性能について、鉛筆硬度、耐アルコール、耐溶剤性を確認し評価した。各測定法以下の通り。
鉛筆硬度：ＪＩＳＫ５６００にのっとり試験を実施した。
耐アルコール：エタノールを布にしみこまし、２０回拭いて変化を見た。
耐溶剤性：ＭＥＫを布にしみこまし、２０回拭いて変化を見た。About the performance of the molded final molded product, pencil hardness, alcohol resistance, and solvent resistance were confirmed and evaluated. Each measurement method is as follows.
Pencil hardness: A compliant test according to JIS K5600.
Alcohol resistance: A cloth was dipped in ethanol and wiped 20 times to see the change.
Solvent resistance: MEK was impregnated into a cloth and wiped 20 times to observe changes.

成型品の性能については以下の通り。

The performance of the molded product is as follows.

発明の効果The invention's effect

以上見てきたように、保護層を紫外線硬化樹脂のような電離線硬化型樹脂を用い、その樹脂のガラス転移温度が３０℃〜１５０℃までの範囲にコントロールされた硬化度合いにすることで、綺麗に凹凸表現が得られるとともに、成型時にひび割れが生じることは無い。また、耐性に優れた表面物性が得られる。 As described above, the protective layer is made of an ionizing radiation curable resin such as an ultraviolet curable resin, and the glass transition temperature of the resin is controlled to be within a range of 30 ° C. to 150 ° C. It provides a clear representation of unevenness and does not crack during molding. Moreover, the surface physical property excellent in tolerance is obtained.

産業上の利用の可能性Industrial applicability

同一の金型で、転写箔の種類を変えるだけで種々のバリエーションの凹凸表現が得られる本発明は、新たに金型を作製する必要も無く、また金型を変更することも必要が無いので、小ロット生産に向いており、産業上の利用の可能性は大きい。 The present invention, which can obtain various variations of irregularities simply by changing the type of transfer foil with the same mold, eliminates the need to create a new mold and to change the mold. It is suitable for small-lot production and has a great potential for industrial use.

本発明の転写箔の一例を示すもので、断面図である。An example of the transfer foil of this invention is shown, and is sectional drawing. 本発明の樹脂成型過程を示すもので、断面図である。It is a sectional view showing the resin molding process of the present invention.

符号の説明Explanation of symbols

１可とう性フイルム
２離型層
３保護層
４絵柄層
５接着層
６凹凸絵柄層
７樹脂成型金型
８樹脂挿入口（ゲート）
９転写箔DESCRIPTION OF SYMBOLS 1 Flexible film 2 Release layer 3 Protective layer 4 Picture layer 5 Adhesive layer 6 Concavity and convexity pattern layer 7 Resin molding die 8 Resin insertion slot (gate)
9 Transfer foil

Claims

可とう性フイルムの片面に、離型層、保護層、絵柄層、接着層を設け、その反対面に凹凸絵柄樹脂層を形成させ、次いで、樹脂成型金型に装着し、金型に樹脂を充填しインモールド成型を行う転写箔において、保護層が紫外線もしくは電子線硬化型樹脂で形成され、その硬化度合いを調整することで、樹脂のガラス転移温度が３０〜１５０℃の保護層から成ることを特徴とする転写箔。A release layer, a protective layer, a pattern layer, and an adhesive layer are provided on one side of the flexible film, and an uneven pattern resin layer is formed on the opposite side, and then mounted on a resin mold, and the resin is applied to the mold. In a transfer foil that is filled and in-mold molded, the protective layer is formed of an ultraviolet ray or electron beam curable resin, and the glass transition temperature of the resin is 30 to 150 ° C. by adjusting the degree of curing. Transfer foil characterized by

紫外線並びに電子線硬化型樹脂が、アクリル系樹脂、スチレンアクリル系樹脂、スチレン系樹脂、エポキシアクリル系樹脂から成ることを特徴とする、請求項１の転写箔。2. The transfer foil according to claim 1, wherein the ultraviolet ray and electron beam curable resin comprises an acrylic resin, a styrene acrylic resin, a styrene resin, or an epoxy acrylic resin.