JP2004175578A

JP2004175578A - Coating method of ceramic base material having transparent protective layer and decorated base material

Info

Publication number: JP2004175578A
Application number: JP2002340048A
Authority: JP
Inventors: Kenichi Tatsumi; 健一巽
Original assignee: Kotobuki Kogyo KK
Current assignee: Kotobuki Kogyo KK
Priority date: 2002-11-22
Filing date: 2002-11-22
Publication date: 2004-06-24
Anticipated expiration: 2022-11-22
Also published as: JP4478780B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating means for forming a smooth and transparent protective layer on a decorated surface of a ceramic base material and a method for performing the same. <P>SOLUTION: A decorative layer is formed on the surface of the ceramic base material which has been subjected to ground treatment. Then, a transparent layer including pigments and capable of being polished is formed on the decorative layer. After curing the transparent layer, the transparent layer is polished to be smooth and to form a flat surface. Further, when a coating material of a transparent ultraviolet ray-curing resin is applied on the transparent layer, a grooved roll is used for forming a film with an exact thickness. The form of the groove is nearly triangle. When the thickness of the base material and the distance between the grooved roll and a receiving roll are defined as t and g, respectively, the value of g-t is set to be -1.2 to -2.0 mm. An accurate amount is applied on the place corresponding to the width of the groove, and equalized with the coating material applied by the neighboring grooves so as to form partially same thickness. The coating having the same thickness is formed over whole coating width by accumulation of these parts. Finally, the coated surface is irradiated with ultraviolet rays so as to be cured. Thereby, the ceramic decorated base material having the transparent protective layer exhibiting reflected light free from fluctuation can be provided. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明が属する技術分野】
本発明は、表面に透明層を有する窯業系化粧板とその製造方法に関する。
【０００２】
【従来の技術】
化粧層を有する窯業系化粧板において、その化粧層を保護するための透明な保護層の形成については多数の先願があり、紫外線硬化型樹脂塗料を用いて平滑な透明層を形成している。透明な保護層を平滑にする方法としては基材をできるだけ平滑にしその上に均一な厚みを有する化粧層を形成することが基本であるが、その上に透明な保護層を形成するためにフローコータを用いて透明樹脂塗料を塗布しレベリングさせるか塗布面にフィルムを被せてその上をロールで押圧し平滑面を得るようにしている。しかしながら透明樹脂層が単層で構成される場合膜厚を厚くする必要があり、硬化させた後蛍光灯などの反射光がゆらいで見える場合が多い。このような欠点を排除するには化粧層の上に透明で研磨可能な炭酸カルシウムのような体質顔料を多く含んだ塗膜を形成し、該塗膜面を平滑に研磨し、更にその上に透明な薄膜を形成することで平滑な面を形成し反射光にゆらぎのない化粧板を得ることができる。しかしながら最後に塗布する透明薄膜の塗装は難しく安定した塗装手段が求められている。本願発明はこの点に鑑み提案するものである。
【０００３】
【発明が解決しようとする課題】
解決しようとする課題は、窯業系基材の化粧面の上に平滑で透明な保護層を形成する塗装手段と実施するための方法を提供することである。
【０００４】
【課題を解決するための手段】
本発明は、ケイ酸カルシウム板など窯業系基材の表面にシーラや目止め等の下地処理を施した上に色彩塗装あるいは転写などによる化粧層を設け、該化粧層の上に顔料を含み研磨可能な透明層を形成しこれを硬化させた後、該透明層を平滑に研磨し研磨粉を除去して先ず平面を形成する工程と、更にその上に透明な紫外線硬化型樹脂塗料を塗布する工程とから成り、後者の工程に使用される溝を形成した塗布ロールは、該ロール表面を構成するブチル、ウレタンなどの高分子弾性材に所定のピッチで同じ形状の溝を形成しており、溝の側面を傾斜面とし、底面と開口部に平坦部を形成した略三角形状を成し、底面の平坦部は開口部の平坦部の幅に等しいかそれより広い形状にする。塗装条件としては、基材厚をｔとして溝ロールと受けロールの間隔をｇとした場合、ｇ−ｔの数値を−１．２〜−２．０ｍｍに設定して溝内に保持されている塗料を前記の研磨された平面に押しつけ、溝の幅に相当する箇所に正確な量を塗布し、隣接する溝で塗布された塗料と平均化して部分的に同じ膜厚を形成し、これらが集合して塗布幅全体に同じ厚みの塗膜を形成し、塗布面に紫外線を照射して硬化させ透明保護層を形成する。この透明保護層はフローコータによる塗装で塗料のレベリングにより得られる塗膜に比較して膜厚が均一であり、反射光特に蛍光灯などの映像がゆらぎ無く写り品質の高さをアピールする。上記のｇ−ｔの値は基材の厚さの精度により、１枚の基材の表面を押圧する圧力が全ての箇所で同じ圧力を示さないが上記の範囲にロール間隔を設定すると基材全体に良好な透明保護層を形成することができることを意図している。基材の厚み精度が高く塗布面の性状が良好であれば、上記ｇ−ｔの値は−１．５〜−１．８ｍｍの範囲に設定し平滑性は向上する。
【０００５】
また、前記の所定のピッチで形成される溝の数は密度で示すのが一般的であり、溝本数は３０〜９０本／吋の範囲が使用できる。但しロール表面部分を構成する弾性材の材質と硬度により溝の耐久性と塗布量を勘案し適宜本数が設定されるべきであり、弾性材のショア硬度が３０度程度と軟らかい場合は溝本数を３０〜６５本／吋とし溝の深さを０．２１〜０．２５ｍｍ、硬度が５０度程度と硬い場合は６５〜９０本／吋とし溝の深さは０．１６〜０．２０ｍｍが好ましい条件である。溝の深さは塗布される面の平滑度や面性状によりバラツキがあり利用しうる深さとしては０．１〜０．３ｍｍの範囲であり、摩耗度合いを考慮して長期間の使用を可能にする場合若干深めに加工されるべきである。塗布量は目安として４０〜５９本／吋、深さ０．２１〜０．２５ｍｍの場合は３０〜３５ｇ／ｍ^２に塗装され、６０〜８０本／吋、深さ０．１６〜−０．２０ｍｍの場合は２０〜２５ｇ／ｍ^２の割合で塗布される。
【０００６】
塗装の際に特に注目されるところは、透明な紫外線硬化型樹脂塗料を塗装する際に、前記の研磨面の上にロールコータによる湿し塗装を行わずに、溝ロールのみで塗装することである。湿し塗装は塗料を塗布面に強く押しつけてその後に塗装される塗料の塗布面との密着性を向上させるために行うが、本発明では溝に含まれる塗料を塗布面に強く押し出す作用を有しており、密着性を確保することができると共に、湿しロールによる塗布面の形状がその後に形成される透明薄膜に与える影響を排除して平滑な透明膜を形成する。その他の塗装時の条件は、透明な紫外線硬化型樹脂塗料を塗装する際に、該塗料温度を４０〜５０℃に加温し、基板の塗布面の温度を４０〜７０℃に設定するが、本発明に於いては塗料のレベリングを積極的に行わないから塗布面の温度は上記範囲の低い温度で行うのが好ましくその方が光沢度は良好となる。
【０００７】
本発明ではケイ酸カルシウム板など窯業系基材の表面に化粧層を保護する透明でゆらぎのない平滑な保護層を形成することを目的としているので塗布量とその塗布された塗料が平滑になり易い条件を見出すことが重要な課題である。透明な保護層は加工場の環境に大きく左右され粉塵やゴミなどが塗布面に付着しやすいから塗布後できるだけ速く乾燥させることが得策であり、また保護層の耐擦傷性の見地から硬度は高い程良いことから、紫外線硬化型樹脂塗料が主として用いられる。本実施例では最上層の透明な保護層を形成するためにアクリル樹脂のオリゴマー、モノマーとシリカやワックスなどの顔料を含む紫外線硬化型樹脂を使用しており、チクソ性の乏しい塗料を使用している。このような塗料は基材の上に付着し難い性質があり強く押しつけて付着性を高めることが必要である。また膜厚が大きいと化粧板として柔軟性に乏しくクラックが生じたり反射光がゆがんだりして壁面に取着したときに高級感が損なわれる。
【０００８】
【発明の実施の形態】
【実施例１】
窯業系基材として、サイズが９１０ｍｍ×１８２０ｍｍで厚さｔが６ｍｍのケイ酸カルシウム板（比重０．８）の表面にメチレンヂイソシアネート７０％、酢酸メチル５％、トルエン２０％酢酸ブチルからなる分子量が約５００の湿気硬化型イソシアネート樹脂塗料（トウペ（株）製、商品名ＡＳシーラ＃５０）をシーラ剤とし、６０ｇ／ｍ^２（Ｗｅｔ）の割合でスポンジロールコータにより塗布し自然乾燥する。そして３６時間後に（通常養生時間は８時間〜１週間程度）塗布面にリバースロールコータを用いて紫外線硬化型アクリル樹脂目止剤（大日本インキ工業（株）製、品番ＳＫＳ６−ＨＶ−Ｗ）を１１０ｇ／ｍ^２の割合で塗布し、３６０ｎｍを主波長とする出力８０Ｗ／ｃｍの紫外線ランプ３本の下をコンベヤー速度１５ｍ／分で通過させ目止剤を硬化させる。その表面を＃２８０、＃３２０の２連式ワイドベルトサンダーを用いて研磨し研磨粉をブラシで除去する。以上周知のシーラーと目止処理の成された基板の表面にアクリルウレタンエナメル（ＵＣカラーＤＲＳ大日本インキ（株）製）をロールコーター及びフローコーターを用いて１１０ｇ／ｍ^２の割合で塗布し８０℃で１０分間乾燥する。次ぎにロールコーターを用いて接着剤（大日本インキ（株）製、プライマーＷ−１００）を２０〜３０ｇ／ｍ^２塗布し赤外線を用いて溶剤を蒸発させ転写ベースを形成し、その後板温を７０〜８０℃まで加熱し、転写フィルムを硬度６０度のシリコンゴムロール２本を用いて圧着温度７０〜８０℃、圧力４ｋｇ／ｍ^２で圧着し、４０〜４５℃まで表面を冷却して基体フィルムを剥がして転写ベース上に大理石調模様の図柄を転写し、転写印刷層を形成させた。更にその上に、紫外線硬化型アクリル樹脂透明ベースコート（伊、アーチコーティング社製、ＲＵ７５８８）をリバースロールコーターで４０ｇ／ｍ^２の割合で転写面に塗布し上記紫外線ランプ３本の下をコンベヤー速度１５ｍ／分で通過させることにより紫外線照射を行い硬化させる。次ぎに＃３２０のワイドベルトサンダーにより硬化した塗面を研磨し転写印刷、ＵＶベースコート工程までに付着したゴミ、異物などを除去して機械的に平滑面を形成するがサンダーの研削面になるため透明感は失われる。研磨粉をブラシロールでなどで入念に除去した後で基材表面を４０℃に加熱し、ショア硬度４０度の弾性材をライニングしたロールの表面に、溝の密度が８０本／吋（溝ピッチ０．３２ｍｍ）、深さ０．１６ｍｍの略三角状の溝を加工した溝付きロールを取り付け、艶消しアクリル樹脂ＵＶトップコートクリヤー（伊、アーチコーティング社製、ＲＺ７７２０）を塗布温度を４５℃に調整してロール間隔を基材厚ｔ−１．５ｍｍで塗装速度１５ｍ／分で塗装を行い、上述した出力８０Ｗ／ｍの紫外線ランプ３本の下をコンベヤー速度１５ｍ／分で通過させることにより紫外線照射を行って硬化させゆらぎのない平滑な艶消しクリヤー塗装化粧板を得た。ワイドベルトサンダーの研削面はその上に塗布された艶消しクリヤーを塗布することで消滅し透明感が回復する。
【０００９】
次ぎに、溝付きロールの溝の形状と平滑な塗装面が得られる理由を説明する。図１（ａ）は厚さｔのケイ酸カルシウム板を用いた基材１を溝ロール２と受けロール３の間に挟んで塗装する状態を示す模式正面図であり、ロールの間隔ｇは基材の厚さと等しくｇ＝ｔの状態を示す。（ｂ）図は側面図で溝付きロール２に彫刻された溝４とこれに接するドクターロール５及び塗料６を示す。塗料は深さｄの溝４を満たして基材１の表面に転移するようになっている。矢印は各ロールの回転方向と基材の進行方向を示す。（ｃ）図は溝ロール２を矢印Ｅの方向に移動させて基材の厚さｔよりロールの間隔ｇをｇ＜ｔの状態にすることで、溝４が基材１の表面で圧縮されて変形し、深さｄの溝の中に含まれた塗料を押し出すところを示している。またｇ−ｔの数値が溝の深さｄより大きくなるが、溝を構成する弾性材が同時に圧縮されるので溝の形状は変形するが塗布面との間に隙間が生じこの隙間に塗料が流れ込み塗布されていく。押し出される塗料は化粧層の上に形成された平滑な研磨面に押しつけられて密着性の向上を図りながら基材の進行方向に対して後方に生じるが、変形した溝の隙間から前方に移動し隣接する溝から同様に塗布された塗料と混じり合い平均化して部分的に同じ膜厚になり結果として塗布面全体が同じ膜厚の塗布面を形成する。溝に含まれる塗料の量は溝の形状により決定されるが、溝に含まれた量の全てが基材の表面に転移するとは限らないが溝が変形する際に塗料の撹拌が行われ塗料の滞留はない。本発明では溝付きロール２の基材に対する圧力を圧力値で示さず、溝ロールと基材の間隔が基材の厚さｔよりどれだけ小さくしたかをマイナス数値で表示するようにしている。
【００１０】
溝の形状は２種類に分類され、図２に示すように（Ａ）と（Ｂ）は溝の側面が垂直であり底面はほぼ平坦である。（Ｃ）と（Ｄ）は溝の側面が傾斜しており、底面はほぼ平坦である。実際にはこれらの溝の各面の形状は溝加工の手段により、各面は直線にならずに曲線になる場合があるが、大略上記の２種類で構成される。溝の加工手段には機械的に行う方法とレーザを用いた光学的手段があり、光学的手段の方が微調整が容易でありこの手段が主に使用されるため製作される溝ロールをオプチロールと呼称している。溝がロールの周面に独立もしくは螺旋状に形成されるが、溝のピッチが１吋あたり３０〜９０本と密であるために著しい差異は認められない。実際にテストした結果を次表に示す。
【００１１】
【表１】

【００１２】
上述したように塗料が紫外線硬化型樹脂塗料でチクソ性が乏しく基材表面に付着しにくいことから、塗料を強く基材表面に押しつけることが必要であり、また膜厚が厚くなると化粧板として柔軟性を損なうことになり、クラックや反射光に歪みが生じて高級感を損なうことになる。このような理由から本願では溝付きロールを選択したのであるが、実験を重ねるうちに特定の条件の時に良好な結果が得られることが判明した。先ず溝のピッチであるが少なくとも全面に一様な塗料を配置するためには１吋間に３０乃至４０本の溝が必要であり、これより少ないとたとえ塗料がレベリングしたとしても全面に塗料を行き渡らせることができない。また溝の密度が８０乃至９０本を超えると、塗布量が少なくなり、溝の機械的強度が無くなり塗料を強く基材表面に押しつけることができない。溝の形状は前出の表１によれば溝の側面が傾斜した（Ｃ）、（Ｄ）が適しており、その中でも（Ｃ）が優れている。（Ｃ）の特徴は溝の側面が傾斜した略三角形状で開口部から延びる平坦部７の幅をｍとし底面の平坦部８の幅をｎとした場合、底面の平坦部の幅が開口部から延びる幅に等しいかそれより大きい条件、即ちｍ≦ｎの時が良い結果を得ることができる。その理由としては平坦部７に圧力が加わったとき凹みやすいことと、これに続く斜面の変形が塗料の流出時に抵抗なく押し出すように作用し残留する塗料が無いことが挙げられる。また開口部から延びる平坦部７の幅ｍはできるだけ小さい方が隣接した溝から塗布される塗料と混じりやすくすじの痕跡が残らない。上述した平坦部の形状は必ずしも平面に限らす湾曲して加工される場合があるが、ここでは説明を簡単にするために単に平坦部として溝形状の特徴を示した。（Ａ）、（Ｂ）は溝内に塗料が残留し易く空気の巻き込み現象が見られ塗膜に小さな気泡が生じやすい。
【００１３】
【発明の効果】
以上述べたように、化粧層を有する窯業系基材に平滑性に優れた透明保護層を形成することができるので、ゆらぎのない反射光を示す化粧基材を提供できる。特に蛍光灯などの映像が歪み無く反射し品質の高さを強調することができる。
【図面の簡単な説明】
【図１】（ａ）は溝付きロールを用いた塗装時の模式正面図であり、（ｂ）図はその側面図であり、（ｃ）図は溝ロールを基材に押しつけた状態を示す側面図である。
【図２】溝の形状の種類を（Ａ）、（Ｂ）、（Ｃ）、（Ｄ）で示す模式断面図である。
【符号の説明】
１窯業系基材
２溝ロール
３受けロール
４溝
５ドクターロール
６塗料
７開口部から延びる平坦部
８底面の平坦部８[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ceramic decorative board having a transparent layer on the surface and a method for producing the same.
[0002]
[Prior art]
There are many prior applications for the formation of a transparent protective layer for protecting the decorative layer of a ceramic decorative panel having a decorative layer, and a smooth transparent layer is formed using an ultraviolet-curable resin paint. . As a method of smoothing the transparent protective layer, it is fundamental to make the base material as smooth as possible and to form a decorative layer having a uniform thickness thereon. Using a coater, a transparent resin paint is applied and leveled, or a film is applied on the applied surface, and a roll is pressed thereon to obtain a smooth surface. However, when the transparent resin layer is formed as a single layer, it is necessary to increase the film thickness, and after curing, the reflected light from a fluorescent lamp or the like often looks fluctuated. In order to eliminate such defects, a coating film containing a large amount of extender such as calcium carbonate, which is transparent and polished, is formed on the decorative layer, and the coating film surface is polished smoothly, and further thereon. By forming a transparent thin film, a decorative plate having a smooth surface and no fluctuation in reflected light can be obtained. However, it is difficult to apply a transparent thin film to be applied last, and stable coating means is required. The present invention is proposed in view of this point.
[0003]
[Problems to be solved by the invention]
The problem to be solved is to provide a coating means for forming a smooth and transparent protective layer on the decorative surface of a ceramic substrate and a method for performing it.
[0004]
[Means for Solving the Problems]
The present invention provides a decorative layer such as a color coating or a transfer on a surface of a ceramic substrate such as a calcium silicate plate on which a base treatment such as a sealer or a filler is applied, and a polishing method including a pigment on the decorative layer. After forming a possible transparent layer and curing it, the transparent layer is polished smoothly and abrasive powder is removed to form a flat surface first, and then a transparent UV-curable resin paint is applied thereon. Coating roll formed with a groove used in the latter step, butyl constituting the surface of the roll, a groove of the same shape is formed at a predetermined pitch in a polymer elastic material such as urethane, The groove has a substantially triangular shape in which a side surface of the groove is an inclined surface and a flat portion is formed on the bottom surface and the opening, and the flat portion on the bottom surface has a shape equal to or wider than the width of the flat portion on the opening. As the coating condition, when the thickness of the base material is t and the interval between the groove roll and the receiving roll is g, the numerical value of gt is set to -1.2 to -2.0 mm and held in the groove. The paint is pressed against the polished flat surface, a precise amount is applied to a portion corresponding to the width of the groove, and the paint applied in the adjacent groove is averaged to partially form the same film thickness. Collectively, a coating film having the same thickness is formed over the entire coating width, and the coated surface is cured by irradiating ultraviolet rays to form a transparent protective layer. This transparent protective layer has a uniform film thickness as compared with a coating film obtained by leveling of a paint by coating with a flow coater, and appeals a high quality of reflected light, particularly an image of a fluorescent lamp without fluctuation. Due to the accuracy of the thickness of the base material, the pressure of pressing the surface of one base material does not show the same pressure at all points, but the roll distance is set in the above range. It is intended that a good transparent protective layer can be formed as a whole. If the thickness accuracy of the base material is high and the properties of the coated surface are good, the value of gt is set in the range of -1.5 to -1.8 mm, and the smoothness is improved.
[0005]
The number of grooves formed at the above-mentioned predetermined pitch is generally indicated by density, and the number of grooves can be in the range of 30 to 90 / inch. However, the number of grooves should be appropriately set in consideration of the durability and application amount of the groove according to the material and hardness of the elastic material constituting the roll surface portion. If the Shore hardness of the elastic material is as soft as about 30 degrees, the number of grooves should be set. When the hardness is 30 to 65 lines / inch, the depth of the groove is 0.21 to 0.25 mm. When the hardness is as hard as about 50 degrees, the groove is 65 to 90 lines / inch, and the depth of the groove is preferably 0.16 to 0.20 mm. Condition. The depth of the groove varies depending on the smoothness and surface properties of the surface to be applied, and the usable depth is in the range of 0.1 to 0.3 mm. It can be used for a long time considering the degree of wear Should be processed slightly deeper. As a guide, the coating amount is 40 to 59 lines / inch, and when the depth is 0.21 to 0.25 mm, the coating amount is 30 to 35 g / m ^2, and the coating amount is 60 to 80 lines / inch, and the depth is 0.16 to −0. In the case of 20 mm, it is applied at a rate of 20 to 25 g / m ² .
[0006]
What is particularly noticed at the time of painting is that when applying a transparent UV-curable resin paint, instead of performing dampening painting with a roll coater on the polished surface, by painting only with groove rolls is there. The dampening coating is performed to strongly press the paint against the coating surface to improve the adhesion of the paint to be subsequently applied to the coating surface, but in the present invention, the paint contained in the groove is strongly pushed to the coating surface. Thus, the adhesiveness can be secured, and a smooth transparent film is formed by eliminating the influence of the shape of the application surface by the dampening roll on the transparent thin film formed thereafter. Other coating conditions, when applying a transparent ultraviolet-curable resin coating, the coating temperature is heated to 40 ~ 50 ℃, the temperature of the application surface of the substrate is set to 40 ~ 70 ℃, In the present invention, since the leveling of the paint is not actively performed, the temperature of the coated surface is preferably performed at a low temperature within the above range, and the glossiness is better.
[0007]
In the present invention, since the purpose is to form a transparent, smooth and smooth protective layer for protecting the decorative layer on the surface of a ceramic substrate such as a calcium silicate plate, the applied amount and the applied paint become smooth. Finding easy conditions is an important issue. Since the transparent protective layer is greatly affected by the environment of the processing site, dust and dirt easily adhere to the application surface, it is advisable to dry as quickly as possible after application, and the hardness is high from the viewpoint of the scratch resistance of the protective layer. Ultraviolet-curable resin paints are mainly used because they are good. In this embodiment, an ultraviolet curable resin containing an oligomer of an acrylic resin, a monomer and a pigment such as silica or wax is used to form a transparent protective layer as the uppermost layer. I have. Such a paint has a property that it does not easily adhere to the base material, and it is necessary to press strongly to enhance the adhesiveness. On the other hand, if the film thickness is large, the decorative board has poor flexibility, cracks are generated, and the reflected light is distorted, so that a high-grade feeling is impaired when the decorative board is attached to a wall surface.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
As a ceramic base material, a molecular weight consisting of 70% methylene diisocyanate, 5% methyl acetate and 20% toluene butyl acetate on the surface of a calcium silicate plate (specific gravity 0.8) having a size of 910 mm x 1820 mm and a thickness t of 6 mm. Is about 500, a moisture curable isocyanate resin paint (manufactured by TOUPE Co., Ltd., trade name: AS Sealer # 50) is used as a sealer, applied by a sponge roll coater at a rate of 60 g / m ² (Wet), and air-dried. After 36 hours (normal curing time is about 8 hours to 1 week), a UV curable acrylic resin filler (manufactured by Dainippon Ink Industries, Ltd., product number SKS6-HV-W) is applied to the coated surface using a reverse roll coater. Is applied at a rate of 110 g / m ² and passed under three ultraviolet lamps having a main wavelength of 360 nm and an output of 80 W / cm at a conveyor speed of 15 m / min to cure the sealant. The surface is polished using a double wide belt sander of # 280 and # 320, and the polishing powder is removed with a brush. Acrylic urethane enamel (manufactured by UC Color DRS Dainippon Ink Co., Ltd.) was applied to the surface of the substrate treated with the sealer and the sealer at a rate of 110 g / m ² by using a roll coater and a flow coater. Dry at 10 ° C. for 10 minutes. Next, using a roll coater, apply an adhesive (primer W-100, manufactured by Dainippon Ink Co., Ltd.) at 20 to 30 g / m ² and evaporate the solvent using infrared rays to form a transfer base. The transfer film is heated to 70 to 80 ° C., and the transfer film is pressed at 70 to 80 ° C. at a pressure of 4 kg / m ² using two silicon rubber rolls having a hardness of 60 degrees, and the surface is cooled to 40 to 45 ° C. to obtain a base film. Was peeled off, and a marble-like pattern was transferred onto a transfer base to form a transfer print layer. Further, a UV-curable acrylic resin transparent base coat (RU7588, manufactured by Arch Coating Co., Ltd.) was applied on the transfer surface with a reverse roll coater at a rate of 40 g / m ² , and the conveyor speed was 15 m below the three UV lamps. UV light is applied for curing at a rate of 1 / min. Next, the coated surface hardened by a # 320 wide belt sander is polished to remove the dust and foreign matter adhered by the transfer printing and UV base coating process to form a smooth surface mechanically, but it becomes the ground surface of the sander. Transparency is lost. After the abrasive powder has been carefully removed with a brush roll or the like, the surface of the base material is heated to 40 ° C., and the density of the grooves is 80 / inch (groove pitch) on the surface of the roll lined with an elastic material having a Shore hardness of 40 degrees. 0.32 mm), a grooved roll with a substantially triangular groove with a depth of 0.16 mm was attached, and a matte acrylic resin UV top coat clear (IZ, made by Arch Coating Co., RZ7720) was applied at a coating temperature of 45 ° C. The coating is performed at a coating speed of 15 m / min by adjusting the roll interval with a base material thickness of t-1.5 mm and passing under the three UV lamps having an output of 80 W / m at a conveyor speed of 15 m / min. Irradiation was carried out to cure to obtain a smooth matt clear painted decorative board without fluctuation. The ground surface of the wide belt sander disappears by applying the matte clear applied thereon, and the sense of transparency is restored.
[0009]
Next, the shape of the groove of the grooved roll and the reason why a smooth painted surface can be obtained will be described. FIG. 1A is a schematic front view showing a state in which a base material 1 using a calcium silicate plate having a thickness t is coated by being sandwiched between a groove roll 2 and a receiving roll 3. It shows the state of g = t equal to the thickness of the material. (B) is a side view showing the groove 4 engraved on the grooved roll 2, the doctor roll 5 and the paint 6 in contact with the groove. The coating material fills the groove 4 having the depth d and transfers to the surface of the substrate 1. Arrows indicate the rotation direction of each roll and the traveling direction of the substrate. (C) The figure shows that the groove 4 is compressed on the surface of the substrate 1 by moving the groove roll 2 in the direction of arrow E so that the gap g between the rolls is smaller than the thickness t of the substrate. FIG. 4 shows a state in which the paint contained in the groove having the depth d is extruded. Also, the value of gt becomes larger than the depth d of the groove, but since the elastic material constituting the groove is simultaneously compressed, the shape of the groove is deformed, but a gap is formed between the groove and the coating surface. It is applied by flowing. The extruded paint is pressed against the smooth polished surface formed on the decorative layer and occurs rearward in the direction of travel of the substrate while improving adhesion, but moves forward from the gap of the deformed groove. It mixes with the paint similarly applied from the adjacent groove and averages it partially to have the same film thickness. As a result, the whole coated surface forms a coated surface having the same film thickness. The amount of paint contained in the groove is determined by the shape of the groove, but not all of the amount contained in the groove is necessarily transferred to the surface of the base material, but the paint is agitated when the groove is deformed. There is no stagnation. In the present invention, the pressure of the grooved roll 2 on the base material is not indicated by a pressure value, and the value of the distance between the grooved roll and the base material smaller than the thickness t of the base material is indicated by a negative value.
[0010]
The grooves are classified into two types. As shown in FIGS. 2A and 2B, the side surfaces of the grooves are vertical and the bottom surface is substantially flat. In (C) and (D), the side surface of the groove is inclined, and the bottom surface is almost flat. In practice, the shape of each surface of these grooves may be curved instead of straight, depending on the groove processing means. However, these surfaces are generally composed of the above two types. There are two types of groove processing means: mechanical methods and optical means using a laser.The optical means is easier to fine-tune, and this means is mainly used. Called a role. The grooves are formed independently or spirally on the peripheral surface of the roll, but no significant difference is recognized because the pitch of the grooves is as dense as 30 to 90 per inch. The results of the actual test are shown in the following table.
[0011]
[Table 1]

[0012]
As described above, the paint is a UV-curable resin paint that has poor thixotropy and does not easily adhere to the base material surface, so it is necessary to strongly press the paint against the base material surface. As a result, cracks and reflected light are distorted, which impairs a sense of quality. For this reason, a grooved roll was selected in the present application, but it was found that good results were obtained under specific conditions during repeated experiments. First, the pitch of the grooves, but at least 30 to 40 grooves per inch are required to arrange a uniform paint over the entire surface, and if less than this, the paint is applied over the entire surface even if the paint is leveled. I can't spread it. On the other hand, when the density of the grooves exceeds 80 to 90, the coating amount is reduced, the mechanical strength of the grooves is lost, and the paint cannot be strongly pressed against the substrate surface. According to Table 1 above, the shape of the groove is suitable for (C) and (D) in which the side surface of the groove is inclined, and (C) is excellent among them. The feature of (C) is that when the width of the flat portion 7 extending from the opening is substantially m and the width of the flat portion 8 on the bottom surface is n, the width of the flat portion on the bottom surface is the opening portion. A good result can be obtained when the condition is equal to or larger than the width extending from, that is, when m ≦ n. The reasons are that the flat portion 7 is easily dented when pressure is applied, and that the subsequent deformation of the slope acts to push out the paint without resistance when the paint flows out, and there is no remaining paint. Also, the width m of the flat portion 7 extending from the opening is as small as possible, so that it is easy to mix with the paint applied from the adjacent groove, and no trace of streaks remains. Although the shape of the above-mentioned flat portion is not necessarily limited to a flat surface and may be processed in a curved shape, here, for the sake of simplicity, the feature of the groove shape is simply shown as the flat portion. In (A) and (B), the paint tends to remain in the groove, and an air entrainment phenomenon is observed, so that small air bubbles are easily generated in the coating film.
[0013]
【The invention's effect】
As described above, since a transparent protective layer having excellent smoothness can be formed on a ceramic substrate having a decorative layer, a decorative substrate showing reflected light without fluctuation can be provided. In particular, an image such as a fluorescent light is reflected without distortion, and the high quality can be emphasized.
[Brief description of the drawings]
1A is a schematic front view at the time of coating using a grooved roll, FIG. 1B is a side view thereof, and FIG. 1C shows a state in which the groove roll is pressed against a substrate. It is a side view.
FIG. 2 is a schematic cross-sectional view showing types of groove shapes in (A), (B), (C), and (D).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ceramic base material 2 Groove roll 3 Receiving roll 4 Groove 5 Doctor roll 6 Paint 7 Flat portion 8 extending from opening 8 Flat portion 8 on bottom surface

Claims

On the surface of a ceramic substrate such as a calcium silicate plate, a decorative layer is provided on a surface treated with a sealer, a filler, and the like, and a transparent layer containing a pigment is formed on the decorative layer and cured. After that, the transparent layer is polished smoothly and abrasive powder is removed to form a flat surface first, and further, an application roll used when applying a transparent ultraviolet curable resin paint thereon constitutes the roll surface. A groove of the same shape is formed at a predetermined pitch in the elastic material to be formed, the side surface of the groove is an inclined surface, a substantially triangular shape in which a flat portion is formed on the bottom surface and the opening, and the flat portion on the bottom is an opening. The width of the flat portion is equal to or larger than the width of the flat portion, and when the substrate thickness is t and the interval between the groove roll and the receiving roll is g, the numerical value of gt is -1.2 to -2.0 mm. And press the paint held in the groove against the polished flat surface to adjust the width of the groove. Apply the exact amount to the corresponding area, average the paint applied in the adjacent groove to partially form the same film thickness, and collectively form a coating film of the same thickness over the entire application width And a method of coating a ceramic substrate having a transparent protective layer that is cured by irradiating an applied surface with ultraviolet light and exhibits reflected light without fluctuation.

The number of grooves formed at the above-mentioned predetermined pitch is 30 to 90 / inch, and the coating is performed using a groove roll selected from the range of 0.1 to 0.3 mm in depth. The method for coating a ceramic substrate according to claim 1.

The method according to claim 1, wherein when applying a transparent ultraviolet-curable resin coating material, the wet polishing is not performed by a roll coater on the polished surface, and the coating is performed only by the groove roll. 4. How to paint ceramic substrate.

A ceramic-type cosmetic having a transparent polishing layer formed on the decorative layer produced by the coating method according to any one of claims 1 to 3, and a transparent protective layer having a transparent resin layer formed thereon and exhibiting reflected light without fluctuation. Base material.