JP5210252B2

JP5210252B2 - Painting defect inspection method

Info

Publication number: JP5210252B2
Application number: JP2009154093A
Authority: JP
Inventors: 勝也上原; 雅文比嘉
Original assignee: Kubota Matsushitadenko Exterior Works Ltd; KMEW Co Ltd
Current assignee: KMEW Co Ltd
Priority date: 2009-06-29
Filing date: 2009-06-29
Publication date: 2013-06-12
Anticipated expiration: 2029-06-29
Also published as: JP2011007751A

Description

本発明は、塗膜が形成された基材の塗装不良を検出するための塗装不良検査方法に関する。 The present invention relates to a coating failure inspection method for detecting a coating failure of a substrate on which a coating film is formed.

従来、塗膜が形成された基材１の塗装不良を検出するためには、基材１に光を照射すると共に反射光を検出し、この検出結果に基づいて塗装不良の有無を判定することがおこなわれている。例えば表面に有機塗膜が形成された基材１の表面に紫外線吸収剤を含有する無機質塗膜を形成した場合や、更にこの無機質塗膜に重ねて光触媒を含有する無機質塗膜を形成する場合には、透明な無機質塗膜の塗装不良の有無を目視により判定することが困難であるが、基材１に紫外線を照射すると共にその反射光を検出すれば、塗装不良の有無を高い確実性をもって判定することができる（特許文献１参照）。 Conventionally, in order to detect a coating failure of the substrate 1 on which a coating film is formed, the substrate 1 is irradiated with light and reflected light is detected, and the presence or absence of a coating failure is determined based on the detection result. Has been done. For example, when an inorganic coating film containing an ultraviolet absorber is formed on the surface of the substrate 1 having an organic coating film formed on the surface, or when an inorganic coating film containing a photocatalyst is formed on the inorganic coating film. It is difficult to visually determine the presence or absence of poor coating of a transparent inorganic coating film, but if the substrate 1 is irradiated with ultraviolet rays and its reflected light is detected, the presence or absence of poor coating is highly reliable. (See Patent Document 1).

図３，４に、塗装不良検査方法の一例を示す。塗装が施された基材１が連続的に搬送される搬路の上方に、光源２及び検出器３が配設されている。光源２は例えばブラックライト等の適宜の紫外線ランプで構成され、検出器３は例えばＣＣＤ紫外線カメラ等で構成される。この検出器３は基材１の搬送方向と直交する方向に並ぶ複数の視野（分割測定エリア５）から反射される反射光の強度を検出する。各分割測定エリア５ごとの測定結果は複数の画素に分割され、検出器３は各分割測定エリア５ごとに各画素における反射光の強度を検出結果として出力する。そして、基材１を搬送しながら検出器３で反射光の検出を順次おこなうことで、基材１の全面に亘って反射光の検出をおこなうようにする。 3 and 4 show an example of a coating defect inspection method. A light source 2 and a detector 3 are disposed above a carrying path through which the coated base material 1 is continuously conveyed. The light source 2 is composed of an appropriate ultraviolet lamp such as black light, and the detector 3 is composed of a CCD ultraviolet camera, for example. The detector 3 detects the intensity of reflected light reflected from a plurality of fields of view (divided measurement area 5) arranged in a direction orthogonal to the conveyance direction of the substrate 1. The measurement result for each divided measurement area 5 is divided into a plurality of pixels, and the detector 3 outputs the intensity of reflected light in each pixel as a detection result for each divided measurement area 5. Then, the reflected light is detected over the entire surface of the substrate 1 by sequentially detecting the reflected light with the detector 3 while conveying the substrate 1.

上記検出器３による検出結果に基づいて、塗装不良の有無が判定される。このとき、例えば各分割測定エリア５ごとに、複数の画素における反射光の強度の平均値を導出する。そして、分割測定エリア５における反射光の強度の平均値が所定の閾値を超える場合、基材１上の前記分割測定エリア５と対応する位置に塗装不良が発生していると判定される。 Based on the detection result by the detector 3, the presence / absence of coating failure is determined. At this time, for example, for each divided measurement area 5, an average value of the intensity of reflected light in a plurality of pixels is derived. When the average value of the intensity of the reflected light in the divided measurement area 5 exceeds a predetermined threshold value, it is determined that a coating defect has occurred at a position corresponding to the divided measurement area 5 on the substrate 1.

しかし、基材１の塗装が施される面に凹凸が形成されている場合、すなわち例えば図６（ａ）に示すように基材１の上面に目地模様６、平坦な領域７、細かい凹凸模様が形成されている領域８、粗い凹凸模様が形成されている領域９が形成されている場合には、この凹凸によって光が散乱し、反射光の強度が低下してしまう。そうすると、例えば、基材１上の凹凸が形成されている領域と凹凸が形成されていない領域とでは反射光の強度が異なってしまい、また凹凸の程度が異なる領域間でも反射光の強度が異なってしまう。このような場合の反射光の検出結果の平均値の例を図６（ｂ）に示す。図６（ｂ）の縦軸は平均値の値（輝度）を示し、横軸は基材１上の位置を示す。この基材１上の位置は、図６（ａ）における符号イで示される基材１上のライン上の位置と対応している。 However, when unevenness is formed on the surface of the substrate 1 to be coated, that is, for example, as shown in FIG. 6A, a joint pattern 6, a flat region 7, a fine uneven pattern on the upper surface of the substrate 1 In the case where the region 8 in which the pattern is formed and the region 9 in which the rough concavo-convex pattern is formed are formed, light is scattered by the concavo-convex pattern, and the intensity of the reflected light is reduced. Then, for example, the intensity of the reflected light is different between the region where the unevenness on the substrate 1 is formed and the region where the unevenness is not formed, and the intensity of the reflected light is different between regions where the degree of unevenness is different. End up. An example of the average value of the detection results of the reflected light in such a case is shown in FIG. In FIG. 6B, the vertical axis represents the average value (luminance), and the horizontal axis represents the position on the substrate 1. The position on the base material 1 corresponds to the position on the line on the base material 1 indicated by the symbol a in FIG.

図６（ｂ）に示されるように、基材１に凹凸が形成されている場合には、塗装不良が発生していない場合であっても、反射光の検出結果はバラツキが大きくなって安定せず、一定の閾値を基準にして塗装不良を検出することが困難になってしまう。 As shown in FIG. 6B, when unevenness is formed on the base material 1, the detection result of the reflected light is widely dispersed and stable even when no coating failure occurs. Without it, it becomes difficult to detect a coating failure based on a certain threshold.

このような問題を解決するためには、例えば基材１上の凹凸の程度が異なる各領域ごとにそれぞれ異なる閾値を設定することも考えられる。 In order to solve such a problem, for example, it is conceivable to set different threshold values for each region where the degree of unevenness on the substrate 1 is different.

しかしながら、この場合は基材１上の反射光の検出位置が変わるたびに閾値を変更しなければならず、煩雑な処理が必要になってしまい、また基材１の種類を変えるごとに閾値を設定し直さなければならないという問題もある。また、このように基材１上の各領域ごとに閾値を設定すると、例えば複数の基材１について塗装不良検査を順次おこなう際に基材１の搬送方向にずれが生じるなどして、基材１に位置ずれが生じる場合には、正確な塗装不良検査ができなくなってしまうという問題もある。 However, in this case, the threshold value has to be changed every time the detection position of the reflected light on the base material 1 is changed, and complicated processing is required, and the threshold value is changed every time the type of the base material 1 is changed. There is also a problem that it must be set again. In addition, when the threshold value is set for each region on the base material 1 in this way, for example, when the coating defect inspection is sequentially performed on the plurality of base materials 1, a shift occurs in the transport direction of the base material 1. When the position shift occurs in 1, there is a problem that an accurate coating defect inspection cannot be performed.

更に、上記のような反射光に基づく塗装不良検査は、基材１上の塗膜とその下地との間の光反射性の相違を利用するものであるが、基材１に凹凸が形成されることで反射光中に散乱光成分が多くなると、塗膜とその下地との間の光反射性の差が小さくなってしまい、正確な塗装不良検査が難しくなるという問題もある。 Furthermore, the coating defect inspection based on the reflected light as described above uses the difference in light reflectivity between the coating film on the base material 1 and the ground, but unevenness is formed on the base material 1. Therefore, when the scattered light component increases in the reflected light, the difference in light reflectivity between the coating film and the ground becomes small, and there is a problem that accurate coating defect inspection becomes difficult.

特開２００９−２５１５５号公報JP 2009-25155 A

本発明は上記の点に鑑みてなされたものであり、凹凸面を有しこの凹凸面に塗膜が形成された基材１に対して光を照射すると共に前記塗膜からの反射光を検出し、この反射光の強度に基づいて塗装不良を検出するにあたり、塗装不良の有無を正確且つ容易に判定することができる塗装不良検査方法を提供することを目的とする。 The present invention has been made in view of the above points, and irradiates light to the substrate 1 having an uneven surface and a coating film formed on the uneven surface, and detects reflected light from the coating film. An object of the present invention is to provide a coating defect inspection method that can accurately and easily determine the presence or absence of a coating defect when detecting a coating defect based on the intensity of the reflected light.

本発明に係る塗装不良検査方法では、凹凸面を有しこの凹凸面に塗膜が形成された基材１に対して光を照射すると共に前記塗膜からの反射光を検出し、この反射光の強度に基づいて塗装不良を検出する。本発明では、前記基材１に代えて、平坦面を有しこの平坦面に前記塗膜と同一組成の判定用塗膜が形成された判定用基材４に光を照射すると共に塗膜からの反射光を検出し、光の入射方向に対する前記判定用基材４の角度θが所定の角度以上の場合の反射光の最大強度を除外強度とする。そして、基材１の塗膜からの反射光の強度に基づいて塗装不良を検出する際に、前記除外強度以下の強度の反射光の検出結果を除外する。 In the coating defect inspection method according to the present invention, the substrate 1 having a concavo-convex surface and having a coating film formed on the concavo-convex surface is irradiated with light and the reflected light from the coating film is detected, and the reflected light is detected. Detect poor coating based on the strength of the. In this invention, it replaces with the said base material 1, and irradiates light to the base material for determination 4 in which the coating film for determination of the same composition as the said coating film was formed in this flat surface, and from a coating film And the maximum intensity of the reflected light when the angle θ of the determination substrate 4 with respect to the light incident direction is equal to or greater than a predetermined angle is defined as the excluded intensity. And when detecting poor coating based on the intensity of the reflected light from the coating film of the substrate 1, the detection result of the reflected light having an intensity equal to or less than the above-described exclusion intensity is excluded.

本発明によれば、塗装不良検査時に除外強度以下の強度の反射光の検出結果を除外することで、反射光の検出結果における基材１の凹凸の影響を低減することができ、基材１における凹凸の位置や程度を考慮することなく塗装不良を正確に検出することができる。 According to the present invention, it is possible to reduce the influence of the unevenness of the base material 1 in the detection result of the reflected light by excluding the detection result of the reflected light having an intensity equal to or less than the excluded intensity at the time of coating defect inspection. It is possible to accurately detect a coating failure without considering the position and degree of the unevenness.

本発明の実施の形態の一例における、判定用基材からの反射光の強度を測定する工程を示す概略図である。It is the schematic which shows the process of measuring the intensity | strength of the reflected light from the base material for determination in an example of embodiment of this invention. 判定用基材の角度と判定用基材からの反射光の強度との関係を示すグラフである。It is a graph which shows the relationship between the angle of the base material for determination, and the intensity | strength of the reflected light from the base material for determination. 本発明の実施の形態の一例における、基材からの反射光の強度を測定する工程を示す概略図である。It is the schematic which shows the process of measuring the intensity | strength of the reflected light from a base material in an example of embodiment of this invention. 同上の斜視図である。It is a perspective view same as the above. （ａ）は基材の一例を示す平面図、（ｂ）は本発明の実施の形態の一例において導出される基材からの反射光の強度の検出結果の平均値を示すグラフである。(A) is a top view which shows an example of a base material, (b) is a graph which shows the average value of the detection result of the intensity | strength of the reflected light from the base material derived | led-out in an example of embodiment of this invention. （ａ）は基材の一例を示す平面図、（ｂ）は従来技術において導出される基材からの反射光の強度の検出結果の平均値を示すグラフである。(A) is a top view which shows an example of a base material, (b) is a graph which shows the average value of the detection result of the intensity | strength of the reflected light from the base material derived | led-out in a prior art.

以下、本発明を実施するための形態について説明する。 Hereinafter, modes for carrying out the present invention will be described.

塗装の対象である基材１としては適宜のものを用いることができるが、好適な例として、セメント系の無機質板等の下地材の表面に有機塗膜を形成したものが挙げられる。有機塗膜を形成するための有機塗料は特に制限されないが、例えばアクリルエマルション系塗料を挙げることができる。この有機塗料は無色透明のクリア塗料であるほか、適宜の顔料や染料等を配合した着色塗料であっても良い。顔料としては、特に限定はされないが、たとえば、カーボンブラック、キナクリドン、ナフトールレッド、シアニンブルー、シアニングリーン、ハンザイエロー等の有機顔料；酸化チタン、硫酸バリウム、弁柄、複合金属酸化物等の無機顔料を挙げることができ、これらの群から選ばれる一種を用いるほか、二種以上を併用することもできる。 As the base material 1 to be coated, an appropriate one can be used, and a preferable example is a base material having an organic coating film formed on the surface of a base material such as a cement-based inorganic board. The organic paint for forming the organic coating film is not particularly limited, and examples thereof include an acrylic emulsion paint. The organic paint may be a colorless and transparent clear paint, or may be a colored paint containing an appropriate pigment or dye. Examples of the pigment include, but are not limited to, organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyanine green, and hansa yellow; inorganic pigments such as titanium oxide, barium sulfate, dials, and composite metal oxides In addition to using one kind selected from these groups, two or more kinds may be used in combination.

下地材に有機塗膜を形成するにあたっては、例えば下地材に対して有機塗料をスプレー等にて塗布した後、有機塗料の組成に応じた適宜の条件、例えば１００〜１５０℃で３０秒以上加熱乾燥することにより成膜して、有機塗膜を形成することができる。有機塗膜の厚みは特に制限されないが、５〜１００μｍの範囲であることが好ましい。 In forming an organic coating film on the base material, for example, an organic paint is applied to the base material by spraying, and then heated under appropriate conditions according to the composition of the organic paint, for example, at 100 to 150 ° C. for 30 seconds or more. An organic coating film can be formed by forming a film by drying. The thickness of the organic coating film is not particularly limited, but is preferably in the range of 5 to 100 μm.

この基材１の上面（塗装が施される面）に凹凸が形成されている。図５(ａ）に示す例では、基材１の上面に目地模様６が形成され、且つこの目地模様６で分割された領域に、平坦な領域７、細かい凹凸模様が形成されている領域８及び粗い凹凸模様が形成されている領域９が形成されている。 Concavities and convexities are formed on the upper surface (surface on which the coating is applied) of the substrate 1. In the example shown in FIG. 5A, a joint pattern 6 is formed on the upper surface of the base material 1, and a flat region 7 and a fine uneven pattern region 8 are formed in a region divided by the joint pattern 6. And the area | region 9 in which the rough uneven | corrugated pattern is formed is formed.

この基材１に形成する紫外線吸収性のクリア塗膜としては、紫外線吸収剤を含有する無機塗膜を挙げることができる。このクリア塗膜は、有機塗膜の表面に紫外線吸収剤を含有する無機質塗料を塗布成膜することで形成することができ、例えば基材１の表面保護や耐候性の向上のために設けられる。 Examples of the ultraviolet-absorbing clear coating film formed on the substrate 1 include an inorganic coating film containing an ultraviolet absorber. This clear coating film can be formed by coating an inorganic coating containing an ultraviolet absorber on the surface of the organic coating film, and is provided, for example, for surface protection of the substrate 1 and improvement of weather resistance. .

無機質塗料としては適宜のものを用いることができるが、例えばオルガノシランのシリカ分散オリゴマー溶液に、ポリオルガノシロキサンや、アルキルチタン酸塩等の縮合反応触媒を加え、或いは更にシリカを加えたケイ素アルコキシド系塗料等を用いることができる。 As the inorganic coating material, an appropriate one can be used. For example, a silicon alkoxide system in which a condensation reaction catalyst such as polyorganosiloxane and alkyl titanate is added to silica dispersion oligomer solution of organosilane, or silica is further added. Paint or the like can be used.

具体的には、例えば下記式〔１〕で表わされる加水分解性オルガノシランを有機溶媒または水に分散されたコロイダルシリカ中で、Ｘ１モルに対し水０．００１〜０．５モルを使用する条件下で部分加水分解してなる、オルガノシランのシリカ分散オリゴマー溶液（Ａ成分）と、下記式〔２〕で表わされ、この式〔２〕中のＲ２にフェニル基を全Ｒ２基に対して１〜３０モル％含有するポリオルガノシロキサン（Ｂ成分）と、このＡ成分とＢ成分との縮合反応を促進する触媒とを必須成分とし、Ａ成分においてシリカを固形分として５〜９５重量％含有し、加水分解性オルガノシランの少なくとも５０モル％がｎ＝１のオルガノシランで、Ａ成分１〜９９重量部に対してＢ成分９９〜１重量部が配合されている無機質塗料を用いることができる。 Specifically, for example, in a colloidal silica in which a hydrolyzable organosilane represented by the following formula [1] is dispersed in an organic solvent or water, 0.001 to 0.5 mol of water is used per 1 mol of X. An organosilane silica-dispersed oligomer solution (component A) formed by partial hydrolysis below, and represented by the following formula [2], wherein R2 in this formula [2] is a phenyl group with respect to all R2 groups. 1 to 30 mol% of polyorganosiloxane (component B) and a catalyst for promoting the condensation reaction between component A and component B are essential components, and silica is contained in component A as a solid component in an amount of 5 to 95% by weight. In addition, an inorganic paint in which at least 50 mol% of the hydrolyzable organosilane is an organosilane having n = 1, and 99 to 1 part by weight of the B component with respect to 1 to 99 parts by weight of the A component can be used. .

Ｒ１ｎＳｉＸ４−ｎ…〔１〕
（式中、Ｒ１は同一または異種の、アルキル基、シクロアルキル基、アルケニル基、ハロゲン置換炭化水素基、γ−メタクリロキシプロピル基、γ−グリシドキシプロピル基、３，４−エポキシシクロヘキシルエチル基およびγ−メルカプトプロピル基からなる群より選ばれる、炭素数１〜８の１価炭化水素基を示し、ｎは０〜３の整数、Ｘはアルコキシ基、アセトキシ基、オキシム基、エノキシ基、アミノ基、アミノキシ基およびアミド基からなる群より選ばれる加水分解性基を示す。）
Ｒ２ａＳｉ（ＯＨ）ｂＯ（４−ａ−ｂ）／２…〔２〕
（式中、Ｒ２は同一または異種の、アルキル基、シクロアルキル基、アルケニル基、ハロゲン置換炭化水素基、γ−メタクリロキシプロピル基、γ−グリシドキシプロピル基、３，４−エポキシシクロヘキシルエチル基およびγ−メルカプトプロピル基からなる群より選ばれる、炭素数１〜８の１価炭化水素基を示し、ａおよびｂはそれぞれ０．２≦ａ≦２、０．０００１≦ｂ≦３、ａ＋ｂ＜４の関係を満たす数である。）
また、この無機質塗料に含有される紫外線吸収剤としては、酸化亜鉛、酸化鉄、酸化セリウム等を挙げることができる。この紫外線吸収剤は、好ましくは無機質塗料中の固形分（クリア塗膜を形成する成分）に対して０．１〜２０重量％の範囲で含有させる。 R1nSiX4-n ... [1]
(In the formula, R1 is the same or different, alkyl group, cycloalkyl group, alkenyl group, halogen-substituted hydrocarbon group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group. And a monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of γ-mercaptopropyl group, n is an integer of 0 to 3, X is an alkoxy group, acetoxy group, oxime group, enoxy group, amino A hydrolyzable group selected from the group consisting of a group, an aminoxy group and an amide group.)
R2aSi (OH) bO (4-ab) / 2 ... [2]
(In the formula, R2 is the same or different, alkyl group, cycloalkyl group, alkenyl group, halogen-substituted hydrocarbon group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group. And a monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of γ-mercaptopropyl group, a and b are 0.2 ≦ a ≦ 2, 0.0001 ≦ b ≦ 3, a + b <, respectively. It is a number that satisfies the relationship of 4.)
Examples of the ultraviolet absorber contained in the inorganic coating material include zinc oxide, iron oxide, cerium oxide and the like. This ultraviolet absorber is preferably contained in the range of 0.1 to 20% by weight with respect to the solid content (component forming the clear coating film) in the inorganic coating material.

このような無機質塗料を基材１に静電塗装等して塗布した後、例えば６０〜１２０℃で焼き付け乾燥等することにより成膜することにより、クリア塗膜を形成することができる。このクリア塗膜の厚みは特に制限されないが、通常は１〜１０μｍの範囲の薄膜に形成される。 After applying such an inorganic coating material to the substrate 1 by electrostatic coating or the like, a clear coating film can be formed by forming a film by baking and drying at 60 to 120 ° C., for example. The thickness of the clear coating film is not particularly limited, but is usually formed as a thin film in the range of 1 to 10 μm.

また、この紫外線吸収性のクリア塗膜に積層して形成される、このクリア塗膜より紫外線吸収性が低い外層クリア塗膜としては、光触媒を含有する無機塗膜を挙げることができる。この外層クリア塗膜は、クリア塗膜の表面に光触媒を含有する無機質塗料を塗布成膜することで形成することができ、例えば基材１の防汚性を向上する目的で形成される。 Moreover, an inorganic coating film containing a photocatalyst can be mentioned as an outer layer clear coating film which is formed by laminating on this UV-absorbing clear coating film and has a lower UV-absorbing property than this clear coating film. This outer layer clear coating film can be formed by applying an inorganic coating containing a photocatalyst to the surface of the clear coating film, and is formed, for example, for the purpose of improving the antifouling property of the substrate 1.

光触媒を含有する無機質塗料としては適宜のものを用いることができるが、例えば上記クリア塗膜を形成するために使用されるケイ素アルコキシド系塗料に酸化チタン等の光触媒を加えたもの等を用いることができる。 As the inorganic paint containing a photocatalyst, an appropriate one can be used. For example, a silicon alkoxide paint used for forming the above clear coating film added with a photocatalyst such as titanium oxide can be used. it can.

このような無機質塗料を基材１にスプレー塗装等して塗布した後、例えば６０〜１２０℃で焼き付け乾燥等することにより成膜して、外層クリア塗膜を形成することができる。この外層クリア塗膜の厚みは特に制限されないが、例えば０．２〜１．０μｍの範囲に形成される。 After applying such an inorganic coating material to the base material 1 by spray coating or the like, the outer layer clear coating film can be formed by baking and drying at 60 to 120 ° C., for example. Although the thickness of this outer layer clear coating film is not particularly limited, for example, it is formed in the range of 0.2 to 1.0 μm.

このようにして上面上に塗膜が形成された基材１について、塗膜の塗装不良検査を行う。図３，４は、塗装不良検査を行うための装置構成の一例を示す。この検査装置は、上面上に塗膜が形成された基材１を搬送するベルトコンベア等の搬送装置１０、紫外線光を照射する光源２、反射光を計測する検出器３にて構成されている。 Thus, the coating-film coating defect inspection is performed about the base material 1 in which the coating film was formed on the upper surface. 3 and 4 show an example of a device configuration for performing a coating defect inspection. This inspection device is composed of a transport device 10 such as a belt conveyor for transporting a base material 1 having a coating film formed on its upper surface, a light source 2 for irradiating ultraviolet light, and a detector 3 for measuring reflected light. .

光源２はブラックライト等の適宜の紫外線ランプにて構成することができる。この光源２は搬送装置１０における基材１の搬送路の上方に、基材１の搬送方向に間隔をあけて二つ設けられている。各光源２は、搬送路上の基材１の一側端から他側端に亘って紫外線を照射するように形成されている。 The light source 2 can be composed of an appropriate ultraviolet lamp such as black light. Two light sources 2 are provided above the transport path of the base material 1 in the transport device 10 with an interval in the transport direction of the base material 1. Each light source 2 is formed so as to irradiate ultraviolet rays from one side end to the other side end of the substrate 1 on the conveyance path.

検出器３は紫外線を受光してその強度を計測する機能を有し、例えばＣＣＤ紫外線カメラ等で構成することができる。この検出器３は、搬送装置１０における基材１の搬送路の上方において、二つの光源２の間の位置の直上に配置される。この検出器３は、二つの光源２の間の領域において基材１の搬送方向と直交する方向に並ぶ複数の視野（分割測定エリア５）からそれぞれ反射される反射光の強度を検出する。この場合、各分割測定エリア５に対応する複数の検出器３を設けてもよく、また一つの検出器３で基材１の搬送方向と直交する方向に走査することにより各分割測定エリア５からの反射光の強度を検出するようにしてもよい。検出器３による各分割測定エリア５ごとの測定結果は複数の画素に分割され、検出器３は各分割測定エリア５ごとに各画素における反射光の強度を検出結果として出力する。そして、基材１を搬送しながら検出器３で各分割測定エリア５からの反射光の検出を順次おこなうことで、基材１の全面に亘って反射光の検出をおこなうことができる。 The detector 3 has a function of receiving ultraviolet rays and measuring the intensity thereof, and can be constituted by, for example, a CCD ultraviolet camera. This detector 3 is disposed directly above the position between the two light sources 2 above the transport path of the base material 1 in the transport device 10. The detector 3 detects the intensity of reflected light reflected from each of a plurality of fields of view (divided measurement areas 5) arranged in a direction orthogonal to the conveyance direction of the base material 1 in a region between the two light sources 2. In this case, a plurality of detectors 3 corresponding to each divided measurement area 5 may be provided, and each detector 3 is scanned from each divided measurement area 5 by scanning in a direction orthogonal to the conveyance direction of the substrate 1. The intensity of the reflected light may be detected. The measurement result for each divided measurement area 5 by the detector 3 is divided into a plurality of pixels, and the detector 3 outputs the intensity of reflected light at each pixel as a detection result for each divided measurement area 5. And by detecting the reflected light from each division | segmentation measurement area 5 with the detector 3 sequentially, conveying the base material 1, a reflected light can be detected over the whole surface of the base material 1. FIG.

検出器３による検出結果はパーソナルコンピュータ等で構成される適宜の演算処理装置１１で処理されて、塗装不良の有無が判定される。このとき演算処理装置１１は各分割測定エリア５ごとにその分割測定エリア５内の複数の画素における反射光の検出結果の平均値を導出し、この平均値が所定の閾値を超えている場合には塗装不良が発生していると判定する。また、この塗装不良の発生が判定された反射光の検出時において分割測定エリア５と重なっていた基材１上の領域を、基材１の塗装不良発生位置と特定することができる。 The detection result by the detector 3 is processed by an appropriate arithmetic processing unit 11 constituted by a personal computer or the like, and the presence or absence of coating failure is determined. At this time, the arithmetic processing unit 11 derives the average value of the detection results of the reflected light in the plurality of pixels in the divided measurement area 5 for each divided measurement area 5, and the average value exceeds a predetermined threshold value. Determines that a coating failure has occurred. In addition, the region on the base material 1 that overlaps the divided measurement area 5 at the time of detection of the reflected light that has been determined to have a poor coating can be identified as the coating failure occurrence position of the base material 1.

このようにして塗装不良検査をおこなうにあたり、演算処理装置１１は、分割測定エリア５内の各画素における反射光の検出結果の平均値を導出する際に、所定の除外強度以下の強度の反射光の検出結果を除外した上で、検出結果の平均値を導出する。 In performing the coating defect inspection in this manner, the arithmetic processing unit 11 determines the reflected light having an intensity equal to or lower than a predetermined exclusion intensity when deriving the average value of the detection results of the reflected light in each pixel in the divided measurement area 5. In addition, the average value of the detection results is derived.

除外強度は、塗装不良検査の前に予め決定しておく。以下、基材１として下地材上に有機塗膜が形成されたものを用い、この基材１に紫外線吸収性の無機質塗膜と、紫外線吸収性が低い無機質塗膜とを順次形成すると共に各無機質膜について塗装不良検査をおこなう場合について、除外強度の決定方法の一例を説明する。 The exclusion strength is determined in advance before the coating defect inspection. Hereinafter, as the base material 1, an organic coating film formed on a base material is used, and an ultraviolet-absorbing inorganic coating film and an inorganic coating film having a low ultraviolet-absorbing property are sequentially formed on the base material 1. An example of a method for determining the exclusion strength will be described in the case where a coating defect inspection is performed on an inorganic film.

除外強度の決定にあたっては、平坦面を有する判定用基材４を使用する。判定用基材４としては、平坦面を有する以外は上記基材１と同一の、下地材上に有機塗膜が形成されたものを用いる。 In determining the exclusion strength, the determination base 4 having a flat surface is used. As the base material 4 for determination, the same thing as the said base material 1 except having a flat surface and using the organic coating film on the base material are used.

この判定用基材４に無機質塗膜を形成することなく、図１に示すように塗装不良検査時と同じ条件で光を照射すると共に反射光の強度を測定する。このとき、光の照射方向に対する判定用基材４の角度θ（平坦面の角度）を、塗装不良検査時における光の照射方向に対する基材１の角度（塗装が施された面の角度）と同じ状態として反射光の強度を測定し、更に前記判定用基材４の角度θを変化させた場合の反射光の強度も測定する。これにより、判定用基材４の角度θと、反射光の強度との関係を導出する。 Without forming an inorganic coating film on the substrate for determination 4, as shown in FIG. 1, light is irradiated under the same conditions as in the coating defect inspection and the intensity of reflected light is measured. At this time, the angle θ (the angle of the flat surface) of the base material for determination 4 with respect to the light irradiation direction is set to the angle of the base material 1 (the angle of the surface on which the coating has been applied) with respect to the light irradiation direction at the time of coating defect inspection. The intensity of the reflected light is measured in the same state, and the intensity of the reflected light when the angle θ of the substrate for determination 4 is changed is also measured. As a result, the relationship between the angle θ of the determination substrate 4 and the intensity of the reflected light is derived.

また、この判定用基材４の平坦面上に紫外線吸収性の無機質塗膜を形成した場合、及び紫外線吸収性が低い無機質塗膜を形成した場合について、上記と同様にして塗装不良検査時と同じ条件で光を照射すると共に反射光の強度を測定し、判定用基材４の角度θと、反射光の強度との関係を導出する。 Also, when an ultraviolet-absorbing inorganic coating film is formed on the flat surface of the substrate for determination 4 and when an inorganic coating film having a low ultraviolet-absorbing property is formed, in the same manner as described above, at the time of coating defect inspection The light is irradiated under the same conditions and the intensity of the reflected light is measured, and the relationship between the angle θ of the determination substrate 4 and the intensity of the reflected light is derived.

図２は、光源２として紫外線ランプを使用した場合の、判定用基材４の角度θと、反射光の強度との関係の一例を示すグラフである。このグラフの横軸は光の照射方向に対する判定用基材４の角度θを示し、この角度θは、塗装不良検査時における光の照射方向に対する基材１の角度を基準（０°）としている。また縦軸は、紫外線吸収性が低い無機質塗膜を有する判定用基材４についての、反射光の輝度を基準（１００％）とした、反射光の相対輝度を示す。グラフ中のａは無機質塗膜が形成されない場合の反射光の強度を、ｂは紫外線吸収性の無機質塗膜が形成された場合の反射光の強度を、ｃは紫外線吸収性が低い無機質塗膜が形成された場合の反射光の強度を、それぞれ示す。 FIG. 2 is a graph showing an example of the relationship between the angle θ of the determination substrate 4 and the intensity of reflected light when an ultraviolet lamp is used as the light source 2. The horizontal axis of this graph represents the angle θ of the base material 4 for determination with respect to the light irradiation direction, and this angle θ is based on the angle (0 °) of the base material 1 with respect to the light irradiation direction at the time of coating defect inspection. . The vertical axis indicates the relative luminance of the reflected light with respect to the luminance of the reflected light as a reference (100%) for the determination substrate 4 having an inorganic coating film with low ultraviolet absorptivity. In the graph, a is the intensity of reflected light when an inorganic coating film is not formed, b is the intensity of reflected light when an ultraviolet absorbing inorganic coating film is formed, and c is an inorganic coating film having low UV absorbing ability. The intensity of the reflected light in the case where is formed is shown respectively.

図２に示すように、紫外線吸収性の無機質塗膜が形成された場合は紫外線反射性が低くなるため、反射光の強度ｂは、無機質塗膜が形成されない場合の反射光の強度ａ及び紫外線吸収性が低い無機質塗膜が形成された場合の反射光の強度ｃと較べると、低下している。塗装不良検査時には、このような反射光の強度の相違を利用して塗装不良の有無を判断する。すなわち、紫外線吸収性の無機質塗膜が形成された基材１の塗装不良検査時には、下地となる基材１からの反射光の強度は紫外線吸収性の無機質塗膜からの反射光の強度よりも高くなるため、反射光の強度が高い場合に塗装不良が発生していると判断することができる。また紫外線吸収性の無機質塗膜に重ねて、更に紫外線吸収性の低い無機質塗膜が形成された基材１の塗装不良検査時には、下地となる基材１からの反射光の強度は塗膜からの反射光の強度よりも高くなるため、反射光の強度が低い場合に塗装不良が発生していると判断することができる。 As shown in FIG. 2, when an ultraviolet-absorbing inorganic coating film is formed, the ultraviolet reflectivity is low. Therefore, the reflected light intensity b is the reflected light intensity a and ultraviolet light when the inorganic coating film is not formed. It is lower than the intensity c of reflected light when an inorganic coating film having low absorbency is formed. At the time of a coating defect inspection, the presence or absence of a coating defect is determined using such a difference in intensity of reflected light. That is, at the time of poor coating inspection of the substrate 1 on which the ultraviolet absorbing inorganic coating film is formed, the intensity of reflected light from the substrate 1 serving as a base is higher than the intensity of reflected light from the ultraviolet absorbing inorganic coating film. Since it becomes high, it can be judged that the coating defect has occurred when the intensity of the reflected light is high. In addition, at the time of poor coating inspection of the substrate 1 on which an inorganic coating film having a lower UV absorption property is formed in addition to the UV-absorbing inorganic coating film, the intensity of reflected light from the substrate 1 serving as a base is determined from the coating film. Therefore, when the intensity of the reflected light is low, it can be determined that a coating failure has occurred.

また、判定用基材４の角度θが大きくなると、それに従って検出器３に入光する各反射光の強度は低くなる。これは、基材１の凹凸部分において基材１表面の角度θが大きい部分では検出器３に入光する反射光の強度が低くなることを示している。 Further, as the angle θ of the determination base 4 increases, the intensity of each reflected light entering the detector 3 decreases accordingly. This indicates that the intensity of the reflected light entering the detector 3 is low at the portion where the angle θ of the surface of the substrate 1 is large in the uneven portion of the substrate 1.

除外強度は、判定用基材４の角度θが所定の角度以上となる場合の反射光の最大強度とする。反射光の強度は判定用基材４の角度θが大きくなるに従って減少するため、除外強度は判定用基材４の角度θが前記所定角度にある場合の反射光の強度となる。前記所定角度は適宜設定されるが、塗装不良検査時における光の照射方向に対する基材１の角度を基準（０°）として、４０°〜６０°の範囲であることが好ましい。 The excluded intensity is the maximum intensity of the reflected light when the angle θ of the determination substrate 4 is equal to or greater than a predetermined angle. Since the intensity of the reflected light decreases as the angle θ of the determination substrate 4 increases, the exclusion intensity is the intensity of the reflected light when the angle θ of the determination substrate 4 is at the predetermined angle. Although the said predetermined angle is set suitably, it is preferable that it is the range of 40 degrees-60 degrees on the basis of the angle of the base material 1 with respect to the irradiation direction of the light at the time of a coating defect test | inspection (0 degree).

また、判定用基材４の角度θが大きくなると、それに従って各反射光間の強度の差が小さくなる。これは、基材１の凹凸部分において基材１表面の角度が大きい部分では、塗装不良検査の対象である塗膜からの反射光の強度とその下地からの反射光の強度との差が小さくなり、反射光の強度差に基づいて塗装不良を判定することが困難になることを示している。そこで、除外強度は、前記のような塗膜と下地との間の反射光の強度差が小さくなる領域が除外されるように設定することが好ましい。このとき、例えば、塗膜と下地との間の反射光の強度差が、塗膜からの反射光の強度に対して所定割合よりも小さくなる領域が除外されるように除外強度を設定することが好ましい。前記所定割合は適宜設定されるが、例えば２０％以下の範囲で設定されることが好ましく、特に５〜２０％の範囲で設定されることが好ましい。 In addition, when the angle θ of the determination substrate 4 increases, the difference in intensity between the reflected lights decreases accordingly. This is because the difference between the intensity of the reflected light from the coating film that is the object of the coating failure inspection and the intensity of the reflected light from the ground is small in the uneven portion of the substrate 1 where the angle of the surface of the substrate 1 is large. This indicates that it is difficult to determine coating failure based on the difference in intensity of reflected light. Therefore, it is preferable to set the exclusion intensity so as to exclude an area where the difference in intensity of reflected light between the coating film and the base is small. At this time, for example, the exclusion strength is set so that the region where the difference in the intensity of the reflected light between the coating film and the ground is smaller than a predetermined ratio with respect to the intensity of the reflected light from the coating film is excluded. Is preferred. Although the said predetermined ratio is set suitably, it is preferable to set, for example in 20% or less of range, and it is preferable to set in the range of 5-20% especially.

例えば基材１上に紫外線吸収性の無機質塗膜を形成した場合の紫外線吸収性の無機質塗膜の塗装不良検査における除外強度は、判定用基材４の角度θが４０°〜６０°の範囲にある場合の、紫外線吸収性の無機質塗膜からの反射光の強度ｂが設定される。またこの除外強度は、反射光の強度ｂよりも所定割合（例えば１０％）だけ高い強度と、無機質塗膜が形成されていない判定用基材４からの反射光の強度ａとが重なるような判定用基材４の角度又はこれよりも小さい角度における反射光の強度ｂが設定される。 For example, in the case of forming an ultraviolet-absorbing inorganic coating film on the substrate 1, the exclusion strength in the coating failure inspection of the ultraviolet-absorbing inorganic coating film is such that the angle θ of the determination substrate 4 is in the range of 40 ° to 60 °. In this case, the intensity b of reflected light from the ultraviolet absorbing inorganic coating film is set. Moreover, this exclusion intensity | strength overlaps the intensity | strength higher by a predetermined ratio (for example, 10%) than the intensity | strength b of reflected light, and the intensity a of reflected light from the base material 4 for determination in which the inorganic coating film is not formed. The intensity b of the reflected light at the angle of the determination substrate 4 or an angle smaller than this is set.

また、基材１上に更に紫外線吸収性の低い無機質塗膜を形成した場合の紫外線吸収性の低い無機質塗膜の塗装不良検査における除外強度は、判定用基材４の角度θが４０°〜６０°の範囲にある場合の、紫外線吸収性の低い無機質塗膜からの反射光の強度ｃが設定される。またこの除外強度は、反射光の強度ｃよりも所定割合（例えば１０％）だけ低い強度と、紫外線吸収性の無機質塗膜からの反射光の強度ｂとが重なるような判定用基材４の角度又はこれよりも小さい角度における反射光の強度ｃが設定される。 In addition, when the inorganic coating film having a lower UV-absorbing property is formed on the substrate 1, the exclusion strength in the poor coating inspection of the inorganic coating film having a lower UV-absorbing property is such that the angle θ of the determining substrate 4 is 40 ° to 40 °. The intensity c of the reflected light from the inorganic coating film having a low ultraviolet absorptivity in the range of 60 ° is set. In addition, the exclusion intensity of the base material for determination 4 is such that the intensity lower by a predetermined ratio (for example, 10%) than the intensity c of the reflected light and the intensity b of the reflected light from the ultraviolet absorbing inorganic coating film overlap. The intensity c of reflected light at an angle or an angle smaller than this is set.

以上のようにして除外強度を設定し、演算処理装置１１において、分割測定エリア５内の複数の画素における反射光の検出結果から前記除外強度以下の検出結果を予め除外した上で、残りの検出結果の平均値を導出すると、基材１の凹凸に起因する前記平均値のバラツキが抑制される。このようにして導出される検出結果の平均値の例を図５（ｂ）に示す。図５（ｂ）の縦軸は平均値の値（輝度）を示し、横軸は基材１上の位置を示す。この基材１上の位置は、図５（ａ）における基材１上の符号イで示されるライン上の位置と対応している。 The exclusion intensity is set as described above, and in the arithmetic processing unit 11, the detection results below the exclusion intensity are excluded in advance from the detection results of the reflected light in the plurality of pixels in the divided measurement area 5, and the remaining detection is performed. When the average value of the results is derived, variation in the average value due to the unevenness of the base material 1 is suppressed. An example of the average value of detection results derived in this way is shown in FIG. In FIG. 5B, the vertical axis represents the average value (luminance), and the horizontal axis represents the position on the substrate 1. The position on the substrate 1 corresponds to the position on the line indicated by the symbol a on the substrate 1 in FIG.

このため、上記検出結果の平均値に基づいて塗装不良の有無を判定する場合には、本実施形態のように基材１の上面に目地模様６、平坦な領域７、細かい凹凸模様が形成されている領域８、粗い凹凸模様が形成されている領域９が形成されるなどして、基材１に凹凸が形成されていたり、凹凸の程度が異なる領域が存在したりしていても、常に一定の閾値を基準にし、この閾値を前記平均値が越えているか否かに基づいて塗装不良の有無を判定することができるようになる。 For this reason, when determining the presence or absence of coating failure based on the average value of the detection results, joint patterns 6, flat regions 7, and fine uneven patterns are formed on the upper surface of the substrate 1 as in the present embodiment. Even if there are irregularities formed on the base material 1 or there are areas with different degrees of irregularities, such as the formation of a region 8 having a rough uneven pattern, etc. Based on a certain threshold value, it is possible to determine the presence or absence of coating failure based on whether the average value exceeds the threshold value.

前記閾値は、塗装不良の有無を高い確実性をもって判定することができるように適宜設定されるものであり、基材１の上面の平坦な領域７における塗膜からの反射光（特に傾斜が０°〜２０°の範囲の平坦な領域の反射光）を検出する際に塗装不良の検出が可能であり、且つ除外強度以下の検出結果を予め除外することによる効果が望めるように適宜設定することが望ましい。例えば予め塗装不良が存在しないことが確認されている基材１について塗装不良検査時と同じ手法で反射光の検出結果の平均値を導出し、塗膜からの反射光の強度が下地からの反射光の強度よりも低い場合（本実施形態における紫外線吸収性の無機質塗膜の塗装不良検査の場合）は、前記平均値よりも５〜２０％高い値を閾値とし、塗膜からの反射光の強度が下地からの反射光の強度よりも高い場合（本実施形態における紫外線吸収性の低い無機質塗膜の塗装不良検査の場合）は、前記平均値よりも５〜２０％低い値を閾値とすることができる。 The threshold value is appropriately set so that the presence or absence of coating failure can be determined with high certainty, and the reflected light from the coating film in the flat region 7 on the upper surface of the substrate 1 (especially, the inclination is 0). Appropriately set so that it is possible to detect a coating failure when detecting the reflected light of a flat region in the range of 20 ° to 20 °, and to expect the effect of excluding detection results below the exclusion intensity in advance. Is desirable. For example, the average value of the detection results of the reflected light is derived for the base material 1 that has been confirmed to have no coating defects in advance by the same method as that for the coating defect inspection, and the intensity of the reflected light from the coating film is reflected from the base. When the intensity is lower than the intensity of light (in the case of inspection for poor coating of an ultraviolet-absorbing inorganic coating film in the present embodiment), the value 5 to 20% higher than the average value is set as a threshold value, and the reflected light from the coating film When the intensity is higher than the intensity of the reflected light from the ground (in the case of the coating failure inspection of the inorganic coating film having low UV absorption in this embodiment), the threshold value is 5 to 20% lower than the average value. be able to.

１基材
４判定用基材
θ 角度 1 Base material 4 Base material for judgment θ angle

Claims

Coating that has an uneven surface and irradiates light onto the substrate on which the coating film is formed, detects reflected light from the coating film, and detects a coating failure based on the intensity of the reflected light A defect inspection method,
Instead of the base material, the flat surface has a flat surface and a judgment coating film having the same composition as that of the coating film is irradiated with light, and reflected light from the coating film is detected. The maximum intensity of reflected light when the angle θ of the substrate for determination with respect to the incident direction of light is a predetermined angle or more is defined as an excluded intensity,
A method for inspecting defective coating, characterized in that, when a coating failure is detected based on the intensity of reflected light from a coating film on a base material, a detection result of reflected light having an intensity equal to or less than the excluded intensity is excluded.