【発明の詳細な説明】
本発明は亀甲状模様塗膜の形成方法に関する。
基材に亀甲状模様を発生させる方法に関し、陶
器などでは熱シヨツクを与える方法が知られてい
るが、その他の基材についてはあまり良い方法が
開発されていない。
本発明者等は基材にコーテイング剤を塗布する
ことにより、基材に亀甲状模様を形成せしめる方
法について検討した結果、本発明に到達した。
本発明は基材に水性エマルシヨン塗料を塗布
し、該水性エマルシヨン塗料の造膜温度以下の温
度、好ましくは造膜温度より10℃〜40℃低い温度
で乾燥して塗膜にひび割れを発生させた後、造膜
温度以上の温度、好ましくは造膜温度より30℃以
上高い温度で乾燥硬化させることを特徴とする亀
甲状模様塗膜の形成方法である。
本発明のように水性エマルシヨン塗料を２段で
乾燥硬化させることにより、基材との接着性およ
び化粧性に優れた亀甲状塗膜を得ることができ
る。本発明方法により発生させた亀甲状模様に更
に立体感或は色相感を与えるために基材と水性エ
マルシヨン塗料との間に下塗り塗料を塗布するこ
とも可能であり、又亀甲状塗膜を保護したり、発
生したひび割れに塵埃等が付着するのを防止した
りするために上面に各種のクリヤー塗料を塗布す
ることも出来る。
本発明に使用される水性エマルシヨン塗料とし
てはアクリル系エマルシヨン塗料、酢酸ビニル系
エマルシヨン塗料、エチレン−酢酸ビニル共重合
エマルシヨン塗料、アクリル−酢酸ビニル共重合
エマルシヨン塗料など各種の水性エマルシヨン塗
料をあげることができ、また該水性エマルシヨン
塗料を塗布する基材としては、布、紙、石綿セメ
ント板、樹脂板、木板、樹脂フイルム、鉄、アル
ミニウム、銅などの金属板、陶器、土器などを使
用することができる。下塗り塗料を用いる場合、
下塗り塗料は基材と水性エマルシヨン塗料との接
着性に優れ、且つ水性エマルシヨン塗料の収縮に
よるひび割れの発生を容易にするため軟質の塗料
が好ましく、各種水性エマルシヨン塗料、溶剤系
塗料などを使用することができる。
上塗り剤は亀甲状塗膜の保護が目的であり必要
に応じ使用されるが、耐久性に優れた硬質の塗装
剤が好ましく、各種水性エマルシヨン塗料、溶剤
系塗料などをクリヤー樹脂の状態で使用する。
下記実施例中、部は重量部である。
実施例 １
メトローズ90SH（信越化学製、分散剤1.5％水溶
液） 120部
ヘキサメタリン酸ソーダ 0.5部
プライマール850（日本アクリル製、分散剤）
2.0部
ノプコNXZ（サンノプコ製、消泡剤） 3.0部
タイペークＲ−930（石原産業製、TiO2顔料）
140部
上記組成物をボールミルで混合し、顔料を分散
させた後、これに造膜温度（MFT）40℃の水性
アクリルエマルシヨン（固形分50％）500部を加
え、水性エマルシヨン塗料を得た。得られた水性
エマルシヨン塗料を磨軟鋼板にスプレーした後、
15℃の雰囲気中で15分間乾燥し、全面に亀甲状の
ひび割れを発生させた（試験体No.1）。
実施例 ２
実施例１により得られた試験体を更に80℃の雰
囲気中で20分間乾燥硬化し、試験体No.2を得た。
実施例 ３
水性アクリルエマルシヨン（MFT10℃、固形分
50％） 80部
SFデフオーマー154（サンノプコ製、消泡剤）
１部
EMブラウンＲ（東洋インキ製、分散顔料） 19部
上記組成物をデイスパーで分散し、下塗り剤を
調合した。該下塗り剤を石綿セメント板にスプレ
ーし、室温で24時間乾燥した後、実施例１で調整
した水性エマルシヨン塗料をスプレーし、15℃の
雰囲気中で15分間乾燥し、全面に亀甲状のひび割
れを発生させた後更に80℃の雰囲気中で20分間乾
燥硬化して試験体No.3を得た。
以上３種類の試験体について、温度25℃、湿度
75％の恒温恒湿室で168時間乾燥した後、各種試
験を行なつたところ下記の通りの結果を得た。
【表】DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a tortoiseshell pattern coating. Regarding the method of generating a hexagonal pattern on a base material, a method of applying heat shock is known for ceramics, etc., but good methods have not been developed for other base materials. The present inventors studied a method of forming a hexagonal pattern on a base material by applying a coating agent to the base material, and as a result, they arrived at the present invention. In the present invention, a water-based emulsion paint is applied to a substrate and dried at a temperature below the film-forming temperature of the water-based emulsion paint, preferably 10°C to 40°C lower than the film-forming temperature to cause cracks in the paint film. This is a method for forming a hexagonal pattern coating film, which is then dried and cured at a temperature higher than the film-forming temperature, preferably at a temperature 30° C. or more higher than the film-forming temperature. By drying and curing the water-based emulsion paint in two stages as in the present invention, a hexagonal-shaped paint film with excellent adhesion to the substrate and cosmetic properties can be obtained. It is also possible to apply an undercoat between the base material and the water-based emulsion paint in order to give the tortoiseshell pattern generated by the method of the present invention a more three-dimensional effect or a sense of hue, and also to protect the tortoiseshell coating film. Alternatively, various clear paints can be applied to the top surface to prevent dust from adhering to cracks that have occurred. The water-based emulsion paints used in the present invention include various water-based emulsion paints such as acrylic emulsion paints, vinyl acetate emulsion paints, ethylene-vinyl acetate copolymer emulsion paints, and acrylic-vinyl acetate copolymer emulsion paints. In addition, as the base material to which the water-based emulsion paint is applied, cloth, paper, asbestos cement board, resin board, wooden board, resin film, metal board such as iron, aluminum, copper, etc., ceramics, earthenware, etc. can be used. . When using primer paint,
As the undercoat paint, a soft paint is preferable because it has excellent adhesion between the base material and the water-based emulsion paint, and cracks easily occur due to shrinkage of the water-based emulsion paint, and various water-based emulsion paints, solvent-based paints, etc. may be used. Can be done. The purpose of the topcoat is to protect the tortoiseshell coating, and it is used as necessary, but hard coatings with excellent durability are preferred, and various water-based emulsion paints, solvent-based paints, etc. are used in the form of clear resin. . In the following examples, parts are parts by weight. Example 1 Metrose 90SH (manufactured by Shin-Etsu Chemical, dispersant 1.5% aqueous solution) 120 parts Sodium hexametaphosphate 0.5 parts Primal 850 (manufactured by Nippon Acrylic, dispersant)
2.0 parts Nopco NXZ (manufactured by San Nopco, antifoaming agent) 3.0 parts Typeke R-930 (manufactured by Ishihara Sangyo, TiO 2 pigment)
140 parts The above composition was mixed in a ball mill to disperse the pigment, and then 500 parts of an aqueous acrylic emulsion (solid content 50%) with a film forming temperature (MFT) of 40°C was added to obtain an aqueous emulsion paint. . After spraying the resulting water-based emulsion paint onto a polished mild steel plate,
It was dried for 15 minutes in an atmosphere of 15°C, and tortoiseshell-shaped cracks were generated on the entire surface (test specimen No. 1). Example 2 The test piece obtained in Example 1 was further dried and cured in an atmosphere at 80°C for 20 minutes to obtain test piece No. 2. Example 3 Aqueous acrylic emulsion (MFT10℃, solid content
50%) 80 parts SF Defoamer 154 (manufactured by San Nopco, antifoaming agent)
1 part EM Brown R (manufactured by Toyo Ink, dispersed pigment) 19 parts The above composition was dispersed with a disper to prepare an undercoat. The primer was sprayed onto an asbestos cement board and dried at room temperature for 24 hours, then the water-based emulsion paint prepared in Example 1 was sprayed and dried in an atmosphere of 15°C for 15 minutes to form tortoiseshell-shaped cracks on the entire surface. After the generation, it was further dried and cured for 20 minutes in an atmosphere of 80°C to obtain test specimen No. 3. For the above three types of test specimens, the temperature was 25℃ and the humidity was
After drying in a constant temperature and humidity room at 75% for 168 hours, various tests were conducted and the following results were obtained. 【table】