JPS6136587B2 - - Google Patents
Info
- Publication number
- JPS6136587B2 JPS6136587B2 JP6048782A JP6048782A JPS6136587B2 JP S6136587 B2 JPS6136587 B2 JP S6136587B2 JP 6048782 A JP6048782 A JP 6048782A JP 6048782 A JP6048782 A JP 6048782A JP S6136587 B2 JPS6136587 B2 JP S6136587B2
- Authority
- JP
- Japan
- Prior art keywords
- parts
- weight
- chromate
- solid content
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 claims description 29
- 229910000831 Steel Inorganic materials 0.000 claims description 22
- 239000010959 steel Substances 0.000 claims description 22
- 239000007788 liquid Substances 0.000 claims description 16
- 239000007787 solid Substances 0.000 claims description 14
- 239000008119 colloidal silica Substances 0.000 claims description 13
- 229920013716 polyethylene resin Polymers 0.000 claims description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 12
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 10
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 10
- 229910052804 chromium Inorganic materials 0.000 claims description 10
- 239000011651 chromium Substances 0.000 claims description 10
- 239000006185 dispersion Substances 0.000 claims description 10
- 229920005989 resin Polymers 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 9
- 150000001845 chromium compounds Chemical class 0.000 claims description 7
- 238000004381 surface treatment Methods 0.000 claims description 7
- -1 polyethylene Polymers 0.000 claims description 5
- 239000004698 Polyethylene Substances 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- 229920000573 polyethylene Polymers 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 description 28
- 239000011248 coating agent Substances 0.000 description 23
- 238000005260 corrosion Methods 0.000 description 17
- 230000007797 corrosion Effects 0.000 description 17
- 239000003973 paint Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 239000011701 zinc Substances 0.000 description 7
- 229910052725 zinc Inorganic materials 0.000 description 7
- PMJNEQWWZRSFCE-UHFFFAOYSA-N 3-ethoxy-3-oxo-2-(thiophen-2-ylmethyl)propanoic acid Chemical compound CCOC(=O)C(C(O)=O)CC1=CC=CS1 PMJNEQWWZRSFCE-UHFFFAOYSA-N 0.000 description 6
- 239000013078 crystal Substances 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 235000019646 color tone Nutrition 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229920002125 Sokalan® Polymers 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- 238000010422 painting Methods 0.000 description 2
- 235000011007 phosphoric acid Nutrition 0.000 description 2
- 239000004584 polyacrylic acid Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 241001163841 Albugo ipomoeae-panduratae Species 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 1
- 229910001335 Galvanized steel Inorganic materials 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- DQXBYHZEEUGOBF-UHFFFAOYSA-N but-3-enoic acid;ethene Chemical compound C=C.OC(=O)CC=C DQXBYHZEEUGOBF-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000007720 emulsion polymerization reaction Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 239000008397 galvanized steel Substances 0.000 description 1
- 238000005246 galvanizing Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000002075 main ingredient Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000028327 secretion Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 210000004243 sweat Anatomy 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/82—After-treatment
- C23C22/83—Chemical after-treatment
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Laminated Bodies (AREA)
- Chemical Treatment Of Metals (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Description
この発明は電気亜鉛めつき鋼板の表面処理法に
関しとくに、指紋付着による汚れが目立たず、塗
料密着性および硬度、そしてさらに耐食性にも優
れた被膜を形成するための表面処理法の改良を提
案しようとするものである。
電気亜鉛めつき鋼板はそのままでは耐食性や塗
料密着性が不十分なためにクロメート処理やりん
酸塩処理が施される。
なかでもクロメート処理鋼板は近年音響機器の
シヤーシやパネルなどに多く使用されるようにな
つて来ているが、この分野においては必ずしも塗
装が行われるとは限らず、部品によつては、例え
ばテープデツキのリアパネルなど、音響機器の仕
様などを示すための部分的なシルク印刷が行わ
れ、またシヤーシなどの部品は無塗装のままクロ
メート処理が露出した状態で組み立てられる。
そのため、部品の組立工程中に作業員が手で触
れたところには指紋も付着し、また油などの付着
による汚れが目立つ。
このようにして指紋などが付着した音響機器は
商品価値が著しく損われるとともにその部分の耐
食性も劣化することになる。
ところで、この指紋付着の現象はクロメート処
理鋼板にのみ見られるものではなく。クロメート
処理前の電気亜鉛めつき鋼板そのものにも明瞭に
観察される。
すなわち、電気亜鉛めつき鋼板の表面は通常シ
ヤープで微細な亜鉛結晶が多数析出し従つて微小
な凹凸が形成されている。そのため亜鉛めつきし
たままの表面やクロム付着量の多くないクロメー
ト処理鋼板の表面において光が散乱反射されるの
で光沢はなく、白つぽく見える。
その表面を手で押さえると、皮膚からの分泌物
が亜鉛結晶の凹部を埋めるように付着し、その結
〓〓〓〓〓
果、その部分だけ光の散乱反射が起こらずに光は
付着物中に吸収されて黒つぽい模様として際立つ
て見える。
クロム付着量が約50mg/m2以下のクロメート被
膜では、亜鉛結晶の凹部は殆んど埋めこまれず、
色調も亜鉛めつき後とさほど変らないので指紋は
著しく付着する。
指紋汚れを目立たなくするには、亜鉛結晶の凹
部を予め埋めこんで平滑にすればよい。しかし、
そのためにクロメート処理時に高濃度の処理液を
用いたり、反応時間の延長や処理液温度の上昇な
どにより、クロム付着量を多く確保しようとして
も凹部を完全に埋めるまでに至らずして、これに
より耐指紋性は若干改良されるがなお不十分であ
る。
一方、厚塗りのクロメート被膜が問題にされる
のは黄色ないしは茶色に強く着色されることであ
り、そのような色調は音響機器用には不適当とさ
れ、白色ないし灰色が好まれる。
耐指紋性を改良するためには取扱いの容易な水
溶性樹脂やエマルジヨンタイプの樹脂を十分な膜
厚で処理してもよい。しかし、このようなタイプ
の樹脂系被膜は耐食性、耐水性および耐溶剤性が
悪い。
上述したように、音響機器のシヤーシなどに使
用される亜めつき鋼板には、耐指紋性、色調、耐
溶剤性、塗料密着性、耐湿性、さらには耐食性な
ど、多くの特性が要求される。
発明者は、上記のような諸特性の向上に関し、
電気亜鉛めつき鋼板の表面にクロメート処理を行
なつたのち、カルボキシル化ポリエステル樹脂デ
イスパージヨンと、水溶性クロム化合物とから成
る水性液を塗布乾燥させる表面処理方法をさきに
提案した（特願昭58−198236号）。
この方法で得られる被膜は、指紋がつかず、ま
た耐食性にもすぐれているがその反面で、被膜硬
さが低いために、コイル状の製品にスリツト加工
などを施すとき、テンシヨンパツドで押えるとす
り疵がつくところに難点を残していた。
この発明は、前述のような諸特性を満足するこ
とのほかに、硬さのより高い被膜を得ることがで
きる表面処理法についてさらに開発研究を重ねて
得られた成果をここに開示するものである。
この発明は、電気亜鉛めつき鋼板の表面にまず
クロム付着量が10〜60mg/m2になるようにクロメ
ート被膜を形成し、次にカルボキシル基を３〜20
モル％含有するカルボキシル化エチレン系樹脂デ
イスパージヨンの固形分100重量部に対し、コロ
イダルシリカを固形分で10〜60重量部の範囲、ま
た、耐食性の要請に対してはさらに水溶性クロム
化合物を10重量部以下の範囲に含む組成の水性液
を、それらの塗布乾燥後に上記クロメート被膜と
の付着量の和で0.3〜４ｇ/m2となる厚さに被成処
理することを、上記課題の解決手段とするもので
ある。
さて第１表は、クロメート処理電気亜鉛めつき
鋼板の上に、コロイダルシリカの配合量を変えて
カルボキシル化ポリエチレン系処理液を処理し、
被膜硬度に及ぼす効果を示したものである。
各被膜の処理条件は以下の通りである。
(1) 下地クロメート被膜
板厚0.8mm亜鉛付着量20ｇ/m2の電気亜鉛めつ
き鋼板を、CrO310ｇ/、Na3AlF62ｇ/から
なる組成の処理液に浸漬後、フラツトゴムロー
ルで絞り、湯洗後85℃の熱風で乾燥した。クロ
ムの付着量は20mg/m2であつた。
(2) 上塗りポリエチレン−コロイダルシリカ系被
膜(1)で得られたクロメート処理鋼板の上に、カ
ルボキシル基を12モル％含有するポリエチレン
系デイスパージヨンと、その固形分100重量部
に対してコロイダルシリカを固形分として90重
量部以下およびクロム酸アンモニウム５重量部
から成る水性液を塗布し、ロール絞りしたのち
200℃の熱風炉内で板温が80℃になるように乾
燥し被膜を形成させた。両被膜の付着量を約
1.5ｇ/m2とした。
〓〓〓〓〓
This invention relates specifically to the surface treatment method for electrogalvanized steel sheets, and proposes an improvement in the surface treatment method to form a film that is less conspicuous due to fingerprints and has excellent paint adhesion, hardness, and corrosion resistance. That is. Electrogalvanized steel sheets have insufficient corrosion resistance and paint adhesion as they are, so they are subjected to chromate treatment or phosphate treatment. In recent years, chromate-treated steel sheets have been increasingly used for the chassis and panels of audio equipment, but painting is not always done in this field, and some parts, such as tape decks, are not necessarily coated. Partial silk printing is carried out to show the specifications of the audio equipment, such as the rear panel of the car, and parts such as the chassis are assembled without painting, with the chromate treatment exposed. Therefore, fingerprints are deposited on the parts touched by workers during the assembly process, and stains due to oil and other substances are noticeable. In this way, the commercial value of audio equipment with fingerprints and the like attached thereto is significantly impaired, and the corrosion resistance of the affected parts is also deteriorated. By the way, this phenomenon of fingerprint adhesion is not only seen on chromate-treated steel sheets. It is also clearly observed in the electrogalvanized steel sheet itself before chromate treatment. That is, the surface of an electrogalvanized steel sheet usually has many sharp and fine zinc crystals precipitated thereon, thereby forming minute irregularities. For this reason, light is scattered and reflected on the surface of the zinc-plated steel sheet or the surface of the chromate-treated steel sheet, which does not have a large amount of chromium deposited, so it looks dull and whitish. When you press the surface with your hand, the secretions from your skin will fill in the recesses of the zinc crystal, and the result will be
As a result, there is no scattering and reflection of light in that area, and the light is absorbed by the deposit, making it appear as a blackish pattern. In a chromate film with a chromium deposition amount of approximately 50 mg/m 2 or less, the recesses of zinc crystals are hardly filled.
The color tone is not much different from after galvanizing, so fingerprints are noticeable. To make fingerprint stains less noticeable, the recesses in the zinc crystal can be filled in in advance to make them smooth. but,
For this reason, even if you try to secure a large amount of chromium deposit by using a highly concentrated treatment liquid during chromate treatment, prolonging the reaction time, or increasing the temperature of the treatment liquid, it may not be possible to completely fill the recesses. Although the fingerprint resistance is slightly improved, it is still insufficient. On the other hand, the problem with thick chromate coatings is that they are strongly colored yellow or brown, and such color tones are considered inappropriate for audio equipment, so white or gray is preferred. In order to improve fingerprint resistance, a water-soluble resin or emulsion type resin that is easy to handle may be treated with a sufficient film thickness. However, these types of resin coatings have poor corrosion resistance, water resistance, and solvent resistance. As mentioned above, sub-galvanized steel sheets used for chassis of audio equipment, etc. are required to have many properties such as fingerprint resistance, color tone, solvent resistance, paint adhesion, moisture resistance, and even corrosion resistance. . Regarding the improvement of various characteristics as described above, the inventors
We previously proposed a surface treatment method in which the surface of an electrogalvanized steel sheet is subjected to chromate treatment, and then an aqueous solution consisting of a carboxylated polyester resin dispersion and a water-soluble chromium compound is applied and dried. 58-198236). The coating obtained by this method does not leave fingerprints and has excellent corrosion resistance, but on the other hand, the coating has low hardness, so when applying slit processing to a coil-shaped product, it may become scratchy when pressed with a tension pad. There were some drawbacks where it could be damaged. This invention discloses here the results obtained through further development and research into a surface treatment method that not only satisfies the various characteristics described above, but also allows a coating with higher hardness to be obtained. be. In this invention, a chromate film is first formed on the surface of an electrogalvanized steel sheet so that the amount of chromium deposited is 10 to 60 mg/ m2 , and then a carboxyl group is added to 3 to 20 mg/m2.
For 100 parts by weight of the solid content of carboxylated ethylene resin dispersion containing mol%, colloidal silica is added in a solid content of 10 to 60 parts by weight, and a water-soluble chromium compound is added to meet the requirements for corrosion resistance. The purpose of the above problem is to coat an aqueous liquid having a composition in the range of 10 parts by weight or less to a thickness of 0.3 to 4 g/m 2 after coating and drying the coating and the chromate coating. It is intended as a solution. Now, Table 1 shows that chromate-treated electrogalvanized steel sheets were treated with a carboxylated polyethylene treatment solution with varying amounts of colloidal silica.
This figure shows the effect on film hardness. The processing conditions for each film are as follows. (1) Substrate chromate coating An electrogalvanized steel sheet with a thickness of 0.8mm and a zinc coating of 20g/ m2 was immersed in a treatment solution consisting of 10g of CrO 3 and 2g of Na 3 AlF 6 and then coated with a flat rubber roll. After squeezing and washing with hot water, it was dried with hot air at 85℃. The amount of chromium deposited was 20 mg/m 2 . (2) A polyethylene dispersion containing 12 mol% of carboxyl groups and colloidal silica based on 100 parts by weight of the solid content are applied on the chromate-treated steel sheet obtained with the top coat polyethylene-colloidal silica coating (1). After applying an aqueous liquid consisting of 90 parts by weight or less as a solid content and 5 parts by weight of ammonium chromate, and squeezing with a roll,
The plate was dried in a hot air oven at 200°C to a temperature of 80°C to form a film. The amount of adhesion of both films is approx.
It was set to 1.5g/ m2 . 〓〓〓〓〓
【表】
以上の結果からカルボキシル化ポリエチレン樹
脂の固形分100重量部に対してコロイダルシリカ
を全く配合しない場合には、被膜硬さは（2B）
であるのに対して、５重量部配合すると(B)、10重
量部では（Ｈ）、30重量部以上では（2H）のよう
に順次硬くなることがわかる。
また指紋の付着はいずれの被膜にも認められな
い。
耐食性については、水溶性クロム化合物を10重
量部以下でさらに上記デイスパージヨンに配合し
た場合に、塩水噴霧試験200時間後、および湿潤
試験（49℃、湿温97％）200時間後ともに被膜の
白錆は殆んど発生しないことが認められた。
なおコロイダルシリカが60重量部を越えると黒
錆がみられ、塗料密着性も劣ることがわかつた。
次にこの発明で用いる処理液および被膜につい
て詳細に説明する。
下地用のクロメート処理液はCrO3を主剤と
し、エツチング剤や反応促進剤として、硫酸
（塩）、りん酸（塩）、弗酸（弗化物）、硼酸などを
含み、この液によりクロム付着量が10〜60mg/m2
となるように被膜を形成するもので特殊なクロメ
ートではない。
クロム付着量が10mg/m2未満では耐食性が十分
ではなく、また60mg/m2より多くなると黄色に着
色するので好ましくない。クロメート処理条件は
特に限定されることなく、スプレーや浸漬法など
により塗布しロールで絞りその後、熱風乾燥すれ
ばよい。
上塗りのポリエチレン系樹脂被膜を形成させる
ための処理液は、カルボキシル基を３〜20モル％
含有するカルボキシル化ポリエチレン系樹脂デイ
スパージヨンの固形分100重量部に対しコロイダ
ルシリカを10〜60重量部、またさらに水溶性クロ
ム化合物を10重量部以下で配合する。
ポリエチレン系樹脂については、例えばエチレ
ン−酢ビ系エマルジヨンやポリエチレンワツクス
などが入手容易であるが、耐食性や耐溶剤性が極
めて悪く、一方粉末樹脂もあるが均一な処理液に
なり難いので薄く処理することは難しい。
現在、水溶性ポリエチレン樹脂は末だ開発され
ておらず、ここにカルボキシル基を含有するカル
ボキシル化ポリエチレン系樹脂デイスパージヨン
がこの発明の目的に有利に適合することを見出し
たところがこの発明の端緒である。
カルボキシル基が３モル％より低いと、ポリエ
チレン樹脂の乳化重合ができないうえ被膜の密着
性が劣り、また逆に20モル％よりカルボキシル基
がふえると、耐食性などの被膜物性が劣化する。
ポリエチレン系樹脂の固形分100重量部に対し
てコロイダルシリカの固形分が10重量部より少な
いと十分な被膜硬さが得られないし、逆に60重量
部を越えると、耐食性や塗料密着性が劣化する。
水溶性クロム化合物は耐性性などをより向上さ
せるために添加するものであるが、ポリエチレン
系樹脂の固形分100重量部に対して10重量部より
多いと処理液が増粘し、不安定になる。水溶性ク
ロム化合物としては、無水クロム酸、クロム酸
塩、重クロム酸塩などを好適例として挙げること
ができる。
被膜の付着量については、下地クロメート被膜
と上塗りポリエチレン系樹脂被膜との和が0.3〜
４ｇ/m2となるように処理することが必要であ
る。付着量が0.3ｇ/m2より少ないと亜鉛結晶の凹
部を埋めきれないので、耐指紋性が劣るとともに
耐食性も悪い。４ｇ/m2より多くなると、耐食性
や耐指紋性は非常に良好であるが、塗料密着性が
劣る傾向にあり、経済的でもない。
この処理液の塗布方法はロールコーター法や浸
漬−ピツチロール絞り法が適している。処理液の
〓〓〓〓〓
濃度は塗布法に合わせて調整すればよい。乾燥時
の板温は50〜100℃が望ましい。
次に本発明を実施例により具体的に説明する。
実施例 １
亜鉛付着量が20ｇ/m2の電気亜鉛めつき鋼板
に、CrO310ｇ/、Na3AlF62ｇ/から成る組成
の下地用クロメート処理液をスプレー塗布したの
ちフラツトゴムロールで絞り熱風乾燥した。クロ
ムの付着量は23mg/m2であつた。その上にカルボ
キシル基を12モル％含有するカルボキシル化ポリ
エチレン系樹脂デイスパージヨンの固形分100重
量部に対しコロイダルシリカを固形分として20重
量部を含み、またさらにクロム酸アンモニウム２
重量部を含む各水性液を塗布し乾燥してａ、b2
種の被膜を形成した、両被膜の付着量は、何れの
場合も1.4mg/m2に揃えた。被膜硬さは2Hであり
スリツト時は疵は付かなかつた。またクロム酸ア
ンモニウムをさらに配合した場合に被膜の耐食性
がさらに改善された。
実施例 ２
CrO310ｇ/、H3PO42ｇ/、H3BO35ｇ/よ
り成る下地用クロメート処理液を用い、実施例１
と同様の処理を行なつた。クロム付着量は35mg/
m2であつた。次いでカルボキシル基を12モル％含
有するカルボキシル化ポリエチレン系樹脂デイス
パージヨンの固形分100重量部に対しコロイダル
シリカを固形分として40重量部およびクロム酸ア
ンモニウムを５重量部含む水性液を塗布し、乾燥
し被膜を形成した。両被膜の和は1.9ｇ/m2であつ
た。被膜硬さは2Hであり、スリツト時にはすり
疵は付かなかつた。
比較例 １
実施例１と同じクロメート処理鋼板の上に樹脂
系液として、実施例１の水性液からコロイダルシ
リカを除き、クロム酸アンモニウムは含む水性液
を実施例１と同要領で処理した。クロメート被膜
と樹脂被膜の和は1.5ｇ/m2であつた。被膜硬さは
2Bであり、スリツト時にテンシヨンパツドです
り疵が付いた。
比較例 ２
実施例１と同じクロメート処理鋼板の上に樹脂
系液として、濃度12％のポリアクリル酸と0.3％
のクロム酸アンモニウムから成る処理液を塗布
し、乾燥して被膜を形成した、両被膜の付着量の
和は1.6ｇ/m2であつた。被膜硬さは2Hで、スリ
ツト時にすり疵は付かなかつたが、耐食性は不十
分であつた。
比較例 ３
実施例１のクロメート被膜のみの鋼板を用い
た。
実施例および比較例で得られた表面処理鋼板に
ついて、次の各種試験を行なつた。その結果を第
２表に示す。
(1) 耐食性
(1‐1) 湿潤試験 温度49℃、湿度99％、200時間、
(1‐2) 塩水噴霧試験 JIS Ｚ 2371、200時間
(2) 耐指数性
人工汗液をスタンプし、その時の汚れを肉眼
的５段階に評価した。評点５（実質的に付着し
ない）、４、３、２、１（著しく付着する）、
(3) 耐溶剤性
メチレンクロライドをしみこませた綿でラビ
レグテスト
〇 変化なし、× 溶出、
(4) 硬 さ
鉛筆硬さ
(5) 耐摩耗性
スリツトでのテンシヨンパツドによる疵の付
着程度
(6) 塗料密着性
基盤目エリクセン試験
塗料−メラミンアルキツド系樹脂
焼付−150℃×30分
膜厚−25μ
〇剥離なし、△一部剥離、×著しく剥離
〓〓〓〓〓
[Table] From the above results, if no colloidal silica is added to 100 parts by weight of the solid content of carboxylated polyethylene resin, the film hardness will be (2B).
On the other hand, it can be seen that when 5 parts by weight is added, the hardness increases sequentially as shown in (B), 10 parts by weight (H), and 30 parts by weight or more (2H). Further, no fingerprints were observed on any of the coatings. As for corrosion resistance, when 10 parts by weight or less of a water-soluble chromium compound was further added to the above dispersion, the coating showed significant improvement in both the 200-hour salt spray test and the 200-hour humidity test (49°C, 97% humidity). It was observed that almost no white rust occurred. It was also found that when the amount of colloidal silica exceeds 60 parts by weight, black rust is observed and paint adhesion is poor. Next, the processing liquid and coating used in this invention will be explained in detail. The chromate treatment solution for the base uses CrO 3 as its main ingredient, and contains sulfuric acid (salt), phosphoric acid (salt), hydrofluoric acid (fluoride), boric acid, etc. as etching agents and reaction accelerators. is 10~60mg/ m2
It is not a special chromate as it forms a film as follows. If the amount of chromium deposited is less than 10 mg/m 2 , corrosion resistance will not be sufficient, and if it is more than 60 mg/m 2 , it will turn yellow, which is not preferable. The chromate treatment conditions are not particularly limited, and may be applied by spraying or dipping, squeezing with a roll, and then drying with hot air. The treatment liquid for forming the top coat polyethylene resin film contains 3 to 20 mol% of carboxyl groups.
10 to 60 parts by weight of colloidal silica and 10 parts by weight or less of a water-soluble chromium compound are added to 100 parts by weight of the solid content of the carboxylated polyethylene resin dispersion. Regarding polyethylene resins, for example, ethylene-vinyl acetate emulsion and polyethylene wax are easily available, but they have extremely poor corrosion resistance and solvent resistance.On the other hand, powder resins are also available, but they are difficult to form into a uniform treatment solution, so they must be processed thinly. It's difficult to do. At present, water-soluble polyethylene resins have not yet been developed, and the present invention originates from the discovery that a carboxylated polyethylene resin dispersion containing carboxyl groups is advantageously suitable for the purpose of the present invention. be. If the carboxyl group content is less than 3 mol%, emulsion polymerization of the polyethylene resin will not be possible and the adhesion of the coating will be poor, while if the carboxyl group content is greater than 20 mol%, the physical properties of the coating, such as corrosion resistance, will deteriorate. If the solid content of colloidal silica is less than 10 parts by weight per 100 parts by weight of the solid content of polyethylene resin, sufficient film hardness will not be obtained, and if it exceeds 60 parts by weight, corrosion resistance and paint adhesion will deteriorate. do. Water-soluble chromium compounds are added to further improve resistance, but if the amount is more than 10 parts by weight per 100 parts by weight of the solid content of the polyethylene resin, the processing liquid will thicken and become unstable. . Preferred examples of the water-soluble chromium compound include chromic anhydride, chromate, dichromate, and the like. Regarding the coating amount, the sum of the base chromate coating and top coat polyethylene resin coating is 0.3~
It is necessary to treat it so that it becomes 4g/m 2 . If the amount of adhesion is less than 0.3 g/m 2 , the recesses in the zinc crystals cannot be filled completely, resulting in poor fingerprint resistance and poor corrosion resistance. When the amount exceeds 4 g/m 2 , corrosion resistance and fingerprint resistance are very good, but paint adhesion tends to be poor and it is not economical. A suitable method for applying this treatment liquid is a roll coater method or a dipping/pitch roll drawing method. Processing liquid〓〓〓〓〓
The concentration may be adjusted according to the coating method. The board temperature during drying is preferably 50 to 100°C. Next, the present invention will be specifically explained using examples. Example 1 An electrogalvanized steel sheet with a zinc coating amount of 20 g/m 2 was sprayed with a chromate treatment solution for the base, consisting of 10 g of CrO 3 and 2 g of Na 3 AlF 6 , and then squeezed with hot air using a flat rubber roll. Dry. The amount of chromium deposited was 23 mg/m 2 . Further, it contains 20 parts by weight of colloidal silica as a solid content per 100 parts by weight of a carboxylated polyethylene resin dispersion containing 12 mol% of carboxyl groups, and further contains 20 parts by weight of ammonium chromate.
Apply each aqueous solution containing parts by weight and dry to form a, b2
The adhesion amount of both films that formed the seed film was set to 1.4 mg/m 2 in each case. The hardness of the coating was 2H, and no scratches were formed during slitting. Furthermore, when ammonium chromate was further added, the corrosion resistance of the coating was further improved. Example 2 Using a base chromate treatment solution consisting of 10g/ CrO3 , 2g / H3PO4 , and 5g / H3BO3 , Example 1
The same process was performed. Chromium adhesion amount is 35mg/
It was m2 . Next, an aqueous solution containing 40 parts by weight of colloidal silica and 5 parts by weight of ammonium chromate was applied to 100 parts by weight of the solid content of the carboxylated polyethylene resin dispersion containing 12 mol% of carboxyl groups, and dried. A film was formed. The sum of both coatings was 1.9 g/m 2 . The hardness of the coating was 2H, and no scratches were formed during slitting. Comparative Example 1 A resin-based liquid was placed on the same chromate-treated steel plate as in Example 1, and an aqueous liquid containing ammonium chromate was treated in the same manner as in Example 1, except that colloidal silica was removed from the aqueous liquid. The sum of the chromate film and the resin film was 1.5 g/m 2 . The coating hardness is
2B, and there was a scratch on the tension pad during slitting. Comparative Example 2 Polyacrylic acid with a concentration of 12% and polyacrylic acid with a concentration of 0.3% were applied as a resin liquid on the same chromate-treated steel plate as in Example 1.
A treatment solution consisting of ammonium chromate was applied and dried to form a film.The sum of the adhesion weights of both films was 1.6 g/m 2 . The coating had a hardness of 2H and no scratches were formed during slitting, but the corrosion resistance was insufficient. Comparative Example 3 The steel plate of Example 1 with only a chromate coating was used. The following various tests were conducted on the surface-treated steel sheets obtained in Examples and Comparative Examples. The results are shown in Table 2. (1) Corrosion resistance (1-1) Humidity test Temperature 49℃, humidity 99%, 200 hours (1-2) Salt spray test JIS Z 2371, 200 hours (2) Index resistance Stamped with artificial sweat liquid, The stains were visually evaluated on a five-level scale. Rating: 5 (substantially no adhesion), 4, 3, 2, 1 (significant adhesion), (3) Solvent resistance Labyleg test with cotton impregnated with methylene chloride 〇 No change, × Elution, (4) Hardness Pencil hardness (5) Abrasion resistance Degree of scratches due to tension pad in slit (6) Paint adhesion Baseline Erichsen test paint - Melamine alkyd resin baking - 150℃ x 30 minutes Film thickness - 25μ 〇No peeling, △Partial peeling, ×Significant peeling〓〓〓〓〓
【表】
〓〓〓〓〓
[Table] 〓〓〓〓〓
Claims (1)
着量が10〜60mg/m2であるクロメート被膜を形成
し、次にカルボキシル基を３〜20モル％含有する
カルボキシル化ポリエチレン系樹脂デイスパージ
ヨンの固形分100重量部に対しコロイダルシリカ
を固形分で10〜60重量部の範囲に含む組成の水性
液を、その塗布乾燥後に上記クロメート被膜との
付着量の和で0.3〜４ｇ/m2となる厚さに被成処理
することを特徴とする電気亜鉛めつき鋼板の表面
処理法。 ２ 電気亜鉛めつき鋼板の表面に、まずクロム付
着量が10〜60mg/m2であるクロメート被膜を形成
し、次にカルボキシル基を３〜20モル％含有する
カルボキシル化ポリエチレン系樹脂デイスパージ
ヨンの固形分100重量部に対しコロイダルシリカ
を固形分で10〜60重量部と水溶性クロム化合物10
重量部以下の範囲に含む組成の水性液を、その塗
布乾燥後に上記クロメート被膜との付着量の和で
0.3〜４ｇ/m2となる厚さに被成処理することを特
徴とする電気亜鉛めつき鋼板の表面処理法。[Scope of Claims] 1. First, a chromate film with a chromium adhesion amount of 10 to 60 mg/m 2 is formed on the surface of an electrogalvanized steel sheet, and then a carboxylated polyethylene film containing 3 to 20 mol% of carboxyl groups is formed. An aqueous liquid having a composition containing 10 to 60 parts by weight of colloidal silica as a solid content per 100 parts by weight of the solid content of the resin dispersion is coated and dried, and then the sum of the amount adhered to the chromate film is 0.3 to 60 parts by weight. A surface treatment method for electrogalvanized steel sheets characterized by subjecting them to a thickness of 4 g/m 2 . 2. First, a chromate film with a chromium adhesion amount of 10 to 60 mg/ m2 is formed on the surface of an electrogalvanized steel sheet, and then a carboxylated polyethylene resin dispersion containing 3 to 20 mol% of carboxyl groups is coated. 10 to 60 parts by weight of colloidal silica and 10 parts by weight of water-soluble chromium compound per 100 parts by weight of solid content.
After applying and drying an aqueous liquid with a composition that is within the range of parts by weight or less,
A method for surface treatment of electrogalvanized steel sheets, characterized in that the surface treatment is carried out to a thickness of 0.3 to 4 g/ m2 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6048782A JPS58177476A (en) | 1982-04-12 | 1982-04-12 | Surface treatment of steel plate electroplated with zinc |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6048782A JPS58177476A (en) | 1982-04-12 | 1982-04-12 | Surface treatment of steel plate electroplated with zinc |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58177476A JPS58177476A (en) | 1983-10-18 |
| JPS6136587B2 true JPS6136587B2 (en) | 1986-08-19 |
Family
ID=13143682
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6048782A Granted JPS58177476A (en) | 1982-04-12 | 1982-04-12 | Surface treatment of steel plate electroplated with zinc |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58177476A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0449898U (en) * | 1990-08-30 | 1992-04-27 |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6050179A (en) * | 1983-08-31 | 1985-03-19 | Nippon Kokan Kk <Nkk> | Manufacturing method of single-sided highly corrosion resistant coated steel plate |
| JPS6123767A (en) * | 1984-07-11 | 1986-02-01 | Nisshin Steel Co Ltd | High-corrosion resistant surface treated steel sheet |
| JPH0723541B2 (en) * | 1984-07-12 | 1995-03-15 | 日新製鋼株式会社 | Highly corrosion resistant surface treated steel sheet |
| JPS6179779A (en) * | 1984-09-26 | 1986-04-23 | Nisshin Steel Co Ltd | Surface treated steel sheet having high corrosion resistance |
| JPS6250480A (en) * | 1985-08-29 | 1987-03-05 | Kawasaki Steel Corp | Production of zn alloy plated steel sheet having excellent corrosion resistance, paintability, solvent resistance, alkali resistance and fingerprint resistance |
| JPH0627357B2 (en) * | 1986-09-11 | 1994-04-13 | 新日本製鐵株式会社 | Surface treatment method for zinc-plated steel sheet |
| JPS63283935A (en) * | 1987-05-18 | 1988-11-21 | Nippon Steel Corp | Organic composite steel sheet |
| JP2524789B2 (en) * | 1987-12-24 | 1996-08-14 | ユケン工業株式会社 | Zinc plated iron parts |
| JPH01177377A (en) * | 1987-12-30 | 1989-07-13 | Nippon Steel Corp | Chromated steel sheet |
| JPH0254779A (en) * | 1988-08-18 | 1990-02-23 | Kawasaki Steel Corp | Manufacture of organic composite-plated steel sheet excellent in press formability and adhesive strength after coating |
| FR2767079B1 (en) * | 1997-08-11 | 1999-10-29 | Lorraine Laminage | PROCESS FOR THE TREATMENT OF METAL SHEET SURFACES TO IMPROVE THEIR ABILITY TO GLUE, STAMP AND DEGREASING |
-
1982
- 1982-04-12 JP JP6048782A patent/JPS58177476A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0449898U (en) * | 1990-08-30 | 1992-04-27 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58177476A (en) | 1983-10-18 |
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