JPS6233320B2 - - Google Patents
Info
- Publication number
- JPS6233320B2 JPS6233320B2 JP8379583A JP8379583A JPS6233320B2 JP S6233320 B2 JPS6233320 B2 JP S6233320B2 JP 8379583 A JP8379583 A JP 8379583A JP 8379583 A JP8379583 A JP 8379583A JP S6233320 B2 JPS6233320 B2 JP S6233320B2
- Authority
- JP
- Japan
- Prior art keywords
- acid
- anionic
- mixed
- metal
- minutes
- 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
- 238000000576 coating method Methods 0.000 claims description 37
- 238000004070 electrodeposition Methods 0.000 claims description 22
- 125000000129 anionic group Chemical group 0.000 claims description 17
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 11
- 150000003839 salts Chemical class 0.000 claims description 10
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 8
- 229920005992 thermoplastic resin Polymers 0.000 claims description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 claims description 6
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 6
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 claims description 6
- 239000002253 acid Substances 0.000 claims description 6
- 239000004094 surface-active agent Substances 0.000 claims description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 4
- 239000000243 solution Substances 0.000 claims description 4
- 239000007864 aqueous solution Substances 0.000 claims description 3
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 claims description 2
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 claims description 2
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 claims description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims description 2
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 2
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims description 2
- 150000007513 acids Chemical class 0.000 claims description 2
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 claims description 2
- 239000003945 anionic surfactant Substances 0.000 claims description 2
- 235000015165 citric acid Nutrition 0.000 claims description 2
- 235000019253 formic acid Nutrition 0.000 claims description 2
- 229910052745 lead Inorganic materials 0.000 claims description 2
- 239000011133 lead Substances 0.000 claims description 2
- 239000001630 malic acid Substances 0.000 claims description 2
- 235000011090 malic acid Nutrition 0.000 claims description 2
- 239000012046 mixed solvent Substances 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 229910017604 nitric acid Inorganic materials 0.000 claims description 2
- 239000002736 nonionic surfactant Substances 0.000 claims description 2
- 239000011975 tartaric acid Substances 0.000 claims description 2
- 235000002906 tartaric acid Nutrition 0.000 claims description 2
- 229910052718 tin Inorganic materials 0.000 claims description 2
- 239000011135 tin Substances 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims 2
- 238000013035 low temperature curing Methods 0.000 claims 1
- 239000011248 coating agent Substances 0.000 description 30
- 229910052751 metal Inorganic materials 0.000 description 17
- 239000002184 metal Substances 0.000 description 17
- 229920005989 resin Polymers 0.000 description 11
- 239000011347 resin Substances 0.000 description 11
- 239000003973 paint Substances 0.000 description 10
- 239000007788 liquid Substances 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 238000007747 plating Methods 0.000 description 7
- 229920000877 Melamine resin Polymers 0.000 description 6
- 238000001723 curing Methods 0.000 description 6
- 239000002932 luster Substances 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000004640 Melamine resin Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- -1 Alkyl sulfosuccinate Chemical compound 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 150000001450 anions Chemical class 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 2
- 238000002845 discoloration Methods 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 2
- POAOYUHQDCAZBD-UHFFFAOYSA-N 2-butoxyethanol Chemical compound CCCCOCCO POAOYUHQDCAZBD-UHFFFAOYSA-N 0.000 description 1
- RNMDNPCBIKJCQP-UHFFFAOYSA-N 5-nonyl-7-oxabicyclo[4.1.0]hepta-1,3,5-trien-2-ol Chemical compound C(CCCCCCCC)C1=C2C(=C(C=C1)O)O2 RNMDNPCBIKJCQP-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229910018100 Ni-Sn Inorganic materials 0.000 description 1
- 229910018532 Ni—Sn Inorganic materials 0.000 description 1
- 229930182556 Polyacetal Natural products 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- YCOASTWZYJGKEK-UHFFFAOYSA-N [Co].[Ni].[W] Chemical compound [Co].[Ni].[W] YCOASTWZYJGKEK-UHFFFAOYSA-N 0.000 description 1
- PDYXSJSAMVACOH-UHFFFAOYSA-N [Cu].[Zn].[Sn] Chemical compound [Cu].[Zn].[Sn] PDYXSJSAMVACOH-UHFFFAOYSA-N 0.000 description 1
- 235000011054 acetic acid Nutrition 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229940044175 cobalt sulfate Drugs 0.000 description 1
- 229910000361 cobalt sulfate Inorganic materials 0.000 description 1
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- YOCUPQPZWBBYIX-UHFFFAOYSA-N copper nickel Chemical compound [Ni].[Cu] YOCUPQPZWBBYIX-UHFFFAOYSA-N 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- LNGNZSMIUVQZOX-UHFFFAOYSA-L disodium;dioxido(sulfanylidene)-$l^{4}-sulfane Chemical compound [Na+].[Na+].[O-]S([O-])=S LNGNZSMIUVQZOX-UHFFFAOYSA-L 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000013007 heat curing Methods 0.000 description 1
- PIJPYDMVFNTHIP-UHFFFAOYSA-L lead sulfate Chemical compound [PbH4+2].[O-]S([O-])(=O)=O PIJPYDMVFNTHIP-UHFFFAOYSA-L 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- GEMHFKXPOCTAIP-UHFFFAOYSA-N n,n-dimethyl-n'-phenylcarbamimidoyl chloride Chemical compound CN(C)C(Cl)=NC1=CC=CC=C1 GEMHFKXPOCTAIP-UHFFFAOYSA-N 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 229920006324 polyoxymethylene Polymers 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000007665 sagging Methods 0.000 description 1
- HFQQZARZPUDIFP-UHFFFAOYSA-M sodium;2-dodecylbenzenesulfonate Chemical compound [Na+].CCCCCCCCCCCCC1=CC=CC=C1S([O-])(=O)=O HFQQZARZPUDIFP-UHFFFAOYSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000007592 spray painting technique Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000001384 succinic acid Substances 0.000 description 1
- 210000004243 sweat Anatomy 0.000 description 1
- 229910002058 ternary alloy Inorganic materials 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Application Of Or Painting With Fluid Materials (AREA)
Description
本発明は、金属めつきされた熱可塑性樹脂製物
品の表面にアニオン電着塗膜を低温で形成させる
方法に関する。
金属めつきされた金属製物品は、めつき金属の
光沢と素材金属の高い機械的な強度を併有すると
いう利点のために多方面に利用せられているが、
電気冷蔵庫、電気レンジ、扇風機などの民生用電
気器具や、電気計算器などの事務用機器、テレビ
受信機などの通信機器、テープレコーダー、電気
畜音機などの音響機器などにおいて、スイツチや
ハンドル、パネルなどして使用するには、冷い感
触、冷い光沢などに難点がある。
光沢の冷さを緩和するために、最近では従来の
主流であるクロムめつきに替えて、スズ−銅、ス
ズ−銅−亜鉛のような二元合金のほか、ニツケル
−コバルト−タングステン、スズ−ニツケル−銅
などの三元合金のめつきが重用せられつゝある。
そのような合金めつきと云つても、金属は金属で
あるから依然冷い光沢をもち、もつと暖味ある光
沢を有することが望まれる。なお、この種合金め
つきの他の難点は、クロムめつきに比して耐食性
が劣るということである。汗や亜鉛酸ガスによつ
て腐食されるのみならず、指紋もまた汚班状に残
り易く、それは一種の腐食である。
上述した光沢ないし外観や、腐食による損傷か
ら保護するために最近では屡々めつき面の上面
に、透明ないし半透明の塗料が塗装せられる。そ
の塗装がハケ塗りとかスプレー塗装による場合に
は、均一厚みの塗膜が得られ難く、たれやカブリ
を生じ易く、したがつて物品表面にホーニング、
ヘヤーライン、スピンなど細かな凹凸が施こされ
ている場合には、その凹凸が正確に再現され難
い。それで、正確な再現が必要とされる場合に
は、その再現の容易な電着塗膜が適用されるよう
になつて来た。
この電着塗膜とは、水溶性塗料ないし水分散性
塗料を用い、被塗物(この場合金属めつき製品)
を陽極または陰極として電解を行い、それによつ
て塗膜を形成させ、該塗膜を加熱硬化させ、こゝ
に強靭な硬化塗膜を転化させる塗装方法である。
電着塗装法が常用せられる理由として
(1) 電圧を調整するだけで、自由に析出塗膜厚さ
をコントロールすることができること。
(2) つきまわり性がすぐれているので、物品の凹
凸など細部に亘つて近一厚みの塗装が可能であ
ること。
(3) 水性塗料であるがために、火災など防災上の
顧慮が少くてすむ。
などが挙げられる。
ところが、このような利点に富む電着塗装方法
も、物品の基体材料が金属である場合には、その
適用に難点はないが、基体材料が熱可塑性樹脂
(以下単に樹脂ともいう)である場合には、適用
できないものとされて来た。その理由はあとで述
べる。
物品の基体材料として近時広く利用されている
熱可塑性樹脂(以下単に樹脂ともいう)は、物品
の凹凸形状が微細かつ複雑であつても、金属に比
して著しく成形加工が容易であり、また物品を軽
量化できる利点があり、しかも樹脂に導電性を付
与することも容易であるから、金属製物品の場合
と同様、その表面に各種金属のめつきが施こされ
ている。この場合にも、当然金属めつき製品と同
様めつき面の不必要なまでの金属光沢とか、腐食
に弱いという難点がともなう。そこでめつきされ
た金属製物品と同様、めつき表面上にアニオン系
塗料の電着塗装を施こすことによつて、上記難点
が改善できる筈であるが、前述の通り実際にはそ
れが行われていない。
その理由は周知のように熱可塑性樹脂物品は、
その変形温度が至つて低く、例えば最も汎用され
ているABS樹脂物品のそれは約90℃にすぎな
い。ところがアニオン電着塗装においては、既述
した通りそれによつて形成された塗膜を硬化させ
る工程が必要とされ、硬化ないし焼付と呼ばれる
160〜200℃で20〜30分熱処理することが必要とさ
れる。この温度ではむろん物品そのものが変形し
てしまう。これが樹脂製物品に対し、アニオン電
着塗装が行われなかつた理由である。
もしも、樹脂製物品の熱変形温度よりも低い温
度で電着塗膜の硬化が完結できる手段が見出され
たならば、金属めつきされた樹脂製物品もまた金
属製物品の場合と同じくアニオン電着塗装の利点
が享受できるだけでなく、軽量、安価、成形加工
の容易性などの樹脂特有の利点が合せ享受できる
筈である。
本発明は、このような観点から為されたもので
あつて、アニオン電着塗膜を被着させた金属めつ
き熱可塑性樹脂製品を、あとで述べるような前処
理液に浸漬して引き上げ、洗滌後75℃前後で少く
とも30分加熱することを特徴とするものである。
こゝにアニオン電着塗膜とは、むろんアニオン
電着塗装法によつて、金属めつきされた樹脂物品
に形成した塗膜であつて、上に従来法として述べ
て来た塗膜と異らない。念のため申し添えられる
が、本発明に使用されるアニオン電着材料として
は、アクリル−メラミン樹脂、エポキシ−メラミ
ン樹脂、アルキツド−メラミン樹脂などから選ば
れた水溶性ないし水分散性樹脂を主成分とし、若
干の溶剤、中和剤を含有するものが挙げられる。
電着塗装に当つては、上記塗料を電解浴中の固
形分濃度5〜30%程度に調整し、被塗物たるめつ
きされた樹脂製物品を陽極とし、カーボン板もし
くはステンレス板SUS304を対極として、10〜
200V好ましくは20〜50Vの電圧で、30秒〜3分間
通電するのである。かくて、物品のめつき面上に
は、光沢に乏しいスポンジ状の塗膜が被着され
る。
本発明にあつては、ついでこのものを前処理液
中に浸漬する。この前処理液とは、具体的には有
機溶剤5〜90%、有機ないし無機の酸5〜90%、
界面活性剤1〜15%、金属塩0.1〜1%を含む水
溶液である。
こゝに使用される有機溶剤としては、メタノー
ル、エタノール、プロピルアルコール、ブタノー
ル、メチルセルソルブ、エチルセルソルブ、アセ
トン、メチルエチルケトンの一種または二種以上
の混合溶剤が挙げられ、また、酸としては塩酸、
硫酸、硝酸、フツ酸、酢酸、ギ酸、クエン酸、酒
石酸、リンゴ酸、アレイン酸などの一種または二
種以上の混合酸が挙げられ、界面活性剤としては
アニオン型およびノニオン型界面活性剤の一種も
しくは二種以上の混合活性剤、さらに金属塩とし
ては、Sn、Pb、Zn、Co、Mg、Niを含む無機塩
もしくは有機塩の一種または二種以上の混合塩
が、それぞれ典型例として挙げられる。
このような前処理液の組成物質の種類及び組成
比率は、本発明者らの実験による試行錯誤の結
果、妥当と認められたものである。しかし、種類
について強いて云えば、金属塩は水性塗料のビヒ
クルが架橋硬化する際の触媒であり、有機溶媒は
電着塗膜を膨潤させ、該触媒を塗膜内部に浸入さ
せ易くする働きをなすものであり、界面活性剤
は、その働きを助長するものであり、酸は塗膜の
硬化を促進させる作用があるものとして、一部よ
く知られているところのものである。
このような前処理液中に、めつき物品を浸漬す
る条件は、常温とくに10〜50℃程度の温度、15秒
〜数分程度で十分である。
前処理液への浸漬が済んだら、むろんこれを引
き揚げ、清浄な水で洗滌して乾燥後、75℃前後と
くに70〜80℃で30分以上加熱し、それによつて電
着塗膜を硬化させる。乾燥は、この加熱の一部と
して行われて差支えない。通常、加熱温度70℃以
下では、十分なる塗面光沢が得られ難く、また80
℃以上では、物品の変形を起こす危険がある。加
熱時間が少くとも30分というのは、ビヒクルが架
橋硬化に必要とされる時間であつて、それより長
くても差支えはない。30分もあれば、いわゆる硬
化反応がほゞ完結し焼付けは完結する。約30分以
下では、塗面の光沢および塗膜性能は劣つたもの
となる。したがつて、作業能率との兼合で、加熱
時間は60〜120分程度が適当とされよう。
実施例 1
常法通りNiめつきしためつきグレードABS樹
脂製の電気機器用つまみ(直径30mm×高さ20mmの
有底内筒体)に、アニオン型水溶性アクリル−メ
ラミン樹脂塗料を常法通りアニオン電着塗装し
た。即ち電着条件は、ビヒクル濃度15%、30ボル
ト、1分である。
このものを下記組成の前処理液中に浸漬した。
ブタノール ………30%
クエン酸 ………20%
アルキルスルフオサクシネート ………1%
硫酸コバルト ………0.3%
25℃で1分間浸漬後、引き上げ水洗後80℃で60
分加熱の硬化処理を行つた。
得られた塗膜の物性第1表所載の通りである。
実施例 2
実施例1と同じつまみではあるが、めつき金属
がNi−Snである物品を用いた。使用した電着塗
料は、アニオン型水溶性エポキシ−メラミン樹脂
塗料である。このものを常法通り、ビヒクル濃度
20%、電解電圧50Vで2分間電着塗装し、つい
で、下記組成の前処理液中に浸漬した。
ブチルセルソルブ ………10%
さく酸 ………50%
ポリオキシエチレンノニルフエノールエーテル
………3%
ナフテン酸コバルト ………0.2%
浸漬条件は25℃、2分間である。
浸漬後引上げて洗滌し、80℃で50分間加熱硬化
処理を施こした。得られた塗膜の物性は第1表所
載の通りである。
実施例 3
使用物品は、実施例1と同じ大きさのつまみで
あるが、基体樹脂は、ポリアセタールで、めつき
金属はSn−Cu合金である。
このものに、アニオン型水分散型アクリル−メ
ラミン樹脂塗料を、常法通り、アニオン電着塗装
した。電着条件は、ビヒクル濃度15%とし、電解
電圧20V、通電時間2分間である。
ついで、このものを下記組成の前処理液中に、
25℃で1分間浸漬した。
エタノール ………60%
硫 酸 ………10%
ラウリルベンゼンスルホン酸ナトリウム
………3%
さく酸鉛 0.1%
液中から引上げたのち、70℃で120分間加熱硬
化処理を施こした。得られた塗膜性状は、第1表
所載の通りである。
なお第1表中には、比較例1〜3を併せ記載し
ておいたが、それは実施例1〜3における前処理
液への浸漬操作を行わなかつたものであつて、そ
の他の電着ないし、加熱硬化は、実施例1〜3記
載のものと同じである。
また塗膜性能試験は下記の通りである。
エタノールふきとり:局方エタノールを含浸させ
たガーゼにより、手で塗面を拭い、塗面のハク
リに至る回数を調べる。20回以上は合格であ
る。
塩水噴霧試験:JIS−H8617の規定にしたがう。
指紋による汚れ試験:指を塗面に押しつけること
によつて、指紋を印加しておき、60日経過後の
変色度合を観察する。
亜硫酸ガス試験:被検物品を、1%チオ亜硫酸ソ
ーダ320mlと、0.1N硫酸80mlの混合水溶液10
を入れたデシケータ中に入れ、室温で20時間放
置後その変色状態を観察する。
The present invention relates to a method for forming an anionic electrodeposition coating film on the surface of a metal-plated thermoplastic resin article at a low temperature. Metal-plated metal articles are used in a wide variety of fields due to their advantages of having both the luster of plated metals and the high mechanical strength of raw metals.
Switches, handles, When used as a panel, it has problems such as a cold feel and a cold shine. In order to reduce the coldness of the luster, recently, instead of the conventional mainstream chrome plating, binary alloys such as tin-copper, tin-copper-zinc, nickel-cobalt-tungsten, and tin-copper are being used. Plating of ternary alloys such as nickel-copper is increasingly being used.
Even with such alloy plating, since the metal is metal, it is desirable that it still have a cool luster, and preferably a warm luster. Another drawback of this type of alloy plating is that it has poorer corrosion resistance than chrome plating. Not only is it corroded by sweat and zinc acid gas, but fingerprints also tend to remain as stains, which is a kind of corrosion. Recently, transparent or translucent paint is often applied to the upper surface of the mating surface in order to improve the gloss or appearance mentioned above and to protect it from damage due to corrosion. If the painting is done by brushing or spray painting, it is difficult to obtain a coating film with a uniform thickness, and sagging and fogging are likely to occur.
When fine irregularities such as hair lines and spin are applied, it is difficult to accurately reproduce the irregularities. Therefore, when accurate reproduction is required, electrodeposited coatings that are easy to reproduce have come to be used. This electrodeposition coating film uses water-soluble or water-dispersible paint to coat the object (in this case, a metal-plated product).
This is a coating method in which electrolysis is carried out using a molten metal as an anode or a cathode, thereby forming a coating film, and then heating and curing the coating film to convert it into a tough cured coating film.
The reasons why the electrodeposition coating method is commonly used are: (1) The thickness of the deposited coating can be freely controlled simply by adjusting the voltage. (2) Since it has excellent throwing power, it is possible to apply thick coatings to fine details such as irregularities on objects. (3) Since it is a water-based paint, there are fewer considerations for disaster prevention such as fire. Examples include. However, although there is no difficulty in applying the electrodeposition coating method, which has such advantages, when the base material of the article is metal, it cannot be applied when the base material is thermoplastic resin (hereinafter also simply referred to as resin). has been considered inapplicable. The reason for this will be explained later. Thermoplastic resins (hereinafter simply referred to as resins), which have recently been widely used as base materials for articles, are significantly easier to mold than metals, even if the uneven shapes of the articles are minute and complex. In addition, it has the advantage of reducing the weight of the article, and it is also easy to impart conductivity to the resin, so the surface of the article is plated with various metals, just as in the case of metal articles. In this case, as with metal-plated products, there are of course disadvantages such as unnecessary metallic luster on the plated surface and susceptibility to corrosion. As with plated metal articles, the above-mentioned difficulties should be remedied by electrocoating an anionic paint on the plated surface, but as mentioned above, this is not actually possible. Not known. The reason for this is that thermoplastic resin articles are
Its deformation temperature is extremely low; for example, the most commonly used ABS resin product has a deformation temperature of only about 90°C. However, as mentioned above, anionic electrodeposition coating requires a process of curing the resulting coating film, which is called curing or baking.
Heat treatment at 160-200°C for 20-30 minutes is required. Of course, at this temperature, the article itself becomes deformed. This is the reason why anionic electrodeposition coating has not been applied to resin articles. If a means is found that allows the curing of the electrodeposited coating to be completed at a temperature lower than the heat distortion temperature of the resin article, then the metal-plated resin article will also be treated with anionic materials in the same way as the metal article. In addition to enjoying the advantages of electrodeposition coating, it should also be possible to enjoy the advantages unique to resins, such as light weight, low cost, and ease of molding. The present invention has been made from this point of view, and involves immersing a metal-plated thermoplastic resin product coated with an anionic electrodeposition coating in a pretreatment liquid as described later, and pulling it up. It is characterized by heating at around 75°C for at least 30 minutes after washing. An anionic electrodeposition coating film is, of course, a coating film formed on a metal-plated resin article by an anionic electrodeposition coating method, and is different from the coating film described above as a conventional method. No. As a reminder, the anionic electrodeposition material used in the present invention mainly consists of a water-soluble or water-dispersible resin selected from acrylic-melamine resins, epoxy-melamine resins, alkyd-melamine resins, etc. Examples include those containing some solvent and neutralizing agent. For electrodeposition coating, the solid content concentration of the above paint is adjusted to about 5 to 30% in the electrolytic bath, and the coated object is made of a glazed resin article as an anode and a carbon plate or stainless steel plate SUS304 is used as a counter electrode. As, 10~
Electricity is applied at a voltage of 200V, preferably 20 to 50V, for 30 seconds to 3 minutes. Thus, a spongy coating film with poor gloss is deposited on the plated surface of the article. In the present invention, this material is then immersed in a pretreatment liquid. Specifically, this pretreatment liquid includes 5 to 90% organic solvent, 5 to 90% organic or inorganic acid,
It is an aqueous solution containing 1-15% surfactant and 0.1-1% metal salt. Examples of organic solvents used here include one or a mixed solvent of two or more of methanol, ethanol, propyl alcohol, butanol, methyl cellosolve, ethyl cellosolve, acetone, and methyl ethyl ketone. ,
Examples of surfactants include one or more mixed acids such as sulfuric acid, nitric acid, hydrofluoric acid, acetic acid, formic acid, citric acid, tartaric acid, malic acid, and areic acid. Examples of surfactants include anionic and nonionic surfactants. Or a mixed activator of two or more types, furthermore, typical examples of metal salts include one or a mixed salt of two or more of inorganic salts or organic salts containing Sn, Pb, Zn, Co, Mg, and Ni. . The types and composition ratios of the constituent substances of the pretreatment liquid were found to be appropriate as a result of trial and error experiments conducted by the present inventors. However, in terms of types, metal salts are catalysts when the vehicle of water-based paint is crosslinked and cured, and organic solvents serve to swell the electrodeposition coating and make it easier for the catalyst to penetrate inside the coating. The surfactant is a substance that promotes its function, and the acid is a substance that is partly well known as having the effect of accelerating the hardening of the coating film. The conditions for immersing the plated article in such a pretreatment liquid are sufficient at room temperature, particularly at a temperature of about 10 to 50°C, for about 15 seconds to several minutes. After being immersed in the pre-treatment liquid, it is of course taken out, washed with clean water, dried, and then heated at around 75℃, especially 70 to 80℃ for 30 minutes or more, thereby curing the electrodeposited coating. . Drying can be performed as part of this heating. Normally, if the heating temperature is below 70℃, it is difficult to obtain sufficient gloss on the coating surface, and
At temperatures above ℃, there is a risk of deformation of the product. The heating time of at least 30 minutes is the time required for the vehicle to crosslink and cure; longer times are acceptable. Within 30 minutes, the so-called hardening reaction is almost complete and baking is complete. If the time is less than about 30 minutes, the gloss of the painted surface and the film performance will be poor. Therefore, in consideration of work efficiency, the appropriate heating time is about 60 to 120 minutes. Example 1 Anionic water-soluble acrylic-melamine resin paint was applied to a knob for electrical equipment made of nickel-plated ABS resin (diameter 30 mm x height 20 mm bottomed inner cylinder) as usual. Anion electrodeposition coating. That is, the electrodeposition conditions were a vehicle concentration of 15%, 30 volts, and 1 minute. This product was immersed in a pretreatment liquid having the following composition. Butanol: 30% Citric acid: 20% Alkyl sulfosuccinate: 1% Cobalt sulfate: 0.3% Immersed at 25℃ for 1 minute, then pulled out and washed with water, then heated to 80℃ for 60 minutes
A hardening process was performed by heating for 30 minutes. The physical properties of the resulting coating film are as listed in Table 1. Example 2 An article was used that had the same knob as in Example 1, but the plating metal was Ni-Sn. The electrodeposition paint used was an anionic water-soluble epoxy-melamine resin paint. This product was prepared in the usual manner, with vehicle concentration
20% and an electrolytic voltage of 50 V for 2 minutes, and then immersed in a pretreatment solution having the following composition. Butyl cellosolve......10% Succinic acid...50% Polyoxyethylene nonyl phenol ether
...3% Cobalt naphthenate ...0.2% Immersion conditions were 25°C for 2 minutes. After dipping, it was pulled out, washed, and heat-cured at 80°C for 50 minutes. The physical properties of the resulting coating film are as listed in Table 1. Example 3 The article used was a knob of the same size as in Example 1, but the base resin was polyacetal and the plating metal was Sn--Cu alloy. This material was coated with an anionic water-dispersible acrylic-melamine resin paint by anionic electrodeposition in a conventional manner. The electrodeposition conditions were a vehicle concentration of 15%, an electrolytic voltage of 20 V, and a current application time of 2 minutes. Next, add this material to a pretreatment solution with the following composition.
It was immersed for 1 minute at 25°C. Ethanol: 60% Sulfuric acid: 10% Sodium laurylbenzenesulfonate
...3% Lead sulfate 0.1% After being pulled out of the solution, it was heat-hardened at 70°C for 120 minutes. The properties of the obtained coating film are as listed in Table 1. Note that Comparative Examples 1 to 3 are also listed in Table 1, but these are those in which the immersion operation in the pretreatment liquid as in Examples 1 to 3 was not performed, and other electrodeposition or , heat curing was the same as that described in Examples 1 to 3. Moreover, the coating film performance test is as follows. Ethanol wiping: Wipe the painted surface by hand with gauze impregnated with pharmacopoeial ethanol and check the number of times the painted surface peels off. 20 times or more is considered a pass. Salt spray test: According to the regulations of JIS-H8617. Fingerprint stain test: Apply a fingerprint by pressing your finger against the painted surface, and observe the degree of discoloration after 60 days. Sulfur dioxide gas test: The test item was mixed with a mixed aqueous solution of 320ml of 1% sodium thiosulfite and 80ml of 0.1N sulfuric acid.
Place it in a desiccator containing 200ml and leave it at room temperature for 20 hours, then observe the state of discoloration.
【表】【table】
【表】
本発明は、上述の通り構成されるから、従来硬
化処理による熱変形のために不可能視されて来た
熱可塑性樹脂を基体としためつき物品に対しても
亦アニオン電着塗装が可能化されたのであつて、
該塗膜の利点が、そのまゝ享受できるようになつ
たのである。[Table] Since the present invention is constructed as described above, it is possible to apply anion electrodeposition coating even to tight articles made of thermoplastic resin, which has conventionally been considered impossible due to thermal deformation caused by curing treatment. Because it has been made possible,
The advantages of the coating can now be enjoyed as is.
Claims (1)
可塑性樹脂製物品を、メタノール、エタノール、
プロピルアルコール、ブタノール、メチルセルソ
ルブ、エチルセルソルブ、アセトン、メチルエチ
ルケトンの一種または二種以上の混合溶剤を5〜
90%、塩酸、硫酸、硝酸、フツ酸、酢酸、ギ酸、
クエン酸、酒石酸、リンゴ酸、アレイン酸の一種
または二種以上の混合酸を5〜90%、アニオン型
およびノニオン型界面活性剤の一種もしくは二種
以上の混合活性剤を1〜15%、Sn、Pb、Zn、
Co、Mg、Niを含む無機塩もしくは有機塩の一種
または二種以上の混合塩を0.1〜1%含む水溶液
からなる前処理液に浸漬して引上げ、洗浄後70〜
80℃で少なくとも30分加熱することを特徴とする
アニオン電着塗膜の低温硬化方法。1. A metal-plated thermoplastic resin article coated with an anionic electrodeposited film is heated with methanol, ethanol,
One or more mixed solvents of propyl alcohol, butanol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone
90%, hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, acetic acid, formic acid,
5-90% of one or more mixed acids of citric acid, tartaric acid, malic acid, and areic acid, 1-15% of one or more mixed surfactants of anionic and nonionic surfactants, Sn , Pb, Zn,
It is immersed in a pretreatment solution consisting of an aqueous solution containing 0.1 to 1% of one or more mixed salts of inorganic salts or organic salts containing Co, Mg, and Ni, and then pulled up after being washed for 70~
A low-temperature curing method for anionic electrodeposition coatings, characterized by heating at 80°C for at least 30 minutes.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8379583A JPS59208096A (en) | 1983-05-12 | 1983-05-12 | Low temperature curing method of anion electrodeposition coating film |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8379583A JPS59208096A (en) | 1983-05-12 | 1983-05-12 | Low temperature curing method of anion electrodeposition coating film |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS59208096A JPS59208096A (en) | 1984-11-26 |
JPS6233320B2 true JPS6233320B2 (en) | 1987-07-20 |
Family
ID=13812580
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP8379583A Granted JPS59208096A (en) | 1983-05-12 | 1983-05-12 | Low temperature curing method of anion electrodeposition coating film |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS59208096A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2587934B2 (en) * | 1987-04-15 | 1997-03-05 | 神東塗料株式会社 | Electrodeposition method |
-
1983
- 1983-05-12 JP JP8379583A patent/JPS59208096A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS59208096A (en) | 1984-11-26 |
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