JPH0515176B2 - - Google Patents
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- Publication number
- JPH0515176B2 JPH0515176B2 JP60245840A JP24584085A JPH0515176B2 JP H0515176 B2 JPH0515176 B2 JP H0515176B2 JP 60245840 A JP60245840 A JP 60245840A JP 24584085 A JP24584085 A JP 24584085A JP H0515176 B2 JPH0515176 B2 JP H0515176B2
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- JP
- Japan
- Prior art keywords
- film
- resin
- organic
- water
- 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.)
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- 238000005260 corrosion Methods 0.000 claims description 60
- 239000011247 coating layer Substances 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 31
- 239000010410 layer Substances 0.000 claims description 19
- 150000002894 organic compounds Chemical class 0.000 claims description 19
- 239000003795 chemical substances by application Substances 0.000 claims description 16
- 229910052782 aluminium Inorganic materials 0.000 claims description 15
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 15
- 229920005989 resin Polymers 0.000 claims description 12
- 239000011347 resin Substances 0.000 claims description 12
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 claims description 11
- 229920000877 Melamine resin Polymers 0.000 claims description 9
- 239000004640 Melamine resin Substances 0.000 claims description 9
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 9
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 9
- 239000012461 cellulose resin Substances 0.000 claims description 7
- 239000004925 Acrylic resin Substances 0.000 claims description 6
- 229920000178 Acrylic resin Polymers 0.000 claims description 6
- 229920001807 Urea-formaldehyde Polymers 0.000 claims description 5
- 239000002131 composite material Substances 0.000 claims description 5
- GZVHEAJQGPRDLQ-UHFFFAOYSA-N 6-phenyl-1,3,5-triazine-2,4-diamine Chemical compound NC1=NC(N)=NC(C=2C=CC=CC=2)=N1 GZVHEAJQGPRDLQ-UHFFFAOYSA-N 0.000 claims description 4
- 229910001593 boehmite Inorganic materials 0.000 claims description 4
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 claims description 4
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 claims description 3
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 2
- 239000010407 anodic oxide Substances 0.000 claims 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 claims 1
- 238000000576 coating method Methods 0.000 description 46
- 239000011248 coating agent Substances 0.000 description 33
- 239000010408 film Substances 0.000 description 26
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- 238000006243 chemical reaction Methods 0.000 description 11
- 238000004132 cross linking Methods 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 230000000694 effects Effects 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000000465 moulding Methods 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 241001163841 Albugo ipomoeae-panduratae Species 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- 150000007974 melamines Chemical class 0.000 description 3
- 235000019353 potassium silicate Nutrition 0.000 description 3
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 238000007744 chromate conversion coating Methods 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 150000001845 chromium compounds Chemical class 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
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- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229920003270 Cymel® Polymers 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 239000004846 water-soluble epoxy resin Substances 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Landscapes
- Laminated Bodies (AREA)
Description
産業上の利用分野
この発明は被覆層を形成したアルミニウム製熱
交換器フイン材に関するものである。
なおこの出願の明細書においては、アルミニウ
ムとは工業用純アルミニウムおよびアルミニウム
合金を総称する。
従来の技術
周知のように、熱交換器フイン材としては軽量
かつ加工性、熱伝導性に優れたアルミニウムが広
く使用されている。
従来、熱交換器フイン材は、金属表面に耐食性
などの特別な性質を与えるための表面処理を行な
わずに、薄板素地をそのまま加工して使用に供し
ていた。しかしながらこのようなフイン材による
熱交換器フインは使用中に、冷却作用により空気
中の水分が表面に凝縮し水分によつてアルミニウ
ムが早期に腐蝕しいわゆる白銹（水酸化アルミニ
ウム）が発生して機器の損傷を招き寿命も短命化
するという欠点があつた。またフイン表面に凝縮
した水の層が通風抵抗となつて熱交換効率を低下
させる。このため冷却用フインの大型化が必要と
され、機器全体の大型化も避けられず、さらに水
の層が送風によつて共鳴し、騒音が発生するとい
う欠点もあつた。これらの欠点を解消するために
アルミニウム表面に白銹が発生するのを防止し
（以後、この性能を耐食性という。）、かつアルミ
ニウム表面の凝縮水分とのぬれ性を改善し、凝縮
水の層を薄く保ち熱交換効率の低下および騒音発
生を防止する被覆層をアルミニウム表面層に形成
する方法が採用されている。
この被覆層の形成をフイン成形後に行う方法
（ポストコート法）もあるが、最近では工程の簡
略化、被覆層の均一性等の観点から、フイン成形
前のアルミニウム薄板に皮膜を形成して、その後
成形する方法（以後「プレコート法」という。）
への要請が高まつている。このプレコート法の採
用においては、フイン表面に形成された被覆層は
前記の耐食性、親水性の他に連続成形性および耐
薬品性と称される特性も要求される。つまり、連
続成形性の劣つた被覆層が形成されたフイン材を
成形する際には、成形工具表面が早期に摩耗して
フイン材の成形不良や工具寿命を縮める原因とな
るとともに、被覆層への亀裂の発生等の破壊が生
じ、耐食性等の特性を悪化させる。また、フイン
成形の際には成形の容易化や成形材への疵の発生
等を防止するために潤滑油や潤滑剤が用いられて
おり、成形後これらを除去するために、トリクレ
ン等の有機溶剤により洗浄される。洗浄の際に被
覆層が洗い流されたり、変質すると前述の所望の
効果が得られないため被覆層は耐薬品性も必要と
される。
これらの要求に対し、従来から耐食性付与のた
め無機皮膜であるクロメート処理皮膜、陽極酸化
皮膜、ベーマイト皮膜、水ガラス等が使用されて
おり、また特に親水性に優れたものとしてシリカ
やアルミナなどの無機物質を有機樹脂に混合した
被覆層を形成する技術（特開昭54−142650号、特
開昭55−99976号）が知られている。連続成形性
と耐食性に優れたものとして水溶性アクリル樹脂
等の有機被覆層が挙げられる。
従来技術の問題点
しかしながら、従来のクロメート処理皮膜等の
無機皮膜は耐食性の改善には役立つものの親水性
は不十分であり、また十分な耐食性を得るために
厚膜とせざるを得ず、連続成形性にも難がある。
またシリカやアルミナなどの無機物質を有機樹脂
に混合した被覆層では親水性は優れているもの
の、連続成形性と耐食性が非常に劣つており、前
述の様にフインの腐蝕や工具の摩耗が生ずるとい
う問題点がある。さらに水溶性アクリル樹脂等の
有機被覆層は連続成形性と耐食性に優れている
が、親水性の点で劣つており、同じく前述のよう
に熱交換効率の低下や騒音の発生という問題があ
る。
したがつて、耐食性、親水性、連続成形性、耐
薬品性の全てに優れた熱交換器フイン材は従来は
全くなかつた。しかも親水性が良好であるという
ことは水を透過させ易いことにもなり、このため
腐蝕し易く耐食性が劣ることになる。また耐食性
が良好であるということは、水分を排除してはじ
き易い、つまり親水性に劣ることとなり、これら
相反する親水性と耐食性の両方に優れた被覆層を
得るのは非常に困難であつた。
そこで本発明者等は耐食性、親水性、連続成形
性、耐薬品性のいずれにおいても優れた特性を有
する熱交換器フイン材、特にプレコート法による
フイン材を得るべく鋭意研究の結果、本願発明を
するに至つたものである。
問題点を解決するための手段
すなわちこの発明の熱交換器フイン材は、アル
ミニウムの薄板の表面に耐食性皮膜が形成され、
その皮膜の上層に、水溶性セルロース樹脂もしく
はポリビニルアルコールの１種または２種からな
る親水性を有する有機化合物に有機硬化剤として
のメラミン樹脂、もしくは尿素樹脂またはベンゾ
グアナミン樹脂を前記親水性有機化合物の固形分
に対し0.1〜50wt％配合してなる被覆層が形成さ
れていることを特徴とする。
さらに耐食性皮膜としてはクロメート処理皮膜
を用いるのが望ましいがその他の有機物、無機物
は勿論のこと、有機・無機複合皮膜を用いること
も可能である。
作 用
この発明によれば、アルミニウム薄板の表面に
耐食性皮膜が形成されているとともに、その皮膜
の上層に親水性を有する有機化合物と、有機硬化
剤とからなる被覆層が形成されている。ここで最
上層における有機化合物としては、水溶性セルロ
ース樹脂もしくはポリビニルアルコールの１種ま
たは２種が選択されており、これらは多数の水酸
基（−OH）を有するため、親水性に優れてい
る。一方有機硬化剤としては、親水性有機化合物
である前述の水溶性セルロースもしくはポリビニ
ルアルコールに対して最適な硬化剤として、メラ
ミン樹脂（メチル化メラミン樹脂の誘導体を含
む）、もしくは尿素樹脂、またはベンゾグアミン
樹脂が選択されている。そしてこのような有機化
合物と有機硬化剤とで架橋反応を生じ、架橋構造
からなる被覆層が形成される。前記有機化合物は
親水性を有しているため水となじみやすいが、そ
れ故に単体では耐食性が劣つている。しかし親水
性を有する有機化合物に対して、それに最適な有
機硬化剤を並存させることにより有機硬化剤と有
機化合物の親水性基と架橋反応を起させ、所望の
親水性を害することなく、被膜層自体の耐食性、
健全性を向上させることができる。この架橋反応
による高分子化により耐薬品性も向上する。さら
に有機硬化剤の存在により塗膜性能における親水
性、成形性を損なうことはなく、さらに耐食性、
親水性が向上し、かつ塗膜量の許容範囲が広くな
る。
また下層の皮膜は耐食性皮膜としたので、上層
の被覆層と相まつて極めて耐食性に優れた熱交換
器フイン材を得ることができる。このような下層
の皮膜は１層に限られるものではなく、２層以上
形成するものであつてもよい。また耐食性皮膜が
有機皮膜からなる場合には、フイン材の連続成形
性に何らの悪影響を及ぼすことはなく、さらに硬
質の無機皮膜であつても、前述の上層被覆層の機
能により下層の皮膜を薄膜とすることができるの
で、フイン材の連続成形性を損わない。
即ち、本願発明によれば、耐食性、親水性、連
続成形性、耐薬品性に優れた熱交換器フイン材を
得ることができる。
なお下層の耐食性皮膜をクロメート処理皮膜と
すれば、皮膜本来の耐食性のみならずクロメート
処理皮膜中のクロム化合物と上層の有機化合物と
の架橋反応等の相互作用により耐食性が増し、両
層の効果の総和以上の耐食特性を得ることができ
る。しかも上述の架橋反応等により上層と下層と
の密着性が向上するという効果も得られる。さら
に耐食性皮膜であるクロメート処理皮膜形成後、
この発明による上層を形成するには同一ライン上
で連続的に作業を行うことができ、作業効率の改
善を得る効果もある。
発明の実施のための具体的説明
下層の耐食性皮膜としては有機皮膜、無機皮
膜、有機・無機複合皮膜のいずれであつてもよ
く、有機皮膜としては例えば水溶性エポキシ樹
脂、水溶性アクリル樹脂、水溶性ウレタン樹脂、
水溶性アルキド樹脂、水溶性酢酸ビニル樹脂など
およびそれらの誘導体を用いることが可能であ
る。無機皮膜としては例えば前述のクロメート処
理被覆、陽極酸化被覆、ベーマイト被覆や水ガラ
ス等を用いることが可能である。
なお、有機・無機複合皮膜としては、水溶性の
有機樹脂にクロム酸を添加した皮膜、例えば水溶
性アクリル樹脂などにクロム酸を添加して処理し
た皮膜を用いることができる。有機被覆、有機・
無機複合皮膜としては被覆量は0.3〜3.0ｇ／m2が
望ましい。また、無機被覆においては、クロメー
ト処理被覆で３mg／m2〜200mg／m2、ベーマイト
被覆、陽極酸化被覆、水ガラス、ジルコニウム処
理皮膜で0.1μｍ〜3.0μｍが望ましい。これら被覆
量の下限未満であると耐食性は不十分であり、上
限を超えると耐食性の向上は僅かにすぎないにも
かかわらず、製造コストは上昇するのみならず、
成形性を悪化させる。したがつて各被覆層の被覆
量は上述の範囲が望ましい。
また上層における有機化合物としては、親水性
を与えるに寄与する水酸基（−OH）を多数有す
る有機化合物として、特に水溶性セルロース樹脂
または／およびポリビニルアルコールを用いる。
ここで水溶性セルロース樹脂とはセルロースおよ
びそのエステルあるいはエーテル等の総称を示
し、さらにこれらの混合物も含まれる。またポリ
ビニルアルコールは、一部ケン化した高分子鎖を
有する水に可溶のポリビニルアルコールを含むも
のである。
有機硬化剤としてはメラミン樹脂、尿素樹脂、
ベンゾグアナミン樹脂を用いる。ここでメラミン
樹脂とは、メチル化メラミン樹脂の誘導体を含
む。これらの有機硬化剤は、親水性有機化合物と
して用いている水溶性セルロース樹脂もしくはポ
リビニルアルコールと架橋反応を起させ、所望の
親水性を害することなく耐食性を向上させるに寄
与する。これらの有機硬化剤の被覆層における含
有量は親水性有機化合物の固形分に対して0.1〜
50wt％の範囲内とする必要がある。含有量が0.1
％未満であると親水性は良好であるが架橋反応が
不十分であるため耐食性が劣る。一方含有量が
50wt％を越えると、架橋反応が過度に起り、耐
食性は良好ではあるが、親水性を発揮する水酸基
が過度の架橋反応により消費され、親水性を害す
る結果となる。したがつて有機硬化剤の含有量は
被覆層の親水性、耐食性ともに良好となる前記範
囲内に限定したい。ここで被覆層の形成は、耐食
性皮膜を形成した後、さらに、例えば被覆成分を
塗布した後、焼付乾燥することにより行う。被覆
層の塗膜量は0.3〜3.0ｇ／m2の範囲内にあるのが
望ましい。これは塗膜量が0.3ｇ／m2未満である
と耐食性、耐薬品性等が劣り、3.0ｇ／m2を超え
ても耐食性の向上は僅かであり、製造コストも上
昇することによる。したがつて塗膜量は上述の範
囲内とするのが好ましい。
被覆層の焼付条件は130℃〜310℃で５〜60秒焼
付を行なうのが望ましい。（130℃×５秒）未満の
焼付では焼付が不十分となり架橋反応も不完全と
なるため、所望の耐食性等が得られない。また
（310℃×60秒）を超える焼付を行うと過焼付とな
り、被覆層が変質したり脆くなり、耐食性、耐薬
品性等が劣化し、さらには被覆層の亀裂、剥離等
により所望の塗膜性能が得られない。またこのよ
うな過焼付はアルミニウム自体の軟化を招き、フ
イン成形後の製品強度を低下させるおそれがあ
る。したがつて塗膜焼付条件は上記範囲内が望ま
しい。
しかしながら、前述の塗膜量、さらに焼付条件
は、フイン材用薄板の材質、有機化合物、クロム
化合物の種類さらに熱交換器の使用環境等により
変更可能なものであり、要は使用条件において、
耐食性等の所望の効果を得られるものであればよ
い。
実施例
以下に、この発明の実施例を従来の親水性の有
機樹脂からなる被覆層を有するフイン材と対比し
て説明する。この発明の実施例は以下に述べるよ
うに実施例１〜10からなり、従来例は比較例１と
２からなる。
実施例１は表１に示すように、板厚0.12mmの工
業用純アルミニウム（JIS A1100）薄板材を脱
脂、清浄した後、クロム酸クロメート系化成浴液
（商品名ボンデライト＃713、日本パーカライジン
グ社製）に浸漬してクロメート化成皮膜（Cr量
として３mg／m2）からなる耐食性皮膜を形成した
後水洗し、乾燥させる。クロメート化成皮膜上に
水溶性セルロース樹脂（10％水溶液、三井東圧化
学株式会社製、商品名ソリダイトWH−10）の樹
脂固形分に対してメチル化メラミン樹脂（三井東
圧株式会社製、商品名サイメル350）を樹脂固型
分で、0.1％含有させたものをバーコーターで塗
布後、260℃×20秒間焼付けて0.3ｇ／m2の被覆層
を形成し、熱交換器フイン材を作成した。
実施例２〜10は表１に従い同様に熱交換器フイ
ン材を作成した。
比較例１は耐食性皮膜下層を除き、実施例１と
同様にして熱交換器フイン材を作成した。比較例
２は有機硬化剤を除き実施例８と同様にして熱交
換器フイン材を作成した。
INDUSTRIAL APPLICATION FIELD This invention relates to an aluminum heat exchanger fin material on which a coating layer is formed. In the specification of this application, aluminum collectively refers to industrial pure aluminum and aluminum alloys. BACKGROUND ART As is well known, aluminum is widely used as a heat exchanger fin material because it is lightweight and has excellent workability and thermal conductivity. Conventionally, heat exchanger fin materials have been used as thin plate base materials without surface treatment to impart special properties such as corrosion resistance to the metal surface. However, when heat exchanger fins made of such fin material are used, moisture in the air condenses on the surface due to the cooling effect, and the moisture quickly corrodes the aluminum, producing so-called white rust (aluminum hydroxide). The drawback was that it caused damage to the equipment and shortened its lifespan. In addition, a layer of water condensed on the fin surface acts as ventilation resistance and reduces heat exchange efficiency. For this reason, it was necessary to increase the size of the cooling fins, which inevitably led to an increase in the size of the entire device.Furthermore, the water layer resonated with the air flow, causing noise. In order to eliminate these drawbacks, we have prevented white rust from forming on the aluminum surface (hereinafter, this performance is referred to as corrosion resistance), and improved the wettability of the aluminum surface with condensed water, thereby reducing the layer of condensed water. A method has been adopted in which a coating layer is formed on the aluminum surface layer to keep it thin and prevent a reduction in heat exchange efficiency and noise generation. There is a method (post-coating method) in which this coating layer is formed after the fins are formed, but recently, from the viewpoint of simplifying the process and ensuring uniformity of the coating layer, a coating is formed on the aluminum thin plate before the fins are formed. A method of forming after that (hereinafter referred to as the "precoat method")
The demand for this is increasing. In employing this precoating method, the coating layer formed on the fin surface is required to have continuous moldability and chemical resistance in addition to the above-mentioned corrosion resistance and hydrophilicity. In other words, when molding a fin material on which a coating layer with poor continuous formability is formed, the surface of the forming tool wears out prematurely, causing molding defects in the fin material and shortening the tool life. Destruction such as cracking occurs, which deteriorates properties such as corrosion resistance. Furthermore, during fin molding, lubricating oil and lubricants are used to facilitate the molding and to prevent scratches from forming on the molded material, and in order to remove these after molding, organic Cleaned with solvent. If the coating layer is washed away or deteriorated during cleaning, the above-mentioned desired effect cannot be obtained, so the coating layer must also have chemical resistance. To meet these demands, inorganic coatings such as chromate-treated coatings, anodized coatings, boehmite coatings, and water glass have traditionally been used to impart corrosion resistance, and silica and alumina, which have particularly excellent hydrophilic properties, have been used. Techniques for forming a coating layer in which an inorganic substance is mixed with an organic resin are known (JP-A-54-142650, JP-A-55-99976). An organic coating layer such as a water-soluble acrylic resin can be used as a material having excellent continuous moldability and corrosion resistance. Problems with conventional technology However, although conventional inorganic coatings such as chromate-treated coatings are useful for improving corrosion resistance, their hydrophilicity is insufficient, and in order to obtain sufficient corrosion resistance, the coating must be thick, and continuous molding Sexuality is also difficult.
Furthermore, although coating layers made by mixing inorganic substances such as silica and alumina with organic resins have excellent hydrophilic properties, they have extremely poor continuous formability and corrosion resistance, resulting in corrosion of the fins and wear of tools as mentioned above. There is a problem. Further, an organic coating layer such as a water-soluble acrylic resin has excellent continuous moldability and corrosion resistance, but is inferior in terms of hydrophilicity, and as mentioned above, there are also problems such as a decrease in heat exchange efficiency and generation of noise. Therefore, there has been no heat exchanger fin material that has excellent corrosion resistance, hydrophilicity, continuous moldability, and chemical resistance. Moreover, good hydrophilicity also means that water can easily permeate through it, which leads to easy corrosion and poor corrosion resistance. In addition, good corrosion resistance means that it is easy to exclude and repel moisture, that is, it is inferior in hydrophilicity, and it has been extremely difficult to obtain a coating layer that is excellent in both hydrophilicity and corrosion resistance, which are contradictory. . Therefore, the present inventors conducted intensive research to obtain a heat exchanger fin material having excellent properties in terms of corrosion resistance, hydrophilicity, continuous formability, and chemical resistance, especially a fin material produced by a pre-coating method, and as a result, the present invention was developed. This is what I came to do. Means for Solving the Problems Namely, the heat exchanger fin material of the present invention has a corrosion-resistant film formed on the surface of a thin aluminum plate,
The upper layer of the film is coated with a hydrophilic organic compound consisting of one or two of water-soluble cellulose resin or polyvinyl alcohol, and a melamine resin, urea resin, or benzoguanamine resin as an organic hardening agent. It is characterized in that a coating layer is formed containing 0.1 to 50 wt% of the amount of Further, as the corrosion-resistant film, it is desirable to use a chromate-treated film, but it is also possible to use other organic and inorganic materials, as well as organic/inorganic composite films. Effects According to the present invention, a corrosion-resistant film is formed on the surface of an aluminum thin plate, and a coating layer made of a hydrophilic organic compound and an organic hardening agent is formed on the top of the film. Here, as the organic compound in the uppermost layer, one or two types of water-soluble cellulose resin or polyvinyl alcohol are selected, and since these have a large number of hydroxyl groups (-OH), they have excellent hydrophilicity. On the other hand, as an organic curing agent, melamine resin (including derivatives of methylated melamine resin), urea resin, or benzogamine resin is the most suitable curing agent for the above-mentioned water-soluble cellulose or polyvinyl alcohol, which are hydrophilic organic compounds. is selected. Then, a crosslinking reaction occurs between such an organic compound and an organic curing agent, and a coating layer having a crosslinked structure is formed. Since the organic compound has hydrophilicity, it is easily compatible with water, but when used alone, it has poor corrosion resistance. However, by coexisting an optimal organic curing agent with an organic compound that has hydrophilic properties, a crosslinking reaction can occur between the organic curing agent and the hydrophilic groups of the organic compound. Its own corrosion resistance,
Health can be improved. Chemical resistance is also improved by polymerization through this crosslinking reaction. Furthermore, the presence of an organic curing agent does not impair the hydrophilicity and formability of the coating film, and further improves corrosion resistance and
Hydrophilicity is improved and the allowable range of coating thickness is widened. Furthermore, since the lower layer coating is a corrosion-resistant coating, together with the upper coating layer, a heat exchanger fin material having extremely excellent corrosion resistance can be obtained. The number of such lower layers is not limited to one layer, but two or more layers may be formed. Furthermore, if the corrosion-resistant coating is made of an organic coating, it will not have any negative effect on the continuous formability of the fin material, and even if it is a hard inorganic coating, the function of the upper coating layer described above will allow the lower coating to be removed. Since it can be made into a thin film, the continuous moldability of the fin material is not impaired. That is, according to the present invention, a heat exchanger fin material having excellent corrosion resistance, hydrophilicity, continuous moldability, and chemical resistance can be obtained. If the lower corrosion-resistant film is a chromate-treated film, the corrosion resistance will increase not only due to the inherent corrosion resistance of the film, but also due to interactions such as cross-linking reactions between the chromium compounds in the chromate-treated film and the organic compounds on the upper layer, and the effects of both layers will be increased. It is possible to obtain corrosion resistance properties that are greater than the sum of the parts. Moreover, the effect of improving the adhesion between the upper layer and the lower layer is also obtained due to the above-mentioned crosslinking reaction and the like. Furthermore, after forming a chromate treatment film, which is a corrosion-resistant film,
In forming the upper layer according to the present invention, work can be performed continuously on the same line, which also has the effect of improving work efficiency. Specific explanation for carrying out the invention The lower layer corrosion-resistant coating may be an organic coating, an inorganic coating, or an organic/inorganic composite coating. Examples of the organic coating include water-soluble epoxy resin, water-soluble acrylic resin, and water-soluble acrylic resin. polyurethane resin,
It is possible to use water-soluble alkyd resins, water-soluble vinyl acetate resins, and derivatives thereof. As the inorganic coating, for example, the above-mentioned chromate coating, anodized coating, boehmite coating, water glass, etc. can be used. Note that as the organic/inorganic composite film, a film obtained by adding chromic acid to a water-soluble organic resin, for example a film obtained by adding chromic acid to a water-soluble acrylic resin, etc., can be used. organic coating, organic
As for the inorganic composite film, the coating amount is preferably 0.3 to 3.0 g/m 2 . In addition, in the case of inorganic coatings, 3 mg/m 2 to 200 mg/m 2 is desirable for chromate-treated coatings, and 0.1 μm to 3.0 μm for boehmite coatings, anodic oxidation coatings, water glass, and zirconium-treated coatings. If the amount of coating is less than the lower limit, the corrosion resistance will be insufficient, and if the amount exceeds the upper limit, although the improvement in corrosion resistance will be slight, the manufacturing cost will not only increase.
Deteriorates moldability. Therefore, the coating amount of each coating layer is preferably within the above-mentioned range. Further, as the organic compound in the upper layer, a water-soluble cellulose resin and/or polyvinyl alcohol is particularly used as an organic compound having a large number of hydroxyl groups (-OH) contributing to imparting hydrophilicity.
Here, the water-soluble cellulose resin is a general term for cellulose and its esters or ethers, and also includes mixtures thereof. Further, polyvinyl alcohol includes water-soluble polyvinyl alcohol having a partially saponified polymer chain. Organic curing agents include melamine resin, urea resin,
Uses benzoguanamine resin. Here, melamine resin includes derivatives of methylated melamine resin. These organic curing agents cause a crosslinking reaction with the water-soluble cellulose resin or polyvinyl alcohol used as the hydrophilic organic compound, and contribute to improving corrosion resistance without impairing the desired hydrophilicity. The content of these organic curing agents in the coating layer is from 0.1 to the solid content of the hydrophilic organic compound.
It must be within the range of 50wt%. Content is 0.1
If it is less than %, the hydrophilicity is good, but the crosslinking reaction is insufficient, resulting in poor corrosion resistance. On the other hand, the content
If it exceeds 50 wt%, the crosslinking reaction occurs excessively, and although corrosion resistance is good, the hydroxyl groups that exhibit hydrophilicity are consumed by the excessive crosslinking reaction, resulting in a loss of hydrophilicity. Therefore, it is desirable to limit the content of the organic curing agent within the above range that provides good hydrophilicity and corrosion resistance of the coating layer. Here, the coating layer is formed by forming the corrosion-resistant film, further applying, for example, a coating component, and then baking and drying. The coating weight of the coating layer is preferably within the range of 0.3 to 3.0 g/m 2 . This is because if the coating amount is less than 0.3 g/m 2 , corrosion resistance, chemical resistance, etc. will be poor, and if it exceeds 3.0 g/m 2 , the improvement in corrosion resistance will be slight and the manufacturing cost will also increase. Therefore, the coating amount is preferably within the above range. The baking conditions for the coating layer are preferably 130°C to 310°C for 5 to 60 seconds. If the baking temperature is less than (130°C x 5 seconds), the baking will be insufficient and the crosslinking reaction will be incomplete, so the desired corrosion resistance etc. cannot be obtained. Furthermore, if baking exceeds (310°C x 60 seconds), it will result in over-baking, which will cause the coating layer to change in quality or become brittle, deteriorate corrosion resistance, chemical resistance, etc., and even cause cracks and peeling of the coating layer, making it difficult to apply the desired coating. Membrane performance cannot be obtained. Moreover, such overbaking may cause the aluminum itself to soften, which may reduce the strength of the product after fin forming. Therefore, the coating baking conditions are preferably within the above range. However, the above-mentioned coating film amount and baking conditions can be changed depending on the material of the thin plate for the fins, the type of organic compound, chromium compound, and the usage environment of the heat exchanger.In short, depending on the usage conditions,
Any material may be used as long as the desired effect such as corrosion resistance can be obtained. Examples Examples of the present invention will be described below in comparison with a conventional fin material having a coating layer made of a hydrophilic organic resin. Examples of the present invention consist of Examples 1 to 10 as described below, and conventional examples consist of Comparative Examples 1 and 2. As shown in Table 1, in Example 1, after degreasing and cleaning a 0.12 mm thick industrial pure aluminum (JIS A1100) thin plate, a chromate-based chemical bath solution (trade name Bonderite #713, Nippon Parkerizing Co., Ltd.) was used. A corrosion-resistant coating consisting of a chromate conversion coating (Cr content: 3 mg/m 2 ) was formed by immersing the sample in a chromate conversion coating (Cr content: 3 mg/m 2 ), followed by washing with water and drying. On the chromate conversion film, methylated melamine resin (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name Cymel 350) containing 0.1% resin solid content was coated with a bar coater and baked at 260℃ for 20 seconds to form a coating layer of 0.3g/m 2 to create a heat exchanger fin material. . In Examples 2 to 10, heat exchanger fin materials were similarly prepared according to Table 1. In Comparative Example 1, a heat exchanger fin material was prepared in the same manner as in Example 1 except for the lower layer of the corrosion-resistant film. In Comparative Example 2, a heat exchanger fin material was prepared in the same manner as in Example 8 except that the organic curing agent was not used.
【表】【table】
【表】
これらの実施例１〜10および比較例の熱交換器
フイン材に対し以下の特性を評価した。
(1) 耐食性
塩水噴霧試験600時間後の白銹発生面積（％）
で評価した。表中、◎は優秀（１％以内）、○
は良好（１％以上５％以内）、×は不良（５％以
上）とした。
(2) 親水性
95％以上の相対湿度で50℃で７時間保持し、
次いで乾燥雰囲気中で常温で17時間保持するの
を１サイクルとし、10サイクル経過後の接触角
で評価した。表中、◎は優秀（水接触角20°以
内）、○は良好（水接触角は20°〜40°）、×は不
良（水接触角は40°以上）とした。
(3) 連続成形性
フインプレス後の工具（ポンチとダイス）の
摩耗状況と成形後のフイン材の成形欠陥とを内
眼観察し、摩耗もくは欠陥発生までのパンチ数
により評価した。表中、◎は優秀（200万パン
チ）、○は良好（150万パンチ）とした。
(4) 耐薬品性
トリクレンで洗浄後、全塗膜量に対する塗膜
減量（％）で評価した。◎は優秀（５％以内）、
○は良好（５％以上10％以内）、×は不良（10％
以上）とした。
各実施例および比較例の上記特性を測定した結
果を表２に示す。[Table] The following characteristics were evaluated for the heat exchanger fin materials of Examples 1 to 10 and Comparative Examples. (1) Corrosion resistance Area where white rust occurs after 600 hours of salt spray test (%)
It was evaluated by In the table, ◎ indicates excellent (within 1%), ○
was considered good (1% or more and within 5%), and × was bad (5% or more). (2) Hydrophilicity: Hold at 50℃ for 7 hours at a relative humidity of 95% or more,
Next, one cycle was holding at room temperature in a dry atmosphere for 17 hours, and the contact angle was evaluated after 10 cycles. In the table, ◎ indicates excellent (water contact angle 20° or less), ○ indicates good (water contact angle 20° to 40°), and × indicates poor (water contact angle 40° or more). (3) Continuous formability The state of wear of the tools (punch and die) after fin pressing and the forming defects of the fin material after forming were visually observed and evaluated by the number of punches until wear or defects occurred. In the table, ◎ indicates excellent (2 million punches) and ○ indicates good (1.5 million punches). (4) Chemical resistance After cleaning with Triclean, evaluation was made based on the weight loss (%) of the coating film relative to the total coating amount. ◎ is excellent (within 5%),
○ is good (5% to 10%), × is poor (10%)
above). Table 2 shows the results of measuring the above characteristics of each Example and Comparative Example.
【表】
表２から明らかなように、この発明の実施例１
〜10は耐食性、親水性、連続成形性、耐薬品性の
いずれかの点においても優れているが、比較例
１、２からなる従来例は親水性、連続成形性はす
ぐれているものの、比較例１では耐食性が劣つて
おり、比較例２では耐食性および耐薬品性が不十
分である。
発明の効果
以上説明したように、この発明によれば、アル
ミニウム薄板表面に耐食性皮膜を形成し、その皮
膜の上層に、親水性有機化合物としての水溶性セ
ルロース樹脂もしくはポリビニルアルコールに有
機硬化剤としてのメラミン樹脂、尿素樹脂もしく
はベンゾグアナミン樹脂を配合した被覆層を形成
したので、下層の耐食性皮膜および上層の被覆層
により、耐食性、親水性、連続成形性、耐薬品性
に優れた、特に耐食性に優れた熱交換器フイン材
を得ることができ、特に被覆層の有機硬化剤とし
て前記有機化合物に最適な種類のものを選択して
最適な量だけ配合しているため、親水性有機化合
物による親水性を損なうことなく、充分に優れた
耐食性を得ることが可能となつた。[Table] As is clear from Table 2, Example 1 of the present invention
-10 are excellent in corrosion resistance, hydrophilicity, continuous moldability, and chemical resistance, but conventional examples consisting of Comparative Examples 1 and 2 are excellent in hydrophilicity and continuous moldability, but Example 1 has poor corrosion resistance, and Comparative Example 2 has insufficient corrosion resistance and chemical resistance. Effects of the Invention As explained above, according to the present invention, a corrosion-resistant film is formed on the surface of an aluminum thin plate, and the upper layer of the film is coated with a water-soluble cellulose resin or polyvinyl alcohol as a hydrophilic organic compound and an organic curing agent. Since a coating layer containing melamine resin, urea resin, or benzoguanamine resin is formed, the lower corrosion-resistant film and upper coating layer provide excellent corrosion resistance, hydrophilicity, continuous moldability, and chemical resistance, especially excellent corrosion resistance. The heat exchanger fin material can be obtained, and in particular, as the organic curing agent for the coating layer, the most suitable type of organic compound is selected and the optimal amount is blended, so that the hydrophilicity due to the hydrophilic organic compound is improved. It has become possible to obtain sufficiently excellent corrosion resistance without any damage.
Claims (1)
成され、その皮膜の上層に、水溶性セルロース樹
脂もしくはポリビニルアルコールの１種または２
種からなる親水性を有する有機化合物に有機硬化
剤としてのメラミン樹脂、もしくは尿素樹脂また
はベンゾグアナミン樹脂を前記親水性有機化合物
の固形分に対し0.1〜50wt％配合してなる被覆層
が形成されていることを特徴とする熱交換器フイ
ン材。 ２ 前記耐食性皮膜は水溶性アクリル樹脂もしく
は水溶性ウレタン樹脂からなる有機皮膜としたこ
とを特徴とする特許請求の範囲第１項記載の熱交
換器フイン材。 ３ 前記耐食性皮膜は、クロメート皮膜、ベーマ
イト皮膜もしくは陽極酸化皮膜からなる無機皮膜
としたことを特徴とする特許請求の範囲第１項記
載の熱交換器フイン材。 ４ 前記耐食性皮膜は、水溶性有機樹脂にクロム
酸を添加して処理した有機・無機複合皮膜とした
ことを特徴とする特許請求の範囲第１項記載の熱
交換器フイン材。[Claims] 1. A corrosion-resistant film is formed on the surface of a thin aluminum plate, and the upper layer of the film contains one or two of water-soluble cellulose resin or polyvinyl alcohol.
A coating layer is formed by blending melamine resin, urea resin, or benzoguanamine resin as an organic hardening agent with a hydrophilic organic compound consisting of seeds in an amount of 0.1 to 50 wt% based on the solid content of the hydrophilic organic compound. A heat exchanger fin material characterized by: 2. The heat exchanger fin material according to claim 1, wherein the corrosion-resistant film is an organic film made of a water-soluble acrylic resin or a water-soluble urethane resin. 3. The heat exchanger fin material according to claim 1, wherein the corrosion-resistant film is an inorganic film consisting of a chromate film, a boehmite film, or an anodic oxide film. 4. The heat exchanger fin material according to claim 1, wherein the corrosion-resistant film is an organic/inorganic composite film obtained by adding chromic acid to a water-soluble organic resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24584085A JPS62105629A (en) | 1985-11-01 | 1985-11-01 | Heat-exchanger fin material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24584085A JPS62105629A (en) | 1985-11-01 | 1985-11-01 | Heat-exchanger fin material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62105629A JPS62105629A (en) | 1987-05-16 |
| JPH0515176B2 true JPH0515176B2 (en) | 1993-02-26 |
Family
ID=17139631
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24584085A Granted JPS62105629A (en) | 1985-11-01 | 1985-11-01 | Heat-exchanger fin material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62105629A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63303729A (en) * | 1987-06-03 | 1988-12-12 | Showa Alum Corp | Aluminum material for molding having ground film for coating |
| JP2518654B2 (en) * | 1987-07-31 | 1996-07-24 | 三菱アルミニウム株式会社 | Heat exchange medium material and manufacturing method thereof |
| JPH01155968A (en) * | 1987-12-11 | 1989-06-19 | Nisshin Steel Co Ltd | Antisweat coated metallic sheet and its production |
| US4973359A (en) * | 1989-01-04 | 1990-11-27 | Nippon Paint Co., Ltd. | Surface treatment chemical and bath for forming hydrophilic coatings and method of surface-treating aluminum members |
| JPH0381139A (en) * | 1989-08-24 | 1991-04-05 | Showa Alum Corp | Aluminum fin material for heat exchanger |
| JP2689358B2 (en) * | 1991-02-18 | 1997-12-10 | 株式会社ゼクセル | Heat exchanger |
| JP2005113228A (en) | 2003-10-09 | 2005-04-28 | Daikin Ind Ltd | Plate stock, and its production method |
| JP4912625B2 (en) * | 2005-06-14 | 2012-04-11 | 古河スカイ株式会社 | Coating composition, aluminum coated plate and pre-coated aluminum fin material |
| CN105921036A (en) * | 2016-06-23 | 2016-09-07 | 宁波艾风环境科技有限公司 | Washable heat exchange membrane, core with washable heat exchange membrane and preparation method for washable heat exchange membrane |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59196782A (en) * | 1983-04-22 | 1984-11-08 | Nippon Seihaku Kk | Manufacture of aluminum material for heat exchanger |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57154895U (en) * | 1981-03-20 | 1982-09-29 |
-
1985
- 1985-11-01 JP JP24584085A patent/JPS62105629A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59196782A (en) * | 1983-04-22 | 1984-11-08 | Nippon Seihaku Kk | Manufacture of aluminum material for heat exchanger |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62105629A (en) | 1987-05-16 |
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