JP2001107204A - Copper tube excellent in discoloring resistance - Google Patents
Copper tube excellent in discoloring resistanceInfo
- Publication number
- JP2001107204A JP2001107204A JP28537199A JP28537199A JP2001107204A JP 2001107204 A JP2001107204 A JP 2001107204A JP 28537199 A JP28537199 A JP 28537199A JP 28537199 A JP28537199 A JP 28537199A JP 2001107204 A JP2001107204 A JP 2001107204A
- Authority
- JP
- Japan
- Prior art keywords
- copper tube
- discoloration
- copper
- annealing
- release agent
- 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.)
- Pending
Links
Landscapes
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、焼鈍後の耐変色性
に優れた銅管に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper tube having excellent resistance to discoloration after annealing.
【0002】[0002]
【従来の技術】伸銅製品の内、銅管は、周知の通り、ク
ーラー、エアコン、ファンコイルユニット、エアハンド
リングユニット用等の伝熱管、および冷媒配管などの冷
凍空調用配管として、汎用されている。2. Description of the Related Art As is well known, copper pipes are widely used as heat transfer pipes for coolers, air conditioners, fan coil units, air handling units and the like, and refrigeration air conditioning pipes such as refrigerant pipes. I have.
【0003】銅管の材料である銅乃至銅合金の表面は、
通常、極薄い酸化皮膜で被覆されている。この酸化皮膜
の保護性は高く、銅自体も貴な金属である。このため、
銅管は、比較的腐食や腐食に伴う変色がしにくい材料で
あり、これが前記用途に汎用されている理由でもある。[0003] The surface of copper or copper alloy, which is the material of the copper tube,
Usually, it is covered with an extremely thin oxide film. This oxide film has high protection, and copper itself is a noble metal. For this reason,
Copper pipe is a material that is relatively resistant to corrosion and discoloration due to corrosion, which is also the reason that it is widely used for the above-mentioned applications.
【0004】しかし、銅管の製造工程や輸送あるいは保
管、更には使用の状況によっては、温度、湿度、腐食物
質などの影響で酸化 (腐食) が進行して、銅管表面の変
色に至ることがある。[0004] However, depending on the manufacturing process, transportation or storage of the copper tube, and the conditions of use, oxidation (corrosion) proceeds under the influence of temperature, humidity, corrosive substances, etc., and the surface of the copper tube may be discolored. There is.
【0005】ここで、銅管コイル製品の一般的な製造工
程について説明する。銅管は、通常、銅および銅合金鋳
塊 (ビレット) を熱間押出等により素管化し、更に、こ
の素管を抽伸或いはレデューサー等の冷間加工によっ
て、所定の径や長さ或いは形状の銅管 (直管状等) 或い
は整列巻きした銅管コイル (LWC;Level wound coil) と
した後、光輝焼鈍処理を行って銅管製品とされる。この
内、光輝焼鈍処理は、H2、CO等の還元物質を含む還元性
のDXガスにより、銅管製品の要求特性に応じて所定の温
度と時間で行われる。Here, a general manufacturing process of a copper tube coil product will be described. Copper pipes are usually made from copper and copper alloy ingots (billets) by hot extrusion or the like, and the pipes are drawn to a predetermined diameter, length or shape by cold working such as drawing or a reducer. After being made into a copper tube (straight tube etc.) or a copper tube coil (LWC: Level wound coil) wound in a line, bright annealing treatment is performed to obtain a copper tube product. Among them, the bright annealing treatment is performed at a predetermined temperature and a predetermined time according to the required characteristics of the copper tube product by using a reducing DX gas containing a reducing substance such as H 2 and CO.
【0006】このような工程で製造される銅管製品の
内、特に銅管コイルは、前記冷凍空調用配管への加工の
過程で、コイルから巻き戻され、切断、ろう付け等が加
えられて配管とされる。[0006] Of the copper tube products manufactured in such a process, the copper tube coil, in particular, is unwound from the coil and cut, brazed, etc. in the process of processing into the aforementioned refrigeration / air-conditioning pipe. Piping.
【0007】なお、前記光輝焼鈍の際に、タイト (密)
に巻かれた銅管コイルの銅管同士の高温での接合 (くっ
つき) が生じる場合がある。この光輝焼鈍の際の銅管同
士の接合を防止するために、離型剤としてシリコン油
が、光輝焼鈍前の銅管のコイル化 (抽伸後) 時に塗布さ
れる場合がある。シリコン油を、前記冷間加工後に銅管
がコイル化される際に塗布するのは、コイル化された銅
管に塗布するよりも、工程上著しく効率的であることに
よる。[0007] During the bright annealing, tight (dense)
At high temperatures, the copper tubes of the copper tube coil wound around the tube may stick together. In order to prevent the joining of the copper tubes during the bright annealing, silicone oil is sometimes applied as a release agent when the copper tubes are coiled (after drawing) before the bright annealing. The application of silicone oil when the copper tube is coiled after the cold working is significantly more efficient in process than the application to the coiled copper tube.
【0008】以上の銅管製造工程を前提として、本発明
が問題とする銅管に生じる変色とは、銅管の変色として
代表的かつ特徴的な、光輝焼鈍処理後の銅管コイルの内
部 (あんこ部) の銅管外表面に、長手方向に長く帯状に
生じる酸化変色である。この変色は、通常、あんこ変色
とも称され、気温や湿度の変化に伴う結露が酸化を促進
すると言われている。このあんこ変色 (以下、単に変色
と言う) は、外観上の銅管の商品価値を損なうともに、
用途によっては、加工時の摩擦抵抗が増大する等の銅管
の性能を阻害することにもつながる。On the premise of the above-described copper tube manufacturing process, the discoloration that occurs in the copper tube, which is a problem of the present invention, is a typical and characteristic discoloration of the copper tube inside the copper tube coil after the bright annealing treatment. This is oxidative discoloration that occurs on the outer surface of the copper tube (anko portion) in a long band in the longitudinal direction. This discoloration is usually called anko discoloration, and it is said that dew condensation accompanying changes in temperature and humidity promotes oxidation. This discoloration of the bean paste (hereinafter simply referred to as discoloration) impairs the commercial value of the copper tube in appearance,
Depending on the application, it also leads to impairing the performance of the copper tube such as an increase in frictional resistance during processing.
【0009】この銅管の変色を防止するために、従来か
ら種々の技術が提案されている。その典型的なものは、
銅管の表面処理である。代表的な表面処理としては、ベ
ンゾトリアゾール(BTA) 系の変色防止剤を塗布すること
であり、他のヘキシレングリコールやアミン化合物等と
混合して、水溶液として使用されている。そして、これ
らの変色防止剤は、光輝焼鈍前の銅管のコイル化 (抽
伸) 時に、或いは光輝焼鈍後のコイルに対し、塗布され
て使用される。Various techniques have been conventionally proposed to prevent the discoloration of the copper tube. The typical one is
This is the surface treatment of copper tubes. A typical surface treatment is to apply a benzotriazole (BTA) -based discoloration inhibitor, which is used as an aqueous solution by mixing with another hexylene glycol or an amine compound. These discoloration inhibitors are applied to the copper tube before the bright annealing at the time of coiling (drawing) or to the coil after the bright annealing.
【0010】更に、前記離型剤として汎用されているシ
リコン油に、化合物や軽油等を混合して、防錆油として
の機能を有するように改質し、前記光輝焼鈍前後に銅管
に塗布し、変色を防止する技術が、特公平8-954 号公報
等で提案されている。[0010] Further, a compound or light oil is mixed with silicone oil, which is widely used as the release agent, to modify it so as to have a function as a rust preventive oil, and applied to a copper tube before and after the bright annealing. A technique for preventing discoloration has been proposed in Japanese Patent Publication No. 8-954 and the like.
【0011】また、銅管の表面側を改質する技術も種々
提案されている。例えば、特開平6-49620 号公報等に
は、銅管の表面の酸化皮膜を、より酸化しにくいもの
(例えば酸化第ニ銅等) に改質することが開示されてい
る。Various techniques for modifying the surface side of a copper tube have also been proposed. For example, Japanese Unexamined Patent Publication No. Hei 6-49620 discloses that an oxide film on the surface of a copper tube is harder to oxidize.
(For example, cupric oxide) is disclosed.
【0012】そして、特開平1- 287258 号公報では、銅
管の変色の内、銅管の表面に残留した抽伸用潤滑油が焼
鈍の際に炭化し、この炭化した潤滑油による変色を防止
するために、潤滑油を除去した後で、焼鈍することが開
示されている。In Japanese Patent Application Laid-Open No. Hei 1-287258, among the discoloration of the copper tube, the drawing lubricating oil remaining on the surface of the copper tube is carbonized during annealing, and the discoloration due to the carbonized lubricating oil is prevented. Therefore, it is disclosed that annealing is performed after removing the lubricating oil.
【0013】[0013]
【発明が解決しようとする課題】しかし、まず、銅管の
表面処理について、BTA 系などの変色防止コーティング
剤は、銅管の酸化による変色防止に有効であることは広
く知られている。しかし、これらのコーティング剤は、
基本的には、光輝焼鈍後の銅管に塗布して、製品銅管の
変色を防止しようとする性質のものである。このため、
元々耐熱性がなく、光輝焼鈍前の銅管に塗布した場合、
例えば、銅管の実体温度が550 ℃以上の高温の光輝焼鈍
中に分解乃至変質してしまう。この結果、却って、銅管
の変色に対して有害な残渣を、銅管表面に残留させ、変
色を生じる乃至助長する可能性がある。また、光輝焼鈍
の際の、銅管コイルの銅管同士の高温での接合 (くっつ
き)も抑制することができない。However, first, regarding the surface treatment of copper tubes, it is widely known that a BTA-based or other discoloration preventing coating agent is effective in preventing discoloration of copper tubes due to oxidation. However, these coating agents
Basically, it has a property of being applied to a copper tube after bright annealing to prevent discoloration of a product copper tube. For this reason,
Originally without heat resistance, when applied to copper tube before bright annealing,
For example, the copper tube is decomposed or deteriorated during bright annealing at a high temperature of 550 ° C. or higher. As a result, a residue harmful to the discoloration of the copper tube may be left on the surface of the copper tube to cause or promote discoloration. In addition, the joining (sticking) of the copper tubes of the copper tube coil at a high temperature during bright annealing cannot be suppressed.
【0014】更に、これらBTA 系などの変色防止コーテ
ィング剤は、前記冷凍空調用配管への加工工程や配管品
質に対して悪影響を与える可能性がある。この悪影響と
は、例えば、銅管のろう付けの際のぬれ性の低下などで
ある。また、これらBTA 系などの変色防止コーティング
剤を焼鈍後の銅管に塗布した場合でも、特に銅管コイル
の場合には、きつく巻締められているために、変色の生
じやすいあんこ部に塗布するのは困難である。Further, these BTA-based and other discoloration-preventing coating agents may have an adverse effect on the processing steps for the refrigeration / air-conditioning piping and on the quality of the piping. This adverse effect is, for example, a decrease in wettability when brazing a copper tube. Even when these BTA-based or other anti-tarnish coating agents are applied to annealed copper tubes, especially in the case of copper tube coils, they are applied to the bean that is subject to discoloration because they are tightly wound. It is difficult.
【0015】つぎに、離型剤として光輝焼鈍前の銅管に
塗布される前記シリコン油も、後述する通り、光輝焼鈍
の条件によっては、光輝焼鈍中に変質し、却って、銅管
コイルの変色を助長する結果となる。そして、この点
は、シリコン油に化合物や軽油等を混合して防錆油に改
質した場合でも同様である。Next, as described later, the silicone oil applied to the copper tube before the bright annealing as a mold release agent is also transformed during the bright annealing depending on the conditions of the bright annealing, and on the contrary, the discoloration of the copper tube coil is changed. The result is to promote. The same applies to the case where a compound, light oil, or the like is mixed with silicone oil to modify the rust-preventive oil.
【0016】また、前記特開平1- 287258 号公報のよう
な、抽伸用潤滑油を、焼鈍する前に、予め除去する方法
では、潤滑油の炭化に起因する変色自体は防止できる。
しかし、抽伸後に、潤滑油を除去した上で離型剤として
のシリコン油を塗布 (被覆)した銅管にも、また、潤滑
油を除去した上で離型剤を塗布しない銅管にも、依然、
本発明で問題とする前記変色は生じている。したがっ
て、抽伸用潤滑油を除去することのみでは、本発明で問
題とする銅管コイルの酸化変色に対する解決策とはなら
ない。In the method of removing the lubricating oil for drawing in advance before annealing as disclosed in JP-A-1-287258, the discoloration itself due to the carbonization of the lubricating oil can be prevented.
However, after the drawing, the lubricating oil was removed and then applied to (coated with) silicone oil as a mold release agent, and also to the copper tube from which the lubricating oil was removed and the mold release agent was not applied. still,
The discoloration in question in the present invention has occurred. Therefore, the mere removal of the drawing lubricating oil does not provide a solution to the oxidative discoloration of the copper tube coil, which is a problem of the present invention.
【0017】更に、銅管の表面側を改質する技術や銅管
の雰囲気側を改善する技術も、実施に際して、設備投資
等の必要コストに比して、本発明で問題とする銅管コイ
ルの変色の改善効果が著しく小さいという問題がある。Furthermore, the technology for modifying the surface side of the copper tube and the technology for improving the atmosphere side of the copper tube also require a copper tube coil which is a problem in the present invention when compared with the required cost such as capital investment. There is a problem that the effect of improving discoloration is extremely small.
【0018】本発明はこの様な事情に着目してなされた
ものであって、その目的は、銅管コイルの変色を根本的
に抑制しうる、耐変色性に優れた銅管を提供しようとす
るものである。The present invention has been made in view of such circumstances, and an object thereof is to provide a copper tube excellent in discoloration resistance, which can fundamentally suppress discoloration of a copper tube coil. Is what you do.
【0019】[0019]
【課題を解決するための手段】この目的を達成するため
に、本発明の耐変色性に優れた銅管の要旨は、光輝焼鈍
など550 ℃以上の高温の焼鈍処理などによって、焼鈍後
の結晶粒径が0.030mm以上であるリン脱酸銅管または無
酸素銅管において、前記焼鈍後の銅管外表面の酸化電流
値が6.0 μA 以下とすることである (請求項1)。In order to achieve this object, the gist of the copper tube excellent in discoloration resistance of the present invention is that the crystal tube after annealing is subjected to a high-temperature annealing treatment at 550 ° C. or more such as bright annealing. In a phosphorus deoxidized copper tube or an oxygen-free copper tube having a particle size of 0.030 mm or more, the oxidation current value on the outer surface of the copper tube after the annealing is 6.0 μA or less (claim 1).
【0020】また、好ましい態様として、この高温の焼
鈍の際の銅管同士の接合を防止するために、焼鈍前に、
離型剤を塗布された銅管とすることである (請求項2)。In a preferred embodiment, in order to prevent the joining of the copper tubes during the high-temperature annealing, before the annealing,
That is, a copper tube coated with a release agent is provided (claim 2).
【0021】更に、好ましい態様として、酸化による変
色が特に生じやすい、銅管がコイル状に巻回されている
銅管コイルを対象とする (請求項3)。Further, as a preferred embodiment, the present invention is directed to a copper tube coil in which a copper tube is wound in a coil shape, in which discoloration due to oxidation is particularly likely to occur (claim 3).
【0022】本発明者らは、銅管コイルの変色の原因に
ついて研究した結果、光輝焼鈍の条件と、前記離型剤と
して汎用されているシリコン油や、銅管表面に付着して
いる外面加工油等の残渣が、変色の発生に深く関わって
いることを知見した。The present inventors have studied the causes of the discoloration of the copper tube coil. As a result, the conditions of bright annealing, silicon oil commonly used as the release agent, and the external surface treatment adhering to the surface of the copper tube have been studied. It was found that residues such as oil were deeply involved in the generation of discoloration.
【0023】銅管乃至銅管コイルは、前記した通り、銅
合金組成や要求特性等に応じて、光輝焼鈍の温度、時間
等の条件が選択される。この内、近年では、銅管のより
厳しくなる加工性等を改善するために、ソフトアニール
と称され、JIS のO 材 (完全焼きなまし) やOL材 (焼き
なまし) の温度(500〜550 ℃) よりも、550 ℃以上で65
0 ℃までの (銅管の実体温度) 、より高温の光輝焼鈍が
汎用される。そして、この高温の光輝焼鈍では、前記O
材やOL材の銅管の結晶粒度が0.030mm 以下、0.030 〜0.
040mm であるのに対し、銅管の結晶粒度は0.040mm 以上
となる。As described above, for the copper tube or copper tube coil, conditions such as the temperature and time of bright annealing are selected in accordance with the composition of the copper alloy and the required characteristics. Of these, in recent years, in order to improve the workability, etc., which becomes more severe for copper tubes, it is called soft annealing, and it is based on the temperature of JIS O material (complete annealing) and OL material (annealing) (500-550 ° C). Also above 550 ℃ 65
Higher temperature bright annealing up to 0 ° C (the actual temperature of the copper tube) is commonly used. In this high-temperature bright annealing, the O
The crystal grain size of copper tubes of materials and OL materials is 0.030 mm or less, 0.030 to 0.
The crystal grain size of the copper tube is 0.040 mm or more compared to 040 mm.
【0024】しかし、この高温の光輝焼鈍を施し、特に
銅管の結晶粒度を0.040mm 以上とした場合、抽伸後に塗
布され、銅管表面に付着しているシリコン油が分解し
て、銅管に対して酸化変色を助長する化合物に変質して
いることを知見した。なお、本発明の範囲については、
後述する通り、この現象が特に顕著となる結晶粒度 (焼
鈍後) が0.040mm 以上の銅管だけではなく、この現象が
起こりうる、結晶粒径が0.030mm 以上の銅管を対象とし
ている。However, when the high-temperature bright annealing is performed, and particularly when the crystal grain size of the copper tube is set to 0.040 mm or more, the silicon oil applied after drawing and adhering to the surface of the copper tube is decomposed to form the copper tube. On the other hand, it was found that the substance had changed to a compound that promoted oxidative discoloration. Incidentally, regarding the scope of the present invention,
As will be described later, not only copper tubes having a crystal grain size (after annealing) of 0.040 mm or more, in which this phenomenon is particularly remarkable, but also copper tubes having a crystal grain size of 0.030 mm or more in which this phenomenon can occur.
【0025】即ち、通常の温度が低い光輝焼鈍において
は、シリコン油の分解乃至変質は生じにくいため、この
シリコン油の分解乃至変質による銅管の変色は生じにく
い。しかし、前記550 ℃以上のより高温の光輝焼鈍で
は、特に顕著にシリコン油の分解乃至変質が生じ、銅管
に対する酸化助長物質が生じやすい。より具体的に、前
記高温の光輝焼鈍では、雰囲気のDXガスおよびごく微量
存在する酸素ガスによりシリコン油が酸化され、シリコ
ン油中のCH3 等の有機基 (疎水基) が失われて、シリコ
ン油の疎水性が低下し、より水との親和力の高い成分に
変化する。また、シリコン油の一部が分解してホルムア
ルデヒドや蟻酸等の酸化性ガス乃至化合物を生じる。そ
して、この疎水性の低下したシリコン油や酸化性ガス乃
至化合物が、銅管の外表面に存在することにより、銅管
に対する酸化変色を助長する化合物として作用し、銅管
の外表面の酸化を促進して、変色に至ることを知見し
た。That is, in bright annealing at a normal low temperature, the decomposition or alteration of the silicon oil does not easily occur, so that the discoloration of the copper tube due to the decomposition or alteration of the silicon oil does not easily occur. However, bright annealing at a higher temperature of 550 ° C. or higher particularly remarkably decomposes or degrades silicon oil, and tends to generate oxidation promoting substances for copper tubes. More specifically, in the high-temperature bright annealing, the silicon oil is oxidized by the DX gas in the atmosphere and a very small amount of oxygen gas, and organic groups (hydrophobic groups) such as CH 3 in the silicon oil are lost. The hydrophobicity of the oil decreases, and it changes to a component having a higher affinity for water. Further, a part of the silicon oil is decomposed to generate oxidizing gases or compounds such as formaldehyde and formic acid. The presence of the silicon oil or oxidizing gas or compound having reduced hydrophobicity on the outer surface of the copper tube acts as a compound that promotes oxidative discoloration of the copper tube, thereby preventing oxidation of the outer surface of the copper tube. It was found that it accelerated and resulted in discoloration.
【0026】この変色発生の原因にもとづき、銅管コイ
ルの変色を防止するためには、変色の原因となるシリコ
ン油等の離型剤を用いないか、用いるとしても、焼鈍前
ではなく、焼鈍後に塗布することが考えられる。しか
し、前記した通り、コイルフォームで加工される銅管の
場合、光輝焼鈍時の銅管同士の接合を防止するために、
離型剤塗布は必要となる場合が多い。また、離型剤を光
輝焼鈍後に、コイル化された銅管に塗布する場合、比較
的緻密にコイル化された前記銅管表面に均一に塗布する
ためには、一旦、コイルフォームを巻き戻すか、巻きを
ルーズにする、またはコイル毎、離型剤に浸漬する等の
方法しかなく、いずれも、銅管コイルの生産性を著しく
阻害する結果となる。また、巻き戻しによる銅管の硬化
も懸念される。In order to prevent the discoloration of the copper tube coil based on the cause of the discoloration, a mold release agent such as silicone oil which causes the discoloration is not used. It is conceivable to apply later. However, as described above, in the case of a copper tube processed by coil form, in order to prevent joining of the copper tubes during bright annealing,
It is often necessary to apply a release agent. Further, when applying the release agent to the coiled copper tube after bright annealing, in order to uniformly apply the surface of the copper tube relatively densely coiled, the coil form must be rewound once. There are only methods such as loosening the winding or immersing each coil in a mold release agent, all of which result in significantly impairing the productivity of the copper tube coil. In addition, there is a concern that the copper tube is hardened by unwinding.
【0027】このため、本発明者らは、銅管コイルの生
産性を阻害しないために、光輝焼鈍前に、離型剤を銅管
に塗布 (被覆) して前記高温の光輝焼鈍を行うことを前
提として、銅管コイルの変色を防止することを検討し
た。そして、基本的に、前記シリコン油に代わり、高温
の光輝焼鈍によっても、銅管に対する酸化助長物質を生
じない離型剤の基本特性なり物性を検討した。[0027] Therefore, in order not to hinder the productivity of the copper tube coil, the present inventors apply (release) a release agent to the copper tube and perform the high-temperature bright annealing before the bright annealing. Based on the premise, we studied how to prevent discoloration of the copper tube coil. Then, instead of the silicon oil, the basic characteristics and physical properties of a release agent that does not generate an oxidation-promoting substance for a copper tube even by bright annealing at a high temperature were examined.
【0028】この結果、高温の光輝焼鈍後のシリコン油
の、銅管外表面の酸化を助長させる変質度合いと、銅管
表面の酸化電流の値との間に相関があることを知見し
た。また、一方、この酸化電流の値は、銅管表面の腐食
のされやすさも表しており、酸化電流値を用いれば、離
型剤を塗布せずに高温の光輝焼鈍が施される銅管につい
ても、銅管表面の変色のされやすさが定量化できること
を知見した。As a result, it has been found that there is a correlation between the degree of deterioration of the silicon oil after the bright annealing at a high temperature, which promotes the oxidation of the outer surface of the copper tube, and the value of the oxidation current on the surface of the copper tube. On the other hand, the value of the oxidation current also indicates the susceptibility of the copper tube surface to corrosion.Using the oxidation current value, the copper tube subjected to high-temperature bright annealing without applying a release agent is used. Also found that the discoloration of the copper tube surface can be quantified easily.
【0029】高温の光輝焼鈍では、シリコン油等の離型
剤を塗布していた場合、前記した通り、銅管表面のシリ
コン油が変性して酸化性ガス乃至化合物等の銅管外表面
の酸化を助長させる物質を生じている。この事実を、塗
布されている離型剤の側からみると、酸化電流値とは、
光輝焼鈍後の離型剤の酸化 (分解) のされやすさ、ある
いは、離型剤の光輝焼鈍時の安定性 (分解性) を示して
いることになる。また、銅管側からみると、表面に離型
剤が存在するしないに拘らず、銅管表面の酸化のされ易
さの目安となる。In high-temperature bright annealing, when a release agent such as silicon oil is applied, as described above, the silicon oil on the surface of the copper tube is denatured to oxidize the outer surface of the copper tube with an oxidizing gas or a compound. The substance which promotes is produced. When this fact is viewed from the side of the applied release agent, the oxidation current value is
This indicates the ease of oxidation (decomposition) of the release agent after bright annealing, or the stability (degradability) of the release agent during bright annealing. Also, when viewed from the copper tube side, it is a measure of the susceptibility of the copper tube surface to oxidation, regardless of the presence of the release agent on the surface.
【0030】一方、金属などの表面の酸化電流は、アノ
ード電流として、金属などの表面の酸化のし易さ乃至腐
食のし易さを測る目安として公知である。この点、高温
の光輝焼鈍後の銅管表面 (銅管および酸化皮膜) の酸化
電流値、離型剤を塗布した場合には、離型剤を含めた銅
管表面の酸化電流値が、銅管表面の酸化されやすさ、即
ち、耐変色性とよく対応していることを知見して、本発
明をなしたものである。したがって、本発明で規定する
酸化電流値は、銅管外表面の変色性を表す指標と言え
る。On the other hand, the oxidation current of the surface of a metal or the like is known as an anode current as a measure for measuring the ease of oxidation or corrosion of the surface of a metal or the like. In this regard, the oxidation current value of the copper tube surface (copper tube and oxide film) after high-temperature bright annealing, and when a mold release agent is applied, the oxidation current value of the copper tube surface including the mold release agent is The present invention was made based on the finding that the surface of the tube is easily oxidized, that is, it is well-corresponding to the discoloration resistance. Therefore, the oxidation current value defined in the present invention can be said to be an index indicating the discoloration of the outer surface of the copper tube.
【0031】[0031]
【発明の実施の形態】本発明における各要件の意義につ
いて、以下に説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The significance of each requirement in the present invention will be described below.
【0032】(酸化電流)まず、本発明で言う酸化電流と
は、前記した通り、金属等の物質の酸化のし易さ乃至腐
食のし易さを測る目安として公知のアノード電流のこと
である。但し、公知のアノード電流においても、その測
定条件は、対象とする具体的な金属等の、具体的な酸化
若しくは腐食の種類に応じて決められるものであり、対
象とする具体的な金属や具体的な酸化若しくは腐食の種
類に応じて、種々異なる。言い換えると、アノード電流
の測定条件の選択によっては、実際の酸化若しくは腐食
の挙動と対応なり相関しないことが起こりうる。(Oxidation current) First, the oxidation current referred to in the present invention is, as described above, an anode current known as a measure for measuring the easiness of oxidation or corrosion of a substance such as a metal. . However, even with a known anode current, the measurement conditions are determined according to the type of specific oxidation or corrosion of the specific metal or the like, and the specific metal or specific It varies depending on the type of typical oxidation or corrosion. In other words, depending on the selection of the conditions for measuring the anode current, it may happen that the anode current does not correlate with the actual oxidation or corrosion behavior.
【0033】この点、本発明で対象とする銅管の変色自
体は、あくまで銅管表面部のみの軽度の酸化であり、し
たがって、これに対応するアノード電流 (以下酸化電流
と言う) の測定条件も、これに見合った、比較的緩い測
定 (電流) 条件とする必要がある。In this respect, the discoloration itself of the copper tube targeted in the present invention is only slight oxidation of only the surface of the copper tube, and therefore, the corresponding measurement condition of the anode current (hereinafter referred to as oxidation current). However, relatively loose measurement (current) conditions need to be met.
【0034】より具体的に、本発明で規定する酸化電流
の測定条件は、測定の誤差を防止して測定値に再現性を
もたせるために、温度が室温(25 ℃) で、0.002 モル
(M) のKCl 水溶液中に、光輝焼鈍後の銅管サンプル(0.2
5cm2、0.5cm ×0.5cm)を測定面積だけ浸漬し、1000秒経
過後の0V (飽和カロメル電極:SCE) で測定した際の、酸
化電流の測定値 (μA)とする。More specifically, the measurement conditions of the oxidation current specified in the present invention are as follows: in order to prevent measurement errors and to provide reproducibility of the measured values, the temperature is room temperature (25 ° C.);
(M) in a KCl aqueous solution, the copper tube sample (0.2
A measurement area (5 cm 2 , 0.5 cm × 0.5 cm) is immersed in a measurement area, and the measured value is an oxidation current (μA) measured at 0 V (saturated calomel electrode: SCE) after 1000 seconds.
【0035】銅管の酸化電流は、通常用いられる、飽和
カロメル電極を参照電極として用いた三電極法により、
定電位電解 (一定電位) による電極銅管 (試料) の電流
値をポテンシオスタットで測定する。したがって、本発
明では、銅管外表面の銅、銅酸化皮膜、および離型剤
(塗布した場合) を含めた、銅管外表面の酸化電流を測
定していることになる。言い換えると、銅管外表面のア
ノード電流特性に影響を及ぼす諸因子の総合の影響を評
価していることになる。The oxidation current of the copper tube is determined by a three-electrode method using a saturated calomel electrode as a reference electrode.
The current value of the electrode copper tube (sample) by constant potential electrolysis (constant potential) is measured with a potentiostat. Therefore, in the present invention, copper on the outer surface of the copper tube, a copper oxide film, and a release agent
This means that the oxidation current on the outer surface of the copper tube, including (when applied), was measured. In other words, the overall influence of various factors affecting the anode current characteristics on the outer surface of the copper tube is evaluated.
【0036】そして、本発明では、光輝焼鈍後の離型剤
を表面に有する銅管または光輝焼鈍後の離型剤を有さな
い銅管の、前記測定条件における酸化電流の測定値 (μ
A)が6.0 μA 以下と規定し、この値となるような離型剤
を光輝焼鈍前に銅管に施すか、および/ または、銅管表
面の酸化皮膜等を調整する。In the present invention, the measured value (μm) of the oxidation current of the copper tube having the release agent after the bright annealing on the surface or the copper tube having no release agent after the bright annealing under the above-mentioned measurement conditions (μ)
A) is specified to be 6.0 μA or less, and a mold release agent having such a value is applied to the copper tube before bright annealing, and / or an oxide film on the surface of the copper tube is adjusted.
【0037】酸化電流の測定値 (μA/cm2)が6.0 μA を
越えた場合、離型剤を用いる場合には、光輝焼鈍前に施
された離型剤層が、高温の光輝焼鈍によって変質して、
或いは変質していなくても、銅管 (表面) に対して腐食
性を有する離型剤層となっている。このため、その後の
銅管の製造工程や輸送あるいは保管、更には使用の状況
によっては、温度、湿度、腐食物質などの影響で酸化が
進行して、本発明で対象とするあんこ変色に至る。When the measured value of the oxidation current (μA / cm 2 ) exceeds 6.0 μA, when the release agent is used, the release agent layer applied before the bright annealing is altered by the high-temperature bright annealing. do it,
Or, even if it is not deteriorated, it is a release agent layer that is corrosive to the copper tube (surface). For this reason, depending on the subsequent manufacturing process, transportation or storage of the copper tube, and furthermore, depending on the situation of use, oxidation proceeds under the influence of temperature, humidity, corrosive substances, and the like, and this causes the discoloration of the bean paste targeted in the present invention.
【0038】また、離型剤を用いない場合においても、
酸化電流の測定値 (μA)が6.0 μAを越えた場合、高温
の光輝焼鈍によって、銅管表面が、腐食されやすい状況
になっている。このため、前記した通り、温度、湿度、
腐食物質などの影響で酸化が進行して、本発明で対象と
するあんこ変色に至る。なお、本酸化電流の測定は、焼
鈍後、適宜実施すれば良い。Further, even when a release agent is not used,
When the measured oxidation current (μA) exceeds 6.0 μA, the copper tube surface is susceptible to corrosion due to high-temperature bright annealing. Therefore, as described above, the temperature, humidity,
Oxidation proceeds due to the influence of corrosive substances and the like, and leads to discoloration of the bean paste, which is the object of the present invention. The measurement of the main oxidation current may be appropriately performed after the annealing.
【0039】(対象とする銅管)なお、本発明において、
対象とする銅管を、焼鈍後の結晶粒径が0.030mm 以上で
あるリン脱酸銅管または無酸素銅管としたのは、焼鈍後
の結晶粒径が0.030mm未満の低温の光輝焼鈍および合金
銅管では、本発明で対象とする変色の問題、即ち、前記
シリコン油等の離型剤の変質による変色の問題や、離型
剤無しの場合の変色の問題が生じないからである。した
がって、本発明で対象とする変色は、焼鈍後の結晶粒径
が0.030mm 以上であるリン脱酸銅管または無酸素銅管、
例えば、550 ℃以上の高温で光輝焼鈍したリン脱酸銅管
または無酸素銅管に、初めて顕著に生じる問題であると
言える。それゆえ、このような高温の光輝焼鈍における
変色の問題に対し、原因の究明と、再現性がある定量的
な対策 (指標) はこれまでになかったのが実情である。
因みに、本発明で言う結晶粒径の測定は、JIS H 0501で
規定される比較法 (試験片の顕微鏡映像と標準結晶粒度
写真との比較により結晶粒径を測定する) に基づく。(Target copper tube) In the present invention,
The target copper tube was a phosphorus deoxidized copper tube or an oxygen-free copper tube having a crystal grain size of 0.030 mm or more after annealing, because the low-temperature bright annealing and the crystal grain size after annealing were less than 0.030 mm. This is because, in the alloy copper tube, the problem of discoloration targeted by the present invention, that is, the problem of discoloration due to deterioration of the release agent such as the silicone oil and the problem of discoloration without the release agent do not occur. Therefore, the discoloration targeted in the present invention is a phosphor deoxidized copper tube or an oxygen-free copper tube having a crystal grain size of 0.030 mm or more after annealing,
For example, it can be said that this is a problem that occurs remarkably for the first time in a phosphor deoxidized copper tube or an oxygen-free copper tube brightly annealed at a high temperature of 550 ° C. or higher. Therefore, it has not been possible to find the cause of the discoloration problem in such high-temperature bright annealing and to have a quantitative measure (index) with reproducibility.
Incidentally, the measurement of the crystal grain size referred to in the present invention is based on a comparison method defined by JIS H0501 (measurement of the crystal grain size by comparing a microscope image of a test piece with a standard crystal grain size photograph).
【0040】(離型剤)本発明に用いる離型剤としては、
焼鈍後の結晶粒径が0.030mm 以上となる高温の焼鈍であ
って、離型剤の変質が問題となる高温の焼鈍において、
該焼鈍後のコーティング層を有する銅管の、前記測定条
件における酸化電流の測定値 (μA)が6.0 μA 以下とな
るような離型剤を用いる必要がある (請求項2 に対応)
。言い換えると、本発明では、前記高温で光輝焼鈍し
た場合でも、銅管 (表面) に対して酸化促進性を有する
ように変質しない離型剤が必要である。また、この基本
特性に加えて、元々の離型剤の要求特性 (塗布目的) で
ある離型性や、この他、ろう付けの際のぬれ性を低下さ
せない等の冷凍空調用配管への加工工程や配管品質に対
して悪影響を与えないという特性が必要である。(Release Agent) The release agent used in the present invention includes:
In high-temperature annealing where the crystal grain size after annealing is 0.030 mm or more, and the quality of the release agent is deteriorated,
It is necessary to use a release agent such that the measured value (μA) of the oxidation current of the copper tube having the coating layer after the annealing under the above measurement conditions is 6.0 μA or less (corresponding to claim 2).
. In other words, in the present invention, a release agent that does not deteriorate so as to have an oxidation-promoting property on the copper tube (surface) is required even in the case of bright annealing at the high temperature. In addition to these basic properties, processing into refrigeration and air-conditioning piping, such as releasability, which is the original required property of the release agent (application purpose), and other factors that do not reduce the wettability during brazing, etc. It is necessary to have characteristics that do not adversely affect the process and piping quality.
【0041】これらの特性を満足する離型剤としては、
ナフテン系の鉱油や、ポリオレフィン系等の合成炭化水
素からなる潤滑油、オレイン酸、オレイン酸メチル、オ
レイルアルコール等の、前記光輝焼鈍のような高温でも
安定性が優れた離型剤が、好ましい態様として例示され
る。Release agents satisfying these characteristics include:
Naphthenic mineral oils, lubricating oils composed of synthetic hydrocarbons such as polyolefins, oleic acid, methyl oleate, oleyl alcohol, and the like, release agents having excellent stability even at high temperatures such as the above-described bright annealing, are preferred embodiments. As an example.
【0042】これに対し、前記ベンゾトリアゾール(BT
A) 系の変色防止剤、非水溶性ポリアルキレングリコー
ル、離型剤として汎用されているシリコン油、或いはこ
れらに化合物や軽油等を混合した防錆油等は、前記光輝
焼鈍のような高温で、酸化電流の測定値 (μA)が6.0 μ
A を越える可能性が大きく、高温の光輝焼鈍によって変
質して、或いは変質していなくても、銅管 (表面) に対
して酸化促進性を有する離型剤層となりやすい。On the other hand, the benzotriazole (BT
A) system discoloration inhibitor, water-insoluble polyalkylene glycol, silicone oil commonly used as a release agent, or a rust-preventive oil mixed with a compound or light oil, etc., at a high temperature such as the bright annealing described above. Measured oxidation current (μA) 6.0 μ
It is likely to exceed A, and it is likely to be a release agent layer having oxidation promoting properties on the copper tube (surface) even if it is modified or not transformed by high-temperature bright annealing.
【0043】しかし、前記好ましい離型剤であっても、
銅管の種類 (合金、形状) や光輝焼鈍条件と塗布量によ
っては、酸化電流の測定値 (μA)が6.0 μA を越え、変
色を生じる可能性もある。したがって、耐変色性の最終
的な評価は酸化電流の測定値によって行うべきである。
そして、銅管の種類と離型剤毎に、変色を生じない光輝
焼鈍条件と塗布量を、酸化電流の測定値にもとづき、選
択すべきである。However, even with the preferred release agent,
Depending on the type of copper tube (alloy, shape), bright annealing conditions and coating amount, the measured oxidation current (μA) may exceed 6.0 μA and may cause discoloration. Therefore, the final evaluation of discoloration resistance should be made by measuring the oxidation current.
Then, for each type of copper tube and release agent, bright annealing conditions and coating amount that do not cause discoloration should be selected based on the measurement value of the oxidation current.
【0044】(離型剤の塗布方法)離型剤の塗布方法は、
現状の銅管製造工程において、光輝焼鈍前の抽伸等の塑
性加工後の銅管または銅管コイルに塗布乃至被覆する通
常の方法が適宜選択される。離型剤の塗布量は、離型剤
の種類や銅管、焼鈍条件等によって異なるため一概には
特定しにくい。前記離型剤の機能発揮のための必要量か
ら下限が決められるが、塗布量が多すぎる場合、冷凍空
調用配管への加工工程や配管品質に対して悪影響を与え
る。したがって、上限はこの観点から決定される。更
に、塗布量の上限は、前記した通り、酸化電流の測定値
(μA)の上限と、変色を生じない条件から決定される。(Method of Applying Release Agent) The method of applying the release agent is as follows.
In the current copper tube manufacturing process, an ordinary method of coating or coating a copper tube or a copper tube coil after plastic working such as drawing before bright annealing is appropriately selected. Since the amount of the release agent applied varies depending on the type of the release agent, the copper tube, the annealing conditions, and the like, it is generally difficult to specify the amount. The lower limit is determined from the required amount of the release agent for exhibiting its function. However, if the applied amount is too large, it adversely affects the process of processing the piping for refrigeration and air conditioning and the quality of the piping. Therefore, the upper limit is determined from this viewpoint. Further, the upper limit of the coating amount is, as described above, the measured value of the oxidation current.
(μA) and conditions that do not cause discoloration.
【0045】(適用銅管)本発明における銅管は、前記し
た通り、本発明で対象とする変色が生じやすい、焼鈍後
の結晶粒径が0.030mm 以上である、リン脱酸銅管または
無酸素銅管とする。リン脱酸銅管または無酸素銅管とし
ては、通常の成分組成のものが、要求特性や用途に応じ
て、適宜選択される。また、本発明は、直管状の銅管へ
の適用も勿論好ましいが、特に変色が生じやすい、前記
LWC などの銅管コイルに適用されることが最も好ましい
(請求項3 に対応) 。(Applicable Copper Tube) As described above, the copper tube according to the present invention is a phosphor-deoxidized copper tube or a copper tube having a crystal grain size of 0.030 mm or more after annealing, which is liable to undergo the discoloration targeted by the present invention. Use an oxygen copper tube. As the phosphorus deoxidized copper tube or the oxygen-free copper tube, a tube having a normal component composition is appropriately selected according to required characteristics and applications. In addition, the present invention is of course preferably applied to a straight tubular copper tube, but in particular, the discoloration easily occurs.
Most preferably applied to copper tube coils such as LWC
(Corresponding to claim 3).
【0046】(銅管の製造方法)銅管の製造方法は、前記
した、通常の製造方法、即ち、銅および銅合金鋳塊を熱
間押出等により素管化し更に、この素管を抽伸或いはレ
デューサー等の冷間加工によって銅管或いは銅管コイル
とした後、光輝焼鈍処理を行って銅管製品とされる。こ
の内、光輝焼鈍処理は、銅管に求められる機械的特性に
応じて、CO等の還元物質を含む還元性のDXガスにより、
例えば、前記した550 〜650 ℃の温度と適宜の時間で行
われる。また、銅管の形状も、通常用いられる、内外面
の溝付管やインナーフィン管、コルゲート管、二重管、
ローフィンチューブ、内面スパイラル管、フィンチュー
ブ、フルーテッド管或いは平滑管等に対し適宜用いるこ
とができる。(Manufacturing method of copper tube) The manufacturing method of the copper tube is the above-mentioned usual manufacturing method, that is, a copper and copper alloy ingot is formed into a raw tube by hot extrusion or the like, and the raw tube is drawn or drawn. After a copper tube or a copper tube coil is formed by cold working with a reducer or the like, a bright annealing process is performed to obtain a copper tube product. Among these, bright annealing treatment is performed by reducing DX gas containing a reducing substance such as CO, depending on the mechanical properties required for the copper tube.
For example, the heat treatment is performed at the above-mentioned temperature of 550 to 650 ° C. and an appropriate time. In addition, the shape of the copper tube is also commonly used, grooved tube on the inner and outer surfaces, inner fin tube, corrugated tube, double tube,
It can be used as appropriate for a low fin tube, an inner spiral tube, a fin tube, a fruited tube, a smooth tube, or the like.
【0047】(銅管外表面の調整)離型剤を塗布しない場
合の銅管外表面の、また離型剤を塗布した場合でも銅管
外表面の酸化電流の測定値 (μA)を6.0 μA 以下とする
方法について説明する。銅管表面の内、銅自体は光輝焼
鈍の前後によっても変わらないので、酸化電流の制御に
は、銅表面の酸化物の制御が大きく寄与する。この点、
銅表面の酸化物の内、Cu2Oの方が、CuO よりも、より酸
化されやすく、変色感受性が高い。したがって、抽伸後
に生成している酸化物をエッチング等により一旦除去
し、光輝焼鈍の前の銅管表面の酸化物をCuO 主体のもの
にするか、光輝焼鈍後の銅管表面の酸化物がCuO 主体と
なるように、焼鈍条件を調整する方法が推奨される。(Adjustment of Copper Tube Outer Surface) The oxidation current measurement value (μA) of the copper tube outer surface when the mold release agent was not applied and on the copper tube outer surface even when the mold release agent was applied was 6.0 μA. The following method will be described. Since the copper itself does not change before and after bright annealing on the surface of the copper tube, the control of the oxide on the copper surface greatly contributes to the control of the oxidation current. In this regard,
Among the oxides on the copper surface, Cu 2 O is more easily oxidized and has higher discoloration sensitivity than CuO. Therefore, oxides generated after drawing are once removed by etching or the like, and the oxide on the surface of the copper tube before bright annealing is made mainly of CuO, or the oxide on the surface of the copper tube after bright annealing is CuO. A method of adjusting the annealing conditions so as to be the main body is recommended.
【0048】しかし、前記離型剤の場合と同様、銅管の
種類や形状、あるいは光輝焼鈍条件と塗布量によって
は、銅管表面の酸化物をCuO 主体のものにしても、酸化
電流の測定値 (μA)が6.0 μA を越え、変色を生じる可
能性もある。したがって、耐変色性の最終的な評価は酸
化電流の測定値によって行うべきである。銅管の種類と
離型剤毎に、変色を生じない、言い換えると、酸化電流
の測定値 (μA)が6.0 μA 以下となる銅管表面を、酸化
電流の測定値にもとづき、選択すべきである。However, as in the case of the mold release agent, depending on the type and shape of the copper tube, or the bright annealing conditions and the amount of coating, even if the oxide on the surface of the copper tube is mainly made of CuO, the measurement of the oxidation current is performed. The value (μA) may exceed 6.0 μA and discoloration may occur. Therefore, the final evaluation of discoloration resistance should be made by measuring the oxidation current. For each type of copper tube and release agent, the surface of the copper tube that does not cause discoloration, in other words, the measured oxidation current (μA) should be 6.0 μA or less, should be selected based on the measured oxidation current. is there.
【0049】[0049]
【実施例】次に、本発明成形方法の実施例を説明する。
前記常法により、厚み0.8mm 、径6.35mmまで抽伸した脱
酸銅製平滑管をアセトンとヘキサンにより洗浄して銅管
表面を脱脂した。この脱脂銅管に、表1 に示す条件で油
剤 (離型剤) を被覆し (無塗布も含む) 、コイル (LWC)
化した (コイル単重約300kg)。この銅管コイルを、焼鈍
後の銅管の結晶粒度が0.04mm以上のソフトアニールとす
べく、570 ℃の銅管実体温度に到達するよう、還元性の
DXガス(CO 、H2、N2からなる混合ガス) 雰囲気におい
て、加熱帯、均熱帯、出側冷却帯からなる半連続焼鈍炉
にて、3 時間光輝焼鈍した。また、比較のために、銅管
の結晶粒度が0.030mm 未満や、0.030 〜0.040mm である
JIS のO 材やOL材とした例も、銅管実体温度のみを500
〜550 ℃と低くして焼鈍を行った。表1 に銅管の結晶粒
度を示す。Next, examples of the molding method of the present invention will be described.
According to the above-mentioned conventional method, a deoxidized copper smooth tube drawn to a thickness of 0.8 mm and a diameter of 6.35 mm was washed with acetone and hexane to degrease the surface of the copper tube. The degreased copper tube was coated with an oil agent (release agent) under the conditions shown in Table 1 (including uncoated), and the coil (LWC)
(Coil single weight about 300kg). This copper tube coil is subjected to a reducing process to reach the actual temperature of the copper tube of 570 ° C in order to reach the actual temperature of the copper tube of 570 ° C in order to perform soft annealing with a crystal grain size of the copper tube after annealing of 0.04 mm or more.
In a DX gas (mixed gas composed of CO 2, H 2 , N 2 ) atmosphere, bright annealing was performed for 3 hours in a semi-continuous annealing furnace consisting of a heating zone, a soaking zone, and an outlet cooling zone. For comparison, the crystal grain size of the copper tube is less than 0.030 mm or 0.030 to 0.040 mm.
In the case of JIS O and OL materials, only the actual copper tube temperature is 500
Annealing was performed at a low temperature of ~ 550 ° C. Table 1 shows the crystal grain size of the copper tube.
【0050】その後、各々のコイルから、銅管長手方向
の全域に渡って、試験片を5 個採取し、各々の試験片の
銅管表面の酸化電流を、前記参照電極を用いた三電極法
による定電位電解方法により、測定するとともに、5 個
の試験片の酸化電流の平均値を求めた。この結果を表1
に示す (発明例No.1〜10、比較例No.11 〜19) 。Thereafter, five test pieces were sampled from each coil over the entire area in the longitudinal direction of the copper tube, and the oxidation current on the copper tube surface of each test piece was measured by the three-electrode method using the reference electrode. And the average value of the oxidation currents of the five test pieces was determined. Table 1 shows the results.
(Examples Nos. 1 to 10 and Comparative Examples Nos. 11 to 19).
【0051】なお、離型剤を塗布しない例は、抽伸後
に、生成している酸化物をエッチングにより一旦除去
し、光輝焼鈍の前の銅管表面の酸化物をCu2O主体のもの
に調整し、更に光輝焼鈍を無酸素雰囲気で行った発明例
No.8、9 を準備した。また、抽伸後に、生成している酸
化物 (CuO 主体) をそのまま光輝焼鈍し、更に光輝焼鈍
雰囲気に、加熱帯で100ppm、出側冷却帯で200 〜300ppm
程度の酸素を含ませた比較例No.19 も準備し、同様に酸
化電流の平均値を求めた。これらの結果を表1 に示す。In the case where the release agent is not applied, after the drawing, the generated oxide is once removed by etching, and the oxide on the surface of the copper tube before bright annealing is adjusted to be mainly composed of Cu 2 O. Example in which bright annealing was further performed in an oxygen-free atmosphere
No.8 and 9 were prepared. After drawing, the generated oxides (mainly CuO) are brightly annealed as they are, and furthermore, in a bright annealing atmosphere, 100 ppm in the heating zone and 200 to 300 ppm in the outlet cooling zone.
Comparative Example No. 19 containing about oxygen was also prepared, and the average value of the oxidation current was determined in the same manner. Table 1 shows the results.
【0052】これらの試験片の耐変色性と離型性を以下
の要領で評価した。変色試験条件は、焼鈍後の銅管コイ
ルを、防錆厚紙で胴巻きするとともに防錆厚紙で挟んだ
梱包状態で、室温40℃およびRH70% の室内に入れ 3日間
放置後、室温25℃およびRH90% の室内に入れ 3日間放置
するサイクル( 各々の室内で室温に昇温および常温に降
温) を行った後の、銅管外表面に生じた変色の程度によ
り評価した。そして、銅管コイルをペイオフリールにて
巻き戻ししながら、酸化電流試験片採取位置を含めた、
銅管長手方向の全域に渡って、変色発生の状況を確認し
た。この結果、2 個のコイルとも銅管外表面に一切変
色が生じなかったものを○、いずれかまたは両方のコ
イルの、銅管外表面に、長手方向に 100mm以上の長さ
で、5mm 以上の幅の帯状の変色が生じたものを×、い
ずれかのコイルの、銅管外表面に、前記の変色の大き
さ未満の小さい( 軽微な) 変色が生じているものを△と
して評価した。The discoloration resistance and releasability of these test pieces were evaluated in the following manner. The discoloration test conditions were as follows: the annealed copper tube coil was placed in a room at room temperature of 40 ° C and 70% RH in a packing state sandwiched between rust-proof cardboard and body-wrapped with rustproof cardboard. % Of each tube, the temperature was raised to room temperature and the temperature was lowered to room temperature in each room, and then evaluated by the degree of discoloration generated on the outer surface of the copper tube. And, while rewinding the copper tube coil with a payoff reel, including the oxidation current test piece sampling position,
The state of discoloration occurrence was confirmed over the entire area in the longitudinal direction of the copper tube. As a result, the case where no discoloration occurred on the outer surface of the copper tube in both coils was evaluated as ○, and the outer surface of the copper tube of either or both coils was longer than 100 mm in the longitudinal direction and 5 mm or more. When the band-shaped discoloration of the width occurred, the evaluation was evaluated as x, and when any of the coils had small (slight) discoloration less than the magnitude of the above-described discoloration on the outer surface of the copper tube, the evaluation was evaluated as Δ.
【0053】更に、前記変色試験したコイルの巻き戻し
時に、銅管長手方向の全域に渡って、銅管同士の接合
(くっつき) が無いかどうかを、同時に目視で判断し、
離型剤や銅管の離型性を評価した。この結果、接合が
コイルに生じていない例を○、接合がコイルの数カ所
だけに部分的に生じている例を△、接合がコイル全般
に渡って生じているものを×として評価した。この結果
も表1 に示す。Further, at the time of rewinding the coil subjected to the discoloration test, the copper tubes are joined together over the entire area in the longitudinal direction of the copper tubes.
At the same time, it is visually determined whether or not there is
The release properties of the release agent and the copper tube were evaluated. As a result, the case where the bonding did not occur in the coil was evaluated as ○, the case where the bonding partially occurred only in several places of the coil was evaluated as Δ, and the case where the bonding occurred throughout the coil was evaluated as ×. The results are also shown in Table 1.
【0054】表1 から分かる通り、ナフテン系の鉱油
(発明例No.1: 粘度300cst,at40 ℃)や、ポリα- オレフ
ィン系の合成炭化水素からなる潤滑油 (発明例No.2、3
、4:粘度155cst,at40 ℃) 、オレイン酸 (発明例No.5)
、オレイン酸メチル (発明例No.6) 、オレイルアルコ
ール (発明例No.7) 等を用い、光輝焼鈍後の酸化電流の
測定値が6.0 μA 以下となるような離型剤を用いた発明
例No.1〜7 、および銅管表面を、離型剤を用いず、無塗
布とした発明例No.8、9 は、変色が生じておらず、変色
が防止できていることが分かる。As can be seen from Table 1, naphthenic mineral oil
(Invention Example No. 1: viscosity 300 cst, at 40 ° C.) or a lubricating oil composed of a polyα-olefin synthetic hydrocarbon (Invention Examples No. 2 and 3
, 4: viscosity 155 cst, at 40 ° C), oleic acid (Invention Example No. 5)
, Methyl oleate (Invention Example No. 6), oleyl alcohol (Invention Example No. 7), etc., and a release agent having a measured oxidation current of 6.0 μA or less after bright annealing. Nos. 1 to 7 and Invention Examples Nos. 8 and 9, in which the surface of the copper tube was not coated without using a mold release agent, showed no discoloration, indicating that discoloration could be prevented.
【0055】また、離型剤を用いた発明例No.1〜7 、10
は、光輝焼鈍時の銅管同士の接合も抑制されており、離
型剤としての本来の機能も果たしている。なお、発明例
No.2、5 は離型剤の塗布量が少ないために、他の発明例
No.1、3 、4 、6 、7 に比して、光輝焼鈍時の銅管同士
の接合の抑制が劣っているものと推考される。更に、離
型剤を用いなかった (無塗布の) 発明例No.8、9 も、離
型剤を用いた発明例よりは劣るものの、光輝焼鈍時の銅
管同士の接合も抑制されている。Inventive Examples Nos. 1 to 7, 10 using a release agent
Has also suppressed the joining of the copper tubes during bright annealing, and also fulfills the original function as a release agent. Examples of the invention
Nos. 2 and 5 are other invention examples because the amount of release agent applied is small.
It is presumed that the suppression of joining of copper tubes during bright annealing was inferior to that of Nos. 1, 3, 4, 6, and 7. Furthermore, the inventive examples No. 8 and 9 in which the release agent was not used (uncoated) were also inferior to the invention examples using the release agent, but the joining of the copper tubes during bright annealing was also suppressed. .
【0056】これに対し、ベンゾトリアゾール(BTA) 配
合の市販防錆油を用いた比較例No.11 、非水溶性ポリア
ルキレングリコールを用いた比較例No.12 、離型剤とし
て汎用されているシリコン油 (ジメチルシリコーン、粘
度100cst,at40 ℃) を用いた比較例No.13 、14、15、耐
熱性のシリコン油 (メチルフェニルシリコーン、粘度13
0cst,at40 ℃) を用いた比較例No.16 、オクタノールを
用いた比較例No.17 、オクタン酸を用いた比較例No.18
、無塗布の比較例No.19 は、550 ℃以上の高温での光
輝焼鈍で、結晶粒度が0.030mm 以上、特に0.040mm 以上
となった場合、いずれも、酸化電流の測定値 (μA)が6.
0 μA を越えている。このため、光輝焼鈍時の銅管同士
の接合は抑制されているものの、銅管 (表面) に対して
酸化変色を助長する被覆層となっているため、変色が生
じており、耐変色性が、発明例に比して、著しく劣って
いる。On the other hand, Comparative Example No. 11 using a commercially available rust-preventive oil containing benzotriazole (BTA), Comparative Example No. 12 using a water-insoluble polyalkylene glycol, and are widely used as release agents. Comparative Examples Nos. 13, 14, and 15 using silicone oil (dimethyl silicone, viscosity 100 cst, at 40 ° C.), heat-resistant silicone oil (methylphenyl silicone, viscosity 13
0cst, at40 ° C), Comparative Example No.17 using octanol, Comparative Example No.18 using octanoic acid
In Comparative Example No. 19, in which no coating was applied, the bright annealing at a high temperature of 550 ° C. or higher resulted in a measured oxidation current (μA) of 0.030 mm or more, particularly 0.040 mm or more. 6.
Exceeds 0 μA. For this reason, although the joining of the copper tubes during bright annealing is suppressed, the copper tube (surface) has a coating layer that promotes oxidative discoloration. , Significantly inferior to the invention examples.
【0057】これらの例から、特に、従来から離型剤と
して汎用されているシリコン油が、光輝焼鈍温度が高
く、結晶粒度が0.030mm 以上、特に0.040mm 以上と大き
いほど、変色の原因となること、また、BTA 系などの変
色防止コーティング剤が、光輝焼鈍温度が高く、結晶粒
度が0.040mm 以上と大きい場合には、銅管の変色防止効
果がなく、逆に、却って変色の原因となることが分か
る。From these examples, it can be seen that, in particular, silicone oil which has been widely used as a mold release agent has a high bright annealing temperature and a grain size of 0.030 mm or more, especially 0.040 mm or more, which causes discoloration. In addition, if the BTA-based discoloration prevention coating agent has a high bright annealing temperature and a crystal grain size of 0.040 mm or more, it does not have the effect of preventing discoloration of the copper tube, but rather causes discoloration. You can see that.
【0058】また、この実施例の中でも、同じ離型剤を
用いても、塗布量等の条件の違いにより、同じ条件で光
輝焼鈍を施しても、酸化電流の測定値 (μA)が異なり、
耐変色性も大きく異なることが分かる。したがって、同
じ離型剤を用いても、塗布量等の条件や、光輝焼鈍条件
によっても、酸化電流の測定値が大きく異なり、耐変色
性を保証するためには、本発明の酸化電流の測定値で検
証する必要があることを示している。In this embodiment, even when the same release agent is used, the measured value (μA) of the oxidation current is different even when the bright annealing is performed under the same conditions due to the difference in the conditions such as the coating amount.
It can be seen that the discoloration resistance is also significantly different. Therefore, even if the same release agent is used, the measurement value of the oxidation current greatly differs depending on the conditions such as the amount of application and the bright annealing conditions, and in order to guarantee the discoloration resistance, the measurement of the oxidation current according to the present invention is performed. Indicates that the value must be verified.
【0059】更に、同じシリコン油を用いた比較例No.1
3 と比較例No.14 、15との比較において、銅管の結晶粒
度が0.030mm 未満の比較例No.13 の場合 (焼鈍温度が比
較的低い場合) には、同じ離型剤および塗布量であって
も銅管コイルに変色は生じてない。したがって、前記し
た通り、本発明で問題とする酸化による銅管の変色が、
結晶粒度が0.030mm 以上、特に0.040mm を越える高温の
焼鈍に特有の問題であることが分かる。Further, Comparative Example No. 1 using the same silicone oil
In the comparison between No. 3 and Comparative Examples Nos. 14 and 15, in the case of Comparative Example No. 13 in which the crystal grain size of the copper tube was less than 0.030 mm (when the annealing temperature was relatively low), the same release agent and coating amount were used. However, no discoloration occurred in the copper tube coil. Therefore, as described above, the discoloration of the copper tube due to oxidation, which is a problem in the present invention,
It can be seen that this is a problem peculiar to high-temperature annealing in which the grain size is 0.030 mm or more, and particularly more than 0.040 mm.
【0060】そして、同じ離型剤を塗布しない銅管同士
(発明例No.8、9 と比較例No.19)の比較でも、光輝焼鈍
雰囲気の違い (比較例No.19 は、前記した通り、焼鈍雰
囲気に、加熱帯で100ppm、出側冷却帯で200 〜300ppm程
度の酸素を含ませている) によっても、或いは酸化電流
の測定値 (μA)が異なり、耐変色性も大きく異なること
が分かる。Then, copper tubes not coated with the same release agent
Also in the comparison of (Invention Examples Nos. 8 and 9 and Comparative Example No. 19), the difference in the bright annealing atmosphere (Comparative Example No. 19, as described above, in the annealing atmosphere, 100 ppm in the heating zone, It can be seen that the measured value (μA) of the oxidation current varies depending on the amount of oxygen contained (about 200 to 300 ppm of oxygen), and the discoloration resistance also varies greatly.
【0061】したがって、これらの結果からも、銅管や
離型剤の種類、塗布量、光輝焼鈍等の条件によって、酸
化電流の測定値が大きく異なり、耐変色性を保証するた
めには、本発明の酸化電流の測定値で検証する必要があ
ることを示している。また、これらの事実から、本発明
の、酸化電流による変色性評価の意義が裏付けられる。
また、本発明の酸化電流の上限値の臨界的な意義も裏付
けられる。Therefore, from these results, the measured value of the oxidation current varies greatly depending on the conditions such as the type of the copper tube and the release agent, the coating amount, and the bright annealing. It shows that it is necessary to verify with the measured value of the oxidation current of the invention. In addition, these facts support the significance of the evaluation of discoloration by the oxidation current of the present invention.
Further, the critical significance of the upper limit value of the oxidation current of the present invention is supported.
【0062】[0062]
【表1】 [Table 1]
【0063】[0063]
【発明の効果】本発明によれば、銅管コイルの変色を根
本的に抑制しうる、耐変色性に優れた銅管を提供するこ
とができる。したがって、銅管の用途を拡げることがで
きる点で、多大な工業的価値を有するものである。According to the present invention, it is possible to provide a copper tube excellent in discoloration resistance, which can fundamentally suppress discoloration of a copper tube coil. Therefore, it has a great industrial value in that the use of the copper tube can be expanded.
フロントページの続き (72)発明者 大塚 剛樹 神戸市西区高塚台1丁目5番5号 株式会 社神戸製鋼所神戸総合技術研究所内 (72)発明者 土屋 昭則 神奈川県秦野市平沢65番地 株式会社神戸 製鋼所秦野工場内 Fターム(参考) 4K062 AA01 AA05 AA10 BB06 BC07 CA10 EA02 FA04 FA05 FA16 GA10 Continuing from the front page (72) Inventor Takeki Otsuka 1-5-5 Takatsukadai, Nishi-ku, Kobe City Inside Kobe Steel Research Institute, Kobe Steel Ltd. (72) Inventor Akinori Tsuchiya 65-8 Hirasawa, Hadano-shi, Kanagawa, Inc. F term in Kobe Steel Hadano Works (reference) 4K062 AA01 AA05 AA10 BB06 BC07 CA10 EA02 FA04 FA05 FA16 GA10
Claims (3)
リン脱酸銅管または無酸素銅管であって、前記焼鈍後の
銅管外表面の酸化電流値が6.0 μA 以下であることを特
徴とする耐変色性に優れた銅管。1. A phosphor deoxidized copper tube or an oxygen-free copper tube having a crystal grain size of 0.030 mm or more after annealing, wherein an oxidation current value of an outer surface of the copper tube after annealing is 6.0 μA or less. A copper tube with excellent discoloration resistance.
焼鈍される請求項1に記載の耐変色性に優れた銅管。2. The copper tube having excellent discoloration resistance according to claim 1, wherein the copper tube is annealed after applying a release agent to the surface.
求項1または2に記載の耐変色性に優れた銅管。3. The copper tube according to claim 1, wherein the copper tube is wound in a coil shape.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28537199A JP2001107204A (en) | 1999-10-06 | 1999-10-06 | Copper tube excellent in discoloring resistance |
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JP28537199A JP2001107204A (en) | 1999-10-06 | 1999-10-06 | Copper tube excellent in discoloring resistance |
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JP2001107204A true JP2001107204A (en) | 2001-04-17 |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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WO2016190347A1 (en) * | 2015-05-26 | 2016-12-01 | ダイキン工業株式会社 | Method for producing evaporator for refrigeration device |
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1999
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2016190347A1 (en) * | 2015-05-26 | 2016-12-01 | ダイキン工業株式会社 | Method for producing evaporator for refrigeration device |
JP2016216811A (en) * | 2015-05-26 | 2016-12-22 | ダイキン工業株式会社 | Production method of vaporizer of freezing device |
CN107614754A (en) * | 2015-05-26 | 2018-01-19 | 大金工业株式会社 | The manufacture method of the evaporator of refrigerating plant |
CN107614754B (en) * | 2015-05-26 | 2018-12-21 | 大金工业株式会社 | The manufacturing method of the evaporator of refrigerating plant |
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