JP2016084512A

JP2016084512A - Plated steel wire excellent in adhesiveness to rubber and rubber composite using the same, and production method therefor

Info

Publication number: JP2016084512A
Application number: JP2014218298A
Authority: JP
Inventors: 児玉　順一; Junichi Kodama; 順一児玉
Original assignee: Nippon Steel and Sumitomo Metal Corp
Current assignee: Nippon Steel Corp
Priority date: 2014-10-27
Filing date: 2014-10-27
Publication date: 2016-05-19
Anticipated expiration: 2034-10-27
Also published as: JP6379999B2

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive plated steel wire that is produced without deteriorating productivity and is excellent in adhesiveness to rubber in which Co salt is not blended, and that has little deterioration of adhesive strength.SOLUTION: There is provided an extra fine plated steel wire which has a wire diameter of 0.1 to 0.4 mm and has on the surface thereof, a plating layer 2 having average thickness of 50 to 500 nm, and in which the plating layer contains, by mass%, carbon black of 1 (hereafter described as CB) of 0.1 to 5 mass% and the balance Cu with inevitable impurities and average diameter of a primary particle of the CB is 10 to 100 nm. There are also provided a rubber composite using the extra fine plated steel wire and a production method for the plated steel wire. This enables the extra fine plated steel wire to have improved strength of adhesion to rubber in which Co salt is not blended and enables the extra fine plated steel wire to have suppressed long-term deterioration of the adhesive strength.SELECTED DRAWING: Figure 1

Description

本発明は、スチールコードなど、タイヤを始めとする各種ゴム製品の補強材に使用される、表面にめっき処理が施された極細鋼線であって、ゴムとの接着性に優れた極細めっき鋼線、ゴム複合体および極細めっき鋼線の製造方法に関するものである。 The present invention is an ultrafine steel wire having a surface plated and used as a reinforcing material for various rubber products including tires such as steel cords, and has an excellent adhesion to rubber. The present invention relates to a method for manufacturing a wire, a rubber composite, and an ultrafine plated steel wire.

ゴム補強材、例えば、タイヤの補強材として使用されているスチールコードの表面には、ブラスめっきが形成されている。このスチールコードを、未加硫ゴムに埋め込み、加硫処理することにより、スチールコードとゴムとを接着させる。なお、加硫処理は、ゴム製品を製造する際の最終工程であり、１５０〜２００℃に２０〜４０分間加圧、加熱する工程である。 Brass plating is formed on the surface of a rubber reinforcing material, for example, a steel cord used as a reinforcing material for a tire. The steel cord is embedded in unvulcanized rubber and vulcanized to bond the steel cord and rubber. In addition, a vulcanization process is a final process at the time of manufacturing a rubber product, and is a process of pressurizing and heating at 150 to 200 ° C. for 20 to 40 minutes.

加硫によって、ゴムの架橋とともにスチールコードのブラスめっきとゴムとの界面に接着層が生成する。この接着層は、ブラスめっきのＣｕ及びＺｎとゴムに含まれるＳ（硫黄）との反応によって形成された硫化物である。 By vulcanization, an adhesive layer is formed at the interface between the steel cord brass plating and the rubber together with the crosslinking of the rubber. This adhesive layer is a sulfide formed by a reaction between Cu and Zn of brass plating and S (sulfur) contained in the rubber.

このように、スチールコードとゴムとは、加硫時に生成する硫化物によって接着される。このため、ブラスめっきの組成は加硫処理後の初期接着性とその後の接着劣化を適正に制御するためにＣｕ比率を６２〜６５％程度の比較的狭い範囲に制御されている。 As described above, the steel cord and the rubber are bonded together by the sulfide generated during vulcanization. For this reason, the composition of the brass plating is controlled in a relatively narrow range of about 62 to 65% in order to appropriately control the initial adhesion after vulcanization and the subsequent adhesion deterioration.

このブラスめっきの製造工程は通常、熱処理後の鋼線に電気銅めっきを行い、さらに、引き続き電気亜鉛めっきを行い層状のめっきとした後に加熱することで、合金化反応を行いブラスめっきとしている。この製造工程では２回の電気めっきと加熱拡散工程が必要となり、エネルギーコストが大きくなる。 In the brass plating manufacturing process, the steel wire after the heat treatment is usually subjected to electrolytic copper plating, and subsequently subjected to electrogalvanization to form a layered plating, followed by heating, thereby performing an alloying reaction to form brass plating. This manufacturing process requires two electroplating and heat diffusion steps, which increases energy costs.

また、ゴム中には、硫化物の生成を促進する触媒としてＣｏを含む有機コバルト塩が配合されることがある。Ｃｏは、スチールコードとゴムとの初期の接着強度を確保するためには有用である。しかし、タイヤなどを高温、高湿環境で使用すると、ブラスめっきのＣｕ及びＺｎとゴムに含まれるＳとの反応が進行する。その結果、接着層が厚くなり、硫化物の組成が変化し、スチールコードとゴムとの接着強度が低下する。 Further, in the rubber, an organic cobalt salt containing Co may be blended as a catalyst for promoting the formation of sulfide. Co is useful for ensuring the initial bond strength between the steel cord and rubber. However, when a tire or the like is used in a high-temperature and high-humidity environment, the reaction between brass and Cu and Zn and S contained in the rubber proceeds. As a result, the adhesive layer becomes thick, the sulfide composition changes, and the adhesive strength between the steel cord and rubber decreases.

さらに、有機コバルト塩は、ゴム分子の二重結合を切断し、ゴムを劣化させるという問題がある。また、ＣｕとＳとの加硫反応の触媒として作用するＣｏは希少金属であり、ゴムにＣｏを含有させると、コストが非常に高くなる。そのため、タイヤなどのゴムから有機コバルト塩を削減することが望まれている。 Furthermore, the organic cobalt salt has a problem of breaking rubber double bonds and deteriorating rubber. Further, Co acting as a catalyst for the vulcanization reaction between Cu and S is a rare metal, and if Co is contained in rubber, the cost becomes very high. Therefore, it is desired to reduce organic cobalt salts from rubber such as tires.

このような問題に対して、各種ブラスめっきが提案されており、非シアン浴による合金ブラスめっき（特許文献１）が提案されているが、高電流密度での製造や、めっき液に有機系添加剤を用いるため薬剤のコストが高くなり、実用性に課題があった。また、接着性改善を目的にブラスめっきにＣｏを含むめっき組成（特許文献２）、Ｎｉをブラスめっきに含むもの（特許文献３）、また、スチールコードの耐食性を改善するためにＣｕ比率を低下し、Ｚｎの犠牲防食を利用するもの（特許文献４）、ＣｕとＺｎの多層めっき後拡散処理を行いブラスめっきにするもの（特許文献５）等各種提案されているが、いずれもＣｕとＺｎめっき組成あるいはこのブラスめっき組成にＣｏ、Ｎｉの微量成分を含むもので、加熱、拡散処理が必要である。 Various types of brass plating have been proposed for such problems, and alloy brass plating using a non-cyan bath (Patent Document 1) has been proposed. However, manufacturing at a high current density and addition of an organic system to the plating solution are proposed. Since the agent is used, the cost of the drug increases, and there is a problem in practicality. Also, for the purpose of improving adhesion, the plating composition containing Co in the brass plating (Patent Document 2), the one containing Ni in the brass plating (Patent Document 3), and reducing the Cu ratio in order to improve the corrosion resistance of the steel cord Various proposals have been made, such as those using sacrificial corrosion protection of Zn (Patent Document 4) and those subjected to diffusion treatment after multilayer plating of Cu and Zn to make brass plating (Patent Document 5). The plating composition or this brass plating composition contains trace amounts of Co and Ni and requires heating and diffusion treatment.

さらに、非合金組成のめっきとしてはコンベアベルト用補強材としてＺｎめっきスチールコード（特許文献６）が提案されているが、Ｚｎめっきとゴム界面に生成する硫化物はＣｕ硫化物に比べ接着強度が低いため、ベルトコンベア以外には適用されていない。 Furthermore, Zn plating steel cord (Patent Document 6) has been proposed as a reinforcing material for conveyor belts as a non-alloy composition plating, but the sulfide produced at the Zn plating and rubber interface has an adhesive strength compared to Cu sulfide. Because it is low, it is not applied to anything other than belt conveyors.

特開２００９−１２７０９７号公報JP 2009-127097 A 特開平１−９８６３２号公報JP-A-1-98632 特開平１−２５９０４０号公報JP-A-1-259040 特開２００７−１００１１９号公報JP 2007-100119 A 特開２００９−２４８１０２号公報JP 2009-248102 A 特開２００６−３１２７４４号公報JP 2006-31744 A

本発明は、生産性を損なわず、低コストでＣｏ塩を配合しないゴムとの接着性に優れ、かつ時間が経過しても接着強度の劣化が少ない、めっき鋼線およびゴム複合体、めっき鋼線の製造方法を提供するものである。 The present invention is a plated steel wire, rubber composite, and plated steel that is excellent in adhesiveness with rubber that does not impair productivity, is low-cost, and does not contain a Co salt, and has little deterioration in adhesive strength over time. A method of manufacturing a wire is provided.

本発明者は、上記課題を解決するために鋭意研究し、Ｃｕめっきを主体とし、１工程で製造でき、ゴムとの接着反応を制御可能なめっき層の形態について検討した。その結果、Ｃｕを母相とし、カーボンブラック（以下ＣＢと記載）をめっき中に分散させることで、めっき線の伸線加工性を確保し、ゴムとの加硫接着時にＣｕの反応を制御するとともに、ＣＢ粒子とゴム界面に強固な反応層が形成され、その結果、ゴム中にＣｏ塩を配合することなく、接着強度を向上させ、かつ、接着強度の経年劣化を抑制することが可能となることを見出して本発明を完成した。 The present inventor has intensively studied in order to solve the above-mentioned problems, and studied the form of the plating layer that can be manufactured in one process mainly with Cu plating and can control the adhesion reaction with rubber. As a result, Cu is used as a parent phase, and carbon black (hereinafter referred to as CB) is dispersed during plating to ensure the drawing workability of the plated wire and to control the reaction of Cu during vulcanization adhesion to rubber. At the same time, a strong reaction layer is formed at the interface between the CB particles and the rubber, and as a result, it is possible to improve the adhesive strength and suppress the deterioration of the adhesive strength over time without blending Co salt in the rubber. As a result, the present invention was completed.

本発明の要旨は以下のとおりである。
（１）線径が０．１〜０．４ｍｍであり、表面に、平均厚さが５０〜５００ｎｍであるめっき層を有し、該めっき層が、質量％で、カーボンブラック（以下ＣＢと記載）：０．１〜５％を含有し、残部がＣｕ及び不可避的不純物からなることを特徴とするゴムとの接着性に優れた極細めっき鋼線。
（２）Ｃｕめきに分散したＣＢの一次粒子の平均径が１０ｎｍ〜１００ｎｍであることを特徴とする（１）のゴムとの接着性に優れた極細めっき鋼線。
（３）ゴム組成物に（１）又は（２）記載の極細めっき鋼線が埋設されたゴム複合体。
（４）ゴム組成物には有機酸コバルト塩を含まないことを特徴とした（３）記載のゴム複合体。
（５）ＣＢ粒子が分散したＣｕめっき鋼線を湿式伸線を行う場合、鋼線とプーリー間の滑りがなく、逆張力を鋼線の破断荷重の５〜３０％付与しつつ湿式伸線を行うことを特徴とする、ＣＢ分散Ｃｕめっき極細鋼線の製造方法。 The gist of the present invention is as follows.
(1) It has a plating layer having a wire diameter of 0.1 to 0.4 mm and an average thickness of 50 to 500 nm on the surface, and the plating layer is in mass% and is carbon black (hereinafter referred to as CB). ): An ultrafine plated steel wire excellent in adhesiveness to rubber, characterized by containing 0.1 to 5%, the balance being made of Cu and inevitable impurities.
(2) The ultrafine plated steel wire excellent in adhesiveness with rubber according to (1), wherein the average diameter of primary particles of CB dispersed in Cu plating is 10 nm to 100 nm.
(3) A rubber composite in which the ultrafine plated steel wire according to (1) or (2) is embedded in a rubber composition.
(4) The rubber composite according to (3), wherein the rubber composition does not contain an organic acid cobalt salt.
(5) When wet-drawing a Cu-plated steel wire in which CB particles are dispersed, there is no slip between the steel wire and the pulley, and wet drawing is performed while applying reverse tension to 5 to 30% of the breaking load of the steel wire. A method for producing a CB-dispersed Cu-plated extra fine steel wire, which is performed.

本発明のめっき鋼線をスチールコードとして使用すれば、ゴムとの接着強度が、加硫直後から良好であり、かつ、タイヤの使用時などの高温および多湿の環境で時間が経過しても接着強度の劣化が小さく、優れたゴムとの接着性を確保することができ、補強効果が高いゴム複合体を得ることができる。また、ゴムに有機Ｃｏ塩を含有させる必要がない。さらに、１工程のめっき処理のみで製造が可能で、合金化させる加熱拡散処理も不要となり、Ｃｕの加工性、ＣＢの固体潤滑性により伸線加工性も悪化しないため製造コストの削減が可能となり、産業上の貢献が極めて顕著である。 If the plated steel wire of the present invention is used as a steel cord, the adhesive strength with rubber is good immediately after vulcanization, and it adheres even when time passes in a high temperature and high humidity environment such as when using a tire. It is possible to obtain a rubber composite that is less deteriorated in strength, can secure excellent adhesion to rubber, and has a high reinforcing effect. Moreover, it is not necessary to make the rubber contain an organic Co salt. In addition, it is possible to manufacture with only one plating process, no heat diffusion treatment to alloy is required, and wire drawing workability is not deteriorated due to Cu workability and CB solid lubricity, thereby reducing production costs. The industrial contribution is very remarkable.

本発明のめっき層の模式図である。It is a schematic diagram of the plating layer of this invention. ＣＢのストラクチャーの模式図Schematic diagram of CB structure 本発明と従来のめっき線の製造工程を示すThe manufacturing process of this invention and the conventional plated wire is shown.

めっき鋼線とゴムとの接着は、鋼線表面のめっき層に含まれるＣｕとゴムに含まれるＳが加硫処理時に反応し、接着層を形成することで発現する。接着強度は接着層のＣｕ硫化物の生成状況に依存し、接着反応層の密度が高い場合は反応層の組成がＣｕ₂Ｓに近い組成となり、高い強度が得られるが、過剰に反応した場合は接着反応層の密度が低下し、ＣｕＳに近い組成となり、接着強度は低下すると考えられている。しかし、Ｃｕ単相めっきでは加硫初期に過剰に反応し、接着層の反応密度が低下し、ＣｕＳに近い組成となるため、接着強度が大きく低下する。 The adhesion between the plated steel wire and the rubber is manifested when Cu contained in the plated layer on the surface of the steel wire and S contained in the rubber react during the vulcanization treatment to form an adhesive layer. Adhesive strength depends on the state of Cu sulfide formation in the adhesive layer. When the density of the adhesive reaction layer is high, the composition of the reaction layer becomes a composition close to Cu ₂ S and high strength is obtained, but when it reacts excessively Is considered to decrease the density of the adhesion reaction layer, become a composition close to CuS, and decrease the adhesive strength. However, Cu single-phase plating reacts excessively at the initial stage of vulcanization, the reaction density of the adhesive layer is reduced, and the composition is close to that of CuS, so that the adhesive strength is greatly reduced.

本発明者らは、Ｃｕ単相めっきでのＣｕとゴム中Ｓの反応制御について検討を行った。その結果、Ｃｕとゴム中のＳの反応を制御するためにはＣｕ中にＣＢの微粒子を分散させることが有効であることを知見した。 The present inventors examined the reaction control between Cu and S in rubber in Cu single-phase plating. As a result, it has been found that it is effective to disperse CB fine particles in Cu in order to control the reaction between Cu and S in rubber.

さらに詳細に、検討を行った結果、Ｃｕめっき中のＣＢには適正な配合率、粒子径の範囲があり、これらを適正に制御することでＣｕとＳの反応が適切に制御できることがわかった。 As a result of further detailed investigation, it was found that CB in Cu plating has an appropriate blending ratio and a range of particle diameter, and the reaction between Cu and S can be appropriately controlled by appropriately controlling these. .

また、Ｃｕめっき中に分散されたＣＢは、伸線加工時にはダイスとの接触面に於いて固体潤滑性能を発揮し、摩擦係数を低下する効果を有し、ゴムとの加硫接着時にはＣＢがＣｕの拡散障壁となり、Ｃｕの過剰反応を抑制するとともにめっき表面に露出したＣＢはゴムとの加熱、加圧による加硫工程で、ゴムとの界面に強固な反応層を形成し、ゴムとめっき層の接着をより強固にする。この反応層は熱や水分の影響を受けず、接着劣化が発生しにくいことも明らかになった。 In addition, CB dispersed in Cu plating exhibits solid lubricating performance at the contact surface with the die at the time of wire drawing, and has an effect of reducing the friction coefficient. CB exposed to the plating surface while serving as a Cu diffusion barrier and suppressing excessive reaction of Cu forms a strong reaction layer at the interface with the rubber in the vulcanization process by heating and pressurizing with the rubber. Strengthen layer adhesion. It was also found that this reaction layer is not affected by heat and moisture, and adhesion deterioration hardly occurs.

また、Ｃｕめっき中にＣＢが分散しためっき層を有する鋼線を伸線加工を行った後でも、同様なめっき構造を維持するためには伸線時にめっき層に作用する摩擦力を低減することが効果的であり、ダイスとの摩擦低減とともに引抜きプーリーと鋼線間での摩擦を低減することで、めっき層の構造の変化がなく、極細鋼線に伸線してもめっき層構造を維持でき、ゴムとの接着性を制御できることを知見し、本発明を完成するに至った。 In addition, to maintain the same plating structure even after drawing a steel wire having a plating layer in which CB is dispersed during Cu plating, the frictional force acting on the plating layer during drawing should be reduced. Is effective, and by reducing friction between the drawing pulley and steel wire as well as reducing friction with the die, there is no change in the structure of the plating layer, and the plating layer structure is maintained even if the wire is drawn to an ultrafine steel wire. It was possible to control the adhesiveness with rubber, and the present invention was completed.

以下、本発明について、詳細に説明する。 Hereinafter, the present invention will be described in detail.

線径：０．１〜０．４ｍｍ
めっき鋼線の線径は、しなやかさを得るために、０．４ｍｍ以下とする。これは、線径が０．４ｍｍより太くなり、しなやかさが低下すると、タイヤのゴム補強材に使用した場合に、自動車の乗り心地が低下するためである。また、線径が太くなると、伸線加工による加工強化代が小さくなり、十分な補強効果が得られない。したがって、極細めっき鋼線の線径は０．４ｍｍ以下が好ましい。一方、線径を細くすると、製造工程が長くなり、最終製品の生産性も低下するために製造に時間とコストがかかる。さらに、めっき線の比表面積が増加し、ゴム中Ｓとめっき中Ｃｕの反応が進行し、ＣＢ分散による反応制御性が低下し、十分な接着性を確保できなくなるため、極細めっき鋼線の線径の下限を０．１ｍｍ以上とすることが好ましい。極細鋼線の線径は、より好ましくは０．１７〜０．３４ｍｍである。 Wire diameter: 0.1-0.4mm
The diameter of the plated steel wire is set to 0.4 mm or less in order to obtain flexibility. This is because when the wire diameter is thicker than 0.4 mm and the flexibility is lowered, the ride comfort of the automobile is lowered when used as a rubber reinforcing material for a tire. Moreover, when the wire diameter is increased, the machining strengthening allowance by wire drawing processing is reduced, and a sufficient reinforcing effect cannot be obtained. Therefore, the wire diameter of the ultrafine plated steel wire is preferably 0.4 mm or less. On the other hand, if the wire diameter is reduced, the manufacturing process becomes longer, and the productivity of the final product also decreases, so that manufacturing takes time and cost. Furthermore, the specific surface area of the plated wire increases, the reaction between S in rubber and Cu in plating proceeds, the reaction controllability due to CB dispersion decreases, and sufficient adhesion cannot be secured. The lower limit of the diameter is preferably 0.1 mm or more. The wire diameter of the ultra fine steel wire is more preferably 0.17 to 0.34 mm.

極細めっき鋼線の強度は、ゴム製品の補強効果を得るため、３２００ＭＰａ以上であることが好ましい。鋼線の成分は必ずしも限定はされないが、強度を確保するため、Ｃ含有量を、０．７〜１．２質量％とすることが好ましい。また、鋼線の金属組織は、パーライト組織が面積率で９５％以上で、粒界にフェライトやセメンタイトの析出を抑制することで、伸線加工性が良好で高強度のめっき線が製造可能となり、好ましい。 The strength of the ultrafine plated steel wire is preferably 3200 MPa or more in order to obtain a reinforcing effect of the rubber product. Although the component of a steel wire is not necessarily limited, in order to ensure intensity | strength, it is preferable that C content shall be 0.7-1.2 mass%. In addition, the steel wire has a pearlite structure with an area ratio of 95% or more, and by suppressing the precipitation of ferrite and cementite at the grain boundaries, it is possible to produce high strength plated wires with good wire drawing workability. ,preferable.

本発明の極細めっき鋼線は、熱間圧延材を伸線加工によって製造され、伸線途中で、熱処理、めっき後に拡散加熱処理なしで、更に伸線加工を行い、所定の線径の極細鋼線を得ることができる。例えば、線径が３〜５．５ｍｍの鋼線を熱間圧延によって製造し、これを線径１〜３ｍｍまで伸線加工する。次に、線径１〜３ｍｍの鋼線に、必要に応じてパテンティング熱処理を行い、湿式めっきを施して、Ｃｕめっき中にＣＢが分散しためっき鋼線を得る。更に湿式伸線により、線径が０．１〜０．４ｍｍになるように伸線加工を行う。鋼線の引張強さは、熱処理以降の伸線加工の加工度によって調整する。 The ultra-fine plated steel wire of the present invention is manufactured by drawing a hot-rolled material, and during the drawing, heat treatment, and after wire plating, without further heat treatment, the wire is further drawn to obtain an ultra-fine steel having a predetermined wire diameter. You can get a line. For example, a steel wire having a wire diameter of 3 to 5.5 mm is manufactured by hot rolling, and this is drawn to a wire diameter of 1 to 3 mm. Next, if necessary, a steel wire having a wire diameter of 1 to 3 mm is subjected to a patenting heat treatment and wet-plated to obtain a plated steel wire in which CB is dispersed in Cu plating. Further, the wire drawing is performed by wet drawing so that the wire diameter becomes 0.1 to 0.4 mm. The tensile strength of the steel wire is adjusted according to the degree of wire drawing after the heat treatment.

本発明の極細めっき鋼線のめっき層は、図１に示すようにＣｕ母相にＣＢが分散しためっきである。上述のとおり、本発明のめっき層は、Ｃｕとゴムとの接着性を向上させるための接着反応を適正に制御するとともに、ＣＢが直接ゴムと反応層を形成し、強固な接着を可能とするものである。さらに、１工程でめっきを行いかつ、拡散のための熱処理が不要となることを最大の特徴とする。以下、好ましいめっき組成、形態について説明する。なお、めっき組成の「％」は、「質量％」を意味する。 The plating layer of the ultrafine plated steel wire of the present invention is a plating in which CB is dispersed in a Cu matrix as shown in FIG. As described above, the plating layer of the present invention appropriately controls the adhesion reaction for improving the adhesion between Cu and rubber, and CB directly forms a reaction layer with rubber, thereby enabling strong adhesion. Is. Further, the greatest feature is that plating is performed in one step and no heat treatment for diffusion is required. Hereinafter, preferable plating compositions and forms will be described. Note that “%” in the plating composition means “mass%”.

ＣＢ：０．１〜５％
ＣＢはＣｕ母相に分散しており、Ｃｕとゴムに含まれるＳ加硫処理時に形成する硫化物相の過剰形成を抑制する効果を有する。また、めっき層の表層に露出したＣＢは加硫処理時に、ゴムとの接着面で緻密な反応層を形成し、直接接着作用を発揮する。この結果、Ｃｕを主体とするめっき層でもゴムとの高い接着強度が得られるものである。Ｃｕは展伸性に富み、湿式伸線時の潤滑性を改善し、伸線加工性を向上させる効果があるが、ＣＢを含むことで、ＣＢの固体潤滑性能によりさらに潤滑性が改善される。Ｃｕめっきに分散したＣＢによるこれらの効果を得るためにはＣｕめっき中のＣＢ分散量を、０．１％以上にすることが好ましい。一方、ＣＢが多く分散するとＣｕとＳとの反応が阻害され、めっき表面に露出したＣＢとゴムの反応層のみの接着効果しかなくなり十分な接着強度が得られないため、Ｃｕめっき中のＣＢ分散量は５％以下にすることが好ましい。伸線加工性と、ゴムとの初期接着と接着劣化性をより改善するにはＣＢの配合量を０．７〜３％にすることがより好ましい。 CB: 0.1 to 5%
CB is dispersed in the Cu matrix and has the effect of suppressing the excessive formation of the sulfide phase formed during the S vulcanization treatment contained in Cu and rubber. In addition, CB exposed on the surface layer of the plating layer forms a dense reaction layer on the adhesive surface with rubber during the vulcanization treatment, and directly exerts an adhesive action. As a result, even with a plating layer mainly composed of Cu, high adhesion strength with rubber can be obtained. Cu is rich in malleability and has the effect of improving the lubricity at the time of wet drawing and improving the wire drawing workability. By including CB, the lubricity is further improved by the solid lubricating performance of CB. . In order to obtain these effects due to CB dispersed in Cu plating, the amount of CB dispersed in Cu plating is preferably 0.1% or more. On the other hand, when a large amount of CB is dispersed, the reaction between Cu and S is hindered, and only the reaction effect of the reaction layer of CB and rubber exposed on the plating surface is lost, so that sufficient adhesive strength cannot be obtained. The amount is preferably 5% or less. In order to further improve the wire drawing workability, initial adhesion to rubber, and adhesion deterioration, it is more preferable to adjust the amount of CB to 0.7 to 3%.

なお、極細めっき鋼線のＣｕめっき層中に分散したＣＢ量は、めっき線をアンモニア原液に過硫酸アンモニウムを１０％混合したアルカリ溶液に浸漬してめっき層を溶解し、めっき全質量を求め、溶解液中のＣｕをＩＣＰ（誘導結合プラズマ発光分光分析）あるいは原子吸光分析により求め、全めっき量からＣｕの質量を差し引いた値をＣＢの質量とし、全めっき質量に対する比率として算出した。 The amount of CB dispersed in the Cu plating layer of the ultrafine-plated steel wire is obtained by immersing the plating wire in an alkaline solution in which 10% ammonium persulfate is mixed in an ammonia stock solution to dissolve the plating layer, and the total mass of the plating is obtained and dissolved. Cu in the solution was obtained by ICP (inductively coupled plasma emission spectroscopy) or atomic absorption analysis, and the value obtained by subtracting the mass of Cu from the total plating amount was defined as the mass of CB, and calculated as a ratio to the total plating mass.

ＣＢの粒子サイズ：１０〜１００ｎｍ
ＣＢは図２に模式的に示すように単一粒子が凝集したストラクチャーを形成する。しかし、伸線加工時にめっき層に作用する大きな面圧によりストラクチャー構造は変形と分断により、一次粒子が並んだ分散状況になる。従って、めっき中のＣｕの拡散パスに影響を及ぼすＣＢの粒径は単一の一次粒子となる。この一次粒子径が小さい場合はＣｕの拡散抑制効果が得られないとともに、ダイスとＣＢ表面の接触面積が低下し、伸線時にダイスと鋼線間の摩擦低減効果も小さくなるため、ＣＢ粒子サイズは１０ｎｍ以上が好ましい。一方、ＣＢの粒径が大きい場合は伸線によりＣｕめっき母相中のＣＢ粒子が粗な状態で分散するために、Ｃｕの拡散制御が不均一となり、接着反応層の形成が局部的に変化し、接着強度ばらつきが大きくなるとともに安定した潤滑性改善効果が得られないためＣＢの平均粒径は１００ｎｍ以下が好ましい。より好ましくは２０〜８０ｎｍである。 CB particle size: 10 to 100 nm
CB forms a structure in which single particles are aggregated as schematically shown in FIG. However, due to the large surface pressure acting on the plating layer during wire drawing, the structure structure is in a dispersed state in which primary particles are aligned due to deformation and fragmentation. Therefore, the particle size of CB that affects the Cu diffusion path during plating is a single primary particle. When the primary particle size is small, the Cu diffusion suppressing effect cannot be obtained, the contact area between the die and the CB surface is reduced, and the friction reducing effect between the die and the steel wire is reduced at the time of wire drawing. Is preferably 10 nm or more. On the other hand, when the particle size of CB is large, CB particles in the Cu plating matrix phase are dispersed in a rough state due to wire drawing, so Cu diffusion control becomes uneven and formation of the adhesion reaction layer changes locally. The average particle size of CB is preferably 100 nm or less because the dispersion of adhesive strength becomes large and a stable lubricity improvement effect cannot be obtained. More preferably, it is 20-80 nm.

ＣＢの粒子サイズはめっき断面のＳＥＭ（走査型電子顕微鏡）あるいはＴＥＭ（透過型電子顕微鏡）観察で、分散粒子を観察し、その画像の粒子を画像解析により、円換算して粒子分布を求め、面積率が５０％となる粒子径を平均粒子径として求めることができる。 The particle size of the CB is obtained by observing the dispersed particles by SEM (scanning electron microscope) or TEM (transmission electron microscope) observation of the plating cross section, and calculating the particle distribution by converting the particles of the image into a circle by image analysis, The particle diameter at which the area ratio is 50% can be determined as the average particle diameter.

本発明で用いるＣＢは一般的な、各種製法によるものが利用可能で、製造方法は熱分解によるサーマル法、アセチレン分解、不完全燃焼法：コンタクト法、ランプ法、ガスファーネス法、オイルファーネス法によるものが使用可能である。 CB used in the present invention can be obtained by various general manufacturing methods, and the manufacturing method is a thermal method by thermal decomposition, acetylene decomposition, incomplete combustion method: contact method, lamp method, gas furnace method, oil furnace method. Things can be used.

また、粒子径の異なるＣＢはそれぞれ異なる種類のＣＢを使用することで変えることが可能で、例えば、ＩＳＡＦ、ＨＡＦ、ＦＥＦ、ＧＰＦ、ＳＲＦの略号で示され、平均粒径が１０ｎｍ〜１００ｎｍのものが使用可能である。 In addition, CBs having different particle sizes can be changed by using different types of CBs, for example, those represented by abbreviations of ISAF, HAF, FEF, GPF, and SRF and having an average particle size of 10 nm to 100 nm. Can be used.

めっき厚さ：５０〜１００ｎｍ
ＣＢが分散したＣｕめっきが薄すぎると、めっきを施す前の鋼線の表面の凹凸に起因して、めっき鋼線の表面に、局所的に地鉄が露出した部分（Ｆｅ露出部）が生じることがある。このＦｅ露出部では、ゴムと接着しないのみではなく、伸線時にダイスとの直接接触による焼き付きが発生し、伸線材の著しい延性の低下、傷の発生、ダイスの割損等のトラブルとなる。したがって、ＣＢが分散したＣｕめっきの平均厚さを５０ｎｍ以上にすることが好ましい。一方、めっきが厚すぎると、使用時に接着層に供給されるＣｕ量が増加し、時間の経過とともに、接着層が成長し、Ｃｕ硫化物の組成がＣｕＳに近くなり、接着強度が低下することがある。したがって、極細めっき鋼線とゴムとの接着強度の経年劣化を抑制するには、ＣＢが分散したＣｕめっきの平均厚さを５００ｎｍ以下にすることが好ましい。さらに好ましくはＣＢが分散したＣｕめっきの平均厚さは１５０〜３５０ｎｍである。 Plating thickness: 50-100nm
If the Cu plating in which CB is dispersed is too thin, a portion (Fe exposed portion) where the ground iron is locally exposed on the surface of the plated steel wire is generated due to the unevenness of the surface of the steel wire before plating. Sometimes. This exposed Fe portion not only does not adhere to the rubber, but also seizes due to direct contact with the die during wire drawing, resulting in troubles such as a marked decrease in ductility of the wire drawing material, scratches, and die breakage. Therefore, the average thickness of Cu plating in which CB is dispersed is preferably 50 nm or more. On the other hand, if the plating is too thick, the amount of Cu supplied to the adhesive layer during use increases, and as time passes, the adhesive layer grows, the composition of Cu sulfide becomes close to CuS, and the adhesive strength decreases. There is. Therefore, in order to suppress the aging deterioration of the adhesive strength between the ultrafine plated steel wire and the rubber, the average thickness of the Cu plating in which CB is dispersed is preferably 500 nm or less. More preferably, the average thickness of Cu plating in which CB is dispersed is 150 to 350 nm.

極細めっき鋼線のめっき層の平均厚さは、めっき線をアンモニア原液に過硫酸アンモニウムを１０％混合したアルカリ溶液に浸漬してめっき層を溶解し、めっき全質量を求め、溶解液中のＣｕをＩＣＰ（誘導結合プラズマ発光分光分析）あるいは原子吸光分析により求め、全めっき量からＣｕの質量を差し引いた値をＣＢの質量とし、Ｃｕ、ＣＢの比重から以下の式でめっきの平均厚さを求める。
めっき厚ｔ＝Ｗ／（Ａ×ρ）（１）
ただし、ｔ：平均めっき厚さ、Ｗ：単位長さのめっき質量、Ａ：単位長さのめっき層の表面積、ρ：めっき層の平均比重である。めっき層の平均比重ρは、下記式によって算出することができる。
ρ＝ρ_Cu×Ｗ_Cu＋ρ_CB×Ｗ_CB （２）
ただし、ρ_Cu：Ｃｕの比重、ρ_CB：ＣＢの比重、Ｗ_Cu：めっき中Ｃｕの質量比、Ｗ_CB：めっき中ＣＢの質量比である。 The average thickness of the plating layer of the ultra-fine plated steel wire is determined by immersing the plating wire in an alkaline solution in which 10% ammonium persulfate is mixed in an ammonia stock solution to dissolve the plating layer, obtaining the total mass of the plating, and determining the Cu in the solution. Obtained by ICP (Inductively Coupled Plasma Emission Spectroscopy) or atomic absorption spectrometry, the value obtained by subtracting the mass of Cu from the total plating amount is taken as the mass of CB, and the average thickness of plating is obtained from the specific gravity of Cu and CB by the following formula. .
Plating thickness t = W / (A × ρ) (1)
Here, t: average plating thickness, W: plating mass of unit length, A: surface area of plating layer of unit length, and ρ: average specific gravity of plating layer. The average specific gravity ρ of the plating layer can be calculated by the following formula.
ρ = ρ _Cu × W _Cu + ρ _CB × W _CB (2)
However, ρ _Cu : specific gravity of Cu, ρ _CB : specific gravity of CB, W _Cu : mass ratio of Cu in plating, W _CB : mass ratio of _{CB in} plating.

次に、本発明の極細めっき鋼線の製造工程の例について説明する。図３の製造工程のブロック図に示すように、まず、熱間圧延によって製造した線径が３〜５．５ｍｍの鋼線を、デスケーリングして、これを線径１〜３ｍｍまで伸線加工（乾式伸線）して、コイルに巻き取る。次に、コイルから繰り出した線径１〜３ｍｍの鋼線に、パテンティング熱処理を施し、加工の影響を除去することが好ましい。さらに、必要に応じて、酸洗によるデスケーリング、脱脂のめっき前処理を施す。 Next, the example of the manufacturing process of the ultra fine plated steel wire of this invention is demonstrated. As shown in the block diagram of the manufacturing process in FIG. 3, first, a steel wire with a wire diameter of 3 to 5.5 mm manufactured by hot rolling is descaled and drawn to a wire diameter of 1 to 3 mm. (Dry wire drawing) and wind it on a coil. Next, it is preferable to perform a patenting heat treatment on a steel wire with a wire diameter of 1 to 3 mm fed from a coil to remove the influence of processing. Furthermore, if necessary, descaling by pickling and degreasing pretreatment for plating are performed.

従来はめっき前処理に引き続き、湿式Ｃｕめっきを行い、その後、湿式Ｚｎめっきを行い、温度４８０〜５５０℃に５〜１０ｓ加熱してＣｕとＺｎを拡散により、合金化処理を行わせ、ブラスめっきとし、さらに伸線を行い、極細鋼線を製造する。 Conventionally, following the pre-plating treatment, wet Cu plating is performed, followed by wet Zn plating, heating to a temperature of 480 to 550 ° C. for 5 to 10 s, diffusion of Cu and Zn, alloying treatment is performed, and brass plating is performed. Then, the wire is further drawn to produce an extra fine steel wire.

一方、本発明は前処理後、ＣＢが分散したＣｕイオンが溶解しためっき浴により湿式電気めっきを行い、めっき層中にＣＢ粒子が分散しためっきとし、めっき後は、全く熱処理を行わず、さらに伸線加工を行い、極細鋼線を製造するものである。 On the other hand, in the present invention, after pretreatment, wet electroplating is performed with a plating bath in which Cu ions in which CB is dispersed are dissolved, and CB particles are dispersed in the plating layer. After the plating, no heat treatment is performed. Wire drawing is performed to produce an ultra fine steel wire.

ＣＢ粒子が分散したＣｕめっきは、例えばピロリン酸銅めっき浴中に、ＣＢ粒子を添加し、攪拌したものを電気めっきすることで得られる。また、高電流密度でめっきを行う場合は、めっき浴流速を１ｍ／ｓ以上とすることで、３０Ａ／ｄｍ²でもめっき焼けが発生せず、通電のＯＮ／ＯＦＦを周期的に繰り返す、パルスめっきを行うことで、より安定した分散めっきを得ることが可能となる。 Cu plating in which CB particles are dispersed can be obtained, for example, by adding CB particles to a copper pyrophosphate plating bath and electroplating the mixture after stirring. Also, when plating at high current density, pulse plating with a plating bath flow rate of 1 m / s or higher does not cause plating burn even at 30 A / dm ² and periodically repeats ON / OFF of energization. By performing the step, it becomes possible to obtain a more stable dispersion plating.

パルスめっきを行う場合は、ｄｕｔｙ（＝ｔ_on／（ｔ_on＋ｔ_off）×１００）を３０〜７０％とし、電硫の印加時間を０．１ｍｓ〜１００ｍｓで制御することが好ましい。ここで、ｔ_onとは通電印加時間を意味し、ｔ_offとは通電停止時間を意味する。 When performing pulse plating, and 30 to 70% of _{duty (= t on / (t} on + t off) × 100), it is preferable to control the application time of Den硫in 0.1Ms～100ms. Here, t _on means the energization application time, and t _off means the energization stop time.

ＣＢが分散したＣｕめっき鋼線はさらに湿式伸線により線径が０．１〜０．４ｍｍまで伸線する。ここで、湿式伸線はめっきの剥離を抑制し、めっき層の構造変化をなくするために伸線材表面の摩擦力を低減して伸線することが好ましい。具体的にはダイスと鋼線の間の潤滑性能を高めるために低摩擦係数となる湿式潤滑剤を使用する。特にめっき表面に露出したＣＢは固体潤滑機能により伸線時の摩擦を低減し、伸線加工性を改善する。この結果、めっき層は伸線加工により長手方向に延びていくが、同時に厚さも薄くなるため、めっき層中のＣＢのストラクチャーが変形、分断することで、単一粒子の分散状況はめっき時の状態が維持されるため、ＣＢの効果が極細伸線後も十分確保される。 The Cu-plated steel wire in which CB is dispersed is further drawn to a diameter of 0.1 to 0.4 mm by wet drawing. Here, it is preferable that the wet wire drawing is performed by suppressing the peeling of the plating and reducing the frictional force on the surface of the wire drawing material in order to eliminate the structural change of the plating layer. Specifically, a wet lubricant having a low coefficient of friction is used in order to enhance the lubrication performance between the die and the steel wire. In particular, CB exposed on the plating surface reduces friction during wire drawing by a solid lubricating function and improves wire drawing workability. As a result, the plating layer extends in the longitudinal direction by wire drawing, but at the same time the thickness is reduced, so that the CB structure in the plating layer is deformed and divided, so that the dispersion state of single particles is Since the state is maintained, the effect of CB is sufficiently ensured even after ultra fine wire drawing.

また、引抜キャプスタンと鋼線の間のスリップがないノンスリップ式伸線を行うことで伸線加工時のめっきの剥離が抑制される。従来のスリップ式伸線ではめっきの剥離が大きいため、伸線後にはめっき中のＣＢの分散状況は粗になり、粒子密度が低下し、目的の効果が得にくい。 Moreover, peeling of the plating at the time of a wire drawing process is suppressed by performing the non-slip type | mold wire drawing without the slip between a drawing capstan and a steel wire. In conventional slip-type wire drawing, the peeling of the plating is large. Therefore, after the wire drawing, the state of CB dispersion during plating becomes rough, the particle density decreases, and the desired effect is difficult to obtain.

さらに、湿式伸線でめっきを剥離することなく、伸線するために逆張力を制御することが好ましい。伸線材の破断荷重に対する割合（逆張力比）で、５％以上の逆張力を負荷することで、ダイスとの接触部で面圧が低減し、伸線材表面に作用する摩擦力が減少し、めっき層に加わる力が低減されるためにめっきの剥離が少なくなり、均一なめっき層の分散状態を維持したままでの伸線加工が可能となり、好ましい。一方、逆張力比が３０％を越えるとワイヤにかかる負荷が大きくなり、断線が発生し易くなるため、３０％の逆張力比を上限とすることが好ましい。より好ましくは５〜２０％の逆張力比を付与して湿式伸線を行う条件である。 Furthermore, it is preferable to control the reverse tension in order to draw the wire without peeling the plating by wet drawing. By applying a reverse tension of 5% or more as a ratio (reverse tension ratio) to the breaking load of the wire drawing material, the surface pressure is reduced at the contact portion with the die, and the frictional force acting on the surface of the wire drawing material is reduced. Since the force applied to the plating layer is reduced, peeling of the plating is reduced, and wire drawing can be performed while maintaining a uniform dispersed state of the plating layer, which is preferable. On the other hand, if the reverse tension ratio exceeds 30%, the load applied to the wire increases and breakage is likely to occur. Therefore, it is preferable to set the reverse tension ratio of 30% as the upper limit. More preferably, the reverse tension ratio of 5 to 20% is applied and wet wire drawing is performed.

湿式伸線時の逆張力の付与する方法は特に限定はされないが、ダンサー式あるいはモーターのトルク制御により逆張力の制御が可能である。特にダンサー式の逆張力の制御方法はリアルタイムに制御できるため、より高精度の逆張力制御が可能となり、好ましい伸線時の逆張力制御方法である。 The method of applying reverse tension during wet drawing is not particularly limited, but reverse tension can be controlled by a dancer type or motor torque control. In particular, since the dancer-type reverse tension control method can be controlled in real time, it is possible to perform reverse tension control with higher accuracy and is a preferable reverse tension control method during wire drawing.

本発明の極細めっき鋼線を補強材としてタイヤに適用する場合は、タイヤの走行性能にあわせて適宜複数本撚り合わせ、スチールコードとしてゴムとＣＢ、硫黄、酸化亜鉛、その他各種添加剤を配合した原材料を練ったシート状ゴムに埋め込み、補強ベルト構造とする。その後、タイヤ構成部材を貼り合わせて加硫機にセットし、プレス、加熱し、ゴムの強度を発現するための架橋と同時にゴムとスチールコードとの接着を行い、ゴムとスチールコードからなるゴム複合体を得ることができる。 When the ultra fine plated steel wire of the present invention is applied to a tire as a reinforcing material, a plurality of wires are appropriately twisted according to the running performance of the tire, and rubber and CB, sulfur, zinc oxide, and other various additives are blended as steel cords. The raw material is embedded in kneaded sheet-like rubber to form a reinforced belt structure. After that, the tire components are bonded together, set in a vulcanizer, pressed and heated, and the rubber and steel cord are bonded together at the same time as crosslinking to develop the strength of the rubber. You can get a body.

また、ゴム配合原料にはブラスめっきとの接着促進剤として配合される、有機酸Ｃｏ塩（例えば、ナフテン酸コバルト、ステアリン酸コバルト、ネオデカン酸コバルト等）を含まなくても、Ｃｕめっき中に分散されたＣＢの作用により十分な接着反応層を形成するために、高い接着強度のゴム複合体を得ることが可能である。 Even if the rubber compounding raw material does not contain organic acid Co salt (for example, cobalt naphthenate, cobalt stearate, cobalt neodecanoate, etc.) blended as an adhesion promoter with brass plating, it is dispersed in Cu plating. In order to form a sufficient adhesion reaction layer by the action of the formed CB, it is possible to obtain a rubber composite having high adhesive strength.

本発明の鋼材成分は特に限定はされないが、Ｃ：０．７２〜１．２質量％、Ｓｉ：０．２〜０．５質量％、Ｍｎ：０．２〜０．６質量％、Ｐ：０．０１質量％以下、Ｓ：０．０１質量％以下、Ｃｒ：０．０１〜０．３５質量％の成分を有し、パーライト面積率が９５％以上からなる材料が極細線の強度を確保し、ゴム複合体の補強効果を発揮させるのに好ましい。 Although the steel material component of this invention is not specifically limited, C: 0.72-1.2 mass%, Si: 0.2-0.5 mass%, Mn: 0.2-0.6 mass%, P: A material having components of 0.01% by mass or less, S: 0.01% by mass or less, Cr: 0.01 to 0.35% by mass, and a pearlite area ratio of 95% or more ensures the strength of the ultrafine wires. However, it is preferable for exerting the reinforcing effect of the rubber composite.

以下、本発明の実施例について説明する。なお、本実施例に記載の内容により本発明の内容は制限されない。 Examples of the present invention will be described below. In addition, the content of this invention is not restrict | limited by the content as described in a present Example.

表１に示す成分を有する鋼材を図３に示す製造工程に従い、線径が５．５ｍｍの熱間圧延線材を原材料とし、熱間圧延線材を酸洗し、スケールを除去した後、石灰処理を行い、ステアリン酸Ｎａを主体とした乾式潤滑剤を用いて１．５ｍｍまで伸線加工した。この伸線材に、熱処理として１０００℃の加熱炉に導入し、４５ｓ保持し、金属組織をオーステナイトにした後、６００℃の鉛浴に６ｓ浸漬するパテンティング処理を行った。 The steel material having the components shown in Table 1 is manufactured in accordance with the manufacturing process shown in FIG. 3. The hot rolled wire material having a wire diameter of 5.5 mm is used as a raw material, the hot rolled wire material is pickled, the scale is removed, and lime treatment is performed. The wire was drawn to 1.5 mm using a dry lubricant mainly composed of Na stearate. The wire drawing material was introduced into a heating furnace at 1000 ° C. as a heat treatment, held for 45 s, and after making the metal structure austenitic, a patenting treatment was performed by immersing in a lead bath at 600 ° C. for 6 s.

パテンティング処理を行った鋼線に、連続して、硫酸による電解酸洗とアルカリ溶液による電解脱脂を施し、ピロリン酸銅めっきにＣＢ粒子が分散しためっき浴を用いて電気めっきを行った。この時のめっき液中のＣＢ濃度、粒子サイズの異なるＣＢを用い、めっき中のＣＢ濃度、ＣＢ粒子サイズの異なるＣＢ分散Ｃｕめっきを有する鋼線を得た。一部の比較例については、電気めっきとして前記に換えてＣｕめっきとＺｎめっきを行った後拡散熱処理を行い、Ｃｕ濃度が６３％であるブラスめっき極細めっき鋼線とした。 The steel wire subjected to the patenting treatment was successively subjected to electrolytic pickling with sulfuric acid and electrolytic degreasing with an alkaline solution, and electroplating was performed using a plating bath in which CB particles were dispersed in copper pyrophosphate plating. At this time, CB having different CB concentration and particle size in the plating solution was used to obtain a steel wire having CB dispersed Cu plating having different CB concentration and CB particle size in plating. About some comparative examples, it changed into the above as electroplating, and after carrying out Cu plating and Zn plating, the diffusion heat treatment was performed, and it was set as the brass plating ultra-thin plating steel wire whose Cu concentration is 63%.

めっき後の湿式伸線については、ノンスリップ式のダンサーにより逆張力が制御可能な伸線機でエマルションタイプの湿式潤滑剤を用いて湿式伸線により、線径が０．１〜０．４ｍｍになるように伸線加工を行い、極細めっき鋼線を製造した。一部実施例では、スリップ式湿式伸線によって極細めっき鋼線を製造した。湿式伸線加工性は、ダイス寿命と断線発生率によって評価し、ブラスめっき鋼線をスリップ式伸線機で伸線した場合（表２の比較例Ｎｏ．１５）の伸線性を１００とし、これに対する指数を極細めっき鋼線の伸線加工性として評価した。伸線性指数が９０以上であれば合格とした。 For wet wire drawing after plating, the wire diameter becomes 0.1 to 0.4 mm by wet wire drawing using an emulsion type wet lubricant with a wire drawing machine whose reverse tension can be controlled by a non-slip dancer. Thus, wire drawing was performed to produce an ultrafine plated steel wire. In some examples, an ultrafine plated steel wire was manufactured by slip-type wet wire drawing. Wet wire drawing workability is evaluated based on the die life and the occurrence rate of wire breakage. The wire drawing property when a brass-plated steel wire is drawn with a slip-type wire drawing machine (Comparative Example No. 15 in Table 2) is defined as 100. Was evaluated as the drawing workability of the ultra-fine plated steel wire. If the drawability index was 90 or more, it was determined to be acceptable.

極細めっき鋼線から試料を採取し、レーザー式非接触線径測定装置によって極細めっき鋼線の線径を測定した。めっき厚さは、原液に過硫酸アンモニウムを１０％混合したアルカリ溶液に浸漬し、めっきを溶解し、溶解液をＩＣＰ分析でＣｕ濃度を求め、めっき溶解質量中Ｃｕ量を求め、全めっき質量からＣｕ質量を除いた質量をＣ質量として、めっき中Ｃ量をＣＢ量とし、前記（１）式、（２）式より求めた。 A sample was taken from the ultrafine plated steel wire, and the wire diameter of the ultrafine plated steel wire was measured with a laser-type non-contact wire diameter measuring device. The plating thickness was immersed in an alkaline solution in which 10% ammonium persulfate was mixed with the stock solution, the plating was dissolved, the Cu concentration was determined by ICP analysis of the solution, the Cu amount in the plating dissolution mass was determined, and the Cu content was calculated from the total plating mass. The mass excluding the mass was defined as C mass, and the C amount during plating was defined as the CB amount, which was obtained from the above formulas (1) and (2).

さらに鋼線の断面を研磨し、めっき層をＳＥＭで観察して、ＣＢ粒子の分散状況を確認した。ＣＢ粒子の分散しためっき層のＳＥＭ写真を用いて、写真中のＣＢストラクチャーを特定し、画像処理を行い、ＣＢ単一粒子の面積率、円相当の粒子サイズを求め、平均粒子径はＣＢ粒子の面積率が５０％となる粒子径とした。 Furthermore, the cross section of the steel wire was grind | polished and the plating layer was observed by SEM, and the dispersion | distribution condition of CB particle | grains was confirmed. Using the SEM photograph of the plating layer in which the CB particles are dispersed, the CB structure in the photograph is specified, image processing is performed, the area ratio of the CB single particles, the particle size corresponding to the circle is obtained, and the average particle size is CB particles The particle size was such that the area ratio was 50%.

表２に極細めっき鋼線の線径、鋼材、めっき性状（めっき組成、ＣＢ質量比、ＣＢ平均粒子径）、平均めっき厚さ、湿式伸線方法を示す。なお、極細めっき鋼線の強度は、試験Ｎｏ．２２を除いて３２００ＭＰａ以上であった。 Table 2 shows the wire diameter, steel material, plating properties (plating composition, CB mass ratio, CB average particle diameter), average plating thickness, and wet wire drawing method of the ultrafine plated steel wire. The strength of the ultra-fine plated steel wire Except for 22, it was 3200 MPa or more.

次に、極細めっき鋼線の性能を評価した。ゴムとの接着性は極細めっき鋼線４本を、５ｍｍのピッチで撚り合わせてコードとし、金型にセットしてゴム組成物に埋め込み、１６０℃で、１８分加熱するホットプレスにより加硫処理を行い、接着性評価用試料を製造した。ゴム組成物の組成として、表３に示すＣｏ塩なしとＣｏ塩ありとを用い、表２に示すように使い分けた。 Next, the performance of the ultrafine plated steel wire was evaluated. Adhesiveness to rubber is obtained by twisting 4 ultra-fine plated steel wires at a pitch of 5 mm to form a cord, setting it in a mold, embedding it in a rubber composition, and vulcanizing it with a hot press heated at 160 ° C. for 18 minutes. The sample for adhesive evaluation was manufactured. As the composition of the rubber composition, those having no Co salt and those having a Co salt shown in Table 3 were used, and they were properly used as shown in Table 2.

ゴム組成物からのコード引抜荷重を測定し、接着性を評価した。加硫直後の初期接着強度は、引張試験装置でコードをゴムから引き抜いた時の引抜力を測定し、最大引抜力で評価した。また、接着強度の経年劣化は、ゴムに埋設した試料を８０℃の水に３日浸漬した後、初期接着強度と同様にして、コードをゴムから引き抜いた時の最大引抜力として評価した。なお、接着性は、比較例である試験ＮＯ．１４のブラスめっき鋼線をＣｏ塩を配合したゴム組成物と加硫接着した場合の初期接着強度を１００とし、これに対する指数で評価した。初期接着指数は、評点７５以上であれば良好、評点７０以上であれば合格とした。劣化後の接着指数は、評点７０以上であれば良好、評点６０以上であれば合格とした。 The cord pull-out load from the rubber composition was measured to evaluate the adhesion. The initial bond strength immediately after vulcanization was evaluated by measuring the pulling force when the cord was pulled out of the rubber with a tensile tester and measuring the maximum pulling force. Further, the aging deterioration of the adhesive strength was evaluated as the maximum pulling force when the cord was pulled out from the rubber in the same manner as the initial adhesive strength after the sample embedded in the rubber was immersed in water at 80 ° C. for 3 days. In addition, adhesiveness is test NO. Which is a comparative example. The initial bond strength when vulcanizing and bonding 14 brass-plated steel wires to a rubber composition containing Co salt was set to 100, and the index was evaluated with respect to this. The initial adhesion index was determined to be good if the score was 75 or higher, and passed if the score was 70 or higher. If the adhesion index after deterioration was 70 or more, it was good, and if it was 60 or more, it was considered acceptable.

表２に、極細めっき鋼線のゴムとの接着性、伸線加工性の評価結果を示す。 Table 2 shows the evaluation results of the adhesion of the ultrafine plated steel wire with the rubber and the wire drawing workability.

表２の試験Ｎｏ．１〜１５が本発明例である。試験Ｎｏ．１〜１３は本発明の好適範囲を具備しており、本発明のめっき鋼線はノンスリップ式伸線、スリップ式伸線のいずれでも、またゴム中に有機酸コバルトを配合有無のいずれのゴム組成でも、評点７５以上の良好な初期接着性が確保された。劣化処理後の接着性の低下については、従来のブラスめっき（比較例の試験Ｎｏ．１６）が評点３５であるのに対して、本発明例試験Ｎｏ．１〜１３はいずれも６５以上であって改善効果が明らかである。ノンスリップ式伸線で製造する場合はスリップ式伸線（試験Ｎｏ．３）より高い接着強度と高い伸線加工性が得られる。 Test No. in Table 2 1 to 15 are examples of the present invention. Test No. Nos. 1 to 13 have the preferred range of the present invention, and the plated steel wire of the present invention is either non-slip type or slip type, or any rubber composition with or without organic acid cobalt blended in the rubber. However, good initial adhesion with a rating of 75 or higher was ensured. Regarding the decrease in the adhesiveness after the deterioration treatment, the conventional brass plating (Test No. 16 of the comparative example) has a rating of 35, whereas the test of the present invention example No. 1 to 13 are all 65 or more, and the improvement effect is clear. When manufacturing by non-slip type wire drawing, higher adhesive strength and high wire drawing workability than slip type wire drawing (Test No. 3) are obtained.

本発明の試験Ｎｏ．１４はめっき中のＣＢ粒子径が好適範囲よりは小さく、Ｃｕの拡散の制御性が低くなるため、初期接着、劣化後の接着性とも合格ではあるが良好には至らなかった例である。試験Ｎｏ．１５はＣｕめっき中のＣＢ粒子が好適範囲よりは大きく、部分的に接着反応層が生成し、接着特性が合格ではあるが良好には至らなかった例である。 Test no. No. 14 is an example in which the CB particle diameter during plating is smaller than the preferred range and the Cu diffusion controllability is low, so that both initial adhesion and adhesion after deterioration are acceptable but not satisfactory. Test No. No. 15 is an example in which the CB particles in the Cu plating were larger than the preferred range, an adhesion reaction layer was partially generated, and the adhesion characteristics were acceptable but not satisfactory.

一方、比較例の試験Ｎｏ．１６は従来の拡散ブラスめっき線をスリップ式湿式伸線機で伸線したもので、ゴム中にナフテン酸コバルトを配合したゴムとの接着性を評価したもので、接着性の基準であるが、Ｃｕ、Ｚｎからなる拡散ブラスめっきのため劣化処理後の接着性が低下した例である。 On the other hand, test No. of the comparative example. 16 is a conventional diffusion brass-plated wire drawn by a slip-type wet wire drawing machine, which evaluates adhesiveness with rubber in which cobalt naphthenate is blended in rubber, and is a standard for adhesiveness. This is an example in which the adhesiveness after the deterioration treatment is lowered due to diffusion brass plating made of Cu and Zn.

めっき性状の影響として、試験Ｎｏ．１７はＣＢを含まないＣｕ単相めっき線で、初期接着、劣化後の接着性とも悪化した例である。試験Ｎｏ．１８はＣＢの配合が少なく、Ｃｕ単相めっきと同様に初期接着、劣化後の接着性が悪化した例である。試験Ｎｏ．１９はＣＢの分散量が多く、めっきとゴム中Ｓの反応が阻害され、十分な接着層が形成されず、初期接着性が低下した例である。 As an effect of plating properties, test No. 17 is a Cu single-phase plated wire that does not contain CB, and is an example in which both initial adhesion and adhesiveness after deterioration deteriorated. Test No. No. 18 is an example in which the amount of CB is small and the initial adhesion and the adhesiveness after deterioration are deteriorated similarly to the Cu single-phase plating. Test No. No. 19 is an example in which the amount of CB dispersed is large, the reaction between plating and S in the rubber is inhibited, a sufficient adhesive layer is not formed, and the initial adhesiveness is lowered.

試験Ｎｏ．２０はめっき層厚が薄く、伸線加工で地鉄が露出し、伸線加工性が悪化するととともに、局部的にゴムとの接着性機能が失われ、接着性も低下した例である。試験Ｎｏ．２１はめっき層が厚く、劣化処理による経時変化によるゴム中Ｓと過剰に反応し、接着反応層の密度が低下し、劣化後の接着性が低下した例である。 Test No. No. 20 is an example in which the thickness of the plating layer is thin, the base iron is exposed by wire drawing, the wire drawing workability is deteriorated, the adhesive function with rubber is locally lost, and the adhesiveness is also lowered. Test No. No. 21 is an example in which the plating layer is thick and reacts excessively with S in the rubber due to the change over time due to the deterioration treatment, the density of the adhesion reaction layer decreases, and the adhesiveness after deterioration decreases.

ゴム補強効果について、試験Ｎｏ．２２は線径が太く、強度が３２００ＭＰａ未満であってゴム複合体としての補強効果が小さくなった例である。試験Ｎｏ．２３は線径が細く、伸線加工性が低下するとともに、比表面積が増加し、ゴム中Ｓとの反応性が高くなり、ＣＢによる反応制御性が低下し、十分な接着強度が得られなかった例である。 Regarding the rubber reinforcing effect, the test No. 22 is an example in which the wire diameter is large, the strength is less than 3200 MPa, and the reinforcing effect as a rubber composite is reduced. Test No. No. 23 has a thin wire diameter, the wire drawing processability is lowered, the specific surface area is increased, the reactivity with S in the rubber is increased, the reaction controllability by CB is lowered, and sufficient adhesive strength cannot be obtained. This is an example.

試験Ｎｏ．２４は拡散ブラスめっきであるがゴム中にナフテン酸コバルトを配合しないために初期接着が低下した。さらにノンスリップ式湿式伸線で高い逆張力比で伸線しており、めっき中にＣＢを含まないために潤滑性改善が見られなかったことと相まって、断線が多発し、伸線性が低下した例である。 Test No. Although 24 is diffusion brass plating, initial adhesion was lowered because cobalt naphthenate was not blended in the rubber. Furthermore, non-slip type wet wire drawing with a high reverse tension ratio, and because there was no improvement in lubricity due to the absence of CB in the plating, an example of frequent wire breakage and reduced wire drawability It is.

本発明のめっき鋼線は、製造コストも低く、ゴムと強固に接着され、時間が経過してもその接着強度の低下が小さいため、ゴム製品の補強材として好適に使用可能で、補強効果を高く維持可能である。また、ゴム中に接着性を改善するための有機酸コバルトを配合する必要がなく、原材料コストの削減も可能なため、タイヤコード及びビードワイヤだけでなく、ゴムホースやベルトの補強材として使用することが可能であり、産業上の利用可能性が極めて高い。 The plated steel wire of the present invention is low in manufacturing cost, is firmly bonded to rubber, and since the decrease in its adhesive strength is small over time, it can be suitably used as a reinforcing material for rubber products and has a reinforcing effect. Highly maintainable. In addition, there is no need to add organic acid cobalt to improve adhesion in rubber, and the raw material cost can be reduced, so it can be used as a reinforcing material for rubber hoses and belts as well as tire cords and bead wires. It is possible and the industrial applicability is extremely high.

１：カーボンブラック（ＣＢ）
２：Ｃｕめっき層
３：地鉄（被めっき線） 1: Carbon black (CB)
2: Cu plating layer 3: Ground iron (wire to be plated)

Claims

線径が０．１〜０．４ｍｍであり、表面に、平均厚さが５０〜５００ｎｍであるめっき層を有し、該めっき層が、質量％で、
カーボンブラック（以下ＣＢと記載）：０．１〜５％、
を含有し、残部がＣｕ及び不可避的不純物からなることを特徴とするゴムとの接着性に優れた極細めっき鋼線。 The wire diameter is 0.1 to 0.4 mm, and the surface has a plating layer having an average thickness of 50 to 500 nm.
Carbon black (hereinafter referred to as CB): 0.1 to 5%,
An ultrafine plated steel wire excellent in adhesiveness to rubber, characterized in that the balance is made of Cu and inevitable impurities.

Ｃｕめっきに分散したＣＢの一次粒子の平均径が１０ｎｍ〜１００ｎｍであることを特徴とする請求項１記載のゴムとの接着性に優れた極細めっき鋼線。 2. The ultrafine plated steel wire excellent in adhesion to rubber according to claim 1, wherein the average diameter of primary particles of CB dispersed in Cu plating is 10 nm to 100 nm.

ゴム組成物に請求項１又は２記載のめっき鋼線が埋設されたゴム複合体。 A rubber composite in which the plated steel wire according to claim 1 or 2 is embedded in a rubber composition.

ゴム組成物には有機酸コバルト塩を含まないことを特徴とした請求項３記載のゴム複合体。 4. The rubber composite according to claim 3, wherein the rubber composition does not contain an organic acid cobalt salt.

カーボンブラック（以下ＣＢと記載）粒子が分散したＣｕめっき鋼線を伸線加工するに際し、引抜プーリーと鋼線の間でスリップせず、鋼線に作用する逆張力を鋼線破断荷重の５〜３０％付与しつつ湿式伸線を行うことを特徴とする、極細めっき鋼線の製造方法。 When drawing a Cu-plated steel wire in which carbon black (hereinafter referred to as CB) particles are dispersed, the reverse tension acting on the steel wire does not slip between the drawing pulley and the steel wire, and the steel wire breaking load is 5 to 5. A method for producing an ultra-fine plated steel wire, characterized by performing wet wire drawing while applying 30%.