JP6410640B2 - Satin nickel plating bath and satin nickel plating method - Google Patents

Description

  The present invention relates to a satin nickel plating bath and a satin nickel plating method capable of forming a nickel plating film having a satin-like appearance on an object to be plated.

  Conventional methods for forming a nickel-plated film with a satin-like appearance include a method of roughing the substrate by a mechanical treatment such as sand blasting or shot blasting, and physically dispersing non-conductive fine particles in a nickel plating bath and co-depositing them. The method (composite method), the method of adding a quaternary ammonium salt and an organic anionic substance in a nickel plating bath, forming an emulsion and inhibiting the film deposition by electrolysis to obtain a satin appearance (emulsion method), etc. I came.

  However, blasting is extremely expensive and is not suitable for current plating processes. The composite method is expensive in constructing an apparatus for uniformly dispersing fine particles, and the resulting satin-like appearance tends to be uneven. Further, in the conventional emulsion method, the emulsion aggregates in a relatively short time, resulting in poor appearance. Therefore, there is a problem that the plating operation time is very short, and there has been a demand for providing a satin nickel plating method capable of operating for a long time.

  As a prior art example of a conventional emulsion method, for example, Patent Document 1 discloses a nickel or nickel / cobalt plating bath containing benzyldimethyltetradecyl ammonium chloride and an organic anionic substance. Patent Document 2 discloses a nickel or nickel / cobalt plating bath containing a quaternary ammonium salt and a sulfosuccinate. Patent Document 3 discloses a nickel or nickel / cobalt plating bath containing a quaternary ammonium salt and a polyether compound.

  Although these prior arts are all capable of operating the plating bath for a long time, in reality, a significant change in the appearance of the plating film was confirmed within a few hours after the plating bath was built. It was also confirmed that emulsion aggregates floated on the surface of the plating bath and adhered to the surface of the object to be plated, leading to poor appearance.

Japanese Patent Laid-Open No. 3-39495 US Pat. No. 6,919,014 Japanese Patent No. 4382656

  The present invention has been made in view of the above-described state of the art, and an object of the present invention is to provide a satin nickel plating bath and a plating method that can be stably operated for a long time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have surprisingly found that at least one quaternary ammonium compound, which has conventionally been an essential component of a satin nickel plating bath, is replaced with at least one kind. It has been found that a satin appearance can be obtained stably for a long time by using primary, secondary and tertiary amines, and further using at least one siloxane compound having a specific structure in combination. Was completed.

（式中、Ｒ１、Ｒ２およびＲ３は、それぞれ独立して水素、炭素数Ｃ_１〜Ｃ_１８の直鎖または分岐鎖アルキル、炭素数Ｃ_１〜Ｃ_１８の直鎖または分岐鎖アルケニル、ジアルキルエーテル、アミノアルキル、フェニルおよびベンジルからなる群から選ばれる基を示す（ただし、Ｒ１、Ｒ２およびＲ３の全てが水素の場合を除く））
で表される第１級、第２級および第３級アミンの少なくとも１種と、
一般式（２）または（３）

（式中、Ｒ４は、水素、アルキル、アミノアルキル、ポリエーテル、エポキシ、脂環式エポキシ、アラルキル、カルビノールおよびカルボキシルからなる群から選ばれる基を示し、ｍは０〜２０の整数を示し、ｎは１〜２０の整数を示す）

（式中、Ｒ５およびＲ６は、それぞれ独立してアルキル、アミノアルキル、エポキシ、脂環式エポキシ、カルビノール、ジオール、メタクリル、ポリエーテル、カルボキシル、フェノール、シラノール、アクリルおよびカルボン酸無水物からなる群から選ばれる基を示し、ｐは１〜２０の整数を示す）
で表されるシロキサン化合物の少なくとも１種とを、
含有することを特徴とするサテンニッケルめっき浴。
（２）被めっき物を上記（１）に記載のサテンニッケルめっき浴で電気めっきすることを特徴とするサテンニッケルめっき方法。
（３）上記（２）方法により得られるサテンニッケル被覆製品。 That is, the gist of the present invention is as follows.
(1) General formula (1)

(Wherein, R1, R2 and R3 are each independently hydrogen, straight or branched chain alkyl having a carbon number of _C 1 _{-C 18,} linear or branched alkenyl of a carbon number of _C 1 _{-C 18,} dialkyl ethers, A group selected from the group consisting of aminoalkyl, phenyl and benzyl is shown (except when R1, R2 and R3 are all hydrogen)
At least one of a primary, secondary and tertiary amine represented by:
General formula (2) or (3)

(Wherein R4 represents a group selected from the group consisting of hydrogen, alkyl, aminoalkyl, polyether, epoxy, alicyclic epoxy, aralkyl, carbinol and carboxyl, m represents an integer of 0 to 20, n represents an integer of 1 to 20)

Wherein R5 and R6 are each independently a group consisting of alkyl, aminoalkyl, epoxy, cycloaliphatic epoxy, carbinol, diol, methacryl, polyether, carboxyl, phenol, silanol, acrylic and carboxylic anhydride. And p represents an integer of 1 to 20)
At least one of siloxane compounds represented by:
A satin nickel plating bath characterized by containing.
(2) A satin nickel plating method characterized by electroplating an object to be plated with the satin nickel plating bath described in (1) above.
(3) A satin nickel-coated product obtained by the method (2).

  According to the present invention, since an emulsion that develops a satin appearance is stably present in the plating solution for a long period of time, continuous operation for a long time is possible as compared with the conventional emulsion method. In addition, the formation of floating substances on the plating bath surface is not recognized, and it is possible to suppress appearance defects due to this.

  The satin nickel plating bath of the present invention (hereinafter referred to as “the bath of the present invention”) is a conventionally known nickel plating bath, and is at least one of primary, secondary and tertiary amines represented by the general formula (1). A seed and at least one siloxane compound represented by the general formula (2) or (3) are contained.

で表される第１級、第２級および第３級アミンにおいて、Ｒ１、Ｒ２およびＲ３は、それぞれ独立して水素、炭素数Ｃ_１〜Ｃ_１８の直鎖または分岐鎖アルキル、炭素数Ｃ_１〜Ｃ_１８の直鎖または分岐鎖アルケニル、ジアルキルエーテル、アミノアルキル、フェニルおよびベンジルからなる群から選ばれる基を示し、好ましくは水素、Ｃ_１〜Ｃ_１８の直鎖アルキル、アミノアルキルおよびベンジルからなる群から選ばれる基であり、より好ましくはＣ_１〜Ｃ_１８の直鎖アルキルである。なお、上記一般式（１）において、Ｒ１、Ｒ２およびＲ３の全てが水素の場合は除かれる。 General formula (1) which is an essential component of the bath of the present invention

In primary, secondary and tertiary amines represented in, R1, R2 and R3 are each independently hydrogen, straight or branched chain alkyl having a carbon number of _C 1 _{-C 18,} carbon atoms _{C 1} straight or branched chain alkenyl, dialkyl ethers -C _18, aminoalkyl, represents a group selected from the group consisting of phenyl and benzyl, comprising preferably hydrogen, straight chain alkyl of C ₁ -C _18, aminoalkyl and benzyl a group selected from the group, more preferably a straight chain alkyl of C ₁ -C _18. In the above general formula (1), the case where all of R1, R2, and R3 are hydrogen is excluded.

  More specific primary, secondary and tertiary amines include laurylamine, octylamine, myristylamine, dimethyllaurylamine, dimethylmyristylamine, dimethyl-cured tallow alkylamine, alkyl-3-aminopropyl ether, N-isopropylbenzylamine, N, N-dimethylbenzylamine, tribenzylamine and the like can be mentioned. Among these, octylamine or dimethyllaurylamine is preferable. These primary, secondary and tertiary amines may be used in combination of two or more.

  The primary, secondary, and tertiary amine contents in the bath of the present invention are not particularly limited, but are, for example, 0.0001 to 0.1 g / L, preferably 0.0005 to 0.05 g / L. More preferably, it is 0.001 to 0.01 g / L.

で表されるシロキサン化合物において、Ｒ４は水素、アルキル、アミノアルキル、ポリエーテル、エポキシ、脂環式エポキシ、アラルキル、カルビノールおよびカルボキシルからなる群から選ばれる基であり、これらの基の中でも好ましくはポリエーテルまたはアラルキルであり、より好ましくはポリエーテルであり、特に好ましくは、ポリエチレングリコール、ポリプロピレングリコール、ポリエチレングリコール・ポリプロピレングリコールコポリマー（アルキレンオキシド付加モル数５〜３０）である。また、ｍは０〜２０の整数、好ましくは２〜１０であり、ｎは１〜２０の整数、好ましくは２〜１０である。 Of the siloxane compounds that are another essential component of the bath of the present invention, the general formula (2)

In the siloxane compound represented by R4, R4 is a group selected from the group consisting of hydrogen, alkyl, aminoalkyl, polyether, epoxy, alicyclic epoxy, aralkyl, carbinol, and carboxyl, and preferably among these groups Polyether or aralkyl, more preferably polyether, particularly preferably polyethylene glycol, polypropylene glycol, polyethylene glycol / polypropylene glycol copolymer (alkylene oxide addition mole number: 5 to 30). M is an integer of 0 to 20, preferably 2 to 10, and n is an integer of 1 to 20, preferably 2 to 10.

で表されるシロキサン化合物において、Ｒ５およびＲ６は、それぞれ独立してアルキル、アミノアルキル、エポキシ、脂環式エポキシ、カルビノール、ジオール、メタクリル、ポリエーテル、カルボキシル、フェノール、シラノール、アクリルおよびカルボン酸無水物からなる群から選択される基であり、これらの基の中でも好ましくはポリエーテルであり、特に好ましくは、ポリエチレングリコール、ポリプロピレングリコール、ポリエチレングリコール・ポリプロピレングリコールコポリマー（アルキレンオキシド付加モル数５〜３０）である。また、ｐは１〜２０の整数、好ましくは２〜１０である。 In addition, the general formula (3)

R5 and R6 are each independently alkyl, aminoalkyl, epoxy, cycloaliphatic epoxy, carbinol, diol, methacryl, polyether, carboxyl, phenol, silanol, acrylic and carboxylic anhydride Among these groups, a polyether is preferable, and a polyethylene glycol, a polypropylene glycol, a polyethylene glycol / polypropylene glycol copolymer (5-30 alkylene oxide addition moles) is particularly preferable. It is. P is an integer of 1 to 20, preferably 2 to 10.

  More specific siloxane compounds include methylphenyl polysiloxane, aminoethylaminopropylmethylsiloxane / dimethylsiloxane copolymer, polyoxyethylene / methylpolysiloxane copolymer, poly (oxyethylene / oxypropylene) methylpolysiloxane copolymer, and the like. Preferred are polyoxyethylene / methylpolysiloxane copolymer and poly (oxyethylene / oxypropylene) methylpolysiloxane copolymer. Two or more of these siloxane compounds may be used in combination.

  Although content of the siloxane compound in this invention bath is not specifically limited, For example, it is 0.0001-0.1g / L, Preferably it is 0.0005-0.05g / L, More preferably, it is 0.001-0.00. 01 g / L.

  What is necessary is just to select the nickel plating bath used as the base of this invention bath from conventionally well-known nickel electroplating baths. Examples of conventionally known nickel electroplating baths include nickel sulfate-based Watt baths and nickel sulfamate baths.

Preferable examples of the nickel plating bath used as the base of the present invention include a nickel sulfate-based Watt bath and a nickel sulfamate bath having the following composition.
<Nickel sulfate base bath>
Nickel sulfate: 280-500 g / L, preferably 350-480 g / L
Nickel chloride: 20 to 100 g / L, preferably 30 to 60 g / L
Boric acid: 20-60 g / L, preferably 30-50 g / L
<Nickel sulfamate base bath>
Nickel sulfamate: 280-650 g / L, preferably 400-550 g / L
Nickel chloride: 0 to 40 g / L, preferably 0 to 20 g / L
Boric acid: 20-60 g / L, preferably 30-50 g / L
In the nickel base bath, nickel chloride may be replaced with nickel bromide, and boric acid may be replaced with citric acid.

  In order to obtain an optimum satin appearance, the bath of the present invention further includes saccharic acid, benzene sulfonic acid, naphthalene disulfonic acid, allyl sulfonic acid, vinyl sulfonic acid, propargyl sulfonic acid and their sodium salts, potassium salts, etc. It is preferred to add a primary brightener. These primary brighteners can be used alone or in combination of two or more.

  Although content of the primary brightener in this invention bath is not specifically limited, For example, it is 0.001-20 g / L, Preferably it is 0.05-10 g / L.

  In order to obtain a stable satin appearance over a long period of time, it is preferable to add an organic anionic substance to the bath of the present invention in order to make the formed emulsion more stable.

式中、Ｒ７およびＲ８は、それぞれ独立して水素、アルカリ金属イオン、アルカリ土類金属イオン、アンモニウムイオン、炭素数Ｃ_１〜Ｃ_１８の直鎖または分岐鎖アルキル、炭素数Ｃ_１〜Ｃ_１８の直鎖または分岐鎖アルケニルおよび環状のアルキル鎖からなる群から選ばれる基である。また、Ａは水素、アルカリ金属イオンおよびアルカリ土類金属イオンからなる群から選ばれる基である。 Examples of the organic anionic substance include sulfosuccinic acid ester represented by the general formula (4) used as a pit inhibitor in a conventionally known nickel plating bath.

Wherein, R7 and R8 are each independently hydrogen, an alkali metal ion, alkaline earth metal ions, ammonium ions, linear or branched chain alkyl having a carbon number of _C 1 _{-C 18,} the number of _C 1 _{-C 18} carbon atoms It is a group selected from the group consisting of linear or branched alkenyl and cyclic alkyl chains. A is a group selected from the group consisting of hydrogen, alkali metal ions and alkaline earth metal ions.

  More specific sulfosuccinic acid esters include sodium di (1,3-dimethylbutyl) sulfosuccinate, sodium diisooctylsulfosuccinate, sodium dihexylsulfosuccinate, sodium diisopropylsulfosuccinate, sodium dibutylsulfosuccinate, and the like. Are sodium di (1,3-dimethylbutyl) sulfosuccinate and sodium dihexylsulfosuccinate. Two or more of these sulfosuccinic acid esters may be used in combination.

  Although content of the organic anion substance in this invention bath is not specifically limited, For example, it is 0.001-0.5 g / L, Preferably it is 0.01-0.1 g / L.

  The bath of the present invention may further contain components that can be added to a conventionally known satin nickel plating bath within a range not impairing the effects of the present invention.

  The bath of the present invention can be prepared, for example, by adding each of the above-described components to the above-described nickel base bath and sufficiently stirring for 30 to 60 minutes with an agitator or a liquid circulation facility until an emulsion is formed.

  A satin nickel-coated product having a satin appearance can be obtained by electroplating an object to be plated using the bath of the present invention described above in the same manner as a conventionally known nickel plating. Moreover, since the emulsion which expresses a satin appearance exists stably in a plating solution for a long time in this invention bath, compared with the conventional method, continuous operation for a long time is attained.

The conditions for electroplating are not particularly limited, and normal nickel plating conditions may be used. For example, the pH of the bath may be in the range of 3 to 6, and preferably in the range of 3.8 to 4.6. The bath temperature may be in the range up to 70 ° C, and preferably in the range of 50-60 ° C. Cathode current density may be in the range of 1~6A / dm ^2, preferably in the range of 2 to 5 A / dm ^2. The electrolytic treatment time in the bath of the present invention is 1 to 20 minutes, preferably 8 to 15 minutes. In electroplating, it is preferable to stir the plating bath with a stirrer or swing the object to be plated with a swinging device.

  In addition, the to-be-plated object which can be satin nickel using this invention bath will not be specifically limited if it is a material which can generally be nickel-plated, and the shape is also not specifically limited. Specific objects to be plated include various parts for decorative plating such as a front grille for automobiles, emblems and interior parts, buttons used for mobile phones, and the like. In addition, before electroplating, the pre-treatment on the metal material such as alkaline degreasing and acid activity and pre-treatment on the resin material such as etching, catalyst application, catalytic activity and chemical nickel plating are performed on the object to be plated, if necessary. Also good.

  Further, after the satin nickel plating, finish plating such as chromium plating, tin / cobalt plating, tin / nickel plating, gold plating or the like may be performed according to a conventionally known method.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
Preparation of a satin nickel plating bath:
A satin nickel plating base bath having the following composition was heated to 52 ° C., and the components shown in Table 1 were added in a state where the liquid circulation was maintained by stirring with a stirrer (300 rpm). Comparative baths 1-4) were prepared. After preparation, the bath temperature and liquid circulation were maintained until the end of the test.
<Satin nickel plating base bath composition>
Nickel sulfate 430g / L
Nickel chloride 45g / L
Boric acid 45g / L
Sodium allyl sulfonate 2g / L
Sodium saccharinate 4g / L
Sodium dihexyl sulfosuccinate 20mg / L

Example 2
Satin nickel plating film formation:
After performing alkaline degreasing (50 ° C., 5 minutes) and acid activity (25 ° C., 1 minute) on a brass substrate (60 × 100 mm), the satin nickel plating bath prepared in Example 1 was subjected to the following conditions. It was immersed and electroplated to obtain a satin nickel plating film. In each bath, a plating film was formed at the lapse of 1 hour and 5 hours after preparation of the satin nickel plating bath.

<Plating conditions>
pH: 4.2
Liquid temperature: 52 ° C
Bath volume: 10L
Anode: Nickel Cathode current density: 4 A / dm ²
Plating time: 10 minutes Stirring: Stirrer stirring (300 rpm) and cathode swing (3 m / min)

After forming the satin nickel plating film, chromium plating EBACHROM E-300 (manufactured by JCU Corporation) was performed as finish plating under the following conditions.
<Chrome plating conditions>
Liquid temperature: 40 ° C
Cathode current density: 10 A / dm ²
Plating time: 3 minutes

Test example 1
Surface Roughness Measurement The surface shape of the plating film obtained in Example 2 was observed with an optical interference type surface roughness meter (WYKO NT9100 manufactured by Veeco Instruments Inc.), and the arithmetic average roughness was measured. Table 2 shows the variation rate of the surface roughness after 5 hours with respect to 1 hour after the preparation of the plating bath.

  In the comparative bath, the emulsion aggregated during 1 to 5 hours after the preparation of the plating bath, and the surface roughness was remarkably increased. On the other hand, in the bath of the present invention, it was found that the fluctuation of the surface roughness was small and the emulsion was stably present in the plating bath. The comparative bath 3 has a bath composition obtained by removing the siloxane compound from the inventive bath 1, but the plating appearance obtained from this bath was a glossy appearance.

Test example 2
Color difference measurement For the appearance evaluation of satin tone, the lightness (L *) and chromaticity (a *, b *) of the plating film obtained in Example 2 were measured using a multi-angle spectrocolorimeter (MA-94 manufactured by x-rite). ) Was measured under the following conditions.
<Lightness / chromaticity measurement conditions>
Light source: D65
Light source incident angle: 45 °
Measurement angle: 25 ° (regular reflection declination)
Measure the color difference (ΔL *, Δa *, Δb *) of the plating film obtained 5 hours after the preparation of the plating bath using the lightness and chromaticity of the plating film obtained 1 hour after the preparation of the plating bath as the standard values. The appearance was evaluated by obtaining (ΔE * ab). The results are shown in Table 3. The total color difference (ΔE * ab) was determined by the following formula (conforming to JIS Z8730).
<All color difference calculation formula>

  Although the evaluation based on the color difference value is originally provided with an allowable range after discussion between the parties, for example, the literature (Japan Printing Society Journal, Vol. 47, No. 5, (2010) P295) describes general visual evaluation. As a general guideline, there is a description of the application range of color difference values (Table 4). Therefore, in the evaluation of the present invention, the range of ΔE * ab <6.0 was set as the allowable range.

  In the comparative baths, ΔE * ab showed a value of 15 or more, and the color tone of the plating film obtained 1 hour after the preparation of the plating bath and the plating film obtained 5 hours later were greatly different. On the other hand, in the bath of the present invention, ΔE * ab shows a value of 4 or less, and even when 5 hours have elapsed after the preparation of the plating bath, the same color tone as that of the plating film obtained 1 hour after the preparation of the plating bath is obtained. I understood that.

Example 3
Confirmation of separation of added components:
The satin nickel plating bath prepared in Example 1 was allowed to stand under the following conditions, and it was confirmed whether floating substances were generated on the plating bath surface. The results are shown in Table 5.
<Satin nickel plating bath leaving condition>
pH: 4.2
Liquid temperature: 52 ° C
Bath volume: 10L
Stirring: Stirrer stirring (300 rpm)
Leaving time: 16 hours

  In comparative baths 1, 2 and 4, it was confirmed that floating substances were formed on the surface of the plating bath by leaving the plating bath. On the other hand, formation of suspended solids was not confirmed in the bath of the present invention, and it was found that the emulsion was stably present in the plating bath for a long time. In addition, although formation of a suspended | floating matter was not recognized also about the comparative bath 3, it should be understood that the emulsion itself is not formed since the plating appearance obtained is a glossy appearance.

The present invention has a longer life than the conventional satin nickel plating bath by the emulsion method and is excellent in workability. Therefore, the present invention can be used in fields such as automotive front grills, emblems and interior parts, and various decorative plating parts such as buttons used in mobile phones.

that's all

Claims (6)

General formula (1)

(Wherein, R1, R2 and R3 are each independently hydrogen, straight or branched chain alkyl having a carbon number of _C 1 _{-C 18,} linear or branched alkenyl of a carbon number of _C 1 _{-C 18,} dialkyl ethers, A group selected from the group consisting of aminoalkyl, phenyl and benzyl is shown (except when R1, R2 and R3 are all hydrogen)
At least one of a primary, secondary and tertiary amine represented by:
General formula (2) or (3)

(Wherein R4 represents a group selected from the group consisting of hydrogen, alkyl, aminoalkyl, polyether, epoxy, alicyclic epoxy, aralkyl, carbinol and carboxyl, m represents an integer of 0 to 20, n represents an integer of 1 to 20)

Wherein R5 and R6 are each independently a group consisting of alkyl, aminoalkyl, epoxy, cycloaliphatic epoxy, carbinol, diol, methacryl, polyether, carboxyl, phenol, silanol, acrylic and carboxylic anhydride. And p represents an integer of 1 to 20)
At least one of siloxane compounds represented by:
A satin nickel plating bath characterized by containing.   Primary, secondary and tertiary amines are laurylamine, octylamine, myristylamine, dimethyllaurylamine, dimethylmyristylamine, dimethyl-cured tallow alkylamine, alkyl-3-aminopropyl ether, N-isopropylbenzylamine The satin nickel plating bath according to claim 1, which is one or more selected from the group consisting of N, N-dimethylbenzylamine and tribenzylamine.   The satin nickel plating bath according to claim 1 or 2, wherein the concentration of primary, secondary and tertiary amines is 0.0001 to 0.1 g / L.   The satin nickel plating bath according to any one of claims 1 to 3, wherein the concentration of the siloxane compound is 0.0001 to 0.1 g / L.   The satin nickel plating bath according to any one of claims 1 to 4, further comprising at least one organic anionic substance. A satin nickel plating method, wherein the object to be plated is electroplated with the satin nickel plating bath according to any one of claims 1 to 5.