KR20190021326A - Water-based compositions for post-treatment of metal surfaces - Google Patents

Abstract

[식 중,
R₁ 은 -H, -CH₃, -C₂H₅, -(C₂H₄O)_p-H, -(C₂H₄O)_p-CH₃, -(C₂H₄O)_p-CH(CH₃)₂,
-(C₂H₄O)_p-C(CH₃)₃ 이고, 여기서 p 는 1 내지 20 이고,
R₂ 는 H 또는 CH₃ 이고,
n 은 0 내지 3 범위의 정수이고,
m 은 0 내지 2 범위의 정수임].A water-based composition for the post-treatment of a metal surface, preferably a silver or silver alloy surface, comprising:
Alkane thiol,
Anionic, cationic, nonionic, amphoteric or zwitterionic surfactants having an HLB value of 12 to 18,
A compound of formula (I)

[Wherein,
R ₁ is _{-H, -CH 3, -C 2 H} 5, - (C 2 H 4 O) p -H, - (C 2 H 4 O) p -CH 3, - (C 2 H 4 O) p -CH (CH ₃ ) ₂ ,
- a _{(C 2 H 4 O) p} -C (CH 3) 3, where p is 1 to 20,
R ₂ is H or CH ₃ ,
n is an integer ranging from 0 to 3,
m is an integer ranging from 0 to 2].

Description

Water-based compositions for post-treatment of metal surfaces

The present invention relates to water-based compositions for the post-treatment of metal surfaces, their use for post-treatment of metal surfaces and their methods.

Silver and silver alloys are used in electronic devices, but it is inevitable that the final product will require additional cleaning and polishing to temporarily remove unwanted tarnish products. It is well known that, depending on exposure to everyday atmospheric conditions, silver and silver alloys generate a glossy-destructive dark film known as discoloration. The prevention of discoloration of metals and metal alloys is a challenge in many industries. The discoloration of metals and metal alloys is particularly problematic in the electronic materials industry where discoloration can cause defective electrical contact between components in an electronic device.

US20070277906A1 discloses a process for the treatment of metals, e. G. Silver or silver alloys, comprising a treating agent selected from alkane thiol, alkyl thioglycolate, dialkyl sulfide or dialkyl disulfide, Discloses a water-based composition comprising at least one of an amphoteric, nonionic or cationic surfactant. Preferably, the composition comprises at least a nonionic relative hydrophobic surfactant such as a cocamide DEA. The compositions are particularly suitable for the treatment of Ag-Cu-Ge alloys.

Object of the Invention

An object of the present invention was to provide a composition for effective post-treatment of metal surfaces, in particular silver or silver alloys, in order to prevent discoloration of the metal surface.

SUMMARY OF THE INVENTION

The present invention provides water-based compositions, their uses and methods for the post-treatment of metal surfaces, preferably silver or silver alloy surfaces. Preferred embodiments are described in the dependent claims.

The metal surface may be used in a variety of applications including automotive, aerospace, construction, communications, furniture, sanitary and consumer goods, as well as surfaces of industrial and decorative surface areas, for example on connectors or IC / leadframe applications, Lt; / RTI >

In particular,

Alkane thiol,

Anionic, cationic, nonionic, amphoteric or zwitterionic surfactant having an HLB value of 12 to 18, preferably 15,

Lt; / RTI >

Further provides a water-based composition for the post-treatment of a metal surface, preferably a silver or silver alloy surface, comprising:

A compound of formula (I)

[Wherein,

R ₁ is _{-H, -CH 3, -C 2 H} 5, - (C 2 H 4 O) p -H, - (C 2 H 4 O) p -CH 3, - (C 2 H 4 O) p -CH (CH ₃ ) ₂ ,

- A is a _{(C 2 H 4 O) p} -C (CH 3) 3, where p is 1 to 20, preferably 1 to 10, more preferably an integer ranging from 2 to 6,

R ₂ is H or CH ₃ , preferably CH ₃ ,

n is an integer ranging from 0 to 3, preferably from 1 to 3, more preferably from 1 or 2,

m is an integer in the range of 0, 1 or 2, preferably 0].

The HLB value was determined by W.C. It was measured according to the method of Griffin.

According to the present invention, in general or in one of the following further embodiments, one or more of the following benefits are obtained:

- Improved anti-fading properties (especially proven by K ₂ S test)

- transparent protective coatings provide high hydrophobic surface properties

- Repel oxidizing agents.

- Prevention of negative effects on the appearance of the transparent composition, the surface treated with the composition

- Improved formation of a self-assembled thiol monolayer on the impregnated silver surface, thereby providing a non-polar film.

- Improved rinsing ability of hydrophobic alkanethiol residues after surface treatment, effective removal of oily residues.

The composition may be an emulsion.

The alkanethiol forms a self-assembled thiol monolayer on the impregnated silver surface, which prevents or delays discoloration.

The compounds of formula I are also referred to as " gemini surfactants ", which have the following general structure:

.

.

The gemini surfactant is composed of two polar heads (hydrophilic groups) arranged on the sides by a spacer to which a hydrophobic tail is connected; The spacers may be rigid or flexible, polar or non-polar. The present invention also discloses the use of such general surfactants in compositions for the post-treatment of metal surfaces. It has been found that by the addition of a surfactant having the above structure, especially by the addition of the constituents of the formula I, an improved anti-tarnish characteristic of the composition can be achieved.

In a preferred embodiment of the compounds of formula I, wherein m = 0, n ranges from 0 to 3, preferably n is in the range of 1 to 3, more preferably n is 1 or 2, R ₁ is independently represents _{-H, -CH 3, -C 2 H} 5 , and _{- (C 2 H 4 O)} p -H is selected from the group consisting of (wherein, p being in the range of 2 to 6).

More preferred compounds of formula I are those selected from the group consisting of 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 2,5,8,11-tetramethyl-6-dodecyne- 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2 , 2 '- [(2,4,7,9-tetramethyl-5-decyne-4,7-diyl) bis (oxy)] diethanol and 2,4,7,9-tetramethyl- 4,7-diol bis polyoxyethylene-ether.

The anionic, cationic, nonionic, amphoteric or zwitterionic surfactant may have a hydrophobic tail which may be linear or branched.

The anionic, cationic, nonionic, amphoteric or zwitterionic surfactants are selected from the group consisting of ethoxylated or propoxylated alkyl, ethoxylated or propoxylated amines, ethoxylated or propoxylated amides, ethoxylated or propoxylated alcohols , Or a mixture thereof. The beneficial surfactant is 3-ethoxy-2-methyl nonane.

The surfactant may have the formula (II)

R ₃ O (CH ₂ CH ₂ O) _x H

[Wherein,

R ₃ is a linear or branched alkyl group of 6 to 15 carbon atoms, preferably 8 to 12 carbon atoms,

and x is an integer ranging from 3 to 15, preferably from 7 to 11.

Preferably, the surfactant is polyethylene glycol, more preferably PEG-11 C10-11 oxo alcohol ethoxylate (CAS Nr: 78330-20-8).

The water-based composition may comprise a co-emulsifying agent, which may also be referred to as a " second surfactant ".

The co-emulsifying agent may have the formula (III)

R ₄ O (CH ₂ CH ₂ O) _y H Formula III

[Wherein,

R ₄ is a linear or branched alkyl group having from 16 to 20 carbon atoms, preferably from 16 to 18 carbon atoms,

and y is an integer ranging from 2 to 10, preferably from 3 to 6.

The co-emulsifying agent is preferably a polyalkylene glycol ether. Preferably, the co-emulsifying agent is an ethoxylated propoxylated alcohol C16-18 (CAS Nr. 68002-96-0).

The alkanethiol is preferably a branched or unbranched C ₁₀ - to C ₂₀ -alkanethiol, more preferably a non-branched C ₁₀ - to C ₂₀ -alkanethiol, such as decanethiol, undecanethiol, dodecanethiol , Hexadecanethiol, heptadecanethiol, octadecanethiol, nonadecanethiol, eicosanthiol, and most preferably heptadecanethiol, octadecanethiol, nonadecanethiol, and eicosanthiol. In one preferred embodiment, the alkanethiol is octadecanethiol.

In a preferred embodiment, the water-based composition does not contain a chromate and / or does not contain an organic solvent.

The water-based composition may have a pH in the range of 1 to 6, preferably 2 to 4. The pH can be controlled by a buffer system. Suitable buffer systems are citric acid / citrate, acetic acid / acetate, tartaric acid / tartrate, phosphoric acid / phosphate or any suitable acid and salt combination.

The water-based composition may comprise the components mentioned in the following quantities:

In another aspect, the invention relates to the use of the water-based composition for the post-treatment of metal surfaces, in particular silver or silver alloy surfaces, after metal deposition, especially after silver or silver alloy deposition to avoid discoloration.

In yet another aspect, the invention relates to a method of post-treatment of a metal surface, in particular a silver or silver alloy surface, comprising the following steps in this order:

a. Providing a metal surface, in particular a silver or silver alloy surface

b. Contacting the metal surface, in particular the silver or silver alloy surface, with the water-based composition described above. Any of the water-based compositions described above may be used.

Contact may be by any suitable method. Step b. May be effected, in particular by impregnation with a water-based composition and / or by spraying onto a surface with a water-based composition.

Step b. May additionally be effected under electroless conditions, i.e. without the supply of current between the metal surface and the electrode.

In another embodiment, step b. Is carried out under application of an electrical current between the at least one electrode and the metal surface, particularly the silver or silver alloy surface, when the metal surface is impregnated with the water-based composition. The metal surface can act as a cathode and the other electrode (which is a counter electrode) can act as an anode, or vice versa. Preferably the metal surface is cathode-like.

The present invention preferably works with composition temperatures in the range of room temperature (22 +/- 2 DEG C) or higher, more preferably in the range of 30 DEG C or higher, and most preferably in the range of 35 to 65 DEG C.

Example

Hereinafter, the present invention will be exemplified by the following working examples.

Inventive Example 1:

c.) a water-based composition wherein the concentration of the compound of formula (I) (compound c1)) varies while the concentration of each of the other components is fixed.

A water-based composition was prepared by dissolving the following components in water:

a. Alkanethiol : octadecanethiol. (CAS No. 2885-00-9)

Amount: 2.5 g / L

b. Surfactant : PEG-11 C10-11 oxo alcohol ethoxylate (CAS Nr: 78330-20-8)

Amount: 17.5 g / l

c. The compounds of formula I: c1) 2,5,8,11- tetramethyl-6-dodecyne-5,8-diol ethoxylate, (CAS Nr 169117-72-0), amount: 2, 3 or 4 g / l

d. Co-emulsifiers: alcohol C16-18 polyalkylene glycol ether, (CAS Nr. 68002-96-0)

Amount: 2.5 g / L.

Inventive Example 2 :

c) the following compounds of the formula I: c2) 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate (CAS Nr. 9014-85-1) and c3) 2, 4,7,9-tetramethyl-5-decyne-4,7-diol (CAS Nr. 126-86-3) was used separately at the same concentration.

A water-based composition was prepared by dissolving the following components in water:

a. Alkanethiol : octadecanethiol. (CAS No. 2885-00-9)

Amount: 2.5 g / L

b. Surfactant : PEG-11 C10-11 oxo alcohol ethoxylate (CAS Nr: 78330-20-8)

Amount: 17.5 g / l

c. Compound of formula I (c2 or c3) : amount: 2 g / l

d. Co-emulsifiers: alcohol C16-18 polyalkylene glycol ether, (CAS Nr. 68002-96-0)

Amount: 2.5 g / L.

Comparative Example:

The concentration of the compound (c1-c3) of formula I is 0 and the other concentrations are the same as in the above, a., B. And d. Lt; / RTI > composition.

1. Method

The post-treatment was performed on the plated copper panel. Such a panel with a copper surface can be provided from the following steps:

● Providing copper panel:

1. Degreasing Uniclean ^TM 260 (Electrophoretic Alkaline Cleaner) Cathode Resistivity 7V / 45 ° C / 30 sec

2. Activation: Impregnation with Uniclean ^TM 675 (weak acid activator) / RT / 30 sec

3. Pre-silver (pre-silver) Pre-silver plating (low silver concentrate solution) Cathode 3V / RT / 15 sec

4. silver plate Silverlume Plus Cathode 1 ASD / RT / 5 min

Or AgO-56 (industrial deposition solution) Cathode 1 ASD / RT / 5 min

Or Argalux ^TM NC mod. (Cyanide-free luster is a deposition solution) Cathode 0.8 ASD / RT / 5 min,

Where RT is the room temperature between 22 ± 2 ° C; DI water is deionized water; ASD is the amperage (A / dm ² ) per decimeter square, and V is the volts / voltage.

The post-treatment composition in the sense of the present invention is used in the field of industrial or decorative (with or without cyanide) silver plating solution for silver plating to avoid discoloration after silver plating, with the silver plating surface obtained otherwise It can also work.

The water-based and comparative-based compositions of the present invention for post-treatment according to the present invention were used under various conditions (see test below).

After the post-treatment in the water-based composition, all samples were rinsed as follows:

- hot DI water rinse,

- cold DI water rinse, and

- Drying by compressed air.

● Post-treatment with the present invention and comparative composition and subsequent visual evaluation after Sulphide test due to:

- Residue after post treatment and rinsing

- coloration and discoloration after the sulfide test.

Observations were performed by a person skilled in the art without any equipment.

● Sulfide test

● Material: glass beaker

● Chemicals: Potassium sulfide 44% K ₂ S, 2% w / w in water

● Temperature: 22 ± 2 ℃

● Immersion temperature: 5 to 10 min

● Evaluation by a person skilled in the art

● Depends on color strength

2. Results

2.1 Rinsing ability test

The water-based compositions of the present invention exhibited improved rinsing capabilities compared to comparative-based compositions and completely eliminated the oil residue problem. Silverlume Plus, AgO-56 and Argalux ^TM NC mod. The surface of the plated silver surface in the treatment with the comparative water-based composition exhibited poor rinsing ability, whereas the water-based composition of the present invention exhibits a very good rinsing ability.

2.2 Anti-discoloration test

The water-based compositions of the present invention exhibited improved anti-discoloration protection compared to comparative-based compositions without the compound (c1-c3) of formula (I). Silverlume Plus, AgO-56 and Argalux ^TM NC mod. The surface of the non-treated surface obtained from the silver plating solution exhibits very poor anti-discoloration protection. These plated silver surfaces treated with the comparative-based composition showed little discoloration after the sulfide test, while the surfaces treated with the water-based compositions of the present invention show almost no discoloration.

Test material: Silver plated surface (Silverlume Plus)

Water-based composition Conditions: pH 2.5 - temperature 55 ° C - shaking 200 RPM - impregnation process for 1 min, rinsing & drying.

Test material: Gloss silver plated surface (Argalux NC ^TM mod), cyanide free

Water-based composition Conditions: pH 2.5 - temperature 55 ° C - shaking 200 RPM - 1 min Impregnation process, rinse & dry.

Test material: Industrial-grade silver plated surface (AgO-56 ^TM )

Water-based composition Conditions: pH 2.5 - temperature 55 ° C - shaking 200 RPM - impregnation process for 1 min, rinsing & drying.

2.3 Use Cathode Castle

Test material: Industrial-grade silver plated surface (AgO-56 ^TM )

Water-based composition Conditions: pH 2.5 - temperature 55 캜 - shaking 200 RPM - impregnation for 1 min, or cathodicity 0.5 A / dm ² for 1 min, rinsing & drying.

3. Conclusion

 The water-based composition of the present invention improves the following:

- wettability of impregnated metal surfaces, especially silver,

- the formation of a self-assembled thiol monolayer on an impregnated silver surface, which produces a non-polar film and improves the anti-fade properties.

Rinsing the hydrophobic alkanethiol residue after silver surface treatment with the water based solution of the present invention.

 Use of impregnation and electrophoresis is suitable for avoiding discoloration of the metal-plated surface after metal plating.

Claims (15)

Alkane thiol,
Anionic, cationic, nonionic, amphoteric or zwitterionic surfactants having an HLB value of 12 to 18
Lt; / RTI >
A water-based composition for the post-treatment of a metal surface, preferably a silver or silver alloy surface, characterized in that it further comprises:
A compound of formula (I)

[Wherein,
R ₁ is _{-H, -CH 3, -C 2 H} 5, - (C 2 H 4 O) p -H, - (C 2 H 4 O) p -CH 3, - (C 2 H 4 O) p -CH (CH ₃ ) ₂ ,
- a _{(C 2 H 4 O) p} -C (CH 3) 3, where p is an integer ranging from 1 to 20,
R ₂ is H or CH ₃ ,
n is an integer ranging from 0 to 3,
and m is an integer ranging from 0, 1 or 2]. 2. A compound of formula I according to claim 1, wherein in the compounds of formula I, m = 0 and n ranges from 0 to 3 and R ₁ is independently -H, -CH ₃ , -C ₂ H ₅ and - (C ₂ H ₄ O ) _p -H, wherein p is in the range of 2 to 6. The process of claim 1, wherein the compound of formula (I) is 2,3,6,7-tetramethyl-4-octyne-3,6-diol, 2,5,8,11-tetramethyl- Diethoxylate, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate, 2,4,7,9-tetramethyl-5- Diol-bis polyoxyethylene ether, and 2,4,7,9-tetramethyl-5-decyne-4,7-diol. 4. The composition according to any one of claims 1 to 3, wherein the surfactant is an ethoxylated or propoxylated alkyl, ethoxylated or propoxylated amine, ethoxylated or propoxylated amide, ethoxylated or propoxylated alcohol, or Water-based composition. 5. A water-based composition according to any one of claims 1 to 4, wherein the surfactant has the formula (II)
R ₃ O (CH ₂ CH ₂ O) _x H (II)
[Wherein,
R ₃ is a linear or branched alkyl group of 6 to 15 carbon atoms, preferably 8 to 12 carbon atoms,
and x is an integer ranging from 3 to 15, preferably from 7 to 11. To claim 1, wherein according to any one of claim 5, wherein the alkane thiol is C ₁₀ - to C ₂₀ - alkane thiol of a water-based composition. 7. The water-based composition of any one of claims 1 to 6, wherein the water-based composition comprises a co-emulsifying agent. 8. The water-based composition of claim 7, wherein the co-emulsifying agent has formula III:
R ₄ O (CH ₂ CH ₂ O) _y H (III)
[Wherein,
R < ₄ > is a linear or branched alkyl group having from 16 to 20 carbon atoms, preferably from 16 to 18 carbon atoms,
and y is an integer ranging from 2 to 10, preferably from 3 to 6. 9. The water-based composition of claim 7 or 8, wherein the co-emulsifying agent is a polyalkylene glycol ether. 10. The water-based composition according to any one of claims 1 to 9, which contains no chromate and / or does not contain an organic solvent. 11. A water-based composition according to any one of claims 1 to 10, wherein the pH is in the range of 1-10. Use of a water-based composition according to any one of claims 1 to 10 for the post-treatment of metal surfaces, in particular silver or silver alloy surfaces, in order to avoid metal discoloration. A method of post-treatment of a metal surface, in particular a silver or silver alloy surface, comprising the following steps in this order:
a. Providing a metal surface, in particular a silver or silver alloy surface,
b. Contacting the metal surface, in particular the silver or silver alloy surface, with the water-based composition according to any one of claims 1 to 11. 14. The method of claim 13, wherein step b. Is applied by any suitable method that allows for contact between the metal and the claimed solution, as impregnation, and / or as a spray, and / or between the metal and the claimed solution. 15. The method according to claim 13 or 14, wherein step b. Is carried out under application of an electrical current between at least one electrode and a metal surface, in particular a silver or silver alloy surface, when the metal is impregnated in the charged solution.