Protective film electrolyte, gold-plated silver ornament and preparation method thereof

文档序号：3654 发布日期：2021-09-17 浏览：56次中文

阅读说明：本技术 保护膜电解液、镀金银饰及其制备方法 (Protective film electrolyte, gold-plated silver ornament and preparation method thereof ) 是由王彤邓川于 2021-06-17 设计创作，主要内容包括：本发明涉及银饰装饰技术领域,公开了一种保护膜电解液、镀金银饰及其制备方法。该保护膜电解液包含硫醇、苯并咪唑类化合物、聚氧乙烯醚类表面活性剂和溶剂；其中,硫醇选自十八硫醇、叔十二硫醇、十六烷基硫醇和1-二十二烷基硫醇中的至少一种；苯并咪唑类化合物选自苯并咪唑、2-巯基苯并咪唑、2-氨基苯并咪唑、2-(氯甲基)苯并咪唑中的至少一种；聚氧乙烯醚类表面活性剂选自辛基酚聚氧乙烯醚、异辛醇聚氧乙烯醚、脂肪醇聚氧乙烯醚、壬基酚聚氧乙烯醚、异构十醇聚氧乙烯醚中的至少一种。利用本发明提供的保护膜电解液制备出的镀金银饰的稳定性好,能有效解决镀金银饰饰品变色的问题。(The invention relates to the technical field of silver ornament decoration, and discloses a protective film electrolyte, a gold-plated silver ornament and a preparation method thereof. The protective film electrolyte comprises mercaptan, a benzimidazole compound, a polyoxyethylene ether surfactant and a solvent; wherein the mercaptan is at least one selected from the group consisting of octadecanethiol, tert-dodecanethiol, hexadecylthiol and 1-docosylthiol; the benzimidazole compound is at least one selected from benzimidazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole and 2- (chloromethyl) benzimidazole; the polyoxyethylene ether surfactant is at least one selected from octyl phenol polyoxyethylene ether, isooctanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonyl phenol polyoxyethylene ether and isomeric decyl polyoxyethylene ether. The gold-plated silver ornament prepared by the protective film electrolyte provided by the invention has good stability, and can effectively solve the problem of color change of the gold-plated silver ornament.)

1. The protective film electrolyte is characterized by comprising mercaptan, a benzimidazole compound, a polyoxyethylene ether surfactant and a solvent; wherein the mercaptan is selected from at least one of octadecanethiol, tert-dodecanethiol, hexadecylthiol and 1-docosylthiol; the benzimidazole compound is selected from at least one of benzimidazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole and 2- (chloromethyl) benzimidazole; the polyoxyethylene ether surfactant is at least one selected from octyl phenol polyoxyethylene ether, isooctanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether and isomeric decyl alcohol polyoxyethylene ether.

2. The protective film electrolyte according to claim 1, wherein the content of the thiol is 1 to 15g/L, the content of the benzimidazole compound is 1 to 20g/L, and the content of the polyoxyethylene ether surfactant is 0.5 to 15 g/L.

3. A preparation method of gold-plated silver ornaments comprises the following steps:

(1) under ultrasonic agitation, putting the silver ornament to be treated into cyanide-free gold plating solution for electroplating to obtain gold-plated silver ornament I; wherein the cyanide-free gold plating solution comprises gold sulfite, 3-nitrobenzoate, organic amine and acid;

(2) putting the gold-plated silver ornament I into protective film electrolyte for electrolysis to obtain a gold-plated silver ornament; the protective film electrolyte comprises mercaptan, a benzimidazole compound, a polyoxyethylene ether surfactant and a solvent.

4. The preparation method according to claim 3, wherein in the cyanide-free gold plating solution, the content of the gold sulfite salt is 5-20g/L in terms of gold element, the content of the sulfite is 30-200g/L, the content of the 3-nitrobenzoate is 1-12g/L, the content of the organic amine is 5-40g/L, and the content of the acid is 10-120 g/L.

5. The production method according to claim 3 or 4, wherein the gold sulfite salt is selected from at least one of gold sodium sulfite, gold potassium sulfite, and gold ammonium sulfite;

the sulfite is selected from sodium sulfite, sodium bisulfite, potassium sulfite, potassium bisulfite, and at least one of ammonium sulfite and ammonium bisulfite;

the 3-nitrobenzoate is at least one of sodium 3-nitrobenzoate, potassium 3-nitrobenzoate and a mixture formed by 3-nitrobenzoic acid and inorganic base;

the organic amine is selected from at least one of ethylenediamine, propylenediamine, butylenediamine, diethylenetriamine, triethylenediamine and tetraethylenepentamine;

the acid is selected from at least one of sulfuric acid, hydrochloric acid, sulfamic acid, phosphoric acid, citric acid, tartaric acid, malic acid, malonic acid and succinic acid.

6. The production method according to claim 3, wherein the conditions of the electroplating include: the gold plating power supply is a single pulse power supply, and the current density is 0.1-1.0A/dm²Preferably 0.2-0.6A/dm²(ii) a The electroplating temperature is 35-65 ℃, preferably 50-65 ℃; the conduction time is 10-30ms, preferably 10-20 ms; the turn-off time is 10-50ms, preferably 10-40 ms; the electroplating time is 5-20min, preferably 10-15 min.

7. The preparation method according to any one of claims 3 to 6, wherein the electroplating conditions further comprise stirring the cyanide-free gold plating solution by ultrasonic waves during electroplating, wherein the frequency of the ultrasonic waves is 10 to 40kHz, preferably 20 to 30kHz, and the intensity of the ultrasonic waves is 100-²Preferably 200-400W/m²。

8. The production method according to claim 3, wherein in the protective film electrolyte, the content of thiol is 1 to 15g/L, the content of benzimidazole compound is 1 to 20g/L, and the content of polyoxyethylene ether surfactant is 0.5 to 15 g/L.

9. The production method according to claim 3, wherein the conditions of electrolysis include: the electrolysis temperature is 40-65 ℃, preferably 45-55 ℃; the electrolytic voltage is 1-8V, preferably 2-6V; the electrolysis time is 0.5-10min, preferably 2-5 min.

10. Gold-plated silver decorations prepared by the process according to claims 3-9.

Technical Field

The invention relates to the technical field of silver ornament decoration, in particular to a protective film electrolyte, a gold-plated silver ornament and a preparation method thereof.

Background

Generally, a casting molding method is adopted for processing the silver ornament product, but sand holes which are irregularly distributed, have different depths and are difficult to distinguish by naked eyes are formed on the surface of the silver ornament product after being melted at high temperature, and are shown in figure 1, and the sand holes are the main reasons of red spots and color change easily generated after gold plating of the silver ornament.

CN111588151A discloses a gold-coated silver ornament and a preparation method thereof, wherein the gold-coated silver ornament comprises a silver substrate, a first isolation layer, a second isolation layer, a gold-plated layer and a protection layer. Although the gold-coated silver ornament product has good wear resistance and corrosion resistance, the first isolating layer formed by electroplating palladium and the second isolating layer formed by PVD deposition cannot completely cover the sand hole defect on the surface of the silver ornament, particularly, the PVD process cannot deposit in the sand hole and cannot play a role of a barrier layer, so that the preparation method cannot essentially solve the problem of color change of the gold-coated ornament.

Therefore, it is desirable to provide gold-plated silver ornaments with good stability and less discoloration, and a preparation method thereof.

Disclosure of Invention

The invention aims to overcome the problem of color change of gold-plated silver ornaments in the prior art, and provides a protective film electrolyte, a gold-plated silver ornament and a preparation method thereof.

In order to achieve the above object, a first aspect of the present invention provides a protective film electrolyte, wherein the protective film electrolyte comprises thiol, a benzimidazole compound, a polyoxyethylene ether surfactant, and a solvent; wherein the mercaptan is selected from at least one of octadecanethiol, tert-dodecanethiol, hexadecylthiol and 1-docosylthiol; the benzimidazole compound is selected from at least one of benzimidazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole and 2- (chloromethyl) benzimidazole; the polyoxyethylene ether surfactant is at least one selected from octyl phenol polyoxyethylene ether, isooctanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether and isomeric decyl alcohol polyoxyethylene ether.

The invention provides a preparation method of gold-plated silver ornaments, which comprises the following steps:

In a third aspect, the invention provides a gold-plated silver ornament prepared by the preparation method of the second aspect.

By adopting the technical scheme, the gold-plated silver ornament prepared by the cyanide-free gold plating solution and the protective film electrolyte has good stability, and no erythema is generated on the surface of the silver ornament within one year in the normal wearing or storage process, so that the problem of color change of a silver ornament gold-plated product can be effectively solved.

Drawings

FIG. 1 is a partially enlarged view of a sand hole on the surface of a gold-plated silver ornament;

FIGS. 2-7 are graphs showing the results of erythema tests on gold-plated silver decorations prepared in examples 1-6;

FIGS. 8-10 are graphs showing erythema test results of the gold-plated silver decorations prepared in comparative examples 1-3.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a protective film electrolyte in a first aspect, wherein the electrolyte comprises mercaptan, a benzimidazole compound, a polyoxyethylene ether surfactant and a solvent; wherein the mercaptan is selected from at least one of octadecanethiol, tert-dodecanethiol, hexadecylthiol and 1-docosylthiol; the benzimidazole compound is selected from at least one of benzimidazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole and 2- (chloromethyl) benzimidazole; the polyoxyethylene ether surfactant is at least one selected from octyl phenol polyoxyethylene ether, isooctanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether and isomeric decyl alcohol polyoxyethylene ether.

The inventor of the invention discovers, through research, that a stable nano film can be formed on the surface of the gold-plated silver ornament by electrolyzing the gold-plated silver ornament by using a protective film electrolyte containing mercaptan, a benzimidazole compound and a polyoxyethylene ether surfactant, sand hole defects on the surface of the gold-plated silver ornament are filled and sealed, a corrosive medium is effectively isolated, and the oxidation resistance and the corrosion resistance of the gold-plated silver ornament are improved.

In a preferred embodiment, in the electrolyte, the content of the mercaptan is 1-15g/L, the content of the benzimidazole compound is 1-20g/L, and the content of the polyoxyethylene ether surfactant is 0.5-15 g/L.

Further preferably, the content of the mercaptan is 2-8g/L, the content of the benzimidazole compound is 2-10g/L, and the content of the polyoxyethylene ether surfactant is 1-10 g/L.

Wherein, in the present invention, the content of the thiol may be any content between 2 and 8g/L, such as 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, 7.5g/L, 8g/L, and any value in the range formed by any two of these contents; the content of the benzimidazole compound can be any content between 2 and 10g/L, such as any value in the ranges of 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, 7.5g/L, 8g/L, 8.5g/L, 9g/L, 9.5g/L, 10g/L and any two of the contents; the polyoxyethylene ether surfactant may be contained in an amount of 1 to 10g/L, for example, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, 7.5g/L, 8g/L, 8.5g/L, 9g/L, 9.5g/L, 10g/L, or any value within a range defined by any two of these contents.

In a preferred embodiment, the solvent is not particularly limited, and any solvent commonly used in the art may be used in the present invention, wherein the solvent may be water, preferably deionized water.

The invention provides a preparation method of gold-plated silver ornaments, which comprises the following steps:

In step (1):

in a preferred embodiment, before the silver ornament to be treated is put into the cyanide-free gold plating solution for electroplating, the silver ornament to be treated is pretreated; wherein the pre-processing comprises: first acid washing activation, ultrasonic cleaning, cathode electrolysis degreasing and second acid washing activation.

In the present invention, the pretreatment operation is a conventional operation in the art, and the present invention is not particularly limited. Wherein, the first acid pickling activation and the second acid pickling activation can be carried out by putting the silver ornament to be treated into 2.5-3.5 wt% sulfuric acid and dipping for 30-60s at room temperature. The room temperature is not particularly limited, and can be 15-40 ℃.

In a preferred embodiment, the cyanide-free gold plating solution can be referred to CN 109881223A (cyanide-free gold plating solution and preparation method and application thereof).

In a preferred embodiment, the cyanide-free gold plating solution further comprises water, and in the cyanide-free gold plating solution, preferably, the content of the gold sulfite salt is 5-20g/L calculated by gold element, the content of the sulfite is 30-200g/L, the content of the 3-nitrobenzoate is 1-12g/L, the content of the organic amine is 5-40g/L, and the content of the acid is 10-120 g/L.

Further preferably, the content of the gold sulfite salt calculated by gold element is 8-16g/L, the content of sulfite is 60-100g/L, the content of 3-nitrobenzoate is 3-8g/L, the content of organic amine is 15-30g/L, and the content of acid is 20-70 g/L.

Preferably, the gold sulfite salt is selected from at least one of gold sodium sulfite, gold potassium sulfite, and gold ammonium sulfite, more preferably, gold sodium sulfite.

Preferably, the sulfite is selected from at least one of sodium sulfite, sodium bisulfite, potassium sulfite, potassium bisulfite, and ammonium sulfite and ammonium bisulfite.

Preferably, the 3-nitrobenzoate is at least one of sodium 3-nitrobenzoate, potassium 3-nitrobenzoate and a mixture of 3-nitrobenzoic acid and inorganic base; wherein the inorganic base is selected from NaOH and/or KOH, and the inorganic base can be matched with 3-nitrobenzoic acid to form 3-nitrobenzoate.

Further preferably, the 3-nitrobenzoate is sodium 3-nitrobenzoate or a mixture of 3-nitrobenzoic acid and an inorganic base containing sodium.

Preferably, the organic amine is selected from at least one of ethylene diamine, propylene diamine, butylene diamine, diethylene triamine, triethylene diamine, and tetraethylene pentamine.

In the present invention, the organic amine is used as an auxiliary complexing agent, and in order to further improve the stability of the gold plating solution, preferably, the organic amine is selected from ethylenediamine. Preferably, the ethylenediamine is added to the gold plating solution in the form of at least one of ethylenediamine, ethylenediamine monohydrate, ethylenediamine sulfate, and ethylenediamine hydrochloride, wherein the ethylenediamine hydrate may be ethylenediamine monohydrate. In the gold plating solution of the present invention, when ethylenediamine is added to the gold plating solution in any of the above forms, the amount of ethylenediamine added is based on the weight of ethylenediamine.

Preferably, the acid is selected from at least one of sulfuric acid, hydrochloric acid, sulfamic acid, phosphoric acid, citric acid, tartaric acid, malic acid, malonic acid and succinic acid. More preferably, the acid is selected from sulfuric acid and/or hydrochloric acid.

In a preferred embodiment, the plating conditions include: the electroplating power supply is a single pulse power supply, and the average current density is 0.1-1A/dm²Preferably 0.2-0.8A/dm²(ii) a The electroplating temperature is 35-65 ℃, preferably 50-65 ℃; the conduction time is 10-30ms, preferably 10-20 ms; the turn-off time is 10-50ms, preferably 10-20 ms; the electroplating time is 5-20min, preferably 10-15 min. Wherein the off-time is the duration for which the current is zero.

In a preferred embodiment, the electroplating conditions further comprise stirring the cyanide-free gold plating solution by using ultrasonic waves during electroplating, wherein the frequency of the ultrasonic waves is 10-40kHz, preferably 20-30kHz, and the intensity of the ultrasonic waves is 100-500W/m²Preferably 200-400W/m²。

In the invention, the cyanide-free gold plating solution is stirred by ultrasonic waves, so that the deep plating capacity of the gold plating solution can be improved, and the difficulty of gold deposition at the sand holes on the surface of the silver ornament can be reduced.

In step (2):

in a preferred embodiment, the mercaptan is selected from at least one of octadecanethiol, t-dodecanethiol, hexadecylthiol, and 1-docosylthiol; the benzimidazole compound is selected from at least one of benzimidazole, 2-mercaptobenzimidazole, 2-aminobenzimidazole and 2- (chloromethyl) benzimidazole; the polyoxyethylene ether surfactant is at least one selected from octyl phenol polyoxyethylene ether, isooctanol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether and isomeric decyl alcohol polyoxyethylene ether.

In a preferred embodiment, in the protective film electrolyte, the content of the thiol is 1 to 15g/L, the content of the benzimidazole compound is 1 to 20g/L, and the content of the polyoxyethylene ether surfactant is 0.5 to 15 g/L.

Further preferably, the content of the mercaptan is 2-8g/L, the content of the benzimidazole compound is 2-10g/L, and the content of the polyoxyethylene ether surfactant is 1-10 g/L.

Wherein the mercaptan may be present in an amount of any of 2 to 8g/L, such as 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, 7.5g/L, 8g/L, and any two of these amounts; the content of the benzimidazole compound can be any content between 2 and 10g/L, such as any value in the ranges of 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, 7.5g/L, 8g/L, 8.5g/L, 9g/L, 9.5g/L, 10g/L and any two of the contents; the polyoxyethylene ether surfactant may be contained in an amount of 1 to 10g/L, for example, 1g/L, 1.5g/L, 2g/L, 2.5g/L, 3g/L, 3.5g/L, 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, 7.5g/L, 8g/L, 8.5g/L, 9g/L, 9.5g/L, 10g/L, or any value within a range defined by any two of these contents.

In a preferred embodiment, the conditions of the electrolysis include: the electrolysis temperature is 40-65 ℃, preferably 45-55 ℃; the electrolytic voltage is 1-8V, preferably 2-6V; the electrolysis time is 0.5-10min, preferably 2-5 min.

In a third aspect, the invention provides a gold-plated silver ornament prepared by the preparation method of the second aspect.

The present invention will be described in detail below by way of examples.

Example 1

(1) Firstly, putting the silver ornament to be treated into 3 wt% sulfuric acid at room temperature for soaking for 30s, taking out the silver ornament to be treated, carrying out ultrasonic cleaning and cathodic electrolysis for oil removal, and then putting the silver ornament to be treated into 3 wt% sulfuric acid again for soaking for 30 s;

placing the pretreated silver ornament to be treated into 1L cyanide-free gold plating solution which has the temperature of 60 ℃ and contains 12g of sodium gold sulfite, 75g of sodium sulfite, 5g of sodium 3-nitrobenzoate, 24g of ethylenediamine and 45g of 98 wt% sulfuric acid for electroplating;

the electroplating conditions comprise stirring the cyanide-free gold plating solution by using ultrasonic waves, wherein the frequency of the ultrasonic waves is 20kHz, and the intensity of the ultrasonic waves is 200W/m²(ii) a The electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 10ms, the off-time is 10ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

(2) and (2) putting the gold-plated silver ornament I into 1L protective film electrolyte containing 3g/L octadecanethiol, 3g/L benzimidazole and 2g/L octyl phenol polyoxyethylene ether (OP-10) for electrolysis, wherein the electrolysis temperature is 45 ℃, the electrolysis voltage is 3V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Example 2

(1) Firstly, putting the silver decorations to be treated into 3 wt% sulfuric acid at room temperature for soaking for 60s, taking out the silver decorations to be treated, carrying out ultrasonic cleaning and cathodic electrolysis for oil removal, and then putting the silver decorations into the 3 wt% sulfuric acid again for soaking for 60 s;

the electroplating conditions comprise stirring the cyanide-free gold plating solution by using ultrasonic waves, wherein the frequency of the ultrasonic waves is 40kHz, and the intensity of the ultrasonic waves is 400W/m²(ii) a The electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 20ms, the off-time is 20ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

(2) and (2) putting the gold-plated silver ornament I into 1L of protective film electrolyte containing 7g/L octadecanethiol, 9g/L benzimidazole and 10g/L octyl phenol polyoxyethylene ether (OP-10) for electrolysis, wherein the electrolysis temperature is 55 ℃, the electrolysis voltage is 6V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Example 3

(1) Firstly, putting the silver ornament to be treated into 3 wt% sulfuric acid at room temperature for soaking for 45s, taking out the silver ornament to be treated, carrying out ultrasonic cleaning and cathodic electrolysis for oil removal, and then putting the silver ornament to be treated into 3 wt% sulfuric acid again for soaking for 45 s;

the electroplating conditions comprise stirring the cyanide-free gold plating solution by using ultrasonic waves, wherein the frequency of the ultrasonic waves is 30kHz, and the intensity of the ultrasonic waves is 300W/m²(ii) a The electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 15ms, the off-time is 15ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

(2) and (2) putting the gold-plated silver ornament I into 1L of protective film electrolyte containing 5g/L octadecanethiol, 6g/L benzimidazole and 6g/L octylphenol polyoxyethylene ether (OP-10) for electrolysis, wherein the electrolysis temperature is 50 ℃, the electrolysis voltage is 5V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Example 4

the electroplating conditions comprise stirring the cyanide-free gold plating solution by using ultrasonic waves, wherein the frequency of the ultrasonic waves is 10kHz, and the intensity of the ultrasonic waves is 200W/m²(ii) a The electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 20ms, the off-time is 50ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

(2) and (2) putting the gold-plated silver ornament I into 1L of protective film electrolyte containing 1g/L octadecanethiol, 1g/L benzimidazole and 1g/L octyl phenol polyoxyethylene ether (OP-10) for electrolysis, wherein the electrolysis temperature is 50 ℃, the electrolysis voltage is 5V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Example 5

the electroplating conditions comprise stirring the cyanide-free gold plating solution by using ultrasonic waves, wherein the frequency of the ultrasonic waves is 20kHz, and the intensity of the ultrasonic waves is 200W/m²(ii) a The electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 20ms, the off-time is 20ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

(2) and (2) putting the gold-plated silver ornament I into 1L of protective film electrolyte containing 1g/L of tert-dodecyl mercaptan, 1g/L of 2-mercaptobenzimidazole and 0.5g/L of isooctanol polyoxyethylene ether for electrolysis, wherein the electrolysis temperature is 50 ℃, the electrolysis voltage is 5V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Example 6

the electroplating conditions include ultrasonic stirring of the cyanide-free gold plating solution, wherein the ultrasonic stirringThe frequency is 20kHz, the ultrasonic intensity is 200W/m²(ii) a The electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 20ms, the off-time is 20ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

(2) and (2) putting the gold-plated silver ornament I into 1L of protective film electrolyte containing 15g/L of tert-dodecyl mercaptan, 20g/L of 2-mercaptobenzimidazole and 10g/L of isooctanol polyoxyethylene ether for electrolysis, wherein the electrolysis temperature is 50 ℃, the electrolysis voltage is 5V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Comparative example 1

the electroplating power supply adopts a single pulse power supply, and the current density is adjusted to be 0.4A/dm²The on-time is 10ms, the off-time is 10ms, and the electroplating time is 12min, so that the gold-plated silver ornament I is obtained through electroplating;

Comparative example 2

(2) and (2) putting the gold-plated silver ornament I into 1L protective film electrolyte containing 3g/L of octadecanol and 2g/L of octyl phenol polyoxyethylene ether (OP-10) for electrolysis, wherein the electrolysis temperature is 45 ℃, the electrolysis voltage is 3V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Comparative example 3

(2) and (2) putting the gold-plated silver ornament I into 1L protective film electrolyte containing 3g/L octadecanethiol, 3g/L imidazole and 2g/L octyl phenol polyoxyethylene ether (OP-10) for electrolysis, wherein the electrolysis temperature is 45 ℃, the electrolysis voltage is 3V, the electrolysis time is 3min, and after electrolysis, washing with water and drying to obtain the gold-plated silver ornament.

Test example 1

The gold-plated silver ornaments prepared in examples 1 to 6 and comparative examples 1 to 3 were subjected to erythema test experiments. Wherein, the simulated sweat used in the test process comprises: 10g/L of sodium chloride, 0.2g/L of cane sugar, 0.8g/L of sodium sulfide, 1.4mL/L of lactic acid, 1.7g/L of urea and ammonia water for adjusting the pH value to 4.5.

The test method comprises the following steps:

laying the dust-free cloth in a plane disc, using a liquid transfer device to transfer 20mL of artificial sweat, and uniformly extruding and coating the artificial sweat on the dust-free cloth;

placing a test sample in the middle of the dust-free cloth, covering one side of the dust-free cloth above the test sample, covering the other side of the dust-free cloth, and tightly wrapping the test sample;

packaging the wrapped test sample by using a sealing bag and placing the sealed test sample in a rubber basket, wherein two small holes with the diameter of 5mm are respectively cut on two side surfaces of the sealing bag, and the two sides of the sealing bag are provided with 4 holes in total;

and (3) putting the test sample into a greenhouse box with 40 ℃ and 90% RH for 24h, then taking out the test sample, placing the test sample under natural conditions for more than 2h, and carrying out appearance observation.

Examples FIGS. 2 to 7 correspond to the test results of the gold-plated silver ornaments prepared in examples 1 to 6, and it can be seen from examples FIGS. 1 to 6 that the gold-plated silver ornaments prepared by the method of the present invention have good stability and no erythema.

Comparing the results of the tests of the gold-plated silver ornaments prepared in comparative examples 1-3 in comparative examples 8-10, it can be seen from fig. 8-10 that the prepared gold-plated silver ornaments have different degrees of erythema on the surface and poor stability.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

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Protective film electrolyte, gold-plated silver ornament and preparation method thereof

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