JPH03109482A - Surface treating agent of jewel - Google Patents

Abstract

PURPOSE:To obtain the title treating agent providing jewels with excellent stain resistance without damaging appearance, preventing deterioration, improving lubricating properties, comprising a specific fluorine-containing silane compound. CONSTITUTION:The aimed composition comprising a fluorine-containing silane compound shown by the formula [Rf is 4-12C perfluoroalkyl; Y is CH2, CH2O, NR<1>, CO2, CONR<1>, S, SO2 or SO2NR<1> (R<1> is H or 1-5C alkyl) A is 1-5C alkyl; X is 1-5C alkoxy; n is 0-3 integer; k and m are 1-3 integer]. In using the compound, preferably the compound is dissolved in an organic solvent such as hexane or methylene chloride into 0.1-20wt.% solution and used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a surface treatment agent for jewelry, a surface treatment method thereof, and a surface-treated jewelry.

[Prior art and problems]

Precious metals and gemstones have high commercial value as jewelry due to their excellent aesthetic appearance. (Hereinafter, "jewelry" refers to precious metals, jewelry, and ornaments made of these materials, which have high commercial value due to their excellent aesthetic appearance.) However, when manufacturing these jewelry, When selling products, it is inevitable that they come into contact with human fingers, which causes fingerprints, hand marks, etc. to adhere to the surface, significantly reducing the luster and reducing the commercial value of jewelry.

This problem is particularly serious for those with a satin finish such as honed finish or cutter finish. For example, those that do not have a satin finish.

Because the surface is smooth, even if there are fingerprints or dirt on the surface, it can be removed to some extent by wiping, but since the surface of matte finish is roughened, it is difficult to remove these stains. There are problems that cannot be easily removed.

In addition, in the manufacturing process of jewelry, cleaning with water is often performed, but wood vinegar tends to remain as a stain during the drying process, making it difficult to remove, especially for items with a satin finish.

In order to prevent these problems, surface treatment using organic polymer compounds conventionally known as polishing agents may be considered, but since the natural aesthetic appearance of jewelry is important, this is not recommended. If conventional polishing agents or the like are used for polishing, there is a problem in that the natural aesthetic appearance inherent to jewelry is impaired and its commercial value is significantly reduced. For example, conventional polishing agents made of organic polymer compounds have the disadvantage of forming a thick film that subtly changes the original color of the jewelry, and also have excessive adhesion strength, which requires removal of the film and polishing. It is difficult to restore the natural appearance. Furthermore, there is a risk that it will react with the surface of the jewelry and spoil its appearance. Also,
Since it is a hydrocarbon compound, it has no effect on preventing oil stains.

[Knowledge related to problem solving]

The present inventors investigated a surface treatment agent that imparts excellent antifouling properties to jewelry without impairing the excellent appearance inherent in the jewelry, and as a result, found that a specific compound containing a perfluoroalkyl group It has been found that a fluorine silane compound is suitable as the above-mentioned treatment agent.

[Structure of the invention]

According to the present invention, the general formula % formula % (1) (wherein R1 is a perfluoroalkyl group having 4 to 12 carbon atoms, Y is CH,, CH2O, NR', CO□, CONR1
, S, SO,, SO, NR', where R1 is hydrogen or an alkyl group having 1 to 5 carbon atoms, A is an alkyl group having 1 to 5 carbon atoms, X is an alkoxy group having 1 to 5 carbon atoms, and n is O
A jewelry surface treatment agent comprising a fluorine-containing silane compound represented by an integer of 1 to 3, k and m are integers of 1 to 3 is provided.

In addition, the above-mentioned fluorine-containing silane compound has the general formula % formula % () (wherein Rf, A, X and m are the same as above, R2
is an alkyl group having 1 to 5 carbon atoms) is preferably used.

Furthermore, as the above-mentioned fluorine-containing silane compound, a compound represented by the general formula % (in which R2 and X are the same as above) is preferably used.

The fluorine-containing silane compound used in the present invention adheres to the surface of jewelry with appropriate strength through its alkoxysilyl group, while the perfluoroalkyl groups arranged on the outside
Provides water and oil repellency, which provides excellent stain resistance. If the adhesion of the coating formed on the surface of jewelry is too strong as with conventional polishing agents, it becomes difficult to remove the coating as necessary to maintain a natural appearance. Fluorine silane compounds have appropriate adhesion strength and can be easily removed if necessary. Furthermore, since a thin film can be formed, the natural appearance of the jewelry is not impaired.

The above-mentioned antifouling effect is even more remarkable in the compound represented by the above-mentioned formula ([). In this compound, the sulfonamide bond facilitates orientation of the perfluoroalkyl group to the surface and further increases appropriate adhesion to the surface of jewelry. Furthermore, the alkyl group bonded to the nitrogen atom increases the solubility in a solvent during surface treatment.

Furthermore, for practical use, the compound represented by the above formula (1) is preferably used. This compound has three reactive groups represented by X in the formula, giving it appropriate adhesion, and since the perfluoroalkyl group has eight carbon atoms, it has remarkable water and oil repellent effects. be. In addition, raw materials are easily available.

There are no limitations on the shape or size of the jewelry to which the surface treatment agent of the present invention is applied.

When using the above-mentioned fluorine-containing silane compound, it is preferable to use it as a solution of 0.1 to 20% by weight dissolved in an organic solvent. As the solvent, compounds of aliphatic hydrocarbons, aromatic carbons, and arsenic compounds can be used as appropriate. For example, commonly used organic solvents such as halogenated hydrocarbons, alcohols, ethers, and ketones are used.

Specific examples include methanol, ethanol, chloroform, isopropyl ether, hexane, methylene chloride, and the like. Among these organic solvents, low-volatility solvents such as hexane and methylene chloride are particularly preferred, and it is preferable to use the above-mentioned fluorine-containing silane compound as a solution containing 1 to 15% by weight of the fluorine-containing silane compound. These solvents are anhydrous or, if necessary, added with a small amount of an aqueous solution of an amine or an acid. The amine used here may be any of -class amines, secondary amines, and tertiary amines, but -class amines are particularly effective. Further, as the acid, various inorganic acids and organic acids such as acetic acid, oxalic acid, and toluenesulfonic acid can be used. When an aqueous acid solution is used, the water in the solution hydrolyzes the alkoxysilyl group of the fluorine-containing silane compound to form a hydroxysilyl group. It has the effect of binding or dehydrating and condensing to adhere. Acids and amines also act as catalysts to promote this hydrolysis and dehydration condensation. The concentration of these amines or acids is 15% by weight or less, preferably 0.0% by weight of the total amount of the treatment solution.
Approximately 5 to 5% by weight is suitable.

The surface treatment method of the present invention is carried out by applying a solution containing the above-mentioned fluorine-containing silane compound to the jewelry. As the coating method, a normal coating method such as a dipping method, a spray method, or a brushing method is used. When processing jewelry, the processing temperature varies depending on each solvent, but it is carried out in a temperature range from room temperature to the boiling point of the solvent. Also after surface treatment with these solutions.

The heat treatment is carried out at a temperature ranging from room temperature to 200°C, preferably from 100 to 150°C. This heat treatment improves the adhesion of the fluorine-containing silane compound and prevents a decrease in surface gloss. If sufficient heating is not performed, the gloss tends to decrease to some extent.

〔Effect of the invention〕

Surface treatment of jewelry with the fluorine-containing silane compound of the present invention prevents fingerprints, hand marks, etc. from adhering to the surface of the jewelry, and also makes it easier to remove adhering fingerprints, improving so-called antifouling properties. In addition, since oxidation of the surface of the jewelry is prevented, deterioration of surface gloss due to this is prevented.

Furthermore, since the lubricity is improved, wear of the joints of chain-shaped items such as necklaces can be prevented.

Furthermore, when washing jewelry after processing, if the surface is treated with the treatment agent of the present invention before drying, water pots will not remain. By treating with a treatment agent, the diffused reflection of light caused by minute scratches on the surface is suppressed, and an unexpected effect can be obtained in which one color tone is higher than that of the base material.

Furthermore, by using the fluorine-containing silane compound of the present invention, the thickness of the coating formed on the surface of jewelry can be made extremely thin, so the visible light reflectance of surface-treated jewelry is almost the same as that of untreated jewelry. Since there is no difference and the natural luster of the base material is not changed, the commercial value of the jewelry is not impaired.

Further, since the fluorine-containing silane compound of the present invention has a suitable adhesive strength, it has the advantage that the coating can be easily removed by placing the jewelry treated with the compound in an alkaline solution and applying ultrasonic vibration.

[Specific disclosure of the invention]

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 A 1 cm square roughly honed platinum plate (manufactured by Kofu Jewelry Center) was thoroughly degreased with acetone and then immersed in a 3% by weight ethanol solution for 10 seconds. Thereafter, it was dried at 120°C for 2 hours. The glossiness of the roughly honed platinum plate thus obtained was measured.

The measurement conditions are as follows.

Color used: Yellow Color gloss: Glossiness = Qog (l / (reflected light / incident light)) Also, JIS standard solution for measuring penetration into fibers (mixture of ethylene glycol heptanoethyl ether and N,N-dimethylformamide: The ease of repelling oil stains was evaluated by measuring the contact angle with respect to a surface tension of 35 dyne/c+*).In addition, after wiping off this measurement solution with a dry cloth, the surface of the metal was observed to determine how easily oil stains could be removed. The results are shown in Table 1.

Examples 2 to 7 Evaluations were conducted in the same manner as in Example 1, except that the treated metal and the fluorine-containing silane compound were changed.

The results are shown in Table 1.

Comparative Examples 1 to 7 Evaluations similar to those in Example 1 were performed on ingots that were only subjected to degreasing treatment without using a fluorine-containing silane compound. The results are shown in Table 1.

Example 8 A commercially available ruby 082 carat was washed in water with an ultrasonic cleaner for 5 minutes, dried at room temperature, immersed in a 5% by weight methylene chloride solution for 10 seconds, and then heated and dried at 100° C. for 30 minutes.

This ruby was immersed in liquid paraffin for 10 seconds and then thoroughly wiped with a dry cloth.

The ruby color after wiping was visually compared with that before treatment. The results are shown in Table 2.

Examples 9 to 23 Evaluations were conducted in the same manner as in Example 8, except that the gemstones to be treated and the fluorine-containing silane compound were changed. The results are shown in Table 2.

Comparative Examples 8 to 21 Evaluations similar to those in Example 8 were performed on jewelry that was only subjected to ultrasonic cleaning without using a fluorine-containing silane compound. The results are shown in Table 3.

Table 0: Gloss does not change Δ: Gloss decreases somewhat ×: Dull state Table 0: Gloss does not change Δ: Gloss decreases somewhat ×: Dull state Example 24 Commercially available necklace (Mitsubishi Metal H) was immersed in a 10% by weight hexane solution for 20 seconds, then 1
It was dried by heating at 20° C. for 30 minutes. This necklace.

The samples were immersed in the standard solution for 10 seconds, then wiped off with a damp cloth, and the ease with which oil stains were removed was visually evaluated as compared to the sample before treatment. The results are shown in Table 4.

Examples 25 to 31 Evaluations were conducted in the same manner as in Example 24, except that the decorative items to be treated were changed. The results are shown in Table 4.

Comparative Examples 22 to 25 Evaluations similar to those in Example 24 were performed on decorative articles that did not use a fluorine-containing silane compound.

The results are shown in Table 4.

Table 4 Example 26 A commercially available ruby (0.1 carat) was immersed in a 5% by weight acetone solution for 10 seconds, and then
It was dried by heating at 0° C. for 20 minutes.

The surface gloss was improved compared to the untreated one.

Example 27 Example 2 except that a commercially available necklace (manufactured by Mitsubishi Metals) was used.
The same treatment as in 6 was performed.

The joints of the necklace became smoother than those before treatment, and no friction was felt at all.

Claims (6)

[Claims] 1. General formula R_f(CH_2)_nY(CH_2)_kSiA_3
____mX_m(I) (in the formula, R_f is a carbon number of 4 to 12
perfluoroalkyl group, Y is CH_2, CH_2O
, NR^1, CO_2, CONR^1, S, SO_2,
SO_2NR^1, where R^1 is hydrogen or an alkyl group having 1 to 5 carbon atoms, A is an alkyl group having 1 to 5 carbon atoms,
X is an alkoxy group having 1 to 5 carbon atoms, n is an integer of 0 to 3,
A jewelry surface treatment agent comprising a fluorine-containing silane compound (k and m are integers of 1 to 3). 2. The fluorine-containing silane compound has the general formula R_fSO_2NR^2(CH_2)_3SiA_3_
-_mX_m(II) (wherein R_f, A, X and m are the same as above, and R^2 is an alkyl group having 1 to 5 carbon atoms). agent. 3. The fluorine-containing silane compound has the general formula C_■F_1_7SO_2NR^2(CH_2)_3S
The jewelry surface treatment agent according to claim 1, characterized in that it is iX_3(III) (in the formula, R^2 and X are the same as above). 4. The fluorine-containing silane compound according to any one of claims 1 to 3 is dissolved in an organic solvent, preferably a low-volatility solvent, at 0.0%.
1-20% by weight, preferably 1-15% by weight. A jewelry surface treatment agent solution characterized by being dissolved. 5. A method for surface treatment of jewelry, which comprises surface treatment with the fluorine-containing silane compound according to any one of claims 1 to 4, and then heat treatment at a temperature from room temperature to 200°C. 6. Jewelry processed by the method of claim 5.