JPH09127261A - Dial for time piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a dial producible at low cost and feel luster of noble metal and a cubic effect on the figures, mark, pattern etc. SOLUTION: On a dial base 1 formed with such non-conductive resin film as urethane resin, acryl resin, etc., a pattern 7 of figures, mark, resin, etc., is formed by printing and after thermal hardening treatment, ground plating 8 such as Cu, Ni and the like is given on the formed pattern by electrodes plating method. Then a finishing metal plating 9 such as Au, Ag and the like is laid. For the conductive paste, epoxy resin, hardening agent and at least one of conductive fine powder of copper fine powder, silver fine powder or nickel fine powder with particle size of 0.1 to 3μm is mixed for 40 to 65 pts.vol. in epoxy resin of 100 pts.vol. Then, the above pattern is formed by printing of screen printing or pad printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece dial.

[0002]

2. Description of the Related Art In a timepiece dial, a pattern such as a basis weight and a metal dial plate on which the pattern is plated, or an inorganic dial plate substrate such as precious stone, glass or ceramics A transparent or semi-transparent non-conductive resin coating film of urethane resin, acrylic resin or the like is formed, and there is a certain thickness on the non-conductive resin coating film to give a three-dimensional effect and metallic luster, As a typical method for forming patterns such as marks and patterns, there is a method called an electroforming method. As shown in (a) to (e) of FIG. 4, this is a vapor-deposited conductive film 13 formed by vapor deposition of Ni, Ag, or the like on a dial substrate 11 on which a transparent or semitransparent non-conductive resin coating film 12 is formed. Is formed ((a) in FIG. 4), and a mask is formed by the resist film 14 on a predetermined portion thereof by a photoresist method ((b) in FIG. 4). The electroformed layer 15 is formed by thick plating such as Ni plating or Cu plating on the portions where the marks and patterns are formed ((c) of FIG. 4), and Au plating and Ag plating are further formed on the electroformed layer 15. A finishing plating layer 16 is formed by finishing plating such as (FIG. 4D), and then the resist film 14 and the vapor deposition conductive film 13 under the resist film 14 are peeled off to complete the dial (FIG. 4).
(E) is a method of obtaining. In addition, as an applied method of making the above, as shown in FIG. 5, an electroformed product having time characters, marks, patterns, etc. is made in advance by an electroforming method, and the electroformed product 17 is made non-conductive with an adhesive 18. There is also a method of obtaining a finished dial by bonding and fixing it on the dial substrate 11 on which the resin coating film 12 is formed.

Recently, various conductive pastes have been developed and have appeared on the market. This is a paste made by mixing a resin with a conductive filler of metal powder and forming a paste, which is a paste having electrical conductivity. There is also known a method in which a pattern such as a time character, a mark, a pattern is printed by a printing method such as screen printing or pad printing with the conductive paste, and plating is performed on the pattern after heat curing treatment.

[0004]

However, although the patterns such as the time letters, marks, and patterns produced by the electroforming method can give a three-dimensional effect and a metallic luster, the manufacturing process is the deposition of the conductive film-resist. Film coating-exposure-development-thick plating-finish plating-resist film stripping-
The number of steps is very large because it involves the steps of peeling the conductive film. Further, in order to give a three-dimensional effect, the electroforming layer is thickly plated to a thickness of several tens of μm to a few hundreds of μm, which requires a considerable amount of plating time, resulting in problems of quality yield and high cost.
In addition, various equipments are required in terms of equipment, the equipment cost is very large, and since a photoresist solution, a developing solution, a stripping solution and the like are also used, it is not preferable in terms of work hygiene.

Next, the method of printing and forming a pattern such as time characters, marks, and patterns with the above-mentioned conductive paste and plating on the formed pattern after the thermosetting treatment has a small number of processing steps and is costly. There is a merit that it can be made very cheap.
However, until now, the conductive paste has a particle size of the conductive filler of about 10 μm and is made for the purpose of achieving continuity, so that the appearance of glossiness of the pattern has not been sufficiently satisfactory. Is. The object of the present invention is a method of printing and forming the pattern with a conductive paste, in which a noble metal gloss feeling is obtained by plating a noble metal even if the pattern thickness is relatively thin,
In other words, the precious metal-colored glitter and shiny luster,
The purpose of this is to provide a dial for timepieces that allows marks and patterns to appear and also gives a three-dimensional effect.

[0006]

As a result of earnest research and development of a conductive paste in the above background, it has been found that the following conductive paste is a conductive paste which can satisfy the above-mentioned object. The invention according to claim 1 of the present invention is characterized in that a conductive paste is used to form time marks and marks on a dial board on which a transparent or semitransparent urethane resin, acrylic resin, or other nonconductive resin coating film is formed. , A pattern such as a pattern is formed by printing, and after the heat curing treatment, a base plating of Cu, Ni or the like is applied on the pattern by an electroless plating method, and then Au, Ag
In a dial for timepiece which is plated with finish metal such as, the conductive paste is an epoxy resin, a curing agent, and at least one of copper fine powder, silver fine powder, or nickel fine powder having a particle diameter of 0.1 to 3 μm. It is characterized by blending various kinds of conductive fine powder.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the conductive fine powder is mixed in an amount of 40 to 65 parts by volume with respect to 100 parts by volume of the epoxy resin. To do.

Further, the invention according to claim 3 is characterized in that, in the invention according to claim 1, patterns such as time characters, marks and patterns are formed by screen printing or pad printing with the conductive paste. Is.

[0009]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a timepiece finished dial obtained using the conductive paste of the present invention. The dial shown in FIG. 1 has a pattern 2 such as a basis weight formed on a metal dial substrate 1 made of aluminum, brass, nickel silver or the like, and a plating film 3 for preventing corrosion and decoration is applied on the dial 2. A transparent or semi-transparent non-conductive resin coating film 4 of urethane resin, acrylic resin or the like is formed thereon. Next, at a predetermined position on the non-conductive resin coating film 4, the conductive paste of the present invention is used to form hour marks, marks,
A pattern 7 such as a pattern is formed by screen printing, and the pattern is further thermoset by heating at 170C for 30 minutes, and then Cu plating and Ni plating are performed by electroless plating to form a base plating film 8. In addition, a finished dial 9 is formed by further applying a precious metal plating of Au plating to form a finish plating film 9 so that the pattern emits a golden shine unique to Au and gives a three-dimensional effect more than the actual pattern rise. is there.

The first feature of the present invention is that, as a conductive filler made of metal powder mixed in a conductive paste, the particle diameter is 0.
This is because at least one kind of conductive fine powder of copper fine powder, silver fine powder, or nickel fine powder of 1 to 3 μm is used. Due to the small size of the particles, the surface of the printed pattern has very small irregularities and exhibits a gentle curved surface.
Undercoating such as Cu or Ni plating is performed on this pattern, and finish plating of precious metal such as Au or Ag plating is further applied, so that a shine peculiar to the precious metal appears on the entire pattern surface. FIG. 2 is a cross-sectional view of a main part of a pattern 5 printed with a conductive paste prepared by mixing a conductive filler 5a having small particles on a metal dial plate substrate 1 on which a non-conductive resin coating film 4 is formed. . Similarly, FIG. 3 shows a cross-sectional view of a main part of a pattern 6 printed with a conductive paste containing a conductive filler 6a having large particles. In addition, the cross section is enlarged and shown for clarity. If the particles of the conductive filler are large, the surface of the printed pattern has large irregularities, and the surface is uneven (FIG. 3). On the contrary, when the particles are small, the printed pattern surface has small irregularities, and exhibits a smooth curved surface (FIG. 2). This pattern is plated with Cu, Ni, etc., of several μm, and further about 1 μm of Au, Ag
As shown in FIG. 3, when a noble metal is plated, the direction of light reflection is not constant in the case of large particles, that is, diffuse reflection occurs and the gloss of the noble metal does not appear well. On the other hand, as shown in FIG. 2, when the particles are very small, the light is reflected in a fixed direction, so that the gloss of the precious metal appears very well. When the particle shape becomes 5 to 6 μm or more, the glossiness of the noble metal gradually decreases, and the glossiness becomes better as the particle diameter becomes smaller. The base plating of Cu, Ni or the like is applied because the glossiness of the noble metal plating such as Au or Ag applied thereon can be further improved.

The second feature of the present invention is that the amount of the conductive fine powder blended in the conductive paste is 100% by weight of the epoxy resin 100.
The reason is that the capacity is 40 to 65 parts by volume.
This is because the above blending amount shows a uniform metal plating condition, the plating condition is very good, and the pattern printing workability is also good. In addition, when the compounding volume of the conductive fine powder is less than 40 volume parts, in the state where the metal plating is attached, the non-plated portion appears in some places, and the unevenness of the plating occurs and the uniform plating quality cannot be obtained. Come on. On the other hand, if the blending volume of the conductive fine powder is more than 65 parts by volume, the thixotropy of the conductive paste becomes high, and the printing workability deteriorates and the printing quality deteriorates.

Further, a third feature of the present invention resides in that a pattern such as a time character, a mark, and a pattern is printed by screen printing or pad printing with the conductive paste. In order to obtain the above-mentioned pattern having a three-dimensional effect, a certain amount of thickness is required, but the present invention is characterized in that even if the pattern thickness is comparatively thin, a three-dimensional effect greater than that thickness is felt. There is. In screen printing and pad printing, the printing thickness is only 10-40 μm, which is relatively thin, but the surface of the pattern printing surface is formed into a curved shape with a roundness due to the surface tension. . This is because by applying precious metal plating on this rounded pattern so that the glossy luster of the precious metal appears, the pattern looks even more embossed and gives a more three-dimensional effect than the actual thickness.

The present invention described above will be described in detail based on experimental examples. Experimental Example 1 100 parts by volume of epoxy resin, 5 parts by volume of curing agent, and copper powder having a particle size of 0.1 to 0.3 μm, 2 to 3 μm, 5 to 6 μm, and 9 as shown in Table 1. ~ 10μ
Using 4 kinds of m, 50 parts by volume were mixed and mixed to prepare the conductive pastes of Samples 1, 2, 3, and 4. Imidazole is used as the curing agent. Next, the samples 1 to 4
Patterns such as time characters, marks, and patterns were printed by screen printing on a dial substrate on which a non-conductive resin coating film was formed with each of the conductive pastes. During printing, the print workability and print pattern quality were confirmed. Then in the dryer 170
C, after 30 minutes of drying and thermosetting of the pattern, Cu plating by electroless plating, Ni plating, and finally Au plating. And gloss were confirmed by a binocular microscope and visually.

[Table 1]

As a result of the above work, the results shown in Table 2 were obtained.
The printing workability was good for all of Samples 1, 2, 3, and 4 (indicated by ○ in the table). Also, the adhesion state of Au plating is
All 3 and 4 were good (indicated by ○ in the table), and there was no unevenness in plating and the plating was uniform. Regarding the glossiness of Au plating, Samples 1 and 2 showed very good glossiness (indicated by ○ in the table), and Sample 3 had slightly less glossiness (indicated by Δ in the table) as the quality of dial plate. Was not a satisfactory result. Sample 4 did not show much gloss (indicated by X in the table). As can be seen from the above results, the powder particle size is 0.1
It has been found that when the particles are as fine as ˜3 μm, the metallic luster is exhibited well, and when the particle size is 5 to 6 μm or more, the lustrousness is gradually decreased.

[Table 2]

Experimental Example 2 100 parts by volume of epoxy resin, 5 parts by volume of curing agent, and 35 parts by volume of copper fine powder having a particle diameter of 2 to 3 μm as shown in Table 3.
40 capacity part, 45 capacity part, 60 capacity part, 65 capacity part, 7
Six kinds of conductive pastes of Samples 5 to 10 were prepared by mixing and mixing 0 parts by volume. Patterns were formed by printing in the same manner as in Experimental Example 1 using these 6 kinds of conductive pastes, and after the pattern was heat-cured, the same plating as in Experimental Example 1 was performed to confirm the quality. As a result, the results shown in Table 4 were obtained.

[Table 3]

The conductive paste containing 35 parts by volume of the copper fine powder of Sample 5 had no problem in printing workability (marked with a circle in the table), but uneven plating occurred and uniform plating could not be obtained ( (Displayed with a cross in the table). That is, there was a part where plating was not adhered, and the plating was not uniform and uniform. Naturally, the glossiness of Au plating did not appear (indicated by X in the table). Next, the conductive paste containing 70 parts by volume of copper fine powder of Sample 10 had a high viscosity and poor workability for printing (indicated by X in the table), and a pattern chipping occurred. The state of adhesion of the plating was almost uniform and a uniform plating state was obtained (indicated by a circle in the table), but the glossiness of the Au plating was uneven and was not sufficient for the dial quality. (Displayed with a triangle in the table) This is probably because the surface of the pattern was uneven and was not a curved and smooth surface. The conductive pastes of Samples 6, 7, 8 and 9 had no problem in printing workability, showed a uniform and uniform plating adhesion state, and also had very good Au plating glossiness ( (All are indicated by a circle in the table). From the above results, if the copper fine powder is less than 40 parts by volume, the pattern surface is not uniformly and uniformly plated, and if it is more than 65 parts by volume, the viscosity becomes high and the printing workability and glossiness are increased. , And 40 to 65 parts by volume was found to be the optimum blending amount.

[Table 4]

Experimental Example 3 100 parts by volume of an epoxy resin, 5 parts by volume of a curing agent, and 35 parts by volume, 40 parts by volume of 5 parts by volume of silver fine powder having a particle diameter of 2 to 3 μm.
Six kinds of conductive pastes, Samples 11, 12, 13, 14, 15, and 16 shown in Table 5 were prepared by mixing and mixing 0 volume part, 60 volume part, 65 volume part, and 70 volume part, respectively. Next, from the six kinds of conductive pastes, pattern printing and final Au plating were performed in the same manner as in Experimental Example 1. As shown in Table 6, the result was exactly the same as that of the fine copper powder of Experimental Example 2.
That is, also in the case of fine silver powder, the conductive paste having a content of 40 to 65 parts by volume is used for printing workability, uniform plating adhesion,
Very good results were obtained with no problems in the glossiness of u plating.

[Table 5]

[Table 6]

Experimental Example 4 Next, with nickel fine powder, in the same amount as silver fine powder used in Experimental Example 3, the samples 17, 18, 19 shown in Table 7 were prepared.
Six kinds of conductive pastes of 20, 21, 22 are prepared,
Pattern printing and final Au plating were performed in exactly the same manner as in Experimental Example 1. As a result, Experimental Example 3
The same result was obtained as in the case of the silver fine powder (1) (similar to Table 6). It was also found that in the case of nickel fine powder, the compounding amount of 40 to 65 parts by volume is the best with respect to 100 parts by volume of the epoxy resin.

[Table 7]

From the results of the above experimental examples, it was found that the conductive filler having a very small particle diameter of 0.1 to 3 μm shows a very good gloss. Also, it was found that the conductive paste of 40 to 65 parts by volume with respect to 100 parts by volume of epoxy resin is the best in terms of printing workability, uniform adhesion of plating, and uniform glossiness. did. It turned out that this is exactly the same for the fine copper powder, fine silver powder and fine nickel powder.

[0020]

As described above in detail, by forming a pattern such as a time character, a mark, and a pattern on the dial board by the conductive paste of the present invention, the pattern is formed on the formed pattern. The luster of precious metal plating appears very well.
Also, because of its gloss, even if the pattern thickness is thin, it feels as if it were thicker, which brings about the effect of creating a three-dimensional effect of the pattern and gives a very high-class feeling. Further, compared with the conventional manufacturing method using the electro-homing method, the manufacturing method using the conductive paste of the present invention has a small number of manufacturing steps and is a simple method, so that the cost is significantly reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a completed timepiece dial obtained by using a conductive paste of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a pattern printed with a conductive paste containing a conductive filler having small particles.

FIG. 3 is an enlarged cross-sectional view of a main part of a pattern printed with a conductive paste formed by mixing a conductive filler having large particles.

4A to 4E are process cross-sectional views of a dial manufacturing process by a conventional electrohoming method.

FIG. 5 is a cross-sectional view of a completed dial plate obtained by conventional electroformed product adhesion.

[Explanation of symbols]

1 Dial Board Substrate 2 Patterns such as Unit Weight 3 Plating Film 4 Non-Conductive Resin Coating 5 Pattern 5a Small Conductive Filer with Small Particles 6 Pattern 6a Large Conductive Filer with Large Particles 7 Time Characters, Marks, Patterns, etc. by the Conductive Paste Printing pattern 8 Undercoat plating 9 Finish plating

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaaki Sato Inventor Masaaki Sato 2 6663 Funatsu, Kawaguchiko-cho, Minamitsuru-gun, Yamanashi Inside Kawaguchiko Precision Co., Ltd. N Watch Co., Ltd. Tanashi Factory

Claims (3)

[Claims] 1. A pattern such as time characters, marks, and patterns is formed by printing with a conductive paste on a dial plate substrate on which a non-conductive resin coating film such as transparent or semitransparent urethane resin or acrylic resin is formed. Then, after the heat curing treatment, a base plating of Cu, Ni or the like is applied on the pattern by an electroless plating method, and further A
In a timepiece dial made by plating with a finish metal such as u or Ag, the conductive paste is an epoxy resin, a curing agent, and a copper fine powder, a silver fine powder, or a nickel fine powder having a particle diameter of 0.1 to 3 μm. A timepiece dial, which is a conductive paste formed by mixing at least one kind of conductive fine powder. 2. The timepiece dial according to claim 1, wherein the conductive paste is formed by mixing 40 to 65 parts by volume of the conductive fine powder with 100 parts by volume of an epoxy resin. 3. The timepiece dial according to claim 1, wherein the pattern is formed by screen printing or pad printing.