JPH0735489B2 - Ink composition for screen printing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink composition for screen printing, and more specifically, the ink composition facilitates the expression of a desired coating film color tone and provides a decorative effect. The present invention relates to a markedly improved screen printing ink composition.

(Prior art and its problems) Conventionally, for decorative items such as writing instrument shafts, cosmetic containers, and watch accessories, the product value is greatly affected even by one surface treatment, and the purchase by the consumer. Since the motivation is also greatly affected, various surface treatments have been devised.

Among them, the screen printing method has become more and more frequently used for the above-mentioned ornaments in recent years because it can relatively easily express matte tone or satin tone. However, on the other hand, it also has the following drawbacks, and the demand for improvement is increasing.

That is, it is known to mix silica powder, resin powder, or the like with the ink composition when a matte or satin finish is not expected to appear on a decorative article by the screen printing method.
However, in this method, if the desired color tone of the coating film is different from that of the powder, it is affected by the color tone of the powder.
In order to alleviate these problems such as the unclear color of the coating film and the inability to obtain the desired color tone, and to reduce these problems, increase the content of the colorant in the ink composition. As a result, the hardness of the coating film decreases, and the problems of abrasion resistance and scratch resistance decrease.

(Means for Solving Problems) The present invention has been made in view of the above circumstances, and in an ink composition for screen printing, an average particle size having the same or similar color tone as the colorant in the ink composition. 0.1-50
The gist of the invention is a screen-printing ink composition containing a colored powder of μm, which is intended to improve the decorative effect on the appearance and design of a decorative article.

In particular, in order to improve the decorative effect by the color tone, the color tone is made clear, the desired color tone is easily expressed, and further, the color tone is easily expressed, whereby the coloring material in the screen printing ink composition is obtained. It is intended to reduce the content rate of slag, improve the hardness of the coating film, and improve wear resistance and scratch resistance.

Examples of the colored powder used in the present invention include silica powder, resin powder, glass, alumina, titanium,
Non-porous or porous materials such as titanium dioxide, other nitrides, carbides, borides and the like can be mentioned.

As the resin powder, those having high solvent resistance are preferable, and thermoplastic resins such as polyethylene, polypropylene, polyamide, polyacrylic acid ester and polyacetal, alkyd resin, phenol resin, melamine resin, silicone resin, fluorine resin, epoxy resin. And other thermosetting resins.

These are used alone or in combination of two or more.
Furthermore, the average particle size of these colored powders is 0.1 to 50 μm, because if the average particle size is smaller than 0.1 μm, it becomes difficult to express matte or satin finish, and 50 μm.
If it is larger than the above range, the screen is likely to be clogged during printing, which is not preferable.

As a method for coloring the inorganic powder, a physical method such as mixing the pigment and the inorganic powder with a ball mill or a mechanomill, and adsorption of a dye, a pigment, or other coloring material on the surface of the inorganic powder by chemisorption After that, a method for stabilizing the adsorption of the coloring material by coating the powder surface with a colloidal gel such as silicate, alumina hydroxide, silica colloid, and water glass, or a colloidal gel Examples thereof include chemical methods such as a method of forming a thin film by dispersing a dye in.

In order to further stabilize the adhesion of the pigment by the above-mentioned physical methods, the surface of the inorganic powder is subjected to a surface treatment with stearic acid, myristic acid, palmitic acid or another fatty acid before the mixing treatment, or The surface may be modified with a coupling agent such as a silane coupling agent, a titanium coupling agent, or an aluminum coupling agent.

Melt blending method,
A generally known method such as a dry blend method is used.

As the ink composition for screen printing excluding the above-mentioned colored powder in the present invention, a conventionally known ink composition is used. Specifically, as a commercially available product, the resin in the component is a thermosetting high kit (( Nagase Screen Printing Co., Ltd., two-component curing type Sericol PS-000, DP-000 (above, Teikoku Ink Co., Ltd.), Seiko 1000, 1690, SG160 (above, Seiko Advance Co., Ltd.) Made), Pinlite 1000 series (made by Jujo Kako Co., Ltd.), SS-25 (made by Toyo Ink Co., Ltd.), natural curing type Sericol JM, same FM-00
0, the same VS-000, the same NAC, the same 5000, the same 7000 (hereinafter, Teikoku Ink Co., Ltd.), Bintop, Bin Eight (above, Nagase Screen Printing Co., Ltd.), UV curing type FDSS21-
000, FDSSKG-000 (above, manufactured by Toyo Ink Co., Ltd.), one-component curing type Seiko 1300 (Seiko Advance Co., Ltd.)
Manufactured by Toyo Ink Co., Ltd., and electron beam curable ink compositions.

These ink compositions are appropriately selected according to the material of the surface to be printed, such as metal or resin. At the time of production, the above-mentioned colored powders are commercially available with an agitator or a three-roll machine. The desired ink composition for screen printing is obtained by sufficiently mixing and dispersing it in the above.

In the present invention, it is important that the surface of the powder is colored in a desired color tone, and this allows the color tone of the colorant in the ink composition for screen printing to differ from the color of the ink composition due to the difference in the color of the powder. Of the ink composition obtained by the above-mentioned method, thereby facilitating the color tone expression of a desired coating film. As a result, the content of the coloring material in the screen printing ink composition can be reduced and abrasion resistance and scratch resistance can be improved.

In particular, when colored inorganic powder is used, by making the shape of the particle spherical, the degree of matte or satin finish of the coating film can be made uniform, and further, the fluidity is improved and the printing is improved. The characteristics are also good.

Furthermore, when using a non-porous material for the inorganic powder to be colored,
It has low water absorption and further improves coating hardness and coating adhesion.

Even if the inorganic powder to be colored is porous, a coloring material is attached or adsorbed on the surface of the powder to create a state almost similar to that of a non-porous inorganic powder with low water absorption. In addition, when the porous inorganic powder is contained, it is possible to prevent the decrease in surface hardness due to the swelling of the coating film and the poor adhesion of the coating film.

When screen printing is performed using the above-mentioned ink composition for screen printing, the surface to be printed may be subjected to clear coating in order to improve the adhesion between the coating film and the surface to be printed.

(Examples) Hereinafter, the present invention will be described in detail based on Examples.

Example 1 As inorganic powder, 10 parts by weight of alumina beads (average particle size 6 μm, manufactured by Sumitomo Chemical Co., Ltd.), carbon black (Mitsubishi Kasei # 850 (average particle size 18 μm), Mitsubishi Kasei Co., Ltd. )) 1 part by weight, and put in a magnetic ball mill 3
After rotating for a while, a black colored inorganic powder was obtained.

Commercially available black screen printing ink composition (Seiko 13
00, Seiko Advance Co., Ltd.) was added with 40% by weight of the above-mentioned colored inorganic powder and sufficiently mixed and dispersed with a three-roll to obtain a black screen printing ink composition.

Example 2 As an inorganic powder, 1 part by weight of Cyanimble-SB-5 (manufactured by Dainichiseika Co., Ltd.) was added to 10 parts by weight of titanium oxide beads (average particle size 6 μm, manufactured by Catalysts & Chemicals Industry Co., Ltd.). In addition, it was placed in a magnetic ball mill and rotated for 3 hours to obtain a blue colored inorganic powder.

Commercially available blue screen printing ink composition (Seiko 10
00, Seiko Advance Co., Ltd.) was added with 60% by weight of the above-mentioned colored inorganic powder and thoroughly mixed and dispersed with a three-roll to obtain a blue screen printing ink composition.

Example 3 As an inorganic powder, silica micro beads (average particle size 1 to
5 μm, Catalyst Kasei Kogyo Co., Ltd. was dispersed in ion-exchanged water, and a nickel nitrate solution and a potassium hydroxide solution were added in that order, and the mixture was thoroughly stirred, washed separately with water and air-dried to obtain a blue colored inorganic powder. .

Commercially available blue screen printing ink composition (Seiko 10
00, Seiko Advance Co., Ltd.) was added with 60% by weight of the above-mentioned colored inorganic powder, and sufficiently mixed and dispersed with a three-roll to obtain a blue screen printing ink composition.

Example 4 As an inorganic powder, γ-form alumina (average particle diameter 30 μm) was dispersed in an aqueous sodium aluminum sulfate solution, dissolved using ion-exchanged water, and then dye No. 504 and sodium hydroxide were added, With sufficient stirring, a thin film of water-insoluble aluminum salt was deposited. Further, it was left overnight to obtain a precipitate, which was separated, washed with water, and air-dried to obtain a red colored inorganic powder.

Commercially available red screen printing ink composition (SS-25-00
20% by weight of the above-mentioned colored inorganic powder was added to Toyo Ink Co., Ltd. and sufficiently mixed and dispersed with a three-roll to obtain a red screen printing ink composition.

Example 5 As a resin powder, an epoxy resin (Trepearl EP-D, average particle size 3 μm, manufactured by Toray Industries, Inc.) was colored with a red dye No. 104 (croxin β) to give a red colored resin powder. Got

Commercially available red screen printing ink composition (SS-25000,
Toyo Ink Co., Ltd.), 40% by weight of the above colored resin powder
The mixture was added and thoroughly mixed and dispersed with a high speed stirrer to obtain a red ink composition for screen printing.

Example 6 A black colored inorganic powder obtained in the same manner as in Example 1 and the substances described below were thoroughly mixed and dispersed in the following proportions with a three-roll mill to obtain a black screen printing ink composition.

Black colored inorganic powder 30 parts Cyanate ester-maleside resin (BT3103, manufactured by Mitsubishi Gas Chemical Co., Inc.) 33.5 parts Polyoxyalkylene glycol type epoxy resin (ED-
506, Asahi Denka Kogyo Co., Ltd. 33.5 parts Carbon black (Mitsubishi Kasei # 850 (average particle size 18μ
m), manufactured by Mitsubishi Kasei Co., Ltd. 2 parts Leveling agent (L-7500, manufactured by Nippon Unicar Co., Ltd.) 0.5 part Defoaming agent (SAG-100, manufactured by Nippon Unicar Co., Ltd.) 0.5 part (above "part" The term "" indicates "parts by weight".) Comparative Example 1 Commercially available black screen printing ink composition (Seiko 13
00, Seiko Advance Co., Ltd.), 40% by weight of alumina beads (average particle size 6 μm, Sumitomo Chemical Co., Ltd.) as non-porous inorganic powder were added and thoroughly mixed and dispersed with a triple roll. Then, an ink composition for screen printing was obtained.

Comparative Example 2 Commercially available blue screen printing ink composition (Seiko 10
00, made by Seiko Advance Co., Ltd.), 60% by weight of titanium oxide beads (average particle size 6 μm, made by Catalysts & Chemicals Co., Ltd.) as non-porous inorganic powder was added, and sufficiently mixed and dispersed with a triple roll. Then, an ink composition for screen printing was obtained.

Comparative Example 3 Commercially available black screen printing ink composition (Seiko 13
00, Seiko Advance Co., Ltd.), 15% by weight of silica powder (Cyroid 161, Fuji Davison Chemical Co., Ltd.) was added as a porous inorganic powder, thoroughly mixed and dispersed, and screen printing ink A composition was obtained.

Comparative Example 4 Commercially available red screen printing ink composition (SS-25-00
0, Toyo Ink Co., Ltd.), 20% by weight of nylon balls (average particle size 5 μm, Toray Co., Ltd.) was added as resin powder, and mixed and dispersed sufficiently to form an ink composition for screen printing. Obtained.

Comparative Example 5 A black screen-printing ink composition obtained by thoroughly mixing and dispersing the following substances with a three-roll mill was mixed with silica powder (Cyroid 244, manufactured by Fuji Devison Co., Ltd.) in the above ink composition. 20 parts by weight, and thoroughly mixed and dispersed with a triple roll to obtain an ink composition for screen printing.

Cyanate ester-maleimide resin (BT3103, manufactured by Mitsubishi Gas Chemical Co., Inc.) 34.5 parts Polyoxyalkylene glycol type epoxy resin (ED-
506, Asahi Denka Kogyo Co., Ltd. 34.5 parts Carbon black (Mitsubishi Kasei # 850 (average particle size 18μ
m), manufactured by Mitsubishi Kasei Kogyo Co., Ltd. 12 parts Barium sulfate (extrinsic pigment) 18 parts Leveling agent (L-7500, manufactured by Nippon Unicar Co., Ltd.) 0.5 part Antifoaming agent (SAG-100, Nippon Unicar Co., Ltd.) Manufacture) 0.5 part (The above "part" means "part by weight.") (Effect) As described above, the ink composition for screen printing obtained in Examples 1 to 6 and Comparative Examples 1 to 5 was used. , 8.8 mm in diameter and 10 cm in length, glossy nickel tubular member (clear coating with acrylic resin) was screen printed and baked at 170 ° C for 30 minutes to obtain a sample. .

These samples were tested for surface hardness under normal conditions, and surface color tones were compared.
The results are shown in the table below.

The results of the abrasion resistance test of the samples obtained by using the ink compositions for screen printing of Example 6 and Comparative Example 5 are as follows.

As described above, according to the ink composition for screen printing of the present invention, the influence of the color tone of the powder can be suppressed, the color of the coating film can be made clear, and the desired color tone can be easily obtained. By reducing the rate and improving the wear resistance and scratch resistance, excellent decorative products can be obtained.

Claims (1)

[Claims] 1. A screen printing ink composition comprising:
An ink composition for screen printing, comprising a colored powder having an average particle diameter of 0.1 to 50 μm and having the same or similar color tone as the colorant in the ink composition.