JPS5823232B2 - Inkjet printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet printing method for printing ink with excellent adhesion onto a glass surface.

Conventional methods for printing or coloring glass surfaces7 include:
The stain method involves applying a coloring agent to the glass surface and then heating it to diffuse Ag, Cu ions, etc. into the glass to color it; 1... An acid treatment method that lowers the refractive index and colors using light interference. Colored glass is produced by printing low melting point colored glass and fine powder on the glass surface using a sticky organic substance as a medium and heating it. Coating methods that fuse thin layers or methods that apply or print ordinary marking inks, printing inks, paints, etc. to the glass surface have been used.

However, conventional methods, such as the stain method, acid treatment method, and coating method, require high-temperature heat treatment.
In addition, there are drawbacks such as the difficulty of high-speed printing, and methods of applying or printing ordinary marking inks, printing inks, paints, etc. have insufficient adhesion of colored substances to glass, especially in the presence of moisture. The adhesion is significantly reduced due to
In addition, there were drawbacks such as difficulty in high-speed printing.

Furthermore, in recent years, a method of jet printing using a diene printer that is simple and suitable for high-speed printing has been developed, but inkjet printing inks that have excellent adhesion to glass surfaces are still lacking.

The present invention provides an inkjet printing method that improves the adhesion to the glass surface, which is a drawback of the conventional printing and coloring methods, does not require additional heat treatment, and is capable of simple and high-speed printing. It is.

That is, the present invention relates to an inkjet printing method in which a surface treatment agent containing lithium silicate and an organic synthetic resin emulsion as main components is applied onto a glass surface, and then jet printing ink is printed using a jet printer.

The surface treatment agent used in the present invention consists of lithium silicate and an organic synthetic resin emulsion.

In addition, lithium silicate has the general formula L + 20・n
The one represented by S102 is used.

However, the molar ratio n is not particularly limited, but 4 to 8 is usually appropriate.

Furthermore, organic synthetic resin emulsions that have been conventionally used in inks, paints, etc. can be used.

Typical emulsions include, for example, vinyl acetate resin, styrene-buccadiene resin, acrylic resin, styrene-acrylic resin, and ethylene-vinyl chloride resin.

Organic synthetic resin emulsions usually have a resin solid content of 30 to 6.
It is 0% by weight, and in addition to the resin, water, a dispersion activator, an organic solvent, a preservative/antifungal agent, etc. may be added as necessary.

In the surface treatment agent, the mixing ratio of lithium silicate and the resin component in the organic synthetic resin emulsion is 10% of the former.
The latter is preferably 250 to 1,500 parts by weight, particularly preferably 500 to 1,000 parts by weight.

By adjusting the ratio in this manner, favorable film-forming properties, water resistance, adhesion properties, etc. can be obtained.

In addition to the lithium silicate and the organic synthetic resin emulsion, water is added to the surface treatment agent used in the present invention to adjust the solid content concentration to about 0.5 to 20% by weight, and if necessary, a colorant, Add various additives.

This surface treatment agent is used for the purpose of improving the adhesion of jet printing ink to glass.

Therefore, the thickness of the coating is not particularly limited, but it needs to be 10 μm or less in order to obtain a transparent coating.

The surface treatment agent is applied to the glass surface cleaned with detergent etc.
Apply by conventional methods such as spraying, rolling or dipping.

The method of the present invention includes applying the surface treatment agent to the glass surface,
After drying, use a jet printer on top of it,
Jet print ink for jet printing.

Jet printers typically use a method in which ink is introduced into a nozzle with a narrow hole of approximately 10 to 400 microns, and ink particles are ejected from the tip of the nozzle and are electrostatically deflected by a deflection electrode placed in front of the nozzle to print characters, etc. used as something.

Due to the characteristics of the inkjet method, the jet printing ink used in the present invention must have an appropriate viscosity and surface tension so that it can be ejected as stable ink particles from a narrow nozzle, and a specific resistance that can control static electricity. It is required that the

That is, the jet printing ink has a viscosity of ~20 centipoise and a surface tension of 2Q ~50 dyn e/(
i.

A material having a specific resistance of 10,000 Ω, preferably 2,000 Ω or less is used.

In addition, various special orders are required, such as good drying properties, water resistance, weather resistance, etc., as well as the necessary hue for various uses, and the ink density necessary for legibility after printing.

The jet printing ink used in the present invention mainly contains a binder, a colorant, and a solvent, and may also contain other additives such as a surfactant, a preservative, and a fungicide, if necessary.

Particularly in the present invention, it is desirable to use a water-based ink using water (solvent) because it has good adhesion to the glass surface.

(More specifically, JP-A-50-8361, JP-A-47-3855, JP-A-51-127809, JP-A-52-9506, JP-A-53-123)
The use of water-based inks described in Japanese Patent Application Laid-open No. 208, Japanese Patent Application Laid-open No. 53-140105, etc. is preferable if necessary.

) In addition, solvent-based inks using organic solvents such as xylene, toluene, ketones, aliphatic hydrocarbons, etc. as solvents or oil-based inks using dehydrated castor oil or the like as a binder can also be used.

The jet printing ink used in the present invention is prepared by filtering it through a membrane filter of 1 to 3 μm in order to prevent nozzle clogging.

The jet printing ink prepared in this way does not clog the nozzle in forced vibration type jet printers.
Electrostatic control is also good.

Therefore, stable continuous printing is possible. As mentioned above, the method of the present invention does not directly print the jet printing ink on the glass surface, but prints via a surface treatment agent, so the conventional method gives undesirable results due to poor adhesion to the glass. Compared to the previous version, there was a marked improvement in adhesion to glass, etc., and therefore high-speed printing became possible.

The present invention will be explained below with reference to Examples.

* Note that "parts" in Examples and Comparative Examples indicate "parts by weight."

Actual Cases 1 to 13 Each glass plate cleaned with a detergent was dip coated with the surface treatment agent shown in Table 1, dried for 3 minutes at room temperature, and then printed with the following jet printing ink using a forced vibration inkjet printer.

After drying at room temperature for 1 hour, the prints did not change even when rubbed strongly with fingers, and had excellent adhesion.

Next, each printed glass plate after drying at room temperature for 24 hours was immersed in water for 24 hours to evaluate the adhesion of the printed matter.

In Example 1, the printed characters were slightly thinner than before immersion in water, but were sufficiently legible, and even when rubbed strongly with a finger, there was no change and there was no practical problem.

In Examples 2 to 4 and 6 to 13, there was no change in the density of the characters, and there was no change even when rubbed strongly with a finger.

In Example 5, there was no change in the density of the characters, and there was no change even when lightly rubbed with a finger, but it peeled off when rubbed strongly.

Comparative Example 1 In an actual case, printing was performed in the same manner as in the example except that no surface treatment agent was applied and printing was performed directly using jet printing ink.

When rubbed lightly with a finger after immersion in water, the printed literature peeled off easily and had poor adhesion.

Comparative Example 2 Printing was carried out in the same manner as in Example 2 except that a surface treatment agent containing no lithium silicate was used (the other components and their amounts were the same).

Comparative Example 3 Printing was carried out in the same manner as in Actual Case 10, except that a surface treatment agent not containing lithium silicate (other components and amounts thereof were the same) was used.

Comparative Example 4 Printing was carried out in the same manner as in Example 12 except that a surface treatment agent containing no lithium silicate (other components and amounts thereof were the same) was used.

When the printed glass plates of Comparative Examples 2, 3, and 4 were immersed in water for 24 hours after drying at room temperature for 24 hours, the printed characters were somewhat thinner than before immersion in water.
Both peeled off when rubbed strongly with fingers.

From the above results, the surface treatment agent coated with lithium silicate and organic synthetic resin emulsion as the main components has a higher adhesion rate than the surface treatment agent coated with organic synthetic resin emulsion alone, which does not contain lithium silicate. It was found that the properties are excellent.

Claims (1)

[Scope of Claims] 1. Inkjet printing characterized in that a surface treatment agent containing lithium silicate and an organic synthetic resin emulsion as main components is applied onto a glass surface, and then jet printing ink is printed using a jet printer. Method. 2 The surface treatment agent has a resin content of 250 parts by weight in the organic synthetic resin emulsion per 100 parts by weight of lithium silicate.
The inkjet printing method according to claim 1, characterized in that the proportion is 1500 parts by weight. 3. The resin component in the organic synthetic resin emulsion is one or a mixture of two or more of vinyl acetate resin, styrene-butadiene resin, acrylic resin, styrene-acrylic resin, and ethylene-vinyl chloride resin. An inkjet printing method according to claim 1 or 2.