JPS59199780A - Aqueous pigment ink - Google Patents

Abstract

PURPOSE:To reduce the color shading of coating and written surface and improve the leveling (surface smoothness), by adding an inorganic colloid to an aqueous pigment ink consisting of a pigment, water, a binder and a surfactant. CONSTITUTION:An aqueous pigment ink obtained by incorporating (A) preferably 5-52wt% pigment, e.g. titanium oxide, with (B) preferably 25-50wt% water, (C) preferably 2-25wt% binder, e.g. a water-dispersible resin or water-soluble resin, (D) preferably 0.01-3wt% surfactant, e.g. anionic, cationic or nonionic surfactant, and (E) preferably 0.01-3wt% inorganic colloid, e.g. silica colloid, titanium sol, iron sol, chromium sol, antimony sol, alumina sol or zirconia sol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-based pigment ink with excellent application and leveling properties on a writing surface.

Conventionally, relatively high viscosity water-based pigment inks consisting of pigment, water, binder, and surfactant have had the problem of poor leveling (surface smoothness) of the application and writing surface when applied or written on. Was.

Therefore, the inventor of the present invention aimed to solve the above problems.

As a result of extensive research, we discovered that by adding an inorganic colloid to a conventional water-based pigment ink composition, it was possible to obtain a water-based pigment ink with excellent leveling properties with less color unevenness on the application and writing surface, and thus completed the present invention. It is something.

That is, the gist of the present invention is an aqueous pigment ink comprising at least a pigment, water, a binder, a surfactant, and an inorganic colloid.

It is not clear why the aqueous pigment ink of the present invention has excellent coating and writing surface leveling properties, but it is speculated as follows.

Since the aqueous pigment ink of the present invention contains an inorganic colloid, the inorganic colloid particles are adsorbed onto the pigment surface and provide electrochemical repulsion between the pigments, so that the pigments are uniformly arranged in a certain gap, resulting in leveling. It seems that the performance will improve.

Next, each component of the present invention will be explained.

Pigments are used as coloring materials and are organic.

Any inorganic type can be used; here are some specific examples:

Titanium oxide, zinc white, carbon black, Hansa Yellow 〇, Hansa Yellow 100. Loess + ” Ndoshinina, Bengala, Lakelet, Carmino 3B, Gun?
There are Phthalonanine Blue, Chrome Clean, Leo 7 Ryo-Stred, and Leo Fast Blue, which can be used alone or in combination, and the amount used varies depending on the type of pigment and other ink components. is preferably 5 to 52% by weight based on the total amount of ink.

Water is used as a solvent, and the amount used is preferably 25 to 50% by weight based on the total amount of ink.

Binder is used to improve the fixation of ink to the surface being coated and written on.

Water-soluble resins, water-dispersible resins, etc. can be used, and the amount used varies depending on the use of the ink, but it is preferably 2 to 25% by weight in terms of solid content based on the total amount of the ink.

Surfactants are used to improve the wettability and dispersibility of pigments, and are anionic surfactants.

Various surfactants such as cationic surfactants and nonionic surfactants can be used, and the amount used is 0 for total ink failure.
01 to 6% by weight is preferred.

Inorganic colloids are of particular importance in the present invention,
Specific examples of materials used to improve the leveling properties of the coating and writing surface are silica colloid, titanium sol, and iron sol.

Chrome sol, antimony sol, cerium sol.

Examples include zirconia sol, alumina sol, silver sol, palladium sol, iridium sol, etc., and the amount used is preferably 0.01 to 3% by weight based on the total amount of the ink. 001% by weight
If the amount is less, the effect will be small, and if it is more than 6% by weight, no further effect can be expected and it is disadvantageous in terms of cost.

In addition to the ingredients listed above, add one other constitution as needed.

Various additives such as preservatives, antifungal agents, complementary color dyes, wetting agents, viscosity modifiers, freeze stabilizers, and antifoaming agents can be selected and used as appropriate.

The aqueous pigment ink of the present invention can be easily obtained by dispersing the above-mentioned components using a dispersing machine such as a ball mill.

The present invention will be explained in more detail below according to examples, but
In the examples, "parts" indicate "parts by weight."

Example 1 B a y e r t it a n RK B
3 (Titanium oxide, manufactured by Bayer) 32
．． jO part water
3817 parts Primal AO-3444 (acrylic acid ester emulsion, resin content 44-45% water-dispersible resin 2 manufactured by Nippon Acrylic ■) 6.50 parts Demol EP (anionic surfactant, manufactured by Kao Atlas ■)
0.13 part disco) N-1
4 (Anionic surfactant.

Daiichi Kogyo Seiyaku ■) 005 parts Zerfinol TG (nonionic surfactant).

Air Products and Ohemi
(manufactured by cals) 005 parts Snowtex C (silica colloid, manufactured by Nichichi Kagaku ■)
2.00 parts 5- Silica powder (constitution) 760 parts ethylene glycol (freeze stabilizer) 760 parts urea (wetting agent)
5. 60 copies to Shinetsu Ricoh, M −
73 (antifoaming agent, manufactured by Shin-Etsu Chemical Co., Ltd.)
0.25 parts Broxel OR,L (preservative and fungicide,
1. C! .

A white water-based pigment ink was obtained by pulverizing and dispersing 0.05 parts or more of each component using a ball mill.

Example 2 The amount of Snowtex C in Example 1 was changed from 2.00 parts to 0.05 parts.
Example 1 except that the amount was reduced to 0 parts and the amount of water was increased by that amount.
A white aqueous pigment ink was obtained in the same manner as above.

Example 3 The amount of Snote Sox C in Example 1 was changed from 2.00 parts to 0.
A white water-based pigment ink was obtained in the same manner as in Example 1, except that the amount of water was reduced to 0.05 parts and the amount of water was increased by that amount.

Comparative Example 1 Example 1 A white aqueous pigment ink was obtained in the same manner as in Example 1, except that Snote Zokus C was removed and the amount of water was increased accordingly.

- Example 4 LIOFAST RED (organic pigment, manufactured by Toyo Ink ■) 25.40 parts water
294 o part Primal A, O-344438,00 parts Discoat N-140,05 parts Susu Finol TG 0.15 parts Snowtex 0 180 parts Ethylene glycol 5,00 parts Shin-Etsu Silicone K M -
730, 15 parts Broxel ORr,
0. [A red aqueous pigment ink was obtained using 15 parts or more of each component in the same manner as in Example 1.

Comparison fll 2 Except for Snowtex O of Example 4, Examples 1 to 4. Table 1 shows the leveling test results of the inks obtained in Comparative Examples 1 and 2.

Table-1 *Leveling test examples 1 to 4. The samples obtained in Comparative Example 1.2 were visually observed, and those with good leveling properties were rated ○, and those with slightly poor leveling properties were rated △.

Those with poor leveling properties were marked as ×.

As shown above, the aqueous pigment ink of the present invention has excellent coating and leveling properties on the writing surface.

Patent applicant: Pentel Co., Ltd. =9-

Claims (1)

[Claims] A water-based pigment ink consisting of at least a pigment, water, a binder, a surfactant, and an inorganic colloid.