JPS5959756A - Pigment ink - Google Patents

Abstract

PURPOSE:To provide a pigment ink having excellent redispersibility with time, consisting of titanium oxide, a color pigment, an inorg. salt electrolyte, a surfactant and water. CONSTITUTION:Titanium oxide (e.g. organic treated titanium oxide, Bayer titan R-FD-1, a product of Bayer A. G., in an amount of pref. 5-40wt% based on the total amount of ink), a color pigment (e.g. carbon black in an amount of pref. 40wt% or less based on the total amount of ink), an inorg. salt electrolyte (e.g. borax in an amount of pref. 0.1-1wt% based on the total amount of ink), a surfactant (e.g. anionic surfactant, Demol EP, a product of Kao-Atlas K.K., in an amount of pref. 0.01-1wt% based on the total amont of ink), water (main solvent in an amount of pref. 25-50wt% based on the total amount of ink) and, if necessary, water-soluble resin, etc. are blended together to obtain the desired pigment ink.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pigment ink with excellent redispersibility over time.

Compared to conventional pigment inks, it has been designed to increase the hiding power of pigment inks.

Dispersion of titanium oxide (I use titanium oxide) Is titanium oxide dispersed into fine particles using a grinding machine such as a ball mill or three rolls as part of the J method?
Although it had good adhesion properties in the J period, it formed heart-shaped particles over time and its internal dispersibility was 4'u, which decreased the hiding power of the pigment ink and had a value of 11 fl. There have also been attempts to improve the dispersibility by using a dispersant, but these have not yet been satisfactory. Therefore, the present applicant filed a patent application in 1986-1
19544 (This is a product that successfully improved the redispersibility of titanium oxide over time using titanium oxide, an inorganic salt electrolyte, a surfactant, and a small amount of water (accompanied by white ink), but since then various research has been carried out. As a result, the dispersibility of titanium oxide over time in so-called pigment ink, which is a mixture of titanium oxide and color pigments other than titanium oxide, is also affected by the electrolyte of the inorganic salt.

The present invention was completed by discovering that surfactants exhibit excellent effects and, as a result, maintain the hiding power of pigment inks. That is, the present invention uses titanium oxide, two colored pigments, an electrolyte of an inorganic salt, a surfactant, and a small amount of water. Although it is unclear whether it maintains its hiding power, the action of the surfactant on the surface of the titanium oxide in the pigment ink allows the titanium oxide to be dispersed by moderately wetting it, and the inorganic salt electrolyte allows the titanium oxide and inorganic salt to be separated. It forms a light inorganic polymer with the electrolyte and exhibits a kind of cushioning effect, making it difficult for titanium oxide to form a hard cake even if it settles.2 As a result, redispersion over time becomes easy.

It is thought that it can maintain the hiding power of the pigment ink because it is uniformly dispersed with the colored pigment.

Below, one component of the present invention will be explained in detail.

Titanium oxide is used as a concealing material as well as a coloring agent, and various types of titanium oxide such as Rudil type and Anatase type can be used, but among them, organically treated titanium oxide is preferable.
tanR-Fl) -1, tanR-K 13-3,
In the same 1 -CK-20 (manufactured by Bayer), l' I
PkQUE I<-63o, same 17-615. Same R
-830 (2 Ishihara Sangyo IIJ), Un
ita neoR-542 (A, C,
C, Inc.), Ti-Pure R-90
0+ R-901 (manufactured by E, 1.Dupon), etc., and the amount used is preferably 3 to 40% by weight based on the total amount of the pigment ink, although it varies depending on the intended use.

The coloring pigment is used as a coloring agent, and any known pigment can be used. -For example, inorganic Ml such as carbon black, Henkara, black iron oxide, Hansaiero-
10G, 0. Hengedine Yellow, Isoindolinone, Vulcan Fast Ore/Di, Perinone Orenno, Brilliant Carmine 6B, Lake Red C, Watching Red, Dioxazine Violet, Phthalonanine Flu, Phthalonoania Clear.

Organic pigments such as fluorescent pigments are available, and these can be used either as a medium or as a mixture, and the amount used is preferably 40% or less based on the entire pigment ink.

Inorganic salt electrolytes are used to improve redistribution over time - for example, borax.

Borate, water glass, sodium carbonate, calcium carbonate, etc. can be used, but among them, use of borax is preferred. The amount of these used is preferably 0.1 to 1.0% compared to all pigment inks.

The surfactant improves the wetting and dispersibility of titanium oxide and the pigment, and various known surfactants can be used. - Examples of anionic interfacial viscosity agents include polycarphonic acid type surfactants such as Thymol FP, Poise 520° and 550 (hereinafter referred to as Nikao Atlas ■), and Tisco 1-N-14 (manufactured by Daiichi Kogyo Seiyaku ■). and Thymol N (manufactured by Kao Atlas ■) are naphthalene sulfonic acid formalin condensate type surfactants.
jAs an activator, Surfynol I'G.

→Nolinor 104B (JIAir Pro
Acetylene glycol type surfactants such as -ducts and chemical products), polyoxylene ethylene alkyl ether type surfactants such as Pecunol (manufactured by Toho Chemical Industry Co., Ltd.), and Phyten E i” (manufactured by Daiichi Kogyo Seiyaku ■). Agent and Nonipole 160 (Air Produ
Examples include polyoxyethylene argylphenyl ether type surfactants such as cts and Cb emica l's) L/Suichiru (manufactured by Toho Chemical Industry Co., Ltd.).

They can be used alone or in combination, and the amount used is preferably 0.001 to 1% by weight based on the total amount of the pigment ink.

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

In addition to the above components, water-soluble resins, water-dispersible resins, and film-forming agents may be used as appropriate to improve fixing properties, and ethyl alcohol, Alcohols such as isopropyl alcohol can also be used as appropriate.Also, in order to improve wettability and freeze stability, polyhydric alcohols, urea, etc. can be used in various colors for complementary colors. Dyes and the like may be used as appropriate, and various additives such as preservatives, antifungal agents, antifoaming agents, etc. may also be used as appropriate.

The pigment ink of the present invention can be easily prepared (ζ) by mixing and dispersing the above-mentioned components in a dispersing machine such as a ball mill.

Hereinafter, the present invention will be explained in more detail based on two examples. In the examples, "1 part" indicates "part by weight."

Example 1 Bayer titanR-KB-ro (titanium oxide) 2
87.0 parts Phthalocyanine blue (free AI charge)
so, o part thymol BP (anionic surfactant)
13 parts Tiscoat N-14 (anionic surfactant)
0.5 parts Finol TG (nonionic surfactant)
0.5 parts water
5 B 8.7 parts Primal AC-344
4 (Acrylic acid Nisdel emulsion.

1:1 acrylic, water-dispersible resin) 660 parts Silica powder 690 parts Ethylene glycol 76.0 parts Urea
760 parts Shin-Etsu Noricone KM-73 (manufactured by Shin-Etsu Chemical Co., Ltd., defoaming agent) 25 parts Broxel CRL (manufactured by Company 1, C, I, preservative and anti-mold agent) o 5 parts By pulverizing and dispersing the above ingredients in a ball mill, a sky blue color is obtained. A pigment ink was obtained.

Comparative Example 1 A sky blue pigment ink was obtained in the same manner as in Example 1, except that 5.0 parts of borax in Example 1 was removed and so many parts of water were added.

Example 2 Bayer l1tan R-K B-560, 0 parts Linole Red (organic pigment) 69.0
Part Lake Red C (organic pigment) 106.
0 parts Borax 40 parts Thymol N 1 part Tiscoto N-140, 5 parts Finol TG Q,
5 parts water 99
7 parts Primal AC-3444220, 0 parts Sori flour
140 parts ethylene glycol 760 parts urea
760 parts Hakuetsu silicone, M
-7625 part Broxel CRL
Part 05: Red color ink was prepared using the same ingredients as in Example 1 (fX).

Comparative Example 2 A red pigment ink was prepared in the same manner as in Example 1 except that 40 parts of borax in Example 2 was removed and 40 parts of water was added.

Above, Examples 1 and 2. Table 1 shows the results of the redispersibility test over time for the pigment inks obtained in Comparative Examples 1 and 2.

Table 1 Test method Number of test tubes with inner diameter of 1.5 crn + volume of 30 tubes A total of 32 tubes, 8 tubes each containing 20 tubes of pigment ink obtained in Example 1.2 and Comparative Examples 1 and 2, were prepared. .

Close the cap and leave it at room temperature for 1 day or 6 days.

20 days later, 301”l later, 40 days later, 60 days later.

After 120 and 150 days, the test tube was taken out and the surface where the titanium oxide in the pigment ink had settled was gently stirred with a micro spatula to thoroughly redisperse it, and the test tube was gently shaken vertically several times. ○ indicates that the concealing power has returned to its original state.

It does not re-disperse even when stirred with a microscopic stirrer, and even when the test tube is gently shaken vertically several times, it does not regain its original hiding power, and some of the titanium oxide remains at the bottom of the test tube. The ones that are present are marked as ×.

As shown below, the pigment ink of the present invention has excellent dispersibility over time (14), and as a result, it can maintain its hiding power over time, and can be used not only for markers but also for A7 and various other uses. It can be used.

Bureau license applicant: Bentel Co., Ltd.

Claims (1)

[Claims] Titanium oxide, 1 colored face 21, an inorganic salt electrolyte, a surfactant, and water make a face of at least 4.
tree .