JPS61291664A - Aqueous fluxorescent pigment ink for marking pen - Google Patents

Abstract

PURPOSE:To titled ink providing various faces including ink immpermeable face with a fluorescent color mark with opacifying properties, containing daylight fluorescent pigment, opacifying pigment consisting of titanium oxide, etc., an alkali-soluble resin and an rosin ester emulsion. CONSTITUTION:(A) 2-30 wt.% daylight fluorescent pigment is blended with (B) 2-50 wt titanium oxide as an opacifying pigment or 2-25 wt.% pearl pigment consisting of mica pieces coated with titanium oxide, (C) 1-50wt.% alkali-soluble resin (e.g., styrene-acrylic acid copolymer, etc.) and (D) 3-20wt.% rosin ester emulsion, to give the titled ink.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a water-based fluorescent pigment ink for marking pens that can be marked on various surfaces including ink-permeable surfaces and provides a fluorescent mark with concealment properties. .

Regarding conventional water-based fluorescent ink for marking pens which is mainly intended for paper and is prepared by dissolving a fluorescent dye in an aqueous medium, for example, Japanese Patent Publication No. 57-29500.58-40593 and 59
Many proposals have been made, such as the disclosure in No. 4453. However, these inks cannot mark an ink-permeable surface such as a hydrophobic plastic surface, and even if they do mark an ink-permeable surface, they do not provide a maskable mark.

On the other hand, many organic solvent-based fluorescent pigment inks for marking marks have been proposed (for example, JP-A-56-152878), which provide fluorescent marks with hiding properties on all types of surfaces. 58-208359 and 59
-75967, etc.) Problems to be Solved by the Invention The water-based fluorescent ink prepared by dissolving the fluorescent dye in an aqueous medium cannot substantially mark the surface permeated with the ink, and is limited to paper. Since the mark is transparent, the fluorescent effect will not be exhibited on colored paper.

Furthermore, fluorescent pigment inks based on organic solvents have the problem of odor and toxicity of organic solvent vapor when marking, and are particularly unsuitable for use in closed rooms.

To obtain a water-based fluorescent ink for marking pens that can mark various surfaces, including ink-penetrating surfaces, and give a fluorescent mark with concealment properties, a daylight fluorescent pigment is used as a coloring agent and a dark-colored surface or ink-penetrating surface. It is necessary to use a concealing pigment such as a white or silvery white titanium oxide or a pearl pigment with high reflectance to conceal the base on the surface. The specific gravity of a daylight fluorescent pigment, which is a solid solution of a fluorescent dye and a synthetic resin, and a concealing pigment such as a Burl pigment, which is made of an inorganic titanium oxide or mica flakes whose surface is coated with titanium oxide (the former is 1.1 to 1.4. The latter has significantly different surface characteristics and other physical properties, including 3.9 to 4.2), and it is difficult to stably disperse them in a low-viscosity aqueous vehicle. Here, the need for the ink of the present invention to have low viscosity is achieved by storing the ink in the barrel and supplying the ink via a valve mechanism to the nib, which is made by binding fiber bundles with resin. This is because it is applied to a marking pen configured to
The ink must have a low viscosity of:

Furthermore, in general, water-based inks do not adhere well to hydrophobic ink-permeable surfaces, making it impossible to obtain strong adhesion.

Means for Solving the Problem The ink of the present invention comprises titanium oxide or mica flakes surface coated with titanium oxide as a daylight fluorescent pigment and a hiding pigment in an aqueous vehicle containing an alkali-soluble resin and a rosin ester emulsion. It is made by dispersing a certain pearl pigment.

As the alkali-soluble resin, styrene-acrylic acid, α
- Methylstyrene-acrylic acid, acrylic acid copolymers such as hinyl acetate-acrylic acid, maleic acid copolymers such as vinyl acetate-maleic anhydride, ethylene-maleic anhydride, styrene-maleic anhydride, Schlag and maleic acid Examples include resin. These resins are dissolved in an aqueous medium in the form of alkali metal salts, ammonium salts, alkanolamine salts or acid amides, and are included in the ink composition with 1 to 5
It is used in an amount of 0% by weight, preferably 5 to 30% by weight.

Rosin ester emulsion is a resin emulsion of ester of rosin and polyhydric alcohol such as ethylene glycol, glycerin, or pentaene-1-notol, and is 3 to 20% by weight in terms of solid content in the ink composition, preferably 5 to 15% by weight. Used in the range of %.

Daylight fluorescent pigments are solid solutions of fluorescent dyes and synthetic resins, and the synthetic resins include sulfonamide resins, alkyd resins, methacrylic acid copolymers, and acrylonitrile.
Examples include styrene copolymers. These fluorescent pigments are used in the ink composition in an amount of 2 to 30% by weight, preferably 10 to 20% by weight.

The titanium oxide pigment as the hiding property-imparting pigment may be either rutile type or anatase type, and is used in the ink composition in an amount of 92 to 50% by weight, preferably 5 to 20% by weight.

In addition, the pearl pigment consisting of mica pieces whose surface is coated with titanium oxide has an average particle diameter of 40 μm or less, and the ink composition is 92 to 25% by weight, preferably 5% by weight.
It is used in a range of 15% by weight.

Other complementary color pigments or dyes, surfactants, volatile water-soluble alcohols, humectants, basic substances,
Preservatives, antifoaming agents, etc. are added.

Function: Of the two resins applied to the aqueous vehicle, the rosin ester emulsion mainly acts as an effective protective colloid for the titanium oxide or Burr pigment as the pigment that imparts hiding properties, preventing the pigment from settling or forming a hard cake. The alkali-soluble resin mainly gives the mark strong adhesion to the ink penetrating surface.
When both are used in combination, their synergistic effects enhance their individual effects. Such a synergistic effect cannot be obtained by combinations of other resins, such as combinations of rosin ester emulsions and water-soluble resins, and combinations of resin emulsions other than rosin esters and alkali-soluble resins.

Furthermore, on a mirror-like surface with high reflectance, this type of ink mark has a low contrast with the surface and is difficult to identify. To avoid this phenomenon, measures are usually taken such as adding an extender pigment to the ink or significantly increasing the pigment/resin ratio. Although these measures are disadvantageous as an ink for marking pens, the ink of the present invention produces matte-like marks due to the action of the two types of resins, so even on mirror-like surfaces without taking the above measures, there is no difference between the mark and the surface. The contrast is large and marks are clearly recognized.

Example Table 1 shows the compositions and physical properties of the inks of Examples and Comparative Examples.

Each ink was prepared according to the following procedure.

(1) Water, resin (aqueous solution), and additives are placed in a beaker and stirred for 15 minutes using a Chemister stirrer.

(2) Next, add the fluorescent pigment paste and the hiding pigment (paste) and stir for 15 minutes.

(3) Finally, add the resin emulsion and stir for 30 minutes to finish.

However, in Comparative Examples 1 and 2, operation (3) was not performed.

The composition numbers in the table represent parts by weight, and the numbers in parentheses represent solid content.

The contents of the note numbers are as follows.

fil Fluorescent yellow dye (C,1,5olvent Y
(2) Fluorescent pink dye (C0lBasic R
ed 1) and a solid solution of acrylonitrile-styrene copolymer (solid content 40%).
) (3) Fluorescent yellow dye (C, T, 5olvent Ye
44 ) and fluorescent red dye (C,1,5ole
nt Red 49) mixture and acrylonitrile-
Aqueous paste of fluorescent pigment consisting of solid solution of styrene copolymer (solid content 40%) (4) Rutile titanium oxide 5
0 parts by weight, 2.5 parts by weight of anionic dispersant and 47.5 parts by weight of water.
Aqueous paste (solid content 50%) dispersed in an aqueous medium consisting of parts by weight (5) 60% aqueous paste of rutile titanium oxide (6) Mica pieces surface coated with titanium oxide (average particle size 10 μm or less) ( 7) Rosin-glycerin ester (acid value 7 or less,
Emulsion with a softening point of 70-80℃ (solid content 40%)
(8) Rosin-pentaerythritol ester (acid value 20 or less, softening point 110-120°C) emulsion (solid content 50%) (9) Maleic acid resin (acid value 140 or less, softening point 13)
Ammonium aqueous solution (solid content 30%) αO) Shellac ammonium aqueous solution (solid content 25
%) (1υ Styrene-maleic acid copolymer (acid value 175~
200, softening point 105-120°C) (solid content 28%) Ammonium aqueous solution of styrene-acrylic acid copolymer (solid content 30%) ■ Acrylic acid ester-styrene copolymer emulsion (solid content 41. 5%) α Xun maleic acid resin (acid value 39 or less, softening point 120
~130°C) emulsion (solid content 50%) αQ Phthalocyanine Green (C, 1, Pigment Gre
Aqueous paste (pigment content: 20%) in which en36) is dispersed in water using a nonionic activator.Effects of the Invention The following performance tests were conducted on the example ink and the comparative example ink.

A marking pen with the following mechanism was filled with a predetermined amount of each ink to prepare samples for tests (1) and (2).

The mechanism of the marking pen is a bottomed aluminum cylinder with a diameter of 159φ and a total length of 110fi.
A pen body holder that accommodates one nφ stainless steel ball and has a valve mechanism is fixed to the open end, and a 41φ pen body made of acrylic fiber bundles bound with resin is fitted to the tip of the holder. When marking, the pen tip is pressed against the marking surface and the valve is pushed open to draw the ink inside the cylindrical body into the pen body.

Performance test (1) Dispersion stability Each sample After marking a predetermined line on each surface of black paper, polyethylene film, and polyester film using a marking pen, each sample was sealed and subjected to a test. After each sample marking pen was left standing for 15 days with the pen tip facing upward, a mark was made on the surface adjacent to the initial mark of each sample on the surface without shaking, and the color tones of both marks were compared.

Display of results O: Same as the initial mark ×: Transparent mark with almost no hiding property (hidden pigment has settled) (2) Separately from the redispersibility (1) sample, with the pen tip facing upward. After standing still for 30 days, each sample pen is shaken up and down and the number of shaking until the dispersion method moves freely is determined by the sound of the dispersion method colliding with each other and the number of shaking is measured.

Display of results ○: Less than 3 times △: 4 to 10 times ×: No sound from the dispersion method even after 10 times of shaking (due to the formation of a hard cake) (3) Adhesion Each sample ink was mixed with 0. It was applied to the surface of the polyester film using a 5-long wire bar, and after being left for one day, the surface of each sample was rubbed at 1.9 kgG using a rubbing tester.

Viewing results Withstands 02100 scratches ×: Peeling occurs after less than 50 times The test results are shown in Table 2.

Table 2 Test Results As seen in the test results, inks containing no rosin ester emulsion or containing other resin emulsions (Comparative Examples 1 to 4) showed poor dispersion stability of the hiding pigment. It cannot be maintained, and hard cake formation is also observed.

On the other hand, in the ink containing no alkali-soluble resin (Comparative Example 5), no hard cake was formed, but stable dispersion of the hiding pigment and strong adhesion could not be obtained. Furthermore, the ink (Comparative Example 6) in which the alkali-soluble resin is replaced with a water-soluble resin (gum arabic) has a problem in adhesion.

In contrast, the ink of the present invention exhibits pigment dispersion stability and good redispersibility, and in addition, provides marks that exhibit strong adhesion to hydrophobic ink-penetrated surfaces. Compared to conventional organic solvent-based fluorescent pigment inks, the mark itself remains clear and has no odor or toxicity, and the present invention also allows for overcoating of other marks. This is the advantage of water-based fluorescent pigment ink.

Claims (1)

[Claims] The essential ingredients are (1) daylight fluorescent pigment, (2) a concealing pigment selected from titanium oxide and a pearl pigment consisting of mica flakes whose surface is coated with titanium oxide, (3) an alkali-soluble resin, and (4) rosin. A water-based fluorescent pigment ink for marking pens containing an ester emulsion.