JPH064803B2 - Black pigment ink - Google Patents

Description

TECHNICAL FIELD The present invention relates to a black pigment ink having excellent hiding power,
More specifically, it relates to a black pigment ink which, when used for a writing instrument, provides a handwriting having high blackness and excellent hiding power.

(Prior Art) Conventionally, inks are roughly classified into water-based and oil-based inks, and carbon black has been used as a coloring material for black pigment inks.

(Problems to be solved by the invention) However, although carbon black has a high degree of blackness, but has a weak hiding power, an ink containing carbon black as a coloring material may be written on a paper on which patterns, ruled lines, etc. are printed. However, there was a problem that the background pattern, ruled lines, etc. were raised.

In order to solve the above problems, it is conceivable to increase the amount of carbon black added, but in that case, the viscosity of the ink increases, and as a result, blurring at the time of writing, or the problem that writing becomes difficult or impossible. Dots occur.

(Means for Solving Problems) Therefore, the present inventors have finally completed the present invention as a result of intensive research to solve the above problems.

That is, the subject matter of the present invention is a black pigment ink in which at least titanium nitride is dispersed as a black colorant in an organic solvent and / or water.

The present invention will be described in more detail.

Titanium nitride, which is the essence of the present invention, is used as a colorant for ink, and the amount used is preferably 2 to 15% by weight.

In addition, known materials used for inks can be used if necessary. First, in the case of aqueous inks, one of water-soluble organic solvents such as alcohols, glycols, cellosolves, carbitols, etc. as a dispersion medium. Alternatively, a mixture of two or more kinds and water can be used. The amount used is preferably 65 to 95% by weight.

As a dispersant for titanium nitride, an anionic surfactant,
One or a mixture of two or more nonionic surfactants and polymer active agents such as styrene-maleic acid copolymer / styrene-acrylic acid copolymer can be used. How much is used
0.2 to 2.0% by weight is preferable.

One or a mixture of two or more water-soluble natural or synthetic resins can be used as a viscosity adjusting agent for ink, preventing precipitation of titanium nitride, and fixing agent on paper surface. The amount used is 15% by weight or less. Is preferred.

In addition, urea, thiourea, ethyleneurea and their derivatives may be used as moisturizing agents (resistant to nibs), and various additives such as antiseptic / antifungal agents and rust inhibitors may be added as necessary. .

Next, in the case of oil-based inks, one or a mixture of two or more of hydrocarbon-based / aromatic organic solvents and alcohols / ethers / ketones can be used as a dispersion medium. The amount used is preferably 65 to 95% by weight.

The titanium nitride precipitation preventing / fixing agent may be of any type as long as it is soluble in the above organic solvent, but may be one or more of alkyd resins, acrylic ester copolymers, nitrocellulose, butyral resins and the like. A mixture is used. The amount used is preferably 15% by weight or less.

In addition, a dispersant, a rust preventive, a leveling agent, etc. may be appropriately selected and used as necessary.

The black pigment ink of the present invention is used in a sand mill, roll mill,
Centrifugal separation using various well-known dispersion equipment such as ball mill
It can be manufactured by removing coarse particles due to excessive use.

(Examples) The present invention will be described below based on examples, but these examples do not limit the scope of the present invention. In addition, “part” simply means “part by weight”.

Example 1 (Water-based ink) Titanium nitride UFP (manufactured by Tokyo Steel Co., Ltd.) 8.0 parts Nikkor BC-10TX 1.0 part (polyoxyethylene cetyl ether, dispersant, manufactured by Nikko Chemicals Co., Ltd.) Peptide PA-100 5.0 parts (Polypeptide, anti-settling agent, manufactured by Nippi Co., Ltd.) Ethylene glycol 10.0 parts (Water-soluble organic solvent) Glycerin (water-soluble organic solvent) 5.0 parts Urea (moisturizer) 10.0 parts Water 60.0 parts In the above components, first, Ethylene glycol, glycerin, Nikkor BC-10TX, peptide PA in 30 parts of water
Put 100 parts of -100 and titanium nitride, and pass through a 3-roll mill 5 times. A solution prepared by dissolving 10 parts of urea in 30 parts of the remaining water was added thereto and mixed uniformly, and then filtered through a 1.0 μm filter to obtain an aqueous black pigment ink.

Example 2 (Water-based ink) Titanium nitride 7.0 parts SMA1440H 5.0 parts (Styrene-maleic acid copolymer ammonia neutralized product 27% aqueous solution, dispersant, manufactured by ARCO Chemical) Ethylene glycol 10.0 parts Propylene glycol 7.0 parts (water-soluble organic solvent ) Nikkor PBC-32 0.3 part (polyoxyethylene / polyoxypropylene cetyl ether, wetting agent, manufactured by Nikko Chemicals Co., Ltd.) Proxel XL2 (preservative, manufactured by ICI Co.) 0.1 part water 70.6 parts All the above components are mixed uniformly. After that, add titanium nitride,
After stirring in a sand mill for 30 minutes, the mixture was filtered through a 1.0 μm filter to obtain an aqueous black pigment ink.

Example 3 (oil-based ink) Titanium nitride 6.0 parts Pegnol O-6 1.2 parts (polyoxyethylene oleyl ether, dispersant, manufactured by Toho Chemical Industry Co., Ltd.) n-butanol 20.0 parts n-propanol 57.8 parts benzyl alcohol 5.0 Part COPONYL HS-200 10.0 parts (acrylic acid ester copolymer resin 50% ethanol solution, fixing agent, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) After mixing all the above components, stir in a ball mill for 20 hours to obtain an oily black pigment I got ink.

Comparative Example 1 (Aqueous ink) Carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.) was used in place of titanium nitride in Example 1, and the other treatments were performed in the same manner to obtain an aqueous black pigment ink.

Comparative Example 2 (Water-based ink) In Example 1, 12.0 parts of carbon black MA-100 and 1.1 of Nikkor BC-10TX were used instead of titanium nitride.
Aqueous black pigment ink was obtained in the same manner except that the amount was 5 parts.

Comparative Example 3 (Oil-based ink) An oil-based black pigment ink was obtained in the same manner as in Example 3 except that 6.0 parts of RAVEN1500 (carbon black, manufactured by Columbia Carbon Co.) was used instead of titanium nitride.

(Effect) The inks of Examples 1 to 3 and Comparative Examples 1 to 3 were filled in a felt-tip pen manufactured by Pentel Co., Ltd. and tested. The results are shown in the table.

As described above, the black pigment ink of the present invention has a high degree of blackness and an excellent concealing property. Specifically, it is a writing instrument using a fiber bundle, felt, or monofilament as a pen tip, or a capillary tube of a fountain pen. It is suitable for writing instruments, rod-shaped writing instruments and ball-point writing instruments, and can also be applied to recorders, printers, stamps, jet printers and the like.

Claims (1)

[Claims] 1. A black pigment ink comprising at least titanium nitride as a black coloring material dispersed in an organic solvent and / or water.