JPH0967536A - Metallic gloss color ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic gloss color ink which can give writing retaining a gloss and is prevented from discoloration even after long storage by mixing an aluminum powder pigment with a resin and a trialkyl phosphate and/or a dialkyl phthalate. SOLUTION: This metallic gloss color ink is prepared by mixing 10-40wt.% aluminum powder pigment with 5-40wt.% resin selected from among coumarone reisns, xylene resins, phenolic resins and ketone resins and optional additives such as a dye or a pigment, a preservative, an antimold, a wetting agent, a drying inhibitor, a viscosity modifier, an antifreeze, a defoaming agent and a surfactant under agitation to uniformly dissolve them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink having excellent gloss lasting, which shows sufficient metallic gloss on a handwriting even after being stored for a long period of time, and more particularly to a metallic gloss color ink suitable for use in writing instruments.

[0002]

2. Description of the Related Art A metallic luster color ink contains at least an aluminum powder pigment, a resin and an organic solvent. As the organic solvent, aromatic hydrocarbons such as xylene and toluene have been widely used because of their low price and high solubility in resins. Since the specific gravity of the aluminum powder pigment used in this ink is large, the pigment will settle during storage. Therefore, when using it for writing instruments, the ink is directly filled in the ink storage chamber of the writing instrument together with the stirring body (metal ball etc.) for redispersing the settled aluminum powder pigment, and the writing instrument is shaken before use.
The precipitated aluminum powder pigment was used by redispersion.
By the way, since the aromatic hydrocarbon-based organic solvents that have been conventionally used as described above have problems such as high odor and toxicity, in recent years, cycloaliphatic hydrocarbons such as methylcyclohexane and ethylcyclohexane, which have low odor and toxicity, have been developed. Many proposals have been made to use hydrogen as a solvent for ink.

[0003]

The above metallic luster color ink has a problem that the metallic luster decreases with time or the color changes to blackish due to discoloration. When an alicyclic hydrocarbon is used as a solvent, this solvent has poor solubility in a resin, and particularly when used in a writing instrument, the ink does not come out well, or scratches occur after long-term storage, There were many problems in that it could be impossible.

[0004]

The present invention is directed to an aluminum powder pigment, a resin, a phosphoric acid trialkyl ester and / or
Another object is a metallic luster color ink characterized by containing at least a dialkyl phthalate ester.

The details will be described below. The aluminum powder pigment is used as a coloring material that gives a metallic luster to the handwriting, and the addition amount is 10 to 40 relative to the total amount of the ink.
% By weight is preferred. If the amount added is less than 10% by weight, the density when used as handwriting tends to decrease, and if the amount added exceeds 40% by weight, the viscosity becomes high, and when used as a writing instrument, ink ejection from the pen tip decreases. Tend to do.

The resin is used to improve the dispersibility of the aluminum powder pigment, the glossiness of the handwriting, and the fixing property of the handwriting. Resins that can be used include coumarone resin, xylene resin, phenol resin, and ketone resin, and the amount used is 5-40% by weight based on the total amount of ink.
It is preferred to add. If it is less than 5% by weight, the effect tends to be small, and if it is more than 40% by weight, the viscosity becomes high, and when it is used for a writing instrument, the ink ejection from the pen tip tends to decrease.

Phosphoric acid trialkyl ester and phthalic acid dialkyl ester are used as a solvent, and are excellent solvents which dissolve the resin well and do not have an adverse effect on the aluminum powder pigment such as deterioration and corrosion over time. . Specifically, trimethyl phosphate, triethyl phosphate, trinormal propyl phosphate, triisopropyl phosphate, trinormal butyl phosphate, trinormalpentyl phosphate, trinormalhexyl phosphate, trinormalheptyl phosphate, phosphorus Trinormal octyl acid, tris (2-ethylhexyl) phosphate, dimethyl phthalate,
Diethyl phthalate, di-n-propyl phthalate, di-n-butyl phthalate, di-n-pentyl phthalate,
Examples thereof include dihexyl phthalate, diheptyl phthalate, dioctyl phthalate, and di-2-ethylhexyl phthalate. These can be used alone or as a mixture of two or more, and the amount used can be added in an amount of 2 to 90% by weight based on the total amount of the ink.
It is preferable to add 2 to 50% by weight.

In addition to phosphoric acid trialkyl ester and phthalic acid dialkyl ester, esters such as butyl acetate, amyl acetate, ethyl acetate, methyl ethyl ketone, methyl ester, etc. are used for adjusting the nib drying resistance and handwriting drying resistance. Ketones such as isobutyl ketone, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, ethylcyclohexane and cyclopentane, and organic solvents such as hydrocarbons such as normal heptane, normal octane and mineral spirit may be used in combination.

In addition to the components shown above, dyes and pigments may be used for producing a color tone such as gold or copper, if necessary, or preservatives conventionally used in inks for writing instruments, etc. Various additives such as a fungicide, a wetting agent, a drying inhibitor, a viscosity modifier, a freeze stabilizer, an antifoaming agent, and a surfactant can be appropriately selected and used.

The metallic luster color ink of the present invention can be obtained by stirring and mixing the above components with a conventionally known stirrer to uniformly dissolve them.

[0011]

It is not clear why the metallic luster color ink according to the present invention improves the luster persistence after aging, but it is presumed as follows. The cause of the decrease in gloss and discoloration after aging is
There are deterioration of the aluminum powder pigment itself, deterioration of the aluminum powder pigment due to the action of the resin, and deterioration of the gloss due to the deterioration of only the resin in the ink. Many of the causes of low gloss are
It is the interaction between the solvent and the aluminum powder pigment, and the poor dissolution stability of the resin in the solvent. The phosphoric acid trialkyl ester and phthalic acid dialkyl ester used in the present invention have a function of protecting the metal surface. Further, for the solubility of the resin, carbonyl-based oxygen and ether-based oxygen in the solvent molecule are required, but phosphoric acid trialkyl ester and phthalic acid dialkyl ester have this oxygen in the molecule. . That is, trialkyl phosphate,
It is considered that the dialkyl phthalate protects the surface of the aluminum powder pigment, and is particularly excellent in the dissolution stability of the resin, and thus it is considered that the phthalic acid dialkyl ester exhibits excellent gloss persistence even after aging.

[0012]

【Example】

Example 1 Alpaste 240T (aluminum powder pigment, manufactured by Toyo Aluminum Co., Ltd.) 25 parts by weight Esclone V120 (coumarone-indene resin, manufactured by Nittetsu Chemical Co., Ltd.) 30 parts by weight Trinormal butyl phosphate 30 parts by weight Methyl Cyclohexane 15 parts by weight The above components were stirred with a stirrer for 4 hours to obtain a silver ink having metallic luster.

Example 2 Alpaste 241M (aluminum powder pigment, manufactured by Toyo Aluminum Co., Ltd.) 20 parts by weight Esclone T120 (coumarone-indene resin, manufactured by Nippon Steel Chemical Co., Ltd.) 30 parts by weight Dibutyl phthalate 5 parts by weight Methylcyclohexane 45 parts by weight The above components were treated in the same manner as in Example 1 to obtain a silver ink having metallic luster.

Example 3 Alpaste 241M (previously described) 30 parts by weight Resin AP (ketone resin: manufactured by huls) 30 parts by weight Trimethyl phosphate 20 parts by weight Butyl acetate 20 parts by weight A glossy silver ink was obtained.

Example 4 Alpaste 241M (described above) 35 parts by weight Exlon V120 (described above) 20 parts by weight Dimethyl phthalate 25 parts by weight Methylcyclohexane 15 parts by weight Normal heptane 5 parts by weight A glossy silver ink was obtained.

Example 5 Alpaste 241M (previously described) 25 parts by weight Esclone G90 (coumarone-indene resin, manufactured by Nittetsu Chemical Co., Ltd.) 30 parts by weight Trinormal butyl phosphate 30 parts by weight Dibutyl phthalate 15 parts by weight Above Using the same components as in Example 1, a silver ink having a metallic luster was obtained.

Comparative Example 1 Example 1 was repeated except that trinormal butyl phosphate was removed and methylcyclohexane was added in that amount.
A silver ink having a metallic luster was obtained in the same manner as in.

Comparative Example 2 A silver ink having a metallic luster was obtained in the same manner as in Example 2 except that dibutyl phthalate was removed and methylcyclohexane was added in that amount.

Comparative Example 3 A silver ink having a metallic luster was obtained in the same manner as in Example 3 except that trimethyl phosphate was removed and butyl acetate was added in that amount.

The metallic luster color inks obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were put in a barrel having a commercially available writing instrument structure (Pentel White 100 W, pen tip: fiber core, valve structure). A writing tool for testing was prepared by filling a mold for directly filling the ink, a filling ball for stirring together with the ink, manufactured by Pentel Co., Ltd. Use a writing instrument for this test at a temperature of 50
After being stored for 6 months in a thermo-hygrostat at a temperature of 30 ° C. and a humidity of 30%, the glass plate was written, and the handwriting before and after the stationary storage was observed. The results are shown in Table 1.

[0021]

[Table 1]

Gloss evaluation ○: With gloss (no change) Δ: With a little gloss (slightly decreased gloss) ×: No gloss (remarkably changed)

Evaluation of discoloration ○: No discoloration ×: Discoloration

As described above in detail, the metallic luster color ink according to the present invention is an ink having excellent properties that gloss is maintained in handwriting even after long-term storage and no discoloration occurs. is there.

Claims (1)

[Claims] 1. A metallic luster color ink comprising at least an aluminum powder pigment, a resin, and a phosphoric acid trialkyl ester and / or a phthalic acid dialkyl ester.