JPS61174277A - Gold ink - Google Patents

Abstract

PURPOSE:To provide a gold ink having excellent resistance to discoloration and formation of a hard cake with time, which comprises a colored Al powder pigment which has been subjected to a specific treatment, a resin and an organic solvent. CONSTITUTION:Al powder is immersed in a weak acidic solution (pH: 1.0-2.5) containing anhydrous chromic acid, 6.0X10<-3>-0.05mol/l of anhydrous chromate (e.g. sodium dichromate), 2X10<-3>-0.1mol/l of a fluoride (e.g. NaF) and 0.05-1.0wt% of a nonionic surfactant and/or an amphoteric surfactant to treat the powder at room temperature ...100 deg.C. 100wt% of the resulting colored Al powder is subjected to a surface treatment with 0.1-3.0wt% of a fatty acid (or its derivative) (e.g. stearic acid) to obtain a colored Al powder pigments (A). 10-40wt% of the above-prepared component (A) is mixed with (B) 5-50wt% of a resin (e.g. gum resin) and (C) 30-80wt% of an organic solvent (e.g. xylene) to obtain a desired gold ink.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to gold ink, and more specifically, it is resistant to discoloration,
The present invention also relates to a golden ink that does not easily form cake over time.

(Prior Art) Conventionally, inks with metallic luster have used metal powder pigments as colorants, and generally, aluminum powder has been used for silver inks and brass powder has been used for gold inks.

(Problems to be Solved by the Invention) However, compared to the aluminum powder used for silver ink, the brass powder used for gold ink is expensive, and the surface of the two particles is easily oxidized. Easily discolored over time.

In addition, because of its high specific gravity, the pigment tends to settle, creating a cake over time and causing unevenness in one color.

(Means for Solving the Problems) Therefore, the inventor of the present invention conducted extensive research in order to obtain a gold-colored ink that causes problems such as discoloration and cake over time, and as a result, as a coloring agent. .

Aluminum powder is immersed in a weakly acidic solution consisting of at least chromic anhydride, dichromate, fluoride, nonionic surfactant, and/or amphoteric surfactant, and after drying, it is treated with fatty acid and/or fatty acid derivative. The present invention was completed based on the discovery that the use of colored aluminum powder pigments obtained by surface treatment causes discoloration and hard cakes to occur over time. Namely, one aspect of the present invention is the above-mentioned colored aluminum powder pigment and a resin.

The gist of the invention is a golden ink consisting of at least an organic solution.

(Function) The reason why the golden ink of the present invention is difficult to cause discoloration or hard cake over time is surmised as follows.

The gold ink of the present invention is produced by immersing aluminum powder in a weakly acidic solution consisting of at least anhydrous chlorine, an acid, a dichromate, a fluoride, a nonionic surfactant, and/or an amphoteric surfactant, and after drying. , a colored aluminum powder pigment obtained by surface treatment with a fatty acid and/or a fatty acid derivative is used, but this colored aluminum powder face t1 has a complex oxide film of chromium and aluminum formed on the surface by the above treatment. I think there are.

This composite oxide film corresponds to a so-called chromate film, and is thought to have excellent corrosion resistance and be less prone to discoloration over time (discoloration of gold ink is caused by surface oxidation of the metallic pigment). Compared to brass powder, the colored aluminum powder pigment used in the present invention has a lower specific gravity, and the surface is covered with an oxide film, making it difficult for the pigment to settle, and even if it settles, the pigments adhere firmly to each other. It is conceivable that it would be difficult to produce a hard cake because there is nothing to do.

(Structure of the invention) Next, each component of the golden ink of the present invention will be explained.

The colored aluminum powder pigment is used to impart a golden color to the ink, and the amount used varies somewhat depending on the use of the ink, but is preferably 10 to 40% by weight based on the total amount of the ink. This colored aluminum powder pigment is obtained by a manufacturing method according to Japanese Patent Application No. 59 252386 (named: Method for manufacturing bi-colored aluminum powder) filed on November 29, 1980 by the present applicant and the same applicant. be. The manufacturing method will be described below.

The colored aluminum powder pigment used in the present invention is:

Aluminum powder is immersed in a weakly acidic solution consisting of anhydrous cross acid, dichromate, fluoride, nonionic surfactant and/or amphoteric surfactant, and after drying, it is treated with fatty acid and/or fatty acid derivative. It can be obtained by surface treatment.

Examples of dichromates include sodium monochromate, potassium dichromate, ammonium dichromate, etc.
Examples of fluorides include sodium fluoride, potassium fluoride, ammonium fluoride, etc., and the amount of each used is 6.5% per total amount of the weakly acidic solution. OX10
~'~0, 05 mob/L, 2 x 10-~0
1rnol/,/- is light and heavy.The pH of a weakly acidic solution is 10-25°.The temperature of a weakly acidic solution is 10 to 25° from room temperature.
Even at 00°C, it is preferable to set the temperature to about 40°C to 80°C. The color tone of the obtained aluminum powder is determined by the above p
-By appropriately changing the H value, treatment time, and treatment temperature,
It can be set as pale yellow to golden yellow to dark brown.

Nonionic surfactants 2 Amphoteric surfactants.

The aluminum powder surface has been treated with stearic acid in advance to prevent dispersibility in the treatment solution, so it is used to solve this problem.At the same time, the stearic acid film that covers the aluminum powder surface is used. It has the purpose of dispersing and cleaning aluminum powder, which must be removed (degreased) by some kind of action with chromate ions. Examples include partial ester type and ester ether type of alcohol.

Examples of amphoteric surfactants include carboxylic acid type surfactants, among them betaine type, etc. These can be used singly or in a mixture of two or more types, and the amount used is 0.05 to 0.05 to the total amount of the weakly acidic solution. 10% by weight is a trick. If the amount is less than 0.005% by weight, the effect of dispersing and cleaning the aluminum powder will not be sufficient, and if it is more than 10% by weight, even if added, no further effect can be obtained, which is disadvantageous in terms of cost.

Next, fatty acids and/or fatty acid derivatives are used for the purpose of imparting metallic luster and leafing power to the aluminum powder colored by the treatment with the weakly acidic solution described above. Salt, fatty acid ester.

Fatty acid amides are preferred, specific examples of which are myristic acid, palmitic acid, and stearic acid.

Examples include arachidic acid, behenic acid, oleic acid, lylunic acid, aluminum stearate, methyl stearate, and stearamide.

These can be used singly or in combination of two or more. Note that fatty acids and/or fatty acid derivatives having 13 or fewer carbon atoms tend to have weak lubricity.

During pulverization, the aluminum powders tend to stick to each other, causing the aluminum powders to adhere to each other, resulting in insufficient gloss and leafing properties.

Furthermore, in the case of fatty acids and/or fatty acid derivatives having 23 or more carbon atoms, the aluminum powder is flattened during grinding, and a sufficient scale shape cannot be obtained, resulting in insufficient gloss and leafing properties. In addition, the amount of fatty acid and/or fatty acid derivative used is 10% by weight of colored aluminum powder.
Compared to that, 01 to TsutaO weight% is light and heavy.

If it is less than 0.1% by weight, the aluminum powder tends to seize together, and 3. If the amount of Oi is more than %, the aluminum powder cannot be flattened properly and a sufficient scale shape cannot be obtained.

The resin is used to improve the fixation of handwriting and to adjust the viscosity of the ink, and various resins can be used as long as they are soluble in organic solvents. Examples include: Gum rosin, maleic acid modified [Gogin, Flukyd resin.

Keto/resin, xylene resin 7 petroleum resin, acrylic resin,
There are terpene resins, phenolic resins, etc., and these are I
) 4-Germany can be used in combination.The amount used varies depending on the type of resin, degree of polymerization, etc., but it is preferably 5 to 50% by weight based on the total amount of the ink. If it is less than 5% by weight, the adhesion of handwriting to the writing surface will not be sufficient, and if it is more than 50% by weight, the ink viscosity will increase, causing blurred handwriting, clogging of the pen tip, etc.

The organic solvent can be selected as appropriate depending on the material used on the writing surface and other materials used, but specific examples include aromatic solvents such as toluene and gilcine, ethyl acetate, butyl acetate, amyl acetate, etc. ester solvents, ketones such as methyl ethyl ketone, methyl ibutyl ketone, etc.

/Aliphatic hydrocarbon solvents such as chlorohexane and n-heptane, ethyl alcohol, propyl alcohol, n
- Phthyl alcoholNatonoalcohol solvents, glycol ether solvents such as ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

These can be used alone or in combination.

The amount used is 30 to 80% by weight based on the total amount of ink.

In addition to the above ingredients, various dispersants may be added as appropriate for the purpose of improving the dispersion of the colored aluminum powder pigment, or additives such as complementary color additives, known pigments, dyes, and other rust preventives may be used as appropriate. You can also do that.

2. The golden ink of the present invention can be easily obtained by mixing the above-mentioned components (and other additives as necessary) in required amounts and stirring thoroughly.

(Example) The present invention will be explained in detail with reference to Examples below.

In the examples, "1 part" indicates [part by weight -1].

Example 1 Chromic anhydride 04 parts Sodium dichromate 0.35 parts Sodium fluoride
008 part Ninosan Nonion N5215
0.5 parts (nonionic surfactant manufactured by NOF) water
9867 parts The above ingredients were mixed to prepare a weakly acidic solution, and 240-'l of aluminum powder (Alpace) was added to this.
'.

5 parts of Toyo Aluminum ■, average particle size 5 lt, dried at 50°C for 48 hours) were added.

The mixture was immersed at 50°C in Cl2O at pH 4.8 with stirring, filtered, and dried. 0.5 parts by weight of stearic acid was added to 100 parts by weight of this dry colored aluminum powder, and the mixture was pulverized using a stamp mill.

Colored aluminum powder pigment A was obtained.

Colored Aluminum Powder Pigment A 20 parts Stone Neopolymer $120' 30 parts (Petroleum Resin 2 Nippon Oil ■) Xylene 40 parts N-Hebutane 10 parts The above components were mixed and stirred at room temperature to obtain a golden ink. is.

Comparative Example 1 Brass powder 20 parts Nisseki Neopolymer #120 30 parts xylene
40 parts n-hebutane
A golden ink was obtained by mixing 10 parts of the above ingredients and stirring at room temperature.

Example 2 Chromic anhydride 04 parts Sodium dichromate 065 parts Sodium fluoride
008 part anon B F
0.1 part (ampholytic surfactant manufactured by NOF) Water
9907 parts" 2. Mix each component to prepare a weakly acidic solution,
Toreni aluminum powder (Chromal X, EC
5 parts of KART-WERKE (manufactured by KART-WERKE, average particle size 6μ) were added.

The mixture was immersed at 50'C for 10 minutes at pH 1.8 with stirring, filtered, and dried. 0.5 parts by weight of oleic acid was added to 100 parts by weight of this dry colored aluminum powder, and the mixture was ground in a stamp mill.

Colored aluminum powder pigment B was obtained.

Colored aluminum powder pigment B 25 parts National xylene resin CJ20 30 parts (xylene resin manufactured by Matsushita Electric Works) Ethanol 10 parts Ethylene glycol monoethyl ether 15 parts Benzyl alcohol 20 parts The above components were mixed,
A golden ink was obtained by stirring at room temperature.

Comparative Example 2 Brass powder 25 parts Nano-Yonal xylene resin CJ20 30 parts Ethanol
10 parts ethylene glycol monoethyl ether 15 parts benzyl alcohol
A golden ink was obtained by mixing 20 parts of the above components and stirring at room temperature.

(Effects of the Invention) The inks obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were filled into a commercially available valve-type structural order marking device (with built-in stirring ball) and tested. Table 1 shows the results.

Table 1 (Note 1) Discoloration P, The handwriting written on the P film was left indoors for one month, and the color of the handwriting before and after aging was visually observed.

○: No discoloration Bow discoloration (Note 2) After leaving the hard cake sample at room temperature for one month, shake the sample 20 times, write on it, and observe the condition of the handwriting.

○: Normal ×: Impossible to judge with solvent alone As shown in 2, the gold ink of the present invention has
Dark color...-hard to cake and stable over time.

In addition, although the ink for jaw writing instruments was shown in the example, it is not limited to the ink for writing instruments.

It can also be used as printing and stamp ink.

Claims (3)

[Claims] (1) immersing aluminum powder in a weakly acidic solution consisting of at least chromic anhydride, dichromate, fluoride, nonionic surfactant and/or amphoteric surfactant,
A golden ink comprising at least a colored aluminum powder pigment obtained by surface treatment with a fatty acid and/or a fatty acid derivative after drying, a resin, and an organic solution. (2) The nonionic surfactant and/or amphoteric surfactant is one of polyethylene glycol type, polyhydric alcohol partial ester type, ester ether type, and carboxylic acid type.
The golden ink according to claim (1), which is one or more kinds. (3) Fatty acid and/or fatty acid derivative has 14 to 2 carbon atoms
2. The golden ink according to claim 1, which is one or more of fatty acids, fatty acid metal salts, fatty acid esters, and fatty acid amides.